Abstract

The direct drive servo valve(DDV) is composed of a DC rotor, link, valve spool and displacement sensor(LVDT) where the spool is directly coupled to the DC motor through the link. Since the DDV is a kind of one-stage valve, the robust controller is required to overcome the flow force effect on the spool motion. The mathematical equations are derived and the stability, accuracy and response speed of a DDV are investigated analytically using a linearized system block diagram. Proportional control, PID control. Time-Delay control, Sliding Mode control, and Proportional control using the load pressure are applied to DDV to find which one shows the best control performance. The digital computer simulation results show that the proportional control using the load pressure satisfies the design requirement of response speed and steady state error regardless of the variation of load pressure,

Keywords

• Direct Drive Servo Valve(DDV);
• Controller Design