Planning of scooping position and approach path for loading operation by wheel loader

Abstract

Our group developed a method for planning of scooping point and approach path as a part of our ongoing research on autonomous loading operation of wheel loader at construction sites. The planning of scooping position and direction is obtained through processing pile model. The pile model represents shape and volume of the pile, changes of shape and volume by scooping, and falling behavior accompanied scooping. Scooping direction should be perpendicular to slope of the pile to avoid unbalance of resistance force around the center line of the bucket. The resistance force imposed on the bucket is estimated using the pile model and bucket trajectory model. The scooping direction with least unbalance of resistance force is selected. V shape path between the scooping position and the loading position to dump track is composed of straight lines and clothoid curves. For given scooping position and loading position, the path with the least length is produced by the proposed planning method using optimization by Lagrange multiplier. For selection of the next scooping point, V shape paths for candidate of scooping points are planned by proposed method.