Identification of 5-Axis Machine Tools Feed Drive Systems for Contouring Simulation
Burak Sencer*, and Yusuf Altintas**
*Ultraprecision Engineering Laboratory, Nagoya University, Furo-cho, Chikusa-ku, Nagoya City, Aichi 464-8603, Japan
**Manufacturing Automation Laboratory, University of British Columbia, 2054-6250 Applied Science Lane Vancouver, B.C. V6T 1Z4 Canada
An identification technique is introduced for identifying closed loop transfer function of machine tool’s feed drive systems to be used in simulation of the tracking and contouring performance of Computer Numerical Controlled (CNC) machine tools. The identification is performed from air-cutting tests utilizing only standard G-codes containing linear motion commands. A general transfer function model is derived for representing the closed loop tracking response of the feed drive system. The model considers the drive to be controlled by commonly used controller schemes such as P-PI Cascade, PID or the Sliding Mode Controller (SMC) with feed-forward dynamic and friction compensation. The parameters of the model transfer function are fitted tominimize the discrepancy between the actual and predicted axis position on the axis. In order to guarantee the stability of the identified model transfer function, bounds on the pole locations are imposed. The resultant constrained non-linear optimization problem is solved efficiently using the Particle Swarm Optimization (PSO) method. For achieving reliable convergence of the stochastic PSO algorithm, a parameter tuning strategy is presented. Simulation and experimental studies show that the identified feed drive model captures the fundamental dynamics of the drives system accurately for simulating their closed loop response. Combined with the kinematics of the machine, contouring errors of 5-axis CNC machine tools during simultaneous multi-axis motion are predicted.
-  Y. Altintas, C. Brecher, M. Weck, and S. Witt, “Virtual Machine Tool,” Annals of CIRP, 54/1, pp. 651-673, 2005.
-  K. Erkorkmaz, Y. Altintas and C.-H. Yeung, “Virtual computer numerical control system,” Annals of CIRP 55/1, pp. 399-402, 2006.
-  R. Sato and M. Tsutsumi, “Modeling, and Controller Tuning Techniques for Feed Drive Systems,” Proc. of the ASME-IMECE’05, Orlando, FL, IMECE2005-80596, 2005.
-  E. D. Tung and M. Tomizuka, “Feed-Forward Tracking Controller Design Based on the Identification of Low Frequency Dynamics,” J. of Dynamic Systems Measurement and Control – Trans. of the ASME, Vol.115, Issue 3, pp. 348-356, 1993.
-  K. Erkorkmaz and Y. Altintas, “High Speed CNC System Design: Part II – Modeling and Identification of Feed Drives,” Int. J. of Machine Tools & Manufacture, Vol.41, Issue 10, pp. 1487-1509, 2010.
-  Y. Altintas and B. Sencer, “Identification of 5-Axis Machine Tool Feed Drive Systems for Contouring Simulation,” 4th CIRP Int. Conf. on High Performance Cutting, Gifu-Japan, 24-26 October, 2009.
-  K. Erkorkmaz and W. Wong, “Rapid Identification Technique for Virtual CNC Drives,” Int. J. of Machine Tools & Manu, Vol.47, pp. 1381-1392, 2007.
-  R. C. Eberhart and J. Kennedy, “A New Optimizer Using Particle Swarm Theory,” Proc. of 6th Int. Symp. on Micromachine Human Sci., Vol.1, pp. 39-43, 1995.
-  B. Sencer, Y. Altintas, and E. A. Croft, “Modeling and Control of Contouring Errors for Five-Axis Machine Tools. Part I – Modeling,” Trans. of ASME J. of Manu. Science and Eng., Vol.131, Issue 3, 031006, 2009.
-  L. Ljung, “System Identification: Theory for the User,” Prentice-Hall Of Canada Ltd., Englewoods Cliffs, NJ, 1998.
-  dSPACE GmbH, www.dspace.com.
-  Y. Altintas, K. Erkorkmaz, and W.-H. Zhu, “Sliding Mode Controller Design for High-Speed Drives,” Annals of CIRP 49/1, pp. 265-270, 2000.
-  O. R. Tutunea-Fatan and H. Y. Feng, “Configuration analysis of Five-Axis Machine Tools Using a Generic Kinematic Model,” Int. J. of Machine Tools and Manufacture, Vol.44, No.11, pp. 1235-1243, 2004.
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