Abstract:  With the in-depth application of building information modeling (BIM) in the phrases of construction, operation and maintenance, the automatic extraction of logical relationship of building electromechanical devices has become a bottleneck for further application. This article proposes an automatic extraction method of logic relationship of electromechanical system based on graph theory. First, the electromechanical system was abstracted as a non-directional connected graph base on the BIM model, and the connector was abstracted as the edge of the graph. Then, the devices, pipelines and pipeline attachments were abstracted as the nodes of the graph. Next, a flat of pipelines were abstracted as a pipeline cluster so that the complex connection could be converted into a simple connection from the device to several pipe clusters. Finally, the problem of automatically generating the logical relationship was changed into the problem of solving the undirected connected graph. This article established a method of extracting the physical connection relationship of electromechanical components, automatically generating logical relations and calculating connection path of devices. In this way, the logical relations can be extracted fast, accurately and intelligently. In addition, the implementation of this method in engineering is beneficial to the operation and maintenance management of electromechanical system based on BIM.

Key words:  building information modeling, electromechanical device, logical relation, connecting path, graph theory, operation maintenance