高速铁路轨道车载近景影像的精确匹配与建模  

Image Coregistration Method of Vehicle-borne Close-range Photogrammetry for High-speed Railway Track

作　　者：陈强[1] 刘丽瑶[1] 杨莹辉[1] 佘毅 

机构地区：[1]西南交通大学,成都610031 [2]四川省测绘产品质量监督检验站,成都610041

出　　处：《铁道工程学报》2015年第1期38-43,共6页Journal of Railway Engineering Society

基　　金：国家自然科学基金项目(51178404);中国铁路总公司科技研究开发计划课题(2013G009-C)

摘　　要：研究目的:为改善高速铁路轨道几何状态检测的速度和效率,引入近景摄影测量技术检测轨道几何平顺性,而轨道影像的准确匹配是图像定向建模的重要技术环节。针对高速铁路轨道近景影像的图像特征相对较少、影像色彩信息较为单一、图像灰度数值具有较高的相似性、轨道边缘匹配较为困难,本文提出一种车载近景影像轨道边缘提取与精确匹配的算法,在分析轨道影像特征及其变化规律的基础上,获得轨道影像同名点之间的坐标几何映射模型,实现轨道影像的准确匹配。研究结论:(1)轨道边缘同名点垂轨向坐标呈三次函数模型关系,沿轨向坐标呈线性模型关系,通过建立同名点坐标的映射转换模型,可实现同名点的自动准确匹配;(2)边缘匹配算法通过试验影像计算出一个像对的转换模型后,可以应用于相同拍摄条件下的其余所有轨道影像;(3)试验结果表明,本文提出的轨道图像匹配算法具有较高的精度潜力,可改善高速铁路轨道影像在灰度信息高相似性时匹配困难的问题,为近景摄影测量检测高速铁路轨道几何平顺性提供重要的技术支持。Research purposes： In order to improve the speed and efficiency of the detection for high - speed railway track, the close -range photogrammetry is introduced to examine the geometric regularity of railway track. The accurate image coregistration is the key process for track photographs orientation. The track photographs have few image characteristics, single color information, and high similarity of image grey value. So track image edge extracting and matching is relatively difficult. The method on extracting and matching track image edge for vehicle - borne close - range photographs was proposed in this paper. Based on the grey feature and its change information between track photographs, the coordinate geometric mapping model for homologous points of track edge was derived, and accurate image matching was carried out. Research conclusions： （ 1 ） The cross - track coordinates for homologous points of track edge was cubic function model, and the along -track coordinates was linear model. The transformation relationship at homologous points was established, automatic and accurate image matching was carried out. （2）The transformation relationship which acquired from one image pair can apply to the other images with same acquisition conditions. （3）The accuracy and reliability oftrack image matching were validated from the experiment, which indicates that it can solve the matching difficulty, and it is a promising technique for examining the static geometric regularity of high - speed railways track with close - rang photogrammetry.

关 键 词：铁路轨道 车载近景摄影测量 影像匹配 建模 精度评估 

分 类 号：U216[交通运输工程—道路与铁道工程]