JPH1090053A - Exhaust gas/smoke discriminator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a generation of exhaust gas and smoke in a tunnel or an indoor parking lot and discriminate whether it is exhaust gas or smoke. SOLUTION: A sight distance mark 12 having a white portion 12W and a black portion 12B is provided in a tunnel 10, and this sight distance mark 12 is photographed by an imaging device 14. When a difference in brightnesses between the white portion 12W and black portion 12B is decreased, it is deemed that a reduction in sight distance in the tunnel 10 is generated due to exhaust gas 30 and smokes 32, 34. The reduction in sight distance due to the exhaust gas 30 is slowly made progress, and on the contrary, the reduction in sight distance due to the smokes 32, 34 is abruptly made progress. A cause of the reduction in sight distance is specified by using this. When the smoke 34 along with a flame is a cause of the reduction in sight distance, paying attention to a fact that flittering easily appears as compared with a case where the smoke 32 without a flame is a cause of the reduction in sight distance, it is discriminated whether or not the smake is along with a flame.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ventilation control device used in an environment such as a tunnel and an indoor parking lot, and particularly to an exhaust gas / smoke discriminating device.

[0002]

2. Description of the Related Art Since the environment such as a tunnel and an indoor parking lot is spatially closed or semi-closed, when the exhaust gas from the vehicle is trapped or when smoke is generated due to an accident or fire, etc. It is desirable to perform ventilation by such means. For that purpose, a means for detecting that exhaust gas or smoke is significantly generated in the environment is required.

As such a means, first, a chemical sensor for detecting the presence or absence of a specific gas component or a specific dust component can be considered. For example, a plurality of chemical sensors each reacting to a different component are provided in parallel, and when a problem component is detected by any one of the chemical sensors, it is determined that exhaust gas or smoke has been generated. Make the device work. However, it is generally difficult to reliably detect exhaust gas and smoke containing various components by such means. In addition, there are two types of smoke that are not always accompanied by flames, such as a vehicle accident, and those that often involve flames, such as a vehicle fire. However, in order to know whether or not a flame is involved, an infrared sensor is further required, which complicates the device configuration.
Furthermore, since the chemical sensor only detects a specific component, it is generally not suitable for quantitatively grasping the amount (concentration) of exhaust gas and smoke containing various components.

Second, as the above means, an image processing apparatus for extracting the contour and color of exhaust gas or smoke from an image captured by a camera can be considered. However, with such means, it is difficult to distinguish between exhaust gas and smoke and whether smoke involves flame. In order to make these determinations, an infrared sensor is required, which complicates the device configuration.
Further, in the extraction of the contour and the color, it is possible to know the spread of exhaust gas and smoke, but not the concentration.

[0005]

SUMMARY OF THE INVENTION One of the objects of the present invention is to detect, store and process physical quantities relating to the transmission of light in a time series, and it is remarkable whether exhaust gas or smoke and whether smoke accompanies a flame. To determine the concentration of smoke and exhaust gas and the color of smoke and exhaust gas, and to perform outline and color extraction processing without using chemical sensors or infrared sensors Without, to be realized. One of the objects of the present invention is to make it possible to execute an appropriate measure such as ventilation / ventilation stop according to the result of this determination.

The present invention is used in environments where vehicles are present and are spatially closed or semi-closed, such as tunnels and indoor parking lots. In the present invention, first, physical quantities related to light transmission are sequentially detected and stored in a time-series manner. Next, in the present invention, a decrease in visibility in this environment is detected from the detected value of the physical quantity. Then, based on the time series of the detected values of the physical quantities, at least when the visibility reduction is detected, it is determined whether the cause of the visibility reduction is the generation of smoke in the environment or the remarkable emission of exhaust gas from the vehicle. Is done. Therefore, in the present invention, it is possible to determine whether it is exhaust gas or smoke without using a chemical sensor, an infrared sensor, or the like, and without executing contour or color extraction processing. As an example of the physical quantity, the luminance of a light beam received from a visual target having a contrast (for example, black and white) and the difference between the luminance of the black part and the luminance of the white part can be exemplified. In addition, the visibility reduction is, for example, by detecting a decrease in the difference between the luminance of the black part and the luminance of the white part,
Can be detected.

