Control Method for the Tool Path in Aspherical Surface Grinding and Polishing

  • Published : 2006.10.01

Abstract

This paper proposes a control algorithm, which is verified experimentally, for aspherical surface grinding and polishing. The algorithm provides simultaneous control of the position and interpolation of an aspheric curve. The nonlinear formula for the tool position was derived from the aspheric equation and the shape of the tool. The function was partitioned at specific intervals and the control parameters were calculated at each control section. The position, acceleration, and velocity at each interval were updated during the process. A position error feedback was introduced using a rotary encoder. The feedback algorithm corrected the position error by increasing or decreasing the feed speed. In the experimental verification, a two-axis machine was controlled to track an aspherical surface using the proposed algorithm. The effects of the control and process parameters were monitored. The results demonstrated that the maximum tracking error with tuned parameters was at the submicron level for concave and convex surfaces.

Keywords

References

  1. Lee, T. M., 'A Study on the Development of CAM Software for Ultra-precision Aspheric Surface,' M.S. Thesis, KAIST, pp. 5-27, 1996
  2. Chen, M. J., Li, D. and Dong, S., 'Research on a large depth-todiameter ratio ultra-precision aspheric grinding system,' Journal of Materials Processing Technology, Vol. 129, No. 1-3, pp. 91-95, 2002 https://doi.org/10.1016/S0924-0136(02)00582-4
  3. Kim, H. S., Kim, E. J. and Song, B. S., 'Diamond turning of large off-axis aspheric mirrors using a fast tool servo with on-machine measurement,' Journal of Materials Processing Technology, Vol. 146, No. 3, pp. 349-353, 2004 https://doi.org/10.1016/j.jmatprotec.2003.11.028
  4. Tsunemoto, K. G., Mohammad, S. S. Z. and Katsuo, S. J., 'A new grinding method for aspheric ceramic mirrors,' Journal of Material Processing Technology, Vol. 62, No. 4, pp. 387-392, 1996 https://doi.org/10.1016/S0924-0136(96)02440-5
  5. Cheng, H. B., Feng, Z. J., Cheng, K. and Wang, Y. W., 'Design of a six-axis high precision machine tool and its application in machining aspherical optical mirrors,' International Journal of Machine Tools & Manufacture, Vol. 45, No. 9, pp. 1085-1094, 2005 https://doi.org/10.1016/j.ijmachtools.2004.11.018
  6. Lei, Z., Tsunemoto, K. G., Tsuyoshi, K. T. and Ji, Z., 'Investigation into electrorheological fluid-assisted polishing,' International Journal of Machine Tools & Manufacture, Vol. 45, No. 12-13, pp. 1461-1467, 2005 https://doi.org/10.1016/j.ijmachtools.2005.01.021
  7. Lee, Y. C., Chen, C. M. and Wu, C. Y., 'A new excimer laser micromachining method for axially symmetric 3D microstructures with continuous surface profiles,' Sensors and Actuators A (physical), Vol. 117, No. 2, pp. 349-355, 2005 https://doi.org/10.1016/j.sna.2004.06.006
  8. Yang, M. Y. and Hong, W. P., 'A PC-NC milling machine with new simultaneous 3-axis control algorithm,' International Journal of Machine Tools and Manufacture, Vol. 41, No. 4, pp. 555-566, 2001 https://doi.org/10.1016/S0890-6955(00)00091-2
  9. Kim, H. T. and Yang, H. J., 'Tool path control algorithm for aspherical surface grinding,' Proceedings of the KSPE Spring Conference, pp. 100-103, 2005
  10. Kim, H. T. and Yang, H. J., 'Semi-continuous interpolation algorithm for aspherical surface grinding,' Proceedings of IEEE Region 10 Conference, 2005