CN114460023B - Detection method, system and device for simultaneously measuring concentration of multiple gases - Google Patents

Detection method, system and device for simultaneously measuring concentration of multiple gases Download PDF

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CN114460023B
CN114460023B CN202210387034.5A CN202210387034A CN114460023B CN 114460023 B CN114460023 B CN 114460023B CN 202210387034 A CN202210387034 A CN 202210387034A CN 114460023 B CN114460023 B CN 114460023B
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light intensity
gas
signal
target
detected
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CN114460023A (en
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姬红波
李自丽
姬二鹤
王腾飞
郭晓鹤
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Huadian Intelligent Control Beijing Technology Co ltd
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Huadian Intelligent Control Beijing Technology Co ltd
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
    • G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/01—Arrangements or apparatus for facilitating the optical investigation

Abstract

The application discloses a detection method, a system and a device for simultaneously measuring the concentration of multiple gases. The method comprises the following steps: controlling a plurality of lasers to alternately emit light beams at different time intervals of the same time period to obtain a plurality of light beams to be detected; acquiring background light intensity signals in a time period measured after a plurality of light beams to be measured penetrate through a background space and target light intensity signals in the time period measured after the light beams to be measured penetrate through a gas space to be measured; respectively preprocessing the background light intensity signal and the target light intensity signal in the time period according to the time interval to obtain a plurality of sections of background light intensity signals and a plurality of sections of target light intensity signals; and calculating the concentration of one to-be-detected type gas in the to-be-detected gas according to each section of target light intensity signal and the corresponding background light intensity signal to obtain the concentrations of various to-be-detected types of gas. Through the application, the problem that the gas concentration measurement is inaccurate due to the fact that multiple paths of optical signals are received through the same detector and the optical signals are overlapped in the related art is solved.

Description

Detection method, system and device for simultaneously measuring concentration of multiple gases
Technical Field
The application relates to the technical field of gas concentration measurement, in particular to a detection method, a system and a device for simultaneously measuring the concentration of multiple gases.
Background
In the measurement of gas concentration, because the gas to be detected is usually a mixed gas of multiple types of gases, in order to detect the concentrations of multiple gases at the same time, a tunable semiconductor absorption spectroscopy technology is used in the related art to detect multiple gases, specifically, because different gases in the nature have corresponding different absorption peaks in an infrared band, the tunable semiconductor absorption spectroscopy technology enables wavelength scanning intervals of multiple lasers to respectively contain characteristic absorption peaks of the gas to be detected by a wavelength tuning method, so as to detect the concentrations of multiple gases and the types of gases.
However, when multiple lasers are used to detect multiple gases simultaneously, multiple detectors are needed to receive corresponding optical signals, and multiple lasers and multiple detectors easily result in a complex structure and an excessively large volume of a measurement system. However, when one detector is used to detect multiple optical signals simultaneously, the intensities of the multiple optical signals are superimposed over time, and the change of the dc component of the detector signal is caused by the change of some factors in the optical path (such as the power of the light source, the pollution of the optical path passing through the window sheet, or the attenuation of the gain of the detector) during the measurement process.
Aiming at the problem that the gas concentration measurement is inaccurate due to the fact that multiple paths of optical signals are received by the same detector and the optical signals are overlapped in the related art, an effective solution is not provided at present.
Disclosure of Invention
The application provides a detection method, a system and a device for simultaneously measuring the concentration of multiple gases, so as to solve the problem that the gas concentration measurement is inaccurate due to the superposition of optical signals when the same detector receives multiple optical signals in the related art.
According to one aspect of the present application, detection methods, systems, and devices are provided for simultaneously measuring the concentration of multiple gases. The method comprises the following steps: controlling a plurality of lasers to alternately emit light beams at different time intervals of the same time period to obtain a plurality of light beams to be detected, wherein the wavelength range scanned by each light beam to be detected covers the absorption peak of a type of gas to be detected; acquiring background light intensity signals in a time period measured after the light beams to be measured penetrate through a background space, and acquiring target light intensity signals in the time period measured after the light beams to be measured penetrate through a gas space to be measured; preprocessing the background light intensity signal in the time period according to the time period to obtain a plurality of sections of background light intensity signals, and preprocessing the target light intensity signal in the time period according to the time period to obtain a plurality of sections of target light intensity signals; and calculating the concentration of one to-be-detected type gas in the to-be-detected gas according to each section of target light intensity signal and the corresponding background light intensity signal to obtain the concentrations of various to-be-detected types of gas.
Optionally, controlling the multiple lasers to alternately emit light beams at different time periods of the same time period, and obtaining multiple light beams to be measured includes: the corresponding laser driver is controlled to send out a driving signal through a plurality of paths of analog signals of the same time period, and the corresponding laser is driven to emit light beams through the driving signal, wherein each path of analog signal is a non-zero signal in one time period of the time period, and is a zero signal in other time periods of the time period.
Optionally, the target time periods of the multiple paths of analog signals in the time period are all zero signals, and the preprocessing is performed on the background light intensity signals in the time period according to the time periods to obtain multiple segments of background light intensity signals includes: dividing the background light intensity signal in the time period according to the time period to obtain a plurality of sections of first light intensity signals and first background signals, and removing the first background signals from the plurality of sections of first light intensity signals respectively to obtain a plurality of sections of background light intensity signals, wherein the first background signals are positioned in a target time period in the time period; preprocessing the target light intensity signals in the time period according to the time period to obtain a plurality of sections of target light intensity signals comprises the following steps: and dividing the target light intensity signal in the time period according to the time period to obtain a plurality of sections of second light intensity signals and second background signals, and removing the second background signals from the plurality of sections of second light intensity signals respectively to obtain a plurality of sections of target light intensity signals, wherein the second background signals are positioned in the target time period in the time period.
Optionally, calculating the concentration of one to-be-measured type of gas in the to-be-measured gas according to each section of the target light intensity signal and the corresponding background light intensity signal includes: determining the absorption intensity type of the corresponding gas to be detected according to the waveform characteristics of each section of target light intensity signal; when the type of gas to be detected is a strong absorption type gas, determining a first target amplitude according to the target light intensity signal and a background light intensity signal corresponding to the target light intensity signal; determining the concentration of the type of gas to be detected in the gas to be detected based on the first target amplitude, the concentration calibration coefficient of the type of gas to be detected and a first calibration formula, wherein the first calibration formula is used for representing the relationship among the first target amplitude, the concentration calibration coefficient of the type of gas to be detected and the concentration of the type of gas to be detected; when the type of gas to be detected is a weak absorption type gas, determining a second target amplitude according to the target light intensity signal and a background light intensity signal corresponding to the target light intensity signal; and determining the concentration of the type of gas to be detected in the gas to be detected based on the second target amplitude, the concentration calibration coefficient of the type of gas to be detected and a second calibration formula, wherein the second calibration formula is used for representing the relationship among the second target amplitude, the concentration calibration coefficient of the type of gas to be detected and the concentration of the type of gas to be detected.
