Disturbance and uncertainty estimator-based cascaded position-current controller for active magnetic bearing system

This article presents a robust control method; all of the unknown disturbances and uncertainty values will be rejected. Suspension of active magnetic bearing system is aimed to figure out that the proposed control method is implementable for highly nonlinear unstable system. First, system state is described by dynamic model, with unknown lump of uncertainty value. Subsequently, the cascade control with inner and outer loops is defined by sliding mode control based on disturbance and uncertainty estimator. The outer control loop is used to force the system state converge on the predefined surface, while inner control loop is used to control the current of electrical part of the system. Finally, the simulation results show that the proposed control method is good at tracking trajectory.