Structure and determination device

Abstract

A structure (10) according to the present disclosure is a structure (10) arranged with respect to an object (S), the structure comprising: a first layer (11) having a reflection characteristic or a transmission characteristic with respect to an electromagnetic wave (L1), the reflection characteristic or the transmission characteristic irreversibly changing in accordance with a state of the object (S); and a second layer (12) configured to reduce the intensity of electromagnetic waves (L1) transmitted through the first layer (11) and incident on the second layer (12).

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority from Japanese Patent Application No. 2023-030444, filed on February 28, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a structure and a determining device. Background Art

[0004] Conventional technology for nondestructively measuring the corrosion state of structures having walls and the like is known. For example, Patent Document (PTL) 1 discloses a device for detecting corrosion caused by a medium in a structure. This device uses a closed disk made of a material that becomes permeable to the medium once corroded by the medium.

[0005] Reference List

[0006] Patent Literature

[0007] PTL 1:JP 2006-511812 A Summary of the Invention

[0008] (Technical Issues)

[0009] However, it is not easy to determine the state of an object at a difficult-to-access location, such as the interior of the object. In addition, the detection structure including the disk is complicated.

[0010] An object of the present disclosure is to provide a structure and a determination device that can improve the degree of freedom of position of state determination with a simple structure.

[0011] (Solution to the problem)

[0012] The structure according to several embodiments is a structure arranged relative to an object, the structure comprising:

[0013] A first layer having a reflection characteristic or a transmission characteristic for electromagnetic waves that irreversibly changes depending on a state of an object; and a second layer configured to reduce the intensity of electromagnetic waves that are transmitted through the first layer and incident on the second layer.

[0014] This configuration increases the degree of freedom in determining the location of an object's state using a simple structure. This increases the degree of freedom in determining the location of an object's state. For example, the determination system can determine the presence of an object's state even in locations that are difficult to access or where electronic equipment is difficult to install, such as inside an object. Consequently, wiring for the object becomes unnecessary, and non-destructive determination using electromagnetic waves becomes possible.

[0015] In the structure according to the embodiment, the first layer can be configured so that the reflectivity of electromagnetic waves irreversibly decreases depending on the state of the object. This configuration allows the reflective properties of the first layer itself to change before and after the object is submerged, thereby facilitating the determination system's determination of the presence of the object's state. This change in the reflective properties of the first layer itself causes the spectral intensity of the electromagnetic waves received by the receiver to change before and after the object is submerged. Therefore, the determination system can easily distinguish whether the object is in the state before or after submersion based on the difference in spectral intensity.

[0016] In the structure according to the embodiment, the second layer may be configured such that a phase difference between an electromagnetic wave reflected at a first surface on the first layer side and an electromagnetic wave reflected at a second surface opposite to the first surface is 180°.

[0017] This configuration enables the second layer to reduce the intensity of electromagnetic waves that transmit through the first layer and are incident on the second layer after the object is immersed. Consequently, the second layer allows the spectral intensity of the electromagnetic waves received by the receiver to change before and after the object is immersed. Consequently, the determination system can easily distinguish whether the object is in a pre-immersion state or a post-immersion state based on the difference in spectral intensity.

[0018] In the structure according to the embodiment, the second layer can be configured to absorb electromagnetic waves incident on the second layer. This configuration enables the second layer to more reliably reduce the intensity of electromagnetic waves that are transmitted through the first layer and incident on the second layer after the object has been immersed. Therefore, the second layer more reliably enables the spectral intensity of the electromagnetic waves received by the receiver to change before and after the object is immersed. Therefore, the determination system can more easily distinguish whether the object is in a state before or after immersion based on the difference in spectral intensity.

[0019] In the structure according to the embodiment, the first and second layers can be stacked adjacent to each other. This further simplifies the structure of the sensor used to detect the state of an object. By adopting this simple two-layer structure, the sensor structure is further simplified. Therefore, a complex structure is not required, and the determination device using this structure can more easily achieve the determination function.

[0020] In the structure according to the embodiment, the first layer can be formed of a material that corrodes depending on the state of the object. This configuration allows the optical properties of the first layer itself, such as its reflection and transmission properties, to change before and after the object is submerged, thereby facilitating the determination system's process of determining the presence or absence of the object's state. This change in the optical properties of the first layer itself allows the spectral intensity of the electromagnetic waves received by the receiver to change before and after the object is submerged. Therefore, the determination system can easily distinguish whether the object is in its pre-submerged state or its post-submerged state based on the difference in spectral intensity.

[0021] In the structure according to the embodiment, the state of the object may include a past submersion state of the object, and the material may include a metal material that corrodes in water. This configuration allows the determination system to determine whether the location in the object where the structure is located has been submerged due to water entering that location. By including a metal material that corrodes in water as the material forming the first layer, rust forms in the first layer after the object is submerged, thereby changing the optical properties of the first layer. Therefore, based on the changes in the optical properties of the first layer of the structure, the determination system can indirectly determine whether the object has deteriorated due to moisture in the location where the structure is located.

[0022] In the structure according to the embodiment, the structure can be embedded inside an object. This configuration enables the determination system to determine the presence of an object's status even in locations that are environmentally difficult to access or where electronic equipment is difficult to install. Therefore, wiring to the object becomes unnecessary, enabling non-destructive determination using electromagnetic waves.

[0023] According to some embodiments, the determination device includes: a controller configured to control the emission of electromagnetic waves toward any one of the above-mentioned structures and the reception of electromagnetic waves reflected by the above-mentioned structures; and a determiner configured to compare the acquired data obtained from the received electromagnetic waves with reference data to determine the existence of the state of the object.

[0024] This enables the determination system to improve the accuracy of the determination process based on the threshold determination regarding the difference between these data. Therefore, based on the difference between the data, the determination system can accurately determine whether the object has deteriorated due to moisture at the location where the structure is arranged.

[0025] In the determination device according to the embodiment, the determiner can be configured to determine the presence of an object's condition by comparing the reflection spectrum of electromagnetic waves at the structure, obtained as acquired data, with a reference spectrum, serving as reference data. This enables the determination system to improve the accuracy of the determination process by determining a threshold value based on the difference between these spectra. Therefore, based on the difference between the spectra, the determination system can accurately determine whether the object has deteriorated due to moisture at the location where the structure is located.

