Method for processing absorption signal of methane sensor

Abstract

The invention provides a method for processing an absorption signal of a methane sensor, and belongs to the technical field of signal processing. The method comprises the following steps: 1, selecting a target methane gas sample and a research area thereof, and configuring and installing a light source and a methane photoelectric sensor; 2, a methane photoelectric sensor receives an optical signal penetrating through the gas sample, signal processing is carried out, and a standard signal is obtained; step 3, processing the standard signal by using a frequency spectrum rotation module, and then carrying out frequency spectrum rotation to separate the effective signal from the noise signal to obtain an absorbed effective signal; 4, converting the absorbed effective signal into effective gas concentration; and 5, calculating the deviation between the effective gas concentration and the actual gas sample concentration, and adjusting the parameters of the light source and the methane photoelectric sensor based on the deviation degree. The spectrum rotation module is used, so that data can be quickly processed, effective signals and noise can be separated, the amplitude of absorption signals can be quickly extracted, and the accuracy of gas concentration analysis can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of signal analysis, and in particular to a method for processing absorption signals of a methane sensor. Background Art

[0002] At present, methane is an important greenhouse gas that has a significant impact on global warming. Its emissions mainly come from agriculture, oil and gas production, landfills, etc. Therefore, accurate monitoring of methane concentration is of great significance for environmental protection, climate change research, and industrial safety. However, the direct sensor method for measuring methane concentration is usually inefficient and the measurement results are inaccurate.

[0003] Therefore, the present invention proposes a method for processing absorption signals of a methane sensor. Summary of the invention

[0004] The present invention provides a method for processing the absorption signal of a methane sensor, which is used to receive and process the light signal transmitted through the sample through the sensor to generate a standard signal. Subsequently, the spectrum rotation module is used to reduce the frequency, which can quickly process the data, separate the effective signal from the noise, and convert the absorbed effective signal into the gas concentration. Finally, the deviation between the effective concentration and the actual concentration is calculated, and the light source and sensor parameters are adjusted according to the deviation to improve the accuracy of the measurement.

[0005] In one aspect, the present invention provides a method for processing a methane sensor absorption signal, comprising:

[0006] Step 1: Select the target methane gas sample and its research area, and configure and install the light source and methane photoelectric sensor;

[0007] Step 2: The methane photoelectric sensor receives the light signal transmitted through the gas sample, performs signal processing, and obtains a standard signal;

[0008] Step 3: Use the spectrum rotation module to process the standard signal, and then rotate the spectrum to separate the effective signal from the noise signal to obtain the effective absorption signal;

[0009] Step 4: Use the Beer-Lambert law to convert the absorption effective signal into effective gas concentration;

[0010] Step 5: Calculate the deviation between the effective gas concentration and the actual gas sample concentration, and adjust the parameters of the light source and the methane photoelectric sensor based on the degree of deviation.

[0011] On the other hand, target methane gas samples and their research areas are selected, including:

[0012] The study location is selected based on the purpose of studying the gas concentration;

[0013] The research area of ​​the target methane gas sample is divided based on the research location, and the basic environmental parameters of the research area are obtained.

[0014] On the other hand, the configuration and installation of the light source and the methane photoelectric sensor include:

[0015] Based on the basic environmental parameters of the study area, the initial wavelength of the light source is selected and the light source is installed at a standard distance from the gas sample;

[0016] A methane photoelectric sensor is installed at the other end of the standard collection distance between the gas sample and the light source. The collection frequency of the methane photoelectric sensor is a preset standard frequency, and the methane photoelectric sensor can receive the light signal emitted by the light source.

