Autonomous Incremental Updating Of Vehicle Navigation Digital Map

Digital map is the data basis for vehicle navigation systems. Since the rapidincreasing of geographic information in China and development of vehicle navigationapplications, the updateness of roadnet in digital map has become a key factor toimprove the performances of vehicle navigation systems. To increase the frequency ofmap updating is an effective way to improve the updateness. So we research onautonomous incremental updating technique for navigation digital map. At first webuilt an automonous road detecting system to obtain incremental data. And wedesigned data structures based on navigation map models, with respect to incrementalupdate requirements. At last an incremental data integration method is proposed toimport incremental data into original structures. The incremental update techniqueenables high frequency updating of navigation digital map. As a result, the updatenessof digital map is improved and the performaces of vehicle navigation systemspromoted.The road detecting system aims to extract unkown road information from vehicletrajectories, and to build incremental road model as an important source of updatingdata. A multi-status trajectory recording machine is applied to collect consecutivemismatched trajectories. We employed procedures of gross error removing, B-Splineapproximation and feature points sampling to get the shape polygon of road segments.Finally the intersection algorithm and user interface export additional attributes tocomplete the incremental road model, which can be used as a standard exchangeupdating format with independence of version.With respect to query demands of various navigation applications, an extensivedata structure of navigation roadnet is designed. Distributed linear list is employed toconstruct extensive structure for vertex block indeces and road segment grid indeces,the expanding pointers reserve storage spaces for incremental data to enable infiniteextending feasibility for incremental updating. We designed a database managementsystem for navigation roadnet based upon this data structures. Standard expansioninterfaces and consistent query interfaces are achieved in this management system,making navigation roadnet extensive, and the navigation applications can queryoriginal and updated data consistently. The navigation local roadnet model is proposed to define the limits of updatingelements, and a standard construction method for this model is designed. Anincremental data integration method is proposed based on local roadnet model, inwhich the updating procedure is compiled to standard operation process for eachfunctional layer. Expansion interfaces of navigation roadnet are employed to achieve aseamless integration. And backup information of updated elements is reserved tosupport inquery and recovery of incremental road.