JPWO2013190728A1 - Structure state determination apparatus and structure state determination method - Google Patents

Abstract

A structure state determination apparatus and a structure state determination method capable of determining the state of a structure with a simple configuration. The structure state determination apparatus (10) of the present invention includes a vibration detection means (11) for detecting the vibration of the structure, and a calculation for performing calculation processing on the vibration waveform data acquired by the vibration detection means (11). The calculation means (12) includes a means (12), and an approximate curve acquisition means (121) for acquiring an approximate curve for an envelope of the vibration waveform data, and a difference between the approximate curve and the vibration waveform data. Determination means (122) for determining the state of the structure with reference to the threshold value.

Description

  The present invention relates to a structure state determination device and a structure state determination method, for example, an intrusion detection device, a water leakage detection device, a structure deterioration detection device, and a state of the structure using the structure state determination device. The present invention relates to an intrusion detection method, a water leakage detection method, and a structure deterioration detection method using a determination method.

  Various methods have been proposed as a method for determining whether a state change such as deterioration or destruction has occurred in a structure. As an example of the method, there has been proposed a glass breakage detector for the purpose of determining the presence or absence of an intruder from a window (see Patent Document 1). This glass breakage detector detects a breaking action to glass or a sash associated with intrusion and opening / closing of a window. The configuration of this glass breakage detector is shown in FIG. As shown in FIG. 16, the glass breakage detector includes a glass breakage detection unit 1, an open / close detection unit 2, a CPU 3, an output unit 4, a clock unit 6, and a power supply unit 7. The glass breakage detection unit 1 compares the vibration sensor unit 1a that converts the vibration of the glass plate into a voltage signal, the amplification unit 1b that amplifies the voltage signal, and the amplitude of a predetermined frequency component extracted from the amplified voltage signal with a threshold value. When a destructive action is detected, the vibration analysis unit 1c outputs an alarm signal to the CPU 3. The open / close detection unit 2 includes a magnet 2b attached to a vertical frame member of an opening frame of the window, and a reed switch 2a that detects opening / closing of the window by detecting magnetism of the magnet 2b. In this glass breakage detector, when an alarm signal is input to the CPU 3, the CPU 3 causes the output unit 4 to notify a breakage action alarm. In the open / close detection unit 2, when the window is closed, the magnet 2b and the reed switch 2a come close to each other and face each other, and the reed switch 2a is turned on. Since the reed switch 2a moves away from the magnet 2b when the window is opened, the reed switch 2a is turned off.

JP 2005-78500 A

  In the glass breakage detector described in Patent Document 1, in order to detect each action of breaking glass or sash, or opening a window, substantially separate sensor elements are required. There is a problem that the number of parts increases, the detector configuration becomes complicated, and it is difficult to reduce the size and cost.

  The problem of complication of the equipment configuration as described above is not only in the glass breakage detector as described above, but also in general judgment of the state of the structure, that is, water leakage or water pipe breakage in the water pipe system of social infrastructure business. Equipment used to detect structural conditions such as detection, detection of deterioration of structures such as buildings or residences, detection of oil leaks or pipeline breaks in oil pipeline systems, and detection of gas leaks or pipeline breaks in gas pipelines Also exist in common.

  An object of the present invention is to provide a structure state determination apparatus and a structure state determination method capable of determining the state of a structure with a simple configuration.

In order to achieve the above object, a state determination apparatus for a structure according to the present invention includes:
Vibration detection means for detecting the vibration of the structure, and calculation means for performing calculation processing on the vibration waveform data acquired by the vibration detection means,
The calculating means determines an approximate curve obtaining means for obtaining an approximate curve for an envelope of the vibration waveform data, and determines a state of the structure based on a threshold provided for a difference between the approximate curve and the vibration waveform data. Determination means.

The structure judgment method of the present invention is
Including a vibration detection step for detecting the vibration of the structure, and a calculation step for performing calculation processing on the vibration waveform data acquired in the vibration detection step,
In the calculation step, an approximate curve acquisition step for acquiring an approximate curve for an envelope of the vibration waveform data, and a state of the structure is determined based on a threshold value provided for a difference between the approximate curve and the vibration waveform data. And a determination step.

  ADVANTAGE OF THE INVENTION According to this invention, the structure state determination apparatus and structure state determination method which can determine the state of a structure with simple structure can be provided.

FIG. 1 is a block diagram showing a configuration of an example (Embodiment 1) of a structure state determination apparatus according to the present invention. FIG. 2 is a flowchart showing an example (Embodiment 1) of the structure state determination method of the present invention. FIG. 3 is a block diagram illustrating a configuration of a first modification of the state determination device according to the first embodiment. FIG. 4 is a flowchart showing Modification 1 of the structure state determination method of the present invention. FIG. 5 is a block diagram illustrating a configuration of a second modification of the state determination device according to the first embodiment. FIG. 6 is a flowchart showing a second modification of the structure state determination method of the present invention. FIG. 7 is a flowchart showing a state determination method according to the second embodiment of the present invention. FIG. 8: is a block diagram which shows the structure of the other example (Embodiment 4) of the state determination apparatus of the structure of this invention. FIG. 9 is a flowchart showing an example of the structure state determination method of the present invention. FIG. 10 is a graph showing the relationship between the vibration waveform data and the approximate curve of the envelope when sashing with a metal tool in Example 1. FIG. 11 is a graph showing the relationship between the vibration waveform data at the time of unlocking and the approximate curve of the envelope in Example 1. FIG. 12 is a graph showing the relationship between vibration waveform data and an approximate curve of an envelope when a water leakage phenomenon occurs in Example 2. FIG. 13 is a graph showing the relationship between vibration waveform data and an approximate curve of an envelope when a destruction phenomenon occurs in a water pipe in Example 2. FIG. 14 is a graph showing the relationship between vibration waveform data in a normal state and an approximate curve of an envelope in Example 3. FIG. 15 is a graph showing the relationship between the vibration waveform data in the building deterioration state and the approximate curve of the envelope in the third embodiment. FIG. 16 is a block diagram showing a configuration of the glass breakage detector described in Patent Document 1. As shown in FIG.

