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US-12618806-B2 - Structure evaluation system, signal processing apparatus, structure evaluation method, and non-transitory computer readable recording medium

US12618806B2US 12618806 B2US12618806 B2US 12618806B2US-12618806-B2

Abstract

According to one embodiment, a structure evaluation system of an embodiment includes one or more sensors, a signal processing apparatus, and an evaluator. The plurality of sensors detect elastic waves generated from a structure. The signal processing apparatus calculates information on a frequency distribution by amplitude scale based on the plurality of elastic waves detected by each of the one or more sensors, and transmits the calculated information on the frequency distribution by amplitude scale in a wireless manner. The evaluator evaluates a state of deterioration of the structure based on the information on the frequency distribution by amplitude scale which is transmitted from the signal processing apparatus.

Inventors

  • Yuki Ueda
  • Takashi Usui

Assignees

  • KABUSHIKI KAISHA TOSHIBA

Dates

Publication Date
20260505
Application Date
20230224
Priority Date
20220916

Claims (18)

  1. 1 . A structure evaluation system comprising: one or more sensors configured to detect elastic waves generated from a structure; a signal processing apparatus configured to calculate information on a frequency distribution by amplitude scale based on the plurality of elastic waves detected by each of the one or more sensors, and transmits the calculated information on the frequency distribution by amplitude scale in a wireless manner; and an evaluator configured to evaluate a state of deterioration of the structure based on the information on the frequency distribution by amplitude scale which is transmitted from the signal processing apparatus, wherein the signal processing apparatus has a plurality of modes including an operation mode and a pause mode, the operation mode is a mode that performs processing based on the frequency distribution by amplitude scale, the processing including calculating the information on the frequency distribution by amplitude scale, the pause mode is a mode in which power consumption is made smaller than the operation mode by limiting a function, the signal processing apparatus includes a peak hold circuit configured to hold a value of a maximum amplitude of the elastic waves detected by the one or more sensors at least during the pause mode, and the signal processing apparatus calculates the information on the frequency distribution by amplitude scale using the value of the maximum amplitude of the elastic waves which is held by the peak hold circuit for a predetermined period after the signal processing apparatus transitions to the operation mode.
  2. 2 . The structure evaluation system according to claim 1 , wherein the signal processing apparatus detects a maximum amplitude of the plurality of elastic waves, and calculates the information on the frequency distribution by amplitude scale based on the detected maximum amplitude of the plurality of elastic waves.
  3. 3 . The structure evaluation system according to claim 1 , wherein the signal processing apparatus includes a calculator configured to calculate the information on the frequency distribution by amplitude scale, and an interruption controller configured to make the signal processing apparatus transition from the pause mode to the operation mode in a case where a signal level of an elastic wave output from the peak hold circuit exceeds a first threshold value, and the calculator calculates the information on the frequency distribution by amplitude scale using the value of the maximum amplitude of the elastic waves which is held by the peak hold circuit for a predetermined period after the transition to the operation mode.
  4. 4 . The structure evaluation system according to claim 3 , wherein the signal processing apparatus further includes a time acquirer configured to acquire time information, and the calculator calculates the information on the frequency distribution by amplitude scale including time information when a value of a maximum amplitude of each elastic wave is detected.
  5. 5 . The structure evaluation system according to claim 1 , wherein the signal processing apparatus further includes a calculator configured to calculate the information on the frequency distribution by amplitude scale, and an interruption controller configured to detect a signal equivalent to an envelope of an elastic wave and makes the signal processing apparatus transition from the pause mode to the operation mode in a case where a condition indicating that no elastic wave has been detected after the detection of the elastic wave is satisfied, and the calculator calculates the information on the frequency distribution by amplitude scale using the value of the maximum amplitude of the elastic waves which is held by the peak hold circuit for a predetermined period after the transition to the operation mode.
  6. 6 . The structure evaluation system according to claim 1 , wherein the signal processing apparatus calculates any one of a frequency distribution by amplitude scale, an intercept obtained by linearly approximating the frequency distribution by amplitude scale, or an inclination obtained by linearly approximating the frequency distribution by amplitude scale as the information on the frequency distribution by amplitude scale.
  7. 7 . The structure evaluation system according to claim 1 , wherein the signal processing apparatus changes at least a period for calculating the information on the frequency distribution by amplitude scale or the number of hits of elastic waves in response to a command wirelessly transmitted from the structure evaluation apparatus.
