Measurement data evaluation apparatus, structure diagnosis apparatus, method for evaluating measurement data, method for structure diagnosis, and program

Abstract

To make an evaluation to determine whether measurement data from a sensor is usable for diagnosis of a structure.SOLUTION: A measurement data evaluation apparatus includes a mode shape acquisition unit that, for each of a plurality of sensors detecting vibration generated in a structure, acquires an amplitude frequency characteristic from measurement data of each sensor and acquires a mode shape indicating the spatial distribution of spectral intensity in the amplitude frequency characteristic for each of one or more frequencies; and an evaluation unit that evaluates validity of the measurement data according to whether the vibration mode shape of a first-order vertical deflection mode is included in the mode shape acquired for each of the one or more frequencies.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a measurement data evaluation device, a structure diagnosis device, a measurement data evaluation method, a structure diagnosis method, and a program. [Background technology]

[0002] There is known a technique for diagnosing damage or soundness of a structure using the vibration characteristics of the structure. The vibration characteristics used for diagnosing damage or soundness of the structure include the natural frequency of a specific natural vibration mode of the structure. The vibration of the structure is measured by a sensor, such as a displacement, velocity, or acceleration sensor, arranged on the structure. The natural vibration mode refers to the way vibration manifests in an object vibrating at a natural frequency. The way vibration manifests, i.e., the natural vibration mode, is represented by the spatial distribution of vibration amplitude in an object vibrating at a natural frequency. Generally, a structure has multiple natural vibration modes.

[0003] As a related technique, Patent Document 1 discloses a vibration determination device that analyzes vibrations. In Patent Document 1, sensors such as acceleration sensors are installed on structures such as bridges. The vibration determination device described in Patent Document 1 acquires measurement data from the sensors via a data logger. The vibration determination device calculates vibration characteristics of the structure from data representing the progression of the vibration of the structure, i.e., from a measurement data set. The vibration determination device compares multiple feature quantities representing the calculated vibration characteristics of the structure with multiple feature quantities representing the characteristics of a reference natural vibration mode that have been acquired in advance.

[0004] In Patent Document 1, the characteristics of the reference natural vibration mode are acquired by intentionally vibrating a structure that has been confirmed to be free of damage or deterioration, and measuring the vibration using a sensor that has been confirmed to be free of malfunctions and installation defects. The vibration determination device determines whether the vibration of the structure is the reference vibration based on the comparison result of the feature quantities. If the vibration determination device determines that the vibration of the structure is not the reference vibration, it detects outliers included in the multiple feature quantities. Furthermore, the vibration determination device identifies, as an abnormal sensor, a sensor installed at a location where the vibration characteristics indicated by the feature quantities detected as outliers are measured. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2019 / 058478 Summary of the Invention [Problem to be solved by the invention]

[0006] The vibration determination device described in Patent Document 1 can detect outliers in measurement data based on characteristics of reference vibration and identify abnormal sensors. However, the vibration determination device does not evaluate whether the measurement data of the sensor is usable for diagnosing a structure. Furthermore, Patent Document 1 does not specify what type of vibration should be used as the reference vibration. If the vibration determination device selects a vibration mode that may not occur in a structure as the reference vibration, it may not be able to detect outliers.

[0007] One of the objectives of the present disclosure is to provide a measurement data evaluation device, a structure diagnosis device, a measurement data evaluation method, a structure diagnosis method, and a program that can evaluate whether sensor measurement data is data that can be used to diagnose a structure. [Means for solving the problem]

[0008] A measurement data evaluation method according to a first aspect of the present disclosure includes: acquiring amplitude-frequency characteristics from measurement data of each of a plurality of sensors, each of which is used to detect vibrations occurring in a structure; acquiring mode shapes indicating the spatial distribution of spectral intensity in the amplitude-frequency characteristics for each of one or more frequencies; and evaluating the validity of the measurement data based on whether or not the mode shapes acquired for each of the one or more frequencies include a vibration mode shape of a first-order vertical deflection mode.

[0009] A structure diagnosis method according to a second aspect of the present disclosure includes acquiring measurement data measured by a plurality of sensors, each of which is for detecting vibrations occurring in a structure; acquiring amplitude-frequency characteristics from the measurement data of each of the plurality of sensors for each of the plurality of sensors; acquiring mode shapes indicating the spatial distribution of spectral intensity in the amplitude-frequency characteristics for each of one or more frequencies; evaluating the validity of the measurement data depending on whether the mode shapes acquired for each of the one or more frequencies include a vibration mode shape of a first-order vertical deflection mode; and, if the measurement data is evaluated to be valid, analyzing the measurement data and diagnosing the structure.

[0010] A measurement data evaluation device according to a third aspect of the present disclosure includes a mode shape acquisition unit that acquires amplitude-frequency characteristics from measurement data of each of a plurality of sensors, each of which is used to detect vibrations occurring in a structure, and acquires a mode shape indicating the spatial distribution of spectral intensity in the amplitude-frequency characteristics for each of one or more frequencies, and an evaluation unit that evaluates the validity of the measurement data depending on whether the mode shapes acquired for each of the one or more frequencies include a vibration mode shape of a first-order vertical deflection mode.

[0011] A structural diagnosis device according to a fourth aspect of the present disclosure includes: a data acquisition unit that acquires measurement data measured by a plurality of sensors, each of which is used to detect vibrations occurring in a structure; a mode shape acquisition unit that acquires, for each of the plurality of sensors, amplitude-frequency characteristics from the measurement data of each sensor and acquires, for each of one or more frequencies, a mode shape that indicates the spatial distribution of spectral intensity in the amplitude-frequency characteristics; an evaluation unit that evaluates the validity of the measurement data depending on whether the mode shapes acquired for each of the one or more frequencies include a vibration mode shape of a first-order vertical deflection mode; and an analysis unit that analyzes the measurement data and diagnoses the structure when the measurement data is evaluated to be valid.

