Nonblocking and deterministic decentralized control for networked discrete event systems under communication delays

Abstract

Nonblocking is an important issue in supervisory control of discrete event systems. In this paper, we investigate nonblocking control for networked discrete event systems. In networked discrete event systems, there are two types of supervisory controls: nondeterministic control and deterministic control. Following the deterministic control, we investigate the nonblocking control problem in a decentralized control framework where communication among the plant and the local supervisors are subject to nondeterministic but bounded delays. We introduce delay co-observability to capture the nondeterminism caused by observation delays. With delay co-observability, we derive a necessary and sufficient condition for the existence of solutions of the nonblocking control problem. When the condition is satisfied, we propose to use state-estimate-based predictive local networked supervisors to control the plant. To illustrate the applications of the results, we consider a black start problem in micro grids.