Researh On Automatic Generation Of Indoor Navigation Network From CityGML

As the base of Indoor Navigation,the generation of navigation network is the key to obtain building interior environment and express the object positions.Traditional methodologies mostly carry out 3D design with 2D plane map of buildings,lacking integrated application of semantic and geometric information.As the semantically-rich 3D data formats,CityGML LOD4 can privide innovative solution to construct network for indoor navigation.Based on practical application demands,this paper addressed the semantic and geometric information of indoor features and proposed a method of indoor network automatic genneration.Also,aiming at the creation error of network in non-convex navigation space,convex decomposition is conducted with the indoor topology optimized.Experiments validate that,the new method is of great practical value and avoids the shortcoming of the existing methods,and thus establishes the foundation for better implementations of indoor positiong and navigation.The major study context in this paper includes as following:(1)Introduction to indoor navigation data standard.This section briefly introduces CityGML and IndoorGML.With integration of these two standard,the paper describes representation of different kinds of information of indoor space and demonstrates their importance for automatically generation of indoor navigation network.(2)Requirement analysis of indoor navigation and parsing process for CityGML LOD4.Based on indoor navigation usual scenarios and demands,this section states key classes available for indoor navigation,and describe parsing process of classes like navigable area,connectivity space,vertical space and non-navigable area.(3)Automatic genneration of three-dimensional network for indoor navigation.Based on network representation of indoor space,this part introduce an automatic method of obtaining three-dimension navigation network.In non-convex navigation space,the calculated centroids fall outside the geometry.The proposed method addressed the problem of inaccurate path and conduct normal network by adopting CGAL algorithms.(4)Implementation of 3d network generation including visualzation and sharing of IndoorGML.CityGML LOD4 semantic model was built by mulitple design and transformation steps using professional tools.Based on key techniques above,the network was created.For built indoor navigation network,the article provides full process of converting the topology stored in database to IndoorGML file.Also,a specific data browser for indoor navigation was developed using open source technology.The developed tool can browse and query relevant information,which completes the navigation data sharing and visual expression.