JP2005004425A - Apparatus for estimating discharge amount of atmospheric contaminant and apparatus for reducing traffic pollution - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge amount estimating apparatus for atmospheric contaminant that can precisely estimate the total amount of atmospheric contaminants discharged from vehicles traveling within a fixed time by improving detection precision of traveling vehicles on a road. <P>SOLUTION: A traffic pollution reducing apparatus 1 processes images picked up by two CCD cameras 2a and 2b which are arranged side by side above a road to generate a stereoscopic image based upon the road surface. Vehicles traveling on the road are detected from the stereoscopic image. Trees lining on the road surface and shadows of vehicles are therefore deterred from being misdetected as vehicles to improve the detection precision of vehicles. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention applies an air pollutant emission estimation device for estimating the amount of air pollutant emissions discharged from a vehicle traveling on a road, and the air pollutant emission estimation device. The present invention relates to a traffic pollution reduction device that suppresses traffic pollution in the vicinity.
[0002]
[Prior art]
Conventionally, a traffic pollution reduction system (EPMS) that suppresses traffic pollution caused by air pollutants such as nitrogen oxides (NO _x ), hydrocarbons (HC), and particulate matter (PM) discharged from vehicles traveling on roads. Development of Protection Management System is underway.
[0003]
This traffic pollution reduction system collects the amount of air pollutants using an exhaust gas measuring device installed on the road, and based on the collected pollutant amounts, it uses the optimal signal control and detour guidance using optical beacons and traffic information boards. -By controlling the inflow, this system distributes and smoothes the traffic flow, contributes to the health of local residents by reducing air pollution, and eliminates noise problems for neighboring residents. In order to realize this system, it is important to accurately measure the amount of exhaust gas discharged from a vehicle. Conventionally, a chemical measuring device has been used for measuring the amount of exhaust gas.
[0004]
However, chemical measuring devices are easily affected by the installation location, topography, wind (wind direction, wind speed), etc., and have a time lag and are expensive. The total amount of exhaust gas discharged could not be measured accurately.
[0005]
On the other hand, according to the “Investigation on Vehicle Emissions Units and Total Volume” report of the Environment Agency Air Conservation Bureau on June 5, 1998, the vehicle type (mini passenger car, passenger car, small freight car, ordinary freight car, bus, special car For each 7-vehicle classification), the amount of air pollutants emitted per 1 km (emission unit) was clarified by travel speed. In addition, an image-type traffic flow measuring device that processes an image captured by a CCD camera and detects the number, type, and traveling speed of vehicles traveling on a road has already been proposed. For this reason, for each vehicle traveling on the road, the image type traffic flow measuring device detects the vehicle type and the traveling speed, and the vehicle is discharged using the emission unit clarified in the above report. It is conceivable to estimate the total exhaust gas emission amount by estimating the exhaust gas emission amount and calculating the sum of the exhaust gas emission amount estimated for each vehicle.
[0006]
Japanese Patent Application Laid-Open No. H10-228561 proposes that an air pollutant is estimated by irradiating light slit light onto a road and capturing a change image of the slit light with a camera to obtain a vehicle type and acceleration.
[0007]
[Patent Document 1]
Japanese Patent Laid-Open No. 5-143887
[Problem to be Solved by the Invention]
However, since the conventional image-type traffic flow measurement device is configured to detect a vehicle traveling on a road by processing a captured image (two-dimensional image) captured by one CCD camera, the vehicle travels on a road. The three-dimensional shape of a running vehicle cannot be detected, and the frequency of erroneous detection for detecting a roadside tree on the road surface or the shadow of the vehicle as a running vehicle is high. For this reason, it is impossible to accurately detect the total amount of air pollutants discharged from vehicles that have traveled on the road within a certain period of time, and as a result, control of traffic lights on the surrounding roads to reduce traffic pollution and drivers Information on the detour route cannot be displayed properly and traffic pollution cannot be sufficiently suppressed.
[0009]
In addition, the technique proposed in Patent Document 1 requires a very powerful slit light irradiation device to capture the slit light on the road with a camera in the presence of strong sunlight in the daytime. It was not realistic.
