Robust control in Toulouse

Monday June 27 2005
LAAS-CNRS, Toulouse, France

Topic

The workshop aims at gathering three well-known speakers in the area of robust control presenting their last results.

Programme

Monday June 27, 2005

  • 14h30 -Tetsuya Iwasaki, University of Virginia, USA

    Feedback Control Synthesis with General Frequency Domain Specifications

    • This talk is concerned with a feedback control synthesis problem for linear systems to meet design specifications given in terms of multiple frequency domain inequalities in (semi)finite ranges. A multiplier expansion is proposed to convert the synthesis condition to a linear matrix inequality (LMI) condition through the linearizing change of variables. In the single objective setting, the LMI condition may or may not be conservative, depending upon the choice of the basis for the multiplier expansion. We provide a qualification for the basis matrix to yield nonconservative LMI conditions. It turns out to be difficult to determine the basis matrix meeting such qualification in general. However, it is shown that qualified bases can be found for some cases, and that the qualification can be used to find reasonable choices of the basis for other cases. Finally, the synthesis method is extended to the multiple objective case where a sufficient condition is given for the existence of a controller to meet the specification.

  •   15h30 - Joao Manuel Gomes da Silva, UFRGS, Porto Alegre, BR

    Stabilization of neutral systems with saturating inputs

    • This talk focuses on the stabilization problem of neutral systems in the presence of control saturation. Based on a descriptor approach and the use of a modified sector-condition, global and local stabilization conditions are derived using Lyapunov-Krasovskii functionals. These conditions allow to consider systems presenting time-varying delays and are formulated directly as linear matrix inequalities (LMIs). Optimization problems are proposed with the aim of computing stabilizing state feedback control laws.
     
  • 16h30 - Shankar Bhattacharyya, Texas A & M University, USA,

    Controller Synthesis without identification

    • This talk will describe recents results on controller synthesis without state estimation and without identification. We show that the complete sets of controllers achieving stability and performance specifications can be achieved based only and directly on Nyquist-Bode frequency domain data without the need for building analytical transfer function or state space models. This raises various questions regarding the validity of model based robust and optimal designs as developed over several decades by control theorists. We discuss several pertinent research areas raised by these results.

    Registration

    No registration is required

    Location

    Main conference hall (salle de conferences) of LAAS-CNRS, Toulouse.
    Access maps and accomodation information can be found here. Under construction - last updated on June 1, 2005