Home | Issues | Profile | History | Submission | Review

Vol: 50(64) No: 1 / March 2005       Robust Servo-System Design Based on Discrete-Time Sliding Mode Control with Active Disturbance Estimator Boban Veselic Department of Automatic Control, University of Nis, Faculty of Electronic Engineering, Aleksandra Medvedeva 14,18000 Nis, Serbia and Montenegro, phone: (+381 18) 529-425, e-mail: bveselic@elfak.ni.ac.yu Cedomir Milosavljevic Department of Automatic Control, University of Nis, Faculty of Electronic Engineering, Aleksandra Medvedeva 14,18000 Nis, Serbia and Montenegro, phone: (+381 18) 529-425 Darko Mitic Department of Automatic Control, University of Nis, Faculty of Electronic Engineering, Aleksandra Medvedeva 14,18000 Nis, Serbia and Montenegro, phone: (+381 18) 529-425 Keywords: servo-system, position tracking, discrete-time sliding mode control, disturbance estimator. Abstract This paper deals with the design of robust positioning servo-system, capable of accurate tracking of complex referent signals under action of parameter uncertainties and external disturbances. Discrete-time sliding mode control approach is employed in servo-system design. Tracking accuracy is improved by using a new digital disturbance estimator, which incorporates an active sliding mode controlled subsystem. The overall servo-system exhibits high tracking accuracy and robustness to internal and exogenous disturbances. Experimental results show effectiveness of the proposed servo-system control structure. References [1] B. Draženović, “The invariance conditions in variable structure systems”, Automatica, no. 5, pp. 287-295, 1969. [2] V. I. Utkin, Sliding Modes in Control and Optimization, Berlin, Springer-Verlag, 1992. [3] Č. Milosavljević, “General conditions of the existence of a quasi-sliding mode on the switching hyperplane in discrete variable structure systems”, Automatic and Remote Control, no. 46, pp. 307-314, 1985. [4] W. C. Su, S. V. Drakunov, and U. Ozguner, “An O(T2) boundary layer in sliding mode for sampled data systems” IEEE Trans. Automatic Control, vol. 45, pp. 482-485, 2000. [5] A. Damiano, G. L. Gatto, I. Marongiu, and A. Pisano, “Second-order sliding-mode control of DC drives”, IEEE Trans. on Industrial Electronics, vol. 51, no. 2, pp. 364-373, 2004. [6] F. Betin, D. Pinchon, and G. A. Capolino, “A time-varying sliding surface for robust position control of a DC motor drive”, IEEE Trans. on Industrial Electronics, vol. 49, no 2, pp. 462-473, 2002. [7] Y. Eun, J. H. Kim, K. Kim, and D. I. Cho, “Discrete-time variable structure controller with a decoupled disturbance compensator and its application to a CNC servomechanism”, IEEE Trans. on Control Systems Technology, vol. 7, no. 4, pp. 414-423, 1999. [8] Č. Milosavljević, D. Mitić, B. Veselić, and M. Pejović, “Digital sliding mode control of x-ray apparatus electrical drives”, Electronics, vol. 7, no. 2, pp. 85-89, 2003. [9] G. Golo and Č. Milosavljević, “Robust discrete-time chattering free sliding mode control”, Systems & Control Letters, vol. 41, pp. 19-28, 2000. [10] Č. Milosavljević, B. Peruničić-Draženović, B. Veselić, and D. Mitić, “A new design of servomechanisms with digital sliding mode”, Electrical Engineering. in press. [11] K. D. Young, V. I. Utkin, and U. Ozguner, “A control engineer’s guide to sliding mode control”, IEEE Trans. Control Systems Technology, vol. 7, no. 3, pp. 328-342, 1999. [12] P. Korondi, K. K. D. Young, and H. Hashimoto, “Discrete-time sliding mode based feedback compensation for motion control”, in Proc. Workshop on Variable Structure Systems, Tokyo, Japan, 1996, pp. 127-131. [13] Y. Chou, K. Yang, W. K. Chung, H. R. Kim, and H. Suh, “On the robustness and performance of disturbance observers for second-order system”, IEEE Trans. Automatic Control, vol. 48, no. 2, pp. 315-320, 2003.