Abstract: A BIM-based indoor topology-grid hierarchical path planning method is introduced to solve the problems of large search space, low efficiency, and poor obstacle avoidance safety in traditional methods in complex indoor environments. Firstly, a BIM model with a complex structure is established to extract the obstacles in the model, the semantic and geometric information of the channel, and the correlation information between channels, etc. The basic navigation map is obtained by the grid mapping method, and the map is layered by using the hierarchical map idea to obtain the topology-grid layered map. Secondly, the offline prior road network between each sub-area in the topology layer is generated through a thinning algorithm, and the optimal path is selected using the Dijkstra algorithm. The optimal path of the raster layer is quickly and efficiently searched using the improved A* algorithm. Construct a complete global optimal path by splicing the local optimal path of the topology layer and the grid layer. Finally, Comparing this method with the standard A* algorithm and ant colony algorithm, while ensuring calculation efficiency, it not only reduces the path search space, but also ensures the safety of the optimal path, comprehensively verifying the superiority of the proposed path planning method.

Key words: BIM, semantic information, path planning, Dijkstra algorithm, improved A* algorithm