The application of disturbance observer-based sliding mode control for magnetic levitation systems

Abstract

A control algorithm for the position tracking of a magnetic levitation system is presented in this article. The magnetic levitation system is well known for its non-linear dynamic characteristics and open-loop instability. The external disturbances will deteriorate the dynamic performance of the magnetic levitation system, and may give rise to system instability. This problem triggers enormous interests in designing various controllers for the non-linear dynamic system. In this article, a magnetic levitation system is first modelled. Then, a sliding mode controller is proposed, with a simple yet effective disturbance observer to perform disturbance rejection. Both the simulation results and the experimental results verify the validity of the robust controller.