Robust stabilization of interval plant family using H/sub /spl infin//-optimization technique

The robust stabilization problem (RSP) of an interval plant family is considered. By representing the nominal plant with the normalized coprime factorization description, the RSP of interval plant family is converted to a particular H/sub /spl infin// control problem. An analytical formula for calculating the parametric stability radius /spl delta//sub max/ of the closed-loop system consisting of the interval plant family and the H/sub /spl infin// controller is given. Using /spl delta//sub max/, the stability margin /spl epsi//sub IP/, of the closed-loop system, described in terms of the H/sub /spl infin//-norm of the uncertain factors in the NCF description, is calculated. Numerical example shows that /spl epsi//sub IP/ is larger than the stability margin of the general unstructured uncertainties case.