A high-sensitivity gas leak detection method based on optical filtering imaging

Abstract

The present invention relates to the field of gas detection technology, and specifically to a high-sensitivity gas leakage detection method based on optical filtering imaging, including setting an adjustable light source to emit multi-band light, adjusting the band and intensity of the light source through an automatic control system, selecting the characteristic absorption band of a specific gas molecule in combination with a bandpass optical filter, using synchronous modulation technology to eliminate ambient light interference, using a CCD camera or a CMOS camera to capture the image of light after passing through a gas leakage area, preprocessing the original image, extracting features from the preprocessed image, identifying the characteristic absorption peak of the gas leakage area, comparing the characteristic absorption spectrum, determining whether there is a gas leakage, calculating the leakage concentration and position, and when a gas leakage is detected, a preset alarm device sends an audible and visual alarm signal, and records the leakage information in a preset database. The present invention significantly improves the sensitivity and accuracy of gas leakage detection, and has good applicability and scalability.

Description

Technical Field

[0001] The present invention relates to the technical field of gas detection, and in particular to a high-sensitivity gas leakage detection method based on optical filtering imaging. Background Art

[0002] With the acceleration of industrialization, various gases have been widely used in industrial production, environmental monitoring and daily life. However, gas leakage not only causes waste of resources, but also poses a serious threat to the environment and human health. Especially in high-risk fields such as petrochemicals, natural gas transportation, and laboratories, gas leakage may lead to major safety accidents such as fire and explosion. Therefore, how to detect gas leakage efficiently and accurately has become an important issue to ensure production safety and environmental protection.

[0003] Existing technologies face the following major technical problems in gas leak detection: first, traditional detection methods have low sensitivity and are difficult to detect low-concentration gas leaks, which can easily lead to missed reports and false alarms; second, ambient light interference has a significant impact on the detection results, making it difficult to ensure the accuracy of the detection; third, the real-time and response speed of the detection system are insufficient, making it impossible to promptly warn and handle gas leakage accidents; finally, the existing system lacks applicability and scalability, making it difficult to adapt to the detection needs of multiple gases and complex environments. Summary of the invention

[0004] Based on the above objectives, the present invention provides a high-sensitivity gas leakage detection method based on optical filtering imaging.

[0005] A high-sensitivity gas leak detection method based on optical filtering imaging comprises the following steps:

[0006] S1, light source configuration: set an adjustable light source in the area where gas leakage may occur. The light source can emit multi-band light, and the band and intensity of the light source can be adjusted according to the detection requirements through a preset automatic control system;

[0007] S2, optical filtering selection: installing a bandpass optical filter between the light source and the preset imaging device;

[0008] S3, synchronous modulation: using a modulation signal of a predetermined frequency to synchronously modulate the light emitted by the adjustable light source to eliminate ambient light interference, enhance the characteristic absorption signal of gas molecules, and improve the detection signal-to-noise ratio;

[0009] S4, image capture: Use a high-resolution CCD camera or CMOS camera as a preset imaging device to capture the image of light after passing through the gas leakage area to ensure the clarity and detail integrity of the image;

[0010] S5, image preprocessing: preprocessing the original image acquired by the imaging device, including denoising, contrast enhancement and filtering, to improve the quality of the image signal and provide a better basis for subsequent image analysis;

[0011] S6, feature extraction and analysis: extract features from the preprocessed image, identify the characteristic absorption peaks of the gas leakage area, determine whether there is a gas leakage by comparing the characteristic absorption spectra, and calculate the leakage concentration and location;

[0012] S7, Alarm and Record: When a gas leak is detected, an audible and visual alarm signal is sent out through the preset alarm device, and the location information, time and concentration of the leak are recorded in the preset database for subsequent analysis.

[0013] Optionally, the adjustable light source is a multi-band laser, which is installed above or around the gas leakage area to ensure that the light can fully cover the area where the leakage may occur. The multi-band laser emits multi-band light, and the emission band and intensity of each laser are adjusted through a preset automatic control system to adapt to the characteristic absorption peaks of different gas molecules, thereby ensuring the sensitivity and accuracy of detection.

