In this paper we present the by now classical solution of the H, control problem. T h e objective is to present the known results in a manner accessible to the nonexpert. We will conclude with a small design example to illustrate the results. -I l n e notation in chis paper is fairly standard. VVe caii i an invariant zero of the system ( A , B, C, D) if the matrix loses rank for s = S. For a rationai matrix G we denote by rankn( G the rank of G a s a rational matrix. It can J be shown that rankR(*,G is equal to the rank of G(sj for all but finitely many s E C. 2 Main result H, is defined as the linear space of matrix-valued functions which are analytic and bounded in the open righthalf complex plane. -4 rational transfer matrix is in H, if and oniy if the transfer matrix is stable and proper. We endow this space with the following norm: 858 A cv,.nn >.,,L-S I,,,-A 11 ..;A.,C , . O C~V . , J Downloaded by NANYANG TECHNICAL UNIVERSITY on August 24, 2015 | http://arc.aiaa.org |