Abstract: Four high speed ON/OFF valves being combined suitably, the position and the direction of the two rod cylinder can be controlled by the means of PWM method. To avoid the influence on the traditional control algorithm; such as the complexity in the modeling of the hydraulic control system and the nonlinearity in the valve - controlled cylinder, a fuzzy controller is designed to implement the precise position control of the PWM high speed ON/OFF valve-controlled hydraulic cylinder. The experiment shows that the fuzzy control is an efficient way for the control of high speed ON/OFF valves, it has a wide prospect for the application of high speed ON/OFF valve in the engineering.

Key words: Fuzzy control, High speed, ON/OFF, Position control Systems, Pulse width modulation(PWM), valves