Stereo vision based measuring system for online welding path inspection

• A stereo vision measuring system for an on-line welding path inspection is developed.
• The time sequence of measured arc positions shows a 3D welding path in time.
• Irregularities in the groove shape or in the electrode motion are visible as anomalies in the 3D welding path.
• A method for automatic detection of anomalies based on the welding path distribution along the weld was proposed.

A welding path measuring system (WPMS) is developed in order to achieve better understanding of the welding execution of the critical welds or weld deposits in multi-pass and repair welding. The developed WPMS system measures the arc position in 3D space based on the stereo vision principle. The time sequence of arc positions shows a 3D welding path in time, which bears information on how the weld or deposit was welded. Test welding was carried out in order to validate the developed system and to demonstrate how the welding path reveals simulated irregularities in the groove shape and in the electrode motion. The simulated irregularities are visible as anomalies in the welding path. A method for their automatic detection based on the welding path distribution along the weld was proposed.