Gas movement estimation device, gas movement estimation method, estimation model generation device, estimation model generation method, and program

Abstract

[Problem] To provide an estimation device and estimation method whereby it can be detected whether gas is flowing in a near-far direction with respect to a viewpoint, even if gas monitoring is performed on the basis of only images from a single viewpoint. [Solution] A gas migration estimation device comprising: an image input unit that receives, as input, a gas distribution video in which a range, in which gas that has leaked into a space is present, is displayed as a gas zone; and a gas migration estimation unit that uses an estimation model which was machine-learned using, as training data, combinations of gas distribution videos for training and the states of gas migration in the near-far direction in the data gas distribution videos for training to thereby estimate the state of gas migration in the near-far direction corresponding to a gas distribution video received by the image acquisition unit.

Description

[Technical Field]

[0001] The present disclosure relates to a method for detecting gas leaks in a space using images, and to an apparatus, system, method, and program for identifying the movement of the leaked gas. [Background technology]

[0002] Gas plants, petrochemical plants, thermal power plants, steelmaking facilities, and other facilities handle large amounts of gas during operation. The risk of gas leaks due to aging or operational errors is recognized in these facilities, and gas detection devices are installed to minimize gas leaks before they lead to major accidents. In addition to gas detection devices that utilize the change in the electrical properties of a detection probe when gas molecules come into contact with the probe, gas visualization imaging devices that utilize infrared absorption by gases have recently been adopted.

[0003] Gas visualization imaging devices detect the presence of gas by capturing changes in the amount of electromagnetic waves that occur when gas absorbs electromagnetic waves, mainly in the infrared range, called blackbody radiation, emitted from background objects with an absolute temperature of 0 K or higher, or when the gas itself emits blackbody radiation.By capturing images of the monitored space with a gas visualization imaging device, gas leaks can be captured as images, making it possible to detect gas leaks earlier and pinpoint the exact location of the gas compared to detection probe methods, which can only monitor grid-like locations. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-326008 Summary of the Invention [Problem to be solved by the invention]

[0005] Even if a valve or other device is operated in the event of a gas leak, gas present between the valve and the leak source may continue to leak. Furthermore, gas that has already leaked may remain in the space near the leak source. Therefore, when personnel are required to check the equipment status or perform repairs, it is preferable to avoid areas with high gas concentrations. If gas is flowing, it is preferable to approach from upwind and avoid downwind areas. However, while gas visualization imaging devices based on images from a single viewpoint can easily capture gas movement in directions that change direction from the imaging viewpoint (left-right and up-down directions in the image), they have difficulty capturing gas movement in directions away from the imaging viewpoint (depth direction in the image). For example, there is a method for observing from multiple viewpoints using mirrors, such as the technology disclosed in Patent Document 1, but this method is not applicable when mirrors cannot be placed.

[0006] In view of the above-mentioned problems, an aspect of the present disclosure aims to provide an estimation device and an estimation method that can detect whether gas is flowing in a direction away from a viewpoint, even when gas monitoring is performed based only on images from a single viewpoint. [Means for solving the problem]

[0007] The gas movement estimation device according to one aspect of the present disclosure includes an image input unit that receives as input a gas distribution video consisting of a plurality of frames, the gas distribution video showing the range of existence of gas leaked into a space as a gas region, and an estimation model that is machine-learned using a combination of a teacher gas distribution video and a gas movement state in a near and far direction in the teacher gas distribution video as training data, to estimate the gas movement state of the image. input and a gas movement estimation unit that estimates the state of gas movement in the near and far direction corresponding to the gas distribution video received by the gas movement estimation unit, wherein the gas movement estimation unit uses a relative near and far speed that indicates the gas movement speed in the near and far direction as a relative value to the movement speed in the viewing angle direction as the state of gas movement in the near and far direction in the training data. [Effects of the Invention]

[0008] According to the above aspect, the movement state of the gas in the near / far direction is estimated based on the characteristics of the gas region in the gas distribution video. Therefore, by appropriately designing the training data, it is possible to identify whether the gas is approaching or receding from the imaging position. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a functional block diagram of a gas detection system 100 according to a first embodiment. [Figure 2] 1 is a schematic diagram showing the relationship between a monitoring target 300 and an image generating unit 10. FIG. [Figure 3] FIG. 1 is a schematic diagram illustrating an overview of the logical configuration of a machine learning model. [Figure 4] 10A and 10B are schematic diagrams showing a process of generating a gas distribution video from captured images. [Figure 5] FIG. 10 is a schematic overhead view illustrating the relationship between the time change tendency of the gas region in the gas distribution video and the gas flow velocity in the near and far directions. [Figure 6] FIG. 10 is a schematic overhead view illustrating the relationship between the gas movement speed in space and the correct answer of the training data and the gas flow speed that is the output of the learning model. [Figure 7] 4 is a flowchart showing the operation of gas detection device 20 in a learning phase. [Figure 8] 10 is an example of a gas distribution video as training data. [Figure 9] 10 is an example of a gas distribution video as training data. [Figure 10] 4 is a flowchart showing the operation of gas detection device 20 in a learning phase. [Figure 11] 10 is an example of an output image showing a result of velocity estimation. [Figure 12] 10 is an example of an output image showing a result of velocity estimation. [Figure 13] 10 is an example of an output image showing a result of velocity estimation. [Figure 14] 10 is an example of an output image showing a result of velocity estimation. [Figure 15] 10 is an example of an output image showing a result of velocity estimation. [Figure 16] The probability distribution of gas velocity is shown. (a) shows the probability distribution for velocity values, and (b) shows the probability distribution when velocity is a relative value to pixel size. [Figure 17] FIG. 10 is a functional block diagram of a gas detection system 101 according to a second modification. [Figure 18] FIG. 10 is a functional block diagram showing a configuration of a gas detection system 200 according to a second embodiment. [Figure 19] 10 is an example of an output image showing a result of velocity estimation. DETAILED DESCRIPTION OF THE INVENTION

