Research On Accuracy Of Theoretical Model Of Rotating Arc Welding And Welding Signal Processing

With the development of automatic welding industry,accurate seam tracking technology is particularly important,the basic conditions of seam tracking is to extract the seam deviation information,and all of these works are based on the theoretical model of rotating arc welding.This is the general trend of improving the extraction accuracy of weld deviation by improving the existing theoretical models of rotating arc welding.Firstly,the influence of the internal force in the welding droplet is analyzed for the establishment of rotating arc droplet growth mathematical model to calculate the droplet radius and get the parameters of wire extension.Then,Fitting welding pool shape by Scanning the weld shape at arc suppression stage to establish the mathematical model of rotating arc sensor based on the actual weld shape.In order to verify the correctness of the theoretical model and finally get the weld deviation,respectively using least squares method fitting line with half cycle and complete alternation current based on this model,extracting weld deviation according to the fitting straight line slope.The comparison results show that the results of the whole cycle welding current fitting line are more stable.Finally the mathematical model of weld deviation extraction is obtained,which provides a theoretical basis for deviation extraction.Because of automatic short circuit suppression function of the low spatter welding power supply.according to the current signal of trial weld,researching the effect of various classical filtering methods on the processing of rotating arc welding current signal in the space and time domain,filtering,maximum filtering,median filter and verage filter are brought together to a combined filtering method clipping which is proposed to eliminate the noise in the original signal and keep better signal waveform.In this paper,because of the welding arc hysteresis,a method of starting point detection based on the lowest point of welding current waveform as the starting point of welding current is proposed to attain weld deviation.The result of weld deviation is more accurate after a Clipping processing,and the experiment results show that this method can be used to extract the deviation of fillet welding,and the error is about 0.5mm.