[0017] On the other hand, the methane photoelectric sensor receives the light signal transmitted through the gas sample and performs signal processing, including:

[0018] The methane photoelectric sensor receives the initial light signal transmitted through the gas sample by the light source and outputs it to the sensitive area of ​​the converter inside the methane photoelectric sensor;

[0019] The photons in the sensitive region interact with the electrons in the material, the photons excite the electrons from the valence band to the conduction band, and the electrons generated by each photon and the corresponding holes form electron-hole pairs;

[0020] The built-in electric field in the converter separates the free electrons and holes, with electrons moving in one direction and holes moving in the opposite direction;

[0021] The separated electrons flow to form an electric current, the magnitude of which is proportional to the intensity of the initial light signal, and ultimately an initial electrical signal is obtained after the initial light signal is converted.

[0022] On the other hand, the standard signal includes:

[0023] Using a filter to remove noise signals from the initial electrical signal to obtain a first electrical signal;

[0024] Converting the first electrical signal into a digital signal based on an ADC module, wherein the ADC module is used to convert a mixed signal including a valid signal and an interference signal, thereby converting the first electrical signal into a digital signal;

[0025] The reference frequency of the conversion of the ADC module is:

[0026] f red =4*f mod ; Among them, f red is the reference frequency, f mod is the preset modulation frequency;

[0027] The ADC module converts the signal according to the preset modulation frequency with m as the factor, where m is an integer greater than 0, to obtain a digital signal;

[0028] The sampling frequency of the ADC module is f red *2^m;

[0029] The digital signal is processed through normalization at all nodes of the digital signal to obtain a standard signal.

[0030] On the other hand, the spectrum rotation module is used to process the standard signal, and then the spectrum is rotated to separate the effective signal from the noise signal to obtain the absorbed effective signal, including:

[0031] The spectrum rotation module obtains a rotated secondary signal by multiplying the standard signal sequence by the mixing sequence:

[0032]

[0033] Among them, X(k) represents the kth signal value of the converted secondary signal sequence, x(k) represents the kth signal value of the standard sequence, and a 0 represents the first phase weight coefficient, a 1 represents the second phase weight coefficient, a 2 represents the third phase weight coefficient;

[0034] After the conversion, the effective signal is moved to near 0Hz, and the interference signal is transferred to near fs / 2Hz. fs represents the filtering wavelength of the spectrum rotation module. The effective signal and the noise signal are separated by frequency domain distribution to obtain the absorbed effective signal.

[0035] On the other hand, the Beer-Lambert law is used to convert the absorption effective signal into the effective gas concentration, including:

[0036] By comparing the signal intensity of the effective absorption signal with the intensity of the incident light signal, and calculating the absorbance as A based on the absorbance formula, the gas concentration of the gas sample is calculated based on the Beer-Lambert law:

[0037] Wherein, c represents the gas concentration of the gas sample, mor represents the molar absorption coefficient, · represents the dot product, σ(X(k0)) represents the signal intensity of the effective signal, and L represents the optical path length.

[0038] On the other hand, the deviation between the effective gas concentration and the actual gas sample concentration is calculated, and the parameters of the light source and the methane photoelectric sensor are adjusted based on the degree of deviation, including:

[0039] The effective gas concentration and the actual gas sample concentration are compared to obtain the absolute value of the deviation. If the absolute value of the deviation is greater than the standard deviation range, it is determined that the signal analysis result has a large deviation. The light source and the methane photoelectric sensor are adjusted for the wavelength of the incident light and the receiving frequency. If the absolute value of the deviation is less than or equal to the standard deviation range, the signal processing result is determined to be correct.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The present invention provides a method for processing the absorption signal of a methane sensor, which is used to receive and process the light signal transmitted through the sample through the sensor to generate a standard signal. Subsequently, the spectrum rotation module is used to reduce the frequency, which can quickly process the data, separate the effective signal from the noise, and convert the absorbed effective signal into the gas concentration. Finally, the deviation between the effective concentration and the actual concentration is calculated, and the light source and sensor parameters are adjusted according to the deviation to improve the accuracy of the measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0043] Figure 1 It is a flow chart of a method for processing a methane sensor absorption signal provided in an embodiment of the present invention.

[0044] Figure 2 It is a diagram of the internal optical path of the sensor device in the present invention.

[0045] Figure 3 It is a schematic diagram of the driving signal and absorption in the present invention.