  Hereinafter, the structure state determination apparatus and the structure state determination method of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following examples. In addition, in the following FIGS. 1-15, the same code | symbol is attached | subjected to the same part. In the drawings, for convenience of explanation, the structure of each part may be simplified as appropriate, and the dimensional ratio of each part may be schematically shown, unlike the actual case.

(Embodiment 1)
The block diagram of FIG. 1 shows the configuration of the structure state determination apparatus of the first embodiment. FIG. 2 is a flowchart of the structure state determination method according to the first embodiment. As shown in FIG. 1, the state determination apparatus 10 according to the present embodiment includes a vibration detection unit 11 and a calculation unit 12 as main components. The calculation means 12 includes an approximate curve acquisition means 121 and a determination means 122.

  The vibration detection means 11 is, for example, a vibration sensor, detects vibration of the structure, and acquires vibration waveform data from the structure. The vibration sensor is not particularly limited, and a known vibration sensor can be used. Specific examples include an acceleration sensor, a speed sensor, a displacement sensor, and the like. The acceleration sensor is preferably of a piezoelectric type and has a built-in signal amplification circuit. It is preferable that the vibration detection means 11 (vibration sensor) has high sensitivity and can detect signals in a wide frequency band. The vibration detection means 11 is installed in a structure, for example. The installation location on the structure is not particularly limited, and is installed at an appropriate location on the structure according to the application of the state determination device 10 as described later.

  The calculation means 12 performs calculation processing on the vibration waveform data acquired by the vibration detection means 11. The computing means 12 is, for example, a central processing unit (CPU), and a microcomputer can be used. As described above, the calculation unit 12 includes the approximate curve acquisition unit 121 and the determination unit 122. The approximate curve acquisition unit 121 acquires an approximate curve for the envelope of the vibration waveform data. The determination unit 122 determines the state of the structure on the basis of a threshold value provided for the difference between the approximate curve and the vibration waveform data. The threshold value may be set by the determination unit 122, for example, or a preset threshold value may be included in the determination unit 122. The acquisition of the approximate curve and the state determination of the structure will be described later.

  As shown in the flowchart of FIG. 2A, the structure state determination method of the present embodiment performs the following steps using the structure state determination apparatus of FIG.

  First, the vibration detection unit 11 detects the vibration of the structure that is the detection target, and acquires vibration waveform data (vibration detection step (step S110)).

  Next, the calculation means 12 performs calculation processing on the vibration waveform data acquired by the vibration detection means 11 (calculation step (step S120)). The calculation step S120 includes an approximate curve acquisition step (step S121) and a determination step (step S122).

  In the approximate curve acquisition step (S121), an approximate curve is acquired for the envelope of the vibration waveform data. The acquisition of the approximate curve will be described using the vibration waveform data shown in FIGS. When the vibration is measured by acceleration, for example, first, the maximum acceleration (A0, maximum vibration amplitude) 202 is extracted. Then, the acceleration time history data is differentiated with reference to the occurrence time of A0 (t = 0), and the acceleration (envelope acceleration) peak 201 (“◯” in FIGS. 10 and 11) when the polarity changes is obtained. Extract. Here, the envelope approximate curve 200 is calculated (defined) as, for example, y (t) = A0 × EXP (−σ × t) as time t and attenuation rate σ.

  Next, in the determination step (S122), a difference 203 between the approximate curve 200 of the envelope obtained in the approximate curve acquisition step and the measured acceleration peak 201 in the vibration waveform data is calculated, and a threshold value provided in the difference 203 The state of the structure is determined based on the above. The threshold value can be appropriately set according to the use of the state determination device. As described above, according to the present invention, it is not necessary to provide a sensor for each event to be detected as in the prior art, and one vibration detection unit 11 (for example, a vibration sensor) can be used for structures related to two or more events. The state (for example, breakage and unlocking of the glass) can be determined, and the apparatus and process can be simplified.

  The threshold value may be one or plural. FIG. 2B is a flowchart showing an example of the determination step S122 in FIG. In FIG. 2 (b), when the criterion by the threshold is met (Yes), it is determined as the state A, and when it does not meet the criterion (No), it is determined as the state B. As described above, according to the present invention, it is possible to separately determine the state A and the state B in which the distribution of the difference is different based on one threshold value in one vibration detection unit 11.

  The vibration waveform data acquired by the vibration detection means 11 may be analog vibration waveform data or digital vibration waveform data, for example. When the vibration waveform data is analog vibration waveform data, it is preferable that the state determination device of the present embodiment further includes unnecessary response removal means. FIG. 3 is a block diagram showing a configuration of the structure state determination apparatus according to the first modification of the first embodiment including the unnecessary response removing unit. FIG. 4 shows a flowchart of a structure state determination method according to the first modification. As shown in FIG. 3, the state determination device according to the first modification includes an unnecessary response removal unit 13 between the vibration detection unit 11 and the calculation unit 12. Except for this point, the state determination apparatus shown in FIG. 3 has the same configuration as the state determination apparatus 10 shown in FIG. Moreover, the state determination method of the modification 1 includes an unnecessary response removal step (S130) between the vibration detection step (S110) and the calculation step (S120). Except for this point, the state determination method shown in FIG. 4 has the same steps as the state determination method shown in FIG.

