Investigation Of Traffic Control Strategy Based On CPN

Urban Intelligent Traffic Control System is a complicated distributed system with characteristics of synchronization, concurrence, conflicts and resource sharing which coincide with Discrete Event System (DES). Petri Net is a theory developed for modeling Discrete Event Systems, which can reflect event behaviors and states switch of Discrete Event Systems explicitly. As traffic system is a typical DES, this thesis focused on establishing models of traffic flow and traffic control system with Colored Petri Net (CPN). With established models system performance is evaluated due to reports of simulation.In this thesis, measures of calculating green time and real-time strategies of choosing phases are presented after analyzing accumulation of cars. Periodic and non-periodic traffic control strategies are analyzed based on flexibility of phases and synchronous /non-synchronous changing of phases. Targets for maximizing efficiency of intersection utilization and minimizing time delay of each car are implemented by means of reducing time delay for synchronization. And measures of reducing time delay for synchronization make great improvements in system performanceCPN is chosen to establish models of traffic flow and traffic control strategy. In this thesis process of establishing models of traffic flow and traffic control strategies are presented. Then performances of system are evaluated with the ample data gained from simulating CPN models of traffic system. And the quantitative analysis with CPN makes the process of transforming logic control strategies into program easier. This thesis mainly uses CPN for quantitative analysis when Ordinary Petri Net just can be used for qualitative analysis.