Model Identification and Control Method Study on Electro-Hydraulic Pressure Servo System

Mathematic model of electro-hydraulic pressure servo test bench was obtained based on xPC technique. In order to improve the tracking performance of the pressure servo system a new nonlinear hybrid controller was developed according to the mathematic model, which composed of a classical PID controller and a fuzzy controller based on self-adjusting modifying factor. And interpolation method was used in the modifying factor fuzzy number model; a fuzzy switching mode was employed to avoid the undesirable disturbances caused by the switchover between the two control methods. The hardware-in-the-loop simulation results show that the problems of steady-state error for fuzzy control and rapidity for PID control are solved, and the comprehensive performance of electrohydraulic pressure servo is enhanced when load rigidity and mass changed.