基于工业机器人的图像引导圆孔定位方法

Image-guided Circular Hole Positioning Method Based on Industrial Robots

在图像引导的圆孔金属工件自动化装配中,由于圆孔金属工件的图像存在弱纹理甚至无纹理的情况,从而导致对圆孔位姿的定位精度低。针对此问题,通过工业机器人带着单目工业相机水平移动构建一个平行双目结构,获取双目图像;通过对双目图像中的圆孔轮廓提取的特征点粗匹配,得到图像的基础矩阵,再通过基于弧段的椭圆检测对双目图像中的圆孔轮廓进行提取,最后通过上述信息进行基于极线约束的双目精立体匹配并求得相关点三维坐标与位姿。实验结果表明:孔位与孔心距精度保持在1 mm内,孔姿态精度保持在0.3°内。

In the image-guided automated assembly of circular hole metal workpieces, the image of the round hole metal workpiece has weak or even no texture, resulting in low positioning accuracy of the round hole pose.In order to solve the problem, a parallel binocular structure was constructed by an industrial robot with a monocular industrial camera moving horizontally to obtain binocular images.The basic matrix of the image was obtained by rough matching the feature points extracted from the contour of the circular hole in the binocular image, and then the contour of the circular hole in the binocular image was extracted by the arc-based ellipse detection.Finally, the above information was used to perform binocular precise stereo matching based on epipolar constraints and the three-dimensional coordinates and poses of the relevant points were obtained.The experimental results show that the accuracy of the distance between the hole position and the hole center is maintained within 1 mm, the accuracy of the position of hole is maintained within 0.3°.