Magnetic Suspension System with Permanent Magnet Motion Control

A novel active mag-lev system, featuring a bearing force control method, is being developed. In conventional systems, bearing force is controlled by an electrical method in which electromagnet coil currents are varied. However, in the proposed system, bearing force is controlled by a mechanical method in which the air gap between a permanent magnet and the levitated object is varied. As permanent magnets are used, the proposed system is effective for eliminating heat generation and saving energy. First, the principle of this suspension system is explained. Next, a 1 DOF ball suspension system based on the proposed concept is introduced. Theoretical analyses of this system prove the feasibility of non-contact suspension and self-sensing controller. Experimental examinations support the analyses well. Additionally, a separate 3 DOF disk suspension system is discussed and analyzed from a control method point view, and another system employing a piezoelectric actuation element and self-sensing controller has been considered. Finally the concept of using electrostatics, in place of permanent magnets as an attractive force means in introduced.