JP2018146370A - Soil monitoring device, soil monitoring system, and method for monitoring soil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device, a system, and a method for monitoring the state of soil, the device and the system having a smaller size and requiring lower cost and power consumption.SOLUTION: The present invention includes: an elastic body buried under the ground; an actuator for vibrating the elastic body; and a sensor for measuring the vibration. Measuring a propagation parameter of the vibration applied in the elastic body by the actuator leads to the determination of the state of soil.SELECTED DRAWING: Figure 1

Description

The present invention mainly relates to an apparatus, system and method for monitoring soil conditions.

  In fields such as civil engineering, architecture, and agriculture, it may be necessary to monitor and diagnose soil conditions. Especially on slopes with villages, roads and tracks in the vicinity, it is desirable to constantly monitor the soil condition in order to detect the danger of collapse. Many methods have been proposed to detect and predict slope failures. Patent Literature 1 discloses a method for generating vibration in the ground by a vibration generator and estimating the strength of the ground from the propagation speed as a ground strength analysis method. However, since these methods need to generate vibrations on the ground, the apparatus becomes large and expensive.

JP-A-9-178863

  This invention is made | formed in view of the above situations, and it aims at providing the soil monitoring apparatus, system, and method which can implement | achieve the small size and low cost of an apparatus.

  The soil monitoring apparatus of the present invention is embedded in an elastic body embedded in soil, a first vibration sensor that acquires vibration data of the elastic body, and is embedded in a position away from the elastic body, and acquires vibration data of the soil. A determination unit that determines the state of the soil based on a second vibration sensor, vibration data acquired by the first vibration sensor, and vibration data acquired by the second vibration sensor.

  The soil monitoring system of the present invention includes at least one soil monitoring device and a soil state evaluation device that detects the state of the soil, and the monitoring device includes an elastic body embedded in the soil and vibration data of the elastic body. A first vibration sensor for acquiring vibration data, a second vibration sensor embedded in a position away from the elastic body and acquiring vibration data of the soil, vibration data acquired by the first vibration sensor, and the second A determination unit for determining the state of the soil based on vibration data acquired by a vibration sensor, the soil detection device acquiring a determination result of the soil monitoring device, and the determination result A prediction unit for predicting a sediment disaster is provided based on the determination result acquired by the acquisition unit.

  The soil monitoring method of the present invention acquires vibration data of an elastic body, acquires vibration data of the soil, and determines the state of the soil based on the vibration data of the elastic body and the vibration data of the soil. .

  According to the soil monitoring apparatus etc. concerning this invention, it is possible to provide the soil monitoring apparatus which can implement | achieve small size and low cost.

It is a figure which shows the structure of the soil monitoring apparatus in the 1st Embodiment of this invention. It is the flowchart which showed the method of the state evaluation of the soil in the 1st Embodiment of this invention. It is a figure which shows the structure of the soil monitoring apparatus in the 2nd Embodiment of this invention. It is the flowchart which showed the method of the state evaluation of the soil in the 2nd Embodiment of this invention. It is the figure which illustrated the frequency spectrum in the 2nd Embodiment of this invention. It is a figure which shows the structure of the soil monitoring apparatus in the 3rd Embodiment of this invention. It is the flowchart which showed the method of the state evaluation of the soil in the 3rd Embodiment of this invention. It is a figure which shows the structure of the soil monitoring apparatus in the 4th Embodiment of this invention.

<First Embodiment>
The structure of the soil monitoring system 1 in the 1st Embodiment of this invention is demonstrated with reference to FIG. FIG. 1 shows a soil monitoring system according to the present embodiment. The soil monitoring system 1 includes a soil monitoring device 10 and a sediment disaster prediction device (not shown).

  The soil monitoring apparatus 10 includes an elastic body 102, an actuator 103, an acceleration sensor 104, an actuator drive circuit 105, a sensor signal analysis unit 106, and a soil condition evaluation unit 107. Here, in FIG. 1, the soil monitoring device 10 is disclosed as one, but the soil monitoring system 1 may include a plurality of soil monitoring devices 10.