  8. 8 . The structure evaluation system according to claim 1 , wherein the plurality of modes further includes a signal reception mode for detecting the elastic waves, wherein the signal processing apparatus further includes: an activation controller configured to switch the signal processing apparatus from the pause mode to the signal reception mode; and an interruption controller configured to switch the signal processing apparatus to the operation mode, wherein the activation controller activates some functional units by switching the signal processing apparatus to the signal reception mode when approach of a vehicle traveling on the structure is detected, and the interruption controller activates a remaining functional units by switching the signal processing apparatus to the operation mode when a predetermined condition is satisfied.
  9. 9 . A structure evaluation system comprising: one or more sensors configured to detect elastic waves generated from a structure; a signal processing apparatus configured to hold a value of a maximum amplitude of an elastic wave detected by each of the one or more sensors, calculates information on the elastic wave using the held value of the maximum amplitude of the elastic wave for a predetermined period, and transmits the calculated information on the elastic wave in a wireless manner; and an evaluator configured to evaluate a state of deterioration of the structure based on the transmitted information on the elastic wave, wherein the signal processing apparatus has a plurality of modes including an operation mode and a pause mode, the operation mode is a mode that performs processing based on the elastic wave, the processing including calculating the information on the elastic wave, the pause mode is a mode in which power consumption is made smaller than the operation mode by limiting a function, the signal processing apparatus includes a peak hold circuit configured to hold a value of a maximum amplitude of the elastic waves detected by the one or more sensors at least during the pause mode, and the signal processing apparatus calculates the information on the elastic wave using the value of the maximum amplitude of the elastic waves which is held by the peak hold circuit for a predetermined period after the signal processing apparatus transitions to the operation mode.
  10. 10 . The structure evaluation system according to claim 9 , wherein the signal processing apparatus includes a calculator configured to calculate the information on the elastic wave, and an interruption controller configured to make the signal processing apparatus transition from the pause mode to the operation mode in a case where a signal level of the elastic wave output from the peak hold circuit exceeds a first threshold value, and the calculator calculates the information on the elastic wave using the value of the maximum amplitude of each elastic wave which is held by the peak hold circuit for a predetermined period after the transition to the operation mode.
  11. 11 . The structure evaluation system according to claim 9 , wherein the signal processing apparatus further includes a calculator configured to calculate the information on the elastic wave, and an interruption controller configured to detect a signal equivalent to an envelope of an elastic wave and makes the signal processing apparatus transition from the pause mode to the operation mode in a case where a condition indicating that no elastic wave has been detected after the detection of the elastic wave is satisfied, and the calculator calculates the information on the elastic wave using the value of the maximum amplitude of the elastic wave which is held by the peak hold circuit for a predetermined period after the transition to the operation mode.
  12. 12 . The structure evaluation system according to claim 9 , wherein the plurality of modes further includes a signal reception mode for detecting the elastic waves, wherein the signal processing apparatus further includes: an activation controller configured to switch the signal processing apparatus from the pause mode to the signal reception mode; and an interruption controller configured to switch the signal processing apparatus to the operation mode, wherein the activation controller activates some functional units by switching the signal processing apparatus to the signal reception mode when approach of a vehicle traveling on the structure is detected, and the interruption controller activates a remaining functional units by switching the signal processing apparatus to the operation mode when a predetermined condition is satisfied.
  13. 13 . A signal processing apparatus comprising: a calculator configured to calculate information on a frequency distribution by amplitude scale based on a plurality of elastic waves detected by each of one or more sensors that detect elastic waves generated from a structure; and a wireless transmitter configured to wirelessly transmit information on the frequency distribution by amplitude scale which is calculated by the calculator to a structure evaluation apparatus that evaluates a state of deterioration of the structure, wherein the signal processing apparatus has a plurality of modes including an operation mode and a pause mode, the operation mode is a mode that performs processing based on the frequency distribution by amplitude scale, the processing including calculating the information on the frequency distribution by amplitude scale, the pause mode is a mode in which power consumption is made smaller than the operation mode by limiting a function, the signal processing apparatus includes a peak hold circuit configured to hold a value of a maximum amplitude of the elastic waves detected by the one or more sensors at least during the pause mode, and the calculator calculates the information on the frequency distribution by amplitude scale using the value of the maximum amplitude of the elastic waves which is held by the peak hold circuit for a predetermined period after the signal processing apparatus transitions to the operation mode.
