A real-time polishing force control system for ultraprecision finishing of micro-optics

• Published in: Precision engineering Vol. 37; no. 4; pp. 787 - 792
• Main Authors: Guo, Jiang, Suzuki, Hirofumi, Morita, Shin-ya, Yamagata, Yutaka, Higuchi, Toshiro
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.10.2013
• Subjects: Control systems; Electric potential; Finishing; Load cells; Material removal function; Micro-optics; Nanostructure; Polishing; Polishing force; Real time; Real-time control; Resolution; Ultraprecision finishing; Real-time control; Material removal function; Polishing force; Ultraprecision finishing; Resolution
• ISSN: 0141-6359; 1873-2372
• DOI: 10.1016/j.precisioneng.2013.01.014

► The polishing force control system is proposed for the first time to precisely control the polishing force in real-time. ► It has a simple mechanism which mainly composes of a load cell, a piezo stage and a linear stage. ► The polishing force is controllable within a range of 0–200mN (resolution: 0.1mN) in real-time (sampling time: 1ms). ► The polishing force control system enables a stable polishing, and the polishing force conditions which generate suitable material removal functions are acquired. Polishing force condition plays a key role in the ultraprecision finishing of micro-optics because it strongly affects the polishing performance. In this paper, a novel polishing force control system is developed to improve the polishing stability. It is proposed for the first time to precisely control polishing force in real-time and has a simple mechanism which mainly composes of a load cell, a piezo stage and a linear stage. The load cell is used to measure the polishing force, whereas the piezo-stage is applied to adjust the force with nano/micro positioning change. The linear stage driven by a stepper motor is employed to prevent force change beyond the travel range of piezo stage which leads to the system out of control. A PID controller is adopted to calculate the command voltage for driving the piezo-stage based on the measured force. The system enables polishing force to be controlled within a range of 0–200mN with a resolution of 0.1mN. Some fundamental experiments are conducted to evaluate the performance of newly developed system. The results indicate that the proposed polishing force control system enables a stable polishing, and the polishing force conditions which generate suitable material removal function are acquired.