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基于非度量校正的大视场图像匹配参数标定法 被引量:1
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作者 张致远 刘巍 +4 位作者 张洋 逯永康 邸宏图 叶帆 贾振元 《光学学报》 EI CAS CSCD 北大核心 2018年第8期60-67,共8页
针对工业环境下拍摄的大视场图像受噪声与畸变影响较大,使用传统匹配参数计算方法的精度无法满足现场测量需求的问题,提出一种基于非度量校正的大视场图像匹配参数标定算法。设计了一种共线特征点布置方案,基于非度量校正完成了特征点... 针对工业环境下拍摄的大视场图像受噪声与畸变影响较大,使用传统匹配参数计算方法的精度无法满足现场测量需求的问题,提出一种基于非度量校正的大视场图像匹配参数标定算法。设计了一种共线特征点布置方案,基于非度量校正完成了特征点坐标的畸变校正,并提出基于该布置方案的特征点识别匹配算法,通过分区域抽样一致性法实现匹配参数的高精度标定。实验结果表明,该算法匹配精度相较于传统方法提高了51%以上,能够满足工业环境下大视场图像匹配参数所需的精度要求。 展开更多
关键词 机器视觉 视觉测量 匹配参数 大视场 度量校正
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未标定单幅结构场景图像的三维重构 被引量:6
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作者 杨敏 沈春林 《中国图象图形学报(A辑)》 CSCD 北大核心 2004年第4期456-459,共4页
提出了一种单视三维重构方法 ,该方法是利用用户提供图像点及其对应的三维点之间几何信息。由于结构场景是由大量平面构成的 ,存在大量的平行性、正交性约束 ,因此该方法主要应用于结构场景的三维重构。首先 ,相机定标和计算每个平面的... 提出了一种单视三维重构方法 ,该方法是利用用户提供图像点及其对应的三维点之间几何信息。由于结构场景是由大量平面构成的 ,存在大量的平行性、正交性约束 ,因此该方法主要应用于结构场景的三维重构。首先 ,相机定标和计算每个平面的度量信息 ,即先基于 3组互相垂直方向的影灭点 ,对方形像素相机标定 ,再利用影灭线和圆环点像 ,对每个平面度量校正 ;然后考虑每个校正平面的尺度因子和非正交平面间的相对面向 ,从而将所有校正后的平面缝合起来。采用真实图像进行实验 ,实验结果表明 。 展开更多
关键词 单视三维重构 圆环点 相机定标 度量校正 计算机视觉 结构场景图像
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Measurement and Correlation for Solubility of Dimethyl-2,6-naphthalene Dicarboxylate in Organic Solvents 被引量:4
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作者 夏清 马沛生 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第2期215-220,共6页
Solubility of dimethyl-2,6-naphthalene dicarboxylate in acetic acid, N,N-dimethylfonnamide, N,N-dimethyl acetamide, dimethyl sulphoxide, and N-methyl-2-ketopyrrolidine were determined using a dynamic method. The measu... Solubility of dimethyl-2,6-naphthalene dicarboxylate in acetic acid, N,N-dimethylfonnamide, N,N-dimethyl acetamide, dimethyl sulphoxide, and N-methyl-2-ketopyrrolidine were determined using a dynamic method. The measured systems were correlated by UNIFAC group contribution method. A new main group (aromatic ester, ACCOO) was defined to express the activity coefficients of the aromatic ester. New interaction parameters of the ACCOO group were expressed as the first-order function of temperature and were determined from the experimental data. The calculated results for the new interaction parameters were satisfactory. The measured systems were also correlated with the Wilson and 2-h models, and the results were compared with those of the UNIFAC model. 展开更多
关键词 solid-liquid equilibrium SOLUBILITY dimethyl-2 6-naphthalene dicarboxylate UNIFAC group contribution method activity coefficient
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Design and optimization of vector coil sensor suited to magnetometric resistivity method 被引量:1
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作者 SONG Shuang SUN De-li +1 位作者 CHEN Chao TENG Fei 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2020年第1期45-53,共9页
Magnetometric resistivity(MMR)method is a new way to detect dam leakage.The coil sensor is generally used to collect data in geophysical exploration methods.Given the characteristics of accurate vector data requiremen... Magnetometric resistivity(MMR)method is a new way to detect dam leakage.The coil sensor is generally used to collect data in geophysical exploration methods.Given the characteristics of accurate vector data requirements and high sensitivity requirement,a three-component MMR air-core coil sensor is designed.Through the analysis of sensor sensitivity and coil structure parameters,the coil structure and turn number are designed.By analyzing the noise source of the sensor,a suitable amplifier is selected to reduce the background noise of the system.Through the analysis of the three-component non-orthogonal angles,the parameters of the non-orthogonal angles of the coils are corrected.Finally,a three-component MMR induction magnetic field sensor is designed.The volume of the sensor is controlled at 0.027 m 3.The background noise of X、Y and Z are 5.030435 nV/Hz@380 Hz and magnetic field sensitivities are 0.18995 pT/Hz@380 Hz.The three channels have good consistency,and the three-component nonorthogonal angles correction error of three components is controlled within 0.2%. 展开更多
