JP2019159742A - Fire smoke detector - Google Patents

Abstract

To provide a fire smoke detector capable of detecting smoke particles derived from fire easily and accurately.SOLUTION: A fire smoke detector 1 capable of detecting smoke derived from a fire includes: a laser radar part 10 for emitting light and acquiring the intensity of the light reflected by smoke particles; an evaluation value calculation part 31 for calculating an evaluation value related to the diameter of the smoke particles and/or the particle density of the smoke particles from the intensity of the reflected light; a storage part 25 for storing a reference value of smoke particle information in the case of smoke derived from a fire; and a determination part 32 for determining that the smoke particles derive from a fire when the evaluation value is greater than or equal to the reference value.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a fire smoke detector that can easily and accurately detect smoke particles derived from a fire.

  2. Description of the Related Art Conventionally, there are fire detectors that detect the smoke particles by monitoring the scattered light from the smoke particles by applying the light of the semiconductor laser to the smoke particles. Also, many fire detectors are installed above the ceiling of a building because smoke particles flow vertically upward.

  For example, Patent Document 1 describes a fire detection device that performs image processing on an image obtained by an imaging unit and determines the presence or absence of a fire from the density of flame color, the size of smoke, changes over time, and the like.

JP 2017-191544 A

  By the way, in a space such as a tunnel, smoke particles derived from other than the fire, for example, fine particles in exhaust gas from an automobile are mixed in addition to the smoke particles derived from the fire. Therefore, it is difficult to detect smoke particles derived from a fire by separating them from other fine particles not derived from a fire even if a laser radar device is simply used.

  Therefore, what can detect only smoke particles derived from a fire by separating smoke particles derived from a fire and other fine particles not derived from a fire from smoke is desired.

  This invention is made | formed in view of the above, Comprising: It aims at providing the fire smoke detection apparatus which can perform the detection of the smoke particle derived from a fire simply and with high precision.

  In order to solve the above-described problems and achieve the object, a fire smoke detection device according to the present invention is a fire smoke detection device capable of detecting smoke originating from a fire, which emits light and emits smoke particles. An optical transmission / reception unit that acquires the intensity of the light reflected by the evaluation unit, an evaluation value calculation unit that calculates an evaluation value of smoke particle information related to the diameter of the smoke particles and / or the particle density of the smoke particles from the intensity of the reflected light, and A storage unit for storing a reference value of smoke particle information in the case of smoke originating from a fire, and a determination that the smoke particles are smoke originating from a fire if the evaluation value is equal to or greater than the reference value And a section.

  The fire smoke detector according to the present invention is characterized in that, in the above invention, the optical transmitter / receiver scans.

  In the fire smoke detection apparatus according to the present invention as set forth in the invention described above, the optical transmission / reception unit is a laser radar.

  In addition, the fire smoke detection device according to the present invention includes, in the above invention, a notification unit that notifies that when the determination unit determines that the smoke particles are smoke derived from a fire. Features.

  Moreover, in the fire smoke detection device according to the present invention, in the above invention, when the time change per unit time of the evaluation value is equal to or greater than a predetermined time change value, the determination unit is derived from a fire. It is characterized by determining that it is smoke.

  Further, in the fire smoke detection device according to the present invention, in the above invention, a plurality of the light transmission / reception units are arranged at predetermined intervals, and the determination unit is an intensity of reflected light detected by an adjacent light transmission / reception unit. When the spatial change of the evaluation value due to is greater than or equal to a predetermined spatial change value, it is determined that the smoke particles are smoke originating from a fire.

  In the fire smoke detector according to the present invention, in the above invention, the intensity of reflected light acquired by the optical transceiver is due to Mie scattering, and the evaluation value of the smoke particle information is smoke particles. It is a multiplication value of the square of the diameter of the particle and the particle density of the smoke particles.

  In the fire smoke detector according to the present invention, the light transmitting / receiving unit emits light of different wavelengths, and the intensity of reflected light acquired by the light transmitting / receiving unit is light of different wavelengths. The evaluation value calculation unit calculates the diameter of the smoke particles and / or the particle density of the smoke particles as an evaluation value based on the intensity of light reflected by the Rayleigh scattering with different wavelengths. It is characterized by doing.

  In the fire smoke detector according to the present invention, the evaluation value calculation unit may be configured such that the diameter of the smoke particles and / or the particles of the smoke particles based on the reflected light intensity distribution image of the light transmitting / receiving unit. The evaluation value is calculated by obtaining a density by a shape recognition process of the smoke particles.