  The earth and sand disaster prediction device is connected to the soil monitoring device 10. Moreover, the earth and sand disaster prediction apparatus predicts the earth and sand disaster based on the soil state detected by the soil monitoring apparatus 10. The earth and sand disaster prediction device can know the state distribution of the soil in the range from the soil state determined by the plurality of soil monitoring devices 10 arranged in a certain range. By comprehensively judging the soil state distribution and its temporal change, it is possible to predict with high accuracy the possibility of soil disasters such as slope failures and temporal disaster probability changes in the area and its vicinity. It becomes possible.

  The elastic body 102 is embedded in the soil 101. Here, the elastic body 102 may be made of stainless steel, stainless steel, or the like. The embedding of the elastic body 102 may be performed vertically with respect to the soil regardless of the direction, or may be embedded in the soil horizontally. Moreover, it is not limited to the depth. The shape of the elastic body 102 is a cylinder, the diameter is 5 mm, and the length is 30 cm. The elastic body 102 is not particularly limited to a cylinder, and may be a quadrangular prism, a triangular prism, or the like.

  The actuator 103 is provided on the elastic body 102 and uses a piezoelectric element. The actuator 103 is connected to an actuator drive circuit 105 that drives the actuator 103. In this embodiment, the actuator 103 uses a piezoelectric element, but a solenoid actuator using an electromagnet, a giant magnetostrictive element, or the like may be used. Moreover, it is good also as a structure provided with two or more actuators 103. FIG. The actuator 103 may be disposed at a position (separated) from the elastic body 102. That is, the elastic body 102 may be disposed anywhere as long as it is a position where vibration is applied. The actuator 103 may be provided with a damping material (not shown) such as rubber so that its mass does not affect the vibration.

  The acceleration sensor 104 is provided on the elastic body 102 and is connected to the sensor signal analysis unit 106. Although one actuator 103 and one acceleration sensor 104 are used, the function of the actuator and the function of vibration sensing can be realized by one piezoelectric element. Note that this case can be dealt with by measuring the intensity difference or time difference between the first reflected wave and the second reflected wave. Moreover, it is good also as a structure provided with two or more acceleration sensors 104. FIG.

  The actuator drive circuit 105 transmits a pulse signal that drives the actuator 103. The actuator drive circuit 105 is connected to the soil condition evaluation unit 107. Here, the actuator drive circuit 105 may be configured to transmit a pulse signal for driving the actuator 103 based on the control timing and the control period stored in advance.

  The sensor signal analysis unit 106 acquires a signal from the acceleration sensor 104 and analyzes the acquired signal. The sensor signal analysis unit 106 is connected to the soil condition evaluation unit 107. The sensor signal analysis unit 106 may be configured using a circuit, or may be configured to perform signal processing and analysis by taking data into a computer such as a PC (Personal Computer).

  The soil state evaluation unit 107 controls the actuator drive circuit 105 to drive the actuator 103. In addition, the soil state evaluation unit 107 determines the state of the soil 101 based on the signal analyzed by the sensor signal analysis unit 106. The soil condition evaluation unit 107 may be configured using a circuit, or may be configured to perform signal processing and analysis by taking data into a computer such as a PC. The soil state evaluation unit corresponds to a determination unit on the claims.

  A method for evaluating the state of the soil 101 according to this embodiment will be described below with reference to FIG. FIG. 2 is a flowchart showing a method for evaluating the state of the soil 101 in the first embodiment.

  In step S11, the drive circuit 105 sends a pulse signal for causing the actuator 103 to generate vibration. The actuator 103 is driven by the pulse signal, causes the elastic body 102 to generate a pulse-like vibration, and proceeds to step S12.

