Ik. Konstantopoulos et Pj. Antsaklis, OPTIMAL-DESIGN OF ROBUST CONTROLLERS FOR UNCERTAIN DISCRETE-TIME-SYSTEMS, International Journal of Control, 65(1), 1996, pp. 71-91
Citations number
38
Categorie Soggetti
Controlo Theory & Cybernetics","Robotics & Automatic Control
This paper presents a fast algorithm for the design of robust output f
eedback controllers for linear uncertain discrete-time systems. The al
gorithm utilizes a version of the Broyden-Fletcher-Goldfarb-Shanno (BF
GS) optimization method of conjugate directions and minimizes a perfor
mance index that includes a linear quadratic regulator (LQR) term to o
ptimize performance and a robustness term based on recently developed
bounds. The minimization of only the robustness term which corresponds
to the maximization of the uncertainty bound is also studied. The cas
e of unstructured perturbations in A has been the only one studied in
the robust controller design literature; the present algorithm introdu
ces a unified approach to both cases of unstructured and structured pe
rturbations in the matrices of a state-space model. For the special ca
se of unstructured perturbations in A only, the algorithm is shown to
improve considerably the existing unstructured uncertainty bound. Seve
ral examples, including an aircraft control system and a paper-machine
head box, are presented to illustrate the results.