Research On Multi-constraint Indoor Pathfinding Method Based On BIM Hybrid Road Network

Indoor pathfinding is one of the important issues to guide agents to choose paths in the fields of smart buildings,unmanned driving,and emergency fire protection.Nowadays,agents such as humans spend more time indoors,and their requirements for indoor paths are becoming more complex and diverse.Therefore,it is one of the important problems of current indoor pathfinding to find a path for each agent to meet its diverse needs.At present,the path of the indoor query system mainly takes the shortest distance of a certain type of agent as the main criterion for optimal path calculation,and the pathfinding that satisfies multiple constraints is rarely considered.The development of outdoor route query is relatively mature,but most of its route query methods are based on topological road networks.If the topological road network is also used for indoor route query,it will lead to problems such as the route passing through walls and detours in the queried route.As an important tool for informatization in the field of architecture,Building Information Modeling(BIM)is the digital representation of buildings,including the geometric and semantic information of buildings,and it can provide reliable basic data and good 3D display effects for indoor route query.Therefore,this paper proposes a multi-constraint indoor pathfinding method based on BIM mixed road network.In this paper,the multi-constraint indoor pathfinding method based on BIM mixed road network is studied for different scenarios faced by any agent in daily life and special scenarios requiring K reference paths.In the relevant part of road network,the corresponding triangular road network and topology road network based on grid are established respectively.Triangular road network can better fit the geometric shape of the building,so as to query the passable path in different scenes.The grid network based on topology can better integrate the semantic information in the building into K pathfinding and the path queried through this network can provide more accurate path for people in special scenes.The main contents are as follows:(1)Propose methods on BIM road network construction and indoor pathfinding for multiscene constraints.These theories are mainly according to the daily life with different mobility of any agent facing multiple scenarios,the maximum slope,height of the lowest passable,maximum climbing height and minimum edge buffer width that four parameters for different limit,to create a more scene entities height field and many scene constraints of continuous across the region.After that,simple polygon contour lines and indoor triangular road network are generated to construct the triangular road network under different scenes selected by users.Then,an indoor pathfinding method with multi-scene constraints is proposed to query the shortest paths from the starting point to the end point for different indoor road networks faced by agents with different mobility capabilities.Finally,experiments are carried out on the working scene of sweeping robot,the activity scene of disabled people and the driving scene of vehicles to prove the rationality and feasibility of the proposed algorithm.(2)Propose methods on BIM road network construction and indoor pathfinding for Koptimal constraints.The pathfinding method can provide users with the selection of K optimal paths.Taking the indoor fire scene as the background,this paper will study the indoor fire pathfinding method according to a variety of constraints,that is,integrating the distance constraints,the number constraints of fire-fighting facilities and the number constraints of dangerous areas,and finally provide users with three paths,namely,the shortest path,fire rescue path and safe escape path.Firstly,BIM Technology is used to extract the data and fire information in the indoor grid based topological road network,and build the fire comprehensive road network data.Then,through the design function and adjusting the function coefficient,we can determine the fire integrated road network under multiple constraints.Next,we call the Dijkstra algorithm to generate K paths satisfying multiple constraints,and provide more humane and personalized route selection for fire evacuation.Finally,the feasibility and practicability of this method are verified by experiments and threedimensional display.