飞行数据加密技术实现

飞行试验是在真实飞行条件下进行的科学研究和产品试验,它所产生的飞行数据极为珍贵,具有信息量大,保密要求高,数据不可重现等特点,因此飞行数据的安全存储管理问题非常重要。本文讨论了数据加密技术,分析了各类加密算法的优缺点和设计原理,在此基础上提出了综合AES（高级加密标准）和ECC（椭圆曲线密码）来对飞行数据进行保护的一种加密方案。实验表明,该方案能够有效对飞行数据进行加密存储,在飞行数据安全管理方面得到了很好的应用。     

飞行数据快速译码系统实现

飞行数据译码分析是进行飞机状态监控、故障诊断与维修、飞行品质分析等的重要技术手段.介绍了QAR记录的原理,在分析了传统译码算法及译码的缺点的基础上,针对ARINC717协议中的飞行参数类型,提出了基于参数类型的动态链表快速译码算法,并开发了基于实时数据库技术的快速译码系统软件,显著提高了飞行数据的译码效率,扩展性好,能满足飞行记录数据新应用的实时快速译码要求.     

建立基于ADS-B系统的飞行数据管理平台

摘要：介绍了广播式自动相关监视（ADS-B）的概念及应用,论述了民航飞行学院在现有质量管理基础上建立基于ADS-B系统的飞行数据管理平台,应用ADS-B系统提高飞行数据查询、飞行质量控制水平的必要性。中国民航飞行学院新津学院成功地引进了ADS-B系统,该系统在飞行学院稳定运行了多年,在飞机的调度指挥、飞行监控、安全保障等方面发挥了巨大的作用。另外,ADS-B系统的飞行数据也应用于飞行事件的调查。但是作为以飞行训练为中心的飞行学院,训练质量是其核心,怎样让ADS-B系统为提高学生飞行训练质量还是一个新的课题,亟待开发应用。     

FDR飞行数据的相空间重构及混沌特性分析

针对现有飞行数据处理研究中,对数据内在属性及不同数据间相互关联性研究不够深入的问题,应用Takens重构理论和方法等对原始FDR飞行数据进行了相空间重构.在此基础上,采用功率图谱等方法进行定性分析研究,数据曲线均连续且有宽峰特征;采用基于相轨迹线演化的Wolf方法进行定量研究,结果最大Lyapunov指数在不同维数上均为正值.定性与定量研究结果揭示并证实了飞行数据具有典型混沌特性,该结论为后续开展飞行数据处理技术研究提供了新思路.     

一种基于CFD的飞行模拟方法

分析了飞行力学模拟与CFD模拟之间的影响关系。详细考虑了机动飞行过程中飞行参数变化与气动力变化之间的相互影响,开发出基于高精度CFD计算的飞行力学模拟方法。改进了传统飞行力学计算方法,保证了气动数据和飞行数据的计算精度。采用此方法,通过一次数值模拟即可得到飞行过程中气动力及飞行轨迹、飞行速度等的变化过程,可用于对飞行器设计方案进行精细模拟。     

ForeFlight在飞行中的实用性研究

ForeFlight是一款基于GPS卫星的机场地图飞行导航Apple应用软件,因其功能强大,被广泛应用于飞行中。在介绍了ForeFlight软件功能的基础上,阐述了其制定飞行计划、监视气象条件、提供飞行数据参考和进近参考的具体应用。为保障飞行安全,针对Foreflight使用的局限性,从数据的实时性和真实性提出了几点改进意见。     

飞行成绩评定及管理系统

在飞行训练中，需要客观考核飞行员的飞行技术，监控飞行质量。依据训练大纲及某型飞机机载飞行参数记录仪的飞行数据，结合人工判分经验，研制开发了飞行成绩自动评定及管理系统。经大量飞行数据检验表明：该系统能对飞行成绩及相关飞行信息进行全自动管理，能快速、准确评定飞行成绩，评定时间为原来人工评定的十二分之一，并完全满足评定误差的要求。     

多维度动态融合建模下4D飞行路径优化

在读取广域空间下的飞行路径数据时,由于空间各类数据汇聚且体量较大,容易出现因飞行数据重叠和实施运行趋势相似造成的飞行特征不明确,使飞行轨迹预测准确性不高。为解决上述问题,完善飞行数据的数学描述,有效推进基于轨迹运行（trajectory based operations,TBO）发展,按飞行阶段建立多维度模板获取数据特征,利用飞行路径动态规整算法（4D Dynamic Warping,4DDW）搭建融合模型,实现飞行路径区间化设计,完成时间预测对比策略。结果表明：4DDW可面向各飞行阶段开展数据采集和预处理,在分析空间位置点时,通过引入国际民航组织（International Civil Aviation Organization,ICAO）缓冲值建议和阈值,有效控制航空器位置区间范围,使飞行路径优化结论具有收敛和多维精准的特性。对比实验证明了4DDW对运行标准优化和容量提升具有明显作用。     

