Experimental backstepping adaptive sliding mode control of hydraulic position servo system

Hydraulic servo system, due to the advantages of strong carrying capacity and fast response speed, has been widely used in industrial motion control field. The hydraulic servo system is susceptible to the non-linearity, parameter uncertainty and unknown disturbance, which makes the high performance position control of the hydraulic servo system become a challenge. In this paper, a backstepping adaptive sliding mode controller is designed to deal with the uncertain parameters in the hydraulic position servo system. A boundary layer shrinking method is used. The parameters adaptive law is given and the stability of the controlled system can be proved using Lyapunov method. The experiment results indicate that the tracking error of the proposed method is smaller, the response speed is faster and the performance is better, as compared with slide mode control with sign and saturation function robust item, and the conventional PID control.