Mixed H2/H∞ control of time-varying delay systems

This paper describes the mixed H₂/H_∞ controller design method of linear systems with time-varying delays in both state and control input. More specifically, the proposed mixed H ₂/H_∞ controller minimizes the H₂ norm of a closed loop system under satisfying a prescribed H_∞ norm bound on some other closed loop system. The sufficient condition for the existence of controller, the mixed H₂/H_∞ controller design method, and the upper bound of performance measure are presented using LMI (linear matrix inequality) technique. Also, all solutions including controller gain and the upper bound of performance measure are obtained simultaneously