Aluminum Alloy Pulsed MIG Welding Process Signal Acquisition And Analysis

Digitization of welding power control is an important development direction of welding technology field in nowadays, and it is also an effective way to improve the effect of arc control technology. Pulsed MIG welding, since the controllable of welding droplet transfer, easy automated and many other advantages, are widely used in various fields. With the increasingly fierce market competition, the welding power with high reliability and stability has got more and more attention by the welding manufacturers and it makes higher demands on the control performance of the welding power. So using advanced and convenient facilities of virtual instrument for quantitative analysis of welding process has become an effective means to improve the control performance.In this study, a platform which can carry out electrical signal acquisition and statistical analysis of pulse MIG welding based on LABVIEW has been built by using NI USB-6009 data acquisition card, and the welding current, voltage sensor and signal conditioning circuit has also been designed; welding electrical parameters of the multi-channel data acquisition, signal processing and analysis procedures are programmed with LabVIEW programming language. Program part which including test conditions recording module, data acquisition and modules, waveform selection and call modules, filter modules and data analysis module is easy to use, its interface is vivid. The statistical analysis module which containing the pulse period, pulse frequency, short-circuit frequency, peak time, the base value of time, pulse energy, average peak voltage/current, the average base value of the voltage/current, weekly, on average, voltage/current and the standard deviation of these parameters etc is mainly about calculating and analyzing the electrical parameters of welding process, the statistics of these parameters is as a basis for judging arc stability.Aluminum alloy pulsed MIG welding test is conducted on this test system platform, and combined with arc shape which can be observed in high-speed camera, making the following three aspects analysis of the pulsed MIG welding process: contrastively analyzing the differences of the welding machine output voltage and the voltage across the arc and the law of welding machine; through pilot studies and data analysis, the information that can characterize the arc length is extracted; integrating the statistical data, the arc voltage and current waveforms and the physical form of the arc, analyzing dynamic adjustment performance of welding power. Experimental results can provide reference and guidance for improving the performance of digital welding power control.