JPH04203100A - Detector of abnormality in tunnel - Google Patents

Abstract

PURPOSE:To make it possible to simultaneously watch various kinds of abnormalties in a tunnel by detecting the occurance of a cave-in or fire based on data calculated by a light projecting and receiving means placed to the inside of the tunnel and a calculation means of the distance to an opposite face and reflection light receiving amount. CONSTITUTION:Distance data L read from a distance measuring meter RF and reflection light receiving amount data R are stored in an operating area RAM to compare the data with standard distance data Lo and standard reflection light receiving amount Ro, and when neither the distance nor the reflection light receiving amount is varied, a normal watching mode is continued. After that, as a result of the comparison, when the distance data L is smaller than the standard distance data Lo and when there is no variation in the reflection light receiving amount R, the occurance of a cave-in is indicated to handle ringing of a warning bell, signals, etc., through interface 1/F4. When there is the occurrence of white smokes, black smokes, etc., the same handle is taken, and various kinds of abnormalities are watched simultaneously.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tunnel abnormality detection device for detecting various abnormalities such as cave-ins and fires in tunnels.

1. Purpose of the Invention Although it is common practice to install a fire detector or the like in a tunnel to monitor the occurrence of a fire, the present invention uses a type of light emitting/receiving means for measuring distance, in particular, a range finder. The aim is to comprehensively and meticulously monitor the occurrence of various abnormalities within tunnels, including the occurrence of fires.

[Means for Achieving the Object] In order to achieve this object, the present invention is arranged in a visible part of the tunnel other than the roadway, emits a beam-shaped light beam, and reflects and returns the beam-shaped light beam. a light emitting/receiving means for receiving light; a calculating means for calculating the distance to the opposing surface and the amount of reflected light from the reflected return light of the beam-shaped light ray on the opposing surface; and the distance calculated by the calculating means. Furthermore, a tunnel abnormality detection device is provided, which includes a discriminating means for detecting a cave-in accident or the occurrence of a fire in a tunnel based on the amount of reflected light received.

Preferably, the determining means also determines the nature of smoke when detecting the occurrence of a fire.

[Function] As explained in detail in the examples, the distance measured by the light emitting/receiving means or the beam type distance meter for measuring the distance and the amount of reflected light received (or reflectance) are used to measure the distance. Experiments have shown that if there is an obstacle such as an object or smoke between the opposing surface, the distance and amount of reflected light will vary depending on the nature of the obstacle. I found out as. In the present invention, various abnormal conditions within the tunnel can be determined and monitored by detecting the determined changes.

[Example code] Examples of the present invention will be described below.

As one embodiment of the present invention, as shown in FIG. Board 2
We will explain the system that monitors the occurrence of cave-ins in the ceiling of tunnels as shown in Figure 2, or generation of smoky white lights or black smoke as shown in Figure 3. Note that a mirror, a reflector, a metal plate, or the like may be used as the reflection plate 2, but it may not be used if the opposing surface is a stable reflector, such as a wall.

In principle, the light beam method measures the distance to the opposing surface by reflecting the light emitted from the light projecting section off an object, wall, or reflector on the opposing surface, and receiving the reflected light at the receiving section. A distance meter is used to monitor fires, cave-ins, etc. by detecting smoke and fallen objects between the distance meter and the opposing surface. I will explain about it.

According to experiments, as shown in Figure 4, when distance measurement is performed using a light beam range finder RF such as a laser range finder in an environment where there is flame or smoke at point F, for example, black smoke or smoke is detected. It has been found that the presence of white light and flame causes the following changes in distance measurements and the amount of reflected and received light. ”).

When a laser range finder RF is used as a beam range finder and the distance to the opposite surface is measured by emitting laser light from the range finder RF to the opposite surface, the distance between the range finder RF and the opposite surface is measured. A fire pan was placed at point F, and an experiment was conducted to burn wood chips and oil with the fire pan.

When a white light was generated in the measuring beam by burning a piece of wood in a fire pan, the rangefinder RF showed a distance shorter than the distance to the opposing surface when there was no smoke, and closer to the position of smoke (
(See Figure 5).

On the other hand, when oil was burned in a fire pan and black smoke was generated in the measuring beam, the rangefinder RF was different from the case with a white light.
The distance shown is greater than the opposing surface, ie the reflection surface of the measuring beam in the absence of smoke (infinite distance in the particular experiment) (see Figure 7).