一种飞行数据译码分析系统的设计

针对MA60飞机加装FDR(飞行数据记录仪)设备以实现飞行品质监控的要求,设计了一种飞行数据译码分析系统。该系统对FDR设备记录的二进制数据自动译码处理,转化为相应的物理量。根据预先设定的监控标准,自动分析并输出超限事件,形成统计报表;并能够以虚拟座舱仪表形式回放整个航段的飞机状态。试运行一年来证明:该系统性能稳定、功能齐全,打破了国外在该领域的技术垄断,并在航空领域具有较大的推广应用价值。     

飞行数据趋势监测在飞机“健康状况”评估中的应用

针对飞行数据属于多状态时域数据的特点提出了一种用于参数趋势监测的方法 ,该方法为“飞机健康”状况提供了一种科学的评估依据。首先对飞机在稳定工作状态和飞行特征时段下的飞行数据进行筛选处理、野点剔除和统计分析 ,并在此基础上建立时间序列AR模型进行参数预测 ,进而采用阈值对比法实现了参数的趋势监测 ,最后讨论了趋势监测在“飞机健康”状况评估中的应用方案。实例表明这一方法具有较高的准确性和重要的工程应用价值     

Flying in a flock comes at a cost in pigeons

Flying birds often form flocks, with social, navigational and anti-predator implications. Further, flying in a flock can result in aerodynamic benefits, thus reducing power requirements, as demonstrated by a reduction in heart rate and wingbeat frequency in pelicans flying in a V-formation. But how general is an aerodynamic power reduction due to group-flight? V-formation flocks are limited to moderately steady flight in relatively large birds, and may represent a special case. What are the aerodynamic consequences of flying in the more usual 'cluster' flock? Here we use data from innovative back-mounted Global Positioning System (GPS) and 6-degrees-of-freedom inertial sensors to show that pigeons (1) maintain powered, banked turns like aircraft, imposing dorsal accelerations of up to 2g, effectively doubling body weight and quadrupling induced power requirements; (2) increase flap frequency with increases in all conventional aerodynamic power requirements; and (3) increase flap frequency when flying near, particularly behind, other birds. Therefore, unlike V-formation pelicans, pigeons do not gain an aerodynamic advantage from flying in a flock. Indeed, the increased flap frequency, whether due to direct aerodynamic interactions or requirements for increased stability or control, suggests a considerable energetic cost to flight in a tight cluster flock.     

Molecular evidence regarding the origin of echolocation and flight in bats

Bats (order Chiroptera) are one of the few orders of mammals that echolocate and the only group with the capacity for powered flight. The order is subdivided into Microchiroptera and Megachiroptera, with an array of characteristics defining each group, including complex laryngeal echolocation systems in microbats and enhanced visual acuity in megabats. The respective monophylies of the two suborders have been tacitly assumed, although microbat monophyly is uncorroborated by molecular data. Here we present a phylogenetic analysis of bat relationships using DNA sequence data from four nuclear genes and three mitochondrial genes (total of 8,230 base pairs), indicating that microbat families in the superfamily Rhinolophoidea are more closely related to megabats than they are to other microbats. This implies that echolocation systems either evolved independently in rhinolophoids and other microbats or were lost in the evolution of megabats. Our data also reject flying lemur (order Dermoptera) as the bat sister group, indicating that presumed shared derived characters for flying lemurs and bats are convergent features that evolved in association with gliding and flight, respectively.     

Wing bone stresses in free flying bats and the evolution of skeletal design for flight.

The primary mechanical functions of limb bones are to resist deformation, and hence provide stiff levers against which muscles can act, and to be sufficiently strong to prevent breaking under static or dynamic loads which arise from normal and accidental activities. If bones perform these functions with a minimum amount of material, the energetic costs associated with building, maintaining and transporting the skeleton will be minimized. Appropriate skeletal architecture for minimizing mass while maximizing strength depends on forces imposed on structural elements. In the evolutionary acquisition of flight in the bat lineage, the forelimb skeleton must have come to experience locomotor-forces that differed from those engendered by the terrestrial locomotion of non-flying bat relatives. Here we successfully measure in vivo strain on the wing bones of flying mammals. Our data demonstrate that torsion and shear are unique and crucial features of skeletal biomechanics during flight, and suggest that the evolution of skeletal design in bats and other flying vertebrates may be driven by the need to resist these loads.     

