Abstract
A pneumatic diaphragm motor controlled by two PWM solenoid valves are studied. First, the characteristics of the PWM solenoid valve is investigated and a simplified mathematical model of the valve is presented. Second, a PWM control law is synthesized by considering the effects of the valve characteristics and the asymmetrical flowcharacteristics between the charging process and the discharging process of the system. The main parameters thatinfluences the performance of the system are analyzed and their values are optimized experimentally. At last, thefrequency response and the stiffness characteristics of the proposed system are obtained and the results show that theperformance of the proposed system is better than the traditional one. These experiments verify the theoretical designwork, and indicate that the PWM controlled pneumatic diaphragm motor is feasible for practical use.
