Deterioration detection device and deterioration detection system

Abstract

Get more detailed information about coating deterioration. [Solution] The deterioration detection device comprises a filter that transmits infrared light in a specific wavelength range, and an imaging unit that captures an infrared image from mid-infrared light that is reflected or emitted from a coating film formed on the surface of an object to be inspected and that has passed through the filter, and detects the deterioration state of the coating film as a two-dimensional distribution based on the infrared image captured by the imaging unit.

Description

[Technical field]

[0001] The present invention relates to a deterioration detection device and a deterioration detection system. [Background technology]

[0002] Patent Document 1 describes a coating deterioration detection method for a coating having a first layer applied to a base material and located on the outermost side and a second layer located directly underneath it, in which the spectroscopic characteristics of the first layer and second layer are used to detect wear of the first layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-120549 A Summary of the Invention [Problem to be solved by the invention]

[0004] For example, on the surface of outdoor equipment, a coating film made of resin paint or the like is formed for the purpose of improving weather resistance, etc. The coating film deteriorates under the stress of wind, rain, solar radiation, etc., and performance decreases, so repairs such as repainting are necessary. However, with conventional deterioration detection methods, it is difficult to obtain detailed information about the deterioration of the coating film, making it impossible to properly determine whether repairs are necessary, which may result in high maintenance costs. The present invention aims to obtain more detailed information regarding deterioration of coating films. [Means for solving the problem]

[0005] The invention described in claim 1 includes a filter that transmits infrared rays in a specific wavelength range, and a photographing unit that photographs an infrared image from mid-infrared rays that are reflected or emitted from a coating film formed on a surface of an inspection object and that have transmitted the filter; a processing unit that acquires infrared rays including periodic fluctuations irradiated onto the coating film as a reference signal, extracts reflected components from time-series data of the infrared images captured by the imaging unit based on the reference signal, and performs processing to detect a deterioration state of the coating film. It is a deterioration detection device. The invention described in claim 2 is The present invention further includes an illumination device that emits the reference signal, and a near-infrared camera that acquires the reference signal that is emitted from the illumination device and reflected from the coating film, and the processing unit performs a process of detecting a deterioration state of the coating film based on the reference signal acquired by the near-infrared camera. A deterioration detection device according to claim 1. Claim 3 The invention described in The processing unit extracts radiation components from time series data of the infrared image captured by the imaging unit, Detect temperature differences caused by physical deterioration of the coating Do the processing A deterioration detection device according to claim 1. Claim 4 The invention described in the is a filter that transmits infrared rays in a specific wavelength range, and an imaging unit that captures an infrared image from mid-infrared rays that are reflected or radiated from a coating film formed on a surface of an inspection object and that have transmitted the filter; Infrared rays including periodic fluctuations irradiated onto the coating film are acquired as a reference signal, and a reflected component is extracted based on the reference signal from time-series data of an infrared image captured by the imaging unit, thereby performing a process of detecting a deterioration state of the coating film. A deterioration detection system comprising: The invention described in claim 5 is 5. The deterioration detection system according to claim 4, further comprising: an illumination that emits the reference signal; and a near-infrared camera that acquires the reference signal emitted from the illumination and reflected from the coating film, wherein the processing unit performs processing to detect a deterioration state of the coating film based on the reference signal acquired by the near-infrared camera. It is. Effect of the Invention

[0006] According to the present invention, more detailed information regarding deterioration of a coating film can be obtained. [Brief description of the drawings]