[0010]
An object of the present invention is to improve the detection accuracy of a traveling vehicle on a road, thereby accurately estimating the sum of air pollutants discharged from vehicles traveling on the road within a certain time. An object of the present invention is to provide an apparatus for estimating emissions.
[0011]
In addition, the present invention provides a traffic pollution reduction device that can appropriately control traffic lights on surrounding roads to reduce traffic pollution and display guidance for detour routes to drivers, and can sufficiently suppress the occurrence of traffic pollution. The purpose is to do.
[0012]
[Means for Solving the Problems]
(1) An air pollutant emission estimation device of the present invention has the following configuration in order to solve the above problems.
[0013]
An imaging means for imaging a vehicle traveling on a road with two cameras arranged side by side above the road;
Three-dimensional shape detection means for detecting the three-dimensional shape of a vehicle traveling on a road using two captured images captured by the two cameras of the imaging means;
Vehicle type discriminating means for discriminating the vehicle type of the vehicle based on the three-dimensional shape of the vehicle detected by the solid shape detecting unit;
A traveling speed detecting means for detecting a traveling speed of a vehicle traveling on a road from a captured image captured by the imaging means;
For each vehicle in which the three-dimensional shape is detected by the three-dimensional shape detection means, the amount of air pollutant emission is estimated based on the vehicle type determined by the vehicle type determination means and the travel speed detected by the travel speed detection means. And an emission amount estimation means.
[0014]
In this configuration, the two cameras of the imaging means are arranged side by side above the road. The three-dimensional shape detecting means obtains the parallax between the two captured images taken by the two cameras, and the three-dimensional shape of the vehicle traveling on the road based on the obtained parallax (vehicle width, vehicle length, vehicle height) ) Is detected. The vehicle type discrimination means discriminates the vehicle type from the three-dimensional shape of the vehicle detected here.
[0015]
The traveling speed detection means detects the traveling speed of the vehicle. The traveling speed of the vehicle can be detected from a captured image captured by one camera, or can be detected based on the three-dimensional shape of the vehicle detected by the three-dimensional shape detecting means. The emission amount estimation means estimates the emission amount of air pollutants discharged from the vehicle based on the detected vehicle type and travel speed.
[0016]
As described above, since the three-dimensional shape of the vehicle traveling on the road is detected from the two captured images captured by the two CCD cameras, the roadside tree or the shadow of the vehicle on the road surface is mistaken for the traveling vehicle. It is possible to prevent detection. Further, since the vehicle type is determined based on the three-dimensional shape of the vehicle, the vehicle type determination accuracy can be improved. Therefore, it is possible to accurately estimate the sum of the air pollutants discharged from the vehicle traveling on the road.
[0017]
In addition, by arranging the two cameras of the imaging means above and below, there is no left-right parallax in the two captured images, and the process for detecting the vehicle width of the imaged vehicle is easier than when arranged side by side. The processing time can be shortened.
[0018]
Furthermore, it comprises a discharge unit storage means for storing a discharge unit which is a reference value of the amount of air pollutants discharged when traveling a predetermined distance for each vehicle type and for each traveling speed of the vehicle,
The emission estimation means is configured to estimate the emission amount of air pollutants for each vehicle using the corresponding vehicle type stored in the emission basic unit storage means and the emission basic unit of traveling speed. The amount of air pollutants discharged from the detected vehicle can be easily estimated, and the processing time can be shortened.
[0019]
(2) Moreover, the traffic pollution reduction device of the present invention includes the device for estimating an air pollutant emission amount of (1),
With respect to the signal control device that controls the traffic signal installed at the upstream intersection in the traveling direction of the vehicle on the road imaged by the imaging unit, for each vehicle estimated by the emission amount estimation unit within a certain time Signal control instructing means for instructing control of the traffic light according to the sum of the estimated emission amounts of air pollutants.
[0020]
In this configuration, as described above, it is possible to accurately estimate the sum of the air pollutants discharged from the vehicles that have traveled on the road within a certain period of time, so that the traffic lights on the surrounding roads can be properly controlled and traffic pollution can be prevented. It can be suppressed sufficiently.
