BIM-based Indoor Path Optimization Method For Public Buildings

Path planning technology,as the basis for realizing spatial services and path guidance,has been rapidly developed and widely used in outdoor environment,which has a positive and important impact on people’s daily life and emergency response.In recent years,with the promotion of urbanization in China,the coverage rate of domestic high-rise buildings has increased year by year,and the urban coverage rate of large public buildings is also gradually increasing.The high volume and high precision of the internal space of public buildings has intensified people’s pathfinding burden,and the increasingly frequent indoor activities have also led to a higher and higher demand for indoor path guidance services,therefore,the application of path planning technology to the complex indoor environments has become the focus of research in the field of location-based services nowadays.However,due to the dimensional differences between the three-dimensional building interior space and the two-dimensional outdoor plane environment,the development of indoor path planning research is relatively slow.The current technology can only realize the generation of the shortest path between two points in the building.This result may meet the basic planning needs of simple buildings,but for some large public buildings with precise structure and complex environment,the shortest path is often not the best path.In the internal space of public buildings,there are often a variety of cross floor access ways,such as stairs,escalators and vertical ladders.Different access ways not only have differences in distance,time consumption and other aspects,but also have different feedback feelings to human body.Therefore,the judgment of path priority should be based on the actual needs of users,rather than simply depending on the length of path distance.In summary,in view of the existing problems of indoor path planning technology,combined with the judgment logic of path optimization,this paper takes public buildings as the research object,proposes a BIM(Building Information Modeling)based indoor path optimization method for public buildings.The specific research contents are as follows:(1)The road network model construction method of classified definition node.In this paper,BIM is used as the data source,parametric model is established as the planning platform,according to the research of IFC industrial standards and entity inheritance relationship,combined with component information extraction method,the extraction method of seven types of road network nodes in building space is proposed,and the spatial topological relationship between horizontal and vertical directions is added to the nodes to build the indoor multi-layer spatial road network model,It provides platform support for the follow-up research of path optimization planning.(2)Optimal path generation method based on demand.Through investigation and analysis,the distance,time consumption and comfort are listed as the influencing factors of path priority.On this basis,the evaluation method of path optimization is proposed.By analyzing and comparing the traditional path planning algorithm,combined with the characteristics of the space environment of public buildings,the heuristic A* algorithm is optimized and improved,and the cross floor application of the algorithm is realized.Then,combining the routing algorithm with the optimization evaluation logic,the calculation method of different attributes of the path is proposed to realize the path generation based on the user’s needs,which ensures the real significance of the optimization of indoor path planning.(3)Mobile terminal indoor path optimization system design.Based on Web GL 3D display technology,via the data format conversion,Delaunay triangulation processing,data lightweight processing and model data rendering for mobile web end,an indoor path optimization system for mobile end is designed.The system is based on B/S architecture and adopts HTML5 standard design,which can not only carry out model-based translation,zooming,cutting and rendering,but also realize the web-side visualization display and application of road network extraction,path optimization planning,path roaming and other functions,meeting the current people’s path planning needs for the internal space of public buildings.