| Mobile probe has been a new and promising traffic information collection technology. The most potential location technologies for mobile probes currently have been handset-based GPS location technology and mobile handover location technology. Mobile handover location technology is to determine the locations of mobile probes through tracking handovers of on-board mobile phones moving along the road from wireless communication network, which have the advantages of making extensive use of current cellular network infrastructures and requiring no extra changes in the mobile terminals, therefore the researches of traffic information extraction based on mobile handover location technology have become one of the popular topics in the intelligent transportation research at home and abroad. However, the researches of traffic information extraction based on mobile handover location technology have still been premature, and it is lack of systematic and comprehensive theoretical research methods in keeping with the characteristics of mobile handover location technology. Therefore, according to the characteristics of mobile handover location technology, the map matching method, traffic data estimation method, traffic states recognition method and lowest sample size determination method based on mobile handover location technology have been studied and presented. The main contents of the dissertation are as follows:(1) Because the issue of map matching based on mobile handover location technology needs develop a relationship between handovers in the wireless communication network and road network in advance, a handover location database development method was presented based on analyzing the characteristics of handover data of mobile probes, and two map matching algorithms separately based on D-S evidence theory and Bayes decision theory were developed. The results of empirical studies of Beijing inner-suburban freeway sections demonstrate that it is feasible and efficient to geo-locate handover data of mobile probes on the GIS map by the proposed method.(2) Traffic data estimation of handover link and geographic link based on mobile handover location technology were detailed studied in the dissertation. A mobile handover location pre-processing method for reducing the location errors was proposed. Due to the nonuniform and sparse distribution of handover location data after map matching, the issue of traffic data estimation of geographic link was converted to the issue of handover link travel time allocation that includes nodes of the geographic link, which is modeled and solved based on the trajectory analyzing methodology and vehicle moving characteristic analysis. The results of empirical studies of Beijing inner-suburban freeway sections demonstrate that it is feasible to estimate correct traffic data of handover link and geographic link under the condition of mobile handover location data with low location accuracy and nonuniform and sparse distribution by the proposed method.(3) Through analyzing the influence of the features of traffic data estimated from mobile handover location data on traffic states recognition, it is necessary to study the issue of traffic data aggregation. Based on robust estimation theory and methodology, an adaptive robust traffic data aggregation method and a traffic data representation method based on interval numbers with three elements were proposed. And then, a computation model of location association degree of interval numbers with three elements based on the concepts of inclusion degree was firstly proposed, and a traffic states recognition method using speed as a unique attribute was presented according to the rule of maximum association degree; afterwards, density was calculated by Van-Aerde speed-density-flow model, and a traffic states recognition method based on the evidence correction strategy using speed and density as multiple attributes was presented. The evaluation results of simulation of Beijing inner-suburban freeway sections on accuracy and reliability demonstrate that the proposed method is feasible and efficient.(4) Based on analyzing the influence of the characteristics of mobile handover location data on the minimum sample size determination, an appropriate probe sampling strategy for mobile handover location technology was presented. Based on the field test data of Beijing inner-suburban freeway sections and simulation test analysis, the link minimum sample size of mobile probes was determined, which was no more than that determined by the simple random sampling strategy. |
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