Optionally, when the type of gas to be detected is a strong absorption type of gas, determining the first target amplitude according to the target light intensity signal and the background light intensity signal corresponding to the target light intensity signal includes: determining a first target signal from the target light intensity signal, wherein the first target signal is a signal outside an absorption signal section in the target light intensity signal; determining a second target signal from the background light intensity signal corresponding to the target light intensity signal, and determining an amplitude proportional relationship according to the amplitude of the second target signal and the amplitude of the first target signal, wherein the abscissa of the second target signal corresponds to the abscissa of the first target signal; converting the amplitude of the target light intensity signal according to the amplitude proportional relation to obtain a converted target light intensity signal; determining a third target signal from an absorption signal section of the converted target light intensity signal, and determining a fourth target signal from a background light intensity signal corresponding to the target light intensity signal, wherein the abscissa of the third target signal corresponds to the abscissa of the fourth target signal; an absolute value of a difference between the amplitude of the third target signal and the amplitude of the fourth target signal is calculated, and the absolute value of the difference is determined as the first target amplitude. Optionally, when the type of gas to be detected is a weak absorption type of gas, determining the second target amplitude according to the target light intensity signal and the background light intensity signal corresponding to the target light intensity signal includes: performing fast Fourier transform on the target light intensity signal to obtain a first frequency domain signal, and normalizing the amplitude of each peak in the first frequency domain signal by taking the amplitude of the central frequency peak of the first frequency domain signal as a reference to obtain a second frequency domain signal; performing fast Fourier transform on a background light intensity signal corresponding to the target light intensity signal to obtain a third frequency domain signal, and normalizing the amplitude of each peak in the third frequency domain signal according to the amplitude of a central frequency peak of the third frequency domain signal as a reference to obtain a fourth frequency domain signal; integrating the third frequency domain signal to obtain a first integrated value, and integrating the fourth frequency domain signal to obtain a second integrated value; the absolute value of the difference between the first integrated value and the second integrated value is calculated, and the absolute value of the difference is determined as the second target amplitude value.
Optionally, when the type of gas to be detected is a strong absorption type gas, controlling a laser driver corresponding to the type of gas to be detected to emit a sawtooth wave type driving signal, and adjusting a voltage value of the driving signal to adjust an absorption peak position of the type of gas to be detected to a region of a rising edge of a sawtooth wave.
Optionally, when the type of gas to be detected is a weak absorption type gas, controlling a laser driver corresponding to the type of gas to be detected to emit a sawtooth wave superposed sine wave type driving signal, and adjusting a voltage value of the driving signal to adjust an absorption peak position of the type of gas to be detected to a region of a rising edge of the sawtooth wave.
According to another aspect of the present application, a detection system for simultaneously measuring a plurality of gas concentrations is provided. The system comprises: the main control unit comprises a plurality of signal generating units and a signal processing unit, the signal generating units are used for outputting first analog signals in different time periods of the same time period, and the signal processing unit is used for receiving second analog signals detected by the detector and determining the concentration of the type of gas to be detected in the gas to be detected according to the second analog signals; the plurality of driving units are respectively connected with one signal generating unit and used for sending out driving signals under the first analog signals output by the signal generating unit; the plurality of lasers are respectively connected with one driving unit and are used for emitting light beams under the driving signals emitted by the driving unit and collimating the emitted light beams through the collimator to obtain a plurality of paths of test light beams; the reflector array is used for reflecting the multi-path test light beams to the reflector; the reflector is used for reflecting the light beams reflected by the reflector array to obtain reflected light beams, and the reflected light beams reach the detector after being converged by the converging element; and the detector is used for receiving the light beams converged by the converging element, determining an analog signal corresponding to the light intensity of the received light beams, obtaining a second analog signal and sending the second analog signal to the signal processing unit.
According to another aspect of the present application, a detection apparatus for simultaneously measuring a plurality of gas concentrations is provided. The device includes: the control unit is used for controlling the plurality of lasers to alternately emit light beams at different time intervals of the same time period to obtain a plurality of light beams to be detected, wherein the wavelength range scanned by each light beam to be detected covers the absorption peak of a type of gas to be detected; the acquiring unit is used for acquiring background light intensity signals in a time period measured after the light beams to be measured penetrate through the background space and acquiring target light intensity signals in the time period measured after the light beams to be measured penetrate through the gas space to be measured; the preprocessing unit is used for preprocessing the background light intensity signals in the time period according to time intervals to obtain multiple sections of background light intensity signals, and preprocessing the target light intensity signals in the time period according to time intervals to obtain multiple sections of target light intensity signals; and the calculating unit is used for calculating the concentration of one to-be-detected type gas in the to-be-detected gas according to each section of target light intensity signal and the corresponding background light intensity signal to obtain the concentrations of various to-be-detected types of gas.
Through the application, the following steps are adopted: controlling a plurality of lasers to alternately emit light beams at different time intervals of the same time period to obtain a plurality of light beams to be detected, wherein the wavelength range scanned by each light beam to be detected covers the absorption peak of a type of gas to be detected; acquiring background light intensity signals in a time period measured after the light beams to be measured penetrate through a background space, and acquiring target light intensity signals in the time period measured after the light beams to be measured penetrate through a gas space to be measured; preprocessing the background light intensity signal in the time period according to the time period to obtain a plurality of sections of background light intensity signals, and preprocessing the target light intensity signal in the time period according to the time period to obtain a plurality of sections of target light intensity signals; the concentration of one type of gas to be measured in the gas to be measured is calculated according to each section of target light intensity signal and the corresponding background light intensity signal to obtain the concentration of multiple types of gas to be measured, and the problem that the gas concentration measurement is inaccurate due to the fact that multiple paths of optical signals are received by the same detector and the optical signals are overlapped in the related art is solved. By the method that each optical signal only occupies one time interval in one period and only one optical signal exists in the time interval, the change of the direct current component of each optical signal is distinguished, and therefore the accurate gas concentration value can be obtained.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application. In the drawings:
FIG. 1 is a schematic diagram of a detection system for simultaneously measuring concentrations of multiple gases provided in accordance with an embodiment of the present application;
FIG. 2 is a flow chart of a detection method for simultaneously measuring the concentration of multiple gases provided in accordance with an embodiment of the present application;
FIG. 3 is a schematic diagram of an output of a plurality of analog signals provided in accordance with an embodiment of the present application;
FIG. 4 is a schematic diagram of an analog signal collected by a detector provided in accordance with an embodiment of the present application;
FIG. 5 is a schematic diagram of a signal corresponding to a strongly absorbing type of gas provided in accordance with an embodiment of the present application;
FIG. 6 is an illustration of a background light intensity signal and a target light intensity signal corresponding to a weakly absorbing type of gas provided in accordance with an embodiment of the present application;
FIG. 7 is a schematic diagram of an FFT signal corresponding to a weakly absorbing type of gas provided in accordance with an embodiment of the present application;
fig. 8 is a schematic diagram of a detection apparatus for simultaneously measuring a plurality of gas concentrations according to an embodiment of the present application.
Detailed Description
It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.
In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only partial embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It should be understood that the data so used may be interchanged under appropriate circumstances such that embodiments of the application described herein may be used. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
According to an embodiment of the present application, there is provided a detection method for simultaneously measuring a plurality of gas concentrations.
