Multi-Parameter and Time-Section Control Algorithm Applying in Dynamic Resistance Controlled Spot Welding Monitored Control Systems

The systematic control modeling of dynamic electric resistance controlled(DRC) spot welding was first divided into different period of time depending on different parameter for real time control in this paper.Namely,after modifying dynamic curve,in the period of valley point,a single output fuzzy controller and a double output were applied respectively depending on advance or lag of valley point time.In the climbing period after valley point,the PID algorithm was applied for control.Considering highly mechanization and automation in spot welding process,a threshold feedforward algorithm was applied in anaphase of climbing period for certifying the consistency between nugget quality and welding time.Furthermore a network voltage feedforward automation was applied before the welding main program in accordance with the web voltage waving frequently.DRC control system became more credible in disturbing condition of spot welding by the mixture of feedforward control algorithm?fuzzy control algorithm and PID control algorithm.