This paper aims at familiarizing the reader with Stochastic Hybrid Systems (SHSs) and enabling her to use these systems to model and analyze Networked Control Systems (NCSs). Towards this goal, we introduce two different models of SHSs and a set of theoretical tools for their analysis. In parallel with the presentation of the mathematical models and results, we provide a few simple examples that illustrate the use of SHSs to models NCSs.Keywords: Network Control Systems; Hybrid Systems; Stochastic Processes; Stability; Markov Processes
Networked Control SystemsThe expression Networked Control Systems (NCSs) typically refers to feedback control systems for which some of the sensors, controllers, and actuators communicate with each other using a shared communication network. The use of a multi-purpose shared network reduces installation and maintenance costs and adds flexibility, as it permits the system reconfiguration and/or expansion with minimal additional infrastructure costs. In view of this, NCSs are finding application in numerous areas that include the automotive industry, the aviation industry, robotics, process control, and building control, among others.While NCSs are attractive from the perspective of cost of deployment and maintenance, they introduce significant design challenges, because the traditional unity feedback loop that operates in continuous time or at a fixed sampling rate is not adequate when sensor data arrives from multiple sources, asynchronously, delayed, and possibly corrupted. Consequently, NCSs have been the focus of intense study in the last few years [16,25,29]. This paper is focused on two aspects of NCSs that are responsible for important challenges in analyzing and designing NCSs and that are prompting the development of new formal tools to study these systems. This paper is partially based on material presented in a plenary lecture at the 4th IFAC Workshop on Distributed Estimation and Control in Networked Systems (NECSYS'13).