  Next, in step S12, the acceleration sensor 104 detects vibration generated in the elastic body 102, and proceeds to step S13. Here, the vibration generated in the elastic body 102 propagates through the elastic body 102 in the length direction, is reflected at one end, propagates through the elastic body 102 again, reaches the acceleration sensor 104, and is detected.

  Next, in step S13, the sensor signal analysis unit 106 calculates a ratio between the magnitude of the vibration first detected by the acceleration sensor 104 and the magnitude of the vibration of the reflected wave detected by the acceleration sensor 104, and then proceeds to step S14. move on. Here, the ratio of the magnitudes of vibration changes depending on the attenuation rate when the vibration propagates through the elastic body 102. In addition, the vibration attenuation rate varies depending on the characteristics of the surrounding soil. The sensor signal analysis unit 106 is configured to calculate the change in the attenuation rate of the vibration propagating through the elastic body 102. It is good also as a structure which measures, and it is good also as a structure which measures multiple among these. The sensor signal analysis unit 106 measures the attenuation rate of the sensor signal. However, the sensor signal analysis unit 106 may perform Fourier transform on the obtained signal to see a change in attenuation for each frequency. In addition, the sensor signal analysis unit 106 may mathematically analyze the obtained sensor signal, for example, perform wavelet transform, and calculate the velocity for each frequency.

  Next, in step S14, the soil condition evaluation unit 107 estimates the condition of the soil based on the vibration attenuation rate, and ends the flow. In the estimation method shown on the left, when the soil is hard and the vibration propagation speed in the soil is high, the attenuation rate increases. Conversely, when the soil is soft and the vibration propagation speed in the soil is slow, the attenuation ratio is small. Due to becoming.

  As mentioned above, in this embodiment, size reduction of a soil monitoring apparatus and a soil monitoring system is realizable by calculating the damping factor of an elastic body based on the reciprocation of the vibration of an elastic body.

<Second Embodiment>
The frequency spectrum of the vibration generated in the acceleration sensor embedded in the soil varies depending on the installation location and the installation location. That is, the frequency spectrum of vibration depends on the state around the installed acceleration sensor. Therefore, the frequency spectrum corresponding to the frequency band unique to the elastic body cannot always be confirmed stably. Specifically, since the frequency spectrum of vibration generated in the acceleration sensor embedded in the soil is a frequency spectrum including other adjacent frequency spectra, the other frequency spectrum is erroneously detected as the frequency spectrum of the elastic body. There is a possibility. Therefore, in 1st Embodiment, the vibration resulting from soils other than an elastic body may be variously superimposed, and it may be unable to measure stably. In this embodiment, in view of the problem on the left, an object is to implement stable soil condition monitoring regardless of the condition of the soil.

The structure of the soil monitoring system 2 in the 2nd Embodiment of this invention is demonstrated with reference to FIG. In addition, the same code | symbol is attached | subjected to the component equivalent to 1st Embodiment, and description is abbreviate | omitted.
FIG. 3 is a diagram illustrating a configuration of the soil monitoring system 2.

  The soil monitoring system 2 includes a soil monitoring device 20 and a sediment disaster prediction device (not shown).

  The soil monitoring apparatus 20 includes an elastic body 102, an acceleration sensor 104 that is a first vibration sensor in the claims, an acceleration sensor 204 that is a second vibration sensor in the claims, and a determination unit 200. Here, in FIG. 3, the soil monitoring device 20 is disclosed as one, but the soil monitoring system 2 may include a plurality of soil monitoring devices 20.

  The determination unit 200 includes a sensor signal analysis unit 106, a sensor analysis unit 206, and a soil condition evaluation unit 207.

  The acceleration sensor 204 is embedded in the ground and is disposed at a position not affected by the vibration of the elastic body 102. That is, the acceleration sensor 204 is embedded in the ground at a position separated (separated) from the elastic body 102. In particular, it is not necessary to be limited to the left configuration, and the acceleration sensor 204 may be installed at a position where the sensitivity to the vibration of the elastic body 102 is lower than that of the acceleration sensor 104.

