Gas Leak Detection Method, Device, Medium and Terminal Based on Image Reconstruction

Abstract

The present application discloses a gas leakage detection method, device, medium and terminal based on image reconstruction, relating to a detection technology field, and mainly aiming to solve the problems of poor detection accuracy and effectiveness of existing gas leakage detections. It includes: obtaining a first grayscale value of a gas absorption band and a second grayscale value of a gas non-absorption band at a target position point in a spectral image of an area to be detected; determining measured absorption band radiation data corresponding to the first grayscale value, and reconstructing theoretical absorption band radiation data based on the second grayscale value; extracting a gas radiation difference value based on the measured absorption band radiation data and the theoretical absorption band radiation data, and performing leakage detection on the gas radiation difference value through threshold segmentation to obtain a gas leakage detection result.

Description

Technical Field

[0001] The present application relates to the field of detection technologies, and in particular, to a gas leakage detection method, device, medium, and terminal based on image reconstruction. Background Art

[0002] With the gradual enhancement of industrial production safety awareness, various industries such as petrochemical, power transportation, and transportation need to detect gas leakage, such as the detection of sulfur hexafluoride (SF6) and methane (CH4) gas leakage in the power system, to ensure the safety of the working environment and workers.

[0003] Currently, existing gas leakage detection usually uses optical detection technology for gas leakage detection, that is, based on active imaging that absorbs the energy of laser radiation to analyze optical images for leakage judgment. However, the radiation source of active imaging is usually heavy, and gas detection is limited by the spectral response range of the laser light source, greatly reducing the detection accuracy and effectiveness of gas leakage. Summary of the Invention

[0004] In view of this, the present application provides a gas leakage detection method, device, medium, and terminal based on image reconstruction, mainly aiming to solve the problem of poor detection accuracy and effectiveness of existing gas leakage.

[0005] According to one aspect of the present application, a gas leakage detection method based on image reconstruction is provided, including:

[0006] Obtain the first gray value of the gas absorption band and the second gray value of the gas non-absorption band at the target position point in the spectral image of the area to be detected;

[0007] Determine the measured absorption band radiation data corresponding to the first gray value, and reconstruct the theoretical absorption band radiation data based on the second gray value;

[0008] Extract the gas radiation difference value based on the measured absorption band radiation data and the theoretical absorption band radiation data, and perform leakage detection on the gas radiation difference value based on threshold segmentation to obtain the gas leakage detection result.

[0009] Further, the reconstructing the theoretical absorption band radiation data based on the second gray value includes:

[0010] Determine the non-absorption band background temperature corresponding to the second gray value based on the temperature calibration mapping relationship;

[0011] Determine the absorption band background temperature of the gas absorption band with the non-absorption band background temperature, and reconstruct the theoretical absorption band radiation data based on the absorption band background temperature;

[0012] Among them, the temperature calibration mapping relationship is obtained by solving the linear relationship between the gray value variable and the non-absorbing band background temperature variable based on the least squares method.

[0013] Furthermore, the reconstructing the theoretical absorption band radiation data based on the absorption band background temperature includes:

[0014] Determining the background radiation data corresponding to the absorption band background temperature based on Planck's law;

[0015] Determining the theoretical absorption band radiation data based on the background radiation data, the atmospheric path radiation, and the corrected atmospheric transmittance.

[0016] Furthermore, the method further includes:

[0017] Obtaining the environmental humidity, environmental temperature, atmospheric pressure, and vapor pressure of the area to be detected;

[0018] Determining the water vapor concentration based on the environmental humidity, environmental temperature, atmospheric pressure, and vapor pressure, and calculating the atmospheric transmittance based on the water vapor concentration, the absorption coefficient of water vapor, and the optical path length to obtain the corrected atmospheric transmittance.

[0019] Furthermore, the determining the measured absorption band radiation data corresponding to the first gray value includes:

[0020] Determining the measured absorption band radiation data corresponding to the first gray value based on the radiation calibration mapping relationship;

[0021] Among them, the radiation calibration mapping relationship is obtained by solving the linear relationship between the gray value variable and the measured absorption band radiation variable based on the least squares method.

[0022] Furthermore, the extracting the gas radiation difference value based on the measured absorption band radiation data and the theoretical absorption band radiation data, and performing leakage detection on the gas radiation difference value based on threshold segmentation to obtain the gas leakage detection result includes:

[0023] Performing difference calculation using the non-absorbing band background temperature and the theoretical absorption band radiation data to obtain the gas radiation difference value;

[0024] Performing leakage comparison on the gas radiation difference value according to threshold segmentation to obtain the gas leakage detection result of the target position point;

[0025] The method further includes:

[0026] Traversing the gas leakage detection results of all target positions in the spectral image to generate the gas differential image of the spectral image.

[0027] Further, the obtaining of the first gray value of the gas absorption band and the second gray value of the gas non-absorption band at the target position point in the spectral image of the area to be detected includes:

[0028] Determine the gas absorption band and the gas non-absorption band of the gas to be detected;

[0029] Collect the spectral image of the area to be detected through a time-synchronized dual-band infrared device, and determine the first gray value corresponding to the target position point and the second gray value corresponding to the gas non-absorption band from the spectral image.

[0030] According to another aspect of the present application, a gas leakage detection device based on image reconstruction is provided, including:

[0031] An acquisition module, configured to acquire the first gray value of the gas absorption band and the second gray value of the gas non-absorption band at the target position point in the spectral image of the area to be detected;

[0032] A reconstruction module, configured to determine the measured absorption band radiation data corresponding to the first gray value, and reconstruct the theoretical absorption band radiation data based on the second gray value;

[0033] A detection module, configured to extract the gas radiation difference value based on the measured absorption band radiation data and the theoretical absorption band radiation data, and perform leakage detection on the gas radiation difference value based on threshold segmentation to obtain a gas leakage detection result.

