A formalism for decentralized control of discrete event systems

Abstract

We propose a formalism for decentralized control of discrete event systems with communications. The formalism is based on PN/sup 2/, a class of agent-oriented Petri nets proposed by the author (2001). The main difference between PN/sup 2/ and Petri nets is that each token, representing an agent, is also a Petri net. The decentralized control system to be modeled has the following features: (1) the system is asynchronous and has no global clock; (2) some events may occur concurrently; (3) the system is controlled by several control agents, each of which perceives only a subset of occurring events, and can control only a subset of events; and (4) each control agent can communicate with other agents. By communications, each agent can know occurrences of events that are not observable for it, and can ask other agents to disable events that are not controllable for it. Using the formalism, we define a problem concerning control synthesis.