Humans possess a remarkable ability to react to sudden and unpredictable perturbations through immediate mechanical responses, which harness the visco-elastic properties of muscles to perform auto-corrective movements to maintain balance. In this paper, we propose a novel design of a robotic leg inspired by this mechanism. We develop multi-material fibre jammed tendons, and demonstrate their use as passive compliant mechanisms to achieve variable joint stiffness and improve stability. Through numerical simulations and extensive experimentation, we demonstrate the ability for our system to achieve a wide range of potentially beneficial compliance regimes. We show the role and contribution of each tendon quantitatively by evaluating their individual force contribution in resisting rotational perturbations. We also perform walking experiments with programmed bioinspired gaits that varying the stiffness of the tendons throughout the gait cycle, demonstrating a stable and consistent behaviour. We show the potential of such systems when integrated into legged robots, where compliance and shock absorption can be provided entirely through the morphological properties of the leg.

翻译：人类具有通过即时机械响应应对突发不可预测扰动的卓越能力，这种响应利用肌肉的黏弹性特性执行自动纠错运动以维持平衡。本文受该机制启发，提出一种新型机器人腿设计。我们开发了多材料纤维阻塞肌腱，并展示其作为被动柔性机构实现可变关节刚度、提升稳定性的应用。通过数值模拟与大量实验，验证了该系统能够实现多种潜在有益顺应性模式。通过量化评估各肌腱在抵抗旋转扰动时的单独力贡献，我们明确了每根肌腱的作用与贡献。我们还采用程序化仿生步态进行行走实验，在步态周期中动态调节肌腱刚度，展现了稳定一致的步态行为。研究结果表明，此类系统集成至腿足机器人中，可通过腿的形态学特性完全实现柔顺性与减震能力。