Research Of DSP-based Pulsed MIG Welding Control System

Pulsed MIG Welding is widely used in the industry. Compared with DirectCurrent MIG Welding, Pulsed MIG Welding has many advantages, such as widerange of current, controllable heat input and full position availability. The researchfocus is the dynamic droplet transfer. Digital control is flexible and has better stabilityand higher precision, as becomes the focus of academia. Therefore, this paper isaiming at the DSP-based Digital Control System research.On the basis of droplet transfer analysis in Pulsed MIG Welding, theelectrical-parameter-control method is brought forward to meet the goal ofone-pulse-and-one-droplet transfer mode. Pulse Peak Time and Wire-feed Speed areobtained when current parameters are given. Pulse Base Time is adjusted on-line toensure the droplet transfer mode. DSP-based digital control system model of PulsedMIG Welding is set up and the hardware of inverter power source control system andwire feed system are successfully designed. Besides, the numerical system model andthe model for simulation are built. Optimal parameters range is obtained bysimulation with MATLAB. Software design is fulfilled with assembler andMATLAB.Simulation experiments indicate that the digital control system designed has finepracticability. The whole system is able to achieve the double-L power sourcecharacteristic curve and the particular droplet transfer mode.