[0026] (Beneficial Effects)

[0027] According to the present disclosure, it is possible to provide a structure and a determination device that can improve the degree of freedom of position determination of a state with a simple structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In the attached figure:

[0029] Figure 1 is a schematic diagram illustrating an example configuration of a determination system including a structure and a determination device according to an embodiment of the present disclosure;

[0030] Figure 2 It shows Figure 1 a schematic diagram of the configuration and function of the structure shown;

[0031] Figure 3 It shows Figure 1 A block diagram of an example configuration of the determination apparatus shown; and

[0032] Figure 4 It shows Figure 1 A flow chart illustrating an example of the operation of the determination device is shown. DETAILED DESCRIPTION

[0033] Hereinafter, embodiments of the present disclosure will be described mainly with reference to the accompanying drawings.

[0034] Figure 1 This is a schematic diagram illustrating an example configuration of a determination system 1 including a structure 10 and a determination device 20 according to an embodiment of the present disclosure. The structure 10 is, for example, embedded within an object S. The determination system 1 uses the structure 10 and the determination device 20 to determine the presence or absence of a state of the object S. In the present disclosure, "the state of the object S" includes, for example, the past submergence state of the object S. The determination system 1 determines whether the location within the object S where the structure 10 is located has been submerged in the past due to water entering the location.

[0035] In the present disclosure, "object S" includes an object that transmits electromagnetic waves to a certain extent, for example, as described below. The object S may be solid, liquid, or gas. Examples of the object S include resin, concrete, and adhesive.

[0036] The determination system 1 includes a structure 10 and a determination device 20. The determination system 1 further includes a transmitter 30 connected to the determination device 20 and a receiver 40 connected to the determination device 20. In the determination system 1 according to the embodiment, the transmitter 30 and the receiver 40 are other constituent elements different from the determination device 20. Figure 1 As shown, both the transmitter 30 and the receiver 40 are arranged to face the structure 10 embedded inside the object S. The transmitter 30 and the receiver 40 are placed symmetrically to each other with respect to the structure 10 .

[0037] Transmitter 30 includes, for example, an electromagnetic wave generating source capable of radiating electromagnetic waves onto structure 10. Transmitter 30 transmits electromagnetic waves toward structure 10, irradiating structure 10 embedded within object S with the electromagnetic waves. In the present disclosure, "electromagnetic waves" include, for example, electromagnetic waves in the frequency range of approximately 100 GHz to several THz. For example, the electromagnetic waves have a frequency in the sub-terahertz band of approximately several hundred GHz. Transmitter 30 includes, for example, an antenna that transmits a high-frequency signal as an electromagnetic wave and circuitry for generating, amplifying, and filtering the high-frequency signal.

[0038] The receiver 40 receives the electromagnetic waves emitted by the transmitter 30 and reflected by the structure 10. The electromagnetic waves reflected by the structure 10 include, for example, information about a reflection spectrum indicating the frequency dependence of the reflectivity of the electromagnetic waves with respect to the structure 10. The receiver 40 includes, for example, an antenna for receiving the electromagnetic waves as high-frequency signals and a circuit for amplifying and filtering the high-frequency signals.

[0039] Figure 2 It shows Figure 1 A schematic diagram of the configuration and function of the structure 10 is shown. Figure 2 The configuration and function of structure 10 will be described.

[0040] Likewise Figure 1 As shown, the structure 10 is arranged on the object S. For example, the structure 10 is embedded inside the object S. The structure 10 has a stacked structure including a plurality of layers. The structure 10 includes, for example, a first layer 11 and a second layer 12 stacked adjacent to each other. The first layer 11 is formed on the side of the structure 10 closest to the transmitter 30 and the receiver 40. Figure 1 and Figure 2 In the arrangement shown, the first layer 11 is located uppermost in the structure 10. The first layer 11 faces the transmitter 30 and the receiver 40 through the object S. The second layer 12 is stacked below the first layer 11 relative to the first layer 11. Figure 1 and Figure 2 In the arrangement shown, the second layer 12 is located lowermost in the structure 10 .

[0041] The first layer 11 is configured such that its reflection characteristics or transmission characteristics with respect to the electromagnetic wave L1 from the transmitter 30 irreversibly change depending on the state of the object S. For example, the first layer 11 is configured such that the reflectivity of the electromagnetic wave L1 irreversibly decreases depending on the state of the object S. The first layer 11 is formed, for example, of a material that corrodes depending on the state of the object S. In the present disclosure, the term "material" includes, for example, a metallic material that corrodes in water. Examples of metallic materials include iron.

[0042] Before the object S is immersed, no rust forms on the metal material in the first layer 11, and the metal material maintains its characteristics as an electrical conductor. In this state, the metal material substantially reflects all electromagnetic waves L1 from the emitter 30 that are incident on the first surface A11 corresponding to, for example, the top surface of the first layer 11. Figure 2 As shown in FIG. 1A , the electromagnetic wave L1 emitted from the transmitter 30 is reflected with a reflectivity of substantially 100% when incident on the first surface A11 of the first layer 11 . The electromagnetic wave L2 , which is a reflected wave of the electromagnetic wave L1 , propagates toward the receiver 40 .

[0043] At this time, as described below, the second reflection spectrum S2 as a reference spectrum shows a constant spectrum intensity that is independent of the frequency. As indicated by the second reflection spectrum S2, before the metal material in the first layer 11 corrodes, a high reflection intensity of the electromagnetic wave L1 is obtained in the entire frequency band of interest. In the present disclosure, the "second reflection spectrum S2" indicates the frequency dependence of the reflectivity of the electromagnetic wave L1 on the structure 10, wherein the structure 10 is in the initial state before the reflection characteristics of the electromagnetic wave L1 are irreversibly changed according to the state of the object S. Figure 2 In the graph, the horizontal axis represents frequency, and the vertical axis represents the reflectivity of the electromagnetic wave L1.

