Light plane calibration and accuracy analysis for multi-line structured light vision measurement system

Abstract

This paper investigates the overall fitting accuracy of the light plane can be improved by changing the relative distance between camera and laser, altering the projection direction of the light stripe and increasing the number of extracted light stripe in the multi-line structure light measurement system. Firstly, a multi-line structured light three-dimensional measurement system platform is built, and the existing calibration plate is modified according to the requirements of the experimental design. Then, laser stripes are projected onto a blank area in the checkerboard to facilitate the extraction of the centerline of the light stripe. Moreover, the three-dimensional (3D) point cloud transformed from centerline of each stripe is used to fit into a plane by a random sample consensus algorithm (RANSAC). Finally, the influence of different experiment methods on the overall fitting accuracy of the light plane is observed. Experiments illustrate that the proposed experimental methods can reduce the relative error of the overall fitting result of the multi-line structured light plane by more than two times, and the overall calibration accuracy of the light plane is improved in terms of the error of angle between the calibrated light planes.