Research Of Map Matching Algorithm In The Vehicle Positioning And Navigation System

With rapid social and economic development and fast growth of the number of car users, traffic congestion has become a serious problem causing enormous economic losses and adverse social influence. As an essential part of smart transit, vehicle navigation system is playing a more and more important role in increasing road capacity and improving traffic condition. Map matching algorithm can be useful in helping improve the precision of car locating. At the help of other positioning technologies, the algorithm can help significantly improve the precision of car locating and reduce deviation. Therefore, the effect of map matching algorithm is directly related to precision of car locating. The algorithm is a key technology deciding the performance of any vehicle navigation system.This paper starts with a brief introduction to smart transit system. Then it gives a brief account of the composition, working theory and influencing factors of GPS. In the third part, this paper proposes curvature analysis-based map matching algorithm, pointing out that existing navigation system, such as INS, though characterized by high precision, accumulates error with time. That’s the focus of this paper. The innovation of the algorithm lies in:(1) Douglas-Peucker algorithm is adopted to extract inertial navigation track; (2)Three B spline functions are used to calculate the curvature of the extracted sequential discrete points.Compared with other existing algorithms, curvature analysis-based map matching algorithm enjoys the following advantages:(1)When the best road section is selected for trajectory matching, it will generate strong ability in discerning road sections with different curvatures; (2)when road sections with obvious change of curvature are selected for matching, more precise navigation signal can be obtained so as to provide information source for INS to correct accumulated error; (3) curvature analysis-based map matching algorithm has stronger robustness against location error of INS. In order to better analyze the effect of the map matching algorithm as designed in this paper, MATLAB is used for simulation test of car dada. Test result shows that the map matching algorithm is reliable in timeliness and precision. Especially, it works with great precision for road sections with obvious change of curvature. Therefore, the algorithm has certain value of application. In order to better analyze the effect of the map matching algorithm as designed in this paper, MATLAB is used for simulation test of car dada. Test result shows that the map matching algorithm is reliable in timeliness and precision. Especially, it works with great precision for road sections with obvious change of curvature. Therefore, the algorithm has certain value of application.