  The unnecessary response removing unit 13 is, for example, an unnecessary response removing filter (hereinafter, simply referred to as “filter”) that removes an unnecessary response from the analog vibration waveform data. The unnecessary response removing unit 13 only needs to remove the unnecessary response. Specifically, for example, a low-pass filter, a high-pass filter, a band-pass filter, or the like can be used, and can be appropriately selected according to the purpose. The pass frequency band of the unnecessary response removing unit 13 is not particularly limited, and is, for example, 10 Hz to 1 kHz. Thus, by narrowing the frequency band of the vibration waveform data, for example, the sampling frequency in analog-digital conversion described later can be reduced. Thereby, for example, a low-cost analog-to-digital converter (analog-to-digital conversion means) can be used, and power consumption can be reduced.

  Furthermore, in this modification, since the band of the vibration waveform data is narrowed by the unnecessary response removing unit 13, erroneous detection can be prevented. Therefore, for example, a digital filter used for avoiding erroneous detection is not required, and further, extraction of acceleration in a plurality of frequency components by Fourier transform processing and determination based on a threshold value are not required. As a result, in addition to being able to determine the state of the structure with a simple configuration, for example, a synergistic effect that a complicated calculation process is unnecessary is obtained.

  When the vibration waveform data is analog vibration waveform data, it is preferable that the state determination device of the present embodiment further includes analog-digital conversion means. FIG. 5 is a block diagram illustrating the configuration of the structure state determination apparatus according to the second modification of the first embodiment including the analog-digital conversion unit. FIG. 6 shows a flowchart of a structure state determination method according to the second modification. As shown in FIG. 5, the state determination device according to Modification 2 further includes an analog-digital conversion unit 14 between the unnecessary response removal unit 13 and the calculation unit 12 in the state determination device according to Modification 1. Except for this point, the state determination apparatus shown in FIG. 5 has the same configuration as the state determination apparatus shown in FIG. Further, the state determination method of Modification 2 includes an analog-digital conversion step (S140) between the unnecessary response removal step (S130) and the calculation step (S120) in the state determination method of Modification 1. Except for this point, the state determination method shown in FIG. 6 has the same steps as the state determination method shown in FIG.

  The analog-digital conversion means 14 is, for example, an analog-digital converter (A / D converter) that converts the analog vibration waveform data into digital vibration waveform data. The A / D converter is only required to convert the analog vibration waveform data into digital vibration waveform data, and for example, a known one can be used.

  According to the structure state determination apparatus and state determination method of Modification 2, in addition to being able to determine the state of the structure with a simple configuration, it is possible to improve detection accuracy and reduce false detection.

  The state determination device of the present embodiment (devices shown in FIGS. 1, 3, and 5) may further include a storage unit (memory), for example. The storage means stores, for example, the analog vibration waveform data and the digital vibration waveform data, the approximate curve of the envelope, the difference between the approximate curve and the vibration waveform data, the threshold value for the difference, and the like. The storage means is not particularly limited, and known ones can be used. Specifically, for example, random access memory (RAM), read-only memory (ROM), hard disk (HD), optical disk, floppy (registered trademark) For example, a disk (FD) is used. The storage means is an arbitrary component and may not be included, but is preferably included.

  The state determination device of the present embodiment (devices shown in FIGS. 1, 3, and 5) may further include, for example, a display for displaying the state determination result of the structure by the determination unit. The display device is not particularly limited, and a known one can be used. Specifically, for example, a speaker that outputs sound, a monitor that outputs images (for example, a liquid crystal display (LCD), a cathode ray tube (CRT) display, etc.) And various other types of image display devices) and printers that output by printing. The indicator is an optional component and may not be included, but is preferably included.

  The structure state determination device and the structure state determination method of the present embodiment can be applied to, for example, an intrusion detection device and an intrusion detection method. When applied to intrusion detection, the installation location on the structure may be, for example, a window frame, glass, door, floor surface, entrance door, gate, fence, wall surface, or the like. The threshold value is, for example, a threshold value for detecting entry into the structure from the outside, and the presence / absence of an entry action from outside to the building or the like is determined as the state of the structure. As the determination result, for example, the determination result of the destruction of the structure such as glass breakage or sash opening, the determination result of the presence or absence of unlocking, the presence or absence of human intrusion due to the vibration of the floor in the structure, etc. As a result, it is possible to obtain a determination result of the presence or absence of an actual intrusion act on the structure.

  The structure state determination device and the structure state determination method of the present embodiment can be applied to, for example, a water leakage detection device and a water leakage detection method. When applied to leakage detection, the installation location on the structure is, for example, a water pipe such as a water intake pipe, a conduit pipe, a water distribution pipe, a water supply pipe, a manhole, a fire hydrant, a water stop valve, a pressure reducing valve A water pressure meter or the like may be used. As for the installation location in the said water pipe, a water pipe wall surface, a flange bolt, etc. are mention | raise | lifted, for example. The threshold value is, for example, a threshold value for detecting an abnormality of the conduit pipe, and the presence / absence of an abnormality of the conduit pipe is determined as a state of the structure with reference to the threshold value. As said determination result, the determination result of the presence or absence of the leak of the said water conduit, the determination result of the presence or absence of the destruction of the said water conduit, etc. can be obtained, for example. For water pipes other than the water conduit, for example, the determination result of the presence or absence of water leakage, the determination result of the presence or absence of destruction, etc. can be obtained in the same manner as the water conduit.

  The structure state determination device and the structure state determination method of the present embodiment can be applied to, for example, a structure deterioration detection device and a structure deterioration detection method. When applied to structure deterioration detection, the installation location on the structure may be, for example, a wall of a building or a house, a pillar, a duct, a beam, a floor, a foundation portion, or the like. The threshold value is, for example, a threshold value for detecting deterioration of the structure, and the presence / absence of the deterioration of the structure is determined as the state of the structure. As the determination result, for example, a determination result of whether or not a joint portion such as a beam member of the structure is loosened, a determination result of the presence or absence of cracks in the work material constituting the structure, and the like can be obtained.

