Research On Key Technologies Of Urban Dynamic Traffic Guidance Systems Based On FCD

With the urban economic development and cars increasing, traffic congestion has become more and more serious. How to alleviate traffic congestion has been an urgent problem. Intelligent Transportation Systems (ITS) is the best solution for relieving traffic jam, improving travel safety and reducing air pollution. Urban Dynamic Traffic Guidance Systems (UDTGS) is an important part of ITS. UDTGS can provide an optimal path according to the position of car and road traffic conditions in real-time, and distribute the traffic flow reasonably. In this dissertation, a framework of UDTGS based on FCD and KD50 is proposed, and some key techniques of dynamic traffic guidance are discussed. The major contributions and innovations of the dissertation are as follows:1. Based on floating car (FC) collection technology and high-performance computer KD50, a framework of UDTGS is proposed; and the key techniques of this framework are described.2. The Parallel processing flow of FCD on KD50 is studied. The algorithm of FCD's task decomposition and integrating is developed. The multi-task decomposition of FCD, dynamic dispatch of the computing nodes and FCD information synthesis are implemented.3. Some important process of FCD's map matching, such as the pre-processing of FCD, the generation of the candidate roads, local route choice, and calculation method of road average speed are discussed in detail. By using these key processes, a map matching algorithm of FCD with long time intervals on a large-scale network is developed.4. Three preconditions for dynamic route search algorithm are summarized. In the case of short travel time, a dynamic route search algorithm based on the short-term traffic prediction (PDSPT) is designed in order to adapt dynamic traffic road network.5. Based on the study of the key techniques of UDTGS, Beijing traffic dynamic guidance system is designed and implemented. The system performances including processing time, coverage rate of updated road and average sample numbers are analyzed.