Dust concentration detection device based on multi-light-path fusion

Abstract

The present application relates to the field of detection equipment, and more particularly to a dust concentration detection device based on multi-light-path fusion. The device comprises a straight-through detection cavity, a laser, and a detector. The straight-through detection cavity is used for the flow of the gas to be detected. The laser is fixed outside the straight-through detection cavity and is used to emit laser light to the gas to be detected in the straight-through detection cavity. The detector is fixed outside the straight-through detection cavity and is used to receive the transmitted light or scattered light obtained after the laser light interacts with the gas to be detected. The detector comprises one transmitted detector and more than one scattered detector. The method for detecting the concentration of particulate matter by the dust concentration detection device is as follows: the intensity data obtained by all the detectors are input into a pre-trained regression model to obtain the concentration C of particulate matter. The dustproof of the detection device is realized by the straight-through cavity and other structures. The use of multi-light-path fusion greatly increases the range. Automatic calibration is realized through dynamic calibration, and the maintenance cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of detection equipment, and specifically to a dust concentration detection device based on multi-optical path fusion. Background Technology

[0002] Currently, light scattering particle sensors are widely used in air quality monitoring. Their core principle is to calculate concentration values ​​by detecting the scattered light signal from incident laser light by particulate matter (usually using a single fixed scattering angle such as 45° or 90°). However, this technology has significant drawbacks in extreme high-concentration scenarios such as sandstorms. First, the single-angle scattering design results in a narrow detection range, typically covering only 0.001 to 10 mg / m³. While a few products extend this to 30 or 50 mg / m³, it is still insufficient to meet the real-world needs of strong sandstorms with concentrations exceeding 1000 mg / m³. This insufficient range stems from the saturation effect of the single-angle optical path: in high-concentration sandstorm environments, excessive particulate matter causes nonlinear distortion of the scattered light signal, making it impossible to accurately capture concentration changes, thus limiting the sensor's applicability in sandstorm monitoring.

[0003] Furthermore, existing sensors are structurally optimized for low-concentration air environments, employing hollow detection cavities and integrating optical elements such as concave mirrors to converge scattered light and enhance the accuracy of weak signals (e.g., for PM2.5 monitoring). However, under high dust load conditions, the cavity interior is easily contaminated by suspended particles, accumulating a large amount of dust over long-term operation, causing drift and attenuation of the scattered light signal; this not only reduces measurement accuracy but also shortens equipment lifespan. Simultaneously, the laser source, as a core component, experiences natural light intensity decay over time, introducing systematic biases. Existing sensors rely on a single-angle detection mechanism and lack built-in calibration compensation functions; accumulated biases require professional factory calibration, resulting in high maintenance costs, frequent monitoring interruptions, and difficulty meeting the reliability requirements for continuous operation in dusty environments. In summary, current technology struggles to balance high-concentration range, pollution resistance, and self-calibration mechanisms, necessitating innovative designs to improve the robustness and practicality of dust monitoring. Summary of the Invention

[0004] To address the above problems, the present invention proposes the following technical solution:

[0005] This invention provides a dust concentration detection device based on multi-optical path fusion, comprising a direct-through detection cavity, a laser, and a detector; the direct-through detection cavity is used for the flow of the gas to be measured.

[0006] The laser is fixed outside the through-type detection cavity and is used to emit laser light into the gas to be tested inside the through-type detection cavity;

[0007] The detector is fixed outside the through-type detection cavity and is used to receive transmitted or scattered light obtained after the laser interacts with the gas to be detected. The detector includes one transmission detector and one or more scattering detectors. The transmission detector is a detector with an angle of 0°. The scattering detector is a detector with an angle range of (0°, 180°). The scattering detector with an angle of (0°, 90°) is a forward scattering detector, and the scattering detector with an angle of [90°, 180°) is a backscattering detector.

[0008] The dust concentration detection device detects particulate matter concentration by inputting the intensity data obtained from all detectors into a pre-trained regression model to obtain the particulate matter concentration C.

