Resistance Welding Data Acquisition And Analysis System

In traditional, the quality of welding is guaranted through stabilizing parameter of weld's arts and crafts and the test after welding. Due to a plenty of random influence factor, can not avoid completely producing welding defect only through stabilizing parameter of arts and crafts; it is necessary that we carry the test after welding, but it hasn't the character of real time, can not discover welding defect in time, some tie-in of defect can but remedying or rejecting. Especially when we using resistance spot welding, it is desiderate to solving identify on-line or quality classify, replaced or reduced crack detection after welding and devastating spot test, improved productivity and reduced cost.All sorts of random influence factor for welding quality is contained in the change of current, voltage, electrode displacement, etc.signals. Take this signal as researching object, the following works had been done in this thesis.A data collection and analyse system based on AduC812 MCU was developed with the designed current transducer and differential transformer displacement transducer for resistance spot welding, by which the current and displacement signals were acquired. We use great capacitance memory 16M byte data and expert data-base of the relation between signals of resistance spot welding and the quality of welding on NN. Designed the circuit of resistance spot welding on-line control.Developed a data collection system based on AC6115 with designed data communication, waveform showing and frequency spectrum analysis based on WINDOWS operation system by taking current, voltage, electrode pressure, displacement, etc.signals as research objects. It provide for explore the mapped relation of the signals of resistance spot welding and the quality of welding.Time-domain, frequency-domain and wavelet were used to analysis current, voltage, electrode pressure, displacement signals in this thesis, researched the relativity between the character of signals and the process of resistance spot welding. It is conclude that the wave form of current, voltage signals and the transformation of dynamic resistance, power of tie-in and nugget form is correlation osculation, so they can used on on-line control of tie-in quality of resistance spot welding. Enriched the comprehend of the the process of welding by the point of view signal analysis, established the basic for welding defect on-line identify and quality classifying.