A switched system approach to scheduling of networked control systems with communication constraints

This paper presents a scheduling strategy for a collection of discrete-time networked control systems (NCSs) subjected to communication constraints. Communication constraints under consideration include medium access constraint, network-induced delays and packet-dropouts. A feedback control system with the communication constraints is modelled as a switched delay system which switches on the open-loop and closed-loop models according to whether the feedback control loop gains access to the network or not. Delay-dependent sufficient conditions for exponential stability with L₂ gain performance are developed for the switched system. Based on the stability conditions, sufficient conditions are presented on the existence of scheduling policy that simultaneously stabilizes the collection of NCSs. Simulation on network-based control of unstable batch reactor systems is performed to demonstrated the effectiveness of the proposed scheduling strategy.