Experimental tests on position control of a pneumatic actuator using on/off solenoid valves

A position-controlled pneumatic actuator using pulsewidth modulation (PWM) valve pulsing algorithms is described. The system consists of a standard double-acting cylinder controlled with two three-way solenoid valves through a 12-bit A/D PC board. The mechatronic system has the advantage of using on/off solenoid valves in place of more expensive servo valves and it may be applied to a variety of practical positioning applications. A proportional-integral (PI) controller with position feedforward has been successfully implemented. Several experimental tests are carried out to evaluate the robustness of the control system and performances of the novel PWM algorithm implemented. The actuator's overall performance is comparable to that achieved by other researchers using servo valves.