Comments on model reduction by minimizing the equation error

Abstract

Minimization of the equation error is a well-known and powerful tool, which has been introduced to the reduction of time-invariant linear systems independently by Obinata and Inooka [1], [2] and by Eitelberg [3]-[5]. The purpose of this note is to examine critically the methods in [1], [2] and to propose to the readers of IEEE TRANSACTIONS ON AUTOMATIC CONTROL an altenative formalism, which has been tested successfully on systems of high order [3]-[5].