Map Matching Algorithm And Software System

Nowadays the development of navigation system for land vehicles is just in the ascendant. It has been widely used in many fields such as physical distribution and intelligent transportation system. The GPS/MM system is one of the preferable projects in the integrated vehicle navigation system. On condition that the accuracy of GPS positioning information and digital map data are both fixed, the map matching algorithm become the key factor in the precision of the navigation and positioning. Hence, it's necessary for us to keep focusing on the map matching algorithm.Firstly, the thesis researches the basic theory of the GPS and GIS, which provide corresponding concepts for researching map matching algorithms with GPS positioning information and digital map data. Based on the point to curve map matching algorithm and fuzzy synthetic evaluation map matching algorithm, three matching modes which are named initial matching mode, tracking matching mode and junction matching mode are founded according to different road topologies by using the Pattern Recognition theory. Combining fuzzy synthetic evaluation and the three matching modes, a novel map matching algorithm named fuzzy synthetic evaluation map matching algorithm based on mode matching is proposed in this thesis. The first step in this algorithm is to form a candidate road set according to the mode of current matching process. The second step is to choose an optimized matching road among the candidate road set by fuzzy synthetic evaluation. In the end, the current position of the vehicle on the selected optimized matching road is determined by perpendicular projection.Secondly, a visualized software is designed by using VC++ 6.0 and MapX control, as well as the map matching algorithm proposed by this paper. Further more, this software provides a software platform with comprehensive functions of sampling and analyzing GPS positioning information out of line, modeling the map matching process and testing different map matching algorithms. Also, it is a well foundation for future research.In the end, the paper compares the new map matching algorithm with the point to curve map matching algorithm and fuzzy synthetic evaluation map matching algorithm by the real road experiments. The result of these experiments testify that the new map matching algorithm can make better matching under some complex road topologies. Meanwhile, this conclusion verifies the validity of the new algorithm.