Model validation of discrete transfer functions using the distortion method

Abstract

The distortion method, developed by Butterfield and colleagues for non-linear systems, is developed for the case of single-and multiple-input linear transfer functions. The assumption of linearity allows expressions for the distortions to be developed analytically, thus significantly reducing the computational cost of the original technique. In the context of transfer function models, the method provides a tool for comparing the performance of one model with another, for example a linearised model of a non-linear system of equations, or of a reduced order model of a high order model.