  The sensor signal analysis unit 206 acquires a signal from the acceleration sensor 204 and analyzes the acquired signal. The sensor signal analysis unit 206 is connected to the soil condition evaluation unit 207. The sensor signal analysis unit 206 may be configured using a circuit, or may be configured to perform signal processing and analysis by taking data into a computer such as a PC (Personal Computer).

  The soil state evaluation unit 207 determines the state of the soil 101 based on the signal analyzed by the sensor signal analysis unit 106 and the signal analyzed by the sensor analysis unit 206. The soil condition evaluation unit 207 may be configured using a circuit, or may be configured to perform signal processing and analysis by taking data into a computer such as a PC.

  A method for evaluating the state of the soil 101 in this embodiment will be described below with reference to FIGS. FIG. 4 is a flowchart showing a method for evaluating the state of the soil 101 in the second embodiment. FIG. 5 is a diagram illustrating a specific example of a frequency spectrum of vibration in the second embodiment.

  In step S21, the acceleration sensor 104 detects vibration generated in the elastic body 102 due to rain or the like. Moreover, the acceleration sensor 204 detects the vibration which has generate | occur | produced in the soil 101 by rain etc., and progresses to step S22. Here, the vibration generated in the elastic body 102 is a vibration that is generated in the soil 101 due to rainfall or the like and immediately propagates through the elastic body 102. The vibration generated in the elastic body 102 vibrates in a specific vibration mode determined from the dimensions and material characteristics of the elastic body 102. Here, the vibration mode refers to the appearance of vibration in an object (in this embodiment, the elastic body 102) that vibrates at a natural frequency. The distribution of vibration amplitude nodes and antinode positions is determined by the object. It refers to a unique state. A plurality of inherent vibration modes are generated in the elastic body 102. In the present embodiment, the vibration mode can be selected and set according to the frequency band to be monitored from among a plurality of unique vibration modes. Examples of the vibration mode include an S (Symmetric) mode, an A (Anti-symmetrical) mode, a bending mode that vibrates in the presence of one belly, and an expansion and contraction mode that is a vibration that expands and contracts. The vibration mode to be monitored depends on the sampling frequency to be measured. Therefore, if the inherent vibration mode is a higher-order vibration mode, it is necessary to increase the sampling frequency for measurement. Further, the higher the frequency band of any frequency band, the greater the distance attenuation, and the smaller the amplitude. On the contrary, the distance attenuation becomes smaller as an arbitrary frequency band is lower, so that the amplitude becomes larger. In order to suppress the power consumption and cost of the apparatus, it is possible to adopt a configuration in which measurement is performed while paying attention to a bending mode that is a low-order vibration mode.

  Next, in step S <b> 22, the sensor signal analysis unit 106 acquires a first frequency spectrum based on the vibration data detected by the acceleration sensor 104. Specifically, the sensor signal analysis unit 106 acquires a first frequency spectrum as shown in FIG. Here, the horizontal axis of FIGS. 5A, 5B, and 5C represents the frequency, and the vertical axis represents the acceleration sensor output. FIG. 5A shows a state in which the frequency spectrum unique to the acceleration sensor 104 attached to the elastic body 102 is confused with the frequency spectrum caused by the surrounding soil and the surrounding environment where the elastic body 102 is installed. For this reason, in FIG. 5A, since spectrum peaks of various frequencies are generated, it is difficult to confirm only the frequency spectrum unique to the elastic body 102. The sensor signal analysis unit 206 acquires the second frequency spectrum based on the vibration data detected by the acceleration sensor 204. Specifically, a frequency spectrum as shown in FIG. FIG. 5B shows a spectrum peak of a frequency caused by the soil around the acceleration sensor 204 installed in the proximity position of the elastic body 102 and the surrounding environment. A known method can be adopted as a method of acquiring the frequency spectrum. Specifically, the frequency spectrum acquisition method can obtain the frequency spectrum by calculating the intensity for each frequency using Fourier transform. Next, the soil condition evaluation unit 207 uses the first frequency spectrum obtained by the sensor signal analysis unit 106 and the second frequency spectrum obtained by the sensor signal analysis unit 206 to use the first frequency spectrum and the second frequency spectrum. The third frequency spectrum that is the difference between the two is calculated, and the process proceeds to step S23. Specifically, as shown in FIG. 5C, the third frequency spectrum is a frequency spectrum that is a difference between the acceleration sensor outputs of FIG. 5A and FIG. 5B. The soil state evaluation unit 207 can remove the frequency spectrum caused by the state around the soil by taking the difference of the frequency spectrum of FIG. 5B from the spectrum of FIG. The resulting frequency spectrum can be canceled (cancelled), and only the frequency spectrum specific to the elastic body 102 to be monitored can be clarified.

