Einladung zum Vortrag im Kolloquium Technische Kybernetik

Set invariance concepts in model predictive control of uncertain discrete time systems

Dr. Sasa Rakovic

Department of Electrical and Electronic Engineering
Imperial College London
London, UK

    Zeit: Dienstag · 16. 8. 2005 · 16:00 Uhr
    Ort: Raum 3.241 · Pfaffenwaldring 9 · Campus Stuttgart-Vaihingen

Abstract

The talk describes an approach to robust control of constrained discrete time systems. Particular emphasis is given to set invariance and model predictive control concepts. The concept of set robust control invariance is introduced. This concept is concerned with extension of the standard concept of set invariance theory concerned with difference equations to discrete time systems described by difference inclusions. The general concept admits a certain degree of simplifications for the linear discrete time systems.

It is shown that these ideas allow for robust model predictive control of constrained linear discrete time systems by using tubes. This is a form of feedback model predictive control that overcomes disadvantages of conventional model predictive control.

Perfect state information case is treated in more details and we present a simple tube controller for efficient robust model predictive control of constrained linear, discrete-time systems in the presence of bounded disturbances. The proposed control policy ensures that controlled trajectories are confined to a given tube despite uncertainty. The robust optimal control problem that is solved on--line is a standard quadratic programming problem of marginally increased complexity compared with that required for model predictive control in the deterministic case. We show how to optimize the tube cross section, how to construct an adequate tube terminal set and we establish robust exponential stability of a suitable robust control invariant set (the `origin' for uncertain system) with enlarged domain of attraction.

The talk is concluded with a brief overview of possible extensions of the proposed method.

Biographical Information

Sasa V. Rakovic received the B.Sc. degree in Electrical Engineering from the Technical Faculty Cacak, University of Kragujevac (Serbia and Montenegro), the M.Sc degree in Control Engineering and PhD degree in Control Theory from Imperial College London. He is currently employed as a research assistant in the Control and Power Research Group at Imperial College London. He closely works with Prof. David Q. Mayne. His research interests include set invariance, optimization, optimization based design, and robust model predictive control.