Supervisory Control of Manufacturing Systems Modeled by Timed Petri Nets

Abstract

Petri nets is a common formalism to model many manufacturing systems. Although Petri nets were originally introduced without the notion of time, time-delays in many processes in manufacturing systems makes it necessary to use this notion in Petri nets. Petri nets, in which the time-delays are also modeled are commonly reffered to as timed Petri nets (TPNs). The representation of the state of any system is necessary in order to simulate the system or to design a controller for it. The representation of the state of a TPN, however, is complicated. One method to overcomne this difficulty is stretching. In this paper, the method of stretching is introduced for TPNs where both transitions and places are timed. Supervisory controller design for TPNs using stretching is then discussed