METHOD FOR JUDGING WHETHER THICKNESS OF HOT ROLLED STRIP IS NORMAL OR NOT ACCORDING TO ROLL ECCENTRICITY

摘要

PURPOSE: A method for judging whether thickness of hot rolled strip is normal or not according to roll eccentricity by using only thickness deviation signals and rolling speed signals of the hot rolled strip basically given in hot rolling process is provided. CONSTITUTION: The method comprises first step (S100) of measuring thickness deviation of finish rolled strip and finish rolling speed; second step (S200) of sampling the measured thickness deviation and rolling speed in a certain time cycle and digitizing the sampled thickness deviation and rolling speed; third step (S300) of calculating rolling length of the rolled strip per cycle time by multiplying the sampled rolling speed by cycle time; fourth step (S400) of converting the thickness deviation sampled in the second step (S200) into thickness deviation for rolling length; fifth step (S500) of sampling the thickness deviation for rolling length as a unit rolling length again by using interpolation; sixth step (S600,S700) of Fourier transforming the re-sampled thickness deviation into frequency and calculating roll eccentricity frequency using the Fourier transformed frequency and roll diameter; and seventh step (S800,S900) of judging that thickness of the hot rolled strip is abnormal if the calculated roll eccentricity frequency value is greater than the set frequency value by comparing value of the calculated roll eccentricity frequency with a set frequency value.