Abstract:Laser 3D measurement is an important means of modern high-precision measurement technology for large and complex surfaces, which is widely used in vehicles, ships, aircraft, and other fields, especially in the digital imaging of large scenes. To address the problem that the accuracy and range of visual tracking 3D measurement cannot be optimized at the same time, this article proposes a 3D measurement method based on multi-camera visual tracking. The method adopts the multi-camera joint calibration algorithm to formulate the global co-baseline position conversion model to realize the position tracking of the laser sensor, establishing the optimal field-of-view decision model with the highest accuracy of stereo target positioning as the optimization goal. The spatial geometric relative position relationship between the target and the laser sensor is established according to the structural characteristics between the stereo target and the line laser sensor. The position-matching algorithm of geometric distance is adopted to obtain the position of the line laser sensor and combines the multi-camera field of view to complete the laser point cloud data splicing. Finally, the three-dimensional point cloud imaging is realized. In order to evaluate the effectiveness of the method, a four-eye laser 3D measurement system is built within the range of 1.8 m×2.5 m×1.5 m. The experimental results show that the measurement method achieves a translational positioning uncertainty of 0.054 3 mm and a rotational positioning uncertainty of 0.047 8° for the stereoscopic target; the lateral measurement range of this method is 0.93, 1.18 and 1.46 m at the distance of 0.5, 1 and 2 m from the binocular system, respectively. Under the condition of using a camera of the same focal length in order to achieve the same accuracy, it is respectively larger than the monocular measurement range of 0.57, 0.7 and 0.82 m; 0.35, 0.46 and 0.49 m larger than the binocular measurement range. It shows that the stereo target position measurement method based on binocular vision has good engineering advantages in terms of accuracy and measurement range.