Liu Lei, Zhang Junshi, Liu Geng, Zhu Zicai, Hu Qiao, Li Pengfei
School of Mechanical and Precision Instrument Engineering, Xi'an University of Technology, Xi'an, China.
School of Aeronautics, Northwestern Polytechnical University, Xi'an, China.
Soft Robot. 2022 Oct;9(5):948-959. doi: 10.1089/soro.2021.0082. Epub 2021 Oct 27.
Compared with traditional rigid grippers, soft grippers are made of lightweight and soft materials and have the characteristics of flexible contact and strong adaptability, which are widely utilized to grasp fragile objects with complex contours and shapes. In this article, we design and fabricate a three-fingered stiffness-tunable soft gripper by integrating the joint-tuning capability. The soft fingers are composed of an internal bending actuator and an external fiber-jamming jacket, under an actuation of pneumatic pressure. Static and kinematic models are established to detect the bending angle and end trajectory of the internal bending actuator. Meanwhile, the bending angle and blocking force of bending actuator are experimentally measured and are comparably analyzed with the theoretical predictions. Jamming pressure is applied in the stiffness-tunable jacket to explore the variable stiffness and load-carrying capability of the soft finger. By incorporating the stiffness-tunable property, the grasping performance of various weights and types of goods, as well as the maximum grasping force of the soft gripper, is investigated. Finally, by patterning the stiffness-tunable jacket on the bending actuator, the variable curvature bending deformation and joint-tuning capability of the soft finger are achieved. This proposed soft gripper holds great potential applications in soft robotics community.
与传统的刚性夹具相比，软夹具由轻质且柔软的材料制成，具有接触灵活、适应性强的特点，被广泛用于抓取轮廓和形状复杂的易碎物体。在本文中，我们通过整合关节调谐能力，设计并制造了一种三指刚度可调的软夹具。软手指由内部弯曲致动器和外部纤维挤压护套组成，在气压驱动下工作。建立了静态和运动学模型，以检测内部弯曲致动器的弯曲角度和末端轨迹。同时，对弯曲致动器的弯曲角度和阻挡力进行了实验测量，并与理论预测进行了对比分析。在刚度可调护套中施加挤压压力，以探索软手指的可变刚度和承载能力。通过结合刚度可调特性，研究了软夹具对各种重量和类型货物的抓取性能以及最大抓取力。最后，通过在弯曲致动器上对刚度可调护套进行图案化，实现了软手指的可变曲率弯曲变形和关节调谐能力。这种提出的软夹具在软机器人领域具有巨大的潜在应用价值。
