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71.
72.
Spherical mobile robot has compact structure, remarkable stability, and flexible motion,which make it have many advantages over traditional mobile robots when applied in those unmanned environments, such as outer planets. However, spherical mobile robot is a special highly under-actuated nonholonomic system, which cannot be transformed to the classic chained form. At present, there has not been a kinematics-based trajectory tracking controller which could track both the position states and the attitude states of a spherical mobile robot. In this paper, the four-state(two position states and two attitude states) trajectory tracking control of a type of spherical mobile robot driven by a 2-DOF pendulum was studied. A controller based on the shunting model of neurodynamics and the kinematic model was deduced, and its stability was demonstrated with Lyapunov's direct method. The control priorities of the four states were allocated according to the magnification of each state tracking error in order to firstly ensure the correct tracking of the position states. The outputs(motor speeds) of the controller were regulated according to the maximum speeds and the maximum accelerations of the actuation motors in order to solve the speed jump problem caused by initial state errors, and continuous and bounded outputs were obtained. The effectiveness including the anti-interference ability of the proposed trajectory tracking controller was verified through MATLAB simulations. 相似文献
73.
为改进某无人机飞行性能,应用最大值原理求解无人机在垂直平面内的最优上升轨迹,推导了无人机最经济爬升所满足的极值方程;并用此方程和最快爬升极值方程这两类目标函数求解了某无人机的最优上升轨迹,计算结果表明,经优化后的爬升轨迹可以节省燃油,延长无人机的续航时间或快速爬升到预定的终点高度具有较好的性能收益。 相似文献
74.
从机构学的角度,基于机器人机构运动方程中原动件角位移及其微分系数的变化关系,利用原动件的角位移在端点附近,其微分系数的值急剧增大的特征,对轨迹曲线上点的坐标进行变换,提出了输出输入角相互切换的基准和算法,以较少的计算量实现了轨迹曲线上输出点的等间隔分布,对机器人轨迹规划的研究具有积极意义。 相似文献
75.
《中国航空学报》2022,35(12):336-356
In comparison to the traditional fixed-angle trajectory, the variable-angle trajectory has a greater design space. However, it is a challenge to determine which common design curve structure is the most effective for improving mechanical performance. This work explores the effects of various design curves such as fixed-angle curve, linear curve, arc curve, sine curve, Bezier curve, and cubic polynomial curve trajectories on mechanical performance of laminates, including vibration modal performance and buckling performance. Genetic algorithm and improved NSGA-II algorithm are then used to optimize various curve structures. The results are confirmed utilizing thermoplastic Carbon Fiber (CF)/Polyether-Ether-Ketone (PEEK) laminates made by robotic fiber placement experiments. The relationship model between different mechanical performance and curve design variables is established. The optimization of variable-angle structure with mechanical properties as input variables is achieved. Meanwhile, a full-process angle-variable laying software platform from trajectory planning (CAD), trajectory optimization to manufacturing (CAM) is developed for facilitating the fiber placement application. 相似文献
76.
对于可重复使用运载器标准轨迹再入制导,准平衡滑翔条件可以将高度-速度平面内各项再入约束形成的飞行走廊,转换为倾侧角-速度空间内的倾侧角走廊.通过在倾侧角走廊内设计倾侧角曲线,可以生成满足飞行走廊的标准轨迹.通过论证标准轨迹再入制导过程中的准平衡滑翔条件及其物理意义,说明了由倾侧角走廊内的倾侧角曲线生成的标准轨迹,存在突破再入飞行走廊边界的可能性.通过对倾侧角走廊边界设置余度,极大地降低了标准轨迹突破再入飞行走廊边界的可能性,提高了标准轨迹的设计成功率. 相似文献
77.
This study presents a novel impact time and angle constrained guidance law for homing missiles. The guidance law is first developed with the prior-assumption of a stationary target, which is followed by the practical extension to a maneuvering target scenario. To derive the closed-form guidance law, the trajectory reshaping technique is utilized and it results in defining a specific poly-nomial function with two unknown coefficients. These coefficients are determined to satisfy the impact time and angle constraints as well as the zero miss distance. Furthermore, the proposed guidance law has three additional guidance gains as design parameters which make it possible to adjust the guided trajectory according to the operational conditions and missile’s capability. Numerical simulations are presented to validate the effectiveness of the proposed guidance law. ? 2016 Chinese Society of Aeronautics and Astronautics. Production and hosting by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). 相似文献
78.
本文基于H^∝最估理论和矩阵奇异值分解技术,对卫星轨道保持系统进行了分攻容错控制,提出了容许执行机构故障和传感器故障的两种分散控制律设计方法,可使卫星控制系统具有明显的容错能力。 相似文献
79.
80.
垂直冷发射防空导弹弹道设计中的参数优化 总被引:1,自引:0,他引:1
根据垂直冷发射防空导弹的飞行程序,分析了影响弹道性能的主要因素,选取相应的参数对弹道进行优化设计。优化前后弹道参数的计算结果表明,该优化方法改善了速度特性,在攻击超低空目标时保证弹道末段俯冲角满足布儒斯特角的要求,是防空导弹弹道的有效设计方法。 相似文献