Abstract 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 empirical characterization of each arm design, post-manufacturing. 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.

中文翻译：

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通过自应力和外部载荷弯曲的软机器人手臂的 Euler-Bernoulli 梁模型

摘要 软机器人手臂在有效建模方面仍然具有挑战性。臂的主要变形是弯曲，伴随着伸展或压缩，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。现有的工作集中在旨在改进控制的模型上，这些模型依赖于每个臂设计、制造后的经验表征。本文提出了一个基于 Euler-Bernoulli 梁理论的准静态模型，该模型可概括广泛的臂设计。该模型是为使用 McKibben 执行器构建的流体驱动软臂实现的。执行器被视为活性材料，它们的力被表征为压力和单轴应变的非线性函数。该模型针对外部载荷下的多个软臂进行了验证，并通过对软臂加载工作空间的调查来证明进一步的使用。更高的负载能力显示集中在手臂的中线。在示例臂设计中检查了远端锥度，与恒定宽度的臂相比，显示出可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排列的变化，并被提议作为软机器人手臂的一阶设计和分析方法。