Distributed Nonblocking Supervisory Control of Timed Discrete-Event Systems with Communication Delays and Losses

TL;DR

This paper develops a framework for distributed nonblocking supervisory control of timed discrete-event systems considering communication delays and losses, modeling communication dynamics and deriving conditions for supervisor existence.

Contribution

It introduces a communication automaton model that incorporates delays and losses into the supervisory control of timed DESs, providing necessary and sufficient conditions for supervisor existence.

Findings

Derived conditions for supervisor existence considering delays and losses

Modeled communication channels as automata within the system

Validated framework with an intelligent manufacturing example

Abstract

This paper investigates the problem of distributed nonblocking supervisory control for timed discrete-event systems (DESs). The distributed supervisors communicate with each other over networks subject to nondeterministic communication delays and losses. Given that the delays are counted by time, techniques have been developed to model the dynamics of the communication channels. By incorporating the dynamics of the communication channels into the system model, we construct a communication automaton to model the interaction process between the supervisors. Based on the communication automaton, we define the observation mappings for the supervisors, which consider delays and losses occurring in the communication channels. Then, we derive the necessary and sufficient conditions for the existence of a set of supervisors for distributed nonblocking supervisory control. These conditions are expressed as network controllability, network joint observability, and system language closure. Finally, an example of intelligent manufacturing is provided to show the application of the proposed framework.