A polynomial approach to decentralised control analysis and design

The analysis sis and synthesis problem of decentralised control is consider ed in this paper First, it is shown that the fixed modes of the plant are t he roots of the greatest common unstable divisor of a set of specific polyn omials, and all these polynomials and the closed-loop characteristic polyno mial are explicitly given. Second, if the system is decentralisedly stabili sable, then a novel method is presented to design the local dynamic feedbac k controllers such that the overall decentralised control system is stable. Third, the so-called decentralised concurrent stabilisation problem (DCSP) is investigated and a new algorithm for solving the DCSP problem is develo ped. Several examples are included to illustrate the results.