共查询到18条相似文献,搜索用时 109 毫秒
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针对使用空间绳网捕获带有太阳帆板等柔性附件的大型失效航天器的碎片清除任务,充分考虑了拖曳过程中柔性附件产生的振动对系统的稳定造成的影响。首先采用凯恩方法建立了失效航天器绳系拖曳系统动力学模型,在建模过程中充分考虑系绳的质量和振动、帆板的振动、系统的轨道运动对姿态的影响等,使动力学模型更加详细和完整,且该动力学模型不受失效航天器所处位置的限制,适用于任意轨道上的失效航天器的拖曳离轨任务;之后根据平衡状态的特点,求取了系统的平衡解,并在平衡解附近对动力学方程线性化,然后采用李雅普诺夫方法分析了系统的稳定性及各参数的变化规律;并针对失效航天器可能产生的姿态章动设计了常值张力切换控制律;最后采用数值仿真的方法分析了失效航天器的帆板振动对绳系拖曳过程的影响,校验了控制律的有效性。 相似文献
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针对基于欧拉角的绳系卫星动力学系统模型在面外角的余弦函数为0时,面内角变得不稳定的奇点问题,提出一种基于修正的罗德里格参数和其阴影相结合的绳系卫星系统动力学模型。在证明了其在消除奇点问题可行性的基础上,进行了仿真,实验结果表明该模型在消除奇点的优势下,修正的罗德里格参数及其阴影的非连续性转换并不会影响到欧拉角的连续性变化和表示,具有全局性。 相似文献
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针对空间绳网系统捕获空间碎片后,在轨道转移过程中的精确控制问题,提出一种使用常值拉力将空间碎片拖曳至坟墓轨道的方法。首先,采用牛顿欧拉法建立绳系组合体动力学模型;其次,通过李雅普诺夫方法证明仅使用恒张力即可实现拖曳过程的稳定控制;再次,提出采用常值拉力切换控制律抑制空间碎片的姿态章动,采用基于相平面控制原理的控制律抑制绳系组合体面内面外摆动,规避在轨道转移过程中系绳松弛造成缠绕、系绳张力过大造成断裂或两星接近发生碰撞等风险。最后,通过拖曳离轨全过程仿真分析,校验了所提出控制方法的有效性。 相似文献
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《中国航天(英文版)》2016,(3)
Electrodynamic tethered deorbit technology is a novel way to remove abandoned spacecrafts like upper stages or unusable satellites. This paper investigates and analyses the deorbit performance and mission applicability of the electrodynamic tethered system. To do so, the electrodynamic tethered deorbit dynamics with multi-perturbation is firstly formulated, where the Earth magnetic field, the atmospheric drag, and the Earth oblateness effect are considered. Then, the key system parameters, including payload mass, tether length and tether type, are analyzed by numerical simulations to investigate their influences on the deorbit performance and to give the setting principles for choosing system parameters. Based on this and given an appropriate group of system parameters, numerical simulations are undertaken to study the impact of the mission parameters, including orbit height and orbit inclination, and thus to investigate the mission applicability of the electrodynamic tethered deorbit technology. 相似文献
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Experiments and numerical simulations of an electrodynamic tether deployment from a spool-type reel using thrusters 总被引:3,自引:0,他引:3
The amount of space debris is ever increasing, and pollution of the space environment has become a serious problem that can no longer be ignored. Consequently, the active removal of large space debris from crowded economically useful orbits should begin as soon as possible. The Japan Aerospace Exploration Agency has been investigating an active debris removal system that employs highly efficient electrodynamic tether (EDT) technology for orbital transfer. This study investigates the tether deployment from a spool-type reel using thrusters by means of numerical simulations of an EDT system. The thrusters are used in order to ensure the deployment of a tether with the length of several kilometers. In the simulations using a multiple mass tether model, the key parameters are estimated from various on-ground experiments. By means of the numerical simulations, the dynamics of tether deployment is studied and requirements of thruster needed for the deployment, such as the thrust forces and the periods of thruster activation, are clarified. 相似文献
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《Acta Astronautica》2004,55(11):917-929
