Sliding mode control with fuzzy tuning for an electrohydraulic position servo system

Abstract

This paper presents a novel robust sliding mode controller for a class of nonlinear systems. The control signal consists of: an equivalent control to assign the desired dynamics to the closed-loop system, a switching control to guarantee a sliding mode, and a fuzzy control to enhance fast tracking and to attenuate chattering. Sufficient conditions for asymptotic tracking are achieved when matching conditions are satisfied. The control method is applied to the position control of an electrohydraulic servo system. To verify the potential and effectiveness of the proposed controller, simulation results are given to demonstrate its strong robustness against a large range of parameter variations, load disturbance and nonlinear spring stiffness.