[0044] On the other hand, when water penetrates the location of the structure 10 in the object S and immerses it, the metal material constituting the first layer 11 gradually corrodes and rusts. As the metal material in the first layer 11 turns into corrosion products (such as iron oxide and iron oxyhydroxide), the transmittance to the electromagnetic wave L1 increases. As the metal material in the first layer 11 gradually rusts due to immersion, the metal material begins to exhibit insulating properties and transmits a portion of the electromagnetic wave L1 incident on the first surface A11 of the first layer 11 from the emitter 30.

[0045] like Figure 2 As shown in FIG. 2B , when electromagnetic wave L1 emitted from transmitter 30 is incident on first surface A11 of first layer 11, a portion thereof is transmitted through first layer 11 to be incident on second layer 12 formed on the second surface A12 side. The remaining portion of electromagnetic wave L1 is reflected by first surface A11 of first layer 11. Electromagnetic wave L21, which is a reflected wave of electromagnetic wave L1, propagates toward receiver 40.

[0046] The second layer 12 reduces the intensity of the electromagnetic wave L1 that is transmitted through the first layer 11 and incident on the second layer 12. The second layer 12 is configured so that the phase difference between the electromagnetic wave L22 reflected at the first surface A21 on the first layer 11 side and the electromagnetic wave L23 reflected at the second surface A22 on the opposite side to the first surface A21 is 180°. The function of the second layer 12 is similar to a λ / 4 reflecting electromagnetic wave absorber. As a result, the electromagnetic wave L22 reflected at the first surface A21 and the electromagnetic wave L23 reflected at the second surface A22 have opposite phases and cancel each other out. Figure 2 In B, the arrows conceptually show the electromagnetic waves L22 and L23, but in reality, the electromagnetic waves L22 and L23 cancel each other out and thus do not contribute to the intensity of the reflected wave.

[0047] The second layer 12 is used to irreversibly reduce the reflectivity of the electromagnetic wave L1 in a predetermined frequency band throughout the structure 10 according to the state of the object S. The second layer 12 causes the phases of the electromagnetic wave L22 and the electromagnetic wave L23 in the predetermined frequency band to be opposite within the electromagnetic wave L1 that is transmitted through the first layer 11 due to the corrosion caused by the immersion of the object S. The second layer 12 cancels out the electromagnetic wave L22 and the electromagnetic wave L23 in the predetermined frequency band, thereby not contributing to the intensity of the reflected wave. Therefore, the first reflection spectrum S1 included as data in the acquisition data D1 described below presents a dip in the predetermined frequency band. As indicated by the first reflection spectrum S1, when the corrosion of the metal material in the first layer 11 becomes severe enough, the reflection intensity of the electromagnetic wave L1 is significantly reduced in the predetermined frequency band. In the present disclosure, "first reflection spectrum S1" indicates the frequency dependence of the reflectivity of the electromagnetic wave L1 relative to the structure 10.

[0048] Several characteristic values ​​appear in the first reflection spectrum S1. In the present disclosure, "characteristic values" include, for example, parameters that appear in a spectrum such as the first reflection spectrum S1. Characteristic values ​​include, for example, peak intensity, peak frequency, valley depth, valley frequency, and baseline intensity. Peak intensity is the intensity of the spectrum at the peak frequency. Valley depth is the difference between the baseline intensity and the intensity of the spectrum at the valley frequency. Baseline intensity is the intensity of the baseline of the spectrum, and corresponds to the intensity of the spectrum at frequencies other than the peak and its base, and the valley and its base. Figure 2 Taking the first reflection spectrum S1 as an example, the characteristic values ​​include valley depth Ld, valley frequency fd and baseline intensity Lb.

[0049] Figure 3 It shows Figure 1 The block diagram of an example configuration of the determination device 20 is shown. Now, mainly refer to Figure 3 To describe Figure 1 An example of the configuration of the determination device 20 is shown.

[0050] The determination device 20 includes, for example, a general electronic device such as a personal computer (PC) or a smartphone. However, these examples are not limiting, and the determination device 20 may be a server device or a plurality of server devices capable of communicating with each other, or any other electronic device dedicated to the determination system 1. The determination device 20 includes a controller 21, a calculator 22, a determiner 23, an input / output interface 24, and a memory 25.

[0051] The controller 21 includes one or more processors. In the present disclosure, a "processor" is a general-purpose processor or a dedicated processor dedicated to a specific process, but these examples are not limiting. The controller 21 is communicatively connected to each component of the determination device 20 and controls the operation of the determination device 20 as a whole.

[0052] In addition, the controller 21 is connected to both the transmitter 30 and the receiver 40. The controller 21 controls the transmission of electromagnetic waves directed toward the structure 10 and the reception of electromagnetic waves reflected by the structure 10. The controller 21 controls the transmission of electromagnetic waves toward the structure 10 by controlling the transmitter 30. For example, the controller 21 controls the frequency and intensity of the electromagnetic waves transmitted by the transmitter 30, the timing of turning on or off the transmission, and the power supply of the transmitter 30. The controller 21 controls the reception of electromagnetic waves reflected by the structure 10 by controlling the receiver 40. For example, by turning on or off the receiver 40, the controller 21 controls the timing of receiving the electromagnetic waves received by the receiver 40. For example, the controller 21 controls the power supply of the receiver 40.

[0053] For example, the controller 21 automatically adjusts the position and angle of the transmitter 30 to meet a predetermined transmission condition. In the present disclosure, the "predetermined transmission condition" includes, for example, a condition in which the electromagnetic wave emitted by the transmitter 30 is incident at a freely selectable angle of incidence relative to a predetermined reflective surface in the structure 10. For example, the angle of incidence may be a small angle close to zero degrees or may be zero degrees. The transmitter 30 may be set to a position and angle that enables measurement under the following conditions: the electromagnetic wave can be considered to be incident on the structure 10 in a vertical or substantially vertical manner. This configuration is not restrictive, and the controller 21 may adjust the position and angle of the transmitter 30 based on a set value input by a user of the use determination device 20.