[0021]
Further, the device for estimating the amount of air pollutant emission of (1) above,
When the sum of the estimated emissions of air pollutants for each vehicle estimated by the emission estimation means within a certain time exceeds a predetermined amount, the vehicle travels on the road imaged by the imaging means By providing guidance instruction means for instructing the guidance indicator installed on the upstream side of the direction to display a message prompting to detour this road, the guidance display of the detour route to the driver is properly performed It can be done and traffic pollution can be suppressed sufficiently.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a traffic pollution reduction system to which a traffic pollution reduction apparatus according to an embodiment of the present invention is applied will be described. In addition, an air pollutant emission estimation apparatus (hereinafter simply referred to as an emission estimation apparatus) according to the present invention is applied to the traffic pollution reduction apparatus of this embodiment.
[0023]
FIG. 1 is a diagram showing a traffic pollution reduction system according to an embodiment of the present invention. In FIG. 1, 1 is a traffic pollution reducing device. This traffic pollution reduction device 1 estimates the amount of air pollutants discharged from this vehicle for each vehicle that has traveled on the road between intersection A and intersection B, and calculates the sum. 2a to 2d are signal control devices for controlling traffic lights installed at intersections A to D, respectively. Reference numeral 3 denotes a guidance indicator installed upstream of the intersection A. The guidance display 3 displays traffic information for the driver and guidance for a detour route.
[0024]
The traffic pollution abatement apparatus 1 estimates the amount of air pollutants discharged from this vehicle for each vehicle that has traveled on the road between the intersection A and the intersection B every predetermined time (for example, 5 minutes). Based on the sum, the signal control devices 2 (2a to 2d) at the intersections A to D are instructed to control the traffic lights. For example, the traffic pollution reducing device 1 is a signal control device 2 that uses a cycle in which blue, yellow, and red make a round, and a split that is a time in which traffic is given during the round of a traffic light (total time in blue and yellow). To instruct.
[0025]
Further, the traffic pollution reducing device 1 is configured to detect an intersection when the total amount of air pollutants discharged from a vehicle traveling on the road between the intersection A and the intersection B within the predetermined time exceeds a predetermined amount. The guidance display 3 installed upstream of A is instructed to prompt the driver to detour the road between the intersection A and the intersection B, and to display a detour route.
[0026]
In this embodiment, the traffic pollution reducing device 1 directly instructs the signal control device 2 and the guidance indicator 3. However, the traffic signal reducing device 1 is connected to the signal control device 2 through a control center (not shown). It is good also as a structure which performs the instruction | indication of display with respect to control and the guidance indicator 3. FIG. Specifically, the traffic pollution reduction device 1 may notify the control center of an instruction for the signal control device 2 and the guidance indicator 3, and the control center may instruct the signal control device 2 and the guidance indicator 3. .
[0027]
FIG. 2 is a block diagram showing the configuration of the traffic pollution reducing apparatus according to the embodiment of the present invention. The traffic pollution reduction device 1 of this embodiment includes a control unit 11 that controls the operation of the main body, and an emission unit storage unit 12 that stores the emission amount (emission unit) of air pollutants when traveling 1 km for each vehicle type. An image pickup unit 13 for picking up an image of a vehicle traveling on the road, a vehicle shape detection unit 14 for processing the image picked up by the image pickup unit 13 to detect a three-dimensional shape of the vehicle, and a vehicle shape detection unit 14 The vehicle type discriminating unit 15 that discriminates the vehicle type from the three-dimensional shape of the vehicle, the traveling speed detecting unit 16 that detects the traveling speed of the vehicle imaged by the imaging unit 13, and an instruction to the signal control device 2 and the guidance display 3 are output. And a communication unit 17.
[0028]
The emission basic unit storage unit 12 stores NO _x , HC, and PM emission basic units that are discharged when the vehicle travels 1 km for each vehicle type and for each vehicle speed (see FIG. 3). FIG. 3A shows NO _x emission intensity, FIG. 3B shows HC emission intensity, and FIG. 3C shows PM emission intensity.
