共查询到20条相似文献,搜索用时 234 毫秒
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随着在轨服务技术的发展和对航天器发射运营成本的控制,航天器在轨服务模式将由“一对一”服务逐步发展为“一对多”“多对多”的服务模式。在具有多个服务目标的模式下,针对服务航天器的任务分配与规划将变得尤为关键。因此,本文研究了多服务航天器为多个地球同步轨道(GEO)卫星进行在轨加注的任务规划问题。首先,考虑服务航天器容量约束、服务路径约束等多类约束条件,以最小化燃料消耗为优化指标,以每个服务航天器的服务顺序为决策变量,建立“多对多”在轨加注任务规划模型。其次,针对遗传算法局部搜索能力差、易陷入局部最优的缺陷,设计了一种将大邻域搜索算法和遗传算法相结合的混合启发式算法(LNS-GA),用以求解该任务规划问题。该算法利用大邻域搜索算法中的“破坏”和“修复”思想,对遗传算法每一代种群中的精英个体进行进一步的迭代搜索,从而增强算法的局部搜索能力。最后,通过设定的仿真场景与单一遗传算法进行仿真对比,验证了本文所提出算法的有效性和优越性。 相似文献
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卫星在轨操作任务主要包括在轨燃料加注、在轨模块更换、在轨发射、在轨空间碎片清除等。值得指出的是,在轨操作可以针对己方航天器进行,也可以针对敌方航天器进行。能够通过在轨加注延长航天器寿命,也可以利用交会对接和空间机械手技术将敌方航天器拖离目标轨道,具有巨大的商业和军用潜力。 相似文献
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空间的在轨补给技术是航天器主要的在轨服务模式之一。它是延长航天器的有效工作寿命、提高航天器经济效益的主要技术手段。本文在大量掌握材料的基础上,分析了在轨补给技术的现状;概括了空间在轨加注的技术要求;对比了三种典型的在轨加注方案:直接加注,更换贮箱,整体更换推进舵;最后以双组元推进剂加注系统为例,简介系统的结构和工作原理。 相似文献
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为确保载人飞行器在长期飞行中的设备安全以及短期飞行中航天员的安全,需要从系统层面进行自主安全设计,使航天器在出现地面无法快速反应的故障时能够启动安全模式进行自我保护。文章以能源安全设计为主对“天宫一号”目标飞行器系统级自主安全设计进行了论述,总结了设计经验,对后续型号的设计提出了建议。 相似文献
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M. V. Levskii 《Cosmic Research》2003,41(2):178-192
A problem of optimal turn of a spacecraft is considered. The time of turn is minimized, as well as the functional having a meaning of the propellant consumption. An analytical solution to the problem stated is derived. It is demonstrated that the solution optimal in this sense belongs to a class of two-impulse controls, under which a spacecraft executes the turn along the trajectory of its free motion. The solution obtained in this paper differs from earlier available solutions considerably. The estimations of the propellant consumption for a realization of the programmed turn are made. 相似文献
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离子推力器羽流特性及其污染分析 总被引:2,自引:0,他引:2
介绍了与电推进系统有关的空间环境效应的形成原因及其对航天器性能、寿命等的影响。阐述了离子火箭发动机羽流内束离子、中性推进剂原子、交换电荷(CEX)离子和电子等主要成分与航天器相互作用的过程及机理。分析表明,离子推力器出口处的中性推进剂原子与高速束离子流碰撞后产生的CEX离子Xe^+,以及带电离子轰击推力器组件特别是加速极所产生的金属CEX离子,是造成离子火箭发动机羽流污染的主要成分。在此基础上提出了若干防污染措施。 相似文献
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叠氮复合固体推进剂技术研究 总被引:5,自引:0,他引:5
分析了航天器和导弹武器系统对固体推进剂提出的新的要求和实现这些要求的技术途径。介绍了国外研制低特征信号叠氮固体推进剂的主要原材料叠氮粘合剂、含能增塑剂、高能高密度氧化剂的发展概况和关键技术。分析认为,由以上材料组成的叠氮复合固体推进剂具有含能量高、密度大、发动机排气羽烟对微波、激光和可见光的透过率高等特征,因此这是一种很有前途的新型推进剂。 相似文献
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Nitrous oxide as a rocket propellant 总被引:1,自引:0,他引:1
Nitrous oxide is introduced as a multi-purpose propellant for spacecraft. Potential space applications of this propellant are given. Based on comparison to conventional systems, a multi-mode nitrous oxide propulsion concept is expected to deliver higher performance. Main features of a self-pressurising, nitrous oxide storage system are described. A nitrous oxide catalytic decomposition technique is suggested for restartable spacecraft propulsion. Up-to-date experimental results are presented. A conclusion describes the long-term feasibility of novel nitrous oxide propulsion option concepts. 相似文献