关键词 magnetometric resistivity(MMR) three-component air-core coil sensor noise analysis high sensitivity three-component correction
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Magnetometer calibration algorithm based on ellipsoid constraint
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作者 董明杰 Chou Wusheng Fang Bin 《High Technology Letters》 EI CAS 2015年第4期407-413,共7页
Calibration of magnetometer is an essential part to obtain high measurement precision.However,the existing calibration methods are basically the calibration of all attitudes,which means tough work when the magnetomete... Calibration of magnetometer is an essential part to obtain high measurement precision.However,the existing calibration methods are basically the calibration of all attitudes,which means tough work when the magnetometer is applied in strapdown inertial navigation system(SINS).So a quick,easy and effective calibration algorithm is developed based on the ellipsoid constraint to calibrate magnetometers.In this paper,the measuring principle and error characteristic of the magnetometer are analysed to study its magnetic interference.During the process,a magnetometer calibration model is set up to convert the calibration to ellipsoid fitting based on the characteristic of hard magnetic interference and soft magnetic interference.Then the algorithm is tested by mimic experiment.The result shows that measurement precision is improved after the calibration,and then the magnetometer is installed in a control cabin of an underwater robot which is designed and developed by us,and actual magnetometer calibration experiments are conducted to further verify the validity of the algorithm. 展开更多
关键词 calibration MAGNETOMETER ellipsoid constraint strapdown inertial navigation sys-tem (SINS)
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Altitude Correction for Breakdown Voltages of Long Air-Gaps
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作者 Wang Xuan Li Yunge +2 位作者 Cao Xiaolong Su Zhiyi Liu Ying 《Electricity》 2006年第1期34-37,共4页
The breakdown voltage of long air-gaps in high-voltage transmission systems depends on not only the waveform of the applied voltage, but also the atmospheric conditions. Based on the results of the research project on... The breakdown voltage of long air-gaps in high-voltage transmission systems depends on not only the waveform of the applied voltage, but also the atmospheric conditions. Based on the results of the research project on the minimum air clearance for 800-kV HVDC substations at high altitudes, and also on the monthly and yearly statistics of the atmospheric data of last ten years and the altitude correction of the atmospheric data of last ten years, the altitude correction of the air-gaps for the 800-kV DC system under plan, 500-kV AC system to be built, and 1000-kV AC system under plan in the Inner Mongolia Plateau and the Yungui Plateau in China were studied with parameter G method. Correction factors for switching and lightning impulses were calculatod and then compared with those achieved according to IEC 71. It is shown that IEC 71 is appropriate for damp regions, and correction factors differ between plateau regions in China because of different atmospheric conditions. 展开更多
关键词 altitude correction air-gaps atmospheric measurements
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