[0012] A program according to a fifth aspect of the present disclosure causes a computer to perform processing including: acquiring amplitude-frequency characteristics from measurement data of each of a plurality of sensors, each of which is used to detect vibrations occurring in a structure; acquiring mode shapes indicating the spatial distribution of spectral intensity in the amplitude-frequency characteristics for each of one or more frequencies; and evaluating the validity of the measurement data depending on whether the mode shapes acquired for each of the one or more frequencies include a vibration mode shape of a first-order vertical deflection mode.

[0013] A program according to a sixth aspect of the present disclosure causes a computer to perform processing including acquiring measurement data measured by a plurality of sensors, each of which is used to detect vibrations occurring in a structure; acquiring amplitude-frequency characteristics from the measurement data of each of the plurality of sensors for each of the sensors; acquiring mode shapes indicating the spatial distribution of spectral intensity in the amplitude-frequency characteristics for each of one or more frequencies; evaluating the validity of the measurement data based on whether the mode shapes acquired for each of the one or more frequencies include a vibration mode shape of a first-order vertical deflection mode; and, if the measurement data is evaluated to be valid, analyzing the measurement data and diagnosing the structure. [Effects of the Invention]

[0014] The measurement data evaluation device, structure diagnosis device, measurement data evaluation method, structure diagnosis method, and program according to the present disclosure can evaluate whether measurement data from a sensor is data that can be used to diagnose a structure. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a block diagram illustrating a schematic configuration example of a structure diagnosis device according to the present disclosure. [Figure 2] 1 is a block diagram illustrating an example of a configuration of a structure diagnosis device according to the present disclosure. [Figure 3] FIG. 1 is a schematic diagram showing an example of the arrangement of multiple sensors in a structure. [Figure 4] 4 is a graph showing an example of a time history waveform of acceleration detected by a sensor. [Figure 5] FIG. 10 is a diagram showing a comparison between a measurement mode shape and a reference shape. [Figure 6] 3 is a flowchart showing an operation procedure of the structure diagnosis device. [Figure 7] 10A and 10B are diagrams illustrating a comparison between a measurement mode shape and a reference shape in the first embodiment. [Figure 8] FIG. 1 is a block diagram illustrating an example of the configuration of a computer device. DETAILED DESCRIPTION OF THE INVENTION

[0016] Prior to describing embodiments of the present disclosure, an overview of the present disclosure will be described. Fig. 1 is a block diagram showing a schematic configuration example of a structure diagnosis device according to the present disclosure. The structure diagnosis device 10 includes a data acquisition unit 11, a mode shape acquisition unit 12, an evaluation unit 13, and an analysis unit 14. In the structure diagnosis device 10, the mode shape acquisition unit 12 and the evaluation unit 13 constitute a measurement data evaluation device.

[0017] A structure to be diagnosed is equipped with multiple sensors, each for detecting vibrations occurring in the structure. A data acquisition unit 11 acquires measurement data measured by the multiple sensors. A mode shape acquisition unit 12 acquires amplitude-frequency characteristics from the measurement data of each of the multiple sensors. The mode shape acquisition unit 12 acquires mode shapes that indicate the spatial distribution of spectral intensity in the amplitude-frequency characteristics for each of one or more frequencies.

[0018] The evaluation unit 13 determines whether the mode shapes acquired for each of one or more frequencies include a vibration mode shape of a first-order vertical deflection mode. The evaluation unit 13 evaluates the validity of the acquired measurement data according to the determination result. If the evaluation unit 13 evaluates that the measurement data is valid, the analysis unit 14 analyzes the acquired measurement data and diagnoses the structure.

[0019] In the present disclosure, the mode shape acquisition unit 12 acquires vibration mode shapes for each of one or more frequencies. When the measurement data from the multiple sensors is normal, the vibration mode shape of the structure acquired from the measurement data is considered to include the vibration mode shape of the first vertical deflection mode. On the other hand, when at least a portion of the measurement data from the multiple sensors is abnormal, the vibration mode shape of the structure acquired from the measurement data is considered to not include the vibration mode shape of the first vertical deflection mode. In the present disclosure, the evaluation unit 13 evaluates the validity of the measurement data depending on whether or not the first vertical deflection mode is present. In this manner, the evaluation unit 13 can evaluate whether the measurement data is suitable for analyzing the vibration of the structure.

[0020] In the present disclosure, the analysis unit 14 analyzes the measurement data when the measurement data is evaluated as valid, thereby preventing the analysis unit 14 from misdiagnosing the structure based on invalid measurement data.

[0021] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the following description and drawings have been omitted and simplified as appropriate for clarity of explanation. In addition, in each drawing, the same or similar elements are designated by the same reference numerals, and duplicate explanations are omitted as necessary.

[0022] An embodiment of the present disclosure will be described. FIG. 2 is a block diagram showing an example of the configuration of a structure diagnosis device according to the present disclosure. The structure diagnosis device 100 shown in FIG. 2 includes a data acquisition unit 101, a data extraction unit 102, a mode shape acquisition unit 103, an evaluation unit 104, and an analysis unit 105. In the structure diagnosis device 100, the mode shape acquisition unit 103 and the evaluation unit 104 configure a measurement data evaluation device 120. The structure diagnosis device 100 corresponds to the structure diagnosis device 10 shown in FIG. 1. The measurement data evaluation device 120 corresponds to the measurement data evaluation device 20 shown in FIG. 1.

