Ocean Observation from Haiyang Satellites: 2012–2014

During 2012 and 2014, China has two Haiyang(which means ocean in Chinese, referred to as HY) satellites operating normally in space which are HY-1B and HY-2A. HY-1B is an ocean color environment satellite which was launched in April 2007 to observe global ocean color and sea surface temperature, and HY-2A is an ocean dynamic environment satellite which was launched in August 2011 to obtain global marine dynamic environment parameters including sea surface height,significant wave height, ocean wind vectors, etc. Ocean observation data provided by HY-1B and HY-2A have been widely used by both domestic and international users in extensive areas such as ocean environment protection, ocean disaster prevention and reduction, marine environment forecast,ocean resource development and management, ocean investigations and scientific researches, etc.     

模拟月壤钻进负载分析与试验研究

月壤与采样机具间的相互作用在月球自主采样器的设计、性能评价、控制和仿真等方面具有重要作用,目前对于月壤与采样机具间相互作用中的钻进负载研究尚不充分。本文基于被动土压力理论,根据不同的土体切削状态,将切削刃前土体分为堆积区和破坏区,重点分析堆积区土体和破坏区土体对总钻头负载的贡献,建立了月壤取心钻头钻进松散土体的钻进负载模型。HIT 2型取心钻头和HIT\|LS1#模拟月壤的钻进试验结果表明,钻进负载理论模型与实际情况具有较高的吻合度。     

基于热响应的卫星推进剂剩余量测量方法研究

介绍了基于热响应法的卫星推进剂剩余量在轨测量方法的原理,给出了国外在Telstar 11,LM 3000,BSS601平台日本通信卫星,Turksat 1C卫星的应用情况。给出了将该方法用于国内卫星的设想,并归纳了推进剂在轨空间分布高精度仿真、带液条件下贮箱内复杂传热过程高精度热仿真、贮箱与整星耦合热分析仿真等关键技术。     

基于层次化分类器的遥感图像飞机目标检测

在大量航空航天遥感图像中,快速发现和统计飞机目标并对其进行准确定位,在军事和民用方面均具有重要意义。结合遥感图像特点,针对飞机目标的特征,文章设计了一种基于层次化的分类器的遥感图像飞机目标检测方法。首先用基于哈尔（Haar）特征的底层AdaBoost分类器快速去除大部分非目标区域;然后用基于梯度方向直方图（Histogram of Oriented Gradient,HOG）特征的顶层支持向量机（Support Vector Machine,SVM）分类器进行精细检测。在分辨率为1m的遥感图像数据集上的实验结果表明,层次化分类器在保证较高检测率的前提下,大大降低了虚警率,可以有效解决遥感图像飞机检测问题。     

液氧温度对某液氧液氢发动机性能影响研究

结合某液氧液氢发动机实际飞行中二次工作段入口液氧温度升高和推力下降现象,分析了液氧温度对发动机性能的影响方式和修正方法.通过过冷液氧的发动机试验,对液氧温度影响性能的两种方式分别进行了修正,可将某液氧液氢发动机二次工作段推力与一次工作段的偏差降低约24％,将发动机飞行燃烧室压力与交付值的偏差降低约8％.     

临近空间大气压力传感器现场校准装置研究

本文针对临近空间大气压力传感器现场校准需求,介绍了临近空间大气压力传感器现场校准装置工作原理, 进行理论分析与仿真,提出需突破的关键技术,给出了不确定度预估。     

Statistical properties of fatigue damage of Gaussian random loadings

Firstly, the fatigue damages associated with the random loadings were always deemed as high-cycle or very-high-cycle fatigue problems, and based on Chebyshev theorem, the number of rainflow cycles in a given time interval could be recognized as a constant by neglecting its randomness. Secondly, the randomness of fatigue damage induced by the distribution of rainflow cycles was analyzed. According to central limit theorem, the fatigue damage could be assumed to follow Gaussian distribution, and the statistical parameters: mean and variance, were derived from Dirlik's solution. Finally, the proposed method was used to a simulate Gaussian random loading and the measured random loading from an aircraft. Comparisons with observed results were carried out extensively. In the first example, the relative errors of the proposed method are 2.29%, 3.52% and 1.16% for the mean, standard deviation and variation coefficient of fatigue damage, respectively. In the second example, these relative errors are 11.70%, 173.32% and 18.20%, and the larger errors are attributable to non-stationary state of the measured loading to some extent.      

有翼再入飞行器的超/高超声速气动力工程方法

有翼再入飞行器气动力的工程计算方法尚有待进一步完善,计算精度有待进一步提高。文章根据有翼再入飞行器的气动布局特点,改进和发展了一套适于其气动布局的部件划分策略和压强计算选取准则。以此对航天飞机轨道器和类X-34飞行器的纵向气动力特性进行工程计算,并与其风洞试验和数值模拟结果进行对比分析。结果表明,文中的工程计算方法在马赫数3以上的超/高超声速范围内可准确预测有翼再入飞行器的升阻特性,其中升力系数和阻力系数误差小于10%;并可准确预测俯仰力矩特性随迎角改变的变化规律。与现有方法相比,文中的部件划分策略和压强计算选取准则在升阻特性精度相当情况下,可明显提高俯仰力矩的预测精度,并反映飞行器表面的压强分布特征。     

不锈钢板式热沉液压胀形工艺参数仿真分析

不锈钢板式热沉具有低温性能好、生产周期短、生产成本低等特点,已经广泛应用于国外航天器环境模拟试验设备中,是热沉发展的新趋势.为掌握不锈钢板式热沉的加工工艺,建立不锈钢热沉液压胀形有限元分析模型,研究滚弯预成形工序、边界压紧力和焊点布局等工艺参数对热沉位移分布、应变分布和厚度分布的影响,以及焊点布局、胀形压力对流道高度和...     

一种加速度辅助“当前”统计模型距离跟踪方法

经典的“当前”统计模型中,机动频率通常为经验值,并需预设加速度极限值。针对这一局限,该文利用递归线性平滑牛顿预测器对加速度进行预估后,得到“当前”统计模型中目标机动频率值的解析解,并避免机动加速度极限值的设置,实现了过程噪声协方差矩阵的自适应计算。此外,利用简化的Sage-Husa滤波方法实现量测噪声协方差矩阵的自适应更新。计算机仿真验证了该文所提算法相比于经典的“当前”统计模型的距离跟踪性能更优。