Weighted sensitivity minimization: General plants in H∞ and rational weights

For general plants in H^∞ and rational weighting functions, the problem of computing the weighted H^∞-optimal sensitivity is considered. A general formula is derived for a function v(λ) whose singularities determine the optimal sensitivity [6]. A determinental expression for the optimal sensitivity is then deduced and related to a conjecture of Zhou and Khargonekar [3].