US 12,135,311 B2
Wire rope inspection method, wire rope inspection system, and wire rope inspection device
Hiromichi Tonami, Kyoto (JP)
Assigned to SHIMADZU CORPORATION, Kyoto (JP)
Filed by Shimadzu Corporation, Kyoto (JP)
Filed on Jul. 11, 2022, as Appl. No. 17/861,647.
Claims priority of application No. 2021-144274 (JP), filed on Sep. 3, 2021.
Prior Publication US 2023/0072626 A1, Mar. 9, 2023
Int. Cl. G01N 27/83 (2006.01); G01N 27/82 (2006.01); G01R 33/02 (2006.01)
CPC G01N 27/83 (2013.01) [G01N 27/82 (2013.01); G01R 33/02 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A wire rope inspection method comprising the steps of:
applying a magnetic field to a wire rope that is an inspection target;
acquiring a detection signal by detecting a change in a magnetic flux of the wire rope to which the magnetic field has been applied, while relatively moving with respect to the wire rope;
acquiring a first-order differential waveform by performing first differential processing on a magnetic flux waveform that is a signal waveform based on the acquired detection signal;
acquiring a second-order differential waveform by performing second differential processing on a positive component or a negative component of the acquired first-order differential waveform;
generating a composite waveform by adding the positive component of the acquired second-order differential waveform and an absolute value of the negative component of the acquired second-order differential waveform in a state in which at least one of portions of the acquired second-order differential waveform corresponding to the positive component and the absolute value of the negative component is shifted along a time axis such that the portions overlap with each other, the portions indicating an abnormal portion of the wire rope; and
determining the abnormal portion of the wire rope in a case where a value based on the generated composite waveform is greater than a predetermined determination threshold.