Theoretical and Empirical Improvement of a Fast-Switching Electro-Pneumatic Valve by Using Different Methods

In this paper, a non-linear model of a 2–2 way, on–off fast-switching valve is used. The model includes subsystems of electrical, magnetic, mechanical and fluid. Pulse width modulation (PWM) technique is adopted to energise the on–off solenoid valve and allow the air to flow towards the actuator. Since the non-linear behaviour of valve is of great importance, to reduce the delay in performance of switching valves, different approaches are proposed. Furthermore, hysteresis, proportional integrator (PI), optimal model predictive and fuzzy logic controller (FLC) are used and compared. Also, to improve the valve behaviour, an empirical setup based on AVR microcontroller with FLC is implemented. Empirical and simulation results indicate that all proposed control methods have superior performance. However, the fuzzy method is easy to implement in practice.