共查询到19条相似文献,搜索用时 109 毫秒
1.
最优气动力辅助空间拦截和交会 总被引:1,自引:0,他引:1
航天器从高轨道向位于低地球圆轨道的靶目标实施拦截或进行交会 ,并用间接求解的直接伴随方法 ,即用D型拉格朗日方法求解其优化问题。拦截条件是指在最终时刻两者的位置相同 ,而交会条件是指不仅位置相同且最终的速度矢量亦相等。文章讨论了最小时间与最小脱靶量 ,或最小时间与最小燃料消耗的复合性能指标 ,以及推力协同机动的优化解。推力协同下 ,对于特定情况 ,如在热流约束边界部分推力弧是奇异的 ,气动力控制是正常的。这种复杂性和奇异问题的求解在拦截和交会问题中都是值得慎重处理的。 相似文献
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由于姿态与轨道运动的耦合,以及制导系统确定的发动机推力矢量方向不通过系统质心所引起的干扰力矩,火箭上面级轨道转移段的姿态运动会受到很大的干扰,为此,研究了利用轨控矢量发动机主动摇摆和滚转姿控发动机喷气的上面级姿态控制技术。首先,利用凯恩方程建立包括上面级本体、发动机旋转支架以及矢量发动机的系统多体动力学方程,推导了矢量发动机工作时偏心引起的干扰力矩和推力矢量控制中矢量发动机的摆角计算公式,利用矢量发动机主动摇摆和滚转姿控发动机喷气控制上面级的姿态。其次,基于变结构控制方法,设计了上面级轨道转移段的姿态控制律,使得上面级轨道转移期间姿态控制的精度达到了10-3级别,且矢量发动机推力矢量既为制导指令方向又通过系统质心,减小了矢量发动机对上面级的干扰力矩。最后,进行了数值仿真,仿真算例结果验证了控制律的可行性。 相似文献
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基于模糊神经网络的导弹最优寻的末制导律 总被引:2,自引:1,他引:2
提出了一种适用于一类末制导段采用推力矢量控制的新型导弹的模糊神经网络最优寻的末制导律.在制导律设计时不仅要求导弹能量最省,脱靶量最小,同时考虑了推力矢量控制的非线性特点,并且为改善该神经网络系统的学习效果,在学习算法中还引入模糊学习规则.数字仿真表明所提出的模糊神经网络制导律对于机动目标具有较好的攻击能力. 相似文献
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大迎角综合飞行/推进控制系统设计与仿真 总被引:1,自引:0,他引:1
以先进推力矢量战斗机为背景,构建了基于力矩解算和分配的大迎角综合飞行/推进控制系统结构方案.在此基础上采用模糊方法设计推进稳定性控制系统;以逆动力学方法计算期望力矩;以饱和控制分配原则协调气动舵面和推力矢量的控制.仿真结果表明大迎角下推进系统可稳定工作,综合飞/推控制系统能合理协调气动舵面和推力矢量,控制系统能够快速准确的跟踪指令,完成机动动作. 相似文献
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基于ARVM模型的液体火箭发动机试验台故障预测方法 总被引:1,自引:0,他引:1
针对液体火箭发动机试验台故障子样少,故障预测精度低,故障维修保障困难等问题,在分析标准RVM优缺点的基础之上,提出了一种自适应能力较强的故障预测模型——ARVM(Adaptive Relevance Vector Machine)。为测试该模型,以某型轨控发动机高空模拟试验台管路流量、燃烧室压力为输入参量对推力矢量进行了预测,预测结果表明,ARVM方法能够有效跟踪推力矢量参数的变化趋势,并且获得了较高的预测精度和模型稀疏性。该方法对于复杂系统的故障预测和维修保障具有一定的理论价值和工程应用意义。 相似文献
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针对垂直/短距起降(V/STOL)飞机在悬停/平移模式下存在的动力学耦合、推力矢量控制冗余以及易受扰动风影响的问题,提出了一种基于高阶线性自抗扰控制(LADRC)的鲁棒协调解耦控制方法。首先根据V/STOL飞机的概念方案,建立了推力矢量模型和扰动风影响下的非线性悬停/平移运动模型。然后在此基础上,给出了该模式下位置和姿态的协调控制策略,据此通过控制量变换设计了六通道的自抗扰解耦控制律,其中利用LADRC对总扰动的实时估计补偿能力避免了多推力矢量的冗余控制。仿真比较结果验证了LADRC对悬停/平移模式控制的有效性以及对飞机内部参数摄动和外界突风干扰的鲁棒性。 相似文献
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推力矢量对飞机操纵面失效的补偿与重构 总被引:1,自引:0,他引:1
讨论了推力矢量控制对飞机俯仰、偏航通道气动力的补偿效果和飞行中操纵面失效故障下利用推力矢量进行控制律重构的概念.给出了系统的控制余度定义和伪逆重构条件.针对飞机方向舵失效故障,利用推力矢量进行了重构设计和仿真研究,结果是令人满意的. 相似文献
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Constant thrust fuel-optimal control for spacecraft rendezvous 总被引:1,自引:0,他引:1
Yongqiang Qi Yingmin Jia 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
In this paper, constant thrust rendezvous is studied and the optimal rendezvous time is calculated by using continuous genetic algorithm. Firstly, the relative position parameters of the target spacecraft are obtained by using the vision measurement and the target maneuver positions are calculated through the isochronous interpolation method. Then, the results of the calculation of constant thrust rendezvous is founded by processing with multivariate linear regression method. Next, a new switching control law is designed based on the thrust acceleration sequence and the on time of thrusters which can be computed by the time series analysis method. The perturbations and fuel consumptions are addressed during the computation of the on time of thrusters. 相似文献
