Adaptive discrete sliding mode control for a non-minimum phase electro-hydraulic actuator system

Abstract

This paper presents an adaptive robust control technique based on discrete sliding mode control (DSMC) for an electro-hydraulic actuator (EHA) system. A new adaptive control strategy with the enhancement of DSMC with two-degree-of-freedom (2-DOF) structure is proposed. The control scheme that will render uncertain system and time-varying in EHA system's parameters can be obtained by the integration of recursive system identification technique. A comprehensive performance evaluation with quantitative measures and validation of the tracking performance is presented. In the experimental studies, Optimal Linear Quadratic Regulator (LQR) and Proportional-Integral-Derivative (PID) are implemented to be compared with the proposed robust controller. The results showed that robust system performance is achieved with DSMC for various system conditions while capable to reduce the control effort and gives better tracking performance as compared to the conventional LQR and PID controllers