# US 11,029,231 B2 · Assessing device, assessing system, assessing method, and computer-readable recording medium > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,029,231 B2 - Document ID: US11029231B2 - Status: Granted - Kind: B2 - Application number: 16/341,488 - Filed: 2017-10-20 - Published: 2019-10-03 - Granted: 2021-06-08 - Earliest claimed: 2016-10-25 - Assignees: NEC Corporation - Applicants: NEC Corporation - Inventors: Shohei Kinoshita; Shigeru Kasai - Web page: https://patentgrep.com/patent/US11029231B2 ## CPC - G01H 13/00: Measuring resonant frequency - G01M 7/025: {Measuring arrangements} - G01M 5/0008: {of bridges} - G01M 5/0033: {by determining damage, crack or wear} - G01M 5/0066: {by exciting or detecting vibration or acceleration (vibration testing of structures G01M7/00)} - G01M 7/00: Vibration-testing of structures; Shock-testing of structures (G01M9/00 takes precedence) - G01M 7/02: Vibration-testing {by means of a shake table} - G01N 29/075: {by measuring or comparing phase angle (measuring frequencies or phase angles per se G01R23/00, G01R25/00)} - G01H: MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES - G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR - 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) ## Abstract An assessing device capable of assessing presence or absence of local damage in a structure is provided. The assessing device includes a dominant frequency identifying unit that identifies a dominant frequency of a vibration at each of a plurality of spots in a structure, based on information indicating the vibration at each of the plurality of spots, a phase difference identifying unit that identifies a phase difference at the dominant frequency between the vibrations at the plurality of spots, based on the dominant frequency and information indicating the vibrations; and an assessing unit that assesses damage in the structure, based on the phase difference. ## Claims ### Claim 1 An assessing device comprising: a dominant frequency identifying unit identifying a dominant frequency of a vibration at each of a plurality of spots in a structure, based on information indicating the vibration at each of the plurality of spots; a phase difference identifying unit identifying a phase difference at the dominant frequency between the vibrations at two spots included in the plurality of spots, based on the dominant frequency and the information indicating the vibrations; and an assessing unit assessing a damage in the structure, based on a change rate of the phase difference between the two spots and a phase difference at a reference timing for same spots. ### Claim 2 (depends on 1) The assessing device according to claim 1, wherein the dominant frequency identifying unit identifies the dominant frequency, based on a damped free vibration included in the information indicating the vibration. ### Claim 3 (depends on 2) The assessing device according to claim 2, wherein the dominant frequency identifying unit identifies, as the dominant frequency, a frequency at which an amplitude is largest among frequency components included in the damped free vibration. ### Claim 4 (depends on 1) The assessing device according to claim 1, wherein the assessing unit assesses the damage at a spot between the two spots. ### Claim 5 (depends on 1) The assessing device according to claim 1, wherein the assessing unit assesses the damage, based on a variation of the phase difference identified for a same place. ### Claim 6 (depends on 1) An assessing system comprising: a plurality of detection units detecting vibrations; and the assessing device according to claim 1 that assesses the damage in the structure, based on the information indicating the vibrations detected by the detection units. ### Claim 7 An assessing method comprising: identifying a dominant frequency of a vibration at each of a plurality of spots in a structure, based on information indicating the vibration at each of the plurality of spots; identifying a phase difference at the dominant frequency between the vibrations at two spots included in the plurality of spots, based on the dominant frequency and the information indicating the vibrations; and assessing a damage in the structure, based on a change rate of the phase difference between the two spots and a phase difference at a reference timing for same spots. ### Claim 8 A computer-readable recording medium that non-temporarily stores a program causing a computer to perform: processing of identifying a dominant frequency of a vibration at each of a plurality of spots in a structure, based on information indicating the vibration at each of the plurality of spots; processing of identifying a phase difference at the dominant frequency between the vibrations at two spots included in the plurality of spots, based on the dominant frequency and the information indicating the vibrations; and processing of assessing a damage in the structure, based on a change rate of the phase difference between the two spots and a phase difference at a reference timing for same spots. ### Claim 9 (depends on 1) The assessing device according to claim 1, wherein, by using an autoregressive model, the dominant frequency identifying unit models a damped free vibration represented by the information indicating the vibration, and identifies the dominant frequency, based on a frequency characteristic of the model. ### Claim 10 (depends on 7) The assessing method according to claim 7, further comprising: by using an autoregressive model, modelling a damped free vibration represented by the information indicating the vibration, wherein the dominant frequency is identified, based on a frequency characteristic of the model. ### Claim 11 (depends on 8) The computer-readable recording medium according to claim 8, wherein the program further causes the computer to perform: processing of, by using an autoregressive model, modelling a damped free vibration represented by the information indicating the vibration, wherein the dominant frequency is identified, based on a frequency characteristic of the model.