  14. 14 . A signal processing apparatus comprising: a peak hold circuit configured to hold a value of a maximum amplitude of an elastic wave detected by each of one or more sensors that detect elastic waves generated from a structure; and a wireless transmitter configured to calculate information on the elastic wave using the value of the maximum amplitude of the elastic wave which is held by the peak hold circuit for a predetermined period, and wirelessly transmits the calculated information on the elastic wave to a structure evaluation apparatus that evaluates a state of deterioration of the structure, wherein the signal processing apparatus has a plurality of modes including an operation mode and a pause mode, the operation mode is a mode that performs processing based on the elastic wave, the processing including calculating the information on the elastic wave, the pause mode is a mode in which power consumption is made smaller than the operation mode by limiting a function, the peak hold circuit holds a value of a maximum amplitude of the elastic waves detected by the one or more sensors at least during the pause mode, and the signal processing apparatus calculates the information on the elastic wave using the value of the maximum amplitude of the elastic waves which is held by the peak hold circuit for a predetermined period after the signal processing apparatus transitions to the operation mode.
  15. 15 . A structure evaluation method comprising: holding, by a peak hold circuit, a value of a maximum amplitude of elastic waves detected by each of one or more sensors that detect elastic waves generated from a structure, at least during a signal processing apparatus a pause mode, the peak hold circuit providing in a signal processing apparatus has a plurality of modes including an operation mode and the pause mode; calculating information on a frequency distribution by amplitude scale using the value of the maximum amplitude of the elastic waves which is held by the peak hold circuit for a predetermined period after the signal processing apparatus transitions to the operation mode; transmitting the calculated information on the frequency distribution by amplitude scale in a wireless manner; and evaluating a state of deterioration of the structure based on the information on the frequency distribution by amplitude scale which is transmitted in a wireless manner, wherein the operation mode is a mode that performs processing based on the frequency distribution by amplitude scale, the processing including calculating the information on the frequency distribution by amplitude scale, and the pause mode is a mode in which power consumption is made smaller than the operation mode by limiting a function.
  16. 16 . A structure evaluation method comprising: Holding, by a peak hold circuit, a value of a maximum amplitude of elastic waves detected by each of one or more sensors that detect elastic waves generated from a structure, at least during a signal processing apparatus a pause mode, the peak hold circuit providing in a signal processing apparatus has a plurality of modes including an operation mode and the pause mode; calculating information on the elastic wave using the value of the maximum amplitude of the elastic waves which is held by the peak hold circuit for a predetermined period after the signal processing apparatus the transitions to the operation mode; transmitting the calculated information on the elastic wave in a wireless manner; and evaluating a state of deterioration of the structure based on the information on the elastic wave which is transmitted in the wireless manner, wherein the operation mode is a mode that performs processing based on the elastic wave, the processing including calculating the information on the elastic wave, and the pause mode is a mode in which power consumption is made smaller than the operation mode by limiting a function.
  17. 17 . A non-transitory computer readable recording medium storing a computer program which enables a computer to execute the following processing: calculating information on a frequency distribution by amplitude scale based on a plurality of elastic waves detected by each of one or more sensors that detect elastic waves generated from a structure; and wirelessly transmitting information on the frequency distribution by amplitude scale which is calculated in the calculating of the information to a structure evaluation apparatus that evaluates a state of deterioration of the structure, wherein the computer calculates the information on the frequency distribution by amplitude scale using the value of the maximum amplitude of the elastic waves, which are held by a peak hold circuit that holds the value of the maximum amplitude of the elastic waves detected by the one or more sensors during the pause mode, for a predetermined period, the operation mode is a mode that performs processing based on the frequency distribution by amplitude scale, the processing including calculating the information on the frequency distribution by amplitude scale, the pause mode is a mode in which power consumption is made smaller than the operation mode by limiting a function.
