A Methodology for Sequential Design of Robust Decentralized Control Systems

A general analysis theory is presented which can incorporate robust performance defined in ¿ framework for sequential design purposes. As a result, a systematic methodology for sequential design of robust decentralized controllers is proposed. To do so, new formulations of linear fractional transformation of complementary sensitivity function and sensitivity function are given. They are used to derive robustness constraints on individual decentralized controllers. When these robustness constraints are satisfied, the closed-loop system is guranteed to possess robust performance if and only if the whole system is nominally stable as well.