Fire extinguishing system

Abstract

This enables appropriate firefighting in response to fires involving electric vehicles inside tunnels. [Solution] An imaging device (16) is installed in a monitoring area divided at a predetermined distance along the length of the tunnel to capture images. A water cannon device (20) is capable of changing the water discharge direction of the water cannon and is installed in the center of the monitoring area along the length of the tunnel. When a fire monitoring unit (66) of a disaster prevention receiving panel (10) detects a fire in the monitoring area monitored by a fire detector (14), a vehicle type determination unit (68) determines that the burning vehicle in the two-dimensional monitoring image captured by the imaging device (16) is an electric vehicle and instructs a fire extinguishing control unit (70) to extinguish the fire in the electric vehicle. The fire extinguishing control unit (70) generates a two-dimensional monitoring image of the monitoring area captured by the imaging device (16) and a distance image with distance information to the target object, detects the distance from the imaging device (16) to the fire source, and controls the water cannon device (20) to spray water toward the fire source based on the position and distance of the fire source.

Description

[Technical Field]

[0001] The present invention relates to a fire extinguishing system that extinguishes a fire in an electric vehicle that is installed in a tunnel having a road and is equipped with a drive battery. [Background technology]

[0002] Conventionally, tunnels on expressways and motorways are ranked according to their length and expected traffic volume under the Road Act and other regulations, and the installation of emergency equipment such as fire hydrants and water spraying equipment is mandatory depending on the rank. The ranking is based on the accident occurrence rate, which is correlated with the tunnel length and traffic volume (Patent Documents 1 and 2).

[0003] Recently, electric vehicles equipped with drive batteries using lithium-ion batteries, known as electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs), have become popular.

[0004] For this reason, vehicle fires occurring in tunnels include fires in electric vehicles. Fires in electric vehicles are caused by thermal runaway in the lithium-ion batteries used in the drive batteries, and the temperature tends to rise suddenly, for example, to 1000 to 1200°C, causing the fire to spread (Patent Document 3).

[0005] On the other hand, in the event of a fire occurring in an electric vehicle due to thermal runaway of a lithium-ion battery, it is recommended to use a continuous spray of large amounts of water as an effective firefighting method. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-014775 [Patent Document 2] Japanese Patent Publication No. 2023-010185 [Patent Document 3] Japanese Patent Application Laid-Open No. 2016-157513 Summary of the Invention [Problem to be solved by the invention]

[0007] However, if a fire breaks out in an electric vehicle traveling through a tunnel due to thermal runaway of a lithium-ion battery, there is a problem in that current fire extinguishing equipment, which is primarily designed for gasoline-powered vehicles and is designed to deal with fires caused by fuel leaks such as gasoline, or the ignition of general flammable materials such as flammable materials inside the vehicle or cables, is difficult to respond to such a fire in an electric vehicle.

[0008] For example, water spray equipment installed inside tunnels is installed for the purposes of fire extinguishing, preventing the spread of fire, protecting the tunnel structure, and protecting equipment.The concept behind this water spraying is to spray a volume of water calculated at 6 liters per minute per square meter into a protective area (radiation range) that protects the surface, while cooling vehicles and tunnel structures within the building limits in three dimensions to protect them.However, the amount of water sprayed is not sufficient for fires involving electric vehicles, which require the continuous spraying of large amounts of water.

[0009] In addition, fire hydrant devices are used by road users who discover a fire by pulling out a fire hose and spraying water from the nozzle, but road users are not aware that a large amount of water needs to be continuously sprayed to treat a fire in an electric vehicle, so the amount of water sprayed tends to be insufficient.Furthermore, if road users carelessly approach an electric vehicle on fire while spraying water, they may be at risk of electric shock.

[0010] Furthermore, even if road users operate a fire extinguisher stored in a fire hydrant device to spray fire extinguishing agent in the event of a fire in an electric vehicle, it is almost impossible to extinguish the fire, with the exception of fires in the very early stages or general flammable materials inside the vehicle.

[0011] Furthermore, although electric vehicles are becoming more popular, their current penetration rate is only about 3%, and even if this rate were to increase significantly in the future, if a fire were to break out in an electric vehicle traveling in a tunnel, the driver would recognize that it was an electric vehicle, but other parties involved would have difficulty immediately recognizing that it was an electric vehicle, and there would be a problem that firefighting efforts would not necessarily be carried out to deal with a fire in an electric vehicle.

[0012] The present invention is characterized by providing a fire extinguishing system that enables appropriate fire extinguishing in response to a fire in an electric vehicle inside a tunnel. [Means for solving the problem]

[0013] (Fire extinguishing system) The present invention provides a fire extinguishing system installed in a tunnel having a road, comprising: an imaging device installed in each of the monitoring areas divided at predetermined intervals in the longitudinal direction of the tunnel, for capturing images of the monitoring area in which it is installed; a water cannon device installed in each of the monitoring areas and capable of changing the direction of water discharge from the water cannon; a vehicle type determination unit that, when a vehicle fire is detected in a tunnel, determines whether the on-fire vehicle imaged by the imaging device is an electric vehicle; an image generation unit that generates, when the vehicle type determination unit determines that the burning vehicle is an electric vehicle, a two-dimensional monitoring image of the monitoring area captured by the imaging device and a distance image to which distance information from the imaging device to an object in the monitoring area is added; a fire source distance detection unit that identifies the position of the fire source of the on-fire vehicle from the two-dimensional monitoring image and detects the fire source distance from the imaging device to the fire source from the distance image; a water discharge control unit that controls the water cannon to discharge water toward the fire source based on the position of the fire source and the distance to the fire source; A fire extinguishing system comprising:

[0014] (Image recognition model for vehicle type determination) The vehicle type determination section an image recognition model unit that recognizes images through predetermined machine learning; a teacher image storage unit that stores teacher images of electric vehicles; a learning control unit that performs machine learning on the image recognition model unit using training images of the electric vehicle; an image preprocessing unit that, when a vehicle fire is detected in a tunnel, extracts and inputs into the trained image recognition model an area including the on-fire vehicle from a two-dimensional surveillance image captured by an imaging device; an image determination unit that determines that the vehicle is an electric vehicle when an estimated value of the electric vehicle output from the trained image recognition model unit satisfies a predetermined determination condition; Equipped with.

[0015] (Details of electric vehicles) The vehicle type determination unit determines whether the vehicle is an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle.

[0016] (Arrangement of imaging device and water cannon device) the imaging device is installed on the boundary of the upstream or downstream side of the monitoring area of ​​the own vehicle, and the imaging direction is fixed so as to capture an image of at least the monitoring area of ​​the own vehicle; The water cannon device is installed at the center of the monitoring area in the longitudinal direction of the tunnel or at a predetermined position near the center, and sprays water at fire sources within its monitoring area.

[0017] (Installation interval of imaging devices and water discharge distance of water cannon devices) The water cannon device has a water discharge distance that exceeds half the area distance of the monitoring area in the longitudinal direction of the tunnel, and is a predetermined distance that allows it to discharge water up to that area distance.

[0018] (Select the water cannon closest to the fire source and spray water) When a fire source of a burning vehicle is located within the monitoring area, the water discharge control unit selects a water cannon device that includes the fire source within its water discharge range and is closest to the fire source and causes it to discharge water.

[0019] (Water discharge control when the vehicle on fire and the adjacent vehicle are electric vehicles) If the vehicle type determination unit determines that another vehicle adjacent to the on-fire vehicle is an electric vehicle, the water discharge control unit selects another water cannon device that includes the other adjacent vehicle in its water discharge range and causes it to discharge water.

[0020] (Delayed water discharge) When the control of directing the water cannon toward the fire source is completed, the water discharge control unit starts discharging water after a predetermined delay time has elapsed.

[0021] (Fire source distance and coordinate detection) Furthermore, a coordinate processing unit is provided which detects the fire source coordinates (Xa, Ya, Za) in an imaging three-dimensional coordinate system with the imaging device as the origin (O1) based on the fire source distance, and converts the fire source coordinates (Xa, Ya, Za) in the imaging three-dimensional coordinate system into fire source coordinates (Xb, Yb, Zb) in a water discharge three-dimensional coordinate system with the water cannon device as the origin (O2), The water discharge control unit a water discharge direction detection unit that detects the water discharge direction of the water cannon device relative to the fire source based on the fire source coordinates (Xb, Yb, Zb) in the water discharge three-dimensional coordinate system; a water discharge driving unit that sets the water discharge direction in the water cannon device and causes the water to be discharged; Equipped with.

[0022] (Configuration and function of water cannon device) The water cannon device A horizontal rotation unit that changes the water discharge direction of the water cannon; A vertical rotation unit that changes the water discharge direction of the water cannon; and The water discharge direction detection unit detects the horizontal rotation angle (α) of the water cannon device directed toward the horizontal two-dimensional fire source coordinates (Xb, Yb) in the fire source coordinates (Xb, Yb, Zb) in the three-dimensional water discharge coordinate system, and also detects the vertical rotation angle (β) of the water cannon device directed toward the vertical two-dimensional fire source coordinates (Xb, Zb) in the fire source coordinates (Xb, Yb, Zb) in the three-dimensional water discharge coordinate system, The water discharge drive unit sets a horizontal turning angle (α) on the horizontal turning unit and a vertical turning angle (β) on the vertical turning unit to discharge water. [Effects of the Invention]

[0023] (Basic effects of fire extinguishing systems) The present invention relates to a fire extinguishing system to be installed in a tunnel having a road, the system comprising: an imaging device installed in each of the monitoring areas divided at predetermined intervals in the longitudinal direction of the tunnel and capturing images of the installed monitoring area; a water cannon device installed in each of the monitoring areas and capable of changing the water discharge direction of the water cannon; a vehicle type determination unit that, when a vehicle fire is detected in the tunnel, determines whether the burning vehicle captured by the imaging device is an electric vehicle; an image generation unit that, when the vehicle type determination unit determines that the burning vehicle is an electric vehicle, generates a two-dimensional monitoring image of the monitoring area captured by the imaging device and a distance image to which distance information from the imaging device to objects in the monitoring area is added; and a fire source determination unit that determines the location of the burning vehicle. The system is equipped with a fire source distance detection unit that identifies the fire source from a two-dimensional monitoring image and detects the distance from the imaging device to the fire source from the distance image, and a water discharge control unit that controls the water cannon to discharge water at the fire source based on the position and distance of the fire source.Therefore, when a vehicle fire is detected in a tunnel, it is possible to determine that the burning vehicle imaged by the imaging device is an electric vehicle, and if it is determined that the burning vehicle is an electric vehicle, the water cannon of the water cannon device can discharge water toward the fire source in the electric vehicle, thereby continuously discharging large amounts of water to extinguish the fire caused by thermal runaway of the lithium-ion battery used in the drive battery.

[0024] Furthermore, if the system determines that the vehicle on fire is an electric vehicle, the system detects the location and distance to the fire source from the two-dimensional surveillance image of the imaging device, and automatically targets the fire source with water from a water cannon device, making it possible to quickly and reliably extinguish a fire in an electric vehicle caused by thermal runaway of a lithium-ion battery without requiring road users to operate the water cannon device to perform firefighting activities.

[0025] In addition, taking into account the differences in the level of danger and amount of water discharged in the firefighting tactics (firefighting methods) for fires in gasoline vehicles and fires in electric vehicles, etc., the system makes it possible to distinguish between fires in electric vehicles, etc. and other fires, and to change the amount of water discharged so that a large amount of water is discharged for electric vehicles, etc. and the normal prescribed amount is discharged for gasoline vehicles, etc.

[0026] (Effect of image recognition model in vehicle type determination section) The vehicle type determination unit also includes an image recognition model unit that recognizes images using predetermined machine learning, a teacher image memory unit that stores teacher images of electric vehicles, a learning control unit that trains the image recognition model unit on machine learning using the teacher images of electric vehicles, an image pre-processing unit that extracts and inputs an area containing the on-fire vehicle contained in a two-dimensional surveillance image captured by an imaging device into the trained image recognition model unit when a vehicle fire is detected in a tunnel, and an image determination unit that determines that the vehicle is an electric vehicle if the estimated value of the electric vehicle output from the trained image recognition model unit satisfies predetermined determination conditions.Therefore, images of commercially available electric vehicles at the time the system begins operation are stored as teacher images in the teacher image memory unit, and the image recognition model unit is trained on machine learning using the teacher images of electric vehicles.When a vehicle fire is detected in a tunnel, an image of the on-fire vehicle extracted from the two-dimensional surveillance image captured by the imaging device is input into the trained image recognition model unit, and an estimated value close to 1 is output if it is an electric vehicle.As a determination condition, for example, an estimated value of 0.8 or higher determines that the vehicle on fire is an electric vehicle, making it possible to determine with high accuracy that the vehicle on fire is an electric vehicle. The image recognition model unit may have any configuration and function, but may use a model suitable for image recognition, such as a convolutional neural network.

[0027] (Effect of electric vehicle type) In addition, in order to determine that at least an electric vehicle (EV), hybrid vehicle (HV) or plug-in hybrid vehicle (PHV) is an electric vehicle, the vehicle type determination unit trains the image recognition model unit in machine learning using training images of electric vehicles, hybrid vehicles or plug-in hybrid vehicles, which serve as training images for electric vehicles, thereby making it possible to reliably determine that an electric vehicle, hybrid vehicle or plug-in hybrid vehicle included in electric vehicles that use lithium-ion batteries as their drive batteries is a vehicle that has caught fire.

[0028] In addition, in the case of an accident involving multiple vehicles, in the case of a fire involving an electric vehicle, hybrid vehicle, or plug-in hybrid vehicle (hereinafter referred to as EVs, etc.) and a gasoline vehicle, it will be possible to prioritize the vehicles to be targeted by the water cannon, allowing for a binary decision to be made, such as concentrating the water cannon on EVs, etc., or on the vehicle with the larger fire.

