Laser gas imaging detection method and system

Abstract

The invention provides a laser gas imaging detection method and system, and the method comprises the steps: demodulating signals outputted by all single-point detectors in an area array detector of a main path to obtain gas concentrations corresponding to single-point detection of all single-point detectors, and combining the gas concentrations into a gas concentration distribution image; the gas concentration corresponding to single-point detection of the single-point detector is obtained by the following steps: collecting a whole-period signal output by the single-point detector in the area array detector, sequentially carrying out two times of effective judgment on the signal as an effective signal, and carrying out gas concentration inversion calculation to obtain a target gas concentration value; when the number of times of gas concentration inversion calculation of the target gas concentration reaches n, concentration sorting is carried out, the maximum value and the minimum value are removed, and after averaging is carried out, the obtained gas concentration value serves as the gas concentration corresponding to single-point detection of the single-point detector.

Description

Technical Field

[0001] This invention relates to the field of laser gas sensing technology, and more specifically, to a laser gas imaging detection method and system. Background Technology

[0002] Tunable diode laser absorption spectroscopy has become an important development direction in the field of gas detection. Utilizing the narrow linewidth and wavelength-dependent characteristics of tunable semiconductor lasers, the laser's output wavelength sweeps across the characteristic absorption lines of the target gas. The signal received by the photodetector is amplified and filtered before gas concentration inversion, thus enabling the detection of trace gases. Compared with other gas detection technologies, this technology has advantages such as strong anti-interference capability, fast response speed, and high detection accuracy, and has been widely applied in fields such as gas leak detection, environmental monitoring, and industrial process control.

[0003] Published on January 6, 2023, with publication number CN115575349A, Chinese invention patent application entitled "An Anti-interference Laser Gas Remote Sensing Method and System" solves the problem of abnormal calculation results of instantaneous concentration of the gas to be measured caused by environmental factors in laser gas remote sensing. However, the system actually uses a laser remote sensing system with a point detector, which requires manual movement of the laser remote sensing system to scan a larger area, resulting in low detection efficiency.

[0004] Published on May 30, 2025, with publication number CN120063587A, Chinese invention patent application entitled "A Gas Detection System and Method Combining Laser Galvanometer Remote Telemetry and Infrared Imaging" discloses a method that uses an infrared imaging system to perform imaging and controls a micro-galvanometer to scan different areas to detect the gas concentration distribution information in the area. However, the method still has problems such as system complexity and long detection time caused by controlling the galvanometer.

[0005] Therefore, it is necessary to propose a laser gas imaging detection method and system that uses a laser to output a diverging beam and an area array detector to image the gas concentration distribution. Summary of the Invention

[0006] Therefore, it is necessary to provide a laser gas imaging detection method and system to address the aforementioned technical problems.

[0007] To achieve the above objectives, a first aspect of the present invention provides a laser gas imaging detection method, comprising: The point signals received by all individual detectors in the main array detector are demodulated to obtain the gas concentration corresponding to the point signal, and combined into a gas concentration distribution image. Different colored points are used to represent gas concentrations of different sizes, and the concentration of the corresponding point is output. The gas concentration corresponding to each signal point is obtained using the following method: The point signal received by a single detector is collected, and after two valid judgments, the gas concentration inversion calculation is performed to obtain the target gas concentration value. When the gas concentration inversion calculation of the target gas concentration reaches N times, the concentration is sorted N times, the maximum and minimum values ​​are removed, and the average is calculated. The resulting gas concentration value is taken as the final target gas concentration. The first valid judgment is: The acquired signal is subjected to FFT calculation to obtain the amplitude of the first harmonic a1, the amplitude of the second harmonic a2, the amplitude of the third harmonic a3, and the amplitude of the fourth harmonic a4. If a1>a2>a3>a4, then the signal collected in this instance is a valid signal. If the condition a1>a2>a3>a4 is not met, then the signal collected in this instance is invalid and should be discarded. The second valid judgment is: For the point signals received by a single detector in the main path array detector, calculate the position of the main path absorption peak; for the point signals received by the reference detector, calculate the position of the reference absorption peak. If the absolute value of the difference between the position of the main absorption peak and the position of the reference absorption peak is greater than the set deviation threshold, the signal collected this time is invalid and discarded. When the absolute value of the difference between the position of the main absorption peak and the position of the reference absorption peak is less than or equal to the set deviation threshold, the acquired signal is a valid signal.

[0008] Based on the above, a laser of a specific wavelength is selected according to the target gas to be measured, and the default absorption peak position of the laser output corresponding to the wavelength is set. Meanwhile, when the laser outputs, the position of the absorption peak is set to move back and forth left and right at fixed intervals, with the default absorption peak position as the center.

