Aerial Rock Fragmentation Analysis in Low-Light Condition Using UAV Technology T. Bamford 1 K. Esmaeili 1 . Schoellig 2 A. P 1 Lassonde Institute of Mining University of Toronto 2 University of Toronto Institute for Aerospace Studies University of Toronto APCOM, August 2017 Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 1 / 26
Forecast We use UAV technology to frequently measure rock fragmentation. In this work we found that: Lighting conditions greatly impact photographic analysis accuracy Artificial lighting applied evenly can improve prediction accuracy and enable measurement in low light conditions Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 2 / 26
Outline Motivation and Problem Statement 1 Related Work 2 Methods 3 Results 4 Summary 5 Future Work 6 Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 3 / 26
Table of Contents Motivation and Problem Statement 1 Related Work 2 Methods 3 Results 4 Summary 5 Future Work 6 Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 4 / 26
Motivation Post-blast rock fragmentation influences: Comminution energy consumption Mill throughput rates Digging and hauling equipment efficiency Measuring it is important for optimizing a mining operation. Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 5 / 26
Motivation Unmanned Aerial Vehicle (UAV) technology can measure rock fragmentation: Provide higher spatial- and temporal-resolution data Automate data collection Collect from typically inaccessible and hazardous areas Improve safety for technicians Frequently measure surface to predict internal distribution Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 6 / 26
Problem Statement To frequently measure rock fragmentation consider: Night shifts in surface mines Underground working conditions However, UAVs equipped with common cameras in poor lighting: Difficult to delineate particles Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 7 / 26
Problem Statement Two questions this work investigates: How much does poor lighting effect accuracy? Can artificial lighting reduce this effect? Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 8 / 26
Table of Contents Motivation and Problem Statement 1 Related Work 2 Methods 3 Results 4 Summary 5 Future Work 6 Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 9 / 26
Related Work Limitations for photographic and 3D measurement of rock fragmentation: Limit Photographic 3D techniques Measure surface not internal distribution � � Particle delineation error � � Perspective distortion � Inability to meaningfully detect fines � Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 10 / 26
Related Work 3D techniques using LIDAR and stereo imaging control some limitations, however: Have not enabled automated measurement Currently capture from fixed locations Addition to UAV can be expensive Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 11 / 26
Table of Contents Motivation and Problem Statement 1 Related Work 2 Methods 3 Results 4 Summary 5 Future Work 6 Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 12 / 26
Methods Compare UAV rock fragmentation measurement using commercial image analysis software with sieve analysis in different lighting conditions for: Controlled lab environment Outdoor Experiment Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 13 / 26
Methods Compare UAV rock fragmentation measurement using commercial image analysis software with sieve analysis in different lighting conditions for: Controlled lab environment Outdoor Experiment Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 14 / 26
Table of Contents Motivation and Problem Statement 1 Related Work 2 Methods 3 Results 4 Summary 5 Future Work 6 Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 15 / 26
Results Raw and delineated photos in ideal (a) and dark (b) lighting. a) b) Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 16 / 26
Results Rock fragmentation analysis results for indoor environment. Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 17 / 26
Results Illuminance Amount of luminous flux per unit area [lx] Error Area between sieve and estimate curves [percent passing × log(mm)] Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 18 / 26
Results Distribution error plotted with illuminance measurement for indoor environment. log(mm)) ambient lighting 10 Very Dark Dark Indoors Dim a 8 Normal Indoors Error (%passing 6 Uneven Lighting b 4 a a c d Artificial Lighting 2 10 1 10 2 10 3 Illuminance of pile (lx) Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 19 / 26
Results Rock fragmentation analysis results for outdoor experiment. Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 20 / 26
Results Distribution error plotted with illuminance measurement for indoor environment. log(mm)) Without Artificial Lighting ambient lighting a 8 Pitch Black Very Dark Dusk Error (%passing Cloudy 6 Artificial Lighting 4 c a b 10 0 10 1 10 2 10 3 10 4 Illuminance of pile (lx) Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 21 / 26
Table of Contents Motivation and Problem Statement 1 Related Work 2 Methods 3 Results 4 Summary 5 Future Work 6 Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 22 / 26
Summary In this work we found that: Lighting conditions greatly impact photographic analysis accuracy Artificial lighting applied evenly can improve prediction accuracy Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 23 / 26
Table of Contents Motivation and Problem Statement 1 Related Work 2 Methods 3 Results 4 Summary 5 Future Work 6 Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 24 / 26
Future Work Items that have been raised during this work: Test concepts in a mining environment Incorporate measurement uncertainty into analysis Configure better cameras (ex. high dynamic range) Light inaccessible areas Increase control over image analysis Understand trade-offs using 3D techniques Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 25 / 26
omre-researchgroup.com dynsyslab.org Thank you! Thomas Bamford thomas.bamford@mail.utoronto.ca Bamford, Esmaeili, Schoellig (UofT) Rock Fragmentation Analysis Using UAV APCOM 2017 26 / 26
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