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分析了当前主要的高清晰度图像插值放大方法,为实现快速放大而选择了基于图像轮廓插值改善清晰度的技术路线,并在已有算法的基础上开展了进一步的研究.提出了新的图像轮廓线光顺数值算法,对轮廓线划分的两类子区域提出了精度更高的插值算法.最后,以典型平面图形的图像和由3DMax生成的三维渲染图像为例对本文方法进行检验,与双线性插值结果的对比说明,该方法可以明显改善插值放大效果. 相似文献
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电磁式跟踪器可以测量物体的位置和姿态,但其测量精度也容易受金属环境干扰。本文根据电磁跟踪器的工作原理,给出了电磁式跟踪器姿态校正的模型,讨论了两种不同的姿态校正实现方法:插值法和拟合法,比较了两种方法的优缺点。最后,对某一金属环境进行了畸变姿态校正的试验,给出了3个不同的姿态实际值和在此金属环境下的畸变和校正结果。试验结果表明本文提出的姿态校正算法能很好地补偿金属环境引起的电磁式跟踪器姿态的畸变。 相似文献
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The grid fin is an unconventional control surface used on missiles and rockets. Although aerodynamics of grid fin has been studied by many researchers, few considers the aeroelastic effects.In this paper, the static aeroelastic simulations are performed by the coupled viscous computational fluid dynamics with structural flexibility method in transonic and supersonic regimes. The developed coupling strategy including fluid–structure interpolation and volume mesh motion schemes is based on radial basis functions. Results are presented for a vertical and a horizontal grid fin mounted on a body. Horizontal fin results show that the deformed fin is swept backward and the axial force is increased. The deformations also induce the movement of center of pressure, causing the reduction and reversal in hinge moment for the transonic flow and the supersonic flow,respectively. For the vertical fin, the local effective incidences are increased due to the deformations so that the deformed normal force is greater than the original one. At high angles of attack, both the deformed and original normal forces experience a sudden reduction due to the interference of leeward separated vortices on the fin. Additionally, the increment in axial force is shown to correlate strongly with the increment in the square of normal force. 相似文献
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Shridhar D. Jawak Alvarinho J. Luis 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
An enhanced digital elevation model (DEM) of the Larsemann Hills region, east Antarctica, is constructed synergistically by using highly accurate ground-based GPS measurements, satellite-derived laser altimetry (GLAS/ICESat) and Radarsat Antarctic Mapping Project (RAMPv2) DEM-based point elevation dataset. Our DEM has a vertical accuracy of about 1.5 times better than RAMPv2 DEM and seven times better than GLAS/ICESAT-based DEM. The accuracy is improved by validating the RAMPv2 DEM elevation by supplementing with GLAS/ICESat and DGPS survey data, when compared to that of DEM constructed by using GLAS/ICESat or RAMPv2 alone. With the use of accurate GPS data as ground control points reference elevations, the DEM extracted is much more accurate with least mean RMSE of 34.5 m than that constructed by using a combination of GLAS/ICESat and RAMPv2 as true reference. The newly constructed DEM 7 achieves highest accuracy with the least average elevation difference of 0.27 m calculated using 46 ground reference points. Available DEMs of Antarctic region generated by using radar altimetry and the Antarctic Digital Database indicate elevation variations in the range of 50–100 m, which necessitates the generation of local DEM and its validation by using ground truth. This is our first attempt of fusing multi-temporal, multi-sensor and multi-source elevation data to generate a DEM of any part of Antarctica, in order to address the ice elevation change to infer the ice mass balance. Our approach focuses on the strengths of each elevation data source to produce an accurate DEM. 相似文献
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介绍了HCM-I型超精密车床数控系统软件的功能及工作流程.详细分析了数控系统软件的关键技术,给出了相应技术的软件流程图. 相似文献
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基于流固耦合传热的思想建立了一套飞机热气防冰系统的的数值模拟方法,并将其与积冰热力学模型结合起来,实现了热气防冰系统开启时的机翼积冰预测.采用格心格式有限体积法求解N-S方程获得防冰腔与外流场;通过欧拉法在外流场的基础上获得过冷水滴撞击特性;求解三维热传导偏微分方程获得蒙皮的传热特性;采用交接面插值的方法实现防冰腔到外流场的热量传递;建立了考虑三维溢流效应的积冰热力学模型并在此基础上开展了机翼冰脊的数值预测.数值模拟结果表明:热气防冰系统开启时加热机翼表面温度最高可达308K,加热区后的上下机翼表面均有冰脊形成,通过对结果的分析表明该方法是合理可行的. 相似文献
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