[0034] Further, the reconstruction module is specifically configured to determine the non-absorption band background temperature corresponding to the second gray value based on the temperature calibration mapping relationship; determine the absorption band background temperature of the gas absorption band from the non-absorption band background temperature, and reconstruct the theoretical absorption band radiation data based on the absorption band background temperature; wherein, the temperature calibration mapping relationship is obtained by solving the linear relationship between the gray value variable and the non-absorption band background temperature variable based on the least squares method.

[0035] Further, the reconstruction module is specifically further configured to determine the background radiation data corresponding to the absorption band background temperature based on Planck's law; determine the theoretical absorption band radiation data based on the background radiation data, the atmospheric path radiation, and the corrected atmospheric transmittance.

[0036] Further, the device further includes: a calculation module.

[0037] The acquisition module is further configured to acquire the environmental humidity, environmental temperature, atmospheric pressure, and vapor pressure of the area to be detected;

[0038] The calculation module is configured to determine the water vapor concentration based on the ambient humidity, the ambient temperature, the atmospheric pressure, and the vapor pressure, and calculate the atmospheric transmittance based on the water vapor concentration, the absorption coefficient of water vapor, and the optical path length, so as to obtain the corrected atmospheric transmittance.

[0039] Further, the reconstruction module is further configured to determine the measured absorption band radiation data corresponding to the first gray value based on the radiation calibration mapping relationship; wherein, the radiation calibration mapping relationship is obtained by solving the linear relationship between the gray value variable and the measured absorption band radiation variable based on the least square method.

[0040] Further, the apparatus further includes: a generation module.

[0041] The detection module is specifically configured to perform a difference calculation using the non-absorption band background temperature and the theoretical absorption band radiation data to obtain a gas radiation difference value; perform a leakage comparison on the gas radiation difference value according to threshold segmentation to obtain the gas leakage detection result of the target position point;

[0042] The generation module is configured to traverse the gas leakage detection results of all target positions in the spectral image to generate a gas difference image of the spectral image.

[0043] Further, the determination module is further configured to determine the gas absorption band and the gas non-absorption band of the gas to be detected; collect a spectral image of the area to be detected through a time-synchronized dual-band infrared device, and determine the first gray value corresponding to the target position point and the second gray value corresponding to the gas non-absorption band from the spectral image.

[0044] According to another aspect of the present application, there is provided a storage medium storing at least one executable instruction, and the executable instruction causes a processor to perform operations corresponding to the above-mentioned gas leakage detection method based on image reconstruction.

[0045] According to still another aspect of the present application, there is provided a terminal including: a processor, a memory, a communication interface, and a communication bus, and the processor, the memory, and the communication interface complete communication with each other through the communication bus;

[0046] The memory is used to store at least one executable instruction, and the executable instruction causes the processor to perform operations corresponding to the above-mentioned gas leakage detection method based on image reconstruction.

[0047] By means of the above technical solutions, the technical solutions provided by the embodiments of the present application have at least the following advantages:

[0048] The present application provides a gas leakage detection method, device, medium, and terminal based on image reconstruction. Compared with the prior art, in the embodiments of the present application, the first gray value of the gas absorption band and the second gray value of the gas non-absorption band at the target position point in the spectral image of the area to be detected are obtained; the measured absorption band radiation data corresponding to the first gray value is determined, and the theoretical absorption band radiation data is reconstructed based on the second gray value; the gas radiation difference value is extracted based on the measured absorption band radiation data and the theoretical absorption band radiation data, and leakage detection is performed on the gas radiation difference value through threshold segmentation to obtain the gas leakage detection result. By performing leakage detection through the difference value, the signal-to-noise ratio of the spectral image is improved, the applicable range of gas detection is greatly improved, and the inversion of the theoretical background radiation is realized by using the same background temperature characteristic, greatly improving the detection accuracy and effectiveness of gas leakage.

[0049] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features, and advantages of the present application more obvious and understandable, the specific embodiments of the present application are specifically described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present application. And throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0051] Figure 1 shows a flowchart of a gas leakage detection method based on image reconstruction provided by an embodiment of the present application;

[0052] Figure 2 shows a schematic diagram of three-layer atmospheric radiation transmission provided by an embodiment of the present application;

[0053] Figure 3 shows a schematic diagram of the detection result of the actually released gas of SF6 provided by an embodiment of the present application;

[0054] Figure 4 shows a schematic diagram of the detection results of the actually released gases of SF6 and NH3 in the field provided by an embodiment of the present application;

[0055] Figure 5 shows a block diagram of a gas leakage detection device based on image reconstruction provided by an embodiment of the present application;

[0056] Figure 6 shows a schematic diagram of the structure of a terminal provided by an embodiment of the present application. Detailed implementation manners

[0057] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art.

[0058] An embodiment of the present application provides a gas leakage detection method based on image reconstruction. As Figure 1 shown, the method includes:

[0059] 101 Obtain a first gray value of a gas absorption band and a second gray value of a gas non-absorption band at a target position point in the spectral image of the area to be detected.

