A method and apparatus for automatic detection of methane leaks

Abstract

The application relates to a methane leakage automatic detection method and device, which comprises the following steps: panoramic scanning of a monitoring area is carried out by driving an infrared spectrum imaging equipment through a holder, and a spectrum image of a target wave band is collected; a point cloud image of a suspected leakage area is generated based on a preset methane absorption peak intensity threshold value, and leakage concentration distribution coordinates are marked; an active light source is started, and a unique recognizable bright-out coding signal is emitted; meanwhile, the infrared spectrum imaging equipment is triggered to enter a high-speed frame mode to capture a dynamic spot of the active light source; a spot position of a corresponding dynamic spot in a spectrum image collected by the infrared spectrum imaging equipment is identified according to the bright-out coding signal, and spot center pixel coordinates (x, y) of the dynamic spot are recorded; the holder is controlled to rotate, so that an optical axis of a methane laser detection module is automatically aligned with the spot center pixel coordinates, detection is carried out, and an accurate leakage concentration value is output.

Description

Technical Field

[0001] This application relates to the field of spectroscopy technology, and in particular to an automatic method and apparatus for detecting methane leaks. Background Technology

[0002] Current multimodal methane leak detection systems consist of a wide-field-of-view spectral imaging module and a high-precision methane laser detector. The wide-field-of-view spectral imaging module performs a large-area scan to identify suspected leak areas; the high-precision methane laser detection module accurately locates the leak concentration. However, current multimodal methane leak detection systems face a major technical bottleneck: the high-precision methane laser detector relies on precise alignment with the leak point, but at different detection distances, traditional mechanical calibration data is prone to failure, exhibiting a significant distance sensitivity defect.

[0003] Existing systems generally employ pre-calibrated optical path mapping tables. The core principle is to pre-establish a database mapping the optical parameters of the detection equipment to their physical spatial positions. In practical applications, the system records the parameter combinations of the optical equipment at different detection distances: gimbal rotation angle (horizontal / vertical), and the pixel coordinates of the laser corresponding to the image sensor, forming a mapping table similar to a map coordinate system. However, this method suffers from high repetitive calibration costs, requires frequent calibration during field deployment, and is particularly inefficient in complex environments. Furthermore, it has poor tolerance to environmental interference; mechanical structures are prone to shifting due to temperature changes, vibrations, and other factors, leading to accumulated errors. It is also incompatible with dynamic scenarios and cannot meet the real-time positioning requirements of mobile detection platforms (such as drones and vehicle-mounted equipment), resulting in delays in leak point tracking.

[0004] In summary, the current system lacks adaptive calibration capabilities, especially in mobile detection scenarios, and cannot synchronously compensate for device displacement and environmental interference, resulting in a significant decrease in the accuracy of leak point location. Summary of the Invention

[0005] In view of this, the main objective of the present invention is to provide an automatic method and apparatus for detecting methane leaks, so as to improve the accuracy of methane leak concentration detection.

[0006] The present invention provides an automatic detection method for methane leakage, comprising the following steps: S1 uses a gimbal to drive an infrared spectral imaging device to perform a panoramic scan of the monitoring area and acquire spectral images of the target band. S2 generates a point cloud map of the suspected leak area based on a preset methane absorption peak intensity threshold, and marks the coordinates of the leak concentration distribution; S3 activates the active light source, emitting a uniquely identifiable brightness-off encoded signal; simultaneously, it triggers the infrared spectral imaging device to enter high-speed frame mode to capture the dynamic light spot of the active light source. S4 identifies the position of the corresponding dynamic light spot in the spectral image acquired by the infrared spectral imaging device based on the brightness-off encoding signal, and records the center pixel coordinates (x, y) of the dynamic light spot. S5 controls the rotation of the gimbal, automatically aligning the optical axis of the methane laser detection module with the coordinates of the center pixel of the light spot, performing detection and outputting an accurate leakage concentration value.

