Study Of Coordinated Signalized Intersection Control Method In Artery Based On Petri Net

The development of science technology and economy leads to the fast increasing of traffic flow, and the problems of congestion and block are getting serious. The large quantity and complexity of urban traffic, typical traffic control methods and traffic congestion are tough problems that puzzling all the countries around the world. Modern traffic control technologies, aiming to combine advanced computer technology, electronic technology and measure and test technology with traditional transportation is one of the best ways to solve traffic problem. One of important parts of traffic control technology is signalized intersection control.But problems of existing traffic control technology are: Firstly, models that can describe actual intersection control system are not available. Secondly, existing traffic control system often can't be applied in actual intersection with different parameters. It is impossible or difficult to alter the existing system. Finally, the effect of coordinated signalized intersection control method is not satisfied.In this thesis, we've studied above-mentioned problems with theories and methods of Petri net and Genetic algorithm:Firstly the model of signalized intersection based on hybrid Petri net is analyzed. Petri net is a kind of computer system model to describe asynchronous and intercurrent system. It owns not only rigid mathematical expression but also the intuitionistic graphic express way, so it can clearly reflect dynamic changes among the system. Based on the analysis of physical characteristic of signalized intersection system we fatherly discuss the model based on Petri net and the relation of variables between signalized intersection system and model. The value of the model is modularity and general. With kinds of coding tool for Petri net, all you need to do is to make a little change with the code when the variables of actual system changed.Secondly, the optimization timing of signalized intersection has been studied with application of Genetic algorithm. On the basis of the hybrid Petri net model for a single signalized intersection, with the purpose of getting minimum delay of the signalized intersection, Genetic algorithm is applied to optimize the parameters of system and get the optimal timing plan of intersection. Finally, this thesis discussed a coordinated signalized intersection control method in artery based on Petri net. Apply the above mentioned method for single signalized intersection into the control system of multi-intersection coordinated control system in artery. How to achieve optimal offsets in a condition that total delay of multi-intersections in artery is minimal is also studied.