DISCRIMINANCE OF CHARACTERISTIC ROOTS AREA FOR INTERVAL SYSTEMS

摘要

This paper describes the existing area of characteristic roots for control systems which are expressed by transfer functions that are composed of interval polynomials. A discrimination method of the number of characteristic roots in a specifiedarea on an s-plane was developed, when a characteristic equation was expressed as an interval polynomial. This paper analyzes an invariance problem of dynamic characteristics such that the dominant roots do not break away from a specified circular area,and presents a discrimination algorithm (i.e., a division algorithm) for the extreme points of the uncertain coefficients. Designing examples of a control system which has a robust performance such that the location of the dominant roots does not varyexcessively, as well as numerical examples for the discrimination method, are presented.