[0029] (Effect of the placement of the imaging device and water cannon device) In addition, the imaging device is installed at the boundary of its own monitoring area on the upstream or downstream side, and the imaging direction is fixed so that it captures at least its own monitoring area, and the water cannon device is installed at the center of the monitoring area in the longitudinal direction of the tunnel or at a specified position near that center, and in order to spray water at fire sources in its own monitoring area, one imaging device monitors each monitoring area divided in the longitudinal direction of the tunnel, and one water cannon device placed in the center of the monitoring area covers the entire monitoring area as a water spray area (protection area), so that no matter where the fire source is located within the monitoring area, the fire source can be accurately targeted by automatic water spray from one water cannon device, making it possible to quickly and reliably extinguish and suppress the fire.

[0030] (Effect of the installation interval of the imaging device and the water discharge distance of the water cannon device) Furthermore, since the water cannon device has a water discharge distance that exceeds half the area distance in the longitudinal direction of the tunnel of the monitored area and is a predetermined distance that allows it to discharge water up to that area distance, for example, if the area distance in the longitudinal direction of the tunnel of the monitored area is 50 meters, the water discharge distance of the water cannon device exceeds half that, 25 meters, but is a predetermined distance shorter than 50 meters, for example, a distance of around 30 meters, and it is possible to protect the entire monitored area as a water discharge area with a water discharge distance of the water cannon device that is equivalent to the water discharge distance of a fire hydrant device.Furthermore, because the water discharge distance of the water cannon device is equivalent to the water discharge distance of a fire hydrant device, it is possible to use the pump equipment and water supply piping of the fire hydrant device as is to extinguish fires with the water cannon device, which simplifies the equipment configuration and reduces equipment costs.

[0031] (The effect of spraying water by selecting a water cannon device close to the fire source) Furthermore, when the source of a fire in a burning vehicle is located within the monitored area, the water discharge control unit selects a water cannon device that includes the source of the fire within its water discharge range and is closest to the source of the fire to discharge water. This ensures that water is discharged from the water cannon device closest to the electric vehicle on fire, making it possible to carry out firefighting activities in response to a fire in an electric vehicle that continuously discharges large amounts of water.

[0032] (Effect of water discharge control when the vehicle on fire and the adjacent vehicle are electric vehicles) Furthermore, if the vehicle type determination unit determines that another vehicle adjacent to the burning vehicle is an electric vehicle, the water discharge control unit selects another water cannon device that includes the other adjacent vehicles in its water discharge range and discharges water from it.Therefore, if it determines that the vehicle parked behind the electric vehicle on fire, i.e., the vehicle adjacent to the burning vehicle (following vehicle), is an electric vehicle, the water cannon device will also discharge water on the following electric vehicle, thereby preventing the spread of the fire due to the adjacent electric vehicle spreading.

[0033] In addition, taking into account the differences in firefighting tactics between gasoline fires and fires involving electric vehicles, etc. (differences in risk level, amount of water sprayed, etc.), it will be possible to distinguish between fires involving electric vehicles, etc. and other fires and change the amount of water sprayed (large amounts of water for electric vehicles, etc., and the normal prescribed amount for gasoline vehicles).

[0034] (Effect of delayed water discharge) Furthermore, once the water cannon control unit has completed control of directing the water cannon at the fire source, it will begin spraying water after a specified delay time has elapsed, ensuring sufficient time to prevent the driver and passengers from being unable to evacuate due to water being sprayed from the water cannon device, and also ensuring that the driver and passengers have enough time to evacuate safely without receiving electric shock.

[0035] (Effect of detecting fire source distance and fire source coordinates) The apparatus further includes a coordinate processing unit that detects the fire source coordinates (Xa, Ya, Za) in an imaging three-dimensional coordinate system with the imaging device as the origin (O1) based on the fire source distance, and converts the fire source coordinates (Xa, Ya, Za) in the imaging three-dimensional coordinate system into fire source coordinates (Xb, Yb, Zb) in a water discharge three-dimensional coordinate system with the water cannon device as the origin (O2). The water discharge control unit includes a water discharge direction detection unit that detects the water discharge direction of the water cannon relative to the fire source based on the fire source coordinates (Xb, Yb, Zb) in the water discharge three-dimensional coordinate system. The water cannon is equipped with a water discharge control unit that sets the water discharge direction on the water cannon of the water cannon device and causes it to discharge water.By converting the first fire source coordinates in the imaging three-dimensional coordinate system of the imaging device into the second fire source coordinates in a different water discharge three-dimensional coordinate system of the water cannon device, the horizontal and vertical rotation angles of the water cannon to direct it at the second fire source coordinates can be accurately determined and the water discharge direction can be automatically set, making it possible to more accurately target the fire source by discharging water from the water cannon device and more reliably extinguish and suppress the fire.

[0036] (Configuration and functional effects of water cannon equipment) The water cannon device has a horizontal rotation unit that changes the water discharge direction of the water cannon horizontally, and a vertical rotation unit that changes the water discharge direction of the water cannon vertically, and the water discharge direction detection unit detects the horizontal rotation angle (α) of the water cannon device directed toward the horizontal two-dimensional fire source coordinates (Xb, Yb) in the fire source coordinates (Xb, Yb, Zb) in the three-dimensional water discharge coordinate system, and detects the vertical rotation angle (β) of the water cannon device directed toward the vertical two-dimensional fire source coordinates (Xb, Zb) in the fire source coordinates (Xb, Yb, Zb) in the three-dimensional water discharge coordinate system, The water discharge drive unit sets a horizontal rotation angle (α) on the horizontal rotation section and a vertical rotation angle (β) on the vertical rotation section to discharge water, so by converting the fire source coordinates in the imaging three-dimensional coordinate system of the imaging device into fire source coordinates in the water discharge three-dimensional coordinate system of a different water cannon device, it is possible to accurately determine the horizontal and vertical rotation angles of the water cannon to direct it at the fire source coordinates and automatically set the water discharge direction, making it possible to more accurately target the fire source by discharging water from the water cannon device and more reliably extinguish and suppress the fire. [Brief explanation of the drawings]

[0037] [Figure 1] FIG. 1 is an explanatory diagram showing an overview of a fire extinguishing system. [Figure 2] FIG. 1 is an explanatory diagram showing an imaging device and a water cannon device installed in a tunnel. [Figure 3] 3 is an explanatory diagram showing the imaging direction of the imaging device and the water discharge area of ​​the water cannon device for the monitoring area Ai of FIG. 2. FIG. [Figure 4] FIG. 10 is an explanatory diagram showing water discharge control in a fire extinguishing system when a fire source is located upstream of a water cannon device. [Figure 5] FIG. 10 is an explanatory diagram showing water discharge control in a fire extinguishing system when a fire source is located downstream of a water cannon device. [Figure 6] FIG. 1 is an explanatory diagram showing an embodiment of a water cannon device viewed from the side of a tunnel. [Figure 7] FIG. 1 is an explanatory diagram showing an embodiment of a water cannon device as seen from the upstream side of a tunnel. [Figure 8] 1 is an explanatory diagram showing an embodiment of a water cannon device in plan view. FIG. [Figure 9] FIG. 1 is an explanatory diagram showing the piping system of a fire hydrant device and a water cannon device. [Figure 10] FIG. 1 is an explanatory diagram showing the equipment configuration of a fire extinguishing system installed in a tunnel. [Figure 11] 11 is an explanatory diagram showing the functional configuration of the terminal processing device, the water cannon device, and the fire hydrant device of FIG. 10. FIG. [Figure 12] 10 is an explanatory diagram showing an embodiment of the functional configuration of a vehicle type determination unit and a fire extinguishing control unit provided in a disaster prevention receiving panel. FIG. [Figure 13] FIG. 10 is an explanatory diagram of a monitor unit displaying a monitoring image including an electric vehicle in which a fire has broken out; [Figure 14] FIG. 1 is an explanatory diagram showing fire source coordinates in a two-dimensional monitoring image. [Figure 15] FIG. 10 is an explanatory diagram showing an imaging three-dimensional coordinate system for detecting fire source coordinates from the fire source distance. [Figure 16] FIG. 2 is an explanatory diagram showing the relationship between the imaging three-dimensional coordinate system and the water discharge three-dimensional coordinate system of the fire extinguishing system. [Figure 17] 4 is a flowchart showing fire extinguishing control of the fire extinguishing system. [Figure 18]This is an explanatory diagram showing a fire in an electric vehicle inside a tunnel and water being sprayed by a water spraying device. [Figure 19] FIG. 10 is an explanatory diagram showing a monitoring image of a monitor unit in which water is being sprayed from a water cannon device onto an electric vehicle on fire. DETAILED DESCRIPTION OF THE INVENTION

[0038] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a fire extinguishing system according to the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments.

[0039] [Basic concept of the embodiment] First, the basic concept of the embodiment will be described. The embodiment generally relates to a fire extinguishing system installed in a tunnel having a road.

[0040] Here, a "fire extinguishing system" is a type of emergency equipment installed in areas subject to fire extinguishing, such as tunnels on expressways and motorways, and is composed of an imaging device, a water cannon device, a vehicle type determination unit, an image generation unit, a fire source distance detection unit, and a water discharge control unit, and is a concept that includes "fire extinguishing equipment."

[0041] Furthermore, an "imaging device" is a device that is installed in each of the monitoring areas divided at predetermined intervals along the length of the tunnel, and captures images of the monitoring area in which it is installed, and includes a television camera that captures color video.

[0042] Furthermore, the "water cannon device" is a device that is installed in each of the monitoring areas divided at predetermined intervals along the length of the tunnel, and allows the direction of the water cannon to be changed. By pointing the water cannon toward the fire source, the water cannon can be targeted and used to extinguish and suppress the fire. Here, the "water cannon" is a device that is installed in each monitoring area and discharges (sprays) pressurized water or other fire extinguishing agent from a nozzle.

[0043] Furthermore, the "vehicle type determination unit" determines whether the on-fire vehicle imaged by the imaging device is an electric vehicle when a vehicle fire is detected in a tunnel. Here, an "electric vehicle" is a vehicle equipped with a drive battery using a specified battery and running using an electric motor as a drive source or part of the drive source, specifically including electric vehicles (EVs), hybrid vehicles (HVs), and plug-in hybrid vehicles (PHVs). Here, the "specified battery" refers to various batteries that can cause a fire, including, for example, storage batteries such as lithium-ion batteries and all-solid-state batteries, but the focus is primarily on lithium-ion batteries.

[0044] Here, an "electric vehicle (EV)" is a vehicle that runs by driving a motor with a drive battery, and the drive battery is charged by an external power source. Also, a "hybrid vehicle (HV)" is a vehicle that runs by combining an internal combustion engine and a motor as two drive sources, and runs by adding or switching between the driving power of the internal combustion engine and the motor, and the drive battery is charged by a generator driven by the internal combustion engine. Also, a "plug-in hybrid vehicle (PHV)" is a hybrid vehicle whose drive battery can be charged by an external power source.

[0045] The "vehicle type determination unit" can have any configuration or function, but it uses an image recognition model unit (image recognition algorithm) that recognizes images through machine learning. The "image recognition model unit" is trained by machine learning using training images of electric vehicles, and when a vehicle fire is detected in a tunnel, the trained image recognition model unit extracts and inputs an area containing the on-fire vehicle from a two-dimensional surveillance image captured by an imaging device, and if the estimated value of an electric vehicle output from the trained image recognition model unit satisfies a predetermined judgment condition, for example, if the estimated value is 0.8 or higher as a judgment condition, it will be determined to be an electric vehicle.

[0046] The configuration and function of the "image recognition model unit" are arbitrary, but for example, a multi-layer neural network suitable for image recognition, which is composed of a convolutional neural network and a fully connected network, is used.

[0047] In addition, the "drive batteries" installed in "electric vehicles" use a large number of lithium-ion batteries, and an "electric vehicle fire" is a fire caused by thermal runaway of the lithium-ion batteries used in the drive batteries.

[0048] Here, "thermal runaway in lithium-ion batteries" refers to the phenomenon in which the heat generated during charging and discharging of lithium-ion batteries becomes uncontrollable. When a lithium-ion battery experiences thermal runaway, it falls into a state of abnormal heat generation and temperature rise, typically reaching high temperatures of 1000-1200°C, and in the worst case scenario, this can lead to accidents such as fire or ignition.

[0049] The causes of thermal runaway in lithium-ion batteries can be divided into physical and electrical mechanisms.

[0050] The "physical mechanism by which lithium-ion batteries experience thermal runaway" is physical damage to the lithium-ion battery itself. Inside a lithium-ion battery, the positive and negative electrodes are filled with separate electrolytes, which are separated by a partition called a separator. When charging or discharging, lithium ions pass through the separator little by little, causing a reaction to proceed, and the lithium ions move back and forth between charging and discharging.

[0051] "Thermal runaway in lithium-ion batteries due to physical mechanisms" occurs when the separator breaks due to some physical cause, causing a short circuit between the positive and negative electrodes. Possible physical causes include impact, pressure, or tearing due to a sharp object. When the positive and negative electrodes short-circuit, a very large current flows through the shorted area, generating a large amount of heat. This then triggers various heat-generating chemical reactions, such as reactions between the negative and positive electrodes and the electrolyte, decomposition of the electrolyte itself, and combustion reactions caused by oxygen released by sparks or the collapse of the positive electrode's crystalline structure during the short circuit, ultimately leading to thermal runaway.

[0052] In addition, the "electrical mechanism that causes thermal runaway in lithium-ion batteries" is due to overcharging or over-discharging the battery. When the battery is overcharged, the potential of the positive electrode rises, and heat is generated by the oxidative decomposition of the electrolyte. This heat causes the separator to gradually shrink, and the separator at the end of the electrode disappears, causing a short circuit. This induces various chemical reactions, accelerating the shrinkage of the separator and leading to thermal runaway.