[0009] Based on the above, the method for combining the gas concentrations corresponding to the single-point detections of all single-point detectors into a gas concentration distribution image is as follows: according to the physical coordinates of the area array detector, the gas concentration values ​​of each point are mapped to image pixels, and bilinear interpolation is used to generate a concentration distribution heatmap.

[0010] To achieve the above objectives, a second aspect of the present invention provides a laser gas imaging detection method, comprising: Starting from the outermost single-point detector layer in the M*N array detector of the main path, single-point detection is performed using this single-point detector layer as the i-th single-point detection layer. When performing single-point detection, one or two single-point detectors are spaced apart in sequence, and the single-point detector at the vertex must be included. The signal output by the single-point detector in the i-th single-point detection layer is demodulated to obtain the gas concentration corresponding to the single-point detection of the corresponding single-point detector. If the gas concentration results of the corresponding single-point detector in the i-th single-point detection layer are all zero, then starting from the i-th single-point detection layer, the single-point detector layer after skipping one single-point detector layer inward is taken as the (i+1)-th single-point detection layer for single-point detection, and so on, until i=n. Where M≤N; i=1,2,……,n, n=(M-1 / 2 / 3 / 4)÷4+1; M-1 / 2 / 3 / 4 means that when 4(n-1)<M≤4n, if 4n-M=3, then n=(M-1)÷4+1; if 4n-M=2, then n=(M-2)÷4+1; if 4n-M=1, then n=(M-3)÷4+1; if 4n-M=0, then n=(M-4)÷4+1; If the gas concentration result of any corresponding single-point detector in the i-th single-point detection layer is positive, then demodulate the signals output by the i-th single-point detection layer and all single-point detectors within the i-th single-point detection layer to obtain the gas concentration corresponding to the single-point detection of the single-point detector; combine the obtained gas concentrations into a gas concentration distribution image. The gas concentration corresponding to a single point detection by a single point detector is obtained using the following method: The system collects the full-cycle signal output from a single-point detector in the array detector, performs two consecutive valid signal determinations, and then performs gas concentration inversion calculation to obtain the target gas concentration value. When the gas concentration inversion calculation of the target gas concentration reaches n times, the gas concentration value obtained after sorting the concentration, removing the maximum and minimum values, and averaging is used as the gas concentration corresponding to the single-point detection of the single-point detector. The method for the first valid judgment is: The acquired signal is subjected to FFT calculation to obtain the amplitude of the first harmonic a1, the amplitude of the second harmonic a2, the amplitude of the third harmonic a3, and the amplitude of the fourth harmonic a4. When a1>a2>a3>a4, the acquired signal is a valid signal; When the condition a1>a2>a3>a4 is not met, the collected signal is invalid and should be discarded. The method for the second valid judgment is as follows: The system collects the full-cycle signal output from a single-point detector in the array detector of the main path and calculates the position of the main path absorption peak based on the signal; it also collects the signal output from the reference detector and calculates the position of the reference absorption peak based on the signal. When the absolute value of the difference between the position of the main absorption peak and the position of the reference absorption peak is greater than the set deviation threshold, the collected signal is invalid and discarded. The signal acquired is considered valid when the absolute value of the difference between the position of the main absorption peak and the position of the reference absorption peak is less than or equal to the set deviation threshold. To achieve the above objectives, a third aspect of the present invention provides a laser gas imaging detection system, comprising: The gas concentration acquisition module is used to demodulate the point signals received by all individual detectors in the main array detector to obtain the gas concentration corresponding to the point signal. The imaging module is used to combine the gas concentrations corresponding to the signals at each point into a gas concentration distribution image, wherein different colored dots are used to represent gas concentrations of different sizes, and the concentration of the corresponding point is output. The gas concentration acquisition module includes an effective judgment module and an inversion calculation module; The effective judgment module is used to collect the point signals received by each individual detector and perform two effective judgments on each point signal; The inversion calculation module is used to perform gas concentration inversion calculation to obtain the target gas concentration value of each signal after the signal at each point is determined to be valid twice; and when the number of gas concentration inversion calculations of the target gas concentration reaches N times, it performs N concentration sorting, removes the maximum and minimum values, calculates the average, and then uses the obtained gas concentration value as the final target gas concentration of each signal. The first valid judgment is: The acquired signal is subjected to FFT calculation to obtain the amplitude of the first harmonic a1, the amplitude of the second harmonic a2, the amplitude of the third harmonic a3, and the amplitude of the fourth harmonic a4. If a1>a2>a3>a4, then the signal collected in this instance is a valid signal. If the condition a1>a2>a3>a4 is not met, then the signal collected in this instance is invalid and should be discarded. The second valid judgment is: For the point signals received by a single detector in the main path array detector, calculate the position of the main path absorption peak; for the point signals received by the reference detector, calculate the position of the reference absorption peak. If the absolute value of the difference between the position of the main absorption peak and the position of the reference absorption peak is greater than the set deviation threshold, the signal collected this time is invalid and discarded. When the absolute value of the difference between the position of the main absorption peak and the position of the reference absorption peak is less than or equal to the set deviation threshold, the acquired signal is a valid signal.

