Study on Jig-less Assembly of Shaft-shaped Parts with an Improved Versatile Hand with Parallel Stick Fingers

In a flexible robotic production system, robots need to grasp target parts in various shapes accurately even under initial pose uncertainty of the parts, and are expected to achieve assembly tasks with a few versatile robotic hands and no jigs. In particular, shaft-shaped parts, which are assumed to be supplied with their longitudinal directions parallel to a horizontal plane, need to be reoriented toward the assembly phase. In this paper, we present a method to realize jig-less assembly of shaft-shaped parts with a single versatile robotic hand with parallel stick fingers. We improve the mechanism of a versatile hand developed in our previous research in order to achieve reorientation of shaft-shaped parts, and propose manipulation strategy for the improved hand. Moreover, we experimentally verify the feasibility of jig-less assembly according to the proposed method.