Aiming at the specificity of pump-valve coordinated control electro-hydraulic actuator (EHA) that valve control loop response higher than pressure loop, the feed-forward fuzzy immune (FFIM) control strategy was applied to the pressure loop control. The position error signal was added to the pressure loop as a feed-forward signal, the dynamic response and control capability of the pressure loop were increased as a result of using optimization immune algorithm and fuzzy algorithm as operator function to adjust PID control parameters in real time. The simulation results showed that the feed-forward signal will increase the response of pressure loop, but will make the pressure value bigger than the setting value, and immune algorithm can effectively reduce the pressure fluctuation around the pressure setting value. So the joint of feed-forward and immune algorithm will not only overcome the high nonlinear and time-varying parameters characters of pressure loop, but also enhance the control capacity of the system.
