基于自适应卡尔曼滤波的飞机气流角估计研究

迎角、侧滑角是飞机重要的飞行状态参数,而大气数据系统在恶劣天气、大迎角或机动飞行情况下是难以准确测量出气流角等数据的.基于飞行数据,研究了一种飞机气流角的估计方法.考虑到飞行数据可能受到外部干扰发生数据突变、各数据采样频率不同以及飞行数据之间的噪声统计特性均未知等情况,建立飞机系统状态方程和量测方程,将非等间隔理论与基于极大似然准则的自适应卡尔曼滤波算法进行融合,以飞机转弯和爬升飞行为实例,施加外部干扰,对飞机迎角、侧滑角进行估计.实验结果表明,该算法的估计精度和抗外部干扰的鲁棒性能均优于扩展卡尔曼滤波算法和无迹卡尔曼滤波算法.     

大攻角下基于信息融合的攻角/侧滑角估计方法

攻角和侧滑角是飞控系统和导航系统的重要参数。针对高性能飞行器在大攻角飞行时攻角和侧滑角不能精确测量问题,引入飞行动力学模型,选取姿态、姿态角速率、气流角和速度等飞行参数作为状态向量,以惯性导航系统提供的姿态、姿态角速率、加速度组成观测向量,构建扩展卡尔曼滤波器,融飞行动力学模型求解和状态估计的过程为一体,实现攻角和侧滑角实时精确估计。利用X-Plane系统的飞行仿真数据对攻角/侧滑角估计方法的可行性和有效性进行了验证。仿真结果表明,该方法不仅具有较高的精度、良好的稳定性和鲁棒性,而且可提高大气数据系统的测量范围和可靠性,能够有效地适用于大攻角飞行环境下攻角和侧滑角的测量。     

基于深度置信网络的QAR飞行数据特征提取分析

民航飞机的快速存取记录仪(QAR)在飞行过程中记录了大量的飞行参数,QAR数据是飞行安全评估的重要依据。针对QAR数据大样本、高维度的特点,提出了一种有效的飞行数据特征提取的高效算法——DBN算法。DBN优势在于其能够摆脱对大量数据处理技术与专家经验的依赖而对飞行数据进行特征提取。在不同类别飞行数据集上进行仿真实验,结果显示与主成分分析法(PCA)相比,通过DBN提取的特征进行分类识别准确率更高。     

一种新的迎角估计方法

针对迎角和侧滑角在大机动的条件下传感器不能准确测量的问题,提出了借助飞机的动力学模型,以惯导数据的姿态角及其角速率、加速度信息和大气数据的动压为量测值,利用扩展卡尔曼滤波的方法估计迎角和侧滑角,从而克服了对硬件的依赖性,实现了依靠算法代替传感器而获得飞行参数,但是该方法对系统数学模型即动力学模型的准确性有着较高的要求,通过仿真验证,该方法结构简单,易于工程实现,并且估计精度在0．4°以内,具有很好的实时性和鲁棒性。     

机载导航系统在海上飞行中的应用

机载导航系统对海上飞行作用十分重大,系统向飞行员提供了大量的领航数据,其数据实时改变,如果按照其数据飞行,就意为着飞机的航向要跟着不断地变化,频繁地改变航向并不有利于飞行。所以,飞行员要充分利用机载导航系统的数据,根据领航原理人工引领飞机航行,这样,既能充分发挥机载导航系统数据多、自动测量的优势,又能充分发挥人的作用,完好地完成领航任务。飞机在海上飞行时,地标少,可以利用机载导航系统的数据,实施检查航迹、修正航迹、控制飞机转弯、空域飞行、从海上归航等飞行任务。     

一种飞行计划航段自动激活方法

飞机从一个航段飞向下一个航段时,需要对下个航段是否激活进行判断.提出了一种新的飞行计划航段自动激活方法,通过获取飞机当前位置及其磁差,并结合临近的3个航路点对应位置的磁差经纬度,分别计算3个航路点与飞机位置对应的磁航向角,通过磁航向角之间做差进行比较,进而判断是否被激活.算法推导完成后,通过基于模型的系统工程工具SCADE SUITE进行了建模,并结合杰普逊航图进行了实际数据采样与仿真.仿真结果表明:该航段自动激活方法能够有效稳定地激活下一航段,比传统方法计算简便,方法实用有效.已在实际飞行中成功应用,达到了预期效果.     

飞行器在高机动条件下迎角、侧滑角的测量

嵌入式大气数据传感(FADS)系统比传统迎角、侧滑角传感器在测量精度、可靠性、隐身性能上都具有较大的优势,因此该系统可被应用于各型飞行器上.但由于该系统在获得大气参数方面存在延时,所以它在飞行器机动飞行状态下迎角和侧滑角的测量精度会下降.针对这一问题,提出了以FADS测量结果为基础,采用惯性导航系统(INS)测量的迎角、侧滑角变化量进行修正的FADS/INS组合迎角、侧滑角测量方法.理论分析和仿真结果表明,该组合系统在飞行器处于平稳和机动飞行时,对迎角、侧滑角的测量均能获得较高精度.     

