Information processing system for nondestructive inspection and nondestructive inspection method
An information processing system is for nondestructive inspection of a measurement target that is a magnetic material covered by a nonmagnetic body. The system includes an information processing device that reduces noise magnetic field components other than magnetic field components coming from the measurement target and/or emphasizes the magnetic field components coming from the measurement target in actual measurement data, based on the actual measurement data and virtual measurement data. The actual measurement data is obtained by applying a magnetic field to the measurement target and actually measuring a magnetic field coming from the measurement target using a magnetic sensor at a measurement position on a surface of the nonmagnetic body. The virtual measurement data is created under virtual conditions that are obtained by modifying actual measurement conditions.
1 . An information processing system for nondestructive inspection of a measurement target that is a magnetic material covered by a nonmagnetic body, the information processing system comprising:
a sensor unit including a casing with a measurement surface, a sensor array with one or more magnetic sensors, and a sensor scan mechanism driven by a motor; and
an information processing device that reduces noise magnetic field components other than magnetic field components coming from the measurement target and/or emphasizes the magnetic field components coming from the measurement target in actual measurement data, which includes reducing the noise magnetic field components in the actual measurement data coming from a magnetic material other than the measurement target, based on the actual measurement data and virtual measurement data, wherein
the actual measurement data is obtained by applying a magnetic field to the measurement target and actually measuring the magnetic field coming from the measurement target using the one or more magnetic sensors at a measurement position on a surface of the nonmagnetic body, the one or more magnetic sensors including at least one main sensor and at least one reference sensor corresponding, respectively, to the at least one main sensor, the at least one reference sensor being disposed further away from the measurement surface than the corresponding at least one main sensor,
the virtual measurement data is created by performing a simulation under virtual conditions that are obtained by modifying actual measurement conditions, the virtual conditions account for the magnetic material other than the measurement target by estimating a position of the magnetic material other than the measurement target on the basis of information obtained from an architectural plan, a survey using electromagnetic radar, or measurement with magnetic flux leakage testing.
2 . The information processing system for nondestructive inspection according to claim 1 ,
wherein the information processing device reduces the noise magnetic field components in the actual measurement data that directly reach the one or more magnetic sensors from a magnetic field source for measurement by performing a calculation based on the actual measurement data and the virtual measurement data,
wherein the virtual measurement data is created under the virtual conditions in which:
the magnetic field source for measurement that applies the magnetic field to the measurement target is present as in the actual measurement; and
the measurement target is absent.
3 . The information processing system for nondestructive inspection according to claim 1 ,
wherein the virtual measurement data is created under the virtual conditions in which:
a magnetic field source for measurement that applies the magnetic field to the measurement target is present as in the actual measurement;
the measurement target is absent; and
the magnetic material other than the measurement target is present in the nonmagnetic body as with in the actual measurement.
4 . The information processing system for nondestructive inspection according to claim 1 ,
wherein the information processing device extracts a proportion of the magnetic field increased by presence of the measurement target in the actual measurement data by performing a calculation based on the actual measurement data and the virtual measurement data,
wherein the virtual measurement data is created under the virtual conditions in which:
a magnetic field source for measurement that applies the magnetic field to the measurement target is present as in the actual measurement; and
the measurement target is absent.
5 . The information processing system for nondestructive inspection according to claim 1 ,
wherein the information processing device differentiates a curve that represents the actual measurement data distributed along the measurement target.
6 . The information processing system for nondestructive inspection according to claim 1 ,
wherein the information processing device detects a decrease of the magnetic field components in the actual measurement data that come from a magnetic field source for measurement and that reach the one or more magnetic sensors through the magnetic material other than the measurement target by performing a calculation based on the actual measurement data and the virtual measurement data, the decrease being caused by a breakage in the measurement target,
wherein the virtual measurement data is created under the virtual conditions in which:
the magnetic field source for measurement that applies the magnetic field to the measurement target is present as in the actual measurement;
the measurement target is sound; and
the magnetic material other than the measurement target is present in the nonmagnetic body as with in the actual measurement.
7 . The information processing system for nondestructive inspection according to claim 1 ,
wherein the information processing device smooths a curve of the actual measurement data that is distributed along the measurement target.
8 . The information processing system for nondestructive inspection according to claim 1 ,
wherein the actual measurement data and the virtual measurement data are in a data format that expresses a two-dimensional distribution of the magnetic field and that expresses a distribution of the measurement position on a two-dimension along the surface of the nonmagnetic body.
9 . The information processing system for nondestructive inspection according to claim 8 , wherein
the information processing device corrects a shift of a central axis of the actual measurement data from a central axis of the measurement target, based on a symmetric property of the two-dimensional distribution of the magnetic field with respect to the central axis of the measurement target.
