Title: A Hand Combining Two Simple Grippers to Pick up and Arrange Objects for Assembly,
Abstract: This paper proposes a novel robotic hand design for assembly tasks. The idea
is to combine two simple grippers -- an inner gripper which is used for precise
alignment, and an outer gripper which is used for stable holding. Conventional
robotic hands require complicated compliant mechanisms or complicated control
strategy and force sensing to conduct assemble tasks, which makes them costly
and difficult to pick and arrange small objects like screws or washers.
Compared to the conventional hands, the proposed design provides a low-cost
solution for aligning, picking up, and arranging various objects by taking
advantages of the geometric constraints of the positioning fingers and gravity.
It is able to deal with small screws and washers, and eliminate the position
errors of cylindrical objects or objects with cylindrical holes. In the
experiments, both real-world tasks and quantitative analysis are performed to
validate the aligning, picking, and arrangements abilities of the design.