Mixed Method of Routh and ISE Criterion Approaches for Reduced-Order Modeling of Continuous-Time Systems

Abstract

A mixed method using the advantages of Routh approximation method and integral-squared-error criterion is proposed for obtaining stable reduced-order models for high-order continuous-time systems. The reduced-order model tends to approximate the transient portion of the system response in the sense of minimum mean-squared-error, while the steady-state portion is matched exactly. Instead of actually evaluating time responses of the system and the reduced-order model, a matrix formula is used to calculate the integral-squared-error from the error transfer function.