Sidewinding, a locomotion strategy characterized by the coordination of lateral and vertical body undulations, is frequently observed in rattlesnakes and has been successfully reconstructed by limbless robotic systems for effective movement across diverse terrestrial terrains. However, the integration of compliant mechanisms into sidewinding limbless robots remains less explored, posing challenges for navigation in complex, rheologically diverse environments. Inspired by a notable control simplification via mechanical intelligence in lateral undulation, which offloads feedback control to passive body mechanics and interactions with the environment, we present an innovative design of a mechanically intelligent limbless robot for sidewinding. This robot features a decentralized bilateral cable actuation system that resembles organismal muscle actuation mechanisms. We develop a feedforward controller that incorporates programmable body compliance into the sidewinding gait template. Our experimental results highlight the emergence of mechanical intelligence when the robot is equipped with an appropriate level of body compliance. This allows the robot to 1) locomote more energetically efficiently, as evidenced by a reduced cost of transport, and 2) navigate through terrain heterogeneities, all achieved in an open-loop manner, without the need for environmental awareness.

翻译：侧向蜿蜒是一种通过横向和纵向身体波动协调实现的运动策略，常见于响尾蛇，且已被无肢体机器人系统成功复现，使其能在多样化陆地环境中有效移动。然而，将柔顺机制整合到侧向蜿蜒无肢体机器人中仍较少被探索，这为在复杂、流变多样的环境中导航带来了挑战。受横向蜿蜒运动中通过机械智能实现控制简化的启发——即利用被动身体力学与环境相互作用来替代反馈控制，我们提出了一种用于侧向蜿蜒的机械智能无肢体机器人的创新设计。该机器人采用类似生物肌肉驱动机制的分散式双侧电缆驱动系统，并开发了一种前馈控制器，将可编程身体柔顺性融入侧向蜿蜒步态模板中。实验结果表明，当机器人配备适当水平的身体柔顺性时，会涌现出机械智能行为，使机器人能够：1）以更高能量效率运动（通过降低运输成本证实）；2）穿越地形异质性区域——所有这些均在开环模式下实现，无需环境感知能力。