空间低温杜瓦瓶凯夫拉支撑结构多约束优化设计

采用新型凯夫拉纤维作为某空间用小型低温杜瓦瓶的支撑材料，在验证其力学性能的基础上，设计了杜瓦瓶的支撑结构，建立了一种新的热力学耦合优化模型，给出支撑结构固有频率、热应力及发射环境下的约束条件，通过一种“离散点加密”新约束优化法计算出了支撑结构满足约束条件范围内的要求的最优设计参数。     

航天器姿态预设性能控制方法综述

针对存在不确定惯量矩阵及其它未知不确定性(如执行器故障、航天器结构发生突变等)下的航天器姿态控制问题，综述了预设性能控制及其应用的研究进展。首先阐释了预设性能控制方法的基本内涵及其关键步骤；然后分析总结了现有航天器姿态控制以及预设性能控制研究的基本概况与发展趋势；最后面向未来复杂化、智能化的空间任务对航天器控制系统提出的新需求，提出航天器预设性能控制值得研究的问题和方向。     

ZL205A合金舱体低压工艺设计及数值仿真应用

针对某ZL205A合金舱体铸件壁薄难充型、壁厚差异大、易产生裂纹等特点,设计了低压底注式浇注工艺。采用立筒缝隙式浇注系统分配充型过程中合金的流量,局部厚大部位放置成形冷铁加快该部位的冷却速度,以控制铸造缺陷的产生。利用ProCast数值仿真软件对工艺进行仿真计算,成功预测了缺陷的产生位置,对工艺方案进行优化,包括倒角过渡、改变型砂使用等,并在优化方案的基础上浇注了舱体铸件,铸件质量良好,没有缩松、缩孔、裂纹等缺陷,符合相关技术要求。     

多变量全局寻优与智能优化在星座组网中的应用

顶层任务规划通常与星座组网紧密结合，小卫星分散灵活的特性尤其适用于星群规模化在轨运行。针对热点区域覆盖和全球覆盖的不同任务需求，提出了对构型多变量进行全局寻优和利用智能优化技术进行星座构型优化的方法，两种优化方法可分别获得小规模星群最优效能与超大型星群的较优效能。优化方法不受轨道类型和任务目标分布的约束，具有良好的鲁棒性。     

利用视加速度补偿和推力逐级释放的垂直着陆制导方法

针对运载火箭子级垂直返回着陆段的制导问题，本文在应用凸优化的滚动时域在线规划基础上研究了制导鲁棒性的改善策略。为应对着陆后期控制能力不足的情况，在滚动规划过程中引入了推力上界逐级释放的策略。同时，考虑缓解干扰和误差累积的影响，在制导周期内引入视加速度信息对在线规划的推力指令进行补偿，以进一步改善滚动规划的递归可行性。最后，通过数值算例仿真及对比分析验证所提出的补偿策略的有效性。     

Evaluation of SARAL/AltiKa performance using GNSS/IMU equipped buoy in Sajafi,Imam Hassan and Kangan Ports

Performance of SARAL/AltiKa mission has been evaluated within 2016 altimeter calibration/validation framework in Persian Gulf through three campaigns conducted in the offshore waters of Sajafi, Imam Hassan and Kangan Ports, while the altimeter overflew the passes 470, 111 and 25 on 13 Feb, 7 March and 17 June 2016, respectively. As the preparation, a lightweight buoy was equipped with a GNSS receiver/choke-ring antenna and a MEMS-based IMU to measure independent datasets in the field operations. To obtain accurate sea surface height (SSH) time series, the offset of the onboard antenna from the equilibrium sea level was predetermined through surveying operations as the buoy was deploying in the onshore waters of Kangan Port. Accordingly, the double-difference carrier phase observations have been processed via the Bernese GPS Software v. 5.0 so as to provide the GNSS-derived time series at the comparison points of the calibration campaigns, once the disturbing effects due to the platform tilt and heave have been eliminated. Owing to comparing of the SSH time series and the associating altimetry 1?Hz GDR-T datasets, the calibration/validation of the SARAL/AltiKa has been performed in the both cases of radiometer and ECMWF wet troposphere corrections so as to identify potential land contamination. An agreement of the present findings in comparison with those attained in other international calibrations sites confirms the promising feasibility of Persian Gulf as a new dedicated site for calibration/validation of ongoing and future altimetry missions.     

