Feedback linearization and fuzzy control for conical magnetic bearings

Conical magnetic bearings with radial and thrust (axial) control using the input-output feedback linearization method are considered. By suitable selection of nine output variables, the nonlinear magnetic bearing system is transformed to nine linear decoupled subsystems with no internal dynamics using feedback linearization control. Furthermore, a hybrid approach integrating feedback linearization and fuzzy control is proposed for improving the transient performance and robustness of the nonlinear magnetic bearings. Computer simulations are shown to illustrate the effectiveness of the proposed control strategy for simultaneous rotor-shaft speed tracking control and gap deviations regulation.