Title :
An alternative to the Youla parameterization for H∞ controller design
Author :
Khatibi, Hamid ; Karimi, Alireza
Abstract :
All ℋ∞ controllers of a SISO LTI system are parameterized thanks to the relation between the Bounded Real Lemma and the Positive Real Lemma. This new parameterization shares the features of Youla parameterization, namely the convexity of ℋ∞ norm constraints for the closed-loop transfer functions. However, by contrast to Youla parameterization, it can deal with any controller order and any controller structure, e.g. PID controllers. Moreover, it can be easily used for systems with polytopic uncertainty. For polytopic systems, the proposed parameterization provides a convex inner approximation of the set of all ℋ∞ controllers, which can be enlarged by increasing the controller order. The effectiveness of the proposed method is shown via simulation results.
Keywords :
H∞ control; approximation theory; closed loop systems; control system synthesis; linear systems; three-term control; transfer functions; uncertain systems; H∞ controller design; H∞ norm constraint convexity; PID controllers; Youla parameterization; bounded real lemma; closed-loop transfer functions; controller order; controller structure; convex inner approximation; parameterized SISO LTI system; polytopic uncertainty; positive real lemma; Aerospace electronics; Linear matrix inequalities; Optimized production technology; Polynomials; Sensitivity; Transfer functions; Uncertainty;
Conference_Titel :
Control Conference (ECC), 2009 European
Conference_Location :
Budapest
Print_ISBN :
978-3-9524173-9-3