SYSTEM FOR DIAGNOSING CONTROL FAULT IN HOT STRIP MILL

摘要

PURPOSE: A system for diagnosing control fault in hot strip mill is provided to increase quality degree of rolled strip by predicting causes for abnormal control property in hot strip mill. CONSTITUTION: The system comprises an SCC (supervisory control computer) setting part(210) for determining target set values such as target thickness, target load, roll speed and roll gap; an excessive thickness deviation judging part(213) for judging if a thickness deviation between the target value set in the SCC setting part and actually measured values is larger than a control tolerance; an operator intervention judging part(214) for finally judging that strip is defected by manual roll gap intervention of operator if the thickness deviation is larger than control tolerance of end user, and a difference between manual roll gap intervention amount of operator at sample 'i' and (i+1)th manual roll gap intervention amount of operator is larger than a value preset in the SCC setting part; an APC (automatic position controller) judging part(214) for finally judging that strip is defected by APC if the thickness deviation is larger than control tolerance of end user, and a deviation between a set roll gap value at sample 'i' and actually measured roll gap values is converged into zero; a rolling load deviation judging part(215) for judging whether there is FSU strain resistance prediction defect or not by judging whether load at the top end part of the strip is correlated with strip thickness or not if the thickness deviation is larger than control tolerance of end user, and a rolling load deviation is larger than a preset value; and a temperature deviation judging part(216) for judging whether there is FSU temperature prediction defect or not by judging whether temperature at an output side of the strip is correlated with actual strip thickness results or not if the thickness deviation is larger than control tolerance of end user, and actual output side temperature results are larger than an arbitrary preset value.