Ore Pile Model for Scooping Task Planning.

This paper proposes a computer model of ore pile for scooping task planning. Ore pile has irregular shape which changes during scooping operation. For the effective task planning in the autonomous scooping system, it would be required to predict the change of pile shape due to gravity flow of rock, initiated by scooping.The proposed model is composed of column elements which simplify the structure and shorten the processing time. The working place is tessellated into sections which are bases of the columns. The hight of a column represents the hight of ore at the center of corresponding section. However, the size of each section and the unit hight of column are not coincident with particle size of ore. The model represents the shape, mass and falling behavior of the pile under the assumption which simplifies the falling motion of ore particles.The small scale experiment of scooping in laboratory shows that the predicted shape and the measured shape after each scooping are consistent with each other, and the predicted and measured scooped volume at each scooping are agree very well. The proposed model has sufficient accuracy and performance for the scooping task planning.