SA gripper: An underactuated gripper with a 6-bar mechanism in a parallelogram structure

Abstract

This paper introduces an underactuated gripper incorporating a 6 bar mechanism within a parallelogram structure. The proposed gripper features a three-phalanx underactuated finger designed without redundant links or additional joints, enhancing structural simplicity and efficiency. Kinematic analysis was conducted to investigate the gripper mechanism under different object shapes and contact conditions. Additionally, static analysis was performed to examine the force and torque vectors according to the gripper mechanism’s DoFs. The proposed design demonstrated the ability to seamlessly transition between parallel and power grasps through initial prototype experiments. Compared to the initial prototype, the optimized design improved stability and grasping force. The final design was validated through simulations. The results confirm that the proposed gripper effectively adapts to objects of varying shapes while maintaining a simple and efficient mechanism, making it suitable for robotic applications requiring adaptive grasping capabilities.