Study Of Method On Centrally Route Optimization Under Large-scale Network

Dynamic route guidance system is an important part of the intelligent transportation systems. Center-type of route guidance can avoid the phenomenon of Braess Paradox, enhance the utilization of network and avoid congestion caused by distributed route guidance. So is recognized as an effective solution to urban traffic congestion and effective way. Currently, conventional serial algorithm is more difficult to solve large-scale road network within the optimal path in a reasonable time. But parallel algorithm can effectively improve the solution efficiency. Based on national natural science foundation of China, this paper mainly researches on centrally route optimization under large-scale network.This paper analyzes the dynamic route guidance research background and significance, reviewed the current international system for urban traffic guidance and path optimization algorithm research, proposed the main idea and content. Expression of the road network and storage methods, the expression of the two connectivity methods were compared, type the path of the center of the road network decomposition algorithm requirements, introduced a variety of network decomposition methods and algorithms and compared, Spectrum of the slice method with the advantages of its introduction to the hierarchical decomposition method to study the spectrum of the points based on hierarchical decomposition method, Taking into account the optimal path algorithm is under the center of a large-scale network-type path optimization an important factor in real time, one-to-all and all-to-all are two types of algorithm parallel algorithms parallel algorithms and improved scalability and efficiency of the method. Parallel computing platform by building validation of the study achieved better results.The thesis comprises of 5 chapters and their contents are as follows:Chapter One: Introduction. First, explain what and why to be investigated in the thesis. Point out the thesis's value both from the perspective of theory and practice, and then summarize the key technologies of the route optimization. After that, the main content and structure of the thesis is given.Chapter Two: The expression of network storage and decomposition method. Large-scale road network in the intersection turn restrictions and intersection delay is more substantial information. Therefore, how to use the structure of economic and reliable network storage structure expression and realistic road conditions in the calculation of optimal routes is particularly important in the process. Introduction and analysis of the commonly used expressions network connectivity and storage methods. Large-scale network is able to split the computational domain, reducing communication time and complexity of follow-up to the purpose of path computation. Research based on hierarchical spectral type of sub-network decomposition method.Chapter Three: Study of Method on Centrally Route Optimization. Large-scale road network is taking into account the huge amount of traffic data. This article provides a new idea to solve the path of large-scale network optimization.Chapter Four: Algorithm verification. This chapter constructs parallel platform to demonstrate the practicality by Simulation and results analysis.Chapter Five: Conclusions and the future work. The thesis is summed up and the research process and the main contents of the thesis are looked back. At the same time, point out the innovation and the existing problems, as well as the problems that need to further study in the future.