[0053] For this reason, measures have been taken to prevent thermal runaway in lithium-ion batteries, such as program control to prevent overcharging and over-discharging, the use of flame retardants that do not ignite even when heated, and physical blocking of reactions at high temperatures.However, it is recognized that it is difficult to completely eliminate thermal runaway in lithium-ion batteries.

[0054] In the event of a fire occurring in an electric vehicle due to thermal runaway of a lithium-ion battery inside a tunnel, the recommended method of extinguishing the fire is to continuously spray large amounts of water.

[0055] The "image generation unit" generates a two-dimensional monitoring image of the monitoring area captured by the imaging device and a distance image to which distance information from the imaging device to the object in the monitoring area is added.

[0056] Here, a "two-dimensional monitoring image of a monitoring area" is an image of the monitoring area captured by an imaging device, which is displayed on a monitor to allow a user to understand the situation in the monitoring area, such as a vehicle fire. Also, a "distance image of a monitoring area" is an image in which each pixel constituting the two-dimensional monitoring image is assigned distance information to the object corresponding to the pixel.

[0057] Any method can be used to generate such a distance image, but examples include a method (PSF method) that measures the distance to an object by analyzing the correspondence between the color and size of blur that appears in an aberration map based on the point spread function (PSF) of the camera lens and the distance, or a method known as the Time of Flight (FOT) method, which detects the reflected light of pulsed light irradiated from a camera onto an object and determines the distance from the time of flight of the light.The distance from the imaging device to the object can be detected using a distance image generated by a single imaging device.

[0058] The "fire source distance detection unit" identifies the location of the fire source, indicating the location of the fire, from a two-dimensional surveillance image of the monitored area when a fire occurs, and detects the distance from the imaging device to the fire source from the distance image. Here, "identifying the location of the fire source" includes identification by manual manipulation, such as by a monitor touching the fire source of a vehicle fire on a monitor screen displaying a two-dimensional surveillance image of the monitored area with a finger or pen, and automatic identification of the location of the fire source through image processing of the two-dimensional surveillance image of the monitored area. Furthermore, the fire source on the two-dimensional surveillance image has a certain degree of spread depending on the scale of the fire, etc., and "identifying the location of the fire source" means identifying a single point within the spread of the fire source area.

[0059] The "water discharge control unit" controls the water cannon to discharge water toward the fire source based on the fire source's position identified from the two-dimensional surveillance image and the fire source distance detected from the distance image. Here, "based on the fire source's position identified from the two-dimensional surveillance image and the fire source distance detected from the distance image" means determining fire source coordinates that indicate the location of the fire in a three-dimensional imaging coordinate system with the imaging device as the origin. Furthermore, "controlling the water cannon to discharge water toward the fire source" means converting the fire source coordinates determined in the three-dimensional imaging coordinate system into fire source coordinates in a three-dimensional water discharge coordinate system with the water cannon device as the origin, determining the horizontal and vertical rotation angles of the water cannon to direct it toward the fire source coordinates, and rotating the water cannon to discharge (discharge) a fire extinguishing agent such as water from the water cannon.

[0060] In this embodiment, the water discharge distance of the water cannon device is assumed to be a predetermined distance that exceeds half the area distance in the longitudinal direction of the tunnel of the monitoring area corresponding to the placement interval of the image capture devices, but is shorter than that area distance. The placement interval of the image capture devices is arbitrary, but for example, if it is 50 meters, the same as the placement interval of the fire hydrant devices, the water discharge distance of the water cannon device will be more than 25 meters but shorter than 50 meters, for example, about 30 meters.

[0061] The positioning of the water cannon device relative to the imaging device is arbitrary, but for example, the imaging device is installed at the boundary of the upstream or downstream side of its own monitoring area, and its imaging direction is fixed so that it captures at least its own monitoring area. The water cannon device is installed at the center of the monitoring area between the imaging devices in the longitudinal direction of the tunnel or at a predetermined position near the center, and it sprays water at fire sources in its own monitoring area.

[0062] For example, if imaging devices are placed at the boundaries of the monitored area, spaced 50 meters apart, and water cannon devices are placed in the center of the monitored area, at or near the center 25 meters from the imaging devices placed on both side boundaries, and the water cannon distance is 30 meters, one water cannon device can cover the entire monitored area as a water cannon area, and the water can be accurately targeted at the source of the fire, making it possible to reliably extinguish and suppress the fire.

[0063] According to the fire extinguishing system of the embodiment, which is thus composed of an imaging device, a water cannon device, a vehicle type determination unit and image generation unit, a fire source distance detection unit and a water discharge control unit, when a vehicle fire is detected in a tunnel, it is possible to determine that the burning vehicle imaged by the imaging device is an electric vehicle.If it is determined to be an electric vehicle, the water cannon of the water cannon device can continuously discharge large amounts of water toward the source of the fire in the electric vehicle, thereby making it possible to extinguish a fire in an electric vehicle caused by thermal runaway of the lithium-ion battery used in the drive battery.

[0064] In the following, a specific embodiment will be described. In the following specific embodiment, the "electric vehicle" is any one of an "electric vehicle (EV), a hybrid vehicle (HV), and a plug-in hybrid vehicle (PHV)," and a "disaster prevention receiving panel" centrally monitors imaging devices and water cannon devices installed in each monitoring area in a tunnel, and when a fire is detected in any of the monitoring areas, if the imaging device is selected and the acquired two-dimensional monitoring image determines that the burning vehicle is an electric vehicle, the water cannon device is controlled to spray water on the source of the fire in the electric vehicle.

[0065] [Specific details of the embodiment] The fire hydrant equipment will be explained in more detail below. a. Overview of the fire extinguishing system a1.Tunnel placement equipment a2. Disaster prevention receiving panel b. Placement of the imaging device and water cannon device c.Monitoring area and fire source distance d. Monitoring area and water discharge area e. Fire control f. Water cannon device structure g. Interlocking of water cannon equipment and fire hydrant equipment h. Water discharge capacity of fire hydrant equipment and water cannon equipment i. Equipment configuration of the fire extinguishing system installed in the tunnel j. Vehicle type determination section of the fire extinguishing system k. Fire extinguishing control section of fire extinguishing system k1. Overview of the Fire Extinguishing Control Unit l. Functions of the image generation unit l1. Generation of 2D surveillance images l2. Generate range images m.Fire source distance detection unit n. Fire source coordinate processing unit n1. Fire source coordinates in the three-dimensional coordinate system n2. Fire source coordinates in the three-dimensional water discharge coordinate system o. Water discharge direction detection unit p. Fire extinguishing control of the embodiment q. Fire extinguishing control for adjacent vehicles r. Modifications of the present invention

[0066] [a. Overview of the fire extinguishing system] An overview of a fire extinguishing system according to an embodiment will be described with reference to Fig. 1 which shows an overview of the fire extinguishing system.

[0067] (a1. Tunnel placement equipment) As shown in FIG. 1, an up-track tunnel 12 (12-1) and a down-track tunnel 12 (12-2) are constructed as tunnels for expressways. The up-track tunnel 12 (12-1) has an entrance (upstream) on the left and an exit (downstream) on the right. The down-track tunnel 12 (12-2) has an entrance (upstream) on the right and an exit (downstream) on the left. Fire detectors 14 are installed along the longitudinal walls of the up-track tunnel 12 (12-1) and the down-track tunnel 12 (12-2), for example, at intervals of 50 meters. Each fire detector 14 is connected to a transmission line 22 extending from the disaster prevention receiving panel 10 and assigned a unique address. The transmission line 22 includes an R-type transmission line 2210 connecting the fire detectors 14 and a P-type signal line 2212 connecting a transmitter, a response lamp, a pump start switch, and the like, installed in the fire hydrant device 18. The R-type transmission line 2210 is a line for transmitting and receiving signals by specifying a terminal address, and the P-type signal line is a line for connecting a plurality of terminal devices in parallel and transmitting and receiving signals on a line-by-line basis.

[0068] The fire detector 14 is well known and is equipped with two sets of fire detection units, one for a right eye and one for a left eye, so that it has detection areas in both the upward and downward longitudinal directions within the tunnel, which is the monitored space, and the detection areas of adjacent fire detectors 14 are arranged continuously so that they overlap in a mutually complementary manner, for example, and the fire is detected by observing infrared rays from the flames associated with a fire that has occurred within the detection area, and a fire detection signal including its own address is transmitted to the disaster prevention receiving panel 10.

[0069] In addition, imaging devices 16 are installed along the longitudinal walls of the up-track tunnel 12 (12-1) and the down-track tunnel 12 (12-2), at intervals of, for example, 50 meters. The imaging devices 16 are connected to a transmission line 24 drawn from the disaster prevention receiving panel 10, and can transmit captured two-dimensional monitoring images, such as video images, to the disaster prevention receiving panel 10 for display on the monitor unit 36. Furthermore, by setting a unique address, remote control such as starting and stopping the transmission of two-dimensional monitoring images can be performed in response to control instructions from the disaster prevention receiving panel 10.

[0070] In addition, in the up-track tunnel 12 (12-1) and the down-track tunnel 12 (12-2), fire hydrant devices 18 are installed along the walls of the guard passages in the longitudinal direction of the tunnels, for example, at intervals of 50 meters. The fire hydrant devices 18 are well known and contain a fire hose with a nozzle, an emergency notification device such as a transmitter, and a fire extinguisher.

[0071] In addition, water cannon devices 20 are installed along the longitudinal walls of the inbound tunnel 12 (12-1) and the outbound tunnel 12 (12-2), for example, at intervals of 50 meters. The water cannon devices 20 are equipped with water cannons that rotate horizontally and vertically, and can extinguish vehicle fires that break out in the tunnels by pointing the water cannons at the source of the fire and spraying water. In this embodiment, the water cannon devices 20 are installed near fire hydrant devices 18, which are installed on the walls along the watchman's passage, and a terminal processing device used to control the water spraying is housed in the fire hydrant device 18. The terminal processing device is connected to a transmission line 26 from the disaster prevention receiving panel 10 and receives horizontal and vertical rotation control signals from the disaster prevention receiving panel 10, enabling fire extinguishing control by directing the water cannon devices 20 to spray water at the source of the fire. The fire hydrant devices 18 are equipped with terminal devices such as transmitters, response lamps, and pump start switches, and a P-type signal line 2212 is provided for each terminal device of a plurality of fire hydrant devices 18 arranged in the longitudinal direction of the tunnel, for example, four fire hydrant devices 18, which form one section, and the plurality of terminal devices are connected in parallel to the corresponding P-type signal lines 2212.

[0072] In addition, in the up-track tunnel 12 (12-1) and the down-track tunnel 12 (12-2), water sprays are installed that spray fire-fighting water from water spray heads to protect the tunnel body and the ducts under the road surface of the guard passage from fire, but these are not shown in the illustration.

[0073] (a2. Disaster prevention receiving panel) A disaster prevention receiving panel 10 is installed in the monitoring center or electrical room, which serves as the management facility for the up-track tunnel 12 (12-1) and the down-track tunnel 12 (12-2). The disaster prevention receiving panel 10 is provided with a panel control unit 28, which is equipped with a computer circuit equipped with a CPU, memory, input / output ports, etc., and the functions of the panel control unit 28 are realized by the execution of a program by the CPU, including the functions of a fire monitoring unit 66, a vehicle type determination unit 68, and a fire extinguishing control unit 70.

[0074] The panel control unit 28 is equipped with a transceiver unit 29 and transmission units 30, 32, and 34. A P-type signal line 2212, which connects the terminal devices of the fire hydrant devices 18 installed in the up-line tunnel 12 (12-1) and the down-line tunnel 12 (12-2) on a section-by-section basis, is connected to the transceiver unit 29. The transceiver unit 29 receives a fire notification signal generated by the operation of a transmitter installed in the fire hydrant device 18 and transmits a response signal to turn on a response lamp. It also receives a pump start signal generated by the operation of a pump start switch. The R transmission line 2210 included in the transmission path 22 from the up-line tunnel 12 (12-1) and the down-line tunnel 12 (12-2) is connected to the transmission unit 30, and the transmission paths 24 and 26 are connected to the transmission units 32 and 34. The panel control unit 28 is also connected to a monitor unit 36, a display unit 38, an operation unit 40, an alarm unit 42, a modem 44, and an I / O unit 46.

[0075] The I / O section 46 of the disaster prevention receiving panel 10 is connected to a fire pump equipment 48, a cooling pump equipment 50 for ducts, an IG substation equipment 52, a ventilation equipment 56, an alarm display board equipment 58, a radio rebroadcasting equipment 60, a television monitoring equipment 62, and a lighting equipment 64, etc.

[0076] Here, the fire pump equipment 48 operates in response to a pump activation signal when the disaster prevention receiving panel 10 receives a fire detection signal from the fire detector 14 or a fire notification signal from the operation of a transmitter installed in the fire hydrant device 18, and the motor drives the fire pump to supply fire-fighting water to the fire hydrant device 18 and water cannon device 20 inside the tunnel, making it possible to spray water.

[0077] The duct cooling pump equipment 50 receives temperature detection signals from a temperature detector installed in a duct under the road surface of the guard passage at the disaster prevention receiving panel 10, and operates in response to a pump start signal when a predetermined threshold temperature is exceeded.The motor drives the cooling pump to supply and spray fire extinguishing water to the sprinkler head in the duct, cooling the inside of the duct and protecting the wiring cables.

[0078] The IG slave station equipment 52 is a communication equipment that connects the disaster prevention receiving panel 10 to an external higher-level equipment, the remote monitoring and control equipment 54, via a network. The ventilation equipment 56 is equipment that generates ventilation air in the longitudinal direction of the tunnel by operating jet fans installed on the ceiling side inside the tunnel.