[0029]
The imaging unit 13 is provided with two CCD cameras 13a and 13b. The two CCD cameras 13a and 13b are mounted at a height of about 8 m from the road surface. The CCD cameras 13a and 13b are arranged one above the other, and the interval is several tens of centimeters. The imaging unit 13 is provided with an image memory (not shown) for temporarily storing captured images for each of the CCD cameras 13a and 13b.
[0030]
The vehicle shape detection unit 14 processes two captured images captured by the two CCD cameras 13a and 13b, and detects the three-dimensional shape of the vehicle. Specifically, feature points in the horizontal direction are extracted from two captured images, and parallax is calculated from the deviation of the feature points in the two captured images. And the three-dimensional shape of the imaged vehicle is detected by converting into the three-dimensional coordinate on the basis of the road surface based on the parallax calculated here.
[0031]
The vehicle type discriminating unit 15 discriminates the vehicle type (bus, ordinary freight car, special car, small freight car, light freight car, passenger car, light passenger car) from the three-dimensional shape of the vehicle detected by the vehicle shape detecting unit 14. Specifically, the vehicle size (range of vehicle width, vehicle length, vehicle height) is stored for each vehicle type, and the vehicle size is obtained from the three-dimensional shape of the vehicle detected by the vehicle shape detection unit 14. It is determined that the vehicle type satisfies the vehicle width, the vehicle length, and the vehicle height.
[0032]
The traveling speed detection unit 16 can detect the amount of movement between frames of the three-dimensional shape of the vehicle converted into the three-dimensional coordinates by the vehicle shape detection unit 14, or can detect the traveling speed, The traveling speed can also be detected by detecting the amount of movement between frames of the captured image captured by the CCD camera 12a (or 12b).
[0033]
Next, operation | movement of the traffic pollution reduction apparatus 1 which is embodiment of this invention is demonstrated. The traffic pollution reduction apparatus 1 of this embodiment repeats the stereoscopic image generation process shown in FIG. First, this stereoscopic image generation process will be described. The traffic pollution reduction device 1 stores captured images captured by the two CCD cameras 12a and 12b in the image capturing unit 13 in an image memory at predetermined time intervals, for example, 500 ms intervals. Each time the captured image is stored in the image memory at the predetermined time interval, the vehicle shape detection unit 14 extracts the horizontal feature point in the two images, and the parallax is calculated from the deviation of the feature point in the two captured images. Calculate (s1). Since the CCD cameras 12a and 12b are arranged one above the other, there is no shift in parallax in the left-right direction in the captured images taken by these two CCD cameras 12a and 12b, and the processing relating to s1 can be performed easily. Then, based on the parallax calculated here, a stereoscopic image converted into three-dimensional coordinates with the road surface as a reference is generated (s2).
[0034]
The traffic pollution reduction device 1 of this embodiment repeats this stereoscopic image generation process to generate a temporally continuous stereoscopic image.
[0035]
Further, the traffic pollution reduction device 1 performs the vehicle type determination and travel speed detection processing shown in FIG. 5 while tracking the vehicle being imaged in the temporally continuous stereoscopic image generated by the stereoscopic image generation processing. Execute. A vehicle width, a vehicle length, and a vehicle height are detected for a vehicle located at a predetermined vehicle detection position on the road (s11). And based on the vehicle size memorize | stored for every vehicle type, the vehicle type of the vehicle detected by the vehicle shape detection part 14 is discriminate | determined (s12). For the vehicle whose vehicle type is determined in s12, a change in the position on the road in the temporally continuous stereoscopic image is detected, and the traveling speed of the vehicle is detected (s13).
[0036]
In s12 and s13, it is not necessary to detect the vehicle type and the traveling speed again for a vehicle that has already detected the vehicle type and the traveling speed.
