Structure and Motion Laboratory, Royal Veterinary College, Hatfield AL9 7TA, UK.
Department of Aerospace Engineering, University of Bristol, Bristol BS8 1TR, UK.
Proc Biol Sci. 2020 Oct 28;287(1937):20201748. doi: 10.1098/rspb.2020.1748. Epub 2020 Oct 21.
Musculoskeletal systems cope with many environmental perturbations without neurological control. These passive preflex responses aid animals to move swiftly through complex terrain. Whether preflexes play a substantial role in animal flight is uncertain. We investigated how birds cope with gusty environments and found that their wings can act as a suspension system, reducing the effects of vertical gusts by elevating rapidly about the shoulder. This preflex mechanism rejected the gust impulse through inertial effects, diminishing the predicted impulse to the torso and head by 32% over the first 80 ms, before aerodynamic mechanisms took effect. For each wing, the centre of aerodynamic loading aligns with the centre of percussion, consistent with enhancing passive inertial gust rejection. The reduced motion of the torso in demanding conditions simplifies crucial tasks, such as landing, prey capture and visual tracking. Implementing a similar preflex mechanism in future small-scale aircraft will help to mitigate the effects of gusts and turbulence without added computational burden.
肌肉骨骼系统在没有神经控制的情况下应对许多环境干扰。这些被动的预反射反应帮助动物在复杂的地形中迅速移动。预反射在动物飞行中是否起重要作用尚不确定。我们研究了鸟类如何应对阵风环境，发现它们的翅膀可以充当悬架系统，通过肩部快速抬升来减轻垂直阵风的影响。这种预反射机制通过惯性效应拒绝阵风脉冲，在气动机制生效之前，在最初的 80 毫秒内将预测的对躯干和头部的脉冲减少 32%。对于每个翅膀，空气动力负载的中心与冲击中心对齐，这有助于增强被动惯性阵风拒绝。在苛刻的条件下，躯干的运动减少简化了关键任务，如着陆、捕食和视觉跟踪。在未来的小型飞机中实施类似的预反射机制将有助于减轻阵风和风湍流的影响，而不会增加计算负担。