In addition, from this experiment, the amount of reflected light received by the measuring light beam received by the rangefinder, that is, the amount of returned light received, varies depending on the distance to the smoke in the case of white light, but does not decrease.
(see figure), and in the case of black smoke, it was found to approach O (see figure 8).

The results of these experiments are shown in FIGS. 5 to 8.

Figure 5 shows the change in distance (vertical axis) in the case of a white light with respect to the passage of time after the occurrence of the white light (horizontal axis), and Figure 6 shows the reflected light reception in the case of a white light. The change in amount (vertical axis) is also shown with respect to the passage of time (horizontal axis), and Figure 7 shows the change in distance (vertical axis) in the case of black smoke, as well as the passage of time after the generation of the black smoke. (horizontal axis), and FIG. 8 also shows changes in the amount of reflected and received light (vertical axis) in the case of black smoke over time (horizontal axis).

In this way, compared to the distance to the opposing surface, white light indicates a short distance, while black smoke indicates a long distance.In the case of white light, the white light reflects the laser light, and the small amount of reflected laser light This is thought to be due to the fact that the range finder detects the light, and in the case of black smoke, the black smoke absorbs the laser light, making it impossible for the range finder to detect the reflected laser light.

Furthermore, when a laser beam was directed at the flame, the rangefinder showed a different distance from the distance to that point when there was no flame, and the distance fluctuated in a way that was different from when there was smoke.

The experimental results in this case are shown as the time elapsed from the onset of the flame (horizontal axis).
FIG. 9 shows the change in measured distance (vertical axis) relative to the measured distance. In addition, when the flame was close (for example, 15 m), contrary to the example shown in FIG. 9, fluctuations were shown that centered around a distance far from the flame point.

Furthermore, even when the laser beam was irradiated onto the opposing surface so as to pass through the flame, the rangefinder similarly showed a different distance compared to the distance when there was no flame.

The reason why the measured distance changes due to the flame is thought to be because the phase of the laser beam irradiated from the range finder changes due to the flame.

By the way, in order to investigate the effects of sunlight and lighting on the rangefinder, we reflected sunlight and lighting on a mirror and input it into the rangefinder, and we also input the light from lighting and rotating lights directly into the rangefinder. However, no change was observed in the distance to the opposite surface of the rangefinder.

Note that these experiments were conducted by reflecting the light beam from the laser rangefinder onto the wall without using a reflector or reflector on the opposing surface. The same result can be obtained even if the distance from the light section to the reflection plate is measured. Further, the experiment was conducted using a laser beam having a wavelength of about 0.6 to 3 microns.

From the above, by using an optical range finder on buildings, especially on opposing surfaces such as walls, ceilings, or floors inside tunnels, or by installing reflectors etc. at the positions of these opposing surfaces,
Set the state to measure the distance to the opposing surface or reflector, etc., and set the measurement distance and/or the amount of reflected light of the measurement beam (
By determining when a change in reflectance (reflectance) occurs, it is possible to detect smoke and flames due to fire, as well as other abnormalities such as cave-ins, using a method different from conventional scattered light and dimming methods.

Based on the above, when considering the cave-in accident shown in Figure 2 and the smoke generation case shown in Figure 3, the table in Figure 10 is obtained. In Figure 10.

and Ro are the distance and the amount of reflected light received from the rangefinder 1 to the reflector plate 2, respectively, in normal conditions without accidents, and these are the reference distance data L0 and the reference amount of reflected light received R0.
is initially set as . Further, L and R are the measured values of the distance and the amount of reflected light received at each time. In addition, in FIG. 10, it is possible that the amount R of reflected light received becomes larger than the reference amount R6 of reflected light received, which is due to some kind of error such as the headlight of a passing car, and furthermore,
If the measured value of distance does not change but only the amount of reflected light received changes, or if the measured value of distance increases even though the measured value of reflected received light does not change, this is considered to be due to some kind of error. The system will be stopped after displaying the error.

Therefore, according to the table in FIG. By providing this in the monitoring control section of a fire receiver or repeater connected to a fire alarm, it is possible to monitor smoke, flames, cave-in accidents, etc.

