一种基于二维平面靶标的线结构光标定方法

A Linear Structured Light Calibration Method Based on 2D Planar Target

为实现对线结构光视觉测量系统的高精度标定,针对传统标定方法中存在特征点数量较少和标定精度一定程度上受结构光灰度提取精度影响的不足,设计了一种基于二维平面靶标改进的线结构光标定算法。该算法在交比不变定理的基础上,通过简单的棋盘靶标获取大量的特征数据点,进而通过最小二乘法获得初始光平面方程。将结构光中心点作为拟合光平面的特征点,依据结构光中心点既在光平面上又在棋盘标定板平面上的特性,筛除误差较大的异常数据点,最后通过筛选得到的数据点优化拟合光平面方程。在一般的试验环境下,光平面标定对比试验结果表明,改进后的标定方法在测量精度方面有非常显著的提升效果。

In order to realize the high-precision calibration of the line-structured light vision measurement system,in view of the shortcomings of the traditional calibration method that the number of feature points is small and the calibration accuracy is affected by the grayscale extraction accuracy of the structured light to a certain extent,a two-dimensional plane-based method is designed.Target Improved Line Structured Light Algorithm.On the basis of the cross-ratio invariance theorem,the algorithm obtains a large number of characteristic data points through a simple checkerboard target,and then obtains the initial light plane equation through the least squares method.According to the characteristic that the center point of the structured light is on the light plane and on the plane of the checkerboard calibration board,the abnormal data points with large errors are screened out,and finally the light plane equation is optimized and fitted by the screened data points.In the general experimental environment,the results of the optical plane calibration comparison test show that the improved calibration method has a very significant improvement in measurement accuracy.