[0011] To achieve the above objectives, a fourth aspect of the present invention provides a laser gas imaging detection system, comprising: The gas concentration acquisition module is used to perform single-point detection starting from the outermost single-point detector layer in the M*N array detector of the main path, using this single-point detector layer as the i-th single-point detection layer. When performing single-point detection, one or two single-point detectors are spaced apart in sequence, and the single-point detector at the vertex must be included. The signal output by the single-point detector in the i-th single-point detection layer is demodulated to obtain the gas concentration corresponding to the single-point detection of the corresponding single-point detector. If the gas concentration results of the corresponding single-point detector in the i-th single-point detection layer are all zero, then starting from the i-th single-point detection layer, the single-point detector layer after skipping one single-point detector layer inward is taken as the (i+1)-th single-point detection layer for single-point detection, and so on, until i=n. Where M≤N; i=1,2,……,n, n=(M-1 / 2 / 3 / 4)÷4+1; M-1 / 2 / 3 / 4 means that when 4(n-1)<M≤4n, if 4n-M=3, then n=(M-1)÷4+1; if 4n-M=2, then n=(M-2)÷4+1; if 4n-M=1, then n=(M-3)÷4+1; if 4n-M=0, then n=(M-4)÷4+1; If the gas concentration result of any corresponding single-point detector in the i-th single-point detection layer is positive, then demodulate the signal output of the i-th single-point detection layer and all single-point detectors within the i-th single-point detection layer to obtain the gas concentration corresponding to the single-point detection of the corresponding single-point detector. The imaging module is used to combine the obtained gas concentrations into a gas concentration distribution image; The gas concentration acquisition module includes an effective judgment module and an inversion calculation module; The effective judgment module is used to collect the point signals received by each individual detector and perform two effective judgments on each point signal; The inversion calculation module is used to perform gas concentration inversion calculation to obtain the target gas concentration value of each signal after the signal at each point is determined to be valid twice; and when the number of gas concentration inversion calculations of the target gas concentration reaches N times, it performs N concentration sorting, removes the maximum and minimum values, calculates the average, and then uses the obtained gas concentration value as the final target gas concentration of each signal. The first valid judgment is: The acquired signal is subjected to FFT calculation to obtain the amplitude of the first harmonic a1, the amplitude of the second harmonic a2, the amplitude of the third harmonic a3, and the amplitude of the fourth harmonic a4. If a1>a2>a3>a4, then the signal collected in this instance is a valid signal. If the condition a1>a2>a3>a4 is not met, then the signal collected in this instance is invalid and should be discarded. The second valid judgment is: For the point signals received by a single detector in the main path array detector, calculate the position of the main path absorption peak; for the point signals received by the reference detector, calculate the position of the reference absorption peak. If the absolute value of the difference between the position of the main absorption peak and the position of the reference absorption peak is greater than the set deviation threshold, the signal collected this time is invalid and discarded. When the absolute value of the difference between the position of the main absorption peak and the position of the reference absorption peak is less than or equal to the set deviation threshold, the acquired signal is a valid signal.

[0012] To achieve the above objectives, a fifth aspect of the present invention provides a computer device comprising a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other via the communication bus; the memory is used to store computer programs; and the processor is used to execute the program stored in the memory to implement the laser gas imaging detection method as described above.

[0013] To achieve the above objectives, a sixth aspect of the present invention provides a readable storage medium having instructions stored thereon that, when executed by one or more processors, cause the processors to perform the laser gas imaging detection method as described above.

[0014] The beneficial effects of this invention are as follows: (1) By regularly moving the absorption peak position of the reference detector signal back and forth, the present invention can effectively reduce the influence of interference noise on the detection results.

[0015] (2) This invention utilizes the characteristic differences between the gas absorption signal and random noise of the detector (whether the magnitude of the harmonic amplitude after the target signal is decomposed into each harmonic satisfies a1>a2>a3>a4) to effectively eliminate invalid concentrations not calculated by gas absorption inversion, thereby further improving detection accuracy.

[0016] (3) The present invention can display a gas concentration distribution map of a certain area, thereby improving the efficiency of laser gas detection without changing the detection accuracy. Attached Figure Description

[0017] Figure 1 This is a block diagram of the principle of a laser gas imaging system.

[0018] Figure 2 Flowchart of laser gas imaging detection method.

[0019] Figure 3 This is a schematic diagram of an area array detector used to explain the method of Embodiment 3. Detailed Implementation

[0020] The technical solution of the present invention will be further described in detail below through specific embodiments.

