Sliding mode control of electro-hydrostatic actuator based on extended state observer

To achieve the desired performance of an electro-hydrostatic actuator (EHA), this paper proposes a linear extended state observer (ESO) based sliding mode control (SMC). An ESO is used to estimate the external disturbance, the uncertainties, speed and acceleration of the EHA. The non linear mathematical model of EHA is a function of the derivatives of the friction force and externally applied force. However it is either difficult or impossible to get these values. To avoid these difficulties the EHA model is constructed in AMESim, the control system is developed in Matlab/Simulink and a co simulation is carried out. The performance of the proposed controller is compared with a PID controller. The simulation results illustrated superior tracking performance and robustness of the ESO based SMC.