Further, when it is determined that the cause of the reduction in visibility is the generation of smoke in the above environment, the smoke is generated based on the time series of the detected values of the physical quantities without using an infrared sensor or the like. It can also be determined whether or not there is a flame. For example, using the fact that when a flame accompanies the smoke, the flame appears and disappears, and as a result, the luminance of the light beam from the diopter or the difference between the luminance of the black part and the luminance of the white part flickers,
It can be determined whether or not the smoke is accompanied by a flame.

Further, it is possible to determine the density or color of the smoke based on the time series of the detected values of the physical quantities, and thus without using a chemical sensor and without executing a color extraction process. For example, the smoke density can be known from the difference in luminance between the black and white portions of the line of sight target. Further, the color of smoke can be determined by comparing the temporal change of the luminance of the black part of the visual range target with the temporal change of the luminance of the white part.

[0009] When the visibility reduction is detected, it is possible to operate / stop the ventilation device in the environment according to the cause of the visibility reduction. For example, if ventilation is performed when the cause of visibility reduction is exhaust gas, and execution is stopped when it is smoke, smoke generated in a fire or the like is agitated by a ventilation device and spreads in a tunnel or the like. , Can be prevented.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a configuration of a system according to an embodiment of the present invention. The system shown in FIG.
An imaging device (for example, an ITV camera) 14 for photographing the visual range target 12 provided inside the camera is provided. Line of sight 12
Has a white portion 12W and a black portion 12B. Therefore, when the visibility target 12 is photographed by the photographing device 14 in a state where no exhaust gas or smoke is present inside the tunnel 10, an image with clear contrast is obtained. . Since it is sufficient that the contrast is clear, it is not always necessary to use a diopter having both black and white portions when practicing the present invention.

An image obtained by the photographing device 14 is input to an image processing device 16. The image processing device 16 includes an A / D converter 18 for A / D converting an analog image signal output from the photographing device 14 and an A / D for digital conversion.
An image memory 20 for storing digital image data obtained by the converter 18, an index extraction unit 22 for extracting an index for a discrimination process described later from the image data on the image memory 20, and extracting the extracted indexes in time series It has a time-series memory 24 for storing and a discriminating unit 26 for executing a discrimination process described later based on an index on the time-series memory 24. What is executed by the determination unit 26 is, for example, the tunnel 1
Determination of whether or not the visibility is reduced within 0;
It is determined whether the cause of the decrease in visibility is the exhaust gas 30 from the vehicle 28, the smoke 32 without flame generated in an accident or the like, or the smoke 34 with flame generated in a fire or the like. The detection of the light transmittance (concentration) of the exhaust gas and smoke existing in the tunnel 10 and the detection of the color of the exhaust gas and smoke are performed. When the occurrence of smoke is detected by the determination unit 26, an alarm / notification device 36 issues an alarm to a system administrator or a vehicle. A communication line is used for alerting the system administrator, and sound, light, wireless communication, and the like are used for alerting the vehicle. In addition, when it is determined by the determination unit 26 that the exhaust gas 30 has become remarkable in the tunnel 10, the ventilation control device 38 operates the ventilation device 40 such as a fan to stir the exhaust gas in the tunnel 10. Conversely, when the generation of smoke is detected, the ventilation control device 38 controls the ventilation device 4 to prevent the smoke from being stirred and filled in the tunnel 10.
0 operation is stopped.

FIG. 2 shows an outline of an operation flow of the index extracting section 22 in this embodiment. As shown in the figure, first, the index extracting unit 22 first extracts the white portion 12W of the visibility target 12 from the image data stored in the image memory 20.
And the image of each of the black portions 12B is cut out (100), and their spatial average luminances L _W and L _B are calculated (102).
Index extraction unit 22 further calculates the difference D between the spatial average luminance L _B of the spatial average luminance L _W and the black portion 12B of the white parts 12W (104). Operation of the index extraction unit 22, the thus obtained L _W, in terms of writing the L _B and D in chronological memory 24 (106), the flow returns to step 100. Therefore, by the procedure shown in FIG. 2 is repeated, the time on the series memory 24, L _W, so that the time series of L _B and D are stored. The discrimination unit 26 includes a time-series memory 24
The procedure shown in FIG. 3 is executed based on the data thus stored, that is, the above-mentioned index.