(Embodiment 2)
In the present embodiment, the threshold is provided for each of the states to be determined for the plurality of states, and the determination unit 122 determines the plurality of states of the structure on the basis of the threshold. Except for this point, the structure state determination apparatus of the present embodiment has the same configuration as the state determination apparatus 10 shown in FIG. FIG. 7 shows a flowchart of the structure state determination method in the present embodiment.

  In the determination step (S122), the state determination method of the present embodiment includes a step of determining whether or not a plurality of states meet a standard for each of the threshold values (two threshold values in the present embodiment). Yes. Except for this point, the structure state determination method of the present embodiment has the same steps as the state determination method shown in FIG. The difference between the approximate curve of the envelope obtained in the approximate curve acquisition step (S121) and the actually measured acceleration peak in the vibration waveform data is calculated. In determination 1 (step S122A), it is determined whether or not the criterion based on the first threshold is met. For example, in the case where the reference based on the first threshold value is satisfied (Yes), the state is determined as, for example, the state A. In determination 2 (S122B), it is determined whether or not the criterion based on the second threshold is met. If the second threshold value is met (Yes), for example, the state B is determined, and if the second threshold value is not met (No), for example, the process returns to the vibration detection step S110. In the determination 2, it is possible to further determine the state C when the second threshold value is not met. Further, in the determination 2, when the criterion based on the second threshold value is not met, the process can proceed to the determination step 3 based on the criterion based on another threshold value. The state determination method of the present embodiment can also include a step of displaying the determination result on the display.

  According to the state determination device and the state determination method of the structure of the second embodiment, a plurality of threshold values are provided for each state to be determined. Further, it can be determined with high accuracy.

(Embodiment 3)
In the structure state determination apparatus of the present embodiment, when the vibration detection means 11 in the block diagram of FIG. 1 exceeds a predetermined vibration amplitude, the acquisition of the vibration waveform data is started, and a predetermined maximum vibration amplitude is determined. The apparatus further includes means for acquiring at least the vibration waveform data until a time when the vibration amplitude becomes a ratio. Further, in the structure state determination method of the present embodiment, when the vibration detection step in the flowchart of FIG. 2 exceeds a predetermined vibration amplitude, acquisition of the vibration waveform data is started, and the predetermined maximum vibration amplitude is determined. The vibration waveform data is acquired until the time when the vibration amplitude becomes a ratio. The vibration amplitude of the predetermined ratio is, for example, a vibration amplitude that is ¼ to 1/15 of the maximum amplitude, and preferably a vibration amplitude that is 1/10 of the maximum amplitude.

  In the structure state determination apparatus and state determination method according to the third embodiment, as described above, when the vibration amplitude (trigger signal) defined in advance is exceeded, acquisition of the vibration waveform data is started. For this reason, for example, compared with the case where the said vibration waveform data is always acquired, power consumption can be reduced. In order to acquire the vibration waveform data in this way, for example, the vibration detection unit 11 may have a trigger function so as to start acquiring vibration waveform data when a predetermined vibration amplitude is exceeded. Moreover, the vibration detection means 11 may be comprised from a piezoelectric element and a preamplifier, for example. The value of the trigger signal may be determined in advance by actual measurement, for example.

  In the structure state determination apparatus and state determination method of Embodiment 3, the vibration waveform data is acquired until a time that is a predetermined multiple of A0. For this reason, it is possible to improve the determination accuracy by increasing the number of data points. Further, for example, the calculation processing time can be shortened as compared with the case where the vibration waveform data is acquired without dividing the time. Thereby, for example, it is possible to suppress the amount of data calculation necessary for the high accuracy determination. In addition, power required for calculation can be reduced. Furthermore, a low-priced and general-purpose type computing means (such as a microcomputer) can be applied.

(Embodiment 4)
In the structure state determination apparatus according to the present invention, for example, a terminal installed at a location distant from the installation location of the vibration detection unit may include the calculation unit. The block diagram of FIG. 8 shows the configuration of the state determination device of this embodiment. As shown in FIG. 8, the state determination device 20 according to the present embodiment includes a vibration detection unit 11, an unnecessary response removal unit 13, an analog-digital conversion unit 14, a terminal 21 including a calculation unit 12, and a display 22. And as a major component. The analog-digital conversion means 14 and the terminal 21 are connected by wire or wireless. The display device 22 is connected to the terminal 21.

  The terminal 21 includes the calculation unit in the first embodiment and performs the above-described calculation process. For example, the terminal 21 is installed at a location away from the installation location of the portion (vibration sensor unit) including the vibration detection unit 11, the unnecessary response removal unit 13 and the analog-digital conversion unit 14 in the state determination device 20. Specific examples of the terminal 21 include a personal computer (PC), a server, an alarm terminal, and a smartphone. The computing means may be in a server (cloud server) connected to the vibration sensor unit via a communication network, for example. In this case, the calculation means and the display 22 are connected via a communication network.

  In the state determination device 20, the terminal 21 includes the calculation unit, but the present invention is not limited to this example. The terminal in the state determination apparatus may include, for example, the unnecessary response removing unit, the analog-digital conversion unit, the storage unit, etc. in addition to the calculation unit. In the case of such a configuration, for example, the vibration detection unit, the calculation unit, the unnecessary response removal unit, the analog-digital conversion unit, and the storage unit including the storage unit may be wirelessly connected to each other. You may connect with. In addition, since the calculation means can be included in a terminal installed at a location away from the installation location of the vibration detection means, it is possible to select the configuration as appropriate according to the application.

(Embodiment 5)
Next, an example of intrusion detection (determination) using the state determination apparatus shown in FIG. 5 will be described based on the flowchart of FIG. Note that the state determination method of the present invention is not limited to this example.

