Straightness Error Compensation Servo-system for Single-axis Linear Motor Stage

Authors: M. S. Kang, D. H. Kim, J. S. Yoon, B. S. Park, J. K. Lee

Abstract:

Since straightness error of linear motor stage is hardly dependent upon machining accuracy and assembling accuracy, there is limit on maximum realizable accuracy. To cope with this limitation, this paper proposed a servo system to compensate straightness error of a linear motor stage. The servo system is mounted on the slider of the linear motor stage and moves in the direction of the straightness error so as to compensate the error. From position dependency and repeatability of the straightness error of the slider, a feedforward compensation control is applied to the platform servo control. In the consideration of required fine positioning accuracy, a platform driven by an electro-magnetic actuator is suggested and a sliding mode control was applied. The effectiveness of the sliding mode control was verified along with some experimental results.

Keywords: Linear Motor Stage, Straightness Error, Friction, Sliding Mode Control.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1330629

References:

[1] G. Pritshcow, "A comparison of linear and conventional electromechanical drives," Annals of the CIRP, vol. 47, no. 2, pp541-548, 1998.
[2] M. Yan and T Cheng, "High accuracy motion control of linear motor drive wired-EDM machines," Proc. Of the 2005 IEEE International Conference on Mechatronics, pp. 346-351, 2005.
[3] O. Kim, S. Lee, and D. Han, "Positioning performance and straightness error compensation of the magnetic levitation stage supported by the linear magnetic bearing," IEEE Trans. on Industrial Electronics, vol. 50, no. 2, pp.374-378, 2003.
[4] J. D. Choi and M. S. Kang, "Development of a servo-system for straightness improvement of linear motor stages," Trans. of the KIEE, vol. 54D, no. 1, pp.33-39, 2005.
[5] B. Amstrong-Helouvry, P. Dupont, and C. Canudas, "A survey of models, analysis tools and compensation methods for control of machines with friction," Automatica, vol. 30, no. 7, pp.1083-1138, 1994.
[6] P. Dupont, "Avoiding stick-slip through PD control," IEEE Trans. On Automatic Control, vol. 39, no. 5, pp. 1059-1097, 1994.
[7] C. Canudas de Wit, H. Olsson, K.J. Astrom, and P. Lischinsky, "A new model for control of system with friction," IEEE Transactions on Automatic Control, vol. 40, pp. 419-425, 1995.
[8] K. Khayati, P. Bigras, and L. Dessaint, "A multistage position/force control for constained robotic systems with friction: Joint-space decomposition, linearization, and multiobjective obser/controller synthesis using LMI formulism," IEEE Trans. on Industrial Electronics, vol. 53, no. 5, pp.1689-1712, 2006.
[9] F. Jatta, G. Legnani, and A. Visioli, "Friction compensation in hybrid force/velocity control of industrial manipulators," IEEE Trans. on Industrial Electronics, vol. 53, no. 2, pp.604-613, 2006.
[10] X.Z. Gao and S. J. Ovaska, "Friction compensation in servo motor systems using neural networks, "Proc. of the 1999 IEEE Midnight-Sun Workshop on Soft Computing Methods in Industrial Applications, pp. 146-151, 1999.
[11] D.K. Young, V.I. Utkin, and Ozguner, "A control engineer-s guide to sliding mode control," IEEE Trans. on Control Systems Technology, vol. 7, no. 3, 1999.
[12] C. L. Chen, M. J. Jang, and K. C. Lin, "Modeling and high-
[recision control of a ball-csrew-driven stage," Precision Engineering, vol. 28, pp. 483-495, 2004.
[13] V. I. Utkin, J. Guldner, and J. Shi, Sliding mode control in electromechanical systems, New-York:Taylor & Francis, 1999.
[14] C. Edward and S. K. Spurgeon, Sliding mode control: Theory and application, Taylor & Francis Ltd, 2004.