Laser gas detection system, method and equipment and storage medium

Abstract

The invention provides a laser gas detection system, method and equipment and a storage medium, and the system comprises a light source module and an optical coupler which is used for dividing a laser beam emitted by the light source module into a first laser beam and a second laser beam; the measuring cell is used for receiving the first laser beam and outputting the first laser beam penetrating through the measured gas in the measuring cell; the first photoelectric detection module is connected with the measuring cell and is used for outputting a first light intensity vector corresponding to the first laser beam penetrating through the detected gas in the measuring cell; the second photoelectric detection module is connected with the optical coupler and is used for outputting a second light intensity vector corresponding to the second laser beam; and the signal processing module is respectively connected with the first photoelectric detection module and the second photoelectric detection module and is used for determining a target compensation vector and determining the gas concentration of the detected gas based on the target compensation vector, the first light intensity vector and the second light intensity vector, so that the influence of the RAM on the accuracy of the gas concentration is eliminated, and the accuracy of determining the concentration of the detected gas is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of laser gas detection, and relates to a laser gas detection system, method, device and storage medium. BACKGROUND

[0002] In the existing laser gas detection system, residual amplitude modulation (RAM) is one of the most core interference problems, which can have the following serious effects on the detection performance of gas concentration: significant decrease in signal-to-noise ratio (SNR): the false harmonic signals (especially the 2f component) generated by RAM form a high background noise base, which seriously masks the weak trace (ppb level) absorption signal. Deterioration of the detection limit (LOD): the raised noise base causes the system to be unable to distinguish between the real absorption and the false signal, resulting in the detection limit deteriorating from the designed ppb level to the ppm level. Baseline drift and non-linear distortion: RAM is sensitive to environmental parameters such as temperature, current and vibration, causing the harmonic baseline to randomly drift and distort, destroying the linear relationship of the Beer-Lambert law, and introducing systematic inversion errors. Cross interference of multi-component detection: the difference in RAM characteristics of different lasers causes the false signals to superimpose and interfere with each other, reducing the detection selectivity of the multi-component system.

[0003] Therefore, how to reduce or eliminate RAM and improve the accuracy of gas concentration detection has become a technical problem to be solved. SUMMARY

[0004] The application provides a laser gas detection system, method, device and storage medium for improving the accuracy of gas concentration detection.

[0005] In a first aspect, the application provides a laser gas detection system, which comprises: a light source module for emitting a laser beam; a light coupler connected with the light source module, for dividing the laser beam emitted by the light source module into a first laser beam and a second laser beam; a measurement cell connected with the light coupler, for receiving the first laser beam and outputting the first laser beam after passing through a measured gas in the measurement cell; a first photodetector module connected with the measurement cell, for outputting a first light intensity vector corresponding to the first laser beam after passing through the measured gas in the measurement cell; a second photodetector module connected with the light coupler, for outputting a second light intensity vector corresponding to the second laser beam; and a signal processing module connected with the first photodetector module and the second photodetector module respectively, for determining a target compensation vector and determining the gas concentration of the measured gas based on the target compensation vector, the first light intensity vector and the second light intensity vector.

[0006] In the application, the laser output by the light source module is divided into two beams of light by the coupler, one of which passes through the measuring cell as in the conventional light path, and the other of which is directly sent to the second photodetector module as a reference light signal. Compared with the conventional scheme, the application does not need a reference gas chamber, and does not need a reference gas, greatly reducing the hardware cost. By obtaining a target compensation vector in the signal processing module, the target compensation vector is used to compensate the RAM caused by the nonlinearity of the wavelength and the driving current, and the RAM caused by the nonlinearity of the laser driver, the photodetector and the analog-to-digital converter, effectively eliminating the influence of the RAM on the accuracy of the gas concentration, and improving the accuracy of the subsequent determination of the measured gas concentration.

[0007] In an implementation form of the first aspect, the system further comprises a control module connected with the light source module, configured to control the modulation of the laser.

[0008] In an implementation form of the first aspect, the system further comprises a display module connected with the signal processing module, configured to display the gas concentration corresponding to the measured gas.

[0009] In the second aspect, the application provides a laser gas detection method, comprising: obtaining a laser beam; dividing the laser beam into a first laser beam and a second laser beam; passing the first laser beam through the measured gas to obtain a first laser beam after passing through the measured gas; performing a conversion operation on the first laser beam after passing through the measured gas to obtain a first light intensity vector corresponding to the first laser beam; performing a conversion operation on the second laser beam to obtain a second light intensity vector corresponding to the second laser beam; determining a target compensation vector; and determining the gas concentration of the measured gas based on the first light intensity vector, the second light intensity vector and the target compensation vector.

[0010] In an implementation form of the second aspect, the target compensation vector is determined by: determining a first compensation vector based on a detection wavelength range corresponding to the laser beam; determining a second compensation vector based on an initial light signal vector corresponding to the laser beam of the laser; and determining the target compensation vector according to the first compensation vector and the second compensation vector.

[0011] In an implementation form of the second aspect, determining the first compensation vector based on the detection wavelength range corresponding to the laser beam comprises: performing N times interpolation on the wavelength-drive current data in the detection wavelength range corresponding to the laser beam to obtain a wavelength vector and a drive current vector; determining a wavelength-current straight line based on a first drive current vector element and a first wavelength vector corresponding point in the drive current vector and the wavelength vector, and a last drive current vector element and a last wavelength vector corresponding point; performing N times interpolation on the wavelength-current straight line to obtain a wavelength-current vector with a length of N; and determining the first compensation vector based on the wavelength vector and the wavelength-current vector.

