Kybernetika

This paper presents a procedure for constructing a stable decentralized output feedback controller for a class of uncertain systems in which the uncertainty is described by Integral Quadratic Constraints. The controller is constructed to solve a problem of robust $H^\infty$ control. The proposed procedure involves solving a set of algebraic Riccati equations of the $H^\infty$ control type which are dependent on a number of scaling parameters. By treating the off-diagonal elements of the controller transfer function matrix as uncertainties, a decentralized controller is obtained by taking the block-diagonal part of a non-decentralized stable output feedback controller which solves the robust $H^\infty$ control problem. This approach to decentralized controller design enables the controller to exploit the coupling between the subsystems of the plant.