Title :
Frequency dependent model phase reduction using convex optimization
Author :
Scorletti, G. ; Rossignol, L. ; Fromion, V.
Author_Institution :
GREYC Equipe Automatique, ISMRA, Caen, France
Abstract :
Model reduction is a long-standing problem. As model reduction as a frequency domain optimization problem can be conjectured NP-hard, several suboptimal but efficient reduction methods were proposed. The obtained suboptimal reduced model are sometimes far away from the optimal reduced model. In this paper, we propose phase model reduction for obtaining reduced models of stable and strictly minimum phase models, possibly close to optimal model. An efficient solution is presented as a finite dimensional convex optimization problem involving linear matrix inequalities. The motivation for phase model reduction is the practical importance of a good phase approximation. Furthermore, our approach allows to constrain a good approximation on a priori specified frequency intervals, without the introduction of weighting functions. The strong interest of this approach for the model reduction with respect to existing model reduction methods is illustrated by two examples.
Keywords :
computational complexity; linear matrix inequalities; multidimensional systems; optimisation; reduced order systems; suboptimal control; a priori specified frequency intervals; convex optimization; finite dimensional convex optimization problem; frequency dependent model phase reduction; frequency domain optimization problem; linear matrix inequalities; model reduction; optimal reduced model; phase approximation; phase model reduction; strictly minimum phase models; suboptimal reduced model; suboptimal reduction methods; Binary search trees; Control design; Error correction; Frequency dependence; Frequency domain analysis; Frequency measurement; Linear matrix inequalities; Optimization methods; Reduced order systems; Transfer functions;
Conference_Titel :
Decision and Control, 2004. CDC. 43rd IEEE Conference on
Print_ISBN :
0-7803-8682-5
DOI :
10.1109/CDC.2004.1428941