A new image processing algorithm for three-dimensional angular velocity measurement and its application in a granular avalanche

作者：Lin Cheng Chuan; Yang Fu Ling^*

来源：Advanced Powder Technology, 2018, 29(3): 506-517.

DOI：10.1016/j.apt.2018.02.004

• Grain rotation
• Dense granular flow
• Image processing technique
• Granular avalanche

This work proposes a novel algorithm to extract three-dimensional angular velocity of a sphere from a sequence of high-speed digital images of this sphere and its marker stickers. This technique can capture the angular velocity omega of a sphere made to move at a specific angle from the camera by an offset DC motor and its speed vertical bar omega vertical bar with an error lower than 5%. The method is then applied to measure individual grain rotation dynamics at the boundary during a bulk avalanche to extract the instantaneous contour of each angular velocity component which is in qualitative agreement to that reported from a complementing discrete element simulation. The angular velocity of individual grains vertical bar omega(p)vertical bar is further analyzed with its local packing density and configuration to confirm that the sudden rise of vertical bar omega(p)vertical bar is always accompanied by local dilatation upon particle rearrangement.

• 出版日期2018-3