[0054] For example, the controller 21 automatically adjusts the position and angle of the receiver 40 to meet the predetermined receiving conditions. In the present disclosure, the "predetermined receiving conditions" include, for example, conditions such that the electromagnetic wave reflected at the above-mentioned predetermined reflection surface of the structure 10 at a predetermined reflection angle is incident on the receiver 40. For example, the reflection angle can match the above-mentioned incident angle, can be a small angle close to zero degrees, or can be zero degrees. The receiver 40 can be set to a position and angle that can also measure under the following conditions: the electromagnetic wave can be considered to be reflected in a vertical or substantially vertical manner at the structure 10. This configuration is not restrictive, and the controller 21 can adjust the position and angle of the receiver 40 based on the set value input by the user using the determination device 20.

[0055] The controller 21 controls the transmitter 30 to transmit electromagnetic waves in the sub-terahertz frequency band toward the structure 10. For example, the controller 21 causes the transmitter 30 to transmit short pulses of electromagnetic waves ranging from 10 picoseconds (ps) to several tens of ps using time domain spectroscopy (TDS). In this case, the transmitter 30 can transmit electromagnetic waves of a predetermined polarization. For example, the transmitter 30 can transmit a linearly polarized electromagnetic wave having a P-polarization component or a linearly polarized electromagnetic wave having an S-polarization component.

[0056] The controller 21 controls the receiver 40 to acquire a time-series pulse signal as a received signal. For example, the controller 21 controls the receiver 40 to receive the aforementioned short pulse of electromagnetic waves in the sub-terahertz frequency band and reflected by the structure 10 using TDS. The receiver 40 can receive electromagnetic waves with a predetermined polarization consistent with the electromagnetic waves transmitted by the transmitter 30. For example, the receiver 40 can receive a linearly polarized electromagnetic wave with a P-polarization component or a linearly polarized electromagnetic wave with an S-polarization component. The controller 21 outputs the received signal acquired from the receiver 40 to the calculator 22.

[0057] The calculator 22 includes one or more processors. The processor may be the same as or different from the processor used as the controller 21. The calculator 22 acquires a reception signal of an electromagnetic wave received by the receiver 40 from the controller 21 and performs arithmetic processing based on the reception signal.

[0058] The calculator 22 generates various data as acquired data D1 from the reception signal of the electromagnetic wave received by the receiver 40. In the present disclosure, the "acquired data D1" includes, for example Figure 2 The calculator 22 calculates the first reflected spectrum S1 in the frequency domain by, for example, performing Fourier transform processing on the time waveform based on the pulse signal acquired from the receiver 40. The Fourier transform includes, for example, discrete Fourier transform.

[0059] The determiner 23 includes one or more processors. The processor may be the same as or different from the processor used as at least one of the controller 21 and the calculator 22. The determiner 23 determines the presence of a state of the object S by comparing the acquired data D1 obtained from the electromagnetic waves received by the receiver 40 with the reference data D2. The determiner 23 determines the presence of a past submerged state of the object S based on the acquired data D1 and the reference data D2. The determiner 23 obtains the acquired data D1 from the calculator 22. The determiner 23 obtains the reference data D2 from the memory 25.

[0060] The determiner 23 determines the presence of the state of the object S by comparing the first reflected spectrum S1 of the electromagnetic wave at the structure 10 obtained as the acquired data D1 with the reference spectrum as the reference data D2. In the present disclosure, the "reference data D2" includes, for example Figure 2 1 and 2. The data of the second reflection spectrum S2 is shown in . The second reflection spectrum S2 corresponds to an example of a reference spectrum.

[0061] The data of the second reflection spectrum S2 is pre-constructed based on design data, simulation data, measurement data, and the like for the transmitter 30, the receiver 40, and the structure 10, and is stored in the memory 25. The measurement data is, for example, data actually measured during the stages of arranging the structure 10 relative to the object S and arranging the determination device 20, the transmitter 30, and the receiver 40 relative to the structure 10 and the object S. Even if accurate prediction based on the design data and simulation data is difficult, accurate data of the second reflection spectrum S2 can be obtained.

[0062] The determiner 23 compares data of the first reflection spectrum S1 obtained by the calculator 22 with data of the second reflection spectrum S2 as a reference spectrum stored in the memory 25. The determiner 23 determines the presence of the state of the object S based on the difference between the first reflection spectrum S1 and the second reflection spectrum S2.

[0063] The difference used in the determination includes the difference between characteristic values. The difference between the characteristic values ​​corresponds to the amount of change in the first reflection spectrum S1 relative to the second reflection spectrum S2, which serves as a reference spectrum. For example, the determiner 23 determines the presence of the state of the object S based on the difference between at least one of the valley depth Ld, valley frequency fd, and baseline intensity Lb of the first reflection spectrum S1 and the corresponding characteristic value of the second reflection spectrum S2. For example, the determiner 23 determines the presence of the state of the object S based on the difference between the valley depth Ld of the first reflection spectrum S1 and the corresponding characteristic value of the second reflection spectrum S2.

[0064] If the difference is greater than a threshold, determiner 23 determines that the location where structure 10 is located in object S has been submerged in the past due to water entering that location. If the difference is less than or equal to the threshold, determiner 23 determines that water has not entered the location where structure 10 is located in object S and that the location has not been submerged in the past. This threshold is appropriately set by the user, for example, based on the design conditions of determination system 1, and is pre-stored in memory 25. For example, the threshold is set to take into account variations caused by the reproducibility of the output, including the electromagnetic wave intensity and transmission frequency, of transmitter 30, and the reproducibility of the reception, including the reception intensity and reception frequency, of receiver 40. A difference exceeding the threshold indicates that the difference is greater than the variation, and is significant in determining whether object S has been submerged in the past.

[0065] For example, if the valley depth Ld in the first reflection spectrum S1 increases to exceed a threshold value, while the valley depth in the second reflection spectrum S2 is zero, the determiner 23 determines that the position where the structure 10 is arranged in the object S has been immersed in the past. For example, if the valley depth Ld in the first reflection spectrum S1 is less than the threshold value and is not significantly different from the valley depth of zero in the second reflection spectrum S2, the determiner 23 determines that the position where the structure 10 is arranged in the object S has not been immersed in the past.