  In the fire smoke detector according to the present invention, the evaluation value calculation unit may be a smoke particle based on a two-dimensional distribution image of a distance between a reflection point of light by the light transmitting / receiving unit and the smoke particle. The evaluation value is calculated by obtaining the diameter and / or the particle density of the smoke particles by the shape recognition process of the smoke particles.

  The fire smoke detector according to the present invention is characterized in that, in the above invention, the light transmitting / receiving unit has an array of light receiving units that receive light reflected by the smoke particles.

  The fire smoke detector according to the present invention is characterized in that, in the above invention, the light receiving parts are integrated and arranged on the same substrate.

  In the fire smoke detection device according to the present invention, in the above invention, the scanning mechanism of the optical transmission / reception unit is disposed on a first scanning mechanism that scans at a first scanning angle, and the first scanning mechanism, And a second scan mechanism that scans at a second scan angle smaller than the first scan angle between the first scan angles, and the light is emitted at the second scan angle.

  The fire smoke detector according to the present invention is characterized in that, in the above invention, the second scan mechanism generates the second scan angle by driving a piezoelectric element.

  According to the present invention, the evaluation value of the smoke particle information related to the diameter of the smoke particles and / or the particle density of the smoke particles is calculated based on the scan data of the reflectance, and the evaluation value is smoke derived from a fire. If the smoke particle information is above the reference value of the smoke particle information in some cases, the smoke particles are determined to be smoke originating from a fire, so that the detection of smoke particles originating from a fire can be performed easily and accurately. it can.

FIG. 1 is a schematic diagram showing an arrangement configuration of a fire smoke detection apparatus according to Embodiment 1 of the present invention. FIG. 2 is a block diagram illustrating a configuration of the fire smoke detection device 1. FIG. 3 is a diagram showing an emission range of pulsed laser light. FIG. 4 is a diagram illustrating an example of an image of smoke particles in the early stage of a fire occurrence. FIG. 5 is a flowchart showing a fire determination processing procedure by the control unit of the first embodiment. FIG. 6 is a flowchart showing a fire determination processing procedure by the control unit of the first modification of the first embodiment. FIG. 7 is a flowchart illustrating a fire determination processing procedure by the control unit according to the second modification of the first embodiment. FIG. 8 is a flowchart showing a fire determination processing procedure by the control unit of the second embodiment. FIG. 9 is a flowchart showing a fire determination processing procedure by the control unit of the first modification of the second embodiment. FIG. 10 is a flowchart illustrating a fire determination processing procedure by the control unit of the second modification of the second embodiment. FIG. 11 is a schematic diagram illustrating an example of the configuration of the light receiving unit according to the third embodiment. FIG. 12 is a schematic diagram illustrating a configuration of a scanning mechanism according to the first modification of the third embodiment. FIG. 13 is a schematic diagram illustrating an arrangement configuration of the light receiving units according to the second modification of the third embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.

(Embodiment 1)
FIG. 1 is a schematic diagram showing an arrangement configuration of a fire smoke detection apparatus 1 according to Embodiment 1 of the present invention. This fire smoke detection device 1 detects the occurrence of a fire by detecting smoke particles originating in the fire that occur in the tunnel T. Here, the tunnel T is an underground or underground passage that is provided relatively horizontally or substantially horizontally along the extending direction (Z direction) where both ends are open to the atmosphere, and is not limited to a tunnel for automobiles. It means a tunnel including a railway tunnel.

  As shown in FIG. 1, the fire smoke detection apparatus 1 includes a plurality of laser radar units 10 and a monitoring unit 20 connected thereto. Each laser radar unit 10 is installed not on the ceiling U in the tunnel T but on the roadside band W in the tunnel T. Each laser radar unit 10 is arranged at predetermined intervals D in the extending direction (Z direction) of the tunnel T. The predetermined interval D is, for example, 50 m.

  FIG. 2 is a block diagram illustrating a configuration of the fire smoke detection device 1. As shown in FIG. 2, in the fire smoke detection device 1, the plurality of laser radar units 10 are connected to the monitoring unit 20 via the communication line 40 as described above.

  The laser radar unit 10 functions as a laser radar and includes a light emitting unit 11, a light receiving unit 12, a scanning mechanism 13, a transfer processing unit 14, and a communication unit 15. The light emitting section 11 emits light by scanning pulsed laser light from the semiconductor laser into the tunnel T. The light receiving unit 12 receives the pulsed laser light scattered by the smoke particles P in the tunnel T. The light receiving unit 12 receives the reflection intensity or reflectance of the pulsed laser light scattered by the particles. The scanning mechanism 13 includes a light emitting unit 11 and a light receiving unit 12, and performs horizontal scanning by emitting and receiving pulsed laser light while rotating the light emitting unit 11 and the light receiving unit 12. This scan range is 180 degrees in the horizontal direction. The light emitting unit 11, the light receiving unit 12, and the scanning mechanism 13 function as an optical transmission / reception unit.