  Next, in step S23, the soil state evaluation unit 207 calculates a change in the attenuation of the frequency of the spectrum peak of the third frequency spectrum, which is the obtained difference. The soil state evaluation unit 207 calculates the vibration attenuation rate based on the obtained change in attenuation, and proceeds to step S24. Here, the spectrum peak of the third frequency spectrum is a spectrum peak corresponding to the inherent vibration mode. The attenuation rate calculated based on the spectrum peak corresponding to the inherent vibration mode varies depending on the soil characteristics around the elastic body 102.

  Next, in step S24, the soil state evaluation unit 207 estimates the state of the soil based on the vibration attenuation rate, and ends the flow. Specifically, when the vibration attenuation rate is large, the soil state evaluation unit 207 determines that the amount of water is relatively low because the soil is hard and the vibration propagation speed in the soil is high. Conversely, when the vibration attenuation rate is large, the soil condition evaluation unit 207 determines that the amount of water is relatively high because the soil is soft and the vibration propagation speed in the soil is slow. Here, the soil state determination unit 207 may be configured to determine the moisture content of the soil based on the contrast relationship between the vibration attenuation rate and the moisture content stored in advance. Furthermore, the soil state evaluation unit 207 may be configured to determine what state the soil is in according to the amount of moisture.

  As described above, in the present embodiment, since only the frequency spectrum unique to the elastic body is clarified and the vibration attenuation rate corresponding to the natural mode is calculated, the state of the soil can be detected more accurately.

<Third Embodiment>
The structure of the soil monitoring system 3 in the 3rd Embodiment of this invention is demonstrated with reference to FIG. Here, the same reference numerals are given to the same components as those in the above-described embodiment, and the description thereof will be omitted. Here, FIG. 6 is a diagram showing a configuration of the soil monitoring system 3. As shown in FIG.

  The soil monitoring system 3 includes a soil monitoring device 30 and a sediment disaster prediction device (not shown).

  The soil monitoring apparatus 30 includes an elastic body 102, an actuator 103 that is a first vibration unit in the claims, an acceleration sensor 104, an acceleration sensor 204, an actuator 303 that is a second vibration unit in the claims, and a determination unit 300. . Here, in FIG. 6, the soil monitoring device 30 is disclosed as one, but the soil monitoring system 3 may be configured to include a plurality of soil monitoring devices 30.

  The determination unit 300 includes a sensor signal analysis unit 106, a sensor analysis unit 206, an actuator drive circuit 305, and a soil condition evaluation unit 307.

  The actuator 303 is provided in the acceleration sensor 204 and uses a piezoelectric element. The actuator 303 is connected to the actuator drive circuit 305. In this embodiment, the actuator 303 uses a piezoelectric element, but a solenoid actuator using an electromagnet, a giant magnetostrictive element, or the like may be used. Further, a configuration including a plurality of actuators 303 may be employed. In addition, the actuator 303 may be configured integrally with the actuator 103 or may be configured only by the actuator 103. By configuring the actuator 303 and the actuator 103 as one body, it is not necessary to synchronize the timing of applying vibration, and the configuration can be simplified. The actuator 303 may be disposed at a position away from the acceleration sensor 204. In other words, the acceleration sensor 204 may be disposed anywhere as long as it can be vibrated. The actuator 303 may be provided with a damping material (not shown) such as rubber so that its mass does not affect the vibration.

