Go to Top

Publications

Use the search function below or simply browse through the Proceedings of the past ISMBs and other publications related to magnetic bearings. For open access to the full pdf files please log in.

Not registered yet? Simply fill out the free registration here!

Matching entries: 0
settings...
Year Author Title Journal/Proceedings
2012 Abrahamsson, J., Hedlund, M. and Bernhoff, H. Prototype of Kinetic Energy Storage System for Electrified Utility Vehicles in Urban Traffic Proceedings of ISMB13  
Abstract: This paper presents theoretical and experimental results on the ongoing construction of a high-speed (30000 rpm) kinetic energy storage system (KESS). The purpose of the device is to function as a power buffer storing up to 1kWh, primarily for utility vehicles in urban traffic. The KESS is connected in series between the primary power source and the tractionmotor of the vehi-cle. It comprises a composite rimof carbon and glass fiber in an epoxymatrix. The power to/from the rotating rim is transferred through an integrated double wound three-phase PM machine. The machine is levitated axially using four units with segmented Halbach arrays in a repulsive con-figuration. Radial centering is achieved through eight separate active electromagnetic actuators controlled by an FPGA. The geometries of the passive thrust units as well as the active actuators were designed using linked CAD and FEM tools controlled by advanced optimization algorithms. The simulated repulsive force from the thrust magnets was verified experimentally. Additionally, the corresponding negative stiffness in radial direction as well as the power loss due to induced eddy currents were simulated. The optimization of the active magnetic bearing (AMB) actuators resulted in a geometry with low resistive power loss, while generating a high current stiffness at the expense of maximum force.
BibTeX:
@inproceedings{ISMB13_51,
  author = {Johan Abrahamsson and Magnus Hedlund and Hans Bernhoff},
  title = {Prototype of Kinetic Energy Storage System for Electrified Utility Vehicles in Urban Traffic},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_51.pdf}
}
2008 Abulrub, A.-H.G., Sahinkaya, M.N., Burrows, C.R. and Keogh, P.S. Robustness of Recursive Auto-Tuning Strategy in Flexible Rotor and Magnetic Bearing Systems Proceedings of ISMB11  
Abstract: Active magnetic bearings offer the capability to control rotor vibration and transmitted forces through the design of adaptive controllers. These controllers can take into account the changing operating conditions and variations in the system dynamics. A Recursive Open-Loop Adaptive Control (ROLAC) algorithm was developed, which minimizes the sum of squares of the measurements in frequency domain. ROLAC is used in addition to local PID controllers, which ensure the stability. Magnetic bearing dynamics depend on the eccentricity of the rotor with respect to magnetic poles. Non-concentric rotation of the rotor within the magnetic bearings causes changes in the bearing dynamic properties. Apart from system faults, non-concentric operation of the rotor can occur due to misalignment of the auxiliary bearings with respect to magnetic poles, changes in sensor calibration, and misalignment of bearings in systems where there are three or more bearings. This misalignment leads to changes in the magnetic bearing characteristics thereby affecting the overall system dynamics. This in turn may necessitate re-tuning of the ROLAC. The paper studies the effect of such misalignments on the controller performance and the robustness of the auto-tuning process.
BibTeX:
@inproceedings{ISMB11_45,
  author = {Abdul-Hadi G Abulrub and M Necip Sahinkaya and Clifford R Burrows and Patrick S Keogh},
  title = {Robustness of Recursive Auto-Tuning Strategy in Flexible Rotor and Magnetic Bearing Systems},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_45.pdf}
}
2006 Abulrub, A.-H.G., Sahinkaya, M.N., Keogh, P.S. and Burrows, C.R. Experiments on ROLAC to Recover Rotor Position Following Contact Proceedings of ISMB10  
Abstract: There is growing interest in magnetic bearing applications because of their advantages for contactless support, high-speed operation, vibration control, condition monitoring and fault diagnostics. However, they have limited force capacity and have to incorporate retainer bearings to protect the laminations when vibration levels reach the clearance level. Retainer bearings can take a relatively small number of rotor drops followed by machine shutdown. There are many potential applications where transient events or sudden changes in operating conditions could drive the rotor into contact with retainer bearings. These include land, sea and air transport applications, which are exposed to external inputs and disturbances, and system shut down is not acceptable. This paper describes the application of a Recursive Open Loop Adaptive Controller (ROLAC), an adaptive and fast acting controller, to prevent contact between a flexible rotor and retainer bearing. If however contact does occur, then the control action will minimize the damage and recover the rotor position without the need to shut down the system. It is assumed that the magnetic bearings are fully operational and contact is due to external disturbances such as sudden un-balance, base excitation, blade loss or damage. Experimental results are presented to demonstrate the effectiveness of the control algorithm.
BibTeX:
@inproceedings{ISMB10_38,
  author = {Abdul-Hadi G. Abulrub and M. Necip Sahinkaya and Patrick S. Keogh and Clifford R. Burrows},
  title = {Experiments on ROLAC to Recover Rotor Position Following Contact},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_38.pdf}
}
2006 Achkar, R., Nasr, C., Miras, J.D. and Charara, A. Neural Networks Implementation to Control An Active Magnetic Bearing Proceedings of ISMB10  
Abstract: No abstract available, please see full paper.
BibTeX:
@inproceedings{ISMB10_86,
  author = {Roger Achkar and Chaiban Nasr and Jerôme De Miras and Ali Charara},
  title = {Neural Networks Implementation to Control An Active Magnetic Bearing},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_86.pdf}
}
2000 van Acht, V., Damen, A., van den Bosch, P. and Compter, J. 6 DOF Magnetically Suspended and Propelled Mirror Proceedings of ISMB7  
Abstract: An actively controlled magnetically levitated mirror with 6 degrees of freedom (DOF) is presented. This mirror is to be used in a measurement system based on laser interferometry. A novel magnetic topology has been developed for actuating all six DOFs of the mirror. This topology almost completely decouples the different degrees of freedom. The forces and torques are independent of the rotor angle and are proportional to the applied currents. This simplifies controller design consider- ably. A contactless differential capacitive position sen- sor system has been designed to measure the position and orientation of the mirror. This capacitive sen- sor system is incorporated in the magnetic actuator topology.
BibTeX:
@inproceedings{ISMB7_86,
  author = {V.M.G. van Acht and A.A.H. Damen and P.P.J. van den Bosch and J.C. Compter},
  title = {6 DOF Magnetically Suspended and Propelled Mirror},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_86.pdf}
}
1998 van Acht, V.M.G., Damen, A.A.H. and van den Bosch, P.P.J. On Self-Sensing Magnetic Levitated Systems Proceedings of ISMB6  
Abstract: As a test-case for magnetic bearings and propulsion a 1 degree of freedom self-sensing magnetically levitated steel ball is under study. In this paper an overview of the design of a levitation system is given. It will appear that the easiest implementation of self-sensing magnetic levitation is to use a current controlled coil, and add a high frequency current to the actuating current for measuring the inductance of the coil. Therefor the voltage over the coil is demodulated using synchronous AM demodulation. An accuracy analysis is made for 1 DOF self-sensing magnetic levitation systems. Finally, upper bounds for the accuracy of such a system are given. It will appear that self-sensing magnetic leviation cannot be used in the system it was proposed for, therefore no experimental results will be given in this paper.
BibTeX:
@inproceedings{ISMB6_51,
  author = {V. M. G. van Acht and A. A. H. Damen and P. P. J. van den Bosch},
  title = {On Self-Sensing Magnetic Levitated Systems},
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_51.pdf}
}
2006 Adler, K., Schalk, C., Nordmann, R. and Aeschlimann, B. Active Balancing of a Supercritical Rotor on Active Magnetic Bearings Proceedings of ISMB10  
Abstract: Balancing of rotors needs a lot of manpower, specific knowledge and is time-consuming. In the rising field of high speed machinery also the requirements for suitable effective balancing concepts increase. Here a combination of active magnetic bearings (AMBs) and active balancing devices (ABDs) on a supercritical rotor creates the possibility for a partial automation of the balancing process. That way critical rotor speeds can be passed and the time effort for the balancing process can be reduced significantly.
BibTeX:
@inproceedings{ISMB10_11,
  author = {Kai Adler and Christoph Schalk and Rainer Nordmann and Beat Aeschlimann},
  title = {Active Balancing of a Supercritical Rotor on Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_11.pdf}
}
2002 Aenis, M. and Nordmann, R. Fault Diagnosis In Rotating Machinery Using Active Magnetic Bearings Proceedings of ISMB8  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB8_96,
  author = {Martin Aenis and Rainer Nordmann},
  title = {Fault Diagnosis In Rotating Machinery Using Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB8},
  year = {2002},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb8/ismb8_submission_96.pdf}
}
2000 Aenis, M. and Nordmann, R. Active Magnetic Bearings for Fault Detection in a Centrifugal Pump Proceedings of ISMB7  
Abstract: Active magnetic bearings (AMB), a typical mechatronic product, have been successfully applied in industrial turbomachinery. They are well suited to operate contactless as actuator and sensor elements in rotating machinery. The aim of the presented projects of the Special Research Program (SFB 241) supported by the German Research Council (DFG) is to use active magnetic bearings as an identification and diagnosis tool for turbomachines. The identification and diagnosis procedures are based on frequency response functions. For this type of diagnosis using transfer functions, an accurate force measurement as well as a precise model are crucial. The paper compares force measurement results and achievable accuracies of radial and axial magnetic bearings using different measurement techniques over a large operating range.
BibTeX:
@inproceedings{ISMB7_34,
  author = {Martin Aenis and Rainer Nordmann},
  title = {Active Magnetic Bearings for Fault Detection in a Centrifugal Pump },
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_34.pdf}
}
1999 Aenis, M. and Nordmann, R. A Precise Force Measurement in Magnetic Bearings for Diagnosis Purposes Proceedings of ISMST5  
Abstract: The aim of the presented project sponsored by the DFG (German Research Council) is to use active magnetic bearings for the diagnosis of centrifugal pumps. Therefore, active magnetic bearings are integrated in a single-stage respectively four-stage pump substituting the conventional ball bearings. The diagnosis procedures are based on evaluating frequency response functions where the active magnetic bearings operate as actuators and as sensors to measure the displacements and the forces induced in the rotating structure. Simulation results of an exemplarily fault applied to the pump system are presented. For this type of diagnosis using transfer functions, an accurate force measurement is crucial. The paper compares force measurement results and achievable accuracies of a radial magnetic bearing using different measurement techniques over a large operating range. Furthermore, a finite-element model is used to investigate fringing and leakage effects to improve the different measurement techniques. The finite element model allows eccentric rotor positions and non-syrmnetrical coil current distributions with nonlinear material properties of the stator and rotor part of the magnetic bearing.
BibTeX:
@inproceedings{ISMST5_31,
  author = {M. Aenis and R. Nordmann},
  title = {A Precise Force Measurement in Magnetic Bearings for Diagnosis Purposes},
  booktitle = {Proceedings of ISMST5},
  year = {1999},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst5/ismst5_submission_31.pdf}
}
2018 Aeschlimann, B. and Hubatka, M. Unbalance Control of Active Magnetic Bearings Proceedings of ISMB16  
Abstract: Unbalance forces are a major source of undesired vibrations in rotating machinery. Active magnetic bearings (AMBs) with special control algorithms, allow for controlling those forces and counteract appropriately. The two basic principles are UFRC and UFCC. They are known for many years and have been published and patented before. There exist excellent publications treating the closed-loop stability of UFRC but not much can be found on the stability of UFCC. This paper presents an adaptive multi-variable implementation of UFCC, its theoretical background and a proof of control stability. UFCC as described in this paper, has shown excellent stability in practice and it can therefore be engaged over the entire speed range of the machine. However in order to minimize the load on power amplifiers and other components a switching strategy is advised, where UFRC and UFCC are switched on and off in the speed ranges where required. Guidelines for tuning UFCC parameter are also given. The effectiveness of UFCC has been proven in several applications and measurement results are given in this paper.
BibTeX:
@inproceedings{ISMB16_037,
  author = {Beat Aeschlimann and Michael Hubatka},
  title = {Unbalance Control of Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_037.pdf}
}
2016 Aeschlimann, B., Hubatka, M., Peter, M.E., Stettler, R. and Housseini, R. Commissioning of Off-Shore Gas Compressor with 9-Axes Magnetic Bearing System: Controller Design Proceedings of ISMB15  
Abstract: This paper presents the system model, model validation, controller design and test measurements for an industrial 9-axes oil-free integrated motor-compressor (tandem HOFIM(TM)) manufactured by MAN Diesel & Turbo (MAN) to be installed off-shore on an oil rig. The magnetic bearing controller of such machines must be designed with high robustness due to large expected uncertainties in the control plant. In addition, the magnetic bearings must have a high force slew rate, and thus a high dynamic controller, since compressor surge that causes high alternating process forces cannot always be avoided in field operation. These two requirements are conflicting and it is a difficult task to find a good compromise. This paper presents an application of robust controller design and a solution to this problem: the LQG/LTR method, well described in literature, is applied for the design of the position controller. Using the proposed method, the compressor was successfully commissioned at the MAN test facility and all specifications were met.
BibTeX:
@inproceedings{ISMB15_26,
  author = {Beat Aeschlimann and Michael Hubatka and Michael Ernst Peter and Robert Stettler and Reza Housseini},
  title = {Commissioning of Off-Shore Gas Compressor with 9-Axes Magnetic Bearing System: Controller Design},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_26.pdf}
}
2000 Aeschlimann, B., Kümmerle, M., Zoethout, J. and Bleuler, H. Model Based Decoupling Control of a Disc Rotor on Active Magnetic Bearings Proceedings of ISMB7  
Abstract: Under certain conditions a coupled system can be decoupled by means of feedback control. In this paper a method is presented to control a hard disc drive prototype on AMBs with a decoupling state feedback. In addition a feedforward matrix for the tracking problem is presented. The method is based on a linear analytical model of the system which is adapted by using frequency domain measurements. The derivation of the model, the design of the feedback controller and the feedforward is shown. Simulations are compared with measurements on the experimental setup. The current work focuses on improving the performance of the deocupling controllers.
BibTeX:
@inproceedings{ISMB7_41,
  author = {Beat Aeschlimann and Matthias Kümmerle and Jurjen Zoethout and Hannes Bleuler},
  title = {Model Based Decoupling Control of a Disc Rotor on Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_41.pdf}
}
1994 Agahi, R., Ershagi, B., Leonhard, M. and Ispas, I. Side Load Effect on Turbomachines with AMB Proceedings of ISMB4  
Abstract: Turbomachinery bearing systems are normally designed for radial loads corresponding to the weight of the rotor. Nonuniform pressure distribution around the wheel(s) of a turbomachine may also contribute to the magnitude of gas dynamic radial load, called side load. Conventional oil bearings have such a comfortable margin of load capacity that dynamic load is not of any design significance. Active Magnetic Bearing (AMB) systems have limited load capabilities. Turbomachinery manufacturers have developed their own methods of calculating side load. When the magnitude of side load exceeds the AMB' s capacity, several corrective actions are available. AMB applications for off-shore platforms or dew point control of natural gas using lurboexpanders are on the rise. Process gas pressures of these applications are in the range of 60-100 Bar and the side load effect is significant for high density process gas or liquid if turbomachine components are not designed correctly. Therefore, it is essential to use Computational Fluid Dynamic (CFD) to calculate the flow field in the casings. Corrective action should not sacrifice turbomachine performance which may result in a less desirable market for AMB. In this paper, the authors present one method of side load calculation and its theoretical background. In conclusion, the merits of alternative solutions are discussed.
BibTeX:
@inproceedings{ISMB4_80,
  author = {R. Agahi and B. Ershagi and M. Leonhard and I Ispas },
  title = {Side Load Effect on Turbomachines with AMB },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_80.pdf}
}
1996 Agahi, R. and Schroder, U. Industrial High Speed Turbogenerator System For Energy Recovery  Proceedings of ISMB5  
Abstract: The developed turbogenerator system is designed for process gas expansion producing a maximum of mechanical turbine power of about 70 kW that is fed as electrical power into the grid. In this arrangement the radial inflow expander turbine is mounted on the shaft of a permanent magnet excited high speed synchronous generator, supported by 5 axis active magnetic bearings. This arrangement eliminates the gearbox and is absolutely oil free. A novel static frequency inverter using flexible closed loop vector control improves machine application and allows a very wide range of speed with a nominal value of 45,000 rpm. On the grid output, pure sine currents with a power factor of 1 is fed to the grid. Active magnetic bearings prevent every type of process fluid contamination and seals are only to prevent excessive loss of process fluid. In the first test phase the proposed package was tuned and tested in steady state and transient conditions on a specially developed test stand using an identical second machine as a motor linked to the generator package under test via a flexible high speed coupling. In a second phase, the turboexpandergenerator package was tested in nominal conditions in an open loop with pressurized air, connected to a 460 VAC 60Hz grid.
BibTeX:
@inproceedings{ISMB5_64,
  author = {R. Agahi and U. Schroder },
  title = {Industrial High Speed Turbogenerator System For Energy Recovery },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_64.pdf}
}
2018 Ahmed, F. and Kalita, K. Controllability of Radial Displacement in Bearingless Switched Reluctance Motor with Bridge Configured Winding Proceedings of ISMB16  
Abstract: Due to the salient features of stator and rotor in Switched Reluctance Motor the air-gap of the machine does not remain uniform during its motoring operation. This innate characteristic is responsible in producing considerable amount of radial force in the motor. However on the other hand eccentricity or radial displacement of the rotor is another key cause to this production of radial force. In this paper a single winding structure called bridged configured winding in a 12/8 BSRM is delineated which can be used to deploy the radial displacement by injecting controlled current within the same winding. Initially a mathematical model of the motor is developed and verified using finite element modeling. The developed model is analyzed by integrating a voltage source asymmetric converter for motoring operation and separate asymmetric converters for injecting currents into the winding to control the radial displacement of the motor. Investigations of radial forces at various rotational positions and controllability of radial displacement are carried out using a simple PID controller system.
BibTeX:
@inproceedings{ISMB16_029,
  author = {Firdausa Ahmed and Karuna Kalita},
  title = {Controllability of Radial Displacement in Bearingless Switched Reluctance Motor with Bridge Configured Winding},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_029.pdf}
}
2014 Ahn, H.J. and You, Y.H. An Eddy Current Damper for Reaction Force Compensation for a Linear Motor Motion Stage Proceedings of ISMB14  
Abstract: This paper presents an eddy current damper (ECD) for reaction force compensation for a linear motor motion stage. A reaction force compensation mechanism with a movable magnet track and an ECD (or conductor plate) is developed. Lumped model of the ECD is derived considering sinusoidal magnetic flux density distribution and effective width of the ECD. In addition, effects of both the location and width of the conductor plate are discussed. Multi-physical transient analysis of ECD is analyzed using commercial finite element software, which is compared with the lumped parameter analysis. Finally, the derived lumped model is validated with experiments.
BibTeX:
@inproceedings{ISMB14_104,
  author = {Hyeong Joon Ahn and Yo Han You},
  title = {An Eddy Current Damper for Reaction Force Compensation for a Linear Motor Motion Stage},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_104.pdf}
}
2018 Ahn, H.-J. Stability Margin Evaluation of AMB Rotor Systems Using Singular Value Decomposition Proceedings of ISMB16  
Abstract: Active magnetic bearings (AMBs) are a proven technology that has been used in numerous rotating machines and is primarily being applied to many new turbomachines. Therefore, proper evaluation of rotordynamic performances is very important for OEM and end-users of AMBs. API 617 requires unbalance response limit and separation margin while ISO 14839-3 checks stability margin using measured sensitivity. In addition, singular value decomposition is mathematical tool used extensively in control community and can be used to analyze problems of rotating machines such as unbalance response, model reduction and stability margin. This paper presents stability margin evaluation of AMB rotor systems using singular value decomposition (SVD). First, Two AMB rotor systems and their frequency measurement are introduced. Then, we review linear control theory related to stability and performance evaluation using SVD. Identifications of two AMB rotor systems are performed and exact stability margins of two AMB rotor systems are analyzed based on linear control theory and SVD. Finally, stability margin evaluation of linear control theory and ISO 14839-3 are compared.
BibTeX:
@inproceedings{ISMB16_072,
  author = {Hyeong-Joon Ahn},
  title = {Stability Margin Evaluation of AMB Rotor Systems Using Singular Value Decomposition},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_072.pdf}
}
2004 Ahn, H.-J., Han, D.-C., Kim, C.-J. and Maslen, E.H. New System Identification Scheme Of AMB Rotor System Considering Sensor And Actuator Dynamics Proceedings of ISMB9  
Abstract: This paper presents an improved identification scheme of AMB rotor systems including sensor and actuator dynamics. First, this paper discusses the necessity and synthesis of the fictitious proportional feedback gain (FPFG). The identification error due to over-parametrization of the MIMO system via a SIMO modeling is minimized using an optimal FPFG. Second, the identification procedure becomes simple and efficient through estimating system poles and zeros simultaneously. Third, more improvement in the identification is achieved through separate parameterization of the additional dynamics. The identification performance is verified with several simulations. Finally, the proposed identification scheme is compared with previous identification methods using experimental data.
BibTeX:
@inproceedings{ISMB9_87,
  author = {Hyeong-Joon Ahn and Dong-Chul Han and Chan-Jung Kim and Eric H. Maslen},
  title = {New System Identification Scheme Of AMB Rotor System Considering Sensor And Actuator Dynamics},
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_87.pdf}
}
2004 Ahn, H.-J., Kim, I.-H. and Han, D.-C. A novel Cylindrical Capacitive Sensor (CCS) For Both Radial And Axial Motion Measurement Proceedings of ISMB9  
Abstract: This paper proposes a novel cylindrical capacitive sensor (CCS) for both radial and axial motion measurement. The proposed CCS has almost the same geometric configuration as the conventional CCS and the unused axial area of the CCS is utilized to measure the axial motion of a rotor, which can reduce complexity of the hardware configuration and offer more degree of freedom in design. First, a theoretical model of the proposed CCS considering the nonlinear characteristic of the CCS is derived. Based on the derived theoretical model, a simple compensation method to decouple the radial and axial motion measurements is proposed. In addition, error analysis is performed and a design rule is proposed to guarantee the same accuracy in measuring both radial and axial motion. Finally, a test rig and electronics for the proposed CCS are built and the performances of the proposed CCS is verified experimentally.
BibTeX:
@inproceedings{ISMB9_86,
  author = {Hyeong-Joon Ahn and Il-Hae Kim and Dong-Chul Han},
  title = {A novel Cylindrical Capacitive Sensor (CCS) For Both Radial And Axial Motion Measurement},
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_86.pdf}
}
2002 Ahn, H.-J., Park, I.-H., Kim, J.-H. and Han, D.-C. Design And Rotor Dynamic Modeling Of High Speed Milling Spindle Supported With Amb Proceedings of ISMB8  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB8_77,
  author = {Hyeong-Joon Ahn and In-Hwang Park and Jong-Hyuk Kim and Dong-Chul Han},
  title = {Design And Rotor Dynamic Modeling Of High Speed Milling Spindle Supported With Amb},
  booktitle = {Proceedings of ISMB8},
  year = {2002},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb8/ismb8_submission_77.pdf}
}
2000 Ahrens, M., Frei-Spreiter, B. and Wieser, R. Cost Efficient Electric High-Speed Drives with Magnetic Bearings for the COG Market Proceedings of ISMB7  
Abstract: Electric high-speed drives with magnetic bearings offer significant technical and economic advantages for gas compression and pipeline operation. Compressors with magnetic bearings and dry gas seals have been successfully used for more than a decade. These installations have demonstrated that the elimination of the compressor lube oil system results in increased availability and is economically viable. Nevertheless, as long as a lube oil system is still necessary for the driver or for a gearbox the benefits of an oil-free operation such as increased safety and increased availability cannot be fully exploited. Electric high-speed drives do not require a gearbox. In combination with the use of magnetic bearings such drives allow the elimination of the entire lube oil system resulting in a dry rotor string. The elimination of the gearbox and of the drive lube oil system results in increased efficiency and increased availability. This leads to reduced operation and maintenance cost. Furthermore, such electric high-speed drives can easily be adjusted to specific requirements, allow a wide operating range and thus the pipeline operation can be optimized. High efficiency, oil-free operation and no emissions make electric high-speed drives the most environmental friendly compressor drive.
BibTeX:
@inproceedings{ISMB7_85,
  author = {Markus Ahrens and Barbara Frei-Spreiter and Rudolf Wieser},
  title = {Cost Efficient Electric High-Speed Drives with Magnetic Bearings for the COG Market},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_85.pdf}
}
1996 Ahrens, M. and Kucera, L. Analytical Calculation of Fields, Forces and Losses of a Radial Magnetic Bearing with Rotating Rotor Considering Eddy Currents  Proceedings of ISMB5  
Abstract: This paper presents an analytical model of a radial magnetic bearing with which magnetic fields, forces and losses are calculated. When an unlaminated rotor rotates in a radial magnetic bearing, eddy currents are caused to flow inside the conducting material of the rotor. These eddy currents change the magnetic field of the radial bearing and, therefore, the forces on the rotor depend on the eddy currents. Additionally to the levitation force, a tangetial force acts on the rotor. This tangential force causes a retardation torque which has been measured for many magnetic bearing systems. When the rotor is excited, the tangential force additionally leads to a cross coupling between the x and y axis which may destabilize the system. It will be shown that the forces and losses of a radial bearing depend on the pole configuration. It can be seen that the configuration NSNS has smaller losses than NNSS. The analytical results presented in this paper correspond with measurements [8].
BibTeX:
@inproceedings{ISMB5_43,
  author = {M. Ahrens and L. Kucera },
  title = {Analytical Calculation of Fields, Forces and Losses of a Radial Magnetic Bearing with Rotating Rotor Considering Eddy Currents },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_43.pdf}
}
1995 Ahrens, M. and Kucera, L. 4 Cross Feedback Control of a Magnetic Bearing System Proceedings of ISMST3  
Abstract: For flywheel rotors or other rotors with significant ratios of moments of inertia ( J z / J S !< 1, see figure 2), t,he influence of gyroscopic effects has to be considered. While conservative or damped systems remain stable even under gyroscopic effects, magnetically suspended rotors can be destabilized with increasing rotational speed. The influence of gyroscopic effects on the stability and behaviour of a magnetic bearing system is analyzed. The analysis is carried out with a rigid body model for the rotor and a nonlinear model for the magnetic bearing and its amplifier. Cross feedback control can compensate gyroscopic effects. This compensation leads to better system pcrformance and can avoid instability. Furthermore, the implementation of this compensation is simple. The main structure of a decentralized controller can still be used. It has only to be expanded by the cross feedback path.
BibTeX:
@inproceedings{ISMST3_13,
  author = {Markus Ahrens and Ladislav Kucera},
  title = {4 Cross Feedback Control of a Magnetic Bearing System},
  booktitle = {Proceedings of ISMST3},
  year = {1995},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst3/ismst3_submission_13.pdf}
}
1996 Ahrens, M., Kucera, L. and Larsonneur, R. Field Experiences with a Highly Unbalanced Magnetically Suspended Flywheel Rotor  Proceedings of ISMB5  
Abstract: This paper describes the behaviour of a highly unbalanced flywheel rotor. The unbalance leads to rotational synchronous harmonic bearing forces which may cause amplifier saturation. It will be shown that the balancing of the rotor can be achieved with data obtained from the magnetic bearings. Additionally, it will be shown that the housing dynamics can have an enormous influence on the balancing data. Furthermore, experiences with unbalance compensation are given. The results presented in this paper show that the rotor does not, as often written, rotate "force-free" and therefore does not spin around its principal axis of inertia. Moreover, for rotors with high gyroscopic coupling an undamped resonance occurs. In this frequency range it is impossible to use unbalance compensation. The results presented in this paper are crucial for magnetic bearing systems and have to be considered in their design.
BibTeX:
@inproceedings{ISMB5_22,
  author = {M. Ahrens and L. Kucera and R. Larsonneur },
  title = {Field Experiences with a Highly Unbalanced Magnetically Suspended Flywheel Rotor },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_22.pdf}
}
2000 Ahrens, M. and Miller, H. What is the Future of Magnetic Bearings for Turbomachinery? Proceedings of ISMB7  
Abstract: Magnetic bearings offer many technical advantages for turbomachines such as oil-free operation, adjustable bearing parameters and the potential of high operating speeds. Although magnetic bearings have been tried for almost all kind of turbomachines, today this technology is mainly used for special applications and, thus, the real commercial breakthrough is still missing. This paper describes how two large global players in the compressor drive market envision the future of magnetic bearings for the turbomachinery business. Based on their past experience with magnetic bearings, end-customer feedback and market surveys, the technical and business challenges that need to be solved, in order to satisfy the needs of turbomachinery manufacturers and end-customers, are described.
BibTeX:
@inproceedings{ISMB7_90,
  author = {Markus Ahrens and Harry Miller},
  title = {What is the Future of Magnetic Bearings for Turbomachinery?},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_90.pdf}
}
2000 Ahrens, M. and Sturgess, K. Oil-Free Compressor Systems for Gas Pipelines: Is now the Time? Proceedings of ISMB7  
Abstract: The "World's First Oil-Free Compressor" was commissioned in the NOVA (now TransCanada Pipelines) gas transmission system in 1985. This move to oil-free technology was driven initially by a desire to reduce unscheduled downtime by removing the problematic oil seal and lubrication systems. Over the years more compressors were equipped with dry gas seals and magnetic bearings. By 1992, 34 compressors totaling about 60 percent of the installed power of the NOVA system were running on magnetic bearings. At that time problems with the reliability of the magnetic bearings were noticed and the oil-free compressor program was reviewed. The main reasons for these problems in the early days were connectors, amplifiers, auxiliary bearings, and some design and training issues (see “Magnetic Bearing Improvement Program: History and Details”, Alves et al, NOVA GTL at MAG ’95). These problems were corrected over the next three years and since then the systems have worked satisfactorily.
BibTeX:
@inproceedings{ISMB7_key02,
  author = {Markus Ahrens and Kim Sturgess},
  title = {Oil-Free Compressor Systems for Gas Pipelines: Is now the Time?},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_key02.pdf}
}
1994 Ahrens, M., Traxler, A., vonBurg , P. and Schweitzer, G. Design of a Magnetically Suspended Flywheel Energy Storage Device Proceedings of ISMB4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB4_89,
  author = {M. Ahrens and A. Traxler and P. vonBurg and G. Schweitzer },
  title = {Design of a Magnetically Suspended Flywheel Energy Storage Device },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_89.pdf}
}
2004 Akamatsu, D., Chiba, A. and Fukao, T. A Novel Rotor Resistance Identification In Slip Frequency Controlled Bearingless Induction Motors Proceedings of ISMB9  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB9_55,
  author = {Daigo Akamatsu and Akira Chiba and Tadahi Fukao},
  title = {A Novel Rotor Resistance Identification In Slip Frequency Controlled Bearingless Induction Motors},
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_55.pdf}
}
1992 Akiba, T., Shingu, S., Kameda, Y., Akabane, S. and Hirai, S. Development of a Magnetically-Suspended Mirror Scanning Mechanism for an Interferometric Proceedings of ISMB3  
Abstract: The Advanced Earth Observation Satellite (ADEOS) will be launched in early 1995. It carries an Interferometric Monitor for Greenhouse gasses (IMG). The IMG program has been implemented under the contract for " An assessment of the environment (A study of the global monitoring)" of the Ministry of International Trade and Industry since 1989. IMG is intended for the global observation of CO2, CH4 , N2O and other greenhouse effect gasses. It is a fourier transform infrared spectrophotometer (FTIR) , and requires a scanning mirror and the mirror scanning mechanism for fourier transform. In the IMG system, the mirror scanning mechanism is a key part. Accordingly, the authors manufactured the Magnetically-Suspended Mirror Scanning Mechanism (MAMS) for IMG. This paper presents the MAMS structure and the results obtained from its functional tests.
BibTeX:
@inproceedings{ISMB3_7,
  author = {T. Akiba and S. Shingu and Y. Kameda and S. Akabane and S. Hirai },
  title = {Development of a Magnetically-Suspended Mirror Scanning Mechanism for an Interferometric },
  booktitle = {Proceedings of ISMB3},
  year = {1992},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb3/ismb3_submission_7.pdf}
}
1994 Akishita, S. and Iwatani, K. Hybrid Nonlinear Robust Control for Magnetically Supported Flexible Beam Proceedings of ISMB4  
Abstract: This paper describes a design and simulation study for nolinear robust control to a magnetic levitation system on a flexible beam. The beam investigated here is supposed so flexible that the gravitation causes noticeable static deflection. An unified dynamic model including static modes is induced an d then an exactly linearized state equation system is derived by utilizing the feedback linearization technique. H2 / Hoc robust control system is applied to the linearized systems to compensate the modelling error. A simulatioon result proves the effectiveness of the proposed design method.
BibTeX:
@inproceedings{ISMB4_17,
  author = {S. Akishita and K. Iwatani },
  title = {Hybrid Nonlinear Robust Control for Magnetically Supported Flexible Beam },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_17.pdf}
}
1996 Akishita, S. and Morimoto, H. Anisotropic Stiffness Effect for Improving Stability of Two-Axes Controlled Rotor by Magnetic Bearings  Proceedings of ISMB5  
Abstract: This paper describes a stability analysis of anisotropic bearing stiffness effect for improving damping characteristics of a two-axes controlled rotor by magnetic bearings. The method of averaging is applied for simplifying the mathematical model of tilting motion of the rotor. The anisotropic stiffness effect is found to be efficient for improving the damping characteristics but it depends on the ratio of moments of inertia of the rotor.
BibTeX:
@inproceedings{ISMB5_5,
  author = {S. Akishita and H. Morimoto },
  title = {Anisotropic Stiffness Effect for Improving Stability of Two-Axes Controlled Rotor by Magnetic Bearings },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_5.pdf}
}
1992 Akishita, S. and Morimura, T. Active Control of Bending Vibration in Magnetically Suspended Flexible Rotor Proceedings of ISMB3  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB3_20,
  author = {S. Akishita and T. Morimura },
  title = {Active Control of Bending Vibration in Magnetically Suspended Flexible Rotor },
  booktitle = {Proceedings of ISMB3},
  year = {1992},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb3/ismb3_submission_20.pdf}
}
1990 Akishita, S., Morimura, T. and Hamaguchi, S. Vibration Control of Magnetically Suspended Flexible Rotor by the Use of Optimal Regulator  Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_21,
  author = {S. Akishita and T. Morimura and S. Hamaguchi },
  title = {Vibration Control of Magnetically Suspended Flexible Rotor by the Use of Optimal Regulator },
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_21.pdf}
}
1996 Alahakoon, S., Walgama, K., Sadarangani, C. and Leksell, M. Digital Control of Active Magnetic Bearings for Precise Eccentric Rotor Positioning  Proceedings of ISMB5  
Abstract: Active Magnetic Bearing ( AMB ) control has been a challenging task for the control engineers since its invention. Various types of control techniques - both analogue and digital - have been tried over the past years. In the application area of rotating machines, the whole concept of AMB control means stabilising the rotor of the machine in the exact centre of the radial AMEs and maintaining that position by counteracting the disturbances exerted on it under running condition. Noise reduction in electrical machines is becoming an increasingly important requirement for the design engineers and rotor eccentricities have been identified as the main source of noise generation. AMB with its relatively large air gap, allows the rotor to move away from the exact centre, provided the controller used is capable of maintaining an eccentric position under running condition. The ability of running the machine with known eccentricities makes the AMB a good actuator to study the noise characteristics of electrical machines. The ultimate objective of the project aims at investigating the magnetic noise from a standard induction machine. This calls for a flexible design of the control that enables the user to move the rotor to an arbitrary position in the air gap. This demand is achieved by using a digital controller based on a DSP.
BibTeX:
@inproceedings{ISMB5_8,
  author = {S. Alahakoon and K. Walgama and C. Sadarangani and M. Leksell },
  title = {Digital Control of Active Magnetic Bearings for Precise Eccentric Rotor Positioning },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_8.pdf}
}
1994 Albanese, R., Delprete, C., Genta, G. and Mosolov, A. Experimental Characterization and Mathematical Modeling of High-Tc Superconductors for Magnetic Bearings Proceedings of ISMB4  
Abstract: An experimental study of the levitation forces aimed to supply informations for the design of superconducting magnetic bearings was conducted on melt-textured YBCO materials. Such materials demonstrate sufficiently good levitation capabilities and complicated strongly non-linear force-position dependence. An analytical model for levitation force which is based on the Bean critical state concept and that takes into account the inhomogeneity of the materials is proposed in this paper. The comparison of experimental and numerical results shows that the proposed model can be used for quantitative prediction of the behaviour of magnetic levitation systems.
BibTeX:
@inproceedings{ISMB4_66,
  author = {R. Albanese and C. Delprete and G. Genta and A. Mosolov },
  title = {Experimental Characterization and Mathematical Modeling of High-Tc Superconductors for Magnetic Bearings },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_66.pdf}
}
1994 Albanese, R., Delprete, C., Genta, G., Tonoli, A., Mazzocchetti, L., Rava, E., Frangi, F. and Zannella, S. Design, Construction and Testing of a Kinetic Energy Storage Device with High Tc Superconductive Suspensions Proceedings of ISMB4  
Abstract: The paper describes a small kinetic energy storage device built to demonstrate the feasibility of a flywheel system in which the rotor is supported on a five axis passive magnetic suspension based on High-Tc superconductors (HTS). The tests aimed to measure the performances of the superconductive magnetic bearing are described together with the details of the design and the analysis and the tests on the prototype. The machine has been operated satisfactorily using a hybrid bearing layout and will be tested using a complete magnetic suspension as soon as superconductors with higher characteristics will be available.
BibTeX:
@inproceedings{ISMB4_71,
  author = {R. Albanese and C. Delprete and G. Genta and A. Tonoli and L. Mazzocchetti and E. Rava and F. Frangi and S. Zannella },
  title = {Design, Construction and Testing of a Kinetic Energy Storage Device with High Tc Superconductive Suspensions },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_71.pdf}
}
2010 Allaire, P. Design and Analysis of Magnetic Suspension for New Artificial Heart Proceedings of ISMB12  
Abstract: Artificial hearts have been developed with magnetic suspension for the last 20 years, starting at the University of Virginia. A new axial flow path, magnetically suspended artificial heart-the Lifeflow-is currently under development. The magnetic suspension consists of two permanent magnet biased active radial bearings and an axial permanent magnet thrust bearing. The radial bearings are six pole bearings which employ self sensing. The pump rotates at approximately 7,000 rpm with a flow rate of approximately 5 liters/min and a pressure rise of 100 mm of Hg. The magnetic suspension system consumes only about 2 watts due to the combined use of the permanent and active magnetic bearings. A finite element analysis has been carried out to determine the magnetic properties of the magnetic suspension system. The thrust bearing has been constructed to not require a thrust disk-which permits a very streamlined flow path for the blood through the pump. The properties of the permanent magnetic thrust bearing-magnetic flux, load capacity, axial/radial stiffness have been determined. For the active radial bearings, the bias flux, radial load capacity, open loop stiffness and current gain have been calculated. A magnetic suspension test rig has been constructed and experimental tests are ongoing. One of the features of most current artificial heart pumps available for human implantation is that only the motor current is available to monitor the operating condition in the pump when implanted. This low level of monitoring is not sufficient to effectively monitor heart pump performance when implanted. For example, many current artificial heart pumps are subject to thrombus formation which can lead to strokes. New features of the Lifeflow pump include pressure sensors to determine the pressure at the inlet and the discharge regions of the pump, impeller radial displacements during implanted pump operation. These operating system measurements, as well as motor currents, will be sent via wifi to the monitoring medical team. It is expected that active, remote monitoring of these pumps will assist in maintaining safe pump operation.
BibTeX:
@inproceedings{ISMB12_key03,
  author = {Paul Allaire},
  title = {Design and Analysis of Magnetic Suspension for New Artificial Heart},
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_key03.pdf}
}
2016 Allaire, P., Cao, J., Dimond, T., Mushi, S., Dousti, S., Newark, R., Lloyd, N. and Alshahrani, O. Design of Active Magnetic Radial and Thrust Bearings for High Speed Turbo Aerator Proceedings of ISMB15  
Abstract: The thrust and radial active magnetic bearing (AMB) designs are presented for a 135 kW vertical axis high speed turbo aerator operating at maximum speed of 27,000 rpm. The thrust AMB is a double acting configuration with upperandlowerstatorsandasinglecoil. TheradialAMBisa12poleE-coredesign. Theresultsofmagneticcircuit design, 2-D finite element, and 3-D finite element modeling are presented, indicating that the simple magnetic circuit model is a good initial design tool for both thrust and radial AMBs. The AMBs were actuated with a steady state bias current and a time varying perturbation (control) current. The current gain and open loop stiffness for the AMBs are evaluated, showing the linearity of the bearings. Also, the coil resistance and inductance were evaluated. The bearings were successfully operated in the initial testing. The rotating AMB components must be attached to the rotor securely using shrink fits. The principal and shear stresses induced in the thrust AMB disk and the radial AMB lamination stack were evaluated and found to be in the safe range.
BibTeX:
@inproceedings{ISMB15_28,
  author = {Paul Allaire and Jianming Cao and Tim Dimond and Simon Mushi and Saeid Dousti and Richard Newark and Nigel Lloyd and Omar Alshahrani},
  title = {Design of Active Magnetic Radial and Thrust Bearings for High Speed Turbo Aerator},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_28.pdf}
}
1999 Allaire, P., Decker, J., Baloh, M., Lee, J. and Long, J. Magnetic Suspension of an Artificial Heart Pump Using EM/PM Bearings (abstract only) Proceedings of ISMST5  
Abstract: An artificial heart pump is under development for use as a ventricular assist device. This paper describes a fourth generation prototype pump of diameter 68 mm (2.62 in) and axial length 33.5 mm (1.32 in). The pump is a small centrifugal pump with a shaftless impeller fully supported in magnetic bearings. It is desired that the magnetic support system have high load capacity, be very compact, and have very low power consumption. A hybrid electromagnet/permanent magnet bearing design has been developed and tested. The bearings consist of two identical rings, one placed on the inlet side of the centrifugal impeller and one placed on the discharge side of the impeller. Each ring has eight poles, four radial and four axial, to control the pump impeller in five axes (x, y, z, a, 13)- three displacements and two angular displacements relative to the x, y axes. The bearings have a radial load capacity of 9.65 N (2.16 Ibf) and an axial load capacity of 19.3 N (4.33 Ibf). The dynamic model of the impeller in the magnetic bearings is developed. The estimated coil ohmic power loss in normal operation is less than 5 watts.
BibTeX:
@inproceedings{ISMST5_20,
  author = {P. Allaire and J. Decker and M. Baloh and J. Lee and J. Long},
  title = {Magnetic Suspension of an Artificial Heart Pump Using EM/PM Bearings (abstract only)},
  booktitle = {Proceedings of ISMST5},
  year = {1999},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst5/ismst5_submission_20.pdf}
}
1994 Allaire, P., Fittro, R., Maslen, E. and Wakefield, W. Eddy Currents, Magnetic Flux and Force in Solid Magnetic Thrust Bearings Proceedings of ISMB4  
Abstract: This paper discusses the force/current relation for a solid magnetic thrust bearing. The particular bearing was designed for a laboratory pump as a bearing/load cell to support the shaft as well as measure the thrust forces on the impeller. The current/force relation is also important for magnetic bearings installed in pumps, compressors, and other rotating machines where the measured current level can be used to determine operating force levels. A non-rotating test rig was constructed to directly measure the force as the current was cycled through major and minor loops for various air gaps. Quasistatic major current loops at a rate of 0.1 A/sec exhibited differences in measured forces of up to 12.6% between increasing and decreasing current trajectories. A dimensionless curve fit was developed for the data, with an error of approximately 4 percent. A bimodal error distribution was found which corresponds to magnetic hysteresis in the magnetic bearing. The error is dependent upon the current/force path followed during the current cycle and represents an uncertainty in the force measurement. Current cycles at frequencies of 0.1 to 40 Hz were also tested and produced differences of up to 34.9%. Plots of magnitude and phase were obtained from the sinusoidal data which showed that the magnitude of the current/force ratio is relatively constant at low frequencies but decreases by 28% at 40 Hz. The phase angle exhibits a relatively large phase lag of approximately 16 degrees at 40 Hz.
BibTeX:
@inproceedings{ISMB4_27,
  author = {P. Allaire and R. Fittro and E. Maslen and W. Wakefield },
  title = {Eddy Currents, Magnetic Flux and Force in Solid Magnetic Thrust Bearings },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_27.pdf}
}
1991 Allaire, P., Humphris, R. and Lewis, D. Professor Jesse W. Beams and the First Practical Magnetic Suspension Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_2,
  author = {P. Allaire and R. Humphris and D. Lewis},
  title = {Professor Jesse W. Beams and the First Practical Magnetic Suspension},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_2.pdf}
}
2014 Allaire, P., Jiang, W., Kailasan, A. and Dimond, T. Magnetic Bearing System for Left Ventricular Assist Artificial Heart Pump - Combined Active and Passive Configuration Proceedings of ISMB14  
Abstract: Magnetic bearings continue to contribute to the development of ventricular assist artificial heart pumps. This paper describes the magnetic suspension for a unique prototype axial flow pump designed for approximately 6 l/min at 100 mm Hg performance with an operating speed of approximately 7,000 rpm. The integrated magnetic suspension design provides a direct non-contact blood flow path through the pump with no obstructions which might create low flow areas and thrombosis (blood clots). The magnetic suspension is a combination of permanent magnets (PMs) and active magnetic bearings (AMBs). There are two radial AMBs which support the four degrees of freedom at the ends of the axial pump impeller and an axial PM thrust bearing. The axial PM bearing supports the direction of the largest fluid force on the impeller. A major objectives of artificial hearts is to have extremely low power consumption. Thus the integrated PM and AMB suspension system has an operating magnetic suspension power of approximately 2 watts. The design, numerical modeling, and testing of the magnetic suspension system to support the fluid loads and the g loads is described in the paper.
BibTeX:
@inproceedings{ISMB14_131,
  author = {Paul Allaire and Wei Jiang and Arunvel Kailasan and Tim Dimond},
  title = {Magnetic Bearing System for Left Ventricular Assist Artificial Heart Pump - Combined Active and Passive Configuration},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_131.pdf}
}
1988 Allaire, P., Kasarda, M., Humphris, R. and Lewis, D. Vibration Reduction in a Multimass Flexible Rotor Using a Midspan Magnetic Damper Proceedings of ISMB1 - Courtesy of Springer-Verlag  
Abstract: The purpose of this study is to investigate the effects of a magnetic damper on a mul t imass rotor. A small three mass rotor which would simulate the dynamics of a centrally mounted steam turbine or compressor was built and a magnetic damper placed near the rotor midspan. The magnetic damper was constructed of four separate radially arranged silicon iron magnets with coil windings. A proportional aud derivative control circuit was employed to control the damper. The rotor was run at speeds frolll 0 to 10,000 rpm, through three natural rotor- bearing- support system resonances.
BibTeX:
@inproceedings{ISMB1_15,
  author = {P.E. Allaire and M. Kasarda and R.R. Humphris and D. Lewis },
  title = {Vibration Reduction in a Multimass Flexible Rotor Using a Midspan Magnetic Damper },
  booktitle = {Proceedings of ISMB1 - Courtesy of Springer-Verlag},
  year = {1988},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb1/ismb1_submission_15.pdf}
}
1996 Allaire, P., Kasarda, M., Maslen, E. and Gillies, G. Rotor Power Loss Measurements for Heteropolar and Homopolar Magnetic Bearings  Proceedings of ISMB5  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB5_46,
  author = {P. Allaire and M. Kasarda and E. Maslen and G. Gillies },
  title = {Rotor Power Loss Measurements for Heteropolar and Homopolar Magnetic Bearings },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_46.pdf}
}
2018 Allaire, P., Nichols, B., Dimond, T., Cao, J., Ma, X., Shang, R., Wang, C. and Wang, H. 5-Axis AMB Suspension Design for 300 HP Industrial Compressor Proceedings of ISMB16  
Abstract: This paper provides the design methodology, bearing geometries, and specifications for both the radial and axial AMBs as designed for an industrial 300 HP motor-blower unit. For each bearing design, the design principles and corresponding 1D circuit models are methodically presented and discussed. Next, the optimized bearing geometries and bearing properties are presented. The algorithms used by the design software, based on the 1D circuit model bearing analyses, refine the design process and verify the results using 2D finite element analysis (FEA). Based on calculated loads for the radial bearing and estimated loads for the thrust bearing, the radial AMB is designed for a load capacity of 2,000 N while the thrust bearing is designed for a load capacity of 3,000 N. The maximum rotational speed of the 200 KW unit is considered to be 21,000 rpm.
BibTeX:
@inproceedings{ISMB16_097,
  author = {Paul Allaire and Brad Nichols and Tim Dimond and Jianming Cao and Xianhao Ma and Raojing Shang and Chunyan Wang and Huajun Wang},
  title = {5-Axis AMB Suspension Design for 300 HP Industrial Compressor},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_097.pdf}
}
2016 Allaire, P., Nichols, B., Dimond, T., Cao, J. and Mushi, S. Low Cost Active Magnetic Bearings - Concepts and Examples Proceedings of ISMB15  
Abstract: The objective of this paper is to present innovative new thrust and radial magnetic bearing designs using permanent magnet bias not previously published. They are expected to be significantly lower in cost than conventional all electromagnetic bearings. The new designs use permanent magnet bias in a way not introduced before. The resulting magnetic bearings are able to use only half of the number of power amplifiers than conventional magnetic bearings, as well as consuming significantly less operating power in the bearing coils. However, the bearings are generally not larger than conventional all electromagnetic bearings. Finally, these new permanent magnet bias bearing designs are generally not longer axially than all electromagnetic bearing designs, unlike other types of permanent magnet bias designs such as homopolar magnetic bearings. This is important from the rotor dynamics point of view. This innovation has the potential to reduce the overall magnetic bearing system hardware volume production cost by 20% to 30% as well as reduce coil current operating costs in the range of 35% to 40%.
BibTeX:
@inproceedings{ISMB15_51,
  author = {Paul Allaire and Brad Nichols and Tim Dimond and Jianming Cao and Simon Mushi},
  title = {Low Cost Active Magnetic Bearings - Concepts and Examples},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_51.pdf}
}
1998 Allaire, P.E., Fujita, L.K. and Kasarda, M.E.F. Rotor Power Losses in Planar Radial Magnetic Bearings-Effects of Number of Stator Poles, Air Gap Thickness, and Magnetic Flux Density,  Proceedings of ISMB6  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB6_37,
  author = {P. E. Allaire and L. K. Fujita and M. E. F. Kasarda},
  title = {Rotor Power Losses in Planar Radial Magnetic Bearings-Effects of Number of Stator Poles, Air Gap Thickness, and Magnetic Flux Density, },
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_37.pdf}
}
1991 Allaire, P.E., Maslen, E.H., Humphris, R.R., Sortore, C.K. and Studer, P.A. Low Power Magnetic Bearing Design for High Speed Rotating Machinery Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_18,
  author = {P. E. Allaire and E. H. Maslen and R. R. Humphris and C. K. Sortore and P. A. Studer},
  title = {Low Power Magnetic Bearing Design for High Speed Rotating Machinery},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_18.pdf}
}
1998 Allaire, P.E. and Sinha , A. Robust Sliding Mode Control of a Planar Rigid Rotor System on Magnetic Bearings Proceedings of ISMB6  
Abstract: A planar rigid rotor supported on magnetic bearings is controlled using a robust sliding mode controller. Linearized magnetic bearings and mass unbalance are considered. A nonlinear sliding mode controller evaluates the magnetic bearing control currents which bring the rotor response to the sliding mode surface and cause it to remain within the boundary layer. A treatment of uncertainty limits is developed for unknown bearing open loop stiffness, actuator gain, and mass unbalance. A numerical simulation showed the desired system response when the rotor was subjected to large initial transient conditions.
BibTeX:
@inproceedings{ISMB6_55,
  author = {P. E. Allaire and A. Sinha },
  title = {Robust Sliding Mode Control of a Planar Rigid Rotor System on Magnetic Bearings},
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_55.pdf}
}
1991 Allan, A.P. and Knospe, C.R. A Six Degree-of-Freedom Magnetic Bearing for Microgravity Vibration Isolation Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_11,
  author = {A. Peter Allan and Carl R. Knospe},
  title = {A Six Degree-of-Freedom Magnetic Bearing for Microgravity Vibration Isolation},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_11.pdf}
}
2006 Alpaugh, H.E., Nelson, F.C. and Fermental, D.W. Real Time Digital Control of an Active Magnetic Bearing using Open Source Software Proceedings of ISMB10  
Abstract: A digital control system using a real time variant of Linux is developed and implemented on a bench-top rotor suspended on active magnetic bearings. The combination of simple hardware and open source software provides a useful educational and research platform for digital control methods that is unencumbered by proprietary constraints as well as one that is more cost effective than available commercial systems. A real time operating system must ensure that specific tasks are executed at a fixed rate regardless of other system level demands. This is achieved with special purpose kernels that allow Linux to run as a low priority task within the real time operating system. Digital filters are constructed and coded in C, the native language of Linux. The controller is implemented on an off-the-shelf Pentium 3 personal computer operating in a multiple channel configuration at 10 KHz.
BibTeX:
@inproceedings{ISMB10_65,
  author = {H. E. Alpaugh and F. C. Nelson and D. W. Fermental},
  title = {Real Time Digital Control of an Active Magnetic Bearing using Open Source Software},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_65.pdf}
}
2008 Amada, M., Miyamoto, N., Enomoto, T., Tanabe, N., Asama, J., Chiba, A., Fukao, T., Iwasaki, S. and Takemoto, M. Inverter Voltage and Suspension Characteristics of a Bearingless Motor Proceedings of ISMB11  
Abstract: A wide magnetic gap consequent-pole type bearingless motor has been developed. The wide magnetic gap makes it difficult to start up and suspend a shaft with reasonable suspension voltage and current. To provide high current, high voltage rating is demanded, although, high voltage causes bad influence on magnetic suspension. In this paper, the authors investigate the start-up and rotational characteristics of a prototype bearingless machine driven by voltage source inverters having the rated voltage of 200V and 100V. When the rated voltage is not suitable, significant problems are occurred. The effectiveness of proper selection in the rated voltage is discussed.
BibTeX:
@inproceedings{ISMB11_58,
  author = {Miya Amada and Naoya Miyamoto and Takehiro Enomoto and Norimasa Tanabe and Junichi Asama and Akira Chiba and Tadashi Fukao and Satoru Iwasaki and Masatsugu Takemoto},
  title = {Inverter Voltage and Suspension Characteristics of a Bearingless Motor},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_58.pdf}
}
2000 Amati, N., Brusa, E. and Gianolio, G. Effects on the Dynamic Behaviour of Rotors on AMB of the Electromechanical Coupling in Induction Motors Proceedings of ISMB7  
Abstract: The role of the unbalanced magnetic pull exerted by the magnetic field of induction motors on rotors sup- ported by active magnetic bearings is investigated at least in the range of spin speeds corresponding to the rigid body behaviour. Under the assumptions that the forces of the bearings can be linearized and the rotor is axially symmetrical, the equations of mo- tion of the system are written including the negative stiffness of the motor due to non uniform air gap. Some numerical results are then compared to the ex- perimental data performed on a spindle on magnetic suspension, with five active axes. The effects at dif- ferent values of the spin speed and in presence of slip in the induction motor are then analysed with par- ticular care to the vibration condition monitoring of the whole machine.
BibTeX:
@inproceedings{ISMB7_100,
  author = {Nicola Amati and Eugenio Brusa and Giuseppe Gianolio},
  title = {Effects on the Dynamic Behaviour of Rotors on AMB of the Electromechanical Coupling in Induction Motors},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_100.pdf}
}
1999 Amrhein, W., Silber, S. and Nenninger, K. Finite Element Design of Bearingless Permanent Magnet Motors Proceedings of ISMST5  
Abstract: In high performance applications with high demands on speed range, lifetime, cleanness or tightness, magnetic bearing systems can provide substantial advantages to classical drive systems using ball or sliding bearings. Some of these applications like pumps, blowers or fans require only three actively controlled degrees of freedom and can be supported by four coil bearingless permanent magnet motors. In these cases three degrees of freedom are passively stabilized by the tensible force of permanent magnets. Depending on the particular application an interior or exterior rotor design of the bearingless motor may be advantageous. A finite element analysis is used to show the interactions between the current density distributions of the stator and the excitation fields of the rotor. Different permanent magnet magnetization forms are examined. It is shown that the results of the interior rotor design differ significantly from the results achieved by exterior rotor design.
BibTeX:
@inproceedings{ISMST5_17,
  author = {Wolfgang Amrhein and Siegfried Silber and Klaus Nenninger},
  title = {Finite Element Design of Bearingless Permanent Magnet Motors},
  booktitle = {Proceedings of ISMST5},
  year = {1999},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst5/ismst5_submission_17.pdf}
}
2002 Amrhein, W., Silber, S., Nenninger, K., Trauner, G. and Reisinger, M. Developments On Bearingless Drive Technology Proceedings of ISMB8  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB8_94,
  author = {Wolfgang Amrhein and S. Silber and K. Nenninger and G. Trauner and M. Reisinger},
  title = {Developments On Bearingless Drive Technology},
  booktitle = {Proceedings of ISMB8},
  year = {2002},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb8/ismb8_submission_94.pdf}
}
2018 Anantachaisilp, P. and Lin, Z. Fractional Order Control of Compressor Surge by Active Magnetic Bearings Proceedings of ISMB16  
Abstract: This paper demonstrates the design, analysis, and implementation of fractional order PID control (FOPID) for the control of compressor surge in a centrifugal compressor test rig by active magnetic bearings (AMBs). This is the first time that the FOPID controller is designed for and implemented on an AMB system for the surge control objective. In order to achieve the desired design specifications, the controller parameters are tuned by using evolutionary algorithms. Furthermore, a comparison of the performance and efficiency of the FOPID, PID, and an optimal controller is given based on simulation and experimental results.
BibTeX:
@inproceedings{ISMB16_054,
  author = {Parinya Anantachaisilp and Zongli Lin},
  title = {Fractional Order Control of Compressor Surge by Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_054.pdf}
}
2016 Anantachaisilp, P. and Lin, Z. Fractional Order Control of Rotor Suspension by Active Magnetic Bearings Proceedings of ISMB15  
Abstract: This paper demonstrates the design, analysis, and implementation of fractional order PID control (FOPID) for the control of rotor vibration in a centrifugal compressor test rig by active magnetic bearings (AMBs). This is the first time that the FOPID controller is designed for and implemented on an AMB system. In order to achieve the desired design specifications, the controller parameters are tuned by using evolutionary algorithms. Furthermore, a comparison of the performance and efficiency of the FOPID, PID, and an optimal controller is given based on simulation and experimental results.
BibTeX:
@inproceedings{ISMB15_31,
  author = {Parinya Anantachaisilp and Zongli Lin},
  title = {Fractional Order Control of Rotor Suspension by Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_31.pdf}
}
2012 Anantachaisilp, P., Lin, Z. and Allaire, P. PID Tuning Methods for Active Magnetic Bearing Systems Proceedings of ISMB13  
Abstract: The use of active magnetic bearings (AMBs) in place of traditional mechanical bearings for rotating machinery has been increasing. AMBs have been used not only in research studies, but also in a wide range of industrial applications. One of the key challenges in AMB appli-cations is the design of control systems that maintain stability in the presence of external loads and disturbances. The most commonly used controller for AMB systems is the Proportional-Integral-Derivative (PID) controller, whose design involves the tuning of control coefficients. Since manual tuning of these coefficients is time consuming, different systematic tuning methods have been developed and reported on in the literature. This paper examines some of these tuning methods in AMB control systems. Both simulation and experiments are carried out on an AMB test rig to compare the performance of the closed-loop systems resulting from these tuning meth-ods in terms of steady state accuracy and robustness. Simulation and experiments of each tuning method are conducted at rotational speeds ranging from 2,000 rpm to 11,000 rpm to evaluate the response peak (orbital size). Also, the frequency responses of the sensitivity function (S) under PID controllers tuned with different methods are measured and used to compare the robustness of the closed-loop system.
BibTeX:
@inproceedings{ISMB13_31,
  author = {Parinya Anantachaisilp and Zongli Lin and Paul Allaire},
  title = {PID Tuning Methods for Active Magnetic Bearing Systems},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_31.pdf}
}
1994 Andrejev, V. Interaction of Permanent Cylindrical Magnets with Axial Magnetization Proceedings of ISMB4  
Abstract: Known equivalence of the field of a permanent magnet having the fonn of a circular cylinder and axial magnetization and that of the field of a circular tape with constant surface current is used. Exact calculation of potential energy of interaction between two circular currents makes it possible: 1) to express in accurate formulae force and moment characteristics of interaction between magnets; 2) retaining the second-order memebers with respect to small displacements of two initially coaxial rings to build "the stiffness matrix" and analyse quantitatively the known static unstabiIity of the system. One of the possible rotor suspension configurations with permanent magnets is given to illustrate why the main quantitative characteristic of unstability - negative relationship of eigenvalues of the stiffness matrix - remains valid for all axially symmetric systems.
BibTeX:
@inproceedings{ISMB4_28,
  author = {V. Andrejev },
  title = {Interaction of Permanent Cylindrical Magnets with Axial Magnetization },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_28.pdf}
}
2016 Annasiwaththa, B.I. and Oka, K. Zero Power Levitation Control of a Magnetically Levitated Linear Slider Platform with Non-Contact Power Supply Proceedings of ISMB15  
Abstract: A magnetically levitated linear slider platform with a non-contact power supply method is presented in this paper. The non-contact power supply was achieved using an open end generator with a plastic core. The objectives of this paper is to present FEM analysis of the open end generator and initial observations from the experimental prototype. The rotor of the open end generator was mounted on the stationary structure of the system and the rotor includes 6 magnetic pole pairs mounted on the surface of the rotor. The levitated platform was constructed by mounting four hybrid electromagnets on four corners of a single rigid rectangular steel plate. The cogging torques introduced by the open end generator on the levitated platform was investigated using FEM method and the results presented. Levitation of the platform was achieved while open end generator is producing electrical power. The performance of the levitated platform with the open end generator was experimentally measured and presented. The rotor of the open end generator was rotated at 1000rpm. The amount of total root mean square electrical power dissipated through 19Ω load resistors by an open end generator with plastic core was 35W. The levitated platform achieved less than 0.25W power consumption per hybrid electromagnet during steady state operation. Estimated power consumption by the sensors and the electronic control boards used in the experimental platform was approximately 15W. The results suggest that the open end generator can produce sufficient amount of power to support platform levitation and control.
BibTeX:
@inproceedings{ISMB15_12,
  author = {Buddhika Imantha Annasiwaththa and Koichi Oka},
  title = {Zero Power Levitation Control of a Magnetically Levitated Linear Slider Platform with Non-Contact Power Supply},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_12.pdf}
}
2016 Anta, A., Selga, R.C., Osama, M. and Alban, T. System Identification for Active Magnetic Bearings at Nonzero Speeds Proceedings of ISMB15  
Abstract: In this paper we consider the problem of obtaining a dynamic model of rotating machinery equipped with magnetic bearings for a given speed range. Theoretical models are typically not accurate enough and cannot be trusted to predict system behaviour for the whole operating range of the machine. In this work we first obtain a dynamic model of the system at several speed levels; second, an extrapolation/interpolation of these models is performed to produce an estimate of the behaviour for the whole speed range. This procedure overcomes two common issues in system identification for magnetic bearings: first, it is costly and time-consuming to perform system identification at many speed levels to cover the whole operating range. Second, it is typically not safe to reach certain speeds unless the stability and unbalance response at high speeds has been verified. This can be only done once a reliable model is available. From a technical perspective, our approach relies on local system identification techniques aimed at linear parameter varying (LPV) systems. Compared to existing work, we believe the main contributions of this work are: we do not rely on global approaches that might lead into nonconvex problems, our approach is amenable to automation, and it allows considering the presence of casing modes in the system.
BibTeX:
@inproceedings{ISMB15_81,
  author = {Adolfo Anta and Rosa Castane Selga and Mohamed Osama and Thomas Alban},
  title = {System Identification for Active Magnetic Bearings at Nonzero Speeds},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_81.pdf}
}
1996 Antila, M., Lantto, E., Saari, J., Esa, H., Lindgren, O. and Saily, K. Design of Water Treatment Compressors Equipped with Active Magnetic Bearings  Proceedings of ISMB5  
Abstract: High Speed Tech Ltd. has constructed a high-speed water treatment compressor. The rotational speed is 42 000 rpm and the power is 75 kW. In this paper, a part of the facts that have to be considered when designing a high-speed machine are treated. In addition, some measurement results from the type tests are presented.
BibTeX:
@inproceedings{ISMB5_65,
  author = {M. Antila and E. Lantto and J. Saari and H. Esa and O. Lindgren and K. Saily },
  title = {Design of Water Treatment Compressors Equipped with Active Magnetic Bearings },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_65.pdf}
}
1998 Antila, M., Lantto, E. and Tommila, V. Determination of Eddy Current Effects on Radial Active Magnetic Bearings Based on a Reluctance Network and ID Eddy Current Model Proceedings of ISMB6  
Abstract: The emphasis of this paper is to study the effects of eddy currents in radial magnetic bearings on the control system design and bearing dynamics. We create a model based on a nonlinear reluctance network and one-dimensional eddy current formulation. The model is a linearised model. We describe the formulation of reluctance network field solution, calculation of the linearised parameters and the implementation of the eddy current model. Two types of measurements have been done. First, we compare the dynamic impedance measurements and secondly, the dynamic bearing force measurements based on acceleration sensors.
BibTeX:
@inproceedings{ISMB6_20,
  author = {M. Antila and E. Lantto and V. Tommila},
  title = {Determination of Eddy Current Effects on Radial Active Magnetic Bearings Based on a Reluctance Network and ID Eddy Current Model},
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_20.pdf}
}
1994 Antilia, M.J. The Load Capacity and Stiffness of the Axial Permanent Magnet Bearings Proceedings of ISMB4  
Abstract: This paper deals with the load capacity and stiffness of axial permanent magnet bearings and their influence on possible applications. We have studied the influence of the geometric parameters of a ring shaped axial bearing on the load capacity and stiffness. We have used the analytical solution of the flux density and calculated the values numerically. Characteristics of both attractive and repulsive bearing types have been analysed.
BibTeX:
@inproceedings{ISMB4_48,
  author = {M. J. Antilia },
  title = {The Load Capacity and Stiffness of the Axial Permanent Magnet Bearings },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_48.pdf}
}
1999 Argondizza, A., Carabelli, S., Genta, G. and Tonoli, A. Magnetically Levitated Reaction Wheel for Space Application Proceedings of ISMST5  
Abstract: The content of the present study is the feasibility asseasment of a reaction wheel on active magnetic bearings (AMB) to be followed by the design of a fully operational engineering model I, which is presently under construction. The stress is laid mainly on the demonstration that a small, simple reaction wheel on AMB can be built and operated reliably with power requiremems which are not in excess than those characteristic of conventional units. A reaction wheel ks usually a part of a complex system whose task is the attitude control of a spacecraft and in some cases also the storage of energy in the form of kinetic energy in the rotor. Here the work is concentrated only on the reaction wheel component, intended as a torque actuator. No attempt to address the problems related to the global system or to the possibility of using the reaction wheel as an energy storage device is performed. AMB technology is at present a well known technology in high speed rotating machinery. Several prototypes of machines of various kinds in which the rotor is magnetically suspended have been built and in some cases are on the market. Several applications of reaction wheels have been studied and many reaction wheels operating on AMB have been built, starting from the seventies 2. The present study is intended to address some specific problems, mostly related with low power consumption, high system integration and design compactness.
BibTeX:
@inproceedings{ISMST5_4,
  author = {A. Argondizza and S. Carabelli and G. Genta and A. Tonoli},
  title = {Magnetically Levitated Reaction Wheel for Space Application},
  booktitle = {Proceedings of ISMST5},
  year = {1999},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst5/ismst5_submission_4.pdf}
}
2000 Argondizza, A., Carabelli, S. and Tonoli, A. Finite Element Model Reduction for Rotating Systems Proceedings of ISMB7  
Abstract: Complex rotors are usually modeled by means of Finite Element Method (FEM) to cope with nonelementary shape of the shaft and of the rotating appendices connected to it (…gure 1). To account for the the complex geometry, the discretization at the base of the FEM model is usually characterized by a high number of nodes and, correspondingly of degrees of freedom. The FE model is then characterized by a high number of densely populated modes. Such an high order model takes the geometrical complexity of the structure into account but may fail to bring into evidence the more relevant modes both in terms of energy content and observability and controllability by available sensors and actuators. Nevertheless, FE high order models may indicate substantial criticities in the design of complex rotors due to unwanted parasitic resonances in the working frequency range of the machine. In any case, modern rotor engineering strongly relies on FE numerical models before undertaking any actual construction. In particular for what the active magnetic bearings (AMB) are concerned, a model is necessary to design the control law to stabilize the system represented by the rotor and the active magnetic suspensions. In such a context, only a few modes are really relevant to the system stability but they must be identi…ed within their densely populated frequency range. In other words, resonant modes due to appendices supported by the rotor must be separated from those due to the rotor itself once they are checked to be of minor importance (energetically speaking).
BibTeX:
@inproceedings{ISMB7_8,
  author = {Andrea Argondizza and Stefano Carabelli and Andrea Tonoli},
  title = {Finite Element Model Reduction for Rotating Systems},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_8.pdf}
}
2000 Ariga, Y., Nonami, K. and Sakai, K. Nonlinear Control of Zero Power Magnetic Bearing Using Lyapunov's Direct Method Proceedings of ISMB7  
Abstract: This paper proposes a new nonlinear control system to realize a zero power control based magnetic bearings. It is not necessary for the proposed scheme to use not only permanent magnet but also bias current. The behavior of a rotor is controlled by the nonlinear control scheme which is derived based on Lyapunov’s direct method. The control currents to the electromagnets which stand opposite to each other are switched like on and off respectively depending on a displacement, a velocity, a rotation and an angular velocity of the rotor. It is clarified through the simulation that the proposed nonlinear control scheme is a useful approach to realize a zero power control of the magnetic bearing system.
BibTeX:
@inproceedings{ISMB7_49,
  author = {Yuichi Ariga and Kenzo Nonami and Katsunori Sakai},
  title = {Nonlinear Control of Zero Power Magnetic Bearing Using Lyapunov's Direct Method},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_49.pdf}
}
2014 Ariga, Y., Saitoh, Y. and Watanabe, K. Controller Structure for Magnetic Bearing for Achieving Both Unbalance Suppression and Stabilization Proceedings of ISMB14  
Abstract: This study proposes a control system in which the controller structure is divided in consideration of the unstable zeros of the controller. This controller can both inhibit a sine wave disturbance intended to produce unbalanced vibrations and stabilize the system with desired bearing stiffness. The effectiveness of the proposed method is verified through a simulation.
BibTeX:
@inproceedings{ISMB14_61,
  author = {Yuichi Ariga and Yohei Saitoh and Keiji Watanabe},
  title = {Controller Structure for Magnetic Bearing for Achieving Both Unbalance Suppression and Stabilization},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_61.pdf}
}
2016 Ariga, Y. and Sakai, Y. Nonlinear Control Type Magnetic Bearing for Adding Damping Force to Existing Rotor Proceedings of ISMB15  
Abstract: This paper proposes a nonlinear control method of magnetic bearings for adding the desired damping force to an existing rotor supported by passive magnetic bearings (PMBs) or gas bearings. PMBs composed only of permanent magnets do not require a control circuit. Therefore, PMBs can be economically manufactured. However, the vibrations cannot be suppressed because PMBs cannot generate damping force. Therefore, studies have been conducted on hybridized magnetic bearings. However, hybridized magnetic bearings have a disadvantage in that they are complicated and expensive. Gas bearings can generate excellent support force and damping force during high-speed rotation. However, it is difficult to dampen certain vibrations such as whirl vibration. Therefore, a method combining gas bearings and active magnetic bearings (AMBs) was considered in order to dampen such vibrations. Because the support rigidity of the AMBs are applied, the dynamics is significantly changed as compared with rotors supported only by the gas bearings. Moreover, because sufficient stiffness can be obtained from the gas bearings, it is useless to add stiffness through the magnetic bearings. To solve the above problems, we propose the use of the AMBs only for the generation of damping force. When using a general linear control, it is necessary to supply the bias current to the AMBs. However, it adversely affects the support stiffness of the rotor because a negative stiffness is generated by the bias current. We have previously proposed a control method with unnecessary bias current through nonlinear control of the AMB, and applied this method to actual equipment. However, this method involved the generation of both support force and damping force. Here, we focus on generating only damping force. This method is verified through the simulation.
BibTeX:
@inproceedings{ISMB15_115,
  author = {Yuichi Ariga and Yasumitsu Sakai},
  title = {Nonlinear Control Type Magnetic Bearing for Adding Damping Force to Existing Rotor},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_115.pdf}
}
2012 Ariga, Y. and Watanabe, K. Unbalance Control of Magnetic Bearings by Multi-Degree of Freedom Internal Model Control Proceedings of ISMB13  
Abstract: This paper suggests a method to control an unbalance vibration of the magnetic bearing by multi-degree of freedom internal model controller which is called Model Bridge Control. This control method can compensate for each control problem, e.g. robust stability and uncertainty compensation, responses, disturbance rejection. By focusing on a disturbance compensator, this paper put forward a control system which rejects agitation due to unbalance. In this paper, a controller design method using a disturbance compensation characteristic of model bridge control is shown. The controller gets possible to control an unbalance forced vibration with the specific frequency by using a disturbance model. The effectiveness of the proposed method has been clarified by simulation.
BibTeX:
@inproceedings{ISMB13_46,
  author = {Yuichi Ariga and Keiji Watanabe},
  title = {Unbalance Control of Magnetic Bearings by Multi-Degree of Freedom Internal Model Control},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_46.pdf}
}
2010 Arkadiusz, M. and Zdzislaw, G. Energy Save Robust Control of Active Magnetic Bearings in Flywheel Proceedings of ISMB12  
Abstract: The paper reports on the investigation and developed of flywheel device as energy storage prototype. The FESS is designed to run in vacuum and is supported on low energy controlled active magnetic bearings (AMBs). The goal was to design and experimental verification of the self integrated flywheel conception with smart control of energy flow and accumulation. The low power control, with reduced bias current, approach of the flywheel active magnetic bearings is used. The weighting functions are designed in order to meet robust control conditions. The laboratory investigations of the flywheel with high gyroscopic effects operated at low speed meet the control and energy performances requirements.
