玻璃测厚系统中激光双光斑中心定位方法

Research of Double Laser Spot Center Location Method in Glass Thickness System

双激光光斑中心定位是利用半导体激光和CCD组成的玻璃厚度测量系统中的重要步骤。双光斑中心测量中由于光斑之间相互干扰,易导致光斑分布不均匀和杂散斑干扰严重等问题。传统的定位算法应用在玻璃测厚系统中均存在精度较低、抗干扰能力差等缺点。提出一种基于高斯拟合法的改进算法。首先采用二维零均值高斯函数进行平滑滤波;然后利用高斯拟合法对光斑进行拟合,以获得表征光斑理想光强分布的高斯函数;最后根据理想光强分布将杂散斑滤除后再进行高斯拟合求得光斑中心坐标。仿真实验结果表明此方法可以提高中心定位的精确度和抗干扰能力,使定位误差小于0.1个像素。

Double laser spot center location is important step in glass thickness system consisted of laser and CCD. Because of mutual interference between two laser flare, it will lead to many problems such as uneven distribution and specklenoise. Traditional laser spot center location algorithms have many weaknesses such as low precision and weak anti-interference ability. So a improvement method based on gauss algorithm is presented. Firstly, using of the 2D zero-mean gauss function for smoothing filter Then using method of gauss fitting to fit laser spot to get the gauss function that describes the ideal laser intensity distribution; lastly, using gauss fitting to get laser flare center coordinates after filtering out stray spot by the ideal laser intensity distribution. The simulation experiment result demonstrates that the method presented by this paper can improve the precision of the location and the ability of anti-interference, and the location offset will be cut down lower than 0. 1 pixel.