Sliding mode nonlinear control of magnetic bearings

This paper presents a sliding mode controller for the robust stabilization of a magnetic bearing system. The approach avoids the need of pre-magnetisation currents frequently used to linearise the system model. It utilises two sliding manifolds achieving desired dynamics and complementarity of coil currents. Two different controllers have been designed. The second one takes into account of discrete inputs as is the case in electronic power amplifiers. Simulations are presented to show the effectiveness and robustness of the designed feedback sliding mode controller.