BibTeX:
@inproceedings{ISMB12_61,
  author = {Mystkowski Arkadiusz and Gosiewski Zdzislaw},
  title = {Energy Save Robust Control of Active Magnetic Bearings in Flywheel },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_61.pdf}
}
1994 Arkkio, A. and Lindgren, O. Finite Element Analysis of the Magnetic Forces Acting on an Eccentric Rotor of a High-Speed Induction Motor Proceedings of ISMB4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB4_38,
  author = {A. Arkkio and O. Lindgren },
  title = {Finite Element Analysis of the Magnetic Forces Acting on an Eccentric Rotor of a High-Speed Induction Motor },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_38.pdf}
}
1993 Arling, R.W. and Kohler, S.M. Six Degree of Freedom Fine Motion Positioning Stage Based on Magnetic Levitation Proceedings of ISMST2  
Abstract: The design of a magnetically suspended six degree of freedom positioning system capable of nanometer positioning is presented. The sample holder is controlled in six degrees of freedom (DOF) over 300 micrometers of travel in X, Y and Z directions. A design and control summary, and test results indicating stability and power dissipation are included. The system is vacuum compatible, uses commercially available materials, and requires minimal assembly and setup.
BibTeX:
@inproceedings{ISMST2_41,
  author = {R. W. Arling and S. M. Kohler},
  title = {Six Degree of Freedom Fine Motion Positioning Stage Based on Magnetic Levitation},
  booktitle = {Proceedings of ISMST2},
  year = {1993},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst2/ismst2_submission_41.pdf}
}
2010 Arredondo, I. and Jugo, J. AMB Vibration Rejection Study: Adaptive Algorithms, Notch filter and Notch Exciter Proceedings of ISMB12  
Abstract: The vibration rejection is one of the main characteristics to study in the AMB based machine’s field, mainly due to the possibility of active control. In this paper four options are studied, on one hand, the well-known solutions utilizing adaptive algorithms and Notch filter, and on the other, the combination of these both (leaving the vibration in open loop) and a new method with a Notch Exciter. As the result of the comparison between them it is concluded that the election of one of the methods depends on the used specific system. Even though, the new proposed solution based on the Notch Exciter seems to be a good alternative for a lot of purposes due to its easy implementation, high working frequency range, low computational cost and high robustness.
BibTeX:
@inproceedings{ISMB12_23,
  author = {Inigo Arredondo and Josu Jugo},
  title = {AMB Vibration Rejection Study: Adaptive Algorithms, Notch filter and Notch Exciter },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_23.pdf}
}
2008 Arredondo, I. and Jugo, J. Frequency Noise Rejection for Vibration Minimization in an AMB System Proceedings of ISMB11  
Abstract: When a vibration suppression adaptive algorithm is implemented to enhance an AMB based system, a good frequency measurement or estimation of the synchronous rotation is essential [1]. In this paper, two frequency disturbance rejection methods applied to the frequency sensor measurement are compared. The ?rst method is based on the use of a Kalman Filter (KF) and the second is the implementation of a Frequency Locked Loop (FLL). Both have advantages and disadvantages related to the available hardware, noise type of the sensor, the fact of vibration minimization and the computational cost of the adaptive algorithm. Finally, experimental proofs in a laboratory testbed, based on the MBC500 Rotor Dynamics, show the effectiveness of each method.
BibTeX:
@inproceedings{ISMB11_6,
  author = {Inigo Arredondo and Josu Jugo},
  title = {Frequency Noise Rejection for Vibration Minimization in an AMB System},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_6.pdf}
}
2014 Asama, J., Fujii, Y., Fukuyo, M., Oiwa, T. and Chiba, A. Realization of Magnetic Suspension and Motor Operation with One Three-Phase Voltage Source Inverter Using a Zero-Phase Current Proceedings of ISMB14  
Abstract: This paper focuses on realization of both the single-axis active magnetic suspension and rotation of a three-phase permanent magnet motor using only one three-phase voltage source inverter. The suspension winding of the electromagnet for the single-axis magnetic suspension is connected between the neutral point of the Y-connected three-phase winding and the middle point of the voltage sources, and the resulting zero-phase current is utilized to control the suspension force. The control method of the zero-phase current is theoretically derived to avoid interference with the motor performance. Experimental apparatus was built and tested, which consists of an iron ball magnetic suspension system and a three-phase interior permanent magnet motor. The experimental results demonstrated stable magnetic suspension and motor rotation at 1200 rpm.
BibTeX:
@inproceedings{ISMB14_103,
  author = {Junichi Asama and Yusuke Fujii and Masato Fukuyo and Takaaki Oiwa and Akira Chiba},
  title = {Realization of Magnetic Suspension and Motor Operation with One Three-Phase Voltage Source Inverter Using a Zero-Phase Current},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_103.pdf}
}
2012 Asama, J., Oiwa, T. and Chiba, A. Performance Improvement of a One-DOF Actively Positioned Bearingless Motor Proceedings of ISMB13  
Abstract: Conventional bearingless motors and magnetic bearings with one- to five-degrees-of-freedom (DOF) active positioning require a number of inverter modules, windings, position sensors, and electromagnets. To reduce the size and power consumption of this type of motor, the authors previously proposed a one-DOF actively positioned bearingless motor, referred to as a single-drive bearingless motor that has only one three-phase winding set and one three-phase inverter. Although the successful non-contact operation of this motor was demonstrated previously, a rotor of the test machine ran up to only 800 r/min because of serious resonance. The aim of this study was to improve the rotation performance of the single-drive bearingless motor. The cause of the rotor vibration was a discontinuous distribution of the magnetic flux density in the air-gap. One possible solution has been proposed in this paper. The test machine with an improved rotor was successfully driven up to 2000 r/min.
BibTeX:
@inproceedings{ISMB13_34,
  author = {Junichi Asama and Takaaki Oiwa and Akira Chiba},
  title = {Performance Improvement of a One-DOF Actively Positioned Bearingless Motor},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_34.pdf}
}
2016 Asama, J., Sasaki, K., Oiwa, T. and Chiba, A. Simplified Configuration of a Two-DOF Actively Controlled Bearingless Motor Using Two H-Bridges Proceedings of ISMB15  
Abstract: This paper introduces a new structure and topology of a two-degrees-of-freedom (DOF) actively controlled bearingless motor using only two H-bridges (four half-bridges). The proposed two-DOF controlled bearingless motor has two-phase integrated motor windings. The neutral point of each phase winding is connected to the middle point of the inverter’s dc power voltage. This bearingless motor, thus, offers common dq-axis current vector control for permanent magnet motor drive as well as radial two-DOF active positioning control of the rotor. In this paper, the suspension force and toque of the 2-pole/8-slot model are theoretically derived from the stored magnetic energy. The magnetic energy is calculated from the inductance matrix where each inductance component is derived with the air-gap magnetic flux distribution. The theoretically calculated results show how the suspension force and torque are regulated with the control currents. To verify the theoretical calculation, two-dimensional FEM analysis is performed. The FEM calculation demonstrates that the proposed bearingless motor topology with 2-pole/8-slot structure using only two H-bridges generates constant suspension force and torque.
BibTeX:
@inproceedings{ISMB15_48,
  author = {Junichi Asama and Kenta Sasaki and Takaaki Oiwa and Akira Chiba},
  title = {Simplified Configuration of a Two-DOF Actively Controlled Bearingless Motor Using Two H-Bridges},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_48.pdf}
}
2012 Asama, J., Takemoto, M., Sugimoto, H. and Chiba, A. Performance Investigation and Power Factor Improvement of a Consequent-Pole Type Bearingless Motor Proceedings of ISMB13  
Abstract: The authors have developed a five-axis actively positioned bearingless drive system intended for a use as an industrial contamination-free centrifugal pump. It includes 1.2 kW consequent-pole type bearingless motor for torque generation and radial/tilting motion control. The aim of this paper is to investigate the motor performance with a test machine. In addition, a proposed rotor is found to improve power factor of a motor function. Based on the three-dimensional finite element method (3D-FEM) analysis, the effectiveness of the proposed structure has been verified in this paper.
BibTeX:
@inproceedings{ISMB13_39,
  author = {Junichi Asama and Masatsugu Takemoto and Hiroya Sugimoto and Akira Chiba},
  title = {Performance Investigation and Power Factor Improvement of a Consequent-Pole Type Bearingless Motor},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_39.pdf}
}
1994 Auer, F. and Beek, H.V. Practical Application of a Magnetic Bearing and Linear Propulsion Unit for Six Degrees of Freedom Positioning Proceedings of ISMB4  
Abstract: This paper describes a system for positioning a body in six degrees of freedom by using three electromagnetic units for suspension and linear propulsion. The X-position and the V-position can be controlled over a range of 10 mm. The Zposition can be controlled over a range of 1 mm. Angles around X Y and Z can be controlled over a range of 5,5 and 50 mrad, respectiv.ely. A single Suspension and linear Propulsion unit (SPU) is an active magnetic suspension (bearing) system combined with a lineae magnetic propulsion system. Firstly, this paper describes the principle of operation of an SPU. It will show how a stable magnetic bearing has been constructed and how propulsion in the direction perpendicular to the suspension direction is achieved. Attention will be paid to the interaction between the suspension and t he propulsion forces. This interaction must be minimised for maximum system performance. The second part of this paper will concentrate on the application of three SPU's in a system for positioning in six degrees of freedom.
BibTeX:
@inproceedings{ISMB4_31,
  author = {F. Auer and H. Van Beek },
  title = {Practical Application of a Magnetic Bearing and Linear Propulsion Unit for Six Degrees of Freedom Positioning },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_31.pdf}
}
2013 Bahr, F., Melzer, M. and Karnaushenko, D. Erfassung der Lufspaltinduktion aktiver Magnetlager auf Basis ultradünner, flexibler Hall-Sensoren Proceedings of Workshop on Magnetic Bearing Technology 9  
Abstract: Abstract is not available
BibTeX:
@inproceedings{WMLT9_9,
  author = {F. Bahr and M. Melzer and D. Karnaushenko},
  title = {Erfassung der Lufspaltinduktion aktiver Magnetlager auf Basis ultradünner, flexibler Hall-Sensoren },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 9},
  year = {2013},
  url = {https://www.magneticbearings.org/wp-content/publications/wmlt9/wmlt9_9.pdf}
}
2012 Bahr, F., Melzer, M., Karnaushenko, D., Makarov, D., Karnaushenko, D., Mönch, J.I., Malane, D., Schmidt, O.G. and Hofmann, W. Flux Based Control of AMBs Using Integrated Ultra-Thin Flexible Bismuth Hall Sensors Proceedings of ISMB13  
Abstract: To increase stiffness and precise rotor positioning of active magnetic bearings (AMB), flux based control algorithms were suggested. However, the typical thickness of air gaps in AMBs is too small to apply conventional magnetic field sensors with a typical thickness of more than 500 µm. Furthermore, the curved surfaces of the sta tor poles require a mechanically flexible sensor design. Here, we propose a flexible Bismuth based Hall sensor with a total thickness of only 80 µm including encapsulation. After wiring th e sensors have a maximum height of 280 µm and could be mounted onto curved surfaces. T he fabricated sensors were characterized and the influence of size, temperature and bending radius on the Hall sensitivity was determined. On a proof-of-concept level we demonstrated the performance of the flexible magnetic field sensors to control an one-axis AMB with a levitating ball. Several algorithms using flux density measurements were tested and compared to conventional control strategies.
BibTeX:
@inproceedings{ISMB13_81,
  author = {Falk Bahr and Michael Melzer and Daniil Karnaushenko and Denys Makarov and Dmitriy Karnaushenko and Jens Ingolf Mönch and Dominic Malane and Oliver G. Schmidt and Wilfried Hofmann},
  title = {Flux Based Control of AMBs Using Integrated Ultra-Thin Flexible Bismuth Hall Sensors},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_81.pdf}
}
2016 Bahr, F., Moench, I., Ernst, D., Zerna, T. and Schmidt, O.G. Direct Field Control of AMBs using Flux Feedback based on Integrable Hall Sensors Proceedings of ISMB15  
Abstract: Within the last years magnetic bearing technology has been pushed by a significant upturn in oil & gas industry as well as in machining applications. Nowadays, specific high speed spindles are equipped with industrially standardized active magnetic bearing systems (AMB) allowing for highly precise rotor positioning due to their contact-free and low-maintenance operation. However, compared to conventional ball bearings well-established AMB systems are limited by their relatively low stiffness. In order to improve dynamic performance flux based control algorithms are under investigation for the last decades already. The main challenge is how to integrate commercially available magnetic field sensors into typical AMB air gaps. Within this research ultra-thin and flexible Bismuth Hall sensors with a total thickness of less than 100 µm were developed and integrated into an actively controlled magnetic suspension system. For the first time an AMB control using the direct feedback of bendable Bismuth sensors was implemented and its operational capability for accurate rotor positioning was demonstrated successfully and investigated by frequency response analysis.
BibTeX:
@inproceedings{ISMB15_86,
  author = {Falk Bahr and Ingolf Moench and Daniel Ernst and Thomas Zerna and Oliver G. Schmidt},
  title = {Direct Field Control of AMBs using Flux Feedback based on Integrable Hall Sensors},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_86.pdf}
}
1999 Baloh, M., Tao, G. and Allaire, P. Feedback Linearization Applied to a MIMO Active Magnetic Bearing: A Systematic Approach and Application to a Balance Beam Proceedings of ISMST5  
Abstract: This paper illustrates a systematic approach to feedback linearization for a magnetic bearing system. This method relies upon the construction of a nonlinear coordinate transformation that insures a unique feedback linearization law exists which has several practical properties: the linearizing feedback is guaranteed regular; the resulting linearized system is guaranteed controllable; and beam angular position regulation is achievable. Moreover, the construction of a diffeomorphism allows the control engineer to assert operating constraints on the actuator fluxes. In particular, this paper investigates constant flux sum and constant product constraints and compares their relative merits.
BibTeX:
@inproceedings{ISMST5_9,
  author = {Michael Baloh and Gang Tao and Paul Allaire},
  title = {Feedback Linearization Applied to a MIMO Active Magnetic Bearing: A Systematic Approach and Application to a Balance Beam},
  booktitle = {Proceedings of ISMST5},
  year = {1999},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst5/ismst5_submission_9.pdf}
}
1998 Baloh, M.J., Allaire, P.E., Hilton, E.F., Wei, N., Maslen, E.H., Baun, D., Flack, R.D., Olson, D.B., Bearnson, G.B. and Khanwilkar, P.S. Magnetic Bearing System for an Artificial Heart Proceedings of ISMB6  
Abstract: This paper describes a prototype continuous flow blood pump (CFVAD3) utilizing magnetic bearings. These bearings support a thin pancake impeller whose shape allows for a very compact pump with total axial length below 5cm and with a diameter of about 10cm. This gives a total volume of about 275cc. The impeller itself has 4 vanes with a designed operating point of 6 l/min at 100 mmHg of differential pressure and 2000 rpm. The advantages of magnetic bearings, such as large clearance spaces and zero mechanical wear, axe elaborated upon. Bearing parameters such as load capacity and current gains will also be described. Another purpose of this article will be to present the results of bearing performance measurements in a simulated adult human circulation system.
BibTeX:
@inproceedings{ISMB6_9,
  author = {M. J. Baloh and P. E. Allaire and E. F. Hilton and N. Wei and E. H. Maslen and D. Baun and R. D. Flack and D. B. Olson and G. B. Bearnson and P. S. Khanwilkar},
  title = {Magnetic Bearing System for an Artificial Heart},
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_9.pdf}
}
1995 Banerjee, B., Allaire, P.E. and Grodsinsky, C.M. Active Vibration Isolation of Microgravity Experiments With Spring Umbilicals Using an Electrodynamic Actuator Proceedings of ISMST3  
Abstract: Microgravity experiments will require active vibration isolation in the low to mid frequency range of 0.1 Hz to 10 Hz. Approximately two orders of acceleration reduction (40 dB) will be required. Previous works have reported results for accelerations transmitted through the umbilical. This paper describes experimental and theoretical results for vibration isolation in one dimension (horizontal) where the simulated experiment is connected to the spacecraft by a spring umbilical. The experiment consisted of a spacecraft (shaker), experiment (mass), umbilical, accelerometer, control electronics, and Lorentz actuator. The experiment mass was supported in magnetic bearings to avoid any stiction problems. Acceleration feedback control was employed to obtain the vibration isolation. Three different spring umbilicals were employed. Acceleration reductions on the order of 40 dB were obtained over the frequency range of 0.1 Hz to 10 Hz. Good agreement was obtained between theory and experiment.
BibTeX:
@inproceedings{ISMST3_6,
  author = {Bibhuti Banerjee and Paul E. Allaire and C. M. Grodsinsky},
  title = {Active Vibration Isolation of Microgravity Experiments With Spring Umbilicals Using an Electrodynamic Actuator},
  booktitle = {Proceedings of ISMST3},
  year = {1995},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst3/ismst3_submission_6.pdf}
}
1995 Banerjee, B.B. and Allaire, P.E. Design of Long-Stroke Noncontact Electromagnetic Actuator - for Active Vibration Isolation Proceedings of ISMST3  
Abstract: A long-stroke moving coil Lorentz Actuator was designed for use in a microgravity vibration isolation experiment. The final design had a stroke of 5.08 cm (2 in) and enough force capability to isolate a mass of the order of 22.7-45.4 kg. A simple dynamic magnetic circuit analysis, using an electrical analog, was developed for the initial design of the actuator. A neodymium-iron-boron material with energy density of 278 T-kA/m (35 MGOe) was selected to supply the magnetic field. The effect of changes in the design parameters of core diameter, shell outer diameter, pole face length, and coil wire layers were investigated. An extensive three-dimensional finite element analysis was carried out to accurately determine linearity with regard to axial position of the coil and coil current levels. The actuator was constructed and tested on a universal testing machine. Example plots are shown, indicating good linearity over the stroke of approximately 5.08 cm (2 in) and a range of coil currents from -1.5 A to +1.5 A. The actuator was then used for the microgravity vibration isolation experiments, described elsewhere.
BibTeX:
@inproceedings{ISMST3_28,
  author = {Bibhuti B. Banerjee and Paul E. Allaire},
  title = {Design of Long-Stroke Noncontact Electromagnetic Actuator - for Active Vibration Isolation},
  booktitle = {Proceedings of ISMST3},
  year = {1995},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst3/ismst3_submission_28.pdf}
}
1991 Banerjee, B.B., Knospe, C.R. and Allaire, P.E. A Microgravity Vibration Isolation Rig Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_24,
  author = {Bibhuti B. Banerjee and Carl R. Knospe and Paul E. Allaire},
  title = {A Microgravity Vibration Isolation Rig},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_24.pdf}
}
1995 Banerjee, B.B. and Rao, D.K. Design and Analysis of an Electromagnetic Thrust Bearing Proceedings of ISMST3  
Abstract: A double-acting electromagnetic thrust bearing is normally used to counter the axial loads in many rotating machines that employ magnetic bearings. It essentially consists of an actuator and drive electronics. Existing thrust bearing design programs are based on several assumptions. These assumptions, however, are often violated in practice. For example, no distinction is made between maximum external loads and maximum bearing forces, which are assumed to be identical. Furthermore, it is assumed that the maximum flux density in the air gap occurs at the nominal gap position of the thrust runner. The purpose of this paper is to present a clear theoretical basis for the design of the electromagnetic thrust bearing which obviates such assumptions.
BibTeX:
@inproceedings{ISMST3_26,
  author = {Bibhuti B. Banerjee and Dantam K. Rao},
  title = {Design and Analysis of an Electromagnetic Thrust Bearing},
  booktitle = {Proceedings of ISMST3},
  year = {1995},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst3/ismst3_submission_26.pdf}
}
2006 Bangcheng, H. and Jiancheng, F. Design of Magnetic Bearing Reaction Wheel for High Precision Attitude Control of Spacecraft Proceedings of ISMB10  
Abstract: In this paper, a kind of 5 degree-of-freedom magnetically suspended reaction flywheel with outer rotor is designed for high-precise stabilization of spacecraft attitude, the rotor velocity is -5000rpm to 5000rpm, its angular momentum is 50Nms. The main structure of this system is given, the rotor is supported by radial active and thrust active magnetic bearings with permanent magnet, a kind of integrated eddy- current sensor for detecting radial and axial displacement of wheel rotor is designed. And the optimization design method of rotor is presented to satisfy the require of strength safety coefficient and first elasticity resonance frequency simultaneously etc. by the software of multidisciplinary design optimization (iSIGHT) and Finite element analysis software (ANSYS).
BibTeX:
@inproceedings{ISMB10_56,
  author = {Han Bangcheng and Fang Jiancheng},
  title = {Design of Magnetic Bearing Reaction Wheel for High Precision Attitude Control of Spacecraft},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_56.pdf}
}
1990 Bardas, T., Harris, T., Oleksuk, C., Eisenbart, G. and Geerligs, J. Problems, Solutions and Applications in the Development of a Wide Band Power Amplifier for Magnetic Bearings  Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_31,
  author = {T. Bardas and T. Harris and C. Oleksuk and G. Eisenbart and J. Geerligs },
  title = {Problems, Solutions and Applications in the Development of a Wide Band Power Amplifier for Magnetic Bearings },
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_31.pdf}
}
1995 Barletta, N. and Schob, R. Design of a Bearingless Blood Pump Proceedings of ISMST3  
Abstract: In the field of open heart surgery, centrifugal blood pumps have major advantages over roller pumps. The main drawbacks to centrifugal pumps are however problems with the bearings and with the sealing of the rotor shaft. In this paper we present a concept for a simple, compact and cost effective solution for a blood pump with a totally magnetically suspended impeller. It is based on the new technology of the "Bearingless Motor" and is therefore called the "Bearingless Blood Pump". A single bearingless slice motor is at the same time a motor and a bearing system and is able to stabilise the six degrees of freedom of the pump impeller in a very simple way. Three degrees of freedom are stabilised actively (the rotation and the radial displacement of the motor slice). The axial and the angular displacement are stabilised passively. The pump itself (without the motor-stator and the control electronics) is built very simply. It consists of two parts only: the impeller with the integrated machine rotor and the housing. So the part which gets in contact with blood and has therefore to be disposable, is cheap. Fabricated in quantities, it will cost less than $10 and will therefore be affordable for the use in a heart-lung-machine.
BibTeX:
@inproceedings{ISMST3_20,
  author = {Natale Barletta and Reto Schob},
  title = {Design of a Bearingless Blood Pump},
  booktitle = {Proceedings of ISMST3},
  year = {1995},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst3/ismst3_submission_20.pdf}
}
2008 Barrot, F. and Bleuler, H. Application of Diamagnetic Levitation to Mechatronic Systems Proceedings of ISMB11  
Abstract: Diamagnetic levitation is the only passive levitation technique working at room temperature. Using planar arrangements of permanent magnets, it is indeed possible to levitate diamagnetic materials at room temperature. Such a principle is particularly interesting to use for the design of mechatronic systems, especially in applications where friction between mechanical parts should be avoided such as, for instance, high precision inertial sensors or actuators for clean-room applications. In this article the authors show with some examples extracted from their research on the subject, that diamagnetic levitation is a promising technique that can be of great interest for the design of small scale mechatronic systems.
BibTeX:
@inproceedings{ISMB11_51,
  author = {Francois Barrot and Hannes Bleuler},
  title = {Application of Diamagnetic Levitation to Mechatronic Systems},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_51.pdf}
}
2006 Barrot, F., Burns, B., Chapuis, D., Bosgiraud, T. and Bleuler, H. Position controlled diamagnetic linear conveyor Proceedings of ISMB10  
Abstract: In micro-factories mini-conveyors will be used to convey small parts and components between storage, production and assembly units. Since a clean environment as well as a low power consumption are some of the prerequisites for a micro-factory, it is essential that mini-conveyors used in such an application respect these requirements. In the present article the authors propose a new kind of position controlled conveyor that meets these conditions.
BibTeX:
@inproceedings{ISMB10_2,
  author = {Francois Barrot and Benjamin Burns and Dominique Chapuis and Thomas Bosgiraud and Hannes Bleuler},
  title = {Position controlled diamagnetic linear conveyor},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_2.pdf}
}
2000 Bartha, A. Dry Friction Backward Whirl of Rotors: Theory, Experiments, Results, and Recommendations Proceedings of ISMB7  
Abstract: This paper presents a theoretical and experimental study into the dry friction backward whirl of rotors. A model is derived that is able to describe the behaviour of a rotor from an excitation up to and including fully established backward whirl. A test rig is presented with which these processes were studied experimentally for a rotor running in conventional (ball-)bearings up to a rotational frequency of 166 Hz (10’000 rpm). Test results are presented and discussed. These results include the whirl behaviour of a rotor in both a very heavy and a stator with compliant mountings and the influence of different system parameters on the whirl behaviour. The numerical predictions are compared to the measured results. Recommendations are given on how to avoid dry friction backward whirl.
BibTeX:
@inproceedings{ISMB7_39,
  author = {Alexader Bartha},
  title = {Dry Friction Backward Whirl of Rotors: Theory, Experiments, Results, and Recommendations},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_39.pdf}
}
2016 Basovich, S., Menaker, Y. and Arogeti, S. Precision Positioning Oriented Modeling of Electromagnetic Actuator Proceedings of ISMB15  
Abstract: This article presents a novel approach for accurate modeling of the relation between force, electric current and the actual air gap in the electromagnetic actuator used in active magnetic bearings (AMB) based precision positioning systems. The novelty of the presented modeling approach lies in a newly derived correlation for the relative permeability term in the electromagnetic actuator force model. This correlation, which can be easily obtained using the B-H curve for a given low-hysteresis actuator core material, describes the relative permeability term by means of electric current, actual air gap and a few parameters of the actuator. The resulting actuator model, which can be used either for more correct implementation of the well-known feedback-linearization technique or for obtaining more reliable results in simulations, was validated experimentally using a real single-degree-of-freedom (S-DoF) AMB plant.
BibTeX:
@inproceedings{ISMB15_90,
  author = {Sergei Basovich and Yonattan Menaker and Shai Arogeti},
  title = {Precision Positioning Oriented Modeling of Electromagnetic Actuator},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_90.pdf}
}
2014 Basovich, S., Moha, T.B., Peretz, M., Arogeti, S. and Brand, Z. Switch-Mode Current Amplifier for Active Magnetic Bearings Proceedings of ISMB14  
Abstract: This paper presents the concept and the practical implementation of a switch-mode current amplifier for the use in Active Magnetic Bearings (AMB). The switch-mode amplifier consists of a full-bridge capable of operating in 2-level, 3- level or phase-shifted PWM mode. An optimal digital currentprogrammed mode controller lays out the foundations to a proximate-optimal, robust, large-signal dynamic response of the system under extreme cases of loading and parameters variations. In particular, the current amplifier developed is capable of following the desired reference for large inductance variations (due to displacement). The power stage combines a newly developed, efficient, passive-based current sensor that is capable of sensing bi-directional and near-zero currents, while being robust to external disturbances and maintaining simple and efficient structure. The presented current amplifier concept has been verified experimentally on a single-axis AMB platform using a dual channel amplifier prototype, controlled by a single 16 bit low-cost microcontroller.
BibTeX:
@inproceedings{ISMB14_59,
  author = {Sergei Basovich and Tomer Ben Moha and Mor Peretz and Shai Arogeti and Ziv Brand},
  title = {Switch-Mode Current Amplifier for Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_59.pdf}
}
2012 Bauer, W. and Amrhein, W. Design Study of Air-Core Coil Winding Topologies for Bearingless Axial-Force/Torque Motors Proceedings of ISMB13  
Abstract: The Bearingless Axial-Force/TorqueMotor is a Lorentz-Force-Type actuator featuring a com-pact and integrated design using a special permanent magnet excitation system and a slotless air gap winding. The end-windings of the concentric air-core stator coils, shaped in circumferential rotor direction, provide active suspension forces in axial direction. The actuator unifies levitation force and drive torque generation in a single device unit sharing one common winding system. Especially for single-phase motor configurations, the resulting drive topology ensures the tilt sta-bilization of the rotor. In general, only a few air gap winding structures are suitable for proper polyphase drive torque generation without any negative side effects. The present article treats the drive torque and axial force generation mechanisms for Bearingless Axial-Force/Torque Motors and its influences regarding the appearance of tilt torques. As the radial drive stabilization is realized by multiple axial displaced passive magnetic ring bearings, the radial force generation due to a mismatch of the number of rotor pole pairs and the number of stator coils is also signif-icant for drive stability considerations. As conclusion, numerical simulations for different drive configurations will prove for the validity of the presented analytical design framework.
BibTeX:
@inproceedings{ISMB13_79,
  author = {Walter Bauer and Wolfgang Amrhein},
  title = {Design Study of Air-Core Coil Winding Topologies for Bearingless Axial-Force/Torque Motors},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_79.pdf}
}
2014 Bauer, W., Freudenthaler, P. and Amrhein, W. Experimental Characterization of a Bearingless Rotating Field Axial-Force/Torque Motor Proceedings of ISMB14  
Abstract: The Bearingless Axial-Force/Torque Motor is an air-core coil motor, that can generate axial forces and drive torques concurrently using a common stator winding system. The radial suspension and the tilting stabilization of the bearingless drive is realized by passive repulsive permanent magnetic ring bearings. The end-windings of the concentric, non-overlapping stator coils create axial directed levitation forces, provided that a non-vanishing common-mode current component is present. In contrast to the existing alternating field motor topology, the proposed redesign features a rotating field motor structure for constant, rotor-angle independent drive torque generation. The current investigation concentrates on the verification of the drive parameters via simple and robust measurements. A presentation of the functional prototype concludes the article.
BibTeX:
@inproceedings{ISMB14_121,
  author = {Walter Bauer and Paul Freudenthaler and Wolfgang Amrhein},
  title = {Experimental Characterization of a Bearingless Rotating Field Axial-Force/Torque Motor},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_121.pdf}
}
2010 Baumann, K., Dohnal, F. and Markert, R. Active Magnetic Bearings as Actuators and Sensor in Journal Bearing Measurements Proceedings of ISMB12  
Abstract: The present paper shows the successful usage of active magnetic bearings (AMBs) to identify the dynamic characteristics of journal bearings in the frequency domain. A test rig is operated using two AMBs supporting a rigid rotor with a centric journal bearing. An identification procedure for the stiffness and damping coefficients of journal bearings is presented. This procedure incorporates the successful application of AMBs for positioning, supporting, sensing and actuating the rotor simultaneously. For identification the real excitation force is needed. Two methods to derive a force-current-position relationship are outlined and compared: an idealized mathematical relation and a measured force-current-position map. Finally, results for applying the pre-measured map and an example of the identified stiffness and damping coefficients are given.
BibTeX:
@inproceedings{ISMB12_77,
  author = {Katrin Baumann and Fadi Dohnal and Richard Markert},
  title = {Active Magnetic Bearings as Actuators and Sensor in Journal Bearing Measurements },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_77.pdf}
}
2002 Baumschlager, R., Schoeb, R. and Schmied, J. Bearingless Hydrogen Blower Proceedings of ISMB8  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB8_38,
  author = {Rainer Baumschlager and Reto Schoeb and Joachim Schmied},
  title = {Bearingless Hydrogen Blower},
  booktitle = {Proceedings of ISMB8},
  year = {2002},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb8/ismb8_submission_38.pdf}
}
1988 Bauser, E., Schweitzer, G., Strunk, H. and Traxler, A. Centrifuge for Epitaxial Growth of Semiconductor Multilayers Proceedings of ISMB1 - Courtesy of Springer-Verlag  
Abstract: We describe a vacuum centrifuge which consists of along vertical rotor that is at its upper end electromagnetically suspended inside a vacuum tank. The design is arrdnged such that it fulfills the requirement for d thoroughly clean vacuum recipient. Experiments are discussed which illustrate the application of the centrifuge to liquid phase epitaxy of silicon multi 1 ayers.
BibTeX:
@inproceedings{ISMB1_7,
  author = {E. Bauser and G. Schweitzer and H.P. Strunk and A. Traxler },
  title = {Centrifuge for Epitaxial Growth of Semiconductor Multilayers },
  booktitle = {Proceedings of ISMB1 - Courtesy of Springer-Verlag},
  year = {1988},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb1/ismb1_submission_7.pdf}
}
1992 Beale, S., Shafai, B., LaRocca, P. and Cusson, E. Adaptive Forced Balancing for Magnetic Bearing Systems Proceedings of ISMB3  
Abstract: This paper presents an autobalancing algorithm with several unique features that differentiate it from traditional (notch filter) and model based autobalancing algorithms. The algorithm, called Adaptive Forced Balancing with Frequency Tracking (AFB/FT), has the following features: 1) there is no effect on control system bandwidth or stability, 2) a dynamic model of the magnetic bearing system is not needed, and 3) regulation of the entire shaft-actuator-control system in a minimum energy state is achieved. This algorithm includes a frequency tracking section which automatically estimates the shaft rotational rate. The combined algorithm simultaneously tracks the amplitude, phase and frequency of a synchronous disturbance in realtime. AFB/FT was implemented on a TI Digital Signal Processor (DSP) as part of a complete control system designed to support a single end suspension test rig. This paper presents the AFB/FT algorithm, describes the test rig and control system components and presents test data which demonstrates the effectiveness of the algorithm. Preliminary results show that AFB/FT provides at least 30 dB reduction in actuator control current at 3600 rpm.
BibTeX:
@inproceedings{ISMB3_57,
  author = {S. Beale and B. Shafai and P. LaRocca and E. Cusson},
  title = {Adaptive Forced Balancing for Magnetic Bearing Systems },
  booktitle = {Proceedings of ISMB3},
  year = {1992},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb3/ismb3_submission_57.pdf}
}
2016 Beatty, M.S. and Mahfoud, J. Control of Flexible Rotor by Using Electromagnetic Actuators Optimization of the Fuzzy Controller Gains Proceedings of ISMB15  
Abstract: The aim is to set an optimization procedure for the determination of a fuzzy based controller gains. The objective function is defined as a combination of the maximum current, the displacements measured and the settling time. Two fuzzy based controllers were developed, the first has displacement and velocity as inputs (a fuzzy Proportional Derivative) and the second utilizes inputs expressed in polar coordinates. Its originality is that it manages two significant physical quantities, namely tangential and radial velocities, associated with steady state and transient behaviours respectively. The gains of the fuzzy PD controllers were determined by using optimization procedures that takes into account the mechanical behavior and the energy consumption. The gains (for the three controllers) were first determined by using numerical simulations, and then implemented for experimental testing. An additional tuning (in-situ) was necessary for the PD controller. The performances of the two fuzzy based controllers were compared to a PD controller experimentally from mechanical and energy consumption points of view. The three controllers were efficient with a better behavior for the fuzzy based controllers for run up conditions. The optimization procedures are efficient and easy to implement in the case of PD fuzzy controllers, and must be enhanced to consider rules with different output, as in the case of polar fuzzy controller.
BibTeX:
@inproceedings{ISMB15_113,
  author = {Michael Soler Beatty and Jarir Mahfoud},
  title = {Control of Flexible Rotor by Using Electromagnetic Actuators Optimization of the Fuzzy Controller Gains},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_113.pdf}
}
2012 Beckerle, P., Schaede, H. and Rinderknecht, S. Model-Based Fault Detection on Active Magnetic Bearings by Means of Online Transfer-Factor Estimation Proceedings of ISMB13  
Abstract: This paper gives a deeper insight in model-based fault detection based on transfer-factor esti-mation on active magnetic bearings. The method aims at performing fault detection and diagnosis at minimal computational efforts. Hence, only a limited number of transfer-factors of the inves-tigated system are considered. These are used as features for the diagnosis and represented by the magnitude and the phase at frequencies showing strong deviations between the examined states. Previously modeled faults are diagnosed by an online-estimation of the transfer-factors and a comparison to reference values. Three algorithms for this fault detection method are de-scribed and compared in detail: Recursive Least Squares (RLS), Least Mean Squares (LMS) and Goertzel-algorithm. For the comparison of the algorithms, their convergence behavior and updat-ing rate are considered as well as the computational and implementation effort. Investigations on a test rig of a centrifugal pump in active magnetic bearings show that the RLS leads to slightly slower convergence with a higher computational effort than the LMS. The Goertzel-algorithm outperforms both in computational effort, but needs several samples for the computation and thus provides a lower updating rate. Based on their findings, the authors assess suitability of the algorithms for fault detection on active magnetic bearings.
BibTeX:
@inproceedings{ISMB13_8,
  author = {Philipp Beckerle and Hendrik Schaede and Stephan Rinderknecht},
  title = {Model-Based Fault Detection on Active Magnetic Bearings by Means of Online Transfer-Factor Estimation},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_8.pdf}
}
2000 Bender, D.A. and Post, R.F. Ambient-Temperature Passive Magnetic Bearings for Flywheel Energy Storage Systems Proceedings of ISMB7  
Abstract: Based on prior work at the Lawrence Livermore National Laboratory ambient-temperature passive magnetic bearings are being adapted for use in highpower flywheel energy storage systems developed at the Trinity Flywheel Power company. En route to this goal specialized test stands have been built and computer codes have been written to aid in the development of the component parts of these bearing systems. The Livermore passive magnetic bearing system involves three types of elements, as follows: (1) Axially symmetric levitation elements, energized by permanent magnets., (2) electrodynamic "stabilizers" employing axially symmetric arrays of permanent magnet bars ("Halbach arrays") on the rotating system, interacting with specially wound electrically shorted stator circuits, and, (3) eddy-current-type vibration dampers, employing axially symmetric rotating pole assemblies interacting with stationary metallic discs. The theory of the Livermore passive magnetic bearing concept describes specific quantitative stability criteria. The satisfaction of these criteria will insure that, when rotating above a low critical speed, a bearing system made up of the three elements described above will be dynamically stable. That is, it will not only be stable for small displacements from equilibrium ("Earnshawstable"), but will also be stable against whirl-type instabilities of the types that can arise from displacement-dependent drag forces. or from mechanical-hysteritic losses that may occur in the rotor. Our design problem thus becomes one of calculating and/or measuring the relevant stiffnesses and drag coefficients of the various elements and comparing our results with the theory so as to assure that the cited stability criteria are satisfied.
BibTeX:
@inproceedings{ISMB7_26,
  author = {Donald A. Bender and Richard F. Post},
  title = {Ambient-Temperature Passive Magnetic Bearings for Flywheel Energy Storage Systems},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_26.pdf}
}
2018 Beneden, M.V., Kluyskens, V. and Dehez, B. Axial Force Evaluation in Permanent Magnet Thrust Bearings Subject to Demagnetization and Temperature Effects Proceedings of ISMB16  
Abstract: This article presents a 2D axisymmetric finite element model allowing to evaluate the axial force developed by a permanent magnet thrust bearings, including demagnetization and temperature effects. For this purpose, a linearized B-H curve is included in the model, with coefficients depending on the temperature. The axial force evaluation, as a function of the operating temperature is validated experimentally on a test bench. Finally, based on this model, the performance of thrust bearings using either SmCo or NdFeB are compared.
BibTeX:
@inproceedings{ISMB16_099,
  author = {Maxence Van Beneden and Virginie Kluyskens and Bruno Dehez},
  title = {Axial Force Evaluation in Permanent Magnet Thrust Bearings Subject to Demagnetization and Temperature Effects},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_099.pdf}
}
2018 Beneden, M.V., Kluyskens, V. and Dehez, B. Passive Compensation of the Temperature Effect on Permanent Magnet Thrust Bearing in Hybrid System Proceedings of ISMB16  
Abstract: Combining a permanent magnet thrust bearing (PMTB) with mechanical bearings inside a hybrid system can be a good compromise for some applications subject to high axial load. The guidance of the shaft is ensured by the mechanical bearings while those latter are relieved from the axial load by the magnetic bearing. However, as the permanent magnet properties depend on the temperature, this load relieve depends on the operating conditions. This paper describes a compensation system to maintain the force developed by the PMTB constant and independent from the temperature. This system consists in a soft spring placed in series with the static part of the PMTB allowing a variation of the airgap thickness. It is shown that when the stiffness of the soft spring is low enough compared to the equivalent stiffness of the PMTB, it is possible to maintain a constant load relieve for a wide range of operating temperature conditions. Practical implementations based on pressurized bellows are described.
BibTeX:
@inproceedings{ISMB16_100,
  author = {Maxence Van Beneden and Virginie Kluyskens and Bruno Dehez},
  title = {Passive Compensation of the Temperature Effect on Permanent Magnet Thrust Bearing in Hybrid System},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_100.pdf}
}
2016 Beneden, M.V., Kluyskens, V. and Dehez, B. Comparison between optimized topologies of permanent magnet thrust bearings with back-iron Proceedings of ISMB15  
Abstract: This paper deals with the optimization and the comparison of passive magnetic thrust bearings made up of radial stacks of permanent magnet rings. Various topologies are considered, depending on the polarization direction of the permanent magnet rings and the presence of back-iron. The coulombian approach and the method of image charges are used to determine the load capacity of topologies with back-iron. On this basis each topology is optimized in order to minimize the permanent magnet volume for a fixed load capacity, airgap thickness and remanent flux density. Varying these parameters, scaling laws of the optimum permanent magnet ring dimensions are derived to allow fast sizing and comparison of the topologies. The latter highlights that the topology with Halbach configuration and back-iron is the most performant, but that the topology with axial polarization is almost as good.
BibTeX:
@inproceedings{ISMB15_118,
  author = {Maxence Van Beneden and Virginie Kluyskens and Bruno Dehez},
  title = {Comparison between optimized topologies of permanent magnet thrust bearings with back-iron},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_118.pdf}
}
1996 Benoit, F., Emi, B., Rochat, E., Bleuler, H. and Mueller, R. Ultra-Precision x-y Stage on AMBs  Proceedings of ISMB5  
Abstract: This paper presents concept and design of a magnetically levitated x-y-z stage combining high precision and large displacement strokes (up to the cm order). The platform, uses inductive sensors for coarse positioning and inteiferometers for the fine sensing, ultimately at sub-nm resolution. It is not yet operational, but preliminary measurement results will be shown at the symposium. Possible applications include usage as a sample stage for scanning probe metrology.
BibTeX:
@inproceedings{ISMB5_76,
  author = {F. Benoit and B. Emi and E. Rochat and H. Bleuler and R. Mueller },
  title = {Ultra-Precision x-y Stage on AMBs },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_76.pdf}
}
2016 Berger, A., Sparing, M., Berger, D., Fuchs, G., Hossain, M., Abdkader, A., Cherif, C. and Schultz, L. Hysteresis in an axial rotating SMB used in the ring spinning process Proceedings of ISMB15  
Abstract: Superconducting magnetic bearings are passive stable magnetic levitating bearings which only need a material depending cryogenic temperature for their operation. The application of a rotating superconducting magnetic bearing (SMB) with high rotational speed in a ring spinning machine replaces the traditional, friction afflicted ring-traveler twist element. Ring spinning is the most common process to produce short stable yarn in textile industry. The SMB twist element significantly reduces the productivity limiting friction heat in the spinning process and thus the process speed will be increased from commonly 25000 rpm up to 50000 rpm. In this application melt textured YBa 2 Cu 3 O 7-x (YBCO) is used as superconductor and NdFeB as permanent magnet (PM). The PM ring rotates driven by the yarn and thereby imparts twist in it. The yarn force on the PM is an eccentric acting point force which leads to a tilt of the PM ring in the position to the superconductor ring. In combination with high rotational speed this tilt leads to a significant heat input in the superconductor due to hysteresis.
BibTeX:
@inproceedings{ISMB15_121,
  author = {Anne Berger and Maria Sparing and Dietmar Berger and Guenter Fuchs and Mahmud Hossain and Anwar Abdkader and Chokri Cherif and Ludwig Schultz},
  title = {Hysteresis in an axial rotating SMB used in the ring spinning process},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_121.pdf}
}
2000 Bermudez, J.L., Zanolli, S., Sandtner, J., Bleuler, H. and Benabderrahmane, C. Preliminary Experiments on an Eddy Current Bearing Proceedings of ISMB7  
Abstract: The present paper concerns a preliminary investigation on the forces produced by eddy currents for magnetic rotating bearing applications. These forces may be conveniently used to achieve stable contactless levitation without active control or superconducting materials, so that passive magnetic bearings operating at ambient temperature can be realised. The bearing configuration utilised here is such that no eddy losses occur in nominal condition. In this paper, details of force measurements of a type of rotating bearing configuration are presented. These, to the best of our knowledge, are not found in previous publications.
BibTeX:
@inproceedings{ISMB7_23,
  author = {José Luis Bermudez and Stefano Zanolli and Jan Sandtner and Hannes Bleuler and Chamseddine Benabderrahmane},
  title = {Preliminary Experiments on an Eddy Current Bearing},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_23.pdf}
}
2000 Betschon, F. and Knospe, C. Gain Scheduled Adaptive Vibration Control Proceedings of ISMB7  
Abstract: A new method for the reduction of either the vibration or AMB current induced by rotor imbalance is presented. The approach is based on previous research on Adaptive Vibration Control for active magnetic bearing systems. To minimize the memory and computational requirements imposed on the hardware, the gain matrix used is synthesized as functionally dependent upon the operating speed with only the diagonal elements varying linearly with speed. The resulting algorithm was experimentally tested on a high-speed spindle. Significant reductions in bearing currents were achieved over a wide range of operating speeds.
BibTeX:
@inproceedings{ISMB7_47,
  author = {Felix Betschon and Carl Knospe},
  title = {Gain Scheduled Adaptive Vibration Control},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_47.pdf}
}
1998 Betschon, F. and Schob, R. On-Line-Adapted Vibration Control  Proceedings of ISMB6  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB6_35,
  author = {F. Betschon and R. Schob},
  title = {On-Line-Adapted Vibration Control },
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_35.pdf}
}
2008 Bian, B., Liu, S., Li, D. and Maslen, E. Automatic Thermal Expansion Compensation of the AMB Used in Precision Grinding Machine Proceedings of ISMB11  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB11_83,
  author = {Bin Bian and Shuqin Liu and Deguang Li and Eric Maslen},
  title = {Automatic Thermal Expansion Compensation of the AMB Used in Precision Grinding Machine},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_83.pdf}
}
1990 Bichler, U. A Low Noise Magnetic Bearing Wheel for Space Application  Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_1,
  author = {U.J. Bichler },
  title = {A Low Noise Magnetic Bearing Wheel for Space Application },
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_1.pdf}
}
1988 Bichler, U. and Eckhardt, T. A 3(5) Degree of Freedom Electrodynamic-Bearing Wheel for 3-Axis Spacecraft Attitude Control Application Proceedings of ISMB1 - Courtesy of Springer-Verlag  
Abstract: This paper deals with two related types of electrodynamically suspended rotors, acting either as momentum or reaction wheels for spacecraft attitude control purposes. One is of the three-axis active type, the other involves five actively controlled degrees of freedom. The wheels are of a pancake design with the control forces acting on the outer rim where the main rotor mass is concentrated thus avoiding low structural resonances. The rim is decoupled from the hub by titanium springs. Both wheels provide a vernier gimballing capability enabling three-axis attitude control of spacecraft with one rotating mass only. A special decoupling tilt control loop design eliminates all gyroscopic effects, such as precessional and nutational oscillations. The electrodynamic bearing principle is advantageous because main parts of the mass can be concentrated on the outer rim of the rotor contributing to the desired inertia. Force generation is linear involving only very small lags and practically no cross-coupling exist between the orthogonal axes facilitating a control strategy to prevent disturbing unbalanced forces from affecting the stator of the bearing for the use in so-called 'micro-gravity' environment. The wheels are actually in the development phase and in the paper the principles, the design, the control loops and first results are presented.
BibTeX:
@inproceedings{ISMB1_2,
  author = {U. Bichler and T. Eckhardt },
  title = {A 3(5) Degree of Freedom Electrodynamic-Bearing Wheel for 3-Axis Spacecraft Attitude Control Application },
  booktitle = {Proceedings of ISMB1 - Courtesy of Springer-Verlag},
  year = {1988},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb1/ismb1_submission_2.pdf}
}
1991 Bichsel, J. The Bearingless Electrical Machine Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_31,
  author = {J. Bichsel},
  title = {The Bearingless Electrical Machine},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_31.pdf}
}
2014 Bleuler, H. Overview on Various Types of AMBs & their Respective Potential for Applications Proceedings of ISMB14  
Abstract: Many different types of magnetic bearings are known since a long time: “Active” and “passive”, “electrodynamic”, “electromagnetic”, “hybrid” etc. Certain types have found many applications and others none. A recent successful realization of a complex system (a momentum reaction sphere) based on a Lorentz-force type of bearing will be presented in more detail and the potential of as yet unexploited types of magnetic bearings will be briefly discussed.
BibTeX:
@inproceedings{ISMB14_key02,
  author = {Hannes Bleuler},
  title = {Overview on Various Types of AMBs & their Respective Potential for Applications},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_key02.pdf}
}
2010 Bleuler, H. Recent Activities in European AMB Research Proceedings of ISMB12  
Abstract: This presentation will give an overview of current activities of research institutes as well as industrial actors in the magnetic bearing field. The technical domains covered will be on various active magnetic bearing projects, on passive magnetic bearings and also on superconducting rotor bearings These various types of AMB will be placed in the context of a basic classification of magnetic levitation principles. Finally some activities on diamagnetic levitation will be included as well. European research on rotor bearings is mainly being done in France, Germany, Italy and Switzerland, examples from all of these will be presented. The application fields cover various industrial activities, biomedical devices, energy and micromanipulation.
BibTeX:
@inproceedings{ISMB12_key01,
  author = {Hannes Bleuler},
  title = {Recent Activities in European AMB Research},
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_key01.pdf}
}
2008 Bleuler, H. 20 Years ISMB: Then, Now, Future Proceedings of ISMB11  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB11_key01,
  author = {Hannes Bleuler},
  title = {20 Years ISMB: Then, Now, Future},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_key01.pdf}
}
1988 Bleuler, H. Controlling Magnetic Bearing Systems with a Digital Signal Processor Proceedings of ISMB1 - Courtesy of Springer-Verlag  
Abstract: First, the succession of magnetic bearing systems designed at the Institute of Mechanics in Zurich is retraced briefly with special emphasis on the control aspects. The most recent examples make use of the digital signal processor. The main body of the paper contains a detailed description of the magnetic bearing control of our first DSP controlled system, a highly elastic rotor. Experimental results pennit to assess the advantages of the new control device. Future possibilities of magnetic bearing control layout are shortly indicated.
BibTeX:
@inproceedings{ISMB1_36,
  author = {H. Bleuler },
  title = {Controlling Magnetic Bearing Systems with a Digital Signal Processor },
  booktitle = {Proceedings of ISMB1 - Courtesy of Springer-Verlag},
  year = {1988},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb1/ismb1_submission_36.pdf}
}
1992 Bleuler, H., Blöchliger, M., Gähler, C. and Dual, J. A New AMB Configuration for Measurement of Material Damping in Metals Proceedings of ISMB3  
Abstract: Material damping can be determined by measuring the damping of eigenmodes of vibrations in probe rods. Conventionally, these probes are supported mechanically and the supports must be moved to the nodes of the vibrational mode considered. Nevertheless, for materials with low damping, considerable amounts of energy may still be dissipated in the supports, thereby affecting the measurement of intrinsic damping of the material. Support losses may be considerably reduced, however, if the rod is suspended magnetically. Furthermore, no support adjustment is required even if this measurement for several eigenmodes is desired. In this paper, the damping of longitudinal vibrations in magnetically levitated steel rods is described. The results show values of intrinsic damping which are in some cases four times lower than those measured using conventional set-ups. The magnetic support uses a homogeneous magnetic field in order to avoid eddy currents. A description of the set-up as well as experimental results are included.
BibTeX:
@inproceedings{ISMB3_26,
  author = {H. Bleuler and M. Blöchliger and C. Gähler and J. Dual },
  title = {A New AMB Configuration for Measurement of Material Damping in Metals },
  booktitle = {Proceedings of ISMB3},
  year = {1992},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb3/ismb3_submission_26.pdf}
}
2010 Bleuler, H., Bonfitto, A., Tonoli, A. and Amati, N. Miniaturized Gyroscope with Bearingless Configuration Proceedings of ISMB12  
Abstract: One of the current topics in magnetic bearings technology is the exploration of their potential in the field of micro machines. Up to now in literature there are very few examples of realization and most of them are just experimental systems but it seems that further investigations can be performed. In this paper the evaluation of the performance of micro magnetic bearings in an application dealing with the navigation of planes and cars is reported. The realization of a miniaturized gyroscopic sensor based on active magnetic bearings (AMBs) is described from the mechanical to the control design. The mechanical and the actuation systems are analyzed along with the realization of the model and of two different control design strategies: a H(inf) and a decentralized MultiSISO control (a classical Proportional Derivative (PD) on each axis). For both the proposed approaches the modelling and the control design phases are discussed. The H(inf) strategy has been evaluated to perform a robust control and consists in a Plant Non-Inverting GS/T Weighting scheme with an explicit integral action and an anti wind-up action. In the case of decentralized strategy, the model of the system containing the transformation from the center mass coordinates to the actuators coordinates is exposed along with the tuning of the proportional and derivative actions. The numerical and experimental results obtained on the prototype with the two control strategies are compared to evaluate their behaviour in this application. Finally, the principle used to make the rotor spinning is exposed and the rotation results are discussed.
BibTeX:
@inproceedings{ISMB12_145,
  author = {Hannes Bleuler and Angelo Bonfitto and Andrea Tonoli and Nicola Amati},
  title = {Miniaturized Gyroscope with Bearingless Configuration },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_145.pdf}
}
1994 Bleuler, H., Jeon, J. and Higuchi, T. Self-Tuning Control for Magnetic Bearings Proceedings of ISMB4  
Abstract: Auto-calibration and auto-tuning for a magnetic bearing system of an industrial turbo-molecular pump (TMP) is presented. The control program is able to calibrate and levitate a system autonomously and then to fine-tune the controller according to some desired stiffness-damping characteristics. Practical issues on auto calibrating are discussed. The basic time constants of the plant are determined automatically in order to find a first stabilizing control autonomously. The tasks of the designer are 1.) to make the choice of operating ranges of all the components and to match those ranges and 2) to give a realistic goal on desired stiffness and damping. Other fine-tuning criteria and autonomous determination of stability ranges of feedback parameters are also investigated.
BibTeX:
@inproceedings{ISMB4_15,
  author = {H. Bleuler and J. Jeon and T. Higuchi },
  title = {Self-Tuning Control for Magnetic Bearings },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_15.pdf}
}
1994 Bleuler, H., Kawakatsu, H., Tang, W., Hsieh, W., Miu, D.K., Tai, Y., Moesner, F. and Rohner, M. Micromachined Active Magnetic Bearings Proceedings of ISMB4  
Abstract: A disc-shaped rotor of 8 mm diameter and 1mm thickness has been levitated and rotated up to 3000 rpm in a miniature magnetic-bearing-motor combination. The levitation type is actively controlled using an optical sensing system in two radial directions. A second rotor of 5 µm thickness and 3 mm diameter is now being built along with four miniature stator magnets using micromachining technology of read-write magnets of disc storage devices. The machining consists of lithographic and electroplating processes. The bearing will be combined with an induction motor. Possible applications could include rate gyros.
BibTeX:
@inproceedings{ISMB4_59,
  author = {H. Bleuler and H. Kawakatsu and W. Tang and W. Hsieh and D. K. Miu and Y.C. Tai and F. Moesner and M. Rohner },
  title = {Micromachined Active Magnetic Bearings },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_59.pdf}
}
2000 Bloodgood, V.D., Groom, N. and Britcher, C. Further Development of an Optimal Design Approach Applied to Axial Magnetic Bearings Proceedings of ISMB7  
Abstract: Classical design methods involved in magnetic bearings and magnetic suspension systems have always had their limitations. Because of this, the overall effectiveness of a design has always relied heavily on the skill and experience of the individual designer. This paper combines two approaches that have been developed to aid the accuracy and efficiency of magnetostatic design. The first approach integrates classical magnetic circuit theory with modern optimization theory to increase design efficiency. The second approach uses loss factors to increase the accuracy of classical magnetic circuit theory. As an example, an axial magnetic thrust bearing is designed for minimum power.
BibTeX:
@inproceedings{ISMB7_82,
  author = {V. Dale Bloodgood and Nelson Groom and Colin Britcher},
  title = {Further Development of an Optimal Design Approach Applied to Axial Magnetic Bearings},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_82.pdf}
}
1998 Blumenstock, K.A., Lee, K.Y. and J. P. Schepis,   A Spaceflight Magnetic Bearing Equipped Optical Chopper with Six-Axis Active Control Proceedings of ISMB6  
Abstract: This paper describes the development of an ETU (Engineering Test Unit) rotary optical chopper with magnetic bearings. An ETU is required to be both flight-like, nearly identical to a flight unit without the need for material certifications, and demonstrate structural and performance integrity. A prototype breadboard design previously demonstrated the feasibility of meeting flight performance requirements using magnetic bearings. The chopper mechanism is a critical component of the High Resolution Dynamics Limb Sounder (HIRDLS) which will be flown on EOS-CHEM (Earth Observing System-Chemistry). Particularly noteworthy are the science requirements which demand high precision positioning and minimal power consumption along with full redundancy of coils and sensors in a miniature, lightweight package. The magnetic bearings are unique in their pole design to minimize parasitic losses and utilize collocated optical sensing. The motor is of an unusual disk-type ironless stator design. The ETU design has evolved from the breadboard design. A number of improvements have been incorporated into the ETU design. Active thrust control has been added along with changes to improve sensor stability, motor efficiency, and touchdown and launch survivability. It was necessary to do all this while simultaneously reducing the mechanism volume. Flight-like electronics utilize a DSP (Digital Signal Processor) and contain all sensor electronics and drivers on a single five inch by nine inch circuit board. Performance test results are reported including magnetic bearing and motor rotational losses.
BibTeX:
@inproceedings{ISMB6_11,
  author = {K. A. Blumenstock and K. Y. Lee and J. P. Schepis  },
  title = {A Spaceflight Magnetic Bearing Equipped Optical Chopper with Six-Axis Active Control},
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_11.pdf}
}
2000 Blumenstock, K. and Brown, G. Novel Integrated Radial and Axial Magnetic Bearing Proceedings of ISMB7  
Abstract: Typically, fully active magnetically suspended systems require one axial and two radial magnetic bearings. Combining radial and axial functions into a single device allows for more compact and elegant packaging. Furthermore, in the case of high-speed devices such as energy storage flywheels, it is beneficial to minimize shaft length to keep rotor mode frequencies as high as possible. Attempts have been made to combine radial and axial functionality, but with certain drawbacks. One approach requires magnetic control flux to flow through a bias magnet reducing control effectiveness, thus resulting in increased resistive losses. This approach also requires axial force producing magnetic flux to flow in a direction into the rotor laminate that is undesirable for minimizing eddy-current losses resulting in rotational losses. Another approach applies a conical rotor shape to what otherwise would be a radial heteropolar magnetic bearing configuration. However, positional non-linear effects are introduced with this scheme and the same windings are used for bias, radial, and axial control adding complexity to the controller and electronics. For this approach, the amount of axial capability must be limited. It would be desirable for an integrated radial and axial magnetic bearing to have the following characteristics; separate inputs for radial and axial control for electronics and control simplicity, all magnetic control fluxes should only flow through their respective air gaps and should not flow through any bias magnets for minimal resistive losses, be of a homopolar design to minimize rotational losses, position related non-linear effects should be minimized, and dependant upon the design parameters, be able to achieve any radial/axial force or power ratio as desired. The integrated radial and axial magnetic bearing described in this paper exhibits all these characteristics. Magnetic circuit design, design equations, and analysis results will be presented.
BibTeX:
@inproceedings{ISMB7_78,
  author = {Kenneth Blumenstock and Gery Brown},
  title = {Novel Integrated Radial and Axial Magnetic Bearing},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_78.pdf}
}
1991 Boden, K. Wide Gap, Permanent Magnet Biased Magnetic Bearing System Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_32,
  author = {Karl Boden},
  title = {Wide Gap, Permanent Magnet Biased Magnetic Bearing System},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_32.pdf}
}
1988 Boden, K. Wide-Gap Electro-Permanent magnetic Bearing System with Radial Transmission of Radial and Axial Forces Proceedings of ISMB1 - Courtesy of Springer-Verlag  
Abstract: The unique features and applications of this magnetic bearing essentially result from two facts: (1) The only bearing components attached to the rotor are non-laminated ferromagnetic steel collars or cylinders; (2) all radial as well as axial forces are transmitted via radial gaps. The stator assembly needs no axially overhanging components that might impose restrictions on the rotor design and axial mobility. Due to the use of flux modulation technique wide radial gaps (25 om are real ised) can be provided at virtually zero-power conditions. The large gaps allow for effective encapsulation and shielding of rotors at elevated (or low) temperatures, corrosive environment, voltage potentials, and pressure. A 2-kg X-ray rotary anode was operated under high-vacuum conditions at + 100 kV anode potential, 6000C temperature at the bearing collars and speed 18,000 r.p.m. with 13 mm radial gaps. The complete X-ray tube is easily exchangeable by removing it from the stator assembly along the axial direction. Similar handling conditions were achieved with hollow cylindrical rotors (up to 500 mls periphal speed at the bearing gap), spin turbines and choppers (up to 90,000 r.p.m.), and with long-stroke supporting shafts for crystal pulling plants.
BibTeX:
@inproceedings{ISMB1_5,
  author = {K. Boden },
  title = {Wide-Gap Electro-Permanent magnetic Bearing System with Radial Transmission of Radial and Axial Forces },
  booktitle = {Proceedings of ISMB1 - Courtesy of Springer-Verlag},
  year = {1988},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb1/ismb1_submission_5.pdf}
}
2004 de Boeij, J., Steinbuch, M. and Gutierrez, H. Modelling The Electromechanical Interactions In A Null-Flux Eds Maglev System Proceedings of ISMB9  
Abstract: The fundamental electromechanical interactions in a passive null- ux EDS maglev system are mediated by the voltages induced in the levita- tion coils by the sled magnets, and by the forces exerted on the sled as a result of the induced currents. This paper presents a reliable and compact method to calculate these interactions by using analytical expressions of the magnetic field of a permanent magnet. The proposed ap- proach provides a highly efficient and numeri- cally stable approach to the computation of the ux induced in the levitation coils as well as the induced voltages and currents and lift, drag and guidance forces acting on the sled's magnets. The analytical model is compared to a simplified algebraic model suitable for real-time control of EDS Maglev suspension dynamics. Both mod- els are compared with measurements and show good predictive quality.
BibTeX:
@inproceedings{ISMB9_16,
  author = {Jeroen de Boeij and Maarten Steinbuch and Hector Gutierrez},
  title = {Modelling The Electromechanical Interactions In A Null-Flux Eds Maglev System },
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_16.pdf}
}
2008 Boeij, J.D. and Lomonova, E. Experimental Verification of Look-Up Table Based Real-Time Commutation of 6-DOF Planar Actuators Proceedings of ISMB11  
Abstract: The control of contactless magnetically levitated planar actuators with stationary coils, moving magnets and 6-DOF is very complicated. In contradiction to normal synchronous AC machines the forces and torques cannot be decoupled using a sinusoidal commutation scheme. Instead, a feedback linearization law has to be applied as commutation scheme that decouples the forces and torques and calculates the required currents to realize the desired forces and torques of the magnetic suspension. This feedback linearization law is based on the coupling matrix that links the current in each coil to the force and torque vector on the actuator. The accurate calculation of this coupling matrix in real-time is critical for controlling the planar actuator. In this paper a look-up table based method is used to apply feedback linearization and the performance of the algorithm is verified with measurements.
BibTeX:
@inproceedings{ISMB11_76,
  author = {Jeroen De Boeij and Elena Lomonova},
  title = {Experimental Verification of Look-Up Table Based Real-Time Commutation of 6-DOF Planar Actuators},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_76.pdf}
}
2004 Boletis, A. and Bleuler, H. Three Axis AMB High Speed Micro Motor Proceedings of ISMB9  
Abstract: This contribution investigates possibilities and limitations of high speed rotation of small rotors supported on active magnetic bearings (AMBs). A sub-millimetric spherical steel ball has reached 2.88 million rpm in partial vacuum. The AMB system actively stabilizes the three translations of spherical rotors with diameters varying from 1 mm down to 0.4 mm. In addition, an interesting method to measure rotational speed is introduced.
BibTeX:
@inproceedings{ISMB9_79,
  author = {Alexis Boletis and Hannes Bleuler},
  title = {Three Axis AMB High Speed Micro Motor },
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_79.pdf}
}
2000 Boletis, A., Vuillemin, R., Aymon, C., Kümmerle, M., Aeschlimann, B., Moser, R., Bleuler, H., Fullin, E. and Bergqvist, J. A Six Magnetic Actuators Integrated Micromotor Proceedings of ISMB7  
Abstract: A contact free actively controlled micromotor bearing structure of a very flat aspect ratio is presented. The system combines contact free suspension and rotation with six magnetic actuators and a minimum of three inductive sensors. The principle of combined suspension and drive could meet price, reliability and performance requirements for integrated micromotors in the field of optical choppers, gyroscopes, hard disk drives and many more. An experimental setup was manufactured with a combination of micromachining techniques such as etching and electroplating.
BibTeX:
@inproceedings{ISMB7_17,
  author = {A. Boletis and R. Vuillemin and C. Aymon and M. Kümmerle and B. Aeschlimann and R. Moser and H. Bleuler and E. Fullin and J. Bergqvist},
  title = {A Six Magnetic Actuators Integrated Micromotor},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_17.pdf}
}
2002 Boletis, A.R. and Bleuler, H. Achieving Ultra-High Rotational Speeds Proceedings of ISMB8  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB8_75,
  author = {A. R. Boletis and H. Bleuler},
  title = {Achieving Ultra-High Rotational Speeds},
  booktitle = {Proceedings of ISMB8},
  year = {2002},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb8/ismb8_submission_75.pdf}
}
2014 Bonfitto, A., Cabrera, L.D.S. and Tonoli, A. Active Magnetic Bearings with Position and Flux Observer Proceedings of ISMB14  
Abstract: Standard Active Magnetic Bearings are controlled using a current reference and the measured or observed current as state variable in the state space controller. Nevertheless since this approach selects the current as the state expressing the behavior of the magnetic bearing, several disadvantages occur. Indeed it is well known that this method leads to an inherent nonlinear relation between the generated force, the current and the air gap. This paper presents the modeling approach, the control design and the experimental validation of a strategy based on the combined observation of position and flux. The technique is designed and tested on a one-degree of freedom mechanical oscillator actuated by a couple of opposite electromagnets.
BibTeX:
@inproceedings{ISMB14_93,
  author = {Angelo Bonfitto and Lester Daniel Suarez Cabrera and Andrea Tonoli},
  title = {Active Magnetic Bearings with Position and Flux Observer},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_93.pdf}
}
2016 Bonfitto, A., Tonoli, A., Amati, N. and Suarez, L.D. Turbomolecular pumps on active conical magnetic bearings Proceedings of ISMB15  
Abstract: A field in which the magnetic suspensions technology is finding wide application with an increasing rate is the vacuum industry and, in particular, the market of turbomolecular pumps. Nowadays, most used solutions adopted in particular for small to medium pumping capacity are based on hybrid architectures where passive magnetic bearings are combined to ceramic ball bearings. By converse, fully active magnetic suspensions with cylindrical configuration represent the standard for medium to high pumping rate machines. Although simple, the cylindrical configuration is prone to drawbacks related in particular to the straines growing in the disc of the axial actuator that motivate the investigation of alternative architectures. As shown in previous literature, the use of conical configuration, besides compacting driving electronics, seems to be promising considering that the control of the radial and axial degree of freedom is performed simultaneously by the same devices in two actuation planes. This paper describes the main design steps and experimental characterization of a turbomolecular pump supported by conical active magnetic bearings. The control design is based on a SISO decentralized technique with position and control embedded loops. A rotor centering technique based on the characterization of current loops is exposed while the external position loop is tuned measuring relevant transfer functions to refine the controller allowing critical speed crossing. The power actuation of the eight electromagnets is performed with a three-phase configuration drive technique instead of standard H-bridges to minimize the number of power switches. Experimental results along with numerical computations obtained with simulation models are reported in order to prove the validity of modeling approach and the effectiveness of the conical actuation system.
BibTeX:
@inproceedings{ISMB15_41,
  author = {Angelo Bonfitto and Andrea Tonoli and Nicola Amati and Lester Daniel Suarez},
  title = {Turbomolecular pumps on active conical magnetic bearings},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_41.pdf}
}
1991 Borisov, S.Y., Iskra, A.L. and Philatov, A.P. Cryogenic Test Rig with an Aerodynamic Magnetically Levitated Carriage Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_30,
  author = {Sergey Yu. Borisov and Anton L. Iskra and Anatoly P. Philatov},
  title = {Cryogenic Test Rig with an Aerodynamic Magnetically Levitated Carriage},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_30.pdf}
}
1993 Bornemann, Zabka, R., Boegler, P., Urban, C. and Rietschel, H. Concepts of Flywheels for Energy Storage Using Autostable High-T, Superconducting Magnetic Bearings Proceedings of ISMST2  
Abstract: A flywheel for energy storage using autostable high-Tc, superconducting magnetic bearings has been built. The rotating disk has a total weight of 2.8 kg. The maximum speed is 9240 rpm. A process that allows accelerated, reliable and reproducible production of melt-textured superconducting material used for the bearings has been developed. In order to define optimum configurations for radial and axial bearings, interaction forces in three dimensions and vertical and horizontal stiffness have been measured between superconductors and permanent magnets in different geometries and various shapes. Static as well as dynamic measurements have been performed. Results are being reported and compared to theoretical models.
BibTeX:
@inproceedings{ISMST2_34,
  author = {Bornemann and R. Zabka and P. Boegler and C. Urban and H. Rietschel},
  title = {Concepts of Flywheels for Energy Storage Using Autostable High-T, Superconducting Magnetic Bearings},
  booktitle = {Proceedings of ISMST2},
  year = {1993},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst2/ismst2_submission_34.pdf}
}
1994 Bornemann, H., Ritter, T., Urban, C., Boegler, P., Zaitsev, O., Weber, K. and Rietschel, H. A Flywheel for Energy Storage with Frictionless High temperature Superconducting Bearings Proceedings of ISMB4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB4_87,
  author = {H. Bornemann and T. Ritter and C. Urban and P. Boegler and O. Zaitsev and K. Weber and H. Rietschel },
  title = {A Flywheel for Energy Storage with Frictionless High temperature Superconducting Bearings },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_87.pdf}
}
1995 Bornemann, H., Siegel, M., Zaitsev, O., Bariess, M. and Laschutza, H. Ultralow Friction in a SuperconductingM agnetic Bearing Proceedings of ISMST3  
Abstract: Passive levitation by superconducting magnetic bearings can be utilized in flywheels for energy storage. Basic design criteria of such a bearing are high levitation force, sufficient vertical and horizontal stability and low friction. A test facility was built for the measurement and evaluation of friction in a superconducting magnetic bearing as a function of operating temperature and pressure in the vacuum vessel. The bearing consists of a commercial disk shaped magnet levitated above single grain, melttextured YBCO high-temperature superconductor material. The superconductor was conduction cooled by an integrated AEG tactical cryocooler. The temperature could be varied from 50 K to 80 K. The pressure in the vacuum chamber was varied from 1 bar to 10-5 mbar. At the lowest pressure setting, the drag torque shows a linear frequency dependence over the entire range investigated (0 < f < 40 Hz). Magnetic friction, the frequency independent contribution, is very low. The frequency dependent drag torque is generated by molecular friction from molecule-surface collisions and by eddy currents. Given the specific geometry of the set-up and gas pressure, the molecular drag torque can be estimated. At a speed of 40 Hz, the coefficient of friction (drag-to-lift ratio) was measured to be p = 1.6 x 10-7 at 10-5 mbar and T = 60 K. This is equivalent to a drag torque of 7.6 x Nm. Magnetic friction causes -1% of the total losses. Molecular friction accounts for about 13% of the frequency dependent drag torque, the remaining 87% being due to eddy currents and losses from rotor unbalance. The specific energy loss is only 0.3% per hour.
BibTeX:
@inproceedings{ISMST3_17,
  author = {Hans Bornemann and Michael Siegel and Oleg Zaitsev and Martin Bariess and Helmut Laschutza},
  title = {Ultralow Friction in a SuperconductingM agnetic Bearing},
  booktitle = {Proceedings of ISMST3},
  year = {1995},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst3/ismst3_submission_17.pdf}
}
2004 Bösch, P.N. and Barletta, N. High Power Bearingless Slice Motor (3-4kW) For Bearingless Canned Pumps Proceedings of ISMB9  
Abstract: In the manufacturing industry many processes involve chemical liquids. There are processes like etching, stripping, cleaning or polishing involving aggressive liquid chemicals. Depen-ding on the process all kinds of acid, organic solvents and bases are used and have to be pumped through the fabrication tools. In these wet processes, pumps are one of the most critical parts. Especially in the semiconductor industry the quality of the processes highly depends on the purity of the chemicals. There-fore process pumps have to fulfill high require-ments on chemical resistance, purity and reliability, which pneumatically driven bellows or diaphragm pumps satisfy. However, these pumps have considerable disadvantages such as: pulsating flow, mechanical wear, short life time and low energy efficiency. Bearingless centrifugal pump systems can be the solution for these problems. In this paper a new 3-phase bearingless permanent magnet slice motor is presented. This bearingless slice motor has a mechanical power of up to 4kW and is used in a centrifugal pump application. A typical appli-cation area for this power range is the semi-conductor and the chemical industry. In delivery applications high purity pump systems with an operating flow of up to 150l/min and an operating pressure of 4,5bar are required. Such an operating point assumes a mechanical drive power of about 3 – 4kW. This deve-lopment has been done in close collaboration with the company Levitronix in Switzerland.
BibTeX:
@inproceedings{ISMB9_10,
  author = {Pascal Nang Bösch and Natale Barletta},
  title = {High Power Bearingless Slice Motor (3-4kW) For Bearingless Canned Pumps },
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_10.pdf}
}
2008 Bosgiraud, T., Chapuis, D., Barrot, F. and Bleuler, H. Overcoming of High Centrifugal Forces in a 5 DOF Micro AMB Gyroscope Proceedings of ISMB11  
Abstract: The need for motion sensing system is constantly growing for civil and mass applications, which require products that ally precision, low cost and compactness. The active magnetic bearing (AMB) technology because of its absence of friction between the rotor and the stator could be an interesting solution to reach the two first requirements. The miniaturization of the AMB system permits to satisfy the last one. Among other sensing devices, gyroscopes can benefit from the high spinning speeds of the rotor that AMB permit. These high speeds guarantee the high precision of the instrument. However, these high speeds have the inconvenience of destabilizing the rotor. Therefore, a good control of the rotor position is a key issue towards a precise gyroscope. On that purpose, this paper presents a two degrees of freedom Hinf controller based on the GS/T weighting scheme strategy and including an explicit integrative part. The simulations run with that controller show a great improvement in the quality of the angular velocity measurements compared to a classical two degrees of freedom Hinf controller as will be shown in this paper.