[0010] First Embodiment Gas detection system 100 according to the first embodiment will be described below with reference to the drawings.

[0011] Fig. 1 is a functional block diagram of gas detection system 100 pertaining to embodiment 1. As shown in Fig. 1, gas detection system 100 includes image generation unit 10 for capturing an image of a monitoring target, gas detection device 20 for detecting gas based on an image acquired by image generation unit 10, and display unit 24. Image generation unit 10 and display unit 24 are each configured to be connectable to gas detection device 20.

[0012] <Image generation unit 10> Image generating unit 10 is a device or system that captures an image of a monitored object and provides the image to gas detection device 20. In the first embodiment, image generating unit 10 is a so-called infrared camera that detects infrared light with a wavelength of 3.2 to 3.4 μm, for example, and generates an image, and is capable of detecting hydrocarbon gases such as methane, ethane, ethylene, and propylene. Note that image generating unit 10 is not limited to this and may be any imaging device that can detect the monitored gas. For example, if the monitored gas is a gas that can be detected with visible light, such as white smoke-like water vapor, it may be a general visible light camera. Note that, in this specification, "gas" refers to gas that has leaked from a closed space such as a pipe or a tank, and that has not been intentionally dispersed into the atmosphere.

[0013] As shown in the schematic diagram of Fig. 2, image generating unit 10 is installed so that monitoring target 300 is included in field of view 310 of image generating unit 10. Image generating unit 10 outputs the captured image as a video signal to gas detection device 20. The video signal is, for example, a signal for transmitting images at 30 frames per second.

[0014] <Configuration of gas detection device 20> Gas detection device 20 is a device that acquires an image of a monitoring target from image generation unit 10, detects a gas region based on the image, and notifies the user of the gas detection via display unit 24. Gas detection device 20 is a device that, for example, comprises a general CPU (Central Processing Unit) and RAM and a program executed by these. As will be described later, gas detection device 20 may further include a GPU (Graphics Processing Unit) and RAM as a computing device. As shown in FIG. 1 , gas detection device 20 includes image acquisition unit 201, gas region video extraction unit 211, gas region video acquisition unit 212, perspective direction velocity acquisition unit 213, machine learning unit 2141, learning model storage unit 2142, and determination result output unit 215. Gas region video extraction unit 211 has the functions of the image acquisition unit of the present disclosure. Furthermore, machine learning unit 2141 and learning model storage unit 2142 constitute perspective direction velocity estimation unit 214. Gas region video extraction unit 211 and perspective direction velocity estimation unit 214 constitute gas velocity estimation device 21.

[0015] The image acquisition unit 201 is an acquisition unit that acquires a moving image of the monitoring target from the image generation unit 10. In the embodiment, the image acquisition unit 201 acquires a video signal from the image generation unit 10, restores the video signal to an image, and outputs the image as a moving image consisting of a plurality of frames to the gas region moving image extraction unit 211. The image is an infrared photograph of the monitoring target, and has infrared intensity as pixel values.

[0016] The gas region video extraction unit 211 is an image processing unit that performs gas detection processing on the video output by the image acquisition unit 201 to generate a gas distribution video including a gas region. A known method can be used for the gas detection processing. Specifically, for example, the method described in International Publication No. 2017 / 073440 (Patent Document 1) can be used. Then, a gas distribution video is generated as a video by extracting a region including a gas region from each frame of the video. Specifically, when gas leaking from equipment is captured by the image generation unit 10, a gas region 310 corresponding to the gas is captured, as shown in frame example 301 in FIG. 4(a). Here, an image 300 of the equipment is not drawn in the image. Therefore, an image including the gas region 310 is generated for each frame of the gas distribution video, as shown in frame example 302 in FIG. 4(b). Therefore, the gas distribution video is composed of multiple frames 302-n captured in chronological order, as shown in FIG. 4(c). The gas region moving image extraction unit 211 may perform processing such as gain adjustment after cutting out an area including a gas region from each frame of the moving image. Furthermore, instead of the pixel values ​​of the moving image themselves, specific frequency components may be extracted using the method described in Patent Document 1. This processing can remove high-frequency noise and low-frequency noise such as overall temperature changes in space.

[0017] Here, each frame constituting the gas distribution video is extracted from the same coordinate range in each frame of the original video at the same scale so that the spatial position indicated by its pixel is the same. That is, temporal and spatial changes in the size of the gas cloud are captured as changes in the angle of view and reflected as changes in the size of the gas region. Therefore, as shown in the overhead view of Figure 5(a), if a gas cloud is flowing away from the image generating unit 10, when a gas cloud at position 511 moves to position 512, an object of the same size will appear smaller at position 512 because it is farther from the image generating unit 10 than at position 511. Therefore, if the size of the gas cloud remains unchanged, image 522 of the gas cloud at position 512 will appear smaller than image 521 of the gas cloud at position 511. Even if the gas cloud expands, the expansion width will be small. On the other hand, because the total amount of gas contained in the gas cloud does not change significantly, the concentration of the gas cloud will remain the same or will decrease inversely proportional to the area of ​​the gas cloud, but to a small extent. In contrast, as shown in the overhead schematic diagram of Figure 5(b), if a gas cloud is flowing toward the image generating unit 10, when a gas cloud at position 513 moves to position 514, an image of the same size will appear larger at position 514, since position 514 is closer to the image generating unit 10 than position 513. Therefore, image 524 of the gas cloud at position 514 will appear larger than image 523 of the gas cloud at position 513, even if the size of the gas cloud has not changed. If the gas cloud is expanding, the magnification will be even greater. On the other hand, since the total amount of gas contained in the gas cloud has not changed significantly, the concentration of the gas cloud decreases in inverse proportion to the area of ​​the gas cloud, and the degree of this decrease is large. Therefore, the expansion of the gas region and the change in concentration are feature quantities indicating the gas flow in the direction of the gas.

[0018] Note that if the size of the gas distribution video or the number of frames of the video is excessive, the amount of calculation required for machine learning and machine learning-based judgment will increase. In the first embodiment, the number of pixels of the gas distribution video is 224 × 224 pixels, the frame rate is 5 frames per second, and the number of frames is 16.

[0019] The gas region video acquisition unit 212 is an acquisition unit that acquires a gas distribution video in the same format as the gas distribution video generated by the gas region video extraction unit 211, in which the scale of the image and the flow velocity (component) of the subject gas in the near and far directions as viewed from the imaging viewpoint are known. Here, the gas flow velocity (component) can be calculated using, for example, the wind speed and wind direction at the time of imaging. Note that if the acquired image is not in the same format as the gas distribution video generated by the gas region video extraction unit 211, the gas region video acquisition unit 212 may perform processing such as cropping or gain adjustment so that the acquired image has the same format.

[0020] The perspective direction velocity acquisition unit 213 is an acquisition unit that acquires gas flow velocity components in the perspective direction from the imaging viewpoint, corresponding to the gas region in the gas distribution video acquired by the gas region video acquisition unit 212. The gas flow velocity components are specified as relative values ​​to the gas flow velocity components in a direction perpendicular to the perspective direction (the direction in which the viewing angle changes, the viewing angle direction). The direction perpendicular to the perspective direction corresponds to the X direction, Y direction, or a combination thereof in the gas distribution video, and is a direction in which the distance from the imaging viewpoint does not change. Note that the gas flow velocity components in the direction perpendicular to the perspective direction may be expressed as relative values ​​to the image size or pixel count of the gas distribution video. In the embodiment, the number of pixels (number of picture elements) is used as a unit. For example, if a gas region having a horizontal width of 10 pixels in the gas distribution video corresponds to a gas cloud in a space with a horizontal width of 1 m, a flow velocity of 3 m / s in the perspective direction is specified as a flow velocity of 30 pixels / s. More specifically, when the gas is moving away, as shown in the overhead view of FIG. 6( a), the value of the velocity component f·cosθ along the optical axis 500 is first calculated using the angle θ between the optical axis 500 of the image generating unit 10 and the wind direction and the wind speed f. Here, f is 3 m / s, and θ = 45°, so f·cosθ is 2.12 m / s. Next, using the distance d between the image generating unit 10 and the gas cloud 514 and the relationship between the angle of view and the number of pixels in the image generating unit 10, the number of pixels in the gas distribution video corresponding to 1 m near the gas cloud 514 is calculated, and this is used to calculate the number of pixels per second of the velocity component f·cosθ along the optical axis 500. For example, if 1 m near the gas cloud 514 corresponds to 88.8 pixels, the gas flow velocity in the near / far direction is 188.3 pixel / s. Similarly, when gas is approaching, as shown in the schematic overhead view of Fig. 6(b), the angle φ between the optical axis 500 of the image generating unit 10 and the wind direction and the wind speed f are used to first calculate the value of the velocity component -f cosφ along the optical axis 500. Here, negative numbers are used because the flow speed is a one-dimensional vector, with the receding direction being positive and the approaching direction being negative.Similarly, using the distance d between the image generating unit 10 and the gas cloud 515 and the relationship between the angle of view and the number of pixels in the image generating unit 10, the number of pixels in the gas distribution video that 1 m in the vicinity of the gas cloud 515 corresponds to is calculated, and this is used to calculate how many pixels per second the velocity component f·cosφ along the optical axis 500 corresponds to.

