A Gripper System for Robustly Picking Various Objects Placed Densely by Suction and Pinching

摘要

Suction is an effective method for picking various objects because it makes trajectory planning and control easy. However, suction has not been used due to misalignment and leakage of suction air when handling a variety of shapes. We therefore develop a hand to handle these characteristics. First, we model the vacuum pump and pad characteristics to allow evaluation of momentum and suction force in the case of leakage. Utilizing this, we select a configuration suitable for the items in the Amazon Robotics Challenge 2017. In addition, we design a mechanism for switching from suction to pinching for grasping items that cannot be sucked. Moreover, robust pinching is made possible by equipping the fingertips with a passive linear motion mechanism. In the Amazon Robotics Challenge 2017, it was shown possible to stably grasp items with irregularities and items with large moments. Furthermore, items that cannot be grasped by suction can also be grasped robustly by switching to the pinching mechanism.