Pneumatic control valves are still the most used in process industries due to their low cost and simplicity This paper presents a design procedure of a PID controller for a pneumatic control valve. For comparison, P and PI controllers are also utilized for the control valve. The bond graph method is used to model the control valve, in order to compare the response characteristics of the valve. Simulation results are found for three controllers of the valve. The integral time absolute error criterion is used to calculate the controller parameters. The results show excellent closed-loop performance and the PID controller is more robust than the P and PI controller.
Pneumatic, control valve, PID controller, bond graph.