[0079] The warning display board equipment 58 is equipment that displays on an electronic display board any abnormalities inside the tunnel, such as no-entry warnings due to fires, to notify users. The radio rebroadcast equipment 60 is equipment that allows drivers and others inside the tunnel to receive information from the road administrator on a radio receiver. The television monitoring equipment 62 is equipment that is used to confirm the size and location of a fire, activate water spray equipment, and grasp the situation inside the tunnel when providing evacuation guidance. The lighting equipment 64 is equipment that drives and manages the lighting equipment inside the tunnel.

[0080] Furthermore, when the fire monitoring unit 66 of the panel control unit 28 receives a fire signal including an address from the fire detector 14 installed on the tunnel side via the transmission unit 30, it outputs a fire alarm specifying the monitoring area, and also specifies the monitoring area in which the fire was detected and notifies the vehicle type determination unit 68. Furthermore, when the fire monitoring unit 66 receives a fire notification signal via the transmission / reception unit 29, generated by operating a transmitter provided in the fire hydrant device 18 installed on the tunnel side, it outputs a fire alarm specifying the section.

[0081] Furthermore, when the vehicle type determination unit 68 of the panel control unit 28 receives a notification from the fire monitoring unit 66 of a monitoring area in which a fire has been detected based on the fire detection by the fire detector 14, the vehicle type determination unit 68 selects the imaging device 16 installed in the monitoring area in which the fire was detected, acquires a two-dimensional monitoring image, extracts an area in the two-dimensional monitoring image that includes the burning vehicle, and determines whether or not the vehicle is an electric vehicle. The configuration and function of the vehicle type determination unit 68 are arbitrary, but an image recognition model unit that recognizes images through machine learning is used. Note that when the fire monitoring unit 66 receives a fire notification signal by operating a transmitter installed in the fire hydrant device 18, for example, a fire occurrence section including four fire hydrant devices is identified, but the monitoring area in which the fire is occurring within that section is not identified. Therefore, the vehicle type determination unit 68 sequentially selects the imaging device 16 installed in the four monitoring areas belonging to the fire occurrence section, acquires a two-dimensional monitoring image, determines the source of the fire, identifies the monitoring area in which the fire source has been identified as the fire occurrence area, and determines whether or not the vehicle is an electric vehicle in the same manner as when receiving a notification of a monitoring area based on the fire detection by the fire detector 14.

[0082] The fire extinguishing control unit 70 of the panel control unit 68 detects the fire source distance based on the two-dimensional monitoring image received from the imaging device 16 installed in the monitoring area where the fire was detected, and calculates the fire source coordinates (Xa, Ya, Za) in the imaging three-dimensional coordinate system. Next, it converts the coordinates into fire source coordinates (Xb, Yb, Zb) in the water-spraying three-dimensional coordinate system to detect the horizontal rotation angle (α) and vertical rotation angle (β) as the water-spraying direction of the water cannon device, and sends these to the water cannon device 20 installed in the monitoring area Ai where the fire was detected, directing the water cannon at the fire source to spray water, accurately targeting the fire source of the electric vehicle where the fire is occurring, and continuously spraying large amounts of water to extinguish and suppress the fire in the electric vehicle caused by thermal runaway of the lithium-ion battery.

[0083] [b. Placement of imaging device and water cannon device] Next, we will explain the placement of the imaging device and water cannon device inside the tunnel of the fire extinguishing system. In this explanation, we will refer to Figure 2, which shows the imaging device and water cannon device installed inside the tunnel of the fire extinguishing system. Note that Figure 2(A) shows the side view inside the tunnel, Figure 2(B) shows the plan view inside the tunnel, and Figure 2(C) shows a cross section perpendicular to the longitudinal direction of the tunnel.

[0084] In the description of FIG. 2, the X, Y, and Z directions are mutually orthogonal. Specifically, the left-right direction when viewing the tunnel longitudinal direction from the upstream side of the tunnel is the X direction, the up-down direction is the Y direction, and the longitudinal direction of the tunnel (front-to-back direction) is the Z direction. The +X side in the X direction is the right side, the -X side is the left side, the +Y side in the Y direction is the upper side, the -Y side is the lower side, and the +Z side in the Z direction is the downstream side and the -Z side is the upstream side. Regarding the longitudinal direction of the tunnel, which is the Z direction, the tunnel entrance side is the upstream side (-Z side) and the tunnel exit side is the downstream side (+Z side) based on the flow of vehicles entering the tunnel entrance and exiting the tunnel exit. This point also applies to the X, Y, and Z directions in FIG. 3 and subsequent figures, which are embodiments of the present invention. Note that in FIG. 2(C), the left and right are shown in reverse because the longitudinal direction of the tunnel is viewed from the downstream side of the tunnel.

[0085] As shown in Figures 2(A) and 2(B), within the up-bound tunnel 12 (12-1), a road surface 15, for example, with two lanes, is constructed in the longitudinal direction of the tunnel, and a guard passage 17 is constructed along one side of the tunnel wall, which is higher than the road surface 15. In addition, fire hydrants 18 are embedded in the wall along the guard passage 17 at predetermined intervals, for example, every 50 meters.

[0086] In this embodiment, the inside of the up-track tunnel 12 (12-1) is virtually divided into monitoring areas at predetermined intervals along the length of the tunnel, and as an example, three monitoring areas Ai-1, Ai, and Ai+1 are shown in Figures 2(A) and 2(B). The distance intervals along the length of the tunnel between the monitoring areas are arbitrary, but for example, they are spaced 50 meters apart, the same as the spacing between fire hydrant devices 18.

[0087] Imaging devices 16(16-i-1), 16(16-i), and 16(16-i+1) are disposed in monitoring areas Ai-1, Ai, and Ai+1. Imaging devices 16(16-i-1), 16(16-i), and 16(16-i+1) are, for example, television cameras capable of capturing color video and video that can generate two-dimensional monitoring images and distance images through image processing.

[0088] In this embodiment, each of the imaging devices 16(16-i-1), 16(16-i), 16(16-i+1) is placed at a predetermined position above the monitor passage 17 at the upstream boundary of the monitoring areas Ai-1, Ai, Ai+1, and has the downstream monitoring areas Ai-1, Ai, Ai+1 as its imaging area starting from its own position.

[0089] Furthermore, the imaging devices 16(16-i-1), 16(16-i), and 16(16-i+1) are fixed in the imaging direction indicated by the imaging axis 1610 so as to image at least their own monitoring areas. The direction of the imaging axis 1610 of the imaging device 16 is arbitrary as long as it is possible to image the own monitoring area, but for example, as shown in Fig. 2(A), when viewed from the side of the tunnel, the imaging axis 1610 is set toward the position where the downstream area boundary intersects with the road surface 15, and as shown in Fig. 2(B), when viewed from above, the imaging axis 1610 is set toward the position where the downstream area boundary intersects with the tunnel wall surface on the opposite side.

[0090] When images of the monitoring area captured by the imaging devices 16(16-i-1), 16(16-i), and 16(16-i+1) with the imaging axes 1610 set in this way are displayed on a monitor screen, the range from the road surface 15 included in the respective monitoring area to the tunnel wall surface is displayed, and also a monitoring image of the inside of the tunnel on the downstream side is displayed. Of course, since the monitoring area is set virtually, it is not possible to identify the monitoring area from the monitoring image on the monitor screen, but it is possible to superimpose the downstream boundary line on the monitoring image by image processing if necessary.

[0091] Water cannon devices 20(20-i-1), 20(20-i), 20(20-i+1) are installed in monitoring areas Ai-1, Ai, Ai+1, respectively, and are capable of changing the water discharge direction of the water cannons indicated by water discharge axis 2010. Here, the water discharge direction of the water cannons can be changed by arbitrarily setting the horizontal rotation angle (α) and vertical rotation angle (β) of the water cannons.

[0092] In this embodiment, the water cannon devices 20(20-i-1), 20(20-i), and 20(20-i+1) are installed at the center of the monitoring areas Ai-1, Ai, and Ai+1, which are located between the imaging devices 16 in the longitudinal direction of the tunnel. Here, the distance between the monitoring areas Ai-1, Ai, and Ai+1 in the longitudinal direction of the tunnel is the same as the spacing between the imaging devices 16 placed at the area boundaries, for example, 50 meters, and therefore the water cannon devices 20(20-i-1), 20(20-i), and 20(20-i+1) are installed at the center of each monitoring area, 25 meters downstream from the imaging devices 16(16-i-1), 16(16-i), and 16(16-i+1) placed at the upstream area boundary.

[0093] Furthermore, the water cannon devices 20(20-i-1), 20(20-i), 20(20-i+1) are placed on the road surface 15 side of the observer passage 17 at the center position in the longitudinal direction of the tunnel of each monitored area, and are installed at a height such that they are below the imaging device 16. Furthermore, the water cannon devices 20(20-i-1), 20(20-i), 20(20-i+1) can initially spray water in any direction, but for example, in order not to obstruct passage through the observer passage 17, they are initially set so that the water cannon axis 2010 is oriented horizontally in the longitudinal direction of the tunnel.

[0094] In the initial setting of these water cannon devices 20(20-i-1), 20(20-i), and 20(20-i+1), the horizontal rotation angle (α) and vertical rotation angle (β) of the water cannon are each set to 0°. Note that the placement positions of the water cannon devices 20(20-i-1), 20(20-i), and 20(20-i+1) are not limited to the central position in the longitudinal direction of the tunnel in each monitoring area, but may include predetermined positions near the central position.

[0095] [c.Monitoring area and fire source distance] Next, we will explain the relationship between the monitoring area monitored by the imaging device and the distance to the fire source, which indicates the location of the fire. In this explanation, we will refer to Figure 3, which shows the imaging direction of the imaging device and the water discharge area of ​​the water cannon device for the monitoring area Ai in Figure 2. Note that Figure 3(A) shows the side view of the inside of the tunnel, and Figure 3(B) shows the plan view of the inside of the tunnel.

[0096] The direction of the imaging axis 1610 of the imaging device 16 (16-i) can be any direction as long as it can capture the entire monitoring area Ai, but for example, on the side of the tunnel in Fig. 3(A), the imaging axis 1610 is set so as to connect the imaging point a of the imaging device 16 (16-i) arranged in the monitoring area Ai and the boundary point b (farthest point) where the downstream rectangular boundary surface intersects with the road surface 15. Therefore, the downstream boundary of the monitoring area Ai is the effective imaging boundary 1620, which is a part of a sphere with the imaging point a as its center and the distance Lab between a and b as its radius.

[0097] 3(B), the imaging axis 1610 is set so as to connect the imaging point a of the imaging device 16 (16-i) with the boundary point b (farthest point) where the downstream rectangular boundary surface intersects with the tunnel wall surface on the opposite side. Therefore, a part of a sphere with the imaging point a as its center and the distance Lab between a and b as its radius becomes the effective imaging boundary 1620. Note that the boundary point b that determines the effective imaging boundary 1620 may be set by placing a predetermined marker at the planned boundary position inside the actual tunnel, and the distance to the marker may be detected from a distance image generated by capturing an image with the imaging device 16 (16-i).

[0098] In the fire extinguishing control of this embodiment, if the fire source distance is equal to or less than the area boundary distance Lab to the effective imaging boundary 1620, the fire source is determined to be within the monitoring area Ai, and water is sprayed on the fire source from the water cannon device 20 (20-i) arranged in the monitoring area Ai. On the other hand, if the fire source distance exceeds the area boundary distance Lab to the effective imaging boundary 1620, the fire source is determined to be outside the monitoring area Ai, and water is not sprayed on the fire source from the water cannon device 20 (20-i) arranged in the monitoring area Ai, but fire extinguishing control is performed using the imaging device 16 (16-i+1) and water cannon device 20 (20-i+1) arranged in the adjacent monitoring area Ai+1 on the downstream side.

[0099] [d. Monitoring Area and Water Discharge Area] Next, the monitoring area Ai of the imaging device 16 (16-i) and the water discharge area of ​​the water cannon device 20 (20-i) will be described. As shown in Figure 3, which shows the monitoring area Ai, the effective water discharge distance of the water cannon device 20 (20-i) does not exceed 50 meters, the area distance in the longitudinal direction of the tunnel of the monitoring area Ai, but is an arbitrary distance exceeding 25 meters, which is half the distance of the monitoring area Ai.

[0100] For example, if the farthest point of the monitoring area Ai as seen from the water discharge point c of the water cannon device 20 (20-i) is the intersection b between the boundary of the monitoring area Ai and the tunnel wall opposite the installation side of the water cannon device 20 (20-i) in the tunnel plane of Figure 3 (B), it is necessary to ensure a water discharge distance such that the distance Lcb from the water discharge point c to the farthest point b of the monitoring area Ai is the minimum distance.

[0101] For example, if the width of road surface 15 is 10 meters and the height of water discharge point c from road surface 15 is 2 meters, this minimum water discharge distance Lcb is approximately 27 meters. Therefore, the effective water discharge distance required for water cannon device 20 is secured to be, for example, 30 meters, with some leeway.

[0102] Here, the effective water discharge distance is the distance that the fire extinguishing agent (fire water) discharged from the water cannon flies in a straight line, and refers to the water discharge distance that allows the fire source to be targeted by a straight line of water discharge. In this way, if the effective water discharge distance of the water cannon device 20 (20-i) is, for example, 30 meters, an effective water discharge boundary 2020 centered on the water discharge point c and having a radius of the effective water discharge distance of 30 meters is set outside the upstream and downstream area boundaries of the monitoring area Ai, and one water cannon device 20 (20-1) can cover the entire monitoring area Ai as a water discharge area.

