钢拱架铰接孔视觉定位方法研究

Research on Visual Localization Method for Hinged Hole in Steel Arch

针对钢拱架自动化拼接过程中需要对钢拱架铰接孔进行定位的实际问题,设计了一种基于双目视觉的钢拱架铰接孔定位方法。首先通过模板匹配对钢拱架铰接孔进行初定位,找到感兴趣区域;采用一种新的自适应阈值算法计算阈值,对感兴趣区域进行二值化处理;利用边缘检测和最小二乘法提取得到铰接孔椭圆轮廓特征;然后找到椭圆轮廓上特殊的两条弦,根据空间几何关系,计算空间圆平面的法向量;利用消影线和椭圆参数矩阵,计算铰接孔圆心在图像上的实际投影点;最后基于双目视觉成像模型计算铰接孔圆心的精确空间坐标。实验证明,本方法可实现钢拱架铰接孔高精度定位,满足实际工业需求,为钢拱架自动化拼接提供技术支撑。

Aiming at the practical problem that the hinged hole need to be positioned in the automatic splice process of steel arches,a localization method of hinged hole in steel arch based on binocular stereo vision is designed.Firstly,the hinged hole in the steel arch was initially positioned through template matching to find the region of interest.A new adaptive threshold algorithm is used to calculate the threshold value,and the binary processing is carried out.Edge detection and least square method were used to extract the elliptical contour features of the hinged hole.Then the two special chords on the elliptical contour were found,and calculate the normal vector of the spatial circular plane according to the space geometry relationship.The real projection point of the center of the hinged hole on the image is calculated by using the vanishing line and the elliptical parameter matrix.Finally,the precise spatial coordinate of the center of the hinged hole were calculated based on the binocular vision.Experimental results show that this method can achieve high-precision localization of hinged holes in steel arch,meet the actual industrial needs,and provide technical support for automatic steel arch splicing.