[0021] Because the feature values ​​for gas flow velocity in a gas distribution video are acquired in pixel units, when the same subject is captured using the same camera, the pixel-by-pixel movement in the image is inversely proportional to the distance between the camera and the gas cloud. For example, if a subject at a distance of 15 m is displayed at a scale of 1.125 cm / pixel, a subject at a distance of 30 m is displayed at a scale of 2.25 cm / pixel. Therefore, when the motion vector in the gas distribution video is expressed in units of pixels per second, it is inversely proportional to the subject distance. On the other hand, the ratio between the absolute value of the velocity in the direction in which the gas cloud changes its orientation from the imaging viewpoint and the absolute value of the velocity in the perspective direction does not depend on the distance between the camera and the gas cloud, the camera's angle of view, or the image resolution. In one embodiment of the present disclosure, by converting the gas flow velocity in the perspective direction to pixel units, the relative relationship between the perspective component and other components of the gas movement corresponding to the gas region in the gas distribution video is learned and utilized.

[0022] The machine learning unit 2141 is a learning model generation unit that performs machine learning based on a combination of the gas distribution video received by the gas region video acquisition unit 212 and the near-far flow velocity of gas corresponding to a gas region in the gas distribution video received by the near-far velocity acquisition unit 213, thereby generating a machine learning model. The machine learning model is configured to predict the near-far flow velocity of gas as a relative ratio to the pixel size of the gas distribution video based on a combination of features of the gas distribution video, such as a time-varying change in the outer shape of the gas region and a time-varying change in the gas density distribution. For example, a convolutional neural network (CNN) can be used for the machine learning, and publicly known software such as PyTorch can be used. FIG. 3 is a schematic diagram illustrating an outline of the logical configuration of the machine learning model. The machine learning model includes an input layer 410, an intermediate layer 420-1, an intermediate layer 420-2, ..., an intermediate layer 420-n, and an output layer 430, and an interlayer filter is optimized through learning. For example, if the gas distribution video has 224 x 224 pixels and 16 frames, the input layer 410 receives a 224 x 224 x 16 three-dimensional tensor containing the pixel values ​​of the gas distribution video. The intermediate layer 420-1 is, for example, a convolutional layer, and receives a 224 x 224 x 16 three-dimensional tensor generated by convolutional computation from the data in the input layer 410. The intermediate layer 420-2 is, for example, a pooling layer, and receives a three-dimensional tensor obtained by resizing the data in the intermediate layer 420-1. The intermediate layer 420-n is, for example, a fully connected layer, and converts the data in the intermediate layer 420-(n-1) into a one-dimensional vector in which the velocity value is the absolute value and the direction is the sign. Note that the configuration of the intermediate layers is an example, and the number n of intermediate layers is approximately 3 to 5, but is not limited to this. Although FIG. 3 illustrates the same number of neurons in each layer, each layer may have any number of neurons. Machine learning unit 2141 receives as input a video image serving as a gas distribution video, performs learning using the gas flow velocity in the near and far directions as a correct answer, generates a machine learning model, and outputs the model to learning model storage unit 2142. Note that if gas detection device 20 includes a GPU and RAM as a computing device, machine learning unit 2141 may be realized by a GPU and software.

[0023] The learning model holding unit 2142 is a learning model operation unit that holds the machine learning model generated by the machine learning unit 2141 and uses the machine learning model to output the gas flow velocity in the near and far direction of the gas corresponding to the gas region in the gas distribution video generated by the gas region video extraction unit 211. The gas flow velocity in the near and far direction is identified and output as a relative value with respect to the pixel size of the input gas distribution video.

[0024] The determination result output unit 215 is an image display unit that converts the gas flow velocity in the near and far directions output by the learning model holding unit 2142 into a spatial velocity and generates an image to be superimposed on the moving image acquired by the image acquisition unit 201 and displayed on the display unit 24. The conversion from the gas flow velocity in the near and far directions to a spatial velocity is performed by using the distance between the image generation unit 10 and the gas cloud and the relationship between the angle of view and the number of pixels in the image generation unit 10 to calculate a conversion coefficient that indicates how many meters in the gas cloud in space one pixel of the gas region in the gas distribution moving image corresponds to, and multiplying the conversion coefficient by the gas flow velocity in the near and far directions output by the learning model holding unit 2142.

[0025] <Other configurations> The display unit 24 is a display device such as a liquid crystal display or an organic EL display.

[0026] <Operation> The operation of gas detection device 20 in this embodiment will now be described with reference to the drawings.

[0027] <Learning Phase> FIG. 7 is a flowchart showing the operation of gas detection apparatus 20 in the learning phase.

[0028] First, a combination of a gas distribution video and the gas flow velocity in the near and far directions is created (step S110). An image with a known gas flow velocity in the near and far directions can be used as the gas distribution video. As described above, the gas flow velocity is a relative value using the scale of the gas area in the gas distribution video. Figure 8(a) shows a combination of one frame of the gas distribution video and the correct data gas flow velocity in the near and far directions, where the gas is approaching. Figure 8(b) shows a combination of one frame of the gas distribution video and the correct data gas flow velocity in the near and far directions, where the gas is receding.

