Contouring Performance Improvement of Biaxial Motion Control Systems Using Friction and Disturbance Compensation

Abstract:

One of the key issues regarding multi-axis contour following tasks in modern high-precision machining applications is how to effectively reduce contour error. Generally, among existing approaches, the Cross-Coupled Control (CCC) structure is widely used in multi-axis contour following tasks to improve contouring accuracy. However, when a servomechanism is operated in reverse or low-speed motions, the inherent friction force and external disturbance effects will degrade the CCC performance. Therefore, to cope with the aforementioned problems, this paper exploits the Karnopp friction model-based compensator and the Virtual Plant Disturbance Compensator (VPDC) to improve tracking performance as well as contouring accuracy. Moreover, an integrated motion control scheme is also developed to further improve contouring performance. The proposed scheme consists of two position loop controllers with velocity command feedforward, a modified CCC, two friction force compensators, and two disturbance compensators. To evaluate the performance of the proposed approach, several free-form contour following experiments have been conducted on an X-Y table driven by two linear motors. Experimental results verify that the proposed approach can significantly enhance contouring performance for free-form contour following tasks.

• Periodical: Advanced Materials Research (Volume 579)
• Pages: 287-296
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.579.287
• Online since: October 2012
• Authors: Ke Han Su, Ming Yang Cheng, Yu Chen Chang
• Keywords: Contour Error, Cross-Coupled Control, Disturbance Compensator, Friction Force

References

[1] O. Masory, Improving contouring accuracy of NC/CNC systems with additional velocity feedforward loop, ASME J. Engineering for Industry 108 (1986) 227–230.

DOI: 10.1115/1.3187068

[2] M. Tomizuka, Zero phase error tracking algorithm for digital control, ASME J. Dyn. Syst. Meas. Control 109 (1987) 65-68.

DOI: 10.1115/1.3143822

[3] Y. Koren, Cross-coupled biaxial computer control for manufacturing systems, ASME J. Dyn. Syst. Meas. Control 102 (1980) 265-272.

DOI: 10.1115/1.3149612

[4] M.Y. Cheng, K.H. Su, S.F. Wang, Contour error reduction for free-form contour following tasks of biaxial motion control systems, Robot. Comput. -Integr. Manuf. 25 (2) (2009). 323-333.

DOI: 10.1016/j.rcim.2008.01.003

[5] M.T. Yan, M.H. Lee, P.L. Yen, Theory and application of a combined self-tuning adaptive control and cross-coupling control in a retrofit milling machine, Mechatron. 15 (2005) 193–211.

DOI: 10.1016/j.mechatronics.2004.07.011

[6] S.S. Yeh, Z.H. Tsai, P.L. Hsu, Applications of integrated motion controllers for precise CNC machines, Int. J. Adv. Manuf. Technol. 44 (2009) 906-920.

DOI: 10.1007/s00170-008-1919-1

[7] M.C. Tsai, I.F. Chiu, M. Y. Cheng, Design and implementation of command and friction feedforward control for CNC motion controllers, IEE Proc. Control Theory & Applic. 151 (1) (2004) 13-20.

DOI: 10.1049/ip-cta:20040100

[8] S. Jee, Y. Koren, A self-organizing fuzzy logic control for friction compensation in feed drives, in Proc. the American Control Conference, Seattle, Washington, (1995) 205-209.

DOI: 10.1109/acc.1995.529238

[9] T. Umeno, T. Hori, Robust speed control of DC servomotor using modern two degrees-of-freedom controller design, IEEE Trans. Ind. Electron. 38 (5) (1991) 363-368.

DOI: 10.1109/41.97556

[10] H. S. Lee, M. Tomizuka, Robust motion controller design for high-accuracy positioning systems, IEEE Trans. Ind. Electron. 43 (1) (1996) 48-55.

DOI: 10.1109/41.481407

[11] M.T. Yan, Y.J. Shiu, Theory and application of a combined feedback–feedforward control and disturbance observer in linear motor drive wire-EDM machines, Int. J. Mach. Tools and Manuf. 48(3-4) (2008) 388-401.

DOI: 10.1016/j.ijmachtools.2007.09.006

[12] D. Karnopp, Computer simulation of slip-stick friction in mechanical dynamic systems, ASME J. Dyn. Syst. Meas. Control, 107 (1985) 100-103.

DOI: 10.1115/1.3140698

[13] J.C. Wu, K.H. Su, M.Y. Cheng, Friction and disturbance compensation for speed control of servo control systems, in Proc. IECON'10, Nov 07-10, Phoenix, AZ, USA, (2010) 1884-1889.

DOI: 10.1109/iecon.2010.5675379

[14] M.C. Tsai, E. C Tseng, M.Y. Cheng, Design of a torque observer for detecting abnormal load, Control Engineering Practice, 8 (2000) 259-269.

DOI: 10.1016/s0967-0661(99)00160-4

[15] M.Y. Cheng, C.C. Lee, Motion controller design for contour following tasks based on real-time contour error estimation, IEEE Trans. Ind. Electron. 54 (3) (2007) 1686-1695.

DOI: 10.1109/tie.2007.894691

[16] C.T. Johnson, R.D. Lorenz, Experimental identification of friction and its compensation in precise, position controlled mechanisms, IEEE Trans. Ind. Applicat. 28 (1992) 1392-1398.

DOI: 10.1109/28.175293

[17] M.Y. Cheng, M.C. Tsai, J.C. Kuo, Real-time NURBS command generators for CNC servo controllers, Int. J. Mach. Tools and Manuf. 42 (7) (2002) 801-813.

DOI: 10.1016/s0890-6955(02)00015-9