[0037]
Moreover, the traffic pollution reduction apparatus 1 performs the emission amount estimation process of an air pollutant shown in FIG. 6 about the vehicle by which the vehicle type was discriminate | determined by the said vehicle type discrimination | determination and a travel speed detection process. The traffic pollution reduction device 1 calculates the NO _x emission amount for the vehicle whose vehicle type is determined (s21). Specifically, discriminated vehicle type in s12, and the emissions per unit of the NO _x corresponding to the traveling speed detected by s13 read from emission intensity storage unit 12, to which the distance between the intersection A-B The multiplied value is calculated as the amount of NO _x discharged from this vehicle. In other words, when the vehicle has traveled intersections A-B, and calculates the emissions discharged the NO _x.
[0038]
Similarly, the traffic pollution reduction device 1 calculates the HC and PM emissions for a vehicle whose vehicle type is determined (s22, s23). The calculation of the HC and PM emission amounts is also performed by reading out the HC and PM emission basic units corresponding to the vehicle type determined in s12 and the traveling speed detected in s13 from the emission basic unit storage unit 12, and A value obtained by multiplying the distance between the intersections A and B is calculated as the discharge amount of HC and PM discharged from the vehicle.
[0039]
The traffic pollution reducing device 1 is provided with an area for storing the total amount of NO _x , HC, and Pm emissions between the intersections A and B and an area for storing the number of vehicles for each vehicle type in the memory of the control unit 11. . The traffic pollution abatement apparatus 1 adds the NO _x , HC, and Pm emissions calculated in s21 to s23 to the sum of the NO _x , HC, and Pm emissions stored in the memory of the control unit 11 ( s24). The total amount of NO _x , HC, and Pm emissions stored in this memory and the number of vehicles for each vehicle type are reset at regular time intervals (5 minute intervals), as will be described later. Further, the number of vehicles of the corresponding vehicle type stored in the memory of the control unit 11 is incremented by 1 (s25).
[0040]
Furthermore, the traffic pollution reduction device 1 executes the inflow adjustment process of the vehicle shown in FIG. 7 at a predetermined time interval (here, every 5 minutes). In this vehicle inflow adjustment process, the amount of air pollutants discharged from the vehicle traveling on the road between the intersections A and B becomes larger than a predetermined threshold, and traffic pollution occurs between the intersections A and B. This is a process of suppressing the number of vehicles flowing into the road between the intersections A and B when it is predicted that the vehicle will occur.
[0041]
The traffic pollution abatement apparatus 1 determines whether the total sum of any of NO _x , HC, and PM exceeds a predetermined threshold between intersections A and B in the last 5 minutes (s31). ~ S33). The threshold value is set for each of NO _x , HC, and Pm that are air pollutants. If the traffic pollution reduction device 1 determines that the total amount of emissions does not exceed the threshold value in any of NO _x , HC, and Pm, it instructs the signal control device 2 to switch signals under normal control ( s34). In addition, the guidance display 3 is not particularly instructed to display.
[0042]
On the other hand, in any of NO _x , HC, and Pm, if the sum of the emissions exceeds the threshold value, the vehicle to the road between the intersections A and B with respect to the signal control device 2 with respect to the signal control device 2 Is instructed to switch the signal in the control for limiting the number of inflows (inflow restriction control) (s35). In this inflow restriction control, the signal cycle or split is converted, and the driver is guided to bypass the road between the intersections A and B. The guidance display 3 is instructed to display a message prompting the driver to detour the road between the intersections A and B (s36). In accordance with this instruction, the message shown in FIG.
[0043]
When the traffic pollution reducing apparatus 1 completes the process of s34 or s36, the total amount of NO _x , HC, and Pm emissions stored in the memory of the control unit 11 and the number of vehicles for each vehicle type are reset (s37). ). This process ends.
[0044]
Thus, the traffic pollution reduction apparatus 1 of this embodiment processes a captured image with the two CCD cameras 12a and 12b, and the three-dimensional shape of the vehicle traveling on the road (vehicle width, vehicle length, vehicle height). Therefore, it is possible to accurately detect a vehicle traveling on a road without detecting a road tree on the road surface or a shadow of a vehicle by mistake. It is also possible to improve the accuracy of vehicle type discrimination.
