Research On Real-time Estimation Method Of Urban Link Travel-time Based On GPS Equipped Floating Car

Link travel-time is reflected in the traffic flow at an important indicator. Real-time or quasi real-time travel time data is an important basis to build ITS subsystems, such as dynamic traffic information service system, signal coordination control system and urban traffic guidance systems. ITS is the research hotspot at home and abroad. Properly giving real-time link travel-time has two meanings. For one thing, it can provide accurate traffic data for traffic management department for management, scheduling. For another, it can provide meaningful information for travelers to enable them to choose the appropriate travel routes, and to avoid wasting time and money while improving road network utilization. Therefore, real-time link travel-time estimation on the road is important to run the system.In this paper, traffic information collection technologies are reviewed, the advantages and disadvantages of various collection techniques are compared, GPS floating car technology is chosen as a source of real-time traffic information; Second, the existing link travel time estimation methods were analyzed, focusing on analysis of the floating car method Estimated travel time for a variety of different algorithms; Ultimately, GPS-based floating car real-time urban traffic link travel time estimation method to do an in-depth research. Complete details are as follows:1. Firstly, ways to obtain real-time traffic information and link travel time estimation methods are reviewed. Common traffic data acquisition technologies are introduced, focusing on the GPS floating car technology, including GPS systems, GPS applications in traffic acquisition, GPS floating car technology, the basic concept, working principle and advantages of the system. Describes the various sections of the existing travel time estimation methods, with emphasis on the floating car used in the estimation of link travel time are introduced, such as the sample median estimation method, exponential smoothing estimation methods, based on speed and time estimation methods, combined with test data section estimation method.2. Secondly, real-time travel time estimation method of urban traffic link based on GPS floating car is mainly researched. Analysis of the impact of using GPS probe vehicle data for real-time estimates of travel time factors; given interval estimation method identified in the calculation of the basic ideas and methods; analysis of real-time GPS probe vehicle data preprocessing, including data to identify and repair faults ; improve the GPS positioning data conversion algorithm and the algorithm used in GPS floating car data and electronic map matching method; combined paper on the definition of urban roads, given the real-time link travel time estimation method. 3. Finally, this paper presents the calculation to determine the method of interval, improved GPS positioning data conversion algorithm, real-time link travel time estimation methods as the core technologies, combined with VB technology, a set of demonstration system is developed. Through a section of Guangzhou GPS floating car data, the method is simulated. Practice shows that the proposed real-time link travel time estimation method can provide a reasonable high computing efficiency section of real-time travel time, with certain practical significance.