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Yongqiang Qi Yingmin Jia 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
A new switching control algorithm under constant thrust is designed for the chaser fast flying around the target spacecraft along a specified fly-around trajectory. The switching control laws are obtained based on the acceleration sequences and the on time of thrusters which can be computed by the time series analysis method. The perturbations and fuel consumptions are addressed during the computation of the on time of thrusters. Furthermore, the relative position parameters of the target spacecraft are obtained by using the vision measurement and the target fly-around positions are calculated through the isochronous interpolation method. The change of the relative position and the relative velocity of the chaser during the constant thrust fast fly-around are presented through simulation example. It is proved that, with the switching control laws, the chaser will fast fly around the target spacecraft along the specified fly-around trajectory. 相似文献
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随着卫星重力测量技术的突破性进展,对航天器试验环境要求也在不断提高,航天器受到的残余扰动必须尽可能减小。作为中国将来重力场测量卫星备选主推力器的会切场推力器,其推力器的控制精度直接决定了测量的准确性。文章首先通过PID方法设计了位移模式下的无拖曳控制器,该控制器在预估阻力系数、参考质量与卫星本体的位移差、速度差等性能方面有良好的表现,在应对卫星运行时的突发情况时表现出很强的稳定性。但PID参数没有达到最优解,在此基础上对于该模型的控制精度进行优化,用遗传算法对PID控制的参数进行筛选。结果分析表明,会切场推力器的控制精度有所改善,NTW方向上的速度和位移误差均减小;推力阻力和显著减少;控制精度提高,更好地满足使用需求。 相似文献
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Yongqiang Qi Yingmin Jia 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
In this paper, the relative position parameters of the chaser are obtained by using the vision measurement and the target departure manoeuvre positions are calculated through the isochronous interpolation method. A guidance algorithm for -V-bar constant thrust departure with consideration of the constraints of field of view and safety distance is investigated. New switching control laws under constant thrust are designed for departure manoeuvres of the chaser. The switching control laws are obtained based on the acceleration sequences and the on time of thrusters in three axes which can be respectively computed by the time series analysis method. The perturbations and fuel consumptions are addressed during the computation of the on time of thrusters. 相似文献
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场发射电推力器具有几种不同的发射模式,分别产生荷质比不同的带电液滴或带电离子,使得不同模式下推力性能差别显著。针对不同的空间应用,需要设计不同种类的场发射电推力器,使其达到相应的推力参数。为此对场发射电推力器的发射过程展开分析,确定了推力参数的调控方法。首先对场发射电推力器的基本工作原理进行了阐述,并对不同发射模式的基础物理机制进行了分析。在此基础上通过理论计算得出采用不同推进剂可达到不同发射模式这一结论,并最终得出推力器性能参数的调控方法,论证了推力性能受到推进剂种类和发射模式的影响,在离子发射模式下处于高比冲、低推力工况,而液滴发射模式下处于低比冲、高推力工况。此外推力参数还受到供给流量、外加电压等多种因素的影响。在得到推力器参数的调控方法后,设计了一种主动供给型离子液体电推力器,以离子液体EMI BF4作为推进剂,进行了相应的试验研究。通过改变外加电压,实现了对推力器推力性能的调控,证实了此调控方法的可行性。推力器达到的推力范围为1.6~10μN,比冲范围为154~978s。 相似文献