Note that the reference distance and/or the reference amount of reflected light received is set in advance by measuring the distance from the range finder to the reflective object, the reflectance of the reflective object, etc., and storing the measured values in a storage device etc. as reference values. By comparing the set reference value with the measured value and monitoring the difference, it is possible to determine whether the difference is due to an accident or abnormality such as smoke, flames, or a cave-in, or whether it is due to the headlights of a passing car, electrical noise, etc. It is also possible to determine whether the alarm is caused by a false alarm, making it possible to prevent the occurrence of an alarm due to a false alarm, and even in the case of smoke, it is possible to know the type or nature of the smoke.

When an accident occurs, it may be difficult to enter the tunnel, but if the characteristics of the smoke generated inside the tunnel can be known from outside the tunnel, it will be extremely advantageous in understanding the situation inside.

Hereinafter, as an embodiment of the present invention, a case will be described in which white lights, black smoke, and a cave-in accident are monitored as abnormalities in a tunnel.

Figure 11 shows that the tunnel is monitored for abnormalities by receiving signals from the laser range finder 1 as shown in Figure 1 or the range finder RF as shown in Figure 4, and detects abnormalities when abnormal lightning occurs. It is a block circuit diagram schematically showing a supervisory control unit MC that notifies a state, and a microprocessor M based on a program stored in a storage area ROM 1 for storing programs.
Through the operation of PtJ, the distance measurement data output from the laser range finder RF is taken in via the interface I, 'F, and the distance measurement data is stored in the storage area R for storing various constants.
By comparing and determining the reference values stored in OM2, we monitor the occurrence of abnormalities such as smoke generation and cave-ins, and if it is determined that an abnormality has occurred, interface I,,'F 2, displays the alarm on a CRT, etc. via the interface I/F 4, and also rings an alarm bell via the interface I/F 4, and sends the alarm status to other locations, such as a fire receiver or fire department, via the interface I y' F s. or transfer information. The supervisory control unit MC is also shown to be provided with a working area RAM associated with the microprocessor MPU, and is further provided with a work area RAM for informing the other location of one's own location when transmitting information to another location. In order to set the self-address etc. as necessary or change the already memorized reference values, the keyboard KY, which allows operation from outside, is the interface I/'F. It is shown connected to the supervisory control unit MC via.

Furthermore, the operation of the range finder RF itself will not be explained in detail since a normal laser range finder can be used.
In this embodiment, the range finder RF includes calculation means for calculating the distance data to the opposing surface and the amount of reflected light received based on the reflected return received light data, and monitors and controls the calculation results by the calculation means. The information shall be output to section MC. Of course, the range finder outputs the data of reflected and received light as it is to the monitoring and control unit, and the monitoring and control unit is provided with the calculation means as described above, and the calculation of the distance and the amount of reflected and received light is performed by the monitoring and control unit MC. It will be easily understood that by receiving the reflected and returned light reception data from the range finder RF, the calculation can be made on the monitoring control section side.

An example of the monitoring mode in the monitoring control unit MC is shown in the table of FIG. 10 and the flowchart of FIG. The reference distance data L is stored in R4 to M.
. and the reference amount of reflected light received R8, and if there is no change in either the distance or the amount of reflected light received ()' in step 104 and Y in step 106), no abnormality has occurred and the state is normal, and normal monitoring is performed. mode (step 10
2) continues.

As a result of the comparison, if the distance data L is the reference distance data L.

(Y in step 112) and the amount of reflected light received R
If there is no change in step 124 (Y), this indicates that a cave-in accident has occurred (Step 1126), an alarm bell is sounded via the interface I/F 4, and an alert for the cave-in accident is sounded via the interface I/F 5. Processing such as notification is performed. In other words, if the laser beam emitted from the range finder RF hits an object outside the smoke volume, it will be totally reflected back and received by the range finder RF itself, so the amount of reflected light received will change to R. If there is no and the distance is short,
This is assumed to be a rockfall accident.

Further, if the distance data L is - smaller than the reference distance data L0 ()' in step 112), and the amount of reflected light received R becomes smaller than the reference amount R8 of reflected light received (Y in step 128),
), as can be seen from FIG. 10, this indicates the generation of white smoke, and at 6° C., processing such as ringing an alarm bell and notifying the occurrence of a fire due to white smoke is performed (step 130).

Furthermore, distance data L is reference distance data L. (N in step 112), and if the amount of reflected light received R is smaller than the reference amount R6 of reflected light received (') in step 114, this indicates the generation of black smoke, and the alarm bell rings and black smoke is also detected. Processing such as notification of the occurrence of a fire is performed (step 116).

If any other situation occurs, it is notified that an error has occurred (steps 108, 120.1B2).

In Fig. 11, we explained the case where data from only one rangefinder RF is taken in, but as shown in Fig. 13, multiple sets of rangefinders and reflectors are arranged in tandem inside the tunnel, and the meandering The entire tunnel can be monitored. In this case, one monitoring control unit MC may collect data from the plurality of groups and perform monitoring, or a monitoring control unit may be provided for each group.

Further, although FIG. 1 shows the case where the light emitting/receiving means 1, that is, the range finder RF is provided on the ceiling surface, it can also be provided within the roadway section 3 instead of on the ceiling surface. In order to prevent collisions from passing vehicles, it is preferable that the range finder RF, that is, the light emitting/receiving means 1, be provided within the protective cover or within the protective cover, as shown in FIG.

Further, in the above embodiment, the reference distance and the reference amount of reflected light received are stored in advance in the storage area ROM1, but the distance data and the amount of reflected light received are periodically read by the range finder RF. It is also possible to store a plurality of pieces of data in chronological order and set the reference data for each piece of data by taking the average of the plurality of pieces of data stored. In this way, even if the amount of reflected light received during normal operation decreases over time due to dirt on the rangefinder, reflector, etc., the reference amount of reflected light received will change accordingly, allowing stable monitoring. becomes possible.

[Effects of the Invention] As described above, the tunnel abnormality detection device of the present invention has the effect of being able to simultaneously monitor various abnormalities such as fire and cave-in accidents. In addition, in the case of a fire, the type of smoke can be detected, making it possible to easily grasp the situation from the outside, even inside tunnels where it is difficult to enter in the event of an accident. There is also.

[Brief explanation of the drawing]

Fig. 1 is a schematic side view showing a state in which a rangefinder is placed in a tunnel, Figs. 2 and 3 are schematic side views showing various abnormal conditions that may occur in a tunnel, and Fig. 4 ~Figure 9 is a diagram for explaining the action used in the present invention,
Figure 4 is a diagram showing the space in which the distance measurement experiment using the range finder RF was conducted, Figure 5 is a diagram showing the change in distance to white smoke obtained as a result of the experiment, and Figure 6 is the result of the same experiment. Figure 7 is a diagram showing the amount of reflected light received for white smoke obtained as a result of the experiment. Figure 8 is a diagram showing the distance change for black smoke obtained as a result of the experiment. Figure 8 is the amount of reflected light received as a result of the experiment. Figure 9 is a diagram showing the amount of received light, and Figure 9 is a diagram showing changes in distance to the flame obtained as a result of the experiment.
Figures showing tables of distance and amount of reflected light received vs. abnormality results used in this example, created to determine various abnormalities based on the data obtained as a result of the experiments shown in Figures 9 to 9. FIG. 11 is a block circuit diagram showing an embodiment of the tunnel abnormality detection device according to the present invention, and FIG.
FIG. 13 is a flowchart showing an example of the determination operation performed by the abnormality detection device of the present invention; FIG.
The figure is a diagram schematically showing a protective cover or a protective cover that protects the light emitting/receiving means, that is, the range finder. In the figure, 1 and RF are laser rangefinders (light emitting and receiving means), MC is a monitoring control unit, MPU is a microcomputer, ROM1 is a storage area for storing programs, etc., R, A
M2 is a storage area for storing reference data. Patent Applicant: Nomi Disaster Prevention Co., Ltd. Agent: Teru Sowado/-3 Go to Figure 2 3 Figure 3 ＼ 11111221111 Figure 5 Time Figure 6 Schedule Interval Figure 7 Figure 8 Time Time Figure 10 Figure 13 Figure 11 7,6

Claims (2)

[Claims] (1) A light emitting/receiving means that is disposed in a visible part of the tunnel other than the roadway and emits a beam-shaped light beam and receives the reflected return light of the beam-shaped light beam, and the beam-shaped light beam is opposed to Calculation means for calculating the distance to the opposing surface and the amount of reflected light received from the light reflected and returned by the surface, and detecting the occurrence of a cave-in accident or a fire in a tunnel from the distance and the amount of reflected light received calculated by the calculation means. A tunnel abnormality detection device comprising: (2) The tunnel abnormality detection device according to claim 1, wherein the determining means also determines the nature of smoke when detecting the occurrence of a fire.