この発見は、将来の自律型無人航空機に影響を与える可能性がある。 The finding could have implications for future agile autonomous aerial vehicles
2022-03-09 ミシガン大学
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＜関連情報＞
Avian secret: The key to agile bird flight is switching quickly between stable and unstable glidingWhile it had been assumed that unstable gliding was the key to agility in bird flight, a collaboration between aerospace...news.umich.edu
Birds can transition between stable and unstable states via wing morphing - NatureAnalysis of inertial characteristics across 22 bird species shows that evolution has selected for avian manoeuvrability ...www.nature.com鳥類は翼の変形によって安定状態と不安定状態を移行することができる Birds can transition between stable and unstable states via wing morphing
C. Harvey, V. B. Baliga, J. C. M. Wong, D. L. Altshuler & D. J. Inman
(DOI: 10.1038/s41586-022-04477-8)
Abstract
Birds morph their wing shape to accomplish extraordinary manoeuvres1,2,3,4, which are governed by avian-specific equations of motion. Solving these equations requires information about a bird’s aerodynamic and inertial characteristics5. Avian flight research to date has focused on resolving aerodynamic features, whereas inertial properties including centre of gravity and moment of inertia are seldom addressed. Here we use an analytical method to determine the inertial characteristics of 22 species across the full range of elbow and wrist flexion and extension. We find that wing morphing allows birds to substantially change their roll and yaw inertia but has a minimal effect on the position of the centre of gravity. With the addition of inertial characteristics, we derived a novel metric of pitch agility and estimated the static pitch stability, revealing that the agility and static margin ranges are reduced as body mass increases. These results provide quantitative evidence that evolution selects for both stable and unstable flight, in contrast to the prevailing narrative that birds are evolving away from stability6. This comprehensive analysis of avian inertial characteristics provides the key features required to establish a theoretical model of avian manoeuvrability.
