Sliding Mode Based Mode Free Control Of Electro-Hydraulic System With Extended State Observer

The position tacking control of Electro-hydraulic system (EHS) with only output feedback is addressed in this paper. The unmeasured states and external disturbance are simultaneously estimated by an extended state observer (ESO) based on the extended model of EHS. Then the sliding mode control (SMC) is employed to design position tracking controller, and the dynamic model of EHS is not explicitly needed. The proposed controller theoretically guarantees finite time tracking performance in the presence of disturbances in the sense of Lyapunov theory. Simulation results are obtained to verify the effectiveness of the proposed controller.