Title :

Distributed Adaptive Control for Synchronization of Unknown Nonlinear Networked Systems

Speaker :

Prof. F. L. Lewis

Head, Advanced Controls & Sensors Group, Automation & Robotics Research Institute

The University of Texas at Arlington, USA

Venue :

Room 215, William M. W. Mong Engineering Building, CUHK

Date :

Jan 21, 2010, Thursday
4:30 PM - 5:30 PM

Abstract :

Traditional research on cooperative networked systems has focused on analysis of given protocols for simple linear systems, mainly the integrator or double integrator dynamics. Pinning control has been developed for nonlinear systems, generally using either a Jacobian linearization method or a Lipschitz assumption. Work has also progressed on nonlinear coupling protocols. In this paper we present a design method for adaptive controllers for distributed systems having non-identical unknown nonlinear dynamics, and for a target dynamics to be tracked that is also nonlinear and unknown. The development is for general digraph communication structures. A Lyapunov technique is presented for designing a robust synchronization control protocol. The proper selection of the Lyapunov function is the key to ensuring that the resulting control laws thus found are implementable in a distributed fashion. Lyapunov functions are defined in terms of a local neighborhood tracking synchronization error and the Frobenius norm. The resulting protocol consists of a linear protocol and a nonlinear control term with adaptive update law at each node. Connections are made between the convergence rate/convergence residual set and graph structural properties such as the sum of the in-degrees and out-degrees, and the difference between the in-degrees and out-degrees. Singular value analysis is used. It is shown that the singular values of certain key matrices are intimately related to structural properties of the graph.

Biography :

Prof. F.L. Lewis, Fellow IEEE, Fellow IFAC, Fellow U.K. Institute of Measurement & Control, PE Texas, U.K. Chartered Engineer, is Distinguished Scholar Professor and Moncrief-O’Donnell Chair at University of Texas at Arlington’s Automation & Robotics Research Institute. He obtained the Bachelor`s Degree in Physics/EE and the MSEE at Rice University, the MS in Aeronautical Engineering from Univ. W. Florida, and the Ph.D. at Ga. Tech. He works in feedback control, intelligent systems, distributed control systems, and sensor networks. He is author of 6 U.S. patents, 216 journal papers, 330 conference papers, 14 books, 44 chapters, and 11 journal special issues. He received the Fulbright Research Award, NSF Research Initiation Grant, ASEE Terman Award, Int. Neural Network Soc. Gabor Award 2009, U.K. Inst Measurement & Control Honeywell Field Engineering Medal 2009. Received Outstanding Service Award from Dallas IEEE Section, selected as Engineer of the year by Ft. Worth IEEE Section. Listed in Ft. Worth Business Press Top 200 Leaders in Manufacturing. He served on the NAE Committee on Space Station in 1995. He is an elected Guest Consulting Professor at South China University of Technology and Shanghai Jiao Tong University. Founding Member of the Board of Governors of the Mediterranean Control Association. Helped win the IEEE Control Systems Society Best Chapter Award (as Founding Chairman of DFW Chapter), the National Sigma Xi Award for Outstanding Chapter (as President of UTA Chapter), and the US SBA Tibbets Award in 1996 (as Director of ARRI’s SBIR Program).

    **************************************** ALL ARE WELCOME ****************************************

Enquiries: Ms. Winnie Wong or Prof. Wen J. Li, Department of Mechanical and Automation Engineering, CUHK at 2609 8337. *MAE Series (2009-10) is contained in the World-Wide Web home page at http://www3.mae.cuhk.edu.hk/maeseminars.php#mae