飞行器性能样机虚拟试验系统研究与实现

为实现航天飞行器研制中性能样机模型的充分利用,提出了飞行器性能样机虚拟试验系统的总体方案,通过试验基础数据库、试验数据管理、验证辅助工具、虚拟试验应用等子系统划分和工作流程设计,提供对虚拟试验的全流程支持。系统突破了试验数据对象化管理、试验流程建模等关键技术,并基于虚拟试验支撑平台VITA完成了相应系统实现,在多个飞行器研制过程中开展了典型应用。     

高功率微波系统仿真数据管理支撑技术

针对目前高功率微波系统仿真平台产生大规模复杂结构时变数据场,提出了新的数据存储与处理需求,而现有数据管理方法难以提供平台所需要的数据存取与分析能力。为此,通过研究科学数据表示、元数据管理、高效I/O、并行处理和快速选择等关键技术,集成应用成果并研制自主产权的科学数据管理软件,实现了高功率微波系统仿真实验数据的高效存储、组织与管理,对于方便平台子系统间的数据交换、提升数据存取效率及研究关键物理问题起到了很好的支撑作用。     

仿真工程管理系统研究

仿真系统中存在不同的应用目的,涉及多种仿真想定、模型、数据、评估等内容,在多用户情况下仿真资源缺乏统一的管理,会严重影响了仿真系统的使用效率。为了提升仿真系统的使用效率,本文提出一种仿真工程管理的方法,利用共享内存实时采集MOM数据实现对邦员负载信息的有效监控;通过服务器统一收集XML格式仿真联邦运行数据和监控日志实现仿真运行回放;通过构建通用模型接口和评价体系实现了基于Web的仿真评估。基于B/S架构构建了仿真工程管理系统,可将模型和数据以仿真工程为单位进行统一管理,实现了对仿真运行的统一监控、数据的统一的收集与管理、评估模型管理和基于仿真试验数据的仿真评估,从而提高仿真系统的使用效率,减少仿真应用系统的集成工作量。     

性能样机模型统一读取及显示系统实现

航天复杂产品研制过程中,形成了大量以CAE有限元模型或实物试验数据形式存在的性能样机模型;性能样机模型统一读取及显示方法,可以支持Nastran、Ansys、Abaqus、Fluent等多种CAE有限元软件数据和实物试验数据文件的直接读取,并支持根据用户需求进行其他格式文件的定制开发,实现了对性能样机模型统一读取和显示的通用化;经测试该系统不需依赖及安装商用CAE软件,文件压缩比可达到2%~30%,易于在PDM、SDM、TDM等外部系统中进行集成使用,能够充分使用产品研制过程中产生的各类数据,为大系统的协同研发打下基础。     

基于低体分SiC/Al主镜框的空间相机主支撑结构热特性分析与验证

基于微小卫星平台对高分辨相机的重量约束,以高分微纳卫星CX6-02数字超分辨相机研制为例,提出一种基于低体分SiC/Al主镜框的空间相机主支撑的结构形式,并开展主镜框一体拓扑优化设计分析和试验验证。Zernike多项式计算及光机热集成仿真结果验证了低体分SiC/Al主镜框作为空间相机主支撑结构的有效性。热光试验数据及在轨成像结果表明,兼具主支撑功能的低体分SiC/Al主镜框的空间相机试验数据与仿真数据基本吻合,且性能稳定,可为未来采用低体分SiC/Al主镜框作为主支撑的航天相机轻量化设计和研制提供理论与技术参考。     

典型大数据仓库-飞行试验数据仓库设计

在现代数据仓库技术思想的指导下,围绕试飞数据的非结构化大数据的特点,面向型号工程对试飞数据的统一管理和高效处理需求,分别针对试飞大数据的粒度描述和综合管理,设计了飞行试验元数据标准和特有的基于二进制文件的数据库管理服务,解决了飞行试验数据仓库设计中结构化与非结构化大数据的统一维度建模和数据关系维护的关键技术问题,为基于数据仓库的试飞大数据在线管理与分析系统的建立提供了基础,满足了型号工程对试飞数据的高效分析需求。     

复杂产品虚拟试验支撑框架

VITA支撑框架作为虚拟试验验证的共性技术支撑平台,主要用于解决复杂航天产品研制试验过程中的异构性、实时性、互联互通等问题。本文提出了一套完整的VITA虚拟试验体系框架,讨论了它的研究背景及体系结构,研究了VITA运行中间件的技术架构,并进行了性能测试,介绍了基于中间件的扩展服务,介绍了VITA目前的应用情况,初步应用表明,VITA支撑框架为复杂产品研发过程提供了有力的虚拟试验技术支持,可在航空、航天等多个行业的复杂产品研发中进行应用。     

系统健康管理中的寿命模型仿真研究

在航空、航天、通信等领域,高可靠性和长寿命设计的产品所占比重逐渐增大。性能退化状态评估和剩余使用寿命预测技术在提高该类产品安全性和维护效率、降低全寿命周期成本等方面意义重大。针对当前国内健康管理研究中缺乏寿命及可靠性基础数据的现状,介绍了系统寿命预测的典型过程,重点分析了寿命模型研究和仿真中存在的若干问题,旨在建立实现简单且与实际系统运行过程相似度高的寿命模型的建模方法,为后续系统性能状态评估提供有效的数据支持。     