飞机飞行参数采集系统

飞机在飞行过程中,其工作参数和飞行状态参数,如发动机的转速、温度、飞机的耗油量、俯仰角度、侧向角、空速、飞行高度和航向等,既是飞行员和地面飞行指挥员随时要掌握的参数,也是保障飞行安全最为重要的数据。但是,这些参数主要由航空仪表指示给飞行员,只能被飞行中的飞行员实时使用,而地面指挥员只有通过无线电通信来获取某些时刻的飞行参数。这不仅需要较长的时间,而且由于频繁地与多架次飞机通信询问,势必分散飞行员的精力。我们设计了一个飞行参数采集遥测系统,它能根据地面指挥监测系统的遥测指令,选择所要测控的目标飞机,自动地完成其飞行参数的采集并将数据实时地传送到地面的任务下面我们对此作一简介。一、系统功能和主要技术指标本系统的功能和主要技术指标如下: 1.由单片机控制完成8个飞行参数的A/D转换(采用12位AD 574)。8个参数是发动机的转速和温度、飞机的耗油量、俯仰角、侧向角、空速、飞行高度和航向。八路A/D转换时间小于500μs。     

基于航向误差的捷联陀螺罗经标定方法

陀螺罗经的航向误差与航向角和器件误差之间存在着非线性映射关系,利用航向误差关系提出了一种捷联陀螺罗经标定方法。该方法根据陀螺罗经的航向效应,在分析了罗经航向误差传播机理的基础上,对航向误差进行曲线拟合,建立航向角与航向误差的数学模型,根据航向误差关系完成对陀螺罗经的标定。实验数据表明:所提标定方法能够有效减小航向误差,提高陀螺罗经的使用精度,具有实际应用价值。     

在超音速情况下自动拦截机系统攻击阶段的理论研究——着重于拦截机的空气动力学及动力学的表达式。

本文介绍的是,自动控制拦截机攻击阶段的理论研究结果。该研究之主要目的,在于研究飞机作为拦截系统中一个组成部分的飞行状态、飞机动力学的表达式,以及非线性空气动力对飞机飞行机动性的影响。为了进行这一研究,在一个大型模拟计算机上,对现代高速拦截机、动力学方面理想之雷达控制的指挥仪型前置拦截航向导引系统及速度型自动驾驶仪进行了模拟。雷达噪音及阵风的影响未作考虑。全部研究结果,以飞机系统运动的时间关系曲线图表示之。 所取的基本飞行机动是,加速度为5g的上升转弯,同时采用横滚和加速度指令。对飞机而言,采用线性表达式,势必产生飞机的运动误差,较大的脱靶距离。非线性空气动力的主要作用,在于改变升降舵及副翼的运动。一些次要的作用,在于改变纵向运动及侧滑与偏航变化速度。     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Technology innovation and process integrations for sub-100nm gate patterning

This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration.     

White organic light-emitting devices based on fac tris（2- phenylpyridine） iridium sensitized 5,6,11,12-tetraphenylnap -hthacene

We have fabricated the white organic light-emitting devices （WOLEDs） based on 4,4＇ -bis（2,2 -diphenyl vinyl）-1,1＇ - biphenyl （DPVBi） and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene （rubrene）. The device structure is ITO/2T-NATA （20 nm）/NPBX （20 nm）/CBP： x%Ir（ppy）3：0.5% rubrene （8 nm）/NPBX （5 nm）/DPVBi （30 nm）/Alq（30 nm）/LiF（0.5 nm）/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris （2-phenylpyridine） iridium [Ir（ppy）3], acts as a yellow light-emitting layer, and N,N＇ -bis- （1-naphthyl）- N,N＇ -diphenyl -1, 1＇ -biphenyl-4,4＇ -diamine （NPBX） acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir （PPY）3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.     

Complete approach to automatic identification and subpixel center location for ellipse feature

To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction.     

小角度扩展相关性近似算法分析

本论文提出一种在多天线MIMO信道相关性建模中小角度扩展近似理论算法,并应用于分析MIMO系统性能。分析中分别对三种不同角能量分布情况下的空间相关性研发快速近似计算法,并同时提出双模(Bi-Modal)角能量分布情况下的近似运算。通过分析这些新方法的近似效率,可以得到计算简单、复杂度低、而且符合实际的MIMO相关信道矩阵,对系统级的快速高效计算法的研究和系统级的评估以及误差分析具有重要的意义。     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.