School of Transportation Science and Engineering, Beihang University, 100191 Beijing, People's Republic of China.
Bioinspir Biomim. 2020 Jul 7;15(5):056001. doi: 10.1088/1748-3190/ab97fc.
Insects are the main source of inspiration for flapping-wing micro air vehicles (FWMAVs). They frequently encounter wind gust perturbations in natural environments, and effectively cope with these perturbations. Here, we investigated the rapid gust response of flies to instruct the gust stability design of FWMAVs. A novel method to produce impulsive wind gusts that lasted less than 30 ms was designed to observe flies' rapid responses. Headwind gust perturbations were imposed on 14 tethered fruit flies, and the corresponding wing motions during perturbations were recorded by three high-speed cameras. The numerical simulation method was then applied to analyze aerodynamic forces and moments induced by the changes in wing kinematics. Results shows that flies mainly utilize three strategies against headwind gust perturbations, including decreasing the magnitude of stroke positional angle at ventral stroke reversal, delayed rotation and making the deviation angles in upstroke and downstroke closer (i.e. the wing tip trajectories of upstroke and downstroke tend be closer). Consequently, flies resist increments in lift and drag induced by the headwind gusts. However, flies seem to care little about changes in pitch moment in tethered conditions. These results provide useful suggestions for the stability control of FWMAVs during headwind gust perturbations.
昆虫是扑翼微型飞行器（FWMAV）的主要灵感来源。它们在自然环境中经常会遇到阵风扰动，并能有效地应对这些扰动。在这里，我们研究了苍蝇对阵风的快速响应，以指导 FWMAV 的阵风稳定性设计。设计了一种产生持续时间小于 30 毫秒的脉冲阵风的新方法，以观察苍蝇的快速响应。对 14 只系绳果蝇施加逆风阵风扰动，并用三台高速摄像机记录扰动过程中的相应翅膀运动。然后应用数值模拟方法分析了机翼运动变化引起的空气动力和力矩。结果表明，苍蝇主要利用三种策略来对抗逆风阵风扰动，包括在腹侧冲程反转时减小冲程位置角的幅度、延迟旋转以及使上冲程和下冲程的偏转角更接近（即上冲程和下冲程的翼尖轨迹更接近）。因此，苍蝇可以抵抗逆风阵风引起的升力和阻力的增加。然而，在系绳条件下，苍蝇似乎不太关心俯仰力矩的变化。这些结果为 FWMAV 在逆风阵风扰动期间的稳定性控制提供了有用的建议。
