Underactuated 3-finger robotic gripper for grasping fabrics

In apparel industries, the handling of fabrics still remains a manual work and its automation is a real challenge. In this paper, a three finger gripper is developed for grasping (pinching and clamping) fabrics under different ways. It is inspired by the human fingers movements in order to grasp a piece of fabric that is laid on a table. The conceptualization, the design and the prototype of the gripper are presented, along with the kinematic and static analysis of its mechanism. The proposed versatile gripper is based on a simple mechanism, where the two of the three fingers (pointer and middle) are underactuated by a tendon. Also, the plan for the sequence and the synchronization of the movements of the fingers is defined according to the grasping task. A prototype of the gripper is produced using 3D printing technique, which keeps the total cost very low. The prototype has been tested experimentally under several grasping tasks, where its agility is demonstrated.