Research on Calibration Method for Line-Structured Light Sensor Based on Spatial Quadratic Surface Fitting

Abstract The calibration of the light plane serves as the fundamental prerequisite for accurate three-dimensional (3D) measurement using line-structured light sensor (LSLS). Aiming at the problem that the light plane projected by the line laser is not an ideal plane, this paper proposes an LSLS calibration method based on spatial quadratic surface fitting. In the LSLS measurement model, the standard conical quadratic surface equation is used to replace the plane equation in the traditional measurement model to solve the 3D coordinates of the light stripe. In the LSLS calibration process, the spatial standard conical quadratic surface fitting algorithm is also used to replace the traditional plane equation fitting method to achieve structural parameter calibration. The calibration experiment results based on general LSLS show that the calibration method described in this paper improves the fitting accuracy by 15.38% and the 3D measurement accuracy by 13.33% compared with the traditional calibration method based on light plane fitting. This not only provides a high-precision measurement solution for low-cost LSLS, but also enables its application in 3D measurements in the presence of lens refraction, where the improvement in accuracy may be even more significant.