[0029] Furthermore, when the gas region video extraction unit 211 outputs a video from which only specific frequency components are extracted as the gas distribution video, the gas distribution video in the training data must also be a video from which only specific frequency components are extracted. Figure 9(a) shows a combination of one frame from a gas distribution video from which only specific frequency components are extracted and the correct data for the gas flow velocity in the near and far directions, illustrating a case in which the gas is approaching. Figure 9(b) shows a combination of one frame from a gas distribution video from which only specific frequency components are extracted and the correct data for the gas flow velocity in the near and far directions, illustrating a case in which the gas is receding. As described above, extracting only specific frequency components can remove high-frequency noise and low-frequency noise, such as overall temperature changes in the space. This prevents high-frequency noise and low-frequency noise from being erroneously learned as features during the learning phase, and also prevents high-frequency noise and low-frequency noise from affecting other features, resulting in a decrease in estimation accuracy, during the operation phase (described later).

[0030] Next, a combination of the gas distribution video and the gas flow velocities in the near and far directions is input to gas detection device 20 (step S120). The gas distribution video is input to gas region video acquisition unit 212, and the corresponding gas flow velocities in the near and far directions are input to near and far direction velocity acquisition unit 213.

[0031] Next, data is input to the convolutional neural network to perform machine learning (step S130). As a result, parameters are optimized by trial and error through deep learning, and a machine-learned model is formed. The formed machine-learned model is stored in the learning model storage unit 2142.

[0032] Through the above operations, a machine-learned model is created that outputs gas flow velocities in the near and far directions based on the feature quantities of a gas distribution video.

[0033] <Operation phase> FIG. 10 is a flowchart showing the operation of gas detection apparatus 20 in the learning phase.

[0034] First, a gas region is detected from each frame of the captured image, and a gas distribution video including the gas region and its surroundings is extracted (step S210). The gas region is detected using a known method based on the time series change in brightness in the captured image, its frequency, etc. Then, a portion is extracted from each frame of the captured image so as to include all pixels in which gas is detected, and a gas distribution video is generated using each of these frames. Here, if a video from which only specific frequency components have been extracted was used as the gas distribution video in the training data in the learning phase, only the specific frequency components are similarly extracted to create the gas distribution video.

[0035] Next, the learned model is used to estimate the gas flow velocity in the near and far directions from the gas distribution video (step S220). By using the machine-learned model formed in step S130, the gas flow velocity in the near and far directions relative to the gas region in the gas distribution video is estimated as a relative value for the pixel in the gas region in the gas distribution video. Since the learned model holding unit 2142 estimates the gas flow velocity in the near and far directions as a relative value for the pixel in the gas region in the gas distribution video, the determination result output unit 215 converts the gas flow velocity in the near and far directions output by the learned model holding unit 2142 into a velocity in space. The conversion from the gas flow velocity in the near and far directions to a velocity in space is performed by calculating a conversion coefficient, which indicates how many meters one pixel of the gas region in the gas distribution video corresponds to in the gas cloud in space, using the distance between the image generating unit 10 and the gas cloud and the relationship between the angle of view and the number of pixels in the image generating unit 10, and multiplying the conversion coefficient by the gas flow velocity in the near and far directions output by the learned model holding unit 2142. Then, the information indicating the calculated gas flow velocity and direction is superimposed on the moving image acquired by the image acquisition unit 201 and output to the display unit 24.

[0036] As a display mode, for example, as shown in the output image examples of Figures 11(a) and (b), along with the absolute value of the velocity, the direction of the flow may be indicated by an arrow indicating whether the flow direction is toward the near side or the far side. In this case, the color and shape of the arrow may be changed depending on whether the flow direction is toward the near side or the far side. Furthermore, as shown in Figure 12(a), when the gas flow velocity in the near direction is 0 or extremely low, no arrow may be displayed in either direction.

[0037] Alternatively, the display mode may be changed depending on the magnitude of the speed. For example, as shown in FIG. 12(b), the arrow may be displayed so that the longer the arrow is, the greater the absolute value of the speed. Alternatively, as shown in FIGS. 13(a) and 13(b), the arrow may be displayed so that the saturation of the arrow is increased, the greater the absolute value of the speed. Alternatively, as shown in FIGS. 14(a) and 14(b), the arrow may be displayed in a two-color gradation, with one color becoming more saturated as the absolute value of the speed increases. In this case, as shown in FIG. 15(a), when the absolute value of the speed is 0 or extremely small, the arrow may be displayed in one color.

[0038] <Summary> With the above configuration, in a gas detection device that uses images to detect gas, if a gas cloud is captured as a video, it is possible to estimate whether the gas is approaching or receding from the imaging device. Therefore, even when the equipment is imaged from a single location, the direction of gas flow can be estimated in three dimensions, so when workers or others approach the equipment, they can approach from the upwind side where the gas concentration is low, thereby ensuring a higher level of safety.

[0039] <<Variation 1>> In the first embodiment, the velocity of the gas in the perspective direction corresponding to the gas region in the gas distribution video is a one-dimensional vector including an absolute value and a direction. However, the gas velocity in the perspective direction may be a probability distribution indicating the probability of the gas velocity.

