Observer based feedback linearization control for electro-hydraulic servo systems

An observer-based feedback linearization control is presented for position tracking of electro-hydraulic servo systems (EHSs). In many hydraulic applications, it is not always possible to measure the full state of the EHS due to cost and space limitation. Therefore, a high gain observer is designed to estimate the full state of the EHS. Feedback linearization control is used to improve tracking performance. The stability of the closed-loop system is analyzed via the Lyapunov method. Simulation results show that the proposed controller has better position tracking performance than a proportional integral (PI) controller.