Limbless locomotors, from microscopic worms to macroscopic snakes, traverse complex, heterogeneous natural environments typically using undulatory body wave propagation. Theoretical and robophysical models typically emphasize body kinematics and active neural/electronic control. However, we contend that because such approaches often neglect the role of passive, mechanically controlled processes (those involving “mechanical intelligence”), they fail to reproduce the performance of even the simplest organisms. To uncover principles of how mechanical intelligence aids limbless locomotion in heterogeneous terradynamic regimes, here we conduct a comparative study of locomotion in a model of heterogeneous terrain (lattices of rigid posts). We used a model biological system, the highly studied nematode worm Caenorhabditis elegans , and a robophysical device whose bilateral actuator morphology models that of limbless organisms across scales. The robot’s kinematics quantitatively reproduced the performance of the nematodes with purely open-loop control; mechanical intelligence simplified control of obstacle navigation and exploitation by reducing the need for active sensing and feedback. An active behavior observed in C. elegans , undulatory wave reversal upon head collisions, robustified locomotion via exploitation of the systems’ mechanical intelligence. Our study provides insights into how neurally simple limbless organisms like nematodes can leverage mechanical intelligence via appropriately tuned bilateral actuation to locomote in complex environments. These principles likely apply to neurally more sophisticated organisms and also provide a design and control paradigm for limbless robots for applications like search and rescue and planetary exploration.

中文翻译：

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机械智能简化了陆地无肢运动的控制

从微观蠕虫到宏观蛇，无肢运动动物通常利用波动体波传播来穿越复杂、异质的自然环境。理论和机器人物理模型通常强调身体运动学和主动神经/电子控制。然而，我们认为，由于此类方法常常忽视被动的机械控制过程（涉及“机械智能”的过程）的作用，因此它们无法重现即使是最简单的生物体的性能。为了揭示机械智能如何帮助异质地形动力学状态下的无肢运动的原理，在这里我们对异质地形模型（刚性柱格子）中的运动进行了比较研究。我们使用了一个模型生物系统，即经过深入研究的线虫秀丽隐杆线虫，以及一种机器人物理设备，其双边执行器形态模拟了跨尺度的无肢生物体。机器人的运动学通过纯开环控制定量再现了线虫的性能；机械智能通过减少主动传感和反馈的需求，简化了障碍物导航和利用的控制。观察到的主动行为线虫，头部碰撞时波状波反转，通过利用系统的机械智能增强运动。我们的研究提供了关于线虫等神经简单无肢生物如何通过适当调整的双边驱动来利用机械智能在复杂环境中运动的见解。这些原理可能适用于神经上更复杂的生物体，也为无肢机器人提供了设计和控制范例，用于搜索和救援以及行星探索等应用。