Key technologies and engineering practice of 3D laser scanning in coal mine roadways

Intelligent and unmanned mining is an inevitable trend in the development of the coal industry. Precise geological information detection is one of the current key research and development directions in the construction of smart coal mines. The precise detection of information on roadways and the rapid acquisition of three-dimensional roadway models are important data sources for geological transparence. Through a comparative analysis of traditional roadway modeling methods and their advantages and disadvantages, a technical idea of using three-dimensional laser scanning reconstruction technology to construct a high-precision transparent working face roadway model is proposed. On the basis of the analysis of the technical problems faced by long-distance 3D laser scanning in underground coal mine working conditions, the principle of 3D laser scanning and the calculation method of spatial point coordinates are studied, and the realization process of the 3D laser scanning reconstruction technology of the roadway in transparent working faces is proposed. The key technologies of the 3D laser scanning reconstruction technology including the dynamic calibration of the 3D laser scanning system and the coordinate conversion method, the large-scale noise filtering method based on the statistical filtering method in the point cloud preprocessing technology and the small-scale noise filtering algorithm based on moving least squares, the SIFT feature detection algorithm and FPFH feature description algorithm in the point cloud key point extraction and feature description technology as well as the coarse registration technology based on the FPFH feature description algorithm in the point cloud registration technology and precise registration technology based on the iterative nearest point algorithm. Finally, the self-developed mobile 3D laser scanning system is used for practical application in three-dimensional laser scanning construction process, roadway point cloud data collection, boundary contour extraction, and joint modeling of roadways and working faces in working faces of Tangjiahui Coal Mine in Jungar Coalfield. The results show that the idea of 3D reconstruction of roadways in working faces based on 3D laser scanning technology proposed in the paper is technically feasible, providing a feasible technical path for fast 3D scanning and reconstruction of complex roadways.