[0012] In an implementation form of the second aspect, determining the second compensation vector based on the initial optical signal vector corresponding to the laser corresponding to the laser beam comprises: determining the initial optical signal vector corresponding to the laser corresponding to the laser beam; determining an optical signal straight line based on a first vector element and a last vector element of the initial optical signal vector; performing N times interpolation on the optical signal straight line to obtain a target optical signal vector with a length of N; and determining the second compensation vector based on the initial optical signal vector and the target optical signal vector.

[0013] In an implementation form of the second aspect, determining the gas concentration of the measured gas based on the first light intensity vector, the second light intensity vector and the target compensation vector comprises: determining a first target light intensity vector based on the first light intensity vector and the target compensation vector; calculating even harmonics and first harmonics of the first target light intensity vector respectively to obtain compensated gas chamber light even harmonics and compensated gas chamber light first harmonics; determining a second target light intensity vector based on the second light intensity vector and the target compensation vector; calculating even harmonics and first harmonics of the second target light intensity vector respectively to obtain compensated reference light even harmonics and compensated reference light first harmonics; and determining the gas concentration of the measured gas based on the compensated gas chamber light even harmonics, the compensated gas chamber light first harmonics, the compensated reference light even harmonics, the compensated reference light first harmonics and a concentration coefficient.

[0014] In a third aspect, an embodiment of the present application provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the laser gas detection method in any one of the second aspect of the embodiments of the present application.

[0015] In a fourth aspect, an embodiment of the present application provides an electronic device, which comprises: a memory storing a computer program; and a processor connected to the memory in communication, and the processor executes the laser gas detection method in any one of the first aspect of the embodiments of the present application when the computer program is called.

[0016] As described above, the laser gas detection system, method, device and storage medium provided by the present application have the following beneficial effects:

[0017] 1) In the present application, the laser output by the light source module is divided into two beams by the coupler, one of which passes through the measuring cell as in the traditional light path, and the other directly enters the second photodetector module as a reference light signal. Compared with the traditional scheme, the present application does not need a reference gas chamber, and even less a reference gas, greatly reducing the hardware cost. By obtaining a target compensation vector in the signal processing module, the target compensation vector is used to compensate the RAM caused by the nonlinearity of the wavelength and the driving current, and the nonlinearity of the laser driver, the photodetector and the analog-to-digital converter, effectively eliminating the influence of the RAM on the accuracy of the gas concentration, and improving the accuracy of the subsequent determination of the measured gas concentration.

[0018] 2) In the embodiment of the present application, the control module is connected with the light source module, and is used for performing relevant control operations on the laser. The system closely combines "light generation" and "light control", so that the laser is no longer a simple "bulb", but becomes a precise measurement tool with adjustable wavelength, frequency-locked and controllable parameters, thereby realizing high sensitivity, high stability and high reliability of gas detection.

[0019] 3) In the embodiment of the present application, the signal processing module processes complex voltage signals or spectral data, which cannot be understood by ordinary users. The display module directly converts it into a gas concentration value, so that the user can understand the safety status of the current environment at a glance. The system can provide intuitive and easy-to-read detection results, so that the user can make the most accurate judgment in the shortest time, reducing the use threshold.

[0020] 4) In the embodiment of the present application, by introducing the target compensation vector, the RAM component caused by the nonlinearity of the laser current-wavelength and the nonlinearity of the electronic circuit can be separated from the mixed signal, so that the calculated gas concentration truly reflects the absorption strength of the gas, and eliminates systematic errors; through vector calculation (usually real-time or quasi-real-time algorithm correction), these drifts can be dynamically adapted and compensated. Even if the laser ages or the driving circuit characteristics change slightly, the system can still maintain accurate readings, reducing the need for frequent recalibration (zeroing), enhancing the long-term stability and anti-interference ability of the system; this method also corrects the non-linear distortion in the system link, so that the final gas concentration output signal and the actual gas concentration maintain an excellent linear relationship, meaning that the system is not easy to saturate when detecting high-concentration gas, and is still sensitive when detecting low-concentration gas, thereby widening the effective detection range of the system.

[0021] 5) The embodiment of the present application determines a first compensation vector based on the detection wavelength range corresponding to the laser beam; determines a second compensation vector based on the initial optical signal vector corresponding to the laser in which the laser beam is located; determines a target compensation vector according to the first compensation vector and the second compensation vector, which can effectively eliminate the influence of RAM on the subsequent determination of gas concentration, and provides an accurate data basis for the target compensation vector for obtaining accurate gas concentration.

[0022] 6) The embodiment of the present application obtains a first compensation vector of RAM caused by the nonlinearity of compensation wavelength and driving current based on the wavelength-driving current data in the detection wavelength range corresponding to the laser beam, grasps the physical root of RAM (i.e. the current-wavelength nonlinearity in a specific wavelength scanning range), and the method is not to apply a general theoretical formula, but to generate a vector based on the measured data, which greatly improves the accuracy of the first compensation vector.