[0046] Figure 4 It is the rotation of the signal flow and spectrum in the present invention.

[0047] Figure 5 It is the ADC sampling point position in the present invention. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] Embodiment 1:

[0050] like Figure 1 As shown, a method for processing a methane sensor absorption signal provided by an embodiment of the present invention includes:

[0051] Step 1: Select the target methane gas sample and its research area, and configure and install the light source and methane photoelectric sensor;

[0052] Step 2: The methane photoelectric sensor receives the light signal transmitted through the gas sample, performs signal processing, and obtains a standard signal;

[0053] Step 3: Use the spectrum rotation module to process the standard signal, and then rotate the spectrum to separate the effective signal from the noise signal to obtain the absorbed effective signal;

[0054] Step 4: Use the Beer-Lambert law to convert the absorption effective signal into effective gas concentration;

[0055] Step 5: Calculate the deviation between the effective gas concentration and the actual gas sample concentration, and adjust the parameters of the light source and the methane photoelectric sensor based on the degree of deviation.

[0056] In this embodiment, the target methane gas sample refers to the methane gas to be tested in a specific study area, and its source may include natural gas leaks, agricultural emissions or other industrial processes.

[0057] In this embodiment, the study area refers to a specific location where methane gas sample measurement and analysis is performed, including natural gas mining areas, agricultural fields, and areas around industrial facilities.

[0058] In this embodiment, the light source refers to a device for emitting light of a specific wavelength, and the wavelength is selected to match the absorption characteristics of methane gas.

[0059] In this embodiment, the methane photoelectric sensor is a device for detecting and measuring the methane concentration in the air, which uses light of a specific wavelength to identify the absorption characteristics of methane molecules, such as Figure 2 shown.

[0060] In this embodiment, the optical signal refers to a light wave emitted by a light source, an electromagnetic wave propagating with a specific wavelength and intensity. The specific signal graph is as follows: Figure 3 shown.

[0061] In this embodiment, signal processing is a process of analyzing and processing the acquired signal, including filtering, amplification, signal shaping, etc.

[0062] In this embodiment, the standard signal refers to a reference signal obtained after processing the optical signal received by the methane photoelectric sensor during the signal processing.

[0063] In this embodiment, the spectrum rotation module is a signal processing tool used for frequency reduction processing and signal separation.

[0064] In this embodiment, the frequency reduction processing is a signal processing technology that reduces the frequency of the signal, thereby extracting the low-frequency components and reducing the high-frequency noise.

[0065] In this embodiment, the effective signal refers to the signal generated by the absorption characteristics of the methane gas sample to the light signal.

[0066] In this embodiment, the noise signal refers to an undesired component that interferes with the target signal during the signal processing.

[0067] In this embodiment, the Beer-Lambert law is a physical law that describes the relationship between light intensity and concentration when light propagates in an absorbing medium.

[0068] In this embodiment, the effective gas concentration is calculated by using the relationship between the absorption signal and the gas concentration after signal processing and noise separation.

[0069] In this embodiment, the actual gas sample concentration refers to the true concentration of the target gas (such as methane) determined by direct measurement or known methods in a specific environment.

[0070] In this embodiment, the deviation degree refers to the difference between the calculated effective gas concentration and the actual gas sample concentration.

[0071] In this embodiment, the parameters refer to some adjustable characteristics of the light source and the methane photoelectric sensor, including: light source intensity, wavelength selection, sensor sensitivity, etc.

[0072] The working principle and beneficial effects of the above technical solution are: measuring the light signal transmitted through the gas sample by a methane photoelectric sensor, converting it into concentration using signal processing and the Beer-Lambert law, achieving efficient and accurate methane monitoring, and optimizing system performance through deviation adjustment.

[0073] Embodiment 2:

[0074] Based on the above embodiment 1, target methane gas samples and their research areas are selected, including:

[0075] The study location is selected based on the purpose of studying the gas concentration;

[0076] The research area of ​​the target methane gas sample is divided based on the research location, and the basic environmental parameters of the research area are obtained.