[0007] [Figure 1] 1 is a diagram illustrating an example of the configuration of a deterioration detection system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram illustrating an example of a hardware configuration of a computer used as a server. [Diagram 3] FIG. 2 illustrates an example of a functional configuration of a server. [Figure 4] FIG. 1 is a diagram showing an example of the relationship between deterioration of a coating film and absorbance. [Diagram 5] FIG. 1 is a graph showing the relationship between deterioration of a polyurethane coating film and absorbance. [Figure 6] FIG. 1 shows the results of detecting deterioration of a polyurethane coating film when a wide-band filter is used, where (a) shows the relationship between the UV irradiation period and the reflection isolation lock-in value, and (b) shows the relationship between the infrared absorption integral value and the reflection isolation lock-in value. [Figure 7] FIG. 1 shows the results of detecting deterioration of a polyurethane coating film when a narrow-band filter is used, where (a) shows the relationship between the UV irradiation period and the reflection separation lock-in value, and (b) shows the relationship between the infrared absorption integral value and the reflection separation lock-in value. [Figure 8] FIG. 11 is a diagram illustrating an example of the flow of a deterioration detection process performed by a server. [Figure 9] 13A and 13B are diagrams illustrating examples of display of an infrared image and a determination result. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. <Configuration of Deterioration Detection System> 1 is a diagram showing an example of the configuration of a deterioration detection system 1 according to the present embodiment. The deterioration detection system 1 detects the deterioration state of a coating film formed on the surface of a subject 200 that is an inspection target. The deterioration detection system 1 includes a mid-infrared camera 10, a filter 30, an active lighting device 40, a near-infrared camera 50, a server 80, and a user terminal 90. The mid-infrared camera 10, the active lighting device 40, and the near-infrared camera 50 are connected to the server 80 and the user terminal 90 via a network 70.

[0009] The mid-infrared camera 10 senses light in the mid-infrared region, captures an object 200 to be inspected, and generates an infrared image. Light in the mid-infrared region is generally light in the wavelength region of 2.5 to 5.0 μm. In this embodiment, a filter 30 is attached to the mid-infrared camera 10, and an infrared image is generated from the light that has passed through the filter 30. In the mid-infrared region, in addition to the infrared rays reflected from the surface of the subject 200, the infrared rays emitted according to the temperature of the subject 200 are also incident on the mid-infrared camera .

[0010] The mid-infrared camera 10 generates an infrared image by converting into brightness the amount of infrared energy reflected and emitted by the subject 200. The generated infrared image contains information about the amount of infrared energy reflected and emitted by the subject 200. The infrared image according to the present embodiment may be an image captured as a still image, or an image corresponding to one frame of a video image. The mid-infrared camera is an example of the imaging unit.

[0011] The filter 30 selectively transmits infrared light in a specific wavelength range. The filter 30 is attached, for example, to a lens portion of the mid-infrared camera 10. The mid-infrared camera 10 generates an infrared image from the infrared light in the specific wavelength range that has passed through the filter 30. Filter 30 is selected according to the type of coating film formed on the surface of subject 200. Filter 30 is selected that has the property of transmitting infrared rays in a wavelength range in which the absorbance changes due to deterioration of the coating film. The selection of the filter will be described in detail later.

[0012] The active lighting 40 emits a reference signal that includes a periodic variation. For example, a video lamp using a halogen lamp is used as the active lighting 40. The irradiation time of the active lighting 40 is controlled using a device including a solid-state relay, and the illuminance varies periodically. For example, the blinking cycle of the active lighting 40 is set to repeat a lighting time of 1.0 second and a lighting time of 1.5 seconds.

[0013] Near-infrared camera 50 senses light in the near-infrared region. Light in the near-infrared region is light in the wavelength region of 0.7 to 2.5 μm. In the near-infrared region, the infrared rays emitted from an object are very small. Therefore, infrared rays reflected from subject 200 are incident on near-infrared camera 50. The near-infrared camera 50 acquires a reference signal emitted from the active illumination 40 and reflected by the object 200 .

[0014] The network 70 is an information and communication network that handles communication between the mid-infrared camera 10, the active lighting 40, the near-infrared camera 50, the server 80, and the user terminal 90. The type of the network 70 is not particularly limited as long as it is capable of transmitting and receiving data, and may be, for example, the Internet, a local area network (LAN), a wide area network (WAN), or the like. The communication line used for data communication may be wired or wireless. Also, the configuration may be such that each device is connected via a plurality of networks or communication lines.

[0015] The server 80 acquires time-series data captured by the mid-infrared camera 10 and the near-infrared camera 50. Then, based on the acquired time-series data, a multi-wavelength lock-in process is performed to detect deterioration of the coating film that is the inspection target. Multi-wavelength lock-in processing is a lock-in process that uses time-series data measured by an infrared camera with different sensitivity wavelengths as a reference signal. Multi-wavelength lock-in processing is performed using reference signals in various wavelength bands that correspond to the deterioration to be detected.

