Robust stabilization of interval plants

A simple necessary condition and sufficient condition for robust Hurwitz stability of interval polynomial is obtained using the results of Nie [13] for fixed polynomials. These conditions provide a simple and quick test to detect many unstable systems. Furthermore, these conditions are used to derive a robust controller for interval plants which involves less computational complexity compared to extreme point results due to Barmish [2]. The proposed method is illustrated by a numerical example.