  18. 18 . A non-transitory computer readable recording medium storing a computer program which enables a computer to execute the following processing: calculating information on an elastic wave using the elastic wave detected by each of one or more sensors that detect elastic waves generated from a structure for a predetermined period; and wirelessly transmitting the information on the elastic wave which is calculated in the calculating of the information to a structure evaluation apparatus that evaluates a state of deterioration of the structure, wherein the computer calculates the information on the elastic wave using the value of the maximum amplitude of the elastic waves, which are held by a peak hold circuit that holds the value of the maximum amplitude of the elastic waves detected by the one or more sensors during the pause mode, for a predetermined period, the operation mode is a mode that performs processing based on the elastic wave, the processing including calculating the information on the elastic wave, the pause mode is a mode in which power consumption is made smaller than the operation mode by limiting a function.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2022-148204, filed Sep. 16, 2022, the entire contents of which are incorporated herein by reference. FIELD Embodiments described herein relate generally to a structure evaluation system, a signal processing apparatus, a structure evaluation method, and a non-transitory computer readable recording medium. BACKGROUND In recent years, problems associated with the aging of structures such as bridges that were built during periods of high economic growth have become apparent. Since damage in the event of an accident on a structure is immeasurable, techniques for monitoring the state of a structure have already been proposed. For example, a technique for detecting damage of a structure by an acoustic emission (AE) method has been proposed, the AE method being a method in which a high sensitivity sensor detects elastic waves generated due to the occurrence of internal cracks or progress of internal cracks. AE is an elastic wave that is generated in association with the progress of a crack of a material. In the AE method, an AE sensor using a piezoelectric element detects an elastic wave as an AE signal (voltage signal). The AE signal is detected as a sign before final fracture of a material occurs. Thus, the frequency of generation and signal intensity of the AE signal are useful as indicators of the soundness of the material. For this reason, research is being conducted into a technique for detecting signs of deterioration of a structure using the AE method. As one method of evaluating the soundness of a structure based on an AE method, an evaluation method using a b-value derived from an empirical rule known as the Gutenberg-Richter rule in the field of seismology is known. The b-value is an evaluation value obtained from an inclination of a frequency distribution by amplitude scale, and is known to be correlated with the state of a crack inside a material. The life of structures such as bridges is generally said to be 50 years. It is essential to build a safe and secure society by monitoring the soundness of structures over a long period of time from several years to several decades. In particular, it is desired to detect signs of deterioration inside a structure before large-scale damage occurs. Long-term monitoring of a structure based on an AE method is considered promising for early detection of signs of deterioration. However, an evaluation method in an AE method of the related art deals with relatively high-frequency signals, which may result in high power consumption. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating a configuration example of a structure evaluation system in a first embodiment. FIG. 2 is a diagram illustrating a configuration example of a signal processing apparatus in the first embodiment. FIG. 3 is a sequence diagram illustrating a flow of processing of the structure evaluation system in the first embodiment. FIG. 4 is a diagram illustrating a configuration example of a signal processing apparatus in a second embodiment. FIG. 5 is a time chart illustrating operations of the signal processing apparatus in the second embodiment. FIG. 6 is a sequence diagram illustrating a flow of processing of a structure evaluation system in the second embodiment. FIG. 7 is a diagram illustrating a configuration example of a signal processing apparatus in a third embodiment. FIG. 8 is a time chart illustrating operations of the signal processing apparatus in the third embodiment. FIG. 9 is a sequence diagram illustrating a flow of processing of a structure evaluation system in the third embodiment. FIG. 10 is a diagram illustrating a configuration example of a signal processing apparatus in a fourth embodiment. FIG. 11 is a diagram illustrating a relationship between the number of hits and a measurement time in the fourth embodiment. FIG. 12 is a diagram illustrating a configuration of a structure evaluation system in a fifth embodiment. FIG. 13 is a diagram illustrating a configuration example of a structure evaluation system in a sixth embodiment. FIG. 14 is a diagram illustrating a configuration example of a signal processing apparatus in the sixth embodiment. FIG. 15 is a sequence diagram illustrating a flow of processing of the structure evaluation system in the sixth embodiment. FIG. 16 is a diagram illustrating a configuration example of a signal processing apparatus in a seventh embodiment. FIG. 17 is a sequence diagram illustrating a flow of processing of a structure evaluation system in the seventh embodiment. DETAILED DESCRIPTION The present invention provides a problem to be solved by the present invention is to provide a structure evaluation system, a signal processing apparatus, a structure evaluation method, and a non-transitory computer readable recording medium which are capable of suppressing power consumption in an acoustic emi