全相位FFT在导弹自动驾驶仪测试中的应用

自动驾驶仪是导弹的姿态控制系统,其性能好坏决定了导弹飞行的稳定性。为了精确测量其性能,对导弹自动驾驶仪测试原理和方法进行了研究,进行了正弦信号测量方法的分析,提出了基于全相位FFT数据处理方法,并结合时移相位差校正方法实现正弦形式信号的频率、幅度和相位等参数的精确测量。利用LabVIEW图形化编程软件设计了算法软件,通过仿真试验考察了该算法在无噪、低噪和大噪环境下信号测量精度,结果表明全相位FFT方法在信号频谱测量方面具有精度高、抗噪能力强等优点,满足自动驾驶仪的测试需求。     

基于信息流模型的自动驾驶仪多故障诊断分析

为了在多故障情况下对自动驾驶仪故障做出正确诊断,提出了基于相关性矩阵的多故障诊断完备性分析方法,并给出了严格的数学证明;首先对系统的软硬件模块进行分析与划分,利用信息流模型建立故障与测试间的相关性矩阵模型;再根据多故障情况下的诊断完备性分析方法对相关性矩阵进行行列变换,说明在多故障情况下此自动驾驶仪的故障诊断正确率理论上能达到100%,最后构建其故障诊断方法;实际应用表明,此方法对于自动驾驶仪的分析是有效的,可满足系统的指标要求。     

基于遗传算法的自动驾驶仪测试性分析

为了提高自动驾驶仪故障测试与诊断的快速性与准确性,提出了一种基于遗传算法的自动驾驶仪测试性分析方法;此方法解决了遗传算法应用于测试项目选择的难点,构建了最优的故障测试策略,能以最短时间完成测试并满足测试覆盖性的要求;利用故障测试获得的知识,简化故障与测试间的相关性矩阵,加快了故障诊断的速度;最终获得了故障测试与诊断一体化的方法;实验结果表明,此方法有效提高了故障测试与诊断的速度,并且易于实现。     

Lower Bounds for the Robustness of Multilevel Coherence

International Journal of Theoretical Physics - Quantum coherence, coming from quantum superposition, occupies a significant position in the field of physics. We put forward a lower bound of the...     

弹道导弹再入段地面红外探测仿真分析

为改善弹道导弹再入段地面红外探测效果,考虑导弹再入过程中气动加热、红外辐射的大气衰减以及背景辐射等因素,建立起弹道导弹再入段地面红外探测仿真分析模型,并估算分析了探测系统在不同状况下信噪比.分析结果表明:优选工作波段、增加系统口径及曝光时间、改善光学设计、选择晴朗无云天气观测等均有利于改进地面红外观测效果.     

弹道导弹再入段地面红外探测仿真分析

为改善弹道导弹再入段地面红外探测效果,考虑导弹再入过程中气动加热、红外辐射的大气衰减以及背景辐射等因素,建立起弹道导弹再入段地面红外探测仿真分析模型,并估算分析了探测系统在不同状况下信噪比.分析结果表明：优选工作波段、增加系统口径及曝光时间、改善光学设计、选择晴朗无云天气观测等均有利于改进地面红外观测效果.     

An Internet-Oriented Multilayer Network Model Characterization and Robustness Analysis Method

The Internet creates multidimensional and complex relationships in terms of the composition, application and mapping of social users. Most of the previous related research has focused on the single-layer topology of physical device networks but ignored the study of service access relationships and the social structure of users on the Internet. Here, we propose a composite framework to understand how the interaction between the physical devices network, business application network, and user role network affects the robustness of the entire Internet. In this paper, a multilayer network consisting of a physical device layer, business application layer and user role layer is constructed by collecting experimental network data. We characterize the disturbance process of the entire multilayer network when a physical entity device fails by designing nodal disturbance to investigate the interactions that exist between the different network layers. Meanwhile, we analyze the characteristics of the Internet-oriented multilayer network structure and propose a heuristic multilayer network topology generation algorithm based on the initial routing topology and networking pattern, which simulates the evolution process of multilayer network topology. To further analyze the robustness of this multilayer network model, we combined a total of six target node ranking indicators including random strategy, degree centrality, betweenness centrality, closeness centrality, clustering coefficient and network constraint coefficient, performed node deletion simulations in the experimental network, and analyzed the impact of component types and interactions on the robustness of the overall multilayer network based on the maximum component change in the network. These results provide new insights into the operational processes of the Internet from a multi-domain data fusion perspective, reflecting that the coupling relationships that exist between the different interaction layers are closely linked to the robustness of multilayer networks.     

Improving the Robustness of Particle Size Analysis by Multivariate Statistical Process Control

The robustness of online particle size analysis in wet processes is improved by applying data based modeling methods to the control of the sample preparation and measurement sequence of the particle size analyzer. The aim is to find a more accurate and reliable method of determining the end of the particle size integration period using multivariate statistical process control (MSPC). The studied approach is tested on analyzers installed at two mineral processing plant sites and validated using two validation tests. Research shows that the proposed method works with two very different slurry types. The main advantage of the adapted approach is that there are no adjustable parameters that have to be set by the user.     

低曝光量下投影算法的稳健性研究

研究了在低曝光量情况下灰度投影算法的稳健性,为提出的稳定成像系统的设计与实现提供可行性论证。通过合成视频实验探讨、实际视频实验论证相结合的研究方法,探讨曝光量不足对灰度投影算法性能的影响。实验结果表明,灰度投影算法在欠曝5档和存在一定随机噪声的情况下,仍能保持良好的运动矢量估计性能,从而说明了投影算法在一定的曝光量范围内仍能准确地得到运动矢量估计,是一种运算量小、实时性好且稳健性较强的电子稳像算法。投影算法在低曝光量情况下良好的稳像稳健特性,使其能在低亮度及高实时性要求等环境下应用于航拍、卫星遥感等稳定成像或高清晰成像场合。     

干涉条纹相位锁定系统分析及其控制

干涉条纹的相位变化与干涉条纹中某一固定点的光强密切相关,基于这一原理,通过对干涉场光强分析,提出并设计了一种用于干涉条纹相位锁定的控制系统.光电探测器检测干涉条纹中固定目标点的光强,并以该光强电压作为反馈控制信号,利用声光调制器对干涉系统中两束高斯光束中的一束进行实时频率调制,将光强电压控制在一个固定值,实现干涉条纹的相位锁定.构建了条纹锁定控制系统控制对象的理论模型,通过实验进行了验证,并基于该模型的特点设计了条纹锁定控制器.实验结果表明:在400Hz的控制频率下,干涉条纹相位漂移不超过±0.04个条纹周期,满足干涉光刻的曝光需求.