As shown in FIG. 3, the determining unit 26 first
L _W and L _{B for the} latest N samples from the time series memory 24
And D are read (200), and the read N samples are divided into m samples and averaged over time (202: L
PF processing). The time average thus obtained,
S _W, S _B, based on S _D, determination unit 26, L _W, L _B
And D are detected (204). The determination unit 26 appropriately executes an alarm and ventilation execution / stop processing based on the detection result.

For example, when the exhaust gas 30, the smoke 32, and the like 34 hardly exist in the tunnel 10, the luminance L _W of the white portion 12W of the visibility target 12 and the LB of the black portion 12B
, A relatively large difference occurs between the two, so that D on the time-series memory 24, that is, S _D obtained in step 202, becomes a relatively large value. Step 20
When it can be considered that such a condition is satisfied from the result of the detection in Step 4 (206), the determination unit 26 gives a command to the ventilation control device 38 so that the exhaust gas 30 does not stay in the tunnel 10. The ventilation in the tunnel 10 by the ventilation device 40 is executed (208). The determination unit 26
Subsequently, the operation after step 200 is repeatedly executed.

When the visibility in the tunnel 10 is reduced due to the exhaust gas 30, the smoke 32, and the like, the brightness L _W of the white portion 12W of the visibility target 12 and the brightness L _B of the black portion 12B are reduced. Is less likely to produce a clear difference. For example, when the exhaust gas 30 and smoke 32 and 34 very large quantities occur, between the L _W and L _B, not occur significant difference. Under these circumstances, D and therefore S _D will be small, and the difference between L _W and S _B will also be small. The determination unit 26
Therefore, from the result of the detection in step 204,
When D can be considered to be relatively small (206), the processing shifts to a determination process regarding the cause of the visibility reduction.

Here, the detected decrease in visibility is caused by exhaust gas 30
The visibility will progress relatively slowly, and conversely, if the smoke 32, 34 associated with an accident, fire, etc. is the cause of the visibility reduction, the visibility will progress rapidly. Will. Therefore, the determination unit 26
Is, from the result of the detection in step 204,
When L _W , L _B or D indicates a rapid or short-term change (210), it is determined that the cause of the visibility reduction is the smoke 32 or 34, and a command is given to the ventilation control device 38, The ventilation by the ventilation device 40 is stopped (212).
Thereby, it is possible to prevent the smokes 32 and 34 from agitating and spreading in the tunnel 10. Conversely, L _W , L _B
Or, when the basic change of D is relatively slow (21
0), the determination unit 26 regards the cause of the visibility reduction as the exhaust gas 30, and gives a command to the ventilation control device 38 to cause the ventilation device 40 to perform ventilation (208). However, in this case, ventilation is better than when visibility is good.
Strong ventilation is preferred. After the execution of step 208 or 212, the operation of step 200 and thereafter is executed.

The discriminating section 26 has a function of discriminating whether the cause of the reduction in visibility is the smoke 32 or the smoke 34. That is, when smoke 34 is reduced visibility as a result of flame glimpses the smoke 34, S _W,
In S _B and S _D , changes, that is, flickers appear in a shorter time than in the case where the smoke 32 causes a decrease in visibility. The determination unit 26 detects the presence or absence of the flicker based on the result of the detection in step 204 (214). When the flicker is detected, the warning / notification device that the cause of the visibility deterioration is the smoke 34 accompanied by flames. An alarm is executed via, at step 216. Conversely, when the smoke 32 without flicker can be considered to be the cause of the decrease in visibility, an alarm process to that effect is executed via the alarm / notification device 36 (218).

