基于LSTM-ResNet模型的时变结构损伤检测

面向火箭结构健康监测，提出了一种基于深度学习的损伤检测方法，直接将多个通道的振动数据作为输入，并基于由长短时记忆网络LSTM（Long Short-Term Memory Networks）和残差卷积神经网络ResNet（Residual Convolutional Neural Networks）组合而成的LSTM-ResNet网络进行损伤识别。其优点在于，首先利用LSTM提取信号的时间依赖特征，减轻了由某些通道信号缺失带来的影响，再利用ResNet在不损耗特征的情况下进一步提取空间特征，提高了训练效率和损伤辨识准确性。通过充液圆筒振动放水实验模拟火箭飞行状态下的燃料消耗，并基于自主构建的数据集和公用数据集对LSTM-ResNet、LSTM、ResNet以及ResNet-LSTM网络进行了训练，训练结果表明，LSTM-ResNet组合网络无论在传感器是否存在故障的情况下都具有更好的性能，损伤检测精度更高。     

故障注入技术在飞行器非电系统中的应用进展

故障注入是一种基于试验的测评方法，是飞行器综合健康管理的重要组成部分，在提高飞行器的安全性方面具有重要作用。本文介绍了故障注入技术的基本原理，详细阐述了故障注入的各种实现方法在飞行器中的应用现状，重点分析了故障注入技术在飞行器结构、防热、液压、机械等非电系统应用中的关键技术以及存在的技术难点，并展望了该领域的发展。     

Improving accuracy of damage quantification based on two-level consistency control of PZT layers

Structural health monitoring-based quantitative damage diagnosis technique plays a key role in real-time condition monitoring. Among the current research, piezoelectric (PZT) sensor and Guided Wave (GW) based damage quantification methods are promising, which normally establish a calibration model between GW feature and damage degree by experiments on batch specimens, and then conduct the calibration model on the monitored specimen. However, the accuracy of PZT and GW based damage quantification is affected by dispersion introduced by sensor network performance, structural material, and damage propagation among the adopted batch specimens. For improving the accuracy of damage quantification, this paper adopts PZT layer as sensor network and creatively implements theoretical and experimental research on batch PZT layers consistency control. On one hand, a two-level consistency control method based on multidimensional features-Euclidean distance is proposed to ensure the performance consistency of PZT layers placed on different specimens. On the other hand, experimental research on typical aircraft lug structures is also carried out to evaluate the requirement on performance consistency of PZT layers when performing quantitative damage diagnosis, and further verify the proposed two-level consistency control method. Experimental results show that the accuracy of damage quantification raises by 38% when the dispersion of different PZT layers is controlled within 5%.     

基于DFT的布林线视角下的信号异常值检测方法

针对装备健康管理中关键部件常出现状态异常、性能退化问题,提出了1种兼顾时域统计性和频域周期性的信号数据异常值检测方法.在频域上,通过离散傅里叶变换(Discrete Fourier Transform,DFT)进行频谱分析,根据幅值大的低频谐波的周期选择布林线的计算周期;在时域上,根据不同的置信度,利用移动平均值和标准...     

航天复合材料智能健康监测技术研究进展北大核心CSCD

航天复合材料智能健康监测技术水平是衡量航天型号可靠性与先进性的重要标志之一,是支撑航天装备向多次重复使用、长期可靠运行发展的关键技术之一。本文总结了近年来复合材料智能健康监测在传感器制作技术、传感器与复合材料集成技术、复合材料状态监测技术、复合材料损伤及失效表征技术、人工神经网络数据处理和分析技术主要研究进展及发展现状,提出了航天复合材料智能健康监测技术存在的问题以及后续未来发展的重要方向。     

固液捆绑火箭发动机健康诊断技术

为使固液捆绑运载火箭发射更具有可靠性和安全性，本文首次提出了一种基于三冗余架构的芯级液体发动机健康诊断系统。在芯级液体发动机点火后，由箭上健康诊断系统根据红线算法对发动机状态进行诊断，确认液体发动机状态正常后再进行固体发动机点火。通过地面发动机试车及飞行试验考核，结果表明:该发动机健康诊断系统设计正确，能够及时有效地检测液体发动机工作状态，且未发生误警报或漏警报。     

