Several models of multirotor and the payload mapping camera are used in the bridge aerial survey, where oblique photogrammetry and close-range photogrammetry are used to obtain high-resolution multi-angle map of the railway bridge and its rugged surroundings. The map can provide effective data support for the daily maintenance and inspection of the Super Bridge and reduce the life risks for the maintenance personnel.
Field aerial photography
Global Aerial Photography: image acquisition required for tilt photogrammetry with a resolution of 3cm for the entire survey area (all areas related to the daily inspection of the bridge).
Aerial photography of bridge main body: collect images required for close photogrammetry with resolution better than 1cm on the details of bridge main body and surrounding ancillary facilities.
Details reshoot: take detailed shots of the key points of the railway management system, and manually hold cameras to reshoot areas that cannot be accessed by unmanned aerial vehicles.
Internal data processing
Data sorting, this time, the two photogrammetry methods are used to integrate modeling. The whole project will have various resolution images from 3cm to better than 1cm. The data must be checked for integrity first and then sorted out.
Upload the collected data to the Huawei cloud OBS bucket, build storage machines, empty three machines, and modeling machines on the cloud based on the amount of data collected, and apply for Smart3D real-life modeling system Image service.
The classified data shall be settled separately by empty three. After the empty three calculation is completed, the empty three results shall be integrated for model production.
The abundance of unmanned aerial vehicles and Mount types provides field acquisition methods for completing fine modeling requirements in complex scenarios, the improvement of cloud high-performance GPU Cluster Services provides sufficient computing power for real-time and field processing of massive data. Take this bridge project as an example, three types of models work at the same time, the effective operation time in the field is about 5 hours, the data transmission is about 3 hours, and the empty three takes about 2 hours, the three-dimensional reconstruction takes about 10 hours, and the whole project takes 20 hours. The three-dimensional reconstruction does not need intervention and is completed at night. The results have been handed over to Party A from the afternoon of the second day when the operation starts, this speed is unimaginable in the past.