[0021] To facilitate understanding, the interactive parties and / or terms and / or custom terms involved in this invention will first be explained in conjunction with the technical solution of this invention: Laser gas detection system like Figure 1 As shown, the laser gas system mainly consists of the following core components: laser and its driving temperature control circuit, collimator, beam shaping unit, focusing lens, area array detector, analog switch circuit, programmable gain I / V conversion filter circuit, label gas detector, and processor.

[0022] The drive temperature control circuit includes a laser operating temperature control circuit and a laser drive current control circuit. The temperature control circuit uses a PID algorithm to achieve constant temperature control of the laser operating temperature; the drive current control circuit, according to the processor's instructions, adjusts the magnitude of the analog signal output by the DAC to achieve real-time constant current control of the laser drive current.

[0023] Optical path transmission: The laser beam output from the laser is processed by a collimator and a beam shaping unit to form a circular or rectangular beam.

[0024] Signal Detection and Processing: The area array detector is responsible for converting the received optical signals into electrical signals. The analog switching circuit selects the output signals of different detection chips in the area array detector according to the processor's preset control logic. Subsequently, the programmable gain I / V conversion and filtering circuit performs current-to-voltage conversion, amplification, and filtering on the selected signals.

[0025] Beam collection: The focusing lens is mainly used to collect diffuse reflection beams and perform preliminary filtering.

[0026] Wavelength calibration: The reference detector is used to track the center wavelength of the laser in real time and make dynamic adjustments accordingly to ensure wavelength stability.

[0027] Absorption peak position: refers to the depression or attenuation region of the waveform at a specific position, representing the absorption of light by the gas under test at a specific frequency or wavelength range.

[0028] Example 1 This embodiment provides a specific implementation method for a laser gas imaging detection method, as shown in the attached figure. Figure 2 As shown, the method includes: Step S1: Select the signal output by the i-th (i=1,2,…,N) single-point detector in the array detector (containing N single-point detectors) of the main output path.

[0029] Step S2: Acquire the signal Xij output by the single-point detector i, j=1,2,…,n.

[0030] Step S3: Perform the first valid judgment on the signal Xij; The method for the first valid judgment is: The collected signal Xij is subjected to FFT calculation to obtain the amplitude of the first harmonic a1, the amplitude of the second harmonic a2, the amplitude of the third harmonic a3, and the amplitude of the fourth harmonic a4 of the signal Xij. When a1>a2>a3>a4 is satisfied, signal Xij is a valid signal, and proceed to step S4; When the condition a1>a2>a3>a4 is not met, the signal Xij is invalid and is discarded, returning to step S2.

[0031] Step S4: Perform a second valid judgment on the signal Xij; The method for the second valid judgment is as follows: The position of the main absorption peak is calculated based on the signal Xij; the signal output by the reference detector is acquired, and the position of the reference absorption peak is calculated based on the signal. When the absolute value of the difference between the position of the main absorption peak and the position of the reference absorption peak is greater than the set deviation threshold, the signal Xij is invalid and is discarded, returning to step S2; When the absolute value of the difference between the position of the main absorption peak and the position of the reference absorption peak is less than or equal to the set deviation threshold, the signal Xij is a valid signal, and the process proceeds to step S4.

[0032] Step S5: Based on signal Xij, perform the j-th gas concentration inversion calculation to obtain the j-th target gas concentration value, and determine whether j reaches n. If yes, proceed to step S6; otherwise, return to step S2 and set j = j + 1.

[0033] Step S6: Sort the n target gas concentration values ​​obtained from the n gas concentration inversion calculations, remove the maximum and minimum values, and calculate the average value. The resulting gas concentration value is used as the gas concentration corresponding to the single-point detector i. Determine if i reaches N. If yes, proceed to step S7; otherwise, return to step S1 and set i = i + 1.

[0034] Step S7: Combine the gas concentrations corresponding to the single-point detectors 1-N into a gas concentration distribution image.

[0035] Due to potential interference noise issues in multi-reflection cavities (the location of interference noise changes randomly with ambient temperature), to eliminate the impact of interference noise on gas detection accuracy (by reducing the probability of interference noise superimposed on useful absorption), in some exemplary embodiments, a method is employed to move the absorption peak position of the reference detector signal back and forth at fixed intervals, centered on the default absorption peak position. Specifically: Select a laser of a specific wavelength according to the target gas to be tested, and set the default absorption peak position of the laser output corresponding to the wavelength; at the same time, when the laser outputs, set the absorption peak position to move back and forth left and right at fixed intervals with the default absorption peak position as the center, that is, in step S2, before each signal acquisition, the absorption peak position is moved once.

[0036] In some exemplary embodiments, the temperature control stability temperature at a specific deviation wavelength of the laser output can be calculated using a linear interpolation algorithm based on the relationship model between the laser response wavelength and the change in driving current and the change in temperature control stability. By regularly adjusting the temperature, the laser output wavelength can be moved back and forth in a regular manner.