[0016] The lock-in process is a process in which fluctuation data containing random noise is integrated with a reference signal related to the fluctuation, thereby extracting the fluctuation component with reduced random noise. For example, when infrared energy is forcibly applied to the inspection object by irradiating it with infrared lighting, it is possible to evaluate paint film deterioration even in an environment affected by disturbance light. However, if there are areas in the measurement area that are affected by disturbance light and areas that are not, the effects of the difference in lighting conditions cannot be canceled out by simply irradiating the entire measurement area with infrared lighting.

[0017] When infrared lighting is repeatedly applied, the same degree of infrared intensity fluctuation occurs in the illuminated area, regardless of whether the area is affected by ambient light or not. By extracting the waveform of the infrared lighting blinking cycle from a partial area within the infrared measurement field of view, it is possible to detect only the infrared intensity fluctuation caused by the infrared lighting. In this embodiment, a reference signal including periodic fluctuations is irradiated onto the subject 200 from the active illumination 40. The server 80 acquires the reference signal from the near-infrared camera 50 and performs lock-in processing, thereby making it possible to extract the reflected component from the infrared time-series data including the reflected component and the radiated component measured by the mid-infrared camera 10.

[0018] When extracting the radiation component from the time series data of the infrared rays measured by the mid-infrared camera 10, a lock-in process is performed using a far-infrared camera that senses light in the far-infrared region. The light in the far-infrared region used here is, for example, light in the wavelength region of 8.0 to 1000 μm, and the far-infrared camera senses light in the wavelength region of 8.0 to 20 μm, for example. The server 80 performs the lock-in process using the time series data measured by the far-infrared camera as a reference signal, and extracts the radiation component from the time series data of the infrared rays measured by the mid-infrared camera 10.

[0019] When detecting chemical deterioration such as a change in the chemical bond state, the server 80 extracts reflected components from the time-series data of infrared rays measured by the mid-infrared camera 10. The server 80 detects the change in the chemical bond state. When detecting physical deterioration such as peeling or cracking of the paint film, or rust under the paint film, the server 80 extracts radiation components from the time-series data of infrared rays measured by the mid-infrared camera 10. The server 80 detects temperature differences caused by physical changes. By separating and extracting the reflected or radiated components from measurement data that captures both, the state of deterioration can be detected in more detail.

[0020] The server 80 performs lock-in processing using the multi-wavelength time-series data to separate and extract the reflected and radiated components of the infrared intensity fluctuations caused by the active lighting 40 from the time-series data of the mid-infrared camera 10. The server 80 then quantitatively evaluates the degree of deterioration of the paint in the mid-wavelength infrared range. The server 80 also outputs the deterioration detection results to the user terminal 90. The server 80 is an example of a processing unit. The functional configuration of the server 80 will be described in detail later.

[0021] The user terminal 90 is a terminal operated by a user who uses the deterioration detection system 1. The user terminal 90 acquires a result of deterioration detection from the server 80 and displays it on a screen of the user terminal 90. The screen of the user terminal 90 is an example of a display unit. The user terminal 90 may have a function of issuing instructions regarding the operations of the mid-infrared camera 10, the active lighting 40, and the near-infrared camera 50.

[0022] FIG. 2 is a diagram showing an example of the hardware configuration of a computer 800 used as the server 80. As shown in FIG. The computer 800 includes a CPU (Central Processing Unit) 801, a RAM (Random Access Memory) 802, and a ROM (Read Only Memory) 803. The RAM 802 is a volatile memory used as a work area when the CPU 801 executes a program. The ROM 803 is a non-volatile memory that stores the programs executed by the CPU 801 and other data. The CPU 801 uses the RAM 802 as a work area and executes the programs read from the ROM 803.

[0023] The computer 800 also includes a network IF (interface) 804 for performing communication via a network, and a display mechanism 805 for performing display output on the user terminal 90. The CPU 801 is a processor that controls the functions of the measurement device 1 through the execution of various software such as an OS (operating system) and application software. In the case of this embodiment, each process is executed by an arbitrary computer.

[0024] Any computer may be implemented as a processor as hardware, a program as software, or a combination of both. Any computer may be a general-purpose computer, a special-purpose computer, a workstation, or any other system capable of executing processes. The processor is configured to execute various processes in cooperation with the program. The processor can function as each unit or each means in the present embodiment. The order in which the processor executes the processes is not limited to the order described in the present embodiment, and can be changed as necessary.

