Development of Spring-Loaded Gripper with Auto Grasping Completion for Soft and Irregular-Shaped Objects

Automation of the food handling process is not an easy problem. Grasping irregular-shaped objects with varying stiffness by robot hands is challenging, especially when the objects frequently change in a short time like Bento box packing lines. This paper proposes a robot finger with an automatic grasping completion mechanism by balancing the force from the objects and the restoring force of installed springs. This mechanism makes the gripper grasp various objects without any setting changes or complicated control algorithms for detecting objects’ shapes and positions even though handling objects may change frequently. We present of the design a robot hand with four proposed fingers and show the effectiveness of the hand by experiments thirteen kinds of food.