Design and implementation of shape-adaptive and multifunctional robotic gripper

Abstract

This paper presents a multifunctional underactuated two fingered adaptive grippers for grasping a wide range of objects in different working scenarios. Two layered-based novel multifunctional gripper design is proposed by stacking a multijointed closed-chain mechanism over a multijointed double parallelogram mechanism to achieve a maximum number of grasping techniques. The multijointed closed-chain mechanism is employed to perform power, shape-adaptive grasping, and a multijointed double parallelogram mechanism is used to perform scooping, parallel, and pinch grasping. For stable shape-adaptive/power grasping, the proposed design allows more contact points between the object and the contact surface of fingers as compared to previous gripper mechanisms. Moreover, a complete mathematical model relating the contact forces at the links of each finger to the linear actuation force and spring torque is developed to conduct stability analysis of the proposed gripper design. Finally, simulations and several experiments are performed using real objects in a reconfigurable environment to demonstrate and validate the stable grasping capabilities of the proposed gripper.