[0023] 7) In the embodiment of the present application, the initial optical signal vector corresponding to the laser in which the laser beam is located is determined; the optical signal straight line is determined based on the first vector element and the last vector element of the initial optical signal vector; the target optical signal vector with a length of N is obtained by performing N times interpolation on the optical signal straight line; the second compensation vector is determined based on the initial optical signal vector and the target optical signal vector, the second compensation vector for compensating the nonlinearity of the laser driver, the photodetector, the analog-to-digital converter and other modules is obtained based on the initial optical signal vector corresponding to the laser in which the laser beam is located, and the accuracy of the second compensation vector is improved. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 A structure diagram of a laser gas detection system provided by the embodiment of the present application is shown.

[0025] Figure 2 A structure diagram of a laser gas detection system based on a control module provided by the embodiment of the present application is shown.

[0026] Figure 3 A structure diagram of a laser gas detection system based on a display module provided by the embodiment of the present application is shown.

[0027] Figure 4 A flowchart of a laser gas detection method provided by the embodiment of the present application is shown.

[0028] Figure 5 A flowchart of determining a target compensation vector provided by the embodiment of the present application is shown.

[0029] Figure 6 A flowchart of determining a first compensation vector provided by the embodiment of the present application is shown.

[0030] Figure 7 A flow chart for determining a second compensation vector is shown.

[0031] Figure 8 A flow chart for determining a gas concentration of the measured gas is shown.

[0032] Figure 9 A schematic diagram of an absorption peak of a conventional optical path and algorithm is shown.

[0033] Figure 10 A schematic diagram of an absorption peak of an optical path and algorithm of the present application is shown.

[0034] Figure 11 A structural diagram of an electronic device is shown.

[0035] Element number explanation

[0036] 100 Laser gas detection system S51~S53 Step 110 Light source module S61~S64 Step 120 Optical coupler S71~S74 Step 130 Measurement cell S81~S85 Step 140 First photodetection module 200 Electronic device 150 Second photodetection module 201 Processor 160 Signal processing module 202 Non-volatile storage medium 170 Control module 203 System bus 180 Display module 204 Internal storage S41~S47 Step 205 Network interface DETAILED DESCRIPTION

[0037] The present application will be described in more detail by the following specific examples. Other advantages and benefits of the present application will be apparent from this description. The present application can be implemented or applied in other different specific embodiments, and the details in the description can be modified or changed based on different views and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0038] It should be noted that the diagrams provided in the following embodiments only schematically illustrate the basic concept of the present application, and only show the components related to the present application in the diagrams, not the number, shape and size of the components when actually implemented. The shape, number and ratio of the components when actually implemented can be arbitrarily changed, and the layout pattern of the components can be more complex.

[0039] The technical solutions in the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0040] As shown in Figure 1 , the present application provides a structural diagram of a laser gas detection system, as shown in Figure 1 , the laser gas detection system 100 provided by the present application includes a light source module 110, an optical coupler 120, a measurement cell 130, a first photodetector module 140, a second photodetector module 150, and a signal processing module 160.

[0041] The light source module 110 is configured to emit a laser beam.

[0042] In an example, the light source module 110 includes a distributed feedback laser (DFB) laser. The DFB laser emits coherent light with extremely stable and single wavelength and extremely narrow spectral line. The physical form of the light is an elliptical divergent laser beam emitted from the side of a semiconductor chip.

[0043] In an example, the light source module 110 includes any one of an Nd:YAG laser, a ruby laser and a titanium sapphire laser.

[0044] It should be noted that the above examples are only used for illustrative purposes. In actual applications, any other suitable laser can be selected based on specific application requirements, and the present application does not limit this.

[0045] The optical coupler 120 is connected to the light source module 110 and configured to divide the laser beam emitted by the light source module 110 into a first laser beam and a second laser beam.

[0046] Specifically, the optical coupler can directly divide the output laser of the output laser. The biggest advantage is low hardware cost.

[0047] The measurement cell 130 is connected to the optical coupler 120 and configured to receive the first laser beam and output the first laser beam after passing through the measured gas in the measurement cell.

[0048] In an example, the measured gas can be carbon dioxide, methane, acetylene (C2H2) and carbon monoxide.

[0049] It should be noted that the above examples are only used for illustrative purposes. In actual applications, any other suitable laser can be selected based on specific application requirements, and the present application does not limit this.

[0050] The first photodetector module 140 is connected to the measurement cell 130 and configured to output a first light intensity vector corresponding to the first laser beam after passing through the measured gas in the measurement cell 130.

[0051] In an example, the first photodetector module 140 converts the first laser beam after passing through the measured gas into a first electrical signal, and performs an analog-to-digital conversion operation on the first electrical signal to obtain a first light intensity vector corresponding to the first electrical signal.

[0052] The second photodetector module 150 is connected to the optical coupler 120 and configured to output a second light intensity vector corresponding to the second laser beam.

[0053] Exemplarily, in the second photoelectric detection module 150, the second laser beam is converted into a second electrical signal; and an analog-to-digital conversion operation is performed on the second electrical signal to obtain a second light intensity vector corresponding to the second electrical signal.

[0054] The signal processing module 160 is connected with the first photoelectric detection module 140 and the second photoelectric detection module 150 respectively, and is configured to determine a target compensation vector, and determine a gas concentration of the measured gas based on the target compensation vector, the first light intensity vector and the second light intensity vector.

