Distributed implementation of discrete event control systems based on Petri Nets

In this paper, we propose a platform for the implementation of Distributed discrete event control systems. We propose an architecture for the Distributed implementation of Petri Nets (PN) in control applications. The architecture covers the local execution of PN and the communication amongst controllers. Both synchronous and asynchronous communication paradigm is supported. A framework of classes for supporting the real time communication and real time execution or remote calls has been developed. The Real Time Wireless Multi-hop Protocol has been adopted. With this protocol and the framework of classes developed, control deadlines of the system can be guaranteed. In order to solve access to common resources, a new class of communications places, the Auction Communication Places, is proposed. To support the real time and concurrent characteristics, we used the Java real-time specification. In order to implement PN, we have extended the concurrent coordinators technique, developed in previous works, to distributed systems introducing the distributed coordinators. To demonstrate the practical utility and feasibility of the architecture, we have applied it to the control of a flexible manufacturing cell.