Recent advances on the problem of output regulation for nonlinear systems repose on a newly-developed notion of steady state behaviors of a nonlinear system. This notion, which utilizes an enhanced version of the concept of limit set, provides a natural tool for the extension to nonlinear systems of a very classical notion in linear feedback design. Forcing a prescribed steady-state response in given nonlinear system can be cast as a problem of robust stability of an augmented system consisting of the controlled plant and of an internal model of the exogenous inputs. This robust stabilization problem becomes particularly challenging if the controlled plant is minimum phase and even in the case of linear systems is largely unsolved. The present lecture describes a newly proposed, unified, approach to the design of the feedback law, by means of which some relevant classes of non-minimum phase systems can be handled. The core of the method is a reduction procedure in which certain degrees of freedom in the design of the internal model are conveniently exploited to the purpose of simplifying the resulting stabilization task.
Alberto Isidori, obtained his degree in EE from the University of Rome in 1965. Since 1975, he is Professor of Automatic Control at this University. He has held visiting positions in various leading Universities, which include the University of Illinois at Urbana-Champaign, the University of California at Berkeley, the ETH in Zurich. Between 1989 and 2006, he has also been regularly collaborating with Washington University in St. Louis.
His research interests are primarily in analysis and design of nonlinear control systems. He is the author of the highgly-cited book Nonlinear Control Systems. He is the recipient of various prestigious awards, which include the ``Georgio Quazza Medal" (in 1996) from the International Federation of Automatic Control. He is also the recipient of the Ktesibios Award, from the Mediterranean Control Association (in 2000) and of the Bode Lecture Award, from the Control Systems society of IEEE (in 2001). In 2009, he received the Galileo Galiei award, from the Italian Rotary Clubs, in recognition of his contributions to the progress of Engineering sciences in Italy. In 2009 he received the Doctor of Science Honorary Degree from the Royal Institute of Technology of Sweden. He received best paper awards on the IEEE Transactions on Automatic Control and Automatica, twice on both journals. In 1986 he was elected Fellow of IEEE and in 2005 he was elected Fellow of IFAC. He is listed in the Highly-Cited database (http://isihighlycited.com) among the top most-cited authors in Engineering. He is currently President the International Federation of Automatic Control.