  The laser radar unit 10 can coherently detect reflected light and scattered light, and can create a B scope in which the distance to the particle can be determined from the time response waveform of the received signal. The B scope is a two-dimensional distribution image of the distance to the reflection point of light by particles. In the first embodiment, scan data that is simply a reflectance distribution image of a scanned pulsed laser beam is acquired as in a normal camera. The reflectance is obtained by adding attenuation due to the distance to the light reflection point to the reflected light intensity. Further, instead of the reflectance distribution image, a reflected light intensity distribution image that is simply a distribution of reflected light intensity may be used as scan data. In addition, the spatial resolution by the laser radar unit 10 is about 1 mm.

  The transfer processing unit 14 performs processing for sequentially transferring the scan data of the scattered light received by the light receiving unit 12 to the monitoring unit 20 side via the communication unit 15.

In addition, the wavelength of the pulsed laser light emitted from the light emitting unit 11 is an eye-safe band of 1.4 μm or more, and specifically 1.4 to 2.6 μm. The output intensity of the pulse laser beam is 25 W / m ^ 2 or less. Also, as shown in FIG. 3, the vertical scanning range of the pulse laser beam is set such that the maximum height H from the roadside band W side is 4.1 m or more. That is, in the direction RA in which the pulse laser beam is emitted, as shown in FIG. 3, the distance from the installation location of the laser radar unit 10 to the roadway of the automobile is Xm, and the installation location of the laser radar unit 10 is installed as Ym from the ground. Then, θ = tan ⁻¹ (4.1−Y / X). By adopting this configuration, even if the pulse laser beam is not limited to eye safety, it is preferable to prevent the pulse laser beam from damaging the driver's eyeball. The installation height Y of the laser radar unit 10 is preferably provided at a position lower than the average height (1 meter) of a 4-year-old infant who may walk.

  In FIG. 2, the monitoring unit 20 includes a communication unit 21, a display unit 22, an input unit 23, a control unit 24, a storage unit 25, and a notification unit 26. The communication unit 21 is an interface unit for communicating with each laser radar unit 10. The display unit 22 is a display device such as a liquid crystal display device. The input unit 23 is an input device such as a keyboard or a mouse. The display unit 22 and the input unit 23 may be integrally formed with a touch panel or the like.

  The storage unit 25 is a storage device such as a nonvolatile memory, and stores scan data D1 sent from each laser radar unit 10 and a reference value D2 described later.

  The control unit 24 is a control unit that controls the entire fire smoke detection device 1, and includes an evaluation value calculation unit 31, a determination unit 32, and a notification processing unit 33. In practice, programs corresponding to these functional units are stored in a ROM or a non-volatile memory (not shown), and these programs are loaded into a CPU (Central Processing Unit) and executed to thereby execute an evaluation value calculation unit 31. Thus, the determination unit 32 and the notification processing unit 33 are caused to execute corresponding processes.

  The evaluation value calculation unit 31 calculates the evaluation value of the smoke particle information related to the diameter of the smoke particles and / or the particle density of the smoke particles based on the scan data of the reflection intensity or the reflectance acquired by each laser radar unit 10. .

  When the evaluation value calculated by the evaluation value calculation unit 31 is equal to or greater than the reference value D2 stored in the storage unit 25, the determination unit 32 determines that the smoke particles are smoke derived from fire. The reference value D2 stored in the storage unit 25 is a reference value of smoke particle information in the case of smoke originating from a fire, and is a value obtained in advance through experiments or the like.

  When the determination unit 32 determines that the smoke particles are smoke derived from a fire, the notification processing unit 33 outputs a notification to that effect from the notification unit 26. The notification unit 26 may be a unit arranged in another department (not shown), or may be configured to serve as the display unit 22.

<Evaluation Value Calculation Processing and Determination Processing>
FIG. 4 is a diagram illustrating an example of an image of smoke particles in the early stage of a fire occurrence. The detection of the occurrence of fire is obtained by obtaining the diameter d of the smoke particles and the particle density M (pieces / mm ² ) of the smoke particles, and when the diameter d or the particle density M is a predetermined value or more, the fire has occurred. This can be determined, but is difficult when the spatial resolution of the laser radar unit 10 is about 1 mm.

