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CN-122003592-A - Gas detection method, system and terminal equipment

CN122003592ACN 122003592 ACN122003592 ACN 122003592ACN-122003592-A

Abstract

The application belongs to the field of gas detection, and provides a gas detection method, a system and terminal equipment, wherein the method comprises the steps of obtaining a test spectrum of gas to be detected, obtaining relative concentration through a least square method based on the test spectrum and a calibration spectrum of standard gas obtained in advance, obtaining the test concentration of the gas to be detected based on the relative concentration and the calibration concentration of the standard gas obtained in advance, obtaining a deviation spectrum based on the test spectrum, the calibration spectrum and the relative concentration, obtaining a discrete degree value of the deviation spectrum based on the deviation spectrum, determining whether the discrete degree value is larger than a reference threshold value, determining that the test concentration is invalid under the condition that the discrete degree value is larger than the reference threshold value, and otherwise determining that the test concentration is valid. The embodiment of the application can improve the accuracy and reliability of the detection result when the gas detection is carried out in a complex interference environment.

Inventors

  • XU HUIJIE
  • CHEN LIANG
  • CHEN BO

Assignees

  • 江苏旭海光电科技有限公司

Dates

Publication Date
20260508
Application Date
20251230

Claims (18)

  1. 1. A gas detection method comprising: Acquiring a test spectrum of the gas to be tested; based on the test spectrum and a calibration spectrum of the standard gas obtained in advance, obtaining relative concentration by a least square method; Acquiring the test concentration of the gas to be tested based on the relative concentration and the calibration concentration of the standard gas acquired in advance; Acquiring a deviation spectrum based on the test spectrum, the calibration spectrum and the relative concentration; Acquiring a discrete degree value of the deviation spectrum based on the deviation spectrum; Determining whether the discrete degree value is larger than a reference threshold value, determining that the test concentration is invalid under the condition that the discrete degree value is larger than the reference threshold value, and otherwise, determining that the test concentration is valid.
  2. 2. The gas detection method of claim 1, wherein the test spectrum and the calibration spectrum are direct absorption spectra or harmonic spectra.
  3. 3. The gas detection method according to claim 1, wherein, based on the test spectrum and a calibration spectrum of a standard gas acquired in advance, before acquiring the relative concentration by a least square method, comprising: Acquiring an initial spectrum of zero gas; acquiring an initial spectrum of a standard gas; Acquiring a difference value between the initial spectrum of the standard gas and the initial spectrum of the zero gas as a calibration spectrum of the standard gas; Correspondingly, obtaining the test spectrum of the gas to be tested includes: Acquiring an initial spectrum of the gas to be detected; acquiring a difference value between the initial spectrum of the gas to be tested and the initial spectrum of the zero gas as a test spectrum of the gas to be tested; wherein the initial spectrum is a direct absorption spectrum or a harmonic spectrum.
  4. 4. The gas detection method of claim 1, wherein prior to determining whether the degree of discretization value is greater than a reference threshold, comprising: Under the extreme test condition and the no strong interference condition, obtaining one discrete degree value or the maximum value in a plurality of discrete degree values as a target discrete degree threshold; And obtaining the product of the target discrete degree value and the margin coefficient as a reference threshold value.
  5. 5. The gas detection method of claim 4, wherein the extreme test conditions include one or more of a high temperature environment, a low temperature environment, a zero atmosphere environment, a maximum concentration standard gas environment.
  6. 6. The gas detection method according to claim 4, wherein the margin coefficient has a value in the range of (1, 10).
  7. 7. The gas detection method of claim 4, wherein the light intensity interference condition comprises one or more of the following interference terms: the position of a reflecting surface for reflecting the detection light beam in the space where the gas to be detected is located is changed; the angle of the emitting end of the detection beam is changed; The reflection surface is condensed with water drops; the space is provided with water vapor; The space is floating with particles; Electromagnetic interference.
  8. 8. The gas detection method according to claim 1, wherein acquiring the relative concentration by a least-squares method based on the test spectrum and a calibration spectrum of a standard gas acquired in advance, comprises: Based on the calibration spectrum, obtaining a summation item of the square of the light intensity of the calibration spectrum and a summation item of the light intensity of the calibration spectrum; Based on the test spectrum, obtaining a summation item of the product of the test spectrum light intensity and the calibration spectrum light intensity, and the summation item of the test spectrum light intensity; And acquiring the relative concentration through a least square method based on the sum term of the square of the light intensity of the calibration spectrum, the sum term of the product of the light intensity of the test spectrum and the light intensity of the calibration spectrum and the sum term of the light intensity of the test spectrum.