FIG. 1 is a schematic diagram of a detection system for simultaneously measuring concentrations of multiple gases according to an embodiment of the present application. As shown in fig. 1, the system includes:
the main control unit 1, wherein the main control unit 1 includes a plurality of signal generating units and a signal processing unit, the plurality of signal generating units are configured to output first analog signals at different time periods of a same time cycle, and the signal processing unit is configured to receive a second analog signal detected by the detector 11, and determine a concentration of a type of gas to be detected in the gas to be detected according to the second analog signal.
And the plurality of driving units 2 are respectively connected with one signal generating unit and used for sending out driving signals under the first analog signals output by the signal generating units.
The plurality of lasers 3 are respectively connected with one driving unit 2 and used for emitting light beams under the driving signals emitted by the driving unit 2, and the emitted light beams are collimated by the collimator 4 to obtain a plurality of paths of test light beams 6.
A reflector array 5 for reflecting the multiple test beams 6 to a reflector 7.
And the reflector 7 is used for reflecting the light beams reflected by the reflector array 5 to obtain reflected light beams, and the reflected light beams reach the detector 11 after being converged by the converging element 8.
And the detector 11 is configured to receive the light beam converged by the converging element 8, determine an analog signal corresponding to the light intensity of the received light beam, obtain a second analog signal, and send the second analog signal to the signal processing unit.
The system comprises a main control unit 1, a multi-path driving unit 2 (which can be an LD driver and comprises temperature control and current driving), a multi-path laser 3 (which can be an LD laser), a multi-path collimator 4, a photoelectric detector 11, a reflector and a converging element 8.
Specifically, the signal generating unit of the main control unit 1 is configured to output first analog signals at different time intervals of the same time period, and output the first analog signals through a plurality of Analog Output (AO) channels to drive the multi-path driving unit 2 (21-24 in fig. 1) to generate driving signals, so as to drive the corresponding lasers 3 (31-34 in fig. 1) to alternately emit laser beams, the collimator 4 is configured to adjust the radius of the beams at a specific position, and emit multi-path test beams 6 (61-64 in fig. 1) after being reflected by the reflector array 5 (51-54 in fig. 1) formed by the reflectors, the multi-path test beams 6 form a beam array, which is spatially compactly distributed to form a "combined beam", and the beam array is finally incident on a reflective plate 7 mounted on a matching target 9 (the matching target 9 may be a mounting base or other form, can fixed reflector panel 7 can), reflector panel 7 comprises a plurality of miniature hollow pyramid structures, can return (realize through adjusting collimator 4) the incident beam array original route of big facula to the transmitting terminal, the backward light beam gathers after gathering element 8, obtain return beam 10, return beam 10 is received by photoelectric detector 11, the analog signal that photoelectric detector 11 gathered is gathered by the Analog Input (AI) passageway of main control unit 1, send to the signal processing unit, convert the digital signal into, and confirm the concentration of the type gas of awaiting measuring of each type in the gas of awaiting measuring based on the signal after the conversion.
Through the embodiment, each optical signal only occupies one time period in one period by the signal generating units, and only one optical signal exists in the time period, so that the signal collected by the detector can distinguish the change of the direct current component of each optical signal, a foundation is laid for accurately obtaining the gas concentration value, and the problem of inaccurate gas concentration measurement caused by the superposition of optical signals when the same detector receives multiple optical signals in the related art is solved.
Fig. 2 is a flowchart of a detection method for simultaneously measuring a plurality of gas concentrations according to an embodiment of the present application. As shown in fig. 2, the method comprises the steps of:
step S201, controlling the plurality of lasers to alternately emit light beams at different time periods of the same time period to obtain a plurality of light beams to be measured, wherein a wavelength range scanned by each light beam to be measured covers an absorption peak of a type of gas to be measured.
Specifically, the time period may be T, the lengths of different periods of the same time period may be equal or unequal, and when the number of the lasers is n, each period may be T/(n +1), that is, in n +1 periods, each laser does not emit light in one period, so as to measure the background signal when no light beam to be measured is irradiated, n light beams to be measured are total, and the wavelength range of each light beam to be measured covers the absorption peak of one type of gas to be measured, so as to detect the concentration of the one type of gas to be measured.
The alternating emission of the light beams by the multiple lasers at different periods of the same time cycle can be achieved by a detection system for simultaneously measuring the concentration of multiple gases. The multiple driving units 2 are driven by a plurality of Analog Output (AO) channels of the main control unit 1 to generate driving signals, so as to drive the corresponding lasers 3 to alternately emit laser beams.
Step S202, obtaining background light intensity signals in a time period measured after the light beams to be measured pass through the background space, and obtaining target light intensity signals in the time period measured after the light beams to be measured pass through the gas space to be measured.
It should be noted that the background space may be a closed space or an open space without the gas to be detected, the gas to be detected may be a greenhouse gas, the background light intensity signal is a light intensity signal acquired after the light beam to be detected passes through the space without the gas to be detected, and the target light intensity signal is a signal acquired after the light beam to be detected passes through the space with the gas to be detected.
Specifically, n paths of lasers are controlled to emit light beams to be detected in turn, penetrate through a background space and enter a photoelectric detector to obtain a background light intensity signal in a time period, then the n paths of lasers are controlled to emit the light beams to be detected in turn, penetrate through a gas space to be detected and enter the photoelectric detector to obtain a target light intensity signal in the time period.
Step S203, preprocessing the background light intensity signal in the time period according to the time period to obtain a plurality of sections of background light intensity signals, and preprocessing the target light intensity signal in the time period according to the time period to obtain a plurality of sections of target light intensity signals.
Specifically, because a time period includes a plurality of direct current component signals, noise signals and self offset components of the detector, the preprocessing mode can include signal segmentation and signal cleaning, the time period is T, the background light intensity signal in the time period T is segmented according to the time period to obtain a plurality of sections of background light intensity signals, and then the noise signals and the offset components are removed from each section of background light intensity signal. And (3) dividing the target light intensity signal in the time period T according to the time period to obtain a plurality of sections of target light intensity signals, and then removing the noise signal and the offset component from each section of target light intensity signal.
And step S204, calculating the concentration of one to-be-detected type gas in the to-be-detected gas according to each section of target light intensity signal and the corresponding background light intensity signal to obtain the concentrations of various to-be-detected types of gas.
Specifically, the type of gas to be measured is different, the characteristics of the signals are different, the calibration coefficients in the concentration calibration formula are also different, the type of gas to be measured is determined for each section of target light intensity signal and the corresponding background light intensity signal, the corresponding concentration calculation mode is selected according to the characteristics of the type of gas to be measured, and the concentration of the type of gas to be measured is calculated.
According to the detection method for simultaneously measuring the concentration of multiple gases, multiple light beams to be measured are obtained by controlling multiple lasers to alternately emit the light beams at different time intervals of the same time period, wherein the wavelength range scanned by each light beam to be measured covers the absorption peak of one type of gas to be measured; acquiring background light intensity signals in a time period measured after the light beams to be measured penetrate through a background space, and acquiring target light intensity signals in the time period measured after the light beams to be measured penetrate through a gas space to be measured; preprocessing the background light intensity signal in the time period according to the time period to obtain a plurality of sections of background light intensity signals, and preprocessing the target light intensity signal in the time period according to the time period to obtain a plurality of sections of target light intensity signals; the concentration of one type of gas to be measured in the gas to be measured is calculated according to each section of target light intensity signal and the corresponding background light intensity signal to obtain the concentration of multiple types of gas to be measured, and the problem that the gas concentration measurement is inaccurate due to the fact that multiple paths of optical signals are received by the same detector and the optical signals are overlapped in the related art is solved. By the method that each optical signal only occupies one time interval in one period and only one optical signal exists in the time interval, the change of the direct current component of each optical signal is distinguished, and therefore the accurate gas concentration value can be obtained.
