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为了实时且精确地获取飞机相对于着陆点的位置坐标,在深入分析机场场地位置几何信息和地面设备制导信息并建立坐标变换测量方程的基础上,提出了一种基于坐标系旋转的旋转坐标迭代解算算法;该算法通过坐标系的旋转消除了飞机纵轴方向上的位移,而后研究其具体迭代解算过程,并通过仿真进行算法性能分析;将所提出的旋转坐标迭代解算算法在TMS320F2812DSP上进行实现,并利用集成开发环境(CCS)进行调试与仿真;结果表明:旋转坐标迭代解算算法收敛快速且精确度高,DSP实现的旋转坐标迭代解算算法所得坐标值与软件仿真结果基本一致,满足系统性能指标要求,对于无人机着陆制导信息的获取具有实用价值。 相似文献
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A versatile metal-organic chemical vapor deposition (MOCVD) system was designed and constructed. Copper films were deposited on silicon (100) substrates by chemical vapor deposition (CVD) using Cu(hfac)2 as a precursor. The growth of Cu nucleus on silicon substrates by H2 reduction of Cu(hfac)2 was studied by atomic force microscopy and scanning electron microscopy. The growth mode of Cu nucleus is initially Volmer-Weber mode (island), and then transforms to Stranski-Rastanov mode (layer-by-layer plus island).The mechanism of Cu nucleation on silicon (100) substrates was further investigated by X-ray photoelectron spectroscopy. From Cu2p, O1s, F1s, Si2p patterns, the observed C=O, OH and CF3/CF2 should belong to Cu(hfac) formed by the thermal dissociation of Cu(hfac)2. H2 reacts with hfac on the surface, producing OH. With its accumulation, OH reacts with hfac, forming HO-hfac, and desorbs, meanwhile, the copper oxide is reduced, and thus the redox reaction between Cu(hafc)2 and H2 occurs. 相似文献
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多重乳液因为具有独特的"两膜三相"的多隔室结构,使得交联剂和聚合物溶解在不同相中,起到延缓交联的作用,可用于油田采油后期深部调剖堵水作业,以提高原油采收率。本文采用用两步法制备了一种稳定的W/O/W型多重乳状液延缓交联体系,并对其在大庆地层条件下成胶性能进行室内静态评价。通过正交试验得到多重乳化最佳工艺条件:W/O乳液在WSpan80=2.8%,Wresidual=5%,VOil∶VWater=3∶7,T=2.5min条件下制备;W/O/W乳液在VW/O∶VHPAM=7∶3,WTween80=1.5%,R=4000r·min-1,T=3.0min条件下制备。在pH=8时所合成的柴油/渣油多重乳液延缓铬溶胶交联体系成胶时间为480h,冻胶强度为28354m Pa·s。 相似文献