A dual-channel vehicle-mounted particulate matter detection device based on 90-degree scattering

Abstract

The application relates to the technical field of particulate matter detection, in particular to a double-channel vehicle-mounted particulate matter detection device based on 90-degree scattering. The double-channel vehicle-mounted particulate matter detection device based on 90-degree scattering comprises a shell, an indoor particulate detection air duct and an outdoor particulate detection air duct are formed in the shell and are isolated from each other; a particle sampling unit is arranged in the indoor particulate detection air duct and the outdoor particulate detection air duct respectively, the particle sampling unit comprises an aperture; wherein the aperture comprises a first aperture, a second aperture and a third aperture which are arranged at intervals, and the aperture diameters of the first aperture, the second aperture and the third aperture decrease successively. The double-channel vehicle-mounted particulate matter detection device based on 90-degree scattering can avoid the cross contamination of indoor and outdoor gases, and can detect the indoor and outdoor particulate matters.

Description

Technical Field

[0001] This application relates to the field of particulate matter detection technology, and in particular to a dual-channel vehicle-mounted particulate matter detection device based on 90-degree scattering. Background Technology

[0002] With rapid industrial development, the atmospheric environment is deteriorating, and fine particulate matter in the air, especially PM2.5, poses a significant threat to human respiratory health. People are gradually recognizing the importance of air quality monitoring. At the same time, the increasing intelligence of automobiles necessitates the installation of various sensors to enable intelligent functions.

[0003] The 90-degree scattering dual-channel vehicle particulate matter sensor can simultaneously monitor the concentration of particulate matter inside and outside the vehicle, providing data support for the car's intelligent air conditioning system and air purification system, enabling automatic adjustment of the air quality inside the vehicle. For example, when the sensor detects poor outside air quality, it automatically switches to the vehicle's recirculation mode to prevent polluted outside air from entering the vehicle.

[0004] However, current dual-channel vehicle particulate matter sensors often share a single detection chamber, which can lead to residual particulate matter adhering to the airflow when the airflow inside and outside the vehicle switches. This results in cross-contamination of the air inside and outside the vehicle, interfering with the detection results. Furthermore, they are easily affected by stray light, leading to low detection accuracy. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this application is to provide a dual-channel vehicle-mounted particulate matter detection device based on 90-degree scattering, which avoids cross-contamination of gases and interference from stray light, thereby improving detection accuracy.

[0006] To achieve the above objectives, this application provides a dual-channel vehicle-mounted particulate matter detection device based on 90-degree scattering, comprising: The housing includes: The upper housing has an in-vehicle particle detection duct and an external particle detection duct that are isolated from each other. The lower housing has a lower rubber layer, a circuit board on the lower rubber layer, and an upper rubber layer on the circuit board. The upper and lower rubber layers are used to seal the in-vehicle particle detection air duct and the out-of-vehicle particle detection air duct. A particle sampling unit is respectively installed in the in-vehicle particle detection air duct and the out-of-vehicle particle detection air duct. The particle sampling unit includes a laser emitter, a focusing lens, an aperture, a light-sensitive area for scattering light, and a photodetector arranged in the optical path. The photodetector is located to the side front of the light-sensitive area and is used to receive scattered light with a scattering angle of 90 degrees emitted from the light-sensitive area. The aperture includes a first aperture, a second aperture, and a third aperture arranged at intervals, with the aperture diameters of the first aperture, the second aperture, and the third aperture decreasing sequentially.

[0007] Furthermore, the particle sampling unit also includes: A light trap, which is placed at the end of the light path, is used to absorb light passing through the light-sensitive area.

[0008] Furthermore, the diameter of the first aperture is 3mm, the diameter of the second aperture is 2mm, and the diameter of the third aperture is 1mm.

[0009] Furthermore, the external particle detection air duct includes, in sequence according to the gas flow path, an external air intake pipe, a filter, an external fan, and an external air intake pipe, with a particle sampling unit disposed between the external fan and the external air intake pipe.

[0010] Furthermore, the filter is used to block large particulate impurities with a particle size greater than 100 micrometers.

[0011] Furthermore, both the external air intake pipe and the external air outlet pipe are connected to the external air intake and outlet grilles.

[0012] Furthermore, the in-vehicle particle detection air duct includes, in sequence, an in-vehicle air inlet, an in-vehicle fan, and an air outlet grid, and a particle sampling unit is provided between the in-vehicle fan and the in-vehicle air inlet.

[0013] Furthermore, a shielding cover for shielding electromagnetic interference is also provided inside the lower housing.

[0014] The dual-channel vehicle-mounted particulate matter detection device based on 90-degree scattering provided in this application adopts a three-stage aperture structure for the particle sampling unit and optimizes the position of the photodetector and the scattering photosensitive area, thereby effectively preventing stray light from entering the scattering photosensitive area, greatly improving the signal-to-noise ratio of the particle sampling unit, and significantly improving the accuracy and real-time performance of particulate matter detection inside and outside the vehicle.

