Supervisory arc of Petri nets and its application on traffic signals control system

Petri net is a tool of graphic contributing to system analyzing and modeling. It has a great power on describing concurrencies, conflicts and synchronizations for a distributed system. Additionally, extended Petri nets proposed before not only enrich the representations but also enhance the ability of modeling. This paper proposes a supervisory arc which can simplify the Petri nets, and it is beneficial for modular design. Finally a Petri net of a four-phase signalized intersection for urban traffic signal control system is modeled and simulated, then the function of supervisory arcs is validated from the result.