High-speed Hitting Grasping with Magripper, a Highly Backdrivable Gripper using Magnetic Gear and Plastic Deformation Control

In this study, Magripper, a highly backdrivable gripper, is developed to achieve high-speed hitting grasping executed seamlessly from reaching. The gripper is designed to achieve both high speed and environmental adaptability. The key element is backdrivability in terms of both hardware and control. In Magripper, a magnetic gear is introduced to passively absorb shock in the moment of contact as a means of hardware backdrivability, and backdrive control is implemented based on the Zener model. After developing a hitting grasping framework, high-speed hitting grasping tasks with a wood block, a wood cylinder, and a plastic coin are conducted using only servo control without sensors, such as cameras and tactile sensors. In particular, coin grasping with high-speed movement is very difficult because collisions with environmental objects such as the floor and desk, are likely, which may break a robot.