  The state determination device includes a vibration sensor 11, a filter 13, an A / D converter 14, and a microcomputer 12. The vibration sensor 11 is installed in a structure such as a window frame or glass or a door, for example. As shown in the flowchart of FIG. 9, in this embodiment, in the vibration measurement standby state (step S <b> 1), vibration due to the intrusion action occurs, and this vibration exceeds a predetermined vibration amplitude (trigger signal). In the case (step S2), acquisition of analog vibration waveform data associated with the intrusion action is started (step S3). Here, steps S1 to S3 correspond to the above-described step S110. An unnecessary response is removed by the filter 13 with respect to the analog vibration waveform data acquired by the vibration sensor 11 (step S130, unnecessary response removal step). Examples of the unnecessary response include environmental vibration. As the filter 13, the above-described unnecessary response removal filter can be used. The analog vibration waveform data from which the unnecessary response has been removed is converted into digital vibration waveform data by the A / D converter 14 (step S140, analog-digital conversion step). Next, the approximate curve of the envelope of the digital vibration waveform data is acquired by the approximate curve acquisition means 121 of the microcomputer 12 (step S121, approximate curve acquisition step).

  Here, the approximate curve acquisition step (S121) will be described with reference to FIG. 10 and FIG. 11 by taking the case where the vibration is measured by an acceleration sensor. FIG. 10 is a graph showing the relationship between the vibration waveform data and the approximate curve of the envelope when sashing with a metal tool. FIG. 11 is a graph showing the relationship between the vibration waveform data at the time of unlocking and the approximate curve of the envelope. 10 and 11, the horizontal axis represents time (ms), and the vertical axis represents sensor output voltage (mV). As shown in FIGS. 10 and 11, first, the maximum acceleration (A0, maximum vibration amplitude) 202 is extracted (step S5). Then, the time history data of acceleration is differentiated with reference to the generation time of A0 (t = 0), and the acceleration (envelope acceleration) peak 201 (in FIGS. 10 and 11) when the polarity changes in the vibration waveform data. “O”) is extracted (step S6). The acceleration peak is acquired until time (t1) which is (1/10) times A0, and the measurement is terminated (step S7). Here, as the time t and the attenuation rate σ, the envelope approximate curve 200 is calculated (defined) as y (t) = A0 × EXP (−σ × t) (step S8). In FIG. 10, acceleration peaks having a negative sensor output voltage are not extracted, but positive acceleration peaks appearing after the next are extracted. This is because the maximum vibration amplitude appears as a positive value with respect to the base line (0 mV), and when an approximate curve of an envelope is calculated for the vibration waveform data, an approximate value is obtained for a negative acceleration peak. This is because it is difficult. As described above, when a negative acceleration peak appears, an approximate curve of the envelope may be calculated from the acceleration peak extracted before the negative acceleration peak appears.

  Next, a determination step (step S122) is performed. First, a difference 203 between the approximate curve 200 of the envelope obtained in the approximate curve acquisition step S121 and the actually measured acceleration peak 201 is calculated (step S9). Then, the difference 203 is determined based on whether or not the threshold value is met (steps S10 to S13). In this example, the determination means 122 is provided with a plurality of threshold values for each state to be determined. For example, as shown in FIG. 10, when a sash or glass breaks due to intrusion, a high frequency component is superimposed on a low frequency vibration component, so the difference becomes large and the distribution of vibration waveforms has a wide tail. Distribution. On the other hand, at the time of the unlocking action accompanying intrusion, the attenuation waveform of the low frequency component due to the crescent spring becomes prominent. For this reason, for example, as shown in FIG. 11, the difference at the time of the unlocking action is smaller than the difference at the time of the breaking action. Therefore, by setting the first threshold so as to include the distribution range of the difference at the time of the unlocking action, it is determined whether or not the obtained vibration waveform data is due to the unlocking action. be able to. Further, by setting a second threshold value so as to include the distribution range of the difference at the time of the vandalism, it is determined whether the obtained vibration waveform data is due to the vandalism. it can. It can be determined that the vibration waveform data that is out of range at any threshold is not caused by either the unlocking action or the breaking action. The threshold may be a range or a single value.

  In this example, based on whether or not the difference 203 is within a predetermined threshold value set in advance, the presence / absence of unlocking of the intrusion is determined (step S10, determination 1). In determination 1, the threshold for the difference (X%) is set to “X1% <X% <X2%”. And in determination 1, when it is in the range of the threshold (Yes, X1% <X% <X2%), it is determined that unlocking has been performed (step S11). On the other hand, if it is not within the threshold range in the determination 1 (No, X% ≦ X1% or X% ≧ X2%), the process proceeds to step S12, and a specified threshold value that is different from the threshold value set in the determination 1 Whether or not the sash is opened in the intruding action is determined based on whether or not it exceeds (step S12, determination 2). In determination 2, the threshold for the difference (X%) is set to “Y% or more (X% ≧ Y%)”. If it is within the range of the threshold (Yes, X% ≧ Y%), it is determined that the sash has been opened (step S13). On the other hand, when it is not within the range of the threshold (No, X% <Y%), the process returns to step S1. Thus, when the tendency of the distribution of the difference is remarkable depending on the action, for example, the threshold values in the determination 1 and the determination 2 can be set so that each action can be distinguished.

  Here, when it is determined in at least one of the determination 1 and the determination 2 that an intrusion act has been performed, for example, the result may be displayed on the display (not shown in FIG. 5). Further, for example, a threatening sound may be generated from a speaker (not shown in FIG. 5), and a warning company or user may be notified as necessary. Note that the sounding of a threatening sound from the speaker and the notification to the security company or the user can be in a known manner. For example, when only unlocking is performed, it is good also as a flow which returns to step S1 noting that it is entrance to a normal structure. In this case, it is good also as an aspect which returns to step S1 in the time slot | zone with which people usually go in and out, such as daytime, and performs notification about the specific time slot | zones, such as nighttime.

