Gas flow rate estimation device, gas flow rate estimation method, gas flow rate estimation program, leaked gas detection device, leaked gas detection method, and detected data processing device

Abstract

To provide a leakage gas detector capable of estimating a flow rate with high accuracy without measuring a distance.SOLUTION: A gas flow rate estimation device of a leaked gas detection device includes a map acquisition unit that acquires map information around a camera 20 from position information of the camera 20 that captures an image including infrared information, a distance calculation unit that calculates a distance from the camera 20 to a gas cloud 70 captured by the camera 20 based on the map information, a first calculation unit that calculates a gas velocity of the gas cloud and a gas passage time during which gas passes through a gas area extracted from time-series images using the time-series images of the gas cloud 70 captured by the camera 20, a second calculation unit that calculates a gas concentration length of the gas area using image data of the gas area included in the time-series images and calculates a gas amount of the gas area using the gas concentration length and the distance calculated by the distance calculation unit, and a third calculation unit that calculates a flow rate estimation value of the gas using the gas passage time and the gas amount.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to an apparatus, method and program for estimating a gas flow rate, an apparatus and method for detecting a leaked gas, and a data processing device for detecting a leaked gas. [Background technology]

[0002] Gas leakage detection devices are known that detect leaked gas from images captured by a camera, taking advantage of the fact that gas absorbs infrared rays of a specific wavelength. Such gas leakage detection devices can remotely inspect gas leaks from gas facilities, etc. Gas leakage detection devices have also been developed that can not only detect the presence or absence of leaked gas but also estimate the gas flow rate. For example, Patent Document 1 describes a system that includes an infrared camera and a gas flow rate estimation device. The gas flow rate is the volume of gas flowing in a certain period of time. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 110411 Summary of the Invention [Problem to be solved by the invention]

[0004] One of the parameters that has a significant impact on the accuracy of flow rate estimation is the distance information (depth distance) between the shooting position and the measurement object when calculating the concentration-thickness product. Conventionally, distance information has been measured by the user using a laser rangefinder or similar, and when performing flow rate estimation, the distance information must be measured and saved at the time of measurement. Distance information is not necessary for measurements that do not involve flow rate estimation, but even if it is not clear whether flow rate estimation will be performed from the captured image data, distance information must be measured and saved each time, which increases the workload for the user. On the other hand, data that does not contain distance information cannot be used to perform flow rate estimation later. The present invention has been made to solve such problems, and aims to provide a leakage gas detection device, leakage gas detection method, etc. that are capable of estimating flow rate with high accuracy while eliminating the need for the user to measure distance when capturing infrared images. [Means for solving the problem]

[0005] In order to solve such problems, the gas flow rate estimation device, gas flow rate estimation method, gas flow rate estimation program, leakage gas detection device, leakage gas detection method, and detection data processing device of the present invention have the following configurations (1) to (16). (1) A gas flow rate estimation device comprising: a map acquisition unit that acquires map information of the surroundings of a camera that captures images including infrared information from position information of the camera; a distance calculation unit that calculates the distance from the camera to a gas cloud imaged by the camera based on the map information; a first calculation unit that calculates, using time-series images of the gas cloud captured by the camera, a gas velocity of the gas cloud and a gas transit time for the gas to pass through a gas region extracted from the time-series images; a second calculation unit that calculates a gas concentration thickness product of the gas region using image data of the gas region included in the time-series images, and calculates a gas amount of the gas region using the gas concentration thickness product and the distance calculated by the distance calculation unit; and a third calculation unit that calculates an estimated gas flow rate value using the gas transit time and the gas amount.

[0006] (2) The gas flow rate estimation device described in (1) further includes a building identification unit that fits the imaging direction of the camera into the map information and identifies the nearest building in the imaging direction, and the distance calculation unit calculates the distance between the building identified by the building identification unit and the camera, and sets this as the distance from the camera to the gas cloud. (3) The gas flow rate estimation device described in (2), wherein the distance calculation unit calculates the three-dimensional distance from the camera to the gas cloud using trigonometry based on the imaging angle of the camera and the planar distance between the building and the camera. (4) The gas flow rate estimation device described in (1), wherein the distance calculation unit determines the location of the gas cloud as a location specified by a user in the map information, and calculates the distance from the camera to the gas cloud.

[0007] (5) The gas flow rate estimation device described in (4), wherein the distance calculation unit calculates the three-dimensional distance from the camera to the gas cloud using trigonometry based on the imaging angle of the camera and the planar distance between the specified position and the camera. (6) A leakage gas detection device comprising the camera, a measurement unit having a position sensor that acquires position information of the camera, an orientation sensor that detects the imaging orientation of the camera, and an angle sensor that detects the imaging angle of the camera, a display unit having a screen that displays an image of the gas cloud, and a gas flow rate estimation device described in any of (1) to (5).

[0008] (7) The leak gas detection device according to (6), further comprising an acquired data storage unit that associates the image with the camera's position information, imaging direction, and imaging angle, and stores the image as acquired data. (8) The leakage gas detection device according to (6), further comprising a display control unit that displays the map information on the screen. (9) The leakage gas detection device according to (8), wherein the display control unit displays the map information so that the imaging direction of the camera passes through the center of the screen.

[0009] (10) A detection data processing device comprising the gas flow estimation device described in any one of (1) to (5), wherein the gas flow estimation device reads acquired data that links an infrared image of the gas cloud with the position information, imaging direction, and imaging angle of the camera that captured the infrared image, and estimates the gas flow rate. (11) The detection data processing device described in (10) further includes a display unit having a screen for displaying an image of the gas cloud, and a display control unit for displaying the map information on the screen. (12) The detection data processing device according to (11), wherein the display control unit displays the map information so that the imaging direction of the camera passes through the center of the screen.

