Abstract
A new technique to make a precise position control of air-cylinder using an electric motor to rotate a piston is proposed. By rotating a piston, the friction of cylinder and piston becomes small, and a stick-slip motion is decreased. A motor is controlled to produce a minimum but enough rotation according to an axial trip of piston, where the rotation is activated a bit earlier than a valve opening. With these proposed techniques, an experimental device achieves 0.02[mm] step motion. A power consumption of the motor is relatively small, which is about 2% of cylinder output.