[0023] The structure diagnosis device 100 is configured as, for example, a computer device or a server device having one or more memories and one or more processors. At least a part of the functions of each unit in the structure diagnosis device 100 can be realized by one or more processors executing processing in accordance with instructions read from one or more memories. The structure diagnosis device 100 does not necessarily have to be configured as a single physical device. The structure diagnosis device 100 may be configured using multiple physically separated devices.

[0024] The structure diagnosis device 100 is a device used to analyze measurement data of vibrations of a structure to be diagnosed and diagnose damage, deterioration, or soundness of the structure. In this embodiment, a plurality of sensors 150 are installed in the structure to be diagnosed. Each of the plurality of sensors 150 is a sensor for detecting vibrations occurring in the structure. The plurality of sensors 150 are installed at different positions in the structure to be diagnosed. For example, an acceleration sensor is used as the sensor 150. The sensor 150 may be any sensor that can detect a time history waveform of displacement, and the sensor 150 is not limited to an acceleration sensor.

[0025] 3 is a schematic diagram showing an example of the arrangement of sensors 150 in a structure to be diagnosed. In this example, the structure to be diagnosed is a bridge 200. As shown in FIG. 3, seven sensors 150-1 to 150-7 are attached to the bridge 200. The sensors 150-1 to 150-7 are attached to, for example, the deck of the bridge 200. The bridge 200 has an expansion joint 210 at a connection portion with another structure such as an abutment.

[0026] In this embodiment, the bridge 200 is assumed to be a bridge over which vehicles 250, which are moving objects such as trucks and trailers, can pass. Vibrations are applied to the bridge 200 as the vehicles 250 pass over. In particular, when the vehicle 250 exits the bridge 200, vibrations are applied to the bridge 200 due to elastic shock waves generated when the vehicle 250 steps over the expansion joint 210. The multiple sensors 150 detect accelerations occurring in the bridge 200 due to the vibrations at the respective positions where the sensors are installed.

[0027] The data collection device 130 receives and stores sensor data, i.e., vibration measurement data, from the multiple sensors 150. The data collection device 130 is also called a data logger. The sensor data indicates a time history waveform of acceleration occurring in a structure. The data collection device 130 may acquire the sensor data from the multiple sensors 150 via cables at a location where a structure such as a bridge is installed, for example. Alternatively, the data collection device 130 may acquire the sensor data from the multiple sensors 150 via a wired network or a wireless network.

[0028] The terminal device 140 is a device used by an operator of a business entity that maintains and manages structures, such as a road management business entity, a civil engineering construction company, or a measurement company. The terminal device 140 is connected to the structure diagnosis device 100 via a network 170 such as the Internet. The terminal device 140 may be configured as a computer device, a tablet device, a smartphone, or other device. The terminal device 140 reads out vibration measurement data from the data collection device 130. In response to an operation by an operator, the terminal device 140 transmits the vibration measurement data to the structure diagnosis device 100 via the network 170.

[0029] The data acquiring unit 101 receives sensor data of the plurality of sensors 150 from the terminal device 140 via the network 170. The data acquiring unit 101 may be connected to the data collecting device 130 and may acquire the sensor data of the plurality of sensors 150 from the data collecting device 130. Alternatively, the data acquiring unit 101 may be connected to the plurality of sensors 150 and may acquire the sensor data from the plurality of sensors 150. The data acquiring unit 101 corresponds to the data acquiring unit 11 shown in FIG. 1 .

[0030] The data extraction unit 102 extracts data used for diagnosing the structure from the sensor data of the multiple sensors 150. For example, the data extraction unit 102 extracts sensor data of a section representing the attenuation portion of the vibration of the structure due to excitation from the time history waveform of acceleration, i.e., the sequence of acceleration measurement values, from each of the sensor data acquired from the multiple sensors 150.

[0031] For example, the data extraction unit 102 identifies the time when the vehicle 250 exits the bridge 200 when only one vehicle 250 is traveling on the bridge 200. The data extraction unit 102 may identify the time when the vehicle 250 last stepped on the extension / retraction device 210, that is, the time when the last wheel of the vehicle 250 passed the extension / retraction device 210, as the time when the vehicle 250 exited the bridge 200. The data extraction unit 102 sets the time when the vehicle 250 exited the bridge 200 as the starting point, and extracts sensor data within a predetermined time from the starting time.

[0032] As an example, the data extraction unit 102 acquires sensor data, i.e., acceleration measurement values ​​at each time, acquired from sensor 150-1, which is closest to the extension / retraction device 210 as shown in FIG. 3 , among the multiple sensors 150. The data extraction unit 102 determines whether the acceleration is equal to or greater than a predetermined threshold. The data extraction unit 102 identifies the last time the acceleration became equal to or greater than the predetermined threshold as the time when the last wheel of the vehicle 250 passed the extension / retraction device 210. The data extraction unit 102 extracts data for a time range of several seconds from the time when the last wheel of the vehicle 250 passed the extension / retraction device 210 from each of the sensor data acquired from sensors 150-1 to 150-7.

[0033] FIG. 4 is a graph showing an example of a time history waveform of acceleration detected by sensor 150-1 installed at a position closest to extension joint 210. In the graph shown in FIG. 4, the vertical axis represents acceleration, and the horizontal axis represents time. From changes in the detected acceleration, data extraction unit 102 identifies time t0, when the last wheel of vehicle 250 passes extension joint 210. Data extraction unit 102 defines time t1 as a predetermined time after time t0, and extracts sensor data for the time range from time t0 to time t1. The extracted data indicates a time history waveform of damped free vibration when vehicle 250 leaves bridge 200. Data extraction unit 102 also extracts sensor data for the time range from time t0 to time t1 for each of the other sensors 150-2 to 150-7.

