Multiprocessor-based equipment for real-time diagnosis of roll-eccentricity influence in finishing hot strip mills

In finishing hot strip mills (FHSM), roll-eccentricity is one of the most important disturbances affecting the thickness quality of rolled strips. The economic issues related to roll-eccentricity are very important. Often, after the rolling of a strip, the mill operators find the thickness measured by the X-ray meter at the exit of the FHSM is not up to desired quality standards, with the cost that this implies. In this case, the operator must diagnose which stands have produced the thickness problems. The solution is to change the rolls in the problematic stand. The diagnosis of which stand is responsible for the defects must be fast and reliable, because meanwhile the mill must stop production. Furthermore, analyzing the historical values of individual stand influence, it is possible to prevent failures of quality thickness. A novel method of diagnosis based on observers and pattern matching using fuzzy technology has been developed. Nevertheless, the high computational cost of the solution requires multiprocessor-based equipment to accomplish the real-time constraints.