Kharitonov's theorem extension to interval polynomials which can drop in degree: a Nyquist approach

This paper studies the Hurwitz stability of interval polynomials which can drop in degree from a Nyquist point of view. These families make it possible to deal with system families taking into account different dynamic behaviors in the modeling of a plant. The behavior of the interval polynomials is studied, and it is proven that Kharitonov's theorem can be extended.