民机数据总线信号综合测试仪

介绍的民机数据总线信号测试仪综合了当前民机上主要采用的ARINC429、ARINC419、CSDB和RS232等数字式航空数据总线规范的接口，具有和这些总线接口设备通讯的能力，可以灵活方便地应用于机载设备检测，装机交联实验当中。     

直升机燃油系统地面模拟试验中试验台转角与油面角的关系

为了在直升机燃油系统地面模拟试验中准确地模拟油面角，本文介绍了试验台转角与油面角的关系，并给出了转换结果，同时，提出了一种用油箱内增压来模拟过载的设想，使在模拟试验时，油泵供油更趋真实，通过简化计算，给出了确定气压力的方法和判断依据。     

Spacecraft optimal rendezvous controller design using simulated annealing

A new global approach for rendezvous Linear Quadratic controller design is presented in this paper. Instead of solving the algebraic Riccati equation, a continuous simulated annealing (SA) algorithm is used to design rendezvous LQ controller. Optimization of one automatic rendezvous controller with 18 design parameters is illustrated. The results show that the SA algorithm can locate the global solution effectively and robust, besides a great number of global solutions have been obtained by the SA. The SA has demonstrated better performance than other optimization algorithms such as floating-coded Genetic Algorithm, Simplex method and Powell algorithm.     

Blind adaptive decision fusion for distributed detection

We consider the problem of decision fusion in a distributed detection system. In this system, each detector makes a binary decision based on its own observation, and then communicates its binary decision to a fusion center. The objective of the fusion center is to optimally fuse the local decisions in order to minimize the final error probability. To implement such an optimal fusion center, the performance parameters of each detector (i.e., its probabilities of false alarm and missed detection) as well as the a priori probabilities of the hypotheses must be known. However, in practical applications these statistics may be unknown or may vary with time. We develop a recursive algorithm that approximates these unknown values on-line. We then use these approximations to adapt the fusion center. Our algorithm is based on an explicit analytic relation between the unknown probabilities and the joint probabilities of the local decisions. Under the assumption that the local observations are conditionally independent, the estimates given by our algorithm are shown to be asymptotically unbiased and converge to their true values at the rate of O(1/k/sup 1/2/) in the rms error sense, where k is the number of iterations. Simulation results indicate that our algorithm is substantially more reliable than two existing (asymptotically biased) algorithms, and performs at least as well as those algorithms when they work.     

获取自由飞模型气动导数的综合飞行试验研究

过去已进行过多个机种的自由飞模型大迎角特性试验，但均为单一项目的试验，现介绍了将获取放宽静稳定度特性和气动导数两个项目综合于一个自由飞模型飞行试验项目中的情况，用脉冲升降舵激发起模型的纵向短周期运动，用参数辩识方法获取气动导数，试验结果表明这种方法是可行的，为从事本专业及相关专业的科研人员提供了参考。     

极光区电离层Hall电导率的观测及其在E层电子加热情况下的特征

本文利用欧洲的ＥＩＳＣＡＴ雷达观测资料及与这配合的地磁观测数据，用电离层参数直接计算和地面磁场反演两种方法导出了极区电离层Ｈａｌｌ电导率，特别显示出在强对流电场激发的Ｅ层等离子体不稳定波对电子加热情况下，电导率明显增高。     

疲劳裂纹扩展随机过程相关参数的估计

对数正态随机过程模型是可靠性与损伤容限分析中常用的裂纹扩展随机模型.在裂纹扩展对数正态随机过程模型的基础上,建立了由试验数据估计一般平稳正态随机过程相关参数的方法.应用这种方法可以直接由试验数据估计随机过程的相关参数.同时,给出了用Monte-Carlo方法估算置信区间的方法.最后,给出了用具体试验数据,这组试验数据共有237个数据点,估计随机过程相关参数的算例.     

星用小型化Ku频段8W固态功率放大器设计

为了满足卫星分系统对于固态功率放大器小型化的要求,提出了一种星用Ku频段8W固态功率放大器的设计方法。首先采用集成化设计技术,将所有射频功能集中在单个模块中,实现固态功率放大器整机的小型化;其次,通过优化整机热设计,使得微波功率单片满足结温降额要求,实现整机高可靠;最后,通过优化电源电路设计,提高电源的抗干扰能力,实现整机的高稳定。利用以上技术,实现了输出功率大于8W、效率高于22%、重量仅为770g的Ku频段星载固态功率放大器研制,相比传统的分立器件单机,体积缩小了近1/2。空间模拟环境试验结果表明,所研制的Ku频段8W固态功率放大器具有较高的可靠性,满足宇航应用要求,目前已实现在轨运行。该单机非常适用于我国“快、智、廉”卫星型号的应用,未来具有广阔的应用前景。     

一种基于VPL的元器件快速建模方法

为了更好地落实航空电子模块的可制造性设计审查工作,结合航空电子模块产品特点和技术要求,建设了基于Valor软件的PCB/PCBA设计与检测自动化分析系统.元器件模型库作为该系统的必要组成部分,其覆盖范围和数据精度对审查结果至关重要.本文将从元器件模型库建设必要性、建设过程和建模工艺要求三个方面进行阐述,并提出一种基于V...     

基于干扰距离控制的直升机桨-涡干扰噪声降噪方法

提出了一种适用于直升机旋翼桨-涡干扰距离计算的方法.针对桨-涡干扰距离计算中必需的旋翼桨盘入流及桨盘倾角,又分别建立了旋翼耦合N-S(Navier-Stokes)/自由尾迹模型和桨盘配平模型进行求解,其特点是兼顾计算精度和计算效率;并从悬停、前飞两方面验证了方法的有效性.应用所建立的桨-涡干扰距离计算方法,着重分析了直...