Laser and Grating Cross-Integrated Calibration Method for Wide Field-of-View 3D Cameras

A new calibration algorithm is proposed to improve the axial accuracy of wide field-of-view 3D cameras by addressing the problem of poor x-axial accuracy in traditional camera calibration methods for such cameras. The grayscale center of gravity method is utilized to extract the coordinates of the light stripe's center, and then the laser is vertically irradiated onto the calibration target to extract the corner points where the light intersects with black and white areas. The x-axial values corresponding to the extracted coordinates are normalized based on the known distances between adjacent corner point coordinates. Subsequently, a cross-fit is applied to the corner point coordinates, and the resulting pixel fit coefficients per column of the sensor are used for camera x-axis calibration. The test results show that the 3D camera calibrated by this calibration method with the farthest field of view width of 3800mm has a maximum average error of 2.99mm toward the measurement accuracy, which meets the practical use requirements of the camera.