  Moreover, you may perform the state determination of the said structure based on the statistical distribution of a difference, and a correlation coefficient in addition to the determination based on the said threshold value, for example.

  As described above, according to the present embodiment, for example, a single vibration sensor can detect a plurality of intrusions according to the set number of thresholds, so that the hardware configuration of the detector can be simplified. The detector can be made inexpensive. Further, in the present embodiment, since the band of the vibration waveform data is narrowed by the filter 13, erroneous detection can be prevented. Therefore, for example, a digital filter used for avoiding erroneous detection is not necessary, and further, extraction of acceleration in a plurality of frequency components by Fourier transform processing and determination based on a threshold value are not necessary. As a result, according to the present embodiment, for example, a synergistic effect that a complicated calculation process is unnecessary is obtained. For this reason, when the vibration sensor (state determination device) of this embodiment is applied to the detection of a series of intrusion actions such as a breaking action, an unlocking action, a window opening action, etc., compared with a glass breakage detector of related technology. Intruders can be detected at an early stage. Furthermore, by acquiring the vibration waveform data until a time that is (1/10) times A0, it is possible to further suppress the amount of data calculation required for high-accuracy determination. In addition, the power required for the calculation can be further reduced. Furthermore, a low-priced and general-purpose type computing means (such as a microcomputer) can be applied.

  In addition, in this embodiment, although the specific example specialized in intrusion detection was demonstrated, according to this, also about other state detections, such as a water leak detection and a structure deterioration detection, a water leak detection and a structure deterioration detection It can be applied by setting a threshold value according to the above.

[Example 1]
This embodiment is an example of determination of an intrusion action when a sash is hit using a metal tool (driver) (sash peg opening action, action B) and crescent unlocking action (action A) is performed. It is.

(1) Preparation and Installation of Intrusion Detection Device In this example, an intrusion detection device having the following configuration was prepared. As the vibration sensor, a piezoelectric acceleration sensor incorporating a signal amplification circuit was used. As the filter, a band pass filter having a pass frequency band of 10 Hz to 1 kHz was used. The microcomputer used was one having an analog-digital processing bit number of 12 bits and a sampling frequency of 50 kHz. This filter and the microcomputer were mounted on the same substrate. This substrate and the vibration sensor were electrically connected by cable wiring. In this way, an intrusion detection device was configured.

  As the sash, an aluminum sash was used. The dimensions of the sash were about 1700 mm in length: about 1700 mm in width. The vibration sensor was affixed around the crescent with an adhesive, and the intrusion detection device of this example was installed.

(2) Determination of intrusion action The intrusion detection apparatus acquired vibration waveform data for the hitting action and the unlocking action. The graph of FIG. 10 shows digital vibration waveform data of the hitting action. The digital vibration waveform data of the unlocking action is shown in the graph of FIG. Then, with respect to both actions, the acceleration time history data is differentiated with respect to the generation time of the maximum acceleration A0 (202) as a reference (t = 0), and the acceleration (envelope acceleration) peak 201 when the polarity changes is extracted. Then, an approximate curve 200 of the envelope of y (t) = A0 × EXP (−σ × t) was calculated. The acquisition of the vibration waveform data was finished when the acceleration peak 201 became 10% or less of A0 (202).

  Next, a difference 203 between the actually measured acceleration peak 201 and the approximate value of the approximate curve 200 of the envelope was calculated for both the actions. For this difference 203, the ratio (%) to the approximate value was obtained. As a result, regarding the batting action, the extracted acceleration peak 201 has a total of 14 points (“◯” in FIG. 10), and the ratio of the difference 203 is about 4% to 95%. On the other hand, regarding the unlocking action, the extracted acceleration peak 201 has a total of 5 points (“◯” in FIG. 11), and the ratio of the difference 203 was 6% to 15%. From these results, for example, as shown in Table 1 below, a threshold value where the ratio (r) is 10% to 15% (10% ≦ r ≦ 15%) is set as the threshold value for the unlocking action, A threshold value at which the ratio (r) is 30% or more (30% ≦ r) is set as the threshold value for the batting action. By doing in this way, if the ratio r (%) of the difference 203 is 10% to 15%, it can be determined that it is the unlocking action (act A: Yes), and the ratio r (%) of the difference 203 is If it is 30% or more, it can be determined that it is the hitting action (action B: Yes), and it can be determined by distinguishing the presence or absence of both actions.

[Example 2]
In this example, the determination of water pipe leakage detection and water pipe breakage detection was performed by a simulation experiment system assuming an actual water pipe.

(1) Preparation and Installation of Water Leakage Detection Device In this example, a water leak detection device having the same configuration as the intrusion detection device used in Example 1 was used. In this water leakage detection device, the applied frequency band of the filter, the sampling frequency of the microcomputer, and the number of analog-digital conversion processing bits of the A / D converter were set to the same conditions as in the first embodiment.

  The simulation experiment system was composed of a steel water pipe and a pump. The water pipe having a diameter of about 5 mm and a total length of about 4 m was used. A pump that is a water supply source was installed in this water pipe. In order to generate a water leakage phenomenon in this simulation experiment system, a plurality of holes were made in advance at a position about 1 m away from the location of the pump in the water pipe, and these holes were closed with a resin cap. And the said vibration sensor was adhesively fixed to the position about 2 m away from the installation location of the said pump in the said water pipe.

(2) Determination of abnormality of water pipe Water was poured into this water pipe at a rate of 400 mL per minute from the pump. And the state which removed the said resin cap and generated the water leak from the water pipe was defined as the state which the simulated water leak phenomenon generate | occur | produced. Further, a state where the surface of the water pipe was slightly plastically deformed by hitting the water pipe with a metal hammer was defined as a state in which a pseudo destruction phenomenon occurred.

