Electrohydraulic positioning servo control based on its adaptive inverse model

This paper studies on improving the track precision of electro-hydraulic positioning servo system. Electro-hydraulic positioning servo system is a typical nonlinear system, and also usually disturbed by internal and external uncertain factor. The nonlinear and uncertainty characteristics make the conventional controller not yield to the system required tracking performance. In this paper, an adaptive controller based on its inverse model paralleled by conventional closed-loop PID controller is proposed. Online parameter estimation is given to adapt the proposed controller due to the system nonlinear characteristic. A detailed case study is shown, including experimental results which show that the system nonlinear parameters are estimated exactly using the proposed method, and the trace accuracy of the electro-hydraulic positioning servo system is greatly enhanced.