Elzinga Michael J, van Breugel Floris, Dickinson Michael H
University of Washington, Box 351800, 24 Kincaid Hall, Seattle, WA 98195, USA.
Bioinspir Biomim. 2014 Jun;9(2):025001. doi: 10.1088/1748-3182/9/2/025001. Epub 2014 May 22.
The ability to regulate forward speed is an essential requirement for flying animals. Here, we use a dynamically-scaled robot to study how flapping insects adjust their wing kinematics to regulate and stabilize forward flight. The results suggest that the steady-state lift and thrust requirements at different speeds may be accomplished with quite subtle changes in hovering kinematics, and that these adjustments act primarily by altering the pitch moment. This finding is consistent with prior hypotheses regarding the relationship between body pitch and flight speed in fruit flies. Adjusting the mean stroke position of the wings is a likely mechanism for trimming the pitch moment at all speeds, whereas changes in the mean angle of attack may be required at higher speeds. To ensure stability, the flapping system requires additional pitch damping that increases in magnitude with flight speed. A compensatory reflex driven by fast feedback of pitch rate from the halteres could provide such damping, and would automatically exhibit gain scheduling with flight speed if pitch torque was regulated via changes in stroke deviation. Such a control scheme would provide an elegant solution for stabilization across a wide range of forward flight speeds.
调节前进速度的能力是飞行生物的一项基本要求。在此，我们使用一个动态缩放的机器人来研究扑翼昆虫如何调整其翅膀运动学以调节和稳定向前飞行。结果表明，不同速度下的稳态升力和推力需求可能通过悬停运动学中相当细微的变化来实现，并且这些调整主要通过改变俯仰力矩来起作用。这一发现与之前关于果蝇身体俯仰与飞行速度之间关系的假设一致。调整翅膀的平均冲程位置可能是在所有速度下调整俯仰力矩的一种机制，而在更高速度下可能需要改变平均攻角。为确保稳定性，扑翼系统需要额外的俯仰阻尼，其大小随飞行速度增加。由来自平衡棒的俯仰速率快速反馈驱动的补偿反射可以提供这种阻尼，并且如果通过冲程偏差的变化来调节俯仰扭矩，它将自动表现出随飞行速度的增益调度。这样的控制方案将为在广泛的向前飞行速度范围内实现稳定提供一个优雅的解决方案。
