Output-based controller synthesis for networked control systems with periodic protocols and time-varying transmission Intervals and delays

In this paper, we will present LMI-based synthesis conditions for designing dynamic output-based controllers for networked control systems (NCSs). In particular, the controller is designed to render a linear time-invariant plant stable given a network that causes the transmission intervals and delays to be time varying and that precludes that all sensors and actuators data can be sent simultaneously. The latter fact necessitates the use of a scheduling protocol and, in this paper, we will focus on a periodic protocol. We will formulate the networked plant model as a discrete-time switched linear parameter-varying system and we will use convex overapproximation techniques to arrive at a model that is amenable for controller synthesis. The controller synthesis result is inspired from controller synthesis results for switched systems and yields a switched controller that is robust for the aforementioned network phenomena. We will illustrate the synthesis results on a benchmark example of a batch reactor, which shows that our novel results can outperform existing results on controller synthesis.