All Years Seminars
[INMA] 2014-11-18 (14.00) : Optimal pits and optimal transportation
At Euler building (A002)
Speaker :
Maurice Queyranne (CORE and University of British Columbia)
Abstract : In open pit mining, one must dig a pit, that is, excavate upper layers of ground before reaching the ore. The walls of the pit must satisfy some geomechanical constraints, in order not to collapse.The question then arises, how to mine the ore optimally, that is, how to find an optimal pit. We set up the problem in a continuous (as opposed to discrete) framework, and we show, under weak assumptions, the existence of an optimum pit. For this, we formulate an optimal transportation problem, where the cost function is lower semi-continuous and is allowed to take the value +infinity. We show that this transportation problem is a strong dual to the optimum pit problem, and also yields optimality (complementarity slackness) conditions. This is joint work with Ivar Ekeland (CEREMADE, Université Paris-Dauphine)
[INMA] 2014-10-28 (14.00) : Multi-objective dynamic optimization: recent developments and applications
At Euler building (A002)
Speaker :
Filip Logist (KUL)
Abstract : Many processes are dynamic in nature and their optimisation involves the determination of optimal time-varying input policies. This results in optimisation problems with the dynamic system as one of the constraints (i.e., so-called dynamic optimization or optimal control problems). Moreover, multiple and conflicting objectives often arise in practice, giving rise to a set of mathematically equivalent Pareto optimal solutions instead of one single solution. For instance in view of sustainable development, not only more profitable (economically sustainable), but also cleaner (environmentally sustainable) and safer (socially sustainable) processes and operations are aimed at. To enhance decision making in practice, it is important to enable the efficient and accurate generation of optimal alternatives (i.e., the Pareto optimal solutions) and the evaluation of the trade-offs between them.
In this talk recent developments in the domain of multi-objective dynamic optimization will be reviewed with a focus on scalarization based multi-objective approaches. Developments include (i) robust multi-objective optimal control, (ii) multi-objective mixed-integer optimal control, (iii) multi-objective dynamic optimal experiment design, (iv) multi-objective optimisation of periodically operated distributed parameter systems and (v) multi-objective tuning of nonlinear model predictive controllers (NMPC).
Examples include, e.g., (i) the control of (bio)chemical reactors in view of conflicting conversion, yield, productivity and/or energy objectives, while accounting for uncertainty, (ii) the driving of a car with gear shifts in view of minimising both the travelling time and the fuel consumption, (iii) the determination of optimal cyclic steady-states for catalytic tubular reactors in view of conversion and energy recovery, (iv) the determination of dynamic profiles in view of different optimal experiment design criteria for estimating microbial kinetics, or (v) the online optimal control of the Tennessee Eastman benchmark in view of trading off several tracking and economic objectives.
[INMA] 2014-10-21 (14.00) : Getting multi-agent systems to cooperate
At Euler building (A002)
Speaker :
Luca Schenato (University of Padova)
Abstract : Getting large scale autonomous multi-agent systems to cooperatively perform tasks is a formidable challenge. A key issue is robustness, since systemic failures can result from component failure for poorly designed cooperation schemes. There is an emerging view that multi-layered architectures, where each layer builds upon few primitive functions from lower layers can provide correct-by-construction robustness guarantees. I will show how many applications which require cooperation, ranging from multi-sensor calibration to networked clock synchronization, from multi-camera perimeter patrolling to multi-robot map building, can be solved via the consensus algorithm, a "primitive" function for which there exists very robust and provably correct implementations. I will close by sharing some personal views about research challenges in the control of large scale networks.
[INMA] 2014-10-14 (12:00) : Presentation of research topics
At Euler building (A002)
Speaker :
Young researchers (UCL)
Abstract : In this talk, three junior researchers will present their research topics. In particular, François Gonze will talk on "The Synchronizing Probability Function and the Triple Rendezvous Time as Approaches to Cerny's Conjecture", Matthew Philippe on "Stability analysis of discrete-time linear switching systems with regular switching sequences" and Luc Rocher on his past realizations with Yves-Alexandre de Montjoye.
[INMA] 2014-09-25 (14.00) : Regional Input-to-State Stabilization of Discrete-Time Nonlinear Quadratic Systems
At Euler building (A002)
Speaker :
Carlos E. de Souza (LNCC/MCTI, Petropolis, Brazil)
Abstract : This talk deals with the design of feedback controllers for discrete-time nonlinear quadratic systems subject to persistent magnitude bounded disturbances. The class of quadratic systems, namely dynamic systems with a state-space model with quadratic nonlinearity in the state variables and bilinear terms in the state and control signal, can represent a large number of processes arising in several fields. We present a methodology based on convex optimization for designing static nonlinear state feedback controllers that achieve local input-to-state stability with a guaranteed bounding set for the system state trajectory under nonzero initial conditions and magnitude bounded disturbances. The proposed controller design isin terms of numerically tractable linear matrix inequality problem.
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