激光微型靶丸位置检测中的图像分析与精度测试

在高功率激光实验装置中,为了实现多路激光精确瞄准到实验靶上,需对实验靶进行高精度定位。根据检测装置需要,建立了一套基于视觉系统的实验靶位置测量模拟系统,从而实现高精度靶瞄准与靶定位检测。本文从利用改进的均值漂移(MeanShift)算法对靶丸图像进行预处理出发,分析光照变化对靶丸中心点检测的影响,并通过相关系数模板匹配方法对靶丸端面中心进行计算分析,利用图像聚焦度分析离焦量对靶丸中心位置检测的影响。实验结果表明,图像检测系统分辨率为0.4μm,最小位移测量精度为1.2μm;当靶面图像离焦量在-10～30μm范围内时,靶丸中心位置的漂移量小于1μm,能够满足靶丸位置检测误差不大于8μm的要求。

Image Analysis and Accuracy Measuring for Location Detection of Micro Laser Target

In order to realize multi-laser beam pointing to the micro-target, the micro-target needs to be located accurately in the experiment of high power laser facility. According to the need of the detecting apparatus, a measuring simulationsystem based on vision system is set up to implement the accurate location and pointing of target. This paper analyzes the effect about illumination light to the detection position of target based on the improved mean shift algorithm. A template matching method about correlation coefficient method is used to detect the center of target pinhole and the focus degree of image is employed to analyze the position accuracy of target hole when the image is out of focus. The experimental results demonstrate that the image detecting resolution is 0.4 μm and the position accuracy of measuring is 1.2 μm. When the defocusing amount is between -10 μm and 30 μm, the drift amount of center point is less than 1μm which can satisfy the measuring accuracy less than 8 μm.