基于单目立体视觉的机床几何误差辨识方法

A Monocular Stereo Vision-based Geometric Error Identification Method for Machine Tools

针对视觉测量手段中成本与精度不能兼顾的问题,提出基于单目立体视觉的机床回转轴几何误差辨识方法。为实现回转轴全量程运动精确描述,基于误差放大思想,设计了基于周向均布精密哑光靶球的高匀、高精、高信噪比成像靶标。提出了单目立体成像光路参数仿真分析方法,定量分析并选取系统结构参数。基于单目立体标定结果,根据序列图像重建得到回转轴三维轨迹。精度验证及误差辨识实验表明:系统的RMSE为0.049 mm,小于平均偏差的1/3,满足测试需求。

A monocular stereo vision-based geometric error identification method for machine tools rotary axes is proposed to consider both cost and accuracy of vision measurement.In order to accurately describe the full-range motion information of the rotary axes,a feature target with the precise low-reflection target balls in circumferential uniform distribution is designed based on the idea of error amplification to guarantee the high-uniformity,high-contrast,and high signal-to-noise ratio(SNR)imaging.A simulation analysis method for monocular stereo imaging optical path is proposed to quantitatively analyze and select system structure parameters.Based on the monocular stereo calibration results,the three-di-mensional trajectories of rotary axes can be reconstructed from the acquired sequence images.The experiments of accuracy verification and error i-dentification show that the root mean square error(RMSE)of the system is 0.049 mm,which is less than 1/3 of the mean measurement error,satisfying the test requirements.