On the computation of the optimal H-infinity norms for two feedback control problems

Numerical computation of the optimal H-infinity norms for the state feedbac k and the output feedback control problems is considered. In 1989, Doyle et al, derived, for a given parameter r > 0, necessary and sufficient conditi ons under which an admissible output feedback controller exists, as well as conditions for the existence of a state feedback controller. We explore nu merical methods to find the infirnum of parameter r that satisfies those co nditions. (C) 1999 Elsevier Science Inc. All rights reserved.