[0060] In the embodiment of the present application, the spectral image of the area to be detected is an infrared detector that performs infrared imaging on the gas that may leak, such as an infrared video imaging system. At this time, the infrared detector can scan and obtain the infrared radiation of the background and the expected leaked gas in the area to be detected and output it in the form of a spectral image. Among them, in order to be applicable to the detection of various gas leaks, a dual-band radiation collection spectral image is adopted. At this time, the central wavelengths of the gas absorption band and the gas non-absorption band are selected based on the gas that may leak for infrared detection and scanning to obtain spectral images corresponding to different central wavelengths. Furthermore, a target position point in the spectral image is selected, such as a pixel point in the spectral image, to obtain two gray values corresponding to this target position point, that is, the first gray value of the gas absorption band and the second gray value of the gas non-absorption band at this target position point. Corresponding spectral images, and then, a target position point in the spectral image is selected, such as a pixel point in the spectral image, to obtain two gray values corresponding to this target position point, that is, the first gray value of the gas absorption band and the second gray value of the gas non-absorption band at this target position point.

[0061] It should be noted that the current execution end, as the execution main body for gas leakage detection, can be a computer device such as a server. Among them, the server can be an independent server or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, Content Delivery Network (CDN), and big data and artificial intelligence platforms. The embodiments of the present application do not make specific limitations.

[0062] 102 Determine the measured absorption band radiation data corresponding to the first gray value, and reconstruct the theoretical absorption band radiation data based on the second gray value.

[0063] In the embodiment of the present application, since the background temperature in the gas absorption band is the same as the background temperature in the gas non-absorption band, the measured absorption band radiation data can be determined based on the first gray value detected in the gas absorption band. At the same time, the second gray value detected in the gas non-absorption band is used for inversion and reconstruction to obtain the theoretical absorption band radiation data with the gas absorption band as the theoretical background.

[0064] It should be noted that since the radiation data in the embodiment of the present application is affected by factors such as the atmosphere and the environment when detected by the detector, the transmission process of the gas in the environment is usually described by the infrared layer radiation transfer model (Layer Model), that is, the transmission path of the infrared radiation is divided into a series of parallel layers, and the input radiation of each layer is the output radiation of the previous layer, and the output radiation of the current layer is used as the input radiation of the next layer. The infrared layer radiation transfer model assumes that the infrared radiation of the background and the leaking gas is transmitted between a series of spatially parallel layers. To simplify the infrared layer radiation transfer model, in the embodiment of the present application, it is assumed that the gas distribution in each atmospheric transmission layer and the gas distribution in the leaking gas layer are both uniform. Therefore, the infrared radiation transfer model can be simplified to three layers, that is, with the leaking gas cloud as the dividing line, the transmission path from the background to the infrared detector is divided into three parts: the background, the target gas to be measured, and the infrared detection instrument. Therefore, when determining the theoretical absorption band radiation data, it is reconstructed using the second gray value on the premise that the background temperature is set to be the same.

[0065] 103. Extract the gas radiation difference value based on the measured absorption band radiation data and the theoretical absorption band radiation data, and perform leakage detection on the gas radiation difference value based on threshold segmentation to obtain the gas leakage detection result.

[0066] In the embodiment of the present application, for the extraction of the gas radiation difference value, the difference can be obtained based on the measured absorption band radiation data and the theoretical absorption band radiation data, and then the threshold segmentation method is used to perform leakage detection on the gas radiation difference value to obtain the gas leakage detection result. Among them, the radiation threshold corresponding to the threshold segmentation method can be configured based on the leakage radiation range of different target gases, so that when it is greater than this radiation threshold, it is determined that there is a leakage of the target gas.

[0067] In another embodiment of the present application, for further limitation and explanation, the step of reconstructing the theoretical absorption band radiation data based on the second gray value includes:

[0068] Determine the non-absorption band background temperature corresponding to the second gray value based on the temperature calibration mapping relationship;

[0069] Determine the absorption band background temperature of the gas absorption band from the non-absorption band background temperature, and reconstruct the theoretical absorption band radiation data based on the absorption band background temperature.

[0070] In order to achieve the purpose of reconstructing the radiation of the target gas in the absorption band under theoretical conditions by using the gray value in the non-absorption band of the gas in the spectral image, so as to improve the accuracy of gas leakage detection. When the current execution end reconstructs the theoretical absorption band radiation data, it first determines the non-absorption band background temperature corresponding to the second gray value based on the temperature calibration mapping relationship. At this time, the temperature calibration mapping relationship is obtained by solving the linear relationship between the gray value variable and the non-absorption band background temperature variable based on the least square method. In the embodiments of the present application, in the case where the target gas to be detected is relatively uniform on the gas surface, the thermal properties of the gas surface material are stable, and the wavelength range collected by the infrared video imaging system is relatively narrow, the gray value of the infrared image and the radiation data on the surface of the target gas can be determined as a linear relationship. Therefore, in the embodiments of the present application, an infrared system is calibrated using a radiation source with a preset temperature.

[0071] In some embodiments, for the temperature calibration mapping relationship, spectral images of radiation sources at different temperatures are first collected. For example, the radiation source temperatures are set to be 30°C to 60°C, with a temperature point every 5°C. Since the signals detected by the infrared video imaging system may be unstable and there may be errors in the radiation source temperature, in order to ensure the accuracy of the radiation calibration result, the method of taking the average value multiple times is used to select the radiation source data of consecutive frames at each temperature point, a total of 100 frames. Furthermore, according to the collected gray values and the radiation data of the radiation source, a gray-temperature curve is plotted. Here, the gray value is the digital value output by the detector, that is, the DN value. The conversion relationship between the DN value and the temperature data is obtained by using the linear fitting method. That is, the temperature calibration mapping relationship is expressed as a linear relationship between the absorption band background temperature and the digital value DN of the collected data: , where represents the non-absorption band background temperature at the position (m, n) on the spectral image, the central wavelength λ, and the radiation source temperature T k under the condition, k is the Boltzmann constant, are the responsivity and response offset of the infrared video imaging system respectively. For in the above temperature calibration mapping relationship, the least square algorithm can be used to solve the temperature calibration coefficients in the above formula, so as to obtain the temperature calibration mapping relationship for solving the non-absorption band background temperature corresponding to the second gray value.

