Nonlinear control of a rigid rotor magnetic bearing system: modeling and simulation with full state feedback

Control strategies for magnetic bearings often focus on linear optimal control techniques. While these methods afford many advantages, the literature is conspicuously sparse with regard to attempts at nonlinear control. Here, we treat the equations of motion of a rigid, horizontal rotor magnetic bearing system. Through feedback linearization and sliding mode control techniques, we formulate a nonlinear control law which maintains the shaft centered in the bearings. This system is then simulated to demonstrate disturbance rejection properties and its robustness to parameter uncertainty and unmodelled dynamics.>