[0040] FIG. 16(a) shows the probability distribution of gas velocity output by the determination result output unit 215. In the graph of FIG. 16(a), the horizontal axis represents the gas velocity value, and the vertical axis represents the relative probability that the gas velocity in the near-far direction is the value shown on the horizontal axis. Such data can be generated by performing coordinate transformation of the horizontal and vertical axes of a probability distribution, as shown in FIG. 16(b), in which the horizontal axis represents the gas velocity value shown in pixel units and the vertical axis represents the probability that the gas velocity in the near-far direction is the value shown on the horizontal axis. One method for outputting such data is, for example, for the gas flow velocity in the near-far direction output by the learning model holding unit 2142, in which the determination result output unit 215 creates and outputs a normal distribution with the velocity as the median. Alternatively, the machine learning model may use the probability distribution of gas velocity as the gas flow velocity in the near-far direction. In this case, the near-far direction velocity acquisition unit 213 acquires a probability distribution of gas velocity as the near-far direction gas flow velocity of the gas corresponding to the gas region in the gas distribution video acquired by the gas region video acquisition unit 212. The intermediate layer 420-n of the machine learning model is designed, for example, as a fully connected layer that converts the data of the intermediate layer 420-(n-1) into a two-row matrix in which a combination of a velocity value and the probability that this value is the gas velocity is stored as data in one row. The learning model holding unit 2142 outputs a probability distribution that is a combination of the near-far direction gas velocity and the probability that the near-far direction gas velocity is the gas velocity for the gas distribution video.

[0041] <Summary> With the above configuration, a gas detection device that uses images to detect gas can estimate whether the gas is approaching or receding from the imaging device if the gas cloud is captured as a video. Therefore, even when imaging a facility from a single location, the gas flow direction can be estimated in three dimensions. This allows workers to approach the facility from the upwind side, where the gas concentration is low, thereby ensuring greater safety. Furthermore, because the gas velocity in the approaching and receding directions is displayed as a probability distribution, it is possible to prevent a decrease in the accuracy of gas velocity estimation due to a lack of training data or over-learning based on biased training data, making it easy to improve estimation accuracy.

[0042] <<Variation 2>> In the first embodiment and the first modification, a single gas detection device is used to estimate the near and far velocity of gas in the operation mode using a machine learning model generated in the learning mode. However, the machine learning and the identification of the near and far velocity estimation of gas do not need to be performed on the same hardware, and may be performed using different hardware.

[0043] Fig. 17 is a functional block diagram of gas detection system 101 according to Modification 2. As shown in Fig. 15, gas detection system 101 includes image generation unit 10 for capturing an image of a monitoring target, gas detection device 41 for detecting gas based on an image acquired by image generation unit 10, learning data creation device 30, and display unit 24. Image generation unit 10, display unit 24, and learning data creation device 30 are each configured to be connectable to gas detection device 41.

[0044] Gas detection device 41 acquires video of a monitored object from image generation unit 10, detects a gas region based on the video, and notifies a user of the gas detection via display unit 24. Gas detection device 41 is realized, for example, as a computer including a general CPU, RAM, and programs executed by these. Gas detection device 41 includes image acquisition unit 201, gas region video extraction unit 211, learning model storage unit 2142, and determination result output unit 215. Learning model storage unit 2142 constitutes perspective direction velocity estimation unit 224. Furthermore, gas region video extraction unit 211 and perspective direction velocity estimation unit 224 constitute gas velocity estimation device 26. Training data creation device 30 is realized, for example, as a computer including a general CPU, GPU, RAM, and programs executed by these. Training data creation device 30 includes gas region video acquisition unit 212, perspective direction velocity acquisition unit 213, and machine learning unit 2141.

[0045] Gas detection device 41 only performs the operation mode operation of gas detection device 20 according to embodiment 1. Furthermore, learning data creation device 30 only performs the learning mode operation of gas detection device 20 according to embodiment 1. Gas detection device 41 and learning data creation device 30 are connected, for example, via a LAN, and the learned model formed by learning data creation device 30 is stored in learning model holding unit 2142 of gas detection device 41. Note that storage of the learned model in learning model holding unit 2142 is not limited to duplication via a network, and may also be performed using, for example, removable media, an optical disk, a ROM, etc.

[0046] <Summary> With the above configuration, a gas detection device that uses images to detect gas can estimate whether the gas is approaching or receding from the imaging device if a video of a gas cloud is captured. Furthermore, because machine learning and gas velocity estimation in the approaching and approaching directions are performed by separate hardware, the gas detection device does not need to have resources for machine learning. Therefore, the gas detection device only needs to have resources to operate the trained model, and can be implemented using simple devices such as laptop computers, smartphones, and tablets. Furthermore, because a trained model constructed through machine learning using a single training data creation device 30 can be operated by multiple gas detection devices 41, gas detection devices 41 can be easily manufactured.

[0047] Second Embodiment In the first embodiment and each of the modifications, the case where only the moving speed of the gas in the near direction is estimated has been described. However, it is also possible to estimate the moving speed of the gas in the direction in which its orientation from the imaging viewpoint changes, and to estimate the moving direction and speed of the gas three-dimensionally.