[0007] This invention enables automated methane leak detection, combining wide-area scanning with an active encoding light source to improve detection accuracy and anti-interference capabilities.

[0008] As one implementation of the first aspect, the method further includes: acquiring a visible light image of the gas leak occurring within the monitoring area; marking the position corresponding to the center pixel coordinates of the light spot in the visible light image, and displaying the leak concentration value. This invention visually marks the leak location using visible light images, facilitating manual verification and on-site location.

[0009] As one implementation of the first aspect, the target wavelength is the 6-8 μm band. This invention covers the strong absorption peak of methane in the 6-8 μm band, thereby improving the sensitivity of spectral detection.

[0010] As one implementation of the first aspect, step S4 includes: The spectral images acquired by the infrared spectral imaging device are binarized to extract the bright areas; Based on the temporal characteristics of brightness and darkness coding, light spots that conform to preset coding rules are selected from the bright areas; The center pixel coordinates (x, y) of the light spot are used as the current alignment position of the methane laser detection module.

[0011] This invention uses an encoding matching algorithm to accurately identify dynamic light spots and reduce the false judgment rate due to ambient light interference.

[0012] As one implementation of the first aspect, the timing features of the brightness-off encoding include pulse width and pulse interval. This invention utilizes pulse width and interval features to enhance encoding uniqueness and improve the robustness of spot recognition.

[0013] In one implementation of the first aspect, the active light source is integrated into the methane laser detection module, and the wavelength of the active light source is consistent with the laser wavelength of the methane laser detection module. This invention utilizes a light source and detection module working in tandem to ensure accurate optical axis alignment.

[0014] The present invention also provides an automatic methane leak detection device, including a pan-tilt unit, an infrared spectral imaging device, an active light source, a methane laser detection module, and a control unit; The gimbal is used to drive the infrared spectral imaging device to perform a panoramic scan of the monitoring area. The infrared spectral imaging device is used for panoramic scanning of the monitoring area; The active light source is used to emit a uniquely identifiable on / off encoded signal; The control unit is used to identify the position of the corresponding dynamic spot in the image acquired by the infrared spectral imaging device according to the brightness-off encoding signal, and to control the rotation of the gimbal so that the optical axis of the methane laser detection module is automatically aligned with the center pixel coordinates of the spot. The methane laser detection module is used to perform TDLAS detection and output accurate leakage concentration.

[0015] This invention features an integrated design that enables fully automated leak detection, improving system response speed and reliability.

[0016] As one implementation of the second aspect, it further includes: a visible light camera for acquiring a visible light image of a gas leak occurring within the monitoring area; the control unit is also used to mark the position corresponding to the center pixel coordinates of the light spot in the visible light image and display the leak concentration value. This invention uses a visible light camera to assist in visual positioning, facilitating rapid identification of the leak point by on-site personnel.

[0017] As one implementation of the second aspect, the target band is the 6-8µm band.

[0018] As one implementation of the second aspect, the active light source is integrated into the methane laser detection module, and the wavelength of the active light source is consistent with the laser wavelength of the methane laser detection module.

[0019] In summary, the present invention has the following beneficial technical effects: (1) It is no longer necessary to rely on a pre-measured distance-angle reference table. By analyzing the characteristics of the laser pulse in real time (such as waveform changes, time difference, etc.), the spatial relationship between the detection target and the equipment can be automatically established, thus eliminating distance dependence; (2) The system automatically optimizes calibration parameters during each test. For example, when the equipment is moved or the ambient temperature changes, it can immediately adjust the optical components to maintain the accuracy of the test and achieve dynamic calibration. (3) When working at a distance, the system’s positioning error of the target position is smaller than that of traditional methods, and the positioning accuracy is significantly improved, which is conducive to improving the overall detection accuracy of the system. Attached Figure Description

