Based On Logistic Regression The Model For Droplet Transfer Judgment Of MIG-Pulse And The Welding Process Assessment

GMAW-P is gas metal active welding with pulsed welding current, which can control pulse energy through controlling pulse peak current and pulse base current, Spray transfer, less splashed material and nice figure, can be obtained within wide current range; Generally speaking the droplet transition of GMAW-P includes one droplet per pulse, multi-droplet per pulse and one droplet of more than one pulse, one droplet per pulse with the advantages of uniform droplet, regular transfer and less spatter is the ideal form of transition; the welding quality can be directly affected by the stability of welding process, the high welding quality can be obtained by the pulse parameter optimization configuration, so the research on GMAW-P welding power, droplet transfer and the stability of welding process becomes more and more importantIn the paper,Pulsed MIG welding power source system is designed based on DSP. The system control the welding process based on TMS320F240 of high performance with high integrated level special chip, so the system has high control accuracy and high stabilization accuracy in base current and peak current. Meanwhile the system is with high flexibility and high superiority of digital control through modifying the software.In the paper, based the Logistic regression, the mathematical model of droplet transfer judgment is established, the probability ( Pi ) of droplet detachment from electrode is established as the dependent variable, through the rigorous mathematical derivation, the falling phase voltage ( U d), pulse base current and voltage slope rate (ΔU 1,dt=0.667ms) are chosen as independent variables, the model is as follows: ,the threshold value is 0.85,in the verification experiment, the forecasting accuracy rate of droplet detachment from electrode per pulse is 92.9%,the one of droplet with the detachment from the electrode per pulse is 93.3%, so a new control strategy for the implementation of GMAW-P precise control of droplet transition has been created through the model.In the paper, based LabVIEW, the system for assessing the stability of GMAW-P welding process is established, which includes the parameters for assessing short-circuiting: DLYZ,DLQX, ones for assessing arc outage: XHPL,XHQX, and ones for assessing the fluctuation of pulse parameter: .S E_tp.S E_Ip.S E_tb和.S E_Ib, in the verification experiment, the stability of GMAW-P welding process can be assessed quickly, the optimization configuration of pulse parameter can be obtained based the assessing results, so the welding quality can be improved...