Proactive supervision control in discrete event systems using Petri nets

The robustness of the supervisory control policies of production systems, considered as discrete-event systems, could be today unsatisfying. In fact, these systems are evolving in a very stormy environment, so that it needs sometimes a modification of the control specifications representing the objectives. To do that, we add a level to the supervisory control, named the proactive level. Its goal is to tune up the reactive level specifications in order to guarantee reaching the objectives. The proactive supervision control is based on a deterministic Petri net and a state vector. The reactive level of the supervisory control allows us to respect the predicates representing the control specifications. The role of proactive level will be then to adjust these predicates according to the objectives trends. An example is presented to illustrate the proposed approach.