  Fillet welding is one of the most widespread types of welding in the
industry, which is still carried out manually or automated by contact. This
paper aims to describe an online programming system for noncontact fillet
welding robots with U and L shaped structures, which responds to the needs of
the Fourth Industrial Revolution. In this paper, the authors propose an online
robot programming methodology that eliminates unnecessary steps traditionally
performed in robotic welding, so that the operator only performs three steps to
complete the welding task. First, choose the piece to weld. Then, enter the
welding parameters. Finally, it sends the automatically generated program to
the robot. The system finally managed to perform the fillet welding task with
the proposed method in a more efficient preparation time than the compared
methods. For this, a reduced number of components was used compared to other
systems, such as, a structured light 3D camera, two computers and a
concentrator, in addition to the six axis industrial robotic arm. The operating
complexity of the system has been reduced as much as possible. To the best of
the authors knowledge, there is no scientific or commercial evidence of an
online robot programming system capable of performing a fillet welding process,
simplifying the process so that it is completely transparent for the operator
and framed in the Industry 4.0 paradigm. Its commercial potential lies mainly
in its simple and low cost implementation in a flexible system capable of
adapting to any industrial fillet welding job and to any support that can
accommodate it.
