A method and system for measuring gas concentration in a variable pressure scenario

Abstract

The application provides a gas concentration measurement method and system under a variable pressure scene, and belongs to the technical field of laser gas sensing, which comprises the following steps: in the system architecture, the environmental pressure is converted into an analog electric signal through a pressure sensor, and the analog electric signal is converted into a digital signal through an ADC and transmitted to a microprocessor; a gain binding model is pre-stored in the microprocessor, and a real-time pressure is substituted into the gain binding model to calculate a target gain; a single-concentration layer feature model is fitted and a three-dimensional response surface model is constructed to realize high-precision decoupling of oxygen concentration and environmental pressure; in real-time measurement, the system collects real-time original absorption intensity values and measured pressure values, and through the inverse function of the three-dimensional response surface model, the real oxygen concentration after decoupling is obtained. The system can automatically calibrate different absorption cells, and takes into account real-time performance, high precision and engineering compatibility.

Description

Technical Field

[0001] This invention belongs to the field of laser gas sensing technology, specifically relating to a method and system for measuring gas concentration under varying pressure conditions. Background Technology

[0002] Gas measurement serves as the "sensory nerve" in fields such as industrial production, energy utilization, and environmental monitoring. Its core purpose is to ensure stable system operation, mitigate safety risks, and achieve efficient resource utilization by accurately grasping key parameters such as gas concentration and composition. In variable pressure scenarios such as hydrogen energy systems (oxygen purity monitoring in electrolyzers) and industrial process control (atmosphere monitoring in semiconductor manufacturing), the interference factors for gas measurement are more complex, and the accuracy control is more challenging.

[0003] In practical applications, fluctuations in environmental pressure can significantly interfere with measurement accuracy. The fundamental flaw in traditional pressure compensation techniques for spectral harmonic detection lies in their failure to simultaneously address the two core issues of "nonlinear attenuation modeling" and "bivariate decoupling," resulting in limitations such as insufficient accuracy and weak engineering adaptability in medium- and high-pressure variable-pressure scenarios. Furthermore, other existing compensation schemes often employ single hardware gain adjustment or offline software modeling, which struggles to resolve the "pressure-concentration" cross-interference problem, and linear compensation models have limited pressure range adaptability, failing to meet the high-precision requirements of wide-range scenarios such as 0-300 kPa. Therefore, there is an urgent need to improve gas concentration measurement techniques under variable-pressure scenarios. Summary of the Invention

[0004] To address the shortcomings of existing technologies for measuring gas concentration in variable pressure scenarios, this invention provides a method for measuring gas concentration in variable pressure scenarios.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for measuring gas concentration under varying pressure conditions includes the following steps: The original absorption intensity signals of the gas to the laser under different gas concentration-ambient pressure combinations are collected to obtain the original absorption intensity matrix; the target gain is calculated based on the collected ambient pressure to obtain the compensated voltage, and the compensated absorption intensity is obtained based on the compensated voltage; For any fixed gas concentration value, the relationship between the compensated absorption intensity and the ambient pressure is fitted to construct a composite function model; based on the composite function model and the compensated absorption intensity, a three-dimensional surface is reconstructed, and the coefficient matrix of the reconstructed three-dimensional surface is fitted and calculated to obtain a three-dimensional response surface model. The real-time absorption intensity value of the gas to the laser and the measured ambient pressure value are collected. The real-time absorption intensity value is then compensated by the measured ambient pressure value to obtain the compensated real-time absorption intensity value. The compensated real-time absorption intensity value and the measured pressure value are then input into the inverse function of the three-dimensional response surface model for calculation to obtain the real gas concentration.

[0006] Preferably, the composite function model is as follows: ; in, For characteristic amplitude parameters; Peak pressure parameters; C is the pressure broadening factor; P is the ambient pressure; C is the pressure broadening factor. i For any fixed gas concentration value.

