A few days ago, I learned from Wuhan Metro Group Wuhan Civil Air Defense Architectural Design and Research Institute Co., Ltd. that a scientific research project of “real-time automatic monitoring system for subway structures” relying on Internet of Things technology and cloud services has passed expert acceptance, increasing the monitoring frequency of subway tunnels to ” seconds”.
This system focuses on the real-time dynamic monitoring requirements of subway tunnel structures, and integrates photogrammetry, image processing, sub-pixel recognition and other technologies to successfully develop a non-contact, flexible layout and high-precision real-time displacement monitoring system.
“Aiming at the existing bottleneck of subway structure monitoring, we have conducted investigations with many universities and scientific research institutes, and finally decided to use the visual displacement technology based on the principle of close-range photogrammetry as a breakthrough, and use the visual method to monitor the structure in the subway.” The project. The person in charge of the group introduced that the farthest effective distance of a measuring instrument can reach 300 meters, the maximum number of measuring points can reach 100, and the measurement accuracy within 200 meters can reach plus or minus 1 mm.
“We also proposed a sub-millimeter-level monitoring algorithm based on close-range photogrammetry, which is not disturbed by ambient light, and effectively solves the problems such as the impact of train vibrations by moving average and removing gross errors. At the same time, we also developed a passive light source pattern. It can automatically calculate the distance between the observation station and the measuring point, and realize the dynamic tracking and calculation of the target.” The person in charge introduced.
At the same time, compared with traditional methods, visual displacement technology saves costs, reduces the number of instruments, reduces maintenance costs, and can be operated remotely. Through monitoring, we can understand the changing trend of tunnels, analyze valuable results, and play a reference role in subway design, construction, operation, and protection.