[0014] Optionally, the optical filtering options include:

[0015] Bandpass optical filter: Select a bandpass optical filter suitable for the characteristic absorption band of the target gas molecules. The center wavelength of the filter matches the characteristic absorption wavelength of the target gas, and the bandwidth range is 10-50nm;

[0016] Filter installation: Install the bandpass optical filter between the light source and the imaging device, ensuring that the optical axis of the filter is aligned with the optical axis of the light source and the imaging device to avoid light deviation.

[0017] Optionally, the synchronous modulation specifically includes:

[0018] S31, modulation signal generation: using a signal generator to generate a modulation signal of a predetermined frequency;

[0019] S32, light source modulation: applying a modulation signal to the adjustable light source, and synchronously modulating the adjustable light source through a preset modulation circuit, so that the light intensity of the light source changes according to a predetermined frequency, the modulation circuit includes a power amplifier, and the power amplifier is used to drive the adjustable light source;

[0020] Modulation signal formula: The modulated light intensity is expressed as:

[0021] ;

[0022] in, is the modulated light intensity, is the average light intensity of the light source, is the modulation depth, is the modulation frequency, For time;

[0023] S33, synchronous detection: Use a phase-locked amplifier to perform synchronous detection on the received optical signal. The received optical signal is input into the phase-locked amplifier. At the same time, the output of the signal generator is input into the phase-locked amplifier as a reference signal. The phase-locked amplifier extracts the optical signal component with the same frequency as 10kHz and outputs the modulated optical signal.

[0024] Optionally, the graphic capture specifically includes:

[0025] S41, select camera: select CCD camera or CMOS camera with a resolution of at least 5 megapixels;

[0026] S42, Lens selection: Choose a high-quality lens to ensure clear imaging. The focal length and aperture size of the lens should be adapted to the size and distance of the detection area.

[0027] S43, camera parameter setting: setting the appropriate exposure time according to the ambient light conditions and light source intensity to avoid overexposure or underexposure;

[0028] S44, Calibrate the camera: perform geometric calibration using a calibration plate, calculate the camera's intrinsic and extrinsic parameters, apply a distortion correction algorithm to correct the distortion in the image, ensure the accuracy of the spatial position, perform radiation calibration using a standard light source, generate a response curve, apply a correction function, correct the nonlinearity of the camera response, and ensure the accuracy of the light intensity measurement.

[0029] Optionally, the image preprocessing specifically includes:

[0030] S51, denoising: Use median filtering to eliminate noise in the image:

[0031] S52, contrast enhancement: histogram equalization is used to increase the difference between different gray levels in the image, making the details of the image more obvious;

[0032] S53, Filtering: Enhance features in the image by Laplacian filtering.

[0033] Optionally, the step S6 performs feature extraction on the preprocessed image to identify characteristic absorption peaks of the gas leakage area, specifically including:

[0034] S61, feature extraction: extracting features from the preprocessed image through spectral analysis;

[0035] S62, extracting characteristic absorption peaks: analyzing the preprocessed image spectrum and extracting characteristic absorption peaks.

[0036] Optionally, the step S6 determines whether there is a gas leak by comparing the characteristic absorption spectra, and calculates the leakage concentration and location, which specifically includes:

[0037] S63, comparing absorption spectra: comparing the extracted characteristic absorption peaks with known gas absorption spectra;

[0038] S64, determining the concentration and location of gas leakage: determining whether there is gas leakage by comparing the absorption spectra, and calculating the leakage concentration and location.

[0039] Optionally, the alarm and record specifically include:

[0040] S71, sound and light alarm device: The preset sound and light alarm device includes a sound alarm (such as a buzzer, a siren) and a light alarm (such as an LED light, a flash light). The gas concentration threshold is set, and the gas leakage concentration is determined according to the spectrum analysis result. When the gas leakage concentration exceeds this threshold, the sound and light alarm device is triggered through an electronic control signal;

[0041] S72, record information to a database: after a gas leak is detected and an alarm is triggered, the leak information is recorded in a preset database, the leak information including time, gas leak location and gas leak concentration.

