Use Of Drones in an Underground Mine for Geotechnical Monitoring

Abstract

Geotechnical monitoring is a significant aspect of mining. This includes traditional monitoring with extensometers and stress meters, as well as new technologies which include Lidar, Radar, advanced wireless sensors, and many other new technologies. Underground mining has unique and significant safety hazards compared to surface mining, due to high stress concentrations, weak rock masses, and limited access and air quality. Underground mining methods that utilize large open stopes is one example. After each production blast in open stopes, for example, the rock can become unstable due to excessive vibrations. Since not all the areas inside stopes are accessible, it can be unsafe to put costly production equipment like Load Haul Dump (LHD) vehicles and drilling jumbos inside the stopes. Secondary blasting also becomes hazardous as it requires mining personnel to enter hazardous areas. Traditional monitoring equipment for stope monitoring is ineffective and impractical in most cases, due to the difficulties in placing the monitoring equipment inside unsafe areas of the stopes. The use of a drone can improve safety compared to other surveying systems. In addition, underground monitoring utilizing drones delivers fast results, gives real-time results, and minimizes human exposure in unsafe underground conditions. The mining industry already is benefiting from the rapidly advancing drone technologies. However, most of the drone use now is for is for surface mining, and its use in underground mining is still an area that needs significant research and development. A drone stabilizes itself using GPS, but in certain places and locations, this is not always possible; for example, under a bridge, inside a building or in an underground mine. Also, it is not safe for human personnel to enter all locations in a mine because areas can be dangerous due to loose hanging rocks and unsafe air quality. The unavailability of GPS, the low light conditions, and the confined spaces make it very difficult and challenging to use drones in an underground space, and hence University research in this area is both important and necessary. The research described in this thesis includes the following four areas: 1. Purchasing a drone and demonstrating that it can be controlled and used to capture images in an underground environment with confined space. 2. Developing a solution for drones to work in the dark underground mine environment with the use of specially designed lights attached to the drone. 3. Optimizing the settings in the drone camera to capture images of significant quality and quantity to producing high-density three-dimensional point clouds. 4. Demonstrating that the point clouds produced from underground drone monitoring are enough to extract geotechnical rock mass characteristics and rock mass movement using point cloud processing programs.