[0010] (13) A gas flow rate estimation method including the steps of: acquiring map information of the surroundings of a camera that captured an infrared image of a gas cloud from position information of the camera; calculating the distance from the camera to the gas cloud based on the map information; calculating the gas velocity of the gas cloud and the gas transit time required for the gas to pass through a gas region extracted from the time series images of the gas cloud captured by the camera using the time series images; calculating a gas concentration thickness product of the gas region using image data of the gas region included in the infrared images, and calculating the gas amount of the gas region using the gas concentration thickness product and the distance to the gas cloud; and calculating an estimated gas flow rate value using the gas transit time and the gas amount.

[0011] (14) A leakage gas detection method including the steps of: capturing an infrared image of a gas cloud with a camera; acquiring sensor information, which is the camera's position information, imaging orientation, and imaging angle; linking the infrared image and the sensor information and storing them as acquired data; acquiring map information of the area around the camera from the camera's position information; fitting the camera's imaging orientation to the map information to identify the closest building in the imaging orientation; calculating the distance between the identified building and the camera; using time-series images of the gas cloud captured by the camera, calculating the gas velocity of the gas cloud and the gas transit time required for the gas to pass through a gas region extracted from the time-series images; calculating a gas concentration thickness product of the gas region using image data of the gas region included in the infrared image, and calculating the gas volume of the gas region using the calculated gas concentration thickness product and the distance to the gas cloud; and calculating an estimated gas flow rate value using the gas transit time and the gas volume.

[0012] (15) A leakage gas detection method including the steps of: capturing an infrared image of a gas cloud with a camera; acquiring sensor information, which is position information, imaging orientation, and imaging angle of the camera; linking the infrared image and the sensor information and storing them as acquired data; acquiring map information of the area around the camera from the position information of the camera; displaying the map information on a screen; accepting a position of the gas cloud specified by a user; calculating the distance between the gas cloud specified by the user and the camera; calculating the gas velocity of the gas cloud and the gas transit time required for the gas to pass through a gas region extracted from the time series images using time series images of the gas cloud; calculating a gas concentration thickness product of the gas region using image data of the gas region included in the time series images, and calculating the gas amount of the gas region using the calculated gas concentration thickness product and the distance to the gas cloud; and calculating an estimated gas flow rate value using the gas transit time and the gas amount.

[0013] (16) A gas flow rate estimation program for causing a computer to execute the following steps: acquiring map information of the surroundings of a camera that captured an infrared image of a gas cloud from the position information of the camera; calculating the distance from the camera to the gas cloud based on the map information; calculating the gas velocity of the gas cloud and the gas transit time required for the gas to pass through a gas region extracted from the time series images using time series images of the gas cloud; calculating a gas concentration thickness product of the gas region using image data of the gas region included in the time series images, and calculating the gas amount of the gas region using the gas concentration thickness product and the distance to the gas cloud; and calculating an estimated gas flow rate value using the gas transit time and the gas amount. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a leak gas detection device, a leak gas detection method, and the like that are capable of estimating a flow rate with high accuracy while eliminating the need for a user to measure distance when capturing an infrared image. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a perspective view illustrating an outline of a leakage gas detection device according to an embodiment; [Figure 2] 1 is a block diagram illustrating a hardware configuration of a gas leakage inspection device according to an embodiment. [Figure 3] 1 is a block diagram illustrating a functional configuration of a gas leakage inspection device according to an embodiment. [Figure 4] FIG. 10 is a diagram showing a screen exemplifying an image displayed on the display unit during imaging. [Figure 5A] FIG. 10 is a diagram showing a screen illustrating an extracted gas region. [Figure 5B] FIG. 1 is a diagram showing a screen for schematically explaining pixels. [Figure 6] 10A and 10B are diagrams showing screens illustrating a distance calculation process in the leakage gas inspection device according to the embodiment. [Figure 7] FIG. 10 is a side view illustrating the positional relationship between the camera and the gas cloud. [Figure 8] 1 is a perspective view illustrating an example of a schematic configuration of a leakage gas detection device according to an embodiment in which a camera and a gas flow rate estimation device are separate entities. FIG. [Figure 9A] FIG. 2 is a diagram showing a screen illustrating map information displayed on the screen of a display unit. [Figure 9B] 10A and 10B are diagrams showing screens illustrating distance calculation processing in a modified example. [Figure 10] FIG. 2 is a block diagram illustrating a functional configuration of a detection data processing device according to an embodiment. [Figure 11] 1 is a flowchart of a leak gas detection method according to an embodiment. [Figure 12] 10 is a flowchart illustrating a process for calculating a flow rate. [Figure 13] 1 is a flowchart of a leak gas detection method according to an embodiment. [Figure 14A] 4 is a flowchart of a data acquisition process in the leakage gas detection method according to the embodiment. [Figure 14B]4 is a flowchart of a data reading process in the leakage gas detection method according to the embodiment. [Figure 15A] 4 is a flowchart of a data acquisition process in the leakage gas detection method according to the embodiment. [Figure 15B] 4 is a flowchart of a data reading process in the leakage gas detection method according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] Embodiments and modifications of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments and modifications.

[0017] [Gas leakage detection device] A gas leakage detection device 1 according to a first embodiment will be described with reference to FIGS. 1 to 8. The gas leakage detection device 1 is a device that detects gas leaking from a facility or the like that stores gas. The gas to be inspected is, for example, a hydrocarbon gas such as methane, ethane, or propane. When there is a gas leak, the gas forms a cloud near the leaked location. The gas leakage detection device 1 can visualize and observe such gas clouds on a screen. As shown in Fig. 1, the leakage gas detection device 1 includes a camera 20, a measurement unit 30, a display unit 40, and a gas flow rate estimation device 10. Here, the leakage gas detection device 1 further includes an acquired data storage unit 45. Note that the display unit 40 is folded in Fig. 1. Each component of the leakage gas detection device 1 will be described below.