  The actuator drive circuit 305 transmits a pulse signal for driving the actuator 103 and the actuator 303. The actuator drive circuit 305 is connected to the soil condition evaluation unit 307. The actuator drive circuit 305 can be configured to instruct the actuator 103 and the actuator 303 to start vibration at the same timing. The actuator drive circuit 305 can also be configured to apply vibration to the actuator 103 and the actuator 303 with the same vibration intensity. Here, the actuator drive circuit 105 may be configured to transmit a pulse signal for driving the actuator 103 based on the control timing and the control period stored in advance.

  The soil state evaluation unit 307 controls the actuator drive circuit 305 so as to drive the actuator 103 and the actuator 303. The soil condition evaluation unit 307 determines the condition of the soil 101 based on the signal analyzed by the sensor signal analysis unit 106 and the signal analyzed by the sensor signal analysis unit 206. The soil condition evaluation unit 307 may be configured using a circuit, or may be configured to perform signal processing and analysis by taking data into a computer such as a PC.

  A method for evaluating the state of the soil 101 according to this embodiment will be described below with reference to FIG. FIG. 7 is a flowchart showing a method for evaluating the state of the soil 101 in the third embodiment.

  In step S <b> 31, the drive circuit 305 sends a pulse signal for causing the actuator 103 and the actuator 303 to generate vibrations based on an instruction from the soil condition evaluation unit 307. The actuator 103 is driven by a pulse signal and causes the elastic body 102 to generate a pulse-like vibration. The actuator 303 is driven by the pulse signal, causes the acceleration sensor 204 to generate pulse vibrations, and proceeds to step S32.

  Next, in step S32, control similar to step S21 of the second embodiment is performed, and the process proceeds to step S33.

  Next, in step S33, the same control as step S22 of the second embodiment is performed, and the process proceeds to step S34.

  Next, in step S34, the same control as step S23 of the second embodiment is performed, and the process proceeds to step S35.

  Next, in step S35, the same control as in step S24 of the second embodiment is performed, and the flow ends.

  As described above, in the present embodiment, vibration can be generated more actively than in the second embodiment, so that the frequency of calculating the damping factor of the elastic body can be improved.

<Fourth Embodiment>
The structure of the soil monitoring system 4 in the 4th Embodiment of this invention is demonstrated with reference to FIG. Here, the same reference numerals are given to the same components as those in the above-described embodiment, and the description thereof will be omitted. FIG. 8 is a diagram showing a configuration of a soil monitoring system 4 according to the fourth embodiment.

  The soil monitoring system 4 includes a soil monitoring device 40 and a sediment disaster prediction device (not shown).

  The soil monitoring apparatus 40 includes a plurality of elastic bodies 102A to 102D, a plurality of acceleration sensors 104A to 104D installed in each of the plurality of elastic bodies 102A to 102D, an acceleration sensor 204, and a determination unit 400. Here, in FIG. 8, the acceleration sensor 204 and the sensor signal analysis unit 206 are disclosed as one, but the soil monitoring device 30 includes a plurality of acceleration sensors 204 and a plurality of sensor signal analysis units 206. Also good. Moreover, the soil monitoring apparatus 40 can also install the actuator which gives a vibration in each of several elastic body 102A-102D. The soil monitoring apparatus 40 can also install an actuator that applies vibration in the acceleration sensor 204.

  The determination unit 400 includes a plurality of sensor signal analysis units 106A to 106D, a sensor analysis unit 206, and a soil condition evaluation unit 407.

