LMI Based Gain Scheduled H-inf Controller Design for AMB Systems under Gyroscopic and Unbalance Disturbance Effect

Ultra high speed rotation in Active Magnetic Bearing (AMB) systems with their comlex structure requires powerful control system design approaches for robust stability and robust performance. Recent studies in robust control theory have offered comprehensive gainscheduled control design approaches such as Linear Matrix Inequality (LMI) based gain-scheduled control for Linear Parameter Varying Systems (LPVS) which are a certain class of linear time-varying systems that statespace matrices of their plants are fixed function of timevarying physical parameters. Rotor systems modelled with inclusion of gyroscopic effect can be considered LPV system because of affine dependence of system natural frequencies to rotational speed which is taken as timevarying parameter. These varying parameter values can be measured on line during control operation. In this study, commercially available and vertically designed a rotor bearing system is modelled and controlled using LMI based gain-scheduled controllers and compared with PID controllers. The results are reasonable and encouraging for future studies of AMB systems.