Diesel truck smoke opacity detection system

Abstract

The present invention discloses a detection system for the opaque smoke of a diesel truck, the system comprising a telemetry device, a regression reflective plate and a host computer, the telemetry device and the regression reflective plate are arranged on both sides of a road detection area, the telemetry device comprises a green light detection module, a red light detection module and an acquisition controller, the green light detection module and the red light detection module work synchronously, a green laser for measuring the opaque smoke is included in a red pulse laser for ranging, the opaque smoke is synchronously judged in combination with the laser reflection distance, and the opaque smoke data in a state where the optical road is not blocked when a vehicle passes by can be effectively extracted.

Description

Technical Field

[0001] The invention relates to the technical field of optical remote sensing, and in particular to a detection system for the opaque smoke of a diesel truck. Background Art

[0002] As people's requirements for the atmospheric environment are increasing, motor vehicle exhaust emissions, as one of the important sources of air pollution, are becoming more and more important. The monitoring and control of black smoke vehicles has become one of the focuses of motor vehicle emission supervision tasks. At present, the supervision methods for black smoke vehicles include the following aspects:

[0003] 1) Pedestrian report:

[0004] Evidence is collected through videos or pictures of smoky vehicles taken directly by citizens on the road. However, since the vehicle is in motion, the effect of manual photography is not good, and it is difficult to obtain license plate information, there is a high degree of randomness and the execution efficiency is low.

[0005] 2) Video surveillance:

[0006] Through video surveillance capture or recording, the data is uploaded to the background, and then manual review or image recognition, pattern training and other methods are used to identify black smoke vehicles, and extract black smoke vehicles from surveillance videos or images; manual review is time-consuming and labor-intensive, and inefficient, while automatic identification through image recognition or pattern training algorithms can improve the efficiency of black smoke vehicle screening to a certain extent, but due to the large background differences, there are still limitations in the algorithm, there is a high misjudgment rate, and it basically cannot work at night.

[0007] 3) Optical remote sensing:

[0008] Optical telemetry technology is used to measure the opaque smoke density of vehicle exhaust with high precision and accuracy. However, current optical telemetry equipment is mainly used for tail-discharge vehicles. Remote sensing alone cannot effectively capture the exhaust gas of large trucks, trailers, and other vehicles whose exhaust pipes are located in the middle of the vehicle body. In particular, heavy-duty diesel vehicles have complex bottom structures that are prone to light blocking, making it difficult to obtain high-quality opaque smoke density data using optical remote sensing technology. Summary of the invention

[0009] The purpose of the present invention is to provide a detection system for the opaque smoke of diesel trucks. The system combines optical remote sensing means and ranging principles to synchronously obtain the opaque smoke and ranging distance when a vehicle passes, judge the light blocking condition of the vehicle's lower structure by distance, filter the light blocking data, and thus effectively obtain the opaque smoke of exhaust gas emitted by heavy-duty diesel vehicles.

[0010] In order to achieve the above object, the present invention provides the following technical solutions:

[0011] A diesel truck opaque smoke detection system includes a telemetry device, a retro-reflective plate and a host computer. The telemetry device and the retro-reflective plate are arranged on both sides of a road detection area. The telemetry device includes a green light detection module, a red light detection module and an acquisition controller.

[0012] The green light detection module emits green laser light to the retro-reflective plate, and receives green reflected laser light reflected back by the retro-reflective plate;

[0013] The red light detection module emits infrared pulse laser to the retro-reflective plate, and receives the infrared pulse reflected laser reflected back by the retro-reflective plate;

[0014] The acquisition controller acquires the light intensity data of the green laser and the green reflected laser, as well as the time data of emitting the infrared pulse laser and receiving the infrared pulse reflected laser, and sends them to the host computer. The host computer identifies the opaque smoke according to the light intensity data and the time data.