In order to distinguish optical signals corresponding to different types of gases to be measured, it is necessary to control the time period of light beam emission, and optionally, control a plurality of lasers to alternately emit light beams at different time periods of the same time cycle, and obtaining a plurality of light beams to be measured includes: the corresponding laser driver is controlled to send out a driving signal through a plurality of paths of analog signals of the same time period, and the corresponding laser is driven to emit light beams through the driving signal, wherein each path of analog signal is a non-zero signal in one time period of the time period, and is a zero signal in other time periods of the time period.
Specifically, the plurality of lasers may be controlled to alternately emit light beams at different periods of the same time period by the detection system for simultaneously measuring the concentrations of a plurality of gases of fig. 1, and specifically, the driving unit 2 may be controlled by a plurality of Analog Output (AO) channels of the main control unit 1.
For example, fig. 3 is a schematic diagram of an output of a plurality of analog signals provided according to an embodiment of the present application, and as shown in fig. 3, a total period T is divided into 5 periods, and a duration of each period is T/5; the non-zero driving signal time interval of each channel AO signal is the nth data segment corresponding to the number n of the signal channels in the period T, such as: the non-zero driving signal of the first channel is only at the 1 st T/5 th time interval, and the driving signals of other time intervals are 0; the non-zero driving signal of the second channel is only at the 2 nd T/5 th time interval, and the driving signals of other time intervals are 0; the non-zero driving signal of the third channel is only at the 3 rd T/5 th time interval, and the driving signals of other time intervals are 0; the non-zero driving signal of the fourth channel is only at the 4 th T/5 time interval, and the driving signals of other data segments are 0; the fifth channel can be a zero driving signal, so that a background signal when no light beam to be detected irradiates is measured.
Further, when the analog signal is a non-zero signal, and the current value of the driving signal of the driving unit 2 after conversion is greater than the light emitting threshold of the laser 3 (so that the non-zero driving signal of each AO channel should ensure that the laser can emit light), the laser 3 emits light, scans according to the trend of the driving signal, and simultaneously realizes wavelength scanning. It should be noted that the principle of setting the driving signal range is as follows: the characteristic absorption peak of the gas to be detected is covered by the wavelength range scanned by the laser, so that the scanning of the gas of the corresponding type is realized, a data base is laid for the segmentation of a plurality of optical signals, and the accuracy of calculating the detection concentration of each type of gas to be detected is improved.
Because the background light intensity signal or the target light intensity signal are the mixture of multichannel signal in same cycle, simultaneously, still contain the bias component of noise signal and detector self in the signal of gathering, so need carry out the preliminary treatment to it before measuring the gas concentration that awaits measuring, optionally, multichannel analog signal is zero signal in the target period of time cycle, carries out the preliminary treatment according to the period to the background light intensity signal in the time cycle, obtains multistage background light intensity signal and includes: dividing the background light intensity signal in the time period according to the time period to obtain a plurality of sections of first light intensity signals and first background signals, and removing the first background signals from the plurality of sections of first light intensity signals respectively to obtain a plurality of sections of background light intensity signals, wherein the first background signals are positioned in a target time period in the time period; preprocessing the target light intensity signals in the time period according to the time period to obtain a plurality of sections of target light intensity signals comprises the following steps: and dividing the target light intensity signal in the time period according to the time period to obtain a plurality of sections of second light intensity signals and second background signals, and removing the second background signals from the plurality of sections of second light intensity signals respectively to obtain a plurality of sections of target light intensity signals, wherein the second background signals are positioned in the target time period in the time period.
Specifically, the AO signal continuously outputs analog signals in each period T according to the sequence shown in fig. 3, n laser beams are controlled to sequentially emit light according to the 1 st, 2 nd, … … th laser beam, and each light emission T/(n +1) duration of the n laser beams completes one wavelength scanning in the time period; the total time of completing one-time scanning by the n-path lasers is T, and in each period T, the detector continuously collects optical signals in each period T and converts the collected optical signals into analog signals.
For example, fig. 4 is a schematic diagram of analog signals acquired by a detector according to an embodiment of the present disclosure, and as shown in fig. 4, the acquired analog signals (AI signals) have a same variation trend as the AO signals, and correspond to the AO channels in sequence one by one, and each includes 5 signals, and the AI signals may be segmented according to a rule and then processed one by one, and the concentration of the corresponding type of gas to be detected is calculated.
The background light intensity signal in a period T is divided into 5 time periods, the 1 st section to the fourth section of the background light intensity signal are first light intensity signals, the target time period is the 5 th section, the 5 th section of the background light intensity signal is a first background signal, and the first background signal is a signal measured by a photoelectric detector when each laser does not emit a light beam to be measured, namely, a signal caused by a bias component of the detector and a noise signal of the detector under the condition that no gas to be measured exists in a space.
Meanwhile, the target light intensity signal in one period T is also divided into 5 time periods, the 1 st to 4 th periods of the target light intensity signal are second light intensity signals, the target time period is the 5 th period, the 5 th period of the target light intensity signal is a second background signal, and the second background signal is a signal measured by the photoelectric detector when each laser does not emit a laser beam, that is, a signal and a noise signal caused by the bias component of the detector itself under the condition that gas is to be measured in the space.
In the embodiment, the background signals (namely, the noise signals and the bias components of the detector) in the background light intensity signal and the target light intensity signal are offset, so that the measured light intensity signal is more accurate, and a data base is laid for improving the calculation precision of the gas concentration.
After preprocessing the background light intensity signal and the target light intensity signal, the concentration of the type of gas to be detected can be calculated, the absorption intensity of different types of gas to be detected under different scenes is different, and optionally, the calculation of the concentration of one type of gas to be detected in the gas to be detected according to each section of target light intensity signal and the corresponding background light intensity signal comprises the following steps: determining the absorption intensity type of the corresponding gas to be detected according to the waveform characteristics of each section of target light intensity signal; when the type of gas to be detected is a strong absorption type gas, determining a first target amplitude according to the target light intensity signal and a background light intensity signal corresponding to the target light intensity signal; determining the concentration of the type of gas to be detected in the gas to be detected based on the first target amplitude, the concentration calibration coefficient of the type of gas to be detected and a first calibration formula, wherein the first calibration formula is used for representing the relationship among the first target amplitude, the concentration calibration coefficient of the type of gas to be detected and the concentration of the type of gas to be detected; when the type of gas to be detected is a weak absorption type gas, determining a second target amplitude according to the target light intensity signal and a background light intensity signal corresponding to the target light intensity signal; and determining the concentration of the type of gas to be detected in the gas to be detected based on the second target amplitude, the concentration calibration coefficient of the type of gas to be detected and a second calibration formula, wherein the second calibration formula is used for representing the relationship among the second target amplitude, the concentration calibration coefficient of the type of gas to be detected and the concentration of the type of gas to be detected.