[0077] In this embodiment, the research location refers to the specific geographical coordinates selected when conducting a gas concentration study.

[0078] In this embodiment, the basic environmental parameters are various environmental factors that affect the change of gas concentration in the study area, including: temperature, humidity, wind speed, pressure, etc.

[0079] The working principle and beneficial effects of the above technical solution are: by selecting a suitable research location and dividing the methane gas sample area, basic environmental parameters are obtained to provide an accurate basis for subsequent concentration measurements, which helps to improve the accuracy and effectiveness of methane monitoring.

[0080] Embodiment 3:

[0081] On the basis of the above-mentioned embodiment 2, a light source and a methane photoelectric sensor are configured and installed, including:

[0082] Based on the basic environmental parameters of the study area, the initial wavelength of the light source is selected and the light source is installed at a standard distance from the gas sample;

[0083] A methane photoelectric sensor is installed at the other end of the standard collection distance between the gas sample and the light source. The collection frequency of the methane photoelectric sensor is a preset standard frequency, and the methane photoelectric sensor can receive the light signal emitted by the light source.

[0084] In this embodiment, the initial wavelength refers to the starting wavelength of the optical signal emitted by the light source.

[0085] In this embodiment, the standard distance refers to a specific distance between the gas sample and the light source.

[0086] In this embodiment, the standard collection distance refers to a fixed distance between the gas sample and the light source.

[0087] In this embodiment, the preset standard frequency refers to a signal collection frequency preset in the methane photoelectric sensor.

[0088] The working principle and beneficial effects of the above technical solution are: by selecting the wavelength of the light source based on environmental parameters and setting the standard collection distance, it is ensured that the methane photoelectric sensor can accurately receive the light signal, thereby improving the sensitivity and reliability of gas concentration measurement.

[0089] Embodiment 4:

[0090] On the basis of the above-mentioned embodiment 1, the methane photoelectric sensor receives the light signal transmitted through the gas sample and performs signal processing, including:

[0091] The methane photoelectric sensor receives the initial light signal transmitted through the gas sample by the light source and outputs it to the sensitive area of ​​the converter inside the methane photoelectric sensor;

[0092] The photons in the sensitive region interact with the electrons in the material, the photons excite the electrons from the valence band to the conduction band, and the electrons generated by each photon and the corresponding holes form electron-hole pairs;

[0093] The built-in electric field in the converter separates the free electrons and holes, with electrons moving in one direction and holes moving in the opposite direction;

[0094] The separated electrons flow to form an electric current, the magnitude of which is proportional to the intensity of the initial light signal, and ultimately an initial electrical signal is obtained after the initial light signal is converted.

[0095] In this embodiment, the converter refers to a core component that converts an optical signal into an electrical signal and is made of semiconductor materials.

[0096] In this embodiment, the sensitive area is the core part of the converter inside the methane photoelectric sensor, and is specifically used to receive and respond to incident light signals.

[0097] In this embodiment, photons are elementary particles of light and have the wave-particle duality.

[0098] In this embodiment, the electron is one of the basic subatomic particles and has a negative electric charge.

[0099] In this embodiment, the valence band is a part that describes the electron energy level in solid physics, and refers to the energy band of the highest energy state that can be occupied by electrons in a solid material.

[0100] In this embodiment, the conduction band is another important energy band in solid materials that describes the energy level of electrons, and the electrons in the conduction band can move freely.

[0101] In this embodiment, hole is a concept in solid state physics used to describe missing electrons in semiconductor materials.

[0102] In this embodiment, an electron-hole pair refers to a pair of particles generated in a semiconductor material when an electron is excited by a photon to transition from a valence band to a conduction band:

[0103] In this embodiment, the built-in electric field refers to an electric field naturally generated inside the semiconductor material due to uneven charge distribution.

