13th Simon Stevin Lecture on Optimization in Engineering
"Adaptive Optimization in the Presence of Uncertainty"
Dominique Bonvin (EPFL, Lausanne)
Flyer,
PosterAbstract
This presentation discusses real-time optimization (RTO) strategies for improving the performance in the presence of uncertainty in the form of plant-model mismatch, drifts and disturbances. RTO typically uses a plant model to compute optimal inputs. In the presence of uncertainty, selected model parameters are estimated and the updated model is used for optimization. This two-step approach is repeated on-line as necessary. Although very intuitive, this approach suffers from the fact that the model is almost invariably inadequate, which prevents from reaching the plant optimum. Other approaches have been developed in the last two decades to overcome this difficulty. Recently, a generic formalization of these ad hoc fixes has been proposed under the label modifier adaptation. The basic idea is to leave the model parameters unchanged but to use the plant measurements to “appropriately” modify the optimization problem. The modifier adaptation approach will be presented and compared to the two-step approach, in particular with regard to the model adequacy condition. We will then go beyond this comparison and discuss different ways of using plant measurements for process improvement in the presence of uncertainty.
There are many questions to be addressed: (i) what can be done off-line prior to process operation, and what should be performed in real time, (ii) how much of the optimization effort is model-based and how much is data-driven, (iii) what to measure, what to adapt, how to adapt? We will then see that there exists another class of measurement-based optimization approaches that turns the optimization problem into a control problem; this class of methods includes NCO tracking, extremum-seeking control and self-optimizing control. A case study will illustrate the applicability of the various approaches.
Biographical Information:
Dominique Bonvin is Professor of Automatic Control and Dean of Bachelor and Master Studies at the Swiss Federal Institute of Technology in Lausanne (EPFL), Switzerland. He received his Diploma in Chemical Engineering from the ETH, Zürich, and his Ph.D. degree from the University of California, Santa Barbara. He worked in the field of process control for the Sandoz Corporation in Basel and with the Systems Engineering Group of ETH Zürich. He joined the EPFL in 1989, where his current research interests include modeling, identification and optimization of dynamic systems as well as process chemometrics. He served as Director of the Laboratoire d'Automatique for the periods 1993-97 and 2003-2007 and as Head of the Mechanical Engineering Department in 1995-97.
About the Lecture Series:
The "Simon Stevin Lecture Series on Optimization in Engineering" is set up in order to promote optimization in engineering. For this aim, every quarter of the year an outstanding international scholar is invited to report on latest progress in the development of optimization algorithms and their applications in engineering.
Simon Stevin (1548-1620) was a Flemish mathematician and engineer. Among other, he helped to advance the use of decimal fractions, was the first to explain the tides by the attraction of the moon, and discovered the hydrostatic paradox. He made numerous inventions, among them a wind propelled carriage with sails, the "land yacht", which once impressed Prince Maurice of Orange as it moved faster than horses, in around 1600 on the beach between Scheveningen and Petten. Simon Stevin was fond of promoting the use of science in daily life and in craftmanship, and translated various mathematical terms into dutch. Among other, he introduced the dutch word for mathematics, "wiskunde".
Directly after this winter's Simon Stevin Lecture, a little reception will be given at 18:00 in the salons of Arenberg Castle, to which all attendants of the lecture are most warmly welcome!
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Please send an e-mail with the subject "STEVIN" to optec.secretariaat@esat.kuleuven.be if you intend to participate in the event. No obligation, just to help us getting an idea how many people plan to come.
This Stevin lecture is co-sponsored by ICCoS (Identification and Control of Complex Systems), a Scientific Research Network of the Research Foundation - Flanders (FWO-Vlaanderen).