Specifically, because the gas in nature has a plurality of corresponding absorption peaks in the infrared band, the wavelength scanning interval of the laser may include the characteristic absorption peak of the gas to be detected, so that the absorption intensity type of the corresponding gas to be detected can be determined according to the waveform characteristics of each target light intensity signal. And calculating the concentration of the gas to be measured by adopting different calculation methods according to the gas to be measured with different absorption types.
Wherein, when the type gas to be detected is a strong absorption type gas, the first target amplitude is Y 1 Concentration is C, the first calibration formula is Y 1 =a 1 C 2 +b 1 C+k 1 The calibration coefficient is a 1 ，b 1 ，k 1 Is a reaction of Y 1 And substituting the first calibration formula to calculate the concentration of the type of gas to be measured.
When the type of gas to be measured is a weakly-absorbing type of gas, the second target amplitude is Y 2 Concentration is C, the second calibration formula is Y 2 =a 2 C 2 +b 2 C+k 2 The calibration coefficient is a 2 ，b 2 ，k 2 Is a reaction of Y 2 And substituting a second calibration formula to calculate the concentration of the gas to be measured.
After the background light intensity signal and the target light intensity signal are preprocessed, the corresponding concentration calibration coefficient and the calibration formula are selected according to the absorption characteristics of the type of gas to be measured, so that the concentration of the type of gas to be measured can be accurately calculated.
After determining that the type of gas to be detected is a strong absorption type gas, selecting a corresponding calculation method to calculate the concentration of the type of gas to be detected, and optionally, when the type of gas to be detected is a strong absorption type gas, determining a first target amplitude according to the target light intensity signal and a background light intensity signal corresponding to the target light intensity signal comprises: determining a first target signal from the target light intensity signal, wherein the first target signal is a signal outside an absorption signal section in the target light intensity signal; determining a second target signal from the background light intensity signal corresponding to the target light intensity signal, and determining an amplitude proportional relationship according to the amplitude of the second target signal and the amplitude of the first target signal, wherein the abscissa of the second target signal corresponds to the abscissa of the first target signal; converting the amplitude of the target light intensity signal according to the amplitude proportional relation to obtain a converted target light intensity signal; determining a third target signal from an absorption signal section of the converted target light intensity signal, and determining a fourth target signal from a background light intensity signal corresponding to the target light intensity signal, wherein the abscissa of the third target signal corresponds to the abscissa of the fourth target signal; an absolute value of a difference between the amplitude of the third target signal and the amplitude of the fourth target signal is calculated, and the absolute value of the difference is determined as the first target amplitude.
Specifically, fig. 5 is a schematic diagram of a signal corresponding to a strong absorption type gas provided according to an embodiment of the present application, as shown in fig. 5, a target data segment is Itn, and a data segment corresponding to a converted target light intensity signal is I' tn.
When processing the signal, the data segment of the unabsorbed area is selected on Itn, the multiple of the data segment corresponding to the horizontal axis of I0n is determined, and the whole Itn is amplified in equal proportion according to the multiple to form a new absorption signal I 'tn, wherein I' tn is consistent with the baseline of I0 n. Subtracting the lowest point F of the I' tn absorption region from the point E on I0n corresponding to the horizontal axis of the point, and recording the absolute value of the obtained difference as the amplitude Y 1 During actual measurement, light intensity signals, namely background light intensity signals and target light intensity signals, of the light path without the measured gas and with the measured gas are measured respectively, and the amplitude Y is measured by the method 1 Is substituted into the firstAnd calibrating a formula to obtain the concentration C of the gas to be detected.
And optionally, when the gas to be detected is the strong absorption type gas, controlling a laser driver corresponding to the gas to be detected to send out a sawtooth wave type driving signal, and adjusting the voltage value of the driving signal so as to adjust the absorption peak position of the gas to be detected to the region of the rising edge of the sawtooth wave.
Specifically, the drive signal may use only a sawtooth wave without superimposing a high-frequency sine wave. Before a driving signal is sent out, the absorption peak position of the strong absorption type gas is adjusted to the middle area of the rising edge of the Itn sawtooth wave by adjusting the voltage values of the starting point and the end point of the sawtooth wave. The position of the absorption peak of the strong absorption type gas is adjusted by adjusting the voltage value of the driving signal, so that the target light intensity signal and the background light intensity signal are conveniently processed.
In the embodiment, the concentration C of the detected gas is measured by the strong absorption type gas according to the corresponding calculation method, so that the condition that the concentration of the gas is misjudged due to misjudgment of the light intensity change as gas absorption in the measurement process can be effectively reduced, and the problem of inaccurate detection concentration caused by the light intensity change is solved.
After determining that the type of gas to be detected is a weak absorption type gas, selecting a corresponding calculation method to calculate the concentration of the type of gas to be detected, and optionally, when the type of gas to be detected is a weak absorption type gas, determining a second target amplitude according to the target light intensity signal and a background light intensity signal corresponding to the target light intensity signal comprises: performing fast Fourier transform on the target light intensity signal to obtain a first frequency domain signal, and normalizing the amplitude of each peak in the first frequency domain signal by taking the amplitude of the central frequency peak of the first frequency domain signal as a reference to obtain a second frequency domain signal; performing fast Fourier transform on a background light intensity signal corresponding to the target light intensity signal to obtain a third frequency domain signal, and normalizing the amplitude of each peak in the third frequency domain signal according to the amplitude of a central frequency peak of the third frequency domain signal as a reference to obtain a fourth frequency domain signal; integrating the third frequency domain signal to obtain a first integrated value, and integrating the fourth frequency domain signal to obtain a second integrated value; the absolute value of the difference between the first integrated value and the second integrated value is calculated, and the absolute value of the difference is determined as the second target amplitude value.
Specifically, fig. 6 is a schematic diagram of a background light intensity signal and a target light intensity signal corresponding to a weak absorption type gas provided according to an embodiment of the present application, as shown in fig. 6, the target light intensity signal is It1n, the background light intensity signal is I01n, and a first frequency domain signal and a second frequency domain signal are obtained by performing fast fourier transform on the target light intensity signal It1n and the background light intensity signal I01n, respectively.
Fig. 7 is a schematic diagram of FFT signals corresponding to a weak absorption type gas according to an embodiment of the present application, and as shown in fig. 7, a first frequency domain signal is normalized based on an amplitude of a center frequency thereof and is denoted as It2n, a second frequency domain signal is normalized based on an amplitude of a center frequency thereof and is denoted as I02n, a third integrated value is an area between It2n and a horizontal axis, and a fourth integrated value is an area between I02n and the horizontal axis. Determining an absolute value of a difference between the third integrated value and the fourth integrated value as a second target amplitude value Y 2 During actual measurement, light intensity signals, namely background light intensity signals and target light intensity signals, of the light path without the measured gas and with the measured gas are measured respectively, and the amplitude Y is measured by the method 2 And substituting the concentration C into a second calibration formula to obtain the concentration C of the gas to be detected.
