Comparison of Servo Positioning Performance of Pneumatic Cylinders Using Proportional Valve Method and PWM Control Method

Abstract

Servo pneumatics is a mechatronic approach that enables accurate position control of pneumatic drives with high speed. The current study presents a comparison of two servo techniques for position control of pneumatic cylinders. One method uses a proportional valve and another method uses PWM controlled solenoid valves. Mathematical models of the system including the nonlinearities such as mass flow rate, pressure in cylinder chambers and frictional forces are presented in this paper. Using the simulation model created in Matlab-Simulink software, the two systems are analyzed for tracking performances. From the responses it is observed that the proportional valve technique has better tracking characteristics than PWM control technique.