Decentralized robust control basedon overlapping decompositions

Abstract

Use of overlapping decompositions in robust decentralized controller design is demonstrated. Using overlapping decompositions and expansions, a robustness bound to account for (i) the neglected interactions between the subsystem models on which controller design is to be based, (ii) uncertainties in the interactions, (iii) uncertainties in the subsystem models is developed for the case of uncertain interconnected systems. These bounds are then used in designing decentralized controllers based on local models. The advantage of the proposed approach is that, all uncertaities and neglected dynamics are summarized in one frequency-dependent scalar function and satisfying a simple condition which involves this function guarantees that the overall closed-loop system under decrtralized controllers, which are designed considering local models, is robustly stable