Introducing Building Indoor Topology Model (BITM) to Store Indoor Topology and Supporting Semantic Objects for Indoor Navigation

Abstract. Indoor navigation models are a key part of indoor navigation systems, especially in microscale routing. Nowadays, indoor navigation approaches are using semantic information to extract indoor navigation graphs. However, the current algorithms suffer from a lack of detection of the semantics of indoor space. This paper proposes a Building Indoor Topology Model (BITM) for extracting indoor topology from BIM and storing the nodes and edges of the indoor navigation graph. BITM simplifies the complex indoor space by using Space and Portal classes and includes the geometric and semantic information required for the indoor navigation graph. BITM can support all indoor space objects. To clarify the structure and usage of BITM, a UML class diagram and a general approach to converting indoor topology to BITM using CityGML data model are provided. XMLSchema complexity comparison between BITM and three other standard navigation models proves the simplification influence of BITM. Hence, the proposed models can enhance the capability of current services for indoor navigation.