Case Study on a Grasping Strategy of a Cylindrical Part along Inner Sides of a Parts Tray Using a Parallel Stick Fingered Hand

In jig-less robotic assembly tasks, parts are assumed to be supplied on a parts tray. If the parts are in contact with the inner side(s) of the tray, it is difficult to grasp the parts with a versatile robotic hand due to the interference between the fingers of the hand and the inner side(s) of the tray. As a case study, in this paper, we address this issue for a cylindrical part, which is often handled in actual assembly tasks, and propose a grasping strategy of the part utilizing pushing operation with a versatile robotic hand with three parallel stick fingers. In the proposed strategy, the part is moved to a position where it is easy to grasp by pushing operation, and then grasped robustly against the variation in the part position based on the permissible initial pose error region of the part. We verify the feasibility of the strategy through experiments.