GPS Floating Car Research Methods To Obtain Real-time Speed Based On Road

Along with the continuous development of social-economy, urban expansion and urban traffic congestion situation is growing worse. In order to protect the smooth traffic of Chongqing.The municipal government decided to build the "Chongqing comprehensive transportation information platform". It is a platform which realized acquisition and convergence the information of distributory road network in Chongqing. And the road speed information collection is particularly important. This article is relying on traffic information platform construction. Carried out covering the main city of Chongqing’s GPS floating vehicle speed algorithm, this way to achieve the monitoring of the operation of the urban road network.GPS floating car is a convenient and effective way to get real-time road speed.This paper firstly introduces the purpose and significance of the research, and the research status of the GPS floating car at home and abroad to sort out, clear the main direction of research, use the taxi as floating cars, integration of more than5,000taxi GPS data, to ensure that the adequacy of the sample size, and the basic theory related to the GPS floating car processing were studied.Secondly, mainly on the GPS floating car data map matching principle and map matching method were studied. On the basis of a variety of pre-treatment on road network (including the topology of road network, road net on treatment, road network gnd treatment), the use of a combination of a variety of map-matching methods, to ensure the matching speed and accuracy of GPS data.Again, this paper based on map matching, carried out the research of shortest path algorithm research, In all kinds of shortest path algorithm on the basis of deep research, we combined with the road network structure, using the A*algorithm on GPS turn delays, the shortest path to achieve accurate search. And the path matching test of each path, ensure the rationality and accuracy.In addition, the operation of the floating car travel speed as the foundation, calculation method of road speed. The polymerization will be floating car travel speed and road speed.At last, this paper evaluated the GPS floating car speed coverage and accuracy of information. Combined with the electronic map, the speed of the spatial distribution and time distribution were assessed using a hand-held GPS instrument, vehicle road test, on the GPS floating car speed compares calculation. We confirmed the reasonableness and accuracy of the algorithm.Proved by practice, the real-time status of the research results of this paper can more accurately reflect the city road, the real-time traffic information collection is of great significance, and has been successfully applied in practical application.