Design of robust decentralised controllers using the M−Δ structure robust stability conditions

Abstract

This article proposes a new frequency domain approach to the design of robust decentralised controllers (DC) for continuous-time systems described by a set of transfer function matrices. Nominal stability, required nominal performance and robust stability (RS) are guaranteed using the independent design approach applied for nominal system, adapted so as to satisfy the M−Δ structure-based RS conditions modified for the closed-loop system under a decentralised controller. The proposed design technique enables us to include nominal interactions in the nominal model thus relaxing the conservatism of the RS conditions.

Keywords:

• decentralised control
• frequency domain
• robust stability
• unstructured uncertainty

Acknowledgement

This work has been supported by the Scientific Grant Agency of the Ministry of Education of the Slovak Republic and the Slovak Academy of Sciences under Grant. No. 1/0544/09.