[0104] The working principle and beneficial effects of the above technical solution are: using methane photoelectric sensors to convert optical signals into electrical signals, exciting electrons through photons to form electron-hole pairs, and separating them under the action of a built-in electric field. The generated current is proportional to the intensity of the optical signal, thereby achieving efficient methane concentration detection.

[0105] Embodiment 5:

[0106] Based on the above embodiment 4, the standard signal includes:

[0107] Using a filter to remove noise signals from the initial electrical signal to obtain a first electrical signal;

[0108] Converting the first electrical signal into a digital signal based on an ADC module, wherein the ADC module is used to convert a mixed signal including a valid signal and an interference signal, thereby converting the first electrical signal into a digital signal;

[0109] The reference frequency of the conversion of the ADC module is:

[0110] f red =4*f mod ; Among them, f red is the reference frequency, f mod is the preset modulation frequency;

[0111] The ADC module extracts the signal according to the preset modulation frequency with m as the extraction factor, where m is an integer greater than 0, to obtain a digital signal;

[0112] The sampling frequency of the ADC module is f red *2^m;

[0113] The digital signal is normalized at all nodes of the digital signal to obtain a standard signal.

[0114] In this embodiment, the sampling frequency of the ADC module refers to the number of times the ADC performs sampling per second, which is usually expressed in Hertz (Hz). The higher the sampling frequency, the more signal details can be captured, but it also increases the processing and storage burden.

[0115] In this embodiment, the filter is a device used for signal processing to remove unwanted components from an input signal.

[0116] In this embodiment, the first electrical signal refers to the electrical signal processed by the filter.

[0117] In this embodiment, the ADC module is a device that converts analog signals into digital signals.

[0118] In this embodiment, the digital signal is a signal composed of discrete numerical values, and the information is stored in binary form, that is, composed of a combination of 0 and 1.

[0119] In this embodiment, the reference frequency refers to a reference frequency used by an ADC (analog-to-digital converter) to set a time reference in the sampling and conversion process, such as Figure 5 shown.

[0120] In this embodiment, the preset modulation frequency refers to a target frequency used for modulation or demodulation during signal processing.

[0121] In this embodiment, the decimation factor is an important parameter in signal processing, and is used to specify the proportion of samples selected from the input signal during the signal extraction process.

[0122] In this embodiment, signal extraction refers to selecting certain specific sample points from a continuous or discrete signal to reduce the number of signal samples.

[0123] The working principle and beneficial effects of the above technical solution are: removing noise from the electrical signal through a filter, converting the effective signal into a digital signal using the ADC module, and extracting it through a preset modulation frequency, and finally achieving normalization processing to ensure a high-quality standard signal and improve the accuracy of data processing.

[0124] Embodiment 6:

[0125] On the basis of the above-mentioned embodiment 1, the standard signal is processed by using a spectrum rotation module, and then the spectrum is rotated to separate the effective signal from the noise signal to obtain the absorption effective signal, including:

[0126] The standard signal sequence is input into the spectrum rotation module for down-conversion processing. The spectrum rotation module obtains the rotated secondary signal by multiplying the standard signal sequence by the mixing sequence:

[0127]

[0128] Among them, X(k) represents the kth signal value of the converted secondary signal sequence, x(k) represents the kth signal value of the standard sequence, and a 0 represents the first phase weight coefficient, a 1 represents the second phase weight coefficient, a 2 represents the third phase weight coefficient;

[0129] After the conversion, the effective signal is moved to near 0Hz, and the interference signal is transferred to near fs / 2Hz. fs represents the filtering wavelength of the spectrum rotation module. The effective signal and the noise signal are separated by frequency domain distribution to obtain the absorbed effective signal.

[0130] In this embodiment, the mixing sequence is composed of a group of sine or cosine waves, which can be multiplied with the input signal at a specific frequency and phase, thereby achieving spectrum shift.

[0131] In this embodiment, the secondary signal is obtained by multiplying the standard signal sequence with the mixing sequence. The specific spectrum rotation is as follows: Figure 4 shown.

