In order to achieve a high precision in three-dimensional（3D） multi-camera measurement system, an efficient multi-cameracalibration method is proposed. A stitching method of large scalecalibration targets is deduced...In order to achieve a high precision in three-dimensional（3D） multi-camera measurement system, an efficient multi-cameracalibration method is proposed. A stitching method of large scalecalibration targets is deduced, and a fundamental of multi-cameracalibration based on the large scale calibration target is provided.To avoid the shortcomings of the method, the vector differencesof reprojection error with the presence of the constraint conditionof the constant rigid body transformation is modelled, and mini-mized by the Levenberg-Marquardt （LM） method. Results of thesimulation and observation data calibration experiment show thatthe accuracy of the system calibrated by the proposed methodreaches 2 mm when measuring distance section of 20 000 mmand scale section of 7 000 mm × 7 000 mm. Consequently, theproposed method of multi-camera calibration performs better thanthe fundamental in stability. This technique offers a more uniformerror distribution for measuring large scale space.展开更多
多相机三维数字图像相关(three-dimensional digital image correlation,3D-DIC)系统在测量核燃料包壳管应变的实际应用中,多相机标定环节存在坐标系转换引发的累计误差增加及全局优化能力不足等问题。为此,提出一种基于空间标定靶的多...多相机三维数字图像相关(three-dimensional digital image correlation,3D-DIC)系统在测量核燃料包壳管应变的实际应用中,多相机标定环节存在坐标系转换引发的累计误差增加及全局优化能力不足等问题。为此,提出一种基于空间标定靶的多相机全局标定方法。首先,提出为各相机在标定靶每个位姿下提供外方位参数初值的方法,保证空间后方交会正确收敛;其次,提出多相机多位姿光束平差(bundle adjustment,BA)方法,保证多相机标定精度达到全局最优。实验结果表明,该方法的标定精度较直接线性变换(direct linear transformation,DLT)方法提高了55.1%,最大位移误差标准差降低了16.3%。同时,该方法无需对标志点进行手动编号,使标定过程实现了自动化,标定效率更高。展开更多
针对内埋舱武器性能鉴定试飞中机弹分离相对位姿测量需求,提出了一种基于高速影像的内埋舱武器分离位姿测量方法。通过加装带有弯管镜头的高速摄像机阵列,实现内埋弹舱狭小空间内弹体分离全过程高速影像数据的分段获取;采用结合机载空...针对内埋舱武器性能鉴定试飞中机弹分离相对位姿测量需求,提出了一种基于高速影像的内埋舱武器分离位姿测量方法。通过加装带有弯管镜头的高速摄像机阵列,实现内埋弹舱狭小空间内弹体分离全过程高速影像数据的分段获取;采用结合机载空间参考点不确定性的相机外参解算、基于You Only Look Once version 8(YOLOv8)的标志点智能检测、基于边缘灰度梯度正交迭代的十字标中心坐标自动提取、直线约束下的多视角非交叠影像测量等方法,实现机载高速摄像机分布快速标定、小视场成像条件下弹体表面标志点亚像素坐标自动提取、机载高速摄像机抖动下的外参动态修正以及武器分离相对位姿分段测量等功能。经地面试验验证,该方法位置解算均方根误差不大于2 mm,满足飞行试验测试精度要求。展开更多
基金supported by the National Natural Science Foundation of China(61473100)
文摘In order to achieve a high precision in three-dimensional（3D） multi-camera measurement system, an efficient multi-cameracalibration method is proposed. A stitching method of large scalecalibration targets is deduced, and a fundamental of multi-cameracalibration based on the large scale calibration target is provided.To avoid the shortcomings of the method, the vector differencesof reprojection error with the presence of the constraint conditionof the constant rigid body transformation is modelled, and mini-mized by the Levenberg-Marquardt （LM） method. Results of thesimulation and observation data calibration experiment show thatthe accuracy of the system calibrated by the proposed methodreaches 2 mm when measuring distance section of 20 000 mmand scale section of 7 000 mm × 7 000 mm. Consequently, theproposed method of multi-camera calibration performs better thanthe fundamental in stability. This technique offers a more uniformerror distribution for measuring large scale space.
文摘多相机三维数字图像相关(three-dimensional digital image correlation,3D-DIC)系统在测量核燃料包壳管应变的实际应用中,多相机标定环节存在坐标系转换引发的累计误差增加及全局优化能力不足等问题。为此,提出一种基于空间标定靶的多相机全局标定方法。首先,提出为各相机在标定靶每个位姿下提供外方位参数初值的方法,保证空间后方交会正确收敛;其次,提出多相机多位姿光束平差(bundle adjustment,BA)方法,保证多相机标定精度达到全局最优。实验结果表明,该方法的标定精度较直接线性变换(direct linear transformation,DLT)方法提高了55.1%,最大位移误差标准差降低了16.3%。同时,该方法无需对标志点进行手动编号,使标定过程实现了自动化,标定效率更高。
文摘针对内埋舱武器性能鉴定试飞中机弹分离相对位姿测量需求,提出了一种基于高速影像的内埋舱武器分离位姿测量方法。通过加装带有弯管镜头的高速摄像机阵列,实现内埋弹舱狭小空间内弹体分离全过程高速影像数据的分段获取;采用结合机载空间参考点不确定性的相机外参解算、基于You Only Look Once version 8(YOLOv8)的标志点智能检测、基于边缘灰度梯度正交迭代的十字标中心坐标自动提取、直线约束下的多视角非交叠影像测量等方法,实现机载高速摄像机分布快速标定、小视场成像条件下弹体表面标志点亚像素坐标自动提取、机载高速摄像机抖动下的外参动态修正以及武器分离相对位姿分段测量等功能。经地面试验验证,该方法位置解算均方根误差不大于2 mm,满足飞行试验测试精度要求。
