Predicting performance in manually controlled rendezvous and docking through spatial abilities

Manually controlled rendezvous and docking (manual RVD) is a challenging space task for astronauts. This study aims to identify spatial abilities that are critical for accomplishing manual RVD. Based on task analysis, spatial abilities were deduced to be critical for accomplishing manual RVD. 15 Male participants performed manual RVD task simulations and spatial ability tests (the object-manipulation spatial ability and spatial orientation ability). Participants’ performance in the test of visualization of viewpoints (which measures the spatial orientation ability) was found to be significantly correlated with their manual RVD performance, indicating that the spatial orientation ability in the sense of perspective taking is particularly important for accomplishing manual RVD.     

Orbit determination and prediction of GEO satellite of BeiDou during repositioning maneuver

In order to establish a continuous GEO satellite orbit during repositioning maneuvers, a suitable maneuver force model has been established associated with an optimal orbit determination method and strategy. A continuous increasing acceleration is established by constructing a constant force that is equivalent to the pulse force, with the mass of the satellite decreasing throughout maneuver. This acceleration can be added to other accelerations, such as solar radiation, to obtain the continuous acceleration of the satellite. The orbit determination method and strategy are illuminated, with subsequent assessment of the orbit being determined and predicted accordingly. The orbit of the GEO satellite during repositioning maneuver can be determined and predicted by using C-Band pseudo-range observations of the BeiDou GEO satellite with COSPAR ID 2010-001A in 2011 and 2012. The results indicate that observations before maneuver do affect orbit determination and prediction, and should therefore be selected appropriately. A more precise orbit and prediction can be obtained compared to common short arc methods when observations starting 1 day prior the maneuver and 2 h after the maneuver are adopted in POD (Precise Orbit Determination). The achieved URE (User Range Error) under non-consideration of satellite clock errors is better than 2 m within the first 2 h after maneuver, and less than 3 m for further 2 h of orbit prediction.     

Characterization of ionospheric amplitude scintillations using wavelet entropy detrended GNSS data

The extensive monitoring networks of Global Navigation Satellite System (GNSS) ionospheric scintillation have been established to continuously log observation data. Further, the amplitude scintillation index and the phase scintillation index, which are derived from scintillation observations, are anticipated to accommodate the accuracy requirement of both the user level and the monitoring station level. However, raw scintillation observations essentially measure superposed waveform impairments of GNSS signals propagating through ionosphere and troposphere. It implies that fluctuations of raw scintillation observations are caused by multiple factors from the entire radio propagation environment. Hence, it is crucial to characterize ionospheric scintillations from GNSS observation data. And the characterization is implemented through extracting fluctuations of raw observations merely induced by ionospheric scintillations. Designed to address this problem by means of Fourier filtering detrending, the present work investigates the influence of varying detrending cutoff frequencies on wavelet statistical energy and wavelet entropy distributions of scintillation data. It consequently derives criteria on the optimum detrending cutoff frequency for three types of raw amplitude scintillation data, which are classified by their wavelet energy distributions. Results of the present work verify that detrending with specific optimum cutoff frequencies rather than the fixed and universally applicable one renders the validity and credibility of characterizing ionospheric scintillations as the part of GNSS observation fluctuations purely induced by ionosphere electron density irregularities whose scale sizes are comparable with or smaller than the Fresnel scale.     

基于开路电压法的电池荷电状态估计误差校正

本文提出分别研究电池开路电压在充电结束后停置过程和放电结束后停置过程的不同变化规律,并考虑了不同停置时间在两个过程中的作用和影响,从而达到提高开路电压法估算荷电状态精度的效果。实验验证表明,此方法的精度比传统开路电压法更加准确。     

固体火箭发动机专用ICT机械扫描系统

以成熟的组合精密镗床为本体, 研制了固体发动机专用ＩＣＴ机械扫描系统。采用４５０ ｋＶ Ｘ射线源, 设计了准直器系统、探测器系统、机械扫描系统（传动控制系统、夹具及同步台）, 实测证明扫描系统符合精度要求     

含能材料低温松驰WLF方程的两种求值法

通过玻璃化转变温度和表同活化能以及由ＶＦＴ方程导得ＷＬＦ方程粘弹系数的两种新方法,用该方法分别计算１０个体系的粘弹系数,结果表明,用ＤＳＣ技术可以获得ＷＬＦ方程,３种计算方法获得的粘弹系数符合较好。     

线性模型跟踪控制系统的模型匹配设计

研究了用完全模型匹配方法求解模型跟踪控制的问题。对通常的模型匹配解法进行了扩展,并所据此引入广义最小方差控制思想,提出一种模型跟踪和误差的新方法。最后,对该方法在惯性导航系统中的应用进行了仿真研究。验证了其可行性和有效性。     

WZ-5发动机改装高温涡轮的试验研究及分析

WZ- 5发动机改装 WJ5A- 1发动机的高温涡轮,在工程上单台发动机总寿命已安全运行达 10 0 0 0 h,现已证明 :结构设计及改进是成功的;WJ5A- 1发动机的前二级燃气涡轮与压气机基本上是匹配的;燃气涡轮第一级导向器与动力涡轮导向器面积调整是合理的;在相对换算转速为0.95时,其喘振裕度与 WZ- 5发动机基本上一样;动力涡轮导向器面积总共放大了 5.32 %,对燃气涡轮特性没有带来很大影响。      

大型星载可展开天线的展开动力学问题

针对大型星载可展开天线所具有的尺寸大、刚性小、展开机构复杂,所处环境恶劣等特点,结合天线的构形特征,着重从可展开天线展开动力学的建模角度,综述了可展开天线的展开动力学问题。对解决途径及办法提出了一些看法。