Model Identification and Control of Electro-hydraulic Position Servo System

In view of introduction of the composition and working principle of the electro-hydraulic position servo control system, the mathematical model of the system was built. In order to acquire more accuracy system mathematical model, System model identification and verification of electro-hydraulic position servo system were carried out based on hardware-in-the-loop simulation environment of Real-time Workshop (RTW) and system identification toolbox in MATLAB. A hybrid controller composed of a proportional controller, a fuzzy controller and a classical PID controller, for which the parameters of the PID controller can be adjusted online by using the fuzzy control rule, The zero position of fuzzy domain was regarded as the switching threshold, and stable switching is implemented between the proportional control and the proportion-fuzzy PID control. The simulation results show that the steady-state error of system is eliminated, the rapidity is enhanced by the hybrid control strategy, Moreover, and its ability of adapting to system parameter variation is superior to the other controllers.