Reduced Order Solution of Nonstandard H_∞ Control Problem

Abstract

In this paper we derive the reduced order solution of the nonstandard H_∞ control problem where the direct feedthrough term from the control input to the controled output is row full rank or that from the external input to the measurement output is colum full rank. More specificaly, we give a reduced order algeblaic Riccati equation which is one of the solvability condition of the problem and derive the reduced order H_∞ controller. The order of the H_∞ controller is equal to that of the reduced order observer based output controller. A numerical example will show the effectiveness of this result.