[0007] Preferably, the three-dimensional response surface model is specifically: ; Where α is the coefficient matrix, C is the gas concentration, P is the ambient pressure, k and l are the polynomial orders of concentration and pressure, respectively, and I comp The absorption strength after compensation Preferably, the target gain is calculated based on the collected environmental pressure to obtain the compensated voltage, and the compensated absorption intensity is obtained based on the compensated voltage. Specifically, the environmental pressure is collected by a pressure sensor and converted into an analog electrical signal. This signal is then converted into a digital signal by an ADC and transmitted to a microprocessor. The target gain under different concentrations of environmental pressure is calculated using a pre-stored gain-binding model in the microprocessor. The compensated voltage is obtained based on the target gain. The compensated voltage is then converted into an analog voltage by a DAC and applied to a voltage-controlled amplifier to output a compensated harmonic signal. The compensated absorption intensity is obtained based on the compensated harmonic signal.

[0008] Preferably, the gain binding model is specifically: ; Where P represents environmental pressure. As the reference gain, , This is the gain compensation coefficient determined through calibration experiments.

[0009] Preferably, the coefficient matrix of the reconstructed three-dimensional surface is calculated using the least squares method.

[0010] This invention also provides a gas concentration measurement system under varying pressure conditions, specifically comprising: The data preprocessing module is used to collect the original absorption intensity signals of the gas to the laser under different gas concentration-ambient pressure combinations to obtain the original absorption intensity matrix; calculate the target gain based on the collected ambient pressure to obtain the compensated voltage, and obtain the compensated absorption intensity based on the compensated voltage.

[0011] The modeling module is used to fit the relationship between the compensated absorption intensity and the change of environmental pressure for any fixed gas concentration value, and construct a composite function model; based on the composite function model and the compensated absorption intensity, a three-dimensional surface is reconstructed, and the coefficient matrix of the reconstructed three-dimensional surface is calculated to obtain a three-dimensional response surface model.

[0012] The concentration measurement module is used to collect the real-time absorption intensity value of the gas to the laser and the measured ambient pressure value. The real-time absorption intensity value is then compensated by the measured ambient pressure value to obtain the compensated real-time absorption intensity value. The compensated real-time absorption intensity value and the measured pressure value are then input into the inverse function of the three-dimensional response surface model for calculation to obtain the real gas concentration.

[0013] The present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps described in the gas concentration measurement method under varying pressure conditions.

[0014] The present invention also provides a computer-readable storage medium storing a computer program that, when loaded by a processor, can execute the steps described in the method for measuring gas concentration under varying pressure conditions.

[0015] The gas concentration measurement method under varying pressure conditions provided by this invention has the following beneficial effects: This invention performs gain compensation on the original absorption intensity matrix to eliminate the attenuation effect of harmonic peaks caused by pressure. The relationship between the compensated absorption intensity and environmental pressure is fitted at a single concentration layer to construct a composite function model. Based on this composite function model and the compensated absorption intensity, a three-dimensional response surface is reconstructed, achieving deep separation and precise quantification of pressure interference. Fitting a single concentration layer using the composite function model ensures that the nonlinear influence of pressure on absorption intensity at a single concentration is accurately captured, avoiding non-absorption factors that could interfere with model accuracy. The three-dimensional response surface model transforms the three-dimensional relationship into a mathematical model, distinguishing between concentration and pressure cross-interference. Furthermore, only recalibration and generation of a new coefficient matrix are needed to quickly adapt to different scenarios, overcoming the shortcomings of traditional techniques in terms of adaptability. In practical applications, only the inverse function of the three-dimensional response surface model needs to be solved to obtain the actual gas concentration, meeting the rapid response requirements of industrial scenarios. Simultaneously, because the model has pre-quantified pressure interference, the decoupled concentration is unaffected by pressure fluctuations, improving the accuracy of full-range measurement errors. Attached Figure Description

[0016] To more clearly illustrate the embodiments and design schemes of the present invention, the accompanying drawings required for this embodiment will be briefly described below. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of a gas concentration measurement method under varying pressure conditions according to the present invention.

[0018] Figure 2 This is a pressure-intensity response curve diagram in an embodiment of the present invention.

[0019] Figure 3 This is a comparison chart of no compensation and compensation in an embodiment of the present invention, wherein, Figure 3 (a) shows the curve of the attenuation of the uncompensated harmonic signal as pressure increases. Figure 3 (b) is the curve showing that the harmonic signal amplitude remains stable throughout the pressure range after gain-binding model compensation.

[0020] Figure 4 This is a comparison chart of measurement errors before and after compensation under different pressures in an embodiment of the present invention.

[0021] Figure 5 This is the overall system architecture under variable pressure scenarios in this embodiment of the invention. Detailed Implementation

[0022] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0023] Example like Figure 5 The diagram illustrates the overall system architecture and workflow under varying pressure conditions, specifically comprising three parts: a hardware layer (laser, absorption cell, detector, pressure sensor), a signal layer (dynamic response adjustment circuit), and an algorithm layer (microprocessor and the core algorithm module), and their interactions. It systematically describes the complete measurement process from signal generation and hardware compensation to software decoupling. Hardware layer: Herriott-type absorption cell (10m optical path) + 0.7623μm DFB laser + pressure sensor. Signal layer: Dynamic response adjustment circuit for real-time harmonic attenuation compensation. Algorithm layer: Three-dimensional multivariable feature reconstruction to achieve concentration-pressure decoupling.

[0024] This invention provides a method for measuring gas concentration under varying pressure conditions, such as... Figure 1 As shown, it includes the following steps: Step 1: Collect the original absorption intensity signal of the gas to the laser under each gas concentration-ambient pressure combination to obtain the original absorption intensity matrix.

[0025] Select n concentration calibration points (e.g., 1%, 2%, 4% oxygen concentration) and m pressure calibration points (0-300 kPa) to cover the concentration and pressure range of the target application. The selection of calibration points must adhere to the principles of systematicity and coverage. Concentration calibration points should cover the minimum, maximum, and critical intermediate points of the sensor's range; pressure calibration points should be evenly distributed throughout the entire operating range (e.g., 0-300 kPa), with an appropriate increase in calibration point density in areas where pressure effects are significant (e.g., medium-high pressure zones) to more accurately capture the system's nonlinear response. The calibration process should be performed under stable ambient temperature conditions to eliminate the interference of temperature drift on the model.

[0026] For each concentration-pressure combination, the original absorption intensity signal was acquired based on the system architecture to obtain the original absorption intensity matrix, as follows: ; in, This is the concentration calibration point; Pressure calibration point; This refers to the original absorption intensity signal. The original absorption intensity signal is the laser intensity signal received by the detector after the laser passes through the target gas. When a laser of a specific wavelength passes through a gas, the gas molecules absorb some of the laser energy, causing the laser intensity to attenuate. The original absorption intensity is the laser intensity remaining after attenuation. Under fixed conditions such as pressure and temperature, it is positively correlated with the gas concentration—the higher the concentration, the stronger the absorption, and the smaller the original absorption intensity.

[0027] Step 2: Perform gain compensation on the original absorption intensity matrix to obtain the compensated absorption intensity. Specifically, substitute the ambient pressure into the gain-binding model to calculate the target gain. Based on the target gain, obtain the compensated voltage, and then obtain the compensated absorption intensity from the compensated voltage. In the system architecture, the ambient pressure P is converted into an analog electrical signal by a pressure sensor, and then converted into a digital signal by an ADC and transmitted to the microprocessor.

[0028] A gain-binding model is pre-stored in the microprocessor. The real-time pressure P is substituted into the gain-binding model to calculate the target gain G. The specific gain-binding model is as follows: ; Among them, coefficient , and reference gain Determined through calibration experiments.

[0029] Convert the target gain G into the corresponding control voltage V c The signal is converted into an analog voltage by a DAC and then applied to a voltage-controlled amplifier. The attenuated second harmonic signal... The signal is amplified to the target gain by the amplifier, and the output amplitude is stabilized after compensation. The compensated harmonic signal satisfies:

[0030] .

[0031] Taking a 4% oxygen concentration as an example, such as Figure 3 As shown, the curves of the uncompensated harmonic signal attenuating as pressure increases, and the curves of the harmonic signal amplitude remaining stable throughout the pressure range after gain-binding model compensation, intuitively demonstrate the effectiveness of hardware-level compensation.