[0025] The processor can be configured with one or more pieces of hardware. The type of hardware that configures the processor is not limited to a specific type. For example, the processor can be configured with hardware such as a programmable logic device such as a CPU (Central Processing Unit), an MPU (Micro Processing Unit), an FPGA (Field Programmable Gate Array), a dedicated circuit for executing specific processing such as an ASIC (Application Specific Integrated Circuit), a GPU (Graphic Processing Unit), or an NPU (Neural Processing Unit).

[0026] The processor is not limited to a combination of multiple pieces of hardware of the same type, but may also be configured by a combination of multiple pieces of hardware of different types. When multiple pieces of hardware are configured to execute one or more processes of a certain processor, the multiple pieces of hardware may exist in devices physically separated from each other, or may exist in the same device. The hardware is configured by an electric circuit (circuitry) combining circuit elements such as semiconductor elements.

[0027] In any of the embodiments, the order in which the processor executes each process is not limited to the order described in each embodiment, and may be changed as necessary. The program may be firmware or software such as microcode. The program may be, for example, a group of program modules. Each function constituting the group of program modules may be realized by a processor configured to execute each function. The program in each embodiment may be a program code or a number of code segments stored in one or more non-transitory computer-readable media (eg, semiconductor memory, magnetic or optical storage media, or other storage).

[0028] The program may be stored in multiple non-transitory computer-readable media that are physically separate from each other. The program code or multiple code segments may be represented as any combination of a procedure, a function, a subprogram, a routine, a subroutine, a module, a software package, a class, an instruction, a data structure, or a program statement. The program code or multiple code segments may be connected to other code segments or hardware circuits by transmitting or receiving information, data, arguments, parameters, or memory contents.

[0029] <Server functional configuration> FIG. 3 is a diagram illustrating an example of the functional configuration of the server 80. As shown in FIG. The server 80 includes an infrared image acquisition unit 81, a reference signal acquisition unit 82, a lock-in processing unit 83, a deterioration degree calculation unit 84, a determination unit 85, and an output unit 86 as functions executed by a CPU 801 which is a processor.

[0030] The infrared image acquisition unit 81 acquires time-series data of a mid-infrared image captured by the subject 200 from the mid-infrared camera 10. The mid-infrared image is, for example, an image corresponding to one frame of a video. The time-series data acquired by the infrared image acquisition unit 81 includes a reflection component and a radiation component of the infrared intensity fluctuation caused by the active illumination 40. The reference signal acquisition unit 82 acquires a reference signal as time-series data from the near-infrared camera 50. The reference signal acquired by the reference signal acquisition unit 82 is a reference signal that is emitted from the active illumination 40 and reflected by the subject 200.

[0031] The lock-in processing unit 83 performs multi-wavelength lock-in processing based on the time-series data acquired by the infrared image acquisition unit 81 and the reference signal acquisition unit 82. The lock-in processing unit 83 performs lock-in processing using the reference signal acquired from the near-infrared camera 50, and separates and extracts the reflected component of the infrared intensity fluctuation due to the influence of the active illumination 40 from the time-series data of the mid-infrared camera 10. The deterioration degree calculation unit 84 calculates the deterioration degree of the coating film from the infrared image from which the reflected components have been extracted. The deterioration degree is a numerical value representing the degree of deterioration based on a predetermined standard. The deterioration degree calculation unit 84 calculates the deterioration degree based on, for example, the energy value of the infrared image. The deterioration degree calculation unit 84 calculates, for example, the area of ​​a portion whose energy value is equal to or greater than a predetermined value as the deterioration degree.

[0032] The determining unit 85 determines whether or not repair is necessary based on the calculated deterioration level. For example, the determining unit 85 determines that repair is necessary when the deterioration level exceeds a predetermined threshold value. The output unit 86 outputs the infrared image from which the reflected components have been extracted to the user terminal 90. The infrared image is a two-dimensional distribution in which luminance differs according to the degree of deterioration of the subject 200. The output unit 86 may output the result of the determination made by the determination unit 85 as to whether or not the repair is appropriate, together with the infrared image.