[0132] In this embodiment, the phase weight coefficients are parameters used to adjust the phase of the mixing sequence. These coefficients affect the distribution of the signal in the frequency domain.

[0133] The working principle and beneficial effects of the above technical solution are: the standard signal sequence is down-converted through the spectrum rotation module, the effective signal is moved to near 0Hz, and the low-frequency noise is transferred to fs / 2Hz, thereby achieving separation of the effective signal and noise and improving the accuracy and reliability of signal processing.

[0134] Embodiment 7:

[0135] Based on the above embodiment 1, the Beer-Lambert law is used to convert the absorption effective signal into the effective gas concentration, including:

[0136] By comparing the signal intensity of the effective absorption signal with the intensity of the incident light signal, and calculating the absorbance as A based on the absorbance formula, the gas concentration of the gas sample is calculated based on the Beer-Lambert law:

[0137] Wherein, c represents the gas concentration of the gas sample, mor represents the molar absorption coefficient, · represents the dot product, σ(X(k0)) represents the signal intensity of the effective signal, and L represents the optical path length.

[0138] In this embodiment, absorbance is a dimensionless quantity used to describe the degree to which light is absorbed when passing through a substance.

[0139] In this embodiment, the optical path length refers to the propagation distance of light when passing through the sample.

[0140] The working principle and beneficial effects of the above technical solution are: by comparing the absorption effective signal with the incident light signal intensity, using the absorbance formula to calculate the absorbance, and then based on the Beer-Lambert law to obtain the gas sample concentration, accurate measurement is achieved, thereby improving the accuracy and reliability of gas concentration analysis.

[0141] Embodiment 8:

[0142] On the basis of the above-mentioned embodiment 1, the deviation between the effective gas concentration and the actual gas sample concentration is calculated, and the parameters of the light source and the methane photoelectric sensor are adjusted based on the degree of deviation, including:

[0143] The effective gas concentration and the actual gas sample concentration are compared to obtain the absolute value of the deviation. If the absolute value of the deviation is greater than the standard deviation range, it is determined that the signal analysis result has a large deviation. The light source and the methane photoelectric sensor are adjusted for the wavelength of the incident light and the receiving frequency. If the absolute value of the deviation is less than or equal to the standard deviation range, the signal processing result is determined to be correct.

[0144] In this embodiment, the absolute value of the deviation refers to the absolute value of the difference between the effective gas concentration and the actual gas sample concentration.

[0145] In this embodiment, the standard deviation range refers to a set interval of allowable deviation, which is used to judge the reliability of the measurement result.

[0146] The working principle and beneficial effect of the above technical solution are: by comparing the deviation between the effective gas concentration and the actual concentration, the accuracy of the signal analysis result is judged. If the deviation exceeds the standard range, the light source and sensor settings are adjusted to ensure the reliability and accuracy of the signal processing result.

[0147] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for processing a methane sensor absorption signal, characterized in that: include: Step 1: Select the target methane gas sample and its research area, and configure and install the light source and methane photoelectric sensor; Step 2: The methane photoelectric sensor receives the light signal transmitted through the gas sample, performs signal processing, and obtains a standard signal; Step 3: Use the spectrum rotation module to process the standard signal, and then rotate the spectrum to separate the effective signal from the noise signal to obtain the absorbed effective signal; Step 4: Use the Beer-Lambert law to convert the absorption effective signal into effective gas concentration; Step 5: Calculate the deviation between the effective gas concentration and the actual gas sample concentration, and adjust the parameters of the light source and the methane photoelectric sensor based on the degree of deviation.

2. The method for processing a methane sensor absorption signal according to claim 1, characterized in that: Select the target methane gas samples and their study areas, including: The study location is selected based on the purpose of studying the gas concentration; The research area of ​​the target methane gas sample is divided based on the research location, and the basic environmental parameters of the research area are obtained.