[0066] The input / output interface 24 includes one or more interfaces for input, which are used to detect user input and obtain input information based on user operations. The input / output interface 24 includes, for example, physical keys, capacitive keys, a touch screen integrated with the display, or a microphone for receiving audio input. The input / output interface 24 receives commands from the user to the determination device 20.

[0067] The input / output interface 24 includes one or more output interfaces for outputting information and notifying the user. The input / output interface 24 includes, for example, a display for outputting information as images, a speaker for outputting information as audio, and a light for visually conveying information. The input / output interface 24 outputs the determination result from the determiner 23. For example, the input / output interface 24 displays to the user via the display whether the object S, as determined by the determiner 23, has been submerged in the past. This configuration is not restrictive; the input / output interface 24 can transmit the determination result from the determiner 23 to an external device not included in the determination system 1, for example, via a network or the like.

[0068] Furthermore, when the input / output interface 24 determines that the object S has been submerged in the past, it can trigger an alarm to notify the user of the submergence. The input / output interface 24 can trigger the alarm by, for example, lighting a light or outputting an alarm sound from a speaker. In this way, the input / output interface 24 can reliably notify the user that the object S has been submerged in the past.

[0069] The memory 25 includes any memory module, including a hard disk drive (HDD), a solid-state drive (SSD), an electrically erasable programmable read-only memory (EEPROM), a read-only memory (ROM), and a random access memory (RAM). The memory 25 can be used as, for example, a main memory, an auxiliary memory, or a cache memory. The memory 25 stores any information used to determine the operation of the device 20, any information obtained from determining the operation of the device 20, and the like.

[0070] For example, the memory 25 stores the acquired data D1 obtained by the calculator 22 from the electromagnetic waves received by the receiver 40. The memory 25 stores pre-configured reference data D2. The memory 25 stores the aforementioned threshold values ​​pre-set by the user, for example, based on the design conditions of the determination system 1. The memory 25 stores system programs, application programs, and the like. The memory 25 is not limited to being within the determination device 20 and may include an external storage module connected via a digital input / output port such as a universal serial bus (USB).

[0071] Figure 4 It shows Figure 1 The flowchart of an example of the operation of the determining device 20 is shown below. Figure 4 An example of a basic flow of processing related to the determination method performed by the determination device 20 is described.

[0072] Before the determination method is performed by the determination device 20, the transmitter 30 and the receiver 40 are first installed with respect to the object S. The transmitter 30 is installed with respect to the object S so that electromagnetic waves are radiated onto the structure 10 embedded in the portion of the object S to be measured. The receiver 40 is installed with respect to the object S so that electromagnetic waves reflected by the structure 10 can be received. The transmitter 30 and the receiver 40 can be manually installed by a user of the determination device 20, or automatically installed by a machine such as a robot.

[0073] Subsequently, for example, the controller 21 of the determination device 20 automatically adjusts the position and angle of the transmitter 30 to meet predetermined transmission conditions. For example, the controller 21 automatically adjusts the position and angle of the receiver 40 to meet predetermined reception conditions. Once the aforementioned installation and adjustment of the transmitter 30 and receiver 40 are completed, the determination method is executed by the determination device 20.

[0074] In step S100, the controller 21 of the determination device 20 controls the emission of electromagnetic waves to the structure 10 by controlling the emitter 30. For example, the controller 21 causes the electromagnetic waves to be emitted from the emitter 30 as a pulse waveform containing a wide range of harmonic components.

[0075] In step S101 , the controller 21 of the determination device 20 controls the reception of electromagnetic waves reflected by the structure 10 by controlling the receiver 40 .

[0076] In step S102 , the controller 21 of the determining device 20 stops transmitting electromagnetic waves to the structure 10 by controlling the transmitter 30 .

[0077] In step S103, the calculator 22 of the determination device 20 generates acquisition data D1 based on the reception signal of the electromagnetic wave received by the receiver 40 in step S101. For example, the calculator 22 performs a discrete Fourier transform on the time waveform of the electromagnetic wave measured using the receiver 40 in step S101, thereby generating the acquisition data D1 as spectrum data in the frequency domain.

[0078] In step S104, the determiner 23 of the determination device 20 compares the acquired data D1 generated in step S103 with the reference data D2 stored in the memory 25. For example, the determiner 23 calculates the difference between the first reflection spectrum S1 and the second reflection spectrum S2 obtained in the calculator 22. For example, the determiner 23 calculates the difference between the valley depth Ld of the first reflection spectrum S1 and the corresponding characteristic value of the second reflection spectrum S2.

[0079] In step S105, the determiner 23 of the determination device 20 determines whether the difference between the feature values ​​is greater than the threshold value based on the comparison process in step S104. If the difference is greater than the threshold value, the determiner 23 performs the process in step S106. If the difference is less than or equal to the threshold value, the determiner 23 ends the process.

[0080] The determiner 23 of the determining device 20 determines the presence of a state of the object S through the processing of step S105. More specifically, when the difference between the characteristic values ​​is greater than a threshold value, the determiner 23 determines that the object S has been submerged in the past. The determiner 23 determines that the location where the structure 10 is arranged in the object S has been submerged in the past due to water entering the location. When the difference between the characteristic values ​​is less than or equal to the threshold value, the determiner 23 determines that the object S has not been submerged in the past. The determiner 23 determines that water has not entered the location where the structure 10 is arranged in the object S and that the location has not been submerged in the past.

[0081] When it is determined in step S105 that the difference between the characteristic values ​​is greater than the threshold value, in step S106 , the determiner 23 of the determination device 20 outputs the determination result to the input / output interface 24 and causes the input / output interface 24 to trigger an alarm.

[0082] According to the determination system 1 including the structure 10 and the determination device 20 in the embodiment described above, the degree of freedom of positional state determination can be increased with a simple structure. This increases the degree of freedom of the target location at which the presence of the state of the object S can be determined. For example, the determination system 1 can determine the presence of the state of the object S even in locations that are environmentally difficult to access or where electronic equipment is difficult to install, such as inside the object S. This eliminates the need for wiring to the object S, thereby enabling lossless determination using electromagnetic waves.

[0083] Since structure 10 has a stacked structure comprising first layer 11 and second layer 12, the structure of the sensor for detecting the state of object S is further simplified. Structure 10 having, for example, a two-layer structure further simplifies the sensor structure. Therefore, there is no need to construct structure 10 as a complex structure, making it easier to implement the determination function using determination device 20 of structure 10. Furthermore, the manufacturing cost of structure 10 is reduced.

[0084] Determination system 1 can easily detect a history of water intrusion into object S. Even in environmentally inaccessible locations, such as inside solid objects and in gases, users can non-destructively and contactlessly confirm whether water has previously entered object S. Even if water has entered object S from the outside and has since dried up, it is still possible to detect deterioration of object S due to moisture. For example, in the case of an adhesive, irreversible degradation due to water is known to occur. Once an adhesive is submerged in water, it cannot be restored to its previous state and remains degraded even after subsequent drying. Embedding structure 10 in an adhesive, adherend, or the like also makes it possible to non-destructively detect, for example, deterioration in the adhesive's strength due to water.

[0085] By configuring the first layer 11 so that the reflectivity of electromagnetic waves irreversibly decreases depending on the state of the object S, the reflective properties of the first layer 11 itself can be changed before and after the object S is immersed, thereby facilitating the process of determining the presence of the state of the object S by the determination system 1. The change in the reflective properties of the first layer 11 itself allows the spectral intensity of the electromagnetic waves received by the receiver 40 to change before and after the object S is immersed. Therefore, the determination system 1 can easily distinguish whether the object S is in the state before or after being immersed based on the difference in spectral intensity.

[0086] The second layer 12 is configured so that the phase difference between the electromagnetic wave L22 reflected at the first surface A21 on the first layer 11 side and the electromagnetic wave L23 reflected at the second surface A22 on the opposite side of the first surface A21 is 180°. This configuration enables the second layer 12 to reduce the intensity of the electromagnetic wave L1 that transmits through the first layer 11 and impinges on the second layer 12 after the object S has been immersed. Therefore, the second layer 12 enables the spectral intensity of the electromagnetic wave received by the receiver 40 to change before and after the object S is immersed. Therefore, the determination system 1 can easily distinguish whether the object S is in a state before or after being immersed based on the difference in spectral intensity.

[0087] By stacking the first layer 11 and the second layer 12 adjacent to each other, the sensor structure for detecting the state of the object S is further simplified. By making the structure 10 a simple two-layer structure, the sensor structure is further simplified. Therefore, there is no need to construct the structure 10 as a complex structure, making it easier to implement the determination function using the determination device 20 of the structure 10. Furthermore, the manufacturing cost of the structure 10 is further reduced.

[0088] By forming the first layer 11 from a material that corrodes depending on the state of the object S, the optical properties of the first layer 11 itself, such as reflective properties and transmittance properties, can change before and after the object S is immersed, thereby facilitating the process by which the determination system 1 determines the presence or absence of the state of the object S. The change in the optical properties of the first layer 11 itself enables the spectral intensity of the electromagnetic waves received by the receiver 40 to change before and after the object S is immersed. Therefore, the determination system 1 can easily distinguish whether the object S is in the state before or after immersion based on the difference in spectral intensity.

[0089] By including the state of object S in the past immersion state of object S, determination system 1 can determine whether the location in object S where structure 10 is located has been submerged in the past due to water entering that location. By including a metal material that corrodes in water as the material forming first layer 11, rust forms in first layer 11 after object S is submerged, thereby changing the optical properties of first layer 11. Therefore, based on the change in the optical properties of first layer 11 of structure 10, determination system 1 can indirectly determine whether object S has deteriorated due to moisture at the location where structure 10 is located.

[0090] By embedding the structure 10 inside the object S, the determination system 1 can determine the presence of the state of the object S even in an environmentally inaccessible location or a location where it is difficult to install electronic equipment. Therefore, wiring of the object S becomes unnecessary, thereby enabling non-destructive determination using electromagnetic waves.

[0091] By having the determiner 23 of the determination device 20 determine the presence of the state of the object S by comparing the acquired data D1 with the reference data D2, the determination system 1 can improve the accuracy of the determination process based on the threshold determination of the difference between these data. Therefore, based on the difference between the data, the determination system 1 can accurately determine whether the object S has deteriorated due to moisture at the location where the structure 10 is arranged.

[0092] The determiner 23 of the determination device 20 determines the presence of the state of the object S by comparing the first reflected spectrum S1 with the reference spectrum. This enables the determination system 1 to improve the accuracy of the determination process based on the threshold determination regarding the difference between these spectra. Therefore, based on the difference between the spectra, the determination system 1 can accurately determine whether the object S has deteriorated due to moisture at the location where the structure 10 is arranged.

[0093] Structure 10 is constructed by stacking a first layer 11 made of a metal material that corrodes significantly in water onto a second layer 12, where second layer 12 functions like a λ / 4-reflecting electromagnetic wave absorber for frequencies in the sub-terahertz band. Because structure 10 is embedded within object S, this configuration suppresses the influence of object S that could potentially form part of a shield, enabling determination system 1 to achieve highly sensitive, non-destructive immersion detection. Determination system 1 uses structure 10 as a marker sensitive to frequencies in the sub-terahertz band, where electromagnetic waves are highly transmissive through object S. This enables determination system 1 to improve electromagnetic wave transmission through the material of object S, suppress the influence of thick shielding, and easily perform determination processing.

[0094] By using the second layer 12 that functions like a λ / 4 reflecting electromagnetic wave absorber in a predetermined frequency band, a valley can be generated in the first reflection spectrum S1 in the predetermined frequency band. Therefore, by acquiring this first reflection spectrum S1, the determination system 1 can suppress the influence of thickness variations of the object S serving as a shield.