[0037] Example 2 Based on the same inventive concept, this embodiment provides a specific implementation of a laser gas imaging detection system. The solution provided by this control system is similar to the solution described in Embodiment 1. Therefore, the specific limitations in one or more control system embodiments provided below can be found in the limitations of the laser gas imaging detection method above, and will not be repeated here.

[0038] The laser gas imaging detection system includes: The gas concentration acquisition module is used to demodulate the point signals received by all individual detectors in the main array detector to obtain the gas concentration corresponding to the point signal. The imaging module is used to combine the gas concentrations corresponding to the signals at each point into a gas concentration distribution image, wherein different colored dots are used to represent gas concentrations of different sizes, and the concentration of the corresponding point is output. The gas concentration acquisition module includes an effective judgment module and an inversion calculation module; The effective judgment module is used to collect the point signals received by each individual detector and perform two effective judgments on each point signal; The inversion calculation module is used to perform gas concentration inversion calculation to obtain the target gas concentration value of each signal after the signal at each point is determined to be valid twice; and when the number of gas concentration inversion calculations of the target gas concentration reaches N times, it performs N concentration sorting, removes the maximum and minimum values, calculates the average, and then uses the obtained gas concentration value as the final target gas concentration of each signal. The first valid judgment is: The acquired signal is subjected to FFT calculation to obtain the amplitude of the first harmonic a1, the amplitude of the second harmonic a2, the amplitude of the third harmonic a3, and the amplitude of the fourth harmonic a4. If a1>a2>a3>a4, then the signal collected in this instance is a valid signal. If the condition a1>a2>a3>a4 is not met, then the signal collected in this instance is invalid and should be discarded. The second valid judgment is: For the point signals received by a single detector in the main path array detector, calculate the position of the main path absorption peak; for the point signals received by the reference detector, calculate the position of the reference absorption peak. If the absolute value of the difference between the position of the main absorption peak and the position of the reference absorption peak is greater than the set deviation threshold, the signal collected this time is invalid and discarded. When the absolute value of the difference between the position of the main absorption peak and the position of the reference absorption peak is less than or equal to the set deviation threshold, the acquired signal is a valid signal.

[0039] Example 3 The difference between this embodiment and Embodiment 1 is that by demodulating the signals output by all single-point detectors in the main path area array detector in a different order, i.e., by adopting the order of coarse detection followed by fine detection, the detection efficiency can be improved. This is because in some areas to be detected with no concentration, if the signals output by all single-point detectors in the main path area array detector are demodulated as in Embodiment 1, the overall detection time is prolonged.

[0040] Specifically, such as Figure 3 As shown, starting from the outermost single-point detector layer in the M*N array detector of the main path, this single-point detector layer is used as the i-th single-point detection layer for single-point detection. When performing single-point detection, one or two single-point detectors should be spaced apart sequentially, and the single-point detector at the vertex must be included (e.g., Figure 3 (The red dot in the image) Demodulates the signal output by the single-point detector in the i-th single-point detection layer to obtain the gas concentration corresponding to the single-point detection of the single-point detector. If the gas concentration results of the corresponding single-point detector in the i-th single-point detection layer are all zero, then starting from the i-th single-point detection layer, the single-point detector layer after skipping one single-point detector layer inward is taken as the (i+1)-th single-point detection layer for single-point detection, and so on, until i=n. If the gas concentration result of any corresponding single-point detector in the i-th single-point detection layer is positive, then demodulate the signals output by the i-th single-point detection layer and all single-point detectors within the i-th single-point detection layer to obtain the gas concentration corresponding to the single-point detection of the corresponding single-point detector.

[0041] In this embodiment, M≤N; i=1,2……,n, n=(M-1 / 2 / 3 / 4)÷4+1; M-1 / 2 / 3 / 4 means that when 4(n-1)<M≤4n, if 4n-M=3, then n=(M-1)÷4+1; if 4n-M=2, then n=(M-2)÷4+1; if 4n-M=1, then n=(M-3)÷4+1; if 4n-M=0, then n=(M-4)÷4+1; For example: M*N=2*3, then M=2. Let n=1, satisfying 0<2≤4. At this time, 4×1-2=2, then n=(2-2)÷4+1=1; hence i=1; M*N=7*8, then M=7. Let n=1, which does not satisfy 0<7≤4; let n=2, which satisfies 4<7≤8. In this case, 4×2-7=1, then n=(7-3)÷4+1=2; hence i=1,2; M*N=11*11, then M=11. Let n=1, which does not satisfy 0<11≤4; let n=2, which does not satisfy 4<11≤8; let n=3, which satisfies 8<11≤12. At this time, 4×3-11=1, then n=(11-3)÷4+1=3; hence i=1,2,3.

[0042] Example 4 Based on the same inventive concept, this embodiment provides a specific implementation of a laser gas imaging detection system. The solution provided by this control system is similar to the solution described in Embodiment 3. Therefore, the specific limitations in one or more control system embodiments provided below can be found in the limitations of the laser gas imaging detection method above, and will not be repeated here.

