Decentralized control using quasi-block diagonal dominance of transfer function matrices

The purpose of this paper is to present a generalization of the Nyquist array method to blockwise decompositions, which is based upon a new version of block diagonal dominance. An additional flexibility of the proposed method is in partitioning of the system matrices into disjoint as well as overlapping submatrices, which increases considerably the class of control systems which can be designed via block diagonal dominance. Within this framework, the controllers for individual subsystems can be designed independently of each other, so that their union represents a decentralized controller for the overall system.