Chang'E-1 Lunar Mission:An Overview and Primary Science Results

Chang'E-1 is the first lunar mission in China, which was successfully launched on Oct. 24th, 2007. It was guided to crash on the Moon on March 1, 2009, at 52.36oE, 1.50oS, in the north of Mare Fecunditatis. The total mission lasted 495 days, exceeding the designed life-span about four months. 1.37 Terabytes raw data was received from Chang'E-1. It was then processed into 4 Terabytes science data at different levels. A series of science results have been achieved by analyzing and applicating these data, especially "global image of the Moon of China's first lunar exploration mission'. Four scientific goals of Chang'E-1 have been achieved. It provides abundant materials for the research of lunar sciences and cosmochemistry. Meanwhile these results will serve for China's future lunar missions.      

机载光电跟踪系统基于遗传算法的模糊控制器优化设计研究

分析了机载光电跟踪系统的构成，并对机载光电跟踪系统的最主要成部分－陀螺平台框架系统设计了基于GA（遗传算法）的模糊控制器，由于遗传算洒可以搜索整个空间，不易陷入局部最优解，不受搜索空间的限制性假设的约束，因此本文通过遗传算法对模糊控制器的控制规则，参数以及量化因子和比例因子进行了优化，在对模糊控制器设计的过程中，为了提高模糊控制的精度并加速遗传算法的收敛速度，还采用了变论域的方法，通过对系统详细的仿真研究，验证了基于GA的模糊控制器设计的良好控制效果。     

基于SA&M-Relax的外辐射源雷达目标DOA估计方法

外辐射源雷达回波信噪比极低,通常在距离-多普勒二维相关后进行目标角度估计。在这种单快拍情况下,经典的超分辨算法由于协方差矩阵的非正定性导致算法性能较差。针对这一问题,在A&M插值迭代算法的基础上,提出了一种适用于稀疏阵列的SA&M-Relax外辐射源雷达目标DOA估计方法。在相同阵元数目的情况下,与原有算法相比提高了目标角度估计的分辨率与精度,同时减少了运算量。通过仿真实验验证了所提方法的有效性。      

Seismic deformation of the Mw 8.0 Wenchuan earthquake from high-rate GPS observations

High-rate GPS positioning has been recognized as a powerful tool in estimating epoch-wise station displacement which is particularly useful for seismology. In this study, station displacements during the 12 May 2008 M_w 8.0 Wenchuan earthquake are derived from the 1-Hz GPS data collected at a set of stations in China. The impacts of integer ambiguity resolution and station environment-dependent effects are investigated in order to yield more accurate results. The position accuracy of horizontal components of better than 1 cm suggests that GPS can sense the rapid position oscillation of about 2 cm in amplitude. Temporal and spatial analysis is applied to the surface displacement at station XANY and the characteristics of the movements due to Rayleigh and Love waves are detected and discussed. The comparison of GPS-derived displacement with relevant synthetic data computed based on a recently published rapture model shows a reasonable agreement in waveform. The various differences in amplitude need further investigation and also imply that rapture inversion might be improved if GPS-derived displacement is assimilated.     

星载大型旋转部件的热平衡试验方法

星载大型旋转部件因其构型复杂和相对星体其他部分转动的特性,给热设计的验证带来诸多难题。文章以“海洋二号”卫星的微波散射计为例,分别采用通过地面试验直接获取在轨预示温度的直接验证方法,以及验证热分析模型、再由热分析模型预示在轨温度的间接验证方法进行热平衡试验。通过对试验结果、热分析结果和在轨飞行结果的对比,验证了这2种试验方法正确、有效。     

基于Pro/Engineer的Pro/toolkit二次开发技术研究

着重讲述了利用Pro/toolkit开发包,在针对Pro/Engineer2001进行二次开发CAD/CAPP系统过程中,所涉及到的一些关键的开发技术,解决了针对SQLServer2000数据库的访问问题。     

非线性自适应控制理论在无人直升机飞行控制系统设计中的应用

最近，国内外很多研究结果表明，基于神经网络的直接自适应控制方法，在飞行器控制系统设计中有着诸多优点。其中最重要的是它减少了设计对飞机动态特性高保真建模的依赖。这种设计方法在某无人直升机上得以实际飞行验证。本文主要介绍这种非线性自适应控制系统及其外回路航迹跟踪器的设计问题。     

流动稳定性中小扰动波传播速度的数值研究

在保守系统中，小扰动波如线性水波及线性重力内波等均以其群速度传播，且群速度等于能流速度，在非保守系统中，波的传播速度还是个不十分清楚的问题。本文用数值计算的方法研究流动稳定性问题中小扰动波的传播速度，结果表明，波的传播速度并不等于能流速度，而与复群速度的实部近似相等。本文还用一简单的模型对此给予了解释。     

齿轮旋翼传动系统动态固有特性识别

通过对齿轮旋翼传动系统进行理论分析,在运转的条件下进行实验测定和在线识别,指出由于旋翼的非线性耦合作用,使得带有旋翼的齿轮传动系统具有不同于其它齿轮系统的特有特性,即动态特性随转速的不同而发生变化,并得到了其变化规律。     

含侧喷流炮弹绕流场数值计算

利用迎风ＴＶＤ格式,在超音速下,分别对无侧喷流和头部含侧喷流的炮弹绕流场进行数值模拟,结果表明侧喷流能够降低炮弹表面的摩擦阻力,对研究炮弹的增程技术有一定的参考价值。