[0018] 2 is a block diagram illustrating an example of the hardware configuration of the leakage gas detection device 1. The leakage gas detection device 1 has a camera 20, a measurement unit 30, a control unit 50, an auxiliary storage device 53, a communication interface 54, an input device 55, and a display unit 40, which are interconnected by a bus 56. Here, the gas flow rate estimation device 10 is incorporated as a function of the control unit 50. Note that the gas flow rate estimation device 10 may also be configured as independent hardware. The control unit 50 is a device that controls the leakage gas detection device 1. As illustrated in FIG. 2, the control unit 50 has a central processing unit (CPU) 51 and a main memory device 52, and performs information processing related to the control of the leakage gas detection device 1. The main memory device 52 is a ROM or RAM. The auxiliary memory device 53 is a hard disk or the like. The communication interface 54 is a connection device to a local area network (LAN) or the Internet. The input device 55 is a touch panel, keyboard, or the like. The display unit 40 is a display or the like. In addition, the memory device of the acquired data memory unit 45 is included in the auxiliary memory device 53.

[0019] (camera) The camera 20 is a device that captures images of leaked gas. The camera 20 can capture infrared images that contain infrared information. The camera 20 can also capture time-series images. As shown in FIG. 2, the camera 20 includes an optical system 22, a filter 24, and an image sensor 26. The optical system 22 is a component that refracts light and forms an image of the subject on the image sensor 26. The filter 24 is a component that passes infrared light of a specific wavelength. The filter 24 is disposed between the optical system 22 and the image sensor 26 and passes only infrared light of a specific wavelength from the light that passes through the optical system 22. The wavelength that is passed varies depending on the type of gas. For example, if methane is the target gas to be detected, the filter 24 is a bandpass filter that passes light with a wavelength between 3.2 μm and 3.4 μm. The image sensor 26 can be, for example, an indium antimonide (InSb) image sensor.

[0020] (Measurement unit 30) The measurement unit 30 is a device that measures the position and orientation of the camera 20. The measurement unit 30 is integrated with the camera 20. The measurement unit 30 has a position sensor 31, an orientation sensor 32, and an angle sensor 33. The position sensor 31 is a device that receives signals from satellites to acquire position information. The position sensor 31 can use a satellite positioning system such as a GPS (Global Positioning System).

[0021] The orientation sensor 32 is a device that acquires the orientation of north, south, east, and west from the attitude information of the camera 20. The orientation sensor 32 can measure the imaging orientation, that is, the orientation in which the camera 20 is facing in the horizontal plane. The orientation sensor 32 can be, for example, a geomagnetic sensor. The angle sensor 33 is a device that acquires the tilt with respect to the horizontal plane, which is part of the attitude information of the camera 20. The angle sensor 33 can measure the imaging angle, that is, the angle between the direction in which the camera 20 is facing and the horizontal plane. The angle sensor 33 can be an acceleration sensor or an inclination sensor. Note that the measurement unit 30 may also have a sensor that combines the orientation sensor 32 and the angle sensor 33 and can measure the orientation and angle simultaneously.

[0022] (Display) The display unit 40 is a display device that displays images and information such as the operating status of each device. The display unit 40 has a screen that displays an image of a gas cloud. The screen of the display unit 40 can be a touch panel that accepts input from the user, and can accept operations and inputs for each device. 4, the user can visually recognize the gas cloud on the screen 60 of the display unit 40. The user can adjust the position and direction of the camera 20 so that the gas cloud 70 is positioned at the center of the screen 60. There may be multiple display units 40, and additional display units 40 can be installed using tablet terminals or the like.

[0023] (Acquired data storage unit) The acquired data storage unit 45 is a means for storing data. The acquired data storage unit 45 associates the infrared image with the position information, imaging direction, and imaging angle of the camera 20, and stores the associated data as acquired data. The position information, imaging direction, and imaging angle are small in data volume, and by associating them with the infrared image, they can be used later for data processing such as flow rate estimation. The acquired data storage unit 45 receives the red line image and sensor information such as position information, links them together, and stores them in a storage device. The linked data is the acquired data. The storage device of the acquired data storage unit 45 can be a hard disk, semiconductor memory, or the like.

[0024] (Gas flow rate estimation device) The gas flow rate estimation device 10 is an information processing device that calculates a gas flow rate value from an image of a gas cloud. The gas flow rate (L / min) is, for example, the volume (L) of gas passing through a cross section perpendicular to the screen per unit time (min). 3, the gas flow rate estimation device 10 includes an area extraction unit 11, a vector calculation unit 12, a transit time calculation unit 13, a concentration thickness product calculation unit 14, a gas amount calculation unit 15, a flow rate calculation unit 16, a map acquisition unit 34, a building identification unit 35, and a distance calculation unit 37. The transit time calculation unit 13 is also referred to as a first calculation unit, the gas amount calculation unit 15 as a second calculation unit, and the flow rate calculation unit 16 as a third calculation unit.

[0025] (Area extraction part) The region extraction unit 11 is a means for visualizing a gas cloud from an infrared image and extracting a gas region. A gas region is a region where pixels constituting the visualized image of a gas cloud are distributed. The region extraction unit 11 receives a time-series infrared image as input and outputs a visualized image and a gas region. As an example, the region extraction unit 11 can perform the following first and second image processing. The first image processing is a process for visualizing images of gas clouds. Temperature changes can be observed from time-series infrared images. The frequency of temperature changes in areas where gas clouds exist is higher than in areas where gas clouds do not exist. The region extraction unit 11 utilizes this fact to perform a process to remove low-frequency components. The infrared image is a time-series image data of, for example, 30 frames per second. The region extraction unit 11 calculates a moving average of the brightness of each pixel over a predetermined number of frames, such as 21 frames, and calculates the difference from the infrared image. The first image processing enables detection of gas clouds even when there are large temperature changes in the background. The region extraction unit 11 can further perform a process to remove high-frequency components derived from noise, etc., to generate a time-series visualized image that visualizes the gas cloud. Figure 4 shows an example of a screen displaying a visualized image superimposed on an infrared image. The first image processing is disclosed, for example, in Japanese Patent No. 6245418. Note that the technology disclosed therein is not necessarily required.

