面向三维复杂焊缝的焊接机器人焊缝跟踪方法

Welding seam tracking method of welding robot oriented to three-dimensional complex welding seam

机器人焊接技术具有质量稳定、效率高等特点,为实现空间内的三维复杂焊缝跟踪,提出基于分段扫描、滤波、特征点采集、路径规划的焊缝四步跟踪方法.通过安装于焊接机器人末端的激光传感器,以分段扫描方式连续多段采集焊缝数据;为提高跟踪精度,采用组合滤波的方式修正数据,有效降低焊件表面毛刺、数据失真和噪声等影响;通过特征点采集与坐标系标定确定焊接点;最后结合焊接机器人路径规划获得空间焊接路径.对二维S型焊缝与三维复杂焊缝进行了实验研究,结果表明提出的四步焊缝跟踪方法可形成完整的焊接路径,两种焊件平均跟踪误差约为0.296 mm和0.292 mm,满足机器人焊接跟踪误差低于0.5 mm的精度要求.表明所提出焊接跟踪方法的有效性,可为复杂焊缝的高精度跟踪和自动焊接研究提供有益参考.

Welding robot is widely used in many kinds and working conditions of welding production in the current machinery manufacturing industry.It plays an essential role in the machinery manufacturing industry.At the moment,in most industries,welding robots still work by teaching and payback.When the welding object or conditions change,the robot cannot make corresponding adjustments in time,which makes the welding gun deviate from the weld center,resulting in the decline of welding quality.The realization of automatic and intelligent welding is the inevitable development trend in the future.The application of machine vision in the welding field will promote the transformation of welding technology from rigid welding automation to flexible welding intelligence.Welding automation and intelligence are intended to improve the working conditions and environment,reduce labor costs,and improve product quality.Robotic welding technology is known for its great efficiency and consistent quality.A four-step welding seam tracking system is suggested based on segmented scanning,filtering,feature points extraction,and path planning.Through the laser sensor installed at the end of the welding robot,the welding seam data is continuously collected in multiple segments in a segmented scanning manner.To improve the tracking accuracy,a combined filtering method is used to correct the data to reduce the effects of burrs,data distortion,and noise on the surface of the weldment.Then the feature points are collected,and the coordinate system is calibrated in order to identify the welding points.Finally,the spatial welding path is obtained by path planning.Two-dimensional type S and three-dimensional complex welding experimental investigations are carried out.The results show that the proposed method can form a complete welding path.The average errors of the two weldments are about 0.296 mm and 0.292 mm,respectively,which are close enough to fulfill the required accuracy of 0.5 mm.It shows that the proposed tracking method is effective and can provide a reference for the research of high-precision tracking and automatic welding.