When the particle size is 1/10 or more of the wavelength of the pulsed laser beam, the reflectance R of the scattered light can be expressed by the Mie scattering equation shown in equation (1).
R = M × π (d / 2) ² × ((n−1) / (n + 1)) ² (1)
Here, M is the particle density (number / mm ² ) of the smoke particles, d is the average diameter of the smoke particles, and n is the refractive index of the smoke particles. n is a material of smoke particles, and since smoke particles are carbon, it can be set as approximately 2.2.

Therefore, M × d ² can be calculated from the equation (1) by measuring the reflectance R. Then, the evaluation value calculation unit 31 calculates M × d ² for each point of all the scan data, and calculates the average value as the evaluation value m. On the other hand, the reference value D2 is, M × d ² is the minimum reference value of the evaluation value m when a fire occurs are stored.

For example, in FIG. 2, the average diameter d of the fine particles is 0.001 mm, the particle density is 78493 (pieces / mm ² ), and FIG. 2 shows the initial state of fire, so the reference value D2 M × d ² = 78493 × (0.001) ² = 0.078493 (pieces). And when evaluation value m is 0.078493 (pieces) or more, it determines with it being a fire.

  When the evaluation value m is greater than or equal to the reference value D2, the determination unit 32 determines that there is smoke particles derived from fire and that a fire has occurred.

<Fire judgment processing>
Here, with reference to the flowchart shown in FIG. 5, the fire determination process procedure by the control part 24 is demonstrated. As shown in FIG. 5, first, the control unit 24 acquires scan data of reflection intensity or reflectance from each laser radar unit 10 (step S101). Thereafter, the evaluation value calculation unit 31 calculates, for each point, a multiplication value M × d ² of the square of the diameter d of the smoke particles and the particle density M of the smoke particles for the scan data of each laser radar unit 10 ( Step S102). Thereafter, the evaluation value calculation unit 31 calculates the average value of the obtained multiplication values M × d ² of the respective points as the evaluation value m (step S103).

  Thereafter, the determination unit 32 determines whether or not the evaluation value m of each laser radar unit 10 has a reference value D2 or more (step S104). If the evaluation value m is greater than or equal to the reference value D2 (step S104, Yes), it is determined that there is a fire (step S105), the notification process is performed (step S106), and then the process ends. On the other hand, if the evaluation value m is not equal to or greater than the reference value D2 (No in step S104), the process is terminated as it is, and the detected smoke particles are smoke particles not derived from fire, for example, exhaust gas of 2.5 μm or less. Recognized as fine particles. The above process is repeated every predetermined time.

In the above-described processing, the average value of the multiplication value M × d ² at each point is set as the evaluation value m. However, the determination of fire is further performed using the variation of the multiplication value M × d ² at each point, for example, the standard deviation. You may make it perform. For example, even if the evaluation value m is greater than or equal to the reference value D2, if the standard deviation is, for example, a predetermined value of 0.0005 mm or less, it may be determined that no fire has occurred.

<Variation 1 of fire determination processing>
In the first modification of the fire determination process, a fire is determined when the time change per unit time (for example, 1 second) of the evaluation value m is a predetermined value D10 or more, for example, 10% or more. In this case, the reference value D2 is not used. This is because, in the event of a fire, unlike the exhaust gas particulates, smoke particles derived from the fire increase rapidly, and the value of the evaluation value m fluctuates rapidly.

FIG. 6 is a flowchart showing the fire determination processing procedure of Modification 1 by the control unit 24. As shown in FIG. 6, first, the control unit 24 obtains scan data of reflection intensity or reflectance from each laser radar unit 10 (step S201). Thereafter, the evaluation value calculation unit 31 calculates, for each point, a multiplication value M × d ² of the square of the diameter d of the smoke particles and the particle density M of the smoke particles for the scan data of each laser radar unit 10 ( Step S202). Thereafter, the evaluation value calculation unit 31 calculates the average value of the obtained multiplication values M × d ² for each point as the evaluation value m (step S203).

  Thereafter, the determination unit 32 determines whether or not a time change per unit time of the evaluation value m, for example, per second is 10% or more (step S204). When the time change per unit time of the evaluation value m is 10% or more (step S204, Yes), it is determined that there is a fire (step S205), the notification process is performed (step S206), and then the process ends. To do. On the other hand, when the time change per unit time of the evaluation value m is not 10% or more (step S204, No), this processing is ended as it is. The above process is repeated every predetermined time.

