This article presents an innovative, motor-driven, three-finger compliant gripper for adaptive grasping of size-varied delicate objects. An optimized compliant finger design is identified numerically through a topology optimization method. A stepper motor is used to actuate three identical compliant fingers, which can operate through elastic bending deformation. Finite-element models are developed to investigate the maximum equivalent stress, input force, and output displacement relations corresponding to the amount of input displacement of the compliant finger. Simulation results show that the proposed finger design is with a lower driving force and a lower maximum equivalent stress during operation comparing to one previous design. The proposed compliant finger is prototyped by three-dimensional printing using thermoplastic elastomer. Experimental results for the input displacement versus input force and input displacement versus geometric advantage relationships of the prototyped finger agree well with simulation results. The developed three-finger soft robotic gripper is mounted on an industrial robot arm to demonstrate its capability in handing size-varied delicate objects, such as egg, fruits, and glass products. Experimental results show that the proposed three-finger gripper can be used to grip object with a maximum weight of 4.2 kg and a maximum object size of 140 mm. The overall weight of the developed three-finger soft robotic gripper is 1.2 kg. The load capacity of the developed gripper can vary according to the friction between gripper and object. The maximum payload of the gripper can be increased to 9.5 kg when an additional antislip foam tape is applied on the grip surfaces of the compliant fingers.

中文翻译：

---

电动三指软机器人夹爪的优化设计

本文介绍了一种创新的，由马达驱动的，三指兼容的抓具，用于自适应抓取大小可变的精致物体。通过拓扑优化方法以数字方式识别优化的顺应手指设计。步进电机用于致动三个相同的顺从指状物，它们可以通过弹性弯曲变形进行操作。开发了有限元模型来研究最大等效应力，输入力和输出位移关系，它们对应于顺从手指的输入位移量。仿真结果表明，与先前的设计相比，所提出的手指设计在操作过程中具有较低的驱动力和较低的最大等效应力。所提出的柔顺手指是通过使用热塑性弹性体的三维印刷制作的原型。原型手指的输入位移与输入力的关系以及输入位移与几何优势的关系的实验结果与仿真结果吻合良好。研发的三指柔软机器人抓爪安装在工业机器人手臂上，以展示其处理大小可变的易碎物品（如鸡蛋，水果和玻璃制品）的能力。实验结果表明，所提出的三指抓爪可用于抓握最大重量为4.2千克，最大物体尺寸为140毫米的物体。研发的三指软机器人抓爪的总重量为1.2千克。显影的抓爪的负载能力会根据抓爪与物体之间的摩擦力而变化。夹持器的最大有效载荷可以增加到9。