Research On Intersecting Curve Welding Robot System Based On Laser Vision

With the rapid development of science and technology,automation technology is becoming more and more popular.Robotic,as the representative of the automation technology and intelligent manufacturing technology,more and more get the favor of the developed countries.In terms of the intersecting line welding area,most companies use the method of manual welding to solve it,but it would cause high intensity of labor,the hostile welding environment,low welding quality and low efficiency of welding defect.Part of companies use the special machine to weld,but it has a poor versatility and cannot meet the demand of all.Also,most robot companies use the arc welding robot to weld the intersecting curve with the method of piecewise linear curve fitting,but the teaching process is complex and the welding precision and quality are poor.Therefore,based on the exiting problem and domestic welding,on the basis of research for different size of orthogonal intersecting curve welds,this research designed a arc welding robot system which used to weld intersecting curve based on laser vision.The whole working process of system has two steps.Firstly,use the laser to scan the intersecting line and get the actual weld information.Secondly,according to the welding seam information,fitting trajectory and interpolating.In this way,the welding task would be completed.The main research content of this article is as follows:For the entire pre-scanning and welding process,we need control robot torches,lasers,and positioner coordination move together,the model of six degrees of freedom arc welding robot is established.We also calculate the relations between the end of robot and the tools which include welding gun and laser to lay the foundation for later research.For the complexity of intersecting carve welds,we establishes a theoretical model of orthogonal intersecting curve and plan speed and trajectory interpolation during the pre-scanning process,then the scan results are extracted to obtain the position information of the weld center point.For the problem of scanning error,a method based on angle and distance is proposed to eliminate the error point in the center point of the weld.Based on the information of a series of actual intersecting curve weld center points,a NURBS curve fitting and interpolation algorithm is designed,and the influence of the bow height error on the interpolation is analyzed.In this paper,the influencing factors in the welding process are analyzed,and the actual welding experiments are carried out on the experimental platform built to verify the validity of the system and the correctness of the relevant algorithms.