[0015] Preferably, the host computer calculates the opaque smoke density according to the difference between the light intensity data of the green laser and the green reflected laser; and calculates the laser reflection distance according to the difference between the time data of emitting the infrared pulse laser and receiving the infrared pulse reflected laser.

[0016] Preferably, the green light detection module comprises a green light detector and a green light laser, the green light laser emits the green laser, and the green light detector receives the green reflected laser.

[0017] Specifically, the green light detection module further includes a green light focusing lens, and the green light detector, the green light laser and the green light focusing lens are sequentially arranged in a collinear manner;

[0018] A through hole is provided at the center of the green light focusing lens, and the green laser emitted by the green light laser passes through the through hole and is emitted to the retro-reflective plate; the green reflected laser is focused by the green light focusing lens and then received by the green light detector.

[0019] Furthermore, the green light detection module also includes a green light bandpass filter, and the green light bandpass filter is arranged between the green light detector and the green light laser.

[0020] Preferably, the red light detection module comprises an infrared pulse laser emitting unit and an infrared pulse laser receiving unit, and the outer pulse laser emitting unit and the infrared pulse laser receiving unit are respectively arranged on both sides of the green light detection module.

[0021] Preferably, the infrared pulse laser emitting unit comprises an infrared pulse laser and an infrared collimating lens which are arranged in a colinear manner, and the infrared pulse laser emitted by the infrared pulse laser is collimated by the infrared collimating lens and then emitted to the retro-reflective plate through the detection area.

[0022] Preferably, the red light receiving unit comprises an infrared focusing lens, an infrared filter and an infrared avalanche detector which are arranged in sequence in a co-linear manner, and the infrared pulse reflected laser is focused by the infrared focusing lens and then received by the infrared avalanche detector.

[0023] Preferably, the telemetry device and the retro-reflective plate are set up opposite to each other in a horizontal direction on both sides of the road, and the installation height of the telemetry device and the retro-reflective plate relative to the road is 5-40 cm.

[0024] Preferably, the diesel truck opaque smoke detection system also includes a first reflector and a second reflector, the first reflector and the second reflector have an angle of 45° with the horizontal direction and the angle between their extended lines is 90°; the telemetry equipment and the retro-reflective plate are respectively arranged vertically above the corresponding reflectors, and the installation height of the telemetry equipment and the retro-reflective plate relative to the road is greater than 80 cm.

[0025] Compared with the prior art, the diesel truck opaque smoke detection system provided by the present invention has the following beneficial effects:

[0026] The detection system of diesel truck opaque smoke provided by the present invention includes telemetry equipment, regression reflective plates and a host computer respectively arranged on both sides of the road, a detection area is formed above the road between the telemetry equipment and the regression reflective plates, and the telemetry equipment includes a green light detection module, a red light detection module and an acquisition controller, the green light detection module emits a green laser and receives a green reflected laser, the green laser is greatly affected by the smoke, and its attenuation degree can effectively represent the opacity of the smoke discharged by the vehicle; the red light detection module emits an infrared pulse laser and receives an infrared pulse reflected laser, when the light penetrates the particulate matter emitted by the vehicle exhaust, the penetration ability of the infrared band is much greater than the visible light with a smaller wavelength, so the infrared pulse laser can effectively penetrate the smoke to achieve accurate distance measurement; the green light detection module and the red light detection module work synchronously, effectively including the green laser for measuring opaque smoke in the red pulse laser for ranging. The host computer synchronously judges the opaque smoke by combining the laser reflection distance, and can effectively extract the opaque smoke data in the unobstructed state of the optical path when the vehicle passes. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0028] Figure 1 It is a structural schematic diagram of a telemetry device in an embodiment of the present invention;

[0029] Figure 2 It is a schematic diagram of the overall structure of a diesel truck opaque smoke detection system in one working mode in an embodiment of the present invention;

[0030] Figure 3 It is a schematic diagram of the overall structure of the diesel truck opaque smoke detection system in another working mode in an embodiment of the present invention;

[0031] Figure 4 Schematic diagram of a data collection example in an embodiment of the present invention.

