ABSTRACT
In this paper we consider the problem of designing a robust stabilizing controller with adjustable parameters for a given linear time invariant system. We consider a fixed order controller with transfer function coefficients lying in prescribed ranges. The objective is to achieve optimal gain or phase margin for the closed loop system over the given set of adjustable parameters. The design technique is based on frequency domain properties of interval systems which have been discovered by Chapellat and Bhattacharyya. Numerical examples are given for illustration.