[0055] Specifically, the signal processing module 160 includes a target compensation vector determination unit and a gas concentration determination unit. In the target compensation vector determination unit, a first compensation vector is determined based on a detection wavelength range corresponding to the laser beam emitted by the light source module 110, wherein the first compensation vector is used to compensate for residual amplitude modulation (RAM) caused by nonlinearity of wavelength and driving current. A second compensation vector is determined based on an initial optical signal vector corresponding to the laser in which the laser beam is located, wherein the second compensation vector is used to compensate for RAM caused by nonlinearity of modules such as laser driver, photoelectric detector and analog-to-digital converter. The product of the first compensation vector and the second compensation vector is obtained as the target compensation vector.

[0056] The product of the target compensation vector and the first light intensity vector is obtained as a first target light intensity vector, and even harmonics and first harmonics of the first target light intensity vector are calculated respectively to obtain compensated gas chamber light even harmonics and compensated gas chamber light first harmonics. The product of the target compensation vector and the second light intensity vector is obtained as a second target light intensity vector, and even harmonics and first harmonics of the second target light intensity vector are calculated respectively to obtain compensated reference light even harmonics and compensated reference light first harmonics.

[0057] The gas concentration of the measured gas is determined based on the compensated gas chamber light even harmonics, the compensated gas chamber light first harmonics, the compensated reference light even harmonics, the compensated reference light first harmonics and a concentration coefficient, and the corresponding expression is:

[0058] The gas concentration = the concentration coefficient K * [the compensated gas chamber light even harmonics / the compensated gas chamber light first harmonics] - [the compensated reference light even harmonics / the compensated reference light first harmonics] peak value or integral area.

[0059] The embodiment of the present application provides a laser gas detection system, in the system, the present application divides the laser output by the light source module 110 into two beams through a coupler, one of which passes through the measuring cell 130 as the traditional light path, and the other directly sends to the second photodetector module 150 as a reference light signal. Compared with the traditional scheme, the present application does not need a reference gas chamber, and does not need a reference gas, greatly reduces the hardware cost, obtains a target compensation vector in the signal processing module 160, and the target compensation vector is used for compensating the RAM caused by the nonlinearity of wavelength and driving current and the RAM caused by the nonlinearity of the laser driver, the photodetector and the analog-to-digital converter and other modules, effectively eliminating the influence of RAM on the accuracy of gas concentration, and improving the accuracy of subsequent determination of the measured gas concentration.

[0060] As shown in Figure 2 The embodiment of the present application provides a structure diagram of a laser gas detection system based on a display module, as shown in Figure 2 The embodiment of the present application provides a laser gas detection system based on a display module 100, which comprises a display module 180, wherein the display module 180 is connected with the signal processing module 160, and is used for displaying the gas concentration corresponding to the measured gas.

[0061] Specifically, the display module 180 is connected with the signal processing module 160, and is used for displaying the gas concentration corresponding to the measured gas.

[0062] For example, the display module 180 is used for displaying the gas concentration corresponding to the measured gas.

[0063] The embodiment of the present application provides a laser gas detection system based on a display module 170, which comprises a display module 180, wherein the display module 180 is connected with the signal processing module 160, and is used for displaying the gas concentration corresponding to the measured gas. The system closely combines "light generation" and "light control", so that the laser is no longer a simple "bulb", but becomes a precise measurement tool with adjustable wavelength, frequency lock and controllable parameters, thereby realizing high sensitivity, high stability and high reliability of gas detection.

[0064] As shown in Figure 3 The embodiment of the present application provides a structure diagram of a laser gas detection system based on a display module, as shown in Figure 3 The embodiment of the present application provides a laser gas detection system based on a display module 100, which comprises a display module 180, wherein the display module 180 is connected with the signal processing module 160, and is used for displaying the gas concentration corresponding to the measured gas.

[0065] Specifically, the display module 180 is connected with the signal processing module 160, and is used for displaying the gas concentration corresponding to the measured gas.

[0066] This application provides a laser gas detection system based on a display module 180. In this system, the signal processing module 160 processes complex voltage signals or spectral data that are incomprehensible to ordinary users. The display module 180 directly converts these into gas concentration values ​​(such as ppm, mg / m³, %LEL, etc.), allowing users to understand the safety status of the current environment at a glance. This system can provide intuitive and easy-to-read detection results, enabling users to make the most accurate judgment in the shortest time and lowering the barrier to entry.

[0067] like Figure 4 As shown, this application provides a flowchart of a laser gas detection method. Figure 4 As shown, the laser gas detection method provided in this application includes the following steps S41 to S47.

[0068] S41, acquire the laser beam.

[0069] For example, a laser beam is emitted by the light source module 110.

[0070] S42, the laser beam is divided into a first laser beam and a second laser beam.

[0071] Specifically, the laser beam can be split into a first laser beam and a second laser beam by means of an optical coupler 120.

[0072] For example, optical coupler 120 may be an optical fiber coupler (e.g., fused biconical tapered type) for optical path splitting.

[0073] S43, the first laser beam is passed through the gas to be tested to obtain the first laser beam after passing through the gas to be tested.

[0074] S44, perform a conversion operation on the first laser beam after it passes through the gas being measured to obtain the first light intensity vector corresponding to the first laser beam.

[0075] Specifically, the first laser beam passing through the gas being measured is converted into a first electrical signal; the first electrical signal is then subjected to an analog-to-digital conversion operation to obtain a first light intensity vector corresponding to the first electrical signal.

[0076] S45, perform a conversion operation on the second laser beam to obtain the second light intensity vector corresponding to the second laser beam.