于不确定性与重要度的改进DSmT健康状态评估

针对目前健康状态评估准确度不高、客观性不强的问题,引入评估指标的不确定性和重要度,提出一种基于不确定性和重要度的改进DSmT（Dezert Smarandache theory）健康状态评估方法.首先,引入指标不确定性和重要度作为加权因子,能够得到比较合理的指标权重；其次,采用模糊综合评判方法,通过构造三角形梯形隶属度函数确定各指标的广义基本信度赋值；然后,基于指标权重对广义基本信度赋值进行改进DSmT融合,得到各指标的广义基本信度赋值加权融合后的评估结果；最后,以某供电系统为例进行了实例验证,结果表明该方法能够赋予各评估指标较合理的权重,健康状态评估结果与系统实际运行状态相符.      

Space law education in China: Status quo,shortcomings and possible ways out

Space law education has an essential role in the space capacity building of a country because of its importance for human resources development in space law. Comparisons between Canada and China, the European Union and China and the United States of America (USA) and China in space law degree education, course, teaching methodology, institute and practice and communication platform are provided in an attempt to review some issues which exist within the Chinese space law educational system and to seek a better choice for China’s space law education reform. Chinese space law education has achieved noticeable progress over the past two decades. However, it is still limited in comparison to its counterparts in Europe and Northern America. The range of the space law degree education programmes and space-law-related courses is comparatively limited. A gap remains between space law education and practice in China. Chinese space law classes are still dominated by the teacher-centred teaching methodology, although several universities have some new teaching practices. The establishment of seven space law-related research institutes plays an increasingly important role in Chinese space law education, space law and policy research and legal advisory services for the Chinese government and non-governmental sectors. However, these institutes still have a long way to go in comparison with their counterparts in Europe and Northern America. While China has established domestic research platforms for space law communication through international cooperation, it does not provide space law practice platforms for space law education. While international space law does not provide a direct legal foundation for space law education in China, Chinese educational laws can lay a profound legal foundation for Chinese space law education. To promote its national expertise and capacity in space law, based on the three-pillar model and the experiences of its counterparts in North America and Europe, China should adopt a systematic and sustainable regime for its space law education.     

分布式协同微纳遥感星群的智能控制系统关键技术

近年来，国内外微纳遥感星座发展不断加速，通过高频重访大幅提升了对地观测的时间分辨率，但是由于单颗微纳卫星观测能力受限，难以满足多源同步与融合、高品质、大幅宽等数据应用需求。为此，将星座与星簇相结合，以星座化分布满足高时间分辨率需求，以星座节点上的星簇协同观测获取多源、高品质、宽幅数据，构建基于微纳卫星的分布式协同遥感系统，是兼顾上述遥感应用需求的有效途径。智能分布式协同控制是该系统的核心关键，为此，必须研究解决星座+星簇大规模动态微纳遥感星群控制系统的分布协同自主导航、智能运动规划与控制、智能健康预测与管理、智能组网等关键技术难题。在梳理分析国内外分布式微纳遥感系统的基础上，给出分布式协同微纳遥感星群的概念内涵，分析其特有的四方面难题，梳理总结相关技术发展现状与趋势，以期为后续该方向的研究起到一定的借鉴作用。     

面向有效载荷的准实时在轨健康评估系统

卫星遥测数据通常有2种手段获得，一种是卫星经过地面测控站下传的实时遥测和延时遥测;另一种手段是通过数传分系统下传的全球遥测。全球遥测作为监视卫星载荷健康状态的主要手段，存在数据量大、文件数量较多、人工处理和判读工作量大等问题。针对该情况，提出准实时在轨健康监视系统的设计方案。该系统具备遥测源码定时获取、有效载荷遥测数据提取和解析、遥测数据存储、遥测数据自动判读和特征统计、超限报警、曲线显示和数据输出等功能，可对卫星有效载荷的健康状态进行准实时、自动化的监视和评估。