[0095] The determination system 1 can separate the reduction in electromagnetic wave intensity based on electromagnetic wave absorption in the object S from the reduction in electromagnetic wave intensity based on the structure 10. The reduction in electromagnetic wave intensity based on electromagnetic wave absorption in the object S depends on the thickness of the object S from the surface of the object S to the location where the structure 10 is arranged. The reduction in electromagnetic wave intensity based on electromagnetic wave absorption caused by the thickness of the object S appears as a reduction in baseline intensity in the reflection spectrum. The reduction in electromagnetic wave intensity based on the structure 10 appears as an increase in valley depth in the reflection spectrum. Therefore, even if the thickness of the object S serving as a shield changes, only the baseline intensity fluctuates, and the influence on the valley depth is small. By acquiring the first reflection spectrum S1 that exhibits frequency dependence, rather than measuring at a single frequency, the determination system 1 can accurately determine the presence of the state of the object S based on the valley depth even if the baseline intensity fluctuates.

[0096] It will be clear to those skilled in the art that the present disclosure may be implemented in a manner different from the above-described embodiments without departing from the spirit or essential features of the present disclosure. Therefore, the above explanations are merely examples that are by no means restrictive. The scope of the present disclosure is defined by the appended claims rather than by the above explanations. In all variations, various variations within the scope of equivalents are considered to be included therein.

[0097] For example, the shape, size, arrangement, orientation, and number of the components described above are not limited to those described above or in the accompanying drawings. The shape, size, arrangement, orientation, and number of each component can be freely selected as long as the component's function is achieved. The components of the determination system 1 in the accompanying drawings are shown as functional concepts. The specific form of each component is not limited to that shown in the accompanying drawings.

[0098] For example, the functions included in the various configurations and steps may be rearranged in any logically consistent manner. In addition, various components or steps may be combined into one or divided.

[0099] For example, the present disclosure may also be implemented as a program or a storage medium having the program recorded thereon containing a description of a process for implementing the functions of the above-mentioned determination device 20. Such embodiments are also understood to fall within the scope of the present disclosure.

[0100] In the above embodiment, the determination device 20 has been described as performing the determination process based on the irreversible decrease in the reflectivity of the electromagnetic wave L1 at the first layer 11 according to the state of the object S, but this configuration is not restrictive. Instead of or in addition to the reflectivity of the electromagnetic wave L1 with respect to the structure 10, the determination device 20 may perform the determination process based on the transmittance of the electromagnetic wave L1 with respect to the structure 10. For example, the determination device 20 may perform the determination process based on information about a transmission spectrum indicating the frequency dependence of the transmittance of the electromagnetic wave transmitted through the structure 10 (instead of or in addition to the electromagnetic wave reflected by the structure 10).

[0101] In the above embodiment, a decrease in reflectivity is provided as an example of irreversibly changing the reflective characteristics of the first layer 11 according to the state of the object S, but this example is not limitative. The irreversible change in reflective characteristics may include an increase in reflectivity.

[0102] In the above embodiment, the second layer 12 has been described as being configured so that the phase difference between the electromagnetic wave L22 reflected at the first surface A21 on the first layer 11 side and the electromagnetic wave L23 reflected at the second surface A22 on the opposite side from the first surface A21 is 180°, but this configuration is not restrictive. Instead of or in addition to functioning as a λ / 4 reflection electromagnetic wave absorber, the second layer 12 may also absorb the incident electromagnetic wave L1. For example, the second layer 12 may absorb the electromagnetic wave L1 in a predetermined frequency band or the entire frequency band while converting the electromagnetic wave L1 into heat energy.

[0103] This configuration enables the second layer 12 to more reliably reduce the intensity of the electromagnetic wave L1 that is transmitted through the first layer 11 and incident on the second layer 12 after the object S has been immersed. Therefore, the second layer 12 more reliably enables the spectral intensity of the electromagnetic wave received by the receiver 40 to change before and after the object S is immersed. Therefore, the determination system 1 can more easily distinguish whether the object S is in a state before or after being immersed based on the difference in spectral intensity.

[0104] In the above embodiment, the second layer 12 has been described as canceling out the electromagnetic waves L22 and L23 in a predetermined frequency band, thereby not contributing to the intensity of the reflected wave. However, this configuration is not restrictive. The second layer 12 may cancel out the electromagnetic waves L22 and L23 in the entire frequency band, thereby not contributing to the intensity of the reflected wave.

[0105] In the above embodiment, the first layer 11 and the second layer 12 are described as being stacked adjacent to each other, but this configuration is not restrictive. The first layer 11 and the second layer 12 do not necessarily need to be stacked adjacent to each other. The structure 10 may have a stacked structure of three or more layers with an intermediate layer between the first layer 11 and the second layer 12.

[0106] In the above embodiment, the first layer 11 has been described as being formed of a material that corrodes in response to the state of the object S, but this configuration is not restrictive. The first layer 11 may be formed of a material that exhibits any other state change other than corrosion, as long as the reflection characteristics or transmission characteristics with respect to the electromagnetic wave L1 irreversibly change according to the state of the object S.

[0107] In the above embodiment, the state of the object S has been described as including the past immersion state of the object S, but this configuration is not restrictive. The state of the object S may include, for example, the past temperature increase state of the object S. In this case, the material may be a material that exhibits corrosion or other state changes due to temperature increase, rather than a metallic material that corrodes in water.

[0108] In the above embodiment, the structure 10 has been described as being embedded within the object S, but this configuration is not restrictive. The structure 10 may be placed on the surface of the object S or in a groove recessed from the surface of the object S. In the case where the object S is an adhesive, the structure 10 may be arranged inside the adherend of the adhered member, inside the adhesive itself, or at the adhesive interface.

[0109] In the above embodiment, the determiner 23 has been described as determining the presence of the state of the object S by comparing the first reflected spectrum S1 with the reference spectrum, but this configuration is not restrictive. Instead of or in addition to the spectrum-based determination, the determiner 23 may determine the presence of the state of the object S by detecting changes in the intensity of electromagnetic waves of a single frequency using the receiver 40. Instead of or in addition to the spectrum-based determination, the determiner 23 may determine the presence of the state of the object S by comparing the intensities of the electromagnetic waves at two points (i.e., the valley frequency and the frequency on the baseline) .

