INNOVATION November-December 2017

F E A T U R E

outflow path is invisible to the public and a need arises for stakeholder communication. Over the course of moving tens of thousands of 40-tonne truck loads of material necessary for just a creek foundation, engineers and biologists working on these projects use UAVs to capture high-definition videos and still images of the progress. UAV flights are typically a few minutes, often consisting of a flyover to provide an overview that can be coupled with a narrator’s voice-over to explain the work and then uploaded to the company’s website. This allows for rapid communication with stakeholders that is less expensive and provides a more intimate view angle as the UAV can fly lower than a helicopter. Photographic data collected is occasionally used to build 3D models. As the habitats are reconstructed, UAVs are being used to develop geospatial databases of habitat elements to enable monitoring of river habitat stability. Some mines also retain other operators to rapidly build 3D models using photogrammetric methods with UAV data when surveys are required of complex areas such as inaccessible bench faces or material stockpiles. UNDERGROUND MINES Underground mines represent a significant challenge but also a huge opportunity for UAVs. The underground mining environment can be confined, with dark, wet and intervening rocks that can interfere with control link radio signals. The same environmental issues that make it difficult to operate a UAV also make it desirable. Many areas of underground mines are unsafe or impossible for personnel to access, yet information about the condition of these areas can be critical to planning operations. Similarly, the crowns of tunnels, particularly rail and traffic can be difficult to access for close inspection. The problem of lighting has been addressed by adding high-powered LEDs and/or fitting the UAV with LiDAR units. Onboard lighting can often allow UAVs to capture photos of sufficient quality to build 3D models using conventional photogrammetric methods. The issue of confined space means that the UAV must be flown by a very experienced pilot, with

stockpile surveys were conventionally conducted using time-consuming and less accurate crest and toe surveys. UAV surveys are now faster, safer, and more accurate than conventional toe and crest surveys. LiDAR (light detection and ranging) is one of the more exciting additions to the UAV sensor suite, with sensors weighing two kilograms or less. In addition to allowing UAVs to replace conventional full-sized aircraft as LiDAR platforms over smaller areas, LiDAR combined with advanced flight controllers allows some UAVs to avoid obstacles and in some cases navigate entirely autonomously where regulations allow. LiDAR on UAVs tends to be accurate to +/- 10 centimetres and offers significantly higher resolution than traditional aerial LiDAR. Perhaps most exciting are the advances in collision avoidance and position hold technology. Previously, UAVs were dependent on a GPS signal or constant user input to hold position. Now, with optical flow, sonar, and, in some cases, LiDAR-based collision avoidance, UAVs can be used in a wider variety of settings such as underground mines and complex infrastructure surveys such as the underside of bridges. Current Transport Canada regulations require the UAV to stay within visual line- of-sight at all times while operating on the surface but this technology already has significant applications in underground mining, warehouses, and other controlled GPS-denied environments. Transport Canada’s approval in November 2016 of the Foremost Unmanned Aircraft System (UAS) Range in Alberta provides companies with a safe and legal location to test UAVs outside of visual line-of-sight. With ever-increasing flight times and improvements in collision avoidance, we could see approval of autonomous UAVs flying pre-programmed missions while actively avoiding obstacles, which could have huge implications for linear infrastructure inspections. TAILINGS DAM FAILURE RESPONSE The failure of tailing storage facilities can release outwash materials into downstream waterway corridors, causing the area to be immediately closed to the public because of safety. As a result, the work that follows to control erosion and reconstruct the creek/

improved, most notably, GPS units, with several units now supporting real time kinematic (RTK) GPS onboard. The addition of RTK GPS has removed the need for ground control points and allows UAVs to replace conventional site surveys. This massively improves UAV application to mining, minerals, and aggregates where

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