Due to limitations in geometric representation and semantic description,the current pedestrian route analysis models are inadequate.To express the geometry of geographic entities in a micro-spatial environment accurately,the concept of a grid is presented,and grid-based methods for modeling geospatial objects are described.The semantic constitution of a building environment and the methods for modeling rooms,corridors,and staircases with grid objects are described.Based on the topology relationship between grid objects,a grid-based graph for a building environment is presented,and the corresponding route algorithm for pedestrians is proposed.The main advantages of the graph model proposed in this paper are as follows:1) consideration of both semantic and geometric information,2) consideration of the need for accurate geometric representation of the micro-spatial environment and the efficiency of pedestrian route analysis,3) applicability of the graph model to route analysis in both static and dynamic environments,and 4) ability of the multi-hierarchical route analysis to integrate the multiple levels of pedestrian decision characteristics,from the high to the low,to determine the optimal path.
