Automated volume analysis of open pit mining productions based on time series aerial survey   Zsolt Domozi John von Neumann Faculty of Informatics Óbuda University Daniel Stojcsics Andras Molnar 11/11/2018

Outline Problems of open-pit mine tracking Surveys of artificial surface formations New method in the survey: UAV IT methods for tracking Results 11/11/2018

Mining and tracking problems Mine plan and reality doesn’t always match Truck scales are precises until Truck scales should be certified from time to time Volume and weight is not in the correlation (wet, dry, material type etc) 11/11/2018

Assessment methods: plane and helicopter Special devices: LIDAR, IMU, GPS Well prepared, big staff Too much preparation High operation costs Optimal only on large areas 11/11/2018

Assessment methods: multicopter Complex control is necessary Unfit to measure huge lands High energy demand Excellent to control small areas 11/11/2018

Assessment methods: RC plane Small area to get off and land Optimal for middle size areas Low energy demand Control without pilot license 11/11/2018

Idea: UAV and camera Hobbyking X8 Planned route Autopilot controlled Canon camera with modded firmware 3D modell creation based on classic photos 11/11/2018

Photogrammetry Resolution: 10-24Mpixel (~3cm/pixel) Picture overlap is 60% Search of point-pairs on pictures (Harris algorythm) Build up point-cloud and detect pair errors (RANSAC RANdom Sample Consensus) Create of 3D object 11/11/2018

Investigation of active mine (1/3) Plane weight is 3000gr Planned route Min 50% overlapping between pictures 50km/h speed 150m altitude 597 pictures, 3GByte 11/11/2018

Investigation of active mine (2/3) Area is 600mx600m Every picture has min 3 neighbor Capture location and orientation of the frames can be determined Spatial position of relevant pixels found in the picture can be determined 11/11/2018

Investigation of active mine (3/3) Production of point cloud Triangulation Getting a full Digital surface model and point cloud 11/11/2018

Point cloud problems (1) 3D models created in different years (2015- 2017) Orientation and location (x,y,z) problems Automatic solution to move and rotate models into “one” 11/11/2018

Point cloud problems (2) Every model built up from 20M points Almost impossible to find the best rotation matrix Downscaling is a help to CPUs With the rotation matrix finally we can eliminate the orientation and location problems 11/11/2018

Point cloud as a result 11/11/2018

Tracking: results Photos made about lot of mines with UAV 3D models compared with free 3D models, difference was checked Geodetic measurements made on the introduced mine – just for back-check our calculations Precision of volume calculation based on photogrammetry is excellent Cost-efficient, fast method to calculate volume 11/11/2018

Questions and answers Zsolt Domozi mr.zsolt.domozi@ieee.org Daniel Stojcsics stojcsics.daniel@nik.uni-obuda.org Andras Molnar molnar.andras@nik.uni-obuda.hu 11/11/2018