Séminaire d'Automatique du Plateau de Saclay

Séminaire le 8 Octobre 2015, 15h15 à Room F.3.06, Supélec, Gif sur Yvette
N. van de Wouw and B. Besselink

The next seminars in the framework of the "Séminaire d'Automatique du Plateau de Saclay" of iCODE will be held on Thursday 8th October in the room F3.06 of CentraleSupelec (Gif-sur-Yvette).

10H00-11H00 Nathan van de Wouw (Eindhoven University of Technology): The convergence property: system theoretic aspects and applications

ABSTRACT: In this talk, the convergence property, which is a system-level stability property of nonlinear dynamical systems originally introduced in the 1960's in Russia, will be discussed in detail. A convergent system exhibits a unique, bounded globally asymptotically steady-state solution. Lyapunov characterisations of sufficient conditions for and properties of convergent systems will be presented. Moreover, relations to notions such as e.g. incremental stability will be briefly addressed. In the second part of the talk it will be advocated that convergence is a useful property in the analysis and design of nonlinear control systems. Particular applications are: steady-state performance analysis through "nonlinear frequency response functions", output regulation (with tracking, synchronisation as particular sub-problems), observer design, model reduction and extremum seeking control.

BIOGRAPHY: Nathan van de Wouw (born, 1970) obtained his M.Sc.-degree (with honours) and Ph.D.-degree in Mechanical Engineering from the Eindhoven University of Technology, Eindhoven, the Netherlands, in 1994 and 1999, respectively. From 1999 until 2015 he has been affiliated with the Department of Mechanical Engineering of the Eindhoven University of Technology as an assistant/associate professor. Nathan van de Wouw currently holds an adjunct full professor position at the University of Minnesota, U.S.A and a (part-time) full professor position at the Delft University of Technology, the Netherlands. In 2000, Nathan van de Wouw has been working at Philips Applied Technologies, Eindhoven, The Netherlands, and, in 2001, he has been working at the Netherlands Organisation for Applied Scientific Research (TNO), Delft, The Netherlands. He has held positions as a visiting professor at the University of California Santa Barbara, U.S.A., in 2006/2007, at the University of Melbourne, Australia, in 2009/2010 and at the University of Minnesota, U.S.A., in 2012 and 2013. He has published a large number of journal and conference papers and the books 'Uniform Output Regulation of Nonlinear Systems: A convergent Dynamics Approach' with A.V. Pavlov and H. Nijmeijer (Birkhauser, 2005) and `Stability and Convergence of Mechanical Systems with Unilateral Constraints' with R.I. Leine (Springer-Verlag, 2008). He currently is an Associate Editor for the journals "Automatica" and "IEEE Transactions on Control Systems Technology". His current research interests are the analysis and control of nonlinear/hybrid systems, with applications to vehicular platooning, high-tech systems, resource exploration and networked control systems.

 

11H00-12H00 Bart Besselink (KTH Stockholm) Model reduction of nonlinear systems using incremental system properties

ABSTRACT: Model reduction is a tool for the approximation of complex dynamical systems by systems of reduced order, hereby enabling efficient analysis or controller synthesis. In this presentation, several methods for model reduction of nonlinear systems will be discussed. These methods have in common that they rely on incremental system properties in obtaining an accurate reduced-order model that preserves relevant stability properties and satisfies an a priori bound on the reduction error. Specifically, (input-to-state) convergent nonlinear systems will be considered, in which reduction is performed by isolating the nonlinearities and the application of linear model reduction techniques. Next, the reduction technique of incremental balanced truncation is introduced, which explicitly takes nonlinearities into account in the reduction procedure and can be regarded as an extension of the well-known technique of balanced truncation to the nonlinear domain.

BIOGRAPHY: Bart Besselink is a Postdoctoral Researcher with the ACCESS Linnaeus Centre and Department of Automatic Control at KTH Royal Institute of Technology, Stockholm, Sweden. He received the M.Sc. degree (cum laude) in Mechanical Engineering from Eindhoven University of Technology, Eindhoven, the Netherlands, in 2008. In 2012, he received the Ph.D. degree from the same university for his thesis on model reduction techniques for nonlinear control systems. He was a short-term Visiting Researcher at the Tokyo Institute of Technology, Tokyo, Japan, in 2012. His main research interest include systems theory and model reduction for nonlinear dynamical systems and large-scale interconnected systems. In addition, he is working on applications in the field of intelligent transportation systems with a particular focus on the control and coordination of heavy-duty vehicle platoons.