RA-L 20224 citations

Prying Grasp for Picking Thin Object Using Thick Fingertips

Qi Zhang, Zhengtao Hu, Keisuke Koyama, Weiwei Wan, Kensuke Harada

Abstract

Picking a thin object placed on a flat surface is challenging as contact regions are limited. Scooping grasp is a commonly used method for handling thin objects. However, the sharp fingertips are required to achieve the successful scooping motion, which are dangerous. This letter proposes a novel grasping strategy, prying grasp, to pick thin objects using the general fingertips. In detail, the fingertip first rotates to reorient the object. While reaching a critical angle, the gripper switches to a pinch gripping, then contacts the larger sides to achieve a more stable grasp. We theoretically analyze the conditions of the successful prying, and propose a method of failure detection and recovery to improve the robustness. In addition, we experimentally validate the method and compare it with the conventional scooping grasp.

BibTeX
@inproceedings{ral2022_pryinggraspforpi,
  title = {Prying Grasp for Picking Thin Object Using Thick Fingertips},
  author = {Qi Zhang and Zhengtao Hu and Keisuke Koyama and Weiwei Wan and Kensuke Harada},
  booktitle = {RA-L 2022},
  year = {2022}
}