An input-output approach to systems described using multiple models

This paper initiates a general theory of systems described by multiple models. A complete characterization of the stability of such a systems is given, based on the concept of stable motion between two states. The approach taken is based on a reformulation of the theory of input-output systems initiated independently by Sandberg and Zames. Our formulation in done in such a way that (1) it permits dealing with local models of a physical system, i.e., mathematical models are only assumed to be valid in a neighborhood on an operating condition and (2) the main stability results of the classical theory remain essentially unchanged.