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研究揭示鸟类栖息策略的优化
2022-06-30 19:54

英国牛津大学Graham K. Taylor团队揭示鸟类栖息策略的优化。相关论文于2022年6月29日在线发表于国际学术期刊《自然》。

研究人员表明,栖息的哈里斯鹰(Parabuteo unicinctus)的俯冲轨迹既不是单纯的时间也不是能量最小化,而是失速后飞行距离最小化。通过将1,576次飞行的动作捕捉数据与飞行动力学模型相结合,研究人员发现,鸟类对从有动力俯冲过渡到无动力爬升的位置的选择使需要高升力系数的距离最小。因此,时间和能量被投入到提供安全滑行到栖息地所需的控制权,而不是像在非线性反馈控制和深度强化学习下自主栖息的技术实现中那样被直接最小化。稚嫩的鸟类在飞行中学习这种行为,所以这个发现表明了一个启发式的原则,可以指导自主栖息的强化学习。
 
据介绍,高速栖息是鸟类最苛刻的飞行行为之一,并且超出了大多数自主车辆的能力。较小的鸟类可以通过悬停来着陆,但较大的鸟类通常会俯冲上去栖息,可能是因为它们的动力余量的不利比例禁止悬停,也因为向上俯冲在碰撞前将动能转为势能。栖息要求精确控制速度和姿势,特别是在大型鸟类中,规模效应使碰撞特别危险。然而,虽然巡航行为,如迁徙和通勤,通常会使运输成本或飞行时间最小化,但这种不稳定的飞行动作的优化在很大程度上仍未得到探索。
 
附:英文原文
 
Title: Optimization of avian perching manoeuvres

Author: KleinHeerenbrink, Marco, France, Lydia A., Brighton, Caroline H., Taylor, Graham K.

Issue&Volume: 2022-06-29

Abstract: Perching at speed is among the most demanding flight behaviours that birds perform1,2 and is beyond the capability of most autonomous vehicles. Smaller birds may touch down by hovering3,4,5,6,7,8, but larger birds typically swoop up to perch1,2—presumably because the adverse scaling of their power margin prohibits hovering9 and because swooping upwards transfers kinetic to potential energy before collision1,2,10. Perching demands precise control of velocity and pose11,12,13,14, particularly in larger birds for which scale effects make collisions especially hazardous6,15. However, whereas cruising behaviours such as migration and commuting typically minimize the cost of transport or time of flight16, the optimization of such unsteady flight manoeuvres remains largely unexplored7,17. Here we show that the swooping trajectories of perching Harris’ hawks (Parabuteo unicinctus) minimize neither time nor energy alone, but rather minimize the distance flown after stalling. By combining motion capture data from 1,576 flights with flight dynamics modelling, we find that the birds’ choice of where to transition from powered dive to unpowered climb minimizes the distance over which high lift coefficients are required. Time and energy are therefore invested to provide the control authority needed to glide safely to the perch, rather than being minimized directly as in technical implementations of autonomous perching under nonlinear feedback control12 and deep reinforcement learning18,19. Naive birds learn this behaviour on the fly, so our findings suggest a heuristic principle that could guide reinforcement learning of autonomous perching.

DOI: 10.1038/s41586-022-04861-4

Source: https://www.nature.com/articles/s41586-022-04861-4

Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:69.504
官方网址:http://www.nature.com/
投稿链接:http://www.nature.com/authors/submit_manuscript.html


本期文章:《自然》:Online/在线发表

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