[0103] [e. Fire Control] Next, the fire extinguishing control in this embodiment will be explained. In this explanation, reference will be made to Fig. 4, which shows the water discharge control when a fire source is located upstream of a water cannon device in a fire extinguishing system, and Fig. 5, which shows the water discharge control when a fire source is located downstream of a water cannon device. In Fig. 4 and Fig. 5, (A) shows the side view inside the tunnel, and (B) shows the plan view inside the tunnel.

[0104] As shown in Figure 4, if a fire in an electric vehicle indicated by fire source P is located upstream (to the left) of the center position of the monitoring area Ai, the fire source distance Lap from the imaging device 16 (16-i) to the fire source P is shorter than the area boundary distance Lab of the effective imaging boundary 1620, so it is determined to be a fire source in the own monitoring area Ai, and the water cannon device 20 (20-i) located at the center position of the own monitoring area Ai is controlled.

[0105] The water cannon device 20 (20-i) rotates the water cannon at a horizontal rotation angle (α) and a vertical rotation angle (β) so as to point the water cannon at the fire source P. The fire source water discharge distance Lcp from the water discharge point c of the water cannon device 20 (20-i) to the fire source P does not exceed the effective water discharge boundary 2020 with a radius of 30 meters, which is the effective water discharge distance of the water cannon device 20 (20-i). Therefore, it is possible to continuously discharge large amounts of water by targeting the fire source P in the electric vehicle, thereby extinguishing and suppressing a fire in the electric vehicle caused by thermal runaway of the lithium-ion battery used in the drive battery.

[0106] Also, as shown in Figure 5, if the location of a fire in an electric vehicle indicated by fire source P is downstream (to the right) of the center position of the monitoring area Ai, the fire source distance Lap from the imaging device 16 (16-i) to the fire source P is shorter than the boundary distance Lab of the effective imaging boundary 1620, so it is determined to be a fire source in the own monitoring area Ai, and the water cannon device 20 (20-i) located at the center position of the own monitoring area Ai is controlled.

[0107] The water cannon device 20 (20-i) rotates the water cannon at a horizontal rotation angle (α) and a vertical rotation angle (β) so as to point the water cannon at the fire source P. Even in this case, the fire source water discharge distance Lcp from the water discharge point c of the water cannon device 20 (20-i) to the fire source P does not exceed the effective water discharge boundary 2020 of 30 meters downstream of the water cannon device 20, so that large amounts of water can be continuously discharged by targeting the fire source P, making it possible to extinguish and suppress a fire in an electric vehicle caused by thermal runaway of the lithium-ion battery used in the drive battery.

[0108] [f. Structure of the water cannon device] Next, the structure of the water cannon device will be explained with reference to Fig. 6, which shows an embodiment of the water cannon device as seen from the side of the tunnel, Fig. 7, which shows an embodiment of the water cannon device as seen from the upstream side of the tunnel, and Fig. 8, which shows an embodiment of the water cannon device as seen from above.

[0109] 6 to 8, the water cannon device 20 is placed on the road side of the lifeguard passage 17. The water cannon device 20 may be placed in any configuration relative to the lifeguard passage 17, but as an example, a water supply pipe 88 is erected from inside a duct below the passage, and the water cannon device 20 is placed on a pipe base 90 fixed to the upper end of the water supply pipe 88.

[0110] In the water cannon device 20, a horizontally swiveling pipe 96 is installed on a horizontal base 92 so as to be rotatable around a horizontal swivel shaft 8210 within a range of a predetermined angle 8212, and a horizontally swiveling unit 82 is provided for the horizontal swivel shaft 8210. The horizontally swiveling unit 82 may have any structure or mechanism, but may be composed of a worm wheel 98, a worm 100, a horizontally swiveling motor 102, and a rotary encoder 104, for example.

[0111] The worm wheel 98 is fixed to the outer periphery of the horizontal swivel pipe 96, and a worm 100 is engaged with the worm wheel 98 from a direction perpendicular to the worm wheel 98. The worm 100 is fixed to the output shaft of a horizontal swivel motor 102 fixed to the horizontal base 92, and the worm wheel 98 is rotated by the rotation of the worm 100 by the horizontal swivel motor 102. The horizontal swivel motor 102 is integrally provided with, for example, a rotary encoder 104, which is capable of detecting the horizontal swivel angle. Note that the rotary encoder 104 may be provided separately from the horizontal swivel motor 102.

[0112] A vertical swivel section 84 is provided at the top of the horizontal swivel piping 96, and the lower end of a water cannon 85 is attached to the vertical swivel shaft 8410 so as to be rotatable within a predetermined angle 8412. As shown in the plan view of Figure 8, the water cannon 85 has a shape in which the piping section rises upward from the lower end and then curves laterally, with the nozzle section at the tip positioned in the direction of the water discharge axis 2010.

[0113] The vertical rotation unit 84 may have any structure or mechanism, but may, for example, be configured with a large gear 105, a small gear 106, a vertical rotation motor 108, and a rotary encoder 110. The large gear 105 is fixed to the outer periphery of the pipe base of the water cannon 85, and the small gear 106 meshes with the large gear 105 from a direction perpendicular to the large gear 105.

[0114] The small gear 106 is fixed to the output shaft of a vertical rotation motor 108 fixed to the horizontal rotation pipe 96, and the rotation of the vertical rotation motor 108 is reduced and transmitted to the large gear 105, thereby causing the water cannon 85 to rotate vertically. The vertical rotation motor 108 is integrally provided with, for example, a rotary encoder 110, which makes it possible to detect the vertical rotation angle. The rotary encoder 110 may be provided separately from the vertical rotation motor 108. The horizontal rotation unit 82 and the vertical rotation unit 84 are provided with covers that cover both of them, but these covers are not shown in the drawings and are exposed.

[0115] [g. Interlocking of water cannon equipment and fire hydrant equipment] Next, the interlocking of the water cannon device and the fire hydrant device will be explained. In this explanation, reference will be made to Figure 9, which shows the piping system of the fire hydrant device and the water cannon device.

[0116] As shown in Figure 2, the water cannon devices 20 installed in each monitoring area within the up-track tunnel 12 (12-1) are located near the fire hydrant devices 18, and are able to spray fire water using the piping system connected to the fire hydrant devices 18.

[0117] The water cannon device 20 may have any structure that utilizes the piping system of the fire hydrant device 18, and one example is shown in Figure 9. First, a water supply pipe 114 that branches off from a main water supply pipe 112 extending from a fire pump facility located in a duct below the lifeguard's passage is drawn into the fire hydrant device 18 from below, and a water supply piping 114 is connected to a water hydrant 116, and a fire hydrant valve 118 and an automatic pressure regulating valve 120 are connected to the pipe that branches off below, and a fire hose 122 is connected to the automatic pressure regulating valve 120. The fire hose 122 is stored in an inwardly coiled state, and a water discharge nozzle 124 is attached to the tip.

[0118] The water supply pipe 114 drawn into the fire hydrant device 18 further branches off to the water discharge gun device 20 side, connecting the water discharge on-off valve 86 and the hydrant interlocking valve 130, and the secondary side of the hydrant interlocking valve 130 is connected as the water supply pipe 88 to the water discharge gun device 20 arranged near the fire hydrant device 18. In addition, an automatic drain valve 131 is connected between the water discharge on-off valve 86 and the hydrant interlocking valve 130.

[0119] The water discharge on-off valve 86 is, for example, a motor-operated valve that opens in response to an external water discharge start signal and closes in response to a water discharge stop signal, and is normally closed. The hydrant interlocking valve 130 opens in response to the closing operation of the hydrant valve 118 provided in the fire hydrant device 18, and closes in response to the opening operation of the hydrant valve 118.

[0120] The linking mechanism 128 that links the hydrant interlocking valve 130 to the opening and closing operation of the hydrant valve 118 is arbitrary, but for example, a wire link mechanism is used to open and close the hydrant interlocking valve 130 in conjunction with the opening and closing operation of the hydrant valve opening and closing lever 126. Therefore, the hydrant interlocking valve 130 is also opened and closed in conjunction with the operation of the hydrant valve opening and closing lever 126 by the linking mechanism 128 that uses a wire link mechanism.

[0121] When the fire hydrant valve opening / closing lever 126 is in the closed position, the fire hydrant valve 118 is in the closed state (normal state), and the fire hydrant interlocking valve 130 is in the open state. Also, when a road user opens the fire hydrant valve opening / closing lever 126 to use the fire hydrant device 18, the fire hydrant interlocking valve 130 is closed in conjunction with the opening of the fire hydrant valve opening / closing lever 126.

[0122] This interlocking of the fire hydrant device 18 and the water cannon device 20 makes it possible for the water cannon device 20 to discharge water when the fire hydrant device 18 is not being used to discharge water, but on the other hand, if the fire hydrant device 18 is operated to discharge water while the water cannon device 20 is discharging water, the water cannon device 20 will stop discharging water.

[0123] Furthermore, as another embodiment in which the hydrant interlocking valve 130 is interlocked with the operation of the hydrant valve 118, the hydrant interlocking valve 130 may be, for example, an electrically operated valve that is opened and closed by an external control signal, and when a predetermined condition for stopping water discharge from the water cannon is met, including the on-operation of a pump start interlocking switch associated with the opening operation of the hydrant valve 118 by a pump start switch or the hydrant valve opening / closing lever 126 provided on the hydrant device 18, a closing signal is output to the hydrant interlocking valve 130 by electrical interlocking, thereby stopping water discharge. Note that if the fire hydrant device and the water cannon device can be used simultaneously, the hydrant interlocking valve 130 may be unnecessary.

[0124] [h. Water discharge capacity of fire hydrant equipment and water cannon equipment] Next, we will explain the water discharge capacity of the fire hydrant equipment and water cannon equipment. The fire pump equipment 48 installed in the tunnel facility, shown in Figure 1, has a capacity of 400 L / min per fire hydrant equipment, so if two are used simultaneously, the capacity becomes 800 L / min. Furthermore, since it is ideal for three fire hydrants to discharge water simultaneously, the capacity becomes 130 L / min x 3 = 390 L / min, ensuring a maximum water discharge of approximately 1200 L / min in total.

[0125] Therefore, by setting the water discharge rate of the water cannon device 20 within the range of the maximum water discharge rate of 1200 (L / min), an effective water discharge distance of, for example, 30 meters can be ensured, making it possible to continuously discharge large amounts of water against fires in electric vehicles. In addition, the fire extinguishing system of this embodiment, in which the imaging device 18 and the water cannon device 20 are installed, can be provided as an effective tunnel emergency facility without changing the basic facility design standards such as the pump capacity of the fire pump equipment 48, the emergency power supply, and the main fire extinguishing pipe.

[0126] [i. Equipment configuration of the fire extinguishing system installed in the tunnel] Next, we will explain the equipment configuration of the fire extinguishing system installed in the tunnel, with reference to Figure 10, which shows the equipment configuration of the fire extinguishing system installed in the tunnel, and Figure 11, which shows the functional configuration of the terminal processing device, water cannon device, and fire hydrant device in Figure 10.

[0127] As shown in Fig. 10, for example, in monitoring areas A1, A2, and A3 divided at predetermined distances along the length of the tunnel from the entrance of the up-track tunnel 12 (12-1), fire detectors 14 (14-1), 14 (14-2), and 14 (14-3), imaging devices 16 (16-1), 16 (16-2), and 16 (16-3), and terminal processing devices 27 (27-1), 27 (27-2), and 27 (27-3) provided in the fire hydrant device 18 are arranged, and as shown in Fig. 1, they are connected to transmission paths 22, 24, and 26 from the disaster prevention receiving panel 10. In addition, water cannon devices 20 (20-1), 20 (20-2), and 20 (20-3) are connected to the terminal processing devices 27 (27-1), 27 (27-2), and 27 (27-3).

[0128] As shown in Fig. 11, the terminal processing device 27 (27-1) arranged in the monitoring area A1 includes a transmission unit 72, a terminal control unit 74, drive units 76, 78, and 80, and an operation display unit 81. Here, the terminal control unit 74 is composed of a computer circuit including a CPU, memory, and various input / output ports, and its functions are realized by the execution of a program by the CPU. The drive units 76, 78, and 80 constitute the function of the water discharge drive unit.

[0129] The terminal control unit 74 receives the horizontal rotation angle (α) and vertical rotation angle (β) for the water cannon device in the monitoring area where a fire in an electric vehicle has been detected, which are transmitted from the fire extinguishing control unit 70 provided in the panel control unit 28 of the disaster prevention receiving panel 10 shown in Figure 1, and outputs a rotation drive signal for the horizontal rotation angle (α) and a rotation drive signal for the vertical rotation angle (β) from the drive units 76, 78 to the horizontal rotation unit 82 and vertical rotation unit 84 of the water cannon device 20 (20-1), thereby controlling the water cannon to be directed toward the source of the fire in the electric vehicle.

[0130] In addition, after completing control to direct the water cannon of the water cannon device 20 (20-1) toward the fire source of the electric vehicle, the terminal control unit 74 outputs a water cannon start signal from the drive unit 80 to the water cannon opening / closing valve 86 of the fire hydrant device 18 to drive it to open, and start discharging water from the water cannon of the water cannon device 20 (20-1).

[0131] Here, when the control of the water cannon device 20 (20-1) to point the water cannon at the fire source coordinates is completed, the terminal control unit 74 controls the device to start discharging water after a predetermined delay time has elapsed. Setting this delay time before water cannon starts ensures that the driver and passengers of an electric vehicle on fire have enough time to avoid being unable to evacuate due to water cannon discharge from the water cannon device, and also ensures that the driver and passengers have enough time to evacuate safely without receiving an electric shock.