[0110] In the above embodiment, the reference spectrum has been described as the second reflection spectrum S2 in the initial state before the reflection characteristics with respect to the electromagnetic wave L1 irreversibly change according to the state of the object S, but this configuration is not restrictive. The reference spectrum may be a reflection spectrum measured after the first layer 11 is corroded due to the immersion of the structure 10.

[0111] In the above embodiment, the determiner 23 has been described as determining the presence of the state of the object S based on the difference between the valley depth Ld of the first reflection spectrum S1 and the corresponding characteristic value of the second reflection spectrum S2, but this configuration is not restrictive. In the case where the reflection characteristics vary uniformly across the entire frequency band, the determiner 23 may determine the presence of the state of the object S based on the difference from the baseline intensity Lb.

[0112] In the above embodiment, the controller 21 of the determination device 20 has been described as causing electromagnetic waves to be emitted from the transmitter 30 in pulses, but this configuration is not restrictive. The controller 21 may also cause electromagnetic waves to be emitted from the transmitter 30 continuously at a constant signal strength.

[0113] In the above embodiment, the transmitter 30 and the receiver 40 have been described as other constituent elements different from the determination device 20, but this configuration is not restrictive. The transmitter 30 and the receiver 40 may be constituent elements of the determination device 20.

[0114] Some embodiments of the present disclosure are described below by way of example. However, it should be noted that the embodiments of the present disclosure are not limited to these examples.

[0115] [Appendix 1] A structure arranged relative to an object, the structure comprising:

[0116] a first layer having a reflection characteristic or a transmission characteristic with respect to electromagnetic waves, the reflection characteristic or the transmission characteristic being irreversibly changed according to a state of the object; and

[0117] A second layer is configured to reduce the intensity of electromagnetic waves transmitted through the first layer and incident on the second layer.

[0118] [Appendix 2] The structure according to Appendix 1, wherein the first layer is configured so that reflectivity of electromagnetic waves is irreversibly reduced according to a state of the object.

[0119] [Appendix 3] The structure according to Appendix 1 or 2, wherein the second layer is configured so that the phase difference between the electromagnetic wave reflected at the first surface on the first layer side and the electromagnetic wave reflected at the second surface opposite to the first surface is 180°.

[0120] [Appendix 4] The structure according to any one of Appendices 1 to 3, wherein the second layer is configured to absorb electromagnetic waves incident on the second layer.

[0121] [Appendix 5] The structure according to any one of Appendices 1 to 4, wherein the first layer and the second layer are stacked adjacent to each other.

[0122] [Appendix 6] The structure according to any one of Appendices 1 to 5, wherein the first layer is formed of a material that corrodes depending on the state of the object.

[0123] [Appendix 7] The structure according to Appendix 6, wherein

[0124] The state of the object includes a past immersion state of the object, and

[0125] The materials include metallic materials that corrode in water.

[0126] [Appendix 8] A structure according to any one of Appendices 1 to 7, wherein the structure is embedded inside the object.

[0127] [Appendix 9] A determining device comprising:

[0128] a controller configured to control transmission of electromagnetic waves toward the structure according to any one of Appendices 1 to 8 and reception of electromagnetic waves reflected by the structure; and

[0129] A determiner is configured to compare acquired data obtained from the received electromagnetic wave with reference data to determine the presence of the state of the object.

[0130] [Appendix 10] The determination device according to Appendix 9, wherein the determiner is configured to determine the existence of the state of the object by comparing a reflection spectrum of the electromagnetic wave obtained as the acquired data at the structure with a reference spectrum as the reference data.

[0131] Reference Signs List

[0132] 1. Determine the system

[0133] 10 Structure

[0134] 11 First Floor

[0135] 12 Second Floor

[0136] 20 Determine the device

[0137] 21 Controller

[0138] 22 Calculator

[0139] 23 Determinator

[0140] 24 input / output interfaces

[0141] 25 Memory

[0142] 30 launchers

[0143] 40 Receiver

[0144] A11 First Surface

[0145] A12 Second Surface

[0146] A21 First Surface

[0147] A22 Second Surface

[0148] D1 Get Data

[0149] D2 Reference Data

[0150] fd valley frequency

[0151] Lb baseline intensity

[0152] Ld valley depth

[0153] L1, L2, L21, L22, L23 electromagnetic waves

[0154] S object

[0155] S1 First Reflection Spectrum

[0156] S2 Second reflection spectrum

Claims

1. A structure arranged relative to an object, the structure comprising: a first layer having a reflection characteristic or a transmission characteristic for electromagnetic waves, the reflection characteristic or the transmission characteristic being irreversibly changed according to a state of the object; as well as A second layer is configured to reduce the intensity of electromagnetic waves transmitted through the first layer and incident on the second layer.

2. The structure according to claim 1, wherein The first layer is configured such that reflectivity of the electromagnetic wave is irreversibly reduced according to a state of the object.

3. The structure according to claim 1 or 2, wherein: The second layer is configured such that a phase difference between an electromagnetic wave reflected at a first surface on the first layer side and an electromagnetic wave reflected at a second surface opposite to the first surface is 180°.

4. The structure according to claim 1 or 2, wherein: The second layer is configured to absorb electromagnetic waves incident on the second layer.

5. The structure according to claim 1 or 2, wherein: The first layer and the second layer are stacked adjacent to each other.

6. The structure according to claim 1 or 2, wherein: The first layer is formed of a material that corrodes depending on the state of the object.

7. The structure according to claim 6, wherein The state of the object includes a past immersion state of the object, and The materials include metallic materials that corrode in water.

8. The structure according to claim 1 or 2, wherein: The structure is embedded inside the object.

9. A determination device, comprising: a controller configured to control the transmission of electromagnetic waves toward the structure according to claim 1 or 2 and the reception of electromagnetic waves reflected by the structure; as well as A determiner is configured to compare acquired data obtained from the received electromagnetic wave with reference data to determine the presence of the state of the object.

10. The determination device according to claim 9, wherein: The determiner is configured to determine the presence of the state of the object by comparing a reflection spectrum of the electromagnetic wave obtained as the acquisition data at the structure with a reference spectrum as the reference data.

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