  9. 9. The gas detection method of claim 8, wherein the sum term of the square of the intensity of the calibration spectrum is expressed as: The expression of the summation term of the calibrated spectrum light intensity is as follows: The expression of the summation term of the product of the test spectrum light intensity and the calibration spectrum light intensity is as follows: the expression of the summation term of the test spectrum light intensity is as follows: The expression of the relative concentration is: Wherein, the A summation term representing the square of the intensity of the calibration spectrum, A summation term representing the intensity of the calibration spectrum, A summation term representing the product of the test spectral light intensity and the calibration spectral light intensity, A summation term representing the intensity of the test spectrum, Representing the number of sampling points i.e. the number of spectral data points involved in the calculation, Indicating that the calibration spectrum is at the first The light intensity at the individual sampling points is, Indicating that the test spectrum is at the first The light intensity at the individual sampling points is, Representing the relative concentrations.
  10. 10. The gas detection method of claim 1, wherein after determining that the test concentration is valid, comprising: acquiring a correction coefficient based on the calibration concentration, the calibration pressure and the calibration temperature when the calibration concentration is acquired, the test concentration, the test pressure and the test temperature when the test concentration is acquired, and a temperature correction factor, a pressure correction factor and a nonlinear correction factor; and obtaining the product of the test concentration and the correction coefficient to be used as the actual concentration of the gas to be tested.
  11. 11. The gas detection method according to claim 10, wherein the expression of the correction coefficient is: Wherein, the The correction coefficient is represented by a value representing the correction coefficient, Is an integer of 1 to 3, Representing the temperature correction factor in question, Representing the pressure correction factor in question, Representing the non-linearity correction factor, The concentration of the test is indicated as such, Representing the calibration concentration.
  12. 12. A gas detection method as claimed in claim 2 or 3, wherein the expression of the direct absorption spectrum is: Wherein, the Representing the direct absorption spectrum of the light, Indicating the intensity of the probe beam before it is incident on any gas, Representing the intensity of the probe beam after it has passed through the arbitrary gas, Representing the wave number of the probe beam.
  13. 13. The gas detection method according to any one of claims 2 and 3, wherein the harmonic spectrum is an N-th harmonic spectrum and N is an integer between 1 and 3.
  14. 14. The gas detection method according to any one of claims 1 to 11, wherein the expression of the test concentration is: Wherein, the The concentration of the test is indicated as such, Which represents the relative concentration of the components in question, Representing the calibration concentration.
  15. 15. The gas detection method according to any one of claims 1 to 11, wherein the expression of the deviation spectrum is: The discrete degree value is a standard deviation or variance of the deviation spectrum, and the expression of the standard deviation is: Wherein, the The spectrum of the deviation is represented by a spectrum of the deviation, Indicating that the test spectrum is at the first The light intensity at the individual sampling points is, Which represents the relative concentration of the components in question, Indicating that the calibration spectrum is at the first The light intensity at the individual sampling points is, The standard deviation is indicated as such, Represents the average value of the deviation spectrum, Representing the number of sampling points, i.e., the number of spectral data points that participate in the calculation.
  16. 16. A gas detection system, comprising: The laser is used for emitting a detection light beam to any gas, wherein the any gas is gas to be detected, standard gas or zero gas; the optical detector is used for receiving the detection light beam transmitted through any gas and converting the detection light beam into an electric signal; The driving module is in communication connection with the laser and the optical detector and is used for controlling the working parameters of the laser according to the electric signal feedback so as to adjust the center wavelength of the detection light beam and dynamically scan the wavelength, so that the absorption peak wavelength of any gas is in the dynamic scanning wavelength range of the detection light beam; the data acquisition module is in communication connection with the optical detector and is used for converting the electric signal into a digital signal; A data processing module in communication with the data acquisition module for processing the digital signal to implement the steps of the gas detection method of any one of claims 1 to 15.
  17. 17. The gas detection system of claim 16, wherein the arbitrary gas is located in free space; or the gas detection system further comprises a gas chamber, which is arranged on the transmission light path of the detection light beam and is used for accommodating any gas.
  18. 18. A terminal device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the steps of the gas detection method according to any one of claims 1 to 15.

