Parametric Computation of Hα Norm of a System

While the computation of H_infin norm of a system is one of the most important theme in H_infin control theory, most of the algorithms proposed so far are numerical ones and cannot be applied to the system with a parameter. In this paper, we propose an algorithm to compute H_infin norm of a system with a parameter k. The H_infin norm is expressed in the form of 1/radic(Psi_q(f(q, k), l_i)) (v_i<k<v_i+1), 1/radic(Psi_q(f(q, k), m_i)) (k=v_i) (v_iisinR, l_i, m_iisinN), where Psi _q(f(q, k), l) denotes l-th real root of bivariate polynomial f(q, k) with respect to q