And optionally, when the gas to be detected is the weak absorption type gas, controlling a laser driver corresponding to the gas to be detected to emit a sawtooth wave superposed sine wave type driving signal, and adjusting the voltage value of the driving signal so as to adjust the absorption peak position of the gas to be detected to the region of the rising edge of the sawtooth wave.
Specifically, a sawtooth wave is used as a current driving signal of the laser to superpose a high-frequency sine wave, the frequency of sine wave modulation signals of multiple paths of driving signals is different, so that each path of light beam carries different information, and the position of an absorption peak of a strong absorption type gas is adjusted to the middle area of a rising edge of the sawtooth wave by adjusting the voltage values of a starting point and an end point of the sawtooth wave before the driving signals are sent; when no gas to be detected exists in the light path, the background light intensity is firstly collected, and when the gas to be detected exists, the absorption light intensity is collected. The target light intensity signal and the background light intensity signal of the weak absorption type gas are processed by superposing a high-frequency sine wave on the driving signal, so that the measured concentration of the to-be-measured type gas is more accurate, and the condition that the light intensity attenuation is wrongly judged as absorption due to the fact that the absorption light intensity is attenuated relative to the background light intensity is eliminated.
In the embodiment, the concentration C of the detected gas is measured by the weak absorption type gas according to the corresponding calculation method, so that the concentration misjudgment caused by the light intensity change can be effectively eliminated, and the problem of inaccurate detection concentration caused by the light intensity change is solved.
It should be noted that the steps illustrated in the flowcharts of the figures may be performed in a computer system such as a set of computer-executable instructions and that, although a logical order is illustrated in the flowcharts, in some cases, the steps illustrated or described may be performed in an order different than presented herein.
The embodiment of the present application further provides a detection apparatus for simultaneously measuring concentrations of multiple gases, and it should be noted that the detection apparatus for simultaneously measuring concentrations of multiple gases in the embodiment of the present application may be used to execute the detection method for simultaneously measuring concentrations of multiple gases provided in the embodiment of the present application. The following describes a detection device for simultaneously measuring the concentrations of multiple gases according to an embodiment of the present application.
FIG. 8 is a schematic diagram of a detection device for simultaneously measuring a plurality of gas concentrations according to an embodiment of the present application. As shown in fig. 8, the apparatus includes: a control unit 801, an acquisition unit 802, a preprocessing unit 803, and a calculation unit 804.
Specifically, the control unit 801 is configured to control the multiple lasers to alternately emit light beams at different time periods of the same time cycle to obtain multiple light beams to be detected, where a wavelength range scanned by each light beam to be detected covers an absorption peak of a type of gas to be detected;
an obtaining unit 802, configured to obtain background light intensity signals within a time period measured after the multiple light beams to be detected pass through the background space, and obtain target light intensity signals within the time period measured after the multiple light beams to be detected pass through the gas space to be detected;
the preprocessing unit 803 is configured to preprocess the background light intensity signal in the time period according to the time period to obtain multiple segments of background light intensity signals, and preprocess the target light intensity signal in the time period according to the time period to obtain multiple segments of target light intensity signals;
the calculating unit 804 is configured to calculate the concentration of one to-be-detected type of gas in the to-be-detected gas according to each section of the target light intensity signal and the corresponding background light intensity signal, so as to obtain the concentrations of multiple to-be-detected types of gas.
According to the detection device for simultaneously measuring the concentrations of multiple gases, the control unit 801 controls the multiple lasers to alternately emit light beams at different time intervals of the same time period to obtain multiple light beams to be measured, wherein the wavelength range scanned by each light beam to be measured covers the absorption peak of one type of gas to be measured; the obtaining unit 802 obtains background light intensity signals within a time period measured after the light beams to be measured pass through the background space, and obtains target light intensity signals within the time period measured after the light beams to be measured pass through the gas space to be measured; the preprocessing unit 803 preprocesses the background light intensity signal in the time period according to the time period to obtain a plurality of sections of background light intensity signals, and preprocesses the target light intensity signal in the time period according to the time period to obtain a plurality of sections of target light intensity signals; the calculating unit 804 calculates the concentration of one to-be-measured type gas in the to-be-measured gas according to each section of target light intensity signal and the corresponding background light intensity signal to obtain the concentration of multiple to-be-measured types of gas, and the problem that the gas concentration measurement is inaccurate due to the fact that multiple paths of optical signals are received by the same detector and the optical signals are overlapped in the related art is solved. By means of the method that each optical signal only occupies one time interval in one cycle and only one optical signal exists in the time interval, the change of the direct current component of each optical signal is distinguished, and therefore the accurate gas concentration value can be obtained.
Optionally, in the detection apparatus for simultaneously measuring the concentrations of a plurality of gases provided in the embodiment of the present application, the control unit 801 includes: and the control module is used for controlling the corresponding laser driver to send out a driving signal through a plurality of paths of analog signals in the same time period, and driving the corresponding laser to emit a light beam through the driving signal, wherein each path of analog signal is a non-zero signal in one time period of the time period, and is a zero signal in other time periods of the time period.
Optionally, in the detection apparatus for simultaneously measuring the concentrations of multiple gases provided in the embodiment of the present application, the obtaining unit 802 includes: the first segmentation module is used for segmenting the background light intensity signal in the time cycle according to the time period to obtain a plurality of sections of first light intensity signals and first background signals, and removing the first background signals from the plurality of sections of first light intensity signals respectively to obtain a plurality of sections of background light intensity signals, wherein the first background signals are positioned in the target time period in the time cycle; the obtaining unit 802 further includes: and the second division module is used for dividing the target light intensity signal in the time period according to the time period to obtain a plurality of sections of second light intensity signals and second background signals, and removing the second background signals from the plurality of sections of second light intensity signals respectively to obtain a plurality of sections of target light intensity signals, wherein the second background signals are positioned in the target time period in the time period.
Optionally, in the detection apparatus for simultaneously measuring the concentrations of multiple gases provided in the embodiment of the present application, the calculation unit 804 includes: the first determining module is used for determining the absorption intensity type of the corresponding gas to be detected according to the waveform characteristics of each section of target light intensity signal; the second determining module is used for determining a first target amplitude according to the target light intensity signal and a background light intensity signal corresponding to the target light intensity signal when the type of gas to be detected is a strong absorption type gas; the third determining module is used for determining the concentration of the type of gas to be detected in the gas to be detected based on the first target amplitude, the concentration calibration coefficient of the type of gas to be detected and the first calibration formula, wherein the first calibration formula is used for representing the relation among the first target amplitude, the concentration calibration coefficient of the type of gas to be detected and the concentration of the type of gas to be detected; the fourth determining module is used for determining a second target amplitude according to the target light intensity signal and a background light intensity signal corresponding to the target light intensity signal when the type of gas to be detected is a weak absorption type gas; and the fifth determining module is used for determining the concentration of the type of gas to be detected in the gas to be detected based on the second target amplitude, the concentration calibration coefficient of the type of gas to be detected and a second calibration formula, wherein the second calibration formula is used for representing the relationship among the second target amplitude, the concentration calibration coefficient of the type of gas to be detected and the concentration of the type of gas to be detected.
