Design of a Novel Parallel and Self-adaptive Under-actuated Robotic Hand

This paper proposes a novel mechanism design of the under-actuated robotic hand that can perform parallel and self-adaptive coupled grasping mode. The robotic hand has three 2-joint under-actuated robotic fingers and each finger includes a gear differential mechanism, a link mechanism, a rolling gear and rack mechanism, a gear transmission mechanism and a torsion spring. The under-actuated robotic finger has 2-DOFs and is controlled by only one motor. The finger can realize the coupled grasping mode, which can pinch the object with the distal phalange, and can also use the distal phalange and proximal phalange to envelope the object. By driving 3 under-actuated robotic fingers, the hand can automatically switch parallel grasping mode and self-adaptive grasping mode according to the shape of the object.