[0026] The second image processing is a process for extracting a gas region. The region extraction unit 11 extracts the maximum brightness value of each pixel for each predetermined number of frames, such as 30 frames, from the time-series visualized image. The region extraction unit 11 then generates an image in which the extracted maximum value is set for each pixel. The region extraction unit 11 further performs noise removal and binarization processing to identify a gas region 72, as shown in FIG. 5A. The gas region 72 is time-series image data and can be displayed superimposed on an infrared image, etc.

[0027] (Vector calculation section) The vector calculation unit 12 is a means for calculating the average motion vector of pixels. A motion vector is a vector that represents the movement of an object on the screen by the direction and magnitude at the position of each pixel. The vector calculation unit 12 receives the visualized image and the gas region as input, and outputs the average motion vector of each pixel in the gas region. The vector calculation unit 12 calculates the movement vector for each pixel corresponding to the gas region 72 in the visualized image and calculates the average. The movement vector can be calculated using a known method such as template matching. Here, as shown in FIG. 5B, the average movement vector 91 of the gas region 72 is a vector in the longitudinal direction of the gas region 72. Note that FIG. 5B exaggerates the pixels 62. The actual number of pixels in the gas region 72 is, for example, 5032 pixels, and the average movement vector is, for example, 25.5 pixels / sec. The average movement vector indicates that gas is moving within the gas region 72.

[0028] (Passage time calculation section) The transit time calculation unit 13 is a first calculation unit, and is a means for estimating the time it takes for gas to pass through the gas region 72. The transit time calculation unit 13 receives the average motion vector and the gas region as input, and outputs the transit time. The transit time calculation unit 13 sets, for example, a rectangle on the screen that circumscribes the gas region 72 and has sides parallel to the average motion vector. Then, it calculates the transit time of the gas from the number of pixels corresponding to the length of the side of the rectangle and the number of pixels of the average motion vector. For example, if the number of pixels on the side of the rectangle is 172 pix and the average motion vector is 25.5 pix / sec, the transit time is 6.75 seconds.

[0029] (Concentration thickness product calculation unit) The concentration thickness product calculation unit 14 is a means for calculating the concentration thickness product of a gas. The concentration thickness product of a gas is the product of the gas concentration and the gas thickness. The concentration thickness product calculation unit 14 receives the visualized image and the gas region as input, and outputs the average value of the concentration thickness product of the pixels in the gas region. Furthermore, a parameter for calculating the concentration-thickness product is distance information (distance in the depth direction) between the imaging position and the measurement target. The gas flow rate estimation device 10 uses the distance calculated by a distance calculation unit (described later) as the value of this distance. The concentration-thickness product is disclosed in Japanese Patent No. 6344533. However, it is not necessary to rely on the technology disclosed therein.

[0030] Because gas clouds fluctuate due to wind and other factors, the intensity of infrared light detected by each pixel changes even when the camera 20 is fixed. This makes it possible to capture changes in infrared intensity when gas is present and when it is not. For example, by determining in advance the correspondence between the proportion of infrared light absorbed by gas and the concentration-thickness product, the concentration-thickness product can be calculated from changes in infrared intensity. The concentration thickness product calculation unit 14 calculates the concentration thickness product of each pixel in the gas region and calculates the average value. The average value of the concentration thickness product is, for example, 0.285% LELm. The gas concentration can be expressed as a ratio to the LEL (Lower Explosion Limit) concentration, which is the lower explosion limit. The volume concentration of the lower explosion limit is expressed as 100% LEL. The concentration thickness product is multiplied by the depth direction as seen from the camera 20, and is expressed in units of % LELm. The lower explosion limit is the lowest concentration at which a flammable gas mixed with air will explode upon ignition. For example, in the case of methane, a volume concentration of 5% is 100% LEL, and 0.285% LELm is equivalent to 0.01425% m.

[0031] (Gas volume calculation section) The gas amount calculation unit 15 is a second calculation unit and is a means for calculating the volume of gas. The gas amount calculation unit 15 receives the concentration-thickness product and the gas region as input, and outputs the gas amount of the gas region. The gas amount calculation unit 15 obtains the amount of gas by multiplying the concentration-thickness product by the area of ​​the gas region. The area of ​​the gas region can be calculated by counting the number of pixels in the gas region 72 as shown in FIG. 5B and multiplying it by the corresponding area. The length corresponding to the width α of one pixel at the location of the gas cloud varies depending on the distance between the camera 20 and the gas cloud. The gas amount calculation unit 15 calculates the amount of gas using the distance calculated by the distance calculation unit. The length corresponding to the width α of a pixel is, for example, a value such as 0.09219 m, and one pixel is 0.008499 m 2 The area of ​​the gas region with 5032 pixels is 42.77 m 2 If the concentration-thickness product is 0.0285%LELm (0.01425%m), the gas volume is 6.095L (0.006095m 3 ) is calculated as follows.

[0032] (Flow rate calculation section) The flow rate calculation unit 16 is a third calculation unit and is a means for calculating the gas flow rate. The flow rate calculation unit 16 receives the gas volume and the gas transit time as input, and outputs the gas volume divided by the gas transit time as the gas flow rate (L / min). For example, if the gas volume is 6.095 L and the transit time is 6.75 seconds, the gas flow rate is calculated to be 54.2 L / min. The processes from the first image processing to the calculation of the gas flow rate are disclosed in, for example, Japanese Patent No. 6693609, except that the distance calculated by the distance calculation unit is used. Note that the technology disclosed therein does not necessarily have to be used.

