Underwater monitoring system and underwater tunnel construction method using the same

Underwater Tunnel Module Joining Monitoring System Combining Sonar and Line Laser Scanning

This technology is an underwater monitoring system that identifies the relative position between an existing tunnel module and a connecting module using sonar, and calculates the gap, height difference, and 3D imagery of the joint using a mobile underwater scanning device equipped with a line laser projector and an underwater camera.

In underwater environments, GPS is unavailable and visibility is low, which limits the use of optical sensors. Furthermore, the difficulty of deploying divers has historically made precise positioning and guidance for tunnel module joining a significant challenge.

This technology proposes a method that first verifies the distance using sonar, then performs a precise scan of the joint with an underwater scanning device to compare the 3D coordinate endpoints of the surface projected by the line laser, thereby deriving the gap and height difference. Applicable to the construction of underwater tunnels and subsea structures, it enables precise joining without the need for divers, significantly enhancing construction safety and accuracy.

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Key Features:

• Sonar device that identifies the relative position between the existing tunnel module and the connecting tunnel module within the sonar imaging range
• Underwater camera that captures images of the area where the two tunnel modules are to be joined
• Laser projector that casts a line laser onto the existing and connecting tunnel modules
• System configuration that calculates the joint gap and height difference by comparing the 3D coordinates of the surface projected by the line laser

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This invention was developed with support from the Smart Underwater Tunnel System Research Center of the Ministry of Science and ICT.