Input-output representation of discrete-time dynamical systems - nonlinear ARMA models

In this paper, the normal form of the state equations is suggested as a convenient starting point for the derivation of input-output representations of discrete time nonlinear systems. In particular, it is argued that the role played by system theoretic properties such as relative degree, observability, and zero dynamics, in both representation and control, is more readily interpreted using the new representation.<
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