[0077] Specifically, the first laser beam passing through the gas being measured is converted into a first electrical signal; the first electrical signal is then subjected to an analog-to-digital conversion operation to obtain a first light intensity vector corresponding to the first electrical signal.

[0078] S46, Determine the target compensation vector.

[0079] S47, determine the gas concentration of the measured gas based on the first light intensity vector, the second light intensity vector and the target compensation vector.

[0080] The embodiment of the present application provides a laser gas detection method, in the method, the laser beam is divided into a first laser beam and a second laser beam, a first light intensity vector corresponding to the first laser beam after passing through the measured gas, a second light intensity vector corresponding to the second laser beam and a target compensation vector are determined, wherein the target compensation vector is used for compensating RAM caused by nonlinearity of wavelength and driving current and RAM caused by nonlinearity of a laser driver, a photoelectric detector and an analog-to-digital converter and the like, the gas concentration of the measured gas is determined based on the first light intensity vector, the second light intensity vector and the target compensation vector, the method can separate the RAM component caused by nonlinearity of the laser current-wavelength and nonlinearity of the electronic circuit from the mixed signal by introducing the target compensation vector, so that the calculated gas concentration truly reflects the absorption strength of the gas, and systematic errors are eliminated; through vector calculation (usually real-time or quasi-real-time algorithm correction), these drifts can be dynamically adapted and compensated. Even if the laser ages or the driving circuit characteristics change slightly, the system can still maintain accurate readings, reduce the need for frequent recalibration (zeroing), enhance the long-term stability and anti-interference ability of the system; the method also corrects the non-linear distortion in the system link, so that the final gas concentration output signal and the actual gas concentration maintain an excellent linear relationship, which means that the system is not easy to saturate when detecting high-concentration gas, and is still sensitive when detecting low-concentration gas, thereby widening the effective detection range of the system.

[0081] As shown in FIG. 1, the embodiment of the present application provides a flowchart for determining a target compensation vector, as shown in FIG. 2, the embodiment of the present application provides a method for determining a target compensation vector, which comprises the following steps S51-S53. Figure 5 Figure 5 As shown in FIG. 1, the embodiment of the present application provides a flowchart for determining a target compensation vector, as shown in FIG. 2, the embodiment of the present application provides a method for determining a target compensation vector, which comprises the following steps S51-S53.

[0082] S51, determine a first compensation vector based on a detection wavelength range corresponding to the laser beam.

[0083] Specifically, the first compensation vector is used for compensating RAM caused by nonlinearity of wavelength and driving current.

[0084] S52, determine a second compensation vector based on an initial light signal vector corresponding to a laser of the laser beam.

[0085] Specifically, the second compensation vector is used for compensating RAM caused by nonlinearity of a laser driver, a photoelectric detector and an analog-to-digital converter and the like.

[0086] ​S53, determining a target compensation vector according to the first compensation vector and the second compensation vector.

[0087] Specifically, the first compensation vector and the second compensation vector are multiplied to obtain the target compensation vector.

[0088] The embodiment of the present application provides a method for determining a target compensation vector, in which a first compensation vector is determined based on a detection wavelength range corresponding to a laser beam; a second compensation vector is determined based on an initial optical signal vector corresponding to a laser in which the laser beam is located; and a target compensation vector is determined according to the first compensation vector and the second compensation vector, which can effectively eliminate the influence of RAM on subsequent determination of gas concentration, and provides an accurate data basis of the target compensation vector for obtaining accurate gas concentration.

[0089] As shown in FIG. 1, the embodiment of the present application provides a flowchart for determining a first compensation vector, as shown in FIG. 2, the embodiment of the present application provides a method for determining a first compensation vector, which comprises the following steps S61-S64. Figure 6 Figure 6 As shown in FIG. 1, the embodiment of the present application provides a flowchart for determining a first compensation vector, as shown in FIG. 2, the embodiment of the present application provides a method for determining a first compensation vector, which comprises the following steps S61-S64.

[0090] S61, performing N times interpolation on wavelength-drive current data in a detection wavelength range corresponding to a laser beam to obtain a wavelength vector and a drive current vector.

[0091] Specifically, the wavelength-drive current data in the detection wavelength range corresponding to the laser beam can be interpolated N times based on the detection report of the laser in the light source module 110 to obtain a wavelength vector W and a drive current vector I, and the length of the wavelength vector W and the corresponding drive current vector I is N.

[0092] Wherein, the wavelength-drive current data represents data corresponding to the mapping relationship between wavelength and drive current.

[0093] Wherein, the input data of the signal processing module 160-phase locked amplifier (i.e., the first light intensity vector and the second light intensity vector) has a length of N.

[0094] S62, determining a wavelength-current straight line based on a first drive current vector element and a first wavelength vector corresponding to a point in the drive current vector and the wavelength vector, and a last drive current vector element and a last wavelength vector corresponding to a point.

[0095] ​For example, the point corresponding to the first driving current vector element and the first wavelength vector in the driving current vector and the wavelength vector is I[0]-W[0], and the point corresponding to the last driving current vector element and the last wavelength vector is I[N-1]-W[N-1]. The wavelength-current straight line is determined based on the points I[0]-W[0] and I[N-1]-W[N-1].

[0096] S63, perform N interpolations on the wavelength-current straight line to obtain a wavelength-current vector of length N.

