Design of the Servo System for the Micro Milling Machine

Abstract:

To manufacture the micro parts or micro structures effectively and precisely, a high precision 3-axis micro milling machine is built. All the three axis are driven by linear piezoelectric ultrasonic motors and the slides are supported by cross-roller guide. Investigations are firstly made to analyze the impact of the non-linear characteristics in the servo mechanism on the performance of the servo system. To achieve the positioning and tracking accuracy at sub-micrometer and micrometer level respectively, on one hand, a optical linear encoder with the resolution of 50nm is applied to close the control loop and a high performance DSP based motion control card is used to carried out the reference command. On the other hand, sophisticated control and compensation strategies are also implemented to overcome the non-linear characteristics in the servo system. Positioning and tracking experiments show that, with this well-tuned control system, the positioning and tracking accuracy are ±0.5μm and ±2.4μm respectively. Using this machine, a micro part with 5μm thin-walled structure is machined successfully.

• Periodical: Key Engineering Materials (Volumes 364-366)
• Pages: 389-393
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.364-366.389
• Online since: December 2007
• Authors: Bo Wang, Ju Xiang Wang, Ying Chun Liang
• Keywords: Micro-Milling, Nonlinear, Piezoelectric Ultrasonic Motor, Servo-System

References

[1] Sun Ya-zhou, Gao Qiang, Liang Ying-chun: Modular Machine Tool & Automatic Manufacturing Technique, No. 4 (2006), p.11.

[2] Sun Yan-zhou, Liang Ying-chun, Dong Shen: Journal of Harbin Institute of Technology, Vol. 137 No. 15(2005), p.591.

[3] Liu Luo-shi, Zhang Tie-min, Zhang Jian-yao: Modular Machine Tool & Automatic Manufacturing Technique, No. 5 (2004), p.32.

[4] Wang Bo, Tong Li-dong, Liang Ying-chun: Journal of Test and Measurement Technology, No. 9 (2006), p.100.

[5] Wang Bo, Liang Ying-chun, Sun Ya-zhou, Tan Ya-ming: Chinese Journal of Sensors and Actuators, No. 5 (2006), p.87.