[0048] Gas detection system 200 according to the second embodiment is further characterized in that it estimates the speed of gas movement in the direction in which the gas changes direction from the imaging viewpoint, and thereby estimates the gas movement direction and speed in three dimensions.

[0049] Fig. 18 is a functional block diagram showing the configuration of gas detection system 200 pertaining to Embodiment 2. As shown in Fig. 18, gas detection device 42 of gas detection system 200 is characterized by including gas velocity estimation device 27 further including screen direction velocity estimation section 271 and velocity synthesis section 272, and determination result output section 275 instead of gas velocity estimation device 21 and determination result output section 215.

[0050] The screen direction speed estimation unit 271 calculates the motion vector of the gas region within the screen from the gas distribution video generated by the gas region video extraction unit 211, and identifies the gas movement speed and direction in the direction in which the gas changes its orientation from the imaging viewpoint (the direction perpendicular to the perspective direction). Specifically, for example, pattern matching is performed between two frames constituting the gas distribution video, and the arithmetic mean of the detected movement vectors is calculated and output as a two-dimensional vector. For example, if the movement speed in the x direction (horizontal direction) is 180 pixel / s and the movement speed in the y direction (vertical direction) is 0 pixel / s, the movement speed is output as (180, 0).

[0051] The velocity synthesis unit 272 estimates the three-dimensional gas movement direction and velocity from the gas movement velocity and direction in the direction in which the orientation from the imaging viewpoint changes, estimated by the screen direction velocity estimation unit 271, and the gas movement velocity and direction in the near / far direction, estimated by the learning model holding unit 2142. If the gas movement vector in the direction in which the orientation from the imaging viewpoint changes, estimated by the screen direction velocity estimation unit 271, is (v x ,v y ) [pixel / s], and the gas movement vector in the near and far direction estimated by the learning model holding unit 2142 is v z When expressed as [pixel / s], The absolute value of the three-dimensional gas movement velocity, v, is given by the following equation: v 2 =v x 2 +v y 2 +v z 2 The velocity synthesis unit 272 synthesizes the absolute value v of the calculated three-dimensional gas movement velocity and the gas movement velocity v in the near and far directions. z is output to the determination result output unit 275.

[0052] The determination result output unit 275 converts the three-dimensional gas flow velocity output by the velocity synthesis unit 272 into a spatial velocity, and generates an image to be superimposed on the moving image acquired by the image acquisition unit 201 and displayed on the display unit 24. The conversion from the three-dimensional gas flow velocity v to a spatial velocity is performed by using the distance between the image generation unit 10 and the gas cloud and the relationship between the angle of view and the number of pixels in the image generation unit 10 to calculate a conversion coefficient that indicates how many meters in the gas cloud in space one pixel of the gas region in the gas distribution moving image corresponds to, and multiplying the conversion coefficient by the three-dimensional gas flow velocity v output by the learning model holding unit 2142.

[0053] The display mode may be, for example, the absolute value of the velocity v, the gas movement velocity in the near and far direction v, z The flow direction is indicated by the direction of the arrow, along with the absolute value of v. In this case, the color and shape of the arrow may be changed depending on whether the flow direction in the perspective direction is towards the front or the back. Also, for example, the display mode may be changed depending on the magnitude of the velocity. For example, the arrow may be displayed so that the longer the absolute value of the velocity is, the longer the arrow. Alternatively, for example, the arrow may be displayed so that the saturation of the arrow is higher as the absolute value of the velocity is higher. Alternatively, for example, the arrow may be displayed in a two-color gradation, with one of the colors becoming more saturable as the absolute value of the velocity is higher. The output image example in FIG. 19(a) displays the arrow in a two-color gradation, and the velocity v in the perspective direction is displayed. z The larger the absolute value of v, the higher the saturation of one color. z If the absolute value of is 0 or extremely small, it may be displayed in one color.

[0054] <Summary> With the above configuration, in a gas detection system that uses images to perform gas detection, if an image of a gas region is captured, it becomes possible to estimate the gas flow velocity three-dimensionally.

[0055] Other Modifications of the Embodiment (1) In the second embodiment, the gas flow velocity is output as a value, but it may also be output as a probability distribution of velocity, as in the first modification. In this case, after calculating the velocity in the near and far direction as a probability distribution, it is possible to calculate a three-dimensional velocity as a probability distribution by combining it with the velocity in the direction in which the gas changes direction from the imaging viewpoint.

[0056] (2) In the second embodiment and the first variant, both machine learning and near-far velocity estimation are performed in a single gas detection device. However, as in the second variant, machine learning may be performed in a learning model generation device, and the gas velocity estimation device may only estimate near-far velocity.

[0057] (3) In each embodiment and each modification, the display unit displays the absolute value of the velocity of the gas in the near and far direction. However, this is not limited to this, and it may simply display whether or not there is movement of the gas in the near and far direction. Also, for example, in the second embodiment, the direction of the gas flow when the camera or the leak source is viewed from above may be displayed. Such a display is possible when the direction of the gas from the imaging viewpoint changes and the velocity of the gas in the horizontal direction, v x and the velocity of the gas in the near and far direction, v z This can be done by calculating the direction of gas flow from the

[0058] (4) In each embodiment and modification, the captured image is an infrared image with a wavelength of 3.2 to 3.4 μm, but this is not limited thereto, and any image that can confirm the presence of the gas to be detected, such as an infrared image in another wavelength range, a visible image, or an ultraviolet image, may be used. Furthermore, the method for detecting a gas region is not limited to the above, and any process that can detect a gas region may be used.

