一种快速高精度激光CCD自准直仪圆目标中心的定位方法

为满足高精度测量和瞄准跟踪系统中对激光CCD自准直仪的测量精度和实时性的要求,提出一种快速高精度激光CCD自准直仪圆目标中心的定位方法。首先利用变结构元广义形态学边缘检测算法,充分提取图像边缘细节信息的同时抑制图像噪声的影响,然后采用多项式插值算法对圆目标轮廓进行快速亚像素定位,最后利用最小二乘拟合方法实现了圆目标中心的精确定位。实验结果表明,该定位方法稳定性好,定位精度高且实时性强,应用该方法改进后激光CCD自准直仪的测量精度由2″提高到±0.25″,且单次测量时间小于0.23s,可满足激光CCD自准直仪在小角度测量和瞄准跟踪等领域的高精度实时测量需求。

Fast and Precise Center Location for Circle Target of CCD Laser Autocollimator

To meet the requirements for measuring accuracy and real-time performance of CCD laser autocollimators in fields of high-accuracy metrology and aiming and tracing system, a fast and precise center location method for circle target of CCD laser autocollimator is proposed. The specific characteristics of the circle target edge are fully extracted by using multiple structuring elements-based generalized morphological edge detection, while the influences of the noises in images are diminished. Then, the edge is quickly located in subpixel precision by adopting the polynomial interpolation method, and the center position of the circle target is acquired accurately by using circle fitting method based on least square fitting method. Experimental results show that the proposed method is fast, stable and accurate, and the measuring accuracy of the modified CCD laser autocollimator is improved from 2 arcsec to ±0.25 arcsec in 0.23 s (a single measurement process) using the proposed method. The proposed method can efficiently fulfill the requirements for high accuracy and real-time performance of CCD laser autocollimators in small angle measuring and tracing systems.