Note: This content is accessible to all versions of every browser. However, this browser does not seem to support current Web standards, preventing the display of our site's design details.


Exploiting Nonlinearities for Observer and Output-Feedback Design

In this talk we present observer and output-feedback designs for a class of systems in which the nonlinearities satisfy a monotone growth property. The approach is to represent the observer error system as the interconnection of a linear block and a feedback nonlinearity which satisfies the sector condition of the multivariable circle criterion. Convergence of the estimates to the true states is then achieved with the help of a linear matrix inequality (LMI) which, if feasible, yields observer matrices that render the linear block positive real. We then show that this observer has “super-exponential” convergence properties, which allow us to recover global stability properties of state-feedback designs with certainty-equivalence-type output-feedback controllers. The observer and output-feedback designs are illustrated with several physically motivated examples.

Type of Seminar:
Public Seminar
Ass. Prof. Murat Arcak
Rensselaer Polytechnic Institute, Troy, New York, USA
May 17, 2004   15:15

ETH Zentrum, Physikstrasse 3, Building ETL , Room K 25
Contact Person:

Prof. M. Morari
File Download:

Request a copy of this publication.
Biographical Sketch:
Murat Arcak was born in Istanbul, Turkey, in 1973. He received the B.S. degree in Electrical and Electronics Engineering from the Bogazici University, Istanbul, in 1996, and the M.S. and Ph.D. degrees in Electrical and Computer Engineering from the University of California, Santa Barbara, in 1997 and 2000. In 2001 he joined the Rensselaer Polytechnic Institute, Troy, New York, as an assistant professor of Electrical, Computer and Systems Engineering. His research interests are in nonlinear control theory and applications. Dr. Arcak is a member of IEEE and SIAM, an associate editor on the Conference Editorial Board of IEEE Control Systems Society. He was a finalist for the student best paper award at the 2000 American Control Conference, and received an NSF CAREER Award in 2003.