Method for detecting abnormal vibration of rolling mill, apparatus for detecting abnormality of rolling mill, rolling method, and method for producing metal strip

1 . A method for detecting abnormal vibration of a rolling mill that has a pair of work rolls and a plurality of backup rolls that support the work rolls, the method comprising:

collecting vibration data of the rolling mill;

generating first analysis data indicative of vibration intensities at respective frequencies by performing frequency analysis of the vibration data;

converting the first analysis data into second analysis data indicative of vibration intensities at respective intervals on a basis of a rolling speed, wherein the rolling speed is a speed of the rolling mill, and the first analysis data is converted into the second analysis data by using the rolling speed to determine the respective intervals; and

generating a vibration map in which a plurality of the second analysis data are arranged in time series, wherein

the vibration map is displayed on a display, and

operation of the rolling mill is adjusted according to the displayed vibration map.

2 . The method according to claim 1 , further comprising performing principal component analysis using reference data indicative of a normal state on the second analysis data and thereby identifying outlier components at respective intervals calculated as a residual of a projection of the second analysis data onto the reference data,

wherein the method further generates an outlier component map in which the outlier components at the respective intervals extracted in the principal component analysis are arranged in time series.

3 . The method according to claim 2 , wherein a plurality of principal components used as the reference data in the principal component analysis are set so that a cumulative value of contribution ratios of the principal components becomes equal to or larger than a reference contribution ratio when principal component analysis is performed on normal analysis data acquired during rolling performed by the rolling mill in a normal state.

4 . The method according to claim 1 , wherein the rolling mill is a cold rolling mill.

5 . An apparatus for detecting an abnormality of a rolling mill that has a pair of work rolls and a plurality of backup rolls that support the work rolls, the apparatus comprising:

a computer configured to:

collect vibration data of the rolling mill;

generate first analysis data indicative of vibration intensities at respective frequencies by performing frequency analysis of the vibration data;

convert the first analysis data into second analysis data indicative of vibration intensities at respective intervals on a basis of a rolling speed, wherein the rolling speed is a speed of the rolling mill, and the first analysis data is converted into the second analysis data by using the rolling speed to determine the respective intervals; and

generate a vibration map in which a plurality of the second analysis data are arranged in time series, wherein

the vibration map is displayed on a display, and

operation of the rolling mill is adjusted according to the displayed vibration man.

6 . The apparatus according to claim 5 , wherein the computer is further configured to perform principal component analysis using reference data indicative of a normal state on the second analysis data and thereby identifies outlier components at respective intervals calculated as a residual of a projection of the second analysis data onto the reference data,

wherein the computer further generates an outlier component map in which the outlier components at the respective intervals extracted in the principal component analysis are arranged in time series.

7 . A rolling method using the method according to claim 1 , the rolling method comprising setting an interval to be monitored corresponding to the rolling mill in advance and replacing the backup rolls of the rolling mill in a case where a vibration intensity at the interval to be monitored in the vibration map or the outlier component map generated exceeds a preset limit vibration intensity.

8 . A method for producing a metal strip, the method comprising producing a metal strip by using the rolling method according to claim 7 .

9 . A rolling method using the method according to claim 2 , the rolling method comprising setting an interval to be monitored corresponding to the rolling mill in advance and replacing the backup rolls of the rolling mill in a case where a vibration intensity at the interval to be monitored in the vibration map or the outlier component map generated exceeds a preset limit vibration intensity.

10 . A rolling method using the method according to claim 3 , the rolling method comprising setting an interval to be monitored corresponding to the rolling mill in advance and replacing the backup rolls of the rolling mill in a case where a vibration intensity at the interval to be monitored in the vibration map or the outlier component map generated exceeds a preset limit vibration intensity.

11 . A rolling method using the method according to claim 4 , the rolling method comprising setting an interval to be monitored corresponding to the rolling mill in advance and replacing the backup rolls of the rolling mill in a case where a vibration intensity at the interval to be monitored in the vibration map or the outlier component map generated exceeds a preset limit vibration intensity.

12 . A method for producing a metal strip, the method comprising producing a metal strip by using the rolling method according to claim 9 .

13 . A method for producing a metal strip, the method comprising producing a metal strip by using the rolling method according to claim 10 .

14 . A method for producing a metal strip, the method comprising producing a metal strip by using the rolling method according to claim 11 .