During robotic locomotion, shock forces from ground impact propagate through the leg and may cause fatigue or damage to joints and sensitive hardware. To attenuate impacts in diverse aspects and directions, multiple approaches, including active control strategies and passive compliant joints, are essential for providing a comprehensive solution. Here, inspired by human knees, a meniscus-like structure was developed for a compliant anthropomorphic joint to provide a complementary way of shock absorption, especially along the axial direction. The proposed meniscus-like structure comprises a pair of curved arms wrapped with preloaded elastic bands whose elongations produce restoring forces against the axial load. This structure simultaneously realized impact attenuation in three aspects: Decreasing contact stress by designing consistently conformal contact interfaces under axial movement; reducing peak impact forces by tuning load-displacement curves to obtain a high-static-low-dynamic nonlinear stiffness; and dissipating energy by hysteresis due to sliding frictions. The effectiveness in attenuating impacts on robotic legs was further verified by both analytical analyses and impact experiments that it outperforms regular elastic buffers at multiple leg configurations. Inserting meniscus-like structures into anthropomorphic joints efficiently utilized the joint space to attenuate axial impacts, complementing the system of interaction safety for the robot community.

中文翻译：

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拟人关节中的半月板状结构可减轻影响


在机器人运动过程中，地面冲击产生的冲击力通过腿部传播，可能会导致关节和敏感硬件疲劳或损坏。为了减轻不同方面和方向的影响，包括主动控制策略和被动柔性接头在内的多种方法对于提供全面的解决方案至关重要。在这里，受人类膝盖的启发，开发了一种类似半月板的结构，用于柔顺的拟人关节，以提供补充的减震方式，尤其是沿轴向的减震方式。所提出的半月板状结构包括一对缠绕有预加载弹性带的弯曲臂，弹性带的伸长产生抵抗轴向载荷的恢复力。该结构同时实现了三个方面的冲击衰减：通过设计一致的共形接触界面，在轴向运动下降低接触应力；通过调整载荷-位移曲线来降低峰值冲击力，以获得高静态-低动态非线性刚度；并通过滑动摩擦产生的滞后作用耗散能量。通过分析分析和冲击实验进一步验证了减弱机器人腿冲击的有效性，表明它在多腿配置下优于常规弹性缓冲器。将半月板状结构插入拟人化关节中，有效利用关节空间来减弱轴向冲击，补充了机器人社区的交互安全系统。