[0072] It should be noted that after obtaining the background temperature in the non-absorption band, since the gas distribution in each atmospheric transmission layer and the gas distribution in the leaked gas layer are both uniform, the infrared radiation transmission can be simplified to three layers, namely, including the background, the gas to be measured, and the data collected by the infrared video imaging system. At this time, for the background temperature of the target gas that may have leakage, the temperature values in the gas absorption band and the gas non-absorption band are the same. Therefore, the background temperature in the non-absorption band is determined as the absorption band background temperature in the gas absorption band. Furthermore, the theoretical absorption band radiation data can be reconstructed based on the absorption band background temperature.

[0073] In another embodiment of the present application, for further limitation and explanation, the step of reconstructing the theoretical absorption band radiation data based on the absorption band background temperature includes:

[0074] Determining the background radiation data corresponding to the absorption band background temperature based on Planck's law;

[0075] Determining the theoretical absorption band radiation data based on the background radiation data, the atmospheric path radiation, and the corrected atmospheric transmittance.

[0076] In order to achieve the purpose of detecting leaked gas based on the reconstructed theoretical absorption band radiation and improve the effectiveness of gas leakage detection, when the current execution end reconstructs the theoretical absorption band radiation data based on the absorption band background temperature, specifically, first, the background radiation data corresponding to the absorption band background temperature is determined based on Planck's law, that is , is the central wavelength of the gas absorption band, T is the background temperature of the absorption band, and furthermore, the theoretical absorption band radiation data is determined based on the background radiation data, the atmospheric path radiation, and the corrected atmospheric transmittance. Among them, the theoretical absorption band radiation data is used as the theoretical measurement background radiation received after atmospheric attenuation and atmospheric path radiation, and the calculation method is expressed as , is the central wavelength is the corrected atmospheric transmittance at the central wavelength is the central wavelength is the atmospheric path radiation at the central wavelength.

[0077] In some measured embodiments, in the infrared video imaging system, the radiation transmission path is set in a uniform atmosphere. At this time, the atmospheric transmittance is When there is no target gas with expected leakage in the scene, the detector entrance pupil radiation data consists of two parts, including: 1. The radiance after atmospheric attenuation of the thermal radiation from the observation background and the thermal radiation reflected by surrounding objects in the observation background; 2. Atmospheric path radiation. It should be noted that the infrared radiation of the background also includes the reflected radiation of other objects, but usually the reflection ability of other objects to radiation is weak. Therefore, it is assumed that the infrared radiation detected by the detector is the infrared radiation emitted by the background. At this time, the radiation formula of the entrance pupil radiation data when there is no target gas in the path is expressed as:

[0078] ;

[0079] Among them, is the central wavelength and the background temperature The background radiation data detected below, is the atmospheric path radiation. Among them, the background radiation data can be equivalently regarded as the radiation data emitted by a radiation source with an emissivity of . At this time, at the central wavelength and the background temperature The radiation data of the equivalent radiation source can be calculated according to Planck's law, which is not specifically limited in the embodiments of the present application. When there is a target gas in the scene, the radiation data detected by the detector includes three parts: 1. The energy of the thermal radiation from the observation background and the thermal radiation reflected by surrounding objects in the observation background after being absorbed by the gas; 2. The self-thermal radiation of the gas; 3. The atmospheric path radiation, as shown in Figure 2 . At this time, the radiation formula of the detector entrance pupil radiation data is expressed as:

[0080] ; Among them, represents the background radiation data detected at the central wavelength and the background temperature , is the gas transmittance, is the self-radiation data of the target gas, is the atmospheric path radiation, that is, the detector entrance pupil radiation data is mainly the thermal radiation from the background after being absorbed by the gas with a transmittance of and the radiation data after atmospheric attenuation, the thermal radiation from the gas itself after atmospheric attenuation, and the atmospheric path radiation . According to Kirchhoff's law, under the condition of thermodynamic equilibrium, the absorptivity of the gas is equal to the emissivity. At this time, the sum of the emissivity and the transmittance of the gas is set to 1. Therefore, the gas emissivity can be expressed as 1 minus the transmittance, that is Furthermore, subtracting the pupil radiation data with the target gas present from that without the target gas can eliminate the above parameters and obtain the amplitude data corresponding to the gas absorption. , which is expressed as:

[0081] ; At this time, the infrared radiation data of the target gas and the atmospheric transmittance , the transmittance of the target gas , the gas temperature, and the radiation data of the background object are directly related. is the radiation data of the equivalent radiation source at the background temperature , is the radiation data of the equivalent radiation source at the radiation source temperature , and both can be calculated based on Planck's law. The embodiments of the present application do not make specific limitations.

[0082] In the above-mentioned measured embodiment, in the dual-band radiation transmission path without the target gas, the change in the radiation data of the dual-band is mainly caused by the band. After detection using different central wavelengths , , the following is obtained:

[0083] ;

[0084] .

