Snakes excel at moving through cluttered environments, and heterogeneities can be used as propulsive contacts for snakes performing lateral undulation. However, sidewinding, which is often associated with sandy deserts, cuts a broad path through its environment that may increase its vulnerability to obstacles. Our prior work demonstrated that sidewinding can be represented as a pair of orthogonal body waves (vertical and horizontal) that can be independently modulated to achieve high maneuverability and incline ascent, suggesting that sidewinders may also use template modulations to negotiate obstacles. To test this hypothesis, we recorded overhead video of four sidewinder rattlesnakes (Crotalus cerastes) crossing a line of vertical pegs placed in the substrate. Snakes used three methods to traverse the obstacles: a Propagate Through behavior in which the lifted moving portion of the snake was deformed around the peg and dragged through as the snake continued sidewinding (115/160 runs), Reversal turns that reorient the snake entirely (35/160), or switching to Concertina locomotion (10/160). The Propagate Through response was only used if the anterior-most region of static contact would propagate along a path anterior to the peg, or if a new region of static contact could be formed near the head to satisfy this condition; otherwise, snakes could only use Reversal turns or switch to Concertina locomotion. Reversal turns allowed the snake to re-orient and either escape without further peg contact or re-orient into a posture amenable to using the Propagate Through response. We developed an algorithm to reproduce the Propagate Through behavior in a robophysical model using a modulation of the two-wave template. This range of behavioral strategies provides sidewinders with a versatile range of options for effectively negotiating obstacles in their natural habitat, as well as provide insights into the design and control of robotic systems dealing with heterogeneous habitats.

蛇擅长在杂乱的环境中移动，而异质性可以用作执行横向波动的蛇的推进接触。然而，通常与沙质沙漠有关的侧风在其环境中开辟了一条宽阔的道路，这可能会增加其对障碍物的脆弱性。我们之前的工作表明侧风可以表示为一对正交体波（垂直和水平），可以独立调制以实现高机动性和倾斜上升，这表明侧风也可以使用模板调制来越过障碍物。为了验证这一假设，我们录制了四条响尾蛇响尾蛇（Crotalus cerastes）的头顶视频) 穿过放置在基材中的垂直钉线。蛇使用三种方法来穿越障碍物：传播通过行为，当蛇继续侧旋（115/160 运行）时，蛇的抬起移动部分在桩周围变形并被拖过，反向转弯使蛇完全重新定向（ 35/160），或切换到六角琴运动 (10/160)。传播通过响应仅在静态接触的最前面区域将沿桩钉前面的路径传播时才使用，或者如果可以在头部附近形成新的静态接触区域以满足此条件；否则，蛇只能使用反向转弯或切换到六角形运动。反向转弯允许蛇重新定向，或者在没有进一步钉接触的情况下逃脱，或者重新定向到适合使用传播通过响应的姿势。我们开发了一种算法，可以使用两波模板的调制在机器人物理模型中重现传播行为。这一系列的行为策略为响尾蛇提供了多种选择，可以有效地解决其自然栖息地中的障碍，并提供有关处理异质栖息地的机器人系统的设计和控制的见解。