[0033] (Map Acquisition Department) Next, a description will be given of the process of calculating the distance between the gas cloud and camera 20 in gas flow rate estimation device 10. The distance is calculated by map acquisition unit 34, building identification unit 35, and distance calculation unit 37. The map acquisition unit 34 is a means for acquiring map information about the area around the camera 20 from the position information of the camera 20 that captured the infrared image. The map acquisition unit 34 receives the position information of the camera 20 as input and outputs map information. When a choice of map information is available, detailed information about the location of the building is selected. It is also preferable that the map information includes information about the perimeter of the building. The map information can be map data provided by the gas facility operator or a map information service provided on the Internet.

[0034] (Building Identification Department) The building identification unit 35 is a means for identifying on a map the building that is the subject of image capture by the camera 20. The building identification unit 35 applies the image capture orientation 93 of the camera 20 that captured the infrared image to the map information, and identifies the closest building 75 in the image capture orientation 93. The building identification unit 35 receives the position information of the camera 20 and the map information, and outputs the position information of the identified building, i.e., the coordinate values. If the map information includes information on the perimeter line of the building, the building identification unit 35 can output the position information of the perimeter line facing the camera 20. The building identification unit 35 automatically detects the nearest building located in the imaging orientation of the camera 20 from map information. Here, as illustrated in FIG. 6 , a map is displayed on a screen 60 of the user's smartphone or tablet terminal, which is the display unit 40, and the position of the camera 20 is displayed. The building identification unit 35 identifies the nearest building 75 in the direction of the imaging orientation 93 of the camera 20. Note that when the building identification unit 35 automatically identifies a building, it is not necessary to display a map on the screen 60, but it can be displayed.

[0035] (Distance calculation section) Distance calculation unit 37 is a means for calculating the distance from camera 20 to the gas cloud based on map information. Distance calculation unit 37 receives position information of camera 20 and position information of a building or its perimeter as input, and outputs the calculated distance. Distance calculation unit 37 can calculate, for example, a horizontal distance to be used as the distance from camera 20 to the gas cloud. In the example of FIG. 6, distance calculation unit 37 calculates the planar distance β from camera 20 to the perimeter of building 75. Distance calculation unit 37 can further input the imaging angle of camera 20, calculate and output the distance. As illustrated in Fig. 7, distance calculation unit 37 can calculate the three-dimensional distance γ to gas cloud 70 by trigonometry from the imaging angle θ of camera 20 that captured the infrared image and the planar distance β between building 75 and camera 20. The three-dimensional distance γ is the distance from camera 20 to gas cloud 70. Equation (1) for calculating the three-dimensional distance γ by trigonometry is shown below. γ=β / cosθ … (1) The imaging angle θ is the angle between the direction 94 in which the camera 20 is facing and the horizontal plane, but since the ground surface 76 is horizontal in this case, it is described as the angle from the ground surface.

[0036] The gas leakage detection device 1 having the above configuration includes a sensor that acquires location information, an imaging direction, and an imaging angle. The gas flow rate estimation device 10 then acquires map information from the location information, calculates the distance from the camera to the gas cloud based on the map information, and calculates the gas flow rate using that distance. This eliminates the need for distance measurement as a separate task from capturing an infrared image, improving user convenience. An important factor in determining the accuracy of gas flow rate estimation is distance information to the object being photographed. The leak gas detection device 1 links the location information, imaging direction and imaging angle information acquired by the sensor of the measurement unit 30 with map information, enabling automatic acquisition of accurate distance information in three dimensions, and enabling simple and highly accurate flow rate estimation.

[0037] The gas leakage detection device 1 has a map acquisition unit that acquires map information, a building identification unit that identifies the nearest building in the imaging direction, and a distance calculation unit that calculates the distance from the position information and imaging angle. As a result, if the map information contains attribute information such as buildings, the device can automatically recognize the first object that the camera encounters in the direction it is pointing as the measurement target based on the attribute information and imaging direction, and can also calculate the distance to the actual position of the imaged object based on the imaging angle, further simplifying user operation and improving convenience. Conventionally, distance measurement and storage was required even when it was unclear whether the gas flow rate would be calculated, imposing a heavy burden on the user and making it impossible to estimate the flow rate (later flow rate estimation) from data that did not store distance information. The gas leakage detection device 1 is equipped with an acquired data storage unit that links the infrared image with the camera's position information, imaging direction, and imaging angle and stores them as acquired data, thereby reducing the user's workload when capturing images and enabling later flow rate estimation.

[0038] 8, the leaking gas detection device 1 may have the camera 20 and the gas flow rate estimation device 10 separate from each other. Here, the camera 20 and the measurement unit 30 are part of an imaging device 110, and the gas flow rate estimation device 10 is incorporated into a computer 120. The leaking gas detection device 1 also has display units 40 corresponding to the separate camera 20 and gas flow rate estimation device 10, respectively. The imaging device 110 and the computer 120 each have a communication interface and can communicate with each other. The acquired data storage unit 45 may be provided in the imaging device 110 or in the computer 120. The leaking gas detection device 1 may be composed of a plurality of imaging devices 110 and a plurality of computers 120.

[0039] (Variation) Next, a leakage gas detection device according to a modified example will be described with reference to Figures 9A and 9B. The leakage gas detection device according to the modified example further includes a display control unit 36 ​​that displays map information on a screen 60. A distance calculation unit 37 calculates the distance between a designated position 95 designated by a user on the map information and the camera 20, and sets this as the distance from the camera 20 to the gas cloud 70. The other points are the same as those of the leakage gas detection device 1 according to the embodiment.