[0020] Figure 1 A flowchart illustrating an automatic methane leak detection method provided in this application embodiment; Figure 2 A flowchart illustrating a specific implementation of an automatic methane leak detection method provided in this application embodiment; Figure 3 This is a schematic diagram of the structure of an automatic methane leak detection device provided in an embodiment of this application. Detailed Implementation

[0021] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate preferred embodiments of the application. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0022] In the following description, the terms “first, second, third, etc.” or module A, module B, module C, etc. are used only to distinguish similar objects and do not represent a specific ordering of objects. It is understood that a specific order or sequence may be interchanged where permitted so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0023] In the following description, the labels of the steps, such as S100, S200, etc., do not necessarily mean that the steps will be executed in this way. The order of the steps can be interchanged or executed simultaneously if permitted.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The use of "belonging" in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0025] like Figure 1 As shown, one embodiment of this application provides an automatic methane leak detection method, comprising: S1 uses a gimbal to drive an infrared spectral imaging device to perform a panoramic scan of the monitoring area and acquire spectral images of the target band. S2 generates a point cloud map of the suspected leak area based on a preset methane absorption peak intensity threshold, and marks the coordinates of the leak concentration distribution; S3 activates the active light source, emitting a uniquely identifiable brightness-off encoded signal; simultaneously, it triggers the infrared spectral imaging device to enter high-speed frame mode to capture the dynamic light spot of the active light source. S4 identifies the position of the corresponding dynamic light spot in the spectral image acquired by the infrared spectral imaging device based on the brightness-off encoding signal, and records the center pixel coordinates (x, y) of the dynamic light spot. S5 controls the rotation of the gimbal, automatically aligning the optical axis of the methane laser detection module with the coordinates of the center pixel of the light spot, performing detection and outputting an accurate leakage concentration value.

[0026] This invention enables automated methane leak detection, combining wide-area scanning with an active encoding light source to improve detection accuracy and anti-interference capabilities.

[0027] Specifically, the method further includes: acquiring a visible light image of the gas leak occurring within the monitoring area; marking the position corresponding to the center pixel coordinates of the light spot in the visible light image, and displaying the leak concentration value. This invention visually marks the leak location using visible light images, facilitating manual verification and on-site location.

[0028] Specifically, the target wavelength is the 6-8 μm band. This invention covers the strong absorption peak of methane in the 6-8 μm band, improving the sensitivity of spectral detection.

[0029] Specifically, such as Figure 2 The diagram shows a flowchart of a specific implementation of an automatic methane leak detection method in this embodiment. Step S4 specifically includes: S41 performs binarization processing on the spectral images acquired by the infrared spectral imaging device and extracts the bright areas; S42 selects light spots that conform to preset coding rules from the high-brightness area based on the timing characteristics of brightness and darkness coding; S43 uses the center pixel coordinates (x, y) of the light spot as the current alignment position of the methane laser detection module.

[0030] This invention uses an encoding matching algorithm to accurately identify dynamic light spots and reduce the false judgment rate due to ambient light interference.

[0031] Specifically, the timing features of the brightness-off encoding include pulse width and pulse interval. This invention utilizes pulse width and interval features to enhance encoding uniqueness and improve the robustness of spot recognition.

[0032] Specifically, the active light source is integrated into the methane laser detection module, and the wavelength of the active light source is consistent with the laser wavelength of the methane laser detection module. This invention utilizes a light source and detection module working in tandem to ensure accurate optical axis alignment.

[0033] The workflow of this method is described in detail below with specific examples: Step S1: Panoramic Scan and Initial Leak Screening An infrared spectral imaging device is mounted on a gimbal (horizontal rotation range 0°-360°) to acquire spectral images in the 6-8μm band, scanning the detection area at an angular velocity of 5° / s. The infrared spectral device operates in low frame rate mode (30fps). Based on the acquired characteristic band images and the leakage situation at the site, a point cloud map of the suspected leak is generated, and the concentration distribution coordinates are marked.

