A Design Method of Sliding Mode Controller Based on Disturbance Observer

In this paper, a design method of sliding controller with the disturbance observer is proposed for the existence of disturbance and parameter perturbation in electromechanical servo system, switch function, gain and control function are given, At the same time, stability analysis is made by means of the Lyapunov function. The sliding controller designed by the method has a lower switch gain , so chattering of sliding mode is reduced greatly. Moreover, the disturbance is compensated quickly. Simulations verified that the proposed control method has the better dynamic performance and the robust capability, and also that it has a decided advantage over the conventional sliding control in the suppression of chattering.