A design of bionic soft gripper for automatic fabric grasping in apparel manufacturing

As a robot end-effector, the soft gripper shows good flexibility and adaptability in the process of grasping the fabric, which provides a new solution for garment production automation. In this article, a soft gripper like a high-heeled shoe was proposed which can separate the fabric layer by layer with high effectiveness. First, by observing the action of human hands grasping fabric, a soft gripper with a fixed finger and a movable finger was designed. Then, the structural parameters, such as the height difference between the fixed finger and the movable finger, the finger’s opening width, and the thickness of cavity of the designed soft finger are determined through force analysis and finite-element analysis. Further, a method was proposed to evaluate the positioning precision after the transportation of cutting pieces. Finally, soft grippers with three different parameters were made by three-dimensional printing to test their performance in grasping fabrics, and the accuracy of separating pieces of fabric layer by layer and the precision of positioning the fabric were tested, respectively. The results show that when the soft gripper with d = 1 mm is used to grasp different fabrics, the accuracy of layer-by-layer separation is above 90%. After the gripper is opened and the fabric is released, the positioning precision of most fabrics gets a tolerance of ±1 mm. Experimental results show that the soft gripper designed in this paper can behave like human hands to operate the motion of grasping fabrics in the manufacturing of garments.