Research On Key Technology Of Vertical Right Angle Seam Tracking Based On Swing Arc

At present,the welding of complex steel structure is still mainly manual welding in China,especially in the face of the problems of low welding automation and poor welding quality in the face of the vertical angle steel structure in the complex steel structure.The effect of track recognition and gun posture recognition in practical application is not satisfactory.The main reason is that vertical right angle is a complex structure,which is difficult to clamp,the position and posture of the inflection point of vertical right angle is complex,and the shape of the weld is difficult to maintain.At the same time,the gravity also affects the welding effect during the vertical welding process,so that the weld track identification is difficult and the forming quality of the vertical right angle weld is poor.Therefore,it is urgent to develop an automatic welding robot for complex steel structure to realize the automatic tracking welding of vertical right angle weld.The welding current model is established in the V-groove of vertical welding,and the welding current model of welding current affected by the displacement of welding gun from the bottom of the workpiece bottom weld line is established.Then,the thickness of molten iron flowing under the molten iron is considered to establish a new welding current model.The welding current simulation diagram is compared and analyzed.It is found that the underwater flow of the clad iron will affect the fluctuation of welding current,It lays a theoretical foundation for the analysis of arc signal in the next step.Combined with the advantages of single filter algorithm,a combined filtering algorithm of median,Butterworth and wavelet denoising is proposed,which greatly improves the accuracy of arc signal.Based on the filtering,the paper analyzes the whole characteristics of arc signal by using multifractal spectrum analysis method.The whole characteristic information of arc signal under different dip angles of flat welding and vertical welding is analyzed and compared,and the best parameters of welding gun inclination are optimized,and the influence of the flowing of molten iron caused by gravity on weld tracking and welding forming quality is eliminated to the greatest extent.In order to improve the welding automation of complex steel structure in industry,the reach range of welding gun inclination angle is studied during the process of tracking the welding seam of opposite welding.Then,the dip angle range of vertical welding gun can meet the requirements of welding quality is analyzed experimentally.The droplet transition analysis,arc signal analysis and welding forming quality analysis are carried out at the opposite right angle inflection point under different parameters respectively.The parameters of the opposite right angle welding are optimized to maximize the welding efficiency.In addition,the curvature of the smooth transition in the tracking of the opposite right angle weld is studied experimentally,and the most suitable curvature of the smooth transition is found,which can guide the industrial application to a certain extent.