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载人航天器空气环境参数控制非定常仿真分析 总被引:2,自引:0,他引:2
为支持乘员在轨驻留,载人航天器需通过空气环境控制系统将众多设计参数和空气环境参数控制在指标范围内。文章建立了一种载人航天器空气环境非定常控制仿真分析模型,包括舱体模块、航天员模块、舱压控制模块、温湿度控制模块以及CO2净化模块。利用该模型分析了载人航天器空气环境参数随乘员代谢水平的非定常变化趋势,并评估了控制系统的工作性能。结果表明:乘员代谢水平变化对空气环境参数有显著影响,通过调节控制系统运行参数可将各空气参数控制在有效指标范围内。人区温度与O2分压、CO2分压和人区湿度有密切的影响关系,不可孤立地进行分析。为载人航天器空气环境参数控制系统的设计和流程改进提供了依据。 相似文献
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Zhaohui Dang 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2013
Navigation sharing as a key technology provides orbit and attitude information broadcasting for the whole fractionated spacecraft cluster (FSC). The navigation sharing concept has already been proposed for some years. However, the problem of achieving the optimal navigation sharing by designing the proper network topology is still unsolved, especially in the case that some members of the cluster have absolute navigation devices, some just have relative navigation devices and some only have communication devices. In this paper, a comprehensive model of describing the navigation sharing problem in FSC is proposed. The model of network topology constructing by relative navigation links and communication links is established. By using the graph theory and genetic algorithm as the tool, the conditions for navigation sharing in FSC with different sharing degrees are obtained. Finally, some examples are presented to test the methods, and it has been found that, the absolute positions and attitudes of all the members can still be determined even some members in FSC have no absolute navigation devices. 相似文献
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Solar wind turbulence during the solar cycle deduced from Galileo coronal radio-sounding experiments
A.I. Efimov L.N. Samoznaev M.K. Bird I.V. Chashei D. Plettemeier 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008
Seven coronal radio-sounding campaigns were carried out during the active lifetime of the Galileo spacecraft in the years 1994–2002. The observational data analyzed in the present work are S-band frequency fluctuation measurements recorded during the solar conjunctions at different phases of solar activity cycle #23, specifically: periods near solar maximum (three conjunctions), near solar minimum (three conjunctions) and during the ascending phase (one conjunction). These data are all applicable to low heliographic latitudes, i.e. to the slow solar wind. The rms frequency fluctuation and power-law index of the frequency fluctuation temporal spectra are determined as a function of heliocentric distance. The turbulence power spectrum tends to be flatter inside ca. 20 solar radii during all phases of the solar cycle. This coincides with a transition in the flow from the inner acceleration region to the outer region of constant velocity. The radial falloff rate and absolute level of the rms frequency fluctuation are essentially invariant over the solar cycle. 相似文献
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重点研究挠性空间结构的H∞辨识,研究表明:依据系统的输入输出空间,对系统的未知动力学参数估计和对高维数截断的适当操作,将导致适合于控制的低维数学模型。模型维数确定时,系统模型与实际系统的距离在H∞范数的意义下几乎为最小,模型维数足够大时,系统模型与实际系统的距离可任意小,这是文下间提出了挠性空间结构H∞辨识的基本思想,为此,以带挠性梁的卫星系统为背景,首先分析了系统的动力学特性,引入了挠性系统H∞ 相似文献