Control of a Pneumatic Actuator Using Proportional Pressure Regulators

Pneumatic driving systems are usually used in manufacturing process where it is necessary to achieve a device that is inexpensive, reliable, clean and simply for realization. They have found widespread application in industrial automation for pick-and-place positioning problems. However, for free positioning tasks, pneumatic drives are difficult to control accurately, because of nonlinearities associated with the compressibility of air, significant friction effects and variations of system parameters. Development of the proportional valves (servovalves) has made possible a flexible, fast and precise positioning of pneumatic drives. In this paper, instead of using relatively costly servovalve, two less expensive proportional pressure valves were used. The primary task of the proportional pressure valves is to continuously control the pressurein both cylinder chambers, and the force of a pneumatic actuator. Here, the position control of a pneumatic actuator using proportional pressure regulators is also considered. The control algorithms have been tested on the experimental equipment of a pneumatic servodrive.