Assessment of between-floor structural and topological properties on cognitive map development in multilevel built environments

The present study investigated cognitive map development in multilevel built environments. Three experiments were conducted in complex virtual buildings to examine the effects of five between-floor structural factors that may impede the accuracy of humans’ ability to build multilevel cognitive maps. Results from Experiments 1 and 2 (of three experiments) revealed that difficulties in developing multilevel cognitive maps are not solely caused by the z-axis offset, as is suggested in the literature, but are due to the factorial combination of a between-floor overlap and a z-axis offset. Results from Experiment 2 showed that this process becomes substantially more difficult when the reference directions between different floors have an angular offset from each other. Finally, results from Experiment 3 demonstrated that confusing between-floor heading shifts in aligned buildings did not make it reliably harder to build multilevel cognitive maps. The implications of these findings are discussed in terms of theories of mental representations in multilayered three-dimensional spaces, as well as for architectural design.     

分析插值误差和斜率的轨迹优化网格细化方法

提出一种基于插值误差和斜率分析的轨迹优化自适应网格细化方法，包括节点插入算法和节点删除算法。节点插入算法分析各个离散节点的控制变量的插值误差。若插值误差较大，则在该节点周围增加节点细化网格；否则，不进行细化。节点删除算法分析各个离散节点处的控制变量斜率。若某个节点的左斜率和右斜率都为零，那么删除该节点；否则，保留该节点。采用三个典型的轨迹优化算例验证了所提出的方法的有效性和特色，并且与其它几种网格细化方法进行了对比。仿真结果表明，本文方法生成的网格规模较小，需要的网格迭代次数较少，能够快速、高精度求解非光滑轨迹优化问题。     

Simulating planetary wave propagation to the upper atmosphere during stratospheric warming events at different mountain wave scenarios

Parameterization schemes of atmospheric normal modes (NMs) and orographic gravity waves (OGWs) have been implemented into the mechanistic Middle and Upper Atmosphere Model (MUAM) simulating atmospheric general circulation. Based on the 12-members ensemble of runs with the MUAM, a composite of the stratospheric warming (SW) has been constructed using the UK Met Office data as the lower boundary conditions. The simulation results show that OGW amplitudes increase at altitudes above 30 km in the Northern Hemisphere after the SW event. At altitudes of about 50 km, OGWs have largest amplitudes over North American and European mountain systems before and during the composite SW, and over Himalayas after the SW. Simulations demonstrate substantial (up to 50–70%) variations of amplitudes of stationary planetary waves (PWs) during and after the SW in the mesosphere-lower thermosphere of the Northern Hemisphere. Westward travelling NMs have amplitude maxima not only in the Northern, but also in the Southern Hemisphere, where these modes have waveguides in the middle and upper atmosphere. Simulated variations of PW and NM amplitudes correspond to changes in the mean zonal wind, EP-fluxes and wave refractive index at different phases of the composite SW events. Inclusion of the parameterization of OGW effects leads to decreases in amplitudes (up to 15%) of almost all SPWs before and after the SW event and their increase (up to 40–60%) after the SW in the stratosphere and mesosphere at middle and high northern latitudes. It is suggested that observed changes in NM amplitudes in the Southern Hemisphere during SW could be caused by divergence of increased southward EP-flux. This EP-flux increases due to OGW drag before SW and extends into the Southern Hemisphere.     

SSPS-OMEGA超大型球形聚光器结构拓扑构型与设计

为同时兼顾千米量级尺度空间太阳能电站聚光系统的在轨发射安装难度、光学收集效率、稳定性及结构工艺等多方面的因素，提出采用基于球面正多面体的经纬线划分法模块化构建球形聚光器。该方法不仅可实现基础划分单元分布均匀、规格种类少，降低在轨构建与运载发射难度。而且只要合理控制弧高等分数和基础划分单元的口径就可以同时保证聚光系统的光学收集效率。理论与仿真结果显示，当弧高等分数为24时，该划分法共有25种基础单元件，整个球面被分成5762块。并且此时模块化构建的实际球形聚光器的光学收集效率与理想球面相比基本保持不变，解决了太阳能电站聚光系统设计中存在的关键问题。