10 . The information processing system for nondestructive inspection according to claim 1 , wherein
the sensor unit further includes a fixed magnetic sensor,
the actual measurement data is scan measurement data obtained by moving the one or more magnetic sensors and performing scanning, and
the information processing device reduces time-varying ambient magnetic field noise in the scan measurement data, based on fixed-point measurement data obtained by the fixed magnetic sensor while the actual measurement data is obtained.
11 . A nondestructive inspection method for a measurement target that is a magnetic material covered by a nonmagnetic body, the nondestructive inspection method comprising:
reducing noise magnetic field components other than magnetic field components coming from the measurement target and/or emphasizing the magnetic field components coming from the measurement target in actual measurement data, including reducing the noise magnetic field components in the actual measurement data coming from a magnetic material other than the measurement target, based on the actual measurement data and virtual measurement data, wherein
the actual measurement data is obtained by applying a magnetic field to the measurement target and actually measuring the magnetic field coming from the measurement target using one or more magnetic sensors of a sensor unit at a measurement position on a surface of the nonmagnetic body, the one or more magnetic sensors including at least one main sensor and at least one reference sensor corresponding, respectively, to the at least one main sensor, the at least one reference sensor being disposed further away from the measurement surface than the corresponding at least one main sensor, and
the virtual measurement data is created by performing a simulation under virtual conditions that are obtained by modifying actual measurement conditions, the virtual conditions account for the magnetic material other than the measurement target by estimating a position of the magnetic material other than the measurement target on the basis of information obtained from an architectural plan, a survey using electromagnetic radar, or measurement with magnetic flux leakage testing.
12 . The nondestructive inspection method according to claim 11 , wherein
the reducing reduces the noise magnetic field components in the actual measurement data that directly reach the one or more magnetic sensors from a magnetic field source for measurement, based on the actual measurement data and the virtual measurement data, and
the virtual measurement data is created under the virtual conditions in which:
the magnetic field source for measurement that applies the magnetic field to the measurement target is present as in the actual measurement; and
the measurement target is absent.
13 . The nondestructive inspection method according to claim 11 , wherein
the virtual measurement data is created under the virtual conditions in which:
a magnetic field source for measurement that applies the magnetic field to the measurement target is present as in the actual measurement;
the measurement target is absent; and
the magnetic material other than the measurement target is present in the nonmagnetic body as with in the actual measurement.
14 . The nondestructive inspection method according to claim 11 , wherein
a proportion of the magnetic field increased by presence of the measurement target in the actual measurement data is extracted, based on the actual measurement data and the virtual measurement data, and
the virtual measurement data is created under the virtual conditions in which:
a magnetic field source for measurement that applies the magnetic field to the measurement target is present as in the actual measurement; and
the measurement target is absent.
15 . The nondestructive inspection method according to claim 11 , wherein
a curve that represents the actual measurement data distributed along the measurement target is differentiated.
16 . The nondestructive inspection method according to claim 11 , wherein a decrease of the magnetic field components in the actual measurement data that come from a magnetic field source for measurement and that reach the one or more magnetic sensors through the magnetic material other than the measurement target is detected, based on the actual measurement data and the virtual measurement data, the decrease being caused by a breakage in the measurement target, and
the virtual measurement data is created under the virtual conditions in which:
the magnetic field source for measurement that applies the magnetic field to the measurement target is present as in the actual measurement;
the measurement target is sound; and
the magnetic material other than the measurement target is present in the nonmagnetic body as with in the actual measurement.
17 . The nondestructive inspection method according to claim 11 , wherein
a curve of the actual measurement data distributed along the measurement target is smoothed.
18 . The nondestructive inspection method according to claim 11 ,
wherein the actual measurement data and the virtual measurement data are in a data format that expresses a two-dimensional distribution of the magnetic field and that expresses a distribution of the measurement position on a two-dimension along the surface of the nonmagnetic body.
19 . The nondestructive inspection method according to 18 , wherein a shift of a central axis of the actual measurement data from a central axis of the measurement target is corrected, based on a symmetric property of the two-dimensional distribution of the magnetic field with respect to the central axis of the measurement target.
20 . The nondestructive inspection method according to claim 11 , wherein
the actual measurement data is scan measurement data obtained by moving the one or more magnetic sensors and performing scanning, and
the reducing reduces time-varying ambient magnetic field noise in the scan measurement data, based on fixed-point measurement data obtained by a fixed magnetic sensor of the sensor unit while the actual measurement data is obtained.