Calibration method of laser plane equation for vision measurement adopting objective function of uniform horizontal height of feature points

摘要

A calibration method with an objective function generated from a uniform horizontal height is presented in this work for the laser plane in active vision measurement. A height target is developed with a center mark as the initial point of the uniform height. The height target is located on the horizontal plane of the 3D calibration board so that the horizontal plane is considered as the terminal of the uniform horizontal height. Based on the pinhole model of the camera and the laser plane equation, we model the objective function to find the optimal coefficients of the laser plane equation. The goal of the objective function is the smallest difference of the uniform height and the reconstructed height according to the feature points of the target. The objective function is optimized by the local particle swarm optimization. The calibrated global equation of a laser plane is obtained from the optimal value 1.153 x 10(3) of the objective function in the experiments. Two projective laser lines of the calibration laser plane cover the original laser lines in the image. The reconstruction errors of the calibration plane are also analyzed in discussions.