摘要: 为实现白车身孔槽类特征三维坐标的视觉测量,在双目立体视觉测量原理的技术上,以激光器辅助扫描被测孔槽完成三维测量,针对圆孔和复合孔槽边缘及孔心坐标的空间定位问题,提出一种在线测量方法。采用Canny边缘检测和Ramer算法分割出圆弧部分完成孔边缘的粗定位,结合Bazen方法与正交多项式拟合法实现亚像素边缘点坐标的精确定位,并通过权重拟合得到椭圆参数方程。在线激光光纹中心线提取过程中,融合极值法、阈值法与重心法,将拟合椭圆与光纹中心线的交点作为双目立体视觉的匹配点,进而完成空间点三维坐标的测量。实验结果表明,提出的方法鲁棒性好,对圆孔类特征的综合定位精度高。
关键词:
白车身,
被测孔槽,
双目立体视觉,
线激光光纹,
亚像素边缘
Abstract: In order to realize the visual measurement for the 3D coordinates of body-in-white hole slot feature,based on the principle of binocular stereo vision measurement,the laser is used as the auxiliary equipment to scan the tested hole slot,to complete 3D measurement.Aiming at the space location problem of round hole,compound hole edge and hole core coordinate,an on-line measurement method is proposed.Canny edge detection and Ramer algorithm are used to segment the circular arcs for completing the rough positioning of hole edges.The precise localization of the sub-pixel edge point coordinates is realized by combining the Bazen algorithm and the orthogonal polynomial fitting method.And the ellipse parameter equation is obtained by weight fitting.During online extraction of laser stripe centerline,combining the extremum method,threshold method and gravity method,the intersection points of the fitted ellipse and the center line of light are used as the matching points of binocular stereo vision,and then the 3D coordinates of space points are measured.Experimental results show that the proposed method is of strong robustness,and the comprehensive positioning accuracy of the round hole type is high.
Key words:
body-in-white,
tested hole slot,
binocular stereo vision,
line laser stripe,
sub-pixel edge
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