BibTeX:
@inproceedings{ISMB11_94,
  author = {Thomas Bosgiraud and Dominique Chapuis and Francois Barrot and Hannes Bleuler},
  title = {Overcoming of High Centrifugal Forces in a 5 DOF Micro AMB Gyroscope },
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_94.pdf}
}
2011 Bräuer, P., Bartscht, M. and Werner, R. Reduzierung des Bauraums bei einem aktiven dreipoligen Radialmagnetlager unter Verwendung von siebgedruckten Wicklungen Proceedings of Workshop on Magnetic Bearing Technology 8  
Abstract: Der nachhaltige Umgang mit der zur Verfügung stehenden Energie und Ressourcen wird in Zukunft einen immer höheren Stellenwert erlangen. Dabei werden Magnetlager eine zunehmende Rolle spielen. Sie arbeiten berührungsfrei und damit schmiermittelfrei, wodurch sie in Umgebungen, in denen es auf höchste Reinheit ankommt, eingesetzt werden können. Der Wartungsaufwand ist durch fehlenden mechanischen Abrieb reduziert und die Lebensdauer dadurch erhöht. Die Betriebskosten sind darüber hinaus geringer, da die auftretenden Verluste gerade im Bereich hoher Drehzahlen 1/5 bis 1/20 derer konventioneller Lager betragen. Es haben sich drei verschiedene Bauformen für magnetische Lager herauskristallisiert, welche sich in ihrem Aufbau, Verlusten, Einsatzmöglichkeiten oder auch ihrer Regelbarkeit unterscheiden. Der vom Aufbau her einfachste Typ ist das Unipolarmagnetlager. In diesem Beitrag soll dafür die Bauraumreduzierung im Bereich der Wicklung durch den Einsatz siebgedruckter Leiter, wie sie bereits seit längerem für Kleinantriebe in der wissenschaftlichen Diskussion sind [1], [2], untersucht werden. Das Siebdruckverfahren erlaubt es, besonders dünne flächige Leiter herzustellen, die aufgrund des Verhältnisses zwischen Querschnittsfläche und Oberfläche ein besseres Wäremeabgabevermögen aufweisen als Runddraht und daher Stromdichten von bis zu 100A/mm2 zulassen. Ziel ist es, bei gleicher Lagerkraft und gleichem Rotordurchmesser das Bauvolumen und damit die Masse des Lagers signifikant zu reduzieren. Erste Berechnungen zeigen, dass eine Reduzierung des Volumens um bis zu 50% denkbar ist. Technisch möglich ist darüber hinaus auch eine Integration von mittels Siebdruck hergestellten Sensoren zur Lagemesseung. Besonders günstig erscheinen in diesem Zusammenhang kapazitive Lagesensoren. Als Ergebnis sollen konstruktive Vorschläge für den Bau magnetischer Lager mit siebgedruckten Wicklungen gemacht werden.
BibTeX:
@inproceedings{WMLT8_15,
  author = {P. Bräuer and M. Bartscht and R. Werner},
  title = {Reduzierung des Bauraums bei einem aktiven dreipoligen Radialmagnetlager unter Verwendung von siebgedruckten Wicklungen },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 8},
  year = {2011},
  url = {https://www.magneticbearings.org/wp-content/publications/wmlt8/wmlt8_15.pdf}
}
1991 Briggs, B.M. and Oman, H. Battery Cars on Superconducting Magnetically Levitated Carriers-One Commuting Solution Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_49,
  author = {B. Mike Briggs and Henry Oman},
  title = {Battery Cars on Superconducting Magnetically Levitated Carriers-One Commuting Solution},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_49.pdf}
}
1992 Britcher, C., Ghofrani, M., Haj, A. and Britton, T. Analysis, Modelling and Simulation of the Large-Angle Magnetic Suspension Test Fixture Proceedings of ISMB3  
Abstract: As part of a NASA program to demonstrate the magnetic suspension of objects over wide ranges of attitudes, a laboratory-scale research project has been undertaken, the Large-Angle Magnetic Suspension Test Fixture (LAMSTF). A cylindrical element containing a permanent magnet core is levitated, above a planar array of electromagnets, permitting demonstration of stability and control in five degrees-offreedom, and of controlled rotation in one degree-of-freedom over a range of 360 degrees. The LAMSTF features a large air-gap (around 0.1 meters), and hence differs fundamentally from typical bearing configurations. Following a brief review of the hardware and the objectives of the research effort, this paper concentrates on analysis, modelling and simulation efforts, considered to be directly relevant to magnetic bearing systems. Prediction of magnetic fields and forces is essential in magnetic suspension system design. This is particularly difficult in the presence of iron cores or yokes, unless the magnetic circuit approximation is used. A sophisticated finite element computer program, VF/GFUN, is being used to calculate magnetic fields for LAMSTF. Selected field calculations are presented with comparison to actual measurements. The design of LAMSTF deliberately includes eddy current paths. The effect of eddy currents on system dynamics is being studied with a view to incorporating modifications into the system dynamic model and digital controller. The latest results are presented. Linearized equations of motion have been developed for this class of configuration, in order to permit system modelling and the design and analysis of controllers. The development of these equations are reviewed briefly. A full, non-linear simulation is also being developed using MATRIXX . The status of this nonlinear model, and difficulties encountered in its development, are discussed.
BibTeX:
@inproceedings{ISMB3_23,
  author = {C.P. Britcher and M. Ghofrani and A. Haj and T.C. Britton },
  title = {Analysis, Modelling and Simulation of the Large-Angle Magnetic Suspension Test Fixture },
  booktitle = {Proceedings of ISMB3},
  year = {1992},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb3/ismb3_submission_23.pdf}
}
1994 Britcher, C. and Groom, N. Current and Future Development of the Annular Suspension and Pointing System Proceedings of ISMB4  
Abstract: The Annular Suspension and Pointing System (ASPS) is a prototype space payload pointing and isolation mount, designed and built for NASA Langley Research Center (LaRC) by Sperry Flight Systems (subsequently Honeywell Satellite Systems). Over the recent decade, magnetic suspension technology has continued to advance, notably in the area of control system design, such that performance improvements from an ASPSlike design are likely to be acheivable. In addition, new applications for magnetic suspensions are being investigated, where the existing ASPS hardware can provide a useful technology demonstration tool. In this paper, the existing ASPS design and hardware will first be described in detail. Next, some of the potential applications currently of interest will be discussed. Finally, the hardware developments completed, underway, or planned will be reviewed.
BibTeX:
@inproceedings{ISMB4_90,
  author = {C. Britcher and N.J. Groom },
  title = {Current and Future Development of the Annular Suspension and Pointing System },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_90.pdf}
}
1997 Britcher, C.P. Wind Tunnel Magnetic Suspension and Balance Systems with Transversely Magnetized Model Cores Proceedings of ISMST4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST4_12,
  author = {Colin P. Britcher},
  title = {Wind Tunnel Magnetic Suspension and Balance Systems with Transversely Magnetized Model Cores},
  booktitle = {Proceedings of ISMST4},
  year = {1997},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst4/ismst4_submission_12.pdf}
}
1991 Britcher, C.P. Large-Gap Magnetic Suspension Systems Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_3,
  author = {Colin P. Britcher},
  title = {Large-Gap Magnetic Suspension Systems},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_3.pdf}
}
1997 Britcher, C.P. and Bloodgood, D.V. Eddy Current Influences on the Dynamic Behaviour of Magnetic Suspension Systems Proceedings of ISMST4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST4_22,
  author = {Colin P. Britcher and Dale V. Bloodgood},
  title = {Eddy Current Influences on the Dynamic Behaviour of Magnetic Suspension Systems },
  booktitle = {Proceedings of ISMST4},
  year = {1997},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst4/ismst4_submission_22.pdf}
}
1993 Britcher, C.P. and Foster, L.E. Some Further Developments in the Dynamic Modelling and Control of the Large Angle Magnetic Suspension Test Fixture Proceedings of ISMST2  
Abstract: Suspension Test Fixture (LAMSTF) has been constructed at NASA Langley Research Center. This paper first presents some recent developments in the mathematical modelling of the system, particularly in the area of eddy current effects. It is shown that these effects are significant, but may be amenable to modelling and measurement. Next, a theoretical framework is presented, together with a comparison of computed and experimental data. Finally, some control aspects are discussed, together with illustration that the major design objective of LAMSTF - a controlled 360" rotation about the vertical axis, has been accomplished.
BibTeX:
@inproceedings{ISMST2_24,
  author = {Colin P. Britcher and Lucas E. Foster},
  title = {Some Further Developments in the Dynamic Modelling and Control of the Large Angle Magnetic Suspension Test Fixture},
  booktitle = {Proceedings of ISMST2},
  year = {1993},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst2/ismst2_submission_24.pdf}
}
1991 Britcher, C.P., Ghofrani, M., Britton, T.C. and Groom, N.J. The Large-Angle Magnetic Suspension Test Fixture Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_54,
  author = {Colin P. Britcher and Mehran Ghofrani and Thomas C. Britton and Nelson J. Groom},
  title = {The Large-Angle Magnetic Suspension Test Fixture},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_54.pdf}
}
1999 Britcher, C.P., Gonzalez, O., Gray, S., Gomeiz, O., Barldey, J.E., Jafri, A. and Smits, A.J. Design of a Magnetic Suspension and Balance System for the Princeton/ONR High Reynolds Number Testing Facility Proceedings of ISMST5  
Abstract: Princeton University is currently constructing a specialized wind tunnel, the Princeton/ONR High Reynolds number Testing Facility (HRTF) to be used for aero/hydrodynamic testing of submersible shapes. The facility will operate at very high pressures, up to 230 atmospheres, and relatively low velocities. Old Dominion University is responsible for the design and commissioning of a Magnetic Suspension and Balance System (MSBS) for use with the HRTF. The HRTF design and operational characteristics will be briefly described, then the paper will concentrate on the design challenges faced by the MSBS. The most unusual problems are related to the fact that the electromagnets will be located outside the wind tunnel pressure shell, with position sensing and other hardware inside. The test section is constructed of stainless steel, so eddy currents generated by unsteady magnetic fields are a serious concern. It is shown by analysis and confirmed by measurements that the system is practical, provided the eddy current effects are properly modeled and accounted for in the control system design. Due to restricted access to the interior of the tunnel, the position sensing and control systems must be configured so as to reliably suspend models for long periods of time, with a variety of aero/hydrodynamic tests conducted in sequence. This leads to a relatively conservative choice of system configuration and hardware. The general design of the MSBS will be presented and plans for completion, commissioning, calibration and operation of the facility will be reviewed.
BibTeX:
@inproceedings{ISMST5_51,
  author = {Colin P. Britcher and Oscar Gonzalez and Steven Gray and Oscar Gomeiz and James E. Barldey and Adeel Jafri and Alexander J. Smits},
  title = {Design of a Magnetic Suspension and Balance System for the Princeton/ONR High Reynolds Number Testing Facility},
  booktitle = {Proceedings of ISMST5},
  year = {1999},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst5/ismst5_submission_51.pdf}
}
1995 Britcher, C.P. and Groom, N.J. Computational Analysis of Static and Dynamic Behavior of Magnetic Suspensions and Magnetic Bearings Proceedings of ISMST3  
Abstract: Static modelling of magnetic bearings is often carried out using magnetic circuit theory. This theory cannot easily include nonlinear effects such as magnetic saturation or the fringing of flux in air-gaps. Modem computational tools are able to accurately model complex magnetic bearing geometries, provided some care is exercised. In magnetic suspension applications, the magnetic fields are highly three-dimensional and require computational tools for the solution of most problems of interest. The dynamics of a magnetic bearing or magnetic suspension system can be strongly affected by eddy currents. Eddy currents are present whenever a time-varying magnetic flux penetrates a conducting medium. The direction of flow of the eddy current is such as to reduce the rate-of-change of flux. Analytic solutions for eddy currents are available for some simplified geometries, but complex geometries must be solved by computation. It is only in recent years that such computations have been considered truly practical. At NASA Langley Research Center, state-of-the-art finite-element computer codes, "OPERA", "TOSCA" and "ELEKTRA" have recently been installed and applied to the magnetostatic and eddy current problems. This paper reviews results of theoretical analyses which suggest general forms of mathematical models for eddy currents, together with computational results. A simplified circuit-based eddy current model proposed appears to predict the observed trends in the case of large eddy current circuits in conducting non-magnetic material. A much more difficult case is seen to be that of eddy currents in magnetic material, or in non-magnetic material at higher frequencies, due to the lower skin depths. Even here, the dissipative behaviour has been shown to yield at least somewhat to linear modelling. Magnetostatic and eddy current computations have been carried out relating to the Annular Suspension and Pointing System, a prototype for a space payload pointing and vibration isolation system, where the magnetic actuator geometry resembles a conventional magnetic bearing. Magnetostatic computations provide estimates of flux density within airgaps and the iron core material, fringing at the pole faces and the net force generated. Eddy current computations provide coil inductance, power dissipation and the phase lag in the magnetic field, all as functions of excitation fi-equency. Here, the dynamics of the magnetic bearings, notably the rise time of forces with changing currents, are found to be very strongly affected by eddy currents, even at quite low frequencies.
BibTeX:
@inproceedings{ISMST3_49,
  author = {Colin P. Britcher and Nelson J. Groom},
  title = {Computational Analysis of Static and Dynamic Behavior of Magnetic Suspensions and Magnetic Bearings},
  booktitle = {Proceedings of ISMST3},
  year = {1995},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst3/ismst3_submission_49.pdf}
}
1995 Britton, T.C. A Digital Control Algorithm for Magnetic Suspension Systems Proceedings of ISMST3  
Abstract: An ongoing program exists to investigate and develop magnetic suspension technologies and modelling techniques at NASA Langley Research Center. Presently, there is a laboratory-scale large air-gap suspension system capable of five degree-of-freedom (DOF) control that is operational and a six DOF system that is under development. Those systems levitate a cylindrical element containing a permanent magnet core above a planar array of electromagnets, which are used for levitation and control purposes. In order to evaluate various control approaches with those systems, the Generic Real-Time St ate-Space Controller (GRTSSC) software package was developed. That control software package allows the user to implement multiple control methods and allows for varied input/output commands. The development of the control algorithm is presented. The desired functionality of the software is discussed, including the ability to inject noise on sensor inputs and/or actuator outputs. Various limitations, common issues, and trade-offs are discussed including data format precision; the drawbacks of using either Direct Memory Access (DMA), interrupts, or program control techniques for data acquisition; and platform dependent concerns related to the portability of the software, such as memory addressing formats. Efforts to minimize overall controller loop-rate and a comparison of achievable controller sample rates are discussed. The implementation of a modular code structure is presented. The format for the controller input data file and the noise information file is presented. Controller input vector information is available for post-processing by mathematical analysis software such as MATLAB1.
BibTeX:
@inproceedings{ISMST3_42,
  author = {Thomas C. Britton},
  title = {A Digital Control Algorithm for Magnetic Suspension Systems},
  booktitle = {Proceedings of ISMST3},
  year = {1995},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst3/ismst3_submission_42.pdf}
}
1988 Brunet, M. Practical Applications of the Active Magnetic Bearings to the Industrial World Proceedings of ISMB1 - Courtesy of Springer-Verlag  
Abstract: Active Magnetic Bearings (AMB) are developed, manufactured and marketed by Societe de Mecanique Magnetique (S2M) since 1976. This company has maGe major improvements to the AMB fundamental technology in order to meet industrial requirements. Each component of the AMB system has been improved through a simple, robust, and patented solution. Among others, inductive sensors, flux feedback control, control loops (automatic balancing system), auxiliary bearings •••• Many industrial applications in various and severe environmental conditions have been set into operation. They have been into operation for years and have shown then reliability.
BibTeX:
@inproceedings{ISMB1_22,
  author = {M. Brunet },
  title = {Practical Applications of the Active Magnetic Bearings to the Industrial World },
  booktitle = {Proceedings of ISMB1 - Courtesy of Springer-Verlag},
  year = {1988},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb1/ismb1_submission_22.pdf}
}
1990 Brunet, M. and Rioland, J. Self-tuning Digital State Controller for Active Magnetic Bearings  Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_4,
  author = {M. Brunet and J. Rioland },
  title = {Self-tuning Digital State Controller for Active Magnetic Bearings },
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_4.pdf}
}
1994 Brunet, M. and Wagner, B. Analysis of the Performance of and AMB Spindle in Creep Feed Grinding Proceedings of ISMB4  
Abstract: An Active Magnetic Bearing (AMB) electrospindle has been used in the process of creep feed grinding. This process requires high speed, power and accuracy. The AMB spindle complies with these requirements and brings additional advantages coming from the signal processing characteristics and rotor position control. The operation experience extends over 8 years and 12 spindles. This opened the door to other CBN grinding applications and motor technology development.
BibTeX:
@inproceedings{ISMB4_84,
  author = {M. Brunet and B. Wagner },
  title = {Analysis of the Performance of and AMB Spindle in Creep Feed Grinding },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_84.pdf}
}
2000 Bucher, I. and Rozenstein, M. On the Determination of External Forces - Application to the Calibration of an Electromagnetic Actuator Proceedings of ISMB7  
Abstract: A method for obtaining an accurate estimate of forces acting upon a vibrating structure is derived in this paper. The method was developed as a means for calibrating an electromagnetic excitation device where the electromagnetic force was sought to be estimated. The unique features of the proposed method are: (a) Compensation of inertial effects; (b) Based on indirect measurement of forces and displacements in conjunction with an accurate dynamical model. The precise account of inertia and elastic effects allows us to model the relationship between the actuall applied forces and various parameters affecting the external forces. In the case of an electromagnetic device those will be ai -gap, current and magnetic flux. The lack of information in this case had lead us to a threefold approach where experimental data is combined with an analytical approach togethe with state-of-the-art measurement-equipment techniques. The necessity to obtain an accurate account of the distribution of inertia in the structure necessitates a precise spatial model extracted by means of a scanning lase - Doppler sensor. The analytical part involves the estimation of Lagrange multipliers with the extended principal of virtual work.
BibTeX:
@inproceedings{ISMB7_1,
  author = {Izhak Bucher and Moshe Rozenstein},
  title = {On the Determination of External Forces - Application to the Calibration of an Electromagnetic Actuator},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_1.pdf}
}
1999 Buckner, G., Palazzolo, A., Kajs, J., Murphy, B. and Beno, J. Control System for Inside-Out Configuration Magnetic Bearings Proceedings of ISMST5  
Abstract: The University of Texas Center for Electromechanics CtYI'-CEM) in association with the Texas A&M Vibration Control Lab (TAMU-VCL) has developed an active magnetic bearing control system for use in a 5 MW, 25 M J, 20,000 RPM flywheel alternator developed under the Combat Hybrid Power Systems (CHPS) program. The inside-out topology of this flywheel (i.e., the 650 lb (294 kg) flywheel rotor is positioned outside the stator) was dictated by the extreme power density and energy density requirements, and presented unique control challenges seldom encountered in conventional magnetic bearing applications. These challenges resulted from a large number of flexible modes in the rotor and stator, requiring a high-order flexible dynamic model and extensive rotordynamic analysis. A simulation-based design effort was implemented to accomplish the primary control objective: to provide robust, efficient magnetic levitation of the CHPS rotor over a wide range of operating speeds and disturbance inputs, while minimizing the occurrence of backup bearing touchdowns. Additionally, this design effort provided critical specifications for CHPS flywheel design and component selection. Details of the CHPS magnetic bearing design, prototyping, and testing are presented in a companion paper "Inside-Out Configuration Active Magnetic Bearing Actuators".
BibTeX:
@inproceedings{ISMST5_33,
  author = {Gregory Buckner and Alan Palazzolo and John Kajs and Brian Murphy and Joe Beno},
  title = {Control System for Inside-Out Configuration Magnetic Bearings},
  booktitle = {Proceedings of ISMST5},
  year = {1999},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst5/ismst5_submission_33.pdf}
}
1994 Budig, P. and Werner, R. Stiffness of Magnetic Bearings Proceedings of ISMB4  
Abstract: The chance to apply magnetic bearings depends on the possibility, to improve their static and dynamic performance. Intensive considerations on the dynamic performance of magnetic bearings made clear, that the stiffness depends on the dynamic performance of the - measuring system, - electronic controller, - power-electronic devices and - the eddy currents in the iron core of the bearing. The paper shows the theoretical description of the dynamic performance of a magnetic bearing. From these are derived demands to the above mentioned components.
BibTeX:
@inproceedings{ISMB4_42,
  author = {P. Budig and R. Werner },
  title = {Stiffness of Magnetic Bearings },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_42.pdf}
}
2011 Budig, P.-K. Betrachtungen zur Theorie und Anwendung magnetischer Lager Proceedings of Workshop on Magnetic Bearing Technology 8  
Abstract: Es wird eine Einführung in einige theoretische Grundlagen magnetischer Lager gegeben wie: Verluste, Dynamisches Betriebsverhalten, Ausführungsformen magnetischer Lager. Einige Anwendungen werden beschrieben, wie: Drehmomenten Messgerät für 140000 min-1, Ventilator Teststand, Kühlwasserpumpe in einem Kraftwerk, Lager für extrem große Lagerkräfte im Bereich der Lagerkräfte von 16000 bis 50000 Newton, Schwungradspeicher im Hochvakuum mit 45000 min-1 mit permanentmagnetischen Radiallagern.
BibTeX:
@inproceedings{WMLT8_12,
  author = {P.-K. Budig},
  title = {Betrachtungen zur Theorie und Anwendung magnetischer Lager },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 8},
  year = {2011},
  url = {https://www.magneticbearings.org/wp-content/publications/wmlt8/wmlt8_12.pdf}
}
2012 Buechsenschuetz, M. and Sattel, T. Controller Design for a High Precision Elastically Supported Hybrid Active Magnetic Guidance Proceedings of ISMB13  
Abstract: The design of multi coordinate drives (MCD) with nanometre positioning uncertainty and long planar motion range of several hundred millimetres is a worldwide research challenge. Ac-tive magnetic guidance (AMG) is suitable for these precision applications due to its non-contact support principle. One drawback is the heat generation due to ohmic loss in the control coil which should be minimized and kept constant to meet high precision demands [1, pp. 83-84]. In [2] an elastically supported hybrid active magnetic guidance (ES-HAMG) is proposed. A hybrid magnet combines a permanent magnet with a coil, additionally it is connected in series with a mechanical spring. This device is capable of reducing the thermal dissipation by 80% at varying load force on a sample ES-HAMG. This contribution gives a more comprehensive view on ES-HAMG inMCD than [2]. A model to estimate possible savings in power dissipation is derived in detail. The employed controller design theory is given. Experiments confirm theoretical energy savings and the nanopositioning capabilities.
BibTeX:
@inproceedings{ISMB13_18,
  author = {Mirko Buechsenschuetz and Thomas Sattel},
  title = {Controller Design for a High Precision Elastically Supported Hybrid Active Magnetic Guidance},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_18.pdf}
}
1996 Bühler, P., Siegwart, R. and Herzog, R. Digital Control for Low Cost Industrial AMB Applications  Proceedings of ISMB5  
Abstract: Active magnetic bearings have many advantages compared to other bearing concepts. However, for many potential industrial applications they have been too complicated and too expensive in the past. Thanks to innovative digital control concepts, active magnetic bearing systems with higher performance, smaller dimensions, lower power consumption, and lower costs are reality today. This paper discusses various control concepts for active magnetic bearings and presents an innovative solution for low cost.
BibTeX:
@inproceedings{ISMB5_15,
  author = {P. Bühler and R. Siegwart and R. Herzog },
  title = {Digital Control for Low Cost Industrial AMB Applications },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_15.pdf}
}
1990 Buhrer, P., Engel, J. and Glass, D. The Malve Experimental Circulator The First Large Nuclear Component with Active Magnetic Bearings  Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_13,
  author = {P. Buhrer and J. Engel and D. Glass },
  title = {The Malve Experimental Circulator The First Large Nuclear Component with Active Magnetic Bearings },
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_13.pdf}
}
2013 Bulic, N., Dirnberger, P. and Silber, S. New Sensor Design for Rotor Displacement Measurement Based on the Coupled Oscillators Theory Proceedings of BWMB2013  
Abstract: Measurement of rotor position in bearingless motors and bearingless systems is of essence for proper operation. Insufficient resolution, sensor insensitivity and low sampling rate in measurement process leads unstable levitation and in worst case to the collision of rotor and stator which could end with motor destruction. Paper presents new concept for rotor position measurement based on Eddy current principle and Coupled oscillators theory in order to get accurate rotor position information. New concept is based on injection locking phenomena between coupled oscillators. Opposite pair of sensing oscillators are electrically coupled via resistor. In injection locking conditions phase shift between coupled oscillators is proportional to rotor movement. Phase shift was measured with Time to Digital Converter (TDC) and information is passed to Digital Signal Processor DSP over SPI communication link. DSP calculates the rotor position which is passed to power electronic circuit for rotor position control.
BibTeX:
@inproceedings{BWMB2013_1,
  author = {Neven Bulic and Peter Dirnberger and Sigfried Silber},
  title = {New Sensor Design for Rotor Displacement Measurement Based on the Coupled Oscillators Theory},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {https://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_1.pdf}
}
2004 Burdet, L., Aeschlimann, B. and Siegwart, R. Thermal Model For A High Temperature Active Magnetic Bearing Proceedings of ISMB9  
Abstract: In order to design an AMB working at high temperature the thermal aspect has to be explored. The limitation of current must be determined as well as the temperature of work of the material. A steady state model including the thermal radiation has been built on the base of a thermal network. Temperature dependent thermal parameters of the component of the AMB were measured with experiments throughout a model fitting. This model programmed in MATLAB is fast enough to work in AMB optimization design routines. An application of choice of coil high temperature wires in function of their life span is presented.
BibTeX:
@inproceedings{ISMB9_6,
  author = {Luc Burdet and Beat Aeschlimann and Roland Siegwart },
  title = {Thermal Model For A High Temperature Active Magnetic Bearing},
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_6.pdf}
}
2006 Burgos, D.C., Sirbu, G.M., Porres, F.M., Landajuela, J.V. and Agorreta, L.F. PD Control and Sliding Mode Control Using Feedback Linearization for 3-Pole Radial Magnetic Bearings of an Energy Storage Flywheel Proceedings of ISMB10  
Abstract: In this paper a model and two control strategies are developed for the two radial active magnetic bearings (AMB) of an energy storage flywheel. The model is detailed, taking account of all significant phenomena in system. A linear control (proportional derivative control – PD control) and a nonlinear control (sliding mode control – SM control) based on the feedback linearization of the nonlinear magnetic bearing system are developed in order to find the best control for this system.
BibTeX:
@inproceedings{ISMB10_59,
  author = {David Cantero Burgos and Gabriel Mihai Sirbu and Fernando Martin Porres and Javier Vadillo Landajuela and Luis Fontan Agorreta},
  title = {PD Control and Sliding Mode Control Using Feedback Linearization for 3-Pole Radial Magnetic Bearings of an Energy Storage Flywheel},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_59.pdf}
}
1994 Buro, N.G. Magnetic Bearings and Non-Stationary Dynamics of Rotors Proceedings of ISMB4  
Abstract: This contribution is an attempt to spur interest in the application of neural networks in actively supported rotors. After some introductory remarks non-stationary rotordynamics is reviewed in short, restricted to the jeffcott Rotor (section 2) . Section 3 than gives an overview of a simple neural network trained by the backpropagation procedure. The latter is then utilized in section 4 to avoid suspended stays of the non-stationary rotor. Section 5 outlines future improvements, realizations and other possible applications. A short summary concludes the contribution.
BibTeX:
@inproceedings{ISMB4_44,
  author = {N. G. Buro },
  title = {Magnetic Bearings and Non-Stationary Dynamics of Rotors },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_44.pdf}
}
1988 Burrows, C., N., Sahinkaya, Traxler, A. and Schweitzer, G. Design and Application of a Magnetic Bearing for Vibration Control and Stabilization of a Flexible Rotor Proceedings of ISMB1 - Courtesy of Springer-Verlag  
Abstract: This paper describes the design of a magnetic actuator designed to control the synchronous vibration of a 2.3m long 100mm diameter rotor supported on oil-film bearings. An algorithm is described which allows the control force to be computed to minimise the synchronous rotor vibration without prior knowledge of oil-film or rotor characteristics nor of the inherent out-of-balance distribution along the rotor. In this approach the magnetic actuator is first used to apply sequential test signals along two orthogonal axes whilst the shaft is rotating. The corresponding displacements are measured and the algorithm used to determine the control forces to be applied by the actuator. The process is applied sequentially as the rotor is run-up from rest to the required operating speed. Some experimental results are presented to demonstrate the ability of this technique to significantly reduce the synchronous vibration. It is also discussed how the electromagnetic actuator can be used to avoid the instability associated with oil-whirl.
BibTeX:
@inproceedings{ISMB1_16,
  author = {C.R. Burrows and N. and Sahinkaya and A. Traxler and G. Schweitzer },
  title = {Design and Application of a Magnetic Bearing for Vibration Control and Stabilization of a Flexible Rotor },
  booktitle = {Proceedings of ISMB1 - Courtesy of Springer-Verlag},
  year = {1988},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb1/ismb1_submission_16.pdf}
}
1991 Burrows, C.R. An Evaluation of Some Strategies for Vibration Control of Flexible Rotors Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_38,
  author = {C. R. Burrows},
  title = {An Evaluation of Some Strategies for Vibration Control of Flexible Rotors},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_38.pdf}
}
2004 Buskirk, E.S., Sanadgol, D., Maslen, E.H. and Brown, N.K. Centrifugal Compressor Test Facility With Active Magnetic Bearings Proceedings of ISMB9  
Abstract: Design of a test facility for assessing wheel loading of a centrifugal compressor is described. The facility uses active radial and axial magnetic bearings to estimate static and dynamic bearing loadings. The central application of the facility is to measure the loading forces on the impeller at non-design conditions. This data is then used to verify and refine analytical models for use in compressor design. In addition, the axial active magnetic bearing provides substantial control authority over the impeller tip-clearance, creating strong potential for active suppression of surge.
BibTeX:
@inproceedings{ISMB9_77,
  author = {Eric S. Buskirk and Dorsa Sanadgol and Eric H. Maslen and Nathan K. Brown},
  title = {Centrifugal Compressor Test Facility With Active Magnetic Bearings },
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_77.pdf}
}
2004 Cade, I.S., Keogh, P.S. and Sahinkaya, M.N. Fault Identification In Rotor/Magnetic Bearing Systems Using Discrete Time Wavelet Coefficients Proceedings of ISMB9  
Abstract: A method of online fault identification in rotor/ magnetic bearing systems is presented using wavelet analysis. A filter bank approach is taken to identify the discrete time wavelet coefficients of the rotor displacement signals. From artifacts present in the discrete time wavelet series associated with specific faults, it is shown that it is possible to identify both the onset time and the fault type. This method is demonstrated for simulations of a flexible rotor/active magnetic bearing assembly during auxiliary bearing contact and direct synchronous forcing for a range of running speeds covering flexural critical speeds.
BibTeX:
@inproceedings{ISMB9_72,
  author = {Iain S. Cade and Patrick S. Keogh and M. Necip. Sahinkaya},
  title = {Fault Identification In Rotor/Magnetic Bearing Systems Using Discrete Time Wavelet Coefficients },
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_72.pdf}
}
2008 Cade, I.S., Sahinkaya, M.N., Burrows, C.R. and Keogh, P.S. On the Design of an Active Auxiliary Bearing for Rotor/Magnetic Bearing Systems Proceedings of ISMB11  
Abstract: This paper considers the design of an actively controlled auxiliary bearing system for use with magnetic bearings. During rotor/auxiliary bearing contact large frictional contact forces can lead to significant thermal stresses. Furthermore, the nonlinear nature of the contact can induce unfavourable rotor dynamic behaviour. An active auxiliary bearing capable of reducing the contact forces and influencing the rotor dynamics during contact is proposed. Active auxiliary bearing design objectives include reducing the rotor / bearing contact forces during impact and influencing the rotor dynamics to prevent a trapped contact mode from becoming established. A piezo actuated system, using a closed hydraulic coupling, is presented. The dynamic performance of the actuators and hydraulic line are identified. In particular, the transfer function from actuator control signal to auxiliary bearing displacement is identified. Closed loop control of the active auxiliary bearing using local proportional integral differential control is also considered.
BibTeX:
@inproceedings{ISMB11_22,
  author = {Iain Stuart Cade and M. Necip Sahinkaya and Clifford R. Burrows and Patrick S. Keogh},
  title = {On the Design of an Active Auxiliary Bearing for Rotor/Magnetic Bearing Systems},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_22.pdf}
}
2010 Cai, J., Deng, Z., Qi, R. and Liu, Z. Modeling of Bearingless Switched Reluctance Motor Based On Artificial Neural Network Proceedings of ISMB12  
Abstract: Accurately calculating and modeling of the flux linkage characteristics is a critical step in design and analysis of optimal control strategies for Bearingless Switched Reluctance Motor (BSRM). But due to the highly nonlinear characteristics of BSRM, it is very difficult to derive a comprehensive mathematical model to satisfy the overall characteristics of the machine. To overcome this problem, in this paper, an edge finite element method (EFE) based 3-D FEM and a new enhanced incremental energy method were utilized for calculating the flux linkage characteristics; using the calculated flux data, an adaptive neural fuzzy inference system (ANFIS) based flux model was developed. Simulation results are presented and compared with the analytical nonlinear modeling method, which verified that the proposed model can modeling the BSRM more accurately and adaptively.
BibTeX:
@inproceedings{ISMB12_103,
  author = {Jun Cai and Zhiquan Deng and Ruiyun Qi and Zeyuan Liu },
  title = {Modeling of Bearingless Switched Reluctance Motor Based On Artificial Neural Network },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_103.pdf}
}
2002 Cai, J. and Henneberger, G. Radial Force Of Bearingless Wound-Rotor Induction Motor Proceedings of ISMB8  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB8_21,
  author = {Jumei Cai and Gerhard Henneberger},
  title = {Radial Force Of Bearingless Wound-Rotor Induction Motor},
  booktitle = {Proceedings of ISMB8},
  year = {2002},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb8/ismb8_submission_21.pdf}
}
1991 Cai, Z., Shen, Z., Zhang, Z. and Zhao, H. Computer Aided Design of Digital Controller for Radial Active Magnetic Bearings Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_23,
  author = {Zhong Cai and Zupei Shen and Zuming Zhang and Hongbin Zhao},
  title = {Computer Aided Design of Digital Controller for Radial Active Magnetic Bearings},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_23.pdf}
}
1990 Cai, Z., Zhang, Z. and Zhoa, H. Performance of the Active Magnetic Bearings  Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_35,
  author = {Z. Cai and Z. Zhang and H. Zhoa },
  title = {Performance of the Active Magnetic Bearings },
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_35.pdf}
}
1994 Canders, W., Ueffing, N., Schrader-Hausmann, U. and Larsonneur, R. MTG400: A Magnetically Levitated 400kW Turbo Generator System for Natural Gas Expansion Proceedings of ISMB4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB4_74,
  author = {W. Canders and N. Ueffing and U. Schrader-Hausmann and R. Larsonneur },
  title = {MTG400: A Magnetically Levitated 400kW Turbo Generator System for Natural Gas Expansion },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_74.pdf}
}
2004 Canders, W.R., Hoffmann, J., May, H. and Palka, R. SMB Design Based On Advanced Calculation Methods Validated By Practical Experience Proceedings of ISMB9  
Abstract: The paper presents advanced three-dimensional calculation methods for the determination of the force and stiffness properties of contact-less, inherently stable superconducting magnetic bearings (SMBs). Based on these methods the magnetic bearings design has been optimized to achieve an utmost reduced amount of HTSC-material for a given force and stiffness. Based on the condition that iron free field excita-tion systems are applied (no iron poles), three dimen-sional analytical calculation methods are compared with numerical ones. 3D numerical field calculation pro-grams have been extended to consider even any com-plex iron structures associated with SMBs exhibiting high force densities. Exemplary different optimized designs of SMBs are presented, capable to suspend the rotor-weight of a turbo compressor or a carbon fiber ring of an inertial energy storage system. Another layout enables a fully 3-dimensional contact-less levitation of a LH2-tank with no degree of freedom in motion. Beside the mere sup-porting functions the SMBs have to withstand the inter-nal and external dynamic forces which occur during the operation.
BibTeX:
@inproceedings{ISMB9_7,
  author = {Wolf R. Canders and Jan Hoffmann and Hardo May and Richard Palka},
  title = {SMB Design Based On Advanced Calculation Methods Validated By Practical Experience},
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_7.pdf}
}
2008 Cantero, D., Izpizua, A., Mabe, J., Perez, I. and Arana, J. Hardware Platform for Magnetic Bearing Control in Machine-Tool Applications Proceedings of ISMB11  
Abstract: In this paper a new and powerful control hardware for magnetic spindle applications is presented. The Hardware consists in two boards. The processor board assembles a floating point DSP, a high density FPGA and a TCP/IP communication Module. It is in charge of the control algorithms processing, system monitoring and real time data acquisition. The interface board assembles all the hardware modules needed to access external devices such as digital I/O, ADCs and DACs, encoder modules and so on. Moreover the most prominent features of the hardware devices and the reasons that have motivated the new design are described. Since control strategy imposes computation requirements, a brief description of control algorithms is included. How this algorithm is distributed along the processor device is discussed as an example for control software implementation in the new hardware. Finally, the new hardware design performance and benefits are enumerated and future work is presented.
BibTeX:
@inproceedings{ISMB11_87,
  author = {David Cantero and Alberto Izpizua and Jon Mabe and Ion Perez and Joseba Arana},
  title = {Hardware Platform for Magnetic Bearing Control in Machine-Tool Applications},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_87.pdf}
}
2012 Cao, G., Li, H., Huang, S., Pan, J. and Qiu, H. Development of a Control Platform for the Magnetic Suspension System Proceedings of ISMB13  
Abstract: A highly integrated open control platform for control algorithms development of magnetic suspension system is proposed based on MATLAB/Simulink, dSPACE and DSP. The schema and work principle of the control platform are presented. A robust H8controller as an example for the system is designed in detail to verify the control platform. Experimental results show that the control platform is successfully set up for carrying out research of complex control algorithms and education of control theory.
BibTeX:
@inproceedings{ISMB13_25,
  author = {Guangzhong Cao and Hanyi Li and Sudan Huang and J.F. Pan and Hong Qiu},
  title = {Development of a Control Platform for the Magnetic Suspension System},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_25.pdf}
}
2018 Cao, G.-Z., Guo, J.-C., Huang, S.-D. and Li, W.-B. Modeling of Levitation Force for a Wireless-Moving-Levitating Light with Multiple Magnetic Fields Proceedings of ISMB16  
Abstract: This paper presents the modeling of the levitation force for a wireless-moving-levitating light (WMLL) developed in the laboratory. The mechanical structure of the WMLL is first given. A control scheme, which is used to regulate the energized current for stable, quick, and accurate levitation of the levitating disk, is then presented. Furthermore, the model of the levitation force is theoretically derived based on the Ampere molecular current hypothesis and the Biot-Savart law. Additionally, a finite element analysis is performed to characterize the levitation force. Finally, the effectiveness of the model is verified through the experimental results.
BibTeX:
@inproceedings{ISMB16_086,
  author = {Guang-Zhong Cao and Jin-Chang Guo and Su-Dan Huang and Wen-Bo Li},
  title = {Modeling of Levitation Force for a Wireless-Moving-Levitating Light with Multiple Magnetic Fields},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_086.pdf}
}
2016 Cao, J., Allaire, P., Dimond, T. and Rensburg, J.J.V. Rotor Drop Analyses and Auxiliary Bearing System Optimization for AMB Supported Rotor - Part I: Analysis Method Proceedings of ISMB15  
Abstract: For rotors supported with active magnetic bearings (AMBs), the auxiliary bearing system (AUX) is needed to avoid potential severe internal damaging due to AMB loss power or overload. The evolution of auxiliary systems has been required by the American Petroleum Institute (API) using analytical or experimental methods. In part I of this paper, a detailed rotor drop transient analysis method including flexible shaft, rolling element bearing components, as well as flexible/damped supporting structures is given. Part 2 gives the experimental validation of the method with a test rig and model optimization. A finite element based flexible rotor model is used to indicate the shaft motion before the drop (operating conditions) and during the rotor drop event. Un-lubricated Hertzian contact models are used for the shaft and inner races, for balls and races. To avoid heavy time consumption, two different methods, which calculate the ball bearing contact loads, are discussed and the simulation results are compared. These models are applied to predict shaft-race-ball displacements and angular speeds, contact loads and ball bearing stresses during the drop for auxiliary bearings. This method also can be used to design and optimize the auxiliary bearing system as presented in the 2nd part of this paper, based upon the experimental testing results and validation.
BibTeX:
@inproceedings{ISMB15_108,
  author = {Jianming Cao and Paul Allaire and Tim Dimond and Jan Janse Van Rensburg},
  title = {Rotor Drop Analyses and Auxiliary Bearing System Optimization for AMB Supported Rotor - Part I: Analysis Method},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_108.pdf}
}
2016 Cao, J., Allaire, P., Dimond, T. and Rensburg, J.J.V. Rotor Drop Analyses and Auxiliary Bearing System Optimization for AMB Supported Rotor - Part II: Experiment and Optimization Proceedings of ISMB15  
Abstract: This paper forms Part II of the rotor drop analysis, focusing on the auxiliary bearing system design and optimization based on the rotor drop analysis methods, as introduced in Part I. Optimization focuses on shaft orbit, maximum ball bearing stress, and how to avoid possible ball bearing damage due to impact loading during rotor drop by optimizing auxiliary design including bearing selection, preload method, radial and axial damping element, and flexible bearing support. The rotor drop modeling process has been validated with test rig result. Using the detailed rotor drop model and time transient method, simulation results are first compared with test data; and a simulation is presented for an 8-stage horizontal centrifugal compressor, are conducted to investigate the effects of auxiliary bearing design and to optimize the auxiliary system. Axial drops, radial drops and combination of radial/axial drops are all evaluated considering angular contact auxiliary bearing size, number of rows, preload, and flexible damped bearing supports in the axial and radial directions. The rotor drop analysis method introduced in this paper may be used as a design toolbox for the auxiliary bearing system.
BibTeX:
@inproceedings{ISMB15_109,
  author = {Jianming Cao and Paul Allaire and Tim Dimond and Jan Janse Van Rensburg},
  title = {Rotor Drop Analyses and Auxiliary Bearing System Optimization for AMB Supported Rotor - Part II: Experiment and Optimization},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_109.pdf}
}
2018 Cao, J., Allaire, P., Nichols, B., Dimond, T., Ma, X., Shang, R., Wang, C. and Wang, H. Auxiliary Bearing Design and Rotor Drop Analysis of High Speed Motor Compressor/AMB System Proceedings of ISMB16  
Abstract: This paper presents the auxiliary bearing design and rotor drop analysis of a single stage motor-compressor. The auxiliary bearing design consists of double row, ceramic ball bearings with cages and with high axial preload. The axial preload is provided by Bellville washers which also provide axial spring stiffness and damping. The auxiliary bearings are laterally mounted on tolerance ring wave springs which provide support stiffness and damping to help absorb the impacts due to the rotor drop. A nonlinear transient rotor dynamics and auxiliary bearing modeling code has been utilized to carry out the rotor drop analysis. The very large mathematical model includes all of the shaft degrees of freedom, the auxiliary bearing races and all of the balls, as well as the Bellville washers and the wave springs. The rotor orbits, the inner and outer race orbits and the ball displacements are all evaluated versus time during the drop. The orbits were found to simply oscillate in the bottom of the auxiliary bearings and do not go into large orbit whirls. Also, the auxiliary bearing maximum compressive stress levels were evaluated and found to be well below the material yield stresses indicating long auxiliary bearing life in terms of number of drops without damaging the auxiliary bearings.
BibTeX:
@inproceedings{ISMB16_098,
  author = {Jianming Cao and Paul Allaire and Brad Nichols and Tim Dimond and Xianhao Ma and Raojing Shang and Chunyan Wang and Huajun Wang},
  title = {Auxiliary Bearing Design and Rotor Drop Analysis of High Speed Motor Compressor/AMB System},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_098.pdf}
}
2000 Cao, J., Yu, L. and Xie, Y. Study on a Magnetic Levitation Flywheel Energy Storage Device Proceedings of ISMB7  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB7_11,
  author = {Jianrong Cao and Lie Yu and Youbai Xie},
  title = {Study on a Magnetic Levitation Flywheel Energy Storage Device},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_11.pdf}
}
2008 Cao, X., Deng, Z., Yang, G. and Wang, X. Independent Control of Torque and Radial Force in Bearingless Switched Reluctance Motors Proceedings of ISMB11  
Abstract: Radial force and torque are the control objectives which determine the machine performance of levitation and rotation in a bearingless switched reluctance motor (BSRM). This paper proposes a control scheme for rotating and levitating a 12/8 BSRM. The motor torque and radial force are independently controlled with hybrid excitations in main windings and levitation windings. Firstly, the mathematical relationship between radial force and currents, which is utilized in this work, is derived with Maxwell stress tensor method. Then the proposed control scheme is analyzed. The average torque of each phase generated in levitation region equals to zero for its symmetry of the aligned position. Accordingly, the current calculating algorithm is deduced to minimize the magnitude of instantaneous torque in levitation region. The principle and realization of the proposed scheme are demonstrated with FE analysis. Experimental results show that the proposed scheme is effective for a stable levitation.
BibTeX:
@inproceedings{ISMB11_74,
  author = {Xin Cao and Zhiquan Deng and Gang Yang and Xiaolin Wang},
  title = {Independent Control of Torque and Radial Force in Bearingless Switched Reluctance Motors},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_74.pdf}
}
2006 Cao, X., Deng, Z., Yang, G. and Wang, X. The Mathematical Model of Bearingless Switched Reluctance Motors With Two-Phase Excitation Proceedings of ISMB10  
Abstract: In view of limitations of mathematical model only suited for the single-phase excitation mode in bearingless switched reluctance motors (BSRM), a novel mathematical model of BSRM with one or two-phase excitation is proposed. The inductance matrix is constructed based on the magnetic equivalent circuits in the two-phase excitation mode. New mathematical formulas of radial force and electromagnetic torque are derived. The operating area of BSRM can be expanded to a great extent. The capability of bearing radial force is enhanced greatly. Computer simulations with magnetic-field analytical-method verify the validity and fine characteristics of the new mathematical model. Two optimizing methods to distribute currents of two-phase windings including main windings and radial force windings for practical applications are also proposed.
BibTeX:
@inproceedings{ISMB10_66,
  author = {Xin Cao and Zhiquan Deng and Gang Yang and Xiaolin Wang },
  title = {The Mathematical Model of Bearingless Switched Reluctance Motors With Two-Phase Excitation},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_66.pdf}
}
2016 Caple, M., Maslen, E., Nagel, J. and Wild, J. Control of an AMB to Zero Static Force Proceedings of ISMB15  
Abstract: Someactivemagneticbearing(AMB)applicationsrequirethatthemean, orstaticforceexertedbytheAMBiszero. Examples include hybrid fluid film – AMB bearing pairings, rotor midspan dampers, and statically indeterminant systems with stiff rotors and more than two radial AMBs. When the position of the rotor relative to magnetic center is not known precisely, this zero force requirement can be hard to meet. A low frequency periodic biasing scheme is developed which enables a controller to detect non-zero static force by sensing rotor motion at the bias carrier frequency. A theoretical basis establishes feasibility but also the potential for coupling between control signals and the periodic bias. Simulation demonstrates that an ad–hoc bias adaptation scheme can successfully drive the static component to zero while permitting otherwise conventional control. The simulation results also show some spurious harmonic content associated with the sum and difference between a control signal frequency and the bias carrier frequency. Experimental results on a small, single DOF test rig further demonstrate the ability to drive the AMB static force to zero while adding damping to the system.
BibTeX:
@inproceedings{ISMB15_74,
  author = {Michael Caple and Eric Maslen and Jacquelyn Nagel and Jacob Wild},
  title = {Control of an AMB to Zero Static Force},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_74.pdf}
}
2004 Caprio, M.T., Murphy, B.T. and Herbst, J.D. Spin Commisionning And Drop Tests Of A 130 kW-hr Composite Flywheel Proceedings of ISMB9  
Abstract: The Center for Electromechanics at the University of Texas at Austin is developing a power averaging flywheel battery for use on high speed passenger trains as part of the Federal Railroad Administration’s Next Generation High Speed Rail Program. The flywheel rotor, which weighs 5100 lb, is designed to store 130 kW-hr of energy at a peak design speed of 15,000 rpm. The graphite-epoxy composite rotor, which runs in a vacuum, is supported by a 5 axis active magnetic bearing system. A high speed 2 MW motor-generator, which is outside the vacuum, is directly coupled to the flywheel with an industrial disk pack coupling, through a custom integral rotary vacuum seal. This paper begins with a brief description of the design of the vertically oriented flywheel rotor/housing system. The partially complete rotor (currently 3000 lb mass) has recently been undergoing system level laboratory commissioning. Test results are presented demonstrating the performance of the magnetic bearings. Since flywheel system safety is such a critical issue at this energy level, satisfactory performance of the backup bearings was demonstrated experimentally. Delevitation “drop” tests have been performed onto rolling element backup bearings, and behavior is reported and compared to related flywheels discussed in the literature. Finally, testing of a semi-passive whirl arresting scheme is presented.
BibTeX:
@inproceedings{ISMB9_40,
  author = {Matthew T. Caprio and Brian T. Murphy and John D. Herbst},
  title = {Spin Commisionning And Drop Tests Of A 130 kW-hr Composite Flywheel},
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_40.pdf}
}
1996 Carabelli, S., Cerruti, F., Delprete, C., Majo, F.D., Genta, G. and Zanolli, S. A Two Active-axes Suspension of Maglev Vehicles  Proceedings of ISMB5  
Abstract: A maglev three passive-axes levitation layout solution, in which the forces supporting the vehicle are supplied by the repulsion acting between permanent magnets located under the vehicle and on the guideway, is shortly described. The control design is aimed to stabilize the plant and to achieve a so-called zero power (control) consumption strategy with a two active-axes configuration of electromagnets.
BibTeX:
@inproceedings{ISMB5_60,
  author = {S. Carabelli and F. Cerruti and C. Delprete and F. Di Majo and G. Genta and S. Zanolli },
  title = {A Two Active-axes Suspension of Maglev Vehicles },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_60.pdf}
}
1996 Carabelli, S., Delprete, C., Maddaleno, F., Mittino, M., Muzzarelli, M. and Ugazio, M. High Efficiency Linear Power Amplifier for Active Magnetic Bearings  Proceedings of ISMB5  
Abstract: To improve the overall efficiency of a transconductance amplifier loaded by the high inductance and low resistance typical of the magnetic bearing coils, a modified class G amplifier has been de veloped. A simple theoretical characterization has been used to provide some diagrams to optimize the power efficiency as a function of a non constant load such as that due to a rotor unbalance. Experimental results are reported showing a more than satisfactory agreement with the developed theory.
BibTeX:
@inproceedings{ISMB5_85,
  author = {S. Carabelli and C. Delprete and F. Maddaleno and M. Mittino and M. Muzzarelli and M. Ugazio },
  title = {High Efficiency Linear Power Amplifier for Active Magnetic Bearings },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_85.pdf}
}
1998 Carabelli, S. and Genta, G. Nonlinear Rotordynamic Behaviour of Rotors on Active Magnetic Bearings Proceedings of ISMB6  
Abstract: A Jeffcott rotor is used to study the rigid body rotordynamic behavior of a rotor on active magnetic suspension. The nonlinearity introduced by the electromagnetic force actuator as well as by the driving power amplifier are expected to cause a softening type behavior for the rotor and anysotropic behavior of the bearing system. A nonlinear model is used to perform numerical time domain simulations for low bias current and the presence of lateral loading. The resuts obtained show that the nonlinearities introduced into the the system are usually not very strong, at least when the airgap is not very large, but the current saturation effects increase the softening character of the response of the system.
BibTeX:
@inproceedings{ISMB6_58,
  author = {S. Carabelli and G. Genta},
  title = {Nonlinear Rotordynamic Behaviour of Rotors on Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_58.pdf}
}
1994 Carrere, F. and Font, S. H( Control Design of Flexible Rotor Magnetic Bearing System Proceedings of ISMB4  
Abstract: A method to design robust controller for flexible rotor magnetic bearing system is considered using H8 multi-blocks standard problem optimization. We described how to take into account controller specifications such as disturbance rejection in bandwidth, modes damping, roll-off behaviour, model uncertainties, by elaborating an augmented plant model with supplementary degrees of freedom on the input and output of the flexible modes. A mathematical model of flexible rotor with six bending modes is taken as reference model and this approach allows to get a same order controller that we can reduce by an appropriate method. Continuous and digital syntheses are shown. This way should allow to conveniently tune closed loop behaviour while satisfying severe constraints on the control capability and should result in a practical realization for controller implementation.
BibTeX:
@inproceedings{ISMB4_12,
  author = {F. Carrere and S. Font },
  title = {H( Control Design of Flexible Rotor Magnetic Bearing System },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_12.pdf}
}
1994 Cerruit, F., Delprete, C., Genta, G. and Carabelli, S. High Efficiency and Low Cost Power Amplifiers and Transducers for Active Magnetic Bearings Proceedings of ISMB4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB4_62,
  author = {F. Cerruit and C. Delprete and G. Genta and S. Carabelli },
  title = {High Efficiency and Low Cost Power Amplifiers and Transducers for Active Magnetic Bearings },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_62.pdf}
}
1990 Chan, H. Vibration Control of a Large Turbogenerator by Electromagnetic Dampers  Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_23,
  author = {H.W.C. Chan },
  title = {Vibration Control of a Large Turbogenerator by Electromagnetic Dampers },
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_23.pdf}
}
1992 Charara, A. and Caron, B. Magnetic Bearing: Comparison between Linear and Nonlinear Functioning Proceedings of ISMB3  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB3_43,
  author = {A. Charara and B. Caron },
  title = {Magnetic Bearing: Comparison between Linear and Nonlinear Functioning },
  booktitle = {Proceedings of ISMB3},
  year = {1992},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb3/ismb3_submission_43.pdf}
}
2002 Chen, C., Paden, B., Antaki, J., Ludlow, J. and Bearnson, G. Optimal Design Of Permanent Magnet Bearings With Application To The Heartquest Tm Ventricular Assist Device Proceedings of ISMB8  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB8_90,
  author = {Chen Chen and Brad Paden and James Antaki and Jed Ludlow and Gill Bearnson},
  title = {Optimal Design Of Permanent Magnet Bearings With Application To The Heartquest Tm Ventricular Assist Device},
  booktitle = {Proceedings of ISMB8},
  year = {2002},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb8/ismb8_submission_90.pdf}
}
2018 Chen, C.-Y., Liu, C.-C., Yuliane, A. and Kuan, Y.-D. Rotor Dynamic Analysis in Power Lost Condition for Maglev High-speed Fluid Machinery Proceedings of ISMB16  
Abstract: The advantages offered by active magnetic bearings make that bearing widely used in high-speed Fluid Machinery, the applications that use active magnetic bearing must be equipped with touchdown (auxiliary) bearing system to prevent the damages of impellers and motor in case of a system failure. When the drop event occurs, active magnetic bearing cannot support the rotor stably, touchdown bearings will be a backup for active magnetic bearings to support the rotor during drop down event. Therefore, the properly designed touchdown bearing system is necessary to protect the active magnetic bearings assembly and other critical machine components from direct contact with the rotor during in a loss of AMB power events. This study has based on the un-lubricated Hertzian contact model to analyze the rotor drop dynamics, and the Finite Element method is used to create the flexible rotor model. Finally, the simulation results of this study will show the rotor orbit, rotor response and contact force under rotor drop events by using MATLAB software.
BibTeX:
@inproceedings{ISMB16_067,
  author = {Chao-Yun Chen and Chung-Che Liu and Aindri Yuliane and Yean-Der Kuan},
  title = {Rotor Dynamic Analysis in Power Lost Condition for Maglev High-speed Fluid Machinery},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_067.pdf}
}
1992 Chen, H. and Lewis, P. Rule-Based Damping Control for Magnetic Bearings Proceedings of ISMB3  
Abstract: The derivative control of a conventional PID controller is modified using fuzzy logic. The modified magnetic bearing controller produces low gains in the high-frequency range. Therefore, the bearings can be made stiff in the low-frequency range with less audible noise.
BibTeX:
@inproceedings{ISMB3_3,
  author = {H.M. Chen and P. Lewis },
  title = {Rule-Based Damping Control for Magnetic Bearings },
  booktitle = {Proceedings of ISMB3},
  year = {1992},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb3/ismb3_submission_3.pdf}
}
1999 Chen, H.M. A Self-Healing Magnetic Bearing Proceedings of ISMST5  
Abstract: A fault tolerantmagneticbeatingcontrolscheme,whichindependentlycontrolseachstatorpoleusinga proportional-integral-derivativ(ePID) displacemenfteedback,hasbeenanalyticallytested. The scheme was applied to a 16-pole magnetic beating with a load capacity of 6000 lb and a static load of 4000 lb. Transient response simulation of pole failures (such as those caused by power amplifier failure or coil short circuit) demonstrated that the rotor recovered its bearing center position in a fraction of a second after two consecutive failures of the two top load-carrying poles. The scheme does not require on-line current monitoring to determine the pole failure patterns or storage of precalculated control data to counteract pole failures.
BibTeX:
@inproceedings{ISMST5_3,
  author = {H. Ming Chen},
  title = {A Self-Healing Magnetic Bearing},
  booktitle = {Proceedings of ISMST5},
  year = {1999},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst5/ismst5_submission_3.pdf}
}
1998 Chen, H.M. A Stator-Controlled Magnetic Bearing  Proceedings of ISMB6  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB6_39,
  author = {H. M. Chen},
  title = {A Stator-Controlled Magnetic Bearing },
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_39.pdf}
}
1997 Chen, H.M. Design of a Stator-Controlled Magnet Bearing Proceedings of ISMST4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST4_8,
  author = {H. Ming Chen},
  title = {Design of a Stator-Controlled Magnet Bearing},
  booktitle = {Proceedings of ISMST4},
  year = {1997},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst4/ismst4_submission_8.pdf}
}
2002 Chen, H.M. and Walter, T. A Rotor-Controlled Magnetic Bearing Proceedings of ISMB8  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB8_57,
  author = {H. Ming Chen and Thomas Walter},
  title = {A Rotor-Controlled Magnetic Bearing },
  booktitle = {Proceedings of ISMB8},
  year = {2002},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb8/ismb8_submission_57.pdf}
}
2004 Chen, H.M., Walter, T., Wheeler, S. and Lee, N. Apassive Magnet Bearing System For Energy Storage Flywheels Proceedings of ISMB9  
Abstract: For flywheel applications, a passive magnet bearing system including two radial permanent-magnet bearings, an active thrust bearing,and an active radial damper has been tested to 50,000 rpm. Test results have verified the need for and predicted performance of the active radial damper for the passive bearing system.
BibTeX:
@inproceedings{ISMB9_13,
  author = {H. Ming Chen and Thomas Walter and Scott Wheeler and Nga Lee},
  title = {Apassive Magnet Bearing System For Energy Storage Flywheels },
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_13.pdf}
}
2006 Chen, H.M. and Walter, T.J. A Foil-Magnetic Thrust Bearing Using LCR Circuit Proceedings of ISMB10  
Abstract: An ac magnet based on the LCR resonance circuit shares load with a foil thrust bearing with eight pads, which supports the weight and impeller thrust load of a vertically oriented gas compressor. For the stability o f the combined beari ng, the amplitude of excit ation voltage to the LCR circuit is controlled as a function of rotor speed. To augment the low damping inherent in the ac suspension, a velocity feedback control is applied to modulate the excitation vo ltage and achieve electricdamping.
BibTeX:
@inproceedings{ISMB10_81,
  author = {H. Ming Chen and Thomas J. Walter},
  title = {A Foil-Magnetic Thrust Bearing Using LCR Circuit},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_81.pdf}
}
2008 Chen, H.M., Walter, T.J., Prisco, C.J., Chapman, P.A. and Donahue, A.C. Magnetically Levitated Blood Pump Using LCR Circuits Proceedings of ISMB11  
Abstract: An implantable blood pump has been developed for use as a left ventricular assist device (LVAD). The pump features total magnetic levitation of the shrouded centrifugal impeller. Sensorless levitation is achieved by using three ac magnets with tuned LCR circuits in the axial direction and a pair of permanent magnet rings in the radial direction. This paper describes design issues related to the pump’s magnetic levitation system; pump impact on patient physiology is not addressed.
BibTeX:
@inproceedings{ISMB11_32,
  author = {H. Ming Chen and Thomas J. Walter and Charles J. Prisco and Peter A. Chapman and Arthur C. Donahue},
  title = {Magnetically Levitated Blood Pump Using LCR Circuits},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_32.pdf}
}
1995 Chen, H.M. and Walton, J. Velocity-Controlled Magnetic Bearings With Solid Cores Proceedings of ISMST3  
Abstract: A methodology for designing velocity-controlled magnetic bearings with laminated cores has been extended to those with solid cores. The eddy-current effect of the solid cores is modeled as an opposing magnetomotive force. The bearing control dynamics is formulated in a dimensionless fashion which can be readily reviewed on a root-locus plot for stability. This facilitates the controller design and tuning process for solid core magnetic bearings using no displacement sensors.
BibTeX:
@inproceedings{ISMST3_54,
  author = {H. Ming Chen and James Walton},
  title = {Velocity-Controlled Magnetic Bearings With Solid Cores},
  booktitle = {Proceedings of ISMST3},
  year = {1995},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst3/ismst3_submission_54.pdf}
}
2010 Chen, J., Liu, K., Xiao, K., Wang, H. and Ruan, Y. Analysis of Unbalanced Force for Flywheel Energy Storage System Based on Active Magnetic Bearing Considering Rotor Eccentricity Effects Proceedings of ISMB12  
Abstract: Flywheel energy storage system(FESS) based on active magnetic bearing(AMB) can be used to generate impulse electric power. The unbalanced forces considering rotor eccentricity need to be calculateded, especially when the discharging current is high. This paper investigates the unbalanced forces in FESS considering rotor eccentricity. The analytic solution for the magnetic flux density distribution in the airgap region is used to calculate the unbalanced Lorentz forces and magnetic forces, which are compared with that of finite element method(FEM). The results show that the unbalanced forces should be calculated for FESS to guarantee the flywheel safe whirling and provide reference to the control system design of AMB.
BibTeX:
@inproceedings{ISMB12_79,
  author = {Junfeng Chen and Kun Liu and Kai Xiao and Haoze Wang and Yigao Ruan },
  title = {Analysis of Unbalanced Force for Flywheel Energy Storage System Based on Active Magnetic Bearing Considering Rotor Eccentricity Effects },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_79.pdf}
}
2018 Chen, J., Zhang, L., Luo, Y., Zhang, H. and Liu, J. Random Response Analysis of Magnetic Bearing Rotor System Proceedings of ISMB16  
Abstract: In the practical application, the magnetic bearingrotor system is subject to various external disturbances in practical application. Under certain control conditions, the random response characteristics of the magnetic bearing-rotor system is a particular concern. This paper analyzes the response characteristics of the magnetic bearing subjected to Gaussian random excitation in the horizontal direction. First, the magnetic bearing-rotor system model is deduced. Then, the random response of the rotor under Gaussian random excitation is derived. The probability of the collision of the rotor between the auxiliary bearing is calculated and the example is given. The paper conclusion provides a theoretical basis for the collision detection and prediction of the magnetic bearing-rotor system.
BibTeX:
@inproceedings{ISMB16_059,
  author = {Jinping Chen and Li Zhang and Yanyan Luo and Haining Zhang and Jun Liu},
  title = {Random Response Analysis of Magnetic Bearing Rotor System},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_059.pdf}
}
2000 Chen, L., Shen, Y. and Yu, L. How Static Precision of an AMB Rotor System is Affected by Heating of the Thrust Disk Proceedings of ISMB7  
Abstract: Structural designs of thrust bearings, using both actual system working condition as well as experimental results in expander applications, were used to analyzed how the static precision of an AMB rotor system affected is affected by two variables – the temperature of environment and heating of thrust disk. A model for temperature distribution of the rotor was formulated. System static precision affected by rotor expansion and sensor temperature drift was analyzed in detail.
BibTeX:
@inproceedings{ISMB7_73,
  author = {Liqun Chen and Yunwen Shen and Lie Yu},
  title = {How Static Precision of an AMB Rotor System is Affected by Heating of the Thrust Disk},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_73.pdf}
}
2004 Chen, M. and Knospe, C.R. Implementation Of Robust Feedback Linearization On Active Magnetic Bearing Actuators Proceedings of ISMB9  
Abstract: Feedback linearization is a promising approach to solve the nonlinear control problem for active mag- netic bearing systems. In this paper, feedback lin- earization is employed in combination with robust control techniques for the regulation of a machine tool system actuated by a magnetic bearing. A nonlinear, high order polynomial model was devel- oped based on experimental calibration of the mag- netic bearing. The e®ect of the ampli¯er and sen- sor dynamics on the feedback linearization perfor- mance was also determined and compensated. Fi- nally, an uncertainty framework was proposed for the linearized plant and a robust controller was de- signed via ¹ synthesis. Experimental results show that the feedback-linearized active magnetic bearing system can achieve both high performance as well as stability over the entire bearing clearance.
BibTeX:
@inproceedings{ISMB9_30,
  author = {Min Chen and Carl R. Knospe},
  title = {Implementation Of Robust Feedback Linearization On Active Magnetic Bearing Actuators },
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_30.pdf}
}
2018 Chen, R., Li, H., Ye, P., Tian, J. and Yu, W. Analysis of the Effect of Air Gap on the Performance of Self-inductance Displacement Sensor Proceedings of ISMB16  
Abstract: Inductive displacement sensor is one kind of the common sensors widely used in magnetic bearing system. In this paper, the working principle and output characteristics of the self-inductance displacement sensor are analyzed. For magnetic levitation rotor with a shaft diameter of 44.2mm, self-inductance displacement sensors with different air gaps are respectively designed. The magnetic field distribution and output characteristics of the designed sensor are simulated by finite element analysis method. Theoretical analysis and simulation results both show that there is a very good linear relationship between the output voltage and the rotor displacement of differential self-inductive displacement sensor when the displacement of rotor is in the range of -0.4 to 0.4(mm). Simulation results show the sensitivity of the self-inductance sensor is inversely proportional to the equilibrium air gap. With the increasement of air gap , the relative change value of total inductance is decreasing. When the rotor displacement is small relative to the equilibrium air gap, the relative change of total inductance is smaller and it can be considered unchanged. At this time, the amplitude of the current in the coil is basically unchanged when the voltage amplitude of the driving power is unchanged.
BibTeX:
@inproceedings{ISMB16_094,
  author = {Rui Chen and Hongwei Li and Pinzhou Ye and Jing Tian and Wentao Yu},
  title = {Analysis of the Effect of Air Gap on the Performance of Self-inductance Displacement Sensor},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_094.pdf}
}
2006 Chen, S.-L. Smooth Stabilizing Controllers for a 3-Pole Active Magnetic Bearing System Proceedings of ISMB10  
Abstract: In this study, a class of smooth controllers is proposed for the stabilization of a 3-pole active magnetic bearing(AMB) system. The 3-pole AMB systemis strongly nonlinear and non-affine. Conventional controllers are non smooth and complicated, which is difficult for implementation and further study. The proposed smooth controllers are designed utilizing a linear transformation on the system inputs (coil currents). Asa result, simple smooth controllers, such as quadratic state feedback controller, can be obtained. The domain of attraction of theorigin under the smooth controller is estimated. The proposed smooth controller is verified through both numerical and experimental results.
BibTeX:
@inproceedings{ISMB10_39,
  author = {Shyh-Leh Chen},
  title = {Smooth Stabilizing Controllers for a 3-Pole Active Magnetic Bearing System},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_39.pdf}
}
2016 Chen, S.-L. and Hsiao, Y.-H. Smooth Voltage Controller and Observer for a Three-pole Active Magnetic Bearing System Proceedings of ISMB15  
Abstract: In this study, a simple and smooth voltage controller for a 3-pole active magnetic bearing (AMB) system is proposed. Based on the voltage-controlled AMB system, an observer is designed for the rotor displacement estimation. The observer will be based on the input voltages and coil currents that drive the magnetic poles. Such an observer can be utilized in the sensorless control of the AMB system. Due to the strong nonlinearity in the dynamics of 3-pole AMB system, the theory of nonlinear high-gain observer is adopted to design the observer. The proposed smooth voltage controller and nonlinear observer are verified numerically and experimentally.
BibTeX:
@inproceedings{ISMB15_55,
  author = {Shyh-Leh Chen and Yung-Ho Hsiao},
  title = {Smooth Voltage Controller and Observer for a Three-pole Active Magnetic Bearing System},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_55.pdf}
}
2008 Chen, S.-L. and Hsu, S.-Y. Analysis and Control of a Three-Pole Permanent Magnet Type Bearingless Motor Proceedings of ISMB11  
Abstract: The active magnetic bearing (AMB) possesses several advantages such as no friction, high rotational speed, less energy loss, and long life span etc. In rotation application, however, it must be connected to a motor, which may degrade its performance. Bearingless motor is the combination of the active magnetic bearing and motor. It saves software and hardware facilities, resulting in lower costs. This paper mainly designed a three-pole permanent-magnet type bearingless motor, and analyzed the rotational magnetic field, magnetic force of the bearing, and resulting torque of the motor. Finally, we established system dynamic mathematical model. The controller design and numerical simulations are implemented, and reach the last target.
BibTeX:
@inproceedings{ISMB11_16,
  author = {Shyh-Leh Chen and Shang-Yu Hsu},
  title = {Analysis and Control of a Three-Pole Permanent Magnet Type Bearingless Motor},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_16.pdf}
}
2012 Chen, S.-L. and Lin, S.-Y. Imbalance Compensation for an AMB System with Adaptive Immersion & Invariance Control Proceedings of ISMB13  
Abstract: This study is concerned with the compensationof imbalance force existing in a three-pole active magnetic bearing (AMB) system. An adaptive compensation scheme is proposed using the method of immersion and invariance (I&I) control. The main idea of I&I control is to immerse a higher-order system intoa lower-order target system. In this study, the target system will be the three-pole AMB system with known imbalance that is stabilized by an integral sliding mode controller (ISMC). In practical applications, the imbalance force may be unknown and may be changing during operation. The information of imbalance needs to be estimated online in order to realize the ISMC levitation control. To this aim, the adaptive compensation scheme is incorporated into the ISMC controller so that the closed-loop system forms the higher-order system for the design of I&I control. Numerical simulations verify the effectiveness of the proposed adaptive compensator for mass imbalance.
BibTeX:
@inproceedings{ISMB13_7,
  author = {Shyh-Leh Chen and Shyu-Yu Lin},
  title = {Imbalance Compensation for an AMB System with Adaptive Immersion & Invariance Control},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_7.pdf}
}
2017 Chen, S.-L. and Liu, K.-Y. Sensorless Control for a Three-pole Active Magnetic Bearing System ACES Journal 2017 vol 3 no 8 - Courtesy of ACES  
Abstract: This study proposes a novel sensorless control of a current-controlled three-pole active magnetic bearing (AMB) system. It is based on the smooth current controller incorporated with the estimated rotor displacements. The rotor position information is extracted from additional sensing coil currents. The sensing coil currents are generated from three phase voltages injected to the additional coils on each magnetic pole. The dynamic model of the 3-pole AMB with the additional high frequency input is derived for levitation control and for position estimation. The results are verified through simulation analysis.
BibTeX:
@inproceedings{aces2017vol3no8_012,
  author = {S.-L. Chen and K.-Y. Liu},
  title = {Sensorless Control for a Three-pole Active Magnetic Bearing System},
  booktitle = {ACES Journal 2017 vol 3 no 8 - Courtesy of ACES},
  year = {2017},
  url = {https://www.magneticbearings.org/wp-content/publications/aces2017vol3no8/aces2017vol3no8_012.pdf}
}
2010 Chen, X. and Liu, K. A BP Neural Network Controller for Magnetic Suspended Flywheel System Proceedings of ISMB12  
Abstract: A BP neural network controller is proposed for direct suspending control for Magnetic Suspended Flywheel System (MSFS) that is supported by Active Magnetic Bearings (AMB). A one hidden layer configuration is adopted in the BP neural network, and the back propagated algorithm for network weights updating is derived based on AMB’s linear model. The discussed controller is implemented in the MSFS with random initial network weights, and it is trained online as the whole system operated. Simulations show the proposed BP neural network controller is apt to succeed in suspending the flywheel, and better performances such as precise position control, disturbance rejection, vibration suppression and quiet control are achieved under power consumption limitation. The results validate the feasibility and effectiveness of the presented BP neural network controller.
BibTeX:
@inproceedings{ISMB12_18,
  author = {Xiaofei Chen and Kun Liu },
  title = {A BP Neural Network Controller for Magnetic Suspended Flywheel System },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_18.pdf}
}
2008 Chen, X., Liu, K. and Xiao, K. A Novel Controller with Force Feedback of Active Magnetic Bearings Proceedings of ISMB11  
Abstract: A novel force feedback controller is presented to overcome disturbing forces acting on magnetic suspended rotors of Active or Hybrid Magnetic Bearings (AMB or HMB). As there is linear relationship between disturbing forces and changes of magnetic field on bearings’ operating point, the force feedback is implemented by measuring bearings’ magnetic flux density by hall components. Detailed analysis is discussed also, the dynamic stiffness and damping of the controlled plant are increased when force feedback added into the controller; meanwhile, dynamic response of power amplifier is improved as the novel controller provides a zero point that counteract with the pole point of the power amplifier. A novel controller is developed based on conventional PID leading correcting network. Both simulation and experiment indicate that this novel controller can effectively decrease the influence of disturbing forces, and thus improves the controller’s performance.
