Construction of Flat Outputs of Nonlinear Discrete-Time Systems in a Geometric and an Algebraic Framework

: This paper introduces a method for the construction of fiat outputs of nonlinear discrete-time systems which is based on the idea of finding state- and input transformations which split the system into a smaller-dimensional subsystem and an endogenous dynamic feedback. If such a transformation exists, the complete system is flat if and only if the subsystem is flat, and thus in the next step we can proceed with the smaller-dimensional subsystem. We show how to find the appropriate coordinate transformations in a geometric and an algebraic framework, which are both well-established for the analysis of discrete-time systems.