  Vibration waveform data was acquired for the water leakage phenomenon and the destruction phenomenon by the water leakage detection device in the same manner as in Example 1. The graph of FIG. 12 shows digital vibration waveform data when the water leakage phenomenon occurs. The graph of FIG. 13 shows digital vibration waveform data when the destruction phenomenon occurs. In the same manner as in Example 1, the maximum acceleration A0 and the approximate curve of the envelope were calculated for both phenomena. Furthermore, the difference between the measured acceleration peak and the approximate value in the approximate curve of the envelope was calculated for both phenomena. For this difference, a ratio (%) to the approximate value was obtained. As a result, regarding the destruction phenomenon, the extracted acceleration peak score was 9 points (“◯” in FIG. 13), and the difference ratio was about 15% to 47%. On the other hand, regarding the water leakage phenomenon, the extracted acceleration peak score was 6 points (“◯” in FIG. 12), and the difference ratio was 5% to 76%. From these results, for example, a threshold value where the ratio (r) is 15% to 47% (15% ≦ r ≦ 47%) is set as the threshold value of the destruction phenomenon, and the ratio (r) is 50% or more. A threshold value that is (50% ≦ r) is set as the threshold value for the water leakage phenomenon. In this way, if the difference ratio r (%) is 15% to 47%, it can be determined that the destruction phenomenon has occurred, and if the difference ratio r (%) is 50% or more. Therefore, it can be determined that the water leakage phenomenon has occurred, and the presence or absence of the occurrence of both phenomena can be distinguished and determined.

[Example 3]
In this example, the determination of deterioration detection of a building or a structure such as a building was performed by a simulation experiment system assuming an actual building.

(1) Preparation and Installation of Structure Deterioration Detection Device In this example, a structure deterioration detection device having the same configuration as the intrusion detection device used in Example 1 was used. In this structure deterioration detection apparatus, the applied frequency band of the filter, the sampling frequency of the microcomputer, and the number of analog-digital conversion processing bits of the A / D converter were set to the same conditions as in the first embodiment.

  As the simulation experiment system, an 8-story small building having a length of 30 cm, a width of 30 cm, and a height of 40 cm was used. In the building, each level was connected with a plurality of beams. The vibration sensor was bonded and fixed to the beam material.

(2) Judgment of deterioration of structure The deterioration mode of the said building assumed the joint strength deterioration by the time-dependent change of the joining location of a beam material. For this reason, the present Example was performed in the state which loosened the joint location of the predetermined beam material intentionally. In this state, each beam member was hit with a metal hammer, and an excitation force was applied. In the same manner as in the first embodiment, the structure deterioration detection device applies the excitation force in a normal state where the coupling strength is not deteriorated and in a pseudo building deterioration state where the coupling strength is deteriorated. Vibration response data (vibration waveform data) was obtained. The graph of FIG. 14 shows digital vibration waveform data in the normal state. The graph of FIG. 15 shows digital vibration waveform data in the building deterioration state. In the same manner as in Example 1, the maximum acceleration A0 and the approximate curve of the envelope were calculated for the two states. Furthermore, the difference between the measured acceleration peak and the approximate value in the approximate curve of the envelope was calculated for both states. For this difference, a ratio (%) to the approximate value was obtained. As a result, in the normal state, the extracted acceleration peaks were 4 points in total (“◯” in FIG. 14), and the difference ratio was about 1% to 11%. On the other hand, regarding the building deterioration state, the extracted acceleration peak score was 5 points (“◯” in FIG. 15), and the difference ratio was 11% to 54%. From these results, for example, a threshold value in which the ratio (r) is 1% to 11% (1% ≦ r ≦ 11%) is set as the normal state threshold value, and the ratio (r) is 30% or more. A threshold value (30% ≦ r) is set as the threshold value of the building deterioration state. By doing in this way, if the difference ratio r (%) is 1% to 11%, it can be determined that the normal state, and if the difference ratio r (%) is 30% or more, the building It can be determined that the state is deteriorated, and the two states can be distinguished and determined.

  Although the present invention has been described with reference to the exemplary embodiments and examples, the present invention is not limited to the above exemplary embodiments and examples. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

  This application claims the priority on the basis of Japanese application Japanese Patent Application No. 2012-139236 for which it applied on June 20, 2012, and takes in those the indications of all here.

  ADVANTAGE OF THE INVENTION According to this invention, the structure state determination apparatus and structure state determination method which can determine the state of a structure with simple structure can be provided. The structure state determination device and the structure state determination method of the present invention include, for example, detection of intrusion to a structure from the outside, detection of water leakage or water pipe breakage in a water pipe system of a social infrastructure business, building or residence It can be applied to the detection of deterioration of structures such as oil leaks or pipeline breakage detection in oil pipeline systems, gas leak detection or pipeline breakage detection in gas pipelines, etc.

10, 20 Structural state determination device 11 Vibration detection means (vibration sensor)
12 Calculation means (microcomputer)
13 Unnecessary response removal means (filter)
14 Analog-digital conversion means (A / D converter)
21 Terminal 22 Display 121 Approximate Curve Acquisition Unit 122 Judgment Unit 200 Envelope Approximate Curve 201 Measured Acceleration Peak 202 Maximum Acceleration (A0)
203 Difference between the approximate curve 200 of the envelope and the actually measured acceleration peak 201

1 Glass Breaking Detection Unit 2 Open / Close Detection Unit 3 CPU
4 Output unit 6 Clock unit 7 Power supply unit 1a Vibration sensor unit 1b Amplification unit 1c Vibration analysis unit 2a Reed switch 2b Magnet

Claims (26)