BibTeX:
@inproceedings{ISMB11_70,
  author = {Xiaofei Chen and Kun Liu and Kai Xiao},
  title = {A Novel Controller with Force Feedback of Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_70.pdf}
}
1994 Chiba, A. and Fukao, T. The Maximum Radial Force of Induction Machine Type Bearingless Motor Using Finite Element Analysis Proceedings of ISMB4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB4_56,
  author = {A. Chiba and T. Fukao },
  title = {The Maximum Radial Force of Induction Machine Type Bearingless Motor Using Finite Element Analysis },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_56.pdf}
}
1996 Chiba, A., Miyatake, R., Hara, S. and Fukao, T. Transfer Characteristics of Radial Force of Induction-type Bearingless Motors with Four-Pole Rotor Circuits  Proceedings of ISMB5  
Abstract: Rotor winding configurations have been proposed for induction type bearingless motors. Con ventional squirrel cage rotor windings can been seen as not only 4-pole path but also 2-pole path. Th us, a part of curren tin 2-pole radial force windings flows into the squirrel cage rotor windings, which results in decreased radial force and serious phaselag. Two rotor windings are proposed, which can been seen as 4-pole winding only. Secondary resistances are calculated and compared with measured values. These values are sHghtly high if rotor-bars are the same diameters. The phase-lags of two proposed rotors are found to be significantly smaller than those of the conventional squirrel cage rotor. Successful high speed operations are realized.
BibTeX:
@inproceedings{ISMB5_54,
  author = {A. Chiba and R. Miyatake and S. Hara and T. Fukao },
  title = {Transfer Characteristics of Radial Force of Induction-type Bearingless Motors with Four-Pole Rotor Circuits },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_54.pdf}
}
1996 Chiba, A., Onoya, S., Kikuchi, T., Ooshima, M., Miyazawa, S., Nakamura, F. and Fukao, T. An Analysis of a Prototype Permanent-Magnet Bearingless Motor using Finite Element Method  Proceedings of ISMB5  
Abstract: An analysis is done for a prototype permanent magnet bearingless motor. A Finite Element Method program is employed to see the influence of demagnetization of permanent magnets. Several critical parts of rotor magnets are made clear for both torque and radial force generations. It is found that tile most serious demagnetization occurs at the permanent magnet located at an edge of rotor poles. At this point, torque and radial force currents are the maximum. Moreover, it is shown that the serious condition occurs when the direction of the radial force flux is oriented so that negative mmf is imposed to the permanent magnet at the pole edge. The location of a critical permanent magnet and current conditions are made clear.
BibTeX:
@inproceedings{ISMB5_59,
  author = {A. Chiba and S. Onoya and T. Kikuchi and M. Ooshima and S. Miyazawa and F. Nakamura and T. Fukao},
  title = {An Analysis of a Prototype Permanent-Magnet Bearingless Motor using Finite Element Method },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_59.pdf}
}
1998 Chiba, A., Yoshida, K. and Fukao, T. Honor Paper: Transient Response of Revolving Magnetic Field in Induction Type Bearingless Motors with Secondary Resistance Variations Proceedings of ISMB6  
Abstract: Optimal parameter selection in a field oriented control method for induction type bearingless motors is proposed to realize stable magnetic suspension. It is experimentally shown that the magnetic suspension is stable with a slight increase in a reference value of a secondary resistance. With the proper value in the secondary resistance reference, a phase angle of generated revolving magnetic field can be adjusted. There is an optimal reference value in the secondary resistance, which realizes the exact correspondence between the controller flux reference and generated revolving magnetic field. It is shown that a flux waveform, obtained from a search coil wound around a stator tooth, is corresponding to the direction of flux reference if operated with the optimal value. It is also shown that successful magnetic suspension without coupling in two orthogonal radial axes can be realized with the optimal reference value.
BibTeX:
@inproceedings{ISMB6_44,
  author = {A. Chiba and K. Yoshida and T. Fukao},
  title = {Honor Paper: Transient Response of Revolving Magnetic Field in Induction Type Bearingless Motors with Secondary Resistance Variations},
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_44.pdf}
}
2010 Chinan, P., Hijikata, W. and Shinshi, T. Fault-Tolerance for a Centrifugal Blood Pump using a Two-DOF Controlled Magnetic Bearing Proceedings of ISMB12  
Abstract: In our laboratory, an implantable centrifugal blood pump (CBP) with a two degrees-of-freedom controlled magnetic bearing (MB) to support the impeller without contact has been developed to assist the pumping function of a weakened heart ventricle. In order to maintain the function of the CBP after damage to the electromagnets (EMs) of the MB, fault-tolerant strategies for the CBP are proposed in this study. Using a redundant design of the MB, the magnetic levitation of the impeller was maintained with damage to up to two out of a total four EMs of the MB. Furthermore, with damage to three EMs, contact-free support of the impeller was also achieved by using hydrodynamic and electromagnetic forces.
BibTeX:
@inproceedings{ISMB12_82,
  author = {Pai Chinan and Wataru Hijikata and Tadahiko Shinshi},
  title = {Fault-Tolerance for a Centrifugal Blood Pump using a Two-DOF Controlled Magnetic Bearing },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_82.pdf}
}
1996 Chinta, M., Palazzolo, A. and Kascak, A. Quasiperiodic Vibration of a Rotor in a Magnetic Bearing with Geometric Coupling  Proceedings of ISMB5  
Abstract: This paper develops a one-dimensional model of the magnetic flux to estimate the magnetic forces by including the pole face curvature. Accounting for the pole face curvature results in a normal force that is perpendicular to the principal force; this causes geometric coupling of forces. The non-dimensional equa- tions of motion are derived for a point mass rotor in one magnetic bearing with P D current feedback and geometric coupling. The steady-state nonlinear vibrations are then investigated. The rotor-bearing system has the softening spring type nonlinearity and exhibits characteristic jumps and hysteresis. When speed is increased, the presence of geometric coupling increases the rotor displacement be- f ore the jump and decreases the displacement beyond the jump. Geometric coupling also causes quasiperiodic vi- bration of the rotor. The (a)periodicity of the rotor mo- tion is discussed using Poincare maps and bifurcation di- agrams. Increasing the differential gain of the controller could not damp the quasiperiodic motion to a periodic one .
BibTeX:
@inproceedings{ISMB5_26,
  author = {M. Chinta and A. Palazzolo and A. Kascak },
  title = {Quasiperiodic Vibration of a Rotor in a Magnetic Bearing with Geometric Coupling },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_26.pdf}
}
2002 Choi, B., Johnson, D., Morrison, C. and Mehmed, O. A Comparison Study Of Magnetic Bearing Controllers For A Fully Suspended Dynamic Spin Rig Proceedings of ISMB8  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB8_100,
  author = {Benjamin Choi and Dexter Johnson and Carlos Morrison and Oral Mehmed},
  title = {A Comparison Study Of Magnetic Bearing Controllers For A Fully Suspended Dynamic Spin Rig},
  booktitle = {Proceedings of ISMB8},
  year = {2002},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb8/ismb8_submission_100.pdf}
}
1991 Chong, P., Commandeur, C., Davis, H. and Whitehead, L. Large-Gab Magnetic Positioning System Having Advantageous Configuration Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_52,
  author = {Paul Chong and Colin Commandeur and Harold Davis and Lorne Whitehead},
  title = {Large-Gab Magnetic Positioning System Having Advantageous Configuration},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_52.pdf}
}
1998 Closs, M., Buhler, P. and Schweitzer, G. Miniature Active Magnetic Bearing for Very High Rotational Speeds Proceedings of ISMB6  
Abstract: For certain special applications, very high rotational speeds may be necessary (Beams, 1937). As a feasibility study, a small experimental system, with a rotor of 5 mm diameter and 38.8 mm in length, was built to operate at I'GOO'OOO r.p.m.. The bearing system and the inductance drive are presented.
BibTeX:
@inproceedings{ISMB6_7,
  author = {M. Closs and P. Buhler and G. Schweitzer},
  title = {Miniature Active Magnetic Bearing for Very High Rotational Speeds},
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_7.pdf}
}
2014 Cole, M., Jimenez, S. and Keogh, P. Feedback Control of a Magnetic Bearing Using Fusion of Rotor Acceleration and Position Measurements Proceedings of ISMB14  
Abstract: This paper considers controlling a magnetic bearing using combined feedback of rotor acceleration and position measurements. A controller design based on sensor fusion via complementary filtering is described. The control method can maintain stability while allowing the cross-over frequency for the acceleration and position feedback loops to be set arbitrarily. In this way, position measurements can be utilized primarily for disturbance cancellation over a low frequency band while acceleration feedback maintains bearing stability and disturbance rejection over a higher frequency band. The approach has the advantage that it gives enhanced robustness to poor quality position measurements. For flexible rotors, stabilization with large axial separation of position sensors and bearing locations can be easily achieved by utilizing collocated rotor-embedded accelerometers. The approach also offers improved robustness to measurement noise, position sensor run-out error and other forms of physical contamination or damage. Through analysis and simulation, important physical effects on vibration control performance are identified and further considered within the design methodology.
BibTeX:
@inproceedings{ISMB14_86,
  author = {Matthew Cole and Samuel Jimenez and Patrick Keogh},
  title = {Feedback Control of a Magnetic Bearing Using Fusion of Rotor Acceleration and Position Measurements},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_86.pdf}
}
2000 Cole, M., Keogh, P. and Burrows, C. Tuneable H-Inf. Vibration Control in Rotor/Magnetic Bearing Systems Using Parameter Dependent Shaping Functions Proceedings of ISMB7  
Abstract: In this paper, a method is presented for the derivation of tuneable multivariable controllers for application to a magnetic bearing/rotor system. Controller design specifications are considered that use H¥ optimisation criteria with linear parameter dependent shaping functions. Linear matrix inequality (LMI) techniques are used to synthesise controllers that satisfy the H¥ design specification over the range of parameter values using a convex interpolation of vertex controllers. In this way the design parameters that determine the shaping functions can be adjusted on-line to tune the performance and robustness characteristics of the controller. Specific performance measures that are considered are those of rotor synchronous vibration levels, transmitted force levels, base motion rejection, as well as controller stability margins. The effectiveness of such an approach for the synthesis of tuneable H¥ controllers for a rotor/magnetic bearing system is evaluated.
BibTeX:
@inproceedings{ISMB7_46,
  author = {Matthew Cole and Patrick Keogh and Clifford Burrows},
  title = {Tuneable H-Inf. Vibration Control in Rotor/Magnetic Bearing Systems Using Parameter Dependent Shaping Functions},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_46.pdf}
}
2008 Cole, M.O.T. Model-Free Control Methods for Recovery from Touchdowns Involving Circular Whirl Proceedings of ISMB11  
Abstract: In this paper, the dynamics associated with rotor-stator touchdowns involving full circular rub are considered. The expected range of phase shifts occurring in various measurable signals are examined from a theoretical standpoint, with the aim of developing model-free control algorithms that can recover contact-free rotor levitation from a state involving persistent rub with touchdown bearings. Two different strategies are proposed, according to whether touchdowns planes can be considered collocated with the AMBs or not. Requirements for successful operation, in terms of available sub-models and measurement information, as well as possible deficiencies are explained and verified through experimental tests on a multi-mode flexible rotor test rig.
BibTeX:
@inproceedings{ISMB11_8,
  author = {Matthew O. T. Cole},
  title = {Model-Free Control Methods for Recovery from Touchdowns Involving Circular Whirl},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_8.pdf}
}
2016 Cole, M.O.T. and Chamroon, C. H-infinity controller design for active magnetic bearing systems considering nonlinear vibrational rotordynamics Proceedings of ISMB15  
Abstract: This paper deals with optimal controller design for active magnetic bearing (AMB) systems for which nonlinear rotordynamic behavior is evident, and so vibration predicted by operating point linearization differs substantially to that which actually occurs. Nonlinear H-infinity control theory is applied with a rotordynamic model involving nonlinear stiffness and/or damping terms. The associated Hamilton-Jacobi-Isaacs (HJI) equation is formulated and solved to obtain a state feedback control law achieving specified vibration attenuation performance in terms of the peak L 2 gain of the nonlinear system. The method is applied in case study to a flexible rotor/AMB system that exhibits nonlinear stiffness properties owing to rotor interaction with a clearance bearing. Simulations are performed to quantify RMS vibration due to harmonic disturbances and the results compared with the norm-bound values embedded in the HJI equations. A feedback controller design method is then presented that is similar in approach to the standard loop-shaping/mixed-sensitivity methods used for linear systems, and involves augmenting the system model with weighting transfer functions. Experiments are undertaken to compare controller performance for design based on nonlinear and linearized models. The results highlight the shortcomings of applying linear optimal control methods with rotor systems exhibiting nonlinear stiffness properties as large amplitude vibration and loss of rotordynamic stability can occur. Application of the described nonlinear H-infinity control method is shown to overcome these problems, albeit at the expense of vibration attenuation performance for operation in linear regimes.
BibTeX:
@inproceedings{ISMB15_45,
  author = {Matthew O. T. Cole and Chakkapong Chamroon},
  title = {H-infinity controller design for active magnetic bearing systems considering nonlinear vibrational rotordynamics},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_45.pdf}
}
2002 Cole, M.O.T., Keogh, P.S. and Burrows, C.R. Predictions On The Dynamic Behaviour Of A Rolling Element Auxiliary Bearing For Rotor/Amb Systems Proceedings of ISMB8  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB8_50,
  author = {Matthew O. T. Cole and Patrick S. Keogh and Clifford R. Burrows},
  title = {Predictions On The Dynamic Behaviour Of A Rolling Element Auxiliary Bearing For Rotor/Amb Systems},
  booktitle = {Proceedings of ISMB8},
  year = {2002},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb8/ismb8_submission_50.pdf}
}
1999 Cole, M.O.T., Keogh, P.S. and Burrows, C.R. Neural Network Based Fault Detection for Fault Tolerant Control of Systems with Multiple Magnetic Actuators and Sensors Proceedings of ISMST5  
Abstract: There is considerable interest in the improvement of fault tolerance in the design of active position and vibration control systems. In the creation of many magnetic actuator position or vibration control systems there exists potential for the inclusion of redundancy in the number of actuators and sensors used for control. This redundancy can provide improved tolerance to actuator or sensor related faults if, when a fault occurs, control of the system can be rapidly reconfigured to bypass control from a faulty component to the remaining healthy ones. To do this requires a system for the detection and identification of faults as and when they occur. The performance of modern computerised control hardware is now sufficient to allow such a system to run in real-time, in parallel to any digital control algorithm. In this paper the development of a method for the detection and isolation of faults relating to control sensors and actuators is presented as a basis for the implementation of a fault tolerant control scheme. The method is based on the use of a neural network, operating in real time, for the detection of signal errors occurring in the plant inputs or outputs. The neural network is trained off-line using identification data taken from the plant and therefore does not require an accurate model of the plant dynamics. Results are presented for the application of this method to an active magnetic beating/rotor system, both in simulation and experiment. The issues of sensitivity to faults, speed of response and the effect of external disturbances on the reliability of the fault detection system are investigated and discussed. It is demonstrated that, through the implementation of a reconfigurable control scheme with a fault detection system, improved tolerance to sensor and actuator related faults can be achieved.
BibTeX:
@inproceedings{ISMST5_52,
  author = {Matthew O. T. Cole and Patrick S. Keogh and Clifford R. Burrows},
  title = {Neural Network Based Fault Detection for Fault Tolerant Control of Systems with Multiple Magnetic Actuators and Sensors},
  booktitle = {Proceedings of ISMST5},
  year = {1999},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst5/ismst5_submission_52.pdf}
}
1998 Cole, M.O.T., Keogh, P.S. and Burrows, C.R. Control and Nonlinear Compensation of a Rotor/Magnetic Bearing System Subject to Base Motion Proceedings of ISMB6  
Abstract: In this paper a study is undertaken which compares the suitability of controllers for a magnetic bearing/rotor system in which motion of the system base can occur. It is demonstrated that controllers which have been selected for directly forced vibration control without consideration of this type of disturbance may give unacceptably poor performance when motion of the base occurs. A method is outlined for designing controllers to give optimal performance for combined base motion and direct rotor forcing disturbances. Controllers were implemented on a flexible rotor/magnetic bearing rig, the base of which was subjected to impulse inputs. The results obtained indicate that motion of the system base, when of sufficient magnitude, can drive the system into a state where magnetic bearing control force saturation occurs. To obtain improved performance a method of on-line compensation was used to linearise the control force characteristics. The results presented in this paper provide a foundation for the controller design of flexible rotor/magnetic bearing systems in applications that induce base motion. These would include transport environments, situations where the system is part of a larger vibratory structure, or in cases where seismic events can occur.
BibTeX:
@inproceedings{ISMB6_59,
  author = {M. O. T. Cole and P. S. Keogh and C. R. Burrows},
  title = {Control and Nonlinear Compensation of a Rotor/Magnetic Bearing System Subject to Base Motion},
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_59.pdf}
}
2014 Collins, T., Masala, A., Shultz, R. and Guo, Z. Numerical and Experimental Results of Auxiliary Bearings Testing on a High Speed Test Rig Proceedings of ISMB14  
Abstract: A test stand including a rotor and active magnetic bearing system, located at Waukesha Magnetic Bearing premises was utilized in 2013 to validate a new auxiliary bearing design. This paper provides an overview of the preparatory activities and an insight on the numerical and experimental results obtained during the testing campaign.
BibTeX:
@inproceedings{ISMB14_98,
  author = {Tim Collins and Andrea Masala and Richard Shultz and Zenglin Guo},
  title = {Numerical and Experimental Results of Auxiliary Bearings Testing on a High Speed Test Rig},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_98.pdf}
}
1991 Cope, D.B. and Fontana, R.R. Attractive and Repulsive Magnetic Suspension Systems Overview Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_43,
  author = {David B. Cope and Richard R. Fontana},
  title = {Attractive and Repulsive Magnetic Suspension Systems Overview},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_43.pdf}
}
2010 da Costa, E.A., Chabu, I.E. and da Cruz, J.J. Active Magnetic Bearing for Tubular Linear Induction Motor Applied to Onshore Oil Exploitation Proceedings of ISMB12  
Abstract: A tubular linear induction motor applied to onshore oil exploitation was proposed recently. Its purpose is to directly drive the sucker-rod pump installed in the down hole of the oil well. In continuing the research an active magnetic bearing (AMB) was developed and applied to the motor in substitution to the existing mechanical bearing. Instead of the usual eight-pole AMB, a different concept is adopted where a DC-excited primitive bearingless machine is used as a magnetic bearing. The magnetic bearing levitation control is executed by a digital controller using an AD/DA converter and a control algorithm implemented in FPGA hardware. A linear model is written to describe its dynamics. In this work the AMB system is studied with particular emphasis to the experimental results obtained with the prototype in operation. Tests performed on this prototype show that the AMB can be an interesting alternative to be considered in this context.
BibTeX:
@inproceedings{ISMB12_97,
  author = {Eduardo Alves da Costa and Ivan Eduardo Chabu and Jose Jaime da Cruz},
  title = {Active Magnetic Bearing for Tubular Linear Induction Motor Applied to Onshore Oil Exploitation },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_97.pdf}
}
2008 da Costa, E.A., Chabu, I.E. and da Cruz, J.J. Application of Active Magnetic Bearing for Tubular Linear Induction Motor in Oil Pumping Proceedings of ISMB11  
Abstract: An active magnetic bearing (AMB) to support the shaft of a tubular linear induction motor (TLIM) applied to oil pumping is proposed. Instead of the usual eight-pole AMB, a different concept is adopted where a DC-excited primitive bearingless machine is used as a magnetic bearing. The AMB is a 3-phase one for which a lower number of wires connections and power devices are among its advantages. This paper focuses on the design of the AMB system. A finite element analysis of the flux density and of the relationship between the radial force and the suspension winding current are explored. The magnetic system is modeled and simulation is performed to tune the controller parameters.
BibTeX:
@inproceedings{ISMB11_34,
  author = {Eduardo Alves da Costa and Ivan Eduardo Chabu and Jose Jaime da Cruz},
  title = {Application of Active Magnetic Bearing for Tubular Linear Induction Motor in Oil Pumping},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_34.pdf}
}
1993 Cox, D.E. and Groom, N.J. Implementation of a Decoupled Controller for a Magnetic Suspension System Using Electromagnets Mounted in a Planar Array Proceedings of ISMST2  
Abstract: An implementation of a decoupled, single-input/single-output control approach for the Large Angle Magnetic Suspension Test Fixture is described. Numerical and experimental results are presented. The experimental system is a laboratory model large gap magnetic suspension system which provides five degree-of-freedom control of a cylindrical suspended element. The suspended element contains a core composed of permanent magnet material and is levitated above five electromagnets mounted in a planar array.
BibTeX:
@inproceedings{ISMST2_17,
  author = {D. E. Cox and N. J. Groom},
  title = {Implementation of a Decoupled Controller for a Magnetic Suspension System Using Electromagnets Mounted in a Planar Array},
  booktitle = {Proceedings of ISMST2},
  year = {1993},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst2/ismst2_submission_17.pdf}
}
1995 Cox, D.E., Groom, N.J., Hsiao, M.-H. and Huang, J.-K. Modeling and Identification of a Large Gap Magnetic Suspension System Proceedings of ISMST3  
Abstract: This paper presents the results of modeling and system identification efforts on the NASA Large-Angle Magnetic Suspension Test Fixture (LAMSTF). The LAMSTF consists of a cylindrical permanent magnet which is levitated above a planar array of five electromagnets mounted in a circular configuration. The analytical model is first developed and open-loop characteristics are described. The system is shown to be highly unstable and requires feedback control in order to apply system identification. Limitations on modeling accuracy due to the effect of eddy-currents on the system are discussed. An algorithm is derived to identify a state-space model for the system from input/output data acquired during closed-loop operation. The algorithm is tested on both the baseline system and a perturbed system which has an increased presence of eddy currents. It is found that for the baseline system the analytic model adequately captures the dynamics, although the identified model improves the simulation accuracy. For the system perturbed by additional unmodeled eddy-currents the analytic model is no longer adequate and a higher-order model, determined through system identification, is required to accurately predict the system's time response.
BibTeX:
@inproceedings{ISMST3_30,
  author = {David E. Cox and Nelson J. Groom and Min-Hung Hsiao and Jen-Kuang Huang},
  title = {Modeling and Identification of a Large Gap Magnetic Suspension System},
  booktitle = {Proceedings of ISMST3},
  year = {1995},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst3/ismst3_submission_30.pdf}
}
2016 Cui, Q., Impinna, F., Detoni, J.G., Amati, N., Tonoli, A. and Bleuler, H. Dynamic Characterization of Electrodynamic Bearings Combined with Active Magnetic Dampers Proceedings of ISMB15  
Abstract: Electrodynamic Bearings (EDBs) are a kind of passive magnetic bearings that exploits the interaction between the eddy currents in a rotating conductor and the stationary magnetic field to provide restoring forces. They have been regarded as an appealing alternative to Active Magnetic Bearings (AMBs), having the possibility to obtain stable levitation using standard conductive materials at room temperature without introducing negative stiffness in any direction. Compared to AMBs, EDBs present advantages such as lower cost, higher reliability due to simplicity of configurations. However, applications of EDBs are still limited due to instability issues. The rotating damping force arising in EDBs causes unstable behavior of the rotor, which requires a stabilizing solution. A hybrid solution is presented in the present paper, where Active Magnetic Dampers (AMDs) are applied to provide non-rotating damping to the rotor supported by EDBs to obtain stable operation. This solution is designed to exploit the high reliability of EDBs, overcoming the stability problem by means of controllable AMDs. Rather than using active electromagnetic actuators to provide stiffness (like in standard AMBs), the AMBs here are used as dampers only (thus called AMDs), resulting in downsized and more efficient AMBs. The effect of the EDB−AMD system has been studied both analytically and experimentally. A dedicated test rig has been built to validate the analytical model and to characterize the system. Dynamic characterization of the system is presented, demonstrating the effectiveness of this solution and dynamics of the system.
BibTeX:
@inproceedings{ISMB15_94,
  author = {Qingwen Cui and Fabrizio Impinna and Joaquim Girardello Detoni and Nicola Amati and Andrea Tonoli and Hannes Bleuler},
  title = {Dynamic Characterization of Electrodynamic Bearings Combined with Active Magnetic Dampers},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_94.pdf}
}
2016 Cui, Q., Napoli, M.D., Detoni, J. and Amati, N. A Systematic Approach for Modeling and Identification of Eddy Current Dampers in Rotordynamic Applications Proceedings of ISMB15  
Abstract: Eddy current dampers (ECDs) exploit Lorentz forces due to the induced eddy currents in a conductor subject to a time–varying magnetic field. ECDs can be used to introduce damping in rotordynamic applications without mechanical contact to the rotor, thus introducing negligible impact on the dynamic response of the whole system. They are suitable for applications where contactless support of a rotor is required, thus being a perfect match for passive magnetic bearings such as permanent magnet bearings and superconducting bearings. However, modeling and identification of the amount of damping induced by ECDs is a difficult task due to complicated geometry and working conditions. A novel and systematic approach for modeling and identification of the damping characteristics of ECDs in rotordynamic applications is proposed in the present paper. The proposed approach employs an analytical dynamic model of the ECD and curve fitting with results of finite element (FE) models to obtain the parameters characterizing the ECD’s mechanical impedance. The damping coefficient can be obtained with great accuracy from a single FE simulation in quasi-static conditions. Finally, the accuracy of the identification approach is verified by comparing the results with experimental tests. The validity of this approach is in the cases where ECDs employ an axisymmetric conductor, thus covering most cases in rotordynamic applications.
BibTeX:
@inproceedings{ISMB15_106,
  author = {Qingwen Cui and Maria Di Napoli and Joaquim Detoni and Nicola Amati},
  title = {A Systematic Approach for Modeling and Identification of Eddy Current Dampers in Rotordynamic Applications},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_106.pdf}
}
2014 Cui, Q., Sandtner, J. and Bleuler, H. Whirl Imposer --- Proposal for a Novel Passive Magnetic Rotor Bearing System Proceedings of ISMB14  
Abstract: Passive magnetic bearing systems are enticing in applications where low stiffness is acceptable, but where cost, life-time, power consumption and reliability are critical. This article investigates a new proposal for stabilization of permanent magnet (i.e. passive) bearing systems based on rotor precession. There will be a minimal and a maximal rotational speed for stable contact-free levitation. The feasibility of this new stabilization scheme is investigated with the help of realistic numerical data, a demonstration system is currently in planning.
BibTeX:
@inproceedings{ISMB14_97,
  author = {Qingwen Cui and Jan Sandtner and Hannes Bleuler},
  title = {Whirl Imposer --- Proposal for a Novel Passive Magnetic Rotor Bearing System},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_97.pdf}
}
2018 Cui, Q., Tonoli, A., Amati, N., Bonfitto, A. and Molina, L.M.C. Damping Strategies on a Horizontal Rotor Supported by Electrodynamic Bearings Proceedings of ISMB16  
Abstract: Electrodynamic Bearings (EDBs) exploit Lorentz type of magnetic force due to the eddy currents induced in a rotating conductor, which has relative motion in a magnetic field, to levitate the rotor. The character of passive levitation without negative stiffness that can be realized using permanent magnets in room temperature with relatively simple configuration makes EDBs an appealing alternative to Active Magnetic Bearings (AMBs). However, the instability of rotors supported by EDBs is the key issue that prevents the application of EDBs. In this paper, the damping strategies for EDB systems are investigated using additional AMBs implemented. The hybrid bearing system has been built to stabilize EDB system using damping from AMBs which work as Active Magnetic Dampers (AMDs). It can be further exploited to investigate the damping strategies with active control of the AMBs. The results are presented in this paper showing different possible solutions of EDB stabilization.
BibTeX:
@inproceedings{ISMB16_076,
  author = {Qingwen Cui and Andrea Tonoli and Nicola Amati and Angelo Bonfitto and Luis Miguel Castellanos Molina},
  title = {Damping Strategies on a Horizontal Rotor Supported by Electrodynamic Bearings},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_076.pdf}
}
1992 Cui, W. and Nomami, K. H Control of Flexible Rotor-Magnetic Bearing Systems Proceedings of ISMB3  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB3_48,
  author = {W.M. Cui and K. Nomami },
  title = {H Control of Flexible Rotor-Magnetic Bearing Systems },
  booktitle = {Proceedings of ISMB3},
  year = {1992},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb3/ismb3_submission_48.pdf}
}
1990 Darling, J. and Burrows, C. The Control of Propeller-induced Vibrations in Ship Transmission Shafts  Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_24,
  author = {J. Darling and C.R. Burrows },
  title = {The Control of Propeller-induced Vibrations in Ship Transmission Shafts },
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_24.pdf}
}
1999 Dauwalter, C.R. Design of a Magnetically Suspended Wheel for a Miniature Gyro Made Using Planar Fabrication Technologies Proceedings of ISMST5  
Abstract: The technical feasibility of a magnetically suspended rotating wheel for miniature gyro and other applications, which was first investigated under a NASA SBIR contract, was assessed in much greater detail under a BMDO SBIR administered by DTRA. The configuration is amenable to economical and highly reproducible batch fabrication using the rapidly emerging planar fabrication technologies. The actuator for the wheel magnetic suspension was optimized for improved performance by exploring the design space through over 600 configuration variations using a finite difference magnetic circuit analysis technique implemented in a spreadsheet environment. Normal and tangential magnetic force components of circumferentially slotted rotors and stators were determined over a range of air gaps, slot width to tooth width ratios, slot depth to tooth pitch ratios and tangential displacements.
BibTeX:
@inproceedings{ISMST5_22,
  author = {Charles R. Dauwalter},
  title = {Design of a Magnetically Suspended Wheel for a Miniature Gyro Made Using Planar Fabrication Technologies},
  booktitle = {Proceedings of ISMST5},
  year = {1999},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst5/ismst5_submission_22.pdf}
}
1995 Dauwalter, C.R. A Magnetically Suspended Wheel for a Miniature Gyro Made Using Planar Fabrication Technologies Proceedings of ISMST3  
Abstract: The technical feasibility of a magnetically suspended rotating wheel for miniature gyro applications was investigated under a NASA SBIR contract. A concept for a configuration for a system of compact, lightweight magnetic actuators capable of generating the necessary suspension forces and fabrication using millimachining planar fabrication technologies was developed. Both capacitive and electromagnetic position sensing concepts were developed for implementing a closed loop control system for supporting the wheel. A finite difference technique, implemented in a spreadsheet environment, for analyzing the force characteristics of the actuator was used and the results verified with Finite Element Analysis.
BibTeX:
@inproceedings{ISMST3_52,
  author = {Charles R. Dauwalter},
  title = {A Magnetically Suspended Wheel for a Miniature Gyro Made Using Planar Fabrication Technologies},
  booktitle = {Proceedings of ISMST3},
  year = {1995},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst3/ismst3_submission_52.pdf}
}
1999 Davey, K. Prediction of Lift and Drag Forces in an EDS Maglev System Proceedings of ISMST5  
Abstract: This document examines the tradeoffs of choosing a null flux excitation system versus a simple coil excitation. In both cases the guideway is considered to be a simple "O" shaped coil positioned vertically on the track. An analysis of both shows that the null flux excitation provides equivalent lift to the open coil system with less drag; further the lift is stabilizing in both directions for the null flux excitation. The full rectangular excitation coil proves to be excellent for guidance especially if the vehicle magnets/coils on either side are arranged in repulsion. The rectangular coils in attraction prove to be expensive for drag production and unable to produce downward restoring forces.
BibTeX:
@inproceedings{ISMST5_36,
  author = {Kent Davey},
  title = {Prediction of Lift and Drag Forces in an EDS Maglev System},
  booktitle = {Proceedings of ISMST5},
  year = {1999},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst5/ismst5_submission_36.pdf}
}
1995 Davey, K.R. Design Optimization for a Maglev System Employing Flux Eliminating Coils Proceedings of ISMST3  
Abstract: Flux eliminating coils have received no little attention over the past thirty years as an alternative for realizing lift in a MAGLEV system. When the magnets on board the vehicle are displaced fiom the equilibrium or null flux point of these coils, they induce current in those coils which act to restore the coil to its null flux or centerline position. The question being addressed in this paper is that of how to choose the best coil for a given system. What appears at first glance to be an innocent question is in fact one that is actually quite involved, encompassing both the global economics and physics of the system. The real key in analyzing that question is to derive an optimization index or hnctional which represents the cost of the system subject to constraints, the primary constraint being that the vehicle lift itself at a certain threshold speed. Outlined in this paper is one scenario for realizing a total system design which uses sequential quadratic programming techniques.
BibTeX:
@inproceedings{ISMST3_8,
  author = {Kent R. Davey},
  title = {Design Optimization for a Maglev System Employing Flux Eliminating Coils},
  booktitle = {Proceedings of ISMST3},
  year = {1995},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst3/ismst3_submission_8.pdf}
}
2014 David, D., Santisteban, J. and Gomes, A.C.D.N. Interconnected Four Poles Magnetic Bearings Simulations and Testing Proceedings of ISMB14  
Abstract: This article proposes and analyses a new idea to be used in magnetic bearings. It is an adaptation of a structure that has already worked successfully in split-winding self-bearing motors. Preliminary theoretical results predict that a greater equivalent stiffness could be achieved when compared with the values associated with the traditional active magnetic bearing conception in the literature.
BibTeX:
@inproceedings{ISMB14_47,
  author = {Domingos David and Jose Santisteban and Afonso Celso Del Nero Gomes},
  title = {Interconnected Four Poles Magnetic Bearings Simulations and Testing},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_47.pdf}
}
2013 David, D., Santisteban, J. and Gomes, A.D.N. Interconnected Four Poles Magnetic Bearing Proceedings of BWMB2013  
Abstract: This article analyses the adaptation of the split-wind bearingless motors structure for magnetic bearings. Preliminary theoretical results predict that a greater equivalent stiffness could be achieved when compared to the values associated with the active magnetic bearing conception traditionally described in the literature.
BibTeX:
@inproceedings{BWMB2013_36,
  author = {D.F.B. David and J.A. Santisteban and A.C. Del Nero Gomes},
  title = {Interconnected Four Poles Magnetic Bearing},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {https://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_36.pdf}
}
2017 David, D.F.B., Santisteban, J.A. and Gomes, A.C.D.N. Modeling and Discussing an Interconnected Flux Magnetic Bearing ACES Journal 2017 vol 3 no 8 - Courtesy of ACES  
Abstract: An alternative idea for the construction of active magnetic bearings, adapted from a successful structure used in split-winding self-bearing motors, has been recently discussed in the literature. A mathematical model for this bearing configuration is developed in this paper. Preliminary theoretical results predict a greater equivalent stiffness for this model, when compared with traditional active magnetic bearings. The use of recently built prototypes for testing if these expectations hold true is also discussed.
BibTeX:
@inproceedings{aces2017vol3no8_008,
  author = {D. F. B. David and J. A. Santisteban and A. C. Del Nero Gomes},
  title = {Modeling and Discussing an Interconnected Flux Magnetic Bearing},
  booktitle = {ACES Journal 2017 vol 3 no 8 - Courtesy of ACES},
  year = {2017},
  url = {https://www.magneticbearings.org/wp-content/publications/aces2017vol3no8/aces2017vol3no8_008.pdf}
}
2016 David, D.F.B., Santisteban, J.A. and Gomes, A.C.D.N. Laboratory Tests on an Interconnected Four Poles Magnetic Bearing Proceedings of ISMB15  
Abstract: A new structure for active magnetic bearings, based on a successfull idea used in self-bearing motors, has been recently discussed in the literature. A flux interconnection characterizes this idea, and theoretical results predict some advantages of this new model, when compared with the traditional one, with independent flux paths. As an example, a greater equivalent stiffness is expected for this new type of bearing. Two recently built prototypes were used to check whether these expectations really hold true. The main goal of this paper is to present and discuss the prototype details.
BibTeX:
@inproceedings{ISMB15_39,
  author = {Domingos F. B. David and Jose A. Santisteban and Afonso Celso D. N. Gomes},
  title = {Laboratory Tests on an Interconnected Four Poles Magnetic Bearing},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_39.pdf}
}
2012 Deckert, A. Thermal-electromechanical Modeling of Magnetically Levitated Rotors under Vacuum Conditions Proceedings of ISMB13  
Abstract: This paper introduces a possibility to couple the thermal analyses of a magnetically levitated rotor, which is driven under vacuum condition, with models of its electromechanical loop. By means of this coupling, effects can be represented that are not visible when considering the ther-mal behavior and the electromechanical loop separately. The models have been parameterized for a huge number of geometrical and physical properties. The derived algorithms are implemented in MATLAB and accessible via the graphical user interface “MagBeS – Magnetic Bearing Sim-ulator�. This makes the algorithm applicable for different users and varying systems. Analyses are presented that demonstrate the interaction of the thermal and electromechanical behavior and it is shown that additional potentially critical operating modes can be identified. Furthermore, a novel approach for the experimental determination of the occurring rotor losses by means of temperature measurements and thermal analyses is presented.
BibTeX:
@inproceedings{ISMB13_43,
  author = {Antje Deckert},
  title = {Thermal-electromechanical Modeling of Magnetically Levitated Rotors under Vacuum Conditions},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_43.pdf}
}
2010 Deckert, A., Keller, U. and Fasoulas, S. MagBeS-Magnetic Bearing Simulator for Analyzing and Designing Magnetically Levitated Rotors Proceedings of ISMB12  
Abstract: MagBeS is aMatlab based Graphical User Interface that can be used to analyze or design magnetically levitated rotors using a parametric multiphysical algorithm. The paper includes a description of the computation algorithm and shows simulation results for analyzing magnetic bearings using MagBeS, with a focus on the capability of this tool.
BibTeX:
@inproceedings{ISMB12_15,
  author = {Antje Deckert and Uwe Keller and Stefanos Fasoulas},
  title = {MagBeS-Magnetic Bearing Simulator for Analyzing and Designing Magnetically Levitated Rotors },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_15.pdf}
}
2014 Defoy, B., Alban, T. and Mahfoud, J. Energy Cost Assessment of the Active Control of a the Flexible Rotor Supported by AMB Proceedings of ISMB14  
Abstract: From a designer point of view, optimizing the energy necessary for the control is an important element that could lead to downsize the control cabinet and to an increase of margins according to power amplifier capabilities. Also, reducing the energy used, generates a less significant environmental impact. Two fuzzy logic based controllers were developed and assessed. First, the “Mechanical” performances are compared with respect to an augmented PID controller. Then, the energy necessary for the control is compared.
BibTeX:
@inproceedings{ISMB14_4,
  author = {Benjamin Defoy and Thomas Alban and Jarir Mahfoud},
  title = {Energy Cost Assessment of the Active Control of a the Flexible Rotor Supported by AMB},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_4.pdf}
}
2012 Defoy, B., Alban, T. and Mahfoud, J. Numerical Assessment of a Polar Fuzzy Controller for Centrifugal Compressors Proceedings of ISMB13  
Abstract: The aim of this study was to develop and to apply a new control approach dedicated to turbomachinery. The controller is fuzzy based usinginputs expressed in polar coordinates. The advantage is that it manages two significant physical quantities, namely tangential and radial speeds that are related to steady state and transient behaviors respectively. A simple synchronous filter is associated to the controller in order to enhance the ratio command force / bearing dynamic capacity. The approach was previously applied experimentally with success for the control of an academic test rig. It is adapted here for the control of an industrial compressor whose flexible rotor is supported by Active Magnetic Bearings (AMB). At this stage, only numerical investigations are performed. The controller has to satisfy the standards and the end users requirements. In addition, it should be easy to implement. The behavior of the machine studied is assessed for several configurations of unbalances. Tests that correspond to usual industrial excitations (subsynchronous excitation, impulse response at nominal speed) are also carried out. Results obtained are satisfactory and give insight into the potential of the approach. In addition, and as the fuzzy controller parametersare independent from the rotor design, the approach is a first step for the standardization ofmagnetic bearing controller synthesis.
BibTeX:
@inproceedings{ISMB13_17,
  author = {Benjamin Defoy and Thomas Alban and Jarir Mahfoud},
  title = {Numerical Assessment of a Polar Fuzzy Controller for Centrifugal Compressors},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_17.pdf}
}
2016 Defoy, B., Lepine, X.D. and Broussard, L. Numerical and experimental assessment of a large industrial thrust bearing Proceedings of ISMB15  
Abstract: Nowadays, Active Magnetic Bearings (AMB) are widely utilized in different industrial applications. Several applications have been successfully implemented in the field of Turbomachinery especially for large centrifugal compressors. These machines are subjected to high axial transient loads due to process operations. Considered simpler than radial bearings, the thrust bearing optimization has been largely neglected. Consequently, the thrust bearing suffers from sizing difficulties that lead to bad overall system optimization. Thrust behavior exhibits several peculiarities mainly due to the specific arrangement of thrust actuator made with a solid disk instead of laminated sheets for radial bearings. The work presented here aims to improve the prediction of thrust dynamic in order to better size this component and ensure smooth operation of machinery. The paper describes the complete analysis of a 25kN thrust bearing. The study is divided in two sections, first the actuator analysis and then the dynamic behavior of the complete system. The thrust bearing electromagnetic design was developed with the aid of Finite Element Analysis (FEA). The thrust bearing performance calculations are disclosed in this paper and compared with those of an actuator characterization test bench. Later, the thrust actuator is mounted on a complete AMB experimental set-up, equipped with a 200 kg rotor on two radial magnetic bearings. The test rig is equipped with a contactless axial actuator that enables the excitation of the rotor with different axial force amplitudes and ramps. The first FEA and experimental results are used to feed a simplified model of the complete thrust bearing. The experimental results are compared with numerical ones. The different phenomena observed are discussed and the system limitations are highlighted. This study enables better understanding of the behavior of large thrust bearings. In addition, the work realized help to predict and optimize thrust bearing response for each machine.
BibTeX:
@inproceedings{ISMB15_13,
  author = {Benjamin Defoy and Xavier De Lepine and Lionel Broussard},
  title = {Numerical and experimental assessment of a large industrial thrust bearing},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_13.pdf}
}
1988 Dell, H., Engel, J., Faber, R. and Glass, D. Developments and Tests on Retainer Bearings for Large Active Magnetic Bearings Proceedings of ISMB1 - Courtesy of Springer-Verlag  
Abstract: Radial and axial active magnetic bearings due to their specific features and operating characteristics can meet technical requirements beyond the scope of conventional bearings. With these bearings rotating machines can be arranged encapsulated in the process medium without any risk of interaction with lubrication oil or stationary component parts during normal operation. They are thus predestined for use in gas-cooled high temperature reactors. This is true in particular because the demand of freedom from maintenance is met here in a way not reached in mechanical engineering before.
BibTeX:
@inproceedings{ISMB1_21,
  author = {H. Dell and J. Engel and R. Faber and D. Glass },
  title = {Developments and Tests on Retainer Bearings for Large Active Magnetic Bearings },
  booktitle = {Proceedings of ISMB1 - Courtesy of Springer-Verlag},
  year = {1988},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb1/ismb1_submission_21.pdf}
}
1994 Delprete, C., Genta, G. and Carabelli, S. Control Strategies for Decentralized Control of Active Magnetic Bearings Proceedings of ISMB4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB4_6,
  author = {C. Delprete and G. Genta and S. Carabelli},
  title = {Control Strategies for Decentralized Control of Active Magnetic Bearings },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_6.pdf}
}
1992 Delprete, C., Genta, G., Santini, L., Tonoli, T., Mazzocchetti, L., Rava, E., Ricca, A., Ripamonti, G., Varesi, E. and Zannella, S. High Speed Asynchronous Motor with Tc Superconducting Magnetic Bearings Proceedings of ISMB3  
Abstract: The discovery of High Tc Superconductors has renewed the interest for practical applications of superconductivity including devices based on magnetic levitation. To evaluate their potential use for near-frictionless high speed passive magnetic bearings, a prototype of an asynchronous motor with the rotor floating on two melt textured YBs^ Cuj 07.x suitably shaped blocks has been built and tested. The low radial stiffness of the bearings compels one to use non-conventional motor configurations, in order to avoid radial instability under load. In the present paper the design of the electric motor and the experimental testing of the superconducting bearings, in terms of levitation force versus rotor height and magnetic stiffness, are described. The characterization of the bearings allows one to perform a rotor-dynamics study of the whole machine, whose results are then validated experimentally. The bearing drag is evaluated through spin-down tests.
BibTeX:
@inproceedings{ISMB3_28,
  author = {C. Delprete and G. Genta and L. Santini and T. Tonoli and L. Mazzocchetti and E. Rava and A. Ricca and G. Ripamonti and E. Varesi and S. Zannella},
  title = {High Speed Asynchronous Motor with Tc Superconducting Magnetic Bearings},
  booktitle = {Proceedings of ISMB3},
  year = {1992},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb3/ismb3_submission_28.pdf}
}
1993 Delprete, C., Gentra, G. and Carabelli, S. Design, Construction and Testing of a Five Active Axes Magnetic Bearing System Proceedings of ISMST2  
Abstract: A high speed electric spindle based on active electromagnetic suspension technology has been designed, built and tested. The main goal of the research work was the construction of a highly modular unit which can be used both for teaching and research purposes. The design of the electromechanical components and of the control unit is described in detail, together with the characterization tests performed on the various subsystems. A description of the preliminary tests on the unit, conducted at speeds not in excess of the first defonnation critical speed of the rotor, concludes the work.
BibTeX:
@inproceedings{ISMST2_10,
  author = {C. Delprete and G. Gentra and S. Carabelli},
  title = {Design, Construction and Testing of a Five Active Axes Magnetic Bearing System},
  booktitle = {Proceedings of ISMST2},
  year = {1993},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst2/ismst2_submission_10.pdf}
}
2004 Deng, Z., Wang, X., Meng, X. and Yan, Y. An Independent Controller Of Radial Force Subsystem For Super-High-Speed Bearingless Induction Motors Proceedings of ISMB9  
Abstract: The bearingless machines which combine the magnetic bearing and motor, is a great progress in recent years of research field of the high speed electrical machinery. Among them the bearingless induction motor (BLIM) is quite paid attention to because of its capability of easily weakening flux and high reliability. The BLIM is a strong coupled complicated nonlinear system. For the high accuracy requirement for the real-time control of air gap flux linkages, the various decoupling control algorithms can not realize this motor operating at super high speed at present. In this paper, an independent control strategy of radial force subsystem is proposed to realize the super high speed operation of BLIM. The air gap flux linkages of motor windings and radial force windings which are required can be identified accurately by the method of simpler voltage-model, in which the two only motor parameters-stator resistance and stator leakage are estimated by LSE based on zero-sequence voltage equations simultaneously. The current regulated PWM inverter is replaced by the air gap flux linkages regulated PWM inverter to improve control precision of air gap flux linkages. In order to reduce time delay of control system, the control period of radial force subsystem can be shortened to a great extent through right resource distribution in digital control systems.
BibTeX:
@inproceedings{ISMB9_12,
  author = {Zhiquan Deng and Xiaolin Wang and Xiaoli Meng and Yangguang Yan},
  title = {An Independent Controller Of Radial Force Subsystem For Super-High-Speed Bearingless Induction Motors },
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_12.pdf}
}
2014 Denk, J., Koehler, B.-U., Siegl, G. and Siebke, P. Landing Tests with a 6300rpm, 9t AMB Rotor in Rolling Element Back-Up Bearings Proceedings of ISMB14  
Abstract: This article describes a systematic approach to qualify backup bearings for very large rotors levitated by active magnetic bearings (AMB). The approach comprises dynamic simulations of the landing events prior to the testing with good prediction quality as part of the safety concept. The approach was applied for the backup bearing qualification of a 9t rotor with a rotational speed up to 6420rpm. The results of the landing tests are shown and compared with the simulation results.
BibTeX:
@inproceedings{ISMB14_76,
  author = {Joachim Denk and Bert-Uwe Koehler and Guenther Siegl and Peter Siebke},
  title = {Landing Tests with a 6300rpm, 9t AMB Rotor in Rolling Element Back-Up Bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_76.pdf}
}
2012 Denk, J., Köpken, H.-G., Stoiber, D. and Viering, F. Active Magnetic Bearing Systems for Turbo Machine Applications based on Standard Drive Technology Proceedings of ISMB13  
Abstract: Around two decades ago, active magnetic bearings (AMB) were introduced into O&G-applications (Oil & Gas- applications), but never gained any relevant market share in large turbomachinery. This paper discusses how standard drive technology from machine tool applications can be used to control AMB systems and how the integrated data acquisition functions simplify the commissioning process. As a proof of the concept, results of prototype testing with a 5 MW induction motor are presented.
BibTeX:
@inproceedings{ISMB13_21,
  author = {Joachim Denk and Hans-Georg Köpken and Dietmar Stoiber and Frank Viering},
  title = {Active Magnetic Bearing Systems for Turbo Machine Applications based on Standard Drive Technology},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_21.pdf}
}
1992 Depret-Guillaume, P., Lewis, D. and Humphris, R. Modeling Stress Effects in Magnetic Thrust Bearings Using Finite Elements Proceedings of ISMB3  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB3_44,
  author = {P.T. Depret-Guillaume and D.W. Lewis and R.R. Humphris },
  title = {Modeling Stress Effects in Magnetic Thrust Bearings Using Finite Elements },
  booktitle = {Proceedings of ISMB3},
  year = {1992},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb3/ismb3_submission_44.pdf}
}
2014 Detoni, J.G., Impinna, F., Amati, N., Tonoli, A., Piccolo, M.P. and Genta, G. Stability of a 4 degree of freedom rotor on electrodynamic passive magnetic bearings Proceedings of ISMB14  
Abstract: Electrodynamic bearings exploit repulsive forces due to eddy currents to produce positive stiffness by passive means without violating the Earnshaw stability criterion. This remarkable characteristic makes this type of bearing a suitable alternative to active magnetic bearings in fields such as kinetic energy storage flywheels, turbo pumps, high speed compressors, among others. However, the suspension can become unstable due to rotating damping. To obtain deeper understanding of this instability phenomenon this paper presents the analysis of stability of a four degree of freedom (4dof) rotor supported by electrodynamic bearings. The 4dof rotor model is coupled to the dynamic model of the eddy current forces generated by the electrodynamic bearing and the stability of the complete system is analyzed. This model is used to study the stability of both cylindrical and conical whirling motion of the rotor. In addition to the well known cylindrical whirl instability the possible occurrence of conical instability is demonstrated. Finally the effects of two stabilization strategies are analyzed.
BibTeX:
@inproceedings{ISMB14_73,
  author = {Joaquim Girardello Detoni and Fabrizio Impinna and Nicola Amati and Andrea Tonoli and Maria Pina Piccolo and Giancarlo Genta},
  title = {Stability of a 4 degree of freedom rotor on electrodynamic passive magnetic bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_73.pdf}
}
1992 Dhar, D., Barrett, L. and Knospe, C. Optimum Design of Decentralized Magnetic Bearings for Rotor Systems Proceedings of ISMB3  
Abstract: Magnetic bearings are currently being explored as viable alternatives to existing hydrodynamic or rolling element support devices for high speed rotating machinery in various applications. Incorporation of active magnetic bearings into rotor systems can lead to enhanced stability characteristics by proper choice of the feedback control law. Traditionally low-order PD type controllers or high-order LQR/LQG based controllers have been used for such bearings. In this paper, a method of designing low—order decentralized magnetic bearing controllers for high-order plants is proposed. The controller is represented by a minimum set of design parameters (numerator and denominator coefficients of the transfer functions of the controller), and the optimum controller parameters are obtained by means of a numerical search in the parameter space. The various design specifications for such a design could be insurance of stability, boundedness of design parameters within upper and lower limits, placement of closed-loop eigenvalues within an acceptable region in the complex plane, and avoidance of closed—loop eigenfrequendes from an envelope around the rotor operating speed. Satisfaction of the multiple specifications is attempted by solving the problem as a sequence of constrained minimization problems, with more and more constraints being introduced in each subsequent stage. The design requirements specified in terms of the closed—loop characteristics of the system are achieved through a step by step process. The algorithm utilizes the method of feasible directions to solve the nonlinear constrained minimization problem at each stage. This methodology emphasizes the designer's interaction with the algorithm to generate acceptable controller designs by changing various specifications and altering the initial guesses interactively. A graphical interface has been developed to facilitate design interaction by the user.
BibTeX:
@inproceedings{ISMB3_5,
  author = {D. Dhar and L.E. Barrett and C.R. Knospe },
  title = {Optimum Design of Decentralized Magnetic Bearings for Rotor Systems },
  booktitle = {Proceedings of ISMB3},
  year = {1992},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb3/ismb3_submission_5.pdf}
}
1991 Dhar, D., Barrett, L. and Knospe, C. Design of Bearings for Rotor Systems Based on Stability Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_37,
  author = {D. Dhar and L.E. Barrett and C.R. Knospe},
  title = {Design of Bearings for Rotor Systems Based on Stability},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_37.pdf}
}
2016 Di, L., Chen, C.Y. and Lin, C.H. Characteristic Model Based All-Coefficient Adaptive Control of a High-Speed Desorption Pump Supported by AMBs Proceedings of ISMB15  
Abstract: Active magnetic beatings (AMBs) have been increasingly adopted in industries that involve high-speed rotating machinery and feedback control design is one of the essential problems in AMB systems. In this paper, we report on the development of the characteristic model based all-coefficient adaptive control (ACAC) method to a high- speed desorption pump supported by AMBs. This control method does not require the actual system model and is able to deliver strong performance and robustness, as validated in many successful engineering applications. The desorption pump studied in this paper is designed to operate at a speed of 60,000 rpm, which indicates that a potentially large unbalance force might be introduced to drive the AMB system into instability. Meanwhile, the rising speed range is wider than typical machines so that the natural modes can split more significantly due to the gyroscopic effect, which will introduce strong uncertainties. Therefore, a successful controller must guarantee the closed-loop stability and minimize the vibration during the speed increase as well as at the operational speed. The simulation results have demonstrated the proposed ACAC method is capable of achieving the control requirements and the controller will be implemented on the test rig for experimental validations.
BibTeX:
@inproceedings{ISMB15_19,
  author = {Long Di and Chao Yun Chen and Chung Hsien Lin},
  title = {Characteristic Model Based All-Coefficient Adaptive Control of a High-Speed Desorption Pump Supported by AMBs},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_19.pdf}
}
2018 Di, L. and Lin, Z. Robust mu Synthesis Control Design for a High Speed Integrated Motor/Compressor System Supported by AMBs Proceedings of ISMB16  
Abstract: Active magnetic beatings (AMBs) have been gradually adopted in high-speed rotating machinery applications and the control design plays a critical role in AMB systems. The mu-synthesis control is one of the most sophisticated robust control design methods and it considers both robust stability and performance. The resulting controller is able to handle uncertainties in the dynamic system and achieve required performance and stability margin, which makes it an ideal solution for AMB control problems. However, since mu-synthesis control design directly depends on the dynamic model, an accurate modeling process of the AMB system needs to be performed prior to the controller design. In this research, we apply the robust mu-synthesis control design to a high speed integrated motor/compressor system supported by AMBs. It briefly describes the modeling of the test rig, summarizes the mu-synthesis control design process and presents the control simulation results. The simulation results have shown that the designed mu-synthesis controller is able to achieve strong control performance as well as strong robustness for the analyzed AMB system.
BibTeX:
@inproceedings{ISMB16_040,
  author = {Long Di and Zongli Lin},
  title = {Robust mu Synthesis Control Design for a High Speed Integrated Motor/Compressor System Supported by AMBs},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_040.pdf}
}
2012 Di, L., Mushi, S., Lin, Z. and Allaire, P. Characteristic Model Based All-coefficient Adaptive Control of a Flexible Rotor Suspended on Active Magnetic Bearings Proceedings of ISMB13  
Abstract: Active magnetic bearings (AMBs) have been used in many high-speed rotating machinery ap-plications. Because of the nonlinear characteristics of magnetic bearings and complex dynamics of the flexible rotors, the problems of stabilization and disturbance rejection need to be exten-sively addressed for their smooth operation over a wide operating speed range. Conventional controller such as the proportional-integral-derivative (PID) design has played a major role in most AMB related applications. Although it is easy to implement, there exist limitations and drawbacks. The µ -synthesis approach can fulfill the requirement of robust performance, but it relies on the plant and uncertainty models, which are sometimes difficult to acquire for practical systems. This paper explores the use of the characteristic model based all-coefficient adaptive control (ACAC) method to stabilize a flexible rotor AMB system. This new control method does not require an actual model of the system. Both simulation and experimental results have shown its strong potential to perform well in spite of its simplicity.
BibTeX:
@inproceedings{ISMB13_64,
  author = {Long Di and Simon Mushi and Zongli Lin and Paul Allaire},
  title = {Characteristic Model Based All-coefficient Adaptive Control of a Flexible Rotor Suspended on Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_64.pdf}
}
2016 Di, L. and Yoon, S.Y. Autobalancing of AMB Systems Using a Differential Regulator Based Output Regulation Approach Proceedings of ISMB15  
Abstract: High speed rotating machines are subject to unbalance forces caused by residue weight. When the rotor’s axis of geometry and its principal axis of inertia are not aligned, unbalance forces synchronous to the rotational speed cause the rotor to deflect from the geometric center and enter a whirling motion. To reduce the effects that the rotor unbalance has on high speed machineries supported by AMBs, the conventional approach has been to either generate counteracting bearing forces or to shift the rotating axis in such a way that the shaft is rotating force-free or performing auto-balancing. In this paper, a differential regulator based output regulation approach is presented to address the autobalancing of AMB systems for varying rotational speeds. After formulating the output regu- lation problem with a time-varying exosystem, it is observed that the compensator gains can be obtained based on the solution of the differential regulator equation (DRE) and the output regulation objective can be achieved approximately with a small bounded error in the regulated output. The proposed method is verified in simulation for autobalancing with both varying and constant rotational speeds on a flexible rotor AMB test rig.
BibTeX:
@inproceedings{ISMB15_101,
  author = {Long Di and Se Young Yoon},
  title = {Autobalancing of AMB Systems Using a Differential Regulator Based Output Regulation Approach},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_101.pdf}
}
2014 Di, L., Zhou, J., Chen, C. and Lin, Z. Experimental Verification of a Rotor Unbalance Response Based Approach to the Identification of Magnetic Bearing Support Parameters Proceedings of ISMB14  
Abstract: The support parameters, the stiffness and damping coefficients, of active magnetic bearings (AMBs) have direct influence on the dynamic response and stability of a rotor bearing system. The unbalance response method is a simple but effective way to identify the AMB support parameters. In this paper, we present experimental verification of this identification method. We first briefly introduce the unbalance response method and the error response surface approach to rectifying the identification error induced by the rotor flexibility. The final AMB stiffness and damping coefficients are determined as the sum of the nominal values identified by the unbalance response method and the identification errors derived from the error response surfaces. We will then present the experimental verification of this combined unbalance response and error response surface identification method on a rotor AMB test rig. In order to verify the identification method, the parameters thus identified based on the experimental data are integrated with the rotor finite element model to form the rotor-AMB model. The model unbalance response is obtained through simulation and compared with experimentally measured unbalance response. The close agreement between the model unbalance response and the experimentally measured response demonstrates that the proposed method is effective in identifying the AMB support parameters.
BibTeX:
@inproceedings{ISMB14_60,
  author = {Long Di and Jin Zhou and Changli Chen and Zongli Lin},
  title = {Experimental Verification of a Rotor Unbalance Response Based Approach to the Identification of Magnetic Bearing Support Parameters},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_60.pdf}
}
2008 Diao, X. and Yu, S. Preliminary Tests for the HTR-10 Helium Circulator with the Active Magnetic Bearings Proceedings of ISMB11  
Abstract: The Helium circulator is one of the key equipment of the high temperature gas-cooled reactor (HTR), which directs helium to flow through the reactor core and the steam generator to achieve the thermal energy transfer between them. At present, there are two optional schemes in the design of the helium circulator. One is the dry gas seal, another is the active magnetic bearing (AMB), but both of them haven’t been used in the reactors beforetime. After the 10 MW High Temperature Gas-cooled Reactor-Test Module (HTR-10) was brought to criticality in December of 2000, Institute of Nuclear and New Energy Technologies (INET) of Tsinghua University dedicated to upgrade the technology of the helium circulator. It takes 3 years to manufacture a helium circulator with the active magnetic bearings in Shanghai Blower Factory, which has the same rated parameters as the one of HTR-10. It stood all the tests in November of 2007, including the 100 hour test at the conditions of high temperature(250°C) and high speed (5000r/min). All of these means INET made a great progress in the area of the active magnetic bearing technology. This circulator will be installed to HTR-10 to endure the further tests at the reactor conditions such as high temperature, radiation, graphite dust and the inert helium atmosphere. In the foundation of these successful tests, the design of the larger scale and higher power level helium circulator with AMBs for the HTR-PM project will enter the official implementation stage. This paper covers the philosophy behind the design and descriptions of the HTR-10 helium circulator and the preliminary tests. Significantly useful information is also derived from temperature distribution in the AMBs.
BibTeX:
@inproceedings{ISMB11_85,
  author = {Xingzhong Diao and Suyuan Yu},
  title = {Preliminary Tests for the HTR-10 Helium Circulator with the Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_85.pdf}
}
2018 Diaz, D., Pinto, F., Ritto, T., Maldonado, D. and Côrtes, V. Nonparametric Identification of a Small AMB Test Rig at Several Rotating Speeds Proceedings of ISMB16  
Abstract: In this paper a comparison of experimental frequency response functions (FRFs) obtained in a small-scale Active Magnetic Bearing (AMB) test rig at several rotating speeds is made, in order to assess the gyroscopic and shaft unbalances effects in practical identification procedures. The excitation frequencies used in this work were established below the critical speed (rigid rotor behavior) and a broadband signal is used as excitation input.
BibTeX:
@inproceedings{ISMB16_074,
  author = {Diego Diaz and Fernando Pinto and Thiago Ritto and David Maldonado and Vinicius Côrtes},
  title = {Nonparametric Identification of a Small AMB Test Rig at Several Rotating Speeds},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_074.pdf}
}
2008 Dietz, S.G., Balini, N.K.H. and Scherer, C.W. Robust Control Against Disturbance Model Uncertainty in Active Magnetic Bearings Proceedings of ISMB11  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB11_68,
  author = {Sjoerd G. Dietz and Navin Kumar H.M. Balini and Carsten W. Scherer},
  title = {Robust Control Against Disturbance Model Uncertainty in Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_68.pdf}
}
2010 Dimond, T., Rockwell, R., Simmons, G. and Allaire, P. Comparison of Load Capacity and Inductance for Common Active Magnetic Bearings Designs Proceedings of ISMB12  
Abstract: Active magnetic bearings have become more popular as an alternative to fluid-film or rolling element bearings in rotating machinery. They have also become a method for force excitation for rotordynamic experiments, including system identification experiments. The current work considers alternate active magnetic bearing designs for a fluid film bearing test rig. The three designs considered include a conventional 8-pole design with equal widths, a 12-pole bearing with e-core quadrants, and a 16-pole alternate with two exterior auxiliary poles and two interior main poles per quadrant. Several previous studies have considered equal pole widths in optimizing magnetic bearing stator geometry. While not an optimization study, this analysis presents a comparison of popular AMB geometries commonly used in industrial applications. The load capacity, magnetic field energy, and inductance were compared. The 16-pole bearing was shown to have the highest load capacity of the three designs. The inductive load also increased with increasing number of poles. The 12 and 16 pole designs, with reduced auxiliary pole width, also exhibited better containment of the magnetic flux within each active magnetic bearing quadrant, which simplifies the control problem. The results are of use for AMB designers and provide guidance for future stator optimization studies.
BibTeX:
@inproceedings{ISMB12_80,
  author = {Timothy Dimond and Robert Rockwell and Gregory Simmons and Paul Allaire},
  title = {Comparison of Load Capacity and Inductance for Common Active Magnetic Bearings Designs },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_80.pdf}
}
2014 Ding, Q., Wu, G., Deng, Z. and Wang, X. Influence of Fault-Tolerant Stator Structure on Performance of Permanent Magnet Bearingless Slice Machines Proceedings of ISMB14  
Abstract: Fault-tolerant capability is a vital requirement for bearingless slice machine which is used in safety critical application field. This paper compares two bearingless slice machines, conventional permanent magnet bearingless slice machine and fault-tolerant permanent magnet bearingless slice machine, from fault-tolerant capability, suspension and drive performance points of view. Due to introduction of fault-tolerant stator structure, a optimization method for reduction of total harmonic distortion(THD) of back-EMF and electromagnetic coupling between different phases is proposed. Then, some relevant performance comparison, such as fault-tolerant performance, suspension performance as well as drive torque performance, is analyzed by finite element analysis. Finally, several design considerations are presented as guideline for design of bearingless slice machines with fault-tolerant stator structure.
BibTeX:
@inproceedings{ISMB14_20,
  author = {Qiang Ding and Guyu Wu and Zhiquan Deng and Xiaolin Wang},
  title = {Influence of Fault-Tolerant Stator Structure on Performance of Permanent Magnet Bearingless Slice Machines},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_20.pdf}
}
2017 Dio, V.D. and Sani, L. Coupled Electromechanical Analysis of a Permanent-Magnet Bearing ACES Journal 2017 vol 3 no 8 - Courtesy of ACES  
Abstract: In this paper we present a new Permanent Magnets (PMs) bearing, which is composed of a rotor capable to levitate at a short distance from a dedicated stator. Proper configurations of PMs arranged on both the stator and the rotor allows having the magnetic suspension. Intrinsic mechanical instability characterizes the device; a passive stabilization is attempted exploiting eddy currents on a conducting sheet that surrounds the magnets on the stator. The system has been simulated by means of a dedicated numerical code that takes into account the effects of magneto-mechanical coupling. The coupled problem has been integrated by means of a prediction-correction nested scheme. Some interesting results, extensively discussed here, has been produced by simulation activity. In particular the stability of to the center of mass with respect to the translations has been passively obtained, if the rotations are actively prevented.
BibTeX:
@inproceedings{aces2017vol3no8_015,
  author = {V. Di Dio and L. Sani},
  title = {Coupled Electromechanical Analysis of a Permanent-Magnet Bearing},
  booktitle = {ACES Journal 2017 vol 3 no 8 - Courtesy of ACES},
  year = {2017},
  url = {https://www.magneticbearings.org/wp-content/publications/aces2017vol3no8/aces2017vol3no8_015.pdf}
}
1992 Dirusso, E. and Brown, G. Performance Tests of a Cryogenic Hybrid Magnetic Bearing for Turbopumps Proceedings of ISMB3  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB3_37,
  author = {E. Dirusso and G.V. Brown },
  title = {Performance Tests of a Cryogenic Hybrid Magnetic Bearing for Turbopumps },
  booktitle = {Proceedings of ISMB3},
  year = {1992},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb3/ismb3_submission_37.pdf}
}
2018 Doenni, E., Achtnich, T. and Zwyssig, C. Vibration Suppression of a Slotless Self-Bearing Permanent-Magnet Motor for Optical Applications Proceedings of ISMB16  
Abstract: Magnetic bearings, particularly of slotless type, are ideally suited for optical applications by enabling operation in vacuum at high speeds with high lifetime, avoiding particle generation and allowing active control, and therefore suppression of bearing stator force and rotor displacements. In this paper, different approaches for vibration suppression are compared and experimentally verified with a dual hetero-/homopolar slotless self-bearing motor. A feed forward has advantages compared to a notch-filter approach as it allows rotor vibration suppression and lowering the stator vibration suppression activation speed into the rigid-rotor critical speed range. Finally, the rotational speed fluctuations, important for optical applications, are investigated.
BibTeX:
@inproceedings{ISMB16_024,
  author = {Elias Doenni and Timon Achtnich and Christof Zwyssig},
  title = {Vibration Suppression of a Slotless Self-Bearing Permanent-Magnet Motor for Optical Applications},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_024.pdf}
}
2011 Dohnal, F. Increasing the external damping of a flexible rotor by periodic control Proceedings of Workshop on Magnetic Bearing Technology 8  
Abstract: The influence of a periodic open-loop control operated in parallel to an existing closed-loop PID control is investigated on a rotor system supported by two radial active magnetic bearings. The transient behaviour of the rotor is studied numerically and first experimental results are shown to demonstrate the applicability of the method. It is highlighted that by tuning the periodic control properly it is possible to amplify artificially the external damping of the rotor system. This concept allows increasing the total external damping well beyond the stability margin of the closed-loop control cycle.
BibTeX:
@inproceedings{WMLT8_13,
  author = {F. Dohnal},
  title = {Increasing the external damping of a flexible rotor by periodic control },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 8},
  year = {2011},
  url = {https://www.magneticbearings.org/wp-content/publications/wmlt8/wmlt8_13.pdf}
}
1993 Downer, J., Goldie, J., Gondhalekar, V. and Hockney, R. Aerospace Applications of Magnetic Bearings Proceedings of ISMST2  
Abstract: Magnetic bearings have traditionally been considered for use in aerospace applications only where performance advantages have been the primary, if not only, consideration. Conventional wisdom has been that magnetic bearings have certain performance advantages which must be traded off against increased weight, volume, electric power consumption, and system complexity. These perceptions have hampered the use of magnetic bearings in many aerospace applications because weight, volume, and power are almost always primary considerations.
BibTeX:
@inproceedings{ISMST2_1,
  author = {James Downer and James Goldie and Vijay Gondhalekar and Richard Hockney},
  title = {Aerospace Applications of Magnetic Bearings},
  booktitle = {Proceedings of ISMST2},
  year = {1993},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst2/ismst2_submission_1.pdf}
}
1991 Downer, J.R., Bushko, D.A., Gondhalekar, V. and Torti, R.P. Performance of a Superconducting Large-AngleMagnetic Suspension Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_53,
  author = {James R. Downer and Dariusz A. Bushko and Vijay Gondhalekar and Richard P. Torti},
  title = {Performance of a Superconducting Large-AngleMagnetic Suspension},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_53.pdf}
}
1997 Driga, M.D. Electromagnetic Launchers for Space Applications: Coilguns for Repetitive Launching Proceedings of ISMST4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST4_25,
  author = {M. D. Driga},
  title = {Electromagnetic Launchers for Space Applications: Coilguns for Repetitive Launching},
  booktitle = {Proceedings of ISMST4},
  year = {1997},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst4/ismst4_submission_25.pdf}
}
1997 Driga, M.D. High Power Electrical Machines for Space Applications Electromagnetic Launchers (Quality Functions and Goodness Factors) Proceedings of ISMST4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST4_32,
  author = {M. D. Driga},
  title = {High Power Electrical Machines for Space Applications Electromagnetic Launchers (Quality Functions and Goodness Factors)},
  booktitle = {Proceedings of ISMST4},
  year = {1997},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst4/ismst4_submission_32.pdf}
}
2019 Du, G., Shi, Z., Zuo, H., Zhao, L. and Sun, Z. Analysis of Unbalanced Response of Rigid Rotor Supported by AMBs under Coupling Dynamic and Control Methods ACES Journal 2019 vol 34 no 4 - Courtesy of ACES  
Abstract: The main helium circulator is the core component of the High Temperature Reactor (HTR). Mechanical machining errors and assembly errors can cause uneven distribution of rotor mass. When the rotor rotates, the unbalanced mass will generate unbalanced force which will change the rotor's axis trajectory. By coupling the rotor dynamics method and the electromagnetic bearing system control theory, the motion of the rotor is modeled. Three representative unbalanced conditions of the impeller position, the bearing position and the centroid position are assumed to simulate the unbalance response of the rotor, and the influence of changes in the stiffness and damping on the unbalance response of the rotor is analyzed by adjusting the stiffness and the damping of the rotor. The results of the analysis show that the bearings farther from the unbalanced position (UBP) have larger rotor displacements and bearing loads. Increasing Active Magnetic Bearings (AMBs) stiffness and damping will increase the bearing load and reduce the response displacement of the rotor. Therefore, the stiffness and damping of AMBs must be designed by considering the bearing capacity and the displacement limit of the rotor.
BibTeX:
@inproceedings{aces2019vol34no4_002,
  author = {G. Du and Z. Shi and H. Zuo and L. Zhao and Z. Sun},
  title = {Analysis of Unbalanced Response of Rigid Rotor Supported by AMBs under Coupling Dynamic and Control Methods},
  booktitle = {ACES Journal 2019 vol 34 no 4 - Courtesy of ACES},
  year = {2019},
  url = {https://www.magneticbearings.org/wp-content/publications/aces2019vol34no4/aces2019vol34no4_002.pdf}
}
2014 Duesterhaupt, S., Neumann, H., Panescu, C., Rottenbach, T. and Worlitz, F. Test Field for Magnetic Bearing Applications Under Extreme Conditions Proceedings of ISMB14  
Abstract: Active magnetic bearings (AMB) are an essential key technology in modern power plant concepts. The application of AMBs in turbo machines (steam turbines, cooling pumps and compressors) is characterized by extreme process and environmental conditions like high temperatures, corrosive fluids and gases. Especially the use of organic materials limits the insulation level of electromagnetic actuators. Currently the allowed maximum continuous temperature of coils and laminated cores is 160C. Known solutions like ceramic insulation systems allow actuator temperatures up to 450C. But their production is complex and the specific actuator size increases compared to conventional insulated actuators. The development of new surface technologies and advances in material science allow new basic approaches for insulations and thereby for High Temperature Active Magnetic Bearings (HTAMBs). For instance the use of the physical vapor deposition technology (PVD) allows low cost coatings with thicknesses of only a few micrometers. Furthermore, the fusion of AMBs with catcher bearings (CB) to an integrated unit is advantageous for a compact machine design. It is one objective to place the bearing units close to the process section, if appropriate into the process section. So the CBs also have to fulfil their functions under extreme conditions.
BibTeX:
@inproceedings{ISMB14_105,
  author = {Stephan Duesterhaupt and Holger Neumann and Christian Panescu and Torsten Rottenbach and Frank Worlitz},
  title = {Test Field for Magnetic Bearing Applications Under Extreme Conditions},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_105.pdf}
}
2016 Duesterhaupt, S., Neumann, H., Rottenbach, T., Vanek, C. and Worlitz, F. High Temperature Active Magnetic Bearings in Industrial Steam Turbines Proceedings of ISMB15  
Abstract: After 8 years of industrial research and development between industry and Zittau/Görlitz University, the prototype of a feed water power turbine (SPAT) with active magnetic bearings was successfully taken in operation at the Jänschwalde power plant in 2015. Due to extended conditions of use (particularly high process and environmental temperatures) the active magnetic bearings in the turbo machines must be cooled elaborately. In conventionally supported turbo machines the lubri- cant in the friction bearings additionally does the cooling. Parts of the heat flux are dissipated from the bearing by the bearing oil. In terms of turbo machines with magnetic bearings lubricant is not used. This leads to significantly higher temperatures in the area of rotor lamination and its sleeves. Particularly demanding is the cooling of the sleeves which is currently very demanding – compressors are necessary. The tube cooling applied reduces the effi- ciency of the magnetic bearing which is high compared with hydrostatic friction bearing. Moreover, the additional peripheral effort has a negative effect for investment and maintenance in cost accounting. This paper shows the stages in developing High Temperature Magnetic Bearings (HTAMB). First approaches of suitable HTAMB concepts are depicted. Within the next 3 years shall on the basis of theoretical and experimental investigations be determined which state of the art materials and construction principles must be used and applied. The focus within that topic is the use of temperature resistant materials for the lamination of active radial magnetic bearings with respect to elimination of high manufacturing effort of sleeve cooling. For this reason the essential tests of magnetic and catcher bearing components shall be realized at the test rig for magnetic and catcher bearings MFLP. Single effects and long-term strain will be analyzed under scaled power plant conditions. The test field is introduced by representing its main parameters.