[0042] Optionally, the alarm device in S7 further includes a wireless communication unit, through which the leakage information is sent to a remote monitoring center so that emergency measures can be taken in time.

[0043] Beneficial effects of the present invention:

[0044] The present invention adopts a multi-band adjustable light source, and adjusts the band and intensity of the light source according to the detection requirements through an automatic control system to ensure effective detection of the characteristic absorption peaks of different gas molecules. The optical filtering selection step further enhances the detection sensitivity of specific gas leaks. Synchronous modulation technology uses a modulation signal of a predetermined frequency to eliminate ambient light interference and improve the detection signal-to-noise ratio. A high-resolution CCD camera or CMOS camera captures the image of light after passing through the gas leakage area to ensure the clarity and detail integrity of the image. The quality of the image signal is further improved through image preprocessing, including denoising, contrast enhancement and filtering. The spectral analysis algorithm identifies the characteristic absorption peaks of the gas leakage area, and accurately determines whether there is a gas leak by comparing the characteristic absorption spectrum, and calculates the leakage concentration and location. The entire process combines advanced optical technology and image processing algorithms to ensure high sensitivity and accuracy in gas leak detection.

[0045] The present invention realizes real-time monitoring and rapid response to gas leaks. When a gas leak is detected, the preset alarm device can immediately send out an audible and visual alarm signal to remind the operator to take emergency measures in time. The audible and visual alarm device includes a sound alarm and a light alarm, which can be triggered by an electronic control signal to achieve a rapid and obvious alarm effect. At the same time, the location information, time and concentration of the leak will be automatically recorded in the database for subsequent analysis. Through this real-time monitoring and rapid response mechanism, the hazards caused by gas leaks can be effectively reduced and the safety of industrial production and environmental monitoring can be improved.

[0046] The present invention has good scalability and applicability. The multi-band adjustable light source and the tunable bandpass filter can be automatically adjusted according to the characteristic absorption bands of different gases to meet the detection needs of various gases. Synchronous modulation technology and high-resolution imaging devices ensure that the system can maintain high sensitivity and high accuracy under different environmental conditions. The spectral analysis algorithm can be adjusted and optimized according to actual application requirements to improve the detection effect. In addition, the system's integrated database management function can automatically store and manage gas leakage data, providing convenience for the query and analysis of historical data. The overall design is scientific and reasonable, suitable for industrial production, environmental monitoring and other fields, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0048] Figure 1 A schematic diagram of the method steps of an embodiment of the present invention;

[0049] Figure 2 Schematic diagram of feature extraction and analysis steps according to an embodiment of the present invention. DETAILED DESCRIPTION

[0050] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. At the same time, it is explained here that in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and those skilled in the art may also adopt other alternatives to implement some known technologies; and the accompanying drawings are only for more specific description of the embodiments, and are not intended to specifically limit the present invention.

[0051] It should be noted that the references to "one embodiment", "embodiment", "exemplary embodiments", "some embodiments" and the like in the specification indicate that the embodiments described may include specific features, structures or characteristics, but not every embodiment may include the specific features, structures or characteristics. In addition, when a specific feature, structure or characteristic is described in conjunction with an embodiment, it should be within the knowledge of a person skilled in the art to implement such feature, structure or characteristic in conjunction with other embodiments (whether or not explicitly described).

[0052] In general, a term can be understood, at least in part, from its use in context. For example, depending, at least in part, on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in the singular sense, or can be used to describe a combination of features, structures, or characteristics in the plural sense. Additionally, the term "based on" can be understood as not necessarily intended to convey an exclusive set of factors, but can instead, depending, at least in part, on the context, allow for the presence of other factors that are not necessarily explicitly described.

