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Gaining Stability of Switched Control Systems
September 23, 2011 — Margareta Stefanovic, Associate professor in
the Department of Electrical and Computer Engineering, was recently
published in Springer Lecture Notes about her work on stability of
switched control systems. Margareta received her education in
electronics engineering at the University of Nis, Serbia in 1996, and
M.S. and Ph.D. in electrical engineering from the University of Southern
California in 2002 and 2005 respectively. Her area of expertise is in
control systems, robust adaptive control of uncertain, data-driven
systems; supervisory and switching control; nonlinear control; and
control in ground transportation, net-centric coordinated control.
The monograph was published by Springer in February 2011, and available from Springer online at www.springer.com
Safe Adaptive Control gives a formal and complete algorithm for assuring the stability of a switched control system when at least one of the available candidate controllers is stabilizing. The possibility of having an unstable switched system even in the presence of a stabilizing candidate controller is demonstrated by referring to several well-known adaptive control approaches, where the system goes unstable when a large mismatch between the unknown plant and the available models exists ("plant-model mismatch instability"). Sufficient conditions for this possibility to be avoided are formulated, and a "recipe" to be followed by the control system designer to guarantee stability and desired performance is provided. The problem is placed in a standard optimization setting. Unlike the finite controller sets considered elsewhere, the candidate controller set is allowed to be continuously parametrized so that it can deal with plants with a very large range of uncertainties.