An improved delay-dependent stability criterion of networked control systems

This paper presents a new stability analysis of networked control systems (NCSs) with network-induced delay and packet dropout. A novel augmented Lyapunov-Krasovskii functional (LKF) is constructed, which takes into account the feature of the sawtooth delay induced by sample-and-hold. Based on an improved version of Wirtinger's inequality and the convex combination method, a delay-dependent stability criterion is derived in terms of linear matrix inequalities (LMIs). The advantage of the proposed criterion lies in its simplicity and less conservativeness than some of the existing results. The new criterion is applied to the network-based state feedback control problems. Numerical examples are given to verify the effectiveness of the proposed criterion.