Department of Mechanical Engineering, Vanderbilt University, 2301 Vanderbilt Place, Nashville, TN 37235-1592, USA.
Field Research Station at Fort Missoula, Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA.
J R Soc Interface. 2024 Oct;21(219):20240391. doi: 10.1098/rsif.2024.0391. Epub 2024 Oct 30.
When a hovering hummingbird performs a rapid escape manoeuvre in response to a perceived threat from the front side, its body may go through simultaneous pitch, yaw and roll rotations. In this study, we examined the inertial coupling of the three-axis body rotations and its effect on the flight mechanics of the manoeuvre using analyses of high-speed videos as well as high-fidelity computational modelling of the aerodynamics and inertial forces. We found that while a bird's pitch-up was occurring, inertial coupling between yaw and roll helped slow down and terminate the pitch, thus serving as a passive control mechanism for the manoeuvre. Furthermore, an inertial coupling between pitch-up and roll can help accelerate yaw before the roll-yaw coupling. Different from the aerodynamic mechanisms that aircraft and animal flyers typically rely on for flight control, we hypothesize that inertial coupling is a built-in mechanism in the flight mechanics of hummingbirds that helps them achieve superb aerial agility.
当一只悬停的蜂鸟为了躲避来自正面的感知威胁而迅速做出逃避动作时，它的身体可能会同时进行俯仰、偏航和滚转运动。在这项研究中，我们通过对高速视频的分析以及对空气动力学和惯性力的高保真计算建模，研究了三轴身体旋转的惯性耦合及其对该动作的飞行力学的影响。我们发现，当鸟类进行俯仰时，偏航和滚转之间的惯性耦合有助于减缓并终止俯仰，因此成为该动作的被动控制机制。此外，俯仰和滚转之间的惯性耦合可以帮助在滚转-偏航耦合之前加速偏航。与飞机和动物飞行员通常依赖的用于飞行控制的空气动力学机制不同，我们假设惯性耦合是蜂鸟飞行力学中的内置机制，有助于它们实现卓越的空中敏捷性。
