Contractibility of overlapping decentralized control

The purpose of this paper is to generalize the concept of contractibility o f decentralized control laws in the Inclusion Principle. After a system wit h overlapping subsystems is expanded into a larger space, and decentralized control laws are formulated for the disjoint subsystems, the laws need to be contracted for implementation in the original space. We propose broader definitions of restriction and aggregation in the framework of inclusion, w hich provide more flexibility in the contraction phase of the expansion-con traction process. In particular, we discuss contractibility conditions for dynamic output controllers including state observers which have been of spe cial interest in applications. (C) 2001 Elsevier Science B.V. All rights re served.