[0032] Step 3: Single-concentration layer feature model fitting and multivariate feature surface reconstruction are the core algorithmic steps for achieving high-precision decoupling between oxygen concentration and environmental pressure. For any fixed oxygen concentration value, the relationship between the compensated absorption intensity and environmental pressure is fitted to construct a composite function model. Based on the composite function model and the compensated absorption intensity, a three-dimensional surface is reconstructed. The coefficient matrix of the reconstructed three-dimensional surface is calculated to obtain the three-dimensional response surface model. The detailed implementation process is as follows:

[0033] (1) Fitting of a single concentration layer feature model. For any fixed oxygen concentration value C i Its compensated absorption intensity I comp The relationship between environmental pressure P and the environmental pressure P is described by a composite function model:

[0034] ; in, The characteristic amplitude parameter reflects the peak intensity of the absorption signal at this concentration and is positively correlated with the gas concentration. The peak pressure parameter indicates the pressure point corresponding to the peak absorption intensity, and is used to characterize the center position of the linear broadening. The pressure broadening factor quantifies the degree to which the absorption line broadens with pressure; the larger the value, the more significant the pressure broadening effect. + The linear baseline drift term is used to fit the changes in signal background caused by non-absorption factors such as light source intensity fluctuations and detector dark current, ensuring the purity of Gaussian feature extraction.

[0035] To visually demonstrate the impact of environmental pressure on the original measurement signal, Table 1 lists the original absorption intensity signal values ​​collected by the calibration system under different pressures, using a 4% oxygen concentration as an example. These data reflect the phenomenon of signal attenuation as pressure increases, serving as the input basis for subsequent hardware gain compensation. Table 1 shows data at a 4% concentration as an example.

[0036] Table 1 Uncompensated oxygen concentration values ​​under different pressures The data in Table 1 are the original, uncompensated signals. In step two, these original signals have been compensated in real time using a gain-binding model to obtain a compensated signal I_comp with stable amplitude. The fitting object in this step (step three (1)) is precisely these compensated signals I_comp, not the original data in Table 1. The compensated experimental data are fitted using a nonlinear least squares method.

[0037] The optimal parameter set was obtained by fitting the experimental data at a 4% concentration using the nonlinear least squares method. a=4011, b=-120, c=950, d=-8.2, e=120.

[0038] For each fixed concentration, the intrinsic physical laws governing the change in absorption intensity with pressure after compensation (such as Gaussian broadening and linear drift) are deeply explored and quantified. Pressure-intensity curves at different concentrations are fitted, resulting in multiple independent concentration-specific pressure-intensity curves. Complex physical phenomena are transformed into sets of specific, physically meaningful parameters, resulting in multiple local curves obtained from fitting a single concentration layer.

[0039] like Figure 2 As shown in the figure, this diagram visually illustrates the typical data processed and the fitting results during the "single-concentration layer characteristic model fitting". The figure displays discrete experimental data points showing the change of compensated absorption intensity with pressure at different fixed concentrations, as well as the continuous curve fitted by the composite function model, verifying the accuracy of the model in describing the pressure-intensity relationship.

[0040] The root mean square error (RMSE) of the model fitting is 0.38%, indicating that the model is in high agreement with the experimental data and fully captures the nonlinear effect of pressure on the compensated absorption intensity.

[0041] (2) Multivariable feature surface reconstruction. To achieve full-range decoupling between concentration and pressure, a feature surface needs to be constructed with concentration C and pressure P as independent variables and the compensated absorption intensity I as the variable. comp Assuming the dependent variable is a three-dimensional surface, we obtain a three-dimensional response surface model of a bivariate quadratic polynomial:

[0042] ; Where C is the gas concentration and P is the ambient pressure. , , , These are the undetermined coefficients of the model. These coefficients together form a 3×3 coefficient matrix α, which is determined by calibration experimental data covering the target concentration and pressure range, and is the key parameter set for achieving decoupling in this method.

[0043] Using the least squares method and the calibration data covering the entire concentration-pressure range collected in step one, the above model is fitted to obtain the uniquely determined optimal coefficient matrix α. .

[0044] Each element in the matrix The coupling strength between the k-th power of concentration C and the l-th power of pressure P was quantified. This matrix is ​​the key converter that simplifies the system from a three-dimensional "concentration-pressure-intensity" response relationship to a computable mathematical model.

[0045] Once the coefficient matrix α is determined through calibration experiments, it is stored as a characteristic parameter of the current sensor system. In subsequent real-time measurements (step four), this matrix will be directly called for concentration calculation.

