Integral Sliding Mode Controller for Magnetically Suspended Balance Beam: Theory and Experimental Evaluation

This paper deals with a sliding mode controller with integral compensation in a magnetic suspension system. The control scheme comprises an integral controller which is designed for achieving zero steady-state error under step disturbance input, and a sliding mode controller which is designed for enhancing robustness under plant parametric variations. A procedure is developed for determining the coefficients of the switching plane and integral control gain such that the overall closed-loop system has stable eigenvalues. A proper continuous design signal is introduced to overcome the chattering problem. The performance of a magnetically suspended balance beam using the proposed integral shding mode controller is illustrated. Simulation and experimental results show that the proposed method is effective under the external step disturbance and input channel parameter variations.