Decentralized Supervisory Control of Petri Nets with Monitor Places

Abstract

In this paper we study the problem of determining a set of decentralized monitors for place/transition nets to enforce a global specification on the net behavior given in terms of Generalized Mutual Exclusion Constraints (GMECs). We generalize our previous results in this topic. In particular, the novel contribution here consists in removing the restrictive assumption that the weights of the GMECs must be positive, while we still assume that all transitions are controllable and observable, and the support of each decentralized GMEC is a singleton. The main feature of the proposed solution is that it guarantees fairness among places.

Minimum-time decentralized control of Choice-Free continuous Petri nets

“…Different from the methods in [14,15] for discrete systems, which focus on enforcing states to satisfy certain constraints (specifications), we address the problem of driving the continuous system from an initial state to a specific final one, which is similar to the set-point control problem in a general continuous-state system. Considering the method in [16], systems are targeted to a set of desired states, but when a specific one is chosen, the control complexity may be increased (because more control places should be added).…”

“…The centralized admissibility concept was extended to d-admissibility for the decentralized setting in [14]; based on the d-admissibility concept, two suboptimal methods to design decentralized supervisors are proposed. Under certain assumptions, the methods in [15] focused on global state specifications given in terms of Generalized Mutual Exclusion Constraints (GMECs) and on a control architecture without central coordinator and communication between local supervisors. In [16], a decentralized approach based on overlapping decompositions was proposed; by adding control places, the system is driven from an initial marking to a set of the desired markings.…”

“…This may be done by partitioning the sets of places and transitions as in [14,15], or by explicitly cutting through a set of places [17,18] or transitions [16]. In this paper, subsystems are first obtained by cutting through a set of (buffer) places, then an abstraction and complementing process is applied.…”

Distributed supervisor synthesis for automated manufacturing systems using Petri nets

“…Manufacturing systems often experience dramatic changes thanks to the emergence of intensive market competition and the availability of advanced automation technology [1]- [4], [6], [9]- [12], [17]. To facilitate a quick response to a market change and allow mass product customization, automated manufacturing systems (AMS) are developed.…”

Compact and decentralized supervisors for general constraint enforcement in Petri net models

“…In a PN model of such a system it is usually possible to characterize the structure of each module by identifying the subset of transitions associated to events whose firing can be locally disabled or detected. In [5], [6] a similar framework is considered where each module is defined in terms of a set of places rather than a set of transitions. This setting is less intuitive and significant in practice since, while transitions are generally associated to events, places do not always have a clear physical meaning.…”