Research On Weld Seam Recognition And Tracking Based On Coaxial Vision Sensor

With the improvement of laser technology and automation level,laser automatic welding technology has been widely used in industrial manufacturing.In the process of automatic welding,due to the thermal deformation,vibration and deviation of the teaching track of the workpiece,the welding quality and efficiency are reduced.In order to solve this series of problems,this dissertation designs a set of laser welding coaxial weld tracking system that can automatically correct the weld track.The system includes a coaxial vision sensor,an image processing module,and a motion control correction module.The software part is a secondary development based on the original control software of the laser welding machine.The overall execution process is as follows:During the working process of the laser welding machine,First,the image of the workpiece being welded is collected by the coaxial vision sensor,and then the image processing module preprocesses the real-time collected image and obtains the weld point coordinates.The preprocessing is to reduce the influence of interference factors,and finally the motion control correction module performs welding.Calculate the seam deviation and correct the deviation.In the process of building the coaxial vision sensor,various components were compared and selected.During the development of the image processing module,the focus was on analysis of ROI acquisition,adaptive brightness and contrast adjustment,filtering and denoising,binarization,weld centerline,welding A series of image processing algorithms such as seam feature points,The brightness and contrast adjustment adopts an adaptive enhancement algorithm,and the binarization processing adopts a custom threshold method,which has a higher ratio.and the addition of functions such as the cross center line,the gray value of the center of the selected area,the welding seam compensation magnification,the horizontal and vertical welding seam test,etc.,so as to obtain the actual trajectory and teaching more accurately The deviation of the trajectory realizes the welding seam identification and correction.Two-dimensional line and curve welding seam tracking experiments were carried out on the laser welding machine,and the effect of welding seam tracking under various welding speeds was tested.Finally,the experimental data was analyzed.The results showed that the system has a good ability to automatically correct the welding seam trajectory.