[0034] Step S2: Dynamic Spot Encoding and Capture The gimbal was rotated to the observation point of the suspected leak, and the active light source (wavelength 1550nm) was activated to emit binary brightness-disappearance encoded signals ("bright dim dim bright bright bright bright dim", interval 10ms). Simultaneously, the infrared spectrometer was triggered to switch to high-speed frame mode (100fps). The timing of the light source and the imaging device was synchronized to ensure accurate signal matching. The background difference algorithm was used to extract the dynamic light spot area to ensure the capture stability under complex lighting conditions.

[0035] Step S3: Spot center positioning: The system employs an inter-frame difference algorithm to isolate dynamic light spots, and calculates the center pixel coordinates (x, y) using a binary image. Kalman filtering optimizes the stability of the coordinate output, achieving a positioning error ≤ 2 pixels. The main control unit converts the pixel coordinates (x, y) into gimbal pitch / yaw angles based on a perspective transformation model, driving a high-precision motor (positioning accuracy ±0.1°) to adjust the optical axis direction of the methane laser module. This ensures that the alignment deviation between the laser spot center and the infrared positioning center is < 0.5 pixels, with a total response time ≤ 0.5 seconds.

[0036] Step S4: TDLAS Quantitative Analysis and Intelligent Alarm A methane laser (wavelength 1650nm±0.1nm) emits wavelength-tuned laser light, calculates the methane absorption intensity according to the Lambert-Beer law, and outputs a concentration value (range 0-10000ppm, accuracy ±1ppm). If the concentration value > 500ppm or the gradient change rate exceeds the threshold, an audible and visual alarm (flashing red light + buzzer) is triggered. Simultaneously, in conjunction with the infrared image acquired by the backend infrared spectroscopy video acquisition equipment, an alarm image and video containing coordinates / concentration / timestamp are generated and stored on the storage device.

[0037] Step S5: Data Loop Closure and Adaptive Optimization A time-series prediction model is trained based on historical leakage data (concentration gradient, temperature and humidity curves) to dynamically optimize the scan path frame rate and alarm threshold. A leakage pattern library is built, and the knowledge base is automatically updated weekly, greatly reducing the false alarm rate.

[0038] like Figure 3As shown, another embodiment of this application provides an automatic methane leak detection device, including a pan-tilt unit 100, an infrared spectral imaging device 200, an active light source 300, a methane laser detection module 400, and a control unit 500; The gimbal 100 is used to drive the infrared spectral imaging device 200 to perform a panoramic scan of the monitoring area; The infrared spectral imaging device 200 is used to perform panoramic scanning of the monitoring area; The active light source 300 is used to emit a uniquely identifiable on / off encoded signal; The control unit 500 is used to identify the position of the corresponding dynamic light spot in the image acquired by the infrared spectral imaging device according to the brightness and darkness encoding signal, and to control the gimbal 100 to rotate so that the optical axis of the methane laser detection module 400 is automatically aligned with the center pixel coordinates of the light spot. The methane laser detection module 400 is used to perform TDLAS detection and output accurate leakage concentration.

[0039] This invention features an integrated design that enables fully automated leak detection, improving system response speed and reliability.

[0040] Specifically, it also includes: a visible light camera 600, used to acquire visible light images of gas leaks occurring within the monitoring area; the control unit 500 is further used to mark the position corresponding to the center pixel coordinates of the light spot in the visible light image and display the leak concentration value. This invention uses a visible light camera to assist in visual positioning, facilitating rapid identification of leak points by on-site personnel.

[0041] Specifically, the target band is the 6-8µm band.

[0042] Specifically, the active light source 300 is integrated into the methane laser detection module 400, and the wavelength of the active light source 300 is consistent with the laser wavelength of the methane laser detection module 400.

[0043] The above and other operations and / or functions of each module in this device are for implementing the corresponding processes of each method in this embodiment. For the sake of brevity, they will not be described in detail here.

