Copy of supplementary material.xlsx from A brittle star-like robot capable of immediately adapting to unexpected physical damage

A major challenge in robotic design is enabling robots to immediately adapt to unexpected physical damage. However, conventional robots require considerable time (more than several tens of seconds) for adaptation because the process entails high computational costs. To overcome this problem, we focus on a brittle star—a primitive creature with expendable body parts. Brittle stars, most of which have five flexible arms, occasionally lose some of them and promptly coordinate the remaining arms to escape from predators. We adopted a synthetic approach to elucidate the essential mechanism underlying this resilient locomotion. Specifically, based on behavioural experiments involving brittle stars whose arms were amputated in various ways, we inferred the decentralized control mechanism that self-coordinates the arm motions by constructing a simple mathematical model. We implemented this mechanism in a brittle star-like robot and demonstrated that it adapts to unexpected physical damage within a few seconds by automatically coordinating its undamaged arms similar to brittle stars. Through the above-mentioned process, we found that physical interaction between arms plays an essential role for the resilient inter-arm coordination of brittle stars. This finding will help develop resilient robots that can work in inhospitable environments. Further, it provides insights into the essential mechanism of resilient coordinated motions characteristic of animal locomotion.

机器人设计领域的核心挑战之一，在于使机器人能够快速适配突发的物理损伤。但传统机器人的适配流程往往需要数十秒以上的时长，究其原因是该过程存在高昂的计算开销。为解决这一难题，我们将研究目光投向海蛇尾（brittle star）——一类具备可牺牲躯体部分的原始棘皮动物。多数海蛇尾拥有五条灵活的腕足，即便部分腕足脱落，它们也能迅速协调剩余腕足以摆脱捕食者。我们采用合成式研究方法，旨在阐明这种韧性运动背后的核心机制。具体而言，我们通过对接受不同方式腕足截肢的海蛇尾开展行为实验，构建简化数学模型，进而推导出一种可自主协调腕足运动的分布式控制机制。我们将该机制部署于类海蛇尾机器人平台，实验结果表明，该机器人可在数秒内适配突发物理损伤，通过自主协调未受损腕足的运动，实现与海蛇尾类似的韧性运动模式。通过上述研究流程，我们发现腕足间的物理交互，对海蛇尾实现韧性腕间协调运动起到了关键作用。这一发现将助力开发可在极端不适宜环境中稳定作业的高韧性机器人。此外，该研究还为解析动物运动所特有的韧性协调运动的核心机制提供了全新的认知视角。