Automation of monitoring construction works based on laser scanning from unmanned aerial vehicles

Introduction. Current publications and technologies for digital modeling of construction projects often entail considerable expenses and lengthy project timelines. In order to effectively monitor and control a large number of objects, there is a need to develop laser scanning technologies specifically for unmanned aerial vehicles, eliminating the need for ground-based imaging. Materials and methods. The study employed a hexacopter-type unmanned aerial vehicle equipped with a laser scanner, as well as specialized software for processing aerial imagery and laser scanning data, which included tools developed by the authors. The octant method was utilized when developing an algorithm for point cloud comparison. Results and discussion. In the course of the study, a technology for automating the monitoring and control of construction work was developed, in accordance with which aerial photography is performed once and an orthophotomap of the object is built (to accommodate laser scanning data). Then, with a certain frequency, laser surveys are carried out from an unmanned aerial vehicle, dense clouds of points are formed for different dates. To compare them, a linear computational algorithm has been developed, which, using data on two dense point clouds, allows obtaining the resulting cloud, which reflects the progress in the construction work. A feature of the algorithm is that the search for points is not carried out over the entire cloud, but within the boundaries of octants. This speeds up data processing and reduces the load on computing power. The technology received software implementation in the web application "Management system for monitoring construction work at facilities that have passed the state examination." It allows the user to quickly get a visual representation of the change in the construction object for the selected period, to carry out all the necessary measurements (coordinates, geometric parameters, material consumption, etc.). Conclusions. The developed technology for automating the monitoring of construction work can be used by developers, customers, state and municipal authorities to quickly obtain information in order to control and support managerial decision-making.