[0132] The length of the delay time until the terminal control unit 74 starts discharging water can be any length, for example, one minute. The terminal control unit 74 may also output the delay time until the start of water discharging as an audio message through a speaker provided in the fire hydrant device 18. For example, the terminal control unit 74 may output an audio message saying, "Water discharging preparations are complete. Water discharging will automatically start in one minute. Please evacuate from the fire vehicle," and thereafter output an audio message every 10 seconds indicating the time remaining until the start of water discharging, such as, "There are XX seconds left until water discharging starts." The operation display unit 81 is used to manually operate the water cannon device 20 (20-1), and includes a horizontal rotation switch, a vertical rotation switch, displays for the horizontal rotation angle and vertical rotation angle, a water discharge start switch, a water discharge stop switch, etc.

[0133] [j. Vehicle type determination section of the fire extinguishing system] Next, the vehicle type determination unit provided in the disaster prevention receiving panel of the fire extinguishing system will be described with reference to Fig. 12, which shows an embodiment of the functional configuration of the vehicle type determination unit and the fire extinguishing control unit provided in the disaster prevention receiving panel, and Fig. 13, which shows a monitor unit displaying a monitoring image including an electric vehicle in which a fire has occurred.

[0134] As shown in Figure 12, the vehicle type determination unit 68 provided in the panel control unit 28 of the disaster prevention receiving panel 10 of Figure 1 determines whether the burning vehicle is an electric vehicle or not based on a two-dimensional monitoring image captured by the imaging device 16 in the monitoring area where the fire was detected, and while its configuration and function are arbitrary, it is composed of, for example, an image recognition model unit 132, a learning control unit 134, a teacher image memory unit 136, an input / output port 138, an image pre-processing unit 140, and an image determination unit 142.

[0135] The image recognition model unit 132 uses, for example, a multi-layer neural network, which is known as a machine learning model with high image recognition accuracy. The multi-layer neural network is a neural network that performs deep learning and has a deep hierarchy in which multiple intermediate layers are connected, and is composed of a convolutional neural network that functions as a feature extraction unit and a fully connected neural network that functions as a recognition unit.

[0136] Convolutional neural networks have slightly different characteristics from regular neural networks, incorporating a biological structure derived from the visual cortex of the brain. The visual cortex contains receptive fields, which are collections of small cells that are sensitive to small regions of the visual field, and the behavior of receptive fields can be mimicked by learning weights in the form of a matrix. This matrix is ​​called a weight filter (kernel), and it is sensitive to similar small regions of an image, similar to the role that receptive fields play biologically.

[0137] The convolutional neural network can represent the similarity between the weight filters and the subregions through the convolution operation, and through this operation, can extract the relevant features of the image.

[0138] A convolutional neural network first performs convolution processing on an input image using a weight filter. For example, the weight filter is a 3x3 matrix filter with predetermined weightings. By performing a convolution operation while aligning the center of the filter with each pixel of the input image, nine pixels of the input image are convolved with one pixel of the feature map, which forms a small region, and multiple feature maps are generated.

[0139] Next, a pooling operation is performed on the feature map obtained by the convolution operation. The pooling operation is a process of removing features unnecessary for classification and extracting features necessary for classification.

[0140] Next, a feature map is obtained by repeating convolution operations and pooling operations using weight filters in multiple stages, and the feature map of the final layer is input into a recognition unit using a conventional fully connected neural network to output an estimate of the input image.

[0141] The learning control unit 134 controls the image recognition model unit 132 to perform machine learning using a large number of training images of electric vehicles stored in advance in a training image storage unit 136 .

[0142] Here, images of electric vehicles made public before the start of operation of the fire extinguishing system, specifically images of electric vehicles including electric vehicles (EVs), hybrid vehicles (HVs), and plug-in hybrid vehicles (PHVs), are stored in an external memory module as training images with the estimated value of the electric vehicle set to 1. Training image storage unit 136 reads and stores these training images from the memory module connected to input / output port 138. In this case, for each model of electric vehicle, multiple images captured from different viewing angles around the electric vehicle are generated as training images and stored in training image storage unit 136. Images of vehicle body parts unique to electric vehicles, vehicle model symbols identifying electric vehicles, emblems, vehicle name badges, etc. are also generated as training images and stored in training image storage unit 136.

[0143] Machine learning of the image recognition model unit 132 by the learning control unit 134 is performed using the backpropagation method with training images. The backpropagation method uses the magnitude of the error between the estimated value and the expected value to propagate values ​​from the rear to the front of the network while correcting the weights and biases. The corrected amount for each weight and bias is treated as a contribution to the error and is calculated using the steepest descent method. The value of the error function is minimized by changing the values ​​of the weights and biases.

[0144] Furthermore, since the number of electric vehicles to be judged by the vehicle type judgment unit 68 increases throughout the operation of the system, teacher images of newly sold electric vehicles are periodically generated and additionally stored in the teacher image storage unit 136, and the learning control unit 134 performs additional machine learning on the image recognition model unit 132 using the newly stored teacher images, thereby making it possible to maintain high recognition accuracy as electric vehicles become more widespread.

[0145] A television signal representing a two-dimensional monitoring image captured by an imaging device 16 (16-1) installed in the monitoring area A1 where a vehicle fire has been detected is input to the image pre-processing unit 140 via the transmission path 24. Here, when a monitoring image 3610 shown on the monitor unit 36 ​​in FIG. 13 is input to the image pre-processing unit 140, for example, an image of a trimming area 182 of a predetermined size including the on-fire vehicle 180 is extracted and input to the trained image recognition model unit 132. The trimming area 182 is set by detecting the fire source of the on-fire vehicle 180 using predetermined image processing, and setting it as an area of ​​a predetermined vertical and horizontal size corresponding to the vehicle, centered on the detected fire source.

[0146] Furthermore, when the imaging device 16 (16-1) outputs a video signal using a television signal, for example, two-dimensional monitoring images of 30 or 60 frames per second are input, and the image preprocessing unit 140 generates and outputs a trimmed image of the two-dimensional monitoring image of all frames or of the two-dimensional monitoring image thinned out every predetermined number of frames.

[0147] The trained image recognition model unit 132 receives the two-dimensional surveillance image including the on-fire vehicle cropped by the image pre-processing unit 140, and outputs an estimated value y of the electric vehicle having a value in the range of 0 to 1.

[0148] When the estimated value y of an electric vehicle output by the image recognition model unit 132 satisfies a predetermined judgment condition, the image judgment unit 142 outputs the judgment result of an electric vehicle to the fire extinguishing control unit 70. The judgment condition in this case is arbitrary, but for example, when an estimated value y equal to or greater than a threshold value of 0.8 is output a predetermined number of times in succession, the image judgment unit 142 outputs the judgment result of an electric vehicle.

[0149] [k. Fire extinguishing control section of fire extinguishing system] Next, the fire extinguishing control unit provided in the panel control unit of the disaster prevention receiving panel will be described with reference to Fig. 12 showing the functional configuration of the fire extinguishing control unit.

[0150] (k1. Overview of Fire Extinguishing Control Unit) An overview of the fire extinguishing control unit will now be described. As shown in Fig. 12, the fire extinguishing control unit 70 provided in the panel control unit 28 of the disaster prevention receiving panel 10 in Fig. 1 is composed of an image generation unit 144, a fire source distance detection unit 146, a fire source coordinate processing unit 148, and a water discharge direction detection unit 150. The function of the water discharge control unit is realized by the water discharge direction detection unit 150 and its output destination, the terminal processing device 27 (27-1) provided in the fire hydrant device 18 shown in Fig. 11.

[0151] A television signal representing a two-dimensional monitoring image captured by an imaging device 16 (16-1) installed in the monitoring area A1 where a vehicle fire has been detected is input to the image generation unit 144 via a transmission path 24. The image generation unit 144 generates a two-dimensional monitoring image 200 of the monitoring area A1 captured by the imaging device 16 (16-1) and a distance image 210 to which information about the distance from the imaging device 16 (16-1) to an object in the monitoring area A1 has been added.

[0152] When a fire breaks out in the monitoring area A1, the fire source distance detection unit 146 identifies the fire source indicating the location of the fire from the two-dimensional monitoring image 200 generated by the image generation unit 144, and detects the fire source distance from the imaging device 16 (16-1) to the identified fire source from the distance image 210 generated by the image generation unit 144.

[0153] The fire source coordinate processing unit 148 detects the fire source coordinates (Xa, Ya, Za) in an imaging three-dimensional coordinate system with the imaging device 16 (16-1) as the origin (O1) based on the fire source distance, and converts the fire source coordinates (Xa, Ya, Za) in the imaging three-dimensional coordinate system into fire source coordinates (Xb, Yb, Zb) in a water discharge three-dimensional coordinate system with the water cannon device 20 (20-1) as the origin (O2).

[0154] The water discharge direction detection unit 150, which constitutes part of the water discharge control unit, detects the horizontal rotation angle (α) and vertical rotation angle (β) of the water cannon directed at the fire source based on the second fire source coordinates (Xb, Yb, Zb) obtained by the coordinate processing unit 148, and outputs them to the terminal processing device 27 (27-1) shown in Figure 11, which is provided in the fire hydrant device 18 installed in the monitoring area A1.

[0155] As described above, the horizontal swivel section 82 and vertical swivel section 84 of the water cannon device 20 (20-1) are connected to the terminal processing device 27 (27-1), and the water discharge on / off valve 86 of the fire hydrant device 18 is also connected to the terminal processing device 27 (27-1). The water cannon of the water cannon device 20 (20-1) is directed toward the fire source by setting the horizontal swivel angle (α) and the vertical swivel angle (β), and after a predetermined delay time has elapsed, the water discharge on / off valve 86 is driven to open to discharge water toward the fire source, thereby performing water discharge control.

[0156] Next, the functions of the image generating unit 144, the fire source distance detecting unit 146, the fire source coordinate processing unit 148, and the water discharge direction detecting unit 150 provided in the terminal processing device 27 (27-1) will be described.

[0157] [l. Functions of the image generation section] The following describes the image generation unit 144 provided in the fire extinguishing control unit 70 of the disaster prevention receiving panel 10. The image generation unit 144 generates a two-dimensional monitoring image 200 of the monitoring area captured by the imaging device 16, and a distance image 210 to which information about the distance from the imaging device to an object in the monitoring area is added.

[0158] (l1. Generation of 2D surveillance images) The generation of the two-dimensional monitoring image 200 will be described in detail. As shown in Fig. 2, taking a monitoring area Ai as an example, the two-dimensional monitoring image 200 is a two-dimensional monitoring image captured so as to include the entire monitoring area Ai, with an imaging device 16 (16-i) installed at an imaging point a at a predetermined height on a monitor passage 17 at the upstream area boundary of the monitoring area Ai, with an imaging axis 1610 fixed toward a boundary point b that intersects with the road surface 15 at the downstream area boundary, and is a video image including the monitoring area Ai displayed on the monitor unit 36 ​​provided in the disaster prevention receiving panel 10 shown in Fig. 1. Note that the video image may be a series of still images (frames) at predetermined intervals.

[0159] (l2. Generation of distance image) The generation of the distance image 210 will now be described in detail. The distance image 210 is an image to which distance information from the image capture device 16 (16-1) to an object in the monitoring area A1 has been added. Any method can be used to generate such a distance image 210, but for example, a PSF method is used, which measures the distance to an object by analyzing the correspondence between the distance and the color and size of blur that appears in an aberration map based on the point spread function (PSF) of the camera lens.

[0160] The DfD (Depth from Defocus) method is a conventional method for estimating distance using blur information from an image captured by a single camera. The DfD method requires two or more images to distinguish between areas in front of and behind the focus point. However, camera lenses that combine multiple lenses always have chromatic aberration. By using this chromatic aberration as a clue to distinguish between areas in front of and behind the focus point, distance can be measured from a single image.

[0161] The point spread function (PSF) is used to analyze aberration characteristics. The PSF represents the extent to which light from a single point (point light source) originating from a subject spreads and forms an image (shape and color of blur) after passing through a camera lens. The PSF varies depending on the distance and in-plane position of the subject relative to the camera lens. The correspondence between this PSF and distance and in-plane position is called an aberration map. By analyzing the correspondence with distance, the distance to the subject can be measured by characterizing the color and size of the blur that appears in an image of the subject, which has various colors and contours, according to the aberration map, and generating a distance image 34 with distance information assigned to each pixel. A color corresponding to the distance is assigned to each pixel in the distance image, and when displayed on a monitor screen, a color image with different colors depending on the distance is displayed.

[0162] When generating the distance image 210 using the PSF method, the imaging device 16 (16-1) uses a color video camera with two color apertures, cyan and yellow, that change the blur of the captured image for each color. In this case, the two-dimensional monitoring image 200 can directly use the frame-by-frame color images captured by the color video camera that generates the distance image using the PSF method.

[0163] Another method for generating distance image 210 is the FOT (Time of Flight) method. The FOT method detects the distance from the time of flight of a pulse of light irradiated from a camera onto an object and detects the reflected light. In this case, to distinguish the light from sunlight, lighting, and other sources, the FOT image sensor applies a predetermined modulation to the emitted light that is imperceptible to the human eye.

[0164] Therefore, by using a video camera equipped with an FOT image sensor as the imaging device 16 (16-1) of this embodiment, it is possible to generate a distance image 210 on a frame-by-frame basis. In this case, the distance image 210, to which distance information is assigned on a pixel-by-pixel basis, is assigned a color corresponding to the distance, and when displayed on a monitor screen, a color image is displayed in which the color varies depending on the distance. Furthermore, the two-dimensional monitoring image 200 can be an image captured by the FOT image sensor without being assigned distance information. Note that the generation of the distance image 210 is not limited to the PSF method or the FOT method, and any appropriate method capable of capturing moving images can be used.

[0165] [m.Fire source distance detection unit] Next, we will explain the fire source distance detection unit 146 provided in the fire extinguishing control unit 70 of the disaster prevention receiving panel 10. When a fire breaks out in its own monitoring area A1, the fire source distance detection unit 146 identifies the fire source indicating the location of the fire from the two-dimensional monitoring image 200 generated by the image generation unit 144, and detects the fire source distance from the imaging device 16 (16-1) to the fire source from the distance image 210 generated by the image generation unit 144.

