MULTIVARIABLE SYSTEM SIMPLIFICATION USING MOMENT MATCHING AND OPTIMIZATION

A generalised formulation of the moment matching problem, which encomp asses previous formulations and is applicable to non-square continuous and discrete systems, is presented. The formulation entails points ab out which moments can be matched. These points can be specified either by trial and error or by means of optimisation, so that the reduced m odel has desirable properties such as stability and accuracy. Novel pr operties of Pade approximants for non-square systems are elucidated, a nd details of the approach are illustrated by means of examples.