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针对微小卫星逼近观测未知的空间翻滚非合作目标星任务,提出一种基于单目视觉的目标星相对状态估计方法。在建立追踪星/目标星相对运动模型的基础上,以单目相机识别并测量获得的目标星固有特征的像素位置为观测输入,通过扩展卡尔曼滤波算法实现对目标星相对位置、相对速度、相对姿态、角速度、惯量比和特征位置等状态的估计。仿真结果表明,该方法能够很好地实现对未知非合作目标星的相对状态估计,姿态估计误差小于2°,位置估计误差小于0.1 m,特征点位置平均估计误差小于0.04 m。 相似文献
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对X射线天文卫星观测需求进行了分析,提炼了观测任务对观测模式、源的高精度定位与对准、轨道、热控、测控数传等多项需求与约束;针对X射线观测的多需求、多约束难点,设计了集巡天观测、定点观测与小天区扫描观测于一体的观测模式,解决了一颗卫星同时实现全天扫描、银道面深度扫描、重要惯性区域扫描、重要及机遇目标深度观测以及伽马暴全天监测的多种观测需求的难题,该技术已在我国硬X射线调制望远镜卫星上得到应用. 相似文献
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Ravi teja Nallapu Jekan Thangavelautham 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2021,67(11):3559-3582
This work describes the design and optimization of spacecraft swarm missions to meet spatial and temporal visual mapping requirements of missions to planetary moons, using resonant co-orbits. The algorithms described here are a part of Integrated Design Engineering and Automation of Swarms (IDEAS), a spacecraft swarm mission design software that automates the design trajectories, swarm, and spacecraft behaviors in the mission. In the current work, we focus on the swarm design and optimization features of IDEAS, while showing the interaction between the different design modules. In the design segment, we consider the coverage requirements of two general planetary moon mapping missions: global surface mapping and region of interest observation. The configuration of the swarm co-orbits for the two missions is described, where the participating spacecraft have resonant encounters with the moon on their orbital apoapsis. We relate the swarm design to trajectory design through the orbit insertion maneuver performed on the interplanetary trajectory using aero-braking. We then present algorithms to model visual coverage, and collision avoidance in the swarm. To demonstrate the interaction between different design modules, we relate the trajectory and swarm to spacecraft design through fuel mass, and mission cost estimations using preliminary models. In the optimization segment, we formulate the trajectory and swarm design optimizations for the two missions as Mixed Integer Nonlinear Programming (MINLP) problems. In the current work, we use Genetic Algorithm as the primary optimization solver. However, we also use the Particle Swarm Optimizer to compare the optimizer performance. Finally, the algorithms described here are demonstrated through numerical case studies, where the two visual mapping missions are designed to explore the Martian moon Deimos. 相似文献
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Lin Cheng Zhenbo Wang Fanghua Jiang Junfeng Li 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2021,67(3):1114-1123
In this study, an adaptive neural network control approach is proposed to achieve accurate and robust control of nonlinear systems with unknown dynamics, wherein the neural network is innovatively used to learn the inverse problem of system dynamics with guaranteed convergence. This study focuses on the following three contributions. First, the considered system is transformed into a multi-integrator system using an input–output linearization technique, and an extended state observation technique is used to identify the transformed states. Second, an iterative control learning algorithm is proposed to achieve the neural network training, and stability analysis is given to prove that the network’s predictions converge to ideal control inputs with guaranteed convergence. Third, an adaptive neural network controller is developed by combining the trained network and a proportional-integral controller, and the long-standing challenge of model-based methods for control determination of unknown dynamics is resolved. Simulation results of a virtual control mission and an aerospace altitude tracking mission are provided to substantiate the effectiveness of the proposed techniques and illustrate the adaptability and robustness of the proposed controller. 相似文献
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针对嫦娥五号飞行程序多舱段、多任务、系统控制复杂的设计特点和难点,采用传统的飞行程序设计方法工作量大,状态控制困难,很难满足任务要求。提出了一种新的基于状态转移的方法对飞行程序进行系统建模,首先将整个飞行过程分解成若干模块状态机;然后针对每个模块状态机的功能划分为状态触发器、评估器、执行器和确认器,并分别开展建模设计;最后通过状态触发器和确认器将各个功能模块进行连接,形成整个飞行程序的有限状态机描述。相比传统方法,该方法具有通用性、可扩展性和可复用性等特点,对于规范飞行程序设计,描述复杂的飞行任务过程有很大的优势。采用该方法对嫦娥五号飞行程序进行了建模和设计,并给出了典型飞行过程的设计结果。在轨飞行试验结果表明,该方法可以满足飞行任务的要求,确保了嫦娥五号在轨飞行控制任务圆满成功。 相似文献
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