DECENTRALIZED CONTROL AND OVERLAPPING DECOMPOSITION OF MECHANICAL SYSTEMS .1. SYSTEM DECOMPOSITION

This paper improves a new inclusion concept, called 'extension' to mec hanical systems described by matrix second-order equations. Recent wor k on specialization of the inclusion principle has been generalized to the expansion and contraction of input, state and output spaces, but without the possibility of constructing completely general contractibl e controllers. In this paper, necessary and sufficient conditions for extensions and contractible feedback controllers are proved. They enab le the construction of general contractible controllers without any co nstraint on the structure of controllers for mechanical systems.