As a countermeasure for suppressing space debris growth (P. Eighler, A. Bade, Chain Reaction of Debris Generation by Collisions in Space—A Final Threat to Spaceflight? in: 40th Congress of the International Astronautical Federation, IAA-89-628, October 1989), the National Aerospace Laboratory of Japan is investigating a satellite capture, repair and removal system for non-cooperative satellites, part of which involves assessing the viability of electrodynamic tether (EDT) technology as an orbital transfer system. In this paper, some results concerning the time required to remove existing satellites, the behavior of flexible tethers during the debris separation phase, and orbital transfer strategies of EDT systems during space debris removal operations are described. From numerical simulations, it is found that EDT systems can transfer satellites from LEO to orbits with a short lifetime within a realistic timeframe. It is also found that the stability of EDT systems is compromised when debris separation occurs both while a tether current is running and when the ratio of the end mass to that of the service satellite is high. To ensure stability, the end mass should be selected from the target debris group with due regard for the maximum possible mass that can be maneuvered safely. Moreover, it is also found that orbital elements (a, e, i) can be changed independently with an adequate current control strategy. 相似文献
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电动系绳离轨装置的设计与分析 总被引:1,自引:1,他引:0
电动系绳离轨效果显著,无需消耗推进剂,是处理LEO(低地球轨道)废弃航天器的有效手段。文章介绍了利用电动系绳进行离轨的原理,提出了电动系绳离轨装置所需的硬件及其设计要求;给出了电动系绳离轨装置的控制策略和工作过程,并利用系绳运动方程对电动系绳离轨的效能进行了分析。结果显示,利用电动系绳可以大大减小离轨的面积时间积。 相似文献
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Yu. M. Zabolotnov 《Cosmic Research》2017,55(3):224-233
Control of an orbital tether system that consists of two small spacecraft has been considered. The proposed control laws are based on the modification of well-known programs for the deployment of tether system systems under the assumption that the masses of spacecraft and the tether are comparable in magnitude. To construct nominal deployment programs, we have developed a mathematical model of the motion of the given system in an orbital moving coordinate system taking into account the specific features of this problem. The performance of the proposed deployment programs is assessed by a mathematical model of the orbital tether system with distributed parameters written in the geocentric coordinate system. The test calculations involve a linear regulator that implements feedback on the tether length and velocity. 相似文献
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针对再入飞行器离轨制动问题,在考虑地球引力J2项摄动及有限推力影响下,设计了一种航天器自主离轨制动控制算法。该算法根据再入点状态约束,确定了离轨过渡轨道的平均轨道根数及其与离轨待命轨道平均轨道根数的关系,从而得到制动参数初值。通过在线数值递推轨迹,实时预报再入点瞬时轨道根数并计算再入点航迹倾角,当预报的航迹倾角满足约束条件时结束制动,并根据再入点纬度幅角误差修正制动起始点,从而修正制动参数。制动过程中,在考虑了J2项摄动影响下实时预报再入点瞬时轨道根数,依据实际任务需求确定关机时机。最后通过考虑初始状态误差、质量误差、推力误差以及姿态误差情况下的蒙特卡洛打靶仿真,分析了不同关机策略的落点散布特性,检验了该算法的自主决策和高精度再入点控制能力。 相似文献
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针对自主机动飞网机器人多系绳编织结构的动力学建模难题,首先提出利用无向图描述飞网机器人的结构,然后依据系绳杨氏模量极大的特点,设计间隙函数和约束反力,基于Hamilton原理建立飞网机器人数学模型,并设计一种基于Lemke算法和龙格库塔积分的解算方法;针对其网型保持问题,设计一种“双层优化伪动态逆内环+变结构控制外环”的控制方法。仿真结果表明,设计的控制器能够有效控制飞网机器人沿指令轨迹运动,并很好保持其网型,避免飞网机器人任务过程的变形和轨道径向移动。 相似文献
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采用类似对地球岁差章动的处理方法,讨论月球物理天平动对月心赤道坐标系 以及月球卫星轨道的影响。在对月球物理天平动的分析表达式与高精度数值历表进行比较的 基础上,给出了相应的月球引力位的变化及相应的坐标系附加摄动解,清楚地表明了对月球 卫星轨道影响的规律。所获结果与数值解进行了比对,证实了从定性和定量两个方面来看本 文的讨论都是有意义的,从而表明月球物理天平动分析解的简单表达式在某些问题中(特别 是定轨和预报)是有实用价值的,而且在建立轨道摄动分析解时,无需像地球卫星那样,去 引进混合形式的轨道坐标系,采用历元月心平赤道坐标系即可。最终表明:无论是采用数值 法定轨和预报还是分析法定轨和预报,均可采用统一的月心平赤道坐标系,这可避免一些不 必要的坐标转换。 相似文献