A delay decomposition approach to H-infinity control of networked control systems

This paper is concerned with H-infinity control of a networked control system (NCS). First, the NCS is modelled as a linear system with an interval time–varying delay. Second, a delay decomposition approach is developed to derive a less conservative bounded real lemma (BRL). Based on this BRL, delay-dependent conditions for the existence of a state feedback controller, which ensures internal asymptotic stability and a prescribed H-infinity performance level of the closed-loop system, are derived in terms of a nonlinear matrix inequality. Third, the nonconvex feasibility problem is converted into a nonlinear minimization problem subject to a set of linear matrix inequalities (LMIs), from which the suitable controller can be designed by an iterative algorithm. Finally, two numerical examples are given to show the effectiveness of the obtained results.