Research On The Dynamic Path Search Algorithm Based On Cooperative Guidance Optimization Method Of Central And Distributed Guidance System

Currently, the intelligent traffic guidance system is classified into central guidance system and distributed system according to the pattern of path generation. Because of the restrictions such as the bandwidth of the communication network, the cost, the calculation ability of the computer and the memory capacity, the central guidance system cannot meet the high real-time requirement of the transmission and processing of the traffic guidance information of traffic guidance system. At the same time, the distributed guidance system can meet the real-time requirement of the information communication, but the working coverage is much smaller than the central guidance system.Therefore, a cooperative route guidance system is proposed in this paper, which can combine the advantages of central guidance system and distributed guidance system. With the hypothesis of a vehicle vehicular ad-hoc network(VANET), firstly it uses the distributed guidance system to Guide the vehicle entity in a traffic subdomain network, then it uses the central guidance system to realize the route guidance from an overall perspective. Therefore, this method can satisfy the real-time requirement and overcome the Braess paradox in the distributed system.Firstly, it assumes that the traffic state information can be freely share between the vehicles in a subdomain without the traffic control center, which means that the traffic network is a self-organizing network. Base on this assumption, it quantitative analyzes the traffic association degree and the traffic similarity of the section in the road network, then it establishes the guidance sub region dividing method based on the AP clustering principle. This method uses the double threshold controlling way to adjust the boundary of the sub region dynamically.Area dynamic traffic assignment model is established based on the efficient road network partition. This model is designed to allocate the traffic flow to the independent traffic inducing sub zones equally. Through the establishment of the dynamic traffic zone allocation game model based on the Shapley value it can balance the distribution of traffic flow between various traffic sub districts. At the same time, the traffic flow distribution in each sub area conform to traffic assignment model based on the user optimization methodology. This model is constructed to provide the network condition of the network parameters to the cooperative path search algorithm in the following.With the traffic condition parameters, it brings out the cooperative inducing algorithm based on the hierarchical road network. Firstly,according to the traveler’s driving preference,the road network was layered and the different forms of path is analyzed. Secondly, according to the dynamic search limitation of the lower level network of the sub region, it finds out the way to confirm the cross-layer nodes based on the modified *A and then establishes the cross-layer path search algorithm based on*A. Finally,The cooperative path guidance algorithm model is established,which applies the central guidance system to complete the main road network’s traffic flow ‘guidance,and use the distributed guidance system complete the sub regional road network’s traffic flow guidance. The performance of the cooperative algorithm model was verified through an experiment. The simulating result shows that the algorithm model performance better than a single guidance algorithm,which can effectively avoid unexpected incidents and congestion.