Approximation of high-order systems by low-order models with delays

Abstract

A method to improve the quality of simplified aggregated models of systems is presented. It consists in the introduction of delays in the output vector of the aggregated model to minimize a quality index, function of the output error vector. Necessary conditions to obtain the optimal performance index for a given order model are derived and the solution of the resulting equations is discussed. Finally, two examples are presented to illustrate the method.