[0033] The functions of the server 80 may be executed by the mid-infrared camera 10. The mid-infrared camera 10 may include a CPU having the hardware configuration shown in Fig. 2 and execute the functions shown in Fig. 3. Also, the mid-infrared camera 10 may be configured to remove the effects of ambient light by other methods. The mid-infrared camera 10 equipped with the filter 30 is an example of a deterioration detection device. The deterioration detection device may be a device including an active lighting 40 and a near-infrared camera 50, or may include a mid-infrared camera 10 equipped with a server 80. The mid-infrared camera 10 and the near-infrared camera 50 may be configured as separate devices, and a configuration may be adopted in which measurement by the mid-infrared camera 10 is performed after measurement by the near-infrared camera 50.

[0034] <Select filter> The filter 30 is selected according to the type of coating film formed on the surface of the subject 200. In this embodiment, the subject 200 to be inspected is, for example, the outer wall of a liquefied natural gas (LNG) terminal facility or a steel road bridge. A coating film such as polyurethane resin is formed on the surface of these subjects 200 to improve weather resistance. Coating films made of resin paints or the like are subject to a decrease in thickness when exposed to ultraviolet light. In addition, chemical structural changes occur on the ultraviolet irradiated surface, mainly due to radical reactions. The chemical structural changes increase or decrease the number of molecules on the coating surface, which changes the absorbance in a specific wavelength range. The filter 30 is selected so as to transmit infrared rays in a wavelength range in which the absorbance changes due to deterioration of the coating film.

[0035] Fig. 4 is a diagram showing an example of the relationship between deterioration of a coating film and absorbance. In Fig. 4, the horizontal axis represents wavelength (μm) and the vertical axis represents absorbance. The absorption characteristics shown in Fig. 4 were obtained by Fourier transform infrared spectroscopy. Fig. 4 shows the results of measuring the absorbance at each wavelength for (1) a new coating, (2) a moderately deteriorated product, and (3) a deteriorated product that requires repainting. In the example shown in Fig. 4, the absorbance changes greatly in the wavelength region X1 to X2 µm according to the deterioration of the coating. More specifically, the absorbance is large for a new coating, and decreases as the deterioration progresses. When inspecting the deterioration of such a coating, a filter 30 that transmits light in the wavelength region X1 to X2 µm is selected.

[0036] When a coating is photographed with a mid-infrared camera 10 using a filter 30 that transmits light in the wavelength region X1 to X2 μm, a mid-infrared image is captured in which the amount of energy varies according to the degree of deterioration. This makes it possible to obtain image data that shows an energy distribution in which areas with little deterioration, close to new, have a small amount of energy, and areas with great deterioration have a large amount of energy. Since the amount of energy is converted into luminance, areas with little deterioration are displayed dark, and areas with great deterioration are displayed bright. From the energy distribution in the image data, the two-dimensional distribution of the deterioration state of the coating can be detected.

[0037] A method for two-dimensionally detecting ultraviolet degradation will be described with reference to an example in which polyurethane paint is used for the coating film, with reference to Figures 5 to 7. For chemical degradation such as structural changes caused by ultraviolet rays, a reference signal is obtained from a near-infrared camera 50 and a lock-in process is performed to separate the reflected components and detect the degradation.

[0038] Figure 5 shows the relationship between the deterioration of a polyurethane coating film and its absorbance. In Figure 5, the horizontal axis represents wavelength (μm) and the vertical axis represents absorbance. The absorption characteristics shown in Figure 5 were obtained by Fourier transform infrared spectroscopy. Figure 5 shows the absorbance of polyurethane coating film when it is not irradiated with ultraviolet light and when it is irradiated with ultraviolet light for periods of 1 month, 3 months, 6 months, and 9 months. As shown in Figure 5, the longer the period of ultraviolet light irradiation for polyurethane coating film at a wavelength of 3.4 μm, the smaller the infrared absorption due to ultraviolet light deterioration becomes. Therefore, when detecting deterioration of polyurethane coating film, a filter 30 that includes a wavelength of 3.4 μm in its transmission range is used. The following shows the case where a wide-band filter with a center wavelength of 3390 nm and a half-width of 344 nm and a narrow-band filter with a center wavelength of 3420 nm and a half-width of 74 nm are used.

