Linear system reduction using Pade approximation to allow retention of dominant modes

Abstract

A new method of reduction in order of linear time-invariant systems is introduced. It combines the desirable features of the time-moments and the modal methods of reduction. The methods is based on the concept of Pade approximation about more than one point. The reduced model derived by this method, retains the dominant modes (or any desirable modes) and fits the initial time-moments of the system The method is extended to the problem of reducing a high-order multivariable system described by its matrix transfer function. Several illustrative examples are discussed throughout the paper.