[0085] During the actual measurement, it is found that the main components of the uniform atmosphere that absorb infrared radiation are nitrogen (78.084%), oxygen (20.946%), water, and carbon dioxide (390 ppm). In the wavelength range of 7 μm - 14 μm, the effects of nitrogen and oxygen can be ignored. At this time, water vapor is the dominant absorption component, especially at both ends of the band, while carbon dioxide only has a weak effect near 14 μm. Therefore, under the condition of assuming a uniform atmosphere, only water vapor affects the atmospheric transmittance. That is, the radiation formula of the pupil radiation data without the target gas is simplified to the radiation data of water vapor at the atmospheric temperature T (i.e., the ambient temperature). The radiation formula is expressed as:

[0086] , where is the equivalent radiation source temperature at the central wavelength . Finally, it can be deduced through that , is the measured absorption band radiation data obtained through calibration, is the reconstructed theoretical measurement background radiation.

[0087] In another embodiment of the present application, for further limitation and illustration, the steps further include:

[0088] Obtain the environmental humidity, environmental temperature, atmospheric pressure, and vapor pressure of the area to be detected;

[0089] Determine the water vapor concentration based on the environmental humidity, environmental temperature, atmospheric pressure, and vapor pressure, and calculate the atmospheric transmittance based on the water vapor concentration, the absorption coefficient of water vapor, and the optical path length to obtain the corrected atmospheric transmittance.

[0090] In order to reduce the influence of environmental temperature and humidity and other states on gas radiation absorption, thereby improving the detection accuracy of gas leakage, before the current execution end determines the theoretical absorption band radiation data based on the background radiation data, atmospheric path radiation, and corrected atmospheric transmittance, it first obtains the environmental humidity, environmental temperature, atmospheric pressure, and vapor pressure of the area to be detected. At this time, the measured environmental humidity can be converted into water vapor concentration, and the conversion formula is:

[0091] ; where RH is the environmental humidity, is the saturated vapor pressure at the environmental temperature , P is the atmospheric pressure. Further, the atmospheric transmittance at the central wavelength can be calculated according to the Lambert-Beer law, expressed as:

[0092] ;

[0093] where, is the absorption coefficient of water vapor, d is the optical path length of water vapor, and the atmospheric transmittance calculated according to the measured relative humidity and the optical path length of water vapor passing through .

[0094] In some actual measurement embodiments, collect the atmospheric parameters of the detection area, such as temperature, humidity, and pressure, and call the HITRAN database to calculate the atmospheric transmittance, that is, calculate the atmospheric transmittance of the gas absorption band and the gas non-absorption band respectively , , as well as the atmospheric path radiation , . Since only the influence of water vapor is considered when calculating the atmospheric transmittance, the relative humidity of water vapor is used to calculate the water vapor volume fraction, and the saturated water vapor pressure is calculated according to the temperature and pressure (using the Magnus formula), expressed as:

[0095] ; furthermore, the atmospheric transmittance can be calculated through the Lambert-Beer law , by considering the gas as a uniform atmosphere, the average atmospheric transmittance in the absorption band and non-absorption band can be obtained.

[0096] In another embodiment of the present application, for further limitation and illustration, the step of determining the measured absorption band radiation data corresponding to the first gray value includes:

[0097] Determining the measured absorption band radiation data corresponding to the first gray value based on the radiation calibration mapping relationship.

[0098] In order to use the linear relationship between the gray value and the radiation data as the basis for determining the measured absorption band radiation data, thereby improving the accuracy of gas leakage detection, the current execution end determines the measured absorption band radiation data corresponding to the first gray value based on the radiation calibration mapping relationship, where the radiation calibration mapping relationship is obtained by solving the linear relationship between the gray value variable and the measured absorption band radiation variable based on the least squares method. In the embodiments of the present application, when the surface of the target gas is relatively uniform, the thermal properties of the target gas surface material are stable, and the wavelength range collected by the system is relatively narrow, the gray value of the spectral image and the radiation data on the surface of the target gas can be set as a linear relationship. Therefore, in order to obtain reliable radiation data, a radiation source with a preset temperature is used to calibrate the infrared video imaging system, that is, through the radiation calibration mapping relationship, the conversion relationship between the gray value and the radiation data in the infrared video imaging system can be calculated. Specifically, the process of radiation calibration enables the spectral gas image to more accurately reflect the radiation distribution on the target surface. At this time, the response of the system spectral channels is set to be uniform. Therefore, each channel corresponds to a radiation calibration curve, according to the central wavelength In the detected spectral image, for the pixel with coordinates (m, n), the temperature of the radiation source is When, the radiation data detected by the detector and the digital values of the collected data are respectively , , and the linear calibration formula is expressed as:

[0099] , where, Represents the gas absorption band radiation data at the position point (m, n) on the spectral image, with the central wavelength , the radiation source temperature T k Under the condition, k is the Boltzmann constant, Are the responsivity and response offset of the infrared video imaging system respectively. For In the above radiation calibration mapping relationship, the least squares algorithm can be used to solve the radiation calibration coefficients in the above formula, so as to obtain the radiation calibration mapping relationship for solving the gas absorption band radiation data corresponding to the second gray value.

[0100] In another embodiment of the present application, for further limitation and illustration, the steps of extracting the gas radiation difference value based on the measured absorption band radiation data and the theoretical absorption band radiation data, and performing leakage detection on the gas radiation difference value based on threshold segmentation to obtain the gas leakage detection result include:

[0101] Performing difference calculation using the non-absorption band background temperature and the theoretical absorption band radiation data to obtain the gas radiation difference value;

[0102] Performing leakage comparison on the gas radiation difference value according to threshold segmentation to obtain the gas leakage detection result of the target position point.