[0045]
In addition, when traffic pollution is predicted to occur on the road between the intersections A and B, the control of the traffic light is switched to the inflow restriction control for restricting the inflow of the vehicle with respect to the upstream signal control device 2. Therefore, it is possible to sufficiently prevent the occurrence of traffic pollution on the road between the intersections A and B.
[0046]
【The invention's effect】
As described above, according to the present invention, since the vehicle traveling on the road is detected using the stereoscopic image generated from the captured image captured by the two CCD cameras, the vehicle detection accuracy can be improved and the vehicle can be improved. The accuracy of vehicle type discrimination can be improved.
[0047]
In addition, since it is possible to accurately estimate the emission amount of air pollutants, it is possible to sufficiently suppress the occurrence of traffic pollution.
[Brief description of the drawings]
FIG. 1 is a diagram showing a traffic pollution reduction system.
FIG. 2 is a block diagram showing a configuration of a traffic pollution reducing apparatus 1 according to an embodiment of the present invention.
FIG. 3 is a diagram illustrating NO _x , HC, and PM emission basic units stored in an emission basic unit storage unit;
FIG. 4 is a flowchart showing a stereoscopic image generation process in the traffic pollution reduction apparatus according to the embodiment of the present invention.
FIG. 5 is a flowchart showing processing relating to vehicle type discrimination and travel speed detection in the traffic pollution abatement apparatus according to the embodiment of the present invention.
FIG. 6 is a flowchart showing an emission amount estimation process in the traffic pollution reduction apparatus according to the embodiment of the present invention.
FIG. 7 is a flowchart showing inflow rate adjustment processing in the traffic pollution reducing apparatus according to the embodiment of the present invention.
FIG. 8 is a diagram illustrating a display example of a message on a display device.
[Explanation of symbols]
1-traffic pollution reduction device 2-signal control device 3-guide display 11-control unit 12-discharge unit storage unit 13-imaging unit 13a, b-CCD camera 14-vehicle shape detection unit 15-vehicle type determination unit 16- Traveling speed detection unit 17-communication unit

Claims (5)

Imaging means for imaging a vehicle traveling on the road with two cameras arranged side by side above the road;
Stereoscopic image generation means for generating a stereoscopic image using two captured images captured by the two cameras of the imaging means;
Vehicle type discriminating means for detecting the 3D shape of a vehicle traveling on a road from the 3D image generated by the 3D image generating unit and discriminating the vehicle type of the vehicle;
A traveling speed detecting means for detecting the traveling speed of the vehicle in which the vehicle type determining means has determined the vehicle type from the stereoscopic image generated by the stereoscopic image generating means or one of the captured images captured by the imaging means;
Emission amount of air pollutants, comprising: a discharge amount estimation means for estimating a discharge amount of air pollutants for a vehicle whose vehicle type is determined by the vehicle type determination means and whose travel speed is detected by the travel speed detection means Estimating device. The apparatus for estimating an emission amount of air pollutants according to claim 1, wherein the two cameras of the imaging means are arranged one above the other. Emission unit storage means for storing a reference value of the amount of air pollutants discharged when traveling a predetermined distance for each vehicle type and for each traveling speed,
The air pollution according to claim 1 or 2, wherein the emission amount estimation means estimates the emission amount of air pollutants using a corresponding vehicle type stored in the emission basic unit storage means and a reference value of traveling speed. Substance emission estimation device. The apparatus for estimating the amount of air pollutant emission according to any one of claims 1 to 3,
With respect to the signal control device that controls the traffic signal installed at the upstream intersection in the traveling direction of the vehicle on the road being imaged by the imaging unit, the air pollutant of each vehicle estimated by the emission estimating unit A traffic pollution reducing device comprising: signal control instruction means for instructing control of a traffic light according to a sum of estimated emission amounts. The apparatus for estimating the amount of air pollutant emission according to any one of claims 1 to 3,
The sum of the estimated emissions of air pollutants for each vehicle estimated by the emission estimation means for the guidance indicator installed on the upstream side of the traveling direction of the vehicle on the road imaged by the imaging means A traffic pollution reducing device, comprising: a display instruction means for instructing display of a message according to

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