飞行事故的一种自适应模糊神经网络预测方法研究

飞行事故预测对于预防飞行事故具有十分重要的意义.首先系统分析了空军飞行事故的主要影响因素,对其中的定性因素进行了量化;然后利用系统分析的成果和历史统计数据建立了空军飞行事故的自适应模糊神经网络预测模型.整个预测过程突破了纯数学模型预测的局限性,实现了预测的定性和定量的结合;由于预测中使用了一种基于高木.关野模糊模型的自适应模糊神经网络,从而使预测模型具有很强的自适应能力,预测结果也比较令人满意.     

Solving the flight perturbation problem with meta heuristics

When there is a perturbation in a carefully constructed aircraft schedule, e.g. an aircraft breakdown, it is important to minimize the negative consequences of this disturbance. Here, a tabu search and a simulated annealing approach to the flight perturbation problem are presented. The heuristics use a tree-search algorithm to find new schedules for the aircraft, and utilize a path relinking strategy to explore paths between structurally different solutions. The computational results indicate that the solution strategies, especially the tabu search, can be successfully used to solve the flight perturbation problem.     

基于一组Kalman滤波器信息融合的故障诊断

为了能及时准确地诊断发动机的传感器和执行机构故障,本文提出了基于一组Kalman滤波器信息融合的方法进行故障诊断。首先根据传感器特性设计了一组滤波器用于传感器故障诊断、隔离,每个滤波器针对一个传感器进行设计;其次根据执行机构故障特性设计了一组Kalman滤波器进行执行机构偏差估计,从而对执行机构进行故障诊断、隔离;接着给出了传感器、执行机构信息融合的诊断方案;最后分别给传感器、执行机构添加故障进行方案验证,仿真结果得出在传感器或者执行机构任意部件出故障的情况下,该融合方法可以有效地诊断并隔离出有故障的传感器或者执行机构。     

用于光学位移传感器的新型数字编码光栅尺的制作

介绍了数字编码光栅尺的结构设计并提出一种制作方法.采用紫外对准光刻、全息光刻及湿法腐蚀结合在(100)硅片上制作母光栅尺,并以具有紫外固化特性的聚氨酯丙烯酸酯为材料,将母光栅尺复制到硬基底上.实验表明,该工艺可重复性高,复制光栅尺的衍射效率高于母光栅尺的90％,并能承受航空环境-55℃～70℃的高低温冲击.光栅尺的制作准确度满足传感器的要求,信号响应准确率100％.该方法可对具有准确度高、图形复杂、工作环境恶劣等特点的微纳米结构的制作提供借鉴.     

Community response to aircraft noise in Ho Chi Minh City and Hanoi

To formulate Vietnamese and global noise policies, social surveys on community response to aircraft noise and combined noise from aircraft and road traffic were carried out in Ho Chi Minh City from August to September 2008 and in Hanoi from August to September 2009. In total, 1562 and 1397 responses were obtained in Ho Chi Minh City and Hanoi, respectively. The aircraft noise was measured for seven successive days, and the combined noise was measured for 24 h. Aircraft and combined noise exposures ranged from 53 to 71 dB and 73 to 83 dB L_den in Ho Chi Minh City and from 48 to 61 dB and 70 to 82 dB L_den in Hanoi, respectively. The dose–response curve for aircraft noise for Vietnam was established and fitted onto the curve for the European Union. For the same noise exposure, the aircraft noise annoyance in Hanoi was higher than that in Ho Chi Minh City because of the lower background noise level in Hanoi.     

基于激光雷达回波的飞机尾涡参量提取

为了实现对飞机尾涡的有效监测,解决机场飞行安全与跑道容量受限的问题,提出了一种基于激光雷达回波的飞机尾涡参量提取算法.从尾涡的物理模型出发研究飞机尾涡的涡旋环量、径向速度分布等参量,对尾涡结构进行描述.依据尾涡参量的性质,给出了参量提取算法的设计流程,即对回波信号进行分解除噪等处理;通过选取门限确定正负速度包络,进而得到径向速度分布;利用径向速度分布反演得到涡核半径、涡核位置及涡旋环量等尾涡参量.最后以某型飞机的激光雷达探测实验数据为例进行了实例计算并与模型仿真结果进行对比,验证了该算法的有效性.     

Polynomial programming prevents aircraft (and other) conflicts

Using a known algebraic result, we obtain a finite polynomial programming reformulation of a semi-infinite program modeling the aircraft deconfliction problem via subliminal speed regulation. Solving the reformulation yields better results than the state of the art for most of the tested instances.     

基于LIBS光谱与成分分析的飞机蒙皮激光除漆可控性研究

激光除漆作为激光清洗技术的分支,有望替代传统打磨及化学除漆工艺,实现飞机蒙皮表面漆层的可控清除,但除漆过程及质量的可控性依赖于有效的原位、在线监测技术。针对飞机铝合金蒙皮表面多漆层结构,采用LIBS技术对不同漆层、不同厚度时漆层特征元素进行光谱与成分分析,在信号解译基础上建立漆层去除层数、去除厚度与LIBS光谱变化的内在关联,实现除漆过程质量的实时监测与反馈控制。结果表明,分层除漆过程中面漆、底漆完全清除后,漆层特征元素（Fe,Ti）的光谱峰消失。LIBS监测到面漆的特征元素Fe在501.494 1和521.517 9 nm处Fe Ⅰ 的光谱特征峰消失时,判定面漆完全清除。监测到底漆特征元素Ti在498.173 0,499.107 0和521.039 0 nm处Ti Ⅰ 的光谱特征峰消失时,判定底漆完全清除。厚度除漆时,随漆层厚度降低或激光脉冲作用次数增加,漆层特征元素（Ca）的光谱峰强相应降低,至漆层厚度为0时（完全去除）,漆层特征元素光谱峰消失,同时基体特征元素（Al）光谱峰出现。LIBS监测616.217 0,643.907 0和422.673 0 nm处Ca Ⅰ 的光谱信号强度变化能够监测激光除漆时剩余漆层厚度,实现对激光除漆厚度的可控清除监测。另外,结合EDS与SEM测试分析,验证了LIBS用于飞机蒙皮激光除漆过程与效果监测、分层与厚度控制的可行性,表明在不损伤基体氧化层的前提下,通过监测对应波长位置的面漆、底漆特征元素光谱与成分变化规律能够实现激光分层可控、厚度可控除漆。     

Equivalent dose measurements on board an Armenian Airline flight and Concorde (correction of Concord) (9-17 km)

The results of investigations of the neutron component (E=1–10 MeV) of cosmic radiation on board the “Armenian Airlines” aircrafts using nuclear photoemulsion are presented. The emulsions were exposed on the flights from Yerevan to Moscow, St.-Petersburg, Beirut, Athens, Frankfurt, Amsterdam, Paris and Sofia, and on Concord supersonic flights from Paris to New York.

The dependence of the neutron fluxes, and on absorbed and equivalent doses on the flight parameters were investigated. On the flights of the supersonic Concord, with an altitude of 17 km, the neutron fluxes were essentially higher in comparison to those measured on Armenian airliners. It is interesting to note, that the neutron flux and equivalent dose rate decrease with altitude up to 470 km in space, for example, on board the STS-57.

The shape of the differential energy spectrum for fast neutrons is the same on all Armenian airlines flights, but significantly different at 17 km altitude, where the flux in the energy region above 3 MeV is increasing.