[0034] It should be noted that the extraction of data indicating the time history waveform of damped free vibration does not necessarily have to be performed in the structure diagnosis device 100. For example, the data indicating the time history waveform of damped free vibration may be extracted in the data collection device 130 or the terminal device 140. In other words, the data extraction unit 102 may be disposed in the data collection device 130 or the terminal device 140. The extraction of data indicating the time history waveform of damped free vibration may also be performed manually.

[0035] The mode shape acquisition unit 103 acquires amplitude-frequency characteristics, i.e., amplitude frequency characteristics, from the extracted data for each of the multiple sensors 150. The mode shape acquisition unit 103 acquires a mode shape indicating the spatial distribution of spectral intensity in the amplitude-frequency characteristics for each of one or more frequencies. For example, the mode shape acquisition unit 103 acquires the mode shape of each frequency by plotting the amplitude spectrum, i.e., spectral intensity, in the amplitude-frequency characteristics for each frequency and sensor position. In the following description, the mode shapes acquired by the mode shape acquisition unit 103 are also referred to as measured mode shapes or observed mode shapes.

[0036] More specifically, the mode shape acquisition unit 103 performs a Fourier transform on the time history waveform of acceleration, i.e., data indicating the amplitude of acceleration at each time, for each sensor 150. The mode shape acquisition unit 103 converts time-domain data into frequency-domain data to acquire amplitude-frequency characteristics for each sensor 150. The mode shape acquisition unit 103 acquires frequencies of one or more spectral peaks (hereinafter also referred to as peak frequencies) in the structure to be diagnosed based on the amplitude-frequency characteristics acquired for at least one of the multiple sensors 150. For each peak frequency, the mode shape acquisition unit 103 acquires an amplitude spectrum of the peak frequency from each of the amplitude-frequency characteristics acquired for the multiple sensors. For each acquired peak frequency, the mode shape acquisition unit 103 acquires a mode shape indicating the spatial distribution of the amplitude spectrum. The mode shape acquisition unit 103 corresponds to the mode shape acquisition unit 12 shown in FIG. 1.

[0037] The evaluation unit 104 determines whether the measurement mode shape includes a vibration mode shape of the first-order vertical deflection mode. Here, the order of the vibration mode is defined as the number of antinodes, where the point where the amplitude is maximum is defined as an antinode and the point where the amplitude is zero is defined as a node. In other words, the order of the vibration mode is defined as the number of positions where the amplitude is large in a structure vibrating at a certain resonant frequency.

[0038] For example, the evaluation unit 104 stores an ideal shape or reference shape of the first vertical deflection mode. The evaluation unit 104 compares the measurement mode shape with the ideal shape of the first vertical deflection mode. The evaluation unit 104 calculates, for example, the similarity between the measurement mode shape and the ideal shape as an evaluation value. If there is a measurement mode shape whose similarity is equal to or greater than a predetermined threshold, the evaluation unit 104 determines that the measurement mode shape includes the vibration mode shape of the first vertical deflection mode. If there is no measurement mode shape whose similarity is equal to or greater than a predetermined threshold, the evaluation unit 104 determines that the measurement mode shape does not include the vibration mode shape of the first vertical deflection mode.

[0039] The evaluation unit 104 evaluates the sensor data acquired by the data acquisition unit 101 depending on whether the measurement mode shape includes the vibration mode shape of the first vertical deflection mode. If the evaluation unit 104 determines that the measurement mode shape includes the vibration mode shape of the first vertical deflection mode, it evaluates the sensor data as valid, that is, the sensor data is data that can be used to diagnose a structure. If the evaluation unit 104 determines that the measurement mode shape does not include the vibration mode shape of the first vertical deflection mode, it evaluates the sensor data as invalid, that is, the sensor data is not suitable for diagnosing a structure. In this case, the evaluation unit 104 transmits a measurement data error to the terminal device 140.

[0040] FIG. 5 is a diagram showing a comparison between the measured mode shape and the reference shape. In each graph shown in FIG. 5, the vertical axis represents the acceleration amplitude, and the horizontal axis represents the sensor position. The measured mode shape includes a mode shape acquired for frequency f1 and a mode shape measured for frequency fi. The evaluation unit 104 calculates an evaluation value indicating the similarity or correlation between the measured mode shape of each frequency and the reference shape.

[0041] As an example, the evaluation unit 104 uses a modal assurance criterion (MAC) as an index representing the similarity or correlation between the measured mode shape and the reference shape, and calculates a MAC value for the measured mode shape at each frequency. If the MAC value calculated for the measured mode shape at any frequency is equal to or greater than a predetermined threshold, the evaluation unit 104 determines that the measured mode shape includes a first-order vertical bending mode. If there is no measured mode shape with a MAC value equal to or greater than the predetermined threshold, the evaluation unit 104 determines that the measured mode shape does not include a first-order vertical bending mode. The evaluation unit 104 corresponds to the evaluation unit 13 shown in FIG. 1.

[0042] If the evaluation unit 104 evaluates the sensor data to be valid, the analysis unit 105 analyzes the structure based on the sensor data. The analysis unit 105 analyzes, for example, the resonance characteristics of the structure. The analysis unit 105 analyzes, for example, the time history waveform of vibration indicated by the sensor data, and diagnoses damage, deterioration, or soundness of the structure. Alternatively or in addition to this, the analysis unit 105 may perform frequency analysis of the sensor data and diagnose damage, deterioration, or soundness of the structure. If the evaluation unit 104 evaluates the sensor data to be invalid, the analysis unit 105 does not analyze the structure. The analysis unit 105 corresponds to the analysis unit 14 shown in FIG. 1.

