Stability analysis and H ∞ output tracking control for linear systems with time-varying delays

The problem of stability analysis and H ∞ output tracking control for linear systems with time-varying delays is studied. First, by construction of a newly augmented Lyapunov-Krasovskii functional, a delay-dependent stability criterion for nominal systems with time-varying delays is established in terms of linear matrix inequalities (LMIs). Second, based on the H ∞ sense, the proposed method is extended to solve the problem of designing an H ∞ output tracking controller to track the output of a given reference model. Finally, three examples are included to show the validity and effectiveness of the presented delay-dependent stability and the H ∞ output tracking controller design.