论文标题
具有双向可调刚度的生物启发的软执行器的设计和刚度分析
Design and Stiffness Analysis of a Bio-inspired Soft Actuator with Bi-direction Tunable Stiffness Property
论文作者
论文摘要
调节软致动器的刚度对于提高与环境的相互作用的效率至关重要。然而，当前的刚度调制机制很难达到高侧向刚度和同时达到较大的弯曲刚度。在这里，我们从手指的解剖结构中汲取灵感，并提出双向可调刚度执行器（BTSA）。 BTSA是一种软韧带杂交结构，结合了空气式杂种致动（ATA）和骨状结构（BLS）。我们开发了一种相应的制造方法和一个刚度分析模型，以支持BLS的设计。结果表明，BLS对弯曲变形的影响可以忽略不计，远端距离误差小于1.5 mm。此外，事实证明，双向可调刚度是功能性的。 ATA可以将弯曲刚度从0.23 N/mm调整为0.70 N/mm，其放大倍率为3次。与无BLS相比，BLS的添加可提高到4.2倍，并且可以将侧向刚度在1.2到2.1次以内调谐（例如，当弯曲角为45度时从0.35 N/mm到0.46 N/mm）。最后，开发了四个BTSA抓手来进行水平提升和抓握任务，以证明BTSA的优势。
Modulating the stiffness of soft actuators is crucial for improving the efficiency of interaction with the environment. However, current stiffness modulation mechanisms are hard to achieve high lateral stiffness and a wide range of bending stiffness simultaneously. Here, we draw inspiration from the anatomical structure of the finger and propose a bi-directional tunable stiffness actuator (BTSA). BTSA is a soft-rigid hybrid structure that combines air-tendon hybrid actuation (ATA) and bone-like structures (BLS). We develop a corresponding fabrication method and a stiffness analysis model to support the design of BLS. The results show that the influence of the BLS on bending deformation is negligible, with a distal point distance error of less than 1.5 mm. Moreover, the bi-directional tunable stiffness is proved to be functional. The bending stiffness can be tuned by ATA from 0.23 N/mm to 0.70 N/mm, with a magnification of 3 times. The addition of BLS improves lateral stiffness up to 4.2 times compared with the one without BLS, and the lateral stiffness can be tuned decoupling within 1.2 to 2.1 times (e.g. from 0.35 N/mm to 0.46 N/mm when the bending angle is 45 deg). Finally, a four-BTSA gripper is developed to conduct horizontal lifting and grasping tasks to demonstrate the advantages of BTSA.