[0009] Preferably, the detector includes at least one forward-scattering detector and at least one backscattering detector;

[0010] The angle of the forward scattering detector ranges from [15°, 75°].

[0011] The backscatter detector angle ranges from [90°, 170°].

[0012] Preferably, a transparent isolation device is provided in the through-type detection cavity to physically separate the laser and detector from the gas to be tested in the through-type detection cavity without affecting the propagation of the laser and detector light.

[0013] Preferably, the inner wall of the through-type detection chamber is coated with a nano-dust-repellent material to reduce dust accumulation on the inner wall of the through-type detection chamber.

[0014] Preferably, the regression model is a piecewise linear logarithmic regression model;

[0015] The specific content of the piecewise linear logarithmic regression model is as follows:

[0016] Use particulate matter concentration marker parameters to qualitatively determine whether the particulate matter concentration is low or high.

[0017] When the particulate matter concentration is low, the regression model formula is:

[0018]

[0019] Where C is the particulate matter concentration;

[0020] Let be the intensity of the i-th forward scattering detector;

[0021] is the low concentration coefficient of the i-th forward scattering detector;

[0022] Let be the intensity of the j-th backscattering detector;

[0023] is the low concentration coefficient of the j-th backscattering detector;

[0024] m is the total number of forward scattering detectors;

[0025] n is the total number of backscatter detectors;

[0026] When the particulate matter concentration is high, the regression model formula is:

[0027]

[0028] in, The intensity of the transmission detector when the concentration of particulate matter in the gas to be detected is zero during initial calibration;

[0029] The intensity of the transmission detector;

[0030] is the high concentration coefficient of the j-th backscattering detector;

[0031] For the transmission detector coefficient.

[0032] Preferred, use The value is used as a marker parameter for particulate matter concentration. Whether the concentration of particulate matter exceeds the threshold is used to qualitatively determine whether the concentration is low or high.

[0033] Preferably, the dust concentration detection device also includes a dynamic calibration function;

[0034] The method for dynamically calibrating the dust concentration detection device is as follows:

[0035] 1) Calculate the reference transmittance:

[0036]

[0037] in, The intensity of the transmission detector when the concentration of particulate matter in the gas to be detected is zero during initial calibration;

[0038] The intensity of the transmission detector;

[0039] The reference transmittance;

[0040] 2) Based on T and the scattering model, the theoretical intensity F of the preset scattering detector is obtained without considering laser attenuation;

[0041] 3) Calculate the calibration coefficient:

[0042]

[0043] in, For calibration coefficients;

[0044] The actual intensity of the preset scattering detector;

[0045] 4) Correct C to obtain the corrected particulate matter concentration. :

[0046]

[0047] Output As the final result of particulate matter concentration.

[0048] Preferably, the dust concentration detection device also includes a particle size classification function;

[0049] The method for laser particle size classification in the dust concentration detection device is as follows:

[0050] 1) Calculate the particle size index:

[0051]

[0052] in, Indicates particle size index;

[0053] Let be the intensity of the i-th forward scattering detector;

[0054] Let be the intensity of the j-th backscattering detector;

[0055] m is the total number of forward scattering detectors;

[0056] n is the total number of backscatter detectors;

[0057] 2) Use The value of d is used to represent the particle size classification result: the larger the value of d, the more PM40 and the less TSP in the particulate matter, and vice versa.

[0058] Beneficial effects:

[0059] 1) Multi-path fusion detection is adopted: forward scattering, back scattering, and transmission light path are detected and calculated simultaneously, which can effectively improve the detection range of dust concentration, up to 1000mg / m3.

[0060] 2) Dust-proof chamber design: In response to high dust pollution, a dust-proof detection chamber design is adopted: a straight-through detection chamber of a specific size is used; the channel uses nano-dust-repellent technology to reduce dust accumulation in the detection chamber; the detection area of ​​the straight-through detection chamber is optically isolated to effectively prevent dust accumulation while ensuring that the light signal is not affected. The optical isolation methods include, but are not limited to, using transparent detection channels (square, round, etc.) and using window isolation for the air path and light path. The dust-proof chamber design reduces the maintenance frequency by 90%.

