All Years Seminars
[INMA] 2009-05-19 (14.00) : Subset Selection
At Euler building
Speaker :
Ilse IPSEN (North Carolina State University )
Abstract : Subset selection methods try identify those columns of a matrix that are
"most" linearly independent. Many subset selection methods are based on a
QR decomposition with column pivoting. We discuss deterministic and
probabilistic methods for subset selection, as well as the application of
subset selection to nonlinear least squares problems in parameter estimation.
[INMA] 2009-05-12 (14.00) : "Influence of tire damping on the ride performance potential of quarter-car active suspensions"
At Euler building
Speaker :
Semiha TURKAY (Institute of Automatic Control, Technical University of Munich
)
Abstract : In this study, constraints on the transfer functions from the road disturbance to the
vertical acceleration, the suspension travel, and the tire deflection are derived for a quarter-car
active suspension systems using the vertical acceleration and/or the suspension travel
measurements for feedback. The influence of tire damping on the design of an active
suspension system is illustrated by a mixture of the LQG methodology and the interpolation
approach. Besides, H2 and mixed H2/H? syntheses of the quarter-car model excited by random
road disturbances are studied. It is demonstrated that the influence of tire damping on the
closed-loop performance of the active suspension system can be significant. Finally, the result
is extended to suspension models with polytopic tire damping uncertainties
[INMA] 2009-05-05 (14.00) : "Robustification hors ligne de lois de commande prédictives multivariables"
At Euler building
Speaker :
Cristina STOICA (SUPELEC-FR.)
Abstract : Cette présentation propose une méthodologie hors ligne pour la robustification de lois de commande prédictives multivariables,
se basant sur une problématique doptimisation convexe dun paramètre de Youla. Le point de départ de la démarche consiste
à synthétiser une loi de commande initiale prédictive multivariable sous forme détat qui stabilise le système. Le but est de garantir
la robustesse en stabilité face à des incertitudes non structurées et dassurer des performances nominales pour le rejet de perturbations,
imposées sous la forme des gabarits temporels sur les sorties. Ce problème doptimisation est résolu par un formalisme LMI. Le paramètre
de Youla obtenu permet de gérer dune part le compromis entre la robustesse en stabilité et les performances nominales et dune autre part
permet de réduire linfluence du couplage multivariable sur le rejet des perturbations.
Le cas de systèmes incertains appartenant à un ensemble donné dincertitudes polytopiques est également traité. Dans ce cas, une condition
supplémentaire BMI est ajoutée pour chaque sommet du polytope considéré, afin de garantir la stabilité sur tout le polytope. Il sagit dun problème
doptimisation non-convexe pour lequel une solution de complexité raisonnable sous une forme LMI sous-optimale est proposée. Loriginalité consiste
à pouvoir garantir la stabilité avec le correcteur robustifié pour le domaine incertain considéré, même dans le cas où le correcteur MPC initial est instable
sur une partie du polytope.
[INMA] 2009-04-28 (14.00) : Water Information Networks: Successes and Challenges
At Euler building
Speaker :
Iven Mareels (University of Melbourne)
Abstract : It is estimated that we harvest and utilize about 65% of the readily available fresh water resources of the world. In general, perhaps
because water is perceived as an abundantly available resource, we use water rather poorly. Typically less than half the water taken from
the environment serves the objective for which it was intended. The UNESCO World Water reports 2003 and 2005 identify in no uncertain terms a water crisis.
In this lecture we provide an overview of a 10 year collaborative research and development effort, between the University of Melbourne
and a local company Rubicon Systems Australia, and more recently with National ICT Australia.
The programme called Water Information Networks (WIN) is a systems engineering approach to water management in irrigation systems.
Because irrigation accounts for 70% of the total water consumption, this is a logical place to start. The ultimate goal is to manage water at the level of an entire
water catchment basin, accounting for surface and ground water and providing for the needs of all users, including the environment. WIN has developed a sensor/actuator
network and a systems engineering approach to water management. The patented technology (commercialized as Total Channel Control) is now being deployed in Australias
largest irrigation district Goulburn Murray Water (GMW), consisting of 6800km of open irrigation canals servicing over 22,000 farms.
The objective for the open canal system is to deliver water on demand (in as much this may be feasible) with maximal overall efficiency meeting the competing demands.
We review the research work, including open questions, and discuss the WIN outcomes from a number of substantial pilot and commercial projects in Australia that have realized
significant gains in either water efficiency or water productivity in irrigation.
[INMA] 2009-04-23 (14.00) : Communications for Coordinated Control via Covariance Management
At Euler building
Speaker :
Robert BITMEAD (University of California, San Diego
)
Abstract :
Interaction between coordinating systems requires communication of
information between the systems. Our aim is to quantify the required level
and content of this communication. In the example considered, the interaction is developed as a non-collision constraint between
vehicles and each vehicle solves a constrained Model Predictive Control (MPC) problem to
determine its path - with the non-collision constraint being central.
The extension of MPC from a full-state feedback strategy to one involving state
estimates allows the adoption of the estimate covariance as a means to manage the communication requirements. This, in turn, admits a
formulation of the communication resource assignment problem as a set of coupled Linear Matrix Inequalities, which link the control objectives, the external
disturbance, and the communications.
Seminars
Subscribe (ICS)
INMA Contact Info
Mathematical Engineering (INMA)
L4.05.01
Avenue Georges Lemaître, 4
+32 10 47 80 36
secretaire-inma@uclouvain.be
Mon – Fri 9:00A.M. – 5:00P.M.
JOIN US