ABSTRACT
This paper shows that the locus of the Nyquist diagrams of the transfer functions of an interval plant-controller family is bounded by the plots of 32 special segments of the family, generated by the 32 Kharitonov segments of the interval plant. Easy proofs of several important results, such as the generalization of the Theorem of Kharitonov for feedback systems with interval plants or the robust version of the small gain theorem for the same class of systems, are constructed by using the general result. A further immediate consequence of the main theorem is that extremal phase and gain margins or sensitivity and complementary sensitivity peaks for systems of the family can be deduced from the 32 Kharitonov segments of the interval plant family.