[0097] Specifically, the wavelength-current vector can be represented by WB.

[0098] S64, determine the first compensation vector based on the wavelength vector and the wavelength-current vector.

[0099] Specifically, the expression for determining the first compensation vector based on the wavelength vector and the wavelength-current vector is: W / WB.

[0100] The first compensation vector can compensate for RAM caused by the nonlinearity of wavelength and drive current.

[0101] This application provides a method for determining a first compensation vector. In this method, wavelength vector and driving current vector are obtained by interpolating the wavelength-driving current data within the detection wavelength range corresponding to the laser beam N times. A wavelength-current straight line is obtained based on the wavelength vector and driving current vector, and the wavelength-current straight line is interpolated N times to obtain a wavelength-current vector of length N. The first compensation vector is determined based on the wavelength vector and the wavelength-current vector. The first compensation vector is specifically obtained based on the wavelength-driving current data within the detection wavelength range corresponding to the laser beam to compensate for the RAM caused by the nonlinearity of the wavelength and driving current. This method captures the physical root cause of RAM (i.e., current-wavelength nonlinearity within a specific wavelength scanning range). Moreover, this method does not apply general theoretical formulas, but generates vectors based on measured data, which greatly improves the accuracy of the first compensation vector.

[0102] like Figure 7 As shown in the figure, this application provides a flowchart for determining the second compensation vector. Figure 7 As shown, the method for determining the second compensation vector provided in this application embodiment includes the following steps S71 to S74.

[0103] S71, determine the initial optical signal vector corresponding to the laser where the laser beam is located.

[0104] Specifically, the laser drive current range is determined based on the wavelength modulation range of the measured gas, the controller generates a triangular wave modulation current signal for M cycles, the second photoelectric detection module 150 (reference light path) detects the optical signal, and in each triangular wave cycle, an optical signal vector SL0 with a length of N is obtained, and the vectors of the M cycles are superimposed and averaged to obtain an initial optical signal vector SL.

[0105] S72, determining an optical signal straight line based on the first vector element and the last vector element of the initial optical signal vector.

[0106] Specifically, the optical signal straight line is determined based on the first vector element SL[0] and the last vector element SL[N-1] of the initial optical signal vector.

[0107] S73, performing N times of interpolation on the optical signal straight line to obtain a target optical signal vector with a length of N.

[0108] Specifically, the optical signal straight line is determined based on the first vector element SL[0] and the last vector element SL[N-1] of the initial optical signal vector.

[0109] S74, determining a second compensation vector based on the initial optical signal vector and the target optical signal vector.

[0110] Specifically, the expression for determining the second compensation vector based on the initial optical signal vector and the target optical signal vector is: SL / SLB.

[0111] The embodiment of the present application provides a method for determining a second compensation vector, in which the initial optical signal vector corresponding to the laser in which the laser beam is located is determined, the optical signal straight line is determined based on the first vector element and the last vector element of the initial optical signal vector, N times of interpolation is performed on the optical signal straight line to obtain a target optical signal vector with a length of N, and the second compensation vector is determined based on the initial optical signal vector and the target optical signal vector. The second compensation vector for compensating the nonlinearity of the laser drive, the photoelectric detector and the analog-to-digital converter is obtained based on the initial optical signal vector corresponding to the laser in which the laser beam is located, and the accuracy of the second compensation vector is improved.

[0112] As shown in FIG. 1, Figure 8 The embodiment of the present application provides a flowchart for determining the gas concentration of the measured gas, as shown in FIG. 2, Figure 8 The embodiment of the present application provides a method for determining the gas concentration of the measured gas, which includes the following steps S81-S85.

[0113] S81, determining a first target optical intensity vector based on the first optical intensity vector and the target compensation vector.

[0114] Specifically, the first target light intensity vector is obtained by multiplying the first light intensity vector P1 and a target compensation vector.

[0115] S82, calculating even harmonics and first harmonics of the first target light intensity vector respectively to obtain compensated gas chamber light even harmonics and compensated gas chamber light first harmonics.

[0116] S83, determining a second target light intensity vector based on the second light intensity vector and the target compensation vector.

[0117] Specifically, the second target light intensity vector is obtained by multiplying the second light intensity vector P2 and a target compensation vector.

[0118] S84, calculating even harmonics and first harmonics of the second target light intensity vector respectively to obtain compensated reference light even harmonics and compensated reference light first harmonics.

[0119] S85, determining the gas concentration of the measured gas based on the compensated gas chamber light even harmonics, the compensated gas chamber light first harmonics, the compensated reference light even harmonics, the compensated reference light first harmonics and a concentration coefficient.

[0120] Specifically, the expression corresponding to determining the gas concentration of the measured gas based on the compensated gas chamber light even harmonics, the compensated gas chamber light first harmonics, the compensated reference light even harmonics, the compensated reference light first harmonics and a concentration coefficient is: the peak value or integral area of gas concentration = concentration coefficient K * [(compensated gas chamber light even harmonics / compensated gas chamber light first harmonics) - (compensated reference light even harmonics / compensated reference light first harmonics)].

