Defect detecting device, defect detecting method, and computer-readable recording medium

Patent metadata

Field	Value
Publication number	US-10788320-B2
Application number	US-201716329029-A
Country	US
Kind code	B2
Filing date	Aug 23, 2017
Priority date	Aug 31, 2016
Publication date	Sep 29, 2020
Grant date	Sep 29, 2020

Abstract

A defect detecting device 10 includes an overall displacement measurement unit 11 that measures, based on observation data output from an observation device that observes a target object, a displacement of an overall movement of the target object relative to an observation point at set time intervals, as an overall displacement; a specific period detection unit 12 that detects a specific period in which the measured overall displacement is in a specific state within a period in which observation is performed; a partial displacement measurement unit 13 that measures, displacements at a plurality of points set on the target object in the detected specific period, as partial displacements; and a defect detection unit 14 that detects a defect in the target object, based on the acquired at least one of the temporal changes and the spatial distributions of the partial displacements.

First claim

The invention claimed is:

1. A defect detecting device comprising:
a memory storing instructions; and
at least one processor configured to process the instructions to implement:
an overall displacement measurement unit configured to measure, based on observation data output from an observation device that observes a target object, a displacement of an overall movement of the target object relative to an observation point at set time intervals, as an overall displacement;
an specific period detection unit configured to detect a specific period in which the measured overall displacement is in a specific state, the specific period being a period between a time when the overall displacement reaches a minimum value and a time when the overall displacement reaches a maximum value, within a period in which observation is performed by the observation device;
a partial displacement measurement unit configured to measure, based on the observation data, displacements at a plurality of points set on the target object in the detected specific period, as partial displacements; and
a defect detection unit configured to acquire at least one of temporal changes and spatial distributions of the partial displacements, and detect a defect in the target object, based on the acquired at least one of the temporal changes and the spatial distributions of the partial displacements.

2. The defect detecting device according to claim 1 , wherein
the specific period detection unit is further configured to detect, as the specific period, a period from a time when the overall displacement reaches a minimum value to a time when the overall displacement reaches a maximum value within a period in which observation is performed by the observation device.

3. The defect detecting device according to claim 1 , wherein the at least one processor is further configured to process the instructions to implement a filtering unit configured to deliver, to the partial displacement measurement unit, only observation data output in the specific period among the observation data.

4. The defect detecting device according to claim 1 , wherein
the overall displacement measurement unit is further configured to detect a movement in a normal direction to a surface of the target object among an overall movement of the target object, and measure, as an overall displacement, a displacement of the detected movement in the normal direction.

5. The defect detecting device according to claim 2 , wherein
the partial displacement measurement unit is further configured to measure the partial displacements, based on observation data acquired at a time when the overall displacement reaches a maximum value and observation data acquired at a time when the overall displacement reaches a minimum value.

6. A defect detecting method comprising:
(a) measuring, based on observation data output from an observation device that observes a target object, a displacement of an overall movement of the target object relative to an observation point at set time intervals, as an overall displacement;
(b) detecting a specific period in which the measured overall displacement is in a specific state, the specific period being a period between a time when the overall displacement reaches a minimum value and a time when the overall displacement reaches a maximum value within a period in which observation is performed by the observation device;
(c) measuring, based on the observation data, displacements at a plurality of points set on the target object in the detected specific period, as partial displacements; and
(d) acquiring at least one of temporal changes and spatial distributions of the partial displacements, and detecting a defect in the target object, based on the acquired at least one of the temporal changes and the spatial distributions of the partial displacements.

7. The defect detecting method according to claim 6 , wherein,
in the (b), a period defined from a time when the overall displacement reaches a minimum value to a time when the overall displacement reaches a maximum value within a period in which observation is performed by the observation device is detected as the specific period.

8. The defect detecting method according to claim 6 , further comprising
(e) using only observation data output in the specific period among the observation data for measuring the partial displacements.

9. The defect detecting method according to claim 6 , wherein,
in the (a), a movement in a normal direction to a surface of the target object is detected among an overall movement of the target object, and a displacement of the detected movement in the normal direction is measured as the overall displacement.

10. The defect detecting method according to claim 7 , wherein,
in the (c), the partial displacements are measured based on observation data acquired at a time when the overall displacement reaches a maximum value and observation data acquired at a time when the overall displacement reaches a minimum value.

11. A non-transitory computer-readable recording medium storing a program causing a computer to execute:
(a) a step of measuring, based on observation data output from an observation device that observes a target object, a displacement of an overall movement of the target object relative to an observation point at set time intervals, as an overall displacement;
(b) a step of detecting a specific period in which the measured overall displacement is in a specific state, the specific period being a period between a time when the overall displacement reaches a minimum value and a time when the overall displacement reaches a maximum value within a period in which observation is performed by the observation device;
(c) a step of measuring, based on the observation data, displacements at a plurality of points set on the target object in the detected specific period, as partial displacements; and
(d) a step of acquiring at least one of temporal changes and spatial distributions of the partial displacements, and detecting a defect in the target object, based on the acquired at least one of the temporal changes and the spatial distributions of the partial displacements.

12. The non-transitory computer-readable recording medium according to claim 11 , wherein,
in the step (b), a period from a time when the overall displacement reaches a minimum value to a time when the overall displacement reaches a maximum value within a period in which observation is performed by the observation device is detected as the specific period.

13. The non-transitory computer-readable recording medium according to claim 11 , wherein
the computer is caused to further execute (e) using only observation data output in the specific period among the observation data for measuring the partial displacements.

14. The non-transitory computer-readable recording medium according to claim 11 , wherein,
in the step (a), a movement in a normal direction to a surface of the target object is detected among an overall movement of the target object, and a displacement of the detected movement in the normal direction is measured as an overall displacement.

15. The non-transitory computer-readable recording medium according to claim 12 , wherein,
in the step (c), the partial displacements are measured based on observation data acquired at a time when the overall displacement reaches a maximum value and observation data acquired at a time when the overall displacement reaches a minimum value.

Assignees

• Nec Corp

Inventors

• Takada Jun

Classifications

• G01B11/026 Primary

  by measuring distance between sensor and object (G01B11/0608 takes precedence) · CPC title

• G01M99/00

  Subject matter not provided for in other groups of this subclass · CPC title

• G01B11/16

  for measuring the deformation in a solid, e.g. optical strain gauge · CPC title

• G01B11/24

  for measuring contours or curvatures · CPC title

• G01B21/32 Primary

  for measuring the deformation in a solid · CPC title