Online model composition for networked discrete-event systems

Networked discrete-event systems consist of physically coupled subsystems that utilise a digital communication network for solving their current tasks. Each subsystem has to be steered from its current state into a situation-dependent target state. Due to the physical couplings among the subsystems, certain state transitions have to be executed synchronously with other subsystems to reach the local target states. To satisfy all local tasks, the subsystems have to find a deadlock-free order of the synchronous state transitions by applying global model information. However, in the networked discrete-event system there does not exist any coordinator and the global model information is distributed among the subsystems. Hence, the subsystems have to exchange model information and to compose it online to find the deadlock-free order of synchronous state transitions. This paper proposes an online model composition algorithm based on the A*-Algorithm that determines the necessary local model information to be communicated and composed by the subsystems. The method is demonstrated by an example. Copyright (C) 2019. The Authors. Published by Elsevier Ltd. All rights reserved.