[0040] (Display control unit) The display control unit 36 ​​is a means for displaying map information on the display unit 40. The display control unit 36 ​​receives map information, position information of the camera 20, and imaging direction as input, and outputs map information including the position of the camera 20. 9A, the display control unit 36 ​​displays the position of the camera 20 on a map displayed on the screen 60. Here, the display control unit 36 ​​positions the camera 20 at the edge of the screen. The display control unit 36 ​​then displays the map information so that the imaging orientation 93 of the camera 20 passes through the center 92 of the screen 60. This allows the imaging orientation 93 side of the camera 20 to be displayed widely on the screen 60.

[0041] While viewing the screen 60, the user can specify the position to be imaged by the camera 20. As shown in Fig. 9B, the user's specified position 95 is near the periphery of the building 75. The user may input the specified position 95 using the screen 60 as a touch panel, using a mouse, or by inputting numerical coordinate values ​​using a keyboard or the like. Then, the distance calculation unit 37 calculates the planar distance φ between the camera 20 and the designated position 95 designated by the user in the map information, and sets this as the distance from the camera 20 to the gas cloud 70. Furthermore, the distance calculation unit 37 can calculate the three-dimensional distance γ by trigonometry from the position of the camera 20, the designated position 95, and the imaging angle θ.

[0042] The modified gas leakage detection device allows the user to specify the location on a map to be imaged, thereby allowing the correct location of the gas cloud to be reflected in the acquired data, thereby increasing the reliability of the acquired data. The gas leakage detection device according to the modified example can calculate an accurate distance by specifying a location by the user even when map information is insufficient for information on buildings, etc. Furthermore, even when the building structure is complex, the user can specify a precise location.

[0043] [Detection data processing device] Next, a detection data processing device 2 according to an embodiment will be described with reference to FIG. 10. The detection data processing device 2 is an information processing device that calculates a gas flow rate from already acquired data. As illustrated in FIG. 10, the detection data processing device 2 does not necessarily have to include a camera 20 and a measurement unit 30. The detection data processing device 2 reads the acquired data and calculates a gas flow rate. Other aspects are the same as those of the leakage gas detection device 1. The detection data processing device 2 includes a gas flow rate estimation device 10. The gas flow rate estimation device 10 reads acquired data that links an infrared image of a gas cloud with the position information, imaging direction, and imaging angle of the camera 20 that captured the infrared image, and estimates the gas flow rate. Here, the detection data processing device 2 reads the acquired data from an acquired data storage unit 45. The acquired data storage unit 45 may be an external storage device.

[0044] The detection data processing device 2 can further include a display unit 40 having a screen for displaying an image of a gas cloud, and a display control unit 36 ​​for displaying map information on the screen, similar to the gas leakage detection device 1. The display control unit 36 ​​can also display the map information so that the imaging direction of the camera 20 passes through the center of the screen.

[0045] Even if the data is infrared image data that does not store distance information, the detection data processing device 2 can later estimate the flow rate as long as it has the position information, imaging direction, and imaging angle of the camera 20 associated with the infrared image. The detection data processing device 2 not only enables highly accurate estimation of the gas flow rate, as with the leak gas detection device 1, but also enables later flow rate estimation. The detection data processing device 2 may include a camera 20 and a measurement unit 30. For example, if the acquired data is stored in the acquired data storage unit 45, it can function as the detection data processing device 2. The leakage gas detection device 1 can also function as the detection data processing device 2 by connecting an external storage device in which the acquired data is stored. The computer 120, which was described in the case where the camera 20 and the gas flow rate estimation device 10 are separate, can also function as the detection data processing device 2.

[0046] [Gas leakage detection method] Next, leakage gas detection methods S1 and S2 according to the embodiment will be described with reference to Fig. 11 to Fig. 13. The leakage gas detection methods according to the embodiment include a leakage gas detection method S1 that automatically identifies a building, and a leakage gas detection method S2 in which a user specifies a location.

[0047] As illustrated in Fig. 11, the leakage gas detection method S1 for automatically identifying a building includes the following steps S10 to S80. The flowchart in Fig. 11 will be described below with reference to the respective parts in Figs. 3 and 10. First, the camera 20 captures a red line image of the gas cloud (step S10), and the measurement unit 30 measures sensor information, including the position information, imaging orientation, and imaging angle of the camera 20 (step S20). The acquired data storage unit 45 associates the infrared image captured by the camera 20 with the sensor information measured by the measurement unit 30 and stores the data as acquired data (step S30). The map acquisition unit 34 of the gas flow rate estimation device 10 acquires map information about the surroundings of the camera 20 from the position information of the camera 20 (step S40). The building identification unit 35 fits the imaging orientation of the camera 20 into the map information to identify the closest building in the imaging orientation (step S50). The distance calculation unit 37 calculates the planar distance between the identified building and the camera 20 (step S60). In step S60, the distance calculation unit 37 may calculate the three-dimensional distance by trigonometry using the imaging angle. Then, when the gas flow rate estimating device 10 calculates the estimated gas flow rate value using the calculated distance (step S80), the process S1 in FIG. 11 ends.

