激光打标中振镜几何畸变误差多项式拟合校正

摘要

In order to eliminate geometric distortion error of marking point caused by 2-D galvanometer scan before the objective in laser marking system , the causes of the distortion was analyzed in detail .On the basis of the ideal formula of galvanometer deflection angle (α,β) , using the least squares curve fitting method , a fitting polynomial for compensating the errors of (α,β) with the marking point coordinates (x,y) was obtained and the distortion error of the galvanometer laser marking point was corrected .After correction, the maximum geometric distortion error of the laser marking point can be reduced from 3.2mm down to less than 20μm with smaller amount of calculation and faster speed .The results show that this error correction algorithm can meet the requirements of high-speed, high-precision laser marking.At the same time, new compensation formula can be calculated by changing the objective lens focal length to be applied to the different parameters laser marking system .%　　为了消除激光打标系统中由2维振镜物镜前扫描引起的打标点几何畸变误差，分析误差产生的原因，在振镜扫描角度（α，β）理想计算公式的基础上，采用最小二乘曲线拟合的方法，得到用打标点坐标（ x，y）表示的补偿（α，β）误差的拟合多项式，从而对激光打标点的畸变误差进行了校正。通过校正，可以将激光打标点的最大几何畸变误差由3.2 mm降至20μm以内，且计算量小、速度快。结果表明，该误差校正算法可以满足高速、高精度激光打标的需要；同时可通过改变物镜焦距计算出新的补偿公式，以应用于不同参量的激光打标系统。