非量测相机标定的室外控制场设计与建立

发布时间：2018-06-16 23:20

本文选题：摄影测量 + 相机标定　；参考：《吉林大学》2017年硕士论文

【摘要】：近景摄影测量,是针对实物及其运动状态的近距离摄影测量,目前,近景摄影测量几乎应用于社会生活的各个领域。在近景摄影测量作业过程中,首先,需要对物体进行摄影,其次,对所摄像片进行再处理以获取物体静态及动态信息。在摄影过程中,主要有量测型和非量测型摄影设备。近年来,随着近景摄影测量技术的快速发展,用非量测型相机特别是普通数码相机进行影像获取逐渐成为一种趋势,但是,非量测型相机不是专门为摄影测量目的设计的,它存在结构不稳,内方位元素未知,畸变差较大等缺陷,因此,在使用时必须对其进行相机标定,而高精度的三维控制场是相机标定时的一种可靠参照对象,通过对控制场的测量,可以获取高精度的标志点坐标,为相机标定提供基础数据。本文以国家自然科学基金面上项目“基于DCRP的岩体复杂结构与质量表征参数精细描述”(41472243)为支持,结合国内外关于三维控制场建立的研究现状,设计和建立了用于非量测相机标定的室外三维控制场。研究主要包括控制场标志及点位分布设计,基于免棱镜全站仪极坐标法的控制场测量,控制场测量的数据预处理,基于轴对准法的控制场坐标系的建立,基于误差理论的控制场测量精度评定及影响因素分析。论文取得了如下研究成果:(1)室外三维控制场的设计。对控制场标志的尺寸、形状、颜色和材料进行了设计;研究和确定了控制场点位的分布,在两栋公寓楼的12个不同的立面上共布设了258个标志点。(2)基于免棱镜全站仪空间极坐标法的控制场测量及数据预处理。采用全站仪Leica TS30基于空间极坐标法对控制场标志点进行测量;根据测量限差,结合观测量信息对标志点的初始坐标进行修正。(3)基于轴对准法的控制场坐标系建立及坐标转换。为实现各立面上标志点的坐标统一和评定标志点测量的实际精度,基于轴对准法建立了稳定的控制场坐标系,并将测量坐标系下的坐标转换到控制场坐标系下,以便不同次测量的坐标对比分析,总结出坐标转换点的选取原则。(4)基于误差理论的精度评定和影响因素分析。基于误差理论对控制场测量成果进行精度评定,得到控制场点位测量的理论精度为±2mm,实际精度为±1.4mm;分析了不同坐标转换点以及观测条件如视线仰角(α),视线与标志法线夹角(β),斜距(S)等因素对于点位精度的影响,得出在室外控制场测量工作中,应尽量控制α小于20°,β小于50°,S小于50m,以获得较高的控制场测量精度。为实现非量测相机的标定,本文设计和建立了高精度的室外三维控制场,提供了控制场建立过程中的点位设计方案、测量技术要求与数据处理方法,进一步补充了室外控制场建立理论,研究成果具有理论和工程实践意义。
[Abstract]:Close-range photogrammetry is a kind of close-range photogrammetry aimed at the object and its moving state. At present, close-range photogrammetry is applied in almost every field of social life. In the process of close-range photogrammetry, first of all, the object needs to be photographed, and secondly, the image is reprocessed to obtain the static and dynamic information of the object. In the process of photography, there are mainly measuring and non-measuring photography equipment. In recent years, with the rapid development of close-range photogrammetry technology, it has become a trend to obtain images by using non-measuring cameras, especially ordinary digital cameras. However, non-measurement cameras are not designed specifically for photogrammetry purposes. It has some defects, such as unstable structure, unknown internal azimuth elements, large distortion difference and so on. Therefore, the camera must be calibrated when it is used, and the high precision 3D control field is a reliable reference object for camera calibration. Through the measurement of the control field, the high precision coordinate of the mark point can be obtained, and the basic data can be provided for the camera calibration. This paper is supported by the project of National Natural Science Foundation of China, "precise description of complex structure and quality characterization parameters of rock mass based on DCRP", and combined with the research status quo of the establishment of three-dimensional control field at home and abroad. An outdoor three-dimensional control field for non-measurement camera calibration is designed and established. The research mainly includes the design of control field mark and point distribution, the control field measurement based on Polar coordinate method of prism free total station, the data preprocessing of control field measurement, and the establishment of control field coordinate system based on axial alignment method. The accuracy evaluation of control field based on error theory and the analysis of influencing factors are presented. In this paper, the following research results are obtained: 1) the design of outdoor three-dimensional control field. The dimensions, shapes, colors and materials of the control field signs are designed, and the distribution of control field points is studied and determined. A total of 258 mark points are arranged on 12 different facades of two apartment buildings. The control field measurement and data preprocessing based on the prism free total station spatial polar coordinate method are presented. The total station Leica TS30 is used to measure the control field mark point based on the spatial polar coordinate method, and the initial coordinate of the mark point is modified according to the measurement limit and the observation information. The control field coordinate system is established and transformed based on the axial alignment method. In order to realize the coordinate unification of the mark points on each elevation and evaluate the actual accuracy of the mark point measurement, a stable control field coordinate system is established based on the axial alignment method, and the coordinate under the measurement coordinate system is converted to the control field coordinate system. In order to compare and analyze the coordinate of different times, the principle of selecting coordinate transformation point is summarized. (4) the accuracy evaluation based on error theory and the analysis of influencing factors are given. Based on error theory, the accuracy of control field measurement is evaluated. The theoretical accuracy of the control field is 卤2 mm and the actual accuracy is 卤1.4 mm. The effects of different coordinate conversion points and observation conditions such as elevation of line of sight (伪), angle of line of sight and normal line of sight (尾), slanting distance S (S) on the accuracy of point position are analyzed. It is concluded that in outdoor control field measurement, 伪 < 20 掳, 尾 < 50 掳S < 50 m should be controlled as far as possible in order to obtain higher precision of control field measurement. In order to realize the calibration of the non-measuring camera, a high precision outdoor 3D control field is designed and established in this paper. The design scheme of the point position, the technical requirements and the data processing method of the control field are provided. The theory of outdoor control field is further supplemented, and the research results are of theoretical and engineering significance.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P23

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