[0048] As shown in Fig. 12, step S80 of calculating the flow rate includes the processing of steps S81 to S86, which will be described below. The same applies to step S80 of calculating the flow rate in other flowcharts. The flowchart in Fig. 12 will be described below with reference to the respective parts in Figs. 3 and 10. The region extraction unit 11 extracts a gas region from a time-series infrared image (step S81). Next, the vector calculation unit 12 calculates the average motion vector of pixels based on the gas region extracted by the region extraction unit 11 (step S82). The concentration thickness product calculation unit 14 calculates the average value of the gas concentration thickness product in the gas region (step S83). The transit time calculation unit 13, which is a first calculation unit, calculates the gas velocity in the gas region and the gas transit time required for the gas to pass through the gas region using time-series images of the gas cloud captured by a camera (step S85). The gas amount calculation unit 15, which is a second calculation unit, calculates the gas concentration thickness product in the gas region using image data of the gas region included in the infrared image, and calculates the gas amount in the gas region using the calculated gas concentration thickness product and the distance to the gas cloud (step S84). The flow rate calculation unit 16, which is a third calculation unit, calculates an estimated gas flow rate using the gas transit time and gas amount (step S86). The process of step S85 for calculating the gas transit time can be performed after the process of step S82 for calculating the average motion vector and before step S86 for calculating the estimated value of the gas flow rate.

[0049] As illustrated in FIG. 13, in the leak gas detection method S2 in which the user specifies a position, steps S52 and S54 are executed instead of step S50. First, the camera 20 captures an infrared image of the gas cloud (step S10), and the measurement unit 30 measures sensor information, including the position information, imaging orientation, and imaging angle of the camera 20 (step S20). The acquired data storage unit 45 associates the infrared image captured by the camera 20 with the sensor information measured by the measurement unit 30 and stores the data as acquired data (step S30). The map acquisition unit 34 acquires map information about the area around the camera 20 from the position information of the camera 20 (step S40). The display control unit 36 ​​shown in FIG. 10 displays map information including the position of the camera 20 on the screen of the display unit 40 (step S52). Thereafter, the distance calculation unit 37 waits for input of a specified position from the user and accepts the input of the specified position (step S54). The process then proceeds to step S60. The distance calculation unit 37 then calculates the distance between the position of the gas cloud designated by the user and the camera 20 (step S60). Then, the gas flow rate estimation device 10 calculates a gas flow rate estimation value using the calculated distance (step S80), and ends the process S2 in FIG.

[0050] In addition, the processing from step S40 of acquiring map information to step S80 of calculating flow rate in the leakage gas detection method S1 that automatically identifies a building, and the processing from step S40 of acquiring map information to step S80 of calculating flow rate in the leakage gas detection method S2 in which a user specifies a location correspond to the gas flow rate estimation method of the embodiment.

[0051] Furthermore, the leak gas detection methods S1 and S2 can be separated into two processes: a data acquisition process and a data reading process. In the data acquisition process, the leak gas detection device 1 captures infrared images and measures sensor information, and links these to store acquired data. In the data reading process, the leak gas detection device 1 reads the stored acquired data, calculates the distance between the camera and the object being photographed, and calculates the gas flow rate using that distance.

[0052] FIG. 14A is a flowchart of the data acquisition process S1A of the leakage gas detection method S1 for automatically identifying a building. First, the camera 20 captures an infrared image (step S10), and the measurement unit 30 measures sensor information (step S20). After that, the acquired data storage unit 45 associates the infrared image with the sensor information and stores them as acquired data (step S30), and then the process S1A in FIG. 14A ends.

[0053] FIG. 14B is a flowchart of the data reading process S1B of the leakage gas detection method S1 for automatically identifying a building. First, the acquired data storage unit 45 reads acquired data in which an infrared image and sensor information are linked (step S35). The sensor information includes camera position information, imaging orientation, and imaging angle. The map acquisition unit 34 of the gas flow estimation device 10 acquires map information about the surroundings of the camera from the camera position information (step S40). The building identification unit 35 fits the camera's imaging orientation into the map information to identify the building closest to the imaging orientation (step S50). The distance calculation unit 37 calculates the planar distance between the identified building and the camera (step S60). Then, the gas flow estimation device 10 calculates a gas flow estimation value using the calculated distance (step S80), and the processing of FIG. 14B ends.

[0054] 15A shows a data acquisition process S2A of the leaked gas detection method S2 in which the user specifies a position. In this process S2A, the same processes as steps S10 to S30 in FIG. 14A are executed. FIG. 15B is a flowchart of the process S2B for calculating the gas flow rate in the leak gas detection method S2 in which the user specifies a position.

[0055] First, the acquired data storage unit 45 reads acquired data in which an infrared image and sensor information are linked (step S35). The sensor information includes camera position information, imaging orientation, and imaging angle. The map acquisition unit 34 of the gas flow estimation device 10 acquires map information around the camera from the camera position information (step S40). The display control unit 36 ​​shown in FIG. 10 displays map information including the camera position on the screen (step S52). Thereafter, the distance calculation unit 37 waits for input of a specified position from the user and accepts the input of the specified position (step S54). Thereafter, the process proceeds to step S60. The distance calculation unit 37 then calculates the distance between the position specified by the user and the camera (step S60). The gas flow estimation device 10 then calculates the gas flow rate using the calculated distance (step S80), and ends the process of FIG. 15B. The leaked gas detection device 1 can independently perform the data acquisition processes S1A and S2A and the data reading processes S1B and S2B.

[0056] [Gas flow rate estimation program] The gas flow rate estimation program according to the embodiment is a program that is read into a computer and causes the computer to execute the processing of a gas flow rate estimation method. The gas flow rate estimation program can be obtained through an electric communication line and can be recorded on a computer-readable recording medium. [Explanation of symbols]

[0057] 1. Gas leak detection device 2. Detection data processing device 10 Gas flow rate estimation device 11 Region extraction part 12 Vector calculation section 13 Passage time calculation section 14 Concentration thickness product calculation unit 15 Gas volume calculation unit 16 Flow rate calculation section 20 Camera 22 Optical system 24 filters 26 Image sensor 30 Measurement section 31 Position Sensor 32 Orientation sensor 33 Angle Sensor 34 Map Acquisition Department 35 Building Identification Department 36 Display control unit 37 Distance calculation unit 40 Display section 45 Acquired data storage unit 50 control section 60 screens 62 pixels 70 Gas Cloud 72 Gas Region 75 Buildings

Claims

1. a map acquisition unit that acquires map information about the surroundings of a camera based on position information of the camera that captures an image including infrared information; a distance calculation unit that calculates a distance from the camera to the gas cloud imaged by the camera based on the map information; a first calculation unit that calculates a gas velocity of the gas cloud and a gas transit time required for the gas to pass through a gas region extracted from the time-series images of the gas cloud captured by the camera; a second calculation unit that calculates a gas concentration thickness product of the gas region using image data of the gas region included in the time-series images, and calculates a gas amount of the gas region using the gas concentration thickness product and the distance calculated by the distance calculation unit; a third calculation unit that calculates an estimated gas flow rate value using the gas transit time and the gas amount.

