基于双目视觉的激光位移传感器标定方法

Calibration method of laser displacement sensor based on binocular vision

为了提高激光位移传感器在工业机器人末端坐标系下的标定精度,提出基于双目视觉的激光位移传感器标定方法.该方法通过双目视觉技术重建激光光束投影在平面上的光斑位置,利用手眼标定参数将光斑位置转换至机器人末端坐标系,同时利用最小二乘方法将光斑拟合成光束直线,获得机器人末端坐标系下的传感器光束方向及零点位置以完成标定.该方法可同时标定机器人末端上的多个激光位移传感器,无须采用有精度要求的辅助工件标定,具备精度高,鲁棒性强优势.基于标准球的精度评价实验结果显示,在3倍标准差范围内该方法标定后的激光位移传感器测量精度范围为0.0386±0.0258 mm,满足机器人加工要求.

A laser displacement sensor calibration method based on binocular visual technology was proposed,in order to increase the calibration precision of laser displacement sensor under the robot end-effector coordinate system.Through binocular visual technology,the location of laser spots projected on the flat was reconstructed.The eye-to-hand calibration parameters were used to transform the light spots into the robot end-effector coordinate system,meanwhile least squares method were used to match light spots into the line of the laser beam and obtain the beam direction as well as zero position of the laser displacement sensor to complete calibration.This method can simultaneously calibrate multiple laser displacement sensors on the robot end-effector coordinate system.No auxiliary component with precision requirement is needed in the calibration process,so the precision is high and the robustness is strong.Result based on standard ball measurement precision evaluation experiment shows that the laser displacement sensor measurement precision range after calibration by this method is 0.0386±0.0258 mm,within the range of three standard deviation,which satisfies the requirement of robot processing.