<Modification 2 of fire determination processing>
In the second modification of the fire determination process, a fire is determined when the spatial change of the evaluation value m of the adjacent laser radar unit 10 is equal to or greater than a predetermined value D20, for example, 10%. In this case, the reference value D2 is not used. This is because, in the event of a fire, unlike the exhaust gas particulates, smoke particles originating from the fire spread spatially abruptly, and the evaluation value m of the adjacent laser radar unit 10 fluctuates rapidly. is there.

FIG. 7 is a flowchart showing the fire determination processing procedure of the first modification by the control unit 24. As shown in FIG. 7, first, the control unit 24 acquires scan data of reflection intensity or reflectance from each laser radar unit 10 (step S301). Thereafter, the evaluation value calculation unit 31 calculates, for each point, a multiplication value M × d ² of the square of the diameter d of the smoke particles and the particle density M of the smoke particles for the scan data of each laser radar unit 10 ( Step S302). Thereafter, the evaluation value calculation unit 31 calculates the average value of the obtained multiplication values M × d ² for each point as the evaluation value m (step S303).

  Thereafter, the determination unit 32 determines whether or not the spatial change of the evaluation value m of the adjacent laser radar unit 10 is 10% or more (step S304). When the spatial change of the evaluation value m of the adjacent laser radar unit 10 is 10% or more (step S304, Yes), it is determined that there is a fire (step S305), and a notification process is performed (step S306). The process ends. On the other hand, when the spatial change of the evaluation value m of the adjacent laser radar unit 10 is not 10% or more (No in step S304), the present process is terminated as it is. The above process is repeated every predetermined time.

(Embodiment 2)
By the way, when the particle size is 1/10 or less of the wavelength of the pulse laser beam, the reflectance of the scattered light can be expressed by the Rayleigh scattering equation shown in the equation (2).
R = A × (2π ² d ⁶ / 3λ ⁴ ) × ((n ² −1) / (n ² +2)) × M (2)
Here, M is the particle density (number / mm ² ) of the smoke particles, d is the average diameter of the smoke particles, and n is the refractive index of the smoke particles. n is a material of smoke particles, and since smoke particles are carbon, it can be set as approximately 2.2. λ is the wavelength of the pulse laser beam. In this equation (2), a variable λ is included as compared with equation (1). Therefore, the average diameter d of smoke particles and the average particle density M of smoke particles can be obtained individually by obtaining the reflectances R1 and R2 of pulse radar light having different wavelengths λ1 and λ2. The wavelength λ1 is, for example, 10 μm, and the wavelength λ2 is, for example, 15 μm.

Specifically, the simultaneous equations of the equations (3) and (4) of the reflectances R1 and R2 for different wavelengths λ1 and λ2 may be solved.
^{R1 = A × (2π 2 d} 6/3 (λ1) 4) × ((n 2 -1) / (n 2 +2)) × M
... (3)
^{R2 = A × (2π 2 d} 6/3 (λ2) 4) × ((n 2 -1) / (n 2 +2)) × M
(4)

  In the configuration of the second embodiment, the light emitting unit 11 shown in FIG. 2 emits pulsed laser beams having different wavelengths λ1 and λ2, and the light receiving unit 12 reflects the reflection intensity of scattered light of pulsed laser beams having different wavelengths λ1 and λ2. Is detected.

In the second embodiment, the average diameter and the average particle density are individually stored in the storage unit 25 as reference values D21 and D22 corresponding to the reference value D2. For example, referring to FIG. 4, reference value D21 of average diameter is 0.001 mm, and reference value D22 of average particle density is 78493 (pieces / mm ² ).

<Fire judgment processing>
Here, with reference to the flowchart shown in FIG. 8, the fire determination process procedure by the control part 24 of this Embodiment 2 is demonstrated. As shown in FIG. 8, the control unit 24 first acquires scan data of reflection intensity or reflectance of different wavelengths from each laser radar unit 10 (step S401). Specifically, scan data of reflectances R1 and R2 having different wavelengths λ1 and λ2 are acquired. Thereafter, the evaluation value calculator 31 calculates the smoke particle diameter d and the smoke particles for each point of the scan data for each wavelength λ1 and λ2 of each laser radar unit 10 based on the equations (3) and (4). The particle density M is calculated (step S402). Thereafter, the evaluation value calculation unit 31 calculates the average value of the obtained diameters d of each point as the evaluation value m1, and calculates the average value of the particle density M of each point as the evaluation value m2 (step S403).

  Thereafter, the determination unit 32 determines whether or not the evaluation value m1 of each laser radar unit 10 is the reference value D21 or more, or the evaluation value m2 is the reference value D22 or more (step S404). When the evaluation value m1 is the reference value D21 or more, or the evaluation value m2 is the reference value D22 or more (step S404, Yes), it is determined as a fire (step S405), and the notification process is performed (step S406). This process ends. On the other hand, when the evaluation value m1 is not equal to or greater than the reference value D21 and the evaluation value m2 is not equal to or greater than the reference value D22 (No in step S404), the present process ends. The above process is repeated every predetermined time.

  Note that the evaluation value m2 is not calculated in step S403, and the determination process in step S404 may be performed using only the evaluation value m1, or the evaluation value m1 is not obtained in step S403, and the determination process in step S404 is performed. The determination may be made using only the evaluation value m2.

<Variation 1 of fire determination processing>
In the first modification of the fire determination process, as in the first modification of the first embodiment, the time change per unit time (for example, 1 second) of the evaluation value m1 or the evaluation value m2 is not less than a predetermined value D31, for example, 10%. In the above case, it is judged as a fire. In this case, the reference values D21 and D22 are not used. This is because when a fire occurs, unlike the exhaust gas particulates, smoke particles derived from the fire increase rapidly, and the evaluation value m1 or the evaluation value m2 fluctuates rapidly.

  FIG. 9 is a flowchart illustrating the fire determination processing procedure of the first modification by the control unit 24 according to the second embodiment. In this fire determination process, the process of step S504 corresponding to step S404 shown in FIG. 8 is only different from the procedure shown in FIG. That is, steps S501 to S503, S505, and S506 are the same processing as steps S401 to S403, S405, and S406.

  In step S504, it is determined whether the time change per unit time of the evaluation value m1 or the evaluation value m2 is 10% or more. And when the time change per unit time of the evaluation value m1 or the evaluation value m2 is 10% or more (step S504, Yes), it determines with it being a fire (step S505). On the other hand, when the time change per unit time of the evaluation value m1 or the evaluation value m2 is not 10% or more (step S504, No), this process ends.

<Modification 2 of fire determination processing>
In the first modification of the fire determination process, as in the second modification of the first embodiment, the spatial change of the evaluation value m1 or the evaluation value m2 of the adjacent laser radar unit 10 is a predetermined value D32 or more, for example, 10% or more. In case of fire. In this case, the reference values D21 and D22 are not used. This is because when a fire occurs, smoke particles derived from the fire spread spatially abruptly, unlike the exhaust gas particulates, and the evaluation value m1 or evaluation value m2 of the adjacent laser radar unit 10 abruptly increases. Because it fluctuates.

  FIG. 10 is a flowchart illustrating the fire determination processing procedure of the second modification by the control unit 24 according to the second embodiment. In this fire determination process, the process of step S604 corresponding to step S404 shown in FIG. 8 is only different from the procedure shown in FIG. That is, steps S601 to S603, S605, and S606 are the same processes as steps S401 to S403, S405, and S406.

  In step S604, it is determined whether the spatial change of the evaluation value m1 or the evaluation value m2 of the adjacent laser radar unit 10 is 10% or more. If the spatial change of the evaluation value m1 or the evaluation value m2 is 10% or more (step S604, Yes), it is determined that there is a fire (step S605). On the other hand, when the spatial change of the evaluation value m1 or the evaluation value m2 is not 10% or more (step S604, No), this process ends.

(Embodiment 3)
In the third embodiment, the spatial resolution is increased, an image indicated by the scan data of the reflectance shown in FIG. 4 is acquired, and image processing for obtaining the diameter of the smoke particles is performed from this image. The spatial resolution is preferably about several μm. The evaluation value calculation unit 31 illustrated in FIG. 2 performs image processing for obtaining the particle diameter of the smoke particles by using a perfect circle function as an approximate function for the acquired high-resolution image, and smoke particles for each image. Find the average diameter of. That is, the evaluation value calculation unit 31 calculates the evaluation value m1. Other fire determination processes are the same as those in the second embodiment.

<Example of high spatial resolution configuration>
FIG. 11 is a schematic diagram illustrating an example of the configuration of the light receiving unit 12 according to the third embodiment. Although the first and second embodiments have been described on the assumption that one photodetector is provided for pulse laser light having one wavelength, in the third embodiment, one pulse laser light is provided. The scattering intensity (reflection intensity or reflectance) is detected by a plurality of photodetectors 12a arranged in an array in the scanning direction AR. In FIG. 11, a plurality of photodetectors 12a are also arranged in the direction perpendicular to the scan direction AR.

  The light receiving unit 12 in which the plurality of photodetectors 12a are arranged in an array can be realized by integrating the photodetectors on the same substrate based on Si material used in a CCD camera or the like. For example, a CMOS image sensor or a CCD image sensor is used as the light receiving unit 12, and the reflectance distribution within a range of one measurement point (1 mm × 1 mm) where one pulse laser beam is reflected can be obtained. Since the intervals between the photodetectors arranged in the array can be integrated up to about 5 μm, the spatial resolution is about 5 μm. As a result, at the end of one scan, a high-resolution image corresponding to FIG. 4 can be obtained, and by performing image processing for obtaining the particle diameter for this image, a fire determination process similar to that of the second embodiment is performed. It can be carried out.

<Variation 1 of high spatial resolution configuration>
The improvement of the spatial resolution can also be realized by making the scan step of the pulse laser light fine. In the first and second embodiments, the scan interval is 0.3 ° intervals. In the first modification, the scan interval is 0.003 ° intervals.

  FIG. 12 is a schematic diagram illustrating a configuration of the scan mechanism 13 according to the first modification of the third embodiment. As shown in FIG. 12, the scan mechanism 13 has a second scan mechanism 62 disposed on the upper surface of the first scan mechanism 61. The first scan mechanism 61 turns at the first scan angle θ1. When the second scan mechanism 62 stops at the first scan angle θ1, the second scan mechanism 62 turns around at a fine second scan angle θ2 smaller than the first scan angle θ1. For example, the first scan angle θ1 is an angle of 10 ° or less, and the second scan angle θ2 is an angle of 0.0003 ° or less. The pulse laser beam is emitted every turn of the second scan angle θ2.

  In the second scanning mechanism 62, a fixing member 63 fixedly arranged on the first scanning mechanism 61 and a support member 64 on which the light emitting unit 11 and the light receiving unit 12 are arranged are connected via piezoelectric elements 65a and 65b. The piezoelectric elements 65a and 65b are disposed on both ends of the gap between the fixing member 63 and the support member 64, respectively. For example, the turn of the second scan angle θ2 is performed by setting the piezoelectric element 65a disposed on the left side to the maximum thickness and the piezoelectric element 65b disposed on the right side having the minimum thickness in the drawing, A voltage changing by θ2 is applied to the piezoelectric element 65a to reduce the thickness of the piezoelectric element 65a, or a voltage changing by the second scan angle θ2 is applied to the piezoelectric element 65b to increase the thickness of the piezoelectric element 65b. To go. The support member 64 turns by a combination of thickness changes with respect to the piezoelectric elements 65a and 65b. The maximum turning angle of the second scan mechanism 62 is the first scan angle θ1.

  In this way, a spatial resolution of several μm level can be obtained by setting the scan angle to a fine increment of 0.0003 ° or less.

<Variation 2 of high spatial resolution configuration>
As shown in FIG. 13, the light emitting units 11 (11a to 11d) are arranged in multiple stages, and each pulse laser beam is scanned in the scan direction AR while scanning the pulse laser beam in a direction perpendicular to the scan direction AR. Thus, the spatial resolution can be further improved.

  In Embodiments 1 to 3 described above, fire determination processing is performed on particles having a size of about 1 μm or more corresponding to FIG. 4 as smoke particles derived from smoke. However, the exhaust gas fine particles are 2.5 μm or less. The fire determination process may be performed by setting the smoke particles derived from the fire to 2.5 μm or more.

  In Embodiments 1 to 3 described above, the reflectance distribution indicated by the reflectance scan data is obtained, but the smoke generation position is acquired using the information of the B scope indicating the distance in the range direction. You may do it.

  You may make it supplement the three-dimensional distribution of smoke particles using the two-dimensional distribution image of the distance of the reflective point of light like this B scope. In this case, in particular, the particle density of the smoke particles can be obtained with high accuracy. Further, it is not necessary to obtain the three-dimensional information of the smoke particles, and the three-dimensional distribution of the smoke particles can be obtained only by using the reflectance distribution image and the two-dimensional distribution image of the distance. Further, reflectance information may be added to the two-dimensional distribution image of distance.

  In the first to third embodiments described above, the pulse radar light is scanned, but the present invention is not limited to this, and the pulse laser light may not be scanned. In this case, the average value for one specific measurement point data is used as the evaluation value of the smoke particle diameter and particle density. For example, information corresponding to FIG. 4 can be obtained from one specific measurement point data, and the evaluation value of the diameter and density of smoke particles is calculated from this information. The average value as the evaluation value for the scan data may be an average value for all measurement points in the scan range, or an average value for each measurement point.

  Furthermore, it is good also as a structure which gave the structure of the control part 24 in the monitoring part 20 to each laser radar part 10 side.

  Although the embodiment to which the invention made by the present inventors has been described has been described above, the present invention is not limited by the description and the drawings, which form part of the disclosure of the present invention according to this embodiment. That is, other embodiments, examples, operational techniques, and the like made by those skilled in the art based on the present embodiment are all included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Fire smoke detection apparatus 10 Laser radar part 11 Light emission part 12 Light receiving part 13 Scan mechanism 14 Transfer processing part 15 Communication part 20 Monitoring part 21 Communication part 22 Display part 23 Input part 24 Control part 25 Storage part 26 Notification part 31 Evaluation value calculation Unit 32 determination unit 33 notification processing unit 40 communication line 61 first scan mechanism 62 second scan mechanism 63 fixing member 64 support member 65a, 65b piezoelectric element AR scan direction D predetermined interval d average diameter D1 scan data D10, D20, D31, D32 Predetermined values D2, D21, D22 Reference values m, m1, m2 Evaluation value M Particle density P Smoke particles R, R1, R2 Reflectance RA Direction T Tunnel U Ceiling W Roadside band θ1 First scan angle θ2 Second scan angle λ1 , Λ2 wavelength

Claims (14)

A fire smoke detection device capable of detecting smoke originating from a fire,
An optical transceiver that emits light and acquires the intensity of the light reflected by the smoke particles;
An evaluation value calculation unit for calculating an evaluation value of smoke particle information related to the diameter of the smoke particles and / or the particle density of the smoke particles from the intensity of the reflected light;
A storage unit for storing a reference value of smoke particle information in the case of smoke derived from a fire;
When the evaluation value is equal to or greater than the reference value, the determination unit determines that the smoke particles are smoke derived from a fire,
A fire smoke detection device characterized by comprising:   The fire smoke detection apparatus according to claim 1, wherein the optical transmission / reception unit performs scanning.   The fire smoke detection device according to claim 1, wherein the optical transceiver is a laser radar.   The fire according to any one of claims 1 to 3, further comprising a notifying unit for notifying that when the determining unit determines that the smoke particles are smoke derived from a fire. Smoke detection device.   The said determination part determines with the said smoke particle being the smoke derived from a fire, when the time change per unit time of the said evaluation value is more than predetermined value change value, The smoke of Claim 1-4 characterized by the above-mentioned. The fire smoke detection device according to any one of the above. A plurality of the optical transceivers are arranged at predetermined intervals,
The determination unit determines that the smoke particles are smoke derived from a fire when a spatial change in an evaluation value due to the intensity of reflected light detected by an adjacent optical transceiver is equal to or greater than a predetermined spatial change value. The fire smoke detection device according to any one of claims 1 to 5. The intensity of the reflected light acquired by the optical transceiver is due to Mie scattering,
The fire smoke detection device according to any one of claims 1 to 6, wherein the evaluation value of the smoke particle information is a product of a square of the diameter of the smoke particles and a particle density of the smoke particles. . The light transmitting / receiving unit emits light of different wavelengths, and the intensity of reflected light acquired by the light transmitting / receiving unit is due to Rayleigh scattering for light of different wavelengths,
The evaluation value calculation unit calculates a diameter of the smoke particles and / or a particle density of the smoke particles as an evaluation value based on the intensity of light reflected by Rayleigh scattering having different wavelengths. The fire smoke detection device according to any one of 1 to 6.   The evaluation value calculation unit calculates the evaluation value by obtaining the smoke particle diameter and / or the particle density of the smoke particles by the shape recognition process of the smoke particles based on the reflected light intensity distribution image of the light transmitting / receiving unit. The fire smoke detection device according to any one of claims 1 to 6, wherein:   The evaluation value calculation unit recognizes the diameter of the smoke particles and / or the density of the smoke particles based on the two-dimensional distribution image of the distance between the light transmitting / receiving unit and the reflection point of the light by the smoke particles. The fire smoke detection device according to any one of claims 1 to 6, wherein the evaluation value is calculated by processing.   The fire smoke detection device according to any one of claims 1 to 6, wherein the light transmitting / receiving unit has an array of light receiving units that receive light reflected by the smoke particles.   The fire smoke detection device according to claim 11, wherein the light receiving units are integrated and disposed on the same substrate. The scanning mechanism of the optical transceiver unit is:
A first scan mechanism for scanning at a first scan angle;
A second scan mechanism disposed on the first scan mechanism and scanning at a second scan angle smaller than the first scan angle between the first scan angles;
Have
The fire smoke detection device according to any one of claims 2 to 12, wherein the light is emitted at the second scan angle.   The fire smoke detection device according to claim 13, wherein the second scan mechanism generates the second scan angle by driving a piezoelectric element.

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