fruit flies sense the orientation of their bodies<\/a> every time they beat their wings, about one beat every 4 milliseconds, in order to stabilize themselves.<\/p>\nHowever, in order to study flight stability in all insects, the researchers would need to build an efficient computational tool to simulate a huge number of species.\u00a0<\/p>\n
\u201cPrevious studies, including ours, have always started with models of real insects, so we\u2019re limited by the things we observe,\u201d Wang said. \u201cWe miss all the other configurations that are also possible for flight.\u201d<\/p>\n
Wang and Owen Wetherbee \u201925, the new paper\u2019s first author, distilled the 3D model into a new version that retained the key physics of the body-wing coupling and unsteady aerodynamics. The resulting equations revealed the critical physical parameters: wing to body mass ratio, wing loading, wing hinge position, wing beat frequency and wing motion amplitude. Taken together, they form what Wang calls a \u201cfive-dimensional morphological and kinematic space.\u201d<\/p>\n
\u201cThe power of this model is to give us something much more explicit than what we had before,\u201d she said. \u201cWe knew the fundamental physics. By capturing the essential physics in the new model, we can understand each piece conceptually as well as facilitate computation to explore a large parameter space.\u201d<\/p>\n
The analyses of the computational results in 5D resulted in two explicit formula that provide a succinct metric for stability. These criteria capture the subtle and often ignored coupling between wing inertia and the body, which depends on the interplay among wing flap frequency, hinge placement, and wing and body mass ratios in order to achieve a kind of anti-resonance state. This sweet spot allows the flapping winged animal to control its body oscillations and remain aloft \u2013 a state known as passively stable flight \u2013 despite air perturbations that would normally cause it to tumble.<\/p>\n
\u201cAll of a sudden, we found that many forms of flapping flight have\u00a0passive stability, which surprised us initially, because works so far showed that most insects, except one or two, are passively unstable, hence the necessity for neural circuitry to control them,\u201d Wang said. \u201cBut when we expanded the morphological space, we realized that what we studied before are but a few dots in this new view.\u201d<\/p>\n
Now that the researchers can characterize the stability boundary, they can offer a concrete design principle for realizing stable flapping flight in robots \u2013 something that has stumped roboticists for decades.<\/p>\n
\u201cIn principle, this offers a completely new route for designing a robotic flapping-winged machine,\u201d Wang said. \u201cInstead of relying on extensive feedback control, which is only partially successful, our results suggest that we can tune the shape and the frequency of the flapping devices such that, according to these two rules, we may find the flyers are passively stable already. This would greatly simplify flight control.\u201d\u00a0<\/p>\n
The new model allows this design work to be done with faster and simpler computation, and the ability to model stability traits also points to a new way for classifying winged animals and charting their evolution.\u00a0<\/p>\n
\u201cDuring evolution, various traits are selected, but we don\u2019t have much idea about what they are, let alone understand why they are being selected and how they evolve, apart from a very few examples, such as an eye,\u201d Wang said. \u201cThis project brings new quantitative methods to study these very big questions in both biology and robotics. Mathematical modeling allows us to go beyond our own ideas and preconceptions to tackle these large questions.\u201d<\/p>\n
The research was supported by the National Science Foundation.<\/p>\n","protected":false},"excerpt":{"rendered":"The way bugs and birds flap their wings may look effortless, but the dynamics that keep them aloft…\n","protected":false},"author":2,"featured_media":647569,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[49,48,66],"class_list":["post-647568","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-ca","tag-canada","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/647568","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/comments?post=647568"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/647568\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/647569"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=647568"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=647568"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=647568"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}