Fast calibration method for line structure light measurement based on homography matrix
                                                       PENG Qianzhi, YANG Xuerong, CHENG Siyuan, LV Wenge
                        (School of Mechatronics Engineering, Guangdong University of Technology,Guangzhou 510006, China)

Abstract: Aiming at the calibration problem of measuring system in threedimensional measurement of line structured light, the camera imaging model, distortion model, homography matrix model and line structured light moving scanning were researched, the characteristics of the existing line structure light measurement system calibration methods were summarized,and the fast calibration method for linear structured light measurement based on homography matrix was proposed. The mechanical auxiliary device was used to make the calibration plate and the structural light plane parallel and coplanar, avoiding multiple position adjustment, and realizing rapid calibration of the line structure light threedimensional measurement system.In addition, the calibration plate was used to calculate the displacement of the line structure light measurement module in the single frame time interval during the scanning process, and the splicing of the global point cloud after the overall scanning of the object was completed. In the test, the mobile platform was used for testing the accuracy of the homography matrix and the measurement point cloud data. The research results indicate that the method can quickly establish the measurement model of the line structure light measurement system. The calibration process is simple and efficient, and meets a certain precision of the 3D scanning.

Key words: line structured light; homography; 3D scanning; point cloud