The welding process of the ferrules is currently a bottleneck in the manufacturing process of the wind turbine towers, since it currently consumes half of the total manufacturing time of the tower. This percentage is increased when referring to offshore towers (because they are structures of greater size, weight and thickness of sheet metal). The traditionally used welding process is submerged arc welding (SAW). It is a very mature technology, which has reached its productivity limit, not being productive enough to address the manufacture of the new thicker fuses that the market demands, with the right quality and with the degree of productivity necessary for its processing to be profitable. On the other hand, the inspection of longitudinal and circumferential welds of the ferrules is carried out today manually, consuming huge amounts of time, which leads to a very low productivity of the manufacturing process. The objective of the PROTOS project is to develop new high productivity welding strategies for the production of wind towers, which will reduce the costs of the process and thus improve the competitiveness of the companies of the consortium and, by extension, the wind turbine manufacturing sector. Within the technologies to be developed, different lines of work are proposed: a) Evaluation of the novel KTIG welding process, especially for the realisation of the root pass in the welds performed on both sides. This innovative high-density energy process would ensure, among other advantages, to avoid having to perform the root pass. b) Analysis of the most productive variants of the current process (SAW tandem, SAW twin-arc, SAW narrow gap) for fill passes. Some of these techniques have already demonstrated important productive improvements, but it will be necessary to test them at an industrial level, with the conditions that this has (tolerances, mismatches, etc.). c) Reengineering of the most appropriate edge preparation according to the characteristics of the previous processes, to optimise consumption of contributing material. d) Simulation of the new welding process and influence on metallurgy of the base material and distortion of the components. Support for parameter definition and sequence. e) Development of a system for monitoring the welding parameters, adapted to the new processes to be evaluated and integrated into the quality control system. f) Development of an automated ultrasonic inspection system, which allows to quickly and reliably inspect the different types of junctions of the ferrules in a wide range of thicknesses. g) Development of a quality control software, which integrates the data provided by a welding monitoring system and an automated inspection system. This software, based on artificial intelligence, will allow complete control and traceability of the process. The use of Artificial Intelligence and Machine Learning techniques as well as Data Fusion algorithms is a clear novelty within this line of research.
