Performance Improvement of Electro-Hydraulic Servo Valve Using a Feed-Forward Control and an Input Shaping Filter

The control performance of hydraulic systems is basically influenced by the performance of electro-hydraulic servo valve used in a hydraulic control system. In this study, the authors propose a control design to improve the control performance of servo valves with a non-contact eddy current type displacement sensor. Mathematical model for the valve is obtained through an experimental identification process. A PI-D controller together with a feedforward (FF) controller is applied to the valve. To further improve the response of the servo valve, an input shaping filter (ISF) is incorporated into the valve control system. Finally, the effectiveness of the proposed control system is verified experimentally.