[0039] Figure 6 shows the results of detecting deterioration of a polyurethane coating film when a wide-band filter is used. Figure 6(a) shows the relationship between the ultraviolet irradiation period and the reflection separation lock-in value, and Figure 6(b) shows the relationship between the infrared absorption integral value and the reflection separation lock-in value. The reflection separation lock-in value is the energy value of the reflection component separated from the infrared rays reflected and emitted by the coating film by acquiring a reference signal from the near-infrared camera 50 and performing lock-in processing. In Figure 6(a), the horizontal axis shows the period (months).

[0040] Figure 6(a) shows the reflection separation lock-in value when the polyurethane coating is not irradiated with UV light and when it is irradiated with UV light for periods of 1 month, 3 months, 6 months, and 9 months. As shown in Figure 6(a), the reflection separation lock-in value tends to increase as the irradiation period increases. By combining the mid-infrared camera 10 with a wide-band filter, it is possible to detect early deterioration even when the UV light irradiation period is less than 9 months.

[0041] Figure 6(b) shows the relationship between the integrated value of infrared absorption in the transmission wavelength range of the wide-band filter and the reflection separation lock-in value in the infrared absorption spectrum shown in Figure 5. As shown in Figure 6(b), the reflection separation lock-in value tends to decrease as the integrated value of infrared absorption increases. In the transmission wavelength range of the wide-band filter, the trends of the infrared absorption spectrum and the reflection separation lock-in value matched.

[0042] Figure 7 shows the results of detecting deterioration of a polyurethane coating film when a narrow-band filter is used. Figure 7(a) shows the relationship between the UV irradiation period and the reflection separation lock-in value, and Figure 7(b) shows the relationship between the infrared absorption integral value and the reflection separation lock-in value. In Figure 7(a), the horizontal axis shows the period (months).

[0043] Figure 7(a) shows the reflection separation lock-in value when the polyurethane coating is not irradiated with UV light and when it is irradiated with UV light for periods of 1 month, 3 months, 6 months, and 9 months. As in the case shown in Figure 6(a), the reflection separation lock-in value tends to increase as the irradiation period increases. By combining the mid-infrared camera 10 with a narrow-band filter, it is possible to detect early deterioration even when the UV light irradiation period is less than 9 months.

[0044] Figure 7(b) shows the relationship between the integrated infrared absorption in the transmission wavelength range of the narrow-band filter and the reflection isolation lock-in value in the infrared absorption spectrum shown in Figure 5. As shown in Figure 7(b), the reflection isolation lock-in value tends to decrease as the integrated infrared absorption value increases. As in the transmission wavelength range of the wide-band filter, the trends of the infrared absorption spectrum and the reflection isolation lock-in value were consistent in the transmission wavelength range of the narrow-band filter as well.

[0045] From the results shown in Figs. 6 and 7, it is possible to quantitatively evaluate the change in infrared absorption due to ultraviolet degradation by the multi-wavelength lock-in process using the reflection separation lock-in value. Comparing the wide-band filter and the narrow-band filter, the narrow-band filter has a narrower transmission wavelength range. Comparing FIG. 6(b) with FIG. 7(b), the use of the narrow-band filter allows for more accurate detection of initial deterioration with UV irradiation for less than six months. In other words, by narrowing the measurement to a wavelength range where the difference in infrared absorption due to UV irradiation is large, the deteriorated area can be detected with high efficiency. On the other hand, when the narrow-band filter is used, the amount of energy captured by the mid-infrared camera 10 is smaller.

[0046] <Deterioration detection process> The flow of the deterioration detection process when detecting chemical deterioration due to irradiation with ultraviolet rays will be described. When using the deterioration detection system 1 to detect the deterioration state of a coating film formed on the surface of the subject 200 to be inspected, a reference signal is first irradiated onto the subject 200 from the active illumination 40. The reference signal reflected by the subject 200 is acquired by the near-infrared camera 50, and the reflected and emitted mid-infrared light is captured by the mid-infrared camera 10. The server 80 acquires a mid-infrared image captured by the mid-infrared camera 10. It also acquires a reference signal from the near-infrared camera 50. Then, a lock-in process is performed based on the acquired mid-infrared image and the reference signal to detect deterioration of the target coating film.