[0043] Next, the operation procedure will be explained. Fig. 6 is a flowchart showing the operation procedure of the structure diagnosis device 100. The operation procedure of the structure diagnosis device 100 corresponds to a structure diagnosis method. The data acquisition unit 101 acquires measurement data of a plurality of sensors 150 (step S1). In step S1, the data acquisition unit 101 may acquire the measurement data of the plurality of sensors 150 from the terminal device 140 via a network 170 such as the Internet, for example.

[0044] The data extraction unit 102 extracts data within a specific time range from the measurement data acquired in step S1 (step S2). In step S2, the data extraction unit 102 extracts, for example, data of a portion of the time history waveform of damped free vibration included in the measurement data for each of the multiple sensors 150. The data extraction may be performed manually.

[0045] The mode shape acquisition unit 103 acquires amplitude-frequency characteristics from the extracted data for each of the multiple sensors. The mode shape acquisition unit 103 acquires a measurement mode shape indicating the spatial distribution of spectral intensity in the amplitude-frequency characteristics for each of one or more frequencies (step S3). The evaluation unit 104 compares the measurement mode shape acquired in step S3 with a reference shape, i.e., the vibration mode shape of the first-order vertical bending mode (step S4). Based on the comparison result, the evaluation unit 104 determines whether the measurement mode shape acquired in step S3 includes the reference shape (step S5).

[0046] In step S4, the evaluation unit 104 calculates an evaluation value indicating the degree of similarity or correlation for each pair of one of the measurement mode shapes acquired in step S3 and a reference shape. In step S5, the evaluation unit 104 compares the evaluation value with a predetermined threshold value, and determines whether the measurement mode shape acquired in step S3 includes a vibration mode shape of the first vertical deflection mode depending on whether the evaluation value is equal to or greater than the threshold value.

[0047] If the evaluation unit 104 determines in step S5 that the reference shape is not included in the measurement mode shape, it evaluates that the measurement data acquired in step S1 is invalid (step S6). In other words, the evaluation unit 104 determines that the deterioration, damage, or soundness of the structure cannot be correctly diagnosed in the diagnosis using the measurement data. In this case, the evaluation unit 104 notifies the terminal device 140 that transmitted the measurement data that the measurement data is invalid. Steps S3 and S4 correspond to a measurement data evaluation method performed in the measurement data evaluation device 120.

[0048] If the evaluation unit 104 determines in step S5 that the measurement mode shape includes the reference shape, it evaluates that the measurement data acquired in step S1 is valid. In this case, the analysis unit 105 analyzes the vibrations occurring in the structure using the measurement data acquired in step S1 and diagnoses the structure (step S7). The analysis unit 105 transmits the diagnosis result to the terminal device 140.

[0049] In this embodiment, the mode shape acquisition unit 103 acquires vibration mode shapes from measurement data from multiple sensors 150. The evaluation unit 104 determines whether the acquired vibration mode shapes include a reference mode shape of the first vertical deflection mode. In other words, the evaluation unit 104 determines whether the first vertical deflection mode is observed. The inventors have confirmed through vibration visualization analysis of over 40 bridges in the past that the first vertical deflection mode is stably expressed. Based on this knowledge, the evaluation unit 104 evaluates the validity of the measurement depending on whether the first vertical deflection mode can be observed. If the first vertical deflection mode is observed, the evaluation unit 104 evaluates the measurement data as valid. On the other hand, if the first vertical deflection mode is not observed, the evaluation unit 104 evaluates the measurement data as invalid.

[0050] Measurement data that is not suitable for diagnosing a structure may be input to the structure diagnosis device 100 due to improper attachment of the acceleration sensor, cable sway, incorrect equipment settings, or malfunction. In this embodiment, the evaluation unit 104 uses the presence or absence of a first-order vertical deflection mode to evaluate the validity of the measurement data, and if measurement data that is not suitable for diagnosing a structure is input, the evaluation unit 104 evaluates the measurement data as invalid. If the evaluation unit 104 evaluates the measurement data as valid, the analysis unit 105 analyzes the measurement data. This prevents the analysis unit 105 from analyzing measurement data that is not suitable for diagnosing a structure and performing an incorrect diagnosis on the structure.

[0051] In this embodiment, an operator of the terminal device 140 may upload invalid measurement data to the structure diagnosis device 100 and request the structure diagnosis device 100 to diagnose a structure. In this case, if the structure diagnosis device 100 performs a structure diagnosis without evaluating the validity of the measurement data, an accurate diagnosis result will not be obtained, and the computer resources of the structure diagnosis device 100 will be wasted. For example, if charges are based on the amount of computer resources required to diagnose a structure, if a diagnosis is performed on invalid measurement data, the business operator requesting the diagnosis will have to pay extra costs. In this embodiment, the validity of the measurement data is evaluated before a diagnosis based on the measurement data is performed. Therefore, even if invalid measurement data is uploaded from the terminal device 140, it is possible to prevent wasteful use of computer resources.

[0052] Examples will be described below. The inventors conducted experiments to confirm the effects of the structure diagnosis device 100 according to this embodiment. In Example 1, the concrete deck of a single-span bridge with known resonance characteristics was used as the structure to be diagnosed. The natural frequency of the first vertical deflection mode of this structure was derived. Of the multiple acceleration sensors installed on the concrete deck, some were installed with intentionally weakened adhesive strength. Measurement data was acquired from these multiple acceleration sensors, and it was verified whether the natural frequency could be derived from the acquired measurement data.

