An Euler–Bernoulli beam model for soft robot arms bent through self-stress and external loads
An Euler–Bernoulli beam model for soft robot arms bent through self-stress and external loads
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DOI：
10.1016/j.ijsolstr.2020.09.015
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发表时间：
2020-09
影响因子：
3.6
通讯作者：
G. Olson;R. Hatton;J. Adams;Y. Mengüç
中科院分区：
文献类型：
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作者：
G. Olson;R. Hatton;J. Adams;Y. Mengüç
软机器人手臂的有效建模仍然具有挑战性。手臂的主要变形是弯曲，再加上延伸或压缩，但所经历的应变可能很高，材料通常是非线性的，并且变形很大。现有的工作主要集中在旨在改善控制的模型上，这些模型依赖于每个手臂设计的制造后经验特征。本文提出了一种基于欧拉-伯努利梁理论的准静态模型，该模型概括了广泛的手臂设计。该模型适用于由 McKibben 执行器构建的流体驱动软臂。执行器被视为活性材料，其力被表征为压力和单轴应变的非线性函数。该模型针对外部负载下的多个软臂进行了验证，并通过对软臂负载工作空间的研究来证明进一步的使用。较高的负载能力集中在手臂的中线。在示例臂设计中检查了远端锥度，与恒定宽度的臂相比，远端锥度可以改善运动范围和负载阻力。该模型可用于评估手臂中执行器数量和布置的变化，并被建议作为软体机器人手臂的一阶设计和分析方法。
Soft robot arms remain challenging to model effectively. The arm’s primary deformation is bending, coupled with extension or compression, but the strains experienced can be high, the materials are generally nonlinear, and the deformations are large. Existing work has focused on models intended to improve control, which rely on post-manufacturing empirical characterization of each arm design. This article presents a quasi-static model based on Euler–Bernoulli beam theory that generalizes across a broad set of arm designs. The model is implemented for fluid-driven soft arms constructed with McKibben actuators. Actuators are treated as active materials, and their force is characterized as a nonlinear function of pressure and uniaxial strain. The model is validated for multiple soft arms under external loads, and further use is demonstrated through an investigation of the soft arms’ loaded workspace. Higher load capacities are shown to be concentrated at the arms’ midlines. Distal taper is examined in an example arm design, and is shown to improve range of motion and load resistance when compared to a constant width arm. The model can be used to evaluate variations on the number and arrangement of actuators in an arm, and it is proposed as a first order design and analysis method for soft robot arms.