2. a building identification unit that identifies the nearest building in the imaging direction by fitting the imaging direction of the camera to the map information; The gas flow rate estimation device according to claim 1 , wherein the distance calculation unit calculates the distance between the building identified by the building identification unit and the camera, and sets the calculated distance as the distance from the camera to the gas cloud.

3. The gas flow rate estimation device according to claim 2 , wherein the distance calculation unit calculates the three-dimensional distance from the camera to the gas cloud by trigonometry based on the imaging angle of the camera and the planar distance between the building and the camera.

4. 2. The gas flow rate estimation device according to claim 1, wherein the distance calculation unit determines a position specified by a user in the map information as the position of the gas cloud, and calculates the distance from the camera to the gas cloud.

5. 5. The gas flow rate estimation device according to claim 4, wherein the distance calculation unit calculates the three-dimensional distance from the camera to the gas cloud by trigonometry based on the imaging angle of the camera and the planar distance between the specified position and the camera.

6. The camera; a measurement unit having a position sensor that acquires position information of the camera, an orientation sensor that detects the imaging orientation of the camera, and an angle sensor that detects the imaging angle of the camera; a display unit having a screen for displaying an image of the gas cloud; A leakage gas detection device comprising: the gas flow rate estimation device according to any one of claims 1 to 5.

7. The leak gas detection device according to claim 6 , further comprising an acquired data storage unit that associates the image with position information, imaging direction, and imaging angle of the camera and stores the image as acquired data.

8. The gas leakage detection device according to claim 6, further comprising a display control unit that displays the map information on the screen.

9. The leaking gas detection device according to claim 8 , wherein the display control unit displays the map information so that the imaging direction of the camera passes through the center of the screen.

10. A gas flow rate estimation device according to any one of claims 1 to 5, The gas flow rate estimation device is a detection data processing device that reads acquired data that links an infrared image of the gas cloud with the position information, imaging direction, and imaging angle of the camera that captured the infrared image, and estimates the gas flow rate.

11. a display unit having a screen for displaying an image of the gas cloud; The detection data processing device according to claim 10 , further comprising: a display control unit that displays the map information on the screen.

12. The detection data processing device according to claim 11 , wherein the display control unit displays the map information so that the imaging direction of the camera passes through the center of the screen.

13. acquiring map information of the surroundings of the camera from position information of the camera that captured the infrared image of the gas cloud; calculating a distance from the camera to the gas cloud based on the map information; Calculating a gas velocity of the gas cloud and a gas transit time required for the gas to pass through a gas region extracted from the time-series images of the gas cloud captured by the camera; calculating a gas concentration thickness product of the gas region using image data of the gas region included in the infrared image, and calculating a gas amount of the gas region using the gas concentration thickness product and a distance to the gas cloud; and calculating an estimated gas flow rate value using the gas transit time and the gas amount.

14. capturing an infrared image of the gas cloud with a camera; acquiring sensor information including position information, imaging orientation, and imaging angle of the camera; a step of linking the infrared image and the sensor information and storing them as acquired data; acquiring map information about the surroundings of the camera from the position information of the camera; A step of fitting the imaging direction of the camera to the map information and identifying the nearest building in the imaging direction; calculating a distance between the identified building and the camera; Calculating a gas velocity of the gas cloud and a gas transit time required for the gas to pass through a gas region extracted from the time-series images of the gas cloud captured by the camera; calculating a gas concentration thickness product of the gas region using image data of the gas region included in the infrared image, and calculating a gas amount of the gas region using the calculated gas concentration thickness product and a distance to the gas cloud; and calculating an estimated gas flow rate using the gas transit time and the gas amount.

15. capturing an infrared image of the gas cloud with a camera; acquiring sensor information including position information, imaging orientation, and imaging angle of the camera; a step of linking the infrared image and the sensor information and storing them as acquired data; acquiring map information about the surroundings of the camera from the position information of the camera; displaying the map information on a screen; receiving a designation of a location of the gas cloud from a user; Calculating a distance between the gas cloud and the camera as specified by a user; Calculating a gas velocity of the gas cloud and a gas transit time required for the gas to pass through a gas region extracted from the time-series images of the gas cloud captured by the camera; calculating a gas concentration thickness product of the gas region using image data of the gas region included in the time-series images, and calculating a gas amount of the gas region using the calculated gas concentration thickness product and a distance to the gas cloud; and calculating an estimated gas flow rate using the gas transit time and the gas amount.

16. a step of acquiring map information around the camera based on position information of the camera that captured the infrared image of the gas cloud; calculating a distance from the camera to the gas cloud based on the map information; a step of calculating a gas velocity of the gas cloud and a gas transit time required for the gas to pass through a gas region extracted from the time-series images of the gas cloud taken by the camera; calculating a gas concentration thickness product of the gas region using image data of the gas region included in the time-series images, and calculating a gas amount of the gas region using the gas concentration thickness product and a distance to the gas cloud; a gas flow rate estimation program for causing a computer to execute a procedure of calculating an estimated gas flow rate value using the gas transit time and the gas amount;

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