激光光斑中心定位方法的研究与改进

On Laser Spot Center Localization Methods and the Improvement

为了更精确有效地测量某检测系统下激光光斑的中心位置和半径,提出了一种基于LabVIEW视觉处理模块中Vision Assistant的激光光斑中心定位方法。在Matlab环境下,对CCD采集到的激光光斑图像预处理后用理论上可行的3种常见光斑中心定位算法分别进行仿真并做了对比实验,如Houng变换与自身改进方案对比,圆拟合算法不同算子之间的对比以及空间矩定位法的二次细化对比,从而对3种定位算法做出利弊分析。最后对光斑中心定位方法做出随机设置不同ROI多次测量取平均值的实用化新方法。仿真结果表明,该方法能够快速、准确地得到光斑中心位置和半径值,并且测量精度可达小数点后两位。

In order to measure the center position and radius of laser spot accurately, a laser spot center locating method was proposed based on Vision Assistant of the LabVIEW visual processing module. Under the Matlab environment, 3 common spot center locating algorithms were adopted for simulation of the pretreated laser spot images collected by CCD camera. And contrast experiments were made with the method, including the comparison of Houng transformation with its improved scheme, the comparison between different operators of circular fitting method, and the comparison of the two-time refining of spatial moment localization method. Analysis was made accordingly to the advantages and disadvantages of the 3 locating algorithms. Finally, different Regions of Interest （ROIs） were taken randomly, and averaging was made to multiple measurements. The simulation results show that the improved scheme can get the spot center position and the radius quickly and accurately.