Asymptotic model matching for nonlinear systems

This paper investigates the problem of designing a compensating control law for a square invertible nonlinear plant so that the response of the closed-loop system asymptotically matches that of a prescribed, driven, nonlinear model. A set of necessary conditions for achieving asymptotic model matching is established. One of these involves the stability properties for subdynamics which are common to every model matching closed loop. These subdynamics, called the “fixed dynamics,” are intrinsically characterized. Based on these results, a new set of sufficient conditions for achieving asymptotic model matching is given. The interrelation between the minimum-phase and vector relative degree properties of a plant and a matchable model are studied