[0046] Step 4: In real-time measurement, the system acquires real-time absorption intensity values. and measured pressure value First, following the method described in step two, the measured pressure value is used. right Gain compensation is performed to obtain the compensated real-time absorption intensity value. By solving the inverse function of the aforementioned three-dimensional response surface model, the decoupled true oxygen concentration can be obtained. :

[0047] Will and Substituting into the model, we obtain a quadratic equation in terms of concentration C: A ( )× +B ( )×C+D( ) = 0 Among them, coefficients A, B, and D are derived from the measured pressure. Strength after compensation The coefficient matrix α together determine: A( )= + × + ×( )² B( )= + × + ×( )² D( )= + × + ×( )²− Based on the formula of a quadratic equation in one variable, combined with the gas concentration... The constraint ≥0 ultimately yields the inverse function, specifically: ; The calculation process relies on a pre-determined coefficient matrix α, which requires little computation and can be completed in real time in an embedded system, ultimately achieving high-precision oxygen concentration measurement unaffected by pressure fluctuations.

[0048] Figure 4 This demonstrates the final performance of the method of this invention after completing the concentration decoupling calculation. By comparing the concentration measurement errors of the conventional method (before compensation) and the method of this invention (after compensation) at different pressure points, the significant advantages of this invention in eliminating pressure interference and improving the accuracy of full-range measurement are quantitatively demonstrated.

[0049] The present invention also provides a gas concentration measurement system under varying pressure conditions, comprising: The data preprocessing module is used to collect the original absorption intensity signals of the gas to the laser under different gas concentration-ambient pressure combinations to obtain the original absorption intensity matrix; calculate the target gain based on the collected ambient pressure to obtain the compensated voltage, and obtain the compensated absorption intensity based on the compensated voltage.

[0050] The modeling module is used to fit the relationship between the compensated absorption intensity and the change in environmental pressure for any fixed gas concentration value, and construct a composite function model. Based on the composite function model and the compensated absorption intensity, a three-dimensional surface is reconstructed, and the coefficient matrix of the reconstructed three-dimensional surface is calculated to obtain a three-dimensional response surface model.

[0051] The concentration measurement module is used to collect the real-time absorption intensity value of the gas to the laser and the measured ambient pressure value. The real-time absorption intensity value is compensated by the gain of the measured ambient pressure value to obtain the compensated real-time absorption intensity value. The compensated real-time absorption intensity value and the measured pressure value are input into the inverse function of the three-dimensional response surface model for calculation to obtain the real gas concentration.

[0052] The system and method of this invention have broad applicability and can be widely applied to scenarios with pressure fluctuations, such as hydrogen energy systems (e.g., oxygen purity monitoring in electrolyzers), industrial process control (e.g., atmosphere monitoring in semiconductor manufacturing), and environmental monitoring (e.g., flue gas analysis). Its core lies in solving the common problem of "pressure-concentration" cross-interference, rather than being limited to a specific application.

[0053] The various modules in the gas concentration measurement system under the aforementioned variable pressure scenario can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0054] The present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory. The processor executes the computer program to implement the steps in an embodiment of a gas concentration measurement method under varying pressure conditions. Specific implementation methods can be found in the method embodiments, and will not be repeated here.

[0055] Furthermore, the present invention also provides a non-transitory computer-readable storage medium containing instructions, on which a computer program is stored. For example, a memory containing instructions that can be executed by a processor of a computer device to perform the above-described method. For example, the non-transitory computer-readable storage medium may be a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc. When the computer program is executed by the processor, it can implement the steps in an embodiment of a gas concentration measurement method under varying pressure scenarios. Specific implementation methods can be found in the method embodiments, which will not be repeated here.

[0056] Those skilled in the art will understand that embodiments of the present invention can provide methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0057] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, as well as combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0058] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0059] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1The steps of the function specified in one or more boxes.

[0060] It should be noted that the specific embodiments described above enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way. Therefore, although the present invention has been described in detail in this specification and embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention; and all technical solutions and improvements that do not depart from the spirit and scope of the present invention are covered within the protection scope of the present invention patent. No reference numerals in the claims should be construed as limiting the scope of the claims. Any simple variations or equivalent substitutions of technical solutions that can be readily obtained by those skilled in the art within the scope of the technology disclosed in the present invention are within the protection scope of the present invention.