[0166] The following describes in more detail how the fire source is identified by the fire source distance detection unit 146. There are two methods for identifying the fire source from the two-dimensional monitoring image 200: a manual method in which an observer identifies the fire source by looking at the monitor image, and an automatic method in which the fire source is identified by image processing of the two-dimensional monitoring image 200.

[0167] In the manual method of identifying the fire source, when a monitor uses a fingertip, pen, or the like to specify the fire source on the screen while a monitoring image 3610 of the monitoring area where a fire has occurred is displayed on the monitor unit 36 ​​of the disaster prevention receiving panel 10, as shown in Figure 13, the monitor performs a control to output information indicating the specified fire source, for example, a coordinate position signal indicating the specified fire source position on the two-dimensional screen of the monitor unit 36, to the fire source position detection unit 146.

[0168] In the automatic method for identifying a fire source, when the vehicle type determination unit 68 of the disaster prevention receiving panel 10 receives a fire detection signal including an address from the fire detector 14 (14-1) in the monitoring area A1, the vehicle type determination unit 68 selects the imaging device 16 (16-1) installed in the monitoring area A1 and inputs the image to identify the fire source by image processing of the two-dimensional monitoring image 200. Identification of the fire source by image processing of the two-dimensional monitoring image 200 is optional, but for example, a fire source image is generated by removing the background, including lighting, from a temporal difference image of the two-dimensional monitoring image 200, the fire source area is detected by generating an outline corresponding to the brightness, and the center of the fire source area is identified as the fire source.

[0169] By manually or automatically identifying the fire source in this way, the coordinates (x, y) of the fire source are identified in a two-dimensional coordinate system with the center of the two-dimensional monitoring image 200 (position of the imaging axis) as the origin.

[0170] [n. Fire source coordinate processing section] Next, we will explain the fire source coordinate processing unit 148 provided in the fire extinguishing control unit 70 of the disaster prevention receiving panel 10. In this explanation, we will refer to Fig. 14 which shows fire source coordinates in a two-dimensional monitoring image, Fig. 15 which shows an imaging three-dimensional coordinate system for detecting fire source coordinates from the fire source distance, and Fig. 16 which shows the relationship between the imaging three-dimensional coordinate system and the water discharge three-dimensional coordinate system of the fire extinguishing system.

[0171] Fig. 14(A) shows the fire source coordinates of a two-dimensional monitoring image, and Fig. 14(B) shows the conversion characteristics between the fire source distance and the distance between one pixel. Fig. 16(A) shows the relationship between the imaging three-dimensional coordinate system and the water discharge three-dimensional coordinate system, and Fig. 16(B) shows the case where the origin of the water discharge three-dimensional coordinate system is aligned with the origin of the imaging three-dimensional coordinate system.

[0172] The fire source coordinate processing unit 148 detects the first fire source coordinates (Xa, Ya, Za) in an imaging three-dimensional coordinate system with the imaging device 16 as the origin based on the fire source distance, and converts the first fire source coordinates (Xa, Ya, Za) into second fire source coordinates (Xb, Yb, Zb) in a water discharge three-dimensional coordinate system with the water discharge gun device 20 as the origin.

[0173] In addition, the water discharge direction detection unit 150 determines the horizontal rotation angle (α) and vertical rotation angle (β) of the water cannon 85 directed toward the fire source coordinates based on the second fire source coordinates (Xb, Yb, Zb) in the three-dimensional water discharge coordinate system, and sets the water discharge direction.

[0174] (n1. Fire source coordinates in the three-dimensional coordinate system of the image) First, we will explain the detection of fire source coordinates by the fire source coordinate processing unit 148. As a first coordinate calculation function, the fire source coordinate processing unit 148 detects fire source coordinates (Xa, Yb) in the captured three-dimensional coordinate system at the fire source distance L based on the fire source coordinates (x, y) identified on the two-dimensional monitoring image 200.

[0175] As shown in Figure 14(A), the two-dimensional surveillance image 200 is a two-dimensional coordinate system with the imaging center (screen center) where the imaging axis is located as the origin O3, and the position of the fire source P indicating the location of the fire on the screen is identified as the fire source coordinates P(x, y).

[0176] Here, if the number of pixels in the horizontal direction from the origin O3 at the image center of the two-dimensional monitoring image 200 to the fire source coordinate P(x, y) is Nx and the number of pixels in the vertical direction is Ny, then based on the characteristic 201 of the predetermined distance conversion magnification K that indicates the actual distance at the fire source distance L corresponding to the distance between one pixel on the two-dimensional monitoring image 200 shown in FIG. 14(B), the fire source coordinates (Xa, Ya) in the captured three-dimensional coordinate system are expressed as follows: Xa=K·Nx Ya=K·Ny It should be noted that although the characteristic 201 of the distance conversion magnification K in FIG. 14B is a linear characteristic, it is not limited to this and may be an appropriate curved characteristic.

[0177] Next, the detection of the Za value of the fire source coordinate in the imaged three-dimensional coordinate system will be described. Fig. 15 shows an imaged three-dimensional coordinate system 160 with the image capturing device 16 as the origin O1. Considering a dotted rectangular parallelepiped with the fire source P at the fire source distance L as its diagonal vertex, the coordinate values ​​Xa and Ya of the fire source coordinate P (Xa, Ya, Za) have already been detected, and the coordinate value Za can be determined by finding the length of the line segment O1, Q. Therefore, for the right-angled triangle O1, P, Q,

[0178]

number

[0179] (n2. Fire source coordinates in the three-dimensional water discharge coordinate system) Next, the coordinate conversion performed by the fire source coordinate processing unit 148 to convert the fire source coordinates in the three-dimensional image coordinate system into the fire source coordinates in the three-dimensional water discharge coordinate system will be described in more detail.

[0180] As a second coordinate calculation function, the fire source coordinate processing unit 148 converts the fire source coordinates P(Xa, Ya, Za) detected in the imaging three-dimensional coordinate system into fire source coordinates P(Xb, Yb, Zb) in the water discharge three-dimensional coordinate system with the water cannon device 20 as the origin.

[0181] 16(A) shows the positional relationship in real space between the imaging three-dimensional coordinate system 160 and the water-discharge three-dimensional coordinate system 170. Here, there are differences in three-dimensional distances Lx, Ly, and Lz between the origin O1 of the imaging three-dimensional coordinate system 160 and the origin O2 of the water-discharge three-dimensional coordinate system 170, and these distances are constants that are uniquely determined based on the arrangement of the imaging devices 16(16-i-1), 16(16-i), and 16(16-i+1) and the water-cannon devices 20(20-i-1), 20(20-i), and 20(20-i+1) relative to the monitored area, as shown in FIG.

[0182] In order to convert the fire source coordinates P(Xa, Ya, Za) in the imaging three-dimensional coordinate system 160 into the fire source coordinates P(Xb, Yb, Zb) in the water discharge three-dimensional coordinate system 170, first, as shown in Figure 16(B), a virtual space is imagined in which the origins O1 and O2 of both are aligned, and the fire source coordinates P(Xa, Ya, Za) in the imaging three-dimensional coordinate system 160 are converted into the fire source coordinates P(Xbv, Ybv, Zbv) in the water discharge three-dimensional coordinate system 170 in the virtual space.

[0183] For this reason, the rotation angles for aligning the coordinate axes X, Y, and Z of the imaging three-dimensional coordinate system 160 with the coordinate axes X, Y, and Z of the water-discharge three-dimensional coordinate system 170 in the virtual space of Figure 16(B) are determined as Euler angles. The Euler angles are a pitch angle φ around the X axis, an azimuth angle θ around the Y axis, and a roll angle ψ around the Z axis, and are determined as constants uniquely from the relative positions of the imaging three-dimensional coordinate system 160 and the water-discharge three-dimensional coordinate system 170 in real space.

[0184] If the imaging three-dimensional coordinate system 160 is the aircraft coordinate system and the water discharge three-dimensional coordinate system 170 is the Earth coordinate system, the fire source coordinates P(Xa, Ya, Za) in the imaging three-dimensional coordinate system 160 in the virtual space of Figure 16(B) are converted to the fire source coordinates P(Xbv, Ybv, Zbv) in the water discharge three-dimensional coordinate system 170 using the following equation based on the Euler angles (φ, θ, ψ).

[0185]

number

[0186]

number

[0187] Here, as described above, there is a difference in three-dimensional distances Lx, Ly, Lz between the origin O1 of the imaging three-dimensional coordinate system 160 and the origin O2 of the water discharge three-dimensional coordinate system 170. Therefore, the fire source coordinates P(Xb, Yb, Zb) of the water discharge three-dimensional coordinate system 170 in the real space are expressed as follows: Xb=Xbv-Lx Yb=Ybv-Ly Zb=Zbv-Lz (However, Lx, Ly, and Lz are positive or negative values ​​depending on the direction of movement on each coordinate axis.) It is calculated as:

[0188] [o. Water discharge direction detection unit] Next, we will explain the water discharge direction detection unit 150 provided in the water discharge control unit 70 of the disaster prevention receiving panel 10. The water discharge direction detection unit 150 detects the horizontal rotation angle (α) and vertical rotation angle (β) of the water discharge gun 54 shown in Figures 6 to 8 based on the fire source coordinates (Xb, Yb, Zb) in the water discharge three-dimensional coordinate system 170.

[0189] The horizontal rotation angle (α) and vertical rotation angle (β) of the water cannon 85 are given by the following equations based on the fire source coordinates (Xb, Yb, Zb).

[0190]

number

[0191] [p. Fire extinguishing control of embodiment] Next, the fire extinguishing control of the fire extinguishing system will be explained. In this explanation, reference will be made to the flowchart of Fig. 17 showing the fire extinguishing control of the fire extinguishing system, Fig. 18 showing a fire in an electric vehicle in a tunnel and water being sprayed by a water cannon, and Fig. 19 showing a monitor image of the water cannon spraying water on the electric vehicle on fire. Note that Fig. 18(A) shows the tunnel plan, and Fig. 18(B) shows the tunnel side. Furthermore, the fire extinguishing control of the fire extinguishing system is a control operation by the disaster prevention receiving panel 10 shown in Fig. 1.

[0192] 17, when the disaster prevention receiving panel 10 receives a fire detection signal from, for example, one of the fire detectors 14 installed in the tunnel by the fire monitoring unit 66 and determines that a fire has been detected (Yes in step S1), it identifies the monitoring area in which the fire was detected from the address included in the fire detection signal, selects the imaging device 16 installed in that monitoring area, receives the television signal output by imaging the monitoring area, and displays it on the monitor unit 36 ​​(step S2).When a fire notification signal is received by operating the transmitter of a fire hydrant device 18, it sequentially selects the imaging devices 16 installed in the monitoring areas corresponding to, for example, four fire hydrant devices 18, which are located in one section corresponding to the fire notification signal, acquires a two-dimensional monitoring image, and identifies the monitoring area in which the fire source was determined as the monitoring area in which the fire was detected and displays it on the monitor unit 36.

[0193] For example, as shown in Fig. 18, if a burning vehicle 180 is present in the monitoring area A3, a fire detection signal is received from a fire detector (not shown) installed in the monitoring area A3, and the monitoring area A3 is identified from the address included in the fire detection signal. The imaging device 16 (16-3) installed in the monitoring area A3 is selected to receive a television signal, and a monitoring image 3610 shown in Fig. 19, for example, is displayed on the monitor unit 36. In addition to the burning vehicle 180, an adjacent vehicle 182 that has stopped following it and another stopped vehicle 190 are also displayed.

[0194] Next, the disaster prevention receiving panel 10 reads in a two-dimensional monitoring image based on a television signal received from the selected imaging device 14, and the vehicle type determination unit 68 cuts out an image of a cropped area 182 of a predetermined vertical and horizontal size that includes the on-fire vehicle 180 from the monitoring image 3610 in Fig. 19 using the image pre-processing unit 140 shown in Fig. 12, and inputs this image to the trained image recognition model unit 132 (step S3). If the estimated value of being an electric vehicle satisfies a predetermined determination condition in the image determination unit 142, for example, if the estimated value is 0.8 or more, the vehicle type determination unit 68 determines that the on-fire vehicle 180 is an electric vehicle (step S4).

[0195] Next, the fire extinguishing control unit 70 of the disaster prevention receiving panel 10 operates based on the notification from the vehicle type determination unit 68 that the burning vehicle is determined to be an electric vehicle. As shown in Fig. 12, the fire extinguishing control unit 70 generates a two-dimensional monitoring image 200 and a distance image 210 using the image generation unit 144, detects the fire source position (coordinates) on the two-dimensional monitoring image 200 as shown in Fig. 14 (step S5), and detects the fire source distance using the fire source distance detection unit 148 based on the distance information assigned to the fire source position in the distance image 210 (step S6).

[0196] Next, the fire source distance is compared with a preset boundary distance, and if the fire source is within the monitored area, the fire source coordinate processing unit 148 detects the fire source coordinates in the imaging three-dimensional coordinate system (step S7), and then converts them into fire source coordinates in the water-discharge three-dimensional coordinate system (step S8). The water-discharge direction detection unit 150 detects the horizontal rotation angle (α) and horizontal rotation angle (β) of the water cannon (step S9), and transmits the horizontal rotation angle (α) and horizontal rotation angle (β) of the water cannon to the terminal processing unit 27 (27-3) of the fire hydrant device 18, which is similar to that shown in FIG. 11, and the water cannon of the water cannon device 20 (20-3) is driven to rotate toward the fire source (step S10).

