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排序方式: 共有153条查询结果,搜索用时 640 毫秒
91.
基于Petri网的故障树分析方法 总被引:5,自引:0,他引:5
故障树是事件间的一种布尔逻辑关系模型,基于故障树的诊断方法的广泛应用由于实际故障树分析过程NP困难问题而受到妨碍。Petri网作为一种特殊的有向网,它能反映系统的状态变化和事件发展,尤其适合于表达故障的传播关系。本文因此提出了两种基于Petri网的改进方法,与下行法相比,用该方法寻找最小割集和最小路集能有效地节省计算时间,提高推理速度和效率,并且其算法便于计算机实现。 相似文献
92.
以铝合金薄壁通壳体零件为例,对工件的定位、装夹、刀具的选择、切削参数设置、程序的编制等方面进行了探索,从而有效地克服了薄壁通壳体类零件在加工过程中出现的颤振、变形、表面质量差、尺寸精度低等问题,并大幅缩短了加工时间。 相似文献
93.
月球车的视觉和自主导航系统 总被引:4,自引:0,他引:4
基于当前对于月球车、火星登陆机器人等的研究结果,介绍了月球车的视觉系统、控制方案和路径规划方法,并提出了对于月球车的控制方案的见解和路径规划的一些方法。 相似文献
94.
肖继明%李言%吴玉生%张立武%李俊峰 《宇航材料工艺》2006,36(1):49-52
针对D406A超高强度钢的性能特点,选用了五种麻花钻进行钻削试验。结果表明,HSP15含钴超硬高速钢麻花钻较适于经热处理强化后D406A超高强度钢的钻削加工,且在钻头几何参数和钻削用量选择合理、使用合适切削液的条件下,可有效地改善D406A超高强度钢的钻削性能。 相似文献
95.
《中国航空学报》2016,(5):1385-1396
Search speed, quality of resulting paths and the cost of pre-processing are the principle evaluation metrics of a pathfinding algorithm. In this paper, a new algorithm for grid-based maps, rectangle expansion A* (REA*), is presented that improves the performance of A* significantly. REA*explores maps in units of unblocked rectangles. All unnecessary points inside the rectangles are pruned and boundaries of the rectangles (instead of individual points within those boundaries) are used as search nodes. This makes the algorithm plot fewer points and have a much shorter open list than A*. REA*returns jump and grid-optimal path points, but since the line of sight between jump points is protected by the unblocked rectangles, the resulting path of REA*is usually better than grid-optimal. The algorithm is entirely online and requires no offline pre-processing. Experi-mental results for typical benchmark problem sets show that REA*can speed up a highly optimized A* by an order of magnitude and more while preserving completeness and optimality. This new algorithm is competitive with other highly successful variants of A*. 相似文献
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《中国航空学报》2020,33(12):3039-3057
As an important part in sortie/recovery process, the dispatch of carrier aircraft not only affects the sortie/recovery efficiency and safety, but also has severe influence on the carrier’s combat efficiency and the comprehensive support capability. Path planning is the key to improve the efficiency and safety during the dispatch process. The main purpose of this paper is to propose a comprehensive investigation of techniques and research progress for the carrier aircraft’s dispatch path planning on the deck. Three different dispatch modes of carrier aircraft and the corresponding modeling technologies are investigated, and the aircraft’s dispatch path planning techniques and algorithms have been classified into different classes. Moreover, their assumptions and drawbacks have been discussed for single aircraft and multiple aircraft. To make the research work more comprehensive, the corresponding tracking control methodologies are also discussed. Finally, due to the similarity of path planning problem between the carrier aircraft’s dispatch and those in other fields, this paper provides an exploratory prospect of the knowledge or method learned from other fields. 相似文献
99.
《中国航空学报》2021,34(9):199-209
In this paper, a bio-inspired path planning algorithm in 3D space is proposed. The algorithm imitates the basic mechanisms of plant growth, including phototropism, negative geotropism and branching. The algorithm proposed in this paper solves the dynamic obstacle avoidance path planning problem of Unmanned Aerial Vehicle (UAV) in the case of unknown environment maps. Compared with other path planning algorithms, the algorithm has the advantages of fast path planning speed and fewer route points, and can achieve the effect of low delay real-time path planning. The feasibility of the algorithm is verified in the Gazebo simulator based on the Robot Operating System (ROS) platform. Finally, an actual UAV autonomous obstacle avoidance path planning experimental platform is built, and a UAV obstacle avoidance path planning flight test is carried out based on this actual environment. 相似文献
100.