FUZZY PWM CONTROL THE POSITIONS OF A PNEUMATIC ROBOT CYLINDER BY HIGH SPEED SOLENOID VALVES

Abstract

In the paper, instead of using the expensive servo valves, three cheap high speed slenoid valves were applied and a fuzzy PWM controller was designed to control the linear and rotational positions of a pneumatic robot cylinder. The modified differential PWM method is proposed to eliminate the dead zone and improve the nonlinear characteristics of the relationships between the pressure difference of the cylinder and the duty ratio. The experimental results have shown that the servo pneumatic system can have both the good performance and the low cost solenoid valves with the proposed fuzzy PWM controller.