基于点阵标定板的视觉测量系统的标定方法  

Calibration Method Based on Lattice Calibration Plate in Vision Measurement System

作　　者：段振云[1] 王宁[1] 赵文辉[1] 赵文珍[1] 

机构地区：[1]沈阳工业大学机械工程学院,辽宁沈阳110870

出　　处：《光学学报》2016年第5期143-151,共9页Acta Optica Sinica

基　　金：十二五国家科技支撑计划(2014BAF08B01)

摘　　要：在应用机器视觉技术进行测量时,测量系统的像素当量、系统误差和光源强度等因素均会对测量精度造成影响,因此必须对像素当量和系统误差进行标定,并分析光源强度对工件图像边缘位置的影响。提出一种基于点阵标定板的视觉测量系统综合标定方法,在提取标定圆圆心坐标的基础上,计算圆心距物理尺寸和像素尺寸的比值,得到像素当量;建立圆心实际坐标和理论坐标的二元三次误差模型,并利用最小二乘法拟合求解误差模型系数;通过确定光源强度引起的图像边缘位置误差补偿量,实现测量系统的综合标定。实验结果表明,该方法可以有效提高系统的测量精度。In the application of machine vision technology for measurement,the factors of pixel equivalent,system errors and light source intensity in measurement system affect measuring accuracy.In order to improve the measuring accuracy,the pixel equivalent and system errors must be calibrated,and we need to analyze light source intensity which influences edge location of work piece image.An integrated calibration method based on lattice calibration plate in vision measurement system is put forward.On the basis of extracting center coordinates of calibration circle,pixel equivalent is got by calculating the center distance of physical value and pixel value.The error model with the actual coordinates and theoretical coordinates of center point is established,the error model coefficients are got by the least squares fitting.By determining the compensation amount of image edge position error caused by light source intensity,composite calibration of measurement system is achieved.The experimental results show that this method can effectively improve the measurement precision.

关 键 词：机器视觉 标定 点阵标定板 像素当量 系统误差 光源强度 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]