Antennal mechanosensors mediate flight control in moths

Flying insects have evolved sophisticated sensory capabilities to achieve rapid course control during aerial maneuvers. Among two-winged insects such as houseflies and their relatives, the hind wings are modified into club-shaped, mechanosensory halteres, which detect Coriolis forces and thereby mediate flight stability during maneuvers. Here, we show that mechanosensory input from the antennae serves a similar role during flight in hawk moths, which are four-winged insects. The antennae of flying moths vibrate and experience Coriolis forces during aerial maneuvers. The antennal vibrations are transduced by individual units of Johnston's organs at the base of their antennae in a frequency range characteristic of the Coriolis input. Reduction of the mechanical input to Johnston's organs by removing the antennal flagellum of these moths severely disrupted their flight stability, but reattachment of the flagellum restored their flight control. The antennae thus play a crucial role in maintaining flight stability of moths.     

微型无人机林火监测系统的设计与实现

为探索林火监测的新手段,提高森林安全管理水平,将实时视频传输和计算机技术相结合,研制了林火监测任务设备．并与无人机飞行平台共同构成了微型无人机林火监测系统。以林区火场影像为样本．像素RGB值为分类依据．使用统计产品与服务解决方案软件进行聚类分析．得到基于颜色特征的烟雾识别模型。该模型经过光谱特性改进和消噪处理后．对于试验影像的烟雾识别率在77％以上。利用该模型．系统可在飞行中实时完成对地面火情的探测并给出报警提示。在飞行试验的基础上,提出无人机林火监测系统的飞行作业流程．并讨论了系统运行的经济性和目前存在的问题。无人机林火监测系统同样可用于林区气象探测、可燃物和病虫害调查等方面．切实提高林区管理的技术水平。图5表2参14     

模糊PID控制无人自转旋翼机飞行姿态仿真

农业植保无人机中自转旋翼机(简称旋翼机)具有机体结构简单、滑跑距离短、飞行高度低和空中失去动力时安全性高等优点,在农业数据采集、农情监测和农业施药等领域广泛应用。文章研究模糊PID控制器控制旋翼机姿态,运用MATLAB作旋翼机飞行姿态仿真。仿真结果显示,该系统在系统阶跃响应下模糊PID控制器相较经典PID收敛时间减少0.04 s,而给定目标角情况下,滚转角和俯仰角误差±0.01°与±0.05°上下。因此,模糊PID控制器可增强PID自适应性与鲁棒性,降低飞行时姿态控制不稳定性,姿态控制效果良好,提高飞行稳定性。     

Enzyme changes in flight muscle correlated with aging and flight ability in the male housefly

Magnesium-activated adenosine triphosphatase activity in the giant mitochondria (sarcosomes) of the flight muscle of aging male houseflies decreases concomitantly with failure in flight as reflected in the loss of wings during the second week of adult life. Preceding the loss of wings, however, there is a rapid decline in the activity of an alpha-glycerophosphate dehydrogenase which is located in the extramitochondrial fraction and is dependent on nicotinamide adenine dinucleotide.     

Smart engineering in the mid-carboniferous: how well could palaeozoic dragonflies Fly?

The wings of archaic Odonatoidea from the mid-Carboniferous of Argentina show features analogous to "smart" mechanisms in modern dragonflies that are associated with the agile, versatile flight necessary to catch prey in flight. These mechanisms act automatically in flight to depress the trailing edge and to facilitate wing twisting, in response to aerodynamic loading. The presence of similar features suggests that the earliest known odonatoids were already becoming adapted for high-performance flight in association with a predatory habit.     

Localization of heart poisons in the monarch butterfly

The cardiac glycosides that monarch butterflies sequester from milkweed plants during the larval stage differ remarkably in their emetic potency and are concentrated to different degrees in the various parts of the body as well as in the two sexes (Fig. 1). The very high concentrations of these compounds in the wings probably facilitate learned taste rejection in predators and account for the relatively high frequency of Danaid butterflies with beak-marked wings in natural populations. The cardiac glycosides in the abdomen have a much higher emetic potency than those in the rest of the body. Consequently, naive, extremely hungry, or forgetful birds which capture and peck off the wings but eat the abdomen discard the least emetic glycosides and ingest the most emetic, and thus again experience emesis. The nonrandom distribution of cardenolides in the wings, abdomen, and thorax, together with the fact that monarch males not only contain lower concentrations of cardiac glycosides than females but also contain cardenolides that are overall less emetic than those in females, is interpreted as evidence that these poisons are incorporated at a physiological cost. This cost, balanced against the benefits of protection from predation, provides a selective basis for the occurrence of both emetic and nonemetic individuals in natural populations. Since birds can discriminate emetic from nonemetic monarchs on the basis of taste, it is not necessary to invoke theories of kind of group selection to explain the evolution of this kind of unpalatability.     

