Design of Controllers for Disturbance Attenuation of Uncertain Systems

In this paper we discuss the design of controllers that provide a desirable disturbance attenuation level (through an appropriately small L2 gain) for systems with structured uncertainty. Recent progress in solving linear matrix inequalities is exploited to simplify the design process and reduce conservatism. In particular, it is shown that for a class of systems, the problem of designing dynamic output feedback can be separated into two stages, each an easily solvable convex problem. This information could be used in system design and configuration (e.g., the actuators and sensors are chosen so that the design stage is simplified). Two examples are presented to illustrate the proposed approach.