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941.
针对卫星编队整体机动的难点,充分考虑编队的“群”运动特性,按照先规划参考卫星轨迹,后规划伴随卫星轨迹的思路,提出一种整体机动的分步规划策略。采用Gauss伪谱法优化参考卫星的轨迹,并检验优化结果的最优性;根据整体机动过程中的路径约束,以参考卫星的轨迹为参考,规划伴随卫星的可行飞行区域;根据终端约束条件,在可行区域规划伴随卫星的飞行轨迹;引入动态逆的思想,根据伴随卫星飞行轨迹反推相应的控制量;最后,分析了伴随卫星轨迹在控制上的可行性,并分析了整体机动轨迹最优性性能。仿真分析表明,该方法计算量小,能满足整体机动的任务要求。
相似文献
相似文献
942.
943.
针对未来军事飞行训练的发展,借鉴美军"基于效果作战"理论,本文提出了效基军事飞行训练综合训练系统发展理念,并对综合训练系统的发展基础"训练效果"和发展理念的主要内容进行了阐述,介绍了发展理念的理论支撑体系,概括了训练态势分析和需求论证、训练效能分析、教练机综合设计、教练机综合训练系统设计、无人机综合训练系统设计、嵌入式训练系统设计理论研究情况。最后,本文提出了对效基军事飞行综合训练系统发展工程学科建设的思考。 相似文献
944.
945.
E.V. Nesterenko V.A. Kozlov S.V. Khizhnyak N.S. Manukovsky V.S. Kovalev Yu.L. Gurevich Hong Liu Yidong Xing Enzhu Hu 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2009
The object of this research is to study a soil-like substrate (SLS) to grow plants in a Bioregenerative Life Support System (BLSS). Wheat and rice straw were used as raw materials to prepare SLS. Anti-fungal activity of SLS using test cultures of Bipolaris sorokiniana, a plant-pathogenic fungus which causes wheat root rot was studied. Experiments were conducted with SLS samples, using natural soil and sand as controls. Infecting the substrates, was performed at two levels: the first level was done with wheat seeds carrying B. sorokiniana and the second level with seeds and additional conidia of B. sorokiniana from an outside source. We measured wheat disease incidence and severity in two crop plantings. Lowest disease incidence values were obtained from the second planting, SLS: 26% and 41% at the first and the second infection levels, respectively. For soil the values were 60% and 82%, respectively, and for sand they were 67% and 74%, respectively. Wheat root rot in the second crop planting on SLS, at both infection levels was considerably less severe (9% and 13%, respectively) than on natural soil (20% and 33%) and sand (22% and 32%). SLS significantly suppressed the germination of B. sorokiniana conidia. Conidia germination was 5% in aqueous SLS suspension, and 18% in clean water. No significant differences were found regarding the impact on conidia germination between the SLS samples obtained from wheat and rice straw. The anti-fungal activity in SLS increased because of the presence of worms. SLS also contained bacteria stimulating and inhibiting B. sorokiniana growth. 相似文献
946.
Siyu Tang Zhi Huang Hong Yuan 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2021,67(2):722-730
Radial basis function (RBF) interpolation with multi-quadric is developed to perform ionospheric total electron content (TEC) mapping for the Chinese region between 15°N ~ 40°N and 100°E ~ 125°E. TEC measurements from the Centre for Orbit Determination in Europe (CODE) covering the solar maximum year 2011 are used to investigate the performance of the proposed RBF interpolation method. The differences between the RBF interpolated TEC and the CODE TEC are within 0.5 TECU and the root mean square error (RMSE) is very small when 49 data points are used. The maximum difference is ~5 TECU and the error is less than 1 TECU with 25 samples. Our study suggests that a random distribution of measurement points gives smaller RMSEs than a homogenous distribution when the number of sample points is low. The study indicates that RBF interpolation offers a powerful and reliable tool for ionospheric TEC mapping. 相似文献
947.
Hong Li Xiangyun Long Hua Feng Qiong Wu Jiahui Huang Weichun Jiang Massimo Minuti Dongxin Yang Saverio Citraro Hikmat Nasimi Jiandong Yu Ge Jin Ming Zeng Peng An Luca Baldini Ronaldo Bellazzini Alessandro Brez Luca Latronico Enrico Costa 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2021,67(1):708-714
PolarLight is a compact soft X-ray polarimeter onboard a CubeSat, which was launched into a low-Earth orbit on October 29, 2018. In March 2019, PolarLight started full operation, and since then, regular observations with the Crab nebula, Sco X-1, and background regions have been conducted. Here we report the operation, calibration, and performance of PolarLight in the orbit. Based on these, we discuss how one can run a low-cost, shared CubeSat for space astronomy, and how CubeSats can play a role in modern space astronomy for technical demonstration, science observations, and student training. 相似文献
948.
949.
飞机道面拦阻系统建模分析 总被引:1,自引:0,他引:1
通过对飞机道面拦阻系统进行静力学、动力学分析,建立了拦阻系统的力学分析模型。通过该模型,结合实际应用中机轮所受的水平阻力应符合起落架的设计范围,得出了飞机进入拦阻面的速度、拦阻材料的压碎强度、起落架所受的最大水平拖力、轮胎最大压力以及拦停距离等变量之间的关系,从而为进一步研究道面拦阻材料的力学特性以及今后进行拦阻材料的自主开发提供了理论依据。 相似文献
950.