[0121] The embodiment of the present application provides a method for determining the gas concentration of the measured gas, in which, the first target light intensity vector is determined based on the first light intensity vector and the target compensation vector; the even harmonic and the first harmonic of the first target light intensity vector are calculated respectively to obtain the compensated gas chamber light even harmonic and the compensated gas chamber light first harmonic, the compensated gas chamber light even harmonic and the compensated gas chamber light first harmonic eliminate the influence of RAM in the conventional technology, and provide accurate data basis for subsequent determination of the gas concentration; the second target light intensity vector is determined based on the second light intensity vector and the target compensation vector; the even harmonic and the first harmonic of the second target light intensity vector are calculated respectively to obtain the compensated reference light even harmonic and the compensated reference light first harmonic; the compensated reference light even harmonic and the compensated reference light first harmonic eliminate the influence of RAM in the conventional technology, and also provide accurate data basis for subsequent determination of the gas concentration; the gas concentration of the measured gas is determined based on the compensated gas chamber light even harmonic, the compensated gas chamber light first harmonic, the compensated reference light even harmonic, the compensated reference light first harmonic and the concentration coefficient, and the accurate gas concentration can be obtained.

[0122] The embodiment of the present application further provides a specific example of a laser gas detection system. The laser is a DFB laser with a wavelength of 1572nm and an FC / APC connector. The optical coupler 120 is a 1:1 optical coupler. The measuring pool 130 is a 20-meter optical path Herriott cavity gas chamber.

[0123] The circuit board uses a domestic ARM chip AT32F435 as a controller and a signal processor. The circuit board is integrated with a laser current driving circuit, a laser temperature control circuit, two photoelectric detection circuits, two signal conditioning circuits and two analog-digital conversion circuits.

[0124] In the same measured gas, Figure 9 is a schematic diagram of the absorption peak of the conventional optical path and algorithm, Figure 10 is a schematic diagram of the absorption peak of the optical path and algorithm of the present application, and it can be obviously seen that the absorption peak of the new optical path algorithm of the present application is clearer.

[0125] In the formula, the horizontal coordinate in the formula (1) and the formula (2) represents the sequence of the collected data, and the physical meaning is that it can be converted into wavelength; the vertical coordinate represents the absorption peak, that is, the gas concentration; series 1 to series 5 represent five groups of test data. Figure 9 Figure 10 The horizontal coordinate in the formula (1) and the formula (2) represents the sequence of the collected data, and the physical meaning is that it can be converted into wavelength; the vertical coordinate represents the absorption peak, that is, the gas concentration; series 1 to series 5 represent five groups of test data.

[0126] The protection scope of the laser gas detection method described in the embodiment of the present application is not limited to the execution order of the steps listed in the embodiment, and the schemes realized by increasing, reducing or replacing the steps of the prior art according to the principle of the present application are also included in the protection scope of the present application.

[0127] ​In the embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, or methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of modules / units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or units may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection of apparatuses or modules or units may be electrical, mechanical, or other forms.

[0128] The modules / units described as separate components may or may not be physically separate. The components shown as modules / units may or may not be physical modules; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules / units can be selected to achieve the objectives of the embodiments of this application, depending on actual needs. For example, the functional modules / units in the various embodiments of this application may be integrated into one processing module, or each module / unit may exist physically separately, or two or more modules / units may be integrated into one module / unit.

[0129] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0130] This application also provides an electronic device. Figure 11 The diagram shown is a structural schematic of an electronic device 200 according to an embodiment of this application. The laser gas detection method provided in this embodiment can be applied to... Figure 11 The electronic device shown is 200, but it is not limited thereto. For example... Figure 11 As shown, the electronic device 200 includes a processor 201, a memory, a system bus 203, and a network interface 205. The memory may include a non-volatile storage medium 202 and internal memory 204.

[0131] The non-volatile storage medium 202 can store an operating system and a computer program. The computer program includes program instructions which, when executed, can cause the processor to perform any one of the laser gas detection methods provided in the embodiments of the present application.

[0132] The processor is configured to provide computing and control capabilities to support the operation of the entire computer device.

[0133] The internal memory 204 provides an environment for the operation of the computer program in the non-volatile storage medium, which, when executed by the processor, can cause the processor to perform any one of the laser gas detection methods provided in the embodiments of the present application.

[0134] The network interface 205 is configured to perform network communication, such as sending assigned tasks, etc. Those skilled in the art can understand that, Figure 11 The structure shown in the figure is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. The specific computer device can include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0135] It should be understood that the processor 201 can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. Among them, the general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0136] The electronic device 200 of the embodiments of the present application can be applied to terminal devices such as tablet computers, notebook computers, mobile phones, supercomputers, smart wearable devices, etc., and can also be applied to databases, servers and terminal artificial intelligence-based service response systems. The embodiments of the present application do not make any limitation on the specific type of electronic device.

[0137] For example, an electronic device can be a station (STATION, STA) in a WLAN, can be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a handheld device having wireless communication function, a computing device or other processing device connected to a wireless modem, a computer, a laptop, a handheld communication device, a handheld computing device, and / or other devices used for communication over a wireless system and next generation communication system, for example, a mobile terminal in a 5G network, a mobile terminal in a future evolved public land mobile network (PLMN), or a mobile terminal in a future evolved non-terrestrial network (NTN), etc.

[0138] The embodiments of the present application further provide a computer readable storage medium. Those skilled in the art can understand that all or part of the steps of the methods described above can be instructed by a program to complete the processor, and the program can be stored in a computer readable storage medium. The storage medium is a non-transitory medium, for example, random access memory, read only memory, flash memory, hard disk, solid state disk, magnetic tape, floppy disk, optical disc and any combination thereof. The storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. integrated with one or more available medium sets. The available medium can be a magnetic medium (for example, floppy disk, hard disk, magnetic tape), an optical medium (for example, digital video disc (DVD)), or a semiconductor medium (for example, solid state disk (SSD)) and the like.

