3D Reconstruction And Analysis Of Rotating Arc Flat Surfacing Arc Based On Dual-view High-speed Images

As automation is becoming more and more popular today,welding automation is getting more and more attention.In the field of welding,the welding arc has always been regarded as the energy embodiment of the welding process.Rotary arc gas shielded welding has a stirring process in the welding process to eliminate the gas as much as possible,so that a higher welding quality can be obtained.In academia,many scholars have analyzed the arc shape based on the two-dimensional map,but few scholars have studied the three-dimensional shape.The 3D reconstruction of the rotating arc can not only observe the whole picture of the rotating arc,but also provide the basis for the simulation of the molten pool and for the evaluation of the welding process.In order to facilitate the acquisition of the data of the rotating arc welding process,a welding experimental platform that can simultaneously collect images,current and voltage,wire feeding speed and the position of the rotating arc sensor is designed and built.In order to obtain a relatively stable rotating arc welding process and better welding quality,the rotating arc spatter is used as the basis for welding stability.A splash extraction method based on multi-threshold and BP neural network is used.Using the multi-threshold method,the rotating arc splash can be extracted without omission.The BP neural network method identifies the splash obtained by the multithreshold method.The correct recognition rate of the neural network can be obtained.up to 97.76%.The 3D reconstruction of the rotating arc is carried out based on the baseframe method.After calibration and distortion correction of the camera,the brightness gradient of the rotating arc is used as the basis for the segmentation of the rotating arc.In order to improve the boundary accuracy,the curve fitting method based on cubic spline was used to fit the boundary of the rotating arc,and the 3D reconstruction of the fitted curve was carried out based on the base-frame method.The analysis of the reconstruction results of the rotating arc shows that the volume of the rotating arc increases sharply after the short-circuit transition.The volume of the rotating arc decreases gradually due to the melting of the end of the welding wire and the endothermic heat;the volume of the rotating arc has two peaks in the process of reducing the volume.The trough is caused by the oscillation during the growth of the droplet and the centrifugal force of the droplet.The analysis results verify the stability and feasibility of the platform,the feasibility of welding parameter optimization,and the robustness and feasibility of the 3D reconstruction method based on the base-frame.