A study on the feedback system of ultra precision positioning apparatus using laser interferometer

Abstract

We make a study of precision apparatus that is used in various industrial machines. The study was carried out to develop a precision positioning apparatus, consisting of servo motor and piezoelectric actuator. This system is composed of fine and coarse apparatus, measurement system and control system. A piezoelectric actuator is designed for fine positioning. Coarse positioning using a lead screw is driven by a servo motor. The control system outputs a signal from the laser interferometer to the amplifier of the servo motor and piezoelectric actuator after digital signal processing (DSP). Resolution of this apparatus is measured with a laser interferometer. We can controlled positioning of one output by the coarse positioning in the system. Also, we obtain a positioning resolution of 10 nm in the system. In this study, design method and control system with ultra precision position apparatus are researched. As the first step, we have estimated for control performance and system stability before an actual apparatus is manufactured by MATLAB with SIMULINK including various functions composed of pre-design and system modeling.