[0197] Next, the disaster prevention receiving panel 10 sends a pump start instruction signal to start the fire pump equipment 48 (step S11), and sends a water discharge start instruction signal to the terminal processing unit 27 (27-3) of the fire hydrant device 18 similar to that shown in Figure 11 (step S12).

[0198] Here, the terminal processing unit 27 (27-3) that has received the water discharge start instruction signal starts a timer to determine a predetermined delay time, and when it determines that the delay time has elapsed (Yes in step S13), it drives the water discharge opening / closing valve 86 provided in the fire hydrant device 18 to open, and starts discharging water from the water cannon device 20 (20-3) to the electric vehicle that has been determined to be a burning vehicle (step S14).

[0199] At this time, the water discharge situation on the on-fire vehicle 180 determined to be an electric vehicle by the water cannon device 20 (20-3) shown in Figure 18 is displayed as a video on the monitoring image 3610 of the monitor unit 36, as shown in Figure 19, making it possible to monitor the situation at the scene remotely.

[0200] While the water is being sprayed from the water cannon device 20 (20-3), it is determined whether a predetermined water cannon stop condition is met (step S15). If it is determined that the water cannon stop condition is met, the water cannon stops spraying (step S16) and the process returns to monitoring for the initial fire detection (step S1).

[0201] Here, the specified water discharge stop condition is met when the fire in the electric vehicle has been extinguished by water discharge from the water cannon device 20 (20-1) and the fire brigade arrives while the water discharge is continuing and spraying large amounts of water. For example, the water discharge stop command signal is sent from the disaster prevention receiving panel 10, or a water discharge stop switch installed at the site is operated, which closes the water discharge opening / closing valve 86 and stops the water discharge from the water cannon device 20 (20-3).

[0202] Furthermore, another water discharge stop condition is met when a road user operates the fire hydrant valve opening / closing lever when using the fire hydrant device 18, or when a firefighter operates the pump start switch. In this case, as shown in FIG. 9, the fire hydrant interlocking valve 130, which is provided in series with the open water discharge opening / closing valve 86, is closed, and water discharge from the water cannon device 20 (20-3) stops.

[0203] [q. Fire extinguishing control for adjacent vehicles] Next, the fire extinguishing control for the adjacent vehicle will be described. For example, as shown in the monitoring image 3610 of the monitor unit 36 ​​in Fig. 19, if the on-fire vehicle 180 is determined to be an electric vehicle and water is sprayed from the water cannon device 20 (20-3), and if the adjacent vehicle 184 that has stopped following the on-fire vehicle 180 is also an electric vehicle, there is a possibility that the radiant heat from the on-fire vehicle 180 will cause a fire due to thermal runaway of the lithium-ion battery provided in the drive battery mounted on the adjacent vehicle 184.

[0204] Therefore, in the disaster prevention monitoring panel 10 shown in Fig. 1, after the vehicle type determination unit 68 determines that the on-fire vehicle 180 is an electric vehicle, the image preprocessing unit 140 sets and cuts out a cropping region 186 for the adjacent vehicle 184, inputs this to the image recognition model unit 132, and outputs an estimated value. If the image determination unit 142 determines that the estimated value satisfies a predetermined determination condition and therefore the adjacent vehicle 184 is also an electric vehicle, it selects another water cannon device whose water discharge area includes the adjacent vehicle 184, for example, the water cannon device 20 (20-2) installed in the water discharge area A2, and controls it to spray water on the adjacent vehicle 184.

[0205] [r. Modifications of the present invention] Modifications of the fire extinguishing system according to the present invention will now be described. In addition to the above-described embodiment, the fire extinguishing system according to the present invention includes the following modifications.

[0206] (Electric vehicle) The above embodiments use electric vehicles (EVs), hybrid vehicles (HEVs), and plug-in hybrid vehicles (PHEVs) as examples of electric vehicles, but other vehicles equipped with a drive battery using a lithium-ion battery are also included in the electric vehicles that are the subject of fire extinguishing in this embodiment. An example of such an electric vehicle is a fuel cell vehicle (FCV). A fuel cell vehicle runs on a motor driven by a fuel cell that generates electricity through a chemical reaction between oxygen and hydrogen, which charges the drive battery.

[0207] (Fire Extinguishing Control Unit) In the above embodiment, the function of the fire extinguishing control unit 70 is provided in the disaster prevention receiving panel 10, but this is not limiting, and the function of the fire extinguishing control unit 70 may be provided separately in the terminal processing device 27 in the fire hydrant device 18 installed in the monitored area. In this case, the television signal from the imaging device 16 installed in the monitored area is transmitted to the terminal processing device 27 installed in its own monitored area and also to the disaster prevention receiving panel 10, so that the monitored image can be selectively displayed on the monitor unit 36.

[0208] (Arrangement of imaging device and water cannon device) In the above embodiment, the imaging device is placed at the boundary of the monitored area and the water cannon device is placed in the center of the monitored area, but the imaging device may also be placed separately and coaxially directly above the water cannon device placed at the boundary of the monitored area, or the imaging device may be placed fixedly and coaxially directly above the water cannon device.

[0209] (Recent fire at water cannon equipment) In the above embodiment, even if the fire source is located very close to the water cannon device, for example, within a few meters, the water is sprayed aimed at the fire source. However, in another embodiment, when the water spray distance is short, a deflector may be placed on the outlet side of the water cannon and some of the water may be sprayed at a short distance by hitting the deflector.

[0210] (Correction of vertical turning angle based on water discharge distance) In the above embodiment, the fire source is targeted by a linear spray of water from the water cannon device. However, as the water spray distance increases, the water spray trajectory becomes parabolic and the water spray distance becomes shorter than the fire source distance. Therefore, the vertical swivel angle of the water cannon may be corrected to increase in accordance with the detected fire source distance.

[0211] (Manual operation of water cannon device) In the above embodiment, the horizontal rotation angle (α) and vertical rotation angle (β) of the water cannon device 20 are detected from the fire source coordinates, and the water cannon is automatically aimed at the fire source to spray water. However, since a two-dimensional image of the monitored area where the fire has occurred is displayed on the monitor unit 36 ​​of the disaster prevention receiving panel 10, it is also possible to provide a water cannon operation unit on the disaster prevention receiving panel 10 for manually operating the horizontal rotation angle (α) and vertical rotation angle (β) of the water cannon device 20, and by switching from automatic water discharge mode to manual water discharge mode, a monitor can operate the water cannon device while watching the monitor screen to spray water at the fire source.

[0212] (others) Furthermore, the present invention includes appropriate modifications that do not impair the objects and advantages thereof, and is not limited to the numerical values ​​shown in the above embodiments. [Explanation of symbols]

[0213] 10: Disaster prevention receiving panel 12(12-1): Up line tunnel 12(12-2): Down line tunnel 14: Fire detector 15: Road surface 16, 16(16-i-1), 16(16-i), 16(16-i+1): Imaging device 17: Guard passage 18: Fire hydrant equipment 20, 20(20-i-1), 20(20-i), 20(20-i+1): Water cannon device 2010: Water discharge shaft 22, 24, 26: Transmission path 2210: R-type transmission line 2212: P-type signal line 27: Terminal processing device 28: Panel control unit 29: Transmitter / receiver 30, 32, 34, 72: Transmission section 36: Monitor section 3610: Surveillance image 38: Display section 40:Operation unit 42: Alarm section 44: Modem 46: I / O section 48: Fire pump equipment 50: Cooling pump equipment 52:IG slave station equipment 54: Remote monitoring and control equipment 56: Ventilation equipment 58: Alarm display board equipment 60: Radio rebroadcasting equipment 62: TV monitoring equipment 64: Lighting equipment 66: Fire monitoring department 68: Vehicle type identification department 70: Fire extinguishing control unit 72: Transmission unit 74: Terminal control unit 76, 78, 80: Drive unit 82: Horizontal turning section 8210: Horizontal pivot axis 84: Vertical rotation section 8410: Vertical pivot axis 85: Water cannon 86: Water discharge valve 88: Water supply piping 90: Piping base 92:Horizontal base 96: Horizontal rotating piping 98: Worm wheel 100: Warm 102: Horizontal rotation motor 105: Large gear 106: Small gear 104,110: Rotary encoder 108: Vertical rotation motor 112: Water main 114: Water supply piping 116: Water tap 118: Fire hydrant valve 120: Automatic pressure regulating valve 122: Fire hose 124: Water nozzle 126: Fire hydrant valve opening / closing lever 128: Interlocking mechanism 130: Fire hydrant interlocking valve 131: Automatic drain valve 132: Image recognition model section 134: Learning control unit 136: Image storage for teachers 138: Input / output port 140: Image preprocessing unit 142: Image judgment unit 144: Image generation unit 146: Fire source distance detection unit 148: Fire source coordinate processing unit 150: Water discharge direction detection unit 152: 2D surveillance image 156: Firefighting target area 160: Imaging three-dimensional coordinate system 170: Water discharge three-dimensional coordinate system 180: Fire vehicle 182,186: Cropping area 184: Adjacent vehicle 190:Stopped vehicle 200: 2D surveillance image 210:Distance image

Claims

1. A fire extinguishing system installed in a tunnel having a road, an imaging device installed in each of the monitoring areas divided at predetermined intervals in the longitudinal direction of the tunnel, for capturing images of the monitoring area in which it is installed; a water cannon device installed in each of the monitoring areas and capable of changing the water cannon direction; a vehicle type determination unit that, when a vehicle fire is detected in a tunnel, determines whether the on-fire vehicle imaged by the imaging device is an electric vehicle; an image generation unit that generates, when the vehicle type determination unit determines that the burning vehicle is an electric vehicle, a two-dimensional monitoring image of the monitoring area captured by the imaging device and a distance image to which distance information from the imaging device to an object in the monitoring area is added; a fire source distance detection unit that identifies the position of the fire source of the on-fire vehicle from the two-dimensional monitoring image and detects the fire source distance from the imaging device to the fire source from the distance image; a water discharge control unit that controls the water cannon to discharge water toward the fire source based on the position of the fire source and the distance to the fire source; A fire extinguishing system comprising:

2. 2. The fire extinguishing system of claim 1, The vehicle type determination unit an image recognition model unit that recognizes images through predetermined machine learning; a teacher image storage unit that stores a teacher image of the electric vehicle; a learning control unit that performs machine learning on the image recognition model unit using a training image of the electric vehicle; an image preprocessing unit that, when a vehicle fire is detected in a tunnel, extracts and inputs to the trained image recognition model unit an area including the on-fire vehicle included in the two-dimensional surveillance image captured by the imaging device; an image determination unit that determines that the vehicle is an electric vehicle when an estimated value of the electric vehicle output from the trained image recognition model unit satisfies a predetermined determination condition; A fire extinguishing system comprising:

3. 2. The fire extinguishing system of claim 1, The vehicle type determination unit determines that the electric vehicle is an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle.

4. 2. The fire extinguishing system of claim 1, the imaging device is installed at the boundary of the upstream or downstream side of its own monitoring area, and its imaging direction is fixed so as to capture an image of at least its own monitoring area; The water cannon device is installed at the center of the monitored area in the longitudinal direction of the tunnel or at a predetermined position near the center, and is characterized in that it cannons water the fire source within its monitored area.

5. 2. The fire extinguishing system of claim 1, The fire extinguishing system is characterized in that the water cannon device has a water discharge distance that exceeds half the area distance of the monitoring area in the longitudinal direction of the tunnel and is a predetermined distance that allows water to be discharged up to that area distance.

6. 2. The fire extinguishing system of claim 1, The fire extinguishing system is characterized in that, when the fire source of the on-fire vehicle is located in the monitored area, the water discharge control unit selects a water cannon device that includes the fire source within its water discharge range and is closest to the fire source and discharges water.

7. 7. The fire extinguishing system of claim 6, When the vehicle type determination unit determines that another vehicle adjacent to the on-fire vehicle is an electric vehicle, the water discharge control unit selects another water cannon device that includes the other adjacent vehicle in its water discharge range and causes it to discharge water.

8. 2. The fire extinguishing system of claim 1, The fire extinguishing system is characterized in that the water discharge control unit starts discharging water after a predetermined delay time has elapsed when control of directing the water cannon toward the fire source has been completed.

9. 10. The fire extinguishing system of claim 1, further comprising: a coordinate processing unit that detects fire source coordinates (Xa, Ya, Za) in an imaging three-dimensional coordinate system with the imaging device as the origin (O1) based on the fire source distance, and converts the fire source coordinates (Xa, Ya, Za) in the imaging three-dimensional coordinate system into fire source coordinates (Xb, Yb, Zb) in a water discharge three-dimensional coordinate system with the water cannon device as the origin (O2); The water discharge control unit is a water discharge direction detection unit that detects the water discharge direction of the water cannon device relative to the fire source based on the fire source coordinates (Xb, Yb, Zb) in the water discharge three-dimensional coordinate system; a water discharge driving unit that sets the water discharge direction in the water cannon device and causes the water cannon device to discharge water; A fire extinguishing system comprising:

10. 10. The fire extinguishing system of claim 9, The water cannon device is A horizontal rotation unit that changes the water discharge direction of the water cannon around the horizontal axis; A vertical rotation unit that changes the water discharge direction of the water cannon in a vertical rotation; and the water discharge direction detection unit detects a horizontal rotation angle (α) of the water cannon device directed toward horizontal two-dimensional fire source coordinates (Xb, Yb) in the fire source coordinates (Xb, Yb, Zb) in the three-dimensional water discharge coordinate system, and detects a vertical rotation angle (β) of the water cannon device directed toward vertical two-dimensional fire source coordinates (Xb, Zb) in the fire source coordinates (Xb, Yb, Zb) in the three-dimensional water discharge coordinate system; The fire extinguishing system is characterized in that the water discharge drive unit sets the horizontal rotation angle (α) on the horizontal rotation unit and the vertical rotation angle (β) on the vertical rotation unit to discharge water.

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