Optionally, in the detection apparatus for simultaneously measuring a plurality of gas concentrations provided in an embodiment of the present application, the second determination module includes: the first determining submodule is used for determining a first target signal from the target light intensity signal, wherein the first target signal is a signal outside an absorption signal section in the target light intensity signal; the second determining submodule is used for determining a second target signal from the background light intensity signal corresponding to the target light intensity signal and determining an amplitude proportional relation according to the amplitude of the second target signal and the amplitude of the first target signal, wherein the abscissa of the second target signal corresponds to the abscissa of the first target signal; the conversion submodule is used for converting the amplitude of the target light intensity signal according to the amplitude proportional relation to obtain a converted target light intensity signal; the third determining submodule is used for determining a third target signal from the absorption signal section of the converted target light intensity signal and determining a fourth target signal from the background light intensity signal corresponding to the target light intensity signal, wherein the abscissa of the third target signal corresponds to the abscissa of the fourth target signal; and the first calculation submodule is used for calculating the absolute value of the difference value of the amplitude of the third target signal and the amplitude of the fourth target signal and determining the absolute value of the difference value as the first target amplitude.
Optionally, in the detection apparatus for simultaneously measuring a plurality of gas concentrations provided in an embodiment of the present application, the fourth determining module includes: the first transformation submodule is used for performing fast Fourier transformation on the target light intensity signal to obtain a first frequency domain signal, and normalizing the amplitude of each peak in the first frequency domain signal according to the amplitude of the central frequency peak of the first frequency domain signal as a reference to obtain a second frequency domain signal; the second transformation submodule is used for performing fast Fourier transformation on a background light intensity signal corresponding to the target light intensity signal to obtain a third frequency domain signal, and normalizing the amplitude of each peak in the third frequency domain signal according to the amplitude of the central frequency peak of the third frequency domain signal as a reference to obtain a fourth frequency domain signal; the second integration submodule is used for integrating the third frequency domain signal to obtain a first integrated value and integrating the fourth frequency domain signal to obtain a second integrated value; and a second calculation sub-module for calculating an absolute value of a difference between the first integrated value and the second integrated value, and determining the absolute value of the difference as a second target amplitude value.
Optionally, in the detection apparatus for simultaneously measuring the concentrations of a plurality of gases provided in the embodiment of the present application, the apparatus further includes: and the adjusting unit is used for controlling the laser driver corresponding to the type gas to be detected to send out a sawtooth wave type driving signal when the type gas to be detected is a strong absorption type gas, and adjusting the voltage value of the driving signal so as to adjust the absorption peak position of the type gas to be detected to the region of the rising edge of the sawtooth wave.
Optionally, in the detection apparatus for simultaneously measuring the concentrations of a plurality of gases provided in the embodiment of the present application, the apparatus further includes: and the driving unit is used for controlling a laser driver corresponding to the type gas to be detected to emit a sawtooth wave superposed sine wave type driving signal when the type gas to be detected is a weak absorption type gas, and adjusting the voltage value of the driving signal so as to adjust the absorption peak position of the type gas to be detected to the region of the rising edge of the sawtooth wave.
The detection device for simultaneously measuring the concentrations of the plurality of gases comprises a processor and a memory, the control unit 801, the acquisition unit 802, the preprocessing unit 803, the calculation unit 804 and the like are stored in the memory as program units, and the processor executes the program units stored in the memory to realize corresponding functions.
The processor comprises a kernel, and the kernel calls the corresponding program unit from the memory. The kernel can be set to be one or more than one, and the problem of inaccurate gas concentration measurement caused by superposition of multiple paths of optical signals received by the same detector in the related art is solved by adjusting the kernel parameters.
The memory may include volatile memory in a computer readable medium, Random Access Memory (RAM) and/or nonvolatile memory such as Read Only Memory (ROM) or flash memory (flash RAM), and the memory includes at least one memory chip.
The embodiment of the application also provides a computer storage medium, and the computer storage medium is used for storing a program, wherein the program controls the equipment where the nonvolatile storage medium is located to execute a detection method for simultaneously measuring the concentrations of a plurality of gases when running.
The embodiment of the application also provides an electronic device, which comprises a processor and a memory; the memory has stored therein computer readable instructions for execution by the processor, wherein the computer readable instructions when executed perform a sensing method for simultaneously measuring a plurality of gas concentrations. The electronic device herein may be a server, a PC, a PAD, a mobile phone, etc.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may 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, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may 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, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
In a typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.
The memory may include forms of volatile memory in a computer readable medium, Random Access Memory (RAM) and/or non-volatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM). The memory is an example of a computer-readable medium.
Computer-readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), Digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information that can be accessed by a computing device. As defined herein, a computer readable medium does not include a transitory computer readable medium such as a modulated data signal and a carrier wave.
It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in the process, method, article, or apparatus that comprises the element.
The above are merely examples of the present application and are not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims (8)

1. A sensing method for simultaneously measuring the concentration of a plurality of gases, comprising:
controlling a plurality of lasers to alternately emit light beams at different time intervals of the same time period to obtain a plurality of light beams to be detected, wherein the wavelength range scanned by each light beam to be detected covers the absorption peak of a type of gas to be detected;
acquiring background light intensity signals within the time period measured after the light beams to be measured penetrate through a background space, and acquiring target light intensity signals within the time period measured after the light beams to be measured penetrate through a gas space to be measured;
preprocessing the background light intensity signals in the time period according to the time period to obtain a plurality of sections of background light intensity signals, and preprocessing the target light intensity signals in the time period according to the time period to obtain a plurality of sections of target light intensity signals;
calculating the concentration of one to-be-detected type gas in the to-be-detected gas according to each section of target light intensity signal and the corresponding background light intensity signal to obtain the concentrations of various to-be-detected types of gas;
wherein, calculating the concentration of one type of gas to be measured in the gas to be measured according to each section of target light intensity signal and the corresponding background light intensity signal comprises:
determining the absorption intensity type of the corresponding gas to be detected according to the waveform characteristics of each section of the target light intensity signal;
when the type of gas to be detected is a strong absorption type gas, determining a first target amplitude according to the target light intensity signal and a background light intensity signal corresponding to the target light intensity signal; determining the concentration of the type of gas to be detected in the gas to be detected based on the first target amplitude, the concentration calibration coefficient of the type of gas to be detected and a first calibration formula, wherein the first calibration formula is used for representing the relation among the first target amplitude, the concentration calibration coefficient of the type of gas to be detected and the concentration of the type of gas to be detected, and the first calibration formula is Y 1 =a 1 C 2 +b 1 C+k 1 ，Y 1 Is the first target amplitude, C is the concentration of the type of gas to be measured, a 1 ，b 1 ，k 1 Calibrating a coefficient for the concentration of the type of gas to be detected;
when the type of gas to be detected is a weak absorption type gas, determining a second target amplitude according to the target light intensity signal and a background light intensity signal corresponding to the target light intensity signal; determining the concentration of the type of gas to be detected in the gas to be detected based on the second target amplitude, the concentration calibration coefficient of the type of gas to be detected and a second calibration formula, wherein the second calibration formula is used for representing the relationship among the second target amplitude, the concentration calibration coefficient of the type of gas to be detected and the concentration of the type of gas to be detected, and theThe second calibration formula is Y 2 =a 2 C 2 +b 2 C+k 2 ，Y 2 Is the second target amplitude, C is the concentration of the type of gas to be measured, a 2 ，b 2 ，k 2 And calibrating the coefficient for the concentration of the type of gas to be detected.