[0032] Reference numerals:

[0033] 1-telemetry equipment, 1-1-infrared collimating lens;

[0034] 1-2-green light focusing lens, 1-3-infrared focusing lens;

[0035] 1-4-infrared pulse laser, 1-5-green laser;

[0036] 1-6-infrared filter, 1-7-green light bandpass filter;

[0037] 1-8-green light detector, 1-9-infrared avalanche detector;

[0038] 1-10-collection control circuit, 2-retro-reflective plate;

[0039] 3-Road, 4-1-First equipment base;

[0040] 4-2-second device base, 5-1-first reflector;

[0041] 5-2-second reflector, 6-vehicle;

[0042] 7- side exhaust plume, 8- host computer. DETAILED DESCRIPTION

[0043] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0044] See also Figure 1 to Figure 3 The diesel truck opaque smoke detection system provided in this embodiment includes a telemetry device 1, a regression reflector 2 and a host computer 8 respectively arranged on both sides of a road 3. A detection area is formed above the road 3 between the telemetry device 1 and the regression reflector 2. The telemetry device 1 includes a green light detection module, a red light detection module and an acquisition controller 1-10.

[0045] Among them, the green light detection module emits the green laser onto the regression reflective plate 2 after it passes through the detection area, and receives the green reflected laser reflected back by the regression reflective plate 2 after it passes through the detection area; the red light detection module emits the infrared pulse laser onto the regression reflective plate 2 after it passes through the detection area, and receives the infrared pulse reflected laser reflected back by the regression reflective plate 2 after it passes through the detection area; the acquisition controller 1-10 acquires the light intensity data of the green laser and the green reflected laser, as well as the time data of emitting the infrared pulse laser and receiving the infrared pulse reflected laser, and sends them to the host computer 8. The acquisition controller 1-10 can be implemented using a PLC programmable logic controller, or it can be directly implemented using an existing light intensity acquisition controller combined with a time acquisition controller; the host computer 8 identifies the opaque smoke according to the light intensity data and the time data, and outputs the identification result.

[0046] Since the green laser is greatly affected by the smoke, its attenuation degree can effectively represent the opacity of the smoke emitted by the vehicle; and when the light penetrates the particulate matter emitted by the vehicle exhaust, the penetration ability of the infrared band is much greater than the visible light with a smaller wavelength, so the infrared pulse laser ranging can effectively penetrate the smoke to achieve accurate distance measurement; in the detection system for the opaque smoke of a diesel truck provided by the embodiment of the present invention, the green light detection module and the red light detection module work synchronously, and the green laser used to detect the opaque smoke is effectively included in the red pulse laser for ranging, ensuring the synchronization of the green laser and the infrared pulse laser being blocked, and providing reliable basic data for the upper computer 8 to analyze and identify the opaque smoke. The upper computer 8 can effectively extract the opaque smoke data when the vehicle passes by by combining the laser reflection distance to synchronously judge the opaque smoke, filter out the light blocking situation, and identify the accurate opaque smoke result when the vehicle passes by and the light path is not blocked.

[0047] The specific method for identifying the opaque smoke is as follows: the host computer 8 calculates the opaque smoke according to the difference in light intensity data between the green laser and the green reflected laser, combined with the laser reflection distance. The specific calculation is based on the physical principle of light attenuation. It can be directly calculated using the Beer-Lambert law, or quickly calculated by establishing a mathematical model. Since the green laser is greatly affected by the smoke, its attenuation degree can effectively represent the opacity of the smoke discharged by the vehicle; the host computer 8 also calculates the laser reflection distance according to the difference in time data between emitting the infrared pulse laser and receiving the infrared pulse reflected laser, so as to judge whether the detection area is blocked according to the laser reflection distance. When the vehicle passes by, the light blocking caused by the front wheel, rear wheel or other body parts of the vehicle is judged according to the laser reflection distance, and then the opaque smoke of the detection area in the unblocked state when the vehicle 6 passes by is screened. Since the penetration ability of the infrared band when light penetrates the particulate matter emitted by the vehicle exhaust is much greater than that of the visible light with a smaller wavelength, the infrared pulse laser ranging can effectively penetrate the smoke to achieve accurate distance measurement.

