非量测相机附加参数光束检校改进算法研究  

Nonmetric camera calibration based on improved bundle adjustment with additional parameters

作　　者：岳文鹏 吴兆福[1] 方云飞 YUE Wenpeng;WU Zhaofu;FANG Yunfei(School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei 230009, China)

机构地区：[1]合肥工业大学土木与水利工程学院,安徽合肥230009

出　　处：《合肥工业大学学报（自然科学版）》2022年第5期633-638,共6页Journal of Hefei University of Technology：Natural Science

基　　金：国家自然科学基金青年科学基金资助项目(42004001)。

摘　　要：非量测相机在无人机航测等领域应用中存在光学畸变大、无法记录内方位元素等缺陷,文章提出一种直接线性变换(direct linear transformation,DLT)和附加参数光束法协同检校算法,利用DLT求解出的内、外方位元素作为附加参数光束平差法的初始值,通过附加参数光束法完成整体平差,弥补DLT只能独立处理单个模型的不足,并满足光束法对初始值高精度的需求;同时考虑非量测相机比例尺不一致误差与坐标轴不正交误差,利用这2类误差参数进一步优化附加参数光束法的数据处理模型。文中以武汉大学室内三维控制场为例,对检校参数进行精度评定,验证该算法的可行性。实验结果表明,该算法可明显提高非量测相机检校精度,其检查点坐标精度在DLT的基础上提高19.17%,且引入的参数不影响其他参数的解算。At present,nonmetric camera has been widely used in UAV aerial survey and other fields.However,defects such as large optical distortion and inability to record internal azimuth elements affect its further application.For this reason,this paper proposes a collaborative calibration method based on direct linear transformation(DLT)and bundle adjustment with additional parameters,using DLT to calculate the internal and external azimuth elements as the initial value of bundle adjustment,and completing the adjustment in one cast by bundle adjustment.It makes up for the deficiency of DLT that can only deal with a single model,and also meets the demand of bundle adjustment method for high-precision initial value.At the same time,considering the scale inconsistency error and non-orthogonal error of the nonmetric camera,the data processing model of the bundle adjustment with additional parameters is further optimized by using these two kinds of error parameters.Finally,the paper takes the indoor three-dimensional control field of Wuhan University as an example to evaluate the accuracy of the calibration parameters.Through comparison,the feasibility of the proposed algorithm is verified.Experimental result shows that the proposed algorithm can significantly improve the calibration accuracy of nonmetric cameras,and the accuracy of the checkpoint coordinate improves by 19.17%on the basis of DLT,and the introduced parameters do not affect the solution of other parameters.

关 键 词：直接线性变换(DLT) 附加参数光束法 非量测相机 协同检校 

分 类 号：P232[天文地球—摄影测量与遥感]