[0053] The data collection device 130 collected measurement data as follows: Seven MEMS (Micro Electro Mechanical Systems) acceleration sensors were installed at equal intervals on the underside of the concrete deck using adhesive. Of the seven acceleration sensors, the adhesive on the acceleration sensors corresponding to sensors 150-4 to 150-7 shown in Figure 3 was intentionally loosened. The data collection device 130 collected time history data of vertical acceleration from the seven installed acceleration sensors as vehicles passed over the bridge as measurement data. Other measurement conditions are shown in the table below. TIFF2025127182000002.tif77121

[0054] The data acquisition unit 101 acquired the measurement data collected by the data collection device 130. The mode shape acquisition unit 103 performed frequency analysis on the collected acceleration time history data and extracted mode shapes at the spectrum peaks. The evaluation unit 104 then calculated a MAC value that indicates the degree of similarity between the mode shape expressed at each spectrum peak and the reference shape of the primary vertical deflection.

[0055] FIG. 7 is a diagram showing a comparison between the measurement mode shape and the reference shape in Example 1. In each graph shown in FIG. 7, the vertical axis represents acceleration amplitude, and the horizontal axis represents sensor position. In Example 1, the acceleration sensors corresponding to sensors 150-4 to 150-7 are loosely attached, so the measurement mode shape does not include a mode shape similar to the reference shape. As such, the first-order vertical bending mode was not observed in the measurement mode shape in Example 1, and the evaluation unit 104 evaluated that the measurement data was not suitable for investigating resonance characteristics.

[0056] In Comparative Example 1, the measurement data was analyzed without evaluating the validity of the measurement data. In Comparative Example 1, measurement data was collected using the same procedure as in Example 1, and the measurement mode shape was obtained from the collected measurement data. After that, the first vertical deflection mode was found by visual inspection, and the corresponding natural frequency was calculated. The calculated natural frequency was different from the known resonance characteristics. Thus, in Comparative Example 1, the resonance characteristics were misevaluated.

[0057] In the embodiment, the evaluation unit 104 obtained an evaluation result that the measurement data was not suitable for investigating the resonance characteristics, and therefore the analysis unit 105 did not use such measurement data to diagnose or evaluate the resonance characteristics of the structure. If the analysis unit 105 had analyzed the vibration of the structure without evaluating the validity of the measurement data, there is a high possibility that the resonance characteristics would be erroneously evaluated based on invalid measurement data. By evaluating the validity of the measurement data in the evaluation unit 104, it was possible to avoid erroneous evaluation of the resonance characteristics.

[0058] The inventor further evaluated the validity of the measurement data by changing some of the conditions based on the procedure of Example 1. In Example 2, the acceleration sensors were properly installed without any looseness, but the cable connections of the acceleration sensors were loosened. The data collection device 130 collected time history data of vertical acceleration when a vehicle passed over a bridge from seven installed acceleration sensors. The mode shape acquisition unit 103 performed frequency analysis on the collected time history data of acceleration and extracted mode shapes at spectral peaks. The evaluation unit 104 then calculated a MAC value indicating the similarity between the mode shape expressed at each spectral peak and the reference shape of the first-order vertical deflection. In Example 2, the first-order vertical deflection mode was not observed, and the evaluation unit 104 evaluated the measurement data as unsuitable for investigating the resonance characteristics. In Example 2, the analysis unit 105 did not diagnose or evaluate the resonance characteristics of the structure using the measurement data evaluated as unsuitable for investigating the resonance characteristics.

[0059] Furthermore, in Example 3, the high-pass filter conditions were incorrectly set to 4.5 Hz, and acceleration in the low frequency band where the first-order mode is likely to occur was not measured. The data collection device 130 collected measurement data lacking low-frequency components. The mode shape acquisition unit 103 performed frequency analysis on the collected acceleration time history data and extracted mode shapes at the spectral peaks. The evaluation unit 104 then calculated a MAC value indicating the similarity between the mode shape occurring at each spectral peak and the reference shape of the first-order vertical deflection. In Example 3, the first-order vertical deflection mode was not observed, and the evaluation unit 104 evaluated the measurement data as unsuitable for investigating resonance characteristics.

[0060] For Comparative Examples 2 and 3, measurement data was collected using the same procedures as in Examples 2 and 3, respectively, and measurement mode shapes were obtained from the collected measurement data. The first-order vertical deflection mode was then visually detected, and the corresponding natural frequency was calculated. The calculated natural frequencies in Comparative Examples 2 and 3 differed from known resonance characteristics, resulting in incorrect evaluation of the resonance characteristics in Comparative Examples 2 and 3. Through these examples and comparative examples, the effects of the present embodiment described above were confirmed.

[0061] Next, a description will be given of the hardware configuration of the structure diagnosis device 100 and the measurement data evaluation device 120. Fig. 8 is a block diagram showing an example of the configuration of a computer device that can be used as the structure diagnosis device 100 or the measurement data evaluation device 120. The computer device 500 has a processor 510 such as a CPU (Central Processing Unit), a storage unit 520, a ROM (Read Only Memory) 530, a RAM (Random Access Memory) 540, a communication interface (IF: Interface) 550, and a user interface 560.

[0062] The communication interface 550 is an interface for connecting the computer device 500 to a communication network via wired communication means or wireless communication means, etc. The user interface 560 includes a display unit such as a display, and an input unit such as a keyboard, a mouse, and a touch panel.

[0063] The storage unit 520 is an auxiliary storage device that can store various types of data. The storage unit 520 can be used as the product information DB 110. The storage unit 520 does not necessarily have to be a part of the computer device 500, but may be an external storage device or a cloud storage connected to the computer device 500 via a network.

[0064] The ROM 530 is a non-volatile storage device. For example, a semiconductor storage device such as a flash memory with a relatively small capacity is used for the ROM 530. The programs executed by the CPU 510 can be stored in the storage unit 520 or the ROM 530. The storage unit 520 or the ROM 530 stores programs for realizing the functions of each unit of the structure diagnosis device 100 or the measurement data evaluation device 120.