[0053] like Figure 1-Figure 2 As shown, a high-sensitivity gas leak detection method based on optical filtering imaging includes the following steps:

[0054] S1, light source configuration: set an adjustable light source in the area where gas leakage may occur. The light source can emit multi-band light, and the band and intensity of the light source can be adjusted according to the detection requirements through a preset automatic control system;

[0055] S2, optical filtering selection: Install a bandpass optical filter between the light source and the preset imaging device. The filter selects the characteristic absorption band of specific gas molecules to ensure that only light of a specific wavelength is allowed to pass, thereby enhancing the detection sensitivity of specific gas leaks;

[0056] S3, synchronous modulation: using a modulation signal of a predetermined frequency to synchronously modulate the light emitted by the adjustable light source to eliminate ambient light interference, enhance the characteristic absorption signal of gas molecules, and improve the detection signal-to-noise ratio;

[0057] S4, image capture: Use a high-resolution CCD camera or CMOS camera as a preset imaging device to capture the image of light after passing through the gas leakage area to ensure the clarity and detail integrity of the image;

[0058] S5, image preprocessing: preprocessing the original image acquired by the imaging device, including denoising, contrast enhancement and filtering, to improve the quality of the image signal and provide a better basis for subsequent image analysis;

[0059] S6, feature extraction and analysis: extract features from the preprocessed image, identify the characteristic absorption peaks of the gas leakage area, determine whether there is a gas leakage by comparing the characteristic absorption spectra, and calculate the leakage concentration and location;

[0060] S7, Alarm and Record: When a gas leak is detected, an audible and visual alarm signal is sent out through the preset alarm device, and the location information, time and concentration of the leak are recorded in the preset database for subsequent analysis.

[0061] The adjustable light source is a multi-band laser. The multi-band laser is installed above or around the gas leakage area to ensure that the light can fully cover the area where the leakage may occur. The multi-band laser emits multi-band light, and the emission band and intensity of each laser are adjusted through a preset automatic control system to adapt to the characteristic absorption peaks of different gas molecules, thereby ensuring the sensitivity and accuracy of detection.

[0062] Optical filtering options include:

[0063] Bandpass optical filter: Select a bandpass optical filter suitable for the characteristic absorption band of the target gas molecules. The center wavelength of the filter matches the characteristic absorption wavelength of the target gas, and the bandwidth range is 10-50nm;

[0064] Filter installation: Install the bandpass optical filter between the light source and the imaging device, ensuring that the optical axis of the filter is aligned with the optical axis of the light source and the imaging device to avoid light deviation.

[0065] Synchronous modulation specifically includes:

[0066] S31, modulation signal generation: using a signal generator to generate a modulation signal of a predetermined frequency. The modulation signal may be a sine wave, a square wave or other suitable waveform. A suitable modulation frequency is selected, generally in the range of 1 Hz to 100 kHz. When selecting the frequency, ensure to avoid the frequency of the ambient light source (such as electric lamp) to reduce interference.

[0067] S32, light source modulation: applying a modulation signal to the adjustable light source, the modulation circuit may include a power amplifier for driving the light source, and synchronously modulating the adjustable light source through a preset modulation circuit so that the light intensity of the light source changes according to a predetermined frequency;

[0068] Modulation signal formula: The modulated light intensity is expressed as:

[0069] ;

[0070] in, is the modulated light intensity, is the average light intensity of the light source, is the modulation depth, is the modulation frequency, For time;

[0071] S33, synchronous detection: Use a phase-locked amplifier to perform synchronous detection on the received optical signal. The phase-locked amplifier can extract the component with the same frequency as the modulated signal and filter out the noise of other frequencies. The received optical signal is input into the phase-locked amplifier. At the same time, the output of the signal generator is input into the phase-locked amplifier as a reference signal. The phase-locked amplifier extracts the optical signal component with the same frequency as 10kHz and outputs the modulated optical signal.

[0072] Graphics capture specifically includes:

[0073] S41, select camera: select CCD camera or CMOS camera with a resolution of at least 5 megapixels;

[0074] S42, Lens selection: Choose a high-quality lens to ensure clear imaging. The focal length and aperture size of the lens should be adapted to the size and distance of the detection area;

[0075] Focal length: determines the field of view of the lens;

[0076] Aperture: controls the amount of light entering the camera, ensuring proper exposure;

[0077] S43, camera parameter setting: setting the appropriate exposure time according to the ambient light conditions and light source intensity to avoid overexposure or underexposure;

[0078] Gain: Adjust the gain to increase signal strength while keeping the noise level low;

[0079] Frame rate: Set an appropriate frame rate to ensure that the dynamic changes of gas leakage are captured;

[0080] S44, Calibrate the camera: perform geometric calibration using a calibration plate, calculate the camera's intrinsic and extrinsic parameters, apply a distortion correction algorithm to correct the distortion in the image, ensure the accuracy of the spatial position, perform radiation calibration using a standard light source, generate a response curve, apply a correction function, correct the nonlinearity of the camera response, and ensure the accuracy of the light intensity measurement.