Flight interneurons in the locust and the origin of insect wings

Interneurons involved in the generation of motor activity for flight in the locust were found in the first three abdominal ganglia as well as in thoracic ganglia. The evidence that sets of homologous flight interneurons occur in abdominal and thoracic ganglia supports theories that insect wings originated from movable appendages which were serially distributed along the thorax and abdomen and which were under central nervous control.     

小型植保无人机喷雾参数对橘树冠层雾滴沉积分布的影响

【目的】探索小型植保无人机对果树喷施作业的雾滴沉积分布效果及应用前景,研究小型植保无人机喷雾参数对橘树冠层雾滴沉积分布的影响。【方法】采用三因素(飞行高度、飞行速度、喷施流量)的正交试验,应用小型六旋翼植保无人机进行喷雾试验。【结果】根据雾滴沉积密度和雾滴沉积均匀性结果,较佳的作业参数是喷头流量1.0 L·min~(-1)、作业高度2.5 m、作业速度4 m·s~(-1),影响雾滴沉积密度的主次顺序依次为作业速度、作业高度、喷头流量;根据雾滴沉积穿透性结果,作业高度均为2.0 m的试验号2(作业速度4 m·s~(-1),喷头流量0.6 L·min~(-1))和试验号8(作业速度1 m·s~(-1),喷头流量1.0 L·min~(-1))中雾滴沉积穿透性分别为22.21%和22.41%,其雾滴覆盖密度大且穿透性较好;影响雾滴沉积穿透性的因素主次顺序为作业高度、作业速度、喷头流量。【结论】针对植保无人机旋翼风场的影响和橘树独特的树形结构,对植保无人机的作业参数进行了优选,以保证航空喷施作业雾滴在橘树冠层的有效沉积分布。本试验研究可为小型无人机对果树的合理喷施、提高喷施效率提供参考和指导。     

基于太阳能的植保无人机续航提升方案

在农业领域对无人机的任务需求中,续航问题无疑是目前植保无人机所面临的重要问题之一。由于电池生产技术的瓶颈,目前植保无人机的有效作业时间大都被限制在12 min左右难以突破。太阳作为一个取之不尽用之不竭的“无源”动力得到了特别的关注,因此设计了一种基于太阳能的植保无人机续航提升方案。在六旋翼无人机平台上对方案的可行性进行实验,结果表明,安装了太阳能续航模块后的无人机相比安装前,飞行续航时间平均提升了70 s。该方案基于多轴无人机飞行平台,在无人机工作时将太阳能转化为电能为锂电池续电,从而减少锂电池在飞行时的电量消耗,增加植保无人机的有效作业时间,在一定程度上缓解了当前植保无人机的续航问题,并能够向其他基于无人机平台的应用延伸。     

植保无人机航空喷施飞行质量的试验与评价

【目的】植保无人机的飞行质量是航空喷施作业效果的重要影响因素。探讨不同类型和不同控制方式的植保无人机航空喷施作业的飞行质量和作业效果,为航空喷施作业机型的选择和植保无人机技术的改进提供数据支持和指导。【方法】采用微轻型机载北斗导航定位系统,获取半自主飞行控制模式下单旋翼油动植保无人机(SoUAV)、单旋翼电动植保无人机(Se-UAV)和半自动四旋翼电动植保无人机(Saqe-UAV)以及全自主控制模式下四旋翼电动植保无人机(Faqe-UAV)的飞行轨迹和飞行参数,并对飞行质量(包括飞行参数均匀性、航线精度和航线长度均匀性)进行了分析和评价。【结果】四旋翼植保无人机飞行质量优于单旋翼植保无人机,且Faqe-UAV飞行质量优于Saqe-UAV;Faqe-UAV在整个作业区域内的飞行参数变化的均匀性最佳,飞行速度和飞行高度参数变化的均匀性分别为3.66%和4.67%;Faqe-UAV的平均飞行航线偏差最小,为0.172 m。飞行方向对Saqe-UAV飞行参数的影响显著,但对Faqe-UAV飞行参数的影响不显著;航线长度对Faqe-UAV飞行参数的影响显著,但对SaqeUAV飞行速度的影响不显著。【结论】在航空喷施作业过程中,全自主控制方式下四旋翼电动植保无人机飞行质量最佳,对药液喷施质量更有保障。     

Feathers of archaeopteryx: asymmetric vanes indicate aerodynamic function

Vanes in the primary flight feathers of Archaeopteryx conform to the asymmetric pattern in modern flying birds. The asymmetry has aerodynamic functions and can be assumed to have evolved in the selective context of flight.     

What relevant information can be identified by experts on unmanned aerial vehicles’ visible images for precision viticulture?

Precision Agriculture - Unmanned aerial vehicles (UAV) offer interesting alternatives to satellites or airplanes regarding flight agility and image resolution. These sensor platforms may well be...     

