SUBOPTIMAL DISCRETE MODEL-REDUCTION BY MULTIPOINT PADE-APPROXIMATION

A multipoint Pade approximation method is presented for obtaining a re duced order z-transfer function, with a pre-determined denominator, su ch that the square-error-sum of time responses between the full and re duced models is minimized. An extension of the method to matching the initial time response values for impulse and step inputs is also given . The method and its extension are seen to be easy to apply and are ve ry amenable to use on modern computer algebra systems, consisting enti rely of simple matrix operations. Numerical examples are given to illu state the application of the technique. Copyright (C) 1996 Published b y Elsevier Science Ltd