On-line high sensitive roll mark detection system : industrialisation and assessment (HIRODS) : final report

This demonstration project aims at completing the industrialisation of the roll mark system installed at the Sagunto cold rolling mill exit and assessing its performance level in real industrial environment. Nineteen new detector modules were developed, tested and integrated in the roll mark beam. They allow the on-line monitoring of the full strip width and deliver three images of the strip surface with a good quality. The development of the data processing was completed in laboratory with a specific care brought to the detection function to highlight the roll marks. The first algorithm version was optimised on a first set of recorded images. This algorithm was implemented and embedded in the DSP chip of each detector module. The first results provide a measurement cycle time close to 15 minutes, that will be improved in the future by the development of new board embedding more powerful DSPs. The system, including user interfaces, has been installed online and constantly monitored for more than one year. The system has been continuously improved, with bug fixes, new functionalities and raising performances to reach a stable level during which the final performances of the system have been assessed: The detection rate is ~76% of the defects detected by the operators ; The false alarm rate is less than 10% ; The working ratio is more than 95%. The system can therefore be considered as the only rollmark detection system with industrially proven performances. Roll-outs are under study in several ArcelorMittal plants.