The avian nature of the brain and inner ear of Archaeopteryx

Archaeopteryx, the earliest known flying bird (avialan) from the Late Jurassic period, exhibits many shared primitive characters with more basal coelurosaurian dinosaurs (the clade including all theropods more bird-like than Allosaurus), such as teeth, a long bony tail and pinnate feathers. However, Archaeopteryx possessed asymmetrical flight feathers on its wings and tail, together with a wing feather arrangement shared with modern birds. This suggests some degree of powered flight capability but, until now, little was understood about the extent to which its brain and special senses were adapted for flight. We investigated this problem by computed tomography scanning and three-dimensional reconstruction of the braincase of the London specimen of Archaeopteryx. Here we show the reconstruction of the braincase from which we derived endocasts of the brain and inner ear. These suggest that Archaeopteryx closely resembled modern birds in the dominance of the sense of vision and in the possession of expanded auditory and spatial sensory perception in the ear. We conclude that Archaeopteryx had acquired the derived neurological and structural adaptations necessary for flight. An enlarged forebrain suggests that it had also developed enhanced somatosensory integration with these special senses demanded by a lifestyle involving flying ability.     

基于TDLAS的管道泄漏检测载机飞行路径规划

从检测仪的检测灵敏度和检测激光对管道自主定位时保证检测管道不漏检两方面对载机的飞行路径进行规划。确定在两管段接头处载机的具体飞行方位。基于检测仪的检测灵敏度得到载机的可飞行高度与偏离管道距离的关系。结果表明:考虑实际检测时各因素的影响,建议载机飞行时偏离管线的距离应在45 m之内,飞行高度应低于110 m,且在保证飞行安全的前提下尽量降低飞行高度。     

蜻蜓捕食婚飞红火蚁的初步观察

报道了黄蜻(Pantala flavescens Fabricius)对婚飞红火蚁的捕食作用。蜻蜓聚集在婚飞红火蚁的蚁巢上方捕食婚飞红火蚁,平均17只?巢.次,最多40只蜻蜓同时出现于一个婚飞的蚁巢上方。距离地面5 m以下,蜻蜓对婚飞红火蚁的捕食率平均为85.66%,捕食行为主要发生在距离地面3 m以下。捕到婚飞蚁后,蜻蜓立即取食其腹部,丢弃其余部分。蜻蜓这种捕食行为与红火蚁的婚飞同时出现在降雨天气之后的1~2 d内。     

蜻蜒捕食婚飞红火蚁的初步观察

报道了黄蜻（Pantala flavescens Fabricius）对婚飞红火蚁的捕食作用。蜻蜓聚集在婚飞红火蚁的蚁巢上方捕食婚飞红火蚁，平均17只／巢．次，最多40只蜻蜓同时出现于一个婚飞的蚁巢上方。距离地面5m以下，蜻蜓对婚飞红火蚁的捕食率平均为85．66％，捕食行为主要发生在距离地面3m以下。捕到婚飞蚁后，蜻蜓立即取食其腹部，丢弃其余部分。蜻蜒这种捕食行为与红火蚁的婚飞同时出现在降雨天气之后的1～2d内。     

军用战机驾驶员操纵品质评估系统研究

分析了驾驶员操纵品质评估对飞行数据的要求，根据军用战机的飞行特点，建立了军用战机驾驶员操纵品质评估模型。利用Visual C 6．0和DirectX混合编程技术研制了可在普通配置的PC机上运行的驾驶员操纵品质评估系统。该系统的核心是基于专家系统理论快速识别飞机飞行状态和机动飞行动作，完成整个飞行课目的飞行成绩自动评定，逼真再现飞行过程。为提高飞行技术，确保飞行安全提供了技术手段。     

面向网络的实时飞行模拟系统模型

为提高培养飞行员的效率和质量,节约费用,从整体上设计并实现了一种实时的、面向网络的飞行系统仿真模型。为了使其具有通用性及实时性,采用数据驱动方式,并通过使用稳定系数方式单独设计了一种适用的空气动力的数学模型。通过简单的配置用XML(extensib le M arkup Language)格式描述的配置文件,可以同时模拟各种类型的飞机飞行驾驶,为飞行员的飞行模拟训练提供了仿真平台,模型的建立方法可以为同类设计和研究提供借鉴。实践证明,本模型在通用性、实时性以及仿真度等方面基本符合要求,应用此模型实现了某种国产初级教练机的仪表飞行系统,并被应用于飞行员的仪表飞行训练中。测试结果表明,如果不加控制信号,飞机能保持平飞状态达30 s以上。     

A Method to Identify Flight Obstacles on Digital Surface Model

In modern low-altitude terrain-following guidance, a constructing method of the digital surface model (DSM) is presented in the paper to reduce the threat to flying vehicles of tall surface features for safef light. The relationship between an isolated obstacle size and the intervals of vertical- and cross-section in the DSM model is established. The definition and classification of isolated obstacles are proposed, and a method for determining such isolated obstacles in the DSM model is given. The simulation of a typical urban district shows that when the vertical- and cross-section DSM intervals are between 3 m and 25 m, the threat to terrain-following flight at low-altitude is reduced greatly, and the amount of data required by the DSM model for monitoring in real time a flying vehicle is also smaller. Experiments show that the optimal results are for an interval of 12.5 m in the vertical- and cross-sections in the DSM model, with a 1:10 000 DSM scale grade.