数据传输卡插拔互换性技术探讨

介绍了数据传输卡(DTC)插拔互换性技术有关的几个问题。在产品有使用延续性要求的限制下,在不提高原零部件制造精度和不改变原装配方式的条件下,提出了按照模拟量传递原则而建立的标准体系——装配检验对合平台,并以此在生产中实施,满足了产品使用互换性要求。同时提出了一种新型弹顶组件的设计,使弹顶位置更合理,弹顶更可靠,从而进一步提高了产品插拔可靠性。     

利用随机森林算法的卫星控制系统故障诊

针对卫星姿态控制系统存在闭环控制，外部干扰强，进而影响故障诊断准确性和实时性的问题，提出了一种利用随机森林算法的卫星姿态控制系统姿态敏感器和执行器故障诊断方法。首先，采集不同故障情形下卫星姿态控制系统的输入输出数据，进行特征提取。随后通过随机有放回抽样划分训练集和测试集，建立基于随机森林算法的故障诊断模型。利用生成的随机森林模型，对实时输入输出数据进行分类，实现卫星姿态控制系统的故障诊断。利用卫星姿态控制系统半物理仿真平台的数据进行实验，对比实验结果表明：本文所提方法可以实现故障高精度分离，并具有更好的实时性，适用于卫星姿态控制系统的故障诊断问题。     

锂离子电池单离子导体聚合物电解质研究进展

锂离子电池在3C电子产品和动力汽车电池行业广泛应用,在航天电源领域也展现出一定的前景。单离子导体是基本仅由参与电化学反应的锂离子迁移的电解质体系,解决传统锂离子电池液态电解质存在的副反应和阴离子的浓差极化等问题,改善电池的库伦效率和循环寿命。研究者们发展了多种类型的单离子导体电解质。本文总结了近5年来不同阴离子类型的单离子导体聚合物电解质合成策略以及分子动力学模拟计算的最新进展。     

Bipartite graph-based control flow checking for COTS-based small satellites

Single event upset(SEU)effect,caused by highly energized particles in aerospace,threatens the reliability and security of small satellites composed of commercial-off-the-shelves(COTS).SEUinduced control flow errors(CFEs)may cause unpredictable behavior or crashes of COTS-based small satellites.This paper proposes a generic software-based control flow checking technique(CFC)and bipartite graph-based control flow checking(BGCFC).To simplify the types of illegal branches,it transforms the conventional control flow graph into the equivalent bipartite graph.It checks the legality of control flow at runtime by comparing a global signature with the expected value and introduces consecutive IDs and bitmaps to reduce the time and memory overhead.Theoretical analysis shows that BGCFC can detect all types of inter-node CFEs with constant time and memory overhead.Practical tests verify the result of theoretical analysis.Compared with previous techniques,BGCFC achieves the highest error detection rate,lower time and memory overhead;the composite result in evaluation factor shows that BGCFC is the most effective one among all these techniques.The results in both theory and practice verify the applicability of BGCFC for COTS-based small satellites.     

Effect of blade sweep on inlet flow in axial compressor cascades

This paper presents comparative numerical studies to investigate the effects of blade sweep on inlet flow in axial compressor cascades. A series of swept and straight cascades was modeled in order to obtain a general understanding of the inlet flow field that is induced by sweep.A computational fluid dynamics(CFD) package was used to simulate the cascades and obtain the required three-dimensional(3D) flow parameters. A circumferentially averaged method was introduced which provided the circumferential fluctuation(CF) terms in the momentum equation.A program for data reduction was conducted to obtain a circumferentially averaged flow field.The influences of the inlet flow fields of the cascades were studied and spanwise distributions of each term in the momentum equation were analyzed. The results indicate that blade sweep does affect inlet radial equilibrium. The characteristic of radial fluid transfer is changed and thus influencing the axial velocity distributions. The inlet flow field varies mainly due to the combined effect of the radial pressure gradient and the CF component. The axial velocity varies consistently with the incidence variation induced by the sweep, as observed in the previous literature. In addition, factors that might influence the radial equilibrium such as blade camber angles, solidity and the effect of the distance from the leading edge are also taken into consideration and comparatively analyzed.     

Survey of orbital dynamics and control of space rendezvous

Rendezvous orbital dynamics and control （RODC） is a key technology for operating space rendezvous and docking missions. This paper surveys the studies on RODC. Firstly, the basic relative dynamics equation set is introduced and its improved versions are evaluated. Secondly, studies on rendezvous trajectory optimization are commented from three aspects： the linear rendez- vous, the nonlinear two-body rendezvous, and the perturbed and constrained rendezvous. Thirdly, studies on relative navigation are briefly reviewed, and then close-range control methods including automated control, manual control, and telecontrol are analyzed. Fourthly, advances in rendezvous trajectory safety and robust analysis are surveyed, and their applications in trajectory optimization are discussed. Finally, conclusions are drawn and prospects of studies on RODC are presented.     

5 代机第2动力系统的发展趋势分析

针对5代机的性能特征,分析了其对第2动力系统的能力需求。通过深入研究第2动力系统发展历程,以及对美国F-22和F-35等先进战斗机典型第2动力系统功能综合集成和能量综合利用等发展规律并进行总结,分析预测未来5代机第2动力系统将沿着以"动力热管理系统"和"涡电综合能源系统"为代表的2个方向发展,并对未来中国第2动力系统提出了发展思路和措施建议,规划了其发展路线图。     

基于智能机械臂的任意扫描曲面天线测试系统

传统的天线测试技术已趋成熟,这些系统主要由扫描架与转台构成,体量大且造价相对高昂.而随着人工智能技术和制造水平的巨幅提升,机械臂产业已得到广泛应用,利用高精度机械臂代替扫描架与伺服控制,加之数据后处理算法,开创了天线测试领域的新纪元.研究的基于智能机械臂的任意曲面天线测试系统为国内天线测试领域的首例实践,可实现任意扫描...     

领域本体的自动维护研究

针对领域本体维护的重要性与合并本体存在的异构本体及不一致性错误等问题,提出了一种基于本体合并的领域本体自动维护方法,对相关实现过程作了详细介绍,重点给出了概念的相似性匹配算法.该算法通过计算概念的定义、实例、属性、关系及推理的相似度,得到了本体中概念之间的相似度.本文还探讨了本体不一致性的错误,分析了概念间的上下位关系、非通用关系及相关特性的不一致,并给出了解决方案.实验结果表明,该方法具有一定的实用性和可靠性,能够得到较正确的领域本体的维护结果,并能够解决相关不一致的错误.