A Research Of Proportion Pneumatic Actuator Based On On/Off Valve

This thesis analysed the structure and principle of the on-off pneumatic linear actuator, and using experimental test build up the math model of the electromagnetics valve, the flow rate equation, and the pressure equation of the cylinder, in virtue of the related theories of electromagnetics, pneumatic dynamics and servo system. And obtain the model of the valve-controlled cylinder system.Based on this model , a system controller was designed using the control law of PI. PID and sliding model.By simulation and test through simulink, the time and frequency field responses of system were analyzed, and method was put forward in order to improve the stability and dynamic response of the system.The results of simulation indicate that the control law can meet the requirement of the system,And the sliding model control is better than others.The thesis designed a controller of system using the control law of PID realized by MCU of PIC16F877, created the matching peripheral circuit. And many performing tests were carried on, and its corresponding static and dynamic performances were analysed.The test results indicated that the designed PID controller, speediness and stability filled the demands of the design target, which provided positive meaning for the future build up and study of the engineering project.