[0103] In order to extract the target gas that may have leaked gas, thereby improving the detection accuracy of gas leakage, the current execution end first performs difference calculation using the non-absorption band background temperature and the theoretical absorption band radiation data to obtain the gas radiation difference value, expressed as . Furthermore, leakage judgment is performed on the gas radiation difference value according to threshold segmentation to obtain the gas leakage detection result of the target position point. Among them, for different target gases that may have leaks, different thresholds can be set, so as to compare the gas radiation difference value . For example, when the gas radiation difference value is greater than the threshold, it is determined that there is a leak of the target gas. The specific setting of the threshold in the embodiment of the present application is not specifically limited.

[0104] Correspondingly, in order to draw the gas leakage situation of all position points in the spectral image, the steps further include: traversing the gas leakage detection results of all target positions in the spectral image to generate the gas difference image of the spectral image.

[0105] In some embodiments, the current execution end can perform leakage identification on a position point (m, n) in the spectral image, and then traverse and identify all position points in the spectral image, and render the position points with gas leakage detection results where there is leakage to generate a gas difference image containing the gas leakage distribution for viewing.

[0106] In another embodiment of the present application, for further limitation and illustration, the steps of obtaining the first gray value of the gas absorption band and the second gray value of the gas non-absorption band at the target position point in the spectral image to be detected include:

[0107] Determine the gas absorption band and the gas non-absorption band of the gas to be detected;

[0108] Collect the spectral image of the area to be detected by a time-synchronized dual-band infrared device, and determine the first grayscale value corresponding to the target position point and the second grayscale value corresponding to the gas non-absorption band from the spectral image.

[0109] To accurately improve the accuracy of gas leakage detection, when the current execution end obtains the first grayscale value and the second grayscale value, it first determines the gas absorption band and the gas non-absorption band of the target gas to be detected that may have leakage. At this time, the gas absorption band is used to characterize the central wavelength that can be absorbed by the gas after the radiation source emits, and the gas non-absorption band is used to characterize the central wavelength that cannot be absorbed by the gas after the radiation source emits, so as to use the above two bands for infrared detection to obtain a spectral image. At this time, the selection of the gas absorption band needs to meet the gas absorption coefficient to be greater than the gas absorption coefficient of the gas non-absorption band .

[0110] In addition, when performing infrared detection, to ensure the stability of radiation absorption, it is collected by a time-synchronized dual-band infrared device, that is, the spectral image of the area to be detected is collected by a time-synchronized dual-band infrared video imaging system, and then a target position point, such as (m, n), is selected as the extraction position of the first grayscale value and the corresponding second grayscale value, which is not specifically limited in the embodiments of the present application.

[0111] In a specific implementation scenario, the target gas that may have leakage is set as SF6, and the corresponding gas absorption band (SF6 is at a strong absorption peak), and the gas non-absorption band . The atmospheric parameters of the area to be detected include a temperature of 25 °C, a humidity of 40%, and a pressure of 1013 pa. After calculating the saturation water vapor pressure and water vapor concentration according to the Magnus formula and obtaining the water vapor absorption coefficient under these atmospheric parameter conditions using HITRAN data, the atmospheric transmittance and atmospheric path radiation in the two-band case can be calculated according to the Lambert-Beer law. Specifically, in the band range with a central wavelength of 10.55 micrometers and a wavelength width of 0.7 micrometers, the atmospheric transmittance is , and at this time the atmospheric emissivity is . The atmospheric path radiation at an ambient temperature of 25 °C is the radiation source condition multiplied by the atmospheric emissivity. Therefore, the radiation data of the equivalent radiation source under the condition that the radiation source is at an absolute temperature T = 25 + 273.15 °C can be calculated by Planck's law, expressed as:

[0112] ;

[0113] Among them, is the first radiation constant, is the second radiation constant, denotes the Planck constant, with a value of 6.6×10 -34 W·s 2 , c is the speed of light in vacuum, with a value of 3.0× 10 10 cm / s -1 , k is the Boltzmann constant, with a value of 1.4×10 -23 J·K -1 , and the calculated . By collecting spectral data of the radiation source at different temperatures multiple times, the corresponding atmospheric path radiation value can be calculated . At this time, set the radiation source temperatures to 30°C to 60°C, with a temperature point every 5°C. After the radiation source temperature is stable and the infrared video imaging system is in a stable operating state, since the measurement signals of the infrared multi-video imaging system may be unstable and there may be errors in the radiation source temperature, to ensure the accuracy of the radiation calibration results, use the infrared video imaging system to image the radiation source multiple times and take the average value. During the actual measurement process, 100 consecutive frames of data of the radiation source at each temperature point are collected, and spectral data of the radiation source at different temperatures are collected multiple times, so as to calculate radiation correction, and temperature correction. At this time, for the point at position (m, n) on the spectral image, the DN values measured in two bands are respectively and . From the temperature correction and radiation correction results, and can be obtained. Under the condition that the background temperatures in the gas absorption band and the gas non-absorption band are the same and the emissivity is set to 1, reconstruct the radiation that should be received theoretically after the background in the gas absorption band is attenuated by the atmosphere and the atmospheric path radiation . Finally, calculate the gas radiation difference . Based on this difference value, judge whether there is gas leakage at the (m, n) position point on the image. As Figure 3 shown. Finally, traverse the entire image for calculation to obtain the gas differential image, as Figure 4 shown.

[0114] In an embodiment of the present application, a gas leakage detection method based on image reconstruction is provided. Compared with the prior art, in the embodiment of the present application, the first gray value of the gas absorption band and the second gray value of the gas non-absorption band at the target position point in the spectral image of the area to be detected are obtained; the measured absorption band radiation data corresponding to the first gray value is determined, and the theoretical absorption band radiation data is reconstructed based on the second gray value; the gas radiation difference value is extracted based on the measured absorption band radiation data and the theoretical absorption band radiation data, and leakage detection is performed on the gas radiation difference value based on threshold segmentation to obtain the gas leakage detection result. By performing leakage detection through the difference value, the signal-to-noise ratio of the spectral image is improved, the applicable range of gas detection is greatly improved, and the inversion of the theoretical background radiation is realized by using the same background temperature characteristic, greatly improving the detection accuracy and effectiveness of gas leakage.

