Abstract: It is educed the calculating equation of the current’s virtual value, and it is erected the ANN calculating model of K and the calculating method of the current’s virtual value in different power factor angle during the alternation resistance spot welding. The current’s virtual value is calculated in real time in the control system of resistance spot welding based on DSP used this calculating model. The error analyzing and actual test result show, the error of this method is less than ±0.9%,and measuring and calculating the current’s virtual value can be completed in half a cycle. This method ensure precision control of quantity during the alternation resistance spot welding.

Key words: Current’s virtual value, ANN, Measure in real time, Resistance spot welding