[0048] See also Figure 4 , Figure 4 The figure shows a set of data collection examples. The telemetry equipment is placed below the chassis of the vehicle. Affected by the wheels and side guardrails, the measured data is blocked by light. At this time, the measured distance is about 2m, while the distance measured when the light path is not blocked is 9m. The opaque smoke density in area 1 is around 0.95, which is mainly caused by light blocking. The opaque smoke density in area 2 is the smoke data collected without light blocking, showing a more obvious diffusion trend. By combining the synchronous judgment of distance, the opaque smoke density data when the vehicle passes by can be effectively extracted, and the influence of light blocking on the opaque smoke density can be filtered out.

[0049] Please continue reading Figure 1In the diesel truck opaque smoke detection system provided in this embodiment, the green light detection module includes a green light detector 1-8, a green light laser 1-5 and a green light focusing lens 1-2. The green light detector 1-8, the green light laser 1-5 and the green light focusing lens 1-2 are arranged in a colinear manner. The green light laser 1-5 is used to emit a green laser, and the green light detector 1-8 is used to receive a green reflected laser. A through hole is provided at the center of the green light focusing lens 1-2. The green laser emitted by the green light laser 1-5 passes through the through hole of the green light focusing lens 1-2 and is scattered in the detection area and then emitted to the retro-reflective plate 2. The green reflected laser reflected back by the retro-reflective plate 2 passes through the detection area and is scattered and then focused by the green light focusing lens 1-2 and then received by the green light detector 1-8. In addition, the green light detection module also includes a green light bandpass filter 1-7. The green bandpass filter is arranged between the green light detector 1-8 and the green light laser 1-5, which can effectively eliminate interference from other bands. During the specific implementation process, the collimated 560nm green laser emitted by the green laser 1-5 has obvious light color characteristics, is not easily filtered out by the green light bandpass filter 1-7, and is greatly affected by smoke. Its attenuation degree can effectively represent the opacity of the smoke exhausted by the vehicle. Those skilled in the art can understand that as long as the light with a wavelength of 500-600nm has the characteristic of being greatly affected by smoke, the technical solution of the present invention of simply changing the light color or the wavelength of light to include the measurement of opaque smoke in the ranging light falls within the protection scope of the present invention.

[0050] Please continue reading Figure 1 In the diesel truck opaque smoke detection system provided in this embodiment, the red light detection module includes an infrared pulse laser emitting unit and an infrared pulse laser receiving unit, and the outer pulse laser emitting unit and the infrared pulse laser receiving unit are respectively arranged on both sides of the green light detection module, so as to ensure that the green laser is included in the ranging optical path, thereby ensuring the synchronization of the blocking of the infrared pulse laser and the green laser, and can effectively extract the opaque smoke data when the vehicle passes by, and filter out the influence of the light blocking condition on the opaque smoke.

