High-precision tunnel cross section detection method and device based on double laser bands

Abstract

The invention relates to the technical field of measuring instruments, in particular to a high-precision tunnel cross section detection method and a high-precision tunnel cross section detection device based on double laser bands. The device is used for measuring the tunnel cross section dimension and the limit detection, and is mainly applicable to the high-precision and high-density cross section detection of railway tunnels. A plurality of linear lasers are utilized for taking photos on the surface of the tunnels, two complete tunnel cross section outline light bands are formed, a high-speed visual system is used for collecting light band images, the images are subjected to high-speed parallel processing for extracting light band positions, the actual tunnel cross section coordinates are calculated through a system calibration technology, and the high-speed real-time tunnel cross section detection function is realized. The method and the device provided by the invention have the advantages that a camera collection region is reasonably utilized, so the cross section detection precision and the density are exponentially improved, the structure is compact, the integrality is high, and the method and the device can also be used in high-speed detection of tunnel local sensitive regions.

Description

technical field [0001] The invention relates to a high-speed real-time tunnel section limit detection system, in particular to a tunnel section high-precision detection method using dual-light band laser photography and high-speed visual detection technology. Background technique [0002] The periodic section measurement and infrastructure limit detection of railway tunnels are of great significance to the safe operation of trains. In recent years, domestic rail transit is in a period of rapid development, especially the rapid development of urban subways, and the demand for tunnel section detection technology is increasing. Due to changes in geological structure, tunnel construction maintenance, long-term impact of trains, etc., local deformation of the cave body, intrusion of infrastructure, and falling off of auxiliary equipment frequently occur. Therefore, high-precision measurement of tunnel sections can find problems and guide maintenance to ensure Driving safety. ...

AI Technical Summary

Problems solved by technology

[0003] Tunnel section detection technologies mainly include laser scanning measurement method and laser triangulation method. In the actual detection process of the existing technology, the main disadvantages are: ①Laser scanning measurement is point-by-point scanning, and the distance is calculated by using the time of laser emission and reception. The rotation is controlled by the motor. Affected by the scanning frequency, angular resolution, detection speed, etc., the light spot scans in a spiral shape, and the detection accuracy of the cross-section is low. Especially for objects with small cross-sections, there are often missed detections.

②Synchronous detection of high-speed cameras by laser triangulation method. Under the premise of satisfying the image resolution, the image acquisition frequency shall not exceed 500Hz. , there are still missed detections

At present, the development of high-resolution real-time image processing hardware for high-speed cameras is relatively difficult, and is limited by image processing algorithms. It is difficult to improve the real-time processing speed of each frame of high-speed images, so bottlenecks are encountered in hardware and algorithm speed-up.

At the same time, due to the increase of tunnel lines and the continuous improvement of detection speed requirements, the existing detection technology is still unable to achieve high-speed and high-precision measurement

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