Integral sliding-mode control of a magnetically suspended balance beam: analysis, simulation, and experiment

This paper presents a sliding-mode controller with integral compensation for a magnetic suspension balance beam system. The control scheme comprises an integral controller which is designed for achieving zero steady-state error under step disturbances, and a sliding-mode controller which is designed for enhancing robustness under plant uncertainties. A procedure is developed for determining the coefficients of the switching plane 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 the balance beam control system is illustrated by simulation and experimental results showing that the proposed integral sliding-mode controller method is effective under external step disturbances and input channel parameter variations.