An Eccentricity Analysis Method Under Time-Varying Roll Speed

Abstract We propose an off-line method for detecting a faulty backup roll that generates eccentricity components when the feeding velocity, equivalently the angular velocity of roll, is not constant. From a newly devised speed-angle conversion algorithm, we transform all process data into those of a virtual process under a constant feeding speed. By this conversion, we can apply a spectral analysis to the original process. In addition, we develop a time-domain curve fitting method for the situation when the Fourier analysis is not enough to specify the more faulty roll of the two (top and bottom) backup rolls of a fixed mill stand.