[0044] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0045] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0046] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0047] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0048] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0049] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0050] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, performs the detector non-uniformity correction method provided in the above embodiments, the method including at least one of the schemes described in the above embodiments.

[0051] The computer storage medium in this application embodiment can be any combination of one or more computer-readable media. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. For example, a computer-readable storage medium can be, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0052] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0053] The program code contained on a computer-readable medium may be transmitted using any suitable medium, including, but not limited to, wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0054] Computer program code for performing the operations of this application can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0055] Note that the above are merely preferred embodiments and the technical principles employed in this application. Those skilled in the art will understand that this application is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of this application, all of which fall within the scope of protection of this application.

Claims

1. An automatic detection method for methane leakage, characterized in that, Includes the following steps: S1 uses a gimbal to drive an infrared spectral imaging device to perform a panoramic scan of the monitoring area and acquire spectral images of the target band. S2 generates a point cloud map of the suspected leak area based on a preset methane absorption peak intensity threshold, and marks the coordinates of the leak concentration distribution; S3 activates the active light source, emitting a uniquely identifiable brightness-off encoded signal; simultaneously, it triggers the infrared spectral imaging device to enter high-speed frame mode to capture the dynamic light spot of the active light source. S4 identifies the position of the corresponding dynamic light spot in the spectral image acquired by the infrared spectral imaging device based on the brightness-off encoding signal, and records the center pixel coordinates (x, y) of the dynamic light spot. S5 controls the rotation of the gimbal, automatically aligning the optical axis of the methane laser detection module with the coordinates of the center pixel of the light spot, performing detection and outputting an accurate leakage concentration value.

2. The automatic methane leak detection method according to claim 1, characterized in that, The method further includes: acquiring a visible light image of a gas leak occurring within the monitoring area; marking the position corresponding to the center pixel coordinates of the light spot in the visible light image and displaying the leak concentration value.

3. The automatic methane leak detection method according to claim 1, characterized in that, The target band is the 6-8µm band.

4. The automatic methane leak detection method according to claim 1, characterized in that, Step S4 includes: The spectral images acquired by the infrared spectral imaging device are binarized to extract the bright areas; Based on the temporal characteristics of brightness and darkness coding, light spots that conform to preset coding rules are selected from the bright areas; The center pixel coordinates (x, y) of the light spot are used as the current alignment position of the methane laser detection module.

5. The automatic methane leak detection method according to claim 4, characterized in that, The timing characteristics of the on / off encoding include pulse width and pulse interval.

6. The automatic methane leak detection method according to claim 1, characterized in that, The active light source is integrated into the methane laser detection module, and the wavelength of the active light source is consistent with the laser wavelength of the methane laser detection module.

7. An automatic methane leak detection device, characterized in that, Includes a gimbal, infrared spectral imaging equipment, active light source, methane laser detection module, and control unit; The gimbal is used to drive the infrared spectral imaging device to perform a panoramic scan of the monitoring area. The infrared spectral imaging device is used for panoramic scanning of the monitoring area; The active light source is used to emit a uniquely identifiable on / off encoded signal; The control unit is used to identify the position of the corresponding dynamic spot in the image acquired by the infrared spectral imaging device according to the brightness-off encoding signal, and to control the rotation of the gimbal so that the optical axis of the methane laser detection module is automatically aligned with the center pixel coordinates of the spot. The methane laser detection module is used to perform TDLAS detection and output accurate leakage concentration.

8. The automatic methane leak detection device according to claim 1, characterized in that, Also includes: A visible light camera is used to acquire visible light images of gas leaks occurring within the monitoring area; the control unit is also used to mark the position corresponding to the center pixel coordinates of the light spot in the visible light image and display the leak concentration value.

9. The automatic methane leak detection device according to claim 1, characterized in that, The target band is the 6-8µm band.

10. The automatic methane leak detection device according to claim 1, characterized in that, The active light source is integrated into the methane laser detection module, and the wavelength of the active light source is consistent with the laser wavelength of the methane laser detection module.

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