Three-Dimensional Unique-Identifier-Based Automated Georeferencing and Coregistration of Point Clouds in Underground Mines

Abstract

Spatially referenced and geometrically accurate laser scans are essential for mapping and monitoring applications in underground mines to ensure safe and smooth operation. However, obtaining an absolute 3D map in an underground mine environment is challenging using laser scanning due to the unavailability of global navigation satellite system (GNSS) signals. Consequently, applications that require georeferenced point cloud or coregistered multitemporal point clouds such as detecting changes, monitoring deformations, tracking mine logistics, measuring roadway convergence rate and evaluating construction performance become challenging. Current mapping practices largely include a manual selection of discernable reference points in laser scans for georeferencing and coregistration which is often time-consuming, arduous and error-prone. Moreover, challenges in obtaining a sensor positioning framework, the presence of structurally symmetric layouts and highly repetitive features (such as roof bolts) makes the multitemporal scans difficult to georeference and coregister. This study aims at overcoming these practical challenges through development of three-dimensional unique identifiers (3DUIDs) and a 3D registration (3DReG) workflow. Field testing of the developed approach in an underground coal mine has been found effective with an accuracy of 1.76 m in georeferencing and 0.16 m in coregistration for a scan length of 850 m. Additionally, automatic extraction of mine roadway profile has been demonstrated using 3DUID which is often a compliant and operational requirement for mitigating roadway related hazards that includes roadway convergence rate, roof/rock falls, floor heaves and vehicle clearance for collision avoidance. Potential applications of 3DUID include roadway profile extraction, guided automation, sensor calibration, reference targets for a routine survey and deformation monitoring.

Template-Guided Hierarchical Multi-View Registration Framework of Unordered Bridge Terrestrial Laser Scanning Data

“…Marker-based methods involve placing unique markers in the scanning scene and identifying these markers from the scanned PCD to assist with registration. For example, Singh et al [ 17 ] developed 3D unique identifiers along with a 3D registration workflow for mapping and monitoring applications in underground mines. Ge et al [ 18 ] presented an automated marker-based approach for the registration of unordered scans in complex forest scenes, which can automatically detect the artificial markers and build a geometric network to judge their connectivity.…”

Practical Aspects of Using Modern Laser Scanning Techniques for Measuring Mine Excavations

“…Looking into the future, we should strive for an increasingly better, faster and less time-consuming method of georeferencing (Singh et al, 2021). It can be assumed that the methods used to combine scans can be greatly improved.…”

Mining Geomatics

“…Nowadays, the mineral mining industry is increasingly acquiring spatial data using modern survey platforms such as satellites or unmanned aerial vehicles (UAVs), which perform measurements using active and passive remote sensing technologies [1]. The most common applications of terrestrial laser scanning are for the purposes of inventorying the infrastructure of mine workings [2][3][4], measuring the volume of workings and heaps in underground and open-pit mining operations [5][6][7]. Mobile laser scanning is used to collect information on the location of mine workings equipment [8,9].…”