Vehicle Navigation System Technology

In recent years people have seen an increasing interest in the development of the automatic vehicle integrated navigation system, which has valuable foreground in military and civil applications. Among all the techniques concerning vehicle location and navigation development, path planning and map matching are crucial components.Considering the requirement of navigation path planning, the design of the geographic information system based on ActiveX component by VC++ is presented, by means of object-oriented design and object-oriented program. Also, the subsystem is integrated path planning subsystem into the automatic integrated vehicular location and navigation system, and it supports not only path planning and vehicle navigation, but also geographic information aided positioning.In this paper, making use of road net to improve the position accuracy of the integrated vehicular location and navigation system is discussed, by addressing on typical structure of geographic information system and aided location techniques' demand for geographic information system. As the car always runs on the road in normal situation and the database of road net has been established in advance before navigating, the error in vertical road direction is eliminated automatically. As the error of along-road-direction is concerned, it is not important for navigating, also it may be eliminated according to the apparent mark along the road by hand when the car is running. A map matching algorithm is proposed to correct the position error in vertical road direction by adding a restricted condition of that the car is running on road. The experimental results show that this algorithm is effective for the improvement of the locating accuracy, reliability and integrity of automatic vehicle integrated navigation system.Path planning according to vector map is widely recognized to be a critical issue in the field of vehicle navigation. By examining fast path planning algorithms used in aided integrated vehicular navigation systems, data structure of navigable electronic map and DBMS are illustrated, and topology based on the database of road net is analyzed, also a high-efficient implementation method of shortest-path searching algorithms is proposed in this paper, which is realized by utilizing heuristic searching algorithm.