Basic study on precise positioning of air bearing lead screw stage by semi-closed loop control

Abstract

As an air bearing lead screw has a great advantage of accurately transforming rotational motion to linear motion due to no friction, no backlash and no hysteresis, precise positioning of a stage can be realized by a precise rotational motion. We developed a positioning controller with servo sampling rate of 10 kHz that employed FPGA (Field Programmable Gate Array) and applied it to positioning an air bearing stage by a semi-closed loop control. We obtained 5 pulse/step (less than 10 nm/step) positioning.