[0115] Further, as an implementation of the method described above Figure 1 shown, an embodiment of the present application provides a gas leakage detection device based on image reconstruction, as Figure 5 shown, the device includes:

[0116] An acquisition module 21, configured to acquire the first gray value of the gas absorption band and the second gray value of the gas non-absorption band at the target position point in the spectral image of the area to be detected;

[0117] A reconstruction module 22, configured to determine the measured absorption band radiation data corresponding to the first gray value, and reconstruct the theoretical absorption band radiation data based on the second gray value;

[0118] A detection module 23, configured to extract the gas radiation difference value based on the measured absorption band radiation data and the theoretical absorption band radiation data, and perform leakage detection on the gas radiation difference value based on threshold segmentation to obtain the gas leakage detection result.

[0119] Further, the reconstruction module is specifically configured to determine the non-absorption band background temperature corresponding to the second gray value based on the temperature calibration mapping relationship; determine the absorption band background temperature of the gas absorption band based on the non-absorption band background temperature, and reconstruct the theoretical absorption band radiation data based on the absorption band background temperature; wherein, the temperature calibration mapping relationship is obtained by solving the linear relationship between the gray value variable and the non-absorption band background temperature variable based on the least squares method.

[0120] Further, the reconstruction module is specifically further configured to determine the background radiation data corresponding to the absorption band background temperature based on Planck's law; determine the theoretical absorption band radiation data based on the background radiation data, the atmospheric path radiation, and the corrected atmospheric transmittance.

[0121] Further, the device further includes: a calculation module.

[0122] The acquisition module is further configured to acquire the environmental humidity, environmental temperature, atmospheric pressure, and vapor pressure of the area to be detected;

[0123] The calculation module is configured to determine the water vapor concentration based on the environmental humidity, environmental temperature, atmospheric pressure, and vapor pressure, and calculate the atmospheric transmittance based on the water vapor concentration, the absorption coefficient of water vapor, and the optical path length, so as to obtain the corrected atmospheric transmittance.

[0124] Further, the reconstruction module is further configured to determine the measured absorption band radiation data corresponding to the first gray value based on the radiation calibration mapping relationship; wherein, the radiation calibration mapping relationship is obtained by solving the linear relationship between the gray value variable and the measured absorption band radiation variable based on the least squares method.

[0125] Further, the device further includes: a generation module.

[0126] The detection module is specifically configured to perform difference calculation using the non-absorption band background temperature and the theoretical absorption band radiation data to obtain a gas radiation difference value; perform leakage comparison on the gas radiation difference value according to threshold segmentation to obtain the gas leakage detection result of the target position point;

[0127] The generation module is configured to traverse the gas leakage detection results of all target positions in the spectral image and generate a gas difference image of the spectral image.

[0128] Further, the determination module is further configured to determine the gas absorption band and the gas non-absorption band of the gas to be detected; collect the spectral image of the area to be detected through a time-synchronized dual-band infrared device, and determine the first gray value corresponding to the target position point and the second gray value corresponding to the gas non-absorption band from the spectral image.

[0129] In an embodiment of the present application, a gas leakage detection device based on image reconstruction is provided. Compared with the prior art, in the embodiment of the present application, the first gray value of the gas absorption band and the second gray value of the gas non-absorption band at the target position point in the spectral image of the area to be detected are obtained; the measured absorption band radiation data corresponding to the first gray value is determined, and the theoretical absorption band radiation data is reconstructed based on the second gray value; the gas radiation difference value is extracted based on the measured absorption band radiation data and the theoretical absorption band radiation data, and leakage detection is performed on the gas radiation difference value based on threshold segmentation to obtain a gas leakage detection result. By performing leakage detection through the difference value, the signal-to-noise ratio of the spectral image is improved, the applicable range of gas detection is greatly increased, and the inversion of the theoretical background radiation is realized by using the same background temperature characteristic, greatly improving the detection accuracy and effectiveness of gas leakage.

[0130] According to an embodiment of the present application, a storage medium is provided. The storage medium stores at least one executable instruction, and the computer executable instruction can execute the gas leakage detection method based on image reconstruction in any of the above method embodiments.

[0131] Figure 6 The structural schematic diagram of a terminal provided according to an embodiment of the present application is shown. The specific implementation of the terminal is not limited in the specific embodiments of the present application.

[0132] As Figure 6 shown, the terminal may include: a processor 302, a communication interface 304, a memory 306, and a communication bus 308.

[0133] Among them: the processor 302, the communication interface 304, and the memory 306 communicate with each other through the communication bus 308.

[0134] The communication interface 304 is used to communicate with network elements of other devices such as clients or other servers.

[0135] The processor 302 is used to execute the program 310, and specifically can execute the relevant steps in the embodiment of the gas leakage detection method based on image reconstruction described above.

[0136] Specifically, the program 310 may include program codes, and the program codes include computer operation instructions.

[0137] The processor 302 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application. One or more processors included in the terminal may be of the same type, such as one or more CPUs; or may be of different types, such as one or more CPUs and one or more ASICs.

[0138] The memory 306 is used to store the program 310. The memory 306 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk memory.