BibTeX:
@inproceedings{ISMB15_3,
  author = {Stephan Duesterhaupt and Holger Neumann and Torsten Rottenbach and Christian Vanek and Frank Worlitz},
  title = {High Temperature Active Magnetic Bearings in Industrial Steam Turbines},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_3.pdf}
}
2017 Duesterhaupt, S. and Worlitz, F. Zuverlässigkeitsbewertung aktiver Magnetlagerungen unter der Berücksichtigung erweiterter Umgebungsbedingungen Proceedings of Workshop on Magnetic Bearing Technology 11  
Abstract: Aktive Magnetlagerungen können in modernen Industrieapplikationen wie Turbomaschinen eine Schlüsseltechnologie darstellen. Gegenwärtig berücksichtigt der Designprozess Nennwerte in der statischen Auslegung und dyna-mischen Simulation des magnetgelagerten Sys-tems. Im praktischen Einsatz jedoch beeinflussen der Prozess und die Umgebung die Funktionsweise der Sensoren, Leistungsverstärker und magnetischen Aktoren. Insbesondere der thermische Einfluss verursacht mehr oder minder starke Driften in den Komponenten- und Bauteilparametern. Die Ursachen dafür können hohe Umgebungstemperaturen sein oder mechanische Stützanregungen bzw. Druckänderungen. Die mechanischen Einflüsse führen zu einer zunehmenden Relativbewegung zwischen Rotor und Stator. Infolge der Auslen-kungen reagiert das aktive Magnetlager mit Regeleingriffen. Die Steuerstromänderungen führen zu einer veränderten Eigenerwärmung der Leistungssteller und Lagerspulen. Die arbeitspunkt- und lastabhängige Beeinflussung der Lagerkomponenten führt letztendlich zu einer veränderten Dynamik der Lage- und ggf. der unter-lagerten Stromregelkreise. Ein unter Nominalbedingungen funktionsfähiges aktives Magnetlager versagt ggf. aufgrund mechanischer, elektrischer und magnetischer Parameterdriften. Für den Einsatz muss daher die Zuverlässigkeit des mechatronischen Systems objektiv nachgewiesen werden. Dies muss unter der Berücksichtigung von Prozess und Umgebung erfolgen.
BibTeX:
@inproceedings{WMLT11_7,
  author = {S. Duesterhaupt and F. Worlitz},
  title = {Zuverlässigkeitsbewertung aktiver Magnetlagerungen unter der Berücksichtigung erweiterter Umgebungsbedingungen},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 11},
  year = {2017},
  url = {https://www.magneticbearings.org/wp-content/publications/wmlt11/wmlt11_7.pdf}
}
2012 Duesterhaupt, S. and Worlitz, F. Complex and Integrated Methods for the Reliability Analysis of Contactless Magnetic Bearings Proceedings of ISMB13  
Abstract: In many fields of energy technology the proof of reliability is required for the application of magnetic bearings. The application of active magnetic bearings in turbo machines for power plants is characterized by extreme process and environmental conditions. The parameters varie-gate due to manufacturing tolerances and the influence of specific operation and load conditions of the control loop components of a magnetic bearing. That involves a load-dependent reliabil-ity of the bearing components. Therefore an active magnetic bearing which is under nominal conditions in terms of its function, may fail due to drifts of mechanical, electrical and magnetic parameters. The objective of this project is the reliability analysis of active magnetic bearings considering their nonlinearities. The analysis will be carried out by means of appropriate methods which consider the specific fuzzy parameters compared to conventional approaches. The part failure probability of the several components will be determined by Monte-Carlo-Simulations. The fail-ure probability of the whole system will be summarized by use of a fault tree analysis. Whether any components have to be integrated redundantly/diversely will be determined in the early de-sign process.
BibTeX:
@inproceedings{ISMB13_61,
  author = {Stephan Duesterhaupt and Frank Worlitz},
  title = {Complex and Integrated Methods for the Reliability Analysis of Contactless Magnetic Bearings},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_61.pdf}
}
2016 Dumont, C., Gilson, A., Kluyskens, V. and Espanet, C. Evaluation of the Electrodynamic Forces in a High-Speed Permanent Magnet Machine with Rotor Eccentricity Proceedings of ISMB15  
Abstract: In permanent magnet motors, the presence of rotor eccentricities can alter the airgap field distribution. This results in parasitic radial detent forces that can be reduced by connecting the stator phases in parallel. As a consequence, currents are passively induced in the windings when the rotor spins in an off-centered position, yielding balancing electrodynamic forces. Specific models were developed to predict these forces, but their complexity can be pro- hibitive. Therefore, this paper proposes to study the effect of the rotor off-centering in permanent magnet motors using a simpler model developed for electrodynamic bearings. This model consists in a linear differential equation with only four parameters that depend neither on the spin speed nor on the rotor position. As an illustration, the paper applies this model to the study of a high-speed, slotted permanent magnet motor. To support this, the main hypotheses of the model are validated in this particular case. Finally, the centering electrodynamic forces in a quasi-static configuration are predicted using the model and compared to finite element simulation results.
BibTeX:
@inproceedings{ISMB15_104,
  author = {Corentin Dumont and Adrien Gilson and Virginie Kluyskens and Christophe Espanet},
  title = {Evaluation of the Electrodynamic Forces in a High-Speed Permanent Magnet Machine with Rotor Eccentricity},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_104.pdf}
}
2017 Dumont, C., Kluyskens, V. and Dehez, B. Performance of Yokeless Heteropolar Electrodynamic Bearings ACES Journal 2017 vol 3 no 8 - Courtesy of ACES  
Abstract: Electrodynamic bearings (EDBs) are a promising way to support rotors passively with no friction. In particular, heteropolar EDBs could allow for combining the motor and guiding functions, thereby optimizing the use of permanent magnets. Despite this advantage, few efforts have been dedicated to the evaluation and optimization of the performance of heteropolar EDBs. In this paper, the performance of a yokeless topology of heteropolar EDB is evaluated and optimized. This is done by evaluating the parameters of a parametric dynamical model of the EDB using a two-dimensional analytical model of the field distribution in the bearing. Compared to existing EDBs, the present one is shown to achieve a reasonable stiffness to permanent magnet volume ratio at high speeds.
BibTeX:
@inproceedings{aces2017vol3no8_007,
  author = {C. Dumont and V. Kluyskens and B. Dehez},
  title = {Performance of Yokeless Heteropolar Electrodynamic Bearings},
  booktitle = {ACES Journal 2017 vol 3 no 8 - Courtesy of ACES},
  year = {2017},
  url = {https://www.magneticbearings.org/wp-content/publications/aces2017vol3no8/aces2017vol3no8_007.pdf}
}
2014 Dumont, C., Kluyskens, V. and Dehez, B. Impact of the Yoke Material on the Performance of Wounded Electrodynamic Bearings Proceedings of ISMB14  
Abstract: This paper concerns null-flux, centering electrodynamic bearings with an internal rotor made of permanent magnets creating a multipole radial magnetic field and with an external airgap wounded conductor attached to a yoke. The inclusion of a ferromagnetic yoke in front of the permanent magnets has the two following effects. On the one hand, it increases the magnetic flux density in the airgap and the magnitude of the centering Lorentz forces between the rotor and the stator of the device. This is positive since the stiffness associated with the centering force of the bearing increases too. On the other hand, it also induces a negative stiffness due to the reluctant force between the yoke and the magnets usually referred to as the unbalanced magnetic force. The goal of this paper is to investigate about the gain in stiffness and performance associated with the presence of a ferromagnetic yoke in multipole electrodynamic bearings. To this purpose, a method is exposed to evaluate the stiffness and stability of the bearing objectively using a root-loci plot. The results are based on a 2-D analytical model of electrodynamic bearings which is briefly presented in the paper. It is shown that in some cases, the magnetic permeability of the yoke has a very low impact on the bearing performance.
BibTeX:
@inproceedings{ISMB14_19,
  author = {Corentin Dumont and Virginie Kluyskens and Bruno Dehez},
  title = {Impact of the Yoke Material on the Performance of Wounded Electrodynamic Bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_19.pdf}
}
1990 Dussaux, M. The Industrial Applications of the Active Magnetic Bearings Technology  Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_6,
  author = {M. Dussaux },
  title = {The Industrial Applications of the Active Magnetic Bearings Technology },
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_6.pdf}
}
2015 Düsterhaupt, S. and Worlitz, F. Magnet- und Fanglagerprüfstand MFLP – Versuchsanlage zum Test von Magnet und Fanglagerungen unter extremen Bedingungen Proceedings of Workshop on Magnetic Bearing Technology 10  
Abstract: Aktive Magnetlagerungen (AMB) stellen eine Schlüsseltechnologie in modernen Turbomaschinen dar. Der Einsatz von AMB in Turbomaschinen der Kraftwerkstechnik (Dampfturbinen, Kühlmittelpumpen und Verdichter) ist durch extreme Prozess- und Umgebungsbedingungen charakterisiert, wie hohe Temperaturen und korrosive Fluide/Gase. Insbesondere der Einsatz organischer Isolationsstoffe begrenzt derzeit den Einsatztemperaturbereich der elektromagnetischen Aktoren. Aktuell sind industrieübliche Isolationssysteme in Spulenwicklungen und Blechpaketen bis 180 °C dauerhaft temperaturstabil. Bekannte Isolationssysteme auf keramischer Basis erlauben Einsatztemperaturen bis zu 450 °C. Die Fertigung ist jedoch aufwendig und das Bauvolumen ist im Gegensatz zu konventionell isolierten Aktoren größer. Fortschritte in der Oberflächentechnik und in den Werkstoffwissenschaften ermöglichen die Entwicklung neuartiger Isolationssysteme. Diese eignen sich aufgrund ihrer Temperaturstabilität für den Einsatz in Hochtemperaturmagnetlagerungen (HTAMB). Beispielsweise erlaubt die Anwendung der PVDBeschichtungstechnologie (Physical Vapor Deposition) die Herstellung kostengünstiger Dünnschichten im einstelligen Mikrometerbereich. Weiterhin ist es ein erklärtes Ziel, Magnet- und Fanglagerungen (CB) in einer Baueinheit unterzubringen. Dies ermöglicht kompakte Maschinendesigns. Es ist geplant, diese Lagereinheiten nahe am oder direkt im Prozessraum unterzubringen. So müssen auch die Fanglagerungen ihre Funktionen unter extremen Umgebungsbedingungen zu erfüllen.
BibTeX:
@inproceedings{WMLT10_4,
  author = {S. Düsterhaupt and F. Worlitz},
  title = {Magnet- und Fanglagerprüfstand MFLP – Versuchsanlage zum Test von Magnet und Fanglagerungen unter extremen Bedingungen},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 10},
  year = {2015},
  url = {https://www.magneticbearings.org/wp-content/publications/wmlt10/wmlt10_4.pdf}
}
2013 Düsterhaupt, S. and Worlitz, F. Komplexe und integrierte Methoden zur Zuverlässigkeitsbewertung berührungsfreier Lager Proceedings of Workshop on Magnetic Bearing Technology 9  
Abstract: Für den Einsatz aktiver Magnetlager in der Energietechnik muss die Zuverlässigkeit des Gesamtsystems nachgewiesen werden. Der Einsatz von Magnetlagerungen in Turbomaschinen, wie sie bspw. Turbinen, Pumpen und Verdichter darstellen, ist durch extreme Prozess- und Umgebungsbedingungen charakterisiert. Fertigungstoleranzen in den Lagerkomponenten und die Beeinflussung durch spezifische Betriebs- und Störszenarien führen zu Parameterdriften, die um die Erwartungswerte einer Nennwertauslegung streuen. Die Folge ist eine arbeitspunkt- und lastabhängige Zuverlässigkeit der Lagerkomponenten. Ein unter Nominalbedingungen funktionsfähiges aktives Magnetlager versagt ggf. aufgrund mechanischer, elektrischer oder magnetischer Parameterdriften. Die Auslegung aktiver Magnetlager soll um die Zuverlässigkeitsanalyse unter Berücksichtigung von Nichtlinearitäten erweitert werden. Dabei werden mit Hilfe geeigneter Methoden im Gegensatz zur diskreten Herangehensweise die spezifischen Lagerparameter unscharf betrachtet. Mit Hilfe der Monte- Carlo-Simulation werden im Rahmen von Simulationen Teilversagenswahrscheinlichkeiten der Komponenten ermittelt und mit Hilfe der Fehlerbaumanalyse zu einer Versagenswahrscheinlichkeit des Gesamtsystems zusammengefasst. Es wird im Auslegungsprozess ermittelt, welche Komponenten des Regelkreises redundant/diversitär ausgeführt werden müssen.
BibTeX:
@inproceedings{WMLT9_10,
  author = {S. Düsterhaupt and F. Worlitz},
  title = {Komplexe und integrierte Methoden zur Zuverlässigkeitsbewertung berührungsfreier Lager },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 9},
  year = {2013},
  url = {https://www.magneticbearings.org/wp-content/publications/wmlt9/wmlt9_10.pdf}
}
2011 Düsterhaupt, S. and Worlitz, F. Modellierung und Simulation der Zuverlässigkeit magnetgelagerter Maschinen Proceedings of Workshop on Magnetic Bearing Technology 8  
Abstract: Der Einsatz aktiver Magnetlager in Turbomaschinen der Kraftwerkstechnik ist durch extreme Prozessund Umgebungsbedingungen gekennzeichnet. Fertigungstoleranzen und der Einfluss spezifischer Betriebs- und Störszenarien auf die Komponenten eines Magnetlagerregelkreises führen zu Parameterstreuungen. Die Folge ist eine last- bzw. arbeitspunktabhängige Zuverlässigkeit der Lagerkomponenten. Die Auslegung aktiver Magnetlager soll um die Zuverlässigkeitsanalyse unter Berücksichtigung von komponentenspezifischen Nichtlinearitäten erweitert werden. Dabei werden mit Hilfe geeigneter Methoden im Gegensatz zur diskreten Herangehensweise die spezifischen Lagerparameter unscharf betrachtet. Mit Hilfe der Monte-Carlo-Simulation werden Teilversagenswahrscheinlichkeiten der Komponenten durch Abtastung des Zustandsraumes ermittelt und unter Anwendung der Fehlerbaumanalyse zu einer Versagenswahrscheinlichkeit des Gesamtsystems zusammengefasst. Es wird im Auslegungsprozess ermittelt, welche Komponenten des Regelkreises redundant/diversitär ausgeführt werden müssen.
BibTeX:
@inproceedings{WMLT8_5,
  author = {S. Düsterhaupt and F. Worlitz},
  title = {Modellierung und Simulation der Zuverlässigkeit magnetgelagerter Maschinen },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 8},
  year = {2011},
  url = {https://www.magneticbearings.org/wp-content/publications/wmlt8/wmlt8_5.pdf}
}
2006 Eckhardt, S. and Rudolph, J. Trajectory Tracking for a Magnetically Levitated Shaft with Three-Phase AMBs in Y -Connection Proceedings of ISMB10  
Abstract: High precision tool path tracking with magnetically supported spindles is considered. If radial bearings with three phases in Y -connection are used standard commercial power electronics can be employed. However, only two independent currents are available then. It is shown how this problem can be overcome. Experimental results show that the tracking precision obtained with Y-connected coils is similar to the one obtained with three independent coils.
BibTeX:
@inproceedings{ISMB10_36,
  author = {St. Eckhardt and J. Rudolph},
  title = {Trajectory Tracking for a Magnetically Levitated Shaft with Three-Phase AMBs in Y -Connection},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_36.pdf}
}
2004 Eckhardt, S. and Rudolph, J. High Precision Synchronous Tool Path Tracking With An Amb Machine Tool Spindle Proceedings of ISMB9  
Abstract: High precision tool path tracking with magnetically supported spindles is considered. It is shown how a new choice of the flat output used may facilitate the control design. Results from simulations and experiments illustrates the usefulness of the approach.
BibTeX:
@inproceedings{ISMB9_78,
  author = {Stephan Eckhardt and Joachim Rudolph},
  title = {High Precision Synchronous Tool Path Tracking With An Amb Machine Tool Spindle },
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_78.pdf}
}
2004 Ehmann, C., Sielaff, T. and Nordmann, R. Comparison Of Active Magnetic Bearings With And Without Permanent Magnet Bias Proceedings of ISMB9  
Abstract: A review of publications dealing with the design of active magnetic bearings reveals that some tend to a design with permanent magnets to create the bias flux, and others prefer a purely electric bias and control flux generation. The main scope of the paper is to compare both design principles, exemplarily for radial bearings. Interesting criterions are the negative stiffness, the coupling between the two radial force directions, the force/ volume ratio and the number and complexity of necessary parts.
BibTeX:
@inproceedings{ISMB9_74,
  author = {Christian Ehmann and Tilo Sielaff and Rainer Nordmann},
  title = {Comparison Of Active Magnetic Bearings With And Without Permanent Magnet Bias },
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_74.pdf}
}
2008 Eirich, M., Ishino, Y., Takasaki, M. and Mizuno, T. Experimental Study on the Adjustability of Radial Stiffness in a Repulsive Magnetic Bearing Device Proceedings of ISMB11  
Abstract: This paper studies the ability to adjust the stiffness in the radial direction on a non-contact levitated rotor by using an independent motion control of permanent magnets. The method of stabilization in the axial direction, by moving a magnet for support like an inverted pendulum, is applied. The repulsive forces in the radial direction depend not only on the size and physical characteristics of magnets but also on the relative positioning of magnets to each other in the axial direction. This work shows the principles and the one of necessary methods of motion control for successful adjustability of the radial stiffness.
BibTeX:
@inproceedings{ISMB11_47,
  author = {Max Eirich and Yuji Ishino and Masaya Takasaki and Takeshi Mizuno},
  title = {Experimental Study on the Adjustability of Radial Stiffness in a Repulsive Magnetic Bearing Device},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_47.pdf}
}
1990 Eisenhaure, D., Downer, J., Hockney, R., Johnson, B., Gondhalekar, V., Gerver, M., Misovec, K., Gaffney, M. and Slocum, A. Extreme Precision Magnetic Bearings for Linear and Rotary Applications  Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_34,
  author = {D.B. Eisenhaure and J.R. Downer and R.L. Hockney and B.G. Johnson and V. Gondhalekar and M. Gerver and K. Misovec and M. Gaffney and A. Slocum},
  title = {Extreme Precision Magnetic Bearings for Linear and Rotary Applications },
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_34.pdf}
}
1988 Eisenhaure, D., Slocum, A. and Hockney, R. Magnetic Bearings for Precision Linear Slides Proceedings of ISMB1 - Courtesy of Springer-Verlag  
Abstract: Early uses of scanning tunneling microscopes indicate that many areas of science could greatly benefit if centimeter scale obj ects could be probed on an atomic scale. This could be accomplished by the development of a linear slide having one Angstrom resolution and a one-tenth meter range of travel. Magnetic suspension technology has been proposed as an ideal candidate for the suspension of the linear slide. This technology is attractive since it combines low noise, excellent positioning accuracy, zero wear, and requires no lubrication. The paper examines the feasibility of developing a magnetic suspension with a required resolution exceeding one Angstrom and establishes the requirements for this suspension. The achievable resolution is shown to be determined by position measurement accuracy, suspension gain, suspension bandwidth, and disturbance force levels. Expected disturbance force levels from ground motion, air currents, and acoustic effects are projected. Given the expected disturbance force levels, measurement accuracy, and required controller performance, a magnetic suspension could be developed which would provide resolution better than the one Angstrom required.
BibTeX:
@inproceedings{ISMB1_8,
  author = {D. Eisenhaure and A. Slocum and R. Hockney },
  title = {Magnetic Bearings for Precision Linear Slides },
  booktitle = {Proceedings of ISMB1 - Courtesy of Springer-Verlag},
  year = {1988},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb1/ismb1_submission_8.pdf}
}
2008 Elder, N. and Maslen, E. Effect of Long Cables on AMB Systems Proceedings of ISMB11  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB11_43,
  author = {Nicholas Elder and Eric Maslen},
  title = {Effect of Long Cables on AMB Systems},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_43.pdf}
}
1999 Enkyo, S. and Nakajima, A. High-Tc Superconducting Accelerometer Proceedings of ISMST5  
Abstract: Ultra-high resolution accelerometer is required in completing the high precision airplane inertial navigation system employing a gravity gradiometer which compensates the geodetic induced error and is also required in micro-g environment in space. The resolution of the conventional accelerometer is limited in the order of 10-6gE. On the contrary, superconducting accelerometer has the potential of 10"12gE. In National Aerospace Laboratory (NAL), a principle model of a high-To superconducting accelerometer operated at the liquid nitrogen temperature (77K) was designed, manufactured and evaluated and some of the characteristics are described in this paper.
BibTeX:
@inproceedings{ISMST5_40,
  author = {Shigeharu Enkyo and Atushi Nakajima},
  title = {High-Tc Superconducting Accelerometer},
  booktitle = {Proceedings of ISMST5},
  year = {1999},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst5/ismst5_submission_40.pdf}
}
1997 Eyssa, Y.M. and Schneider-Muntau, H.J. Resistive and Superconducting Magnet Configurations for Levitation of Weakly Diamagnetic Materials Proceedings of ISMST4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST4_15,
  author = {Y. M. Eyssa and H. J. Schneider-Muntau},
  title = {Resistive and Superconducting Magnet Configurations for Levitation of Weakly Diamagnetic Materials },
  booktitle = {Proceedings of ISMST4},
  year = {1997},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst4/ismst4_submission_15.pdf}
}
2000 Fairbert, M. Design Considerations for an Active Magnetic Bearing System Used in Aerospace Environmental Control Systems Proceedings of ISMB7  
Abstract: The purpose of this paper is to share with magnetic bearing enthusiasts the design considerations that have lead to the successful application of an active magnetic bearing system used in aircraft environmental control system. The use of a magnetic bearing system in an aerospace application must meet the rigid standards for in-flight systems. This includes both mechanical and electrical operational and safety requirements. An introduction to the application of the magnetic bearing will be explained. A detailed discussion of the C-130E magnetic bearing system will explain the physical design of the bearing assembly and the design of the control system. Further discussion will explain the significance of the manufacturing process and minimizing the costs of maintainability of the magnetic bearing system in the field. Milestones of the magnetic bearing development and operational data will be provided.
BibTeX:
@inproceedings{ISMB7_87,
  author = {Mark Fairbert},
  title = {Design Considerations for an Active Magnetic Bearing System Used in Aerospace Environmental Control Systems},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_87.pdf}
}
2002 Fan, Q., Shi, S. and Nonami, K. Robust Switching Control Strategy For A Class Of Second Order Uncertain Systems With Application In Active Control Of Unbalancing Vibration For Magnetic Bearing Proceedings of ISMB8  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB8_87,
  author = {Qifu Fan and Songjiao Shi and Kenzo Nonami},
  title = {Robust Switching Control Strategy For A Class Of Second Order Uncertain Systems With Application In Active Control Of Unbalancing Vibration For Magnetic Bearing},
  booktitle = {Proceedings of ISMB8},
  year = {2002},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb8/ismb8_submission_87.pdf}
}
2019 Fan, T., Yu, J., Sun, Z., Liu, X., Zhang, X., Zhao, J., Yan, X., Zuo, H. and Shi, Z. Theory and Simulation of Linearized Force Coefficients for Active Magnetic Bearings with Multiple Magnetic Poles ACES Journal 2019 vol 34 no 4 - Courtesy of ACES  
Abstract: Active magnetic bearing (AMB) is a kind of typical mechatronic product which is widely used due to its high performance. Since the electromagnetic force is strongly nonlinear, the force-displacement coefficient and the force-current coefficient need to be linearized in the process of controlling the AMB. This paper analyzes the three most common magnetic bearings and gives their linearized force formulas. Simulations show that the formulas have high precision. In addition, the source of errors is also analyzed in this paper.
BibTeX:
@inproceedings{aces2019vol34no4_013,
  author = {T. Fan and J. Yu and Z. Sun and X. Liu and X. Zhang and J. Zhao and X. Yan and H. Zuo and Z. Shi},
  title = {Theory and Simulation of Linearized Force Coefficients for Active Magnetic Bearings with Multiple Magnetic Poles},
  booktitle = {ACES Journal 2019 vol 34 no 4 - Courtesy of ACES},
  year = {2019},
  url = {https://www.magneticbearings.org/wp-content/publications/aces2019vol34no4/aces2019vol34no4_013.pdf}
}
2004 Fan, Y. and Fang, J. Experimental Research On The Nutational Stability Of Magnetically Suspended Momentum Wheel In Control Moment Gyroscope (CMG) Proceedings of ISMB9  
Abstract: Aimed at the stability problem of magnetically suspended momentum wheel (MSMW) caused by gyroscopic effect, a criterion based on the frequency characteristic of control circuits is used to analysis and predict whirl modes stability of the flywheel system, and a proportional cross feedback control algorithm based on decentralized control is proposed to stabilize both precession and nutation. Particular simulation and experimental research on nutation stability shows that the phase lag of controller, especially the nonlinearity of amplifier caused by limited current rate is the main factor that influences the stability of nutation at high speed. A series of measurements and experiments are executed on a MSMW prototype under development at Beijing University of Aeronautics and Astronautics (BUAA). Results show good agreement between the analysis and the experiment. The maximum design speed 24,000 rpm is achieved through parameters adjusting.
BibTeX:
@inproceedings{ISMB9_85,
  author = {Yahong Fan and Jiancheng Fang},
  title = {Experimental Research On The Nutational Stability Of Magnetically Suspended Momentum Wheel In Control Moment Gyroscope (CMG) },
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_85.pdf}
}
2012 Fan, Y., Liu, S. and Li, H. Application of 115kW blower supported by magnetic bearing Proceedings of ISMB13  
Abstract: Because of its superior characteristics, magnetic bearing have been applied in many fields. The topic of this paper is the control system ofmagnetic bearing in blower application. Thermal expansion effects have the impact on measurement of axial displacement, we use two eddy current sensors which are in the radial symmetrical arrangement to achieve measurement of the axial displacement, and theoreticalcalculations and experiment verified the possibility of this method.In order to reduce vibration of the rotor, a chebyshev IInotch filter is designed to suppress the special frequency, the effect of notch depth and bandwidth are discussed in the paper, through the rational allocation, the vibration of rotor are greatly suppressed; In order to improve the response of the rotor, phase compensation are used in this system, through the use of two phase compensation,the stability of the rotor rotation are improved. Simulation and experimental results show that the system has a good dynamic characteristics, the speed of the rotor is 15000rpm.
BibTeX:
@inproceedings{ISMB13_47,
  author = {Youpeng Fan and Shuqin Liu and Hongwei Li },
  title = {Application of 115kW blower supported by magnetic bearing},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_47.pdf}
}
2012 Fan, Y.-H., Lee, Y.-T., Chung, W.-C., Su, C.-X. and Lin, C.-H. Design of a Variable Structure Controller Based on the Force Estimator for a Single Active Magnetic Bearings Suspended Rotor System Proceedings of ISMB13  
Abstract: This study proposes a variable structure controller with a force estimator for a single active magnetic bearing suspended rotor system to eliminate the vibration associated with unbalance of mass. The model of a single active magnetic bearing suspended rotor system is build and a displacement and unbalancing force estimator of the system is established. A variable structure controller is also established according to the estimated force to decrease the influence of the unbalance force and increase the robust of the system. The experimental results showed that thevariable structure controller based on the force estimator for a single active magnetic bearing suspended rotor system was established successfully and has good accuracy.
BibTeX:
@inproceedings{ISMB13_90,
  author = {Yi-Hua Fan and Ying-Tsun Lee and Wei-Cheng Chung and Chong-Xian Su and Chung-Hsien Lin},
  title = {Design of a Variable Structure Controller Based on the Force Estimator for a Single Active Magnetic Bearings Suspended Rotor System},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_90.pdf}
}
1996 Fedigan, S., Williams, R., Shen, F. and Ross, R. Design and Implementation of a Fault Tolerant Magnetic Bearings Controller  Proceedings of ISMB5  
Abstract: A digital controller designed to meet the demanding performance and reliability requirements of high-speed magnetic bearing applications is presented. The controller architecture is a fault-tolerant design, consisting of four processor modules arranged in a triple modular redundant (TMR) configuration with a hot spare. A voting module provides active repair and reconfiguration in the event of data disagreements or "lost" processors. The processor modules are independent computers based on the Texas Instruments' TMS320C40, a high speed 32-bit floating point digital signal processor (DSP), capable of executing 220 million operations per second (MOPs). Reliability is further enhanced by a fault tolerant IJO bus, whose data / address buses are each augmented with a set of check bits for single-bit error correction (SEC). Support for the development of control algorithms is provided by a multi-tasking, real-time operating system (RTOS).
BibTeX:
@inproceedings{ISMB5_52,
  author = {S. Fedigan and R. Williams and F. Shen and R. Ross },
  title = {Design and Implementation of a Fault Tolerant Magnetic Bearings Controller },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_52.pdf}
}
1998 Fedigan, S.J., Knospe, C.R. and Williams, R.D. Honor Paper: Gain-Scheduled Control for Substructure Properties in AMBs Proceedings of ISMB6  
Abstract: n AMB systems, machine performance can be degraded by the dynamics of the substructure (i.e. the object to which the sensors and actuators are mounted). These dynamics, unlike those of the rotor, actuators, and sensors are not completely known at the time of controller design. This paper introduces a novel approach called a posteriori gain scheduling for addressing this problem and evaluates the suitability of LPV and D-K iteration design methods by applying them to a benchmark problem. An LPV design method modified for time-invariant parameters exhibits performance close to H„ optimal designs, and is modified to account for parameter estimation errors. The resulting robust, gain-scheduled controller exhibits performance close to mixed- n controllers designed using D,G-K iteration.
BibTeX:
@inproceedings{ISMB6_30,
  author = {S. J. Fedigan and C. R. Knospe and R. D. Williams},
  title = {Honor Paper: Gain-Scheduled Control for Substructure Properties in AMBs},
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_30.pdf}
}
1994 Feeny, B. Stability of Cylindrical and Conical Motions of a Rigid Rotor in Retainer Bearings Proceedings of ISMB4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB4_37,
  author = {B. Feeny },
  title = {Stability of Cylindrical and Conical Motions of a Rigid Rotor in Retainer Bearings },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_37.pdf}
}
1992 Feeny, B., Fumagalli, M. and Schweitzer, G. Dynamics of Rigid Rotors in Retainer Bearings Proceedings of ISMB3  
Abstract: We present results on the dynamics and loads of a rigid rotor in a simple rigid bearing with clearance. For a sliding rotor in "cylindrical motion" with Coulomb friction, the nonlinear solution yields information on the effects of both the coefficient of friction and the air gap on such motion. A more general model indicates when cylindrical and "conical" motions exist. At high speeds, cylindrical motions produce the highest bearing loads, although loads are also intolerable for conical motions.
BibTeX:
@inproceedings{ISMB3_15,
  author = {B. Feeny and M. Fumagalli and G. Schweitzer },
  title = {Dynamics of Rigid Rotors in Retainer Bearings },
  booktitle = {Proceedings of ISMB3},
  year = {1992},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb3/ismb3_submission_15.pdf}
}
2014 Felscher, P., Baumann, K. and Alber, O. Active Magnetic Bearings As a Tool for Parameter Identification of Journal Bearings Proceedings of ISMB14  
Abstract: In this overview, it is presented how Active Magnetic Bearings (AMBs) can successfully be used for the measurement of equilibrium positions and the identification of stiffness and damping coefficients of journal bearings. Therefore, the theory of force measurements in AMBs by using either a theoretical or an experimentally derived relation is provided. Different operation modes of AMBs are considered, including the operation as a magnetic actuator. The successful parameter identification of journal bearing properties using AMBs is demonstrated by measurements.
BibTeX:
@inproceedings{ISMB14_24,
  author = {Patrick Felscher and Katrin Baumann and Oliver Alber},
  title = {Active Magnetic Bearings As a Tool for Parameter Identification of Journal Bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_24.pdf}
}
1991 Fenn, R.C. A Six Degree-of-Freedom Lorentz Force Vibration Isolator with Nonlinear Controller Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_12,
  author = {Ralph C. Fenn},
  title = {A Six Degree-of-Freedom Lorentz Force Vibration Isolator with Nonlinear Controller},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_12.pdf}
}
1990 Fermental, D., Cusson, E. and LaRocca, P. A Decomposition of the Jeffcott Rotor  Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_40,
  author = {D. Fermental and E. Cusson and P. LaRocca },
  title = {A Decomposition of the Jeffcott Rotor },
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_40.pdf}
}
2013 Ferreira, H.P., de M. Endalecio, A.D. and Stephan, R.M. Development of Levitation Experiments for Teaching Purposes Proceedings of BWMB2013  
Abstract: The objective of this paper is to present two magnetic levitation experiments, which give a first didactic approach to the concepts necessary to understand magnetic bearings. On the first experiment, an electrodynamic levitation system with alternating current, capable of levitating metallic rings will be presented. On the second experiment, an electromagnetic levitation system, using a Hall effect sensor to measure the levitated object position – a ferromagnetic sphere combined with permanent magnets – will be described. These laboratory rigs demonstrate the importance of simulation tools and experimental work on the verification of theoretical concepts learned in Electrical/Electronic Engineering classes.
BibTeX:
@inproceedings{BWMB2013_31,
  author = {H. P. Ferreira and A. D. de M. Endalecio and R. M. Stephan},
  title = {Development of Levitation Experiments for Teaching Purposes},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {https://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_31.pdf}
}
1998 Field, R.J. and Iannello, V. A Reliable Magnetic Bearing System for Turbomachinery  Proceedings of ISMB6  
Abstract: A reliable magnetic bearing system for turbomachinery was fabricated and tested. The bearing system features high performance, high temperature actuators with integrated sensors, and an advanced rotor control system. Fault tolerance was achieved by using redundant sensors and actuator coils. The control system, which uses a triple modular redundant architecture with four processors, was integrated with the sensor electronics, amplifiers, and power supplies. The control software takes advantage of the redundant sensors and coils to provide continuous operation even in the event of a sensor, coil, or amplifier failure. The control system also includes an automatic inertial balancing system, which minimizes forces transmitted to the stationary structure by shaft unbalance. An advanced monitoring system was developed, which interfaces to the control system. It monitors system performance such as rotation rate, rotor position, and unbalance. The monitoring system also analyzes the unbalance, calculating its location and magnitude. The bearing was tested at temperatures up to 800 degF (427 degC).
BibTeX:
@inproceedings{ISMB6_5,
  author = {R. J. Field and V. Iannello},
  title = {A Reliable Magnetic Bearing System for Turbomachinery },
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_5.pdf}
}
2014 Filatov, A. and Hawkins, L. Comparative Study of Axial/Radial Magnetic Bearing Arrangements for Turbocompressor Applications Proceedings of ISMB14  
Abstract: This article presents results of a comparative study of different radial/axial actuator solutions for an Active Magnetic Bearing (AMB) system in a real-life turbocompressor application.
BibTeX:
@inproceedings{ISMB14_27,
  author = {Alexei Filatov and Larry Hawkins},
  title = {Comparative Study of Axial/Radial Magnetic Bearing Arrangements for Turbocompressor Applications},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_27.pdf}
}
2012 Filatov, A. and Hawkins, L. Constant-Flux Edge Sensor Proceedings of ISMB13  
Abstract: A novel axial position sensor is presented. The sensor offers a unique combination of advantageous properties not found collectively in other axial position sensing solutions. These include ability to work in dusty environments and in many working fluids, low sensitivity to temperature as well as external electricaland magnetic fields, good linearity over a large displacement range, large intrinsic gain, easy integration into a machine, robustness to the variations in parametersof the external wiring, simplicity of the signal processing electronics, sufficient frequency bandwidth and a commonality of used elements with radial magnetic reluctance position sensors. This paper describes the operating principle, test procedure and test results of the constant-flux edge sensor in both single-sided and differential configurations. Presently the sensor has been successfully integrated into several commercial machines and extensively tested under various operating conditions.
BibTeX:
@inproceedings{ISMB13_84,
  author = {Alexei Filatov and Larry Hawkins},
  title = {Constant-Flux Edge Sensor},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_84.pdf}
}
2008 Filatov, A., Hawkins, L., Krishnan, V. and Lam, B. Active Axial Electromagnetic Damper Proceedings of ISMB11  
Abstract: In magnetic bearing applications with rather limited axial loads and/or relaxed requirements for the axial positioning accuracy of the rotor it can be attractive to achieve the axial suspension using passive reluctance centering. In this case, however, it might be difficult to obtain the damping necessary to limit transient response to unexpected dynamic loads. A concept of an active electromagnetic axial damper developed for a 1MW 15,000RPM motor on magnetic bearings with passive axial reluctance centering is presented. The damper features a PM-biased actuator with a flux feedback. Using the flux feedback allows reducing the negative axial stiffness of the actuator to a level sufficient for using it in combination with a passive axial bearing exhibiting rather low positive axial stiffness 2400 lbf/in (420kN/m). The other advantages of the flux feedback include more linear relationship between the output force and the control command than in conventional current control as well as significant reduction of the gain and phase roll offs caused by the eddy currents. The design delivers 8760 Ns/m damping coefficient, which represents 20% of the critical damping, and 670N load capacity sufficient to address the worst-case-scenario dynamic response.
BibTeX:
@inproceedings{ISMB11_86,
  author = {Alexei Filatov and Larry Hawkins and Venky Krishnan and Bryan Lam},
  title = {Active Axial Electromagnetic Damper},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_86.pdf}
}
2016 Filatov, A., Hawkins, L. and Ukidve, C. Bias Flux Compensation in the 'Side-By-Side' Combination Radial/Axial Homopolar PM-Biased Active Magnetic Bearing Proceedings of ISMB15  
Abstract: ‘Side-By-Side’ (SBS) Combination Radial/Axial Homopolar PM-Biased Active Magnetic Bearing design has been demonstrated to be an attractive solution for many applications requiring magnetic bearings. One of the key parts of this design is a bias flux compensation coil, which is needed to maintain a constant bias flux level under various axial loads and positions of the rotor. This is important, because variations in the bias flux in the SBS combo bearing affect operating parameters of both the radial and axial channels, including actuator gains and negative stiffnesses. Besides complicating the controls, changes of the bias flux may result in losses of the load capacities, which cannot be recovered thru improving the control algorithms. Previously, the results of testing a standalone SBS combo bearing on a test rig have been presented. These included demonstrations of the effectiveness of the compensation for the effects of the axial control current on the overall bias flux. Those results showed good agreement with theoretical predictions, however, no analytical details of the compensation coil operation were given. The current paper presents the theoretical basis of the bias flux compensation. In addition, effects of the bias flux compensation on the properties of the magnetic suspension are demonstrated using a fully operational machine – a 200kW power range turbocompressor equipped with a SBS combination bearing.
BibTeX:
@inproceedings{ISMB15_88,
  author = {Alexei Filatov and Larry Hawkins and Chinmay Ukidve},
  title = {Bias Flux Compensation in the 'Side-By-Side' Combination Radial/Axial Homopolar PM-Biased Active Magnetic Bearing},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_88.pdf}
}
2000 Filatov, A. and Maslen, E. A Passive Magnetic Bearing Proceedings of ISMB7  
Abstract: A novel design for a fully passive magnetic bearing is presented. In the proposed structure, non-contact suspension of a rotor is provided without additional electronic components or an external energy supply. Also, the bearing does not make use of superconducting materials and therefore can operate over a wide range of temperatures, including room temperature. Stable suspension of the rotor in the axial direction is provided by the interaction between permanent magnets and soft-magnetic elements, installed on the rotor and the stator. Consistent with Earnshaw's theorem, since this system is stable in the axial direction, it cannot also be stable in the radial directions. To overcome this radial instability, a passive radial electromagnetic suspension system is proposed, which provides radial centering of the rotor when rotating above some critical speed. The system exploits the interaction of currents induced in shorted conducting loops installed on the rotor with the axial component of a magnetic field emanating from permanent magnets installed on the stator. This type of bearing can provide adequate stiffness and load capacity for many applications. At the same time, the lack of mechanical contact between a rotor and a stator along with lack of external energy supplies and control systems will be significant advantages compared to other magnetic bearings. To give some numerical estimates of expected bearing performance: 60N/mm theoretical estimate of a radial stiffness and 120 N radial load capacity has been obtained for a radial suspension system with a outer diameter of 28 cm and a thickness of 3.3 cm. This suspension system will support a diskshaped 2.5-kg rotor rotating above 9000rpm.
BibTeX:
@inproceedings{ISMB7_25,
  author = {Alexei Filatov and Eric Maslen},
  title = {A Passive Magnetic Bearing },
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_25.pdf}
}
2006 Filatov, A., McMullen, P., Davey, K. and Thompson, R. Flywheel Energy Storage System with Homopolar Electrodynamic Magnetic Bearing Proceedings of ISMB10  
Abstract: The goal of this research was to evaluate the potential of homopolar electrodynamic magnetic bearings for flywheel energy storage systems (FESSs). The primary target was a FESS for Low Earth Orbit (LEO) satellites, however, the design can also be easily adapted for Earth-based applications. The main advantages of Homopolar Electrodynamic Bearings compared to more conventional Active Magnetic Bearings (AMB) are simplicity and very low power ratings of their electronics. These result in higher system reliability, which is a critical factor for space applications. For commercial applications, these technologies may equally be found very attractive due to a potentially lower cost when compared to AMB.
BibTeX:
@inproceedings{ISMB10_57,
  author = {Alexei Filatov and Patrick McMullen and Kent Davey and Richard Thompson},
  title = {Flywheel Energy Storage System with Homopolar Electrodynamic Magnetic Bearing},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_57.pdf}
}
2013 Filatov, A.V. and Hawkins, L.A. Novel Combination Radial/Axial Homopolar Active Magnetic Bearing Proceedings of BWMB2013  
Abstract: A novel combination radial/axial homopolar permanent-magnet-biased electromagnetic actuator for application in active magnetic bearings is proposed. The design combines the best features of the earlier solutions: shorter axial length, lower part count, lower aerodynamic drag, lower negative stiffness and lower cost typical for combination bearings along with better axial bandwidth typically demonstrated in arrangements of separate radial and axial bearings. Furthermore, for most machines, the actuator topology leads to rotor construction that results in a higher first bending mode frequency than previous designs.
BibTeX:
@inproceedings{BWMB2013_12,
  author = {Alexei V. Filatov and Lawrence A. Hawkins},
  title = {Novel Combination Radial/Axial Homopolar Active Magnetic Bearing},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {https://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_12.pdf}
}
2004 Filatov, A.V., McMullen, P.T., Hawkins, L.A. and Blumber, E.J. Magnetic Bearing Actuator Design For A Gas Expander Generator Proceedings of ISMB9  
Abstract: A magnetic bearing system for a high-speed cryogenic gas expander/generator is presented. The expander represents a new class of such devices that, in contrast to the earlier technologies, converts the expanding gas energy into electrical power using a direct drive generator. The magnetic bearing and generator constitute a functionally complete unit that can be used in a variety of applications utilizing different expander wheels and operating at various speeds. In order to obtain a compact design and increase rotor first bending frequency, the axial magnetic bearing is designed to have different pole areas on different sides of the thrust disk. This results in different load capacities in different directions, matching operational conditions of the unit. Regardless this anisotropy, the bearing features linear force vs current dependence. Radial and angular suspension of the rotor is achieved using two patented homopolar PM-biased radial bearings. The paper discusses design and analysis of these bearings. In spite of the three-dimensional nature of the electromagnetic problem, combination of analytical solution and 2D FEA was found to be an adequate tool for the bearing analysis. Theoretical predictions of the bearing performance have been found to be in a good agreement with experimental data.
BibTeX:
@inproceedings{ISMB9_54,
  author = {Alexei V. Filatov and Patrick T. McMullen and Lawrence A. Hawkins and Eric J. Blumber},
  title = {Magnetic Bearing Actuator Design For A Gas Expander Generator },
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_54.pdf}
}
1996 Fittro, F., Knospe, C. and Stephens, S. Experimental Results of mu-Synthesis Applied to Point Compliance Minimization  Proceedings of ISMB5  
Abstract: Many practical problems in magnetic bearing control concern essentially the minimization of the compliance of the rotor at a particular pOint, often not a bearing or sensor location. Experimental results are presented which demonstrate that controller design problems of this type can be tackled via f..l-synthesis. The problem of minimizing the peak compliance at the midspan of a rotor test rig is examined. A significant improvement in performance is obtained by a multivariable f..l controller over a benchmark optimal decentralized PD controller. interestingly, the f..l controller obtained is unstable. Therefore, the rotor is first levitated with a PD controller and then the multivariable algorithm is implemented. Careful attention is given to developing an accurate system model, especially the transfer function of the magnetic actuators with solid stators.
BibTeX:
@inproceedings{ISMB5_35,
  author = {F. Fittro and C. Knospe and S. Stephens },
  title = {Experimental Results of mu-Synthesis Applied to Point Compliance Minimization },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_35.pdf}
}
1998 Fittro, R.L. and Knospe, C.R. u-Synthesis Control Design Applied to a High-Speed Machining Spindle with Active Magnetic Bearings Proceedings of ISMB6  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB6_43,
  author = {R. L. Fittro and C. R. Knospe},
  title = {u-Synthesis Control Design Applied to a High-Speed Machining Spindle with Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_43.pdf}
}
1993 Fittro, R.L., Pang, D.-C. and Anand, D.K. Neural Network Controller Development for a Magnetically Suspended Flywheel Energy Storage System Proceedings of ISMST2  
Abstract: A neural network controller has been developed to accommodate disturbances and nonlinearities and improve the robustness of a magnetically suspended flywheel energy storage system. The controller is trained using the back-propagation-through-time technique incorporated with a time averaging scheme. The resulting nonlinear neural network controller improves system performance by adapting flywheel stiffness and damping based on operating speed. In addition, a hybrid multi-layered neural network controller is developed off-line which is capable of improving system performance even further. All of the research presented in this paper was implemented via a magnetic bearing computer simulation. However, careful attention was paid to developing a practical methodology which will make future application to the actual bearing system fairly straightforward.
BibTeX:
@inproceedings{ISMST2_25,
  author = {Roger L. Fittro and Da-Chen Pang and Davinder K. Anand},
  title = {Neural Network Controller Development for a Magnetically Suspended Flywheel Energy Storage System},
  booktitle = {Proceedings of ISMST2},
  year = {1993},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst2/ismst2_submission_25.pdf}
}
2014 Fleischer, E. and Hofmann, W. Linear and Nonlinear Control of a Three Pole Combined Active Magnetic Bearing - a Comparison Proceedings of ISMB14  
Abstract: This paper analyses a linear and a nonlinear control strategy for a 5-axis magnetic suspension system built with two three pole combined bearings. In these soft magnetic composites (SMC) are used as iron core material to carry the required threedimensional flux distribution. While the linear approach is designed around the CLARKE-Transformation to stabilize the bearing, the nonlinear one is based on feedback linearization to achieve a stable system even in the case of minimal bias flux. The paper outlines the control strategies and the controller design. Both schemes are compared regarding tracking behavior, decoupling performance and stability margin based on experimental results in the time and frequency domain.
BibTeX:
@inproceedings{ISMB14_88,
  author = {Erik Fleischer and Wilfried Hofmann},
  title = {Linear and Nonlinear Control of a Three Pole Combined Active Magnetic Bearing - a Comparison},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_88.pdf}
}
2013 Fleischer, E. and Hofmann, W. Elektromechanische Modellierung eines dreipoligen Kombilagers mittels des Lagrange-Formalismus Proceedings of Workshop on Magnetic Bearing Technology 9  
Abstract: Entwickelt wurde ein neuartiges dreipoliges Kombilager und erstmals Pulververbundwerkstoffe (SMC, Soft Magnetic Composite) eingesetzt. Vorgestellt wird ein elektromechanisches Simulationsmodell, das zur Verifikation des Regelsystems dient. Die angewendete Methodik auf Basis des Lagrangeschen Formalismus erlaubt eine systematische Modellierung aktiver Magnetlager als elektromechanischer Energiewandler und ber¨ucksichtigt die R¨uckwirkung der Rotorbewegung auf die Wicklungsstr¨ome, Kreiseleffekte und die magnetische Kopplung der Lagerachsen und Wicklungen. Nach einer Einf¨uhrung in den Lagrangeschen Formalismus wird seine Anwendung auf die neue Lagerstruktur gezeigt und im Experiment nachgewiesen.
BibTeX:
@inproceedings{WMLT9_11,
  author = {E. Fleischer and W. Hofmann},
  title = {Elektromechanische Modellierung eines dreipoligen Kombilagers mittels des Lagrange-Formalismus},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 9},
  year = {2013},
  url = {https://www.magneticbearings.org/wp-content/publications/wmlt9/wmlt9_11.pdf}
}
2011 Fleischer, E. and Hofmann, W. Auslegung eines Asynchronversuchsmotors mit Massivläufer für ein Hochgeschwindigkeitsmagnetlager Proceedings of Workshop on Magnetic Bearing Technology 8  
Abstract: Im Rahmen des DFG–Projekts „Verlustarme magnetische Lagerung“ werden an einem Hochgeschwindigkeitsmagnetlager Untersuchungen zu den Rotorverlusten durchgeführt. Da die magnetische Lagerung und der Antrieb eine Einheit bilden, wird zur erfolgreichen Durchführung von Auslaufversuchen eine Antriebsmaschine mit minimalen Schleppverlusten benötigt. Aufgrund der Eignung für hohe Drehzahlen und des geringen Fertigungsaufwandes wurde dafür ein Asynchronmotor mit massivem Läufer und axialen Schlitzen ausgewählt. Im folgenden wird die Auslegung dieses Versuchsmotors für einen Betrieb im Vakuum vorgestellt.
BibTeX:
@inproceedings{WMLT8_9,
  author = {E. Fleischer and W. Hofmann},
  title = {Auslegung eines Asynchronversuchsmotors mit Massivläufer für ein Hochgeschwindigkeitsmagnetlager },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 8},
  year = {2011},
  url = {https://www.magneticbearings.org/wp-content/publications/wmlt8/wmlt8_9.pdf}
}
2012 Fleischer, E., Tröger, S. and Hofmann, W. Control of a Novel Integrated Radial-Axial Magnetic Bearing Proceedings of ISMB13  
Abstract: An important application area of magnetic bearings is machinery running in vacuum. Examples include vacuum pumps, flywheels and spin wheels for space craft. Here even small rotor losses can overheat the rotor because of the low heat transfer in vacuum. Therefore this project aims at realizing a magnetic suspension with minimal rotor losses. Thus a novel magnetic bearing structure has been developed. It can generate both radial and axial forces and employs a minimal number of poles and soft magnetic composites as iron core material for minimal losses. This paper presents the new bearing structure and a control strategy for it. The designed controller is verified in simulations and first experimental results are presented as well.
BibTeX:
@inproceedings{ISMB13_76,
  author = {Erik Fleischer and Stefan Tröger and Wilfried Hofmann},
  title = {Control of a Novel Integrated Radial-Axial Magnetic Bearing},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_76.pdf}
}
1993 Flueckiger, K., Mark, S., Caswell, R. and McCallum, D. Control of Maglev Vehicles With Aerodynamic and Guideway Disturbances Proceedings of ISMST2  
Abstract: A modeling, analysis, and control design methodology is presented for maglev vehicle ride quality performance improvement as measured by the Pepler Index. Ride quality enhancement is considered through active control of secondary suspension elements and active aerodynamic surfaces mounted on the train. To analyze and quantify the benefits of active control, the authors have developed a five degree-of-freedom lumped parameter model suitable for describing a large class of maglev vehicles, including both channel and box-beam guideway configurations. Elements of this modeling capability have been recently employed in studies sponsored by the U.S. Department of Transportation (DOT). A perturbation analysis about an operating point, defined by vehicle and average crosswind velocities, yields a suitable linearized state space model for multivariable control system analysis and synthesis. Neglecting passenger compartment noise, the ride quality as quantified by the Pepler Index is readily computed from the system states. A statistical analysis is performed by modeling the crosswind disturbances and guideway variations as filtered white noise, whereby the Pepler Index is established in closed form through the solution to a matrix Lyapunov equation. Data is presented which indicates the anticipated ride quality achieved through various closed-loop control arrangements.
BibTeX:
@inproceedings{ISMST2_6,
  author = {Karl Flueckiger and Steve Mark and Ruth Caswell and Duncan McCallum},
  title = {Control of Maglev Vehicles With Aerodynamic and Guideway Disturbances},
  booktitle = {Proceedings of ISMST2},
  year = {1993},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst2/ismst2_submission_6.pdf}
}
2014 Fohler, A. and Zulehner, W. Nitsche-Type Mortaring for Simulation of Electrical Machines Proceedings of ISMB14  
Abstract: We will present a finite element program implementing the idea of Nitsche-type mortaring in the framework of simulating electrical machines. Using this method it is possible to split the domain into subdomains only connected via a function on the interface. From this approach we gain the advantage that adjacent meshes (e.g. rotor and air gap) do not have to fit together nodewise. The mortaring will be used on the interface between rotor and air gap as well as on the symmetry edges of the motor, since only a part of the machine is considered in the simulation due to motor symmetry.
BibTeX:
@inproceedings{ISMB14_109,
  author = {Armin Fohler and Walter Zulehner},
  title = {Nitsche-Type Mortaring for Simulation of Electrical Machines},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_109.pdf}
}
2014 Fohr, F., Volbers, N. and Gerster, J. High Strength Iron-Cobalt Materials for Magnetic Bearings Proceedings of ISMB14  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB14_13,
  author = {Frederik Fohr and Niklas Volbers and Joachim Gerster},
  title = {High Strength Iron-Cobalt Materials for Magnetic Bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_13.pdf}
}
2016 Fonseca, C.A., Santos, I. and Weber, H. Influence of Unbalance Levels on Nonlinear Dynamics of a Rotor-Backup Rolling Bearing System Proceedings of ISMB15  
Abstract: Rotor drops in magnetic bearing and unbalance in rotors have been objective of study for many years. The com- bination of these two well-known phenomena led to an interesting chaotic response, when the rotor touches the inner race of the back-up bearing. The present work explores the nonlinear rotor-backup-bearing dynamics both theoretically and experimentally using a fully instrumented test rig, where the position of shaft, its angular velocity and the contact forces between the shaft and the backup bearing are sampled at 25 kHz. The test rig is built by a removable passive magnetic bearing, which allows for simulation of magnetic bearing failure (loose of carrying capacity and rotor fall). A theoretical approach is given beforehand and supplies the basis of the study. Finally the presented results are commented on the point of view of nonlinear dynamics applied to the practical use. The theoretical and numerical analyzes are shown through Poincaré maps and double sided spectrum. The latter is important to characterize the condition at different levels of unbalance between forward of backwards whirl. Our preliminary results indicate that for small levels of unbalance the rotor oscillates at the bottom of the backup bear- ing. When the levels of unbalance increase, the dynamical behaviour of the rotor changes, leading to extremely harmful conditions, since the rotor can be lifted from the bottom of the bearing (contact state) and return, starting to impact on the backup inner race innumerable times without reaching a steady state.
BibTeX:
@inproceedings{ISMB15_96,
  author = {Cesar Augusto Fonseca and Ilmar Santos and Hans Weber},
  title = {Influence of Unbalance Levels on Nonlinear Dynamics of a Rotor-Backup Rolling Bearing System},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_96.pdf}
}
1996 Forch, P., Gahler, C. and Nordmann, R. AMB System for Rotordynamic Experiments: Calibration Results and Control  Proceedings of ISMB5  
Abstract: An AMB system designed especially for rotordynamic experiments has been developed. It allows selective sinusoidal excitation of forward and backward modes of the f ree rotating rotor, as well as the simulation of unbalance fo rces. A main requirement is precise force measurement. This has been achieved using flUX measurement by means of Hall sensors. Much attention has been paid to assessing the force measurement accuracy. Results are included. Furthermore, a new controller design method for AMB systems with highly flexible and gyroscopic rotors is presented.
BibTeX:
@inproceedings{ISMB5_30,
  author = {P. Forch and C. Gahler and R. Nordmann },
  title = {AMB System for Rotordynamic Experiments: Calibration Results and Control },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_30.pdf}
}
2016 Franz, D. Algorithms for self-sensing magnetic bearings using current signals and least square identification Proceedings of ISMB15  
Abstract: This paper discusses self-sensing algorithms based on least square identification for active magnetic bearings under strong eddy current influence. The considered algorithms use current data which are acquired at high frequency to estimate the air gap size by means of the actuator inductance. Eddy currents lead to a nonlinear current increase. This can result in poor position estimation accuracy when linear approximations are used. To face this problem, two approaches are considered. In the first an exponential trial function is introduced to compensate the eddy currents. Potential problems arise, because the exponent cannot be fitted with least square identification and therefore has to be taken as constant. The other utilizes the current data of two counteracting electromagnets, which are driven asymmetrically. To compensate eddy currents as well as movement induction the signals are added up, unlike other publications where they are subtracted. The estimation algorithms are investigated with measured current data. The first reduces the error to 40 % of a reference algorithm. The second shows further improvement to 20 % of the reference. However, the error absolute values are still too high for industrial applications. The paper closes with a proposal for further improvement.
BibTeX:
@inproceedings{ISMB15_63,
  author = {Daniel Franz},
  title = {Algorithms for self-sensing magnetic bearings using current signals and least square identification},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_63.pdf}
}
2018 Franz, D., Schneider, M., Richter, M. and Rinderknecht, S. Magnetically Levitated Spindle for Long Term Testing of Fiber Reinforced Plastic Proceedings of ISMB16  
Abstract: This article describes a magnetically levitated spindle for long term cyclic fatigue strength testing of cylinders made of fiber reinforced plastic. These cylinders represent the outer-rotor of a kinetic energy storage. The realized spindle design has multiple eigenmodes below the operational speed range, which are described in the first part of this paper. Because the system is operated under vacuum conditions, the second part of this paper focuses on the heat generation and distribution on the rotor during operation. First, transient electromagnetic finite element simulations are described for the active magnetic bearings. These simulations are used to derive power losses of the active components on the rotor. Second, a finite element simulation characterizes the thermal behavior of the rotor and includes thermal radiation and conduction. Using the power losses calculated in the electromagnetic simulation, the thermal simulation provides the temperature of the rotor. Finally, these results are compared with measured data from the spindle. The comparison shows that the losses in the upper bearings are underestimated by the electromagnetic simulation. Nevertheless, the simulations show that the rotor overheats during long term operation, and thus further improvements on the control of the system have to be carried out.
BibTeX:
@inproceedings{ISMB16_004,
  author = {Daniel Franz and Maximilian Schneider and Michael Richter and Stephan Rinderknecht},
  title = {Magnetically Levitated Spindle for Long Term Testing of Fiber Reinforced Plastic},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_004.pdf}
}
1988 Fremerey, J. and Lindenau, B. Ultra-Low-Friction, Zero-Power Magnetic Suspension System of the Spinning Rotor Vacuum Gauge Proceedings of ISMB1 - Courtesy of Springer-Verlag  
Abstract: Magnetic suspension systems have been developed at the University of Virginia Holmes and Beams 1937) for the special purpose of spinning small bodies up to ultimate speed. The frictional torque acting on a rotating body when being suspended in a magnetic field with a highly symmetric flux distribution around the vertical axis was found to be many orders of magnitude lower than the torque exerted by gas friction at atmospheric pressure. Consequently, that type of suspension system was proposed and used 1ateron for pressure determination in rarefied gases. Drag torques down to 10-17 Nm have been resolved under optimum laboratory conditions. The present paper describes the magnetic suspension system of the "Spinning Rotor Vacuum Gauge" (SRG) which as a commercial unit resolves about 10-14 Nm under regular laboratory conditions. This figure corresponds to a pressure resolution of about 10-7 mbar, nitrogen equivalent, of the gauge. The SRG was introduced as a transfer standard in 1979 by BIPM and is commercially available since 1981. The gauge head functions will be discussed with special emphasis on minimization of the residual drag.
BibTeX:
@inproceedings{ISMB1_6,
  author = {J.K. Fremerey and B.E. Lindenau },
  title = {Ultra-Low-Friction, Zero-Power Magnetic Suspension System of the Spinning Rotor Vacuum Gauge },
  booktitle = {Proceedings of ISMB1 - Courtesy of Springer-Verlag},
  year = {1988},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb1/ismb1_submission_6.pdf}
}
1999 Fremerey, J.K. and Kolk, M. A 500-Wh Power Flywheel on Permanent Magnet Bearings Proceedings of ISMST5  
Abstract: A 500-Wh disk-and-shaft power flywheel test prototype for possible application in uninterruptible power supply (UPS) systems is described. The system was set up in order to evaluate the stability of a passive radial permanent-magnet bearing system under static and dynamic power load of the integrated motor generator. Preliminary tests have been run under up to 15-kW transient discharge power load with no significant effect on the bearing stability.
BibTeX:
@inproceedings{ISMST5_23,
  author = {Johan K. Fremerey and Michael Kolk},
  title = {A 500-Wh Power Flywheel on Permanent Magnet Bearings},
  booktitle = {Proceedings of ISMST5},
  year = {1999},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst5/ismst5_submission_23.pdf}
}
2019 Frishman, E. The Interaction Forces in Magnetic Support Systems of Vertical Type ACES Journal 2019 vol 34 no 4 - Courtesy of ACES  
Abstract: In this article, the vertical and horizontal forces of the interaction of permanent magnets in a Magnetic Suspension (support) System of Vertical Type (MSVT) are considered. The magnetic support system contains multi-row magnetic bands (strips), which have alternating polarity. The magnetization vector, M, is directed horizontally, as opposed to classical support systems where M is directed vertically. The results of the comparison of the vertical and lateral forces for the classic Magnetic System of Horizontal Type (MSHT) and the MSVT are presented too. An effectiveness factor, mu eff = fz/mg, is adopted (where fz is the vertical force per unit length of magnetic band and mg is its weight) and is used as the principle criterion for comparison. In this paper it is shown that when the vertical displacement of the moving part of the support system of MSVT causes the vertical force, fz, to reach its maximum, the lateral force fy is at its minimum.
BibTeX:
@inproceedings{aces2019vol34no4_015,
  author = {E. Frishman},
  title = {The Interaction Forces in Magnetic Support Systems of Vertical Type},
  booktitle = {ACES Journal 2019 vol 34 no 4 - Courtesy of ACES},
  year = {2019},
  url = {https://www.magneticbearings.org/wp-content/publications/aces2019vol34no4/aces2019vol34no4_015.pdf}
}
2017 Frishman, E. A Stepped Magnetic Suspension System (SMSS) ACES Journal 2017 vol 3 no 8 - Courtesy of ACES  
Abstract: In this article, the vertical and horizontal forces of interaction of permanent magnets in a magnetic support system (magnetic suspension, MS) are considered. Permanent magnets have a stepped structure and uniform magnetization M throughout their entire volume (M = const ). The magnetic support system contains multi-row magnetic strips. The results of the comparison of the vertical and lateral forces for the classic horizontal magnetic system (HMS) are presented too. A stability factor index, the ratio of vertical to lateral force of interaction gamma= fZ/ fY, and an effectiveness factor mu eff=f Z/(mg) are defined (where mg is the weight of the magnets per unit length). A prototype of the proposed magnetic support system was built, and measurements were performed. Analysis of the obtained data indicates that the investigated magnetic suspension system performs better than the classical horizontal MS system.
BibTeX:
@inproceedings{aces2017vol3no8_014,
  author = {E. Frishman},
  title = {A Stepped Magnetic Suspension System (SMSS)},
  booktitle = {ACES Journal 2017 vol 3 no 8 - Courtesy of ACES},
  year = {2017},
  url = {https://www.magneticbearings.org/wp-content/publications/aces2017vol3no8/aces2017vol3no8_014.pdf}
}
1997 Fujii, N. Magnet Wheel Using Permanent Magnets for Repulsive Magnetic Levitation and Induction Type Thrust Proceedings of ISMST4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST4_13,
  author = {Nobuo Fujii},
  title = {Magnet Wheel Using Permanent Magnets for Repulsive Magnetic Levitation and Induction Type Thrust},
  booktitle = {Proceedings of ISMST4},
  year = {1997},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst4/ismst4_submission_13.pdf}
}
1997 Fujii, N. and Kihara, T. Two Dimensional Drive Motor with Circular Core Proceedings of ISMST4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST4_3,
  author = {N. Fujii and T. Kihara},
  title = { Two Dimensional Drive Motor with Circular Core},
  booktitle = {Proceedings of ISMST4},
  year = {1997},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst4/ismst4_submission_3.pdf}
}
1996 Fujii, N., Ogawa, K., Ohmija, K., Chida, M. and Matsumoto, T. Forces of Magnet Wheels with PMs of Various Sizes  Proceedings of ISMB5  
Abstract: To research a optimal "magnet wheel" which had proposed by the authors as a new type electromagnetic device with both magnetic levitation and linear drive function, five magnet wheels with various arrangements and sizes of permanent magnets are examined. As the results, magnet wheel with bigger magnets has better performance, and the construction with properly large number poles is favorable.
BibTeX:
@inproceedings{ISMB5_62,
  author = {N. Fujii and K. Ogawa and K. Ohmija and M. Chida and T. Matsumoto },
  title = {Forces of Magnet Wheels with PMs of Various Sizes },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_62.pdf}
}
1997 Fujimoto, H. Possibility of a Superconducting Bulk Magnet for the Maglev Train Proceedings of ISMST4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST4_1,
  author = {Hiroyuki Fujimoto},
  title = {Possibility of a Superconducting Bulk Magnet for the Maglev Train},
  booktitle = {Proceedings of ISMST4},
  year = {1997},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst4/ismst4_submission_1.pdf}
}
2002 Fujishiro, T., Hanawa, R., Sakata, Y., Chiba, A. and Fukao, T. An Analysis Of An Induction Bearingless Motor With A Squirrel Cage Rotor Proceedings of ISMB8  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB8_92,
  author = {Tsuyoshi Fujishiro and Riichirou Hanawa and Yuuji Sakata and Akira Chiba and Tadashi Fukao},
  title = {An Analysis Of An Induction Bearingless Motor With A Squirrel Cage Rotor},
  booktitle = {Proceedings of ISMB8},
  year = {2002},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb8/ismb8_submission_92.pdf}
}
1992 Fujita, M., Matsumura, F. and Namerikawa, T. Analysis and Synthesis of a Flexible Beam magnetic Suspension System Proceedings of ISMB3  
Abstract: This paper is concerned with µ-analysis and synthesis of a flexible beam magnetic suspension system. The experimental apparatus utilized in this study is a simplified model of magnetic bearings with an elastic rotor. After introducing the apparatus, a nominal model as well as a set of plant models which accounts for additive model uncertainty, is derived. We then setup robust performance objective as a structured singular value (µ) test. There, for all the possible plant models, the closed-loop system is required to be internally stable, and in addition, the weighted sensitivity is required to satisfy a certain H8 -norm condition. For the design, we make use of an iterative computing environment µ-Analysis and Synthesis Toolbox, where the so-called D-K iteration approach is employed. The designed controller is implemented using a digital signal processor µPD77230. Several experiments are carried out in order to evaluate robust performance of this design. These experimental results show that the closed-loop system achieves robust performance against various real perturbations.
BibTeX:
@inproceedings{ISMB3_47,
  author = {M. Fujita and F. Matsumura and T. Namerikawa },
  title = {Analysis and Synthesis of a Flexible Beam magnetic Suspension System },
  booktitle = {Proceedings of ISMB3},
  year = {1992},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb3/ismb3_submission_47.pdf}
}
1990 Fujita, M., Matsumura, F. and Shimizu, M. H Robust Control Design for a Magnetic Suspension System  Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_50,
  author = {M. Fujita and F. Matsumura and M. Shimizu },
  title = {H Robust Control Design for a Magnetic Suspension System },
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_50.pdf}
}
2002 Fujiwara, H., Ebina, K., Ito, M., Takahashi, N. and Matsushita, O. Control Of Flexible Rotors Supported By Active Magnetic Bearings Proceedings of ISMB8  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB8_47,
  author = {Hiroyuki Fujiwara and Koji Ebina and Makoto Ito and Naohiko Takahashi and Osami Matsushita},
  title = {Control Of Flexible Rotors Supported By Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB8},
  year = {2002},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb8/ismb8_submission_47.pdf}
}
2006 Fujiwara, H., Ito, M. and Matsushita, O. Application of Tracking Solver for Active Magnetic Bearing Controller Design Proceedings of ISMB10  
Abstract: The tracking solver we propose is defined by sliding mode control theory so that the numerical time history of the solution traces exact values. If one of the initial solutions is provided, the solver calculates all solutions as parameters change from initial to final. The solver solves linear or nonlinear equations. Here we apply it to controller design based on several control design strategies, i.e., direct pole placement, optimal control, and phase adjustment. These control design methods mainly determine control feedback gain ane other parameters required for closed-loop behavior of the system. Because this solver obtains gain and parameters as the final condition is selected, control is easier to design. We effectively tuned the controller of an active magnetic bearing using this solver.
BibTeX:
@inproceedings{ISMB10_76,
  author = {Hiroyuki Fujiwara and Makoto Ito and Osami Matsushita},
  title = {Application of Tracking Solver for Active Magnetic Bearing Controller Design},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_76.pdf}
}
2000 Fujiwara, H., Matsushita, O. and Okubo, H. Stability Evaluation of High Frequency Eigen Modes for Active Magnetic Bearing Rotors Proceedings of ISMB7  
Abstract: The servo feedback system of the active magnetic bearing (AMB) is commonly regulated by the PID control law. This law results in a very simple design. However it still contains several problems for the tuning of the control unit. In order to compensate for the insufficiency of the PID controller, a notch filter and a zero-pole canceling filter(z-p filter) are successfully introduced for tuning and stabilizing the high frequency vibration in our simulation and experiment. The stability margin of high frequency modes is increased by using these filters. For the stability evaluation, a new Nyquist plot on the log scale chart is introduced in this paper. The Nyquist plot provides the analysis of the global behavior of the locus of all eigen modes. The case study of the stability margin is presented concerning two rotors of the "long" and "flat" types, and the effective usage is demonstrated with respect to the new Nyquist plot.
BibTeX:
@inproceedings{ISMB7_14,
  author = {Hiroyuki Fujiwara and Osami Matsushita and Hiroki Okubo},
  title = {Stability Evaluation of High Frequency Eigen Modes for Active Magnetic Bearing Rotors},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_14.pdf}
}
2004 Fujiwara, H., Mizokami, Y. and Matsushita, O. Fluid Dynamic Characteristics Of A Floating Object Measured By A Magnetic Suspension And Balance System Proceedings of ISMB9  
Abstract: A Magnetic Suspension and Balance System (MSBS) provides the electromagnetic and non-contact support of a model in a wind tunnel to measure fluid-induced forces[1]-[7]. The purpose of this study is to measure the fluid-induced dynamic coefficients of an object suspended in fluid using the MSBS. We would like to propose a method for determining the effect of the fluid-induced dynamic coefficients by comparing the experimental results of the open-loop transfer function with the numerically simulated ones. In order to show the effectiveness of this method, we measured fluid-induced dynamic coefficients by exciting an object magnetically supported in water.
BibTeX:
@inproceedings{ISMB9_67,
  author = {Hiroyuki Fujiwara and Yosuke Mizokami and Osami Matsushita},
  title = {Fluid Dynamic Characteristics Of A Floating Object Measured By A Magnetic Suspension And Balance System },
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_67.pdf}
}
2008 Fukata, S. A Model of Magnetic Reluctance of Cylindrical Solid Iron Cores Proceedings of ISMB11  
Abstract: A model of magnetic reluctance is considered in the frequency domain for cylindrical solid iron-cores when magnetic flux normally enters and leaves on the circumferential surface. To have an analytical model, we take a iron core that is sufficiently high to spread the magnetic flux over the circumferential surface and not out over the upper and lower ends. First, a three-dimensional distribution of the magnetic field is solved with Laplace transform. Then, the magnetomotive force between the two pole faces is obtained by a mean value along flux paths on the surface to describe the magnetic reluctance. The model given by Bessel functions is approximated in a simple form. The numerical result is compared with an experimental result to check the applicability of the model to actual cores.
BibTeX:
@inproceedings{ISMB11_95,
  author = {Satoru Fukata},
  title = {A Model of Magnetic Reluctance of Cylindrical Solid Iron Cores },
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_95.pdf}
}
2002 Fukata, S. Electromagnetic Passive Dampers Proceedings of ISMB8  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB8_39,
  author = {Satoru Fukata},
  title = {Electromagnetic Passive Dampers},
  booktitle = {Proceedings of ISMB8},
  year = {2002},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb8/ismb8_submission_39.pdf}
}
2000 Fukata, S. A Frequency-Domain Model of Electromagnets Composed of Solid Iron Cores Proceedings of ISMB7  
Abstract: A dynamic model in the frequency domain is considered for electromagnets composed of solid iron cores with a U-shaped stator and an I-shaped moving core. Fringing effect and leakage flux, which were neglected, are considered to improve a model presented before in a simple form with a half-power of frequency. The numerical frequency response of incremental magnetic flux to magnet-coil current is compared with the experimental response. We conclude that the fringing effect is significant, but the effect of leakage flux is small in the improvement of the model.
BibTeX:
@inproceedings{ISMB7_12,
  author = {Satoru Fukata},
  title = {A Frequency-Domain Model of Electromagnets Composed of Solid Iron Cores},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_12.pdf}
}
1992 Fukata, S. and Kouya, Y. Dynamics of Active Magnetic Bearings with Magnet Cores in Shape of a Cone Proceedings of ISMB3  
Abstract: An approximately decoupling control system is designed for an active magnetic bearing system whose electromagnet cores are in the shape of a cone to have both functions of radial and thrust bearings. The bearing system is symmetric in structure: the rotor is symmetric and supported by two bearings composed of similar electromagnets at symmetrical positions with respect to the center of gravity. The magnet cores are made of solid steel. Experimental results are given for frequency responses of the rotor motion to a disturbance input and for transient responses to impact given to the rotor. The former is compared with the numerical results. The results show the usefulness of the design method of the control system.