[0015] The dual-channel vehicle-mounted particulate matter detection device based on 90-degree scattering provided in this application also employs a light trap in the particle sampling unit to avoid secondary scattering caused by the reflection of transmitted light back to the sensitive area, which would affect the detection results and improve the detection accuracy.

[0016] The dual-channel vehicle-mounted particulate matter detection device based on 90-degree scattering provided in this application features an in-vehicle particulate matter detection air duct and an external particulate matter detection air duct that are isolated from each other and sealed by an upper rubber layer. This allows for accurate delivery of external particulate matter samples to the sensor, avoiding cross-contamination of gases inside and outside the vehicle during the detection process and improving detection accuracy.

[0017] The dual-channel vehicle-mounted particulate matter detection device based on 90-degree scattering provided in this application optimizes the spatial structure of the detection device and achieves high space utilization by optimizing the structure and multiple protection and pre-processing devices, effectively reducing external interference and ensuring detection stability.

[0018] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing this application. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the present application and form part of the specification. Together with the embodiments of the present application, they serve to explain the present application but do not constitute a limitation thereof. In the drawings: Figure 1 This is an exploded schematic diagram of the dual-channel vehicle-mounted particulate matter detection device based on 90-degree scattering according to Embodiment 1 of this application; Figure 2 This is a schematic diagram of the gas flow path of the dual-channel vehicle-mounted particulate matter detection device based on 90-degree scattering in Embodiment 1 of this application; Figure 3 This is a schematic diagram of the particle sampling unit in Embodiment 1 of this application. Detailed Implementation

[0020] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While some embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this application. It should be understood that the drawings and embodiments of this application are for illustrative purposes only and are not intended to limit the scope of protection of this application.

[0021] It should be understood that the steps described in the method embodiments of this application may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of this application is not limited in this respect.

[0022] The term "comprising" and its variations as used herein are open-ended inclusions, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the description below.

[0023] It should be noted that the terms "one" and "multiple" used in this application are illustrative rather than restrictive, and those skilled in the art should understand that, unless explicitly stated otherwise in the context, they should be understood as "one or more". "Multiple" should be understood as two or more.

[0024] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0025] Example 1 One embodiment of this application provides a dual-channel vehicle-mounted particulate matter detection device based on 90-degree scattering, which will be referred to below. Figure 1-3 This application provides a detailed description of the dual-channel vehicle-mounted particulate matter detection device based on 90-degree scattering, such as... Figures 1-3 As shown, it includes: The housing includes: The upper housing 13 has an internal particle detection duct 9 and an external particle detection duct 7 that are isolated from each other. The lower housing 18 has a lower rubber layer 16, a circuit board 15 on the lower rubber layer 16, the circuit board 15 is connected to the particle sampling unit, and an upper rubber layer 14 is provided on the circuit board 15. The lower rubber layer 16 and the upper rubber layer 14 are used to cooperate in sealing the in-vehicle particle detection air duct 9 and the out-of-vehicle particle detection air duct 7.

[0026] The in-vehicle particle detection duct 9 and the out-of-vehicle particle detection duct 7 are respectively provided with a first particle sampling unit 5 and a second particle sampling unit 10. The first particle sampling unit 5 and the second particle sampling unit 10 each include a laser emitter 501, a focusing lens 502, an aperture, a light-sensitive area 507, a photodetector 510, and a light trap 511 arranged along the optical path. The photodetector 510 is located directly below the light-sensitive area and is used to receive the scattered light with a scattering angle of 90 degrees scattered from the light-sensitive area 507.

[0027] In this embodiment, the external particle detection air duct 7 includes, in sequence according to the gas flow path, an external air intake pipe 3, a filter, an external fan 4, and an external air intake pipe 2. A first particle sampling unit 5 is provided between the external fan 4 and the external air intake pipe 3.

[0028] In this embodiment, the filter screen installed in the external particle detection air duct 7 is made of stainless steel, which can block large particle impurities with a particle size greater than 100 micrometers, helping to extend the system life and increase the system detection accuracy.

[0029] In this embodiment, both the external air intake pipe 3 and the external air outlet pipe 2 are connected to the external air intake / exit grille 1.

[0030] In this embodiment, the in-vehicle particle detection air duct 9 includes an in-vehicle air inlet 8, an in-vehicle fan 12, and an air outlet grid 11 in sequence according to the gas flow path. A second particle sampling unit 10 is provided between the in-vehicle fan 12 and the in-vehicle air inlet 8.

[0031] In this embodiment, a shielding cover 17 for shielding electromagnetic interference is also provided inside the lower housing 18. The shielding cover 17 is located below the photodetector 510 and is tightly fitted to the lower housing 18.

[0032] In this embodiment, the selected laser emitter 501 is a solid-state laser. Solid-state lasers have characteristics such as high power output, excellent stability and good beam quality. At the same time, when driven by a constant current driving power supply, they can effectively suppress the fluctuation of laser output power and further improve the stability of the light source.