虚拟试验支撑框架VITA研究与实现

虚拟试验验证技术可为复杂航天产品的试验验证提供有效的技术支撑。本文主要介绍了虚拟试验支撑框架VITA研究与实现情况,包括其系统组成及主要技术特点,重点介绍系统实现方案及其在飞行器研制过程中的应用情况。实践表明VITA支持对产品关键系统的技术性能验证,有效解决了产品难以开展大系统联合试验的难题。     

基于HLA的仿真运行控制方法设计

仿真运行控制是仿真运行支撑平台的关键技术,大型复杂仿真试验需要将仿真运行平台部署在多个运行终端上,针对分布式网络通信的需求,基于HLA分布式网络通信协议,提出一种基于HLA的仿真运行控制方法;该方法基于HLA的6大标准服务设计了包括对象管理、试验调度、事件管理等功能的仿真引擎,并考虑终端的承载能力实现终端节点的分布式部署,在仿真试验运行过程中对系统运行状态和成员信息进行动态实时监控,较好地提高了仿真试验的运行效率。     

Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide

Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.     

Effect ofγ-radiation on the spectral luminescence characteristics of impure cadmium tungstate crystals

Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·10⁴ Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.     

Femtosecond Transform-Limited Pulse Generation by Compensating for the Linear Chirp of SPM Spectra in Dispersion Shifted Fibers

A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.     

Sorting of bending magnets for the SSRF booster

The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.     

Measurement of nonlinear coefficient of optical fiber based on small chirped soliton transmission

We measure the waveform and phase curves of short optical pulses before and after transmission over different lengths of fibers by use of the pulse analyzer with the frequency-resolved optical gating (FROG),and numerically simulate pulse evolution under the experimental conditions.The nonlinear coefficient of the fiber is given by comparing the experimental results with the numerical ones.Difference between the experiment and numerical simulation is analyzed.     

Resonance scattering of canonical elastic shells in absorbing fluid medium

Resonance scattering of elastic spherical shell and cylindrical shell while the surrounding fluid medium has absorption is studied. The normal mode solution derived using exact elastic theory and the separation of variables is still applicable. However, the scattering form function has to be modified for the absorbing medium, otherwise the unreasonable result would be obtained. The backscattering form function in the absorbing medium is redefined, and the form function of elastic spherical and cylindrical shell with vacuum or solid matter filled is calculated in various absorption conditions. The results show that the absorption of surrounding fluid leads to notable attenuation of the coincidence resonances in the mid-frequency, but it has a little influence on the low-frequency resonance scattering induced by the filler inside the shell.     

Single-beam self-referenced phase-sensitive surface plasmon resonance sensor with high detection resolution

A versatile and low-cost single-beam self-referenced phase-sensitive surface plasmon resonance(SPR)sensing system with ultra-high resolution performance is presented.The system exhibits a root-mean-square phase fluctuation of ±0.0028.over a period of 45 min.i.e.a resolution of±5.2×10-9 refractive index units.The enhanced performance has been achieved through the incorporation of three design elements:a true single-beam configuration enabling complete self-referencing so that only the phase change associated with SPR gets detected,a differential measurement scheme to eliminate spurious signals not related to the sensor response,and the elimination of retardation drifts by incorporating temperature stabilization in the liquid crystal phase modulato .Our design should bring the detection sensitivity of non-labeling SPR biosensing closer to that achievable by conventional fluorescence-based techniques.     

Influences of SiO2 protective layers and annealing on the laser-induced damage threshold of Ta2O5 films

Ta2O5 films are prepared on BK7 substrates with conventional electron beam evaporation deposition.The effects of SiO2 protective layers and annealing on the laser-induced damage threshold (LIDT) of the films are investigated.The results show that SiO2 protective layers exert little influence on the electric field intensity(EFI)distribution,microstructure and microdefect density but increase the absorption slightly.Annealing iS effective on decreasing the microdefect density and the absorption of the films.Both SiO2 protective layers and annealing are beneficial to the damage resistance of the films and the latter is more effective to improve the LIDT.Moreover,the maximal LIDT of Ta2O5 films is achieved by the combination of SiO2 protective layers and annealing.     

A stereo matching algorithm using multi-peak candidate matches and geometric constraints

Gray cross correlation matching technique is adopted to extract candidate matches with gray cross correla- tion coefficients less than some certain range of maximal correlation coefficient called multi-peak candidate matches. Multi-peak candidates are extracted corresponding to three closest feature points at first. The corresponding multi-peak candidate matches are used to construct the model polygon. Correspondence is determined based on the local geometric relations between the three feature points and the multi-peak candidates. The disparity test and the global consistency checkout are applied to eliminate the remaining ambiguous matches that are not removed by the local geometric relational test. Experimental results show that the proposed algorithm is feasible and accurate.