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91.
执行器故障下的运载火箭非奇异终端滑模容错控制 总被引:2,自引:0,他引:2
针对存在未知外部干扰和执行器卡死故障的运载火箭,提出了一种基于非奇异终端滑模面的姿态跟踪控制算法。首先,建立了考虑干扰和执行器卡死故障的运载火箭姿态控制系统多输入多输出系统模型;然后定义了运载火箭姿态跟踪系统模型,针对定义的模型,设计了一种非奇异终端滑模面,使得系统在执行器故障情况下仍能较为精确地跟踪参考信号。基于李雅普诺夫函数证明了运载火箭姿态跟踪控制系统的稳定性和有限时间收敛特性。数值仿真检验了本文基于非奇异终端滑模运载火箭姿态跟踪控制算法的有效性。 相似文献
92.
Design, analytical investigation, laboratory and in-flight testing of the attitude determination and control system (ADCS) of a microsatellites are considered. The system consists of three pairs of reaction wheels, three magnetorquers, a set of Sun sensors, a three-axis magnetometer and a control unit. The ADCS is designed for a small 10–50 kg LEO satellite. System development is accomplished in several steps: satellite dynamics preliminary study using asymptotical and numerical techniques, hardware and software design, laboratory testing of each actuator and sensor and the whole ADCS. Laboratory verification is carried out on the specially designed test-bench.In-flight ADCS exploitation results onboard the Russian microsatellite “Chibis-M” are presented. The satellite was developed, designed and manufactured by the Institute of Space Research of RAS. “Chibis-M” was launched by the “Progress-13M” cargo vehicle on January 25, 2012 after undocking from the International Space Station (ISS). This paper assess both the satellite and the ADCS mock-up dynamics. Analytical, numerical and laboratory study results are in good correspondence with in-flight data. 相似文献
93.
This paper presents an adaptive unscented Kalman filter (AUKF) to recover the satellite attitude in a fault detection and diagnosis (FDD) subsystem of microsatellites. The FDD subsystem includes a filter and an estimator with residual generators, hypothesis tests for fault detections and a reference logic table for fault isolations and fault recovery. The recovery process is based on the monitoring of mean and variance values of each attitude sensor behaviors from residual vectors. In the case of normal work, the residual vectors should be in the form of Gaussian white noise with zero mean and fixed variance. When the hypothesis tests for the residual vectors detect something unusual by comparing the mean and variance values with dynamic thresholds, the AUKF with real-time updated measurement noise covariance matrix will be used to recover the sensor faults. The scheme developed in this paper resolves the problem of the heavy and complex calculations during residual generations and therefore the delay in the isolation process is reduced. The numerical simulations for TSUBAME, a demonstration microsatellite of Tokyo Institute of Technology, are conducted and analyzed to demonstrate the working of the AUKF and FDD subsystem. 相似文献
94.
Route generation and description using the notions of object's influence area and spatial conceptual map 总被引:1,自引:0,他引:1
In the GRAAD Project we aimed at creatinga system which could generate route directions thatare comparable to route directions created by humanparticipants. With this goal in mind, we started froma linguistic and cognitive study of route directionsproduced by people and the study of cognitive modelsof mental maps. We proposed a new qualitative spatialmodel that can support the spatial properties of humanroute directions. This model is based on the notion ofobject's influence area which is used to modelneighborhood, orientation and distance. The proposedapproach relies on the manipulation of spatialentities in a spatial conceptual map (SCM) which isthe computarized analog of a mental map used bypeople. We developped the GRAAD System, software thatgenerates routes in a SCM and describes them innatural language. Finally, we conducted an experimentin order to compare GRAAD's route directions androutes described by human participants in similarexperimental conditions. GRAAD's output was notdistinguishable from route directions created by humanparticipants. In this paper we present the mainresults obtained during all phases of the GRAADProject. 相似文献
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96.
本文基于雷达间电磁兼容性(Electromagnetic Compatibility,EMC)的考虑,提出了一种与雷达性能相关的兼容性判决模型。与以往用于EMC判决的干扰余量等概念不同,将干扰信号强度与雷达性能指标参数联系起来。对两者间的关系进行量化分析,从而确切了解雷达间的电磁兼容问题,使EMC预测更有实际意义。 相似文献
97.
中国深空网首次△DOR联合测轨试验分析 总被引:1,自引:0,他引:1
通过分析中国深空网首次△DOR(Delta Differential One way Ranging,双差分单向测距)联合测轨试验的干涉测量事后数据,重点从观测量随机精度、闭合时延等方面讨论了国内深空网与国内VLBI(Very Long Baseline Interferometry,甚长基线干涉测量)观测网、国内深空网与国际深空网的联合干涉处理情况,并与ESOC(European Space Operation Center,欧洲空间操作中心)数据处理结果进行了比对.试验结果表明:我国深空网已具备独立或联合开展深空探测器导航测轨的系统支持能力;深空站系统具备高速率数据接收、采集、记录、传输能力,采集数据处理精度优于1 ns;深空网干涉测量信号处理中心具备多体制信号的干涉处理分析能力,其分析精度与ESOC处理精度差异在0.1 ns量级. 相似文献
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99.
研究了一种星敏感器一陀螺组合定姿方式中的姿态敏感器误差的实时在轨标定方法。首先,选择直观的欧拉角作为姿态描述参数,根据星敏感器和陀螺的测量原理建立星敏感器一陀螺在轨标定的测量方程和状态方程,并以此建立数学模型。其次,采用简单高效的EKF(ExtendedKalmanFilter,扩展卡尔曼滤波)作为估值算法,进行了在轨标定数值仿真。对于航天器姿态定向中出现的姿态角和星敏感器安装角之间的耦合问题,通过在特定姿态通道上施加简单姿态机动实现了解耦。数值结果表明,该实时在轨标定方法,尤其是所提出的姿态角和星敏感器安装角解耦策略,可以实现对航天器姿态的实时精确估计以及对星敏感器安装误差、陀螺常值漂移和相关漂移等误差的实时在轨标定。该方法可用于航天器姿态测量设备的实时在轨标定和航天器姿态的高精度实时确定。 相似文献
100.