BibTeX:
@inproceedings{ISMB3_33,
  author = {S. Fukata and Y. Kouya },
  title = {Dynamics of Active Magnetic Bearings with Magnet Cores in Shape of a Cone },
  booktitle = {Proceedings of ISMB3},
  year = {1992},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb3/ismb3_submission_33.pdf}
}
1999 Fukata, S., Kouya, Y. and Feng, S.P. A Frequency-Domain Model of Electromagnetic Actuators Composed of Solid Iron Cores With Hysteresis Effects Proceedings of ISMST5  
Abstract: A model in the frequency domain is considered and checked with experimental results for the dynamic characteristics of magnetic actuators with solid iron core. First, an analytical magnetic reluctance based on a two-dimensional analysis is approximated in a simple form with a half-power of frequency and an accompanying complex number. This approximation is used to describe the dynamic characteristics of the electromagnet system with a C-shaped stator. Magnetic hysteresis effect is considered with a simple phase shift and with the conception of a complex value of permeability; leakage flux is ignored. The model is given by relations in the form of Laplace transform with the variation of working air-gap. For the symmetric electromagnet system with a uniform cross-sectional area, the frequency responses are compared with the experimental results when the working air-gap is fixed.
BibTeX:
@inproceedings{ISMST5_15,
  author = {Satoru Fukata and Yoshinori Kouya and Shuang Ping Feng},
  title = {A Frequency-Domain Model of Electromagnetic Actuators Composed of Solid Iron Cores With Hysteresis Effects},
  booktitle = {Proceedings of ISMST5},
  year = {1999},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst5/ismst5_submission_15.pdf}
}
1994 Fukata, S. and Matsuoka, S. Control Systems and Dynamics of Cone-Shaped Magnetic Bearings Actuated by Five Electromagnets Proceedings of ISMB4  
Abstract: A five-axis control system actuating five electromagnets is considered for a symmetric magnetic bearing system composed of six electromagnets whose pole faces are in the shape of a cone to combine radial bearings with a thrust bearing. The extra one electromagnet is used only as a bias actuator. The square-root compensation is applied to linearize the control force. The linearized model is obtained with the five resultant inputs which are given by the combination of actual inputs of the electromagnets. The control system is realized with the actual inputs asigned to generate these resultant inputs, the control inputs into the individual control axes. A little modification of the assignment of the actual inputs leads to a simpler form that gives some interaction. Experimental data are obtained for frequency responses of the control systems and transient responses to impact to show the characteristics of the system.
BibTeX:
@inproceedings{ISMB4_41,
  author = {S. Fukata and S. Matsuoka },
  title = {Control Systems and Dynamics of Cone-Shaped Magnetic Bearings Actuated by Five Electromagnets },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_41.pdf}
}
1997 Fukata, S. and Yutani, K. Characteristics of Active Magnetic Bearings Biased with Permanent Magnets on the Rotor Proceedings of ISMST4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST4_18,
  author = {Satoru Fukata and Kazuyuki Yutani},
  title = {Characteristics of Active Magnetic Bearings Biased with Permanent Magnets on the Rotor},
  booktitle = {Proceedings of ISMST4},
  year = {1997},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst4/ismst4_submission_18.pdf}
}
1996 Fukata, S. and Yutani, K. Characteristics of the Magnetic System of Magnetic Bearing Biased with Permanent Magnets Attached to a Rotor  Proceedings of ISMB5  
Abstract: The characteristics of radially interacting magnetic systems are examined with respect to magnetic radial bearings consisting of permanent magnets for biasing and electromagnets for control. The permanent magnets with axial magnetization are positioned on a rotor and share the magnet poles with the electromagnets. The electromagnet coils of a pair of opposing stators are connected in series and are driven by a single power amplifier. The magnet cores are made of solid iron. The static and dynamical characteristics of the magnetic flux are measured with fixed airgap. The results are compared with the numerical results.
BibTeX:
@inproceedings{ISMB5_66,
  author = {S. Fukata and K. Yutani },
  title = {Characteristics of the Magnetic System of Magnetic Bearing Biased with Permanent Magnets Attached to a Rotor },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_66.pdf}
}
1995 Fukata, S. and Yutani, K. Dynamics of Permanent-Magnet Biased Active Magnetic Bearings Proceedings of ISMST3  
Abstract: Active magnetic radial bearings are constructed with a combination of permanent magnets to provide bias forces and electromagnets to generate control forces for the reduction of cost and the operating energy consumption. Ring-shaped permanent magnets with axial magnetization are attached to a shaft and share their magnet stators with the electromagnets. The magnet cores are made of solid iron for simplicity. A simplified magnetic circuit of the combined magnet system is analyzed with linear circuit theory by approximating the characteristics of permanent magnets with a linear relation. A linearized dynarnical model of the control force is presented with the first-order approximation of the effects of eddy currents. Frequency responses of the rotor motion to disturbance inputs and the motion for impulsive forces are tested in the non-rotating state. The frequency responses are compared with numerical results. The decay of rotor speed due to magnetic braking is examined. The experimental results and the presented linearized model are similar to those of the all-electromagnetic design.
BibTeX:
@inproceedings{ISMST3_50,
  author = {Satoru Fukata and Kazuyuki Yutani},
  title = {Dynamics of Permanent-Magnet Biased Active Magnetic Bearings},
  booktitle = {Proceedings of ISMST3},
  year = {1995},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst3/ismst3_submission_50.pdf}
}
1998 Fukata, S. and Yutani , K. Characteristics of Electromagnetic Systems of Magnetic Bearings Biased with Permanent Magnets Proceedings of ISMB6  
Abstract: Two electromagnetic systems interact each other in the active magnetic radial bearings that are combined with permanent magnets to provide bias force and electromagnets to supply control force. The characteristics are studied when a single electromagnet system is excited by a sinusoidal input with fixed working airgap. The frequency characteristics of incremental fluxes are measured in the exciting and non-exciting magnetic systems. The experimental results are compared with the numerical results based on an analysis, to check the validity of the analysis giving a deeper understanding of the complicated magnetic systems.
BibTeX:
@inproceedings{ISMB6_23,
  author = {S. Fukata and K. Yutani },
  title = {Characteristics of Electromagnetic Systems of Magnetic Bearings Biased with Permanent Magnets},
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_23.pdf}
}
2000 Fukuyama, H. and Takizawa, T. Analysis of Levitation Characteristics of Radial-Type Superconducting Magnetic Bearings Proceedings of ISMB7  
Abstract: In the design of large-scale flywheel, load capacity and bearing constants (i.e. spring and damping constants) should be accurately calculated. In this report, a newly developed analysis method for radial-type superconducting magnetic bearings (SMBs) composed of several couples of magnet rings and magnetic material spacers is described. The analysis method is based both on electromagnetic FEM of the magnetic field and the 2- Dimensional Bean Model for analysis of magnetization of oxide superconductors. To obtain accurate magnetization hysteresis that reflects the complex magnetic fields, a superconductor is meshed into cells. Then the electromagnetic force between the magnetic fields of magnets and the magnetization of the superconductor are calculated. Recently, computer programs which can calculate the axial load capacity and bearing constants of radial-type SMBs have been developed. Calculated results on axial load capacity showed good agreement with experimental results.
BibTeX:
@inproceedings{ISMB7_104,
  author = {Hiromasa Fukuyama and Takeshi Takizawa},
  title = {Analysis of Levitation Characteristics of Radial-Type Superconducting Magnetic Bearings},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_104.pdf}
}
1998 Fukuyama, H. and Takizawa, T. Honor Paper: Analysis of the Levitation Characteristics of Superconducting Magnetic Bearings  Proceedings of ISMB6  
Abstract: A new calculation method for the levitation characteristics of superconducting magnetic bearings (SMBs) is presented. The method is based both on electromagnetic FEM of the magnetic field and the 2 dimensional Bean Model for analysis of magnetization of type n superconductors. To obtain magnetizing hysteresis, a superconductor is meshed into cells for calculation. The patterns of the hysteresis are grouped into 31 cases according to variation of the parameters which are the length of the a and b sides of the cell, critical current density Jc, amplitude of the varying magnetic field ? H and the field cooling magnetic field strength Ho. Computer subroutines were made for all 31 cases in order to calculate levitation force hysteresis of any kind of SMBs in a short time. Close agreement was achieved between calculation and experiment on levitation characteristics.
BibTeX:
@inproceedings{ISMB6_18,
  author = {H. Fukuyama and T. Takizawa},
  title = {Honor Paper: Analysis of the Levitation Characteristics of Superconducting Magnetic Bearings },
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_18.pdf}
}
1996 Fumagalli, M. and Schweitzer, G. Motion of a Rotor in Retainer Bearings  Proceedings of ISMB5  
Abstract: The experimental results on the contact interaction of a spinning rotor with its retainer bearing, and the onset of the whirl motion are shown together with an analysis. Measurement data for various material combinations and for ball bearings are presented.
BibTeX:
@inproceedings{ISMB5_86,
  author = {M. Fumagalli and G. Schweitzer },
  title = {Motion of a Rotor in Retainer Bearings },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_86.pdf}
}
1994 Fumagalli, M., Varadi, P. and Schweitzer, G. Impact Dynamics of High Speed Rotors in Retainer Bearings and Measurement Concepts Proceedings of ISMB4  
Abstract: This paper presents results on the impact dynamics of a high speed rigid rotor in a simple rigid retainer bearing with small clearance. The contact between the rotor and the bearing is modelled with the Coulomb-friction law and the coefficient of restitu..tion. To measure the contact force and the contact time during the impact, we have developed a force sensing device based on Hertz Impact Theory. Analysis shows that a small air-gap is an important parameter, which influences to the whirling motion of the rotor around the bearing.
BibTeX:
@inproceedings{ISMB4_40,
  author = {M. Fumagalli and P. Varadi and G. Schweitzer },
  title = {Impact Dynamics of High Speed Rotors in Retainer Bearings and Measurement Concepts },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_40.pdf}
}
2008 Furutachi, M., Inaba, S., Takasaki, M., Ishino, Y. and Mizuno, T. Experimental Study on the Basic Characteristic of Flux Path Control Magnetic Suspension Proceedings of ISMB11  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB11_77,
  author = {Munehiro Furutachi and Shunsuke Inaba and Masaya Takasaki and Yuji Ishino and Takeshi Mizuno},
  title = {Experimental Study on the Basic Characteristic of Flux Path Control Magnetic Suspension},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_77.pdf}
}
1991 Gaffney, M.S. and Johnson, B.G. Application of Narrow Band Control to Reduce Vibrations in Magnetic Bearing Systems Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_8,
  author = {Monique S. Gaffney and Bruce G. Johnson},
  title = {Application of Narrow Band Control to Reduce Vibrations in Magnetic Bearing Systems},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_8.pdf}
}
1994 Gähler, C. and Förch, P. A Precise Magnetic Bearing Exciter for Rotordynamic Experiments Proceedings of ISMB4  
Abstract: An AMB configuration for rotor dynamic experiments is described. It allows precise test force generation while keeping the rotor floating. As the force is the primary control variable, the position is considered mainly as a disturbance input. This results in the need for new concepts: In order to achieve the desired force precision, the force is measured with Hall effect sensors. A novel geometry, a novel AMB modelling method, force computation method, and multi-level digital controller structure have been developed for this purpose. The whole system can be conveniently controlled through a MATLAB interface. It thus offers new possibilities for rotor dynamic experiments. The novel modelling method yields important new results also for conventionally used bearing geometries.
BibTeX:
@inproceedings{ISMB4_33,
  author = {C. Gähler and P. Förch },
  title = {A Precise Magnetic Bearing Exciter for Rotordynamic Experiments },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_33.pdf}
}
1994 Gähler, C. and Herzog, R. Identification of Magnetic Bearing Systems Proceedings of ISMB4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB4_49,
  author = {C. Gähler and R. Herzog },
  title = {Identification of Magnetic Bearing Systems },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_49.pdf}
}
1996 Gähler, C., Mohler, M. and Herzog, R. Multivariable Identification of Active Magnetic Bearing Systems  Proceedings of ISMB5  
Abstract: Magnetic bearing systems are unstable MIM01 plants. In addition, if the levitated rotors are flexible, there may be poorly damped resonances of the levitated rotors. Advanced control is a crucial issue. System identification is therefore an important prerequisite for fast and reliable commissioning. Reported algorithms have difficulties to estimate the real unstable poles in magnetic bearing systems. Therefore a novel algorithm for multi variable identification has been developed. One of the key ideas is to identify the system poles from the determinant of the measured frequency response function matrix. The algorithm provides a state-space model of pre-defined order and structure, suited for controller design and verification. Experimental results with measured data from a magnetic bearing system with flexible rotor are included.
BibTeX:
@inproceedings{ISMB5_2,
  author = {C. Gähler and M. Mohler and R. Herzog },
  title = {Multivariable Identification of Active Magnetic Bearing Systems },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_2.pdf}
}
2018 Gancitano, P., Schwartz, B., Fittro, R. and Knospe, C. Development of an Active Load Cell Force Measurement Test Rig Proceedings of ISMB16  
Abstract: As industrial machine performance requirements progress, accurate high frequency fluid-film bearing coefficients are necessary in order to ensure accurate prediction of system level machine rotordynamics. Traditional fluid-film bearing test rigs have been shown to enable accurate dynamic bearing coefficient identification. However, the uncertainty of these coefficients significantly increase at higher frequencies (>250 Hz). Therefore, as modern high performance machinery require high accuracy high frequency dynamic coefficient validation, a new bearing test rig design is required. This work solves this problem through the development of a new test rig based on the development of an “Active Load Cell”. The theoretical development, test rig design and detailed simulation results are presented to demonstrate the dynamic force measurement performance capabilities of an Active Load Cell over a broad frequency range.
BibTeX:
@inproceedings{ISMB16_018,
  author = {Paul Gancitano and Benstone Schwartz and Roger Fittro and Carl Knospe},
  title = {Development of an Active Load Cell Force Measurement Test Rig},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_018.pdf}
}
2018 Gao, T.-y., Zhou, J. and Jin, C.-w. Rotor Loss Optimization and Comprehensive Analysis of High-speed Magnetic Levitation Turbine Generator Proceedings of ISMB16  
Abstract: The high speed magnetic levitation turbine generator used in Organic Rankine cycle (ORC) system will produce wind friction loss due to the high density of work environment and high eddy current loss in the part of permanent magnet (PM) rotor, which obviously effect the performance and stability of PM. In order to minimize the loss of PM rotor, this paper presented a comprehensive optimization design for the stator and rotor structure of turbine-generator. Firstly, the physical performances coupled with design variables, such as loss, generator power, rotor dynamic, strength and axial force of AMB were analyzed, mainly analyzed the structural variables coupled with design variables due to the effects of single constraint and the decoupling methods, which eliminated irrelevant variables in the final optimization. Neural network was used to establish agent models for each physical performance and brought into comprehensive optimization process of total PM rotor, which greatly improved the efficiency of optimization. The result of optimization is that the total rotor loss decreased 28% and all of other physical performance meet the requirements.
BibTeX:
@inproceedings{ISMB16_063,
  author = {Tian-yu Gao and Jin Zhou and Chao-wu Jin},
  title = {Rotor Loss Optimization and Comprehensive Analysis of High-speed Magnetic Levitation Turbine Generator},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_063.pdf}
}
1993 Garbutt, K.S. and Goodyer, M.J. The Simulation of a Propulsive Jet and Force Measurement Using a Magnetically Suspended Wind Tunnel Model Proceedings of ISMST2  
Abstract: odels featuring the simulation of exhaust jets were developed for magnetic levitation in a wind tunnel. The exhaust gas was stored internally producing a discharge of sufficient duration to allow nominal steady state to be reached. The gas was stored in the form of compressed gas or a solid rocket propellant. Testing was performed with the levitated models although deficiencies prevented the detection of jet-induced aerodynamic effects. Difficulties with data reduction led to the development of a new force calibration technique, used in conjunction with an exhaust simulator and also in separate high incidence aerodynamic tests.
BibTeX:
@inproceedings{ISMST2_19,
  author = {K. S. Garbutt and M. J. Goodyer},
  title = {The Simulation of a Propulsive Jet and Force Measurement Using a Magnetically Suspended Wind Tunnel Model},
  booktitle = {Proceedings of ISMST2},
  year = {1993},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst2/ismst2_submission_19.pdf}
}
2014 Garcia, J.D.G., Gomes, A.C.D.N. and Stephan, R.M. Performance Assessment of a Self-Bearing Motor: an Application of ISO 14839 Proceedings of ISMB14  
Abstract: Two different controllers have been applied for the stabilization of a self-bearing motor prototype existing at LASUP/UFRJ (Laboratory of Applied Superconductivity – Federal University of Rio de Janeiro): a PID controller and a LQR controller. This paper compares the performance of those controllers based on criteria described on the ISO 14839 standard, which establishes requirements for AMB (Active Magnetic Bearing) applied to turbo machinery.
BibTeX:
@inproceedings{ISMB14_10,
  author = {Jose Dalvio Ghirello Garcia and Afonso Celso Del Nero Gomes and Richard M. Stephan},
  title = {Performance Assessment of a Self-Bearing Motor: an Application of ISO 14839},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_10.pdf}
}
2010 Garcia, J.D.G., del Nero Gomes, A.C. and Stephan, R.M. Benchmarking Control Techniques Applied to Magnetic Bearings: Performance Assessment Criteria Analysis Proceedings of ISMB12  
Abstract: Active Magnetic Bearings, due to a plant-intrinsic instability, require a control system for normal operation. Many control strategies have been proposed for the stabilization task, in some instances emphasizing market recognized control approaches, as PID controllers arranged in decentralized structures, and in other instances modern control approaches are envisaged, like LQR or H8 structures. The objective of this paper is to present criteria to assess the performance of such proposed controllers, in order to establish a metric to compare different control schemes. The performance assessment criteria discussed include time domain as well as frequency domain approaches. Such criteria are applied to two control systems used in a laboratory prototype to stabilize a bearingless motor, being one based on PID controllers and the other being a LQR scheme. Discussion of the results is used to select a metric to be applied in the comparison of some controller algorithms, both centralized and decoupled, in order to determine which control law best suits such a bearingless motor.
BibTeX:
@inproceedings{ISMB12_30,
  author = {José Dalvio Ghirello Garcia and Afonso Celso del Nero Gomes and Richard Magdalena Stephan},
  title = {Benchmarking Control Techniques Applied to Magnetic Bearings: Performance Assessment Criteria Analysis },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_30.pdf}
}
2004 Garvey, S.D., Kalita, K., Khoo, W.K.S. and Bradley, K.J. A 2½-D Linear Magnetic Analysis For Parallel-Airgap Radial Magnetic Bearings Proceedings of ISMB9  
Abstract: This paper provides methods for investigating the design of a class of radial magnetic bearings in which axial MMF is provided in each one of a set of flat, uniform-thickness circular discs arranged in alternation such that every second disc is mechanically attached to the rotor and the interleaving discs are fixed to the stator. The axial MMF in the rotor discs is a sinusoidal function of angle and is taken to be independent of radius. Similarly, the axial MMF in the stator discs varies sinusoidally with respect to angle and is invariant with respect to radius. Provided that both the numbers of pole-pairs of rotor and stator discs differ by 1, a net transverse force can be produced. Many questions arise with regard to the design of radial bearings of this configuration. A particular motivation behind these bearings is to achieve a high specific load capacity. This paper sets out a linear magnetic analysis for providing a first-cut approximate assessment of the force which can be generated from such bearings. The analysis proceeds using the assumption that lines of magnetic flux remain in concentric cylinders. Then for each radius, the problem of predicting the distribution of magnetic flux reduces to a 2D problem. This 2D problem is addressed using linear superposition. The flux field due to the MMF on the stator-discs is computed assuming that the rotor-discs contribute no MMF. Then the flux field due to the MMF on the rotor-discs is computed assuming that the stator-discs contribute no MMF. When these two fields are added, it is possible to compute Maxwell stresses at every position in the airgap. The net transverse components of force due to flux in a thin-walled cylindrical volume are computed and then integrated with respect to radius to produce a prediction of the total transverse flux in the bearing. This paper investigates three different arrangements. In Class I: both rotor and stator discs are considered to be made up of permanent magnet materials and the necessary MMF is generated by the distribution of permanent magnet materials in the discs. Class I is a hypothetical case only since the net force produced between rotors is a known function of the relative rotation of the two components and cannot be controlled. In Class II: the rotor is considered to be made of permanent magnet and stator is wound. In Class III: both rotor and stator are wound. Results have been shown for the Class I & II in this paper.
BibTeX:
@inproceedings{ISMB9_91,
  author = {Seamus D. Garvey and Karuna Kalita and W. K. Steve Khoo and Keith J. Bradley },
  title = {A 2½-D Linear Magnetic Analysis For Parallel-Airgap Radial Magnetic Bearings},
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_91.pdf}
}
1994 Gauss, S. and Elschner, S. Levitation and Magnetic Properties of Melt Processed High Temperature Superconductor Cylinders Proceedings of ISMB4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB4_67,
  author = {S. Gauss and S. Elschner },
  title = {Levitation and Magnetic Properties of Melt Processed High Temperature Superconductor Cylinders },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_67.pdf}
}
2016 Gavrilenko, O., Sattel, T. and Reger, J. Identification of Active Magnetic Bearing Systems Utilizing a Modulating Function Technique Proceedings of ISMB15  
Abstract: An application of modulating function (MF) technique to the direct closed-loop identification for the estimation of a continuous-time model of multi-input-multi-output magnetic bearing system from sampled data are presented in this paper. The plant description given as a differential matrix polynomial is transformed into a matrix of difference equations using the modulating function approach, which allows to avoid numerical problems by aproximating time derivatives. Additionally, the initial conditions can be neglected as a characteristic of the MF technique. The system parameter estimation represents a solution of a least-squares problem derived from the difference system model with experimental data from an industrial magentic bearing system.
BibTeX:
@inproceedings{ISMB15_84,
  author = {Olga Gavrilenko and Thomas Sattel and Johann Reger},
  title = {Identification of Active Magnetic Bearing Systems Utilizing a Modulating Function Technique},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_84.pdf}
}
1996 Gempp, T. and Schob, R. Design of a Bearingless Canned Motor Pump  Proceedings of ISMB5  
Abstract: Motors of pumps used in aggressive environments have to be protected from the fluid. A common approach is to enclose both the rotor and the stator with a metallic can: a canned pump. In today's systems the rotor is held in position with slide bearings. In this paper an approach with magnetic bearings is described. The shaft of the rotor is thereby levitated magnetically with one conventional 3-phase AC bearing, a bearingless motor and a semiactive axial bearing. Positioning and field probes sense all through the metallic can; there is no direct contact between any sensor and the medium. The pump is of centrifogal design, rated 0.6 kW and delivering 60 llmin against a pressure of 16 bar. To supply the pump, conventional industrial switched power converters are used and controlled by a digital multiprocessor system. The application of the pump is planned in the pharmaceuticallchemical industry. A prototype was built to prove the principle of a bearingless canned motor pump.
BibTeX:
@inproceedings{ISMB5_56,
  author = {T. Gempp and R. Schob },
  title = {Design of a Bearingless Canned Motor Pump },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_56.pdf}
}
2014 Genta, G. Kinetic Energy Storage: an Ideal Application for Magnetic Bearings Proceedings of ISMB14  
Abstract: Kinetic energy storage systems have a long history, but in the last half a century many studies and projects aimed to make this form of energy storage competitive with other systems were developed. One of the main problems related to flywheel energy storage is linked to the energy dissipations due to aerodynamic and bearing drag: Magnetic bearings, also due to their ability of working in vacuum, are thus intrinsically required for these applications.
BibTeX:
@inproceedings{ISMB14_2,
  author = {Giancarlo Genta},
  title = {Kinetic Energy Storage: an Ideal Application for Magnetic Bearings},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_2.pdf}
}
2004 Genta, G. and Amati, N. Geometrical Coupling Between Axial And Radial Dynamics Of AMB Proceedings of ISMB9  
Abstract: The coupling between angular and radial motion in rotors supported by AMB has been studied in a previous paper by the Authors. The present paper generalized these results to conical AMB actuators taking into account also radial-axial coupling. The aim is to assess how much these effects influence the dynamics in the small of the rotor but does not restrict to the traditional linearization. The linearized model is studied together with the complete nonlinear one, to deal also with second-order effects.
BibTeX:
@inproceedings{ISMB9_63,
  author = {Giancarlo Genta and Nicola Amati},
  title = {Geometrical Coupling Between Axial And Radial Dynamics Of AMB},
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_63.pdf}
}
2000 Genta, G. and Carabelli, S. Noncolocation Effects on Rigid Body Rotordynamics of Rotors on AMB Proceedings of ISMB7  
Abstract: The effect of sensor-actuator non-colocation on the behaviour of machines running on acive magnetic bearings is studied under the assumptions that the rotor behaves as a rigid body, the controller is an ideal decentralized proportional-derivative one, the behaviour of the bearings can be linearized and the whole machine is axially symmetrical. The possi- ble presence of an instability range, which in some cases can extend down to the zero-speed condition, is demonstrated. The effect of damping on the insta- bility range is studied, showing that it is stabilizing and that, with damping high enough, it is possible to achieve stable running in the whole working range. A simple centralized controller which cures the con- sequences of non-colocation is shown to exist and its gains are computed. The paper includes also an ex- ample related to an actual machine showing strong non-colocation effects.
BibTeX:
@inproceedings{ISMB7_10,
  author = {Giancarlo Genta and Stefano Carabelli},
  title = {Noncolocation Effects on Rigid Body Rotordynamics of Rotors on AMB},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_10.pdf}
}
1993 Genta, G., Delprete, C. and Carabelli, S. Active Magnetic Bearing Control Loop Modeling for a Finite Element Rotordynamics Code Proceedings of ISMST2  
Abstract: A mathematical model of an active electromagnetic bearing which includes the actuator, the sensor and the control system is developed and implemented in a specialized finite element code for rotordynamic analysis. The element formulation and its incorporation in the model of the machine are described in detail. A solution procedure, based on a modal approach in which the number of retained modes is controlled by the user, is then shown together with other procedures for computing the steady-state response to both static and unbalance forces. An example of application shows the numerical results obtained on a model of an electric motor suspended on a five active-axis magnetic suspension. The comparison of some of these results with the experimental characteristics of the actual system shows the ability of the present model to predict its performance.
BibTeX:
@inproceedings{ISMST2_21,
  author = {Giancarlo Genta and Cristiana Delprete and Stefano Carabelli},
  title = {Active Magnetic Bearing Control Loop Modeling for a Finite Element Rotordynamics Code},
  booktitle = {Proceedings of ISMST2},
  year = {1993},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst2/ismst2_submission_21.pdf}
}
1992 Genta, G., Delprete, C., Tonoli, T., Rava, E. and Mazzocchetti, L. Analytical and Experimental Investigation of a Magnetic radial Passive Damper Proceedings of ISMB3  
Abstract: Passive radial magnetic bearings are well suited for magnetic bearing systems both for one active-axis type and for hybrid solutions in which a passive radial magnetic bearing works together with a conventional rolling element bearing for stability. In both cases^ and particularly in the first one, the damping of the system is a critical factor to achieve the required performance, as the very low stiffness and damping characterizing the radial passive suspension can cause severe dynamic problems. The possible existence of instability regions within the supercritical working range must be avoided by adding adequate damping elements. An eddy-current passive radial damper with a simple geometrical configuration is studied firstly using analytical techniques of different complexity. The distribution of the magnetic flux density in the conductor is obtained through FEM numerical modeling. The.results obtained through the combined analytical and numerical technique are found in very good agreement with those obtained through experimental testing. The passive radial damper here studied can have applications beyond the field of passive radial magnetic bearing as it allows to raise the threshold of instability of a rotor of any type with the addition of a simple and basically low-cost device. If the magnetic field is supplied by an electromagnet instead of a permanent magnet, the possibility of supplying a damping which is both controllable and well predictable is an attractive feature added to its simplicity and low cost.
BibTeX:
@inproceedings{ISMB3_25,
  author = {G. Genta and C. Delprete and T. Tonoli and E. Rava and L. Mazzocchetti },
  title = {Analytical and Experimental Investigation of a Magnetic radial Passive Damper },
  booktitle = {Proceedings of ISMB3},
  year = {1992},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb3/ismb3_submission_25.pdf}
}
1990 Genta, G., Mazzocchetti, L. and Rava, E. Magnetic Suspension for a Turbomolecular Pump  Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_10,
  author = {G. Genta and L. Mazzocchetti and E. Rava },
  title = {Magnetic Suspension for a Turbomolecular Pump },
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_10.pdf}
}
2014 Gerami, A., Allaire, P. and Fittro, R. Modeling and Control of Magnetic Bearings with Nonlinear Magnetization Proceedings of ISMB14  
Abstract: In this paper a nonlinear modeling approach is proposed to operate magnetic bearings above the linear range and near the material saturation point. The goal is to get higher load capacity from an existing AMB system by just changing the software. In order to do this, the system should be operated in the nonlinear region of the magnetization curve and therefore should be modeled nonlinearly. Simulation results show approximately twice the force capability. The controller designed using this approach has a much better transient response and domain of attraction.
BibTeX:
@inproceedings{ISMB14_21,
  author = {Ali Gerami and Paul Allaire and Roger Fittro},
  title = {Modeling and Control of Magnetic Bearings with Nonlinear Magnetization},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_21.pdf}
}
2016 Gerami, A. and Fittro, R. Modeling and Control of Magnetic Bearings With Nonlinear Magnetization (Simulation vs. Experiment) Proceedings of ISMB15  
Abstract: This paper is a continuation of the work presented in (Gerami,,et al., 2015), which explored the use of the Lur’e formulation to achieve increased dynamic load capacity in active magnetic bearings (AMBs). The increase in the load capacity was achieved by developing a nonlinear model that enabled the system to operate in the nonlinear region of the magnetization curve. While the previous work focused on the theoretical development of the modeling and control approach, this paper verifies the results by experiments conducted on a rocking beam test rig. The experiment demonstrates that the proposed modeling and control approach significantly improves the transient response and disturbance rejection capabilities of the magnetic bearing system compared with present industrial practice. Based on the excellent agreement between simulation and experimental results, it is shown that existing industrial AMBs could be modified to be significantly more resilient to unknown external disturbances, and therefore result in fewer shutdowns and less associated damage to backup bearings. In addition, for new AMB applications, smaller AMBs could be designed using this method which would be able to handle the same worst-case disturbance forces as larger AMB systems based on standard modeling and control methods.
BibTeX:
@inproceedings{ISMB15_87,
  author = {Ali Gerami and Roger Fittro},
  title = {Modeling and Control of Magnetic Bearings With Nonlinear Magnetization (Simulation vs. Experiment)},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_87.pdf}
}
2006 Ghodsi, M., Ueno, T., Higuchi, T., Teshimab, H. and Hiranob, H. Shape Dependency in Levitation System Using HTS and Soft Magnetic Material Proceedings of ISMB10  
Abstract: It is well known that a ferromagnetic material can be levitated by a field cooled superconductor. This paper presents a new method to model the pinning effect by using a Finite Element Method (FEM). Being comparedwith the experimental results the validity of the presented method is verified. Furthermore, the effect of pole shape on the stiffness of the levitation system is investigated. The relationship between the attractive force and the air gap was numerically analyzed and experimentally measured at both, room temperature (RT) and superconductivity state (77 K). Results obtained from FEM modeling show a good agreement with experimental results. It was found that the stiffness of the system becomes almost double (6 N/mm) when the ring pole is used instead of cylindrical pole with the same surface area.
BibTeX:
@inproceedings{ISMB10_6,
  author = {Mojtaba Ghodsi and Toshiyuki Ueno and Toshiro Higuchi and Hidekazu Teshimab and Hosei Hiranob },
  title = {Shape Dependency in Levitation System Using HTS and Soft Magnetic Material},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_6.pdf}
}
2008 Ginzinger, L. and Ulbrich, H. Simulation-Based Controller Design for an Active Auxiliary Bearing Proceedings of ISMB11  
Abstract: A framework for the development of a feedback controller for an active auxiliary bearing is presented. Experiments show the success the developed control concept. A simulation for the elastic rotor and the auxiliary bearing including the non-smooth nonlinear dynamics of the rubbing contact is used to de-velop the feedback controller. The auxiliary bearing is attached to the foundation via two unidirectional actuators. The control force is applied indirectly using the active auxiliary bearing only in case of rubbing. Experimental studies have been carried out at a rotor test rig. The experiments show the outstanding success of the strategy. In case of rubbing, the contact forces are reduced up to 85%.
BibTeX:
@inproceedings{ISMB11_64,
  author = {Lucas Ginzinger and Heinz Ulbrich},
  title = {Simulation-Based Controller Design for an Active Auxiliary Bearing},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_64.pdf}
}
1988 Girault, J. Implementation of Active Magnetic Bearings on Advanced Rocket Engine Turbopumps Proceedings of ISMB1 - Courtesy of Springer-Verlag  
Abstract: Preliminary studies are conducted at SEP to clarify the advantages and drawbacks of using S2M ACTIVE MAGNETIC BEARINGS (AMB) to suspend rotors of rocket engine turbopumps. After having pointed out their specific interest for rocket propulsion, technological keys for development will be presented. These latter are found among the following subjects: AMB materials properties (mechanical and chemical), miniaturization of the electronic controller, rotordynamic prediction, fluid and electrical interfaces.
BibTeX:
@inproceedings{ISMB1_20,
  author = {J.P. Girault },
  title = {Implementation of Active Magnetic Bearings on Advanced Rocket Engine Turbopumps },
  booktitle = {Proceedings of ISMB1 - Courtesy of Springer-Verlag},
  year = {1988},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb1/ismb1_submission_20.pdf}
}
1991 Girault, J.P. Magnetic Bearings: A Key Technology for Advanced Rocket Engines? Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_4,
  author = {J. Ph. Girault},
  title = {Magnetic Bearings: A Key Technology for Advanced Rocket Engines?},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_4.pdf}
}
2006 Glauser, M. and Sanadgol, D. Automatic Initial Levitation with Active Magnetic Bearings Proceedings of ISMB10  
Abstract: Active magnetic bearings (AMBs) require a feedback controller for stable operation. This paper describes a procedure which allows for fully automated initial levitation with no knowledge about the AMB system. Combined with some adaptive or self-tuning techniques, bearings could be setup automatically with minimal human interaction, without calibration or tuning. Based on the ideal and linearized model of a single mass one degree of freedom levitated body, the criterion for a stable suspension is reviewed. A step-by-step description outlines how the needed parameters are found which lead to a stabilizing controller. A more general, hybrid model including sensor and amplifier dynamics as well as a discrete-time PID controller is used to compare the regions of stabilizing control parameters to the ideal case. The presentation of experimental data and a discussion conclude this paper.
BibTeX:
@inproceedings{ISMB10_43,
  author = {Matthias Glauser and Dorsa Sanadgol},
  title = {Automatic Initial Levitation with Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_43.pdf}
}
2018 Gloess, R. and Goos, A. Nanometer Resolution of Magnetic Levitation Stages for Planar and Linear Scan Application Proceedings of ISMB16  
Abstract: This article describes the design rules for the magnetic constraints, the sensors, and the controller for planar and linear stages for a scan application with nanometer resolution. For a new planar maglev system, it is shown that very low- and high-resolution optical incremental sensor heads can be used in small gaps inside and below the PCB. The “inside coils sensor” design leads to nonlinearities in the force generation. The article shows that the resulting nonlinearities can be eliminated by a current pre-shaping method. It is also shown that it is possible to use only incremental encoders for linear maglev scan modules as well as for gantry maglev systems, and that this is necessary for low-price area in high-precision automation.
BibTeX:
@inproceedings{ISMB16_002,
  author = {Rainer Gloess and Alexander Goos},
  title = {Nanometer Resolution of Magnetic Levitation Stages for Planar and Linear Scan Application},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_002.pdf}
}
2004 Gnaedinger, J. Increasing Market Growth By Price Cutting? Proceedings of ISMB9  
Abstract: Traditional magnetic bearings in relation to the existing ball bearing market, cover a market share in the per mil area, whereas oil and air bearing markets are in the per cent area. Achieving the cost level of oil and air bearing systems gives the magnetic bearing technology the chance to penetrate into traditional oil and air bearing markets by tippling today’s market share. This paper describes approaches, frame- and pre-conditions to reach this target with as well as the entrepreneurial consequences for magnetic bearing solution provider.
BibTeX:
@inproceedings{ISMB9_81,
  author = {Jochen Gnaedinger},
  title = {Increasing Market Growth By Price Cutting? },
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_81.pdf}
}
2004 Goethem, J.V. and Henneberger, G. Dynamic Simulation Of The Novel Xlev Magnetically Levitated Conveyor Vehicle Proceedings of ISMB9  
Abstract: In this paper a novel magnetic levitation system XLEV is presented. It is designed as a bearing system for a conveyor vehicle with very high demands on operational availability and conveyor speed combined with a minimum need for maintenance. After presentation of the mode of operation a simulation environment is described for the analysis of the dynamic behaviour. Appropriate control algorithms together with the special features of the XLEV system enable a magnetically levitated vehicle to pass a passive switch without interrupting the levitation state. Simulation results prove this remarkable feature.
BibTeX:
@inproceedings{ISMB9_73,
  author = {Jan Van Goethem and Gerhard Henneberger},
  title = {Dynamic Simulation Of The Novel Xlev Magnetically Levitated Conveyor Vehicle },
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_73.pdf}
}
2006 Gomes, R.R., Stephan, R.M. and Santisteban, J. Self-bearing Motor with DSP Based Control System Proceedings of ISMB10  
Abstract: This paper presents an adaptive digital controller for a self-bearingmotor. The controller is implemented using a DSP platform. Initially, the motor operation is explained and a mathematical model derived. The optimized performance is achieved adjusting the controller parameters as a function or the rotor angular speed. Finally, some characteristics of the DSP implementation are described.Key words– Bearingless machines, Magnetic bearings, High-speed electric motors, Feedback control systems, Emerging technologies.
BibTeX:
@inproceedings{ISMB10_20,
  author = {Rafael R. Gomes and Richard M. Stephan and Jose Santisteban},
  title = {Self-bearing Motor with DSP Based Control System},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_20.pdf}
}
1991 Goodyer, M.J. Wind Tunnel Magnetic Suspension Systems at the University of Southampton, England Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_42,
  author = {Michael J. Goodyer},
  title = {Wind Tunnel Magnetic Suspension Systems at the University of Southampton, England },
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_42.pdf}
}
2004 Gosiewski, Z. Diagnostic Of Rotating Machinery With Magnetic Bearings and Rigid Rotor Proceedings of ISMB9  
Abstract: A magnetic suspension system for bearing single axis consists of displacement and two current sensors, two opposite coils, two amplifiers, and suspended mass. Such unstable open-loop magnetic bearing system is stabilized by a microprocessor control system. The proposed diagnostic system should detect deterioration or failure of above mentioned system and indicate the failure component.A diagnostic algorithm consists of four tests. 1) Test of measurement system which we are using the observer bank in. It allows us to detect any failure in the system. 2) Test which recognizes whether the failure is in measurement system or in other components. Having a failure is in measurement system the previous test indicates which sensor is failure. 3) Identification of state and control matrices in their physical form. Identification of open-loop matrices is realized by Markov parameters model detected by the ERA algorithm. 4) Localization of failure by inspection of state and control matrices.
BibTeX:
@inproceedings{ISMB9_14,
  author = {Zdzisław Gosiewski},
  title = {Diagnostic Of Rotating Machinery With Magnetic Bearings and Rigid Rotor },
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_14.pdf}
}
1998 Gosiewski, Z. Control Design of Sensorless Magnetic Bearings for Rigid Rotor Proceedings of ISMB6  
Abstract: A model of axially-symmetric lateral motion of rigid rotor supported by two radial sensorless magnetic bearings was reduced to the modal model with complex variables. Next, this model was divided into two subsystems connected with two lateral modes: translation and rotation. The controller and observer was designed independently for each mode. This approach allows to express analytically the controller and observer gains in fimction of values of desired closed-loop poles and of plant model parameters. It was appeared that gyroscopic effects influences the controller and observer parameters.
BibTeX:
@inproceedings{ISMB6_52,
  author = {Z. Gosiewski},
  title = {Control Design of Sensorless Magnetic Bearings for Rigid Rotor},
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_52.pdf}
}
1996 Gosiewski, Z. and Falkowski, K. Two-Axial Gyroscope with Magnetically Supported Rotor  Proceedings of ISMB5  
Abstract: Gyroscope with magnetically suspended rotor is considered in the paper. There are used two models of gyroscope dynamics: full and simplified. The control law is designed for simplified linear instrument model. Controller consists of observer and LQR regulator. The same control law is joined to the full model and simplified one. To check performance of the gyroscope its dynamics and measurement path are simulated. The results of simulation can be useful for gyroscope designer.
BibTeX:
@inproceedings{ISMB5_12,
  author = {Z. Gosiewski and K. Falkowski },
  title = {Two-Axial Gyroscope with Magnetically Supported Rotor },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_12.pdf}
}
2000 Gosiewski, Z., Falkowski, K. and Sawicki, J. Introduction to Smart Magnetic Bearings Design Proceedings of ISMB7  
Abstract: Magnetic bearing systems have been studied for a number of years. Only limited work, however, has been completed on the smart magnetic bearings technology. In this paper, we provide the overview of the concept and present the formulation for control and dynamics of rigid rotor supported on smart magnetic bearings.
BibTeX:
@inproceedings{ISMB7_89,
  author = {Zdzislaw Gosiewski and Krzysztof Falkowski and Jerzy Sawicki},
  title = {Introduction to Smart Magnetic Bearings Design},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_89.pdf}
}
2000 Gosiewski, Z. and Paszowski, M. Diagnostics of Magnetic Bearings via Identification of Its Physical Parameters Proceedings of ISMB7  
Abstract: Identification of physical parameters of unstable system is an important problem, for example in the design of its diagnostic system. In the diagnostics, there are usually observed trends in physical parameters changes. An identification method of the state-space model resulting from the physics laws is presented in the paper. The method is a modification of the OKID method [3] and it works exactly in the case when the sum of the input number and output number equals to the dimension of the state vector. The existing estimator is replaced by the deadbeat state observer, and the ARX model of the observer/controller is computed. This model is used to obtain the physical state-space model of the open-loop system for voltage controlled magnetic bearing.
BibTeX:
@inproceedings{ISMB7_2,
  author = {Zdzislaw Gosiewski and Marek Paszowski},
  title = {Diagnostics of Magnetic Bearings via Identification of Its Physical Parameters},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_2.pdf}
}
2006 Gosiewski, Z. and Zokowski, M. Sliding Mode Control for Active Magnetic Bearings Proceedings of ISMB10  
Abstract: The paper evaluates the sliding mode control methodology as a control law for an active magneticbearing. Developments in power electronics has made it possible to implement a modern control theory to various kinds of electrical and mechanical systems. This paper describes sliding mode control of a single-axis magnetic bearing’s actuator. Sliding mode control (SMC) offers several advantages over the other control methods as follows: robustness; good dynamic response; simple implementation. Sliding mode control is a non-linear, model-based control method supported by the Lyapunov stability theory. It has been proved to be an efficient technique to provide good tracking performance, applied to non-linear systems with external disturbances. It also allows the plant model to be imprecise, for example a model that has been simplified due to difficulties in representing system dynamics. Among applications where sliding mode control has been applied successfully there are: submarines, ground vehiclesand aeroplanes.
BibTeX:
@inproceedings{ISMB10_72,
  author = {Zdzislaw Gosiewski and Mariusz Zokowski},
  title = {Sliding Mode Control for Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_72.pdf}
}
2015 Gouws, J., Rensburg, J.V. and Vanek, C. Backup-Bearing Lifetime Prediction using Quantified Delevitation Severity Indicators Proceedings of Workshop on Magnetic Bearing Technology 10  
Abstract: In order to improve backup bearing reliability and safety, the applicability of using quantified delevitation severity indicators Dval, Vval (as described in [1]) and AVval for predicting backup bearing life is investigated. Degradation data is gathered using a small-scale experimental test bench to delevitate a rotor under specific initial conditions and simultaneously logging the Dval value for several repeated rotor delevitation events (RDEs). Three individual sets of backup bearing degradation data is shown indicating that delevitation severity indicators change as the bearing degrades. This change could enable condition monitoring of the backup bearings where the ultimate goal of this research is to induce repeatable backup bearing failures, and subsequently analyse the Dval, Vval and AVval data in order to predict future failures on a new set of backup bearings.
BibTeX:
@inproceedings{WMLT10_7,
  author = {J.M. Gouws and J.J. Van Rensburg and C. Vanek},
  title = {Backup-Bearing Lifetime Prediction using Quantified Delevitation Severity Indicators},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 10},
  year = {2015},
  url = {https://www.magneticbearings.org/wp-content/publications/wmlt10/wmlt10_7.pdf}
}
2016 Gouws, J.M. and Rensburg, J.J.V. An Investigation into Backup Bearing Life using Quantified Rotor Delevitation Severity Indicators Proceedings of ISMB15  
Abstract: Safe and continuous operation of an active magnetic bearing (AMB) system relies heavily on its mechanical, electronic and software components. If one of these components fail, a rotor delevitation event (RDE) could be induced and possibly damage the backup bearing (BB) system. To improve BB reliability and safety, the usability of delevitation severity indicators (DVAL, VVAL and AVVAL) for predicting BB life is investigated. A small-scale active magnetic bearing system is used to generate BB degradation data by subjecting steel-caged rolling-element bearings to multiple RDEs. The RDEs are induced at specific initial conditions to analyze the statistical distribution of bearing failure. Delevitation severity indicators are subsequently used to compare a series of RDEs to find changes in BB performance characteristics. Using only shaft position and rotating speed data, this investigation showed that delevitation severity indicators change as the bearing degrades. A distinctive linear pattern of degradation is identified by calculating AVVAL for the duration when rotor whirl and bouncing occur. This linear degradation pattern is used to identify a failure zone wherein the probability of bearing failure is extremely high. A BB life prediction method based on this linear degradation pattern and AVVAL is developed and validated.
BibTeX:
@inproceedings{ISMB15_99,
  author = {Jacob Marthinus Gouws and Jan Janse Van Rensburg},
  title = {An Investigation into Backup Bearing Life using Quantified Rotor Delevitation Severity Indicators},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_99.pdf}
}
2004 Grabner, H., Bremer, H., Amrhein, W. and Silber, S. Radial Vibration Analysis Of Bearingless Slice Motors Proceedings of ISMB9  
Abstract: The bearingless slice motor with PM excited two pole rotor naturally shows a non-linear force distribution. It is common to use standard PID-positioncontrollers for industrial applications, hence it is important to know how linear control schemes will be influenced by the non-linear part. Thus, this paper is concerned with rotordynamic phenomena caused by linearly controlled bearingless slice motors. The eigenvalues of the equation of motion illustrate a region of rotational speed, at which instability occurs. It is shown that with an appropriate value of damping established by the controller or by the surrounding medium asymptotical stability can be achieved. Furthermore, the effect of applying arbitrary disturbance forces and the effect of static unbalance are treated and the maximum stationary radial amplitudes of the centre of mass are pictured. Finally, the possible benefits of a complex non-linear controller design will be discussed.
BibTeX:
@inproceedings{ISMB9_95,
  author = {Herbert Grabner and Hartmut Bremer and Wolfgang Amrhein and Siegfried Silber},
  title = {Radial Vibration Analysis Of Bearingless Slice Motors},
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_95.pdf}
}
2010 Grabner, H., Reisinger, M., Silber, S., Amrhein, W., Redemann, C. and Jenckel, P. Nonlinear Feedback Control of a Five Axes Active Magnetic Bearing Proceedings of ISMB12  
Abstract: The demands on active magnetic bearings concerning performance as well as costs are high. The proposed five axes active magnetic bearing has a compact design and runs with simplified power electronics. Owing to the nonlinearity of the plant, the use of linear control design methods alone is not suitable for achieving a high operation performance. This paper introduces a novel combined radial and axial position control algorithm. Experimental results demonstrate the effectiveness of the proposed approach.
BibTeX:
@inproceedings{ISMB12_81,
  author = {Herbert Grabner and Martin Reisinger and Siegfried Silber and Wolfgang Amrhein and Christian Redemann and Peter Jenckel},
  title = {Nonlinear Feedback Control of a Five Axes Active Magnetic Bearing },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_81.pdf}
}
2012 Grabner, H., Silber, S. and Amrhein, W. Bearingless Torque Motor - Modeling and Control Proceedings of ISMB13  
Abstract: In recent years, demands for magnetically supported direct drives which operate con-tactless and feature a high torque capacity arise in industry. This paper presents an advantageous solution for a bearingless torque motor. The proposed configuration consists of a six phase winding cofiguration with concentrated coils in double star connection to keep power electronics efforts to a minimum. The six phase winding system generates simultaneously both, the actively controlled motor torque and the radial bearing forces for radial position control. The disk shaped hollow shaft rotor carries 26 permanent mag-nets. To reduce the systems costs, tilting de ection and the axial position of the rotor are stabilized passively by the magnetic reluctance forces. The mathematical model and an appropriate control for current and voltage drivers is introduced. Finally, the prototype motor is shown with special attention to the angle and rotor position sensor evaluation.
BibTeX:
@inproceedings{ISMB13_12,
  author = {Herbert Grabner and Siegfried Silber and Wolfgang Amrhein},
  title = {Bearingless Torque Motor - Modeling and Control},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_12.pdf}
}
1998 Grbesa , B. Low Loss and Low Cost Active Radial Homopolar Magnetic Bearing Proceedings of ISMB6  
Abstract: This paper describes an analytical modeling of a new magnetic bearing with an additional permanent magnet circuit. The suggested design offers various advantages opposite conventional magnetic bearings with regard to the mechanical and electrical expenditure. Using additional permanent magnet circuits the possibility is offered to reduce the required drive power, which is necessary to obtain the radial carrying forces. A simple drive with conventional three-phase current power amplifier becomes practicable. The calculation, design and optimization of the permanent magnetic and electromagnetic circuits is realized by technical and economical point of view. The theoretical executions are concentrated on the calculation of the magnetic forces and the investigation of the coupling of the x- and y-axis. Pure analytical methods are used for this purpose. On the strength of the special arrangement of the stator rings there is a linearization and decoupling of the force characteristics. For the control behavior it leads to, that for example a stabilization of a disturbance force in x-direction causes a negligible force change in the y-axis. At this style there is nearly no coupling of the rotor position. All these influences are shown in diagrams and discussed in detail.
BibTeX:
@inproceedings{ISMB6_28,
  author = {B. Grbesa },
  title = {Low Loss and Low Cost Active Radial Homopolar Magnetic Bearing},
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_28.pdf}
}
2006 Grochmal, T.R. and Lynch, A.F. Vibration Compensation and Precision Tracking of a Rotating Shaft by Nonlinear State Feedback Proceedings of ISMB10  
Abstract: In this paper, a nonlinear observer-based state feedback is derived to achieve precision tracking of a rotating shaft supported by active magnetic bearings (AMBs). Velocity and disturbance observers are constructed which operate in a hierarchical manner. This approach reduces the order of the design and modularizes compensation for synchronous vibration. Experimental results on a commercially available five degree-of-freedom system demonstrate accurate position tracking over the bearing air gap.
BibTeX:
@inproceedings{ISMB10_75,
  author = {Thomas R. Grochmal and Alan F. Lynch},
  title = {Vibration Compensation and Precision Tracking of a Rotating Shaft by Nonlinear State Feedback},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_75.pdf}
}
2013 Gronek, M. Qalitätsplanung in der Entwurfsphase magnetgelagerter Systeme Proceedings of Workshop on Magnetic Bearing Technology 9  
Abstract: Die Markteinführung neuer Technologien und Produkte bedarf einer umfangreichen Vorarbeit. Diese beinhaltet einerseits die Entwicklung des Produktes selbst, aber gleichsam bedeutend sind die Maßnahmen zur Absicherung der Produkteigenschaften hinsichtlich der Anforderungen, die es zu erfüllen gilt. Sonder- und Einzelfertigung machen den wesentlichen Anteil in der Magnetlagertechnik aus, was dem Entwicklungsaufwand und den erforderlichen Komponenten geschuldet ist. Erreicht eine Magnetlagerentwicklung die Serienreife, so muss in den überwiegenden Fällen von einer anwendungsspezifischen Kleinserie gesprochen werden. Eine tatsächliche Standardisierung, die mit konventionellen Lagerungsarten vergleichbar wäre, gibt es nicht. Der Beitrag widmet sich dem Thema der Anforderungsanalyse einerseits aus systemtechnischer Sicht und weiter gefasst auf Anforderungen vom Anwender an das Produkt Magnetlager. Es werden die Aspekte der Qualitätsplanung und Risikominimierung für sicherheitsrelevante Maschinenbaugruppen erörtert.
BibTeX:
@inproceedings{WMLT9_12,
  author = {M. Gronek},
  title = {Qalitätsplanung in der Entwurfsphase magnetgelagerter Systeme },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 9},
  year = {2013},
  url = {https://www.magneticbearings.org/wp-content/publications/wmlt9/wmlt9_12.pdf}
}
2010 Gronek, M., Worlitz, F. and Lindenau, B.E. Experimental Investigations on the Properties and Dynamic Behaviour of a Hybrid Bearing System for Turbo Machines Proceedings of ISMB12  
Abstract: Within the frame of an international research program that was supported by the European Commission, one subtask was to determine the dynamic behaviour of rotating shafts of turbo machines using a Hybrid Magnetic Bearing Concept (HMBC). This HMBC denotes the combination of Active Magnetic Bearings (AMB) with an additional Permanent Magnetic Bearing (PMB). For the present investigations a permanent magnetic radial shear force bearing was used. Due to their characteristics the conventional active magnetic suspension and the permanent magnetic support affect each other. This mutual action has to be considered at the benefit analysis of a hybrid bearing system. This contribution outlines the scientific approach of these studies. The overarching objective was to make the results sustainable to use. Therefore validated models will be necessary that are able to recreate the dynamic behaviour of a magnetic suspended rotor with the support of an additional permanent magnetic bearing. The basis of this approach is the application of methods of theoretical and experimental modelling. The validation of the created models was made with reference to experimental tests on the FLP 500 test facility in Zittau, Germany. For the necessary experiments the completely AMB-supported test rig was equipped with an additional permanent magnetic radial bearing.
BibTeX:
@inproceedings{ISMB12_86,
  author = {Martin Gronek and Frank Worlitz and Bernd E. Lindenau},
  title = {Experimental Investigations on the Properties and Dynamic Behaviour of a Hybrid Bearing System for Turbo Machines },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_86.pdf}
}
1991 Groom, N. Overview of Magnetic Suspension Research at Langley Research Center Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_1,
  author = {Nelson Groom},
  title = {Overview of Magnetic Suspension Research at Langley Research Center},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_1.pdf}
}
2006 Gruber, W. and Amrhein, W. Design of a Bearingless Segment Motor Proceedings of ISMB10  
Abstract: Active magnetic bearings and bearingless motors have begun to be used in industry and medical technology. When the rotor is short with respect to its diameter, it is possible to stabilize three degrees of freedom passively by reluctance forces. For this type of motor a new approach to a mechanical design is presented – the Bearingless Segment Motor. This paper deduces a model of the new motor for current injection. Finite element simulations allow the optimisation of force and torque, the reduction of cogging torque and reluctance forces as well as the consideration of the passive radial and passive axial stiffness. However, the force distribution and the mathematical model are nonlinear. Therefore a suitable nonlinear control scheme is presented. The introduction of a prototype and first measurements complete the paper.
BibTeX:
@inproceedings{ISMB10_16,
  author = {Wolfgang Gruber and Wolfgang Amrhein },
  title = {Design of a Bearingless Segment Motor},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_16.pdf}
}
2008 Gruber, W., Amrhein, W. and Stallinger, T. Bearingless Segment Motor with Buried Magnets Proceedings of ISMB11  
Abstract: Bearingless motors combine contactless levitation and rotation in a preferably compact system design, because the bearing as well as motor windings are located on the same lamination stack. By the use of a proper control scheme and the superposition of different current components, bearing forces and motor torque can be generated simultaneously by applying concentrated windings. This leads to a further simplification of the mechanical configuration. The bearingless segment motor features such concentrated coils on separated stator elements, which reduce the stator iron and therefore weight and cost, especially for constructions with large diameters. However, most of the bearingless motors are de-signed with surface mounted permanent magnets on the rotor, neglecting the advantages of buried permanent magnets. In this paper a bearingless segment motor with buried permanent magnets is investigated. The mathematical model is presented, a proper control scheme is introduced and the optimization of the prototype motor is outlined. Some motor specific considerations concerning the angular sensors and the rotordynamic are also given. Finally, the performance of the bearingless segment motor with buried permanent magnets is shown by the comparison of simulation results with measurement data of the manufactured prototype.
BibTeX:
@inproceedings{ISMB11_56,
  author = {Wolfgang Gruber and Wolfgang Amrhein and Thomas Stallinger},
  title = {Bearingless Segment Motor with Buried Magnets},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_56.pdf}
}
2013 Gruber, W., Bauer, W., Amrhein, W. and Schöb, R. Betrachtungen zum lagerlosen Flux-switching Scheibenläufer Proceedings of Workshop on Magnetic Bearing Technology 9  
Abstract: Der lagerlose Flux-Switching Scheibenläufermotor ist ein sehr kompakt aufgebauter magnetisch gelagerter Antrieb, der gänzlich ohne Permanentmagnete im Rotor auskommt. Die Funktionsweise dieser neuartigen lagerlosen Motortopologie wird in diesem Aufsatz untersucht und die Eignung für einen Betrieb als lagerloser Motor mittels Gütefunktionalen bewertet. Dreidimensionale Finite-Elemente-Simulationen für eine vielversprechende Motorvariante liefern gute Ergebnisse, die in Zukunft auch mit einem Prototyp verifiziert werden sollen.
BibTeX:
@inproceedings{WMLT9_13,
  author = {W. Gruber and W. Bauer and W. Amrhein and R. Schöb},
  title = {Betrachtungen zum lagerlosen Flux-switching Scheibenläufer },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 9},
  year = {2013},
  url = {https://www.magneticbearings.org/wp-content/publications/wmlt9/wmlt9_13.pdf}
}
2014 Gruber, W., Bauer, W. and Radman, K. Comparison of Homopolar and Heteropolar Bearingless Reluctance Slice Motor Prototypes Proceedings of ISMB14  
Abstract: This paper focuses on the operational behavior of two bearingless reluctance slice motor prototypes. After a brief introduction of the two systems, experiences, obtained from both novel bearingless drives, are presented. On this basis, communalities and differences, in various areas, e. g. construction, geometric constraints, winding systems, force to torque ratio, power electronic utilization and efficiency, will be outlined. This will help to point out the applicability of the reluctance slice motor concepts for industrial utilization.
BibTeX:
@inproceedings{ISMB14_124,
  author = {Wolfgang Gruber and Walter Bauer and Karlo Radman},
  title = {Comparison of Homopolar and Heteropolar Bearingless Reluctance Slice Motor Prototypes},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_124.pdf}
}
2013 Gruber, W., Bauer, W., Radman, K., Amrhein, W. and Schoeb, R.T. Considerations Regarding Bearingless Flux-Switching Slice Motors Proceedings of BWMB2013  
Abstract: The bearingless flux-switching slice motor is a compact magnetically levitated drive featuring no permanent magnets in the rotor. In this article the working principle of this novel bearingless motor topology is studied and its operational behavior is evaluated using performance factors for bearing and torque generation. Three dimensional finite element simulations are performed to optimize a promising motor variant, showing encouraging results, that will be verified in the future with the help of a prototype.
BibTeX:
@inproceedings{BWMB2013_27,
  author = {W. Gruber and W. Bauer and K. Radman and W. Amrhein and R. T. Schoeb},
  title = {Considerations Regarding Bearingless Flux-Switching Slice Motors},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {https://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_27.pdf}
}
2012 Gruber, W., Briewasser, W., Rothböck, M., Schöb, R. and Amrhein, W. Bearingless Reluctance Slice Motors Proceedings of ISMB13  
Abstract: Bearingless permanent magnet motors are very compact and favorable for high speed designs. Especially the bearingless slice motor (using a permanent magnet excited rotor disc) features a mechanically simple and very cost effective fully magnetically levitated system by stabilizing some degrees of freedom by permanent magnetic reluctance forces. This work focuses on constructional possibilities to apply the slice rotor principle with its passive stabilization without any permanent magnetsin the rotor part. As a matter of fact, the permanent magnets are necessary and are therefore located in the stator. Possible stator compositions are outlined and separated into homopolar and heteropolar permanent magnet air gap flux types. The definition of performance parameters allows evaluating the operational behavior of the two considered bearingless reluctance slice motor types (one with hompolar and one with heteropolar air gap flux distribution). The composition, optimization and construction of a prototype are outlined in the last section. Measurements are conducted to show the proper functionality of the bearingless reluctance slice motor prototype.
BibTeX:
@inproceedings{ISMB13_82,
  author = {Wolfgang Gruber and Wolfgang Briewasser and Michael Rothböck and Reto Schöb and Wolfgang Amrhein},
  title = {Bearingless Reluctance Slice Motors},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_82.pdf}
}
2010 Gruber, W., Huber, M., Jungmayr, G. and Amrhein, W. Passive Tilt Bearings with Zero Translational Stiffness Composed of Two Permanent Magnet Rings Proceedings of ISMB12  
Abstract: This paper presents the current state of art in the control systems applied to levitation control and typical structure of digital control system. A new approach based on programmable analogue devices is proposed and an architecture of the levitation controller is presented. Some advantages and disadvantages of the considered technology are given. Finally the possible application of typical control laws and signal processing are discussed. In the experimenThis paper deals with the computation of the axial, radial and tilt stiffness of two concentric permanent magnetic rings with axial polarization. Such compositions normally correspond to either radial or axial passive magnetic bearings. In contrast to the translational degrees of freedom this paper focuses on therotational and therefore passive tilting stiffness of such systems. An important result is the exact relative position of the concentric rings for which the radial and axial stiffness is zero and the tilt stiffness is positive. Thus, such a configuration represents a pure passive magnetic tilt bearing.
BibTeX:
@inproceedings{ISMB12_20,
  author = {Wolfgang Gruber and Manfred Huber and Gerald Jungmayr and Wolfgang Amrhein},
  title = {Passive Tilt Bearings with Zero Translational Stiffness Composed of Two Permanent Magnet Rings },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_20.pdf}
}
2016 Gruber, W. and Silber, S. 20 Years Bearingless Slice Motor - its Developments and Applications Proceedings of ISMB15  
Abstract: Bearingless slice motors are very compact and cost effective systems that allow full magnetic levitation in all degrees of freedom. Due to the disc shaped rotor, tilting and axial position are passively stabilized by the permanent magnetic biased air gap field, whereas the radial position and the rotor speed are actively controlled. This paper summarizes the continuous development in the field of bearingless slice motors ongoing for over 20 years. Different implemented topologies are outlined and basic characteristic values are compared. Such an extensive overview will help to show general trends, limits and capabilities of bearingless slice motors and their applicability in industry and academia.
BibTeX:
@inproceedings{ISMB15_9,
  author = {Wolfgang Gruber and Siegfried Silber},
  title = {20 Years Bearingless Slice Motor - its Developments and Applications},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_9.pdf}
}
2014 Grund, C. and Haje, D. Qualification of Magnetic Bearings for Industrial Turbines Proceedings of ISMB14  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB14_123,
  author = {Christoph Grund and Detlef Haje},
  title = {Qualification of Magnetic Bearings for Industrial Turbines},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_123.pdf}
}
2013 Grund, C. and Rotenbach, T. Untersuchungen zu einer magnetgelagerten Industriedampfurbine Proceedings of Workshop on Magnetic Bearing Technology 9  
Abstract: Der Einsatz aktiver Magnetlager an Turboma-schinen in Kraftwerken reduziert die Brandmasse durch den Wegfall des Ölkreislaufes zur Lagerschmierung gegenüber konventionell gelagerten Turbomaschinen erheblich und ver-ringert folglich das Gefährdungspotential. Die magnetlagerspezifisch geringe Lagerreibung führt zudem zu einer Erhöhung des Wirkungsgrades und zu einer Senkung des Wartungs- und Instandhaltungsaufwandes. Die Auswertung der inhärenten Signale der Magnetlagerung – Wellenlagen und Lagerströme – bietet zusätzliche Möglichkeiten der Überwachung und Diagnose der Magnetlager als auch des Gesamtsystems.Zur Qualifizierung des Einsatzes aktiver Magnetlager an einer Speisepumpenantriebsturbine (SPAT) im Kraftwerk wurde in einem gemeinsamen Projekt zwischen der Siemens AG, der EAAT GmbH Chemnitz und dem IPM der Hochschule Zittau/Görlitz ein Großversuchsstand konzipiert und aufgebaut. Nach der Inbetriebnahme der komplexen Anlage wurden Versuche unter praxisrelevanten Bedingungen durchgeführt. Der Beitrag gibt einen Überblick über die Ver-suchsanlage und stellt die Möglichkeiten der experimentellen Untersuchungen und erste Ergebnisse vor.
BibTeX:
@inproceedings{WMLT9_1,
  author = {C. Grund and T. Rotenbach},
  title = {Untersuchungen zu einer magnetgelagerten Industriedampfurbine },
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 9},
  year = {2013},
  url = {https://www.magneticbearings.org/wp-content/publications/wmlt9/wmlt9_1.pdf}
}
2004 Gu, H., Zhao, L. and Zhao, H. Alqg Controller Design For An AMB-Flexible Rotor System Proceedings of ISMB9  
Abstract: Because active magnetic bearing (AMB) has many particular virtues, it might be the best way to support the motor rotor and gas turbine rotor in the 10MW high temperature gas-cooled test module reactor (HTR-10). The two rotors are designed to pass through the first two bending critical speed (BCS) to reach the working point. In this paper, firstly, aiming at the small experiment setup, more accurate mathematic model of AMB flexible rotor system than the rigid one heretofore is formulated with subsection discrete method (SDM). Then some valuable results, such as, eigen-frequencies changing with supporting stiffness, eigen-shapes and gyroscopic effect, etc., are drawn in figures. Finally, a controller with linear quadratic Gaussian (LQG) control synthesis adding some phase compensators is designed after some simulations. In actual experiments, the rotor could not only run up to 340 Hz, above the first BCS, but also stay at that speed stably and safely for a long time.
BibTeX:
@inproceedings{ISMB9_21,
  author = {Huidong Gu and Lei Zhao and Hongbin Zhao},
  title = {Alqg Controller Design For An AMB-Flexible Rotor System },
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_21.pdf}
}
2018 Gu, T., Zhang, Y. and Liu, S. Research on Influence of Annular Magnetic Pole on Airgap Magnetic Field and Bearing Capacity of Axial Magnetic Bearing Proceedings of ISMB16  
Abstract: In order to enhance the radial bearing capacity of the axial magnetic bearing, the magnetic field distribution of the air gap in the double-annular magnetic axial magnetic bearing and the three-annular magnetic axial magnetic bearing is simulated and studied, and the dual-ring magnetic pole shaft is established. Based on the magnetic circuit model of the magnetic bearing and the three-ring magnetic pole magnetic bearing, the effect of the annular magnetic pole on the air gap permeability and the total magnetic flux of the magnetic circuit was analyzed. The spatial distribution of air gap magnetic field between magnetic poles was obtained by finite element simulation. The distributions of axial and radial components of the air gap magnetic induction intensity were analyzed. Compared with the traditional single annular magnetic pole axial magnetic bearing structure, the multi-annular magnetic pole structure was enhanced. With the edge effect of the air gap flux, the proportion of the edge flux increases, and the axial flux ratio decreases. After that, the axial component of the magnetic induction intensity and the radial component of the radial displacement of the two-ring magnetic structure and the three-ring magnetic structure are compared and analyzed. The results show that the annular magnetic pole reduces the axial force and enhances the radial force, that is, the radial bearing capacity increases, and the axial component of the magnetic induction intensity of the three-ring magnetic structure is larger than that of the double-ring magnetic structure. The radial component of the displacement to the displacement is reduced, which provides a theoretical and experimental reference for the radial suspension of the annular magnetic axial magnetic bearing.
BibTeX:
@inproceedings{ISMB16_095,
  author = {Ting Gu and Yuzhe Zhang and Shuqin Liu},
  title = {Research on Influence of Annular Magnetic Pole on Airgap Magnetic Field and Bearing Capacity of Axial Magnetic Bearing},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_095.pdf}
}
1993 Guckel, H., Christenson, T.R., Skrobis, K.J., Klein, J. and Karnowsky, M. Planar Rotational Magnetic Micromotors With Integrated Shaft Encoder and Magnetic Rotor Levitation Proceedings of ISMST2  
Abstract: Deep x-ray lithography and electroplating may be combined to form a fabrication tool for micromechanical devices with large structural heights, to 500 _tm, and extreme edge acuities, less than 0.1 ktm run-out per 100 I.tm of height. This process concept which originated in Germany as LIGA[ 1] may be further extended by adding surface micromachining[2]. This extension permits the fabrication of precision metal and plastic parts which may be assembled into three-dimensional micromechanical components and systems. The processing tool may be used to fabricate devices from ferromagnetic material such as nickel and nickel-iron alloys. These materials when properly heat treated exhibit acceptable magnetic behavior for current to flux conversion and marginal behavior for permanent magnet applications. The tool and materials have been tested via planar, magnetic, rotational micromotor fabrication. Three phase reluctance machines of the 6:4 configuration with 280 lam diameter rotors have been tested and analyzed[3,4]. Stable rotational speeds to 34,000 rpm with output torques above 10 x 10 -9 N-m have been obtained. The behavior is monitored with integrated shaft encoders which are photodiodes which measure the rotor response. Magnetic levitation of the rotor via reluctance forces has been achieved and has reduced frictional torque losses to less than 1% of the available torque. The results indicate that high speed limits of these actuators are related to torque ripple. Hysteresis motors with magnetic bearings are under consideration and will produce high speed rotational machines with excellent sensor application potential.
BibTeX:
@inproceedings{ISMST2_32,
  author = {H. Guckel and T. R. Christenson and K. J. Skrobis and J. Klein and M. Karnowsky},
  title = {Planar Rotational Magnetic Micromotors With Integrated Shaft Encoder and Magnetic Rotor Levitation},
  booktitle = {Proceedings of ISMST2},
  year = {1993},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst2/ismst2_submission_32.pdf}
}
2010 Guo, L., Wan, L. and Yu, S. Theoretical Investigation on Dynamic Behavior of AMB-Rotor System subject to Base Motion Disturbances Proceedings of ISMB12  
Abstract: A theoretical investigation on the dynamic behavior of an AMB-rotor system subject to base motion disturbances was carried out in the present paper. The rotor responses of the AMB-rotor system under the rigid and flexible base supporting conditions were compared, which will provide theoretical basis on the base disturbance rejection performance research of AMB-rotor systems. The results show that under the rigid base supporting condition, the capacity of the AMB’s controller to suppress the base disturbances is very limited. In order to attenuate the disturbance responses, a flexible base with specified mass and stiffness should be adopted in the AMB-rotor system.
BibTeX:
@inproceedings{ISMB12_43,
  author = {Leilei Guo and Li Wan and Suyuan Yu },
  title = {Theoretical Investigation on Dynamic Behavior of AMB-Rotor System subject to Base Motion Disturbances },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_43.pdf}
}
2018 Guo, Z., Qian, M., Wang, H., Masala, A., Shultz, R.R., Yang, W., Lu, H. and Yang, T. Commissioning and Testing of Active Magnetic Bearings for HTR Production Fuel Ball Blowers Proceedings of ISMB16  
Abstract: High temperature gas cooled reactor (HTR) nuclear power plants depend on high-performance fluid machinery, including helium circulators and fuel ball blowers, for safe, reliable and efficient operation. Active magnetic bearings (AMB) have been utilized in all recent high temperature helium-cooled reactor designs as the only mature oil-free bearing technology to provide high reliability and availability of operations for these highly demanding applications. With the successful operation of the prototype, HTR production fuel ball blowers have been manufactured and the commissioning and qualification testing have been recently completed. This paper describes the technical challenges, solutions and results in the commissioning phase, and the qualification testing of the HTR production fuel ball blowers. The qualification testing included running the machine with helium gas to ensure the cooling and thermal conditions of the machine were stable at the maximum speed condition. The bearing temperatures, vibration levels and bearing dynamic loads were measured and were all as expected. In addition, five full speed landings were successfully performed on one of the production fuel ball blower machines.
BibTeX:
@inproceedings{ISMB16_006,
  author = {Zenglin Guo and Minlong Qian and Hong Wang and Andrea Masala and Richard R. Shultz and Weichang Yang and Haifei Lu and Tao Yang},
  title = {Commissioning and Testing of Active Magnetic Bearings for HTR Production Fuel Ball Blowers},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_006.pdf}
}
2016 Guo, Z., Zhou, G., Shultz, R.R. and Qian, M. Design and Qualification Testing of Active Magnetic Bearings for High-Temperature Gas-Cooled Reactors Proceedings of ISMB15  
Abstract: Active magnetic bearings have been utilized in all recent high-temperature helium-cooled reactor designs as the only mature dry bearing technology to provide high reliability and availability of operations for these highly demanding applications. High reliability and availability is accomplished through proper design of the magnetic bearings, auxiliary bearings, and control and monitoring systems, as well as the exploitation of provisions for remote observability and diagnostics. Designing magnetic bearings into HTR fluid machines such as primary helium circulators and fuel ball blowers eliminates bearing lubricant contamination and also eliminates the ancillary equipment associated with the sealing systems for bearing lubricant. Recently a helium circulator and a fuel ball blower supported with magnetic bearings were tested separately and fully qualified for HTR plant operation. The magnetic bearings and auxiliary bearing systems were fully tested in a helium environment inside the machines. The current paper addresses the unique attributes in the design of magnetic bearing systems and the qualification testing performed for the HTR-PM fuel ball blower.
BibTeX:
@inproceedings{ISMB15_15,
  author = {Zenglin Guo and Guohui Zhou and Richard R. Shultz and Minlong Qian},
  title = {Design and Qualification Testing of Active Magnetic Bearings for High-Temperature Gas-Cooled Reactors},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_15.pdf}
}
1993 Gurumoorthy, R. and Pradeep, A.K. Modelling and Control of a Rotor Supported by Magnetic Bearings Proceedings of ISMST2  
Abstract: In this paper we develop a dynamical model of a rotor and the active magnetic bearings used to support the rotor. We use this model to develop a stable state feedback control of the magnetic bearing system. We present the development of a rigid body model of the rotor, utilizing both Rotation Matrices (Euler Angles) and Euler Parameters (Quaternions). In the latter half of the paper we develop a stable state feedback control of the actively controlled magnetic bearing to control the rotor position under imbalances. The control law developed takes into account the variation of the model with rotational speed. We show stability over the whole operating range of speeds for the magnetic bearing system. Simulation results are resented to demonstrate the closed loop system performance. We develop the model of the magnetic bearing, and present two schemes for the excitation of the poles of the actively controlled magnetic bearing. We also present a scheme for averaging multiple sensor measurements and splitting the actuation forces amongst redundant actuators.