[0043] The laser gas imaging detection system includes: The gas concentration acquisition module is used to perform single-point detection starting from the outermost single-point detector layer in the M*N array detector of the main path, using this single-point detector layer as the i-th single-point detection layer. When performing single-point detection, one or two single-point detectors are spaced apart in sequence, and the single-point detector at the vertex must be included. The signal output by the single-point detector in the i-th single-point detection layer is demodulated to obtain the gas concentration corresponding to the single-point detection of the corresponding single-point detector. If the gas concentration results of the corresponding single-point detector in the i-th single-point detection layer are all zero, then starting from the i-th single-point detection layer, the single-point detector layer after skipping one single-point detector layer inward is taken as the (i+1)-th single-point detection layer for single-point detection, and so on, until i=n. Where M≤N; i=1,2,……,n, n=(M-1 / 2 / 3 / 4)÷4+1; M-1 / 2 / 3 / 4 means that when 4(n-1)<M≤4n, if 4n-M=3, then n=(M-1)÷4+1; if 4n-M=2, then n=(M-2)÷4+1; if 4n-M=1, then n=(M-3)÷4+1; if 4n-M=0, then n=(M-4)÷4+1; If the gas concentration result of any corresponding single-point detector in the i-th single-point detection layer is positive, then demodulate the signal output of the i-th single-point detection layer and all single-point detectors within the i-th single-point detection layer to obtain the gas concentration corresponding to the single-point detection of the corresponding single-point detector. The imaging module is used to combine the obtained gas concentrations into a gas concentration distribution image; The gas concentration acquisition module includes an effective judgment module and an inversion calculation module; The effective judgment module is used to collect the point signals received by each individual detector and perform two effective judgments on each point signal; The inversion calculation module is used to perform gas concentration inversion calculation to obtain the target gas concentration value of each signal after the signal at each point is determined to be valid twice; and when the number of gas concentration inversion calculations of the target gas concentration reaches N times, it performs N concentration sorting, removes the maximum and minimum values, calculates the average, and then uses the obtained gas concentration value as the final target gas concentration of each signal. The first valid judgment is: The acquired signal is subjected to FFT calculation to obtain the amplitude of the first harmonic a1, the amplitude of the second harmonic a2, the amplitude of the third harmonic a3, and the amplitude of the fourth harmonic a4. If a1>a2>a3>a4, then the signal collected in this instance is a valid signal. If the condition a1>a2>a3>a4 is not met, then the signal collected in this instance is invalid and should be discarded. The second valid judgment is: For the point signals received by a single detector in the main path array detector, calculate the position of the main path absorption peak; for the point signals received by the reference detector, calculate the position of the reference absorption peak. If the absolute value of the difference between the position of the main absorption peak and the position of the reference absorption peak is greater than the set deviation threshold, the signal collected this time is invalid and discarded. When the absolute value of the difference between the position of the main absorption peak and the position of the reference absorption peak is less than or equal to the set deviation threshold, the acquired signal is a valid signal.

[0044] Example 5 Based on the above embodiments, this embodiment provides a specific implementation of a computer device, which includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, used to store computer programs; The processor, when executing the program stored in the memory, implements the laser gas imaging detection method as described in Example 1.

[0045] Based on the above embodiments, this embodiment also provides a readable storage medium storing instructions that, when executed by one or more processors, cause the processors to perform the laser gas imaging detection method as described in Embodiment 1: Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0046] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0047] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A laser gas imaging detection method, characterized in that, include: The signals output by all point detectors in the main array detector are demodulated to obtain the gas concentration corresponding to each point detection of each point detector, and the obtained gas concentrations are combined into a gas concentration distribution image. The gas concentration corresponding to a single point detection by a single point detector is obtained using the following method: The system collects the full-cycle signal output from a single-point detector in the array detector, performs two consecutive valid signal determinations, and then performs gas concentration inversion calculation to obtain the target gas concentration value. When the gas concentration inversion calculation of the target gas concentration reaches n times, the gas concentration value obtained after sorting the concentration, removing the maximum and minimum values, and averaging is used as the gas concentration corresponding to the single-point detection of the single-point detector. The method for the first valid judgment is: The acquired signal is subjected to FFT calculation to obtain the amplitude of the first harmonic a1, the amplitude of the second harmonic a2, the amplitude of the third harmonic a3, and the amplitude of the fourth harmonic a4. When a1>a2>a3>a4, the acquired signal is a valid signal; When the condition a1>a2>a3>a4 is not met, the collected signal is invalid and should be discarded. The method for the second valid judgment is: The system collects the full-cycle signal output from a single-point detector in the array detector of the main path and calculates the position of the main path absorption peak based on the signal; it also collects the signal output from the reference detector and calculates the position of the reference absorption peak based on the signal. When the absolute value of the difference between the position of the main absorption peak and the position of the reference absorption peak is greater than the set deviation threshold, the collected signal is invalid and discarded. The signal collected is considered valid when the absolute value of the difference between the position of the main absorption peak and the position of the reference absorption peak is less than or equal to the set deviation threshold.