[0139] The embodiments of the present application can also provide a computer program product, which includes one or more computer instructions. When the computer instructions are loaded and executed on a computing device, all or part of the processes or functions described in the embodiments of the present application are generated. The computer instructions can be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, the computer instructions can be transmitted from one website, computer or data center to another website, computer or data center through wired (for example, coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (for example, infrared, wireless, microwave, etc.) mode.

[0140] The computer program product is executed by a computer, and the computer executes the method of the foregoing method embodiments. The computer program product can be a software installation package, and in a case where the foregoing method needs to be used, the computer program product can be downloaded and executed on the computer.

[0141] The descriptions of the corresponding processes or structures of the various drawings are each focused on, and parts not described in detail in a certain process or structure can be referred to the related descriptions of other processes or structures.

[0142] The above embodiments only exemplarily illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and category of the present application. Therefore, all equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical thought of the present application should be covered by the claims of the present application.

Claims

1. A laser gas detection system, characterized in that, The system includes: The light source module is used to emit a laser beam; An optical coupler, connected to the light source module, is used to split the laser beam emitted by the light source module into a first laser beam and a second laser beam; A measuring cell, connected to the optical coupler, is used to receive the first laser beam and output the first laser beam after passing through the gas to be measured in the measuring cell; The first photoelectric detection module is connected to the measurement cell and is used to output the first light intensity vector corresponding to the first laser beam after passing through the gas to be measured in the measurement cell. The second photoelectric detection module is connected to the optical coupler and is used to output the second light intensity vector corresponding to the second laser beam. The signal processing module is connected to the first photoelectric detection module and the second photoelectric detection module respectively, and is used to determine the target compensation vector and determine the gas concentration of the gas being measured based on the target compensation vector, the first light intensity vector and the second light intensity vector.

2. The system according to claim 1, characterized in that, The system also includes a control module connected to the light source module, which is used to control the modulation of the laser.

3. The system according to claim 1, characterized in that, The system also includes a display module, which is connected to the signal processing module and is used to display the gas concentration corresponding to the gas being measured.

4. A laser gas detection method, characterized in that, Applied to the system according to any one of claims 1 to 3, the method comprises: Acquire the laser beam; The laser beam is divided into a first laser beam and a second laser beam; The first laser beam is passed through the gas being tested to obtain the first laser beam after passing through the gas being tested; A conversion operation is performed on the first laser beam after it passes through the gas being measured to obtain the first light intensity vector corresponding to the first laser beam. The second laser beam is converted to obtain the second light intensity vector corresponding to the second laser beam. Determine the target compensation vector; The gas concentration of the gas being measured is determined based on the first light intensity vector, the second light intensity vector, and the target compensation vector.

5. The method according to claim 4, characterized in that, Determine the target compensation vector, including: The first compensation vector is determined based on the detection wavelength range corresponding to the laser beam. The second compensation vector is determined based on the initial optical signal vector corresponding to the laser where the laser beam is located. The target compensation vector is determined based on the first compensation vector and the second compensation vector.

6. The method according to claim 5, characterized in that, Determining the first compensation vector based on the detection wavelength range corresponding to the laser beam includes: The wavelength-driving current data within the detection wavelength range corresponding to the laser beam are interpolated N times to obtain the wavelength vector and the driving current vector. The wavelength-current straight line is determined based on the first driving current vector element and the point corresponding to the first wavelength vector, as well as the last driving current vector element and the point corresponding to the last wavelength vector. By interpolating the wavelength-current line N times, a wavelength-current vector of length N is obtained; The first compensation vector is determined based on the wavelength vector and the wavelength-current vector.

7. The method according to claim 5, characterized in that, Determining the second compensation vector based on the initial optical signal vector corresponding to the laser where the laser beam is located includes: Determine the initial optical signal vector corresponding to the laser where the laser beam is located; The optical signal straight line is determined based on the first and last vector elements of the initial optical signal vector; The optical signal line is interpolated N times to obtain a target optical signal vector of length N; The second compensation vector is determined based on the initial optical signal vector and the target optical signal vector.

8. The method according to claim 4, characterized in that, Determining the gas concentration of the gas being measured based on the first light intensity vector, the second light intensity vector, and the target compensation vector includes: The first target light intensity vector is determined based on the first light intensity vector and the target compensation vector; The even harmonics and the first harmonic of the first target light intensity vector are calculated respectively to obtain the compensated even harmonics and the compensated first harmonics of the air chamber light. The second target light intensity vector is determined based on the second light intensity vector and the target compensation vector; The even harmonics and the first harmonic of the second target light intensity vector are calculated respectively to obtain the compensated even harmonics and the compensated first harmonics of the reference light. The gas concentration of the gas being measured is determined based on the compensated even harmonics of the gas chamber light, the compensated first harmonics of the gas chamber light, the compensated even harmonics of the reference light, the compensated first harmonics of the reference light, and the concentration coefficient.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method of any one of claims 4 to 8.

10. An electronic device, characterized in that, The electronic device includes: A memory that stores a computer program; The processor, which is communicatively connected to the memory, executes the method of any one of claims 4 to 8 when the computer program is invoked.

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