Study On Positioning Navigation Subsystem Algorithm In Intelligent Traffic Terminal

With the development of our country in recent years,more and more people have the cars.It can bring convenience but also a lot of serious traffic problems.The majority of scholars at home and abroad put forward and began to study ITS(intelligent transportation system)for the current situation.However,due to the complexity of urban traffic roads and imperfection of some technology,there are still serious traffic congestion.In order to ease the traffic problems,this paper designs the vehicle intelligent traffic integrated terminal.Which can provide real-time traffic information for the driver and achieve driving or parking guidance.At the same time,the terminal is the basis of realizing automatic driving and car networking.The paper studies the key technology of the positioning navigation subsystem which is the core part of the terminal,and a new map matching technology and optimal path planning algorithm are proposed.MM(Map Matching)is the key technology in positioning navigation subsystem.On the basis of the existing algorithms,an adaptive map matching algorithm based on road network topology is proposed in the paper,and different methods are adopted for different sections.The improved maximum threshold buffer method is used to determine the error region.Considering the four weights of vehicle direction,distance,road connectivity and road similarity to calculate the comprehensive matching degree of candidate road segment.The corresponding matching method is also introduced for special sections,such as parallel sections,intersecting sections and urban tunnels.Through the experimental simulation analysis,the algorithm has a great improvement in precision.Another key technology of positioning navigation subsystem is the optimal path planning algorithm.Through the research and analysis of the traditional Dijkstra algorithm,an improved algorithm is proposed from two aspects.In this paper,we design a new data table method which can store the starting point and end point of the road network graph,also insert the weight between two points into it.In addition,paper improves the algorithm structure.Using inverted thinking for the shortest path search based on the data table and the logic is more simple.By testing in the shortest path simulation system designed in paper,the improved algorithm has a faster searching speed and better results.