BibTeX:
@inproceedings{ISMST2_22,
  author = {R. Gurumoorthy and A. K. Pradeep},
  title = {Modelling and Control of a Rotor Supported by Magnetic Bearings},
  booktitle = {Proceedings of ISMST2},
  year = {1993},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst2/ismst2_submission_22.pdf}
}
2014 de Haas, O. and Kuehn, L. Superconducting Magnetic Bearings for Industrial Applications Proceedings of ISMB14  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB14_129,
  author = {Oliver de Haas and Lars Kuehn},
  title = {Superconducting Magnetic Bearings for Industrial Applications},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_129.pdf}
}
1988 Hackenberg, R. and Ebert, W. High Precision Particle Beam Choppers Proceedings of ISMB1 - Courtesy of Springer-Verlag  
Abstract: The special requirements of fast rotating particle beam choppers comply best with magnetic bearings. Three types of magnetic bearings for rotor weights between 1 kg and 12 kg are described, which are used in chopper systems. The most important advantages of this bearings are a very low power consumption, a high phase stability and the suitability for high vacuum.
BibTeX:
@inproceedings{ISMB1_3,
  author = {R. Hackenberg and W. Ebert },
  title = {High Precision Particle Beam Choppers },
  booktitle = {Proceedings of ISMB1 - Courtesy of Springer-Verlag},
  year = {1988},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb1/ismb1_submission_3.pdf}
}
1988 Hackenberg, R. and Ebert, W. High Precision Particle Beam Choppers Proceedings of ISMB1 - Courtesy of Springer-Verlag  
Abstract: The special requirements of fast rotating particle beam choppers comply best with magnetic bearings. Three types of magnetic bearings for rotor weights between 1 kg and 12 kg are described, which are used in chopper systems. The most important advantages of this bearings are a very low power consumption, a high phase stability and the suitability for high vacuum.
BibTeX:
@inproceedings{ISMB1_4,
  author = {R. Hackenberg and W. Ebert },
  title = {High Precision Particle Beam Choppers },
  booktitle = {Proceedings of ISMB1 - Courtesy of Springer-Verlag},
  year = {1988},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb1/ismb1_submission_4.pdf}
}
2015 Haje, D. Oelfreie Siemens Industriedampfturbine - Erste Betriebserfahrungen Proceedings of Workshop on Magnetic Bearing Technology 10  
Abstract: Die erste ölfreie Siemens Industriedampfturbine wurde Anfang 2015 erfolgreich in Betrieb genommen und treibt seitdem eine Kesselspeisepumpe an. Dieser Beitrag berichtet über die ausgeführte Technik und erste Betriebserfahrungen.
BibTeX:
@inproceedings{WMLT10_6,
  author = {D. Haje},
  title = {Oelfreie Siemens Industriedampfturbine - Erste Betriebserfahrungen},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 10},
  year = {2015},
  url = {https://www.magneticbearings.org/wp-content/publications/wmlt10/wmlt10_6.pdf}
}
1995 Haldar, P., Hoehn, J., Selvamanickam, V., Farrell, R.A., Balachandran, U., Iyer, A.N., Peterson, E. and Salazar, K. Development of Prototype HTS Components for Magnetic Suspension Applications Proceedings of ISMST3  
Abstract: We have concentrated on developing prototype lengths of bismuth and thallium based silver sheathed superconductors by the powder-in-tube approach to fabricate high temperature superconducting (HTS) components for magnetic suspension applications. Long lengths of mono and multi filament tapes are presently being fabricated with critical current densities useful for maglev and many other applications. We have recently demonstrated the prototype manufacture of lengths exceeding 1 km of Bi-2223 multi filament conductor. Long lengths of thallium based multi-filament conductor have also been fabricated with practical levels of critical current density and improved field dependence behavior. Test coils and magnets have been built from these lengths and characterized over a range of temperatures and background fields to determine their performance. Work is in progress to develop, fabricate and test HTS windings that will be suitable for magnetic suspension, levitation and other electric power related applications.
BibTeX:
@inproceedings{ISMST3_4,
  author = {P. Haldar and J. Hoehn and V. Selvamanickam and R. A. Farrell and U. Balachandran and A. N. Iyer and E. Peterson and K. Salazar},
  title = {Development of Prototype HTS Components for Magnetic Suspension Applications },
  booktitle = {Proceedings of ISMST3},
  year = {1995},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst3/ismst3_submission_4.pdf}
}
1991 Hampton, R.D. and Knospe, C.R. Extended H2 Synthesis for Multiple Degree-of-Freedom Controllers Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_20,
  author = {R. David Hampton and Carl R. Knospe},
  title = {Extended H2 Synthesis for Multiple Degree-of-Freedom Controllers },
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_20.pdf}
}
1993 Hampton, R.D., Knospe, C.R., Allaire, P.E. and Grodinsky, C.M. Microgravity Lsolation System Design: A Modern Control Synthesis Framework Proceedings of ISMST2  
Abstract: Manned orbiters will require active vibration isolation for acceleration-sensitive microgravity science experiments. Since unibilicals are highly desirable or even indispensable for many experiments, and since their presence greatly affects the complexity of the isolation problem, they should be considered in control synthesis. In this paper a general framework is presented for applying extended H, synthesis methods to the three-dimensional microgravity isolation problem. The methodology integrates control- and state frequency weighting and input- and output disturbance accommodation techniques into the basic H2 synthesis approach. The various system models needed for design and analysis are also presented. The paper concludes with a discussion of a general design philosophy for the microgravity vibration isolation problem.
BibTeX:
@inproceedings{ISMST2_15,
  author = {R. D. Hampton and C. R. Knospe and P. E. Allaire and C. M. Grodinsky},
  title = {Microgravity Lsolation System Design: A Modern Control Synthesis Framework},
  booktitle = {Proceedings of ISMST2},
  year = {1993},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst2/ismst2_submission_15.pdf}
}
2014 Han, C., Xu, L. and Lin, Y. Researches on Substrates of High Temperature Eddy Current Sensor Proceedings of ISMB14  
Abstract: In this paper, substrates of eddy current sensor were composed by silver films and glass ceramic disks, all of these can resist high temperature . The thin silver films were deposited by radio frequency magnetron sputtering on machinable glass ceramic at room temperature. Variations of sputtering power, bios voltage and power density were carried out for each deposition, then parts of as-deposited samples were subjected to annealing at 600 ? within a vacuum chamber. Structural properties were studied by X-ray diffraction (XRD) and scanning electron microscope (SEM). It was shown that structural properties had a strong dependency on sputtering power and annealing temperature. Electrical contact resistance measured by a four point probe instrument was directly affected by the thickness of films. It was also found that the film conductivity, especially in thinner films, was improved by the increasing grain size. Further more, the film adhesion was observed by scratch tests experiment. Finally, the subsequent processes of high temperature eddy current sensor were introduced.
BibTeX:
@inproceedings{ISMB14_41,
  author = {Chao Han and Longxiang Xu and Yingzhe Lin},
  title = {Researches on Substrates of High Temperature Eddy Current Sensor},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_41.pdf}
}
1999 Han, D.-C., Lee, S.-W., Ahn, H.-J. and Lee, S.-H. Iterative Control-Relevant Identification and Controller Enhancement of a MIMO Magnetic Bearing System Proceedings of ISMST5  
Abstract: he magnetic bearing systems are intrinsically unstable, and need the feedback control of electromagnetic forces with measured displacements. So the controller design plays an important role in constructing high performance magnetic bearing system. In case of magnetic bearing systems, the order of identified model can be high because of unknown dynamics included in closed loop systems - such as sensor dynamics, actuator dynamics - and non-linearity of magnetic bearings. "Identification for control"-joint optimization of system identification and controller design - is proposed to get the limited-order model which is suited for the design of high-performance controller. We applied the joint identification/controller design scheme to MIMO rigid rotor system supported by magnetic bearings. First, we designed controller of a nonlinear simulation model of MIMO magnetic bearing system with this scheme and proved its feasibility. Then, we performed experiments on M/MO rigid rotor system supported by magnetic bearings, and the results shows that the performance of the closed-loop system is gradually improved during the iteration.
BibTeX:
@inproceedings{ISMST5_12,
  author = {Dong-Chul Han and Sang-Wook Lee and Hyeong-Joon Ahn and Sang-Ho Lee},
  title = {Iterative Control-Relevant Identification and Controller Enhancement of a MIMO Magnetic Bearing System},
  booktitle = {Proceedings of ISMST5},
  year = {1999},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst5/ismst5_submission_12.pdf}
}
1995 Haney, J.W. and Lenzo, J. Issues Associated with a Hypersonic Maglev Sled Proceedings of ISMST3  
Abstract: Magnetic levitation has been explored for application from motors to transportation. All of these applications have been at velocities where the physics of the air or operating fluids are fairly well known. Application of Maglev to hypersonic velocities (Mach > 5) presents many opportunities, but also issues that require understanding and resolution. Use of Maglev to upgrade the High Speed Test Track at Holloman Air Force Base in Alarnogordo New Mexico is an actual hypersonic application that provides the opportunity to improve test capabilities. However, there are several design issues that require investigation. This paper presents an overview of the application of Maglev to the test track and the issues associated with developing a hypersonic Maglev sled. The focus of this paper is to address the issues with the Maglev sled design, rather than the issues with the development of superconducting magnets of the sled system.
BibTeX:
@inproceedings{ISMST3_43,
  author = {J. W. Haney and J. Lenzo},
  title = {Issues Associated with a Hypersonic Maglev Sled},
  booktitle = {Proceedings of ISMST3},
  year = {1995},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst3/ismst3_submission_43.pdf}
}
1992 Hara, S. and Echigo, K. A Trial Product of Ultra Precision Spindle Proceedings of ISMB3  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB3_40,
  author = {S. Hara and K. Echigo },
  title = {A Trial Product of Ultra Precision Spindle },
  booktitle = {Proceedings of ISMB3},
  year = {1992},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb3/ismb3_submission_40.pdf}
}
1996 Hara, S., Namerikawa, T. and Matsumura, F. Improvement of Dynamic Response by Flux Feedback on Active Magnetic Bearings  Proceedings of ISMB5  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB5_9,
  author = {S. Hara and T. Namerikawa and F. Matsumura },
  title = {Improvement of Dynamic Response by Flux Feedback on Active Magnetic Bearings },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_9.pdf}
}
2016 Hasan, S.M., Mizuno, T., Takasaki, M. and Ishino, Y. Design of an Enlarged Wind Tunnel System for Spinning Body Using Magnetic Suspension Proceedings of ISMB15  
Abstract: A new wind tunnel system for a spinning body is designed for the measurement of the hydrodynamic forces acting on the body. In this system a ferromagnetic sphere (floator) is considered to be suspended and rotated by electromagnets. The diameter and weight of this floator are 19.5mm and 28.4 g, respectively. For observing the accurate hydrodynamic phenomena around the floator by reducing the interferences with the walls, the cross section of the test chamber of the wind tunnel in the vertical plane is set to be 100×100 mm. Wind flow is considered to be in the negative x-axis direction. For compensating the effect of the wind flow, force in the opposite direction is necessary. To make a significant difference of the resultant horizontal force in this direction, the poles are arranged asymmetrically, which is a special characteristic of this design. Stable suspension and three-dimensional positioning of the body is achieved in the developed system. Spinning of the body is realized by superimposing two-phase AC signals on the control signal.
BibTeX:
@inproceedings{ISMB15_60,
  author = {Shahajada Mahmudul Hasan and Takeshi Mizuno and Masaya Takasaki and Yuji Ishino},
  title = {Design of an Enlarged Wind Tunnel System for Spinning Body Using Magnetic Suspension},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_60.pdf}
}
1991 Hawkey, T. and Torti, R. An Electrostatically Suspended, Micro-Mechanical Rate Gyroscope Nasa Contract NAS1-19282 Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_48,
  author = {Timothy Hawkey and Richard Torti},
  title = {An Electrostatically Suspended, Micro-Mechanical Rate Gyroscope Nasa Contract NAS1-19282},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_48.pdf}
}
1999 Hawkins, L.A., Murphy, B.T. and Kajs, J. Application of Permanent Magnet Bias Magnetic Bearings to an Energy Storage Flywheel Proceedings of ISMST5  
Abstract: The design and initial testing of a five axis magnetic beating system in an energy storage flywheel is presented. The flywheel is under development at the University of Texas Center for Electromechanics (UT-CEM) for application in a transit bus. CalNetix performed the system dynamic analysis, developed the magnetic bearing control algorithms, and developed the digital control hardware to meet the needs of the flywheel system. The beating system for the prototype features two types of homopolar, permanent magnet bias magnetic bearings: a combination radial/thrust bearing and a pure radial bearing. The backup bearing system features a viscously damped, compliant mount. The system has been successfully tested to the maximum design speed of 42,000 rpm. A gainscheduled, MIMO control algorithm was required to control the system modes affected by rotor gyroscopics. The implementation and basis for this control scheme is discussed. Dynamic test results are discussed relative to the rotordynamic and control system design.
BibTeX:
@inproceedings{ISMST5_25,
  author = {Lawrence A. Hawkins and Brian T. Murphy and John Kajs},
  title = {Application of Permanent Magnet Bias Magnetic Bearings to an Energy Storage Flywheel},
  booktitle = {Proceedings of ISMST5},
  year = {1999},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst5/ismst5_submission_25.pdf}
}
2004 Hawkins, L., Imani, S., Prosser, D. and Johnston, M. Design And Shop Testing Of A 165kW Cryogenic Expander/Generator On Magnetic Bearings Proceedings of ISMB9  
Abstract: A low cost cryogenic expander system that incorporates a high performance, high-speed permanent magnet generator and low loss magnetic bearings is described. The expander system will be used in industrial air separation plants that produce gases such as nitrogen, oxygen, and argon using a cryogenic distillation process. Magnetic bearings enable the key advantage of a completely oil-free system that reduces the risk of accidental contamination of the process. A single generator/bearing module was designed to accommodate a wide range of expander aerodynamic stages that operate at different speeds and power levels ranging from 9,000 RPM to 30,000 RPM and 10 kW to 165 kW. Shop testing of the unit to 30,000 rpm was completed in December 2003. The prototype unit will undergo additional loop testing at the system manufacturer’s facility and is scheduled for field installation in mid 2004. System design and test results are presented.
BibTeX:
@inproceedings{ISMB9_35,
  author = {Lawrence Hawkins and Shamim Imani and Darren Prosser and Matthew Johnston},
  title = {Design And Shop Testing Of A 165kW Cryogenic Expander/Generator On Magnetic Bearings },
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_35.pdf}
}
2002 Hawkins, L., Murphy, B., Zierer, J. and Hayes, R. Shock And Vibration Testing Of An Amb Supported Energy Storage Flywheel Proceedings of ISMB8  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB8_26,
  author = {Lawrence Hawkins and Brian Murphy and Joseph Zierer and Richard Hayes},
  title = {Shock And Vibration Testing Of An Amb Supported Energy Storage Flywheel},
  booktitle = {Proceedings of ISMB8},
  year = {2002},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb8/ismb8_submission_26.pdf}
}
2016 Hawkins, L., Wang, Z. and Wadhvani, V. Transient Simulation of Magnetic Bearing and Backup Bearing Interaction in a High Speed Rotary Atomizer Subjected to Impulsive Loads Proceedings of ISMB15  
Abstract: A high speed rotary atomizer supported by active magnetic bearings (AMB) has been in service in a pharmaceutical-processing plant for over three years. This process challenges the AMBs by imposing variable, quasi-periodic external impulses on the atomizer. The impulses are occasionally large enough to overload the AMBs, resulting in backup bearing contact during operation. Implementation of a novel impulse detection and Impulse Recovery Compensator (IRC) introduced to allow continuous operation has been previously reported. In this work, a transient, nonlinear rotordynamic simulation of the atomizer, together with field measured position and current time histories, is used to help characterize the impulsive loads, the magnetic bearing control response and backup bearing reaction loads. The simulation results provide a reasonable match to field measured position and current time histories when the impulse load is produced by a sudden large unbalance, temporary or permanent. The simulation correctly predicts that amplifier saturation is relieved and the rotor re-levitates when the control is switched to the IRC. Predicted backup bearing loads during whirl are reasonable and subsequently calculated stress levels are consistent with favorable inspections of backup bearings removed from service. Future work with the simulation will include further improvements to the amplifier and backup bearing modelling.
BibTeX:
@inproceedings{ISMB15_98,
  author = {Larry Hawkins and Zhiyang Wang and Vishal Wadhvani},
  title = {Transient Simulation of Magnetic Bearing and Backup Bearing Interaction in a High Speed Rotary Atomizer Subjected to Impulsive Loads},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_98.pdf}
}
2010 He, D., Shinshi, T., andTakashi Yuzawa, X.Z. and Sato, T. Cooperative Control of a Maglev Local Actuator with a Conventional EDM Machine for High Speed Electrical Discharge Machining Proceedings of ISMB12  
Abstract: During the process of electrical discharge machining (EDM), the distance between a work-piece and an electrode, which are submerged in dielectric machining fluid, changes as material is being removed from the work-piece and the electrode. In order to maintain a suitable distance to the work-piece to achieve a constant electrical discharge, a cooperative control system, consisting of a maglev local actuator and a conventional EDM machine, re-positions the electrode precisely and speedily.
BibTeX:
@inproceedings{ISMB12_55,
  author = {Dongjue He and Tadahiko Shinshi and Xiaoyou Zhang andTakashi Yuzawa and Tatsushi Sato},
  title = {Cooperative Control of a Maglev Local Actuator with a Conventional EDM Machine for High Speed Electrical Discharge Machining },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_55.pdf}
}
2006 He, H., Shi, L., Zhao, L. and Zhang, L. Identification of Active Magnetic Bearing System Based on Virtual Instruments Proceedings of ISMB10  
Abstract: The dynamics of the contact-free hovering active magnetic bearing (AMB) depends mainly on the implemented control law. The more of the whole rotor system characteristics are known, the higher quality controller is designed, and the more reliable rotating operation can be realized. In order to make the identification procedure more convenient, a new development platform based on virtual instruments was chosen to design the identification system. Experiment was done on an active magnetic bearing system after the identification system was finished. The model parameters of HTR-10GT principle AMB system were identified by the help of the designed identification system, and the amplitude-frequency curve, phase-frequency curve and transfer function of the AMB system in the working frequency-domain were achieved. The identified information not only lays foundation for analyzing the characteristics of the AMB system (such as zero-pole distribution, stability margin, stiffness and damping), but also offers a kind of analysis and experimental tool for the optimized designing of the control system.
BibTeX:
@inproceedings{ISMB10_63,
  author = {Hangyu He and Lei Shi and Lei Zhao and Liangju Zhang },
  title = {Identification of Active Magnetic Bearing System Based on Virtual Instruments},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_63.pdf}
}
2018 He, J., Deng, Z., Peng, C. and Li, K. Optimal Vibration Control for a Centrifugal Compressor with Magnetic Bearings by a Phase-shift Notch Filter Proceedings of ISMB16  
Abstract: Undesired vibration caused by mass imbalance is common for a centrifugal compressor supported by magnetic bearings. It poses a potential threat to system stability and operation performance. In this work, a phase-shift notch filter is adopted to suppress the synchronous vibration and stability analysis is given to ensure the system stability in the varying speed range. In order to achieve optimal dynamic performance of vibration control, the objective function is set up based on the time domain response of current, and the optimal notch filter is obtained based on the minimization of the objective function value. Finally, the effectiveness of the proposed optimal notch filter on the advancement of dynamic performance is validated through simulation results.
BibTeX:
@inproceedings{ISMB16_034,
  author = {Jiaxi He and Zhiquan Deng and Cong Peng and Kexiang Li},
  title = {Optimal Vibration Control for a Centrifugal Compressor with Magnetic Bearings by a Phase-shift Notch Filter},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_034.pdf}
}
1991 He, J.L., Rote, D.M. and Coffey, H.T. Computation of Magnetic Suspension of Maglev Systems Using Dynamic Circuit Theory Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_51,
  author = {J. L. He and D. M. Rote and H. T. Coffey},
  title = {Computation of Magnetic Suspension of Maglev Systems Using Dynamic Circuit Theory},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_51.pdf}
}
2010 He, Y., Hu, Y. and Wang, Z. Compact AMB-flywheel structure design and support control system Proceedings of ISMB12  
Abstract: In this paper, an AMB-flywheel energy storage system with 3-electromagnets is developed for minimizing flywheel size and reducing the production cost. The system description and dynamics characteristic of the AMB-flywheel system are discussed. Based on analyzing the dynamic model of the magnetic flywheel disc, the digital control system based on TMS320F2812 via using integral-separated PID control algorithm is designed, which realize the stable suspension of magnetic suspension platform.
BibTeX:
@inproceedings{ISMB12_124,
  author = {Yong He and Yefa Hu and Ziyan Wang },
  title = {Compact AMB-flywheel structure design and support control system },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_124.pdf}
}
2014 He, Y., Nonami, K. and Shimizu, F. A Method of Simple Adaptive Control for MIMO Nonlinear AMB-Flywheel Levitation System Proceedings of ISMB14  
Abstract: In this paper, AMB-flywheel is desirable to minimize the energy required for its stabilization control. We propose a design method for performing SAC control for a MIMO AMB-flywheel system with five degrees of freedom; The SAC controller was proposed for application to an AMB-flywheel system and control performance was improved by combining SAC with PID controller. The PID based SAC controller is evaluated via experiments. We present the analysis results of the influence of external disturbances from the EV driving on the road and high-speed rotation experimental results about the AMB-flywheel system. The results demonstrate that the SAC controller is feasible and effective.
BibTeX:
@inproceedings{ISMB14_82,
  author = {Yong He and Kenzo Nonami and Fumiya Shimizu},
  title = {A Method of Simple Adaptive Control for MIMO Nonlinear AMB-Flywheel Levitation System},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_82.pdf}
}
2014 He, Y., Sun, Z., Zhao, J., Shi, Z. and Shi, L. Comparison of a Model-Based and a Model-Free Unbalance Control Methods in Magnetic Bearing System Proceedings of ISMB14  
Abstract: Synchronous vibration caused by rotor imbalance is an obvious vibration problem in rotating machinery. Since active magnetic bearing has been proved to be an effective approach to solve this problem, many researchers have proposed various methods to reduce synchronous vibration and those methods can be classified into two categories: model-based method and mode-lfree method. In the paper, we use a model-free method, iterative learning control (ILC) and a model-based adaptive forced balancing methods (MBAFB) to attenuate synchronous vibration respectively and then compare their performances in several aspects. The results of this paper can provide references for the users to choose an appropriate unbalance control algorithm.
BibTeX:
@inproceedings{ISMB14_34,
  author = {Ying He and Zhe Sun and Jingjing Zhao and Zhengang Shi and Lei Shi},
  title = {Comparison of a Model-Based and a Model-Free Unbalance Control Methods in Magnetic Bearing System},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_34.pdf}
}
2014 Hearn, C., Pratap, S., Chen, D. and Longoria, R. Superconducting Bearing Design for Outer Rotor Flywheel Using Lumped Parameter Techniques Proceedings of ISMB14  
Abstract: This paper describes the application of lumped parameter modeling techniques to designing high temperature superconducting bearings for outer-rotor flywheel energy storage systems. The lumped parameter models decrease computational time by 99% compared to Finite Element Analysis (FEM) without compromising fidelity needed to capture the non-linear and hysteretic force-displacement behavior between a levitated permanent magnet and bulk superconductor. The techniques formulated can be used to quickly evaluate lifting capacity and translational stiffness for a superconducting bearing design. The validity of the modeling approach has been verified by comparing results from FEM studies and experimental tests.
BibTeX:
@inproceedings{ISMB14_51,
  author = {Clay Hearn and Siddharth Pratap and Dongmei Chen and Raul Longoria},
  title = {Superconducting Bearing Design for Outer Rotor Flywheel Using Lumped Parameter Techniques},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_51.pdf}
}
2013 Hedlund, M., Abrahamsson, J., Perez-Loya, J.J., Lundin, J. and Bernhoff, H. Passive Axial Thrust Bearing for a Flywheel Energy Storage System Proceedings of BWMB2013  
Abstract: Two types of passive magnetic lift bearings are evaluated in terms of lift force and eddy current losses. Two sources of eddy currents are analyzed with help of the finite element method, firstly losses due to non-radial magnetization of magnets, and secondly losses due to variations in remanence. Magnets placed are placed in a Halbach array on the rotor and ring-magnets are placed on the stator. Denoted semi-segmented bearings, these produce low losses in the rotor, thus limiting the need of heat transport during vacuum operation. Experimental results of lift force are presented, together with simulations results. The losses were found to be in the order of 9 W at a rotational speed of 30 000 rpm while producing 900 N of thrust. The FEM-problem is solved with time-dependent terms, and is compared with a stationary approximation.
BibTeX:
@inproceedings{BWMB2013_3,
  author = {Magnus Hedlund and Johan Abrahamsson and Jesus Jose Perez-Loya and Johan Lundin and Hans Bernhoff},
  title = {Passive Axial Thrust Bearing for a Flywheel Energy Storage System},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {https://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_3.pdf}
}
2019 Heikkinen, J.E., Kauppila, H., Smirnov, A., Sillanpaa, T., Sikanen, E. and Sopanen, J. Dynamics of an Electromechanical Touchdown Bearing Mechanism ACES Journal 2019 vol 34 no 4 - Courtesy of ACES  
Abstract: Safety bearings are used as a back-up system for the rotor-systems that use active magnet bearings for supporting the rotor. When the control fails due to unexpected events, the rotor drops on the safety bearings that prevent further damages of the system. This paper presents dynamic studies of a novel electromechanical safety bearing solution. The parts of the studied system are modeled as rigid bodies and the purpose is the study the dynamics of a real system in means of simulation. The safety bearing mechanism is manufactured and measured in the laboratory environment. The study shows that the dynamic behavior of the system can be repeated using the simulation tools that combines mechanical description of the system, electromagnetics and control system. Also, the electromechanical safety bearing solution seems to be feasible from the dynamic perspective.
BibTeX:
@inproceedings{aces2019vol34no4_005,
  author = {J. E. Heikkinen and H. Kauppila and A. Smirnov and T. Sillanpaa and E. Sikanen and J. Sopanen},
  title = {Dynamics of an Electromechanical Touchdown Bearing Mechanism},
  booktitle = {ACES Journal 2019 vol 34 no 4 - Courtesy of ACES},
  year = {2019},
  url = {https://www.magneticbearings.org/wp-content/publications/aces2019vol34no4/aces2019vol34no4_005.pdf}
}
2006 Herrmann, M. and Ulbrich, H. Studies on Coil-less Reluctance Force Actuators Proceedings of ISMB10  
Abstract: Flux control in magnetic actuators can be achieved by additional field superposition or flux path ma-nipulation. Usually, coils are used for external flux control, but inductance lags and ohmic losses degrade actuator effi-ciency. To design energy-efficient reluctance force actuators innovative concepts for controlling the magnetic flux without coils are investigated. On the one hand, this contribution deals with variable reluctance elements based on the in-verse magnetostrictive effect. On the other, magnetic flux is redirected in the magnetic circuit by means of small displacements of reluctance switch elements. For high ma-nipulation rates these elements feature cog-slot structures. Some general design rules are outlined and two examples of application are presented. An active magnetic bearing and a bidirectional actuator are simulated and compared to a bipolar electromagnetic actuator. Finally, all results show the capability of coil-less reluctance force actuators to outperform present electromagnetic systems in terms of bandwidth and energy balance.
BibTeX:
@inproceedings{ISMB10_18,
  author = {Marcus Herrmann and Heinz Ulbrich},
  title = {Studies on Coil-less Reluctance Force Actuators},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_18.pdf}
}
2000 Hertel, L. and Hofmann, W. Basic Approach for the Design of Bearingless Motors Proceedings of ISMB7  
Abstract: In this paper a basic approach for the design of bearingless motors is presented. The particularity is, that the rated values for radial force and power must be attained for the same air gap area. Starting from the known design of AC-machines the reduction of the utilization factor C by the radial force generation is considered. By an iterative sequence a reduction factor is varied until the rated values of output power and maximum radial force are reached.
BibTeX:
@inproceedings{ISMB7_57,
  author = {Lars Hertel and Wilfried Hofmann},
  title = {Basic Approach for the Design of Bearingless Motors},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_57.pdf}
}
1992 Herzog, R. A Comparison Between "Passively" and "Actively" Controlled Magnetic Bearings Proceedings of ISMB3  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB3_22,
  author = {R. Herzog },
  title = {A Comparison Between "Passively" and "Actively" Controlled Magnetic Bearings },
  booktitle = {Proceedings of ISMB3},
  year = {1992},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb3/ismb3_submission_22.pdf}
}
2008 Herzog, R., Amstad, R., Vullioud, S., Galdos, G., Muellhaupt, P. and Longchamp, R. Self-Sensing of Nonlaminated Axial Magnetic Bearings : Modelling and Validation Proceedings of ISMB11  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB11_89,
  author = {Raoul Herzog and Roman Amstad and Sebastien Vullioud and Gorka Galdos and Philippe Muellhaupt and Roland Longchamp},
  title = {Self-Sensing of Nonlaminated Axial Magnetic Bearings : Modelling and Validation},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_89.pdf}
}
2010 Herzog, R. and Blanc, P. A Comparison of Linear Periodic and Nonlinear Control Strategies for Self-Sensing Magnetic Bearings Proceedings of ISMB12  
Abstract: In this paper, the controller design for self–sensing magnetic bearings is considered using a linear time periodic (LTP) framework. The time periodicity comes from a deliberate bias flux excitation signal allowing to improve the plant properties. Design trade–offs using periodic controllers are investigated. Three design objectives are considered: 1) low sensitivity norm to ensure good robustness, 2) low controller gain to attenuate current measurement noise and to avoid voltage saturation, and 3) low mechanical compliance against external perturbation forces to ensure high bearing stiffness. Different LTP H8 controllers are designed using lifting techniques and linear matrix inequalities (LMI). The resulting controllers are validated using closed–loop simulations with the nonlinear plant.
BibTeX:
@inproceedings{ISMB12_35,
  author = {Raoul Herzog and Philippe Blanc},
  title = {A Comparison of Linear Periodic and Nonlinear Control Strategies for Self-Sensing Magnetic Bearings},
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_35.pdf}
}
1992 Herzog, R. and Bleuler, H. On Achievable H Disturbance Attenuation in AMB Control Proceedings of ISMB3  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB3_46,
  author = {R. Herzog and H. Bleuler },
  title = {On Achievable H Disturbance Attenuation in AMB Control },
  booktitle = {Proceedings of ISMB3},
  year = {1992},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb3/ismb3_submission_46.pdf}
}
1990 Herzog, R. and Bleuler, H. Stiff AMB Control Using an H Approach  Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_49,
  author = {R. Herzog and H. Bleuler },
  title = {Stiff AMB Control Using an H Approach },
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_49.pdf}
}
1993 Herzog, R. and Siegwart, R. High Performance Data Acquisition, Identification, and Monitoring for Active Magnetic Bearings Proceedings of ISMST2  
Abstract: Future Active Magnetic Bearing systems (AMB) must feature easier on-site tuning, and foundation, and enhanced monitoring and identification abilities. To get closer to these goals we developed fast parallel link from the digitally controlled AMB to Matlab, which is used on a host computer for data processing, identification and controller layout. This enables the magnetic bearing to take its frequency responses without using any additional measurement equipment. These measurements can be used for AMB identification.
BibTeX:
@inproceedings{ISMST2_3,
  author = {Raoul Herzog and Roland Siegwart},
  title = {High Performance Data Acquisition, Identification, and Monitoring for Active Magnetic Bearings},
  booktitle = {Proceedings of ISMST2},
  year = {1993},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst2/ismst2_submission_3.pdf}
}
1991 Hibner, D. and Rosado, L. Feasibility of Magnetic Bearings for Advanced Gas Turbine Engines Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_17,
  author = {David Hibner and Lewis Rosado},
  title = {Feasibility of Magnetic Bearings for Advanced Gas Turbine Engines},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_17.pdf}
}
2016 Hida, S. and Morishita, M. Modeling of a Single Point Suspended Electromagnetic Suspension Carrier System Study on Rolling Motion Proceedings of ISMB15  
Abstract: Authors made a single point suspended electromagnetic suspension (EMS) system. This EMS system was applied to a transport system. This transport system has a carrier and a guide. The carrier is provided with a magnet unit and a carrier body. The magnet unit which comprises two coils, two iron core and a permanent magnet, suspends the carrier with no contact. The guide comprises an iron plate and propelling coils. When the carrier passes through the curved section of the guide, pendulum motion occurs in the rolling direction. This is rolling motion. The rolling motion continues longer than the pitching motion caused by acceleration and deceleration. When the carrier is swaying, eddy current mainly induces in the iron plate because a magnetic field in an air gap between the iron core and the iron plate changes. The eddy current makes a difference of the convergence times between the rolling and the pitching motions. Our former research modeled the pitching motion of the carrier by considering the eddy current loss and a movement of the action point of the attractive force acting on the magnet unit. In this paper, authors make the model of the rolling motion by the same method. The validity of the modeling method is verified with simulational and experimental results.
BibTeX:
@inproceedings{ISMB15_49,
  author = {Shogo Hida and Mimpei Morishita},
  title = {Modeling of a Single Point Suspended Electromagnetic Suspension Carrier System Study on Rolling Motion},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_49.pdf}
}
1991 Higgins, M.A., Plant, D.P., Ries, D.M., Kirk, J.A. and Anand, D.K. Development of a Differentially Balanced Magnetic Bearing and Control System for Use with a Flywheel Energy Storage System Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_36,
  author = {Mark A. Higgins and David P. Plant and Douglas M. Ries and James A. Kirk and Davinder K. Anand},
  title = {Development of a Differentially Balanced Magnetic Bearing and Control System for Use with a Flywheel Energy Storage System},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_36.pdf}
}
1990 Highuchi, T., Otsuka, M., Mizuno, T. and Ide, T. Application of Periodic Learning Control with Inverse Transfer Function Compensation in Totally Active Magnetic Bearings Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_36,
  author = {T. Highuchi and M. Otsuka and T. Mizuno and T. Ide},
  title = {Application of Periodic Learning Control with Inverse Transfer Function Compensation in Totally Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_36.pdf}
}
1993 Higuchi, T. Magnetically Suspended Stepping Motors for Clean Room and Vacuum Environments Proceedings of ISMST2  
Abstract: To answer the growing needs for super-clean or contact free actuators for uses in clean room, vacuum chamber and space, innovated actuators which have the functions of stepping motors and magnetic bearings in one body have been developed. The rotor of the magnetically suspended stepping motor is suspended exactly like a magnetic bearing and totalled and positioned exactly like a stepper motor. The important trait of the developed motor is that it is not a simple mixture or combination of a stepping motor and a conventional magnetic bearing, but an amalgam of a stepping motor and a magnetic bearing. Owing to optimal design and feed-back control, a toothed stator and rotor are all that are needed structure wise for stable suspension. More than ten types of motor, such as linear type, high accurate rotary type, two-dimensional type and high vacuum type have been built and tested. This paper describes the structure and design of these motors and their performance for such applications as precise positioning rotary table, linear conveyor system and 0-Z positioner for clean room and high vacuum use.
BibTeX:
@inproceedings{ISMST2_40,
  author = {Toshiro Higuchi},
  title = {Magnetically Suspended Stepping Motors for Clean Room and Vacuum Environments},
  booktitle = {Proceedings of ISMST2},
  year = {1993},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst2/ismst2_submission_40.pdf}
}
1988 Higuchi, T. Applications of Magnetic Bearings in Robotics Proceedings of ISMB1 - Courtesy of Springer-Verlag  
Abstract: Magnetic bearings have the ability to support objects without mechanical contact. In addition they have the functions of controlling the stiffness and damping of levitation and controlling the position and attitude of the supported object wi th an accuracy of a micro meter or submicrons. By taking advantages of these characteristics of magnetic bearings, robots are expected to improve their abilities, to expand the field of activity in clean rooms and in vacuums, and to have good tools for the tasks which need precise manipulation. In this paper the following researches and attempts which are related to applications of magnetic bearings in robotics are introduced. These are: development of clean room robot of which joints are composed of magnetic bearings, development of super clean actuators which have the function of magnetic bearings and stepping motors in one construction, and development of magnetically supported intelligent hand as an end effector of robots to do precise assembling.
BibTeX:
@inproceedings{ISMB1_9,
  author = {T. Higuchi },
  title = {Applications of Magnetic Bearings in Robotics },
  booktitle = {Proceedings of ISMB1 - Courtesy of Springer-Verlag},
  year = {1988},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb1/ismb1_submission_9.pdf}
}
1990 Higuchi, T., Horikoshi, A. and Komori, T. Development of an Actuator for Super Clean Rooms and Ultra High Vacua  Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_17,
  author = {T. Higuchi and A. Horikoshi and T. Komori },
  title = {Development of an Actuator for Super Clean Rooms and Ultra High Vacua },
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_17.pdf}
}
1993 Higuchi, T., Kelley, A.J. and Tsutsui, Y. Measurement and Characterization of Force Dynamics in High T, Superconductors Proceedings of ISMST2  
Abstract: Magnetic bearing implementations using more exotic superconducting phenomena have been proliferating in recent years because they have important advantages over conventional implementations. For example, the stable suspension of an object in 6 degrees-of-freedom by superconducting means can be achieved without a control system and with the use of only a single superconductor. It follows that the construction becomes much simpler with decreased need for position sensors and stabilizers. However, it is recognized that the design of superconducting systems can be difficult because important characteristics relating to the 6 degree-of-freedom dynamics of an object suspended magnetically are not readily available and the underlying principles of superconducting phenomena are not yet completely understood. To eliminate some of the guesswork in the design process, this paper proposes a system which can resolve the mechanical properties of suspension by superconductivity and provide position and orientation dependent data about the system's damping, stiffness, and frequency response characteristics. This system employs an actively-controlled magnetically-suspended fine-motion device that can also be used as a 6 degree-of-freedom force sensor. By attaching the force sensor to a permanent magnet that is being levitated above a superconducting magnet, mechanical characteristics of the superconductor levitation can be extracted. Such information would prove useful for checking the validity of theoretical models and may even give insights into superconducting phenomena.
BibTeX:
@inproceedings{ISMST2_8,
  author = {Toshiro Higuchi and Allan J. Kelley and Yukio Tsutsui},
  title = {Measurement and Characterization of Force Dynamics in High T, Superconductors},
  booktitle = {Proceedings of ISMST2},
  year = {1993},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst2/ismst2_submission_8.pdf}
}
1988 Higuchi, T. and Mizuno, T. Balancing Measurement System Using Magnetic Bearings Proceedings of ISMB1 - Courtesy of Springer-Verlag  
Abstract: The principles and features of a measurement system with magnetic bearings for providing information for balancing a rotor are described. The proposed system uses magnetic bearings not only as a device supporting a rotor but also as a device measuring and compensating unbalance forces. In the system the total forces acting on a rotor can be balanced by controlling the bearing forces actively; measuring and locating unbalance on the rotor are performed in such states. Some experiments of measurement are carried out by using a magnetic bearing spindle as a single-plane balancing machine. The obtained results show the feasibility of a measurement system for balancing a rotor based upon the proposed principles of measuring.
BibTeX:
@inproceedings{ISMB1_31,
  author = {T. Higuchi and T. Mizuno },
  title = {Balancing Measurement System Using Magnetic Bearings },
  booktitle = {Proceedings of ISMB1 - Courtesy of Springer-Verlag},
  year = {1988},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb1/ismb1_submission_31.pdf}
}
1990 Higuchi, T., Mizuno, T. and Tsukamoto Digital Control System for Magnetic Bearings with Automatic Balancing  Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_5,
  author = {T. Higuchi and T. Mizuno and Tsukamoto },
  title = {Digital Control System for Magnetic Bearings with Automatic Balancing },
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_5.pdf}
}
1992 Higuchi, T., Otsuka, M. and Mizuno, T. Identification of Rotor Unbalance and Reduction of Housing Vibration by Periodic Learning Control in Magnetic Bearings Proceedings of ISMB3  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB3_54,
  author = {T. Higuchi and M. Otsuka and T. Mizuno },
  title = {Identification of Rotor Unbalance and Reduction of Housing Vibration by Periodic Learning Control in Magnetic Bearings },
  booktitle = {Proceedings of ISMB3},
  year = {1992},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb3/ismb3_submission_54.pdf}
}
1990 Higuchi, T., Otsuka, M. and Watanabe, K. Real Time Balancing of a Flexible Rotor Supported by Magnetic Bearing  Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_37,
  author = {T. Higuchi and M. Otsuka and K. Watanabe },
  title = {Real Time Balancing of a Flexible Rotor Supported by Magnetic Bearing },
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_37.pdf}
}
1990 Higuchi, T., Takahashi, H., Takahara, K. and Shingu, S. Development of Magnetically-Suspended, Tetrahedron-shaped Antenna Pointing  Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_2,
  author = {T. Higuchi and H. Takahashi and K. Takahara and S. Shingu },
  title = {Development of Magnetically-Suspended, Tetrahedron-shaped Antenna Pointing },
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_2.pdf}
}
2010 HIijikta, W., Mamiya, T., Shinshi, T. and Takatani, S. Cost-effective Magnetic Bearing System Using a Single-Use Magnet-Less Rotor for an Extracorporeal Centrifugal Blood Pump Proceedings of ISMB12  
Abstract: In the field of rotary blood pumps, contactless support of an impeller by a magnetic bearing has been identified as a promising method to reduce blood damage and enhance the durability. We have developed a two-degrees-of-freedom controlled magnetic bearing system without any permanent magnet in the impeller, so that a single-use pump head of an extracorporeal centrifugal blood pump could be manufactured more easily at a low cost. A prototype blood pump with the magnetic bearing realized stable levitation and contactless rotation of the impeller. The run-out of the impeller position from 1,000 rpm to 3,000 rpm was less than 70 µm (3?) in the radial controlled directions. The total power consumption of the magnetic bearing was less than 1 W at the same rotational speeds. The pump could yield a flow rate of 5 L/min against a head pressure of 590 mmHg (78.7 kPa) at the speed of 4,000 rpm, which provided sufficient performance for an extracorporeal circulation support.
BibTeX:
@inproceedings{ISMB12_12,
  author = {Wataru HIijikta and Taichi Mamiya and Tadahiko Shinshi and Setsuo Takatani},
  title = {Cost-effective Magnetic Bearing System Using a Single-Use Magnet-Less Rotor for an Extracorporeal Centrifugal Blood Pump },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_12.pdf}
}
2000 Hilton, E., Humphrey, M., Stankovic, J. and Allaire, P. Design of an Open Source, Hard Real Time, Controls Implementation Platform for Active Magnetic Bearings Proceedings of ISMB7  
Abstract: Suspension of an active magnetic bearing (AMB) system involves significant computational and monitoring effort. Modern AMB systems need 1) logically complex and computationally expensive controller algorithms and I/O; 2) real time data storage of plant information such as states, inputs, and outputs; 3) real time plotting capabilities (such as rotor displace- ment as a function of time, actuator forces as a function of time, and FFTs); 4) real time controller parameter updates; and 5) real time access to reference signals; and 6) remote monitoring for safety purposes. Control systems based upon embedded Digital Signal Processors (DSP) boards often require specialized programming and development tools, may lack flexibility when computational requirements change, are often financially expensive, and may not directly address the aforementioned needs. Even worse, newer and faster DSPs may not be fully pin compatible with their predecessors, thus requiring total redesign of the embedded electronics for a given project. A novel DSP-less controller implementation system - the Real Time Controls Laboratory (RTiC-Lab) - has been developed explicitly to address these problems. It uses the concept of Real Time Operating Systems to guarantee hard real time constraints. Its design is based on the use of both commodity personal computers and RT-Linux, a free and Open Source modification of Linux intended to support hard real-time computation. RTiC-Lab is also free and Open Source and is intended to serve as a communal effort among the controls engineers in both the controls and AMB community. Discussion is presented on the design of the software architecture, defining timing requirements of the control tasks, and measuring the predictability of RTiC-Lab. An example application is presented which uses RTiC-Lab in the controls implementation on a five degree of freedom AMB.
BibTeX:
@inproceedings{ISMB7_55,
  author = {Edgar Hilton and Marty Humphrey and John Stankovic and Paul Allaire},
  title = {Design of an Open Source, Hard Real Time, Controls Implementation Platform for Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_55.pdf}
}
1998 Hilton, E.F., Allaire, P.E., Baloh, M.J., Wei, N., Bearnson, G., Olsen, D. and Khanwilkar, P. Magnetic Suspension Test Controller for a New Continuous Flow Ventricular Assist Device  Proceedings of ISMB6  
Abstract: A new continuous flow ventricular assist device using a full magnetic suspension has been constructed and tested. The magnetic suspension centers the centrifugal pump impeller within the clearance passages in the pump, thus avoiding any form of contact. The non-contact operation is designed to give very high expected mechanical reliability, large clearances, low hemolysis, and relatively small size compared to current pulsatile devices. A unique configuration of magnetic actuators on the inlet side and exit sides of the impeller give a full five axis control and suspension of the impeller. The bearing system is divided into segments which allow for three displacement axes and two angular control axes. The controller chosen for the first suspension tests consists of a decentralized set of five PID controllers. This document describes both the controller and an overview of some results pertaining to the magnetic bearing performance.
BibTeX:
@inproceedings{ISMB6_10,
  author = {E. F. Hilton and P. E. Allaire and M. J. Baloh and N. Wei and G. Bearnson and D. Olsen and P. Khanwilkar},
  title = {Magnetic Suspension Test Controller for a New Continuous Flow Ventricular Assist Device },
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_10.pdf}
}
1999 Hilton, E.F., Humphrey, M., Stankovic, J. and Allaire, P. Real Time Control of a Magnetic Bearing Suspension System for Flexible Rotors Proceedings of ISMST5  
Abstract: Suspension of a magnetic bearing system involves significant computational effort. Control systems based upon embedded Digital Signal Processors (DSP) boards often require specialized programming and development tools, may lack flexibility when computational requirements change, and are often relatively expensive. Magnetic bearing systems need 1) real time monitoring of the plant states, inputs, and outputs 2) real time plotting functions such as rotor position vs. time, Fast Fourier Transform (FFT) functions and user specified filters, 3) controller parameter updates, and 4) access to reference signals. It is desired to employ a hardware/software system which is low cost, easy to use, is extensible as more advanced versions of hardware/software become available, and distributable over local networks of DSPs. A system with all of the above desired characteristics has been implemented for control of a magnetic bearing supported flexible rotor using RT-Linux, a free modification of Linux, intended to support hard real-time computation. Experiences designing the software architecture, defining timing requirements of the control tasks, implementing the control tasks in RT-Linux, and measuring the predictability of RT-LimL, c for this application are discussed.
BibTeX:
@inproceedings{ISMST5_34,
  author = {Edgar F. Hilton and Marry Humphrey and John Stankovic and Paul Allaire},
  title = {Real Time Control of a Magnetic Bearing Suspension System for Flexible Rotors},
  booktitle = {Proceedings of ISMST5},
  year = {1999},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst5/ismst5_submission_34.pdf}
}
2014 Hinterdorfer, T., Schulz, A., Sima, H., Hartl, S. and Wassermann, J. Compensation of Unbalance Forces of a Switched Reluctance Machine with Combined Current and Fluxlinkage Control Proceedings of ISMB14  
Abstract: The presented work handles the compensation of unbalance forces for a 6/4-Switched Reluctance Machine (SRM), which generate significant radial magnetic forces in an eccentric motor shaft position. When the rotor is operating e.g. in its principal axis of inertia, these forces must be compensated by the bearings. This is of major interest for long term storage Flyweels where bearing efficiency is a key factor for the overall system performance. Due to the back electromotive force (BEMF) in high speed operation, precise current control is a major challenge. Hence a combination of current and fluxlinkage control is used to minimize the generated radial forces. It can be used for low and high speed applications. For the observation of fluxlinkage two different methods are described. The functionallity is shown by means of simulations and measurement.
BibTeX:
@inproceedings{ISMB14_115,
  author = {Thomas Hinterdorfer and Alexander Schulz and Harald Sima and Stefan Hartl and Johann Wassermann},
  title = {Compensation of Unbalance Forces of a Switched Reluctance Machine with Combined Current and Fluxlinkage Control},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_115.pdf}
}
2014 Hinterdorfer, T., Schulz, A., Sima, H., Hartl, S. and Wassermann, J. Topology Optimization of a Flywheel Energy Storage Rotor Using a Genetic Algorithm Proceedings of ISMB14  
Abstract: This paper deals with topology optimization of the rotor of a flywheel energy storage system (FESS). For isotropic materials the constant stress disc (CSD) is the best choice to maximize energy density. Modern FESS are manufactured of fiber reinforced plastics (FRP), due to their high specific strength. Because of the transverse isotropic material description the optimal rotor topology changes. A genetic algorithm (GA) for nonlinear integer problems will be used to find the best rotor structure which can be manufactured within one filament winding process.
BibTeX:
@inproceedings{ISMB14_116,
  author = {Thomas Hinterdorfer and Alexander Schulz and Harald Sima and Stefan Hartl and Johann Wassermann},
  title = {Topology Optimization of a Flywheel Energy Storage Rotor Using a Genetic Algorithm},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_116.pdf}
}
1997 Hippner, M. and Piech, Z. Efficient Method of Force Calculation for Biased Magnetic Bearings Proceedings of ISMST4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST4_35,
  author = {Maciej Hippner and Zbigniew Piech},
  title = {Efficient Method of Force Calculation for Biased Magnetic Bearings},
  booktitle = {Proceedings of ISMST4},
  year = {1997},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst4/ismst4_submission_35.pdf}
}
1998 Hirata, M., Nonami, K. and Ohno , T. Robust Control of a Magnetic Bearing System Using Constantly Scaled H-infinity Control  Proceedings of ISMB6  
Abstract: In this paper, we propose a design method for a robust controller of a magnetic bearing system with structured time-varying uncertainties. We apply the method of constantly scaled H8 control to this system. The constantly scaled H8 controller is solved by using a dual iterative algorithm based on LMI constraints. Simulation results are presented to demonstrate the control effects.
BibTeX:
@inproceedings{ISMB6_68,
  author = {M. Hirata and K. Nonami and T. Ohno },
  title = {Robust Control of a Magnetic Bearing System Using Constantly Scaled H-infinity Control },
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_68.pdf}
}
2002 Hirschmnner, M. and Springer, H. Adaptive Vibration And Unbalance Control Of A Rotor Supported By Active Magnetic Bearings Proceedings of ISMB8  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB8_5,
  author = {Martin Hirschmnner and Helmut Springer},
  title = {Adaptive Vibration And Unbalance Control Of A Rotor Supported By Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB8},
  year = {2002},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb8/ismb8_submission_5.pdf}
}
1996 Hisanaga, Y., Matsushita, O. and Saitoh, S. Analysis and Evaluation of Unbalance Resonance Vibration and Bearing Reaction Force for Active Magnetic Bearing Equipped Flexible Rotor  Proceedings of ISMB5  
Abstract: Flexible Rotors supported by active magnetic bearing (AMB) must pass through critical speeds of two rigid modes and several bending modes. The AMB equipped rotor requires control means to achieve low unbalance vibrations with the low driving current during the spin-up operation and the rated rotation. For this requirement, an unbalance vibration analysis program is developed including calculation of the resultant bearing reaction force. By the use of this developed program, the optimum control technique is evaluated for flexible rotors supported by AMBs, regarding the fol1owing four means: PID, Ncross, Ncut + Ncross, Feed Forward (FF) Excitation. In addition to the numerical evaluation, a rotation test is performed to determine experimenta11y the best strategy for the AMB control. The obtained numerical evaluation is accepted by the experimental results gained from the rotation test. It is concluded numerica11y and experimenta11y that the technique of FF excitation is the best one among the four above methods with respect of low resonance amplitude and low control current to pass the first bending critical speed.
BibTeX:
@inproceedings{ISMB5_13,
  author = {Y. Hisanaga and O. Matsushita and S. Saitoh },
  title = {Analysis and Evaluation of Unbalance Resonance Vibration and Bearing Reaction Force for Active Magnetic Bearing Equipped Flexible Rotor },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_13.pdf}
}
1988 Hisatani, M. Identification and Optimization of Active Magnetic Bearing Systems Using Measured Nyquist Diagrams Proceedings of ISMB1 - Courtesy of Springer-Verlag  
Abstract: An effective measurement and identification technique of the stability of active magnetic bearing systems is introduced. Frequency response is reduced into an open-loop transfer function and displayed as the Nyquist diagram. This shows the stability of the syste  both qualitatively and quantitatively. This technique is applied both for the axial direction, and for the radial direction with a strong gyroscopic effect. Measured Nyquist diagrams along the radial direction clearly show the divergence of eigenvalues caused by gyroscopic effect. A guide to optimize the system is indicated for the safe high speed rotation of the machine.
BibTeX:
@inproceedings{ISMB1_25,
  author = {M. Hisatani },
  title = {Identification and Optimization of Active Magnetic Bearing Systems Using Measured Nyquist Diagrams },
  booktitle = {Proceedings of ISMB1 - Courtesy of Springer-Verlag},
  year = {1988},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb1/ismb1_submission_25.pdf}
}
1990 Hisatani, M., Inami, S., Ohtsuka, T. and Fujita, M. Design and Testing of a Flexible Rotor-Magnetic Control  Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_19,
  author = {M. Hisatani and S. Inami and T. Ohtsuka and M. Fujita },
  title = {Design and Testing of a Flexible Rotor-Magnetic Control },
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_19.pdf}
}
1994 Hisatani, M. and Koizumi, T. Adaptive Filtering for Unbalance Vibration Suppression Proceedings of ISMB4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB4_22,
  author = {M. Hisatani and T. Koizumi },
  title = {Adaptive Filtering for Unbalance Vibration Suppression },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_22.pdf}
}
2000 Ho, Y.S., Jiang, P. and Yu, L. Dynamics of a Rotor - Magnetic Bearing System Equipped with a Thrust Magnetic Bearing Proceedings of ISMB7  
Abstract: This paper is concerned with the dynamics of a rigid rotor supported by journal and thrust active magnetic bearings. For small perturbation, the action of the thrust bearing can be described by a series of stiffness coefficients. The system equations are formulated by combining the equations of motion of the rotor and the equations of the decentralized PID controllers. The eigenvalues of system are calculated and examined. The results indicate that the thrust magnetic bearing has great influence on the eigenvalues corresponding to lowfrequency conical whirls, and causes the system stability to degrade.
BibTeX:
@inproceedings{ISMB7_98,
  author = {Yick Sing Ho and Peilin Jiang and Lie Yu},
  title = {Dynamics of a Rotor - Magnetic Bearing System Equipped with a Thrust Magnetic Bearing},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_98.pdf}
}
2014 Hofer, M., Hutterer, M., Nenning, T. and Schrödl, M. Improved Sensorless Control of a Modular Three Phase Radial Active Magnetic Bearing Proceedings of ISMB14  
Abstract: This paper discusses new results and improvements on the sensorless control of a permanent magnet biased three phase radial active magnetic bearing (AMB), which are also known as hybrid magnetic bearings (HMB). Self-sensing methods offer cost potentials because of a more simple bearing system architecture, but show lower performance in accuracy and bandwidth compared to external position sensors. Thus, making selfsensing technologies competitive to systems with position sensors is a broad field of research and as well a goal of this paper. The proposed sensorless method is based on inductance measurement by voltage pulse injection. Applying an oversampling strategy for current slope measurement reduces the noise of the sensorless obtained rotor position significantly. Timing limitations and operational bandwidth can be improved by utilizing alternative voltage pulse sequences. Further, variations of the permanent magnet bias flux of the HMB prototype are investigated to show the influences on the sensorless rotor position detection method and limitations for applications.
BibTeX:
@inproceedings{ISMB14_18,
  author = {Matthias Hofer and Markus Hutterer and Thomas Nenning and Manfred Schrödl},
  title = {Improved Sensorless Control of a Modular Three Phase Radial Active Magnetic Bearing},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_18.pdf}
}
2016 Hofer, M., Hutterer, M. and Schroedl, M. Application of Soft Magnetic Composites (SMCs) in Position-Sensorless Controlled Radial Active Magnetic Bearings Proceedings of ISMB15  
Abstract: In this paper a soft magnetic composite (SMC) material is applied to permanent magnet (PM) biased radial active magnetic bearings (AMB) and investigated regarding position-sensorless control. A bias flux generation by per- manent magnets with a homopolar bearing structure requires the closure of the bias flux in axial direction. Thus, accordant magnetic properties in all three dimensions are required from the applied materials. The isotropic behav- ior of SMCs may offer advantages compared to a classical realization with laminated electrical steel. Further, for a self-sensing AMB operation the high frequency (HF) aspects of the iron path have relevance for the sensorless position evaluation regarding dynamics and accuracy. Because of these two reasons applying SMC material to this AMB topology is an interesting alternative to common setups with laminated electrical steel. Two AMB proto- types at same geometry and different materials are investigated by experiments. In this work key parameters of bias flux density, force-current characteristic, operational losses and self-sensing properties are compared. Finally, a conclusion shows, that the apparent material advantages of SMC are not utilized in this AMB application.
BibTeX:
@inproceedings{ISMB15_64,
  author = {Matthias Hofer and Markus Hutterer and Manfred Schroedl},
  title = {Application of Soft Magnetic Composites (SMCs) in Position-Sensorless Controlled Radial Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_64.pdf}
}
2016 Hofer, M., Hutterer, M. and Schroedl, M. PCB Integrated Differential Current Slope Measurement for Position-Sensorless Controlled Radial Active Magnetic Bearings Proceedings of ISMB15  
Abstract: This paper discusses a current slope measurement principle for self-sensing active magnetic bearings (AMBs). So called sensorless or self-sensing principles avoid external position sensors in the AMB and use the inductance dependency on the rotor position of the AMB itself to determine the rotor position for feedback control. By the help of a transformer core a combined evaluation of both opposite AMB coil inductances is possible. This differential approach determines the sensorless rotor position with high accuracy which allows a robust self-sensing AMB operation. The disadvantage of applying a wound transformer core can be overcome by a novel planar coil arrangement integrated in the printed circuit board of the AMB inverter. Different yoke materials for an optimal flux closure of the novel current slope sensing unit are investigated regarding to dynamic response and a high position sensitivity. Finally, experimental results of high permeable materials with well high frequency properties as ferrites or SMC confirm the sensing principle and allow a position-sensorless control of a three phase AMB.
BibTeX:
@inproceedings{ISMB15_56,
  author = {Matthias Hofer and Markus Hutterer and Manfred Schroedl},
  title = {PCB Integrated Differential Current Slope Measurement for Position-Sensorless Controlled Radial Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_56.pdf}
}
2008 Hofer, M. and Schroedl, M. Test Bench for Three Phase Permanent Magnet Biased Radial AMBs with a Sensorless Control Strategy Based on INFORM Method Proceedings of ISMB11  
Abstract: In this paper a test bench for permanent magnet biased radial Active Magnetic Bearing (AMB) with respect to a sensorless control strategy based on INFORM method is presented. The purpose of this Hybrid Magnetic Bearing (HMB) prototype is to research the capability of the INFORM method for sensorless control of HMBs. The well known INFORM method for sensorless control of Permanent Magnet Synchronous Motors (PMSM) is adapted for the HMB and also described in principle. For the test bench a three phase MOSFET inverter was build up. First measurement results of the INFORM capability are presented.
BibTeX:
@inproceedings{ISMB11_99,
  author = {Matthias Hofer and Manfred Schroedl},
  title = {Test Bench for Three Phase Permanent Magnet Biased Radial AMBs with a Sensorless Control Strategy Based on INFORM Method},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_99.pdf}
}
2010 Hofer, M., Staffler, W. and Schrödl, M. Sensorless Control of a Three Phase Radial Active Magnetic Bearing Proceedings of ISMB12  
Abstract: This paper presents results of a three phase radial active magnetic bearing architecture combined with a sensorless position control algorithm. Therefore the three coil bearing structure is utilized by a three phase voltage source drive inverter. To reduce bias current consumption permanent magnet bias fluxing is used and iron losses are reduced by gaining homopolar architecture. The sensorless position detection algorithm and the control architecture are presented. Experimental results confirm the sensorless concept by measurements and quality measures for the sensorless method are investigated to show the limits of operation.
BibTeX:
@inproceedings{ISMB12_112,
  author = {Matthias Hofer and Wolfgang Staffler and Manfred Schrödl},
  title = {Sensorless Control of a Three Phase Radial Active Magnetic Bearing },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_112.pdf}
}
2018 Hofer, M., Wimmer, D. and Schroedl, M. Analysis of a Current Biased Eight Pole Radial Active Magnetic Bearing Regarding Self-Sensing Proceedings of ISMB16  
Abstract: In this work a current biased radial active magnetic bearing is investigated with regard to a possible self-sensing operation. The bearing is designed by the help of finite element methods. The force characteristic is investigated and bearing parameters are identified by simulation. Additionally, the position dependency of the coil inductances is evaluated which is the basis for self-sensing. The fundamental principle of the rotor position determination based on current slopes by using the differential open loop transformers approach is presented. Further, simulations are performed to analyze AMB current signals with regard to the rotor position. Finally, experimental tests with an AMB prototype are shown to verify the theoretical analysis. The measured rotor position at constant eccentricity confirms the functionality and represents the starting point for a future implementation of the self-sensing control to the prototype and detailed analysis of the self-sensing performance.
BibTeX:
@inproceedings{ISMB16_065,
  author = {Matthias Hofer and Dominik Wimmer and Manfred Schroedl},
  title = {Analysis of a Current Biased Eight Pole Radial Active Magnetic Bearing Regarding Self-Sensing},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_065.pdf}
}
1998 Hoffmann, K.-J., Laier, D., Markert, R., Renner, F.-M. and Glesner , M. Integrated Active Magnetic Bearings, Proceedings of ISMB6  
Abstract: Three aspects of the structural and functional integration of electromagnetic bearings are presented: 1. In self-sensing bearings the rotor position is identified from the electric state variables directly at the power amplifiers. 2. The non-linearity of the magnetic force is compensated by software, integrated in the digital controller. 3. Adaptive control and compensation strategies are realized to minimize resonance phenomena. The necessary design cycle for integrating the procedures into micro-computers is described as well.
BibTeX:
@inproceedings{ISMB6_25,
  author = {K.-J. Hoffmann and D. Laier and R. Markert and F.-M. Renner and M. Glesner },
  title = {Integrated Active Magnetic Bearings,},
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_25.pdf}
}
2015 Hoffmann, L. Wirbelstrommessketten speziell für Magnetlager Proceedings of Workshop on Magnetic Bearing Technology 10  
Abstract: Die Anwendung von Magnetlagern sind vielfältig, so werden diese unter anderem im Werkzeugmaschinenbau eingesetzt. Anwendungsbeispiele sind dabei Fräsen, Schleifen, Bohren, Zentrifugen und Pumpen. Weiterhin eignen sich Magnetlager auch für Bearbeitungsspindeln für das Polieren von Oberflächen. Um eine sichere Regelung zu realisieren, werden hochauflösende und hochdynamische Messsysteme zur exakten Lagebestimmung eingesetzt. Hierfür werden oftmals Wirbelstrommesssysteme verwendet, da diese unempfindlich gegenüber Staub, Öl und weiteren Umgebungseinflüssen sind. Besondere Vorteile von Wirbelstromsensoren sind deren verhältnismäßig niedrige Preis und die Synchronisierbarkeit bei Wellendurchmessern unter 25 mm. Gegenwärtig werden in der EAAT u.a. Untersuchungen zur Herstellung eigener Wirbelstromsensoren durchgeführt. Hierzu werden neben den geeigneten Materialien für die Sensoren, deren notwendige Induktivität, der Einfluss verschiedener Sensorkopfdurchmesser etc. ermittelt. Grundlegende Schwerpunkte bilden geeignete Speisekabel und das Temperaturdriftverhalten, da Magnetlager auch für höhere Temperaturen einsetzbar sind. Die bevorzugten Baugrößen der Wirbelstromsensoren belaufen sich auf (6 und 8) mm Durchmesser. Das Fanglagerspiel und der kleinste Wellendurchmesser bestimmten dabei diese Baugrößen. Um Untersuchungen der Sensoren durchführen zu können, bedarf es einer geeigneten Auswerteelektronik. Die Anforderungen an diese Elektronik liegt in deren Universalität, d.h. es sollen nach Möglichkeit nicht nur eigens hergestellte Sensoren angeschlossen werden können, sondern ebenso auch Sensoren von Fremdherstellern. Dabei wird eine kostengünstige Auswerteelektronik angestrebt, welche zwischen Spannungs- und Stromcharakteristik umschaltbar ist. Bei Bedarf ist eine Linearisierung der Wirbelstrommesssignale möglich. Im Beitrag wird die Low-Cost Auswerteelektronik mit verschiedenen Linearisierungsvorschlägen der Sensorsignale als auch deren Universalität vorgestellt.
BibTeX:
@inproceedings{WMLT10_9,
  author = {L. Hoffmann},
  title = {Wirbelstrommessketten speziell für Magnetlager},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 10},
  year = {2015},
  url = {https://www.magneticbearings.org/wp-content/publications/wmlt10/wmlt10_9.pdf}
}
1991 Hollis, R.L. and Salcudean, S. Precise Positioning and Compliance Synthesis for Automatic Assembly Using Lorentz Levitation Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_35,
  author = {R. L. Hollis and S. Salcudean},
  title = {Precise Positioning and Compliance Synthesis for Automatic Assembly Using Lorentz Levitation},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_35.pdf}
}
1998 Holmes, M., Trumper, D. and R. Hocken,   Magnetically-Suspended Stage for Accurate Positioning of Large Samples in Scanned Probe Microscopy  Proceedings of ISMB6  
Abstract: This paper describes a magnetically-suspended six-degree-of-freedom precision motion control stage which was built in the Precision Engineering Laboratory at the University of North Carolina at Charlotte (Holmes, 1998). This Long-Range Scanning (LORS) stage has travel in the horizontal plane of 25 mm by 25 mm with 100 //m of vertical travel. Vertical position feedback is provided by three capacitance probe sensors while heterodyne laser interferometry is used for lateral position feedback. The forces to suspend and servo the moving element are provided by four six-phase linear motors. The stage was designed to have a positioning resolution of 0.1 nm, positioning repeatability of 1 nm, and a positioning accuracy of 10 nm. These performance objectives were chosen to match the measurement requirements associated with present and future production needs for devices such as integrated circuits, photo-masks, and micromechanical actuators. The LORS stage is used to position samples beneath a scanning-tunneling microscope (STM). The STM will ultimately be used to characterize the performance of the LORS stage. This paper presents a summary of the final design along with some initial performance characterization data.
BibTeX:
@inproceedings{ISMB6_13,
  author = {M. Holmes and D. Trumper and R. Hocken  },
  title = {Magnetically-Suspended Stage for Accurate Positioning of Large Samples in Scanned Probe Microscopy },
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_13.pdf}
}
2004 Hong, P., Lei, S., Shi, Z., Zha, M., Lei, Z. and Yu, S. Study Of Online Monitoring System Of Active Magnetic Bearings For The Htr-10Gt Proceedings of ISMB9  
Abstract: fter successful operation and experiments on the steam-circle of the 10 MW high temperature gas cooled reactor (HTR-10), the project of the HTR-10 coupled with direct gas-turbine circle (HTR-10GT) is designed by the Institute of Nuclear Energy Technology (INET) of Tsinghua University [1]. In this project, active magnetic bearings (AMBs) are chosen to support the generator rotor and the turbocompressor rotor in the power conversion unit because of their numerous advantages over the conventional bearings [2]. In order to detect how the AMB system works in operation and make diagnosis whether the system behaves normally or not, an online monitoring system of AMB needs to be designed. The construction of the whole monitoring system is based on a personal computer, Windows 2000 system and VI (Virtual Instruments) technology. The development is divided into the following three steps: First, a data acquisition platform to collect and acquire all the necessary and useful data from the operation of the AMB system is developed. Second, the data acquired need to be analyzed in time domain, frequency domain and joint time-frequency domain to find the characteristics of the operation. Finally, based on all the former work, a diagnostic component will be designed in the future.
BibTeX:
@inproceedings{ISMB9_17,
  author = {Peng Hong and Shi Lei and Zhengang Shi and Meisheng Zha and Zhao Lei and Suyuan Yu},
  title = {Study Of Online Monitoring System Of Active Magnetic Bearings For The Htr-10Gt },
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_17.pdf}
}
2013 Horikawa, O., Yamamoto, R.I. and da Silva, I. Development of Single Axis Controlled Attraction Type Magnetic Bearing and its Application in Ventricular Assist Device Proceedings of BWMB2013  
Abstract: Aiming the development of an implantable Ventricular Assist Device – VAD, or an artificial heart, a joint project was started in 2007, involving the Escola Politécnica of São Paulo University (EPUSP) and the Dante Pazzanese of Cardiology (IDPC). One of objectives of the project is the development of a VAD with a rotor levitated by a magnetic bearing. Here, a magnetic bearing proposed by authors, called as EPUSP bearing, is elected mainly because of its simplicity. This work presents the entire development work. One of most important work is related with the mitigation of a topology of the EPUSP bearing that enables a robust levitation, enough for supporting the rotor of a VAD. Moreover some complementary studies are developed so as to execute the Zero Power control in the EPUSP bearing, identify the best way of driving the rotor supported by the EPUSP bearing and finally, use the Hall sensor in the measurement of the rotor position in the EPUSP bearing.
BibTeX:
@inproceedings{BWMB2013_5,
  author = {Oswaldo Horikawa and Rogerio I. Yamamoto and Isaias da Silva},
  title = {Development of Single Axis Controlled Attraction Type Magnetic Bearing and its Application in Ventricular Assist Device},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {https://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_5.pdf}
}
1996 Horiuchi, Y., Inoue, M., Miyoshi, K., Sugimoto, T., Okamoto, T. and Hariu, K. Development of Magnetically Suspended Sliders for Deployable Antenna Test Facility  Proceedings of ISMB5  
Abstract: Maguetically suspended sliders which can move freely in horizontal plane were developed and applied to original deployable antenna test facility for large antenna deployability tests on the ground. This paper describes slider construction for stable magnetic suspension, control methods and safeguards for reliability improvement. Moreover, as a result of several tests including single slider tests and I-module antelma deployment tests, we obtained that the Oliginal test facility using magnetically suspended sliders was practical.
BibTeX:
@inproceedings{ISMB5_61,
  author = {Y. Horiuchi and M. Inoue and K. Miyoshi and T. Sugimoto and T. Okamoto and K. Hariu },
  title = {Development of Magnetically Suspended Sliders for Deployable Antenna Test Facility },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_61.pdf}
}
2000 Horiuchi, Y., Inoue, M., Sato, N., Hashimoto, T. and Ninomiya, K. Development of Magnetic Bearing Momentum Wheel for Ultra-Precision Spacecraft Attitude Control Proceedings of ISMB7  
Abstract: This paper describes a magnetic bearing momentum wheel (MBMW) for ultra-precise stabilization of spacecraft attitude. For suppressing bearing reaction torque, which disturbs the spacecraft attitude stability, the control bandwidth of the magnetic bearings is designed to be as narrow as possible. Using a prototype of the MBMW, sufficiently quiet and stable rotation up to 8,000 r/min. (64 Nms) is accomplished. Moreover, the accurate measurement of the bearing reaction force and torque showed that small reaction torque remains even if the MBMW rotates in the super-critical speed range. Considering not only the wobbles of the sensor measurement surface but also those of the rotor surface of the bearing, the cause of this residual reaction torque is clarified.
BibTeX:
@inproceedings{ISMB7_88,
  author = {Yasushi Horiuchi and Masao Inoue and Norio Sato and Tatsuaki Hashimoto and Keiken Ninomiya},
  title = {Development of Magnetic Bearing Momentum Wheel for Ultra-Precision Spacecraft Attitude Control},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_88.pdf}
}
1991 Horwath, T.G. The Concept of the Mechanically Active Guideway as a Novel Approach to Maglev Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_45,
  author = {T. G. Horwath},
  title = {The Concept of the Mechanically Active Guideway as a Novel Approach to Maglev},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_45.pdf}
}
1991 Horwath, T.G. Vibration Damping of Elastic Waves in Electrically Conducting Media Subjected to High Magnetic Fields Proceedings of ISMST1  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST1_25,
  author = {T. G. Horwath},
  title = {Vibration Damping of Elastic Waves in Electrically Conducting Media Subjected to High Magnetic Fields},
  booktitle = {Proceedings of ISMST1},
  year = {1991},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst1/ismst1_submission_25.pdf}
}
1994 Hoskinen, H. and Lindgren, O. Fuzzy Logic in Active Magnetic Bearing Control Proceedings of ISMB4  
Abstract: Active magnetic bearings are special bearings for demanding applications. With modem hardware and sophisticated control methods the problems, that arise from the nonlinear structure of the active magnetic bearing system, can be overcome. In this paper a fuzzy derivate gain adjusting method for active magnetic bearing control is presented. The method is based on the error and error derivate signals that are used as the basis of the fuzzy inference. With this method the effects of the vibration noise can be decreased. To achieve adequately high sampling rate for the control algorithm a powerful digital signal processor (DSP) was used in the experiments.
BibTeX:
@inproceedings{ISMB4_16,
  author = {H. Hoskinen and O. Lindgren },
  title = {Fuzzy Logic in Active Magnetic Bearing Control },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_16.pdf}
}
2010 Hou, E. and Liu, K. Study on Dynamic Characteristics of Magnetic Suspending Flywheel Based On Finite Element Method Proceedings of ISMB12  
Abstract: The configuration and principle of a magnetic suspending flywheel which was supported by hybrid magnetic bearings were introduced. A 3D finite element model of flywheel rotor was established by ANSYS10.0. The initial several vibration modes and frequencies were got in static state. The results of rigid vibration were compared with the theoretical ones, which proved the reasonability of the finite element model. The influence of radial and axial bearing stiffness and centrifugal prestress to dynamic characteristics was studied. The findings will be useful for the selection of control parameters and the optimization of the system.
