Einladung zum Vortrag im Kolloquium Technische Kybernetik
Feedback: The simple and best solution.
Applications to self-optimizing control
and stabilization of new operating regimes
Prof. Sigurd Skogestad
Department of Chemical Engineering
Norwegian University of Science and Technology
Zeit: Freitag · 14. 7. 2006 · 14:00 Uhr
Ort: Seminarraum 3.241 · Pfaffenwaldring 9 · Campus Stuttgart-Vaihingen
Most engineers are (indirectly) trained to be "feedforward thinkers"
and they immediately think of "model inversion'' when it comes to doing control. Thus, they prefer to rely on models instead of data, although simple feedback solutions in many cases are much simpler and certainly more robust.
The seminar starts with a simple comparison of feedback and feedforward control and their sensitivity to uncertainty. Then two nice applications of feedback are considered:
1. Implementation of optimal operation by "self-optimizing control".
The idea is to turn optimization into a setpoint control problem, and the trick is to find the right variable to control. Applications include process control, pizza baking, marathon running, biology and the central bank of a country.
2. Stabilization of desired operating regimes.
Here feedback control can lead to completely new and simple solutions. One example would be stabilization of laminar flow at conditions where we normally have turbulent flow. In the seminar a nice application to anti-slug control in multiphase pipeline flow is discussed.
Sigurd Skogestad is a professor in chemical engineering at the Norwegian University of Science and Technology (NTNU) in Trondheim. Born in Norway in 1955, he received the Siv.Ing. degree (M.S.) in chemical engineering at NTNU in in 1978. After finishing his military service at the Norwegian Defence Research Institute, he worked from 1980 to 1983 with Norsk Hydro in the areas of process design and simulation at their Research Center in Porsgrunn, Norway. Moving to the US and working 3.5 years under the guidance of Manfred Morari, he received the Ph.D. degree from the California Institute of Technology in 1987. He has been a full professor at NTNU since 1987 and since 1999 Head of Department of Chemical Engineering ( Kjemisk prosessteknologi ). He was at sabattical leave at the University of California at Berkeley in 1994-95, and at the University of California at Santa Barbara in 2001-02.
The goal of his research is to develop simple yet rigorous methods to solve problems of engineering significance. Research interests include the use of feedback as a tool to (1) reduce uncertainty (including robust control), (2) change the system dynamics (including stabilization), and (3) generally make the system more well-behaved (including self-optimizing control). Other interests include limitations on performance in linear systems, control structure design and plantwide control, interactions between process design and control, and distillation column design, control and dynamics.