Fuzzy gain scheduling control for electro-hydraulic servo velocity system

Considering the nonlinear and the parameters variability, which vary widely with the working condition in the electro-hydraulic servo velocity system, fuzzy gain scheduling controller was developed. Based on the change of output error and its differential, the PID (proportion integral differential) parameters of controller were changed online by fuzzy reasoning in order to adapt the variety of set point and this made the control parameters reach the global optimization, solved the local optimization problem in the common gain scheduling. In the course of determine membership function of P and I, exponential function was introduced and this ensured the fast response and stability of system. Test results indicate that comparing with PID, the method accelerates the dynamic response, reduces the overshoot and load turbulence effectively too. So it is very validity for nonlinear system and the mathematic prototype system that can't be built easily.