Abstract
Recentry, various studies on positioning with pneumatic pistons have been carried out by using proportional valves or pulse method, etc., but the accuracies of positioning by these methods are still insufficient. A new electro-pneumatic servo-system is proposed to realize higher accuracy. The system has an analogue proportional control circiut which uses a new electro-pneumatic converter. The converter is composed of a flapper driven by solenoid, a pneumatic micrometer and a pneumatic relay. A high converting gain with wide linear range can be obtained by the device, and it can be less expensive.
The reproducibility of positioning of the servo-system was tested with a 50mm bore and 50mm stroke piston cylinder. As a result, standard deviations of the stopping position could be reduced to less than 0.004mmin the best condition of friction with replaced piston seals.
