Architecture Of Data Acquisition Hardware System And Research On Generation Mechanism Of Arc Sound In MIG Welding

MIG welding is an efficient, inexpensive, wide adaptability of welding manufacturing technology, its metal structure manufacturing wide range of applications. For the stability of the welding process and welding quality monitoring issues such as online, this article in order to MIG welding arc sound signal for the study conducted the following three aspects.May make use of existing research results, through market research and selection, MIG welding arc architecture of the acoustic signal data acquisition hardware system. System is mainly composed AWA14423 microphone, signal conditioning modules and PCI-1713 acquisition card component. Experimental test results show that the system has been basically have the sound of arcing high-speed multi-channel real-time data acquisition, meets the required topics. At the same time, the entire system with a good noise on the inhibitory effect of welding.Through the microphone, the protection of gas, droplet transfer and welding spatter experiments completed a preliminary study of the arc sound. MIG welding arc sound signal frequency is mainly distributed at 7000Hz within one of the transition has two drop shot waveforms, 1000Hz and 6000Hz living separately, while the relative concentration of jet transition waveform, the vast majority of the distribution of energy at 3000Hz ~ 6000Hz range. Arc sound signal by the microphone, the protection of gas and welding spatter influenced the performance of a good microphone to do at the effective recognition of the signal at the same time, but also can achieve an effective shielding of the noise; the protection of gas flow rate is too small, arc combustion instability, Voice of intermittent arc; too large, easy to solder to wear, accompanied by "whistling" sound. Arc welding spatter on acoustic signal amplitude has increased role. Spatter of liquid metal from the blast, at the local instantaneous gas expansion, the thermal energy into mechanical energy, and fluctuations in the form of media.Arc on the sound generation mechanism. Sound arc discharge with gas are biological, are collective oscillations of plasma in order to disseminate the results of waveform, but also a sound source and channel the combined effect of the product characteristics of its spectrum depends primarily on channel frequency response. On this basis, the set up of the arc generated linear acoustic model, using Levinson-Durbin recursive algorithm extracted Acoustic Signal arc linear prediction coefficient, and coefficient of Reconstruction from the acoustic signal, Reconstruction of signals with the original signal to maintain the waveform and spectral characteristics of consistency. Acoustic signal confirms the arc of linear prediction analysis of arc-channel system is an estimate.