Extended High-Gain Observers in Nonlinear Feedback Control

March 07, 2014, Webb 1100

Hassan Khalil

Michigan State University, Electrical & Computer Engineering


High-gain observers have evolved as one of the useful tools in nonlinear feedback control. This talk will describe an extension of the theory to the so-called Extended High-Gain Observers (EHGO). The talk will describe the use of EHGOs as disturbance estimators and soft sensors of the internal dynamics. The use of EHGO as disturbance estimators is based on the work of Freidovich and Khalil (IEEE Trans. AC, 2008) where the EHGO enables recovery of the performance of state feedback linearization in the presence of model uncertainty. The use of EHGO to estimate the internal dynamics is based on the work of Boker and Khalil (Automatica, 2013) where the EHGO provides a signal that serves as virtual output for the internal dynamics; hence, allowing the design of internal-dynamics observer, which together with the EHGO estimate the full state.

Speaker's Bio

Hassan K. Khalil received electrical engineering degrees from Cairo University (BS 1973; MS 1975) and the University of Illinois (PhD 1978). Since 1978 he has been with Michigan State University, where he is currently University Distinguished Professor of Electrical and Computer Engineering. He has consulted for General Motors and Delco Products, and published several papers on singular perturbation methods and nonlinear control. He is the author of Nonlinear Systems (Macmillan 1992; Prentice Hall 1996 & 2002) and coauthor, with P. Kokotovic and J. O'Reilly, of Singular Perturbation Methods in Control: Analysis and Design (Academic Press 1986; SIAM 1999). He was named IEEE Fellow in 1989 and IFAC Fellow in 2007. He received the 1989 IEEE-CSS George S. Axelby Outstanding Paper Award, the 2000 AACC Ragazzini Education Award, the 2002 IFAC Control Engineering Textbook Prize, the 2004 AACC O. Hugo Schuck Best Paper Award, and the 2009 AGEP Faculty Mentor of the Year Award. At Michigan State University, he received the 2003 Teacher Scholar Award, the 1994 Withrow Distinguished Scholar Award, and the 1995 Distinguished Faculty Award. He served as Associate Editor of IEEE Transactions on Automatic Control, Automatica and Neural Networks, and as Editor of Automatica for nonlinear systems and control. He was the Registration Chair of the 1984 CDC, Finance Chair of the 1987 ACC, Program Chair of the 1988 ACC, and General Chair of the 1994 ACC.

Video URL: