10-12 Janvier : Séminaire du groupe MAC à Bolquère.
- Thomas Loquen - Analyse des systèmes avec ŕeinitialisation : Stabilit́e et performances (
pdf).
- Yacine Ariba - Systèmes à retard : application aux réseaux de communication (
pdf).
- Sophie Tarbouriech - Analyse de la stabilit́e pour un système avec backlash (
pdf).
- Lucie Baudouin - Problème Inverse.
- Hael Khansah - LPV.
- Georgio Valmorbida - Stabilit́e des systèmes avec saturation en commande et dynamiques ńegliǵees (
pdf).
- Wilfried Gilbert - Synthèse LPV appliqúee à la commande de moteurs d’avion (
pdf).
- Didier Henrion - Geometry of LMIs and determinantal representations of algebraic plane curves (
pdf).
- Vincent Boyer - Heuristique Efficace Pour Le Problème Knapsack Multicontraint (
pdf).
- Dimitri Peaucelle - Robustesse et Commade Adaptative (
pdf).
- 17-18 Janvier : Meeting GARTEUR Flight Mechanic Action Group AG15 organisé au LAAS-CNRS par I. Queinnec, S. Tarbouriech et G. Garcia.
- 22 Février : Séminaire de groupe à 14h30. D. Henrion parle de commande optimale.
- 15 Mars : Séminaire de Bernard Mourrain, à 14h, salle Europe "Polynomes et matrices structurées"
- 16 Mars : Séminaire de groupe à 14h30. C. Prieur parlera de systèmes hybrides.
27 Mars : Séminaire de Michal Kvasnica, de 14h à 16h en Salle Tourmalet.
Title : Complexity reduction in Model Predictive Control.
Abstract : In this talk we will cover various aspects of on-line implementation of the so-called explicit solutions to Model Predictive Control (MPC) problems. First we will show how the concept of parametric programming can be used to obtain optimal solutions to MPC problems for linear and hybrid systems. The solution, computed off-line, takes a form of a Piecewise Affine state feedback law defined over a finite number of convex polytopes. Once such a solution is available, the on-line implementation reduces to a simple set-membership test, which can be performed in time proportional to the number of underlying polytopes. We then discuss various methods which allow to reduce the complexity of the polytopic partition either by solving simpler problems, or by post-processing the optimal solution. Various search procedures which serve to speed up the set-membership test will be discussed as well.
17 Avril : Séminaire de Branislav Rehák, de 14h à 16h en Salle Tourmalet.
Title : FEM-based methods for the solution of the Output Regulation Problem
Abstract : The problem of asymptotic reference tracking is one of central problems of the modern control theory. If the reference signal and/or the disturbance is generated by an autonomous system then this problem is called "the Output Regulation Problem".
The crucial task when solving this problem is finding the solution of the so called regulator equation. Its solution describes the manifold where the perfect tracking is achieved (zero-error manifold). In the linear case, this equation can be formulated as a matrix equation, its solvability conditions are known. In the nonlinear case, the regulator equation is a nonlinear partial differential equation of first order. Moreover, this system is augmented by an algebraic condition - the zero-error output condition.
Solution of such systems of algebraic and differential equation is still not well investigated area. The most commonly used method is based on expansion of all terms into Taylor series and then determining the coefficients of the Taylor series of the solution. The drawbacks of this method are lack of convergence analysis and of error estimates.
Another method, based on the approximate solution of the regulator equation by the finite-element method, was proposed. The system is solved iteratively - a feedforward is chosen, then the "differential part" of the regulator equation is solved. After this, the error made in the "algebraic part" is evaluated, this value is used for the next choice of the feedforward. Results concerning error analysis and convergence of this method will be presented. Some simulation results will be shown at the end.
- 19 Avril : Séminaire de groupe à 14h30. F. Gouaisbaut présente ses derniers travaux sur les systèmes à retard.
- 15 Mai : Séminaire de groupe à 14h30 en salle du conseil. D. Arzelier parlera de "information et commande, le contre exemple de Wistenhausen".
- 21 Juin : Séminaire de groupe à 14h30 par G. Garcia. "Stabilisation pratique des systèmes linéaires".
12 Septembre : Séminaire par Mihai Putinar, Math. Dept. Univ of California, Santa Barbara, "Moments et sommes de carrés".
19 Septembre : Séminaire par Mihai Putinar, Math. Dept. Univ of California, Santa Barbara, "Commutative and non-commutative cases: a Comparison".
29 Novembre : J.C. Geromel fait un séminaire à 10h30 en salle Tourmalet.
Titre : H2 robust filtering with optimality gap certification
Résumé : In this seminar, H2 robust filtering is discussed. Particular attention is devoted to what we call optimality gap certification of robust filters for both continuous and discrete time invariant systems subject to polytopic parameter uncertainty. After a brief discussion on some of the most expressive methods available for H2 robust filter design, a new one based on a performance certificate calculation is presented. The performance certificate is given in terms of the gap produced by the robust filter between lowerand upper bounds of a minimax programming problem where the H2 norm of the estimation error is maximized with respect to the feasible uncertainties and minimized with respect to all linear, rational, stable and causal filters. The calculations are performed through convex programming methods developed to deal with linear matrix inequality (LMI). Many examples borrowed from the literature are solved and it is shown that the proposed method outperforms all other designs.