[0051] Specifically, the infrared pulse laser emitting unit includes an infrared pulse laser 1-4 and an infrared collimating lens 1-1 arranged in a collinear manner. The infrared pulse laser emitted by the infrared pulse laser 1-4 is collimated by the infrared collimating lens 1-1 and then transmitted through the detection area to the retro-reflective plate 2. The red light receiving unit includes an infrared focusing lens 1-3, an infrared filter 1-6 and an infrared avalanche detector 1-9 arranged in a collinear manner in sequence. The infrared pulse reflected laser is focused by the infrared focusing lens 1-3 and then received by the infrared avalanche detector 1-9. In the specific implementation process, the infrared pulse laser with a wavelength of 905nm emitted by the infrared pulse laser 1-4 has obvious light color characteristics and is not easily filtered out by the infrared filter 1-6. It also has strong penetrating ability and can effectively penetrate the smoke puff to realize accurate measurement of the laser reflection distance, thereby effectively extracting the opaque smoke data when the vehicle passes by, while filtering out the influence of light blocking on the opaque smoke. Similarly, those skilled in the art can understand that a wavelength greater than or equal to 800nm ​​has the strong penetrating ability of the infrared pulse laser in the present invention, and the technical solutions of the present invention of measuring opaque smoke density by simply changing the light color or wavelength of light fall within the scope of protection of the present invention.

[0052] Please continue reading Figure 2 , Figure 2 It is a schematic diagram of the overall structure of the diesel truck opaque smoke detection system in an embodiment of the present invention in one working mode, wherein the telemetry device 1 is fixed on the first device base 4-1, and the regression reflector 2 is fixed on the second device base 4-2; the telemetry device 1 and the regression reflector 2 are relatively set up on both sides of the road 3 in the horizontal direction, and the installation height of the telemetry device 1 and the regression reflector 2 relative to the road is 5-40cm, preferably about 25cm, with low installation cost, and can ensure that the data of the non-light-blocking area at the bottom can be effectively collected when most large trucks pass by, which is especially suitable for vehicles with exhaust emissions at the bottom of the vehicle, while ensuring the synchronization of light blocking.

[0053] During the specific implementation, the road is used as the baseline, and the first device base 4-1 and the second device base 4-2 are adjusted so that the height of the light emitted by the green laser 1-5 and the infrared pulse laser 1-4 in the telemetry device 1 is about 25 cm, and can be directly emitted horizontally to the retro-reflective plate 2, thereby ensuring that the data of the bottom non-light-blocking area when most large trucks pass by can be effectively collected. At the same time, in order to ensure the synchronization of light blocking, the telemetry device integrates the green laser beam used for smoke measurement into the red pulse laser beam used for ranging. The green light detector 1-8 and the infrared avalanche detector 1-9 are synchronously collected, and the collection frequency reaches more than 1M to ensure the effectiveness of the collected data. When the light penetrates the particulate matter emitted by the vehicle exhaust, the penetration ability of the infrared band is much greater than that of the visible light with a smaller wavelength, and can effectively penetrate the smoke to achieve accurate distance measurement, while the green laser is greatly affected by the smoke, and its attenuation degree can effectively represent the opacity of the smoke discharged by the vehicle.

[0054] See also Figure 3 , Figure 3 The overall structural diagram of the diesel truck opaque smoke detection system in another working mode in the embodiment of the present invention, the diesel truck opaque smoke detection system also includes a first reflector 5-1 and a second reflector 5-2, the telemetry device 1 and the first reflector 5-1 are fixed on the first device base 4-1, and the regression reflector 2 and the second reflector 5-2 are fixed on the second device base 4-2. Among them, the first reflector 5-1 and the second reflector 5-2 are both 45° with the horizontal direction and the extended line angle between the two is 90°; the telemetry device 1 and the regression reflector 2 are respectively arranged vertically above the corresponding reflectors, and the installation height of the telemetry device 1 and the regression reflector 2 relative to the road is greater than 80cm, preferably set to about 1.5m, which can realize the effective measurement of the opaque smoke of vehicles with side exhaust (the exhaust pipe of the vehicle exhaust is on the side, and the exhaust plume is discharged horizontally to the side of the vehicle).

