# US 11,307,175 B2 · Diagnosis apparatus, diagnosis method, and computer-readable recording medium

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- Number: US 11,307,175 B2
- Document ID: US11307175B2
- Status: Granted
- Kind: B2
- Application number: 15/734,782
- Filed: 2018-06-05
- Published: 2021-07-29
- Granted: 2022-04-19
- Earliest claimed: 2018-06-05
- Assignees: NEC Corporation
- Applicants: NEC Corporation
- Inventors: Yu Kiyokawa; Shigeru Kasai; Shohei Kinoshita
- Web page: https://patentgrep.com/patent/US11307175B2

## CPC

- G01N 29/12: by measuring frequency or resonance of acoustic waves {(measuring frequency or resonant frequency of mechanical vibrations or acoustic waves in general G01H1/06, G01H3/04, G01H13/00; acoustic resonators G10K11/04; vibration or shock testing of structures G01M7/00)}
- G01N 29/4436: {with a reference signal (amplitude comparison G01N29/48)}
- G01M 7/02: Vibration-testing {by means of a shake table}
- G01N 29/04: Analysing solids (using acoustic emission techniques G01N29/14)
- G01N 29/4454: {Signal recognition, e.g. specific values or portions, signal events, signatures}
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR

## Abstract

A diagnosis apparatus 1 including: a target vibration information generation unit 2 that generates pieces of target vibration information; a comparative relationship information generation unit 3 that generates pieces of comparative relationship information indicating relationships among the pieces of target vibration information, or the pieces of comparative relationship information indicating relationships among pieces of reference vibration information and the pieces of target vibration information, the pieces of reference vibration information indicating vibrations in the target mode among vibrations that are measured in a reference period; and a diagnosis unit 5 that diagnoses that a change has occurred in the structure 20 between the diagnosis period and the reference period based on a result of comparison between a distribution of pieces of reference relationship information and the distribution that has been calculated in relation to the pieces of comparative relationship information.

## Claims

### Claim 1

A diagnosis apparatus comprising:
a target vibration information generation unit that generates pieces of target vibration information indicating mode vector vibrations in a target mode among vibrations of a structure that are measured in a diagnosis period using a plurality of sensors mounted on the structure during vibration tests of the structure and pieces of reference vibration information indicating the mode vector vibrations in the target mode among the vibrations of the structure that are measured using the plurality of sensors mounted on the structure during the vibration tests of the structure in a reference period that is different from the diagnosis period;
a comparative relationship information generation unit that generates reference relationship information that is an index indicating a similarity degree between the pieces of reference vibration information and comparative relationship information that is an index indicating a similarity degree between the pieces of reference vibration information and the pieces of target vibration information;
a distribution calculation unit that calculates a distribution of the reference relationship information and a distribution of the comparative relationship information; and
a diagnosis unit that diagnoses that a change has occurred in the structure between the diagnosis period and the reference period when there is a distribution difference equal to or larger than a predetermined difference between the distribution of the reference relationship information and the distribution of the comparative relationship information.

### Claim 2 (depends on 1)

The diagnosis apparatus according to claim 1, wherein
the target vibration information generation unit generates the pieces of target vibration information indicating the vibrations in a mode that is included in a predetermined range including the target mode.

### Claim 3

A diagnosis method comprising:
generating pieces of target vibration information indicating mode vector vibrations in a target mode among vibrations of a structure that are measured in a diagnosis period using a plurality of sensors mounted on the structure during vibration tests of the structure and pieces of reference vibration information indicating the mode vector vibrations in the target mode among the vibrations of the structure that are measured that are measured using the plurality of sensors mounted on the structure during the vibration tests of the structure in a reference period that is different from the diagnosis period;
generating reference relationship information that is an index indicating a similarity degree between the pieces of reference vibration information and comparative relationship information that is an index indicating a similarity degree between the pieces of reference vibration information and the pieces of target vibration information;
calculating a distribution of the reference relationship information and a distribution of the comparative relationship information; and
diagnosing that a change has occurred in the structure between the diagnosis period and the reference period when there is a distribution difference equal to or larger than a predetermined difference between the distribution of the reference relationship information and the distribution of the comparative relationship information.

### Claim 4 (depends on 3)

The diagnosis method according to claim 3, wherein
generating pieces of target vibration information comprises generating the pieces of target vibration information indicating the vibrations in a mode that is included in a predetermined range including the target mode are generated.

### Claim 5

A non-transitory computer-readable recording medium having recorded therein a diagnosis program for causing a computer to carry out:
generating pieces of target vibration information indicating mode vector vibrations in a target mode among vibrations of a structure that are measured in a diagnosis period using a plurality of sensors mounted on the structure during vibration tests of the structure and pieces of reference vibration information indicating the mode vector vibrations in the target mode among the vibrations of the structure that are measured in a reference period that are measured using the plurality of sensors mounted on the structure during the vibration tests of the structure that is different from the diagnosis period;
generating reference relationship information that is an index indicating a similarity degree between the pieces of reference vibration information and comparative relationship information that is an index indicating a similarity degree between the pieces of reference vibration information and the pieces of target vibration information;
calculating a distribution of the reference relationship information and a distribution of the comparative relationship information; and
diagnosing that a change has occurred in the structure between the diagnosis period and the reference period when there is a distribution difference equal to or larger than a predetermined difference between the distribution of the reference relationship information and the distribution of the comparative relationship information.

### Claim 6 (depends on 5)

The non-transitory computer-readable recording medium according to claim 5, wherein
generating pieces of target vibration information comprises generating the pieces of target vibration information indicating the vibrations in a mode that is included in a predetermined range including the target mode are generated.