[0081] Image preprocessing specifically includes:

[0082] S51, denoising: Use median filtering to eliminate noise in the image and retain the main information of the image. The median filter removes noise by replacing each pixel value of the image with the median value of the pixel values ​​in its neighborhood. The formula for median filtering is:

[0083] ;

[0084] in, is the original image, is the image after median filtering, median means taking the median operation, is half the window size:

[0085] S52, enhancing contrast: improving the difference between different gray levels in the image through histogram equalization, making the details of the image more obvious. Histogram equalization adjusts the gray level distribution of the image to make the gray level of the image more uniform and enhance the contrast. The steps are as follows:

[0086] (1) Calculate the grayscale histogram of the image : ;

[0087] in, Indicates grayscale, ranging from 0 to 255. is the Kroneckerdelta function, when 1 when it is, otherwise 0;

[0088] (2) Calculate the cumulative distribution function : ;

[0089] (3) Calculate the grayscale after equalization: ,in: and is the width and height of the image, is the smallest non-zero value in the cumulative distribution function;

[0090] S53, filtering: Enhance the features in the image, such as edges, textures, etc., through Laplace filtering. The Laplace filter detects the edges in the image by calculating the second-order derivative of the image. The formula of Laplace filtering is:

[0091] ;

[0092] in, is the original image, is the image after Laplace filtering, is the Laplace kernel function, for example: ;

[0093] Through these preprocessing steps, the quality of the image can be significantly improved, providing a better basis for subsequent image analysis.

[0094] In S6, feature extraction is performed on the preprocessed image to identify the characteristic absorption peaks of the gas leakage area, specifically including:

[0095] S61, feature extraction: extract features from the preprocessed image through spectral analysis. Spectral analysis is used to identify characteristic absorption peaks of gas molecules. The type and concentration of the gas are determined by analyzing the spectral information of the image. The steps are as follows:

[0096] (1) Use Fourier transform to convert the image from the spatial domain to the frequency domain, expressed as:

[0097] in, is the intensity value in the image space domain, is the spectrum of the image in the frequency domain;

[0098] (2) Calculate the amplitude spectrum of the frequency spectrum :

[0099] ;

[0100] in, and are the real and imaginary parts of the spectrum, respectively;

[0101] S62, extracting characteristic absorption peaks: analyzing the preprocessed image spectrum and extracting characteristic absorption peaks;

[0102] (3) Extract characteristic absorption peaks: Extract characteristic absorption peaks through spectrum analysis:

[0103] ;

[0104] in, is the position of the characteristic absorption peak, is the amplitude of the characteristic absorption peak.

[0105] In S6, by comparing the characteristic absorption spectra, it is determined whether there is a gas leak and the leakage concentration and location are calculated, including:

[0106] S63, comparing absorption spectra: comparing the extracted characteristic absorption peaks with known gas absorption spectra;

[0107] (4) Compare absorption spectra: Compare the extracted characteristic absorption peaks with known gas absorption spectra

[0108] ;

[0109] in, The reference absorption spectrum is at position The absorption peak intensity at

[0110] S64, determining the concentration and location of gas leakage: determining whether there is gas leakage by comparing the absorption spectra, and calculating the leakage concentration and location;

[0111] (5) Calculation of leakage concentration: gas concentration It can be calculated by the intensity ratio of the characteristic absorption peak to the intensity ratio of the reference absorption spectrum:

[0112] ,in, is the proportionality coefficient;

[0113] (6) Determine the leak location: Determine the location of the gas leak by image coordinates: ;

[0114] Through the above steps, spectral analysis can be used to extract features from the preprocessed image, identify the characteristic absorption peaks of the gas leakage area, determine the gas leakage situation by comparing the characteristic absorption spectra, and calculate the leakage concentration and location.