[0033] In this embodiment, the aperture includes a first aperture 503, a second aperture 505, and a third aperture 506. The radii of the three apertures decrease sequentially along the direction of light propagation. The radius of the first aperture 503 is 3 mm, the radius of the second aperture 505 is 2 mm, and the radius of the third aperture 506 is 1 mm. The distance between the laser emitter 501 and the photosensitive area 507 is 23 mm, thereby effectively preventing stray light from entering the scattered light sensitive area 507, so that the focal point of the beam 504 emitted by the laser emitter 501 is located in the scattered light sensitive area 507, forming a light spot. When particles pass through the scattered light sensitive area 507, Mie scattering occurs, and the scattered light reaches the effective receiving surface of the photodetector 510.

[0034] In some other embodiments, the positions and aperture sizes of the first aperture 503, the second aperture 505, and the third aperture 506 can be adjusted according to the actual distance between the laser emitter 501 and the photosensitive area 507, so that the focal point of the beam 504 emitted by the laser emitter 501 is located in the scattered light sensitive area 507.

[0035] In this embodiment, a light trap 511 is set to absorb the laser light passing through the scattered light sensitive area 507, so as to avoid the transmitted light being reflected back to the sensitive area and causing secondary scattering, which would affect the detection results.

[0036] The working process of this embodiment is as follows: During detection, the laser emitter 501 emits a beam that is focused by the focusing lens 502, and then passes through the first aperture 503, the second aperture 505 and the third aperture 506 in sequence. Finally, the focal point of the beam 504 is located in the scattered light sensitive area 507 to form a light spot. When the laser encounters particulate matter in the scattered light sensitive area 507, it will generate 90-degree scattered light. This scattered light is collected by the photodetector 510 and converted into an electrical signal. The magnitude of the electrical signal is proportional to the intensity of the scattered light. After being amplified and filtered by the signal processing circuit on the circuit board 15, the weak scattered light signal is converted into a detectable electrical signal, and a digital signal related to the particulate matter concentration is obtained, thereby realizing the preliminary measurement of the particulate matter concentration.

[0037] The above description is merely a partial embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of disclosure in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

[0038] Furthermore, while the operations are described in a specific order, this should not be construed as requiring these operations to be performed in the specific order shown or in sequential order. Multitasking and parallel processing may be advantageous in certain environments. Similarly, while several specific implementation details are included in the above discussion, these should not be construed as limiting the scope of this application. Certain features described in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.

[0039] Although the subject matter has been described using language specific to structural features and / or methodological logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely illustrative examples of implementing the claims.

Claims

1. A dual-channel vehicle-mounted particulate matter detection device based on 90-degree scattering, characterized in that, include: The housing includes: The upper housing has an in-vehicle particle detection duct and an external particle detection duct that are isolated from each other. The lower housing has a lower rubber layer, a circuit board on the lower rubber layer, and an upper rubber layer on the circuit board. The upper and lower rubber layers are used to seal the in-vehicle particle detection air duct and the out-of-vehicle particle detection air duct. A particle sampling unit is respectively installed in the in-vehicle particle detection air duct and the out-of-vehicle particle detection air duct. The particle sampling unit includes a laser emitter, a focusing lens, an aperture, a light-sensitive area for scattering light, and a photodetector arranged in the optical path. The photodetector is located to the side front of the light-sensitive area and is used to receive scattered light with a scattering angle of 90 degrees emitted from the light-sensitive area. The aperture includes a first aperture, a second aperture, and a third aperture arranged at intervals, with the aperture diameters of the first aperture, the second aperture, and the third aperture decreasing sequentially.

2. The dual-channel vehicle-mounted particulate matter detection device based on 90-degree scattering according to claim 1, characterized in that, The particle sampling unit further includes: A light trap, which is placed at the end of the light path, is used to absorb light passing through the light-sensitive area.

3. The dual-channel vehicle-mounted particulate matter detection device based on 90-degree scattering according to claim 1, characterized in that, The diameter of the first aperture is 3mm, the diameter of the second aperture is 2mm, and the diameter of the third aperture is 1mm.

4. The dual-channel vehicle-mounted particulate matter detection device based on 90-degree scattering according to claim 1, characterized in that, The external particle detection air duct includes, in sequence according to the gas flow path, an external air intake pipe, a filter, an external fan, and an external air intake pipe. A particle sampling unit is provided between the external fan and the external air intake pipe.

5. The dual-channel vehicle-mounted particulate matter detection device based on 90-degree scattering according to claim 4, characterized in that, The filter is used to block large particulate impurities with a particle size greater than 100 micrometers.

6. The dual-channel vehicle-mounted particulate matter detection device based on 90-degree scattering according to claim 4, characterized in that, Both the external air intake pipe and the external air outlet pipe are connected to the external air intake and outlet grilles.

7. The dual-channel vehicle-mounted particulate matter detection device based on 90-degree scattering according to claim 1, characterized in that, The in-vehicle particle detection air duct includes, in sequence, an in-vehicle air inlet, an in-vehicle fan, and an air outlet grid, and a particle sampling unit is provided between the in-vehicle fan and the in-vehicle air inlet.

8. The dual-channel vehicle-mounted particulate matter detection device based on 90-degree scattering according to claim 1, characterized in that, The lower housing is also equipped with a shielding cover for shielding electromagnetic interference.

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