2. The laser gas imaging detection method according to claim 1, characterized in that: Select a laser of a specific wavelength according to the target gas to be tested, and set the default absorption peak position of the laser output corresponding to the wavelength. Meanwhile, when the laser outputs, the position of the absorption peak is set to move back and forth left and right at fixed intervals, with the default absorption peak position as the center.

3. The laser gas imaging detection method according to claim 1 or 2, characterized in that: The method for combining the gas concentrations corresponding to the single-point detections of all single-point detectors into a gas concentration distribution image is as follows: based on the physical coordinates of the area array detector, the gas concentration values ​​at each point are mapped to image pixels, and bilinear interpolation is used to generate a concentration distribution heatmap.

4. A laser gas imaging detection method, characterized in that, include: Starting from the outermost single-point detector layer in the M*N array detector of the main path, single-point detection is performed using this single-point detector layer as the i-th single-point detection layer. When performing single-point detection, one or two single-point detectors are spaced apart in sequence, and the single-point detector at the vertex must be included. The signal output by the single-point detector in the i-th single-point detection layer is demodulated to obtain the gas concentration corresponding to the single-point detection of the corresponding single-point detector. If the gas concentration results of the corresponding single-point detector in the i-th single-point detection layer are all zero, then starting from the i-th single-point detection layer, the single-point detector layer after skipping one single-point detector layer inward is taken as the (i+1)-th single-point detection layer for single-point detection, and so on, until i=n. Where M≤N; i=1,2,……,n, n=(M-1 / 2 / 3 / 4)÷4+1; M-1 / 2 / 3 / 4 means that when 4(n-1)<M≤4n, if 4n-M=3, then n=(M-1)÷4+1; if 4n-M=2, then n=(M-2)÷4+1; if 4n-M=1, then n=(M-3)÷4+1; if 4n-M=0, then n=(M-4)÷4+1; If the gas concentration result of any corresponding single-point detector in the i-th single-point detection layer is positive, then demodulate the signals output by the i-th single-point detection layer and all single-point detectors within the i-th single-point detection layer to obtain the gas concentration corresponding to the single-point detection of the single-point detector; combine the obtained gas concentrations into a gas concentration distribution image. The gas concentration corresponding to a single point detection by a single point detector is obtained using the following method: The system collects the full-cycle signal output from a single-point detector in the array detector, performs two consecutive valid signal determinations, and then performs gas concentration inversion calculation to obtain the target gas concentration value. When the gas concentration inversion calculation of the target gas concentration reaches n times, the gas concentration value obtained after sorting the concentration, removing the maximum and minimum values, and averaging is used as the gas concentration corresponding to the single-point detection of the single-point detector. The method for the first valid judgment is: The acquired signal is subjected to FFT calculation to obtain the amplitude of the first harmonic a1, the amplitude of the second harmonic a2, the amplitude of the third harmonic a3, and the amplitude of the fourth harmonic a4. When a1>a2>a3>a4, the acquired signal is a valid signal; When the condition a1>a2>a3>a4 is not met, the collected signal is invalid and should be discarded. The method for the second valid judgment is as follows: The system collects the full-cycle signal output from a single-point detector in the array detector of the main path and calculates the position of the main path absorption peak based on the signal; it also collects the signal output from the reference detector and calculates the position of the reference absorption peak based on the signal. When the absolute value of the difference between the position of the main absorption peak and the position of the reference absorption peak is greater than the set deviation threshold, the collected signal is invalid and discarded. The signal collected is considered valid when the absolute value of the difference between the position of the main absorption peak and the position of the reference absorption peak is less than or equal to the set deviation threshold.

5. A laser gas imaging detection system, characterized in that, include: The gas concentration acquisition module is used to demodulate the point signals received by all individual detectors in the main array detector to obtain the gas concentration corresponding to the point signal. The imaging module is used to combine the gas concentrations corresponding to the signals at each point to form a gas concentration distribution image; The gas concentration acquisition module includes an effective judgment module and an inversion calculation module; The effective judgment module is used to collect the point signals received by each individual detector and perform two effective judgments on each point signal; The inversion calculation module is used to perform gas concentration inversion calculation to obtain the target gas concentration value of each signal after the signal at each point has been determined to be valid twice. When the gas concentration inversion calculation of the target gas concentration reaches N times, the concentration is sorted N times, the maximum and minimum values ​​are removed, the average is calculated, and the obtained gas concentration value is used as the final target gas concentration of each point signal. The first valid judgment is: The acquired signal is subjected to FFT calculation to obtain the amplitude of the first harmonic a1, the amplitude of the second harmonic a2, the amplitude of the third harmonic a3, and the amplitude of the fourth harmonic a4. If a1>a2>a3>a4, then the signal collected in this instance is a valid signal. If the condition a1>a2>a3>a4 is not met, then the signal collected in this instance is invalid and should be discarded. The second valid judgment is: For the point signals received by a single detector in the main path array detector, calculate the position of the main path absorption peak; for the point signals received by the reference detector, calculate the position of the reference absorption peak. If the absolute value of the difference between the position of the main absorption peak and the position of the reference absorption peak is greater than the set deviation threshold, the signal collected this time is invalid and discarded. When the absolute value of the difference between the position of the main absorption peak and the position of the reference absorption peak is less than or equal to the set deviation threshold, the acquired signal is a valid signal.

