无人机摄影测量技术在铁路桥梁巡检中的应用

Application of UAV Photogrammetry Technology in Railway Bridge Inspection

针对铁路桥梁无人机巡检成果量化识别困难问题,基于摄影测量的原理,结合铁路常用跨度简支梁的结构构造特点与尺度特征,提出了采用合理规划路径对铁路简支梁的梁体侧面进行无人机巡检作业的方法。介绍了铁路桥梁的结构特征与巡检技术现状,数字摄影测量和贴近摄影测量原理与方法。针对全景贴近摄影测量现场作业效率低、后处理计算机资源消耗大的问题,采用不同作业模式对32 m跨度铁路简支T梁进行了贴近摄影测量快速巡检。通过优选无人机作业模式,单组无人机每天至少完成长约1.3 km简支梁桥的梁体检查,其重建模型结构尺寸偏差小于2%,可识别宽度小于0.20 mm的混凝土裂缝。

Aiming at the difficulty of quantitative identification of the inspection results of UAV(Unmanned Aerial Vehicle) on railway bridges,based on the principle of photogrammetry and combined with the structural and dimensional characteristics of simply supported girders with common spans in railway,the method of using a reasonable planning path to conduct UAV inspection operations on the side of those girders was proposed. It introduces the structural characteristics of railway bridges and the current status of inspection technology,the principles and methods of digital photogrammetry and nap-of-the-object photogrammetry. In view of the low operation efficiency and the large consumption of post-processing computer resources in panoramic nap-of-the-object photogrammetry,different operation modes were adopted to carry out nap-of-the-object photogrammetry for rapid inspection of 32 m simply supported Tgirder of railway. By optimizing the operation mode of UAV,a single group of UAVs can complete the girder inspection of about at least 1.3 km long simply supported girder bridge every day. The structural size deviation of the reconstructed model is less than 2%,and the width of concrete crack can be identified is less than 0.20 mm.