[0059] Furthermore, the gas to be detected and the gas corresponding to the image shown in the captured image do not have to be the same, and for example, when it is known that two or more types of gases exist in the same location, an image of one type of gas may be used and processed as an image of another gas. For example, when water vapor and the gas to be detected exist in approximately the same location in a space, an image in which the image of water vapor is the gas region may be used, and the image of water vapor may be treated as an image of the gas to be detected.

[0060] (5) In each embodiment and modification, a gas distribution video in which the gas flow velocity in the near and far directions is known is used as training data. However, the training data is not limited to this. For example, a gas distribution video may be created by simulation. More specifically, for example, a modeling is performed to lay out structures in a three-dimensional space based on three-dimensional voxel data of the facility. Next, conditions such as the type of gas, flow rate, wind speed, wind direction, and the shape, diameter, and location of the gas leak source are determined, and a three-dimensional fluid simulation is performed to calculate the gas distribution state. A viewpoint is set in space for the three-dimensional model created in this way, and a two-dimensional image from that viewpoint is generated as a gas distribution image. Specifically, for a line passing through the viewpoint in space, which corresponds to one pixel in the gas distribution image, the light intensity for each pixel is calculated by calculating the gas concentration thickness product for the gas present between the viewpoint and the surface of the facility, and the pixel value is calculated. Then, training data can be created by pairing the wind speed in the near and far directions from the viewpoint as the correct answer.

[0061] (6) Although the present invention has been described based on the above embodiment, the present invention is not limited to the above embodiment, and the following cases are also included in the present invention.

[0062] For example, in the present invention, the gas velocity estimation device may be a device that uses an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit) as a processor.

[0063] Furthermore, some or all of the components constituting each of the above-described devices may be configured as a single system LSI (Large Scale Integration). A system LSI is an ultra-multifunctional LSI manufactured by integrating multiple components on a single chip, and specifically, is a computer system configured to include a microprocessor, ROM, RAM, etc. These may be individually integrated into a single chip, or some or all of them may be integrated into a single chip. Note that LSIs are sometimes referred to as ICs, system LSIs, super LSIs, or ultra LSIs depending on the level of integration. The RAM stores a computer program that achieves the same operation as each of the above-described devices. The system LSI achieves its function when the microprocessor operates in accordance with the computer program. For example, the present invention also includes a case where the gas velocity estimation method of the present invention is stored as a program in an LSI, and the LSI is inserted into a computer to execute a predetermined program.

[0064] The method of integration is not limited to LSI, but may be realized by dedicated circuits or general-purpose processors. After LSI manufacturing, it is also possible to use FPGAs that can be programmed, or reconfigurable processors that can reconfigure the connections and settings of circuit cells inside LSIs.

[0065] Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology or other derived technologies, it is of course possible to use that technology to integrate functional blocks.

[0066] The division of functional blocks in the block diagram is an example, and multiple functional blocks may be realized as a single functional block, one functional block may be divided into multiple blocks, or some functions may be moved to another functional block.Furthermore, the functions of multiple functional blocks having similar functions may be processed in parallel or in time-sharing by a single piece of hardware or software.

[0067] The order in which the steps are performed is merely an example for specifically explaining the present invention, and other orders may be used. Some of the steps may be performed simultaneously (in parallel) with other steps.

[0068] Furthermore, at least some of the functions of the gas velocity estimation device according to each embodiment and its modified examples may be combined. Furthermore, all of the numbers used above are merely examples for specifically explaining the present invention, and the present invention is not limited to the exemplified numbers.

[0069] Furthermore, various modifications of the present embodiment that are within the scope of what would occur to a person skilled in the art are also included in the present invention.

[0070] <Summary> (1) A gas movement estimation device according to one aspect of the present disclosure includes an image input unit that receives as input a gas distribution video consisting of multiple frames, in which the range of existence of gas leaked into space is shown as a gas region, and a gas movement estimation unit that estimates the gas movement state in the near and far directions corresponding to the gas distribution video received by the image acquisition unit using an estimation model that has been machine-learned using as training data a combination of a teacher gas distribution video and the gas movement state in the near and far directions in the teacher gas distribution video.

[0071] In addition, a gas movement estimation method according to one aspect of the present disclosure receives as input a gas distribution video consisting of multiple frames, in which the range of existence of gas leaked into space is shown as a gas region, and estimates the gas movement state in the near and far directions corresponding to the received gas distribution video using an estimation model machine-learned using as training data a combination of a teacher gas distribution video and the gas movement state in the near and far directions in the teacher gas distribution video.

[0072] Furthermore, a program according to one aspect of the present disclosure is a program that causes a computer to perform a gas movement estimation process, in which the gas movement estimation process receives as input a gas distribution video consisting of multiple frames, in which the range of existence of gas that has leaked into a space is shown as a gas region, and estