Fire monitoring system

Abstract

Reduce false fire alarms caused by sunlight. [Solution] Fire detectors 104 to 107 include a light receiving means that receives infrared light of a first wavelength and outputs a first signal corresponding to the amount of light received, a determination means that determines that there is a fire when the value of the first signal satisfies predetermined conditions, and a vehicle passage detection means that outputs a second signal according to the presence or absence of a passing vehicle 103. Even if the value of the first signal satisfies predetermined conditions, if the first signal and the second signal are synchronized, a fire is not determined.

Description

Technical Field

[0001] The present invention relates to a fire monitoring system.

Background Art

[0002] Conventionally, a flame detection system for detecting a fire occurring in a tunnel has been known. For example, Patent Document 1 describes disaster prevention monitoring equipment using a light beam type fire detector. In this disaster prevention monitoring equipment, a plurality of fire detectors for monitoring a fire in the tunnel are installed at regular intervals on the wall surface and ceiling in the tunnel, and each fire detector monitors both side areas in the longitudinal direction of the tunnel, at least the area up to the adjacent fire detectors. That is, since the fire detector monitors a fire in the longitudinal direction of the tunnel, detection elements for monitoring fires on the left side and the right side are provided separately for monitoring. Further, the fire detector receives light and radiant heat from the flame through a light-transmitting window by a detection element to detect a fire, and sends a fire signal to a disaster prevention receiving panel.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The above-described fire detector detects a fire by receiving light. Therefore, a fire detector installed near the entrance of the tunnel may erroneously detect a fire by receiving sunlight. The present invention has been made in view of such circumstances, and an object thereof is to reduce non-fire reports caused by sunlight.

Means for Solving the Problems

[0005] To solve the above problems, the fire monitoring system according to the present invention comprises: a first light receiving means that receives infrared light of a first wavelength and outputs a first signal corresponding to the amount of light received; a determination means that determines that there is a fire when the value of the first signal satisfies predetermined conditions; and a vehicle passage detection means that outputs a second signal according to the presence or absence of a passing vehicle. The determination means does not determine that there is a fire even if the value of the first signal satisfies the predetermined conditions, if the first signal and the second signal are synchronized. [Effects of the Invention]

[0006] According to the present invention, false fire alarms caused by sunlight can be reduced. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 illustrates an example of how reflected sunlight can generate a false fire alarm. [Figure 2] Figure 2 shows an example of the waveform of a weak radio wave received from the driver's smartphone and an example of the signal waveform of reflected light received by the solar cell of the fire detector. [Figure 3] Figure 3 shows an example of the flame detection system 300. [Figure 4] Figure 4 shows an example configuration of the fire detector 301. [Figure 5] Figure 5 shows an example configuration of the disaster prevention receiving panel 302. [Figure 6] Figure 6 is a flowchart showing an example of the fire detection process 600. [Modes for carrying out the invention]

[0008] 1. Examples An embodiment of the present invention will be described with reference to the drawings. 1-1. Overview First, we will describe the overview of the examples. Traditionally, tunnel fire detectors have been equipped with two sensors, a solar cell and a pyroelectric element, on each side, referred to as the "right eye" and the "left eye." These fire detectors are prone to misinterpreting sunlight as a fire. Therefore, fire detectors near tunnel entrances are fitted with a light-blocking plate on the eye facing the entrance. However, reflected sunlight from the morning or evening (reflections from the back of trucks or walls) can cause false alarms in the eye without a light-blocking plate, or in the eye facing the entrance where a light-blocking plate is not installed.

[0009] Fire detectors use spectral characteristics and flicker frequency to determine if a fire is occurring. The color temperature of sunlight, such as that of the rising or setting sun, is close to that of a gasoline fire, making it difficult to distinguish between the two based on spectral characteristics alone. Therefore, in tunnels with heavy traffic, the flicker caused by the reflection of sunlight off the walls can also meet the fire detection criteria, as the flicker frequency can also be a factor.

[0010] Figure 1 illustrates an example of how reflected sunlight can generate a false fire alarm. In Figure 1, reference numeral 101 indicates the sun, reference numeral 102 indicates an automatic alarm area, reference numeral 103 indicates a passing vehicle, reference numerals 104-107 indicate fire detectors, and reference numeral 108 indicates incident sunlight.

[0011] Of the symbols 104 to 107, symbol 104 indicates a non-operating fire detector, and symbol 105 indicates an operating fire detector. Symbol 106 indicates a non-operating fire detector with a light-shielding plate installed on the entrance side. Symbol 107 indicates an operating fire detector with a light-shielding plate installed on the entrance side.

[0012] Figure 1(a) shows how incident sunlight 108 is reflected off the back of a passing vehicle (e.g., a truck) 103 and enters the eye of the fire detector 107 on the side without the light shield. If multiple such incidents occur consecutively, it can cause flickering, which may satisfy the fire detection criteria.

[0013] On the other hand, FIG. 1(b) shows a state where the incident light 108 of the sun is reflected by the tunnel wall and enters the fire detector 105 without a light shielding plate. When this incident light is intermittently blocked by the passing vehicle 103, it flickers, and there may be a case where the fire determination condition is satisfied.

[0014] In view of such circumstances, in this embodiment, a mechanism for reducing false alarms caused by sunlight is provided. Hereinafter, the mechanism will be briefly described.

[0015] Generally, a vehicle driver has a smartphone. A weak radio wave is constantly transmitted from this smartphone. The fire detector is made to recognize this weak radio wave, and it is determined whether the frequency of receiving this weak radio wave synchronizes with the frequency of the solar cell of the fire detector. Thereby, it is possible to determine whether it is flickering due to the reflected light of sunlight or flickering of the fire source.

[0016] FIG. 2 is a diagram showing an example of the waveform of the weak radio wave received from the driver's smartphone and an example of the signal waveform of the reflected light received by the solar cell of the fire detector. The upper part of FIG. 2 shows the waveform of the weak radio wave of the smartphone. Each of the plurality of convex portions constituting this waveform indicates the weak radio wave received from a different smartphone. On the other hand, the lower part of FIG. 2 shows the signal waveform of the reflected light. This FIG. 2 shows that the weak radio wave of the smartphone and the signal waveform of the reflected light are synchronized.

[0017] When both are synchronized in this way, the fire detector is made to determine that it is flickering due to the reflected light of sunlight and is not determined as a fire. Thereby, false alarms are reduced.

[0018] In addition, in FIG. 2, the rising timings of the signals in the upper and lower parts are substantially the same, but the example in this figure is merely an example of "synchronization" in this specification. The "synchronization" in this specification shall include not only the case where the rising timings of the signals completely match but also the case where there is a slight time lag in the rising timings of the signals.

[0019] For example, when receiving sunlight reflected on the back of the passing vehicle 103 as in the example shown in Fig. 1(a), the fire detector 107 will receive the reflected light after receiving the radio wave transmitted from the passing vehicle 103. In this case, although there is a slight time lag between the reception of the radio wave and the reception of the reflected light, such a time lag is also included in the "synchronization" in this specification.

[0020] 1-2. Configuration Fig. 3 shows an example of the flame detection system 300 according to this embodiment. This flame detection system 300 is installed in the tunnel 303. This tunnel 303 is divided into a plurality of sections from A to Z.

[0021] The flame detection system 300 includes a plurality of fire detectors 301 and a disaster prevention receiving panel 302.

[0022] The fire detectors 301 are installed at equal intervals along the running direction of the vehicle on the inner wall of the tunnel 303. Each fire detector 301 is a binocular flame detector, and includes a right-side flame detection unit for monitoring the section on the right side as seen from the device and a left-side flame detection unit for monitoring the left-side section. Each fire detector 301 is installed at the boundary of the section and monitors two sections simultaneously. Therefore, one section is redundantly monitored by two fire detectors 301. The arrows shown in Fig. 3 indicate the monitoring directions of the fire detectors 301.

[0023] Each fire detector 301 is electrically connected to the disaster prevention receiving panel 302, and when detecting a flame, transmits a flame detection signal to the disaster prevention receiving panel 302. Each fire detector 301 is an example of a fire monitoring system.

[0024] When receiving a flame detection signal from the fire detector 301, the disaster prevention receiving panel 302 activates a fire extinguishing pump (not shown) and controls a water spray facility (not shown).

[0025] 1-1-1. Fire Detector 301 Next, a detailed description will be given with reference to the fire detector 301. Fig. 4 shows a configuration example of the fire detector 301. The fire detector 301 includes a main memory device 401 such as RAM, an auxiliary storage device 402 such as an HDD, a processor 403 such as a CPU, an input / output interface 404, and a communication interface 405 such as a network card.

[0026] The fire detector 301 also includes long-wavelength side-view sensors 406R and 406L, and short-wavelength side-view sensors 407R and 407L. These light sensors output signals corresponding to the intensity of light emitted by the flame. Each of these light sensors is connected to the input / output interface 404 via an amplifier 408.

[0027] The long-wavelength side-side light sensors 406R and 406L are optical sensors that respond with high sensitivity to the long-wavelength band emitted by a flame (heat source). These optical sensors receive infrared light at a second wavelength longer than a first wavelength and output a signal corresponding to the amount of light received. These optical sensors are, for example, pyroelectric elements. In the following description, the long-wavelength side-side light sensors 406R and 406L will be collectively referred to as "long-wavelength side-side light sensor 406".

[0028] The short-wavelength side-view sensors 407R and 407L are optical sensors that respond with high sensitivity to the short-wavelength range emitted by a flame (heat source). These optical sensors receive infrared light of the first wavelength mentioned above and output a signal corresponding to the amount of light received. These optical sensors are, for example, photodiodes and solar cells. In the following description, the short-wavelength side-view sensors 407R and 407L will be collectively referred to as "short-wavelength side-view sensor 407".

[0029] The long-wavelength side-light sensor 406R and the short-wavelength side-light sensor 407R are sensors for detecting flames occurring in the compartment to the right of the fire detector 301. In contrast, the long-wavelength side-light sensor 406L and the short-wavelength side-light sensor 407L are sensors for detecting flames occurring in the compartment to the left of the fire detector 301.

[0030] Amplifier 408 amplifies the signal generated by the light sensor in response to light.

[0031] The wireless receiving circuit 409 is a circuit for receiving radio waves from a device carried by a passenger in a passing vehicle (for example, a smartphone, mobile phone, tablet, or laptop). This circuit outputs a signal corresponding to the strength of the received radio waves.

[0032] The main memory 401 stores various programs. These programs are distributable via non-temporary storage media or networks such as the Internet. Furthermore, various functions are realized when the processor 403 executes these programs. These functions include the signal recording units 411R and 411L, the fire detection units 412R and 412L, the fire alarm unit 413, and the signal recording unit 414. Each function will be described below.

[0033] The signal recording unit 411R periodically acquires the signals output from the long-wavelength side-view sensor 406R and the signals output from the short-wavelength side-view sensor 407R. The signal recording unit 411R then records the amplitude values ​​of the acquired signals in the auxiliary storage device 402, corresponding them to the current time.

[0034] The signal recording unit 411L periodically acquires the signals output from the long-wavelength side-view sensor 406L and the signals output from the short-wavelength side-view sensor 407L. The signal recording unit 411L then records the amplitude values ​​of the acquired signals in the auxiliary storage device 402, corresponding them to the current time.

[0035] The signal recording unit 414 periodically acquires the signal output from the wireless receiving circuit 409. The signal recording unit 414 then records the amplitude value of the acquired signal in the auxiliary storage device 402, corresponding to the current time.

[0036] The fire detection unit 412R determines a fire when the signal value of the short-wavelength side-light sensor 407R meets predetermined conditions. More specifically, it determines a fire when the signal value of the long-wavelength side-light sensor 406R and the signal value of the short-wavelength side-light sensor 407R meet predetermined conditions. However, even in such cases, the fire detection unit 412R does not determine a fire if the signal of the short-wavelength side-light sensor 407R and the signal of the wireless receiving circuit 409 are synchronized. Note that the term "signal synchronization" here includes not only cases where the rising edges of the signals perfectly match, but also cases where there is a slight time lag in the rising edges of the signals. The following describes in detail the process of the fire detection unit 412R.

[0037] The fire detection unit 412R sequentially reads out sets of amplitude values ​​recorded by the signal recording unit 411R and performs a fire detection. At that time, the fire detection unit 412R determines whether the amplitude values ​​of the signals output from the long-wavelength side-light sensor 406R and the amplitude values ​​of the signals output from the short-wavelength side-light sensor 407R meet predetermined conditions. An example of the predetermined conditions is shown below.

[0038] (Condition 1) The amplitude value of the signal output from the long-wavelength side-view sensor 406 is greater than or equal to threshold T1. (Condition 2) The amplitude value of the signal output from the short-wavelength side-view sensor 407 is greater than or equal to threshold T2. (Condition 3) The ratio of the amplitude value of the signal output from the long-wavelength side light sensor 406 to the amplitude value of the signal output from the short-wavelength side light sensor 407 is greater than or equal to threshold T3 and less than or equal to threshold T4 (however, T3 <T4)である。 These conditions are merely examples and may be modified as needed.

[0039] If all of the above conditions 1 to 3 are met a predetermined number of times or more within a predetermined period of time in the past (in this embodiment, this is 10 seconds as an example), the fire detection unit 412R performs the following further processing.

[0040] In other words, the fire detection unit 412R reads the amplitude values ​​of the short-wavelength side-view sensor 407R for the past 10 seconds, which have been recorded by the signal recording unit 411R. The fire detection unit 412R then counts the number of times the read-out amplitude value is equal to or greater than a first threshold.

[0041] Next, the fire detection unit 412R reads the amplitude values ​​of the wireless receiving circuit 409 for the past 10 seconds, which were recorded by the signal recording unit 414. The fire detection unit 412R then counts the number of times the read amplitude value exceeds the second threshold.

[0042] The fire detection unit 412R then takes the difference between the two counts and determines whether the absolute value of that difference is less than or equal to the third threshold. If the absolute value of the difference is less than or equal to the third threshold, the fire detection unit 412R determines that the signal from the short-wavelength side-light sensor 407R and the signal from the wireless receiving circuit 409 are synchronized, and stores the flame non-detection data in the auxiliary storage device 402 in association with the current time. On the other hand, if the absolute value of the difference is not less than or equal to the third threshold, the fire detection unit 412R determines that the signal from the short-wavelength side-light sensor 407R and the signal from the wireless receiving circuit 409 are not synchronized, and stores the flame detection data in the auxiliary storage device 402 in association with the current time.

[0043] Furthermore, the flame detection data and flame non-detection data are associated with information identifying the detection direction as "right" and stored in the auxiliary storage device 402.

[0044] Next, I will explain the fire detection unit 412L. The fire detection unit 412L determines a fire when the signal value of the short-wavelength side-light sensor 407L meets predetermined conditions. More specifically, it determines a fire when the signal value of the long-wavelength side-light sensor 406L and the signal value of the short-wavelength side-light sensor 407L meet predetermined conditions. However, even in such cases, the fire detection unit 412L does not determine a fire if the signal of the short-wavelength side-light sensor 407L and the signal of the wireless receiving circuit 409 are synchronized. Note that the term "signal synchronization" here includes not only cases where the rising edges of the signals perfectly match, but also cases where there is a slight time lag in the rising edges of the signals. The following details the process performed by the fire detection unit 412L.

[0045] The fire detection unit 412L sequentially reads out sets of amplitude values ​​recorded by the signal recording unit 411L and performs a fire detection. At that time, the fire detection unit 412L determines whether the amplitude values ​​of the signal output from the long-wavelength side-light sensor 406L and the amplitude values ​​of the signal output from the short-wavelength side-light sensor 407L satisfy predetermined conditions. The predetermined conditions are the same as those for the fire detection unit 412R.

[0046] If all of the above conditions 1 to 3 are met a predetermined number of times or more within a predetermined period of time in the past (in this embodiment, this is 10 seconds as an example), the fire detection unit 412L performs the following further processing.

[0047] In other words, the fire detection unit 412L reads the amplitude values ​​of the short-wavelength side-light sensor 407L for the past 10 seconds, which have been recorded by the signal recording unit 411L. The fire detection unit 412L then counts the number of times the read-out amplitude value is equal to or greater than a first threshold.

[0048] Next, the fire detection unit 412L reads the amplitude values ​​of the wireless receiving circuit 409 for the past 10 seconds, which were recorded by the signal recording unit 414. The fire detection unit 412L then counts the number of times the read amplitude value exceeds the second threshold.

[0049] The fire detection unit 412L then takes the difference between the two counts and determines whether the absolute value of that difference is less than or equal to the third threshold. If the absolute value of the difference is less than or equal to the third threshold, the fire detection unit 412L determines that the signal from the short-wavelength side-light sensor 407L and the signal from the wireless receiving circuit 409 are synchronized, and stores the flame non-detection data in the auxiliary storage device 402 in association with the current time. On the other hand, if the absolute value of the difference is not less than or equal to the third threshold, the fire detection unit 412L determines that the signal from the short-wavelength side-light sensor 407L and the signal from the wireless receiving circuit 409 are not synchronized, and stores the flame detection data in the auxiliary storage device 402 in association with the current time.

[0050] Furthermore, the flame detection data and flame non-detection data are associated with information identifying the detection direction as "left" and stored in the auxiliary storage device 402.

[0051] Next, I will explain the fire alarm unit 413. The fire alarm unit 413 continuously transmits a flame detection signal to the fire prevention receiver panel 302 while the auxiliary storage device 402 contains the latest flame detection data. The transmitted flame detection signal includes information that identifies the direction of detection.

[0052] Next, we will describe the auxiliary storage device 402. The auxiliary storage device 402 stores optical sensor signal data 421, flame detection / non-detection data 422, and radio wave signal data 423.

[0053] 1-1-2. Disaster Prevention Receiving Panel 302 Next, we will explain the details of the disaster prevention receiving panel 302. Figure 5 shows an example of the configuration of the disaster prevention receiving panel 302. The disaster prevention receiver panel 302 includes a main memory device 501 such as RAM, an auxiliary storage device 502 such as an HDD, a processor 503 such as a CPU, an input / output interface 504, and a communication interface 505 such as a network card.

[0054] The disaster prevention receiving panel 302 also includes a display 506, an operation unit 507, and a speaker 508. These devices are each connected to an input / output interface 504.

[0055] The main memory 501 described above stores various programs. These programs are distributable via non-temporary storage media or networks such as the Internet. Furthermore, various functions are realized when the processor 503 executes these programs. The functions realized include the display control unit 511 and the sound output control unit 512. Each function will be described below.

[0056] When the display control unit 511 receives a flame detection signal from the fire detector 301, it identifies the section in which the flame was detected and displays a message on the display 506 indicating that a flame was detected in that section.

[0057] When the sound control unit 512 receives a flame detection signal from the fire detector 301, it outputs an alarm sound from the speaker 508.

[0058] 1-3.Operation Next, we will describe the fire determination process 600 performed by the fire detector 301. Figure 6 is a flowchart showing an example of this fire determination process 600. The following description will explain the process performed by the fire determination unit 412R.

[0059] First, the fire determination unit 412R sequentially reads out the sets of amplitude values ​​recorded by the signal recording unit 411R and performs a fire determination (step 601). At that time, the fire determination unit 412R determines whether the amplitude values ​​of the signal output from the long-wavelength side-light sensor 406R and the amplitude values ​​of the signal output from the short-wavelength side-light sensor 407R satisfy predetermined conditions. The predetermined conditions are as described above.

[0060] The fire detection unit 412R determines whether all of the above conditions 1 to 3 have been met a predetermined number of times or more in the past 10 seconds (step 602). If the result of this determination is that the conditions have been met a predetermined number of times or more (YES in step 602), the fire detection unit 412R proceeds to step 603. On the other hand, if the result of this determination is that the conditions have not been met a predetermined number of times or more (NO in step 602), the fire detection unit 412R proceeds to step 610.

[0061] In step 603, the fire detection unit 412R reads the amplitude values ​​of the short-wavelength side-light sensor 407R for the past 10 seconds, which were recorded by the signal recording unit 411R. The fire detection unit 412R then counts the number of times the read amplitude value is equal to or greater than a first threshold (step 604).

[0062] Next, the fire detection unit 412R reads the amplitude values ​​of the wireless receiving circuit 409 for the past 10 seconds, which have been recorded by the signal recording unit 414 (step 605). Then, the fire detection unit 412R counts the number of times the read amplitude value is equal to or greater than the second threshold (step 606).

[0063] The fire detection unit 412R then takes the difference between the two counts (step 607) and determines whether the absolute value of the difference is less than or equal to the third threshold (step 608). If the result of this determination is that the absolute value of the difference is less than or equal to the third threshold (YES in step 608), it determines that the signal from the short-wavelength side light sensor 407R and the signal from the wireless receiving circuit 409 are synchronized, and proceeds to step 610. In step 610, the fire detection unit 412R stores the flame non-detection data in the auxiliary storage device 402 in association with the current time.

[0064] On the other hand, if the result of the determination in step 608 is that the absolute value of the difference is not less than or equal to the third threshold (NO in step 608), the fire determination unit 412R determines that the signal from the short-wavelength side light sensor 407R and the signal from the wireless receiving circuit 409 are not synchronized, and stores the flame detection data in the auxiliary storage device 402 in association with the current time (step 609). The above is an explanation of the fire detection process 600.

[0065] The fire detection process 600 described above determines whether the signal from the short-wavelength side-light sensor 407R and the signal from the wireless receiving circuit 409 are synchronized. In other words, it determines whether the radio waves transmitted from the driver's terminal and the signal waveform of the reflected sunlight are synchronized. If both are synchronized, it is determined to be flickering caused by reflected sunlight and not a fire. This reduces false fire alarms caused by flickering reflected light.

[0066] In the above explanation, the process performed by the fire detection unit 412R was used as an example, but the same process is performed by the fire detection unit 412L. In that case, the fire detection unit 412R, signal recording unit 411R, long-wavelength side light sensor 406R, and short-wavelength side light sensor 407R in the above explanation are replaced by the fire detection unit 412L, signal recording unit 411L, long-wavelength side light sensor 406L, and short-wavelength side light sensor 407L, respectively.

[0067] 2. Variations The above embodiment may be modified as follows. The following modifications may be combined with each other. (1) Variation 1 Generally, fire detectors may trigger false alarms when sunlight exceeds 10,000 lux, and the altitude of sunlight at that time is said to be 7 degrees or higher. Therefore, the synchronization check described above (steps 603-608 in Figure 6) may be performed only during periods when sunlight enters the tunnel at an altitude of 7 degrees or higher. This reduces the processing load for fire detection during periods when sunlight does not enter the tunnel.

[0068] In this case, the fire detector 301 is equipped with a function to manage the current date and time. The fire determination unit 412R is then instructed to determine whether the signal from the short-wavelength side light sensor 407R and the signal from the wireless receiving circuit 409 are synchronized if the current date or time falls within a predetermined period (the period during which sunlight enters the tunnel). On the other hand, if the current date or time falls outside the predetermined period, this synchronization determination is omitted.

[0069] Similarly, the fire detection unit 412L is instructed to determine whether the signal from the short-wavelength side light sensor 407L and the signal from the wireless receiving circuit 409 are synchronized, if the current date or time falls within a predetermined period (the period during which sunlight enters the tunnel). On the other hand, if the current date or time does not fall within the predetermined period, this synchronization determination is omitted.

[0070] Alternatively, the fire alarm receiver 302 may be equipped with a function to manage the current date and time instead of the fire detector 301. In that case, the synchronization determination in the fire detector 301 can be turned on or off by control from the fire alarm receiver 302.

[0071] In another embodiment, the threshold for determining synchronization may be relaxed during periods when sunlight enters the tunnel. This makes it easier to determine that synchronization has occurred during those periods.

[0072] In this case, the fire detector 301 is equipped with a threshold control unit. This threshold control unit (not shown) is a means of changing the third threshold value described above according to the current date or time. If the current date or time is within a predetermined period (within the period during which sunlight enters the tunnel), this threshold control unit increases the third threshold value. This makes it easier to determine that synchronization has occurred. On the other hand, if the current date or time is not within the predetermined period, this threshold control unit maintains or decreases the third threshold value.

[0073] Alternatively, the fire alarm receiver panel 302 may be equipped with a threshold control unit instead of the fire detector 301. In that case, the third threshold value in the fire detector 301 can be raised or lowered by control from the fire alarm receiver panel 302.

[0074] (2) Modification example 2 Generally, fire detectors closer to the tunnel entrance are more likely to be hit by sunlight. Therefore, the synchronization determination described above (steps 603-608 in Figure 6) may be performed only for fire detector 301 that is close to the tunnel entrance. This reduces the processing load for fire determination for fire detector 301 that is farther from the tunnel entrance.

[0075] In this case, the fire detector 301 is instructed to store its own identification information. The fire determination unit 412R is then instructed to determine whether the signal from the short-wavelength side light sensor 407R and the signal from the wireless receiving circuit 409 are synchronized if the device's own identification information matches a predetermined set of identification information. On the other hand, if the device's own identification information is not the predetermined set of identification information, this synchronization determination is omitted. Here, the predetermined identification information is the identification information assigned to the fire detector 301 closest to the mine entrance.

[0076] Similarly, the fire detection unit 412L is instructed to determine whether the signal from the short-wavelength side light sensor 407L and the signal from the wireless receiving circuit 409 are synchronized if the device's identification information is a predetermined identification information. On the other hand, if the device's identification information is not a predetermined identification information, this synchronization determination is omitted.

[0077] The following explains the case where the identification information is an address number. Typically, address numbers are assigned in ascending or descending order, starting from the side closest to the disaster prevention receiving panel 302. Therefore, a fire detector 301 whose address number is near the minimum or maximum value in tunnel 303 will be the fire detector 301 installed near the tunnel entrance. For this reason, each fire detector 301 is instructed to store its own address number and the minimum and maximum values ​​of the address numbers in tunnel 303. Then, each fire detector 301 may be instructed to determine whether its own address number is within a predetermined range (for example, within "2") from the minimum or maximum value, and if it is within the predetermined range, it may be instructed to perform a synchronization check. On the other hand, if it is not within the predetermined range, the synchronization check is omitted.

[0078] Alternatively, instead of the fire detector 301, the disaster prevention receiving panel 302 may be used to determine whether the detector's identification information matches a predetermined identification information. In this case, the synchronization determination in the fire detector 301 can be turned on or off by control from the disaster prevention receiving panel 302.

[0079] In another embodiment, the threshold for synchronization determination in the fire detector 301 near the mine entrance may be relaxed. This makes it easier to determine that synchronization has occurred near the mine entrance.

[0080] In this case, the fire detector 301 is equipped with a threshold control unit. This threshold control unit (not shown) is a means of changing the third threshold value described above according to the identification information assigned to the unit. When the identification information of the unit is predetermined, this threshold control unit increases the third threshold value. This makes it easier to determine that synchronization has occurred. On the other hand, when the identification information of the unit is not predetermined, this threshold control unit maintains or decreases the third threshold value. The predetermined identification information referred to here is the identification information assigned to the fire detector 301 closest to the tunnel entrance. If this identification information is assumed to be an address number, then, as described above, it is a number within a predetermined range from the minimum and maximum values ​​of the address numbers in the tunnel 303.

[0081] Alternatively, the fire alarm receiver panel 302 may be equipped with a threshold control unit instead of the fire detector 301. In that case, the third threshold value in the fire detector 301 can be raised or lowered by control from the fire alarm receiver panel 302.

[0082] (3) Modification example 3 In the flicker detected by the short-wavelength side-view sensors 407R and 407L, the peak of reflected sunlight is constant, while the peak of the flame differs each time. In light of this, in addition to the synchronization determination described above, a determination of peak variation may also be performed. This improves the accuracy of fire detection.

[0083] In this case, the fire determination unit 412R does not determine that there is a fire if the signal from the short-wavelength side light sensor 407R and the signal from the wireless receiving circuit 409 are synchronized, and the maximum amplitude value of the signal from the short-wavelength side light sensor 407R for each predetermined period falls within a predetermined range. This non-fire determination is also made if the signal value of the short-wavelength side light sensor 407R satisfies predetermined conditions (more specifically, if the signal value of the long-wavelength side light sensor 406R and the signal value of the short-wavelength side light sensor 407R satisfy predetermined conditions). On the other hand, the fire detection unit 412R determines that there is a fire if the signal from the short-wavelength side light sensor 407R and the signal from the wireless receiving circuit 409 are not synchronized, or if the maximum amplitude value of the signal from the short-wavelength side light sensor 407R for each predetermined period does not fall within a predetermined range.

[0084] Similarly, the fire determination unit 412L does not determine that there is a fire if the signal from the short-wavelength side-light sensor 407L and the signal from the wireless receiving circuit 409 are synchronized, and the maximum amplitude value of the signal from the short-wavelength side-light sensor 407L for each predetermined period falls within a predetermined range. This non-fire determination is also made if the signal value of the short-wavelength side-light sensor 407L satisfies predetermined conditions (more specifically, if the signal value of the long-wavelength side-light sensor 406L and the signal value of the short-wavelength side-light sensor 407L satisfy predetermined conditions). On the other hand, the fire detection unit 412L determines that there is a fire if the signal from the short-wavelength side light sensor 407L and the signal from the wireless receiving circuit 409 are not synchronized, or if the maximum amplitude value of the signal from the short-wavelength side light sensor 407L for each predetermined period does not fall within a predetermined range.

[0085] Alternatively, the peak variation determination described above may be performed by the fire prevention receiving panel 302 instead of the fire detector 301.

[0086] (4) Modification 4 The functional arrangement in the flame detection system 300 described above may be changed as appropriate. For example, the functions of the fire determination units 412R and 412L of the fire detector 301 may be provided in the fire prevention receiving panel 302. Alternatively, some of the functions of the fire detector 301 and the fire prevention receiving panel 302 may be provided in different devices.

[0087] (5) Variation 5 The fire detector 301 in the above embodiment is a dual-wavelength flame detector, but the number of wavelength bands to be detected may be one or three or more.

[0088] (6) Variation 6 In the above embodiment, the passage of a vehicle is detected using a wireless receiving circuit 409. However, the wireless receiving circuit 409 is just one example of a means for detecting the passage of a vehicle. As another means, for example, a vehicle detection sensor may be used. A vehicle detection sensor is a sensor that outputs a signal according to the presence or absence of a passing vehicle. More specifically, it is a sensor that outputs a signal with a pulse width corresponding to the time the vehicle passes. When the signal output by this sensor and the signal from the short-wavelength side-light sensor 407R (or 407L) are synchronized, the fire determination unit 412R (or 412L) may be prevented from determining that there is a fire. Furthermore, there are no particular limitations on the type of vehicle detection sensor; any of the following may be used: loop coil type sensor, magnetic type sensor, infrared sensor, ultrasonic sensor, or microwave sensor.

[0089] (7) Other variations It should be noted that the present invention is not limited to the embodiments described above, and various modifications are included. For example, the embodiments described above are described in detail to make the present invention easier to understand, and are not necessarily limited to those having all the configurations described. Furthermore, it is possible to replace parts of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add configurations from other embodiments to the configuration of one embodiment. In addition, it is possible to add, delete, or replace parts of the configuration of each embodiment with other configurations.

[0090] Furthermore, each of the above configurations, functions, processing units, and processing means may be implemented in hardware, either partially or entirely, by designing them as integrated circuits, for example. Alternatively, each of the above configurations and functions may be implemented in software by having the processor interpret and execute programs that implement each function. Information such as programs, tables, and files that implement each function can be stored in memory, a recording device such as a hard disk or SSD (Solid State Drive), or a recording medium such as an IC card, SD card, or DVD.

[0091] Furthermore, the control lines and information lines shown are those deemed necessary for explanatory purposes, and not all control lines and information lines are necessarily shown in the actual product. In reality, it is safe to assume that almost all components are interconnected. Furthermore, the above-described embodiments disclose at least the configuration described in the claims. [Explanation of Symbols]

[0092] 101...Sun, 102...Automatic notification area, 103...Passing vehicles, 104-107...Fire detector, 108...Incident sunlight, 300...Flame detection system, 301...Fire detector, 302...Disaster prevention receiving panel, 303...Tunnel, 411R, 411L...Signal recording unit, 412R, 412L...Fire determination unit, 413...Fire alarm unit, 414...Signal recording unit, 421...Optical sensor signal data, 422...Flame detection / non-detection data, 423...Radio wave signal data, 511...Display control unit, 512...Sound control unit

Claims

1. A first light-receiving means that receives infrared light of a first wavelength and outputs a first signal corresponding to the amount of light received, A determination means that determines that a fire has occurred when the value of the first signal satisfies predetermined conditions, A vehicle passage detection means that outputs a second signal depending on whether or not a vehicle is passing, Equipped with, The determination means does not determine that there is a fire even if the value of the first signal satisfies the predetermined conditions, if the first signal and the second signal are synchronized. Fire monitoring system.

2. The system further includes a second light-receiving means that receives infrared light of a second wavelength longer than the first wavelength and outputs a third signal corresponding to the amount of light received, The determination means determines that there is a fire if the relationship between the value of the first signal and the value of the third signal satisfies the predetermined conditions. Even if the relationship between the value of the first signal and the value of the third signal satisfies the predetermined conditions, the determination means does not determine that there is a fire if the first signal and the second signal are synchronized. The vehicle passage detection means is a wireless receiving means that receives radio waves from a terminal carried by a vehicle occupant and outputs a second signal corresponding to the strength of those radio waves. The fire monitoring system according to claim 1.

3. The determination means determines whether the first signal and the second signal are synchronized when the current date or time falls within a predetermined period. The fire monitoring system according to claim 1.

4. The first signal and the second signal are synchronized if the absolute value of the difference between the number of times the amplitude value of the first signal exceeds a first threshold during a predetermined period and the number of times the amplitude value of the second signal exceeds a second threshold during the predetermined period is less than or equal to a third threshold, The system further comprises threshold control means for changing the third threshold according to the current date or time. The fire monitoring system according to claim 1.

5. The aforementioned fire monitoring system is a fire detector, The determination means determines whether the first signal and the second signal are synchronized when the identification information assigned to the fire detector is predetermined identification information. The fire monitoring system according to claim 1.

6. The aforementioned fire monitoring system is a fire detector, The first signal and the second signal are synchronized if the absolute value of the difference between the number of times the amplitude value of the first signal exceeds a first threshold during a predetermined period and the number of times the amplitude value of the second signal exceeds a second threshold during the predetermined period is less than or equal to a third threshold, The system further includes threshold control means for changing the third threshold according to the identification information assigned to the fire detector. The fire monitoring system according to claim 1.

7. Even if the value of the first signal satisfies the predetermined conditions, the determination means does not determine that there is a fire if the first signal and the second signal are synchronized and the maximum amplitude value of the first signal for each predetermined period falls within a predetermined range. The fire monitoring system according to claim 1.

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