基于Fast-RCNN与结构光纵焊缝三维形态参数检测方法

A Fast-RCNN & structured light based three-dimensional shape parameter detection method for longitudinal welds

焊缝三维形态检测是提高焊接件安全运行的有效措施,该文提出一种基于Fast-RCNN与结构光的纵焊缝三维形态参数检测方法。首先应用Fast-RCNN卷积神经网络从视觉图像中检测并定位焊缝区域、测量焊缝宽度;其次采用颜色阈值分割与形态学处理相结合的方法提取激光中心线,从激光中心线沿焊缝方向的极大、极小值点计算出焊缝余高、咬边深度;最后,提取激光中心线处于焊缝热影响区部分,通过拟合圆弧曲线,检测焊缝错边量与棱角度。构造实验装置对输油管道的纵焊缝进行检测试验表明,能够一次性准确地检测出焊缝余高、宽度、咬边、错边量、棱角度5个参数,具有较低的测量不确定度,焊缝宽度、余高的测量不确定度较JJG704-2005说明的焊缝检验尺测量不确定度分别降低89%、85%。

Three-dimensional shape inspection of welds is an effective measure to improve the safe operation of welded parts.This paper proposes a three-dimensional shape parameter detection method based on the vertical weld of Fast-RCNN and structured light.Firstly,the method uses the Fast-RCNN convolutional neural network to detect and locate the weld area from the visual image and measure the weld width.Secondly,the color center segmentation and morphological processing are combined to extract the laser center line from the laser center line.The maximum and minimum values points of the weld direction are calculated to calculate the weld height and the undercut depth.Finally,the extracted laser center line is in the heat affected zone of the weld,the wrong side and edge angle of weld misalignment is detected by fitting the arc curve.The test of the longitudinal seam of the oil pipeline by the structural test device shows that the parameters of the weld height,width,undercut,wrong side and edge angle can be accurately detected at one time,and the measurement uncertainty is low.The measurement uncertainty of weld width and residual height is89%and85%lower than that of JJG704-2005.