As described above, according to the present embodiment, it is not necessary to use a chemical sensor or an infrared sensor, and it is not necessary to execute the contour / color extraction processing of the exhaust gas 30 and the smoke 32, 34. Therefore, the device configuration and processing contents are simplified. In addition, since the ventilation device 40 is operated or stopped according to the cause of the reduction in visibility, the exhaust gas 30 and the smoke 32 and 34 are less likely to be trapped or agitated in the tunnel 10.

Further, the present embodiment can be subjected to various modifications. For example, as shown in FIG. 4, on the basis of the S _W and S _B obtained in step 202, calculates the transmittance of light τ in the tunnel 10 (220), via the alarm and notification system 36, the administrator Or to the vehicle 28 (222). The transmittance τ is, for example, the following equation

[Number 1] _{τ = | S W -S B |} / | can be calculated on basis of | S _WS -S _{BS. Where} S _WS and S _BS
Is S _W and S _B in a state that does not exist the exhaust gas 30, smoke 32, 34, etc. in the tunnel 10, is set in advance. Such a modification allows the system manager and the vehicle 28 to know the environment in the tunnel 10 in more detail.

Alternatively, as shown in FIG.
08 or 212, the exhaust gas 30, the smoke 32,
The processing for determining the color of No. 4 may be executed. That is, from the result of detection in step 204, _SW
When both S and _B are increasing (224), it can be considered that the increase is caused by the white exhaust gas 30 or the white smoke 32, 34. The white color is notified to the manager and the vehicle 28 (226). Conversely, when the S _W and S _B is reduced together notifies a (228), black (230). Otherwise, it is sufficient to notify that the color cannot be specified (232). As described above, in the present embodiment, the color of the exhaust gas 30 and the colors of the smoke 32 and 34 can be known without obtaining color information by the photographing device 14.

In the above embodiment, the tunnel 10
However, the vehicle 28 may travel, for example, as in an indoor parking lot, and the exhaust gas 30 and the smoke 3
The present invention can also be applied to an environment where there is a risk of filling and agitation of 2, 34. In addition, it is not necessary to limit the present invention to the details of the functions of the image processing apparatus 16.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a system according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a procedure of an operation of an index extracting unit according to the embodiment.

FIG. 3 is a flowchart illustrating a procedure of an operation of a determination unit according to the embodiment.

FIG. 4 is a flowchart showing a modification of FIG.

FIG. 5 is a flowchart showing another modification of FIG. 3;

[Explanation of symbols]

10 tunnel, 12 visibility mark, 12W white part, 12
B black part, 14 photographing device, 16 image processing device, 2
0 image memory, 22 index extraction unit, 24 time series memory, 26 discrimination unit, 30 exhaust gas, 32, 34 smoke, 3
6. Alarm / notification device, 38 ventilation control device, 40 ventilation device.

Claims (4)

[Claims] 1. A means for sequentially detecting a physical quantity related to light transmission and storing it in a time series in an environment such as a tunnel or an indoor parking lot where a vehicle exists and is spatially closed or partially closed, Means for detecting a decrease in visibility from the detected value of the physical quantity, and at least, when a decrease in visibility is detected, based on a time series of the detected values of the physical quantity, whether the cause of the reduced visibility is generation of smoke in the environment. Or means for determining whether or not the exhaust gas from the vehicle has become noticeable. 2. The exhaust gas / smoke discriminating apparatus according to claim 1, wherein when it is determined that the cause of the visibility reduction is the generation of smoke in the environment, the determination is performed based on the time series of the detected values of the physical quantity. An exhaust gas / smoke discriminating apparatus comprising means for discriminating whether or not smoke is accompanied by a flame. 3. An exhaust gas / smoke discriminating apparatus according to claim 1, further comprising means for discriminating a concentration or a color of the exhaust gas or smoke based on a time series of the detected values of the physical quantity. / Smoke identification device. 4. An exhaust gas / smoke discriminating apparatus according to claim 1, further comprising: means for operating / stopping a ventilator in the environment according to a cause of the visibility reduction when the visibility reduction is detected. A ventilation control device comprising: