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Thermal Error Measurement and Modeling Techniques for the 5 Degree of Freedom(DOF) Spindle Unit Drifts in CNC Machine Tools

CNC 공작기계 스핀들 유닛의 5자유도 열변형 오차측정 및 모델링 기술

Park, Hui-Jae;Lee, Seok-Won;Gwon, Hyeok-Dong
박희재;이석원;권혁동

  • Published : 2000.05.01

Abstract

Thermally induced errors have been significant factors affecting the machine tool accuracy. In this paper, the spindle thermal error has been focused, where the 5 degree of freedom thermal error components are considered. An effective measurement system has been devised for the 5 DOF thermal errors, consisting of gap sensors and thermocouples around the micro-computer interfaced environment. Several thermal error modeling techniques are also implemented for the thermal error prediction: multiple linear regression, neural network and system identification methods, etc. The performance of the thermal error modeling techniques is evaluated and compared, giving the system identification method as the optimum model having the least deviation. The developed system for the thermal error measurement and modeling was practically applied to a CNC machining center, and the spindle thermal errors were effectively compensated around the micro computer-machine tool interfaced networks. The machine tool accuracy was improved about 4-5 times typically.

Keywords

Machine Tool;Error Measurement;Modeling;Error Compensation

References

  1. CHEN, J. S., 1995, 'Computer Aided Accuracy Enhancement for Multi Axis CNC Machine Tool,' Int. J. Mach. Tools Manufact. Vol. 35, No.4 pp. 593-605 https://doi.org/10.1016/0890-6955(94)P4352-U
  2. Yule, G.U., 'On a Method of Investigating Periodicities in Disturbed Series, with Special Reference to Wolfer's Sumspot Numbers,' Phil. Trans., A-226, p. 267
  3. PANDIT, S. M., WU, S. M., 1983,'Time series and system analysis with applications,' John Wiley and Sons
  4. ANSI Standard B89.3.4M-1985, American Society of Mechanical Engineerings, United Engineering Center, 345 East 47th St., New York, NY 10017
  5. Francis S.Tse and Ivan E.Morse, 1989, 'Measuerment and Instrumentation in Engineering: Principles and Basic Laboratory Experiments,' MARCEL DEKKER,INC.
  6. Bryan, J., 1968, 'International Status of Thermal Error Research(Keynote),' Annals of CIRP,Vol. 16, pp.203-215
  7. Narayan Srinivasa, John C.Ziegert, 1996, 'Automated Measurement and Compensation of Thermally Induced Error Maps in Machine Tools,' Precision engineering, Vol.19, pp. 112-132 https://doi.org/10.1016/S0141-6359(96)00042-6