Cylindrical tube structures can be manufactured by bending flat steel plates and welding
the joint side. The tube structures considered in this work, typically have an internal diameter,
ID, ranging from 6 mm to 50 mm and a wall thickness of about 1 mm to 3 mm. These tubes
are often subjected to bending to create various structural components. The welded joints
experience significant stress, making them highly susceptible to fatigue cracking. To mitigate
this risk, it is essential to position the weld line in the region of zero curvature (neutral axis)
while bending. To achieve this, an automatic procedure for weld line detection and tube
rotation is required. Consequently, this procedure has become increasingly important in the
tube bending industry, as it directly impacts manufacturing efficiency, product quality and
compliance to the design specifications.