3. The method for processing a methane sensor absorption signal according to claim 2, characterized in that: Configuration and installation of light source and methane photoelectric sensor, including: Based on the basic environmental parameters of the study area, the initial wavelength of the light source is selected and the light source is installed at a standard distance from the gas sample; A methane photoelectric sensor is installed at the other end of the standard collection distance between the gas sample and the light source. The collection frequency of the methane photoelectric sensor is a preset standard frequency, and the methane photoelectric sensor can receive the light signal emitted by the light source.

4. The method for processing a methane sensor absorption signal according to claim 1, characterized in that: The methane photoelectric sensor receives the light signal transmitted through the gas sample and performs signal processing, including: The methane photoelectric sensor receives the initial light signal transmitted through the gas sample by the light source and outputs it to the sensitive area of ​​the converter inside the methane photoelectric sensor; The photons in the sensitive region interact with the electrons in the material, the photons excite the electrons from the valence band to the conduction band, and the electrons generated by each photon and the corresponding holes form electron-hole pairs; The built-in electric field in the converter separates the free electrons and holes, with electrons moving in one direction and holes moving in the opposite direction; The separated electrons flow to form an electric current, the magnitude of which is proportional to the intensity of the initial light signal, and ultimately an initial electrical signal is obtained after the initial light signal is converted.

5. The method for processing a methane sensor absorption signal according to claim 4, characterized in that: The standard signal includes: Using a filter to remove noise signals from the initial electrical signal to obtain a first electrical signal; Converting the first electrical signal into a digital signal based on an ADC module, wherein the ADC module is used to convert a mixed signal including a valid signal and an interference signal, thereby converting the first electrical signal into a digital signal; The reference frequency of the conversion of the ADC module is: f red =4*f mod ; Among them, f red is the reference frequency, f mod is the preset modulation frequency; The sampling frequency of the ADC module is f red *2^m; The ADC module converts the signal according to the preset modulation frequency with m as the factor, where m is an integer greater than 0, to obtain a digital signal; The digital signal is normalized at all nodes of the digital signal to obtain a standard signal.

6. The method for processing a methane sensor absorption signal according to claim 1, characterized in that: The standard signal is processed by the spectrum rotation module, and then the spectrum is rotated to separate the effective signal from the noise signal to obtain the absorbed effective signal, including: The spectrum rotation module obtains a rotated secondary signal by multiplying the standard signal sequence by the mixing sequence: Wherein, X(k) represents the kth signal value of the converted secondary signal sequence, x(k) represents the kth signal value of the standard sequence, a0 represents the first phase weight coefficient, a1 represents the second phase weight coefficient, and a2 represents the third phase weight coefficient; After the conversion, the effective signal is moved to near 0Hz, and the interference signal is transferred to near fs / 2Hz. fs represents the filtering wavelength of the spectrum rotation module. The effective signal and the noise signal are separated by frequency domain distribution to obtain the absorbed effective signal.

7. The method for processing a methane sensor absorption signal according to claim 1, characterized in that: The Beer-Lambert law is used to convert the absorption effective signal into the effective gas concentration, including: By comparing the signal intensity of the effective absorption signal with the intensity of the incident light signal, and calculating the absorbance as A based on the absorbance formula, the gas concentration of the gas sample is calculated based on the Beer-Lambert law: Wherein, c represents the gas concentration of the gas sample, mor represents the molar absorption coefficient, · represents the dot product, σ(X(k0)) represents the signal intensity of the effective signal, and L represents the optical path length.

8. The method for processing a methane sensor absorption signal according to claim 1, characterized in that: The deviation between the effective gas concentration and the actual gas sample concentration is calculated, and the parameters of the light source and the methane photoelectric sensor are adjusted based on the degree of deviation, including: The effective gas concentration and the actual gas sample concentration are compared to obtain the absolute value of the deviation. If the absolute value of the deviation is greater than the standard deviation range, it is determined that the signal analysis result has a large deviation. The light source and the methane photoelectric sensor are adjusted for the wavelength of the incident light and the receiving frequency. If the absolute value of the deviation is less than or equal to the standard deviation range, the signal processing result is determined to be correct.

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