Pressure Regulators Applied to Force/Position Control of a Pneumatic Actuator

Proportional pressure regulators are usually used in different automation processes where continuous pressure or force control is required. They originated from the combination of an electro-pneumatic pilot valve, pressure regulator and pressure sensor for achieving an internal pressure feedback. These valves have practically linear pressure output regarding to an electrical signal from a control device. By controlling pressures in both cylinder chambers they can be used for direct force control of a pneumatic system. However, in this paper, also the position control of a pneumatic actuator using two proportional pressure regulators has been considered. A simplified dynamic model of the process has been derived, followed by a design of the PD controller for the system control. The control algorithms are experimentally verified on an industrial pneumatic cylinder controlled by two proportional pressure valves. The results demonstrate that the proportional pressure valves have a potential for successful implementation in hybrid force/position control tasks.