LMI-based robust iterative learning controller design for discrete linear uncertain systems

This paper addresses the design problem of robust iterative learning controllers for a class of linear discrete-time systems with norm-bounded parameter uncertainties. An iterative learning algorithm with current cycle feedback is proposed to achieve both robust convergence and robust stability. The synthesis problem of the proposed iterative learmng control （ILC） system is reformulated as a γ-suboptimal H-infinity control problem via the linear fractional transformation （LFT）. A sufficient condition for the convergence of the ILC algorithm is presented in terms of linear matrix inequalities （LMIs）. Furthermore, the linear wansfer operators of the ILC algorithm with high convergence speed are obtained by using existing convex optimization techniques. The simulation results demonstrate the effectiveness of the proposed method.

LMI_based robust iterative learning controller design for discrete linear uncertain systems

This paper addresses the design problem of robust iterative learning controllers for a class of linear discrete-time systems with norm-bounded parameter uncertainties. An iterative learning algorithm with current cycle feedback is proposed to achieve both robust convergence and robust stability. The synthesis problem of the proposed iterative learning control (ILC) system is reformulated as a y-suboptimal H-infinity control problem via the linear fractional transformation (LFT) .A sufficient condition for the convergence of the ILC algorithm is presented in terms of linear matrix inequalities (LMIs) . Furthermore, the linear transfer operators of the ILC algorithm with high convergence speed are obtained by using existing convex optimization techniques. The simulation results demonstrate the effectiveness of the proposed method. The research work was supported by the National Natural Science Foundation of China (No. 60474005,60274034). Jianming XU received his B. S. degree in engineering from Nanchang University in 1998, and his M. S. degrees from Zhejiang University of Technology, Hangzhou, China in 2003. He is currently a Lecturer in the College of Information Engineering, Zhejiang University of Technology, China. His research interests include iterative I learning control and robust control. Mingxuan SUN received the B.Eng. degree from the Xi an University of Technology, China, in 1982, the M. Sc.(Eng.) degree from the Beijing Institute of Technology, China, in 1987, and the Ph.D. degree from the Nanyang Technological University, Singapore, in 2002. From 1982 to 1984, he was with the Hefei General I Machinery Research Institute, China, where he became an Assistant Engineer of the Institute in 1983. He joined the Department of Electrical Engineering, Xi’an Institute of Technology, China, in 1987, becoming an Associate Professor in 1994 and the Deputy Director of the Department in 1997. He held Research Fellow positions at the Nanyang Technological University and the National University of Singapore from 2001 to 2004. Since 2004, he has been with the Zhejiang University of Technology, China, and is currently a Professor of the College of Information Engineering. His current research interests include iterative learning control and repetitive control as well as their applications. Li YU received his B.S. degree in Control Theory from Nankai University in 1982, and his M.S. and Ph. D. degrees from Zhejiang University, Hangzhou, China. He is currently a Professor in the College of Information Engineering, Zhejiang University of Technology, China. His research interests include robust control,time-delay systems,decentralized control.