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对航天器六自由度控制的推力分配问题进行了研究,参考卫星导航系统中几何精度衰减因子(GDOP) 的定义,首次提出了推力器构型燃料消耗因子(FCF)的概念,并将此概念用于定义推力器相对几何关系引起的期望控制量与燃料消耗间的比例关系。通过矩阵理论分析得到了燃料消耗因子随推力器数目增加而减少的结论,并通过仿真计算对结论进行了验证。 相似文献
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Qi Yongqiang Jia Yingmin 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012,49(1):150-161
In this paper, a field-of-view constrained guidance algorithm for -V-bar constant thrust departure under thruster failure is investigated. First of all, the relative position parameters of the chaser are obtained by using the vision measurement and the target departure manoeuvres positions are calculated through the isochronous interpolation method. Then, a new switching control law under constant thrust is designed for the departure manoeuvres. The switching control law is obtained based on the acceleration sequences and the on time of thrusters which can be computed by the time series analysis method. The perturbations and fuel consumptions are addressed during the computation of the on time of thrusters. With the switching control law, the constant thrust-V-bar departure under the thruster failure in the x-axis is carried out by using coupling effects.On the basis of the toolbox of matlab, practical examples for simulation and application are given. The half cone angle of the cone-shaped field-of-view of the target spacecraft is α = 30°, the simulation results show that the proposed guidance algorithm can well satisfy the conditions for the constraints and can make sure the chaser departures from the target spacecraft safely. 相似文献
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基于Lyapunov最优反馈控制的月球中继卫星转移轨道设计 《空间控制技术与应用》2017,43(6):20-24
摘要: 随着电推进器及小推力转移变轨的研究逐渐深入,在深空探测领域应用电推力器是必然的发展趋势.文章基于以月球中继卫星的运行轨道地月L2点Halo轨道为目标轨道的轨道转移任务,采用Lyapunov最优反馈控制方法,计算单一轨道根数的局部最优控制率,通过遗传算法调整五个轨道根数的权重,得到时间最优的月球中继卫星小推力轨道转移方案,具有工程应用意义. 相似文献
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Yongqiang Qi Yingmin Jia 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
In this paper, the collision avoidance maneuver under the chaser’s thruster failure in radial direction is investigated. First, based on the vision measurement, the relative position parameters of the target spacecraft are obtained and the target maneuvre positions are calculated through the isochronous interpolation method. Then, by using coupling effects, the thrusters working time intervals can be computed by the time series analysis method. The perturbations and fuel consumptions are addressed during the computation of the thrusters working time intervals. Next, the switching control law under constant thrust is designed for active collision avoidance maneuvres along a specified trajectory. 相似文献