Sliding Mode Control with PID Sliding Surface of an Electro-hydraulic Servo System for Position Tracking Control

This paper presents the position tracking performance of an electro-hydraulic hydraulic servo (EHS) system using sliding mode control (SMC) with proportional-integral-derivative (PID) sliding surface. In modelling process, a mathematical model of the EHS system is developed by considering its nonlinearities as represented by a Lu-Gre friction model. The control strategy is derived from the developed dynamics equation and stability of the control system is theoretically proven by Lyapunov theorem. Simulation results show that the proposed controller has a better tracking performance compared to conventional PID controller