[0047] The flow of the process performed by the server 80 will be described with reference to FIG. FIG. 8 is a diagram showing an example of the flow of the deterioration detection process performed by the server 80. 8, first, the infrared image acquisition unit 81 acquires an infrared image captured by the mid-infrared camera 10 (step 1001). Then, the reference signal acquisition unit 82 acquires a reference signal from the near-infrared camera 50 (step 1002).

[0048] Next, the lock-in processing unit 83 extracts the reflected components by lock-in processing (step 1003). The time-series data acquired from the mid-infrared camera 10 includes infrared intensity fluctuations caused by the active illumination 40. The lock-in processing unit 83 performs lock-in processing using the reference signal acquired from the near-infrared camera 50, thereby separating and extracting the reflected components of the infrared intensity fluctuations.

[0049] Next, the deterioration degree calculation unit 84 calculates the deterioration degree from the infrared image from which the reflected components have been extracted (step 1004). The deterioration degree calculation unit 84 calculates the deterioration degree based on, for example, the energy value of the infrared image. Then, the judgment unit 85 judges whether repair is necessary by comparing the deterioration degree with a predetermined threshold value (step 1005). For example, the judgment unit 85 judges that repair is necessary when the deterioration degree exceeds the predetermined threshold value. Then, the output unit 86 outputs the infrared image and the determination result (step 1006). The output infrared image and the determination result are displayed on the screen of the user terminal 90.

[0050] A display example of the infrared image and the determination result on the user terminal 90 will be described with reference to FIG. Fig. 9 is a diagram showing a display example of an infrared image and a determination result. Fig. 9 shows a case where the subject 200 is rectangular. For simplification, Fig. 9 shows the subject 200 divided into two areas: an area that requires repair and an area that does not require repair.

[0051] In an infrared image, areas with significant degradation are displayed brightly, while areas with minor degradation are displayed darkly. In the example shown in Figure 9, areas with significant degradation that require repair are shown in white, while areas with minor degradation that do not require repair are shown in shaded areas. In the example shown in Fig. 9, the date of shooting (yyyy / mm / dd) and the judgment result "The area of ​​the deteriorated part exceeds XX. Paint film repair is required" are displayed together with the infrared image. Note that these displays are only examples, and other texts, images, etc., or notifications by voice, etc. may be displayed. In addition, the judgment of whether repair is appropriate is not limited to the area of ​​the deteriorated part, but is judged based on the obtained infrared image and a predetermined standard. [Explanation of symbols]

[0052] 1...deterioration detection system, 10...mid-infrared camera, 30...filter, 40...active lighting, 50...near-infrared camera, 70...network, 80...server, 200...subject

Claims

1. A filter that transmits infrared light in a specific wavelength range; an imaging unit that captures an infrared image from mid-infrared rays that are reflected or radiated from a coating film formed on a surface of an object to be inspected and that have passed through the filter; a processing unit that acquires infrared rays including periodic fluctuations irradiated onto the coating film as a reference signal, extracts reflected components from time-series data of the infrared image captured by the imaging unit based on the reference signal, and performs processing to detect a deterioration state of the coating film; A deterioration detection device comprising:

2. A light that emits the reference signal; a near-infrared camera that captures the reference signal emitted from the illumination and reflected from the coating; The processing unit performs a process of detecting a deterioration state of the coating film based on the reference signal acquired by the near-infrared camera. The deterioration detection device according to claim 1 .

3. The deterioration detection device described in Claim 1, wherein the processing unit extracts radiation components from time series data of infrared images captured by the photographing unit and performs processing to detect temperature differences due to physical deterioration of the coating film.

4. A filter that transmits infrared light in a specific wavelength range; an imaging unit that captures an infrared image from mid-infrared rays that are reflected or radiated from a coating film formed on a surface of an object to be inspected and that have passed through the filter; a processing unit that acquires infrared rays including periodic fluctuations irradiated onto the coating film as a reference signal, extracts reflected components from time-series data of the infrared image captured by the imaging unit based on the reference signal, and performs processing to detect a deterioration state of the coating film; A deterioration detection system comprising:

5. A light that emits the reference signal; a near-infrared camera that captures the reference signal emitted from the illumination and reflected from the coating; The processing unit performs a process of detecting a deterioration state of the coating film based on the reference signal acquired by the near-infrared camera. The deterioration detection system according to claim 4 .

Images