A 1-Dof bidirectional graspable finger mechanism for robotic gripper

Abstract

The grasping flexibility and control simplicity are essential requirements for robotic gripper. Take above requirements into consideration, we present a 1-Dof four-bar finger mechanism which could produce bidirectional symmetric grasping motion and exhibit a bidirectional grasping ability like soft gripper. The finger mechanism could not only to grasp the object’s outer surface from outside to inside, but also able to extend itself from inside to outside and “grasp” the inner surface of the object. The effects of structural parameters of the finger mechanism on kinematic behavior have been investigated by kinematic modeling and simulations, and some design suggestions are given. A gripper prototype composed of two finger mechanisms is developed, and the effectiveness of the finger mechanism in bidirectional grasping is validated by grasping experiments. Results reveal that due to the symmetrical movement of the two finger mechanisms, they could apply a pair of symmetrical grasping force to the object and keep the stability of the grasping.