  The soil state evaluation unit 407 determines the state of the soil 101 based on the signal analyzed by the sensor signal analysis unit 106A and the signal analyzed by the sensor signal analysis unit 206. Similarly, the soil state evaluation unit 407 determines the state of the soil 101 based on the signal analyzed by the sensor signal analysis unit 106B and the signal analyzed by the sensor signal analysis unit 206. The soil state evaluation unit 407 determines the state of the soil 101 based on the signal analyzed by the sensor signal analysis unit 106C and the signal analyzed by the sensor signal analysis unit 206. The soil state evaluation unit 407 determines the state of the soil 101 based on the signal analyzed by the sensor signal analysis unit 106D and the signal analyzed by the sensor signal analysis unit 206. The soil condition evaluation unit 407 may be configured using a circuit, or may be configured to take in data into a computer such as a PC and perform signal processing and analysis.

  Since the soil state evaluation method according to this embodiment is a control flow according to the second embodiment, a description thereof will be omitted.

  As mentioned above, in this embodiment, since the soil state in multiple points can be detected, the soil state can be detected with higher accuracy. Moreover, since the soil state at a plurality of points can be detected, the state of the soil in the entire area where the acceleration sensor group is installed can be detected.

  As described above, the present invention has been described based on the embodiments. However, the first to fourth embodiments described above are merely examples, and various modifications may be made to the above-described embodiments without departing from the gist of the present invention. Changes, increases / decreases, and combinations may be added. It will be understood by those skilled in the art that modifications to which these changes, increases / decreases, and combinations are also within the scope of the present invention. Furthermore, the application of the present invention is not necessarily applicable to monitoring systems for preventing sediment disasters but also to other fields related to soil.

[Appendix 1]
An elastic body embedded in the soil;
A first vibration sensor for acquiring vibration data of the elastic body;
A second vibration sensor embedded in a position away from the elastic body and acquiring vibration data of the soil;
A soil monitoring apparatus comprising: a determination unit that determines the state of the soil based on vibration data acquired by the first vibration sensor and vibration data acquired by the second vibration sensor.
[Appendix 2]
The determination unit calculates a first frequency spectrum based on the vibration data acquired by the first vibration sensor, and calculates a second frequency spectrum based on the vibration data acquired by the second vibration sensor. The soil monitoring apparatus according to appendix 1, wherein the state of the soil is determined based on the first frequency spectrum and the second frequency spectrum.
[Appendix 3]
The determination unit calculates a difference based on the first frequency spectrum and the second frequency spectrum, calculates a third frequency spectrum, and determines the state of the soil based on the third vibration spectrum. The soil monitoring device according to supplementary note 2, characterized by:
[Appendix 4]
The soil monitoring according to appendix 3, wherein the determination unit calculates a propagation parameter of an elastic body based on the spectrum of the third vibration, and determines the state of the soil based on the propagation parameter. apparatus.
[Appendix 5]
The determination unit specifies a vibration frequency specific to the elastic body based on the third frequency spectrum, and calculates the propagation parameter based on the vibration frequency specific to the elastic body. The soil monitoring device described in 1.
[Appendix 6]
The soil monitoring apparatus according to appendix 4 or 5, wherein the propagation parameter includes at least one of a propagation speed, an attenuation rate, and a resonance frequency.
[Appendix 7]
First vibration means for applying vibration to the elastic body;
Second excitation means for applying vibration to the second vibration sensor,
The first vibration sensor acquires vibration data vibrated by the first vibration means,
The second vibration sensor acquires vibration data vibrated by the second vibration means;
The determination unit determines the state of the soil based on vibration data vibrated by the first vibration means and vibration data vibrated by the second vibration means. The soil monitoring apparatus according to 1 to 6.
[Appendix 8]
The second vibration means is an actuator,
The soil monitoring device according to appendix 7, wherein the actuator is installed in the second vibration sensor via a damping material.
[Appendix 9]
The soil monitoring apparatus according to appendix 7 or 8, wherein the first vibration means and the second vibration means are configured by separate actuators.
[Appendix 10]
The soil monitoring apparatus according to appendix 7 or 8, wherein the first vibration means and the second vibration means are configured by one actuator.
[Appendix 11]
At least one soil monitoring device;
A soil condition evaluation device that detects the condition of the soil,
The monitoring device
An elastic body embedded in the soil;
A first vibration sensor for acquiring vibration data of the elastic body;
A second vibration sensor embedded in a position away from the elastic body and acquiring vibration data of the soil;
A determination unit for determining the state of the soil based on the vibration data acquired by the first vibration sensor and the vibration data acquired by the second vibration sensor;
The soil detection device
A determination result acquisition unit for acquiring a determination result of the soil monitoring device;
A soil monitoring system comprising: a prediction unit that predicts a sediment disaster based on the determination result acquired by the determination result acquisition unit.
[Appendix 12]
Acquire vibration data of elastic body,
Obtain soil vibration data,
The soil monitoring method characterized by determining the state of the soil based on vibration data of the elastic body and vibration data of the soil.

