A Sufficient Condition for the Stability Margin of Control Systems with Interval Set Parameters

Abstract

Parameters of physical systems are uncertain and are accompanied by nonlinearity. The state space equation and the characteristic polynomial of control systems should, therefore, be expressed by an interval set of parameters. This paper examines the stability margin of that type of control system, based on the existing area of characteristic roots (i.e., eigenvalues). Particularly, in this paper, a sufficient condition for the characteristic roots that exist in the sectorial area on the left half s-plane is given by using the result of our previous paper.