Abstract Recently, a variable stiffness robotic link based on the rotating beam concept has been developed for applications in physical human robot interaction. A substantial challenge for design of such links is the modeling of stiffness behavior to permit stiffness control. In this paper we present a general 3D model of the link stiffness using screw theory and compliance matrices as well as a planar model for the lateral and torsional stiffness. Since axial buckling is a major failure mode, we also derive an analytical model for predicting axial buckling behavior. The analytical models are compared to the finite element method and experimental results. One of the challenges involved in design and analysis of variable stiffness links is the parasitic compliance of the mechanical elements that support and drive the active portion of the mechanism. For the design analyzed in this paper, we use the models we derive to identify the major sources of parasitic compliance and suggest optimizations to minimize their effects. These results can be used as guidelines for designing variable stiffness links.

中文翻译：

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可变刚度柔性连杆的刚度建模

摘要 最近，已经开发了一种基于旋转梁概念的可变刚度机器人连杆，用于物理人机交互中的应用。这种连杆设计的一个重大挑战是刚度行为的建模以允许刚度控制。在本文中，我们使用螺钉理论和柔量矩阵以及横向和扭转刚度的平面模型来展示连杆刚度的一般 3D 模型。由于轴向屈曲是一种主要的失效模式，我们还推导出了一个用于预测轴向屈曲行为的分析模型。将分析模型与有限元方法和实验结果进行比较。可变刚度连杆的设计和分析所涉及的挑战之一是支撑和驱动机构活动部分的机械元件的寄生柔度。对于本文分析的设计，我们使用我们推导出的模型来确定寄生顺应性的主要来源，并提出优化建议以最大限度地减少其影响。这些结果可用作设计可变刚度连杆的指南。