6. The laser gas imaging detection system according to claim 5, characterized in that, Select a laser of a specific wavelength according to the target gas to be tested, and set the default absorption peak position of the laser output corresponding to the wavelength. Meanwhile, when the laser outputs, the position of the absorption peak is set to move back and forth left and right at fixed intervals, with the default absorption peak position as the center.

7. The laser gas imaging detection system according to claim 5 or 6, characterized in that, The method for combining the gas concentrations corresponding to the single-point detections of all single-point detectors into a gas concentration distribution image is as follows: based on the physical coordinates of the area array detector, the gas concentration values ​​at each point are mapped to image pixels, and bilinear interpolation is used to generate a concentration distribution heatmap.

8. A laser gas imaging detection system, characterized in that, include: The gas concentration acquisition module is used to perform single-point detection starting from the outermost single-point detector layer in the M*N array detector of the main path, using this single-point detector layer as the i-th single-point detection layer. When performing single-point detection, one or two single-point detectors are spaced apart in sequence, and the single-point detector at the vertex must be included. The signal output by the single-point detector in the i-th single-point detection layer is demodulated to obtain the gas concentration corresponding to the single-point detection of the corresponding single-point detector. If the gas concentration results of the corresponding single-point detector in the i-th single-point detection layer are all zero, then starting from the i-th single-point detection layer, the single-point detector layer after skipping one single-point detector layer inward is taken as the (i+1)-th single-point detection layer for single-point detection, and so on, until i=n. Where M≤N; i=1,2,……,n, n=(M-1 / 2 / 3 / 4)÷4+1; M-1 / 2 / 3 / 4 means that when 4(n-1)<M≤4n, if 4n-M=3, then n=(M-1)÷4+1; if 4n-M=2, then n=(M-2)÷4+1; if 4n-M=1, then n=(M-3)÷4+1; if 4n-M=0, then n=(M-4)÷4+1; If the gas concentration result of any corresponding single-point detector in the i-th single-point detection layer is positive, then demodulate the signal output of the i-th single-point detection layer and all single-point detectors within the i-th single-point detection layer to obtain the gas concentration corresponding to the single-point detection of the corresponding single-point detector. The imaging module is used to combine the obtained gas concentrations into a gas concentration distribution image; The gas concentration acquisition module includes an effective judgment module and an inversion calculation module; The effective judgment module is used to collect the point signals received by each individual detector and perform two effective judgments on each point signal; The inversion calculation module is used to perform gas concentration inversion calculation to obtain the target gas concentration value of each signal after the signal at each point is determined to be valid twice; and when the number of gas concentration inversion calculations of the target gas concentration reaches N times, it performs N concentration sorting, removes the maximum and minimum values, calculates the average, and then uses the obtained gas concentration value as the final target gas concentration of each signal. The first valid judgment is: The acquired signal is subjected to FFT calculation to obtain the amplitude of the first harmonic a1, the amplitude of the second harmonic a2, the amplitude of the third harmonic a3, and the amplitude of the fourth harmonic a4. If a1>a2>a3>a4, then the signal collected in this instance is a valid signal. If the condition a1>a2>a3>a4 is not met, then the signal collected in this instance is invalid and should be discarded. The second valid judgment is: For the point signals received by a single detector in the main path array detector, calculate the position of the main path absorption peak; for the point signals received by the reference detector, calculate the position of the reference absorption peak. If the absolute value of the difference between the position of the main absorption peak and the position of the reference absorption peak is greater than the set deviation threshold, the signal collected this time is invalid and discarded. When the absolute value of the difference between the position of the main absorption peak and the position of the reference absorption peak is less than or equal to the set deviation threshold, the acquired signal is a valid signal.

9. A computer device, characterized in that: It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, used to store computer programs; The processor, when executing a program stored in the memory, implements the laser gas imaging detection method as described in any one of claims 1 to 4.

10. A readable storage medium, characterized in that: It stores instructions that, when executed by one or more processors, cause the processors to perform the laser gas imaging detection method as described in any one of claims 1 to 4.

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