Real-time detection and control of torch-height in waveform controlled short-circuit CO2 arc welding

The waveform controlled short-circuit CO2 arc welding has been developed and applied in industries widely. To guarantee its process stability and weld quality in automatic applications further, the torch-height, the distance from torch to workpiece, which may be altered by the welding distortion and assembling errors of joints, is detected via measuring the wire electrode extension during the metaphase of short-circuit and then controlled. The acquired data is Filtered by rule-based fuzzy algorithm and/or shift-average method. The experimental results, validated by slope and lap-joint welding, show that the detection and control system has excellent stability and dynamic response under different welding conditions, such as slope angle, wire feeding rate and welding speed, this will make the welding process more stability and the weld quality improved.