The aerodynamics of free-flight maneuvers in Drosophila

Using three-dimensional infrared high-speed video, we captured the wing and body kinematics of free-flying fruit flies as they performed rapid flight maneuvers. We then "replayed" the wing kinematics on a dynamically scaled robotic model to measure the aerodynamic forces produced by the wings. The results show that a fly generates rapid turns with surprisingly subtle modifications in wing motion, which nonetheless generate sufficient torque for the fly to rotate its body through each turn. The magnitude and time course of the torque and body motion during rapid turns indicate that inertia, not friction, dominates the flight dynamics of insects.     

A basal dromaeosaurid and size evolution preceding avian flight

Fossil evidence for changes in dinosaurs near the lineage leading to birds and the origin of flight has been sparse. A dinosaur from Mongolia represents the basal divergence within Dromaeosauridae. The taxon's small body size and phylogenetic position imply that extreme miniaturization was ancestral for Paraves (the clade including Avialae, Troodontidae, and Dromaeosauridae), phylogenetically earlier than where flight evolution is strongly inferred. In contrast to the sustained small body sizes among avialans throughout the Cretaceous Period, the two dinosaurian lineages most closely related to birds, dromaeosaurids and troodontids, underwent four independent events of gigantism, and in some lineages size increased by nearly three orders of magnitude. Thus, change in theropod body size leading to flight's origin was not unidirectional.     

A flexible unmanned aerial vehicle for precision agriculture

An unmanned aerial vehicle (??VIPtero??) was assembled and tested with the aim of developing a flexible and powerful tool for site-specific vineyard management. The system comprised a six-rotor aerial platform capable of flying autonomously to a predetermined point in space, and of a pitch and roll compensated multi-spectral camera for vegetation canopy reflectance recording. Before the flight campaign, the camera accuracy was evaluated against high resolution ground-based measurements, made with a field spectrometer. Then, ??VIPtero?? performed the flight in an experimental vineyard in Central Italy, acquiring 63 multi-spectral images during 10?min of flight completed almost autonomously. Images were analysed and classified vigour maps were produced based on normalized difference vegetation index. The resulting vigour maps showed clearly crop heterogeneity conditions, in good agreement with ground-based observations. The system provided very promising results that encourage its development as a tool for precision agriculture application in small crops.     

Comment on "Narrow primary feather rachises in Confuciusornis and Archaeopteryx suggest poor flight ability"

Nudds and Dyke (Reports, 14 May 2010, p. 887) compared the rachis diameters of the primary feathers of Archaeopteryx and Confuciusornis to those of modern birds and found that the primary feathers of these two basal birds were too weak to support sustained flight. Our measurements of Confuciusornis specimens suggest that their conclusions need to be further evaluated.     

基于微型无人机航测的大比例尺地形图测绘

微型无人机航测技术凭借其成本低廉、机动灵活、操作简单的特点,被广泛应用于地理空间信息数据获取。为了研究其能否应用于大比例尺地形图测绘,测量精度是否能达到规范要求,借鉴传统航空摄影测量方法,在某管道测绘中的29个测区应用微型无人机航测技术。通过优化微型无人机航飞设计、合理布设地面像控点、全面进行空中三角测量加密等操作,得到了正射影像图和地面高程模型。利用野外实测方法验证微型无人机测量结果,结果表明:微型无人机航测技术平面精度满足规范要求,可以应用于大比例尺地形图的平面测量。     

平纹古毒蛾的生物学及防治研究

平纹古毒蛾Ｏｒｇｙｉａ ｐａｒａｌｌｅｌａ Ｇａｅｄｅ在四川省南充市生态环境中，年发生５代，以卵越冬。雄虫为４个龄期，雌虫为５个龄期。雌成虫无翅，仅产卵块１个，雄成虫具翅两对，趋光性弱。两性生殖。卵量各代平均为１８９．３２粒，第一代最高为３４７．７８粒，各代孵化率平均为９０．４７％，捕食性天敌对该虫控制效果显著，彻底清除越冬卵，生长季节加强监测，人工修剪或喷药挑治１，２龄虫团，保护鸟类及马蜂等捕食     

Paleognathous carinate birds from the early tertiary of north america

Fossils newly discovered in the Paleocene and early Eocene of western North America document some of the oldest birds known from nearly complete skeletons. These were medium-sized carinates with powers of sustained flight but which had a paleognathous palate like that of the flightless ostrich-like birds and the tinamous. The fossils provide additional evidence that the paleognathous palate is probably primitive and therefore should not be cited as a derived character state to define the ostrich-like birds as a monophyletic group.     

Spider web protection through visual advertisement: role of the stabilimentum

The conspicuous white silken adornments known as stabilimenta, which are commonly found in the orb webs of some spiders, appear to be protective devices that warn birds of the presence of webs in their flight path. Webs endowed with artificial equivalents of stabilimenta tended to survive intact the early morning period when birds are on the wing; unmarked webs showed a high incidence of destruction.