Ultra Precision Positining System for Servo Motor-piezo Actuator Using the Dual Servo Loop and Digital Filter Implementation

이중서보제어루프와 디지털 필터를 통한 서보모터-업전구동기의 초정밀위치결정 시스템 개발

In this paper, an ultra precision positioning system has been developed using dual servo loop control. For positioning system having long distance with ultra precision , the combination of global stage and micro stage was required. A servo motor based ball screw is used as a global stage and the piezo actuator as a micro stage. For the improvement of positional precision, the digital Chebyshev filter is implemented in the developed to dual servo system. Therefore, the positional repeatability has been achieved within ${\pm}$ 10 mm, and this technique can be applied to develop precision semiconductor equipments such as lithography steppers and probers.