[0055] In the specific implementation process, taking the road as the baseline, the first device base 4-1 and the second device base 4-2 are adjusted so that the height of the telemetry device 1 and the regression reflector 2 is about 1.5m from the ground. The light emitted by the green laser 1-5 and the infrared pulse laser 1-4 in the telemetry device changes the direction of the optical path through the first reflector 5-1 in turn, passes horizontally through the road, and then changes the optical path by the second reflector 5-2 and is emitted to the regression reflector 2. The collection frequency reaches more than 1M to ensure the effectiveness of the collected data. At this time, when the vehicle 6 passes by, the side exhaust plume 7 diffuses laterally onto the optical path, thereby realizing the effective measurement of the opaque smoke density and improving the capture rate of the side exhaust vehicles.

[0056] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0057] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A diesel truck smoke opacity detection system, characterized in that: It includes a telemetry device, a regression reflector and a host computer. The telemetry device and the regression reflector are arranged on both sides of the road detection area. The telemetry device includes a green light detection module, a red light detection module and an acquisition controller. The green light detection module emits green laser light to the retro-reflective plate, and receives the green reflected laser light reflected by the retro-reflective plate; the green light detection module includes a green light detector and a green light laser, the green light laser emits the green laser light, and the green light detector receives the green reflected laser light; The red light detection module emits an infrared pulse laser onto the retro-reflective plate, and receives the infrared pulse reflected laser reflected by the retro-reflective plate; the red light detection module includes an infrared pulse laser emitting unit and an infrared pulse laser receiving unit, and the external pulse laser emitting unit and the infrared pulse laser receiving unit are respectively arranged on both sides of the green light detection module; The acquisition controller acquires the light intensity data of the green laser and the green reflected laser, as well as the time data of emitting the infrared pulse laser and receiving the infrared pulse reflected laser, and sends them to the host computer, and the host computer identifies the opaque smoke according to the light intensity data and the time data; The host computer calculates the opaque smoke according to the difference between the light intensity data of the green laser and the green reflected laser; and calculates the laser reflection distance according to the difference between the time data of emitting the infrared pulse laser and receiving the infrared pulse reflected laser.

2. The diesel truck smoke opacity detection system according to claim 1 is characterized in that: The green light detection module further includes a green light focusing lens, and the green light detector, the green light laser and the green light focusing lens are sequentially arranged in a collinear manner; A through hole is provided at the center of the green light focusing lens, and the green laser emitted by the green light laser passes through the through hole and is emitted to the retro-reflective plate; the green reflected laser is focused by the green light focusing lens and then received by the green light detector.

3. The diesel truck smoke opacity detection system according to claim 2 is characterized in that: The green light detection module further comprises a green light bandpass filter, and the green light bandpass filter is arranged between the green light detector and the green light laser.

4. The diesel truck smoke opacity detection system according to claim 1 is characterized in that: The infrared pulse laser emitting unit comprises an infrared pulse laser and an infrared collimating lens arranged in a colinear manner. The infrared pulse laser emitted by the infrared pulse laser is collimated by the infrared collimating lens and then passes through the detection area and is emitted to the retro-reflective plate.

5. The diesel truck smoke opacity detection system according to claim 1 is characterized in that: The infrared pulse laser receiving unit comprises an infrared focusing lens, an infrared filter and an infrared avalanche detector which are arranged in sequence and in a co-linear manner. The infrared pulse reflected laser is focused by the infrared focusing lens and then received by the infrared avalanche detector.

6. The diesel truck smoke opacity detection system according to claim 1, characterized in that: The telemetry device and the retro-reflective plate are set up opposite to each other in the horizontal direction on both sides of the road, and the installation height of the telemetry device and the retro-reflective plate relative to the road is 5-40 cm.

7. The diesel truck smoke opacity detection system according to claim 1, characterized in that: The diesel truck opaque smoke detection system also includes a first reflector and a second reflector, the first reflector and the second reflector have an angle of 45° with the horizontal direction and the angle between their extended lines is 90°; the telemetry equipment and the regression reflector are respectively arranged vertically above the corresponding reflectors, and the installation height of the telemetry equipment and the regression reflector relative to the road is greater than 80 cm.

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