Finite difference solution of discrete-time regulator equation and its application to digital output regulation problem

A method for the solution of the regulator equation for the discrete-time nonlinear output regulation problem is presented. This method is based on solution of the regulator equation by finite differences. Moreover, the algebraic condition guaranteeing zero tracking error is replaced by an error functional whose value decreases to zero in an iterative process. The conditions guaranteeing convergence are shown together with some important details for implementation of the scheme. The method is verified on an example.