Reorientation of a Part by Parallel Gripper Allowing Interference with the Gripper Jaw and Release in an Unstable Orientation

Abstract

In jig-less robotic assembly, robots often need to reorient a part into an orientation suitable for a desired assembly task. In our previous work, we proposed a reorientation strategy to make a transition to a desired orientation of a part with a parallel-jaw gripper by releasing it in an unstable orientation and making it topple under the gravity. However, possible interference between the part and the gripper jaw during the toppling, which may cause undesirable orientational transitions, was not considered. In this paper, targeting two-dimensional shaped parts, we propose an improved reorientation strategy allowing such interference as well as releasing in an unstable orientation, and verify the feasibility of the proposed strategy through experiments.