A TOKEN PLAYER ALGORITHM FOR THE CONTROL OF TIME CRITICAL SYSTEMS

Petri nets are a powerful formalism for the specification and verification of concurrent systems, such as sequential systems and manufacturing systems. To deal with systems whose time issues become essential, different extensions of Petri nets with time have been proposed in the literature, each one being dependent on the application considered. In this paper, a new control technique for time Petri nets is proposed. It is based on the firing instant notion and it consists in determining an inequalities system generated for a possible evolution (in terms of a feasible firing sequence for the untimed underlying Petri net) of the model considered. This system can be used to check reachability problems as well as evaluating the performances of the model considered and determining the associated control for a definite functioning mode. Furthermore, the proposed approach is not restricted to subclasses or safe Petri nets.