Stable linear systems simplification via padé approximations to hurwitz polynomials

In many problems of control and simulation of a high order system, it is often advantageous to have an appropriate lower order model for approximate design. Introducing the concept of (mixed) Pade approximations to Hurwitz polynomials, a novel method for linear time invariant system simplification is established. The method offers many models of the same order that are stable for a stable system, approximate a desired number of the system eigenvalues near to and far from the origin, and emphasize differently the approximation of the low frequency /steadystate and high frequency /transient responses of the system. The presented method is based entirely on a simple unified Padé technique.