101 soil 102, 102A-102D elastic body 103, 303 actuator 104, 204 acceleration sensor 105, 305 actuator drive circuit 106, 106A-106D, 206 sensor signal analysis unit 107, 207, 307, 407 soil state evaluation unit 200, 300, 400 judgment part

Claims (10)

An elastic body embedded in the soil;
A first vibration sensor for acquiring vibration data of the elastic body;
A second vibration sensor embedded in a position away from the elastic body and acquiring vibration data of the soil;
A soil monitoring apparatus comprising: a determination unit that determines a state of the soil based on vibration data acquired by the first vibration sensor and vibration data acquired by the second vibration sensor.   The determination unit calculates a first frequency spectrum based on the vibration data acquired by the first vibration sensor, and calculates a second frequency spectrum based on the vibration data acquired by the second vibration sensor. The soil monitoring device according to claim 1, wherein a state of the soil is determined based on the first frequency spectrum and the second frequency spectrum.   The determination unit calculates a difference based on the first frequency spectrum and the second frequency spectrum, calculates a third frequency spectrum, and determines the state of the soil based on the third vibration spectrum. The soil monitoring device according to claim 2, wherein   The soil according to claim 3, wherein the determination unit calculates a propagation parameter of an elastic body based on the spectrum of the third vibration, and determines the state of the soil based on the propagation parameter. Monitoring device.   The soil monitoring apparatus according to claim 4, wherein the propagation parameter includes at least one of a propagation speed, an attenuation rate, and a resonance frequency. First vibration means for applying vibration to the elastic body;
Second excitation means for applying vibration to the second vibration sensor,
The first vibration sensor acquires vibration data vibrated by the first vibration means,
The second vibration sensor acquires vibration data vibrated by the second vibration means;
The determination unit determines the state of the soil based on vibration data vibrated by the first vibration means and vibration data vibrated by the second vibration means. The soil monitoring apparatus according to claim 1. The second vibration means is an actuator,
The soil monitoring apparatus according to claim 6, wherein the actuator is installed in the second vibration sensor via a damping material.   The soil monitoring apparatus according to claim 6, wherein the first vibration unit and the second vibration unit are configured by separate actuators. At least one soil monitoring device;
A soil condition evaluation device that detects the condition of the soil,
The monitoring device
An elastic body embedded in the soil;
A first vibration sensor for acquiring vibration data of the elastic body;
A second vibration sensor embedded in a position away from the elastic body and acquiring vibration data of the soil;
A determination unit for determining the state of the soil based on the vibration data acquired by the first vibration sensor and the vibration data acquired by the second vibration sensor;
The soil detection device
A determination result acquisition unit for acquiring a determination result of the soil monitoring device;
A soil monitoring system comprising: a prediction unit that predicts a sediment disaster based on the determination result acquired by the determination result acquisition unit. Acquire vibration data of elastic body,
Obtain soil vibration data,
The soil monitoring method characterized by determining the state of the soil based on vibration data of the elastic body and vibration data of the soil.

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