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This paper provides a detailed mission analysis and systems design of a near-term and far-term pole-sitter mission. The pole-sitter concept was previously introduced as a solution to the poor temporal resolution of polar observations from highly inclined, low Earth orbits and the poor high-latitude coverage from geostationary orbit. It considers a spacecraft that is continuously above either the north or south pole and, as such, can provide real-time, continuous and hemispherical coverage of the polar regions. Being on a non-Keplerian orbit, a continuous thrust is required to maintain the pole-sitter position. For this, two different propulsion strategies are proposed, which result in a near-term pole-sitter mission using solar electric propulsion (SEP) and a far-term pole-sitter mission where the SEP thruster is hybridized with a solar sail. For both propulsion strategies, minimum propellant pole-sitter orbits are designed. In order to maximize the spacecraft mass at the start of the operations phase of the mission, the transfer from Earth to the pole-sitter orbit is designed and optimized assuming either a Soyuz or an Ariane 5 launch. The maximized mass upon injection into the pole-sitter orbit is subsequently used in a detailed mass budget analysis that will allow for a trade-off between mission lifetime and payload mass capacity. Also, candidate payloads for a range of applications are investigated. Finally, transfers between north and south pole-sitter orbits are considered to overcome the limitations in observations due to the tilt of the Earth's rotational axis that causes the poles to be alternately situated in darkness. It will be shown that in some cases these transfers allow for propellant savings, enabling a further extension of the pole-sitter mission. 相似文献
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M. V. Levskii 《Cosmic Research》2011,49(2):131-149
The problem of optimal control over spatial reorientation of a spacecraft is considered. The functional having a sense of
propellant consumption is minimized. The analytical solution to the formulated problem is presented. It is shown that the
optimal solution can be found in the class of two-impulse control at which the spacecraft’s turn is performed along a free
motion trajectory. In order to improve the accuracy of spacecraft guidance into a specified angular position, methods of control
are suggested that realize the method of free trajectories. The synthesized controls are invariant with respect to both external
perturbations and parametric errors. The results of mathematical modeling are presented that demonstrate high efficiency of
developed control algorithms. Propellant consumption for realizing a programmed turn is numerically estimated taking into
account considerable gravitational and aerodynamic moments acting upon the spacecraft. 相似文献
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空间热物理技术发展的探讨 总被引:1,自引:1,他引:0
文章以航天器和火箭发动机中的工程热物理问题为背景,探讨了航天器热控技术的现状和发展趋势,介绍了火箭发动机热设计、推进剂燃烧等问题的发展方向. 相似文献
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This paper introduces a novel Lyapunov-based adaptive control strategy for spacecraft maneuvers using atmospheric differential drag. The control forces required for rendezvous maneuvers at low Earth orbits can be generated by varying the aerodynamic drag affecting each spacecraft. This can be accomplished, for example, by rotating dedicated sets of drag panels. Thus, the relative spacecraft motion can be controlled without using any propellant since the motion of the panels can be powered by solar energy. A novel adaptive Lyapunov controller is designed, and a critical value for the relative drag acceleration that ensures Lyapunov stability is found. The critical value is used to adapt the Lyapunov controller, enhancing its performance. The method is validated using simulations. The results show that the Adaptive Lyapunov technique outperforms previous control strategies for differential drag based spacecraft maneuvering. 相似文献