Vibration detection means for detecting the vibration of the structure, and calculation means for performing calculation processing on the vibration waveform data acquired by the vibration detection means,
The calculating means determines an approximate curve obtaining means for obtaining an approximate curve for an envelope of the vibration waveform data, and determines a state of the structure based on a threshold provided for a difference between the approximate curve and the vibration waveform data. A structure state determination device including a determination unit. For the plurality of states, the threshold is provided for each state to be determined,
The structure determination apparatus according to claim 1, wherein the determination unit determines the plurality of states of the structure based on the threshold value. When the vibration detection unit exceeds a predetermined vibration amplitude, the vibration detection unit starts acquiring the vibration waveform data,
And the vibration waveform data is acquired until the time when the vibration amplitude becomes a predetermined ratio of the maximum vibration amplitude,
The state determination apparatus for a structure according to claim 1 or 2. The state determination device for a structure according to claim 3, wherein the vibration detection means acquires the vibration waveform data until a time when the vibration amplitude becomes 1/4 to 1/15 of the maximum vibration amplitude. The vibration waveform data is analog vibration waveform data,
Furthermore, the structure state determination apparatus as described in any one of Claim 1 to 4 including the unnecessary response removal means for removing an unnecessary response about the said analog vibration waveform data. The vibration waveform data is analog vibration waveform data,
Furthermore, the structure state determination apparatus according to any one of claims 1 to 5, further comprising analog-digital conversion means for converting the analog vibration waveform data into digital vibration waveform data. Including the state determination device for a structure according to any one of claims 1 to 6,
In the determination means, the threshold value is a threshold value for detecting entry into the structure from outside,
An intrusion detection apparatus that determines an intrusion action to the structure from the outside based on the threshold value. The intrusion detection device according to claim 7, wherein the determination of the intrusion action from the outside is at least one of a destruction action of the structure and an actual intrusion action into the structure. The determination means further includes a threshold value for determining a destructive action on the structure and a threshold value for determining an unlocking action of the structure,
The intrusion detection device according to claim 8, wherein a determination is made by distinguishing a breaking action on the structure and an unlocking action of the structure on the basis of the threshold value. Including the state determination device for a structure according to any one of claims 1 to 6,
In the determination means, the threshold value is a threshold value for detecting an abnormality of a water pipe,
A water leakage detection device for determining an abnormality of a water pipe with reference to the threshold value. The water leakage detection device according to claim 10, wherein the determination of abnormality of the water pipe is determination of at least one of leakage from the water pipe and destruction of the water pipe. The determination means further includes a threshold for determining water leakage from the water pipe and a threshold for determining breakage of the water pipe,
The water leakage detection device according to claim 11, wherein water leakage from the water pipe and destruction of the water pipe are distinguished and determined based on the threshold value. Including the state determination device for a structure according to any one of claims 1 to 6,
In the determination means, the threshold value is a threshold value for detecting deterioration of the structure,
A structure deterioration detection apparatus that determines deterioration of a structure with reference to the threshold value. Including a vibration detection step for detecting the vibration of the structure, and a calculation step for performing calculation processing on the vibration waveform data acquired in the vibration detection step,
In the calculation step, an approximate curve acquisition step for acquiring an approximate curve for an envelope of the vibration waveform data, and a state of the structure is determined based on a threshold value provided for a difference between the approximate curve and the vibration waveform data. A structure state determination method including a determination step. The structure determination method according to claim 14, wherein, in the determination step, the state of the structure is determined based on the threshold value provided for each state to be determined for a plurality of states. In the vibration detection step, when the vibration amplitude defined in advance is exceeded, acquisition of the vibration waveform data is started,
16. The state determination method for a structure according to claim 14 or 15, wherein the vibration waveform data is acquired until a time when the vibration amplitude becomes a predetermined ratio of the maximum vibration amplitude. The structure determination method according to claim 16, wherein in the vibration detection step, the vibration waveform data is acquired until a time when the vibration amplitude is ¼ to 1/15 of the maximum vibration amplitude. The vibration waveform data is analog vibration waveform data,
Furthermore, the structure state determination method as described in any one of Claims 14-17 including the unnecessary response removal process for removing an unnecessary response about the said analog vibration waveform data. The vibration waveform data is analog vibration waveform data,
The method for determining a state of a structure according to any one of claims 14 to 18, further comprising an analog-digital conversion step for converting the analog vibration waveform data into digital vibration waveform data. A method for determining the state of a structure according to any one of claims 14 to 19,
In the determination step, the threshold is a threshold for detecting entry into the structure from outside,
An intrusion detection method for determining an intrusion action to the structure from the outside based on the threshold value. 21. The intrusion detection method according to claim 20, wherein the determination of the intrusion action from the outside is determination of at least one of a destruction action of the structure and an actual intrusion action into the structure. The determination step further includes a threshold value for determining a destructive action for the structure and a threshold value for determining an unlocking action for the structure,
The intrusion detection method according to claim 21, wherein a determination is made by distinguishing a destructive action on the structure and an unlocking action of the structure on the basis of the threshold value. A method for determining the state of a structure according to any one of claims 14 to 19,
In the determination step, the threshold is a threshold for detecting an abnormality of a water pipe,
A water leakage detection method for determining an abnormality of a water pipe on the basis of the threshold value. The water leakage detection method according to claim 23, wherein the determination of abnormality of the water pipe is determination of at least one of water leakage from the water pipe and destruction of the water pipe. In the determination step, further includes a threshold value for determining leakage of water from the water pipe and a threshold value for determining destruction of the water pipe,
25. The water leakage detection method according to claim 24, wherein leakage determination from the water pipe and destruction of the water pipe are distinguished from each other based on the threshold value. A method for determining the state of a structure according to any one of claims 14 to 19,
In the determination step, the threshold is a threshold for detecting deterioration of the structure,
A structure deterioration detection method for determining deterioration of a structure based on the threshold value.

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