Modeling,Simulation And Control Of Consumable De-GMAW

With the rapid development of manufacturing, how to improve the welding quality and productivity has become an urgent requirement。Usually using more current to get higher productivity will cause the change of drop transfer, welding pool and arc shape even lead to welding defect such as humping bead and under cut. To deal with this problem, consumable DE-GMAW was proposed by Professor Zhang Yuming at university of Kentucky. Consumable DE-GMAW is established on a conventional GMAW system by adding a bypass torch to provide a second loop for the welding current, but the second loop brings more instability. Aming to this question, the simulation and control were carried out in the paper to guarantee the stability of welding process and to control the base metal current.Based on the analysis of consumable DE-GMAW process, aming to the arc dynamic characteristic, a mathematical model was established by the method of equivalent current path and simulated the influence between welding parameters and welding process. Then the SISO control scheme which use feedspeed of bypass torch to control the bypass arc, MIMO control scheme which use feedspeed of bypass tourch to control the bypass arc and use bypass current to control the base metal current, MIMO decoupling control scheme were proposed. And the simulation of control scheme was carried out and analyzed.By using rapid prototyping, the software and hardware for consumable DE-GMAW welding experiment were designed. And the process test was carried out to display the merits of consumable DE-GMAW.At last, based on Matlab/Simulink, compared the simulation results, the control tests such as SISO control, MIMO control, and MIMO decoupling control were accomplished and analyzed.