[0065] The program includes instructions (or software code) that, when loaded into a computer, cause the computer to perform one or more functions described in the embodiments. The program may be stored in a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, computer-readable media or tangible storage media include random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD) or other memory technologies, compact discs (CDs), digital versatile discs (DVDs), Blu-ray discs or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices. The program may also be transmitted on a transitory computer-readable medium or communication medium. By way of example and not limitation, transitory computer-readable media or communication media include electrical, optical, acoustic, or other forms of propagated signals.

[0066] The RAM 540 is a volatile storage device. Various semiconductor memory devices such as a DRAM (Dynamic Random Access Memory) or an SRAM (Static Random Access Memory) are used for the RAM 540. The RAM 540 can be used as an internal buffer for temporarily storing data, etc. The CPU 510 loads a program stored in the storage unit 520 or the ROM 530 into the RAM 540 and executes it. The CPU 510 executes the program, thereby realizing the functions of each part of the structure diagnosis device 100 or the measurement data evaluation device 120. The CPU 510 may have an internal buffer for temporarily storing data, etc.

[0067] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. Each embodiment can be combined with other embodiments as appropriate.

[0068] Each drawing is merely an example for describing one or more embodiments. Each drawing may relate not only to one particular embodiment, but also to one or more other embodiments. As will be understood by those skilled in the art, various features or steps described with reference to any one drawing can be combined with features or steps shown in one or more other drawings to create, for example, an embodiment not explicitly shown or described. Not all features or steps shown in any one drawing are necessary to describe an exemplary embodiment, and some features or steps may be omitted. The order of steps described in any drawing may be changed as appropriate.

[0069] A part or all of the above-described embodiments can be described as, but not limited to, the following supplementary notes.

[0070] [Appendix 1] For each of a plurality of sensors each for detecting vibration occurring in a structure, an amplitude-frequency characteristic is obtained from measurement data of each sensor, and for each of one or more frequencies, a mode shape indicating a spatial distribution of spectral intensity in the amplitude-frequency characteristic is obtained; A measurement data evaluation method comprising: evaluating the validity of the measurement data depending on whether or not a vibration mode shape of a first-order vertical flexure mode is included in the mode shapes acquired for each of the one or more frequencies.

[0071] [Appendix 2] 2. A measurement data evaluation method according to claim 1, further comprising: comparing the acquired mode shape with a reference shape representing the vibration mode shape of the first vertical deflection mode; and determining, based on the result of the comparison, whether or not the acquired mode shape includes the vibration mode shape of the first vertical deflection mode.

[0072] [Appendix 3] 3. The measurement data evaluation method according to claim 2, further comprising: calculating an evaluation value indicating the degree of similarity between the acquired mode shape and the reference shape; and determining whether the acquired mode shape includes a vibration mode shape of a first-order vertical deflection mode depending on whether the evaluation value is equal to or greater than a threshold value.

[0073] [Appendix 4] If the evaluation value is equal to or greater than a threshold value, it is determined that the acquired mode shapes include a vibration mode shape of a first-order vertical deflection mode; 4. The measurement data evaluation method according to claim 3, wherein, if the evaluation value is less than a threshold value, it is determined that the acquired mode shapes do not include a vibration mode shape of a first-order vertical deflection mode.

[0074] [Appendix 5] 5. The measurement data evaluation method according to claim 1, wherein the mode shape is acquired for a frequency of a spectrum peak in the amplitude frequency characteristic.

[0075] [Appendix 6] 6. The measurement data evaluation method according to any one of claims 1 to 5, further comprising receiving the measurement data from the plurality of sensors via a network.

[0076] [Appendix 7] Acquire measurement data measured by multiple sensors, each of which detects vibrations occurring in the structure, For each of the plurality of sensors, an amplitude-frequency characteristic is acquired from the measurement data of each sensor, and a mode shape indicating a spatial distribution of spectral intensity in the amplitude-frequency characteristic is acquired for each of one or more frequencies; evaluating the validity of the measurement data depending on whether or not the mode shapes acquired for each of the one or more frequencies include a vibration mode shape of a first-order vertical flexure mode; A structure diagnosis method comprising: analyzing the measurement data and diagnosing the structure when the measurement data is evaluated to be valid.

[0077] [Appendix 8] a mode shape acquisition unit that acquires amplitude-frequency characteristics from measurement data of each of a plurality of sensors, each of which detects vibrations occurring in a structure, and acquires a mode shape that indicates a spatial distribution of spectral intensity in the amplitude-frequency characteristics for each of one or more frequencies; and an evaluation unit that evaluates the validity of the measurement data depending on whether or not the mode shapes acquired for each of the one or more frequencies include a vibration mode shape of a first-order vertical deflection mode.

[0078] [Appendix 9] a data acquisition unit that acquires measurement data measured by a plurality of sensors, each of which detects vibrations occurring in a structure; a mode shape acquisition unit that acquires amplitude-frequency characteristics from measurement data of each of the plurality of sensors and acquires, for each of one or more frequencies, a mode shape that indicates a spatial distribution of spectral intensity in the amplitude-frequency characteristics; an evaluation unit that evaluates the validity of the measurement data depending on whether or not a vibration mode shape of a first-order vertical deflection mode is included in the mode shapes acquired for each of the one or more frequencies; and an analysis unit that, if the measurement data is evaluated to be valid, analyzes the measurement data and diagnoses the structure.

[0079] [Appendix 10] For each of a plurality of sensors each for detecting vibration occurring in a structure, an amplitude-frequency characteristic is obtained from measurement data of each sensor, and for each of one or more frequencies, a mode shape indicating a spatial distribution of spectral intensity in the amplitude-frequency characteristic is obtained; a program that causes a computer to perform processing including evaluating the validity of the measurement data depending on whether or not the mode shapes acquired for each of the one or more frequencies include a vibration mode shape of a first-order vertical deflection mode.

