Performance Evaluation of Self-Moving Cell Linear Motor for Ultra-Precision Nano Positioning

초록

This paper presents the performance evaluation of miniaturized self-moving cell linear motor (SCLM) with macro-micro driving scheme for generating ultra-high precision positioning up to nano resolutions. SCLM is very applicable to optical and semi-conductor systems as a nano stage with merits in terms of macro-micro driving mechanism, fail-safe lock and high push-clamping force. For the micro motion, the compensation of actuator’s hysteresis is very important in controlling the position of first cell to achieve high accuracy with open-loop control technique. So Preisach model for the actuator is considered and experimental approaches are addressed. The motor exhibits a slow operation mode near 10mm/s and fast mode up to 70mm/s by changing excitation voltage and frequency. The excitation voltage to displacement ratio is about 50nm/volt and micro-positioning resolution of around 20nm was observed by using a laser sensor. Key words: self-moving cell, linear motor, nano positioning/stage, Preisach model, stack actuator, hysteresis