BibTeX:
@inproceedings{ISMB12_101,
  author = {Eryong Hou and Kun Liu },
  title = {Study on Dynamic Characteristics of Magnetic Suspending Flywheel Based On Finite Element Method },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_101.pdf}
}
2002 Hu, T., Lin, Z. and Allaire, P.E. Power-Loss Reduction By Optimizing Current Allocation In Magnetic Bearings Proceedings of ISMB8  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB8_72,
  author = {Tingshu Hu and Zongli Lin and Paul E. Allaire},
  title = {Power-Loss Reduction By Optimizing Current Allocation In Magnetic Bearings},
  booktitle = {Proceedings of ISMB8},
  year = {2002},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb8/ismb8_submission_72.pdf}
}
2002 Hu, T., Lin, Z., Huang, B., Jiang, W. and Allaire, P.E. Control Of Balance Beam With Magnetic Bearings: A Linear Design Approach Proceedings of ISMB8  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB8_74,
  author = {Tingshu Hu and Zongli Lin and Bin Huang and Wei Jiang and Paul E. Allaire},
  title = {Control Of Balance Beam With Magnetic Bearings: A Linear Design Approach},
  booktitle = {Proceedings of ISMB8},
  year = {2002},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb8/ismb8_submission_74.pdf}
}
2018 Hu, Y., Geng, J., Huang, W. and Wang, T. Research on Eddy Current Field Characteristics of Eddy Current Displacement Sensor Based on ANSOFT Proceedings of ISMB16  
Abstract: The eddy current field characteristics of the probe based on the eddy current magnetic field sensing principle of eddy current displacement sensor are the key to influence the performance of the sensor. In this paper, the eddy current field simulation of probe coils with different structures is performed. The effect of coil size and shape on the performance of the sensor is analyzed. The eddy current field characteristics of probe coils with different structures are studied. And build an experimental platform to test and analyze, verify the correctness of the simulation results, and lay the foundation for perfecting the eddy current displacement sensor theory and further optimization design.
BibTeX:
@inproceedings{ISMB16_085,
  author = {Yusheng Hu and Jiqing Geng and Weicai Huang and Tuo Wang},
  title = {Research on Eddy Current Field Characteristics of Eddy Current Displacement Sensor Based on ANSOFT},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_085.pdf}
}
2018 Hu, Y., Guo, W., He, Y., Hu, D. and Li, X. Design and Application for Power Amplifier of Magnetic Bearing Proceedings of ISMB16  
Abstract: Power Amplifier is a crucial part in the magnetic bearing control system, so the performance of power amplifier plays an important role in the magnetic bearing control system. According to the 5-DOF active magnetic bearing system, the half bridge structure which needs twenty power parts in total is generally used, with a bulky bearing controller. so this kind of power amplifier cannot be appropriate for the magnetic compressor who has a strict installation size require。A novel kind of power amplifier is proposed which is based on the common lower bridge structure, with the ability of decreasing the amount of the power parts to 15 and cutting down the volume of bearing controller. The simulation and test shows that the common lower bridge has a good response of capability and actual performance.
BibTeX:
@inproceedings{ISMB16_075,
  author = {Yusheng Hu and Weilin Guo and Yongling He and Daofu Hu and Xue Li},
  title = {Design and Application for Power Amplifier of Magnetic Bearing},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_075.pdf}
}
2008 Hu, Y., Wu, H., Wei, L. and Wang, X. Study on the Unbalance of Magnetic Suspended Rotor Based on Holospectrum Proceedings of ISMB11  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB11_15,
  author = {Yefa Hu and Huachun Wu and Li Wei and Xiaoguang Wang},
  title = {Study on the Unbalance of Magnetic Suspended Rotor Based on Holospectrum},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_15.pdf}
}
2018 Hu, Y., Zhang, F., Zhang, X., Gong, G., Su, J. and Zhang, C. Rotor Dynamic Analysis on the Bearing-rotor System of Magnetic Centrifugal Compressor Proceedings of ISMB16  
Abstract: Modal frequency and modal vibration mode of a centrifugal compressor rotor-bearing system, which equipped with magnetic bearings, are significant target parameters to insure stable operation of the compressor. Meanwhile, calculations and optimizations of those parameters are also necessary processes of compressor structure designing. In this paper, basing on the basic theories of rotor dynamics, ANSYS is used to analyze vibration mode and modal frequency of a compressor rotor-bearing system. The correction coefficient of modulus of elasticity of laminated and basic excitation sources caused by impellers in pneumatic section and magnetic bearings’ stiffness parameters are considered when doing rotor dynamics modeling simultaneously throughout the simulation. Influences on critical speed of the rotor-bearing system caused by rotor speed is analyzed through the simulation. It has provided a reference to designing shafts in long axis system of magnetic high-speed centrifugal compressor by obtaining the simulation results.
BibTeX:
@inproceedings{ISMB16_084,
  author = {Yusheng Hu and Fang Zhang and Xiaobo Zhang and Gao Gong and Jiuzhang Su and Chao Zhang},
  title = {Rotor Dynamic Analysis on the Bearing-rotor System of Magnetic Centrifugal Compressor},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_084.pdf}
}
2018 Hu, Z., Jiang, D., Han, X., Sun, H. and Qu, R. A Common-leg Power Electronics Converter for Multi-axis Active Magnetic Bearing Drive Proceedings of ISMB16  
Abstract: This paper has proposed a common-leg structure power electronics converter to drive the multi-axis active magnetic bearing(AMB) system. With this new structure, the number of devices is obviously reduced compared to existing topologies so that the cost can be decreased. Simulation and experiment are carried out to validate the feasibility of this converter. The results show that the current in either coil can be controlled independently and will not be influenced by the variation of other coil current. It also shows the performance of common-leg converter in the 4-DOF AMB system. The position of the rotor can be well controlled with this converter while the cost of the control system is greatly reduced.
BibTeX:
@inproceedings{ISMB16_055,
  author = {Zaidong Hu and Dong Jiang and Xun Han and Hongbo Sun and Ronghai Qu},
  title = {A Common-leg Power Electronics Converter for Multi-axis Active Magnetic Bearing Drive},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_055.pdf}
}
2018 Huang, C., Dai, C. and Luo, G. Study on Signal Processing Technology of Relative Position Detection Sensor for High Speed Maglev Train Proceedings of ISMB16  
Abstract: Relative position detection sensor is critical component for High Speed Maglev Train (HSMT) as they provide direction, speed, tooth-slot count and phase angle for traction system which drives maglev train. The traction system has higher requirements on the accuracy and stability of the phase angle signal. The demodulated wave signal directly affects the precision of the phase. In order to obtain higher accuracy of the demodulation signal, a demodulation approach based on an analog switch is proposed. The difference between early and present signal generating circuit is compared. Then the proposed demodulation method is analyzed mathematically. Moreover, the comparison between demodulation of the early sensor based on the analog multiplier and that based on the analog switch is implemented. A series of tests have been adopted to validate the performance of the proposed demodulation method and show that a more stable and accurate demodulation signal can be obtained.
BibTeX:
@inproceedings{ISMB16_079,
  author = {Cuicui Huang and Chunhui Dai and Guibin Luo},
  title = {Study on Signal Processing Technology of Relative Position Detection Sensor for High Speed Maglev Train},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_079.pdf}
}
2010 Huang, C., Zhou, J. and Guo, Q. The Dynamic Characteristic of Rotor-Active Magnetic Bearings System on Flexible Base subjected to Base Vibration Proceedings of ISMB12  
Abstract: Magnetic bearings are the core and key technology of a multi-electric engine. The aero engine will have no lubrication system, less weight, high reliability and efficiency, and low maintenance costs if magnetic bearings be used instead of rolling bearings. Many papers had been published research results on rotor-AMB system on ground based support, which can not better describe the real condition of aero engine. This paper models the rotor-active magnetic bearing (AMB) system hanging from a cantilever beam to simulate the effect of flexible wing on the rotor dynamic characteristics. Besides, in order to observe the effect of wing vibration on the engine rotor, the beam’s free end receives excitation and the frequency response of rotor is analyzed. From simulation analysis result, it can be found that change of hanging position results in change of the base spatial modal properties (Mand K). Consequently, the modal frequency of some rotor shapes changes irregularly. Under the same excitation conditions, imposed on the flexible base (as opposed to a rigid foundation), the rotor frequency response slightly decreased except in the beam type modal frequencies.
BibTeX:
@inproceedings{ISMB12_105,
  author = {Chunxin Huang and Jin Zhou and Qintao Guo },
  title = {The Dynamic Characteristic of Rotor-Active Magnetic Bearings System on Flexible Base subjected to Base Vibration },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_105.pdf}
}
2018 Huang, W., Deng, Z., Peng, C., Li, K., Cai, K. and Mei, L. A Method of Suppressing Unbalance Vibration of AMBs Based on Flux Feedback Control Proceedings of ISMB16  
Abstract: In this paper, an unbalance vibration suppression method based on flux feedback control strategy is proposed. The air gap flux is obtained from an improved flux observer. The principle of generalized notch filter is analyzed in detail and the transmission matrix parameters are reasonably designed so that the system can keep stable in a wide speed range. The simulation results show that adding generalized notch filter algorithm into the control system can restrain the vibration force caused by the mass unbalance of rotor during rotation.
BibTeX:
@inproceedings{ISMB16_042,
  author = {Wei Huang and Zhiquan Deng and Cong Peng and Kexiang Li and Kaiwen Cai and Lei Mei},
  title = {A Method of Suppressing Unbalance Vibration of AMBs Based on Flux Feedback Control},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_042.pdf}
}
2016 Huang, Z., Le, Y. and Han, B. Design of AMB and Rotordynamics for a 30kW, 60 000 rpm Permanent-magnet Machine Proceedings of ISMB15  
Abstract: Due to the long lifetime requirement and high rotating speed, an active magnetic bearing is designed for a 30 kW, 60 000 rpm permanent magnet machine application. The electromagnetic distribution characteristics of the active magnetic bearing are analyzed under the static levitation and the maximum bearing capacity using 2D finite element method. According to the large error problems of the calculation of the critical speed of the rotor assembly, this paper presents a model updating method to establish the finite element model of the rotor assembly. The calculated results of the first two bending critical speeds are verified by using the modal testing. The errors of the first two bending critical speed are 3.2 % and 1.8, respectively.
BibTeX:
@inproceedings{ISMB15_53,
  author = {Ziyuan Huang and Yun Le and Bangcheng Han},
  title = {Design of AMB and Rotordynamics for a 30kW, 60 000 rpm Permanent-magnet Machine},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_53.pdf}
}
2018 Hubatka, M. and Aeschlimann, B. Tuning Guidelines for Generalized Notch Filters used for Unbalance Compensation for Magnetic Bearings Proceedings of ISMB16  
Abstract: Unbalance compensation in magnetic bearing control algorithms are state of the art in modern applications of active magnetic bearings. The compensation is vital to keep synchronous vibrations on the housing on a minimum level and to avoid actuator saturation. There exist different possibilities to implement the compensation in the control loop. One of it is the generalized notch filter [1]. This filter technology has been successfully used in magnetic bearings for more than 20 years. One drawback of this filter is the speed dependent parameter set. For radial bearings of a five axis rotor, the notch filter parameters are in general two dense 4x4 matrices for one rotational speed. This high demand on computational power and memory is not a problem any more for modern digital signal processors. With a well tuned parameter set the unbalance compensation can be turned on well before crossing the rigid body modes. The paper presents a novel observer based stability proof of the generalized notch filter and introduces two bode diagrams to visualize the notch filter performance and robustness. The results are verified with a simple example and on a small 5-axis test rotor system.
BibTeX:
@inproceedings{ISMB16_043,
  author = {Michael Hubatka and Beat Aeschlimann},
  title = {Tuning Guidelines for Generalized Notch Filters used for Unbalance Compensation for Magnetic Bearings},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_043.pdf}
}
2011 Hübner, N. Dimensionierung von hochtourigen Magnetlagern am Beispiel einer Magnetlagerspindel für 140.000 U/min Proceedings of Workshop on Magnetic Bearing Technology 8  
Abstract: Am Beispiel der Auslegung einer Magnetlager-spindel für 140.000 U/min sollen die Besonder-heiten bei der Dimensionierung hochtouriger Antriebe dargestellt werden. So ist es unerlässlich, dass neben der Festig-keitsauslegung auch besonderes Augenmerk auf die Rotordynamik gelegt wird. Dies bedingt, dass bezüglich des Wellenaufbaus der Spagat zwischen dem Platzbedarf der einzelnen auf der Welle befindlichen Komponenten und dem zum unterkritischen Betrieb zwingend nötige, biege-steife Aufbau umgesetzt wird. Es wird gezeigt durch welche Maßnahmen dies realisiert werden kann und wie die für den Be-trieb zwingend benötigten Komponenten wie Messsystem, Motor- und Lagerkomponenten sehr kompakt aufgebaut werden können. Hierzu musste zum Teil auf bisher für Magnetlager eher unkonventionelle Werkstoffe und Aufbauten zurückgegriffen werden. Ein weiteres Problem stellt die möglichst ver-koppelungsfreie Anbindung des Prüflings an die Magnetlagerspindel dar. Ebenfalls nicht unwesentlich sind die im Betrieb auftretenden Verluste durch Luftreibung und Ummagnetisierung. Diese Verluste werden vom Antriebsmotor gedeckt und müssen durch eine geeignete Kühlung abgeführt werden. Hierfür wurde auf eine kostengünstige Wasser-kühlung zurückgegriffen, welche eigentlich für die PC Kühlung vorgesehen ist. Die vorhandene Realisierung und die Leistungsfähigkeit dieser PC - Flüssigkühler wird in diesen Beitrag kurz erläutert.
BibTeX:
@inproceedings{WMLT8_2,
  author = {N. Hübner},
  title = {Dimensionierung von hochtourigen Magnetlagern am Beispiel einer Magnetlagerspindel für 140.000 U/min},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 8},
  year = {2011},
  url = {https://www.magneticbearings.org/wp-content/publications/wmlt8/wmlt8_2.pdf}
}
2011 Hübner, N. and Paditz, M. Erfahrungen bei der Anwendung passiver Radialmagnetlager in einem Schwungradenergiespeicher Proceedings of Workshop on Magnetic Bearing Technology 8  
Abstract: Von EAAT wurde ein magnetisch gelagertes Schwungradenergiespeichersystem entwickelt. Die Schwungradwelle läuft dabei im Vakuum. Um die zur Lagerung erforderliche Leistung gering zu halten, wurden passive, d.h. permanentmagnetische Radiallager eingesetzt. Die axiale magnetische Lagerung wurde durch ein aktives (elektromagnetisches) Axiallager realisiert. In diesem Beitrag soll auf den Aufbau des Systems und die Erfahrungen im Einsatz des Systems eingegangen werden. Einen Schwerpunkt bilden dabei die Verluste im System, sowie deren Abhängigkeiten von z.B. Temperatur und Rotordynamik.
BibTeX:
@inproceedings{WMLT8_3,
  author = {N. Hübner and M. Paditz},
  title = {Erfahrungen bei der Anwendung passiver Radialmagnetlager in einem Schwungradenergiespeicher},
  booktitle = {Proceedings of Workshop on Magnetic Bearing Technology 8},
  year = {2011},
  url = {https://www.magneticbearings.org/wp-content/publications/wmlt8/wmlt8_3.pdf}
}
2002 Huettner, C. Nonlinear State Control Of A Left Ventricular Assist Device (Lvad) Proceedings of ISMB8  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB8_41,
  author = {Christian Huettner},
  title = {Nonlinear State Control Of A Left Ventricular Assist Device (Lvad)},
  booktitle = {Proceedings of ISMB8},
  year = {2002},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb8/ismb8_submission_41.pdf}
}
1992 Hustak, J. and Peer, D. Design Considerations for Compressors with Magnetic Bearings Proceedings of ISMB3  
Abstract: Development of magnetic bearings and dry gas seals has altered the standard design criteria used on centrifugal compressors with conventional oil-film seals and bearings. The authors' company started testing their first oil free compressor i n 1979. Since that time much experience has been gained through fieldoperation as shown in Table 1.
BibTeX:
@inproceedings{ISMB3_36,
  author = {J.F. Hustak and D.J. Peer },
  title = {Design Considerations for Compressors with Magnetic Bearings },
  booktitle = {Proceedings of ISMB3},
  year = {1992},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb3/ismb3_submission_36.pdf}
}
2014 Hutterer, M., Hofer, M., Nenning, T. and Schrödl, M. LQG Control of an Active Magnetic Bearing with a Special Method to Consider the Gyroscopic Effect Proceedings of ISMB14  
Abstract: It could be very difficult to find an acceptable feedback path for coupled differential equations like a FIVE degree of freedom (DOF) AMB system. This paper describes a linear quadratic Gaussian (LQG) approach on this problem. Due to the time variant gyroscopic part of the AMB system equation the controller could only be optimized for a specific angular velocity. For this reason a time variant state feedback is developed and added to the LQG controller in a way that the system is nearly equal for all angular velocities. The feedback matrix which is the result of the LQG problem uses all feedback terms. Compared to a decentralized controller which only uses the diagonal terms, the LQG method also uses the cross feedback terms which are able to provide instability. After developing the LQG method was compared to a decentralized PID controller.
BibTeX:
@inproceedings{ISMB14_29,
  author = {Markus Hutterer and Matthias Hofer and Thomas Nenning and Manfred Schrödl},
  title = {LQG Control of an Active Magnetic Bearing with a Special Method to Consider the Gyroscopic Effect},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_29.pdf}
}
2016 Hutterer, M., Hofer, M. and Schroedl, M. New Results on the Robustness of Selfsensing Magnetic Bearings Proceedings of ISMB15  
Abstract: This paper shows the design and new results of a self-sensing homopolar active magnetic bearing (AMB). The considered magnetic bearing provides the bias flux using permanent magnets. Only the control flux for the stabi- lization of the system is provided by electro-magnets. This so called hybrid magnetic bearing (HMB) minimizes the energy losses and shows a high linearity. Therefore, this structure is a good choice for industrial applications which uses position sensors for closing the control loop. However, the self-sensing control of such bearing types require a position dependent inductance. Many homopolar structures share the same flux at two opposite poles and the coils of these poles are connected in serial. Hence, the inductance is almost independent of the rotor position. The proposed bearing type shows a way where also a hybrid homopolar magnetic bearing can be controlled with- out external position sensors. The self-sensing method is based on inductance measurement by applying voltage pulses to the system. The current slope is measured directly using an induction ring. A differential evaluation of the current slopes increases the position dependent part of the signal and decreases the errors due to eddy currents and the leakage flux. The last part of the paper shows the measured sensitivity function of the system at standstill and rotational speed.
BibTeX:
@inproceedings{ISMB15_54,
  author = {Markus Hutterer and Matthias Hofer and Manfred Schroedl},
  title = {New Results on the Robustness of Selfsensing Magnetic Bearings},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_54.pdf}
}
2008 Hyeong-Joon, A. Dynamic Performance Limitation in Driving a Radial AMB with Space Vector PWM Proceedings of ISMB11  
Abstract: This paper presents a new modeling method and a control system design procedure for a flexible rotor with many elastic modes by using active magnetic bearings. The purpose of our research is to rotate the rotor for passing through critical speeds caused by flexible modes. To achieve this, it is necessary to control motion and vibration of the flexible rotor simultaneously. The new modeling method named as Extended Reduced Order Physical Model is presented to express its motion and vibration uniformly. By using this model, a PID (Proportional-Integral-Derivative) controller to levitate the rotor and a LQ (Linear-Quadratic) controller to suppress its vibration are designed.
BibTeX:
@inproceedings{ISMB11_9,
  author = {Ahn Hyeong-Joon},
  title = {Dynamic Performance Limitation in Driving a Radial AMB with Space Vector PWM},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_9.pdf}
}
2008 Hynynen, K., Jastrzebski, R. and Pöllänen, R. Identification and Modeling of AMB Rotor System Using Complex Lead and Lag Compensator Structures Proceedings of ISMB11  
Abstract: Control design of AMB rotor system demands very accurate system model. Modeling of the rotor is traditionally made using Finite Element Method (FEM) or Experimental Modal Analysis (EMA), but Active Magnetic Bearings (AMB) offer a possibility to obtain the model using system identification. The purpose of this study is to identify the flexible modes of the rotor and determine its transfer function model using complex lead and lag compensator structures. The results demonstrate that the proposed method suits for modeling the flexible modes of an AMB rotor system.
BibTeX:
@inproceedings{ISMB11_96,
  author = {Katja Hynynen and Rafal Jastrzebski and Riku Pöllänen},
  title = {Identification and Modeling of AMB Rotor System Using Complex Lead and Lag Compensator Structures},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_96.pdf}
}
2010 Hynynen, K.M., Jastrzebski, R.P. and Smirnov, A. Experimental Analysis of Frequency Response Function Estimation Methods for Active Magnetic Bearing Rotor System Proceedings of ISMB12  
Abstract: System identification can be used in automated retuning of an active magnetic bearing (AMB) rotor system during commissioning. In the case of good signal-to-noise ratio (SNR), the identification measurements are more time effective using multisine excitation than stepped sine excitation. A multisine signal contains selected frequencies in the desired frequency range. Since in multisine excitation the signal distributes the power over F frequencies, the SNR of the measurement deteriorates. The SNR is improved by averaging the measured frequency response function (FRF) over several measurements. The purpose of this study is to investigate the suitability of different frequency response function estimators for an AMB rotor system identification. The results show that the most accurate estimator for this setup with non-synchronous measurements and the excitation used, is a joint-input-output estimator.
BibTeX:
@inproceedings{ISMB12_94,
  author = {Katja M. Hynynen and Rafal P. Jastrzebski and Alexander Smirnov},
  title = {Experimental Analysis of Frequency Response Function Estimation Methods for Active Magnetic Bearing Rotor System },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_94.pdf}
}
1999 Ide, O. Possibility of Existence of Non-Linear Electromotive Force (EMF) Proceedings of ISMST5  
Abstract: It is well known that a conventional Faraday electromotive force (EMF) is proportional to the time derivative of the magnetic flux. The author made a prototype of a motor driven by the current discharged from the capacitor of an LC circuit and performed an investigation of its characteristics, experimentally and theoretically. The results - when motor drive units of a specific design are installed to drive the motor - confirm the phenomenon that unknown EMF components are created and that these can not be explained only with the conventional Faraday EMF model. The unknown EMF is, for the most part, proportional to a function of the second-order time derivative of the magnetic flux applied. It is also evident that there is even a possibility of the existence of components that are dependent on the third-order, or higher, time derivatives of the magnetic flux applied. Furthermore, it must be noted that the direction of the EMF generated is always in the direction that accelerates the current flow discharged from the circuit.
BibTeX:
@inproceedings{ISMST5_53,
  author = {Osamu Ide},
  title = {Possibility of Existence of Non-Linear Electromotive Force (EMF)},
  booktitle = {Proceedings of ISMST5},
  year = {1999},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst5/ismst5_submission_53.pdf}
}
2004 Ikenaga, K., Matsushita, O., Fujiwara, H. and Ito, M. Evaluation Of Stability Margin Including Non-Linear Control For AMB-Equipped Flexible Rotor Proceedings of ISMB9  
Abstract: Designing controllers is generally based on linear or non-linear control theory. An example of the former is the PID control that is the most popular and widely used in industries. An example of the latter is Variable Structure Control (VSC). In this study, we added the VSC to an AMB-equipped flexible rotor under the PID control. We used the sensitivity function, a way to potentially evaluate the stability margin of the AMB linear system by applying to the non-linear system of the VSC on the system stability. In order to study the VSC’s stability effect quantitatively, we selected the following parameters: s and ? of k?sign[(sx + x&)x]x , and the property of a front-stage filter.
BibTeX:
@inproceedings{ISMB9_64,
  author = {Kazuki Ikenaga and Osami Matsushita and Hiroyuki Fujiwara and Makoto Ito},
  title = {Evaluation Of Stability Margin Including Non-Linear Control For AMB-Equipped Flexible Rotor },
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_64.pdf}
}
2014 Imani-Nejad, M. and Trumper, D. Hysteresis Self-Bearing Motor Proceedings of ISMB14  
Abstract: This paper presents a hysteresis self-bearing motor along with its nonlinear analysis. In this work we introduced a new type of self-bearing motor with segmented stator. The major advantages of this stator are: easy and low cost manufacturing, higher filling factor and shorter magnetic path for the stator. We tested the self-bearing concept successfully with this new configuration. Hysteresis motors are suitable for high speed application since their rotor has neither permanent magnets nor any winding or mechanical features. We used FEA analysis to check the feasibility of proposed idea. Then we used Chua’s hysteresis model to simulate the nonlinear behavior of this system.
BibTeX:
@inproceedings{ISMB14_101,
  author = {Mohammad Imani-Nejad and David Trumper},
  title = {Hysteresis Self-Bearing Motor},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_101.pdf}
}
2004 Imlach, J. Development And Testing Of A Passive Magnetic Support And Damping (PMSD) System Proceedings of ISMB9  
Abstract: This paper details the development and preliminary testing of a new type of passive magnetic bearing with integrated damping elements. The development of a “base excitation/resonant mass” test rig, which was developed to measure the stiffness and damping characteristics of the passive bearings, is also discussed. The results of parametric testing, which is being conducted to determine the effects of using different configurations of magnets and damping materials, is ongoing.
BibTeX:
@inproceedings{ISMB9_83,
  author = {Joe Imlach},
  title = {Development And Testing Of A Passive Magnetic Support And Damping (PMSD) System },
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_83.pdf}
}
1999 Imlach, J. Development and Testing of a Four Pole Magnetic Bearing Proceedings of ISMST5  
Abstract: A 4 pole radial active magnetic bearing actuator has been developed, constructed, and tested. Among the anticipated characteristics of this configuration were: higher specific load capacity, lower power losses, and improved stability as compared to otheT heteropolar configurations. The theoretical basis of each of these aspects will be investigated, and some limitations of the design will be discussed. Testing of the new actuator verified that higher load capacities are achievable. Stability problems with the prototype, due to interaction with the power amplifiers, limited the ability of the testing to investigate actuator stability improvements.
BibTeX:
@inproceedings{ISMST5_47,
  author = {Joe Imlach},
  title = {Development and Testing of a Four Pole Magnetic Bearing},
  booktitle = {Proceedings of ISMST5},
  year = {1999},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst5/ismst5_submission_47.pdf}
}
1990 Imlach, J., Humphris, R., Blair, B. and Allaire, P. Testing of a Magnetic Bearing Equipped Canned Motor Pump for Installation in the Field  Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_7,
  author = {J. Imlach and R.R. Humphris and B.J. Blair and P.E. Allaire },
  title = {Testing of a Magnetic Bearing Equipped Canned Motor Pump for Installation in the Field },
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_7.pdf}
}
1998 Imlach, J. and Kipp, R.W. Development of an Integrated Flux/Position Sensor Proceedings of ISMB6  
Abstract: A novel and practical internal flux sensor for a magnetic bearing has been developed. The bearing uses an integral shunt flux path to provide a measurement of the flux density in the bearing stator. The flux density measurement can be used to improve control functions of the magnetic bearing system. Alternatively, the measurement can be combined with the measurement of coil current in the bearing axis to determine the rotor position. The shunt flux path is created in such a way that the bearing specific load capacity is not diminished, and the bearing package envelope is not increased.
BibTeX:
@inproceedings{ISMB6_53,
  author = {J. Imlach and R. W. Kipp},
  title = {Development of an Integrated Flux/Position Sensor},
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_53.pdf}
}
2010 Imoberdorf, P., Nussbaumer, T. and Kolar, J.W. Analytical Model of Current-Force Characteristics of a Combined Radial-Axial Magnetic Bearing Proceedings of ISMB12  
Abstract: In today’s industry high-speed and high-power-density drives are attracting much interest, e.g. for applications with mesoscale gas turbine generator systems or turbocompressors for fuel cells. In all high-speed drive systems the bearing technology is a key component. Therefore, this paper presents the analysis of an active magnetic bearing suitable for a permanent magnet machine, being part of a high-speed electrical drive system. The analysis has its focus on the detailed characterization of the magnetic forces, the coupling between the different axes and the verification of the theoretical considerations by means of 3D-FEM simulations. To understand the behavior of the bearing forces is needed to implement the position control to the prototype of the bearing system, which already has been built.
BibTeX:
@inproceedings{ISMB12_88,
  author = {Philipp Imoberdorf and Thomas Nussbaumer and Johann W. Kolar},
  title = {Analytical Model of Current-Force Characteristics of a Combined Radial-Axial Magnetic Bearing },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_88.pdf}
}
2012 Impinna, F., Detoni, J.G., Amati, N. and Tonoli, A. Non-dimensional design approach for Electrodynamic Bearings Proceedings of ISMB13  
Abstract: Electrodynamic bearings (EDBs) are passive magnetic bearings that exploit the interaction between eddy currents developed in a rotating conductor and a static magnetic field to generate forces. Similar to other types of magnetic suspensions, EDBs provide contactless support, thus avoiding problems with lubrication, friction and wear. The most interesting aspect of EDBs is that levitation can be obtained by passive means, hence, no electronic equipment, such as power electronics or sensors, are necessary. Despite their promising characteristics, rotors running on EDBs are still lacking a design procedure; furthermore, at present the static behavior of a bearing can only be defined by means of finite element analyses. The aim of the present paper is to present a methodology that allows performing a first approximation design without resorting to detailed FE analyses. The methodology is based on the use of non-dimensional parameters, similar to the analysis of fluid bearings (Sommerfeld number). The non-dimensional quantities are derived using dimensional analysis, and contain the main geometrical and physical parameters determining the EDBs' performance. The relation between the non-dimensional quantities characterizing the static performance of the EDB is derived using FE simulations and is presented in the form of graphs.
BibTeX:
@inproceedings{ISMB13_19,
  author = {Fabrizio Impinna and Joaquim Girardello Detoni and Nicola Amati and Andrea Tonoli},
  title = {Non-dimensional design approach for Electrodynamic Bearings},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_19.pdf}
}
2014 Impinna, F., Detoni, J.G., Tonoli, A. and Amati, N. Test and Theory of Electrodynamic Bearings Coupled to Active Magnetic Dampers Proceedings of ISMB14  
Abstract: Electrodynamic bearings (EDBs) are passive magnetic bearings that exploit the interaction between eddy currents developed in a rotating conductor and a static magnetic field to generate forces. Similar to other types of magnetic suspensions, EDBs provide contactless support, thus avoiding problems with lubrication, friction and wear. Electrodynamic bearings have also drawbacks such as the difficulty in insuring a stable levitation in a wide speed range. The paper presents a solution where the EDBs are coupled with active magnetic dampers (AMDs) to guarantee a stable levitation.
BibTeX:
@inproceedings{ISMB14_65,
  author = {Fabrizio Impinna and Joaquim Girardello Detoni and Andrea Tonoli and Nicola Amati},
  title = {Test and Theory of Electrodynamic Bearings Coupled to Active Magnetic Dampers},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_65.pdf}
}
2008 Inoue, A., Fujioka, H., Morii, S. and Komori, M. Study on Shape Control and Vibration Absorber of Strip in Steel Process Line Proceedings of ISMB11  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB11_28,
  author = {Atsushi Inoue and Hironori Fujioka and Shigeki Morii and Mochimitsu Komori},
  title = {Study on Shape Control and Vibration Absorber of Strip in Steel Process Line},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_28.pdf}
}
2008 Inoue, A., Fujioka, H., Morii, S. and Komori, M. Study on Stability of Steel Strip under the Electromagnetic Shape Controller Proceedings of ISMB11  
Abstract: In a steel process line, shape controllers of steel strip using electromagnets are important devices for improving strip quality and line speed. It is confirmed that the devices are beneficial when these are applied to Continuous Galvanizing Line (CGL). However, it is necessary to avoid a static instability phenomenon by negative spring of the electromagnet, and a spill-over phenomenon by the high gain of the control system in this device. We proposed an analysis model combining the control system with the steel strip. The model was applied to a real machine to confirm the availabilities. Moreover, this paper discusses the static instability phenomenon and the spill-over phenomenon.
BibTeX:
@inproceedings{ISMB11_61,
  author = {Atsushi Inoue and Hironori Fujioka and Shigeki Morii and Mochimitsu Komori},
  title = {Study on Stability of Steel Strip under the Electromagnetic Shape Controller},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_61.pdf}
}
1990 Inoue, T., Takagi, M., Matsushita, O. and Kaneko, R. Loading Test in an Air Turbine Borne by Active Magnetic Bearings  Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_9,
  author = {T. Inoue and M. Takagi and O. Matsushita and R. Kaneko },
  title = {Loading Test in an Air Turbine Borne by Active Magnetic Bearings },
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_9.pdf}
}
1990 Ishida, S. Linear Compensation for Magnetic Bearings  Proceedings of ISMB2  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB2_44,
  author = {S. Ishida },
  title = {Linear Compensation for Magnetic Bearings },
  booktitle = {Proceedings of ISMB2},
  year = {1990},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb2/ismb2_submission_44.pdf}
}
2008 Ishikawa, T., Matsuda, K.-i., Masuzawa, T. and Kondo, R. 5-DOF Controlled Self-Bearing Motor Proceedings of ISMB11  
Abstract: A novel 5-DOF actively controlled self-bearing motor that combines the functions of a motor, two radial AMBs, and an axial AMB has been developed to achieve smaller size and higher performance simultaneously. In this paper, radial control performance of the developed self-bearing motor is evaluated by static and dynamic experiments. The radial control force and the negative stiffness due to the permanent magnets are measured statically. The dynamic performance was tested by measuring the impulse response and the frequency response and the maximum oscillation amplitude of the suspended rotor during rotation. The developed 5-DOF self-bearing motor displays sufficient radial position controllability.
BibTeX:
@inproceedings{ISMB11_71,
  author = {Tatsuya Ishikawa and Ken-ichi Matsuda and Toru Masuzawa and Ryou Kondo },
  title = {5-DOF Controlled Self-Bearing Motor},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_71.pdf}
}
2014 Ishino, Y., Takasaki, M. and Mizuno, T. Fablication of Non-Contact Carrier System Using Solar Magnetic Suspension Proceedings of ISMB14  
Abstract: A solar-powered magnetic suspension carrier system is fabricated which achieves noncontact power supply to the carrier. There are two conventional methods of supplying power to a carrier. One is through wires or contacts such as pantograph and the other is a battery in the carrier. However, the noncontact characteristics are lost in the former, and stations for charging the battery are necessary in the latter. These problems are overcome by the proposed carrier system using solar magnetic suspension that can achieve continuous levitation. In rooms like in factory, the generation of power by solar cells is low so that the magnetic suspension needs power saving. A zero power control system is applied to the suspension of the floator. In addition, low-power peripheral devices are also fabricated.
BibTeX:
@inproceedings{ISMB14_52,
  author = {Yuji Ishino and Masaya Takasaki and Takeshi Mizuno},
  title = {Fablication of Non-Contact Carrier System Using Solar Magnetic Suspension},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_52.pdf}
}
2012 Ishino, Y., Takasaki, M. and Mizuno, T. Development of a Solar Photovoltaic Magnetic Suspension System Proceedings of ISMB13  
Abstract: Extra low-power suspension in gravitational field is achieved by a magnetic suspension system whose power source is solely solar photovoltaics. Presently, solar photovoltaic cells become more efficient and cost-saving year by year. In this study, solar photovoltaic generation technique is combined with the zero-power magnetic suspension. The zero-power control achieves the steady state in which the attractive force produced by the permanent magnets balances the weight of the floator and the control current converges to zero. In this system, the power necessary for generating the suspension forceis very small. However, the peripheral devices including sensors and a controller need power for operation. The power consumed in the peripheral devices becomes dominant in the total power in the steady state. In this work, dedicated power-saving peripheral devices are newlyfabricated. The average power consumed in the electromagnet is 20[mW] to suspend a 90-glammass, while the power consumed in the peripheral devices is 24[mW]. The photovoltaic cells used in the apparatus has a maximum power capacity of about 2[W] in the summer sunlightof 120[kLx]. The system achieves stable suspension even under the illuminance of a fluorescent lamp of 7[kLx].
BibTeX:
@inproceedings{ISMB13_35,
  author = {Yuji Ishino and Masaya Takasaki and Takesh Mizuno},
  title = {Development of a Solar Photovoltaic Magnetic Suspension System},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_35.pdf}
}
1997 Ito, E., Chiba, A. and Fukao, T. A Measurement of VA Requirements in an Induction Type Bearingsless Motor Proceedings of ISMST4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST4_10,
  author = {Eichi Ito and Akira Chiba and Tadashi Fukao},
  title = { A Measurement of VA Requirements in an Induction Type Bearingsless Motor},
  booktitle = {Proceedings of ISMST4},
  year = {1997},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst4/ismst4_submission_10.pdf}
}
2004 Ito, M., Fujiwara, H., Takahashi, N. and Matsushita, O. Evaluation Of Stability Margin Of Active Magnetic Bearing Control Systems Combined With Several Filters Proceedings of ISMB9  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB9_66,
  author = {Makoto Ito and Hiroyuki Fujiwara and Naohiko Takahashi and Osami Matsushita},
  title = {Evaluation Of Stability Margin Of Active Magnetic Bearing Control Systems Combined With Several Filters},
  booktitle = {Proceedings of ISMB9},
  year = {2004},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb9/ismb9_submission_66.pdf}
}
2006 Ito, M., Fujiwaraand, H. and Matsushita, O. Rotational Test of Flexible Rotor Supported by Active Magnetic Bearings (Passing the 3rd Bending Critical Speed) Proceedings of ISMB10  
Abstract: In industrial rotational machinery, it has been required that a long span and a high-speed rotor are designed in order to improve efficiency and reduce costs. In concerning many flexible rotors, the 1st bending critical speed and the 2nd bending critical speed have been passed, but never the 3rd critical speed. In this study a flexible rotor having the 3rd bending critical speed within the rated speed was designed, and was tested to pass the 3rd bending critical speed, owing to fine tuning of Active Magnetic Bearing controller and accurate balancing method.
BibTeX:
@inproceedings{ISMB10_5,
  author = {Makoto Ito and Hiroyuki Fujiwaraand and Osami Matsushita },
  title = {Rotational Test of Flexible Rotor Supported by Active Magnetic Bearings (Passing the 3rd Bending Critical Speed)},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_5.pdf}
}
2000 Iwatsubo, T., Matsushita, O., Adachi, K. and Nakajima, A. Development of Compensator for Active Magnetic Bearing Rotor System by Using Modified Bang-Bang Controller with Dead Zone Element Proceedings of ISMB7  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB7_93,
  author = {Takuzo Iwatsubo and Osami Matsushita and Kazuhiko Adachi and Atsushi Nakajima},
  title = {Development of Compensator for Active Magnetic Bearing Rotor System by Using Modified Bang-Bang Controller with Dead Zone Element},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_93.pdf}
}
1997 Iwaya, M. and Tanaka, M. The HSST Maglev Train – Development, Technology and Prospect Proceedings of ISMST4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMST4_2,
  author = {Mituru Iwaya and Masao Tanaka},
  title = {The HSST Maglev Train – Development, Technology and Prospect},
  booktitle = {Proceedings of ISMST4},
  year = {1997},
  url = {https://www.magneticbearings.org/wp-content/publications/ismst4/ismst4_submission_2.pdf}
}
2008 Izpizua, A., Almandoz, X., Martin, M.S., Cantero, D. and Perez, I. Design and Manufacturing of a 70 kW, 36000 rpm Milling Spindle Proceedings of ISMB11  
Abstract: This work shows the development of magnetically levitated high speed spindles and the possibilities they give for the interaction with the milling process. A fully magnetically levitated spindle with 70 kW up to 36000 rpm is presented; its design and manufacturing issues and his performance in comparison with conventional high speed spindles. Furthermore the possibility to estimate cutting forces and parameters by an state-space approach, using the internal signals of the magnetic bearings as a whole adaptronic system, is shown; and even some preliminary attempts of damping process vibrations.
BibTeX:
@inproceedings{ISMB11_84,
  author = {Alberto Izpizua and Xanti Almandoz and Manex San Martin and David Cantero and Ion Perez},
  title = {Design and Manufacturing of a 70 kW, 36000 rpm Milling Spindle},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_84.pdf}
}
1998 J.K. Lähteenmäki, E.L. Optimization of the Conical Angle of Cone-Shaped Active Magnetic Bearings Proceedings of ISMB6  
Abstract: The conical angle of cone-shaped active magnetic bearings is studied. A model of a conical bearing system and load forces is made. A minimax decision approach is used with the model. The conical angle is optimized so that the control forces required are as small as possible for a given load combination. Also, the conical angle is optimized so that the size of the conical bearing can be made as small as possible. The effect of control strategy on optimization is discussed. As a result, formulae for an optimal conical angle are given. The results also show the effect of using an angle other than the optimum angle, e.g., for manufacturing reasons.
BibTeX:
@inproceedings{ISMB6_22,
  author = {J.K. Lähteenmäki, E.J. Lantto},
  title = {Optimization of the Conical Angle of Cone-Shaped Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB6},
  year = {1998},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb6/ismb6_submission_22.pdf}
}
2016 Jaatinen, P., Sillanpaa, T., Jastrzebski, R.P., Sikanen, E. and Pyrhonen, O. Automated Parameter Identification Platform for Magnetic Levitation Systems: Case Bearingless Machine Proceedings of ISMB15  
Abstract: This paper presents automated platform that can be used to identify parameters of magnetic levitated systems. Identification platform itself consists of 3-axis force measurement sensors and 2-axis stepper motors driven linear ball screw tracks. This kind of construction enables to measure the force produced by electromagnets in any angle and in any position in the air gap. Measurement system is controllable so the identification process can be automated. As a case study, self and mutual inductances of an interior permanent magnet bearingless machine are identified for the motor control purposes. Force sensors are used to measure the unbalance magnetic pull inflicted by the permanent magnets embedded in the rotor. Automated measuring procedure is used to determine self and mutual inductances of the bearingless motor. System functionality is validated by comparing the measured magnetic pull results to FEM analysis and inductance measurement to different prediction method based on standard motor drive identification process. Based on achieved results presented automated platform can be used to identify parameters of magnetically levitated system.
BibTeX:
@inproceedings{ISMB15_34,
  author = {Pekko Jaatinen and Teemu Sillanpaa and Rafal P. Jastrzebski and Eerik Sikanen and Olli Pyrhonen},
  title = {Automated Parameter Identification Platform for Magnetic Levitation Systems: Case Bearingless Machine},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_34.pdf}
}
2010 Jan, Z., Bronislaw, T. and Dawid, W. Discretization Mesh Design for a Magnetic Bearing in the 3D Field Analysis Proceedings of ISMB12  
Abstract: In this paper, nonsymmetrical 12-pole (AMB12) magnetic bearings are analyzed. 3D Finite Element Method (FEM) was used for the magnetic field computations and nonlinear boundary problem was investigated. Discretization process is described for the AMB modeling, [5]. Research applies adaptation meshing method with the aid of high-order finite elements.
BibTeX:
@inproceedings{ISMB12_117,
  author = {Zimon Jan and Tomczuk Bronislaw and Wajnert Dawid},
  title = {Discretization Mesh Design for a Magnetic Bearing in the 3D Field Analysis },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_117.pdf}
}
2010 Jan, Z., Bronislaw, T. and Dawid, W. Eddy Current Influence on the Parameters of Active Magnetic Bearing Proceedings of ISMB12  
Abstract: In this work, a symmetrical 8-pole (AMB8) magnetic bearing has been analyzed. The 3D Finite Element Method (FEM) was used for magnetic field computations and nonlinear boundary problem was investigated. We describe discretization process for the AMB modeling, [1]. The power losses and the force of the magnetic suspension have been calculated.
BibTeX:
@inproceedings{ISMB12_76,
  author = {Zimon Jan and Tomczuk Bronislaw and Wajnert Dawid},
  title = {Eddy Current Influence on the Parameters of Active Magnetic Bearing },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_76.pdf}
}
2008 Janssen, J., Paulides, J. and Lomonova, E. Passive Magnetic Suspension Limitations for Gravity Compensation Proceedings of ISMB11  
Abstract: The development of sophisticated advanced vibration isolation is important, since even the minutest vibrations have disastrous effects on the performance of static and moving parts in high-precision machines. This paper concerns with the isolation of these vibrations for a large static body in an advanced micro-lithographic system, where a passive/active electromagnetic solution is presented. In these configurations passive permanent magnets (PM) provide the gravity compensation and active electromagnets the accurate positioning. However, this paper only considers the applicability of a passive magnetic solution for this high force gravity compensation application, or, more specifically, the influence of various PM array topologies on the force density. Further, fast-solving analytical models will be presented and will consequently be used to illustrate the feasibility of using passive permanent magnets for gravity compensation in this demanding high precision industrial application.
BibTeX:
@inproceedings{ISMB11_13,
  author = {J.L.G. Janssen and J.J.H. Paulides and E. Lomonova},
  title = {Passive Magnetic Suspension Limitations for Gravity Compensation},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_13.pdf}
}
2018 Jarroux, C., Mahfoud, J., Defoy, B. and Alban, T. Control Investigations of Rotor Supported by AMBs During Severe Foundation Excitations Proceedings of ISMB16  
Abstract: The study is devoted to numerical and experimental investigations of the dynamic behavior of base excited rotating machines supported by Active Magnetic Bearings (AMBs). In case of strong base motions, the rotor can contact its touchdown bearings (TDBs) which are emergency bearings. The objective is to analyze the effect of the combination of mass unbalance forces, base motion excitations and contact nonlinearities on a rotor-AMB system response. In particular, the capacity of an augmented PID controller to maintain the system stable. FE method was developed to model the on-board rotor-AMB system. An academic scale test rig was used for the experimental investigations. Predicted and measured responses due to impulse excitations applied on the foundations were compared. The capacity of the controller to maintain the system stability is discussed.
BibTeX:
@inproceedings{ISMB16_036,
  author = {Clement Jarroux and Jarir Mahfoud and Benjamin Defoy and Thomas Alban},
  title = {Control Investigations of Rotor Supported by AMBs During Severe Foundation Excitations},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_036.pdf}
}
2016 Jarroux, C., Mahfoud, J., Dufour, R. and Defoy, B. On the dynamics of rotating machinery supported by AMB during base motion Proceedings of ISMB15  
Abstract: This study is devoted to rotor supported by Active Magnetic Bearings (AMBs) and subject to base motion. The machine casing is considered rigid and able to move along the 3 translations and the 3 rotations. The objective of this work is to assess the suitability of machine supported by AMBs to withstand base motions for applications such as compressors on FPSO (Floating production storage and offloading) or emergency steam turbines in nuclear plants. The model developed takes into account the base motion, unbalances on rotor, gravity and bearings properties. The consideration of the base motions has a significant impact on equations of motion and introduces parametric excitations. The centrifugal stiffening effect due to the base rotations is considered. The developed model, is compared with previous experiments performed with a light rotor mounted on classical ball- bearings. The dynamic behavior is analyzed for different types of base motion. Then, the capability of AMB to sustain base motions is examined. Numerical simulations are performed with a rigid rotor supported by two AMBs. The latter are controlled with an augmented PID not specifically tuned for base motion purpose. Finally, the results are discussed. The model developed is a first step for the improvement of turbomachinery supported by AMB. The aim is to eliminate a blocking point to the penetration of AMB technology in on board applications.
BibTeX:
@inproceedings{ISMB15_75,
  author = {Clement Jarroux and Jarir Mahfoud and Regis Dufour and Benjamin Defoy},
  title = {On the dynamics of rotating machinery supported by AMB during base motion},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_75.pdf}
}
2006 Jastrzebski, R., Pöllänen, R., Pyrhönen, O., Kärkkäinen, A. and Sopanen, J. Modeling and Implementation of Active Magnetic Bearing Rotor System for FPGA-based Control Proceedings of ISMB10  
Abstract: This article reveals an implementation of a flexible rotor model with the nonlinear actuator for an LQ-control realization using field programmable gate arrays. The presented AMB-rotor model can be utilized both for the controller (as a state observer and nonlinearity compensator) and for the system development as a real-time plant emulator. The different variants of the LQ position control are considered in regard to the rotor model, used as a part of the observer. The model of the studied rotor was obtained using the finite element modeling, modal reduction technique and experimental analysis.
BibTeX:
@inproceedings{ISMB10_77,
  author = {Rafal Jastrzebski and Riku Pöllänen and Olli Pyrhönen and Antti Kärkkäinen and Jussi Sopanen},
  title = {Modeling and Implementation of Active Magnetic Bearing Rotor System for FPGA-based Control},
  booktitle = {Proceedings of ISMB10},
  year = {2006},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb10/ismb10_submission_77.pdf}
}
2012 Jastrzebski, R., Smirnov, A., Lin, Z., Pyrhönen, O. and Allaire, P. Extended Kalman Filter Applied to an AMB System with Strong Magnetic Saturation Proceedings of ISMB13  
Abstract: The main aim of the paper is to operate an AMB system inside the magnetically saturated region. We investigate how to stabilize a highly nonlinear AMB system with the actuator magnetic saturation by estimating the system states and parameters of the unconstrained bearing in real time. The stabilization is achieved by a combination of the controller and the extended Kalman filter to estimate the states of the plant. In the extended Kalman filter, the magnetization behavior has been modeled by using low-order piecewise polynomial approximation. The extended Kalman applied to the AMB system introduces an additional challenge because of the computational burden, numerical stability when computing the inverse of the innovation covariance matrix, and the non-continuous derivative in the computed Jacobeans. Feasibility of different control configurations is examined. As the case study we use the 1 DOF balancing beam model. The proposed solution for the system operation in the magnetic saturation provides such benefits as: the reduced size and costs of bearings, improved robust performance and stability, and an increased controllability region with respect to control variables.
BibTeX:
@inproceedings{ISMB13_28,
  author = {Rafal Jastrzebski and Alexander Smirnov and Zongli Lin and Olli Pyrhönen and Paul Allaire},
  title = {Extended Kalman Filter Applied to an AMB System with Strong Magnetic Saturation},
  booktitle = {Proceedings of ISMB13},
  year = {2012},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb13/ismb13_submission_28.pdf}
}
2010 Jastrzebski, R.P., Hynynen, K.M. and Smirnov, A. Uncertainty Set, Design and Performance Evaluation of Centralized Controllers for AMB System Proceedings of ISMB12  
Abstract: In this paper an industrially recognized modal control approach, a linear-quadratic-Gaussian (LQG) control, and an H8 control designs are compared using automated weights tuning based on a genetic algorithm. The robust stability analysis is carried out based on the uncertainty set, which comprises parametric and nonparametric uncertainties. The uncertainty set is updated to be compliant with the measured frequency responses of the test rig. The studied combination of the uncertainties proves too conservative for the direct application in the H8 control synthesis. However, a robust stability of the controllers synthesized using the nominal plant can be verified using µ-analysis and the very uncertainty set that cannot be used for the controller design directly. It is demonstrated that for the rigid rotor without strong gyroscopic coupling all of the control approaches result in a similar performance. For the more slender rotor with an additional disc and the dynamics dependent on the rotational speed the best results are achieved by the LQG and H8 controllers. When no gain scheduling is applied, the modal control results in the unstable system.
BibTeX:
@inproceedings{ISMB12_110,
  author = {Rafal P. Jastrzebski and Katja M. Hynynen and Alexander Smirnov},
  title = {Uncertainty Set, Design and Performance Evaluation of Centralized Controllers for AMB System },
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_110.pdf}
}
2016 Jastrzebski, R.P., Jaatinen, P. and Chiba, A. Efficiency of buried permanent magnet type 5kW and 50kW high-speed bearingless motors with 4-pole motor windings and 2-pole suspension windings Proceedings of ISMB15  
Abstract: This work focuses on loss prediction for varying operation conditions of the high-speed buried-type interior permanent magnet (IPM) bearingless motors. The investigated motors are 5 kW and 50 kW units configured as twin motor sets, which provide radial suspension and motoring in 5 degrees of freedom levitated rotor systems with the maximum speed of 30000 r/min. The maximum output power of studied rotor systems is 10 kW and 100kW, respectively. Additionally, the power factors of motor and suspension windings as well as inductance maps for various operating conditions are studied. The magnetic field 2-dimentional transient section analysis and time stepping are applied. The selected results are compared with the measured values. In the loss calculation various rotor and stator iron losses, resistive losses, windage losses and additional losses are taken into account. Efficiency maps and power factor estimation are valuable for application of electrical machines. These studies have been performed using various methods for classical motors and generators but are uncommon for bearingless motors working with different loading conditions. The comprehensive efficiency map prediction of the high-speed IPM bearingless motors for different suspension loading is presented for the first time. The variations of motor inductances for different rotor angles and current amplitudes are derived. The differences in results between the machines with the same geometry but different power are discussed.
BibTeX:
@inproceedings{ISMB15_20,
  author = {Rafal Piotr Jastrzebski and Pekko Jaatinen and Akira Chiba},
  title = {Efficiency of buried permanent magnet type 5kW and 50kW high-speed bearingless motors with 4-pole motor windings and 2-pole suspension windings},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_20.pdf}
}
2016 Jastrzebski, R.P., Jaatinen, P. and Pyrhonen, O. Modelling and control design simulations of Permanent Magnet Flux-Switching Linear Bearingless Motor Proceedings of ISMB15  
Abstract: For permanent magnet (PM) motor structures in rotating systems, it is typical to retain the magnets in the rotor. This constrains the rotor structure and limits applicability, e.g., for high-speed and high-temperature conditions. Flux-switching PM (FSPM) motors can overcome this limitation. Recently, the FSPM bearingless motors have been developed for special applications. The FSPM concept can be adapted to liner motors. For the linear motors, magnets or windings placed on the mover significantly decrease complexity and cost for longer distances. Still, to separate control of airgap and torque (thrust) two sets of windings or multiphase windings have been required for both rotating FSPM and linear PM machines. The linear FSPM bearingless motor solution, which integrates the magnets, winding structure and all the driving and control electronics on the mover is desired for many applications. However, because of electromagnetic unbalances the machine design is entangled with the control limitations and requirements. We reveal a modelling methodology for accurate derivation of bearingless machine dynamic and static force parameters as a function of airgap, control currents and track position in extended operational range. Model-based control simulations based on the accurate derived plant models determine the achievable machine performance and levitation limitations. The design and modelling methodology is general and can be applied to different PM bearingless motors. In the case study of linear FSPM bearingless motor the airgap control is possible in the equivalent to classical AMBs manner where it is independent from the thrust control.
BibTeX:
@inproceedings{ISMB15_37,
  author = {Rafal Piotr Jastrzebski and Pekko Jaatinen and Olli Pyrhonen},
  title = {Modelling and control design simulations of Permanent Magnet Flux-Switching Linear Bearingless Motor},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_37.pdf}
}
2008 Jastrzebski, R.P. and Pöllänen, R. Observer-Based Unbalance Compensation in LQ-Control of AMBs Proceedings of ISMB11  
Abstract: In this work, a model-based linear-quadratic controller with an optimal observer-based unbalance force rejection control for variable speed magnetically suspended rotors is presented. The unbalance force rejection control is considered in two variants. In the first one, the unbalance forces are canceled and the system can maintain an accurate reference rotor position. This variant results in low measured vibration amplitudes. In the second one, the magnetic force vibrations are canceled and the rotor spins about its principal axis of inertia within the bearing clearance. The control currents and energy usage are minimal, and the vibrations are slightly decreased. Both cases are designed as a periodic disturbance observer. Simulations for the variable speed and an experimental evaluation at the constant speed are presented.
BibTeX:
@inproceedings{ISMB11_69,
  author = {Rafal Piotr Jastrzebski and Riku Pöllänen},
  title = {Observer-Based Unbalance Compensation in LQ-Control of AMBs},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_69.pdf}
}
2008 Jastrzebski, R.P. and Pöllänen, R. Trade Offs in LQ/LTR Control Designs for MIMO AMB Systems Proceedings of ISMB11  
Abstract: This study evaluates the design tradeoffs of linear-quadratic (LQ) and LQ / loop transfer recovery (LTR) controllers for MIMO AMB system. The comparison of the LQ regulator with the Kalman filter, LQ/LTR design, and classical PID and PI/PD cascaded controllers is presented. The properties of the tested control configurations are examined using maximum singular values of the output sensitivity function of the close-loop system and the tolerated disturbance force at the input of the plant. Furthermore, the indexes such as measured peak output sensitivity, responses to the step reference position and step disturbance are examined. The simulation and experimental results from the test-rig are compared.
BibTeX:
@inproceedings{ISMB11_67,
  author = {Rafal Piotr Jastrzebski and Riku Pöllänen},
  title = {Trade Offs in LQ/LTR Control Designs for MIMO AMB Systems},
  booktitle = {Proceedings of ISMB11},
  year = {2008},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb11/ismb11_submission_67.pdf}
}
2016 Jastrzebski, R.P., Sillanpaa, T., Jaatinen, P., Smirnov, A., Vuojolainen, J., Lindh, T. and Laiho, A. Automated Design of AMB Rotor Systems with Standard Drive, Control Software and Hardware Technologies Proceedings of ISMB15  
Abstract: Industrial applications of active magnetic bearings (AMBs) technology have been continuing to grow for over 4 decades. However, the volume and cost reduction for consumer products are still lower than industrial potential. Particularly, bearing design to match the application, control design, commissioning, control tuning, electronics design and scaling of VA rating to match the bearings make the significant contribution to overall cost of new AMBs. This paper describes how to design and implement an industrial 5 degrees of freedom AMB suspension and model-based control for rotating systems quickly and efficiently. The presented solution leverages the existing commercialized drives and automation components for making the AMB products. With the automated analytical design of AMB actuators and control in respect to design constrains the design & engineering of the product are completed. This leads to easier scalability, standardization, lead-time reduction, and broadening the application area.
BibTeX:
@inproceedings{ISMB15_7,
  author = {Rafal P. Jastrzebski and Teemu Sillanpaa and Pekko Jaatinen and Alexander Smirnov and Jouni Vuojolainen and Tuomo Lindh and Antti Laiho},
  title = {Automated Design of AMB Rotor Systems with Standard Drive, Control Software and Hardware Technologies},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_7.pdf}
}
2010 Jastrzebski, R.P., Tolsa, K. and Iskanius, M. Customization of Digital Circuit for Material-Independent Eddy Current Proximity Sensor for Active Magnetic Bearings Proceedings of ISMB12  
Abstract: The state of the art, commercial eddy current sensors can provide excellent quality of the measured position; however, the easier system integration, size of the conditioning electronics, cost, and interfacing delays are unfavorable. In this paper, a customization of the basic conventional single-coil eddy current proximity sensor for active magnetic bearings is presented. The signal conditioning is designed to be integrated with the main signal processing unit, which can also incorporate the active magnetic bearing system controller. The nonlinearities and dependencies on the electromagnetic properties of the target material are eliminated using software implementation. The highest signal to noise ration is observed for the aluminium-alloy target. It is shown that for the studied sensor the measuring range and accuracy are limited when under the materialindependent operation.
BibTeX:
@inproceedings{ISMB12_51,
  author = {Rafal P. Jastrzebski and Kimmo Tolsa and Matti Iskanius},
  title = {Customization of Digital Circuit for Material-Independent Eddy Current Proximity Sensor for Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB12},
  year = {2010},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb12/ismb12_submission_51.pdf}
}
2018 Javed, A., Mizuno, T., Takasaki, M., Ishino, Y. and Yamaguchi, D. Variable Stiffness Approach to Reduce Vibration Induced in Passively-supported Directions of an Active Magnetic Suspension System Proceedings of ISMB16  
Abstract: This study focuses on the vibration reduction in lateral directions by varying the stiffness of the system in a vertically active magnetic suspension system. Vibration can easily be induced in the lateral directions while the normal directions are actively controlled with a pair of electromagnets working in a differential driving mode. Switching stiffness control is applied to such a system to reduce the lateral vibration of a floator that is a 25 mm ferromagnetic ball. The normal position of the floator is unchanged even if the stiffness control is applied to the system. The efficacy of the control is evaluated by several experiments which show the reduction of lateral vibrations.
BibTeX:
@inproceedings{ISMB16_083,
  author = {Asief Javed and Takeshi Mizuno and Masaya Takasaki and Yuji Ishino and Daisuke Yamaguchi},
  title = {Variable Stiffness Approach to Reduce Vibration Induced in Passively-supported Directions of an Active Magnetic Suspension System},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_083.pdf}
}
2018 Jayawant, R., Avetian, T., McRobb, N. and Shultz, R. Development and Certification of a Skid Mounted AMB Controller for Hazardous Area Installation Proceedings of ISMB16  
Abstract: Active magnetic bearing (AMB) controllers for hydrocarbon and other hazardous area applications are normally installed within a control room inside a safe (unclassified) area. This article describes the design and certification of an AMB controller for skid mounting within the hazardous area, drawing on recent development of a first of class system. The design challenges raised by the environmental requirements for outdoor installation are discussed together with the challenges resulting from the hazardous area certification requirements. The routes to hazardous area certification considered during the early phases of the development project are presented together with a description of the route finally chosen.
BibTeX:
@inproceedings{ISMB16_001,
  author = {Richard Jayawant and Tadeh Avetian and Nigel McRobb and Richard Shultz},
  title = {Development and Certification of a Skid Mounted AMB Controller for Hazardous Area Installation},
  booktitle = {Proceedings of ISMB16},
  year = {2018},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb16/ismb16_001.pdf}
}
2013 Jayawant, R. and Dabbs, S. A Novel Digital Circuit for Position Sensor De-modulation Using Advanced FPGA, Including Field Experience with a 1.45MW Motor Driven Compressor Proceedings of BWMB2013  
Abstract: This paper describes a novel demodulation circuit which has been developed for use with inductive position sensors for Active Magnetic Bearing applications. The circuit is designed to operate with conventional bridge type inductive position sensors. This circuit is novel in that the implementation is fully digital and uses a mixture of FPGA and DSP to ensure noise immune phase sensitive de-modulation. We present the architecture and implementation of the new circuit. The techniques to perform the phase sensitive de-modulation are described, including the techniques necessary to handle the phase shifts due to cable capacitance. In conventional analogue based systems these phase shifts are compensated by field changes to component values. The experience of using this sensor on a 1.5MW motor driven hydrogen compressor is described. We present the results and experiences of commissioning the machine. The noise levels recorded during testing, and the overall response of the machine both whilst levitated (non-rotating) and during operation are included. We finish with a comparison of the two methodologies; the precision analogue circuitry versus the digital along with our conclusions.
BibTeX:
@inproceedings{BWMB2013_7,
  author = {Richard Jayawant and Steve Dabbs},
  title = {A Novel Digital Circuit for Position Sensor De-modulation Using Advanced FPGA, Including Field Experience with a 1.45MW Motor Driven Compressor},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {https://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_7.pdf}
}
2014 Jayawant, R. and Davies, N. Field Experience with Automated Commissioning Tools in Both Remote and Local Commissioning of Active Magnetic Bearing Systems Proceedings of ISMB14  
Abstract: This paper describes field experience with 3rd generation AMB automated commissioning tools. This covers experience on “first of class” machinery on sites where both AMB specialists were present using the automated commissioning tools and other installations where no AMB specialist was present and all commissioning was conducted by remote guidance of local non-specialist staff and remote use of automated commissioning tools.
BibTeX:
@inproceedings{ISMB14_35,
  author = {Richard Jayawant and Nigel Davies},
  title = {Field Experience with Automated Commissioning Tools in Both Remote and Local Commissioning of Active Magnetic Bearing Systems},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_35.pdf}
}
2013 Jayawant, R. and Davies, N. Integration of Signal Processing Capability in an AMB Controller to Support Remote and Automated Commissioning Proceedings of BWMB2013  
Abstract: One major limitation to the wide adoption of active magnetic bearings (AMBs) in industry is the time required for commissioning and tuning. In this paper we will report how integration of signal processing capability (especially multi-channel transfer function measurements) within the AMB controller can reduce total commissioning time and especially, the time required on site by a highly skilled AMB specialist. We also show how PC based automatic commissioning tools make it possible for OEM and end user engineers to commission, tune and maintain AMB machines with only occasional remote support from the AMB vendor and without specialist rotor-dynamic test equipment. Secondary benefits from this approach include increased traceability and repeatability of the tuning process. The automated commissioning is based on MATLAB scripts and data analysis capabilities. This runs on a separate PC which (via the controller network interface) configures the measurements to be made by the AMB controller. Analysis of the resulting measurements allows automatic modification of controller parameters. These scripts cover several control loops and estimators within the AMB controller including current, flux and position servo control. The robustness and vibration performance are used to assess the resulting control loop. This is based around a concept of dynamic templates which correlate to acceptance criteria according to ISO 14839-2 and ISO 14839-3. Results from running the automated commissioning process on a high speed test rig are presented. The results show that the dynamic template model provides good control performance with rapid tuning time. This technology has the potential for the development of sophisticated diagnostic routines which could be activated in the event of anomalous readings, and this further future work is briefly described.
BibTeX:
@inproceedings{BWMB2013_6,
  author = {Richard Jayawant and Nigel Davies},
  title = {Integration of Signal Processing Capability in an AMB Controller to Support Remote and Automated Commissioning},
  booktitle = {Proceedings of BWMB2013},
  year = {2013},
  url = {https://www.magneticbearings.org/wp-content/publications/bwmb2013/bwmb2013_submission_6.pdf}
}
2016 Jayawant, R. and Masala, A. Design and Commissioning of a 3.3 MW Motor-Driven Compressor Fully Supported on Active Magnetic Bearings Proceedings of ISMB15  
Abstract: This paper describes the design and commissioning of active magnetic bearings (AMBs) for a 3.3 MW motor- driven compressor. The total string comprises a motor coupled (via a flexible coupling) to a compressor, with the two machines mounted in separate casings. The design of the compressor AMBs, in particular the rotordynamic design, is described together with the commissioning experience for both the compressor and the coupled string. The use of third-generation Automated Commissioning tools in the initial setup and the dynamic tuning of the machine is described. These tools were deployed remotely and the impact of this remote mode of commissioning on the required work methods, including the impact of variable performance in Internet connectivity and the tools required for communication across large differences in time zones, is examined. Particular issues encountered during the commissioning, triggered by use of close clearance seals, are discussed; these include impact on the use of the Automated Commissioning tools, impact on the vibration performance of the machine (with solutions to overcome these problems), and impact of stiction in the seals on the rotordynamic measurements. The results of the vibration measurements and sensitivity function measurements for the tuned machine are presented.
BibTeX:
@inproceedings{ISMB15_25,
  author = {Richard Jayawant and Andrea Masala},
  title = {Design and Commissioning of a 3.3 MW Motor-Driven Compressor Fully Supported on Active Magnetic Bearings},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_25.pdf}
}
1996 Jeon, J., Jin, J. and Higuchi, T. Rotary Actuators with Electrostatic Suspension  Proceedings of ISMB5  
Abstract: This paper studies two types of electrostatically suspended rotary actuators: electrostatically suspended variable- capacitance motors (ESVCM) and electrostatically suspended induction motors (ESIM). The ESVCM is an electrostatic stepping motor which features electrostatic suspension. Thus, ESVCM possesses the rotating and positioning ability of an ordinary stepping motor, in addition to providing contactless support by electrostatic suspension. To accomplish these two functions, a feedback control strategy and the operating principle of an ordinary electrostatic variable-capacitance motor are used. The ESIM is an induction motor where the rotor is suspended stably, like ESVCM, by actively controlling the electrostatic forces exerted on it. To implement a rotation, the operating principle of an ordinary electrostatic induction motor is used. In this paper, the working principle of the ESVCM and the ESIM, electrode design, a linear dynamic model of the suspension system, feedback control strategy and operating principle of rotation are described. Experimental results show that the rotor has been rotated with a speed of approximately 60 rpm while being suspended stably at a gap length of 300 µm.
BibTeX:
@inproceedings{ISMB5_69,
  author = {J. Jeon and J. Jin and T. Higuchi },
  title = {Rotary Actuators with Electrostatic Suspension },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_69.pdf}
}
2014 Jeon, J.-W., Lee, C.-L., Oh, H.-S. and Kim, J.-M. Novel Cylindrical Magnetic Levitation Stage with High Precision Motion Proceedings of ISMB14  
Abstract: This paper proposed novel cylindrical magnetic levitation stage. This stage can move the cylinder to rotations and translations as well as levitations with high precision in vacuum. This advantage is useful to make a nano patterning on the surface of cylindrical specimen by using electron beam lithography. In this paper, a conceptual design and a detailed design of the novel cylindrical magnetic levitation stage are shown. Firstly, mathematical modeling and simulation results are shown and then experimental results are compared after manufactured.
BibTeX:
@inproceedings{ISMB14_14,
  author = {Jeong-Woo Jeon and Chang-Lin Lee and Hyeon-Seok Oh and Jong-Moon Kim},
  title = {Novel Cylindrical Magnetic Levitation Stage with High Precision Motion},
  booktitle = {Proceedings of ISMB14},
  year = {2014},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb14/ismb14_submission_14.pdf}
}
2000 Jeon, S., Ahn, H.-J. and Han, D.-C. New Design of Cylindrical Capacitive Sensor for On-line Precision Control of AMB Spindles Proceedings of ISMB7  
Abstract: A new design of cylindrical capacitive sensor (CCS) for the displacement measurement of precision active magnetic bearing (AMB) spindle is presented in this paper. This research is motivated by the problem that existing 4-segment CCS is still sensitive to the 3rd harmonic component of the geometric errors of a rotor. The procedure of designing new CCS starts from modeling and the error analysis of CCS. The angular size of CCS is set up as a design parameter, and new 8- segment CCS is introduced to possess an arbitrary angular size. The optimum geometry of CCS to minimize the effect of geometric errors is determined through minimum norm approach. Experimental results with test rotors have confirmed the improvement in geometric error suppression. Keywords : Cylindrical capacitive sensor, Geometric error, Active magnetic bearing.
BibTeX:
@inproceedings{ISMB7_83,
  author = {Soo Jeon and Hyeong-Joon Ahn and Dong-Chul Han},
  title = {New Design of Cylindrical Capacitive Sensor for On-line Precision Control of AMB Spindles},
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_83.pdf}
}
1994 Jeong, H., Kim, C. and Lee, C. Modeling and Control of Cone-Shaped Active Magnetic Bearing System Proceedings of ISMB4  
Abstract: No abstract available, please see full pdf.
BibTeX:
@inproceedings{ISMB4_5,
  author = {H. Jeong and C. Kim and C. Lee },
  title = {Modeling and Control of Cone-Shaped Active Magnetic Bearing System },
  booktitle = {Proceedings of ISMB4},
  year = {1994},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb4/ismb4_submission_5.pdf}
}
1996 Jeong, H. and Lee, C. Robust Motion Control of the Frictionless Positioning Device Suspended by Cone-Shaped Active Magnetic Bearings  Proceedings of ISMB5  
Abstract: A time delay controller with state feedback is proposed for the frictionless positioning device which is subject to the variations of inertia and the presence of measurement noise. The time delay controller, which is combined with a low-pass filter to attenuate the effect of measurement noise, ensures the asymptotic stability of the closed loop system. It isfound that the low-pass filter tends to increase the robustness in the design of time delay controller as well as the gain and phase margins of the closed loop system. Simulation results support that the proposed controller guarantees a good tracking performance irrespective of the variation o..finertia and the presence of measurement noise.
BibTeX:
@inproceedings{ISMB5_11,
  author = {H. Jeong and C. Lee },
  title = {Robust Motion Control of the Frictionless Positioning Device Suspended by Cone-Shaped Active Magnetic Bearings },
  booktitle = {Proceedings of ISMB5},
  year = {1996},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb5/ismb5_submission_11.pdf}
}
2016 Jeong, S. and Jeon, D. Rotordynamic Behavior and Rigid Mode Vibration Control by Hybrid Foil-Magnetic Bearing System Proceedings of ISMB15  
Abstract: In a hybrid foil-magnetic bearing (HFMB), an air foil bearing (AFB) serve as auxiliary bearings for an active magnetic bearing (AMB). This enables design simplification and weight reduction, and it can reduce the energy consumption of the AMB. Therefore, an HFMB has higher efficiency and reliability. This study conducts vibration control tests of an HFMB at increasing rotor speeds for various AMB control parameters. AMB control parameters are experimentally determined for achieving an appropriate load distribution between the AMB and the AFB. Furthermore, to minimize the vibration and energy consumption, the ON/OFF period control of the AMB is adjusted properly according to the operating speed. Accordingly, the HFMB can afford the high load capacity of the AFB at high speed as well as the high static stiffness to prevent initial rubbing and the control capability of the AMB to suppress excessive vibration. Therefore, the HFMB improves the performance of rotating machinery significantly in terms of range of operation and reliability. In addition, the effects of the load distribution between the AMB and the AFB are investigated by changing the control characteristics to produce different stiffness and damping effects. The HFMB for a high-speed rotor is experimentally optimized by altering the load distribution of the two bearings in terms of rigid mode vibration.
BibTeX:
@inproceedings{ISMB15_73,
  author = {Sena Jeong and Doyoung Jeon},
  title = {Rotordynamic Behavior and Rigid Mode Vibration Control by Hybrid Foil-Magnetic Bearing System},
  booktitle = {Proceedings of ISMB15},
  year = {2016},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb15/ismb15_submission_73.pdf}
}
2000 Ji, J.C. and Leung, A.Y.T. Non-Linear Behavior of a Magnetically Supported Rotor Proceedings of ISMB7  
Abstract: Non-linearity is an inherent and essential characteristic of active magnetic bearings. For simplicity, only the non-linearity between force, current and displacement of the electromagnets is considered while other nonlinearities are neglected. The nonlinear response of a rotor in active magnetic bearings is investigated for the case of a primary resonance. The method of multiple scales is used to obtain four first-order ordinary differential equations that describe the modulation of the amplitudes and phases of oscillations in the horizontal and vertical directions. The steady state response and its stability are obtained numerically from the reduced equations. In the regime of multiple coexisting solutions, two stable solutions are found. Finally, the analytical results are verified by integrating the governing equations.
BibTeX:
@inproceedings{ISMB7_3,
  author = {J. C. Ji and A. Y. T. Leung},
  title = {Non-Linear Behavior of a Magnetically Supported Rotor },
  booktitle = {Proceedings of ISMB7},
  year = {2000},
  url = {https://www.magneticbearings.org/wp-content/publications/ismb7/ismb7_submission_3.pdf}
}
2012 Ji, L. and Xu, L. Research on an Inverter-fed Six-Pole Permanent Magnet Biased Magnetic Bearing Proceedings of ISMB13  
Abstract: The configuration and working principle of a six-pole heteropolar permanent magnet biased magnetic bearing is introduced. And the mathematical models of the suspension forces are deduced through coordinate transformation. Then the paper studies the performances of the magnetic bearing for various area ratios between the permanent magnetic pole and the electromagnetic pole. The mathematical models are verified by finite element simulation. The results show that the current stiffness error rate between theoretical calculation and finite-element simulation is less than 3%, while the displacement stiffness error rate is much greater. A controller for this magnetic bearing is designed. To confirm the c