2018 Volume 58 Issue 4 Pages 721-726
In the present study, a quality monitoring system in small scale resistance spot welding based on dynamic resistance and neural network was proposed. A precise dynamic resistance curve was obtained directly from the welding machine. Dynamic resistance and nugget development were found sensitive to the change of welding current. The second resistance peak gradually disappeared as welding current increased. Weld expulsion occurrence could be detected through the obvious fluctuation in dynamic electrical signals. The resistance valley and end resistance were found highly correlated with the nugget development. Features extracted from the dynamic resistance curve were selected as inputs in the neural network analysis. A reliable weld quality estimation through the neural network approach could be finally achieved.