[0080] [Appendix 11] Acquire measurement data measured by multiple sensors, each of which detects vibrations occurring in the structure, For each of the plurality of sensors, an amplitude-frequency characteristic is acquired from the measurement data of each sensor, and a mode shape indicating a spatial distribution of spectral intensity in the amplitude-frequency characteristic is acquired for each of one or more frequencies; evaluating the validity of the measurement data depending on whether or not the mode shapes acquired for each of the one or more frequencies include a vibration mode shape of a first-order vertical flexure mode; A program that causes a computer to perform processing including analyzing the measurement data and diagnosing the structure if the measurement data is evaluated to be valid.

[0081] Some or all of the elements (e.g., configurations and functions) described in Supplementary Notes 2 to 6 that are dependent on Supplementary Notes 1 may also be dependent on Supplementary Notes 7 to 11 in the same dependency relationship as Supplementary Notes 2 to 6. Some or all of the elements described in any Supplementary Note may be applied to various hardware, software, recording means for recording software, systems, and methods. [Explanation of symbols]

[0082] 10: Structural diagnostic equipment 11: Data acquisition section 12: Mode shape acquisition section 13: Evaluation section 14:Analysis Department 20: Measurement data evaluation device 100: Structural diagnostic equipment 101: Data acquisition section 102: Data extraction unit 103: Mode shape acquisition unit 104: Evaluation section 105: Analysis Department 120: Measurement data evaluation device 130: Data collection device 140: Terminal device 150: Sensor 170: Network

Claims

1. For each of a plurality of sensors each for detecting vibration occurring in a structure, an amplitude-frequency characteristic is obtained from measurement data of each sensor, and a mode shape indicating a spatial distribution of spectral intensity in the amplitude-frequency characteristic is obtained for each of one or more frequencies; A measurement data evaluation method comprising: evaluating the validity of the measurement data depending on whether or not a vibration mode shape of a first-order vertical flexure mode is included in the mode shapes acquired for each of the one or more frequencies.

2. 2. The measurement data evaluation method according to claim 1, further comprising the steps of: comparing the acquired mode shape with a reference shape that indicates the vibration mode shape of the first vertical deflection mode; and determining, based on a result of the comparison, whether or not the acquired mode shape includes the vibration mode shape of the first vertical deflection mode.

3. 3. The measurement data evaluation method according to claim 2, further comprising: calculating an evaluation value indicating a degree of similarity between the acquired mode shape and the reference shape; and determining whether the acquired mode shape includes a vibration mode shape of a first-order vertical deflection mode depending on whether the evaluation value is equal to or greater than a threshold value.

4. The measurement data evaluation method according to claim 1 , wherein the mode shape is acquired for a frequency of a spectrum peak in the amplitude-frequency characteristic.

5. The measurement data evaluation method according to claim 1 , further comprising receiving the measurement data from the plurality of sensors via a network.

6. Acquire measurement data measured by multiple sensors, each of which detects vibrations occurring in the structure, For each of the plurality of sensors, an amplitude-frequency characteristic is acquired from measurement data of each sensor, and a mode shape indicating a spatial distribution of spectral intensity in the amplitude-frequency characteristic is acquired for each of one or more frequencies; evaluating the validity of the measurement data depending on whether or not the mode shapes acquired for each of the one or more frequencies include a vibration mode shape of a first-order vertical flexure mode; A structure diagnosis method comprising: analyzing the measurement data and diagnosing the structure when the measurement data is evaluated to be valid.

7. a mode shape acquisition unit that acquires amplitude-frequency characteristics from measurement data of each of a plurality of sensors, each of which detects vibrations occurring in a structure, and acquires a mode shape that indicates a spatial distribution of spectral intensity in the amplitude-frequency characteristics for each of one or more frequencies; and an evaluation unit that evaluates the validity of the measurement data depending on whether or not the mode shapes acquired for each of the one or more frequencies include a vibration mode shape of a primary vertical deflection mode.

8. a data acquisition unit that acquires measurement data measured by a plurality of sensors, each of which detects vibrations occurring in a structure; a mode shape acquisition unit that acquires amplitude-frequency characteristics from measurement data of each of the plurality of sensors and acquires, for each of one or more frequencies, a mode shape that indicates a spatial distribution of spectral intensity in the amplitude-frequency characteristics; an evaluation unit that evaluates the validity of the measurement data depending on whether or not a vibration mode shape of a first-order vertical flexure mode is included in the mode shapes acquired for each of the one or more frequencies; and an analysis unit that, if the measurement data is evaluated to be valid, analyzes the measurement data and diagnoses the structure.

9. For each of a plurality of sensors each for detecting vibration occurring in a structure, an amplitude-frequency characteristic is obtained from measurement data of each sensor, and a mode shape indicating a spatial distribution of spectral intensity in the amplitude-frequency characteristic is obtained for each of one or more frequencies; A program that causes a computer to perform processing that includes evaluating the validity of the measurement data depending on whether or not the mode shapes acquired for each of the one or more frequencies include a vibration mode shape of a primary vertical deflection mode.

10. Acquire measurement data measured by multiple sensors, each of which detects vibrations occurring in the structure, For each of the plurality of sensors, an amplitude-frequency characteristic is acquired from measurement data of each sensor, and a mode shape indicating a spatial distribution of spectral intensity in the amplitude-frequency characteristic is acquired for each of one or more frequencies; evaluating the validity of the measurement data depending on whether or not the mode shapes acquired for each of the one or more frequencies include a vibration mode shape of a first-order vertical flexure mode; A program that causes a computer to perform processing including analyzing the measurement data and diagnosing the structure if the measurement data is evaluated to be valid.

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