[0139] The program 310 is specifically configured to cause the processor 302 to perform the following operations:

[0140] Obtain a first gray value of a gas absorption band and a second gray value of a gas non-absorption band at a target position point in the spectral image of the area to be detected;

[0141] Determine the measured absorption band radiation data corresponding to the first gray value, and reconstruct the theoretical absorption band radiation data based on the second gray value;

[0142] Extract a gas radiation difference value based on the measured absorption band radiation data and the theoretical absorption band radiation data, and perform leakage detection on the gas radiation difference value based on threshold segmentation to obtain a gas leakage detection result.

[0143] Obviously, those skilled in the art should understand that the above-mentioned modules or steps of the present application can be implemented by a general-purpose computing device. They can be concentrated on a single computing device, or distributed on a network composed of multiple computing devices. Optionally, they can be implemented by program codes executable by the computing device, so that they can be stored in the storage device and executed by the computing device. And in some cases, the steps shown or described can be executed in a different order than here, or they can be made into individual integrated circuit modules respectively, or multiple modules or steps among them can be made into a single integrated circuit module to implement. Thus, the present application is not limited to any specific combination of hardware and software.

[0144] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A gas leakage detection method based on image reconstruction, characterized in that, Including: Obtaining a first gray value of a gas absorption band and a second gray value of a gas non - absorption band at a target position point in a spectral image of a region to be detected; Determining measured absorption band radiation data corresponding to the first gray value, and reconstructing theoretical absorption band radiation data based on the second gray value; Extracting a gas radiation difference value based on the measured absorption band radiation data and the theoretical absorption band radiation data, and performing leakage detection on the gas radiation difference value based on threshold segmentation to obtain a gas leakage detection result; The reconstructing the theoretical absorption band radiation data based on the second gray value includes: Determining a non - absorption band background temperature corresponding to the second gray value based on a temperature calibration mapping relationship; Determining the absorption band background temperature of the gas absorption band with the non - absorption band background temperature, and reconstructing theoretical absorption band radiation data based on the absorption band background temperature; Wherein, the temperature calibration mapping relationship is obtained by solving the linear relationship between the gray value variable and the non - absorption band background temperature variable based on the least - squares method.

2. The method according to claim 1, characterized in that The reconstructing the theoretical absorption band radiation data based on the absorption band background temperature includes: Determining background radiation data corresponding to the absorption band background temperature based on Planck's law; Determining theoretical absorption band radiation data based on the background radiation data, atmospheric path radiation, and corrected atmospheric transmittance.

3. The method according to claim 2, characterized in that The method further includes: Obtaining the environmental humidity, environmental temperature, atmospheric pressure, and vapor pressure of the region to be detected; Determining the water vapor concentration based on the environmental humidity, the environmental temperature, the atmospheric pressure, and the vapor pressure, and calculating the atmospheric transmittance based on the water vapor concentration, the absorption coefficient of water vapor, and the optical path length to obtain the corrected atmospheric transmittance.

4. The method according to claim 1, characterized in that, The determining the measured absorption band radiation data corresponding to the first gray value includes: Determining the measured absorption band radiation data corresponding to the first gray value based on a radiation calibration mapping relationship; Wherein, the radiation calibration mapping relationship is obtained by solving the linear relationship between the gray value variable and the measured absorption band radiation variable based on the least - squares method.

5. The method according to claim 1, characterized in that The extracting the gas radiation difference value based on the measured absorption band radiation data and the theoretical absorption band radiation data, and performing leakage detection on the gas radiation difference value based on threshold segmentation to obtain the gas leakage detection result includes: Performing a difference calculation using the non - absorption band background temperature and the theoretical absorption band radiation data to obtain a gas radiation difference value; Performing a leakage comparison on the gas radiation difference value according to threshold segmentation to obtain the gas leakage detection result of the target position point; The method further includes: Traversing the gas leakage detection results of all target positions in the spectral image to generate a gas differential image of the spectral image.

6. The method according to claim 1, characterized in that, The obtaining the first gray value of the gas absorption band and the second gray value of the gas non - absorption band at the target position point in the spectral image of the region to be detected includes: Determining the gas absorption band and the gas non - absorption band of the gas to be detected; Collect the spectral image of the area to be detected by a dual-band infrared device with time synchronization, and determine the first gray value corresponding to the target position point and the second gray value corresponding to the gas non-absorption band from the spectral image.

7. A gas leakage detection device based on image reconstruction, characterized in that, Including: An acquisition module for acquiring the first gray value of the gas absorption band and the second gray value of the gas non-absorption band at the target position point in the spectral image of the area to be detected; A reconstruction module for determining the measured absorption band radiation data corresponding to the first gray value and reconstructing the theoretical absorption band radiation data based on the second gray value; A detection module for extracting the gas radiation difference value based on the measured absorption band radiation data and the theoretical absorption band radiation data, and performing leakage detection on the gas radiation difference value based on threshold segmentation to obtain the gas leakage detection result; The reconstruction module is specifically configured to determine the non-absorption band background temperature corresponding to the second gray value based on the temperature calibration mapping relationship; determine the absorption band background temperature of the gas absorption band from the non-absorption band background temperature, and reconstruct the theoretical absorption band radiation data based on the absorption band background temperature; wherein, the temperature calibration mapping relationship is obtained by solving the linear relationship between the gray value variable and the non-absorption band background temperature variable based on the least squares method.

8. A computer-readable storage medium having computer programs / instructions stored thereon, characterized in that, When the computer program / instructions are executed by a processor, the steps of the method described in claim 1 are implemented.

9. A computer device, comprising a memory, a processor, and a computer program stored on the memory, characterized in that, The processor executes the computer program to implement the steps of the method described in claim 1.

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