Approximation of optimal moving paths of huge robot reclaimer with a 3D range finder

Abstract

This paper proposes a simple method for approximating the optimal moving paths of a huge robot reclaimer located in the outdoor material stock yard with emphasis on safety, energy consumption, and transfer time. The reclaimer is equipped with a 3D range finder to measure the shape of material piles in the yard, and the material yard is modeled into 3D space where 2D section of grid type is constructed in several layers. To define a safety function against moving between grids, a simplified Voronoi diagram that has a minimized extension error of vertex is used. In addition, the function of energy consumption and transfer time required when the control point of the reclaimer moves between 3D grids is defined. This is used as a cost evaluation factor of path optimization along with the safety function. The proposed method can be readily applied to low-performance industrial control devices.