الفهرس | Only 14 pages are availabe for public view |
Abstract An experimental and theoretical studies are carried out for pneumatic position control of a double acting cylinder using a modified method of sliding mode control based on error modification (SMCE). High speed on-off solenoid air valves instead of the proportional control valve are used to control the air motion into the pneumatic cylinder utilizing the pulse width modulation technique (PWM). A simulation model based on the flow governing equations of both the pneumatic cylinder and air valves is developed to optimize the SMCE and PID parameters to start with during the experiments. The experimental results for square and sinusoidal position reference show superiority of the SMCE over the PID in terms of lower steady state error, faster settling time, and less overshoot. The root mean square errors for a sinusoidal input of 0.1 Hz, is 0.22 mm for SMCE and 0.69 mm for PID controller. The maximum absolute errors are 0.66 mm and 1.46 mm for SMCE and PID respectively. The oscillation behavior for the sinusoidal response of the traditional PID controller is improved by the SMCE controller and better performance is achieved. Also, the actuator sinusoidal wave response acts smoothly and uniformly compared to the traditional PID controller. |