Drax develops vision-guided systems for welding applications. The vision systems are based on laser scanners designed and build by Drax. These scanners can scan a variety of surfaces, especially highly reflective surfaces, which are common for milled and ground weld grooves. A scanner can be equipped with several image sensors and laser modules that enable the scanner to read the groove from several different directions. By this, specular reflections can be avoided, and almost vertical groove walls can be scanned. In addition, a scanner can also be equipped with non-coplanar laser modules so that the orientation of the weld torch relative to the workpiece can be constantly measured.

Drax’s vision system has been mostly used for joint tracking, where the groove is scanned during welding. The resulting weld path is constantly adjusted due to workpiece movements arising from, for example, weld deformations or transverse/vertical movements of the workpiece when resting on roller beds. During the joint tracking, several geometrical properties of the groove can be measured such as variation in groove area, edge offset, weld layer width, groove depth, etc. These measurements can be fed into an autonomous welding system that adjusts the welding parameters so that the weld groove is evenly filled when the welding is completed.

Drax also develops sensors for accurate measurements of the circumferential and axial positions of large circular workpieces resting on roller beds.

Drax has recently started to develop a vision-guided milling/grind system for joint beveling. The aim is to produce grooves with very small variations in the groove face height. The system is referenced to datum locations in the fixturing so that the groove face plane is aligned with the fixturing. This will ensure small gap width variations between the two workpieces to be welded together, and therefore a good fit between them.

Recently, Drax has also started developing systems for welding inspection. The purpose is to measure cap height, cap width and undercuts after the weld is complete. Deformations that have occurred during the welding process will also be able to be measured.