[0115] Alarm and record include:

[0116] S71, sound and light alarm device: The preset sound and light alarm device includes a sound alarm (such as a buzzer, a siren) and a light alarm (such as an LED light, a flash light). The gas concentration threshold is set, and the gas leakage concentration is determined according to the spectrum analysis result. When the gas leakage concentration exceeds this threshold, the sound and light alarm device is triggered through an electronic control signal;

[0117] When a gas leak is detected, the sound and light alarm device is triggered:

[0118] Sound alarm signal: trigger buzzer or siren;

[0119] Light alarm signal: trigger LED light or flash light;

[0120] S72, recording information to a database: after a gas leak is detected and an alarm is triggered, the leak information is recorded in a preset database, the leak information including time, gas leak location and gas leak concentration;

[0121] Through these steps, an audible and visual alarm signal can be issued in time when a gas leak is detected, and the location information, time and concentration of the leak can be recorded in the database for subsequent analysis and processing;

[0122] The alarm device in S7 also includes a wireless communication unit, which sends the leakage information to a remote monitoring center through the wireless communication unit so that emergency measures can be taken in time.

[0123] The present invention covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present invention. In order to make the public have a thorough understanding of the present invention, specific details are described in detail in the following preferred embodiments of the present invention, but those skilled in the art can fully understand the present invention without the description of these details. In addition, in order to avoid unnecessary confusion about the essence of the present invention, well-known methods, processes, procedures, components and circuits are not described in detail.

[0124] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A high-sensitivity gas leak detection method based on optical filtering imaging, characterized in that: The following steps are involved: S1, light source configuration: set an adjustable light source in the area where gas leakage occurs, and adjust the wavelength and intensity of the light source according to the detection requirements through a preset automatic control system; S2, optical filtering selection: installing a bandpass optical filter between the light source and the preset imaging device; S3, synchronous modulation: using a modulation signal of a predetermined frequency to synchronously modulate the light emitted by the adjustable light source to eliminate ambient light interference, enhance the characteristic absorption signal of gas molecules, and improve the detection signal-to-noise ratio. The synchronous modulation specifically includes: S31, modulation signal generation: using a signal generator to generate a modulation signal of a predetermined frequency; S32, light source modulation: applying a modulation signal to the adjustable light source, and synchronously modulating the adjustable light source through a preset modulation circuit, so that the light intensity of the light source changes according to a predetermined frequency, the modulation circuit includes a power amplifier, and the power amplifier is used to drive the adjustable light source; Modulation signal formula: The modulated light intensity is expressed as: ; in, is the modulated light intensity, is the average light intensity of the light source, is the modulation depth, is the modulation frequency, For time; S33, synchronous detection: using a phase-locked amplifier to perform synchronous detection on the received optical signal, input the received optical signal into the phase-locked amplifier, and input the output of the signal generator into the phase-locked amplifier as a reference signal, the phase-locked amplifier extracts the optical signal component with the same frequency as 10kHz, and outputs a modulated optical signal; S4, image capture: using a CCD camera or a CMOS camera as a preset imaging device to capture an image of light after passing through the gas leakage area; The graphic capture specifically includes: S41, select camera: select CCD camera or CMOS camera; S42, lens selection: the focal length and aperture size of the lens are adapted to the size and distance of the detection area; S43, camera parameter setting: setting exposure time according to ambient light conditions and light source intensity to avoid overexposure or underexposure; S44, calibrate the camera: perform geometric calibration using a calibration plate, calculate the camera's intrinsic and extrinsic parameters, apply a distortion correction algorithm to correct the distortion in the image, ensure the accuracy of the spatial position, perform radiation calibration using a standard light source, generate a response curve, apply a correction function, correct the nonlinearity of the camera response, and ensure the accuracy of the light intensity measurement; S5, image preprocessing: preprocessing the original image acquired by the imaging device, including denoising, contrast enhancement and filtering; S6, feature extraction and analysis: extract features from the preprocessed image, identify the characteristic absorption peaks of the gas leakage area, determine whether there is a gas leakage by comparing the characteristic absorption spectra, and calculate the leakage concentration and location; The feature extraction of the preprocessed image to identify the characteristic absorption peak of the gas leakage area specifically includes: S61, feature extraction: extract features from the preprocessed image through spectral analysis. Spectral analysis is used to identify characteristic absorption peaks of gas molecules. The type and concentration of the gas are determined by analyzing the spectral information of the image. The steps are as follows: Use Fourier transform to convert the image from spatial domain to frequency domain, expressed as: ； in, is the intensity value in the image space domain, is the spectrum of the image in the frequency domain, M and N are the width and height of the image; Calculate the magnitude spectrum of the frequency spectrum : ； in, and are the real and imaginary parts of the spectrum, respectively; S62, extracting characteristic absorption peaks: analyzing the preprocessed image spectrum and extracting characteristic absorption peaks; Extract characteristic absorption peaks: Extract characteristic absorption peaks through spectrum analysis: ； in, is the position of the characteristic absorption peak, is the amplitude of the characteristic absorption peak; The determination of whether there is a gas leak and calculation of the leakage concentration and location by comparing the characteristic absorption spectra specifically includes: S63, comparing absorption spectra: comparing the extracted characteristic absorption peaks with known gas absorption spectra; Compare absorption spectra: Compare the extracted characteristic absorption peaks with known gas absorption spectra ； in, The reference absorption spectrum is at position The absorption peak intensity at S64, determining the concentration and location of gas leakage: determining whether there is gas leakage by comparing the absorption spectra, and calculating the leakage concentration and location; Leakage concentration calculation: gas concentration It can be calculated by the intensity ratio of the characteristic absorption peak to the intensity ratio of the reference absorption spectrum: ,in, is the proportionality coefficient; Leak location determination: Determine the location of the gas leak by image coordinates: ; S7, alarm and record: When a gas leak is detected, an audible and visual alarm signal is sent out through the preset alarm device, and the location information, time and concentration of the leak are recorded in the preset database.

