Synthesis of multivariable systems of prescribed accuracy. II. Use of procedures of H-infinity-optimization

Our earlier results [Avtomat. Telemekh., No. 7, 83-95 (1998)] are extended to the general case of multivariable plants. In addition, account is taken of the requirements for the boundedness of control actions in the steady st ate and the presence of polyharmonic noise of measurements. The notion of a radius of the steady stale of a closed-loop system is introduced, and a pr oblem is stated for the synthesis of a controller which ensures the prescri bed radius. Necessary and sufficient conditions of problem solvability are defined on the basis of the procedures of the H-infinity-suboptimal control by way of the choice of weighting coefficients of a quadratic functional o f the optimization which corresponds to the minimax problem.