The hostile nature of welding environments makes welding a prime candidate for process automation. Among the variety of welding processes available, gas metal arc welding is one of the most frequently used, primarily because it is highly suited to a wide range of applications, and also to automation.
Automatic seam tracking method is the most demanded basic technique for automatic control of arc welding. In this study a seam tracking system has been developed by using the welding arc itself as a sensor. This paper describes the principle and experimental results of the arc sensor system, as well as the development and application of the automatic $CO_2$ welding for the horizontal fillet welding.
A basic problem in the horizontal fillet welding process is to prevent hanging bead formation such as undercut at vertical plate and overlap at horizontal plate. To produce symetric bead shape, the relationships of bead shape to welding parameters (welding velocity, weaving width, weaving speed, tip to workpiece distance) must be studied.
It was revealed that the control system which using the proposed arc sensor principle has practical advantages, such as precision tracking, real time sensing, low cost of equipment. And in addition there is no need to change the shape of the welding unit.