2. A high-sensitivity gas leak detection method based on optical filtering imaging according to claim 1, characterized in that: The adjustable light source is a multi-band laser, which emits multi-band light. The emission band and intensity of each laser are adjusted through a preset automatic control system to adapt to the characteristic absorption peaks of different gas molecules.

3. The high-sensitivity gas leak detection method based on optical filtering imaging according to claim 1, characterized in that: The optical filtering options include: Bandpass optical filter: Select a bandpass optical filter suitable for the characteristic absorption band of the target gas molecules, and the center wavelength of the filter matches the characteristic absorption wavelength of the target gas; Filter installation: Install the bandpass optical filter between the light source and the imaging device, ensuring that the optical axis of the filter is aligned with the optical axis of the light source and the imaging device to avoid light deviation.

4. The high-sensitivity gas leak detection method based on optical filtering imaging according to claim 1, characterized in that: The image preprocessing specifically includes: S51, denoising: using median filtering to remove noise in the image; S52, contrast enhancement: histogram equalization is used to increase the difference between different gray levels in the image, making the details of the image more obvious; S53, Filtering: Enhance features in the image by Laplacian filtering.

5. The high-sensitivity gas leak detection method based on optical filtering imaging according to claim 1, characterized in that: The alarm and record specifically include: S71, sound and light alarm device: The preset sound and light alarm device includes a sound alarm and a light alarm. A gas concentration threshold is set. The gas leakage concentration is determined according to the spectrum analysis result. When the gas leakage concentration exceeds the threshold, the sound and light alarm device is triggered by an electronic control signal; S72, record information to a database: after a gas leak is detected and an alarm is triggered, the leak information is recorded in a preset database, the leak information including time, gas leak location and gas leak concentration.

6. The high-sensitivity gas leak detection method based on optical filtering imaging according to claim 1, characterized in that: The alarm device in S7 further includes a wireless communication unit, through which the leakage information is sent to a remote monitoring center so that emergency measures can be taken in time.

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