2. The detection method of claim 1, wherein controlling the plurality of lasers to alternately emit light beams at different periods of the same time cycle to obtain a plurality of light beams to be measured comprises:
the method comprises the steps of controlling a corresponding laser driver to send out a driving signal through a plurality of paths of analog signals of the same time period, and driving the corresponding laser to emit light beams through the driving signal, wherein each path of analog signal is a non-zero signal in one time period of the time period, and is a zero signal in other time periods of the time period.
3. The detection method according to claim 2, wherein the target time periods of the plurality of paths of analog signals in the time period are all zero signals, and the preprocessing of the background light intensity signals in the time period according to the time periods to obtain a plurality of segments of background light intensity signals comprises:
dividing the background light intensity signal in the time period according to the time period to obtain a plurality of sections of first light intensity signals and first background signals, and removing the first background signals from the plurality of sections of first light intensity signals respectively to obtain the plurality of sections of background light intensity signals, wherein the first background signals are located in the target time period in the time period;
preprocessing the target light intensity signals in the time period according to the time period, and obtaining multiple sections of target light intensity signals comprises the following steps:
and dividing the target light intensity signal in the time period according to the time period to obtain a plurality of sections of second light intensity signals and second background signals, and removing the second background signals from the plurality of sections of second light intensity signals respectively to obtain the plurality of sections of target light intensity signals, wherein the second background signals are located in the target time period in the time period.
4. The detection method according to claim 1, wherein when the gas of the type to be detected is a strongly absorbing gas, determining a first target amplitude value according to the target light intensity signal and a background light intensity signal corresponding to the target light intensity signal comprises:
determining a first target signal from the target light intensity signal, wherein the first target signal is a signal outside an absorption signal section in the target light intensity signal;
determining a second target signal from a background light intensity signal corresponding to the target light intensity signal, and determining an amplitude proportional relationship according to the amplitude of the second target signal and the amplitude of the first target signal, wherein the abscissa of the second target signal corresponds to the abscissa of the first target signal;
converting the amplitude of the target light intensity signal according to the amplitude proportional relation to obtain a converted target light intensity signal;
determining a third target signal from an absorption signal section of the converted target light intensity signal, and determining a fourth target signal from a background light intensity signal corresponding to the target light intensity signal, wherein the abscissa of the third target signal corresponds to the abscissa of the fourth target signal;
calculating an absolute value of a difference between the amplitude of the third target signal and the amplitude of the fourth target signal, and determining the absolute value of the difference as the first target amplitude.
5. The detection method according to claim 1, wherein when the type of gas to be detected is a weak absorption type gas, determining a second target amplitude value according to the target light intensity signal and a background light intensity signal corresponding to the target light intensity signal comprises:
performing fast Fourier transform on the target light intensity signal to obtain a first frequency domain signal, and normalizing the amplitude of each peak in the first frequency domain signal by taking the amplitude of the central frequency peak of the first frequency domain signal as a reference to obtain a second frequency domain signal;
performing fast Fourier transform on a background light intensity signal corresponding to the target light intensity signal to obtain a third frequency domain signal, and normalizing the amplitude of each peak in the third frequency domain signal according to the amplitude of the central frequency peak of the third frequency domain signal as a reference to obtain a fourth frequency domain signal;
integrating the third frequency domain signal to obtain a first integrated value, and integrating the fourth frequency domain signal to obtain a second integrated value;
an absolute value of a difference between the first integrated value and the second integrated value is calculated, and the absolute value of the difference is determined as the second target amplitude value.
6. The detection method according to claim 1, wherein when the gas to be detected is a strongly absorbing gas, the laser driver corresponding to the gas to be detected is controlled to emit a sawtooth wave type driving signal, and a voltage value of the driving signal is adjusted to adjust an absorption peak position of the gas to be detected to a region of a rising edge of the sawtooth wave.
7. The detection method according to claim 1, wherein when the gas to be detected is a weak absorption gas, the laser driver corresponding to the gas to be detected is controlled to emit a driving signal of a sawtooth wave superposed sine wave type, and a voltage value of the driving signal is adjusted to adjust an absorption peak position of the gas to be detected to a region of a rising edge of the sawtooth wave.
8. A sensing device for simultaneously measuring the concentration of a plurality of gases, comprising:
the control unit is used for controlling the plurality of lasers to alternately emit light beams at different time intervals of the same time period to obtain a plurality of light beams to be detected, wherein the wavelength range scanned by each light beam to be detected covers the absorption peak of a type of gas to be detected;
the acquisition unit is used for acquiring background light intensity signals in the time period measured after the light beams to be measured penetrate through a background space and acquiring target light intensity signals in the time period measured after the light beams to be measured penetrate through a gas space to be measured;
the preprocessing unit is used for preprocessing the background light intensity signals in the time period according to time intervals to obtain multiple sections of background light intensity signals, and preprocessing the target light intensity signals in the time period according to time intervals to obtain multiple sections of target light intensity signals;
the calculating unit is used for calculating the concentration of one to-be-detected type gas in the to-be-detected gas according to each section of target light intensity signal and the corresponding background light intensity signal to obtain the concentrations of various to-be-detected types of gas;
wherein the calculation unit includes:
the first determining module is used for determining the absorption intensity type of the corresponding gas to be detected according to the waveform characteristics of each section of the target light intensity signal;
the second determining module is used for determining a first target amplitude according to the target light intensity signal and a background light intensity signal corresponding to the target light intensity signal when the type of gas to be detected is a strong absorption type gas; a third determining module, configured to determine a concentration of the type of gas to be detected in the gas to be detected based on the first target amplitude, the concentration calibration coefficient of the type of gas to be detected, and a first calibration formula, where the first calibration formula is used to represent a relationship among the first target amplitude, the concentration calibration coefficient of the type of gas to be detected, and the concentration of the type of gas to be detected, and the first calibration formula is Y 1 =a 1 C 2 +b 1 C+k 1 ，Y 1 Is the first target amplitude, C is the concentration of the type of gas to be measured, a 1 ，b 1 ，k 1 Calibrating a coefficient for the concentration of the type of gas to be detected;
a fourth determining module, configured to determine whether the type of gas to be detected is a weak absorption type gas according to the target light intensity signal and the target light intensity signalDetermining a second target amplitude value according to the corresponding background light intensity signal; a fifth determining module, configured to determine the concentration of the type of gas to be detected in the gas to be detected based on the second target amplitude, the concentration calibration coefficient of the type of gas to be detected, and a second calibration formula, where the second calibration formula is used to represent a relationship among the second target amplitude, the concentration calibration coefficient of the type of gas to be detected, and the concentration of the type of gas to be detected, and the second calibration formula is Y 2 =a 2 C 2 +b 2 C+k 2 ，Y 2 Is the second target amplitude, C is the concentration of the type of gas to be measured, a 2 ，b 2 ，k 2 And calibrating the coefficient for the concentration of the type of gas to be detected.
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