Description

Gas detection method, system and terminal equipment Technical Field The present application relates to the field of gas detection, and in particular, to a gas detection method, system, and terminal device. Background Tunable semiconductor laser absorption spectroscopy (Tunable Diode Laser Absorption Spectroscopy, TDLAS) technology is an important technical means in the field of gas detection. However, in the practical application process, the TDLAS technology is susceptible to various environmental factors, which causes abnormal interference of the light intensity received by the light detector, and further affects the accuracy and reliability of the gas detection result. Therefore, an effective solution is needed to improve the accuracy and reliability of the detection result of the TDLAS gas detection system when performing gas detection in a complex interference environment. Technical problem One of the purposes of the embodiments of the present application is to provide a gas detection method, a system, a terminal device and a storage medium, so as to improve the accuracy and reliability of a detection result when gas detection is performed in a complex interference environment. Technical solution A first aspect of an embodiment of the present application provides a gas detection method, including: Acquiring a test spectrum of the gas to be tested; based on the test spectrum and a calibration spectrum of the standard gas obtained in advance, obtaining relative concentration by a least square method; Acquiring the test concentration of the gas to be tested based on the relative concentration and the calibration concentration of the standard gas acquired in advance; Acquiring a deviation spectrum based on the test spectrum, the calibration spectrum and the relative concentration; Acquiring a discrete degree value of the deviation spectrum based on the deviation spectrum; Determining whether the discrete degree value is larger than a reference threshold value, determining that the test concentration is invalid under the condition that the discrete degree value is larger than the reference threshold value, and otherwise, determining that the test concentration is valid. A second aspect of an embodiment of the present application provides a gas detection system, including: The laser is used for emitting a detection light beam to any gas, wherein the any gas is gas to be detected, standard gas or zero gas; the optical detector is used for receiving the detection light beam transmitted through any gas and converting the detection light beam into an electric signal; The driving module is in communication connection with the laser and the optical detector and is used for controlling the working parameters of the laser according to the electric signal feedback so as to adjust the center wavelength of the detection light beam and dynamically scan the wavelength, so that the absorption peak wavelength of any gas is in the dynamic scanning wavelength range of the detection light beam; the data acquisition module is in communication connection with the optical detector and is used for converting the electric signal into a digital signal; The data processing module is in communication connection with the data acquisition module and is used for processing the digital signals so as to realize the steps of the gas detection method provided by the first aspect of the embodiment of the application. A third aspect of the embodiments of the present application provides a terminal device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, the processor implementing the steps of the gas detection method provided in the first aspect of the embodiments of the present application when the computer program is executed. A fourth aspect of the embodiments of the present application provides a computer readable storage medium storing a computer program which, when executed by a processor, implements the steps of the gas detection method provided in the first aspect of the embodiments of the present application. Advantageous effects According to the first aspect of the embodiment of the application, the test spectrum of the gas to be tested is obtained, the relative concentration is obtained through a least square method based on the test spectrum and the calibration spectrum of the standard gas obtained in advance, the test concentration of the gas to be tested is obtained by combining the calibration concentration of the standard gas obtained in advance, and the deviation spectrum for judging the validity of the data and the corresponding discrete degree value are defined based on the test spectrum, the calibration spectrum and the relative concentration, so that the test concentration is determined to be invalid under the condition that the discrete degree value is larger than the reference threshold value, otherwise, the test concentration is determined to be valid, and the