针对热真空环境条件对视觉测量精度影响的问题,提出了一种新的基于像素当量的二维尺寸视觉测量系统实时标定方法。该方法采用光刻已知尺寸线条的石英标准件作为测量基准,利用一阶微分期望亚像素细分算法和最小二乘拟合,可实时获取较高精度的像素当量值从而减小环境误差。热真空环境下的实验结果表明,该方法可用于热真空环境下二维小尺寸视觉测量的标定。
A new real-time calibration method of dual dimensions size vision measuring system based on pixel equivalent is proposed to resolve the existing problems of thermal vacuum environment′s effect on vision measurement accuracy.This method makes use of standard component made of quartz material and carved with lines in known sizes as measuring base,and it can obtain real-time pixel equivalent value in high precision to reduce measurement error of environment by using first-order differential expectations of sub-pixel algorithm and least square fitting algorithm.Experiment results in thermal vacuum environment show that this method can be used in the calibration of dual dimensions small size vision measurement.