Investigation of Robotic Material Loading Strategies using an Earthmoving Simulator

A kinematic earthmoving simulation environment was used to investigate job planning strategies which could increase the performance of automated material loading with a robotic compact skid-steered wheel loader. One new problem studied was the subdivision of a larger rectangular workspace using the smaller rectangular Scoop Area (SA). Two methods for selecting scooping approach vectors were also compared: a Zero Contour (ZC) method which assesses all possible perpendicular approaches along the bottom of the slope, and the proposed alternative High Point (HP) method which scoops towards the highest point in the current workspace from a ?xed point. Three jobs were simulated to determine which scooping method and SA dimensions resulted in the highest excavation rate in a truck loading scenario. Assuming the same scoop ?lling effectiveness, the HP method was found to offer a higher rate than the ZC method due to its more limited driving envelope. The maximum HP rates were achieved with SA dimensions which were narrower and longer than with the ZC method, while the optimal SA dimensions were also found to be dependent on the job parameters. When a higher amount of material to excavate per area was present, smaller SAs resulted in higher rates.