Claims

1. A method for measuring gas concentration under varying pressure conditions, characterized in that, Includes the following steps: The original absorption intensity signals of the gas to the laser under different gas concentration-ambient pressure combinations are collected to obtain the original absorption intensity matrix; based on the collected ambient pressure, the target gain is calculated using a pre-stored gain binding model; the compensated voltage is obtained based on the target gain, and the compensated absorption intensity is obtained based on the compensated voltage. The gain binding model is as follows: Where P represents environmental pressure, As the reference gain, , The gain compensation coefficient is determined through calibration experiments; For any fixed gas concentration value, the relationship between the compensated absorption intensity and the ambient pressure is fitted to construct a composite function model; based on the composite function model and the compensated absorption intensity, a three-dimensional surface is reconstructed, and the coefficient matrix of the reconstructed three-dimensional surface is fitted and calculated to obtain a three-dimensional response surface model. The real-time absorption intensity value of the gas to the laser and the measured ambient pressure value are collected. The real-time absorption intensity value is then compensated by the measured ambient pressure value to obtain the compensated real-time absorption intensity value. The compensated real-time absorption intensity value and the measured pressure value are then input into the inverse function of the three-dimensional response surface model for calculation to obtain the real gas concentration.

2. The method for measuring gas concentration under varying pressure conditions according to claim 1, characterized in that, The composite function model is specifically as follows: ； in, For characteristic amplitude parameters; Peak pressure parameters; C is the pressure broadening factor; P is the ambient pressure; C is the pressure broadening factor. i For any fixed gas concentration value.

3. The method for measuring gas concentration under varying pressure conditions according to claim 1, characterized in that, The three-dimensional response surface model is specifically: ； Where α is the coefficient matrix, C is the gas concentration, P is the ambient pressure, k and l are the polynomial orders of concentration and pressure, respectively, and I comp This represents the absorbed intensity after compensation.

4. The method for measuring gas concentration under varying pressure conditions according to claim 1, characterized in that, Based on the collected environmental pressure, the target gain is calculated using a pre-stored gain-binding model. The compensated voltage is obtained based on the target gain, and the compensated absorption intensity is obtained based on the compensated voltage. Specifically, the environmental pressure is collected by a pressure sensor and converted into an analog electrical signal. This signal is then converted into a digital signal by an ADC and transmitted to a microprocessor. The target gain under the environmental pressure is calculated using a pre-stored gain-binding model in the microprocessor. The compensated voltage is obtained based on the target gain. The compensated voltage is then converted into an analog voltage by a DAC and applied to a voltage-controlled amplifier to output a compensated harmonic signal. The compensated absorption intensity is obtained based on the compensated harmonic signal.

5. The method for measuring gas concentration under varying pressure conditions according to claim 1, characterized in that, The coefficient matrix of the reconstructed three-dimensional surface is calculated using the least squares method.

6. A gas concentration measurement system under varying pressure conditions, characterized in that, include: The data preprocessing module is used to collect the raw absorption intensity signals of the gas to the laser under different gas concentration-ambient pressure combinations, and obtain the raw absorption intensity matrix. Based on the collected environmental pressure, the target gain is calculated using a pre-stored gain-binding model; the compensated voltage is obtained based on the target gain, and the compensated absorption intensity is obtained based on the compensated voltage. The gain binding model is as follows: Where P represents environmental pressure, As the reference gain, , The gain compensation coefficient is determined through calibration experiments; The modeling module is used to fit the relationship between the compensated absorption intensity and the ambient pressure for any fixed gas concentration value, and construct a composite function model; based on the composite function model and the compensated absorption intensity, a three-dimensional surface is reconstructed, and the coefficient matrix of the reconstructed three-dimensional surface is calculated to obtain a three-dimensional response surface model. The concentration measurement module is used to collect the real-time absorption intensity value of the gas to the laser and the measured ambient pressure value. The real-time absorption intensity value is then compensated by the measured ambient pressure value to obtain the compensated real-time absorption intensity value. The compensated real-time absorption intensity value and the measured pressure value are then input into the inverse function of the three-dimensional response surface model for calculation to obtain the real gas concentration.

7. A computer device, comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the method according to any one of claims 1 to 5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is loaded by the processor, it is able to perform the steps of the method according to any one of claims 1 to 5.

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