一种全局优化的激光光斑亚像素定中算法  

A globally optimized sub-pixel centering algorithm of laser spot

作　　者：徐尤南 高文海 宋小科 余昌鑫 XU You-nan;GAO Wen-hai;SONG Xiao-ke;YU Chang-xin(School of Mechanical and Vehicle Engineering,East China Jiaotong University,Nanchang 330013,China)

机构地区：[1]华东交通大学机电与车辆工程学院,江西南昌330013

出　　处：《激光与红外》2020年第5期623-629,共7页Laser & Infrared

基　　金：国家自然科学基金项目(No.51675180)资助。

摘　　要：根据激光光斑特征提出其中心位置检测方法,该法先假定激光光斑中心位置,再利用假定激光光斑中心点的投影圆上等效光强原理对其进行重建,并将重建前后两者的光强差的绝对值之和作为评价假定点与真实光斑中心距离的指标,最后,根据所述指标最小化原则求取激光光斑中心位置。理论分析表明,对于标准高斯分布的激光光斑,所述评价指标与假定点及真实光斑中心间的距离成正比,在真实光斑中心处,其评价指标值为零。对于实际激光光斑,在其中心处所述评价指标的值接近于零,为提高其抗噪声干扰能力,采用距离加权法作为其改进的评价指标。对有噪声干扰的实例计算结果表明,该法中心定位达到亚像素精度优于0.1 pixels,不仅定中精度高,而且算法速度快、稳定性好、抗干扰能力强。According to the characteristics of laser spot,a method for detecting the center position of laser spot is proposed.First,the center position of the laser spot is assumed.Then,it is reconstructed by the principle of equivalent intensity on projection circle of the assumed center point of the laser spot.And then,the absolute sum of the intensity difference between the two before and after the reconstruction of the laser spot is used as an index to evaluate the distance between the assumed point and the center of real spot.Finally,the index minimization principle is used to obtain the center position of laser spot.The theoretical analysis shows that for the standard Gauss distribution laser spot,the evaluation index is proportional to the distance between the hypothetical point and the real spot center,and the evaluation index value is zero at the real spot center.For the actual laser spot,the value of the evaluation index at its center is close to zero.In order to improve its anti-noise ability,the distance weighting method is used as the improved evaluation index.The results of the study example with noise interference show that the accuracy of sub-pixel center location is better than 0.1 pixels;the proposed method is of high accuracy,fast operation,good stability and strong anti-noise ability.

关 键 词：激光光斑 整数圆投影 距离加权算法 亚像素 

分 类 号：TN249[电子电信—物理电子学] TP391[自动化与计算机技术—计算机应用技术]