H_∞ Controller Reduction by D-R Iteration Method Based on the Free-Parameter

Abstract

In this paper, a new H_∞ controller reduction method which considers to maintain the H_∞ property is proposed. The generalized H_∞-controllers are able to described using free-parameters which are stabe and bounded. If a low order controller can be written with a free-parameter which satisfies the stability and the bounded condition, the low order controller become an H_∞-controller. In order to satisfy the conditions, we employ an iteration method which contains the D-scaling matrix calculation and the balanced model reduction. Some numerical examples are illustrated to show the effectiveness of our method.