[0061] 3) Dynamic differential calibration: Using scattered and transmitted light signals, the attenuation rate of transmitted light is compared with the deviation of the scattered signal in real time, and the laser power attenuation is automatically compensated to achieve automatic calibration. Attached Figure Description

[0062] Figure 1 This is a schematic diagram of the structure in an embodiment of the present invention.

[0063] Reference numerals: 1-Straight-through detection cavity, 2-Laser, 3-Transmission detector, 4-Forward scattering detector, 5-Backscattering detector, 6-Data processing unit, 7-Transparent isolation device. Detailed Implementation

[0064] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0065] A dust concentration detection device based on multi-optical path fusion includes a direct-through detection cavity 1, a laser 2, and a detector; the direct-through detection cavity is used for the flow of the gas to be measured.

[0066] The laser 2 is fixed outside the through-type detection cavity 1 and is used to emit laser light into the gas to be tested inside the through-type detection cavity 1.

[0067] The detector is fixed outside the through-type detection cavity 1 and is used to receive transmitted or scattered light obtained after the laser interacts with the gas to be detected. The detector includes one transmission detector 3 and one or more scattering detectors. The transmission detector 3 is a detector with an angle of 0°. The scattering detector is a detector with an angle range of (0°, 180°). The scattering detector with an angle of (0°, 90°) is a forward scattering detector 4, and the scattering detector with an angle of [90°, 180°) is a backscattering detector 5.

[0068] In a preferred embodiment, the angle of the forward scattering detector 4 ranges from [15°, 75°]; the angle of the backscattering detector 5 ranges from [90°, 170°].

[0069] A transparent isolation device 7 is provided inside the direct-access detection chamber 1. Figure 1 The green box in the middle is used to physically separate the laser 2 and detector from the gas to be tested in the direct-through detection cavity 1 without affecting the propagation of the light from the laser 2 and detector, thereby effectively preventing dust accumulation on the laser 2 and detector while ensuring that the optical signal is not affected.

[0070] Nanoparticle dust-repellent material is coated on the inner wall of the straight-through detection chamber 1 to reduce dust accumulation on the inner wall of the straight-through detection chamber.

[0071] In this invention, the detector angle refers to the angle between the detector direction and the laser direction.

[0072] Forward scattering detector 4 is mainly sensitive to particle size, backscattering detector 5 is mainly sensitive to particle shape / refractive index, and transmission detector 3 is used to monitor the occlusion rate, which can be converted into concentration.

[0073] The method for detecting particulate matter concentration using the dust concentration detection device is as follows: the particulate matter concentration C is obtained by inputting the intensity data obtained from all detectors into a pre-trained regression model. Specifically, the hardware implementation is as follows: the data processing unit 6 is electrically connected to the detector, so that the data processing unit 6 receives the intensity data from each detector and then calculates C. The hardware implementation is existing technology and will not be described in detail here.

[0074] There are many regression models to choose from, such as linear regression, multinomial regression, neural network models, and some common variations.

[0075] In a preferred embodiment, the regression model is a piecewise linear logarithmic regression model;

[0076] The specific content of the piecewise linear logarithmic regression model is as follows:

[0077] The particulate matter concentration is qualitatively determined using particulate matter concentration marker parameters to determine whether the particulate matter concentration is low or high; in some implementations, it is used... The value is used as a marker parameter for particulate matter concentration. Whether the particulate matter concentration exceeds a threshold is used to qualitatively determine whether the concentration is low or high; among which, The intensity of the transmission detector 3;

[0078] Because as the concentration of particulate matter in the gas to be detected increases, The value will decrease monotonically, so it can be used directly. Whether the concentration of particulate matter exceeds the threshold is used to qualitatively determine whether the concentration is low or high.

[0079] When the particulate matter concentration is low, the regression model formula is:

[0080]

[0081] Where C is the particulate matter concentration;

[0082] Let be the intensity of the i-th forward scattering detector;

[0083] is the low concentration coefficient of the i-th forward scattering detector;

[0084] Let be the intensity of the j-th backscattering detector;

[0085] is the low concentration coefficient of the j-th backscattering detector;

[0086] m is the total number of forward scattering detectors;

[0087] n is the total number of backscatter detectors;

[0088] When the particulate matter concentration is high, the regression model formula is:

[0089]

[0090] in, The intensity of the transmission detector when the concentration of particulate matter in the gas to be detected is zero during initial calibration;

[0091] The intensity of the transmission detector;

[0092] is the high concentration coefficient of the j-th backscattering detector;

[0093] For the transmission detector coefficient;

[0094] The regression model described above utilizes multi-angle signal fusion to offset particle size distribution errors at low concentrations; at high concentrations, it is dominated by the transmitted light signal algorithm, with backscattered signals used for compensation and error correction. If there is no backscatter detector in the embodiment, no correction is performed at high concentrations. Field experiments have also demonstrated that this regression model performs well.

[0095] The method for dynamically calibrating the dust concentration detection device is as follows:

[0096] 1) Calculate the reference transmittance:

[0097]

[0098] in, The reference transmittance;

[0099] 2) Based on T and the scattering model, the theoretical intensity F of the preset scattering detector is obtained without considering laser attenuation;

[0100] The scattering model is an existing technology. It can be directly calculated using models such as Mie scattering, or the scattering model can be obtained by establishing the statistical relationship between the scattering intensity of the preset detector and T through experimental calibration based on the actual local particulate matter. The details will not be elaborated here.

[0101] 5) Calculate the calibration coefficient:

[0102]

[0103] in, For calibration coefficients;

[0104] The actual intensity of the preset scattering detector;

[0105] 6) Correct C to obtain the corrected particulate matter concentration. :

[0106]

[0107] The method for laser particle size classification in the dust concentration detection device is as follows:

[0108] 1) Calculate the particle size index:

[0109]

[0110] in, Indicates particle size index;

[0111] 2) Use The value of d is used to represent the particle size classification result: the larger the value of d, the more PM40 and the less TSP in the particulate matter, and vice versa.

[0112] For example, we can classify them more specifically like this:

[0113] when At that time, the output particle size classification results showed that particulate matter was mainly PM40.

[0114] when At that time, the amounts of PM40 and TSP in particulate matter were in balance;

[0115] when At that time, the output particle size classification results showed that particulate matter was mainly TSP;

[0116] A more specific embodiment is described below.

[0117] like Figure 1 As shown, in this embodiment, a dust concentration detection device based on multi-optical path fusion includes a direct-through detection cavity 1, a laser 2, and a detector; the direct-through detection cavity is used for the flow of the gas to be measured.

[0118] The laser 2 is fixed outside the through-type detection cavity 1 and is used to emit laser light into the gas to be tested inside the through-type detection cavity 1.

[0119] The detector is fixed outside the through-hole detection cavity 1 and is used to receive the transmitted light or scattered light obtained after the laser interacts with the gas to be detected.

[0120] A transparent isolation device 7 is provided inside the direct-access detection chamber 1. Figure 1 The green box in the middle is used to physically separate the laser 2, the detector and the gas to be tested in the direct-through detection cavity without affecting the propagation of the light from the laser 2 and the detector.

[0121] The detector includes a transmission detector 3, a forward scattering detector 4 with an angle of 45°, and a backscattering detector 5 with an angle of 135°.

[0122] In this embodiment, the above-described method is used to calculate particulate matter concentration, perform dynamic calibration, and classify particle size.

[0123] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A dust concentration detection device based on multi-optical path fusion, characterized in that, It includes a through-hole detection cavity, a laser, and a detector; the through-hole detection cavity is used for the flow of the gas to be tested; The laser is fixed outside the through-type detection cavity and is used to emit laser light into the gas to be tested inside the through-type detection cavity; The detector is fixed outside the through-type detection cavity and is used to receive transmitted or scattered light obtained after the laser interacts with the gas to be detected. The detector includes one transmission detector and one or more scattering detectors. The transmission detector is a detector with an angle of 0°. The scattering detector is a detector with an angle range of (0°, 180°). The scattering detector with an angle of (0°, 90°) is a forward scattering detector, and the scattering detector with an angle of [90°, 180°) is a backscattering detector. The method for detecting particulate matter concentration using the dust concentration detection device is as follows: by inputting the intensity data obtained from all detectors into a pre-trained regression model, the particulate matter concentration C is obtained. The detector includes at least one forward scattering detector and at least one backscattering detector; The regression model is a piecewise linear logarithmic regression model; The specific content of the piecewise linear logarithmic regression model is as follows: Use particulate matter concentration marker parameters to qualitatively determine whether the particulate matter concentration is low or high; When the particulate matter concentration is low, the regression model formula is: Where C is the particulate matter concentration; Let be the intensity of the i-th forward scattering detector; is the low concentration coefficient of the i-th forward scattering detector; Let be the intensity of the j-th backscattering detector; is the low concentration coefficient of the j-th backscattering detector; m is the total number of forward scattering detectors; n is the total number of backscatter detectors; When the particulate matter concentration is high, the regression model formula is: in, The intensity of the transmission detector when the concentration of particulate matter in the gas to be detected is zero during initial calibration; The intensity of the transmission detector; is the high concentration coefficient of the j-th backscattering detector; For the transmission detector coefficient.

2. The dust concentration detection device based on multi-optical path fusion according to claim 1, characterized in that, The forward scattering detector angle ranges from [15°, 75°]; The backscatter detector angle ranges from [90°, 170°].

3. The dust concentration detection device based on multi-optical path fusion according to claim 1, characterized in that, A transparent isolation device is installed inside the direct-through detection cavity to physically separate the laser and detector from the gas to be tested inside the direct-through detection cavity without affecting the propagation of the laser and detector light.

4. The dust concentration detection device based on multi-optical path fusion according to claim 1, characterized in that, Nanoparticles of dust-repellent material are coated on the inner wall of the straight-through detection chamber to reduce dust accumulation on the inner wall of the chamber.

5. The dust concentration detection device based on multi-optical path fusion according to claim 1, characterized in that, use The value is used as a marker parameter for particulate matter concentration. Whether the concentration of particulate matter exceeds the threshold is used to qualitatively determine whether the concentration is low or high.

6. The dust concentration detection device based on multi-optical path fusion according to claim 1, characterized in that, The dust concentration detection device also includes a dynamic calibration function; The method for dynamically calibrating the dust concentration detection device is as follows: 1) Calculate the reference transmittance: in, The intensity of the transmission detector when the concentration of particulate matter in the gas to be detected is zero during initial calibration; The intensity of the transmission detector; The reference transmittance; 2) Based on T and the scattering model, the theoretical intensity F of the preset scattering detector is obtained without considering laser attenuation; 3) Calculate the calibration coefficient: in, Calibration coefficient The actual intensity of the preset scattering detector; 4) Correct C to obtain the corrected particulate matter concentration. : Output As the final result of particulate matter concentration.

7. The dust concentration detection device based on multi-optical path fusion according to claim 1, characterized in that, The dust concentration detection device also includes a particle size classification function; The method for laser particle size classification in the dust concentration detection device is as follows: 1) Calculate the particle size index: in, Indicates particle size index; Let be the intensity of the i-th forward scattering detector; Let be the intensity of the j-th backscattering detector; m is the total number of forward scattering detectors; n is the total number of backscatter detectors; 2) Use The value of d is used to represent the particle size classification result: the larger the value of d, the more PM40 and the less TSP in the particulate matter, and vice versa.

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