Distributed switched supervisory control to achieve almost sure safety for a class of interconnected networked systems

An interconnected wireless networked system consists of numerous coupled subsystems that need to exchange information over wireless communication channels. The use of these wireless networks induces a great deal of stochastic uncertainty that often results from deep fades, where a severe drop in the quality of communication link occurs. Such uncertainty negatively impacts the system's performance and causes unexpected safety issues. This paper proposes a distributed switched supervisory control scheme under which the local controller is reconfigured in response to the changes of channel state, to assure almost sure safety for the interconnected system. Here, almost sure safety means that the likelihood of the system state entering a safe region asymptotically goes to one as time goes to infinity. Sufficient conditions are provided for each local supervisor to determine when and which controller is placed in the feedback loop to assure almost sure safety in the presence of deep fades.