An improved stability criterion of networked control systems with dynamic controllers in the feedback loop

Despite the solid contribution of recent techniques for the analysis of networked controls systems (NCSs), the use of dynamic controllers has received little attention in the literature. Adapting these methods to consider dynamic controllers in the feedback loop is seldom trivial, however, neglecting this class of controllers restricts the universe of applications of these techniques and, consequently, the importance of previous results. In this paper, we establish a new stability criterion suitable for the analysis of NCSs with dynamic controllers. The technique stems from novel Lyapunov-Krasovskii terms and the synthesis of modern techniques for the analysis of time-delay systems adapted to this new scenario. The proposed strategy yields superior results even when particularized for the analysis of NCSs with proportional controllers. Numerical results are provided in order to illustrate the advantages of the proposed criterion and the effectiveness of the theoretical results.