A novel real-time fuzzy-based diagnostic system of roll eccentricity influence in finishing hot strip mills

This paper proposes a method for the diagnosis of roll eccentricity influence on the strip thickness at the exit of a finishing hot strip mill (FHSM). Each exit strip thickness defect is related to one roll of the FHSM, allowing the implementation of an optimal policy for the substitution and maintenance of the rolls, while maintaining the required quality level of the strip. This policy allows the minimization of roll changes and the concentration of several changes at the same time, reducing production costs. Fuzzy logic is used to compare spectra, looking for common patterns, which enables a totally-automated diagnostic system. Likewise, as part of the solution, a novel estimate of roll eccentricity, based on a least-squares algorithm has been developed, which provides higher accuracy than classical algorithms as well as a drastic reduction in the time required to perform eccentricity tests.