Research on underwater 3D measurement system for metal surface crack detection

The underwater 3D measurement system is based on the principle of line structured light measurement. It realizes high-precision 3D measurement of underwater targets within the field of view by mapping the morphology and position changes of the laser line in the camera module one by one. This paper designs an underwater 3D measurement system, which is an optical measuring instrument integrating optics, machinery, electricity, software, laser technology, computer vision measurement technology, etc. It mainly includes an underwater measurement module and a water-based control processing module. The underwater measurement module is composed of a camera module, laser, light source unit, power module, transmission module, sealed cavity, cable, which can realize the status data acquisition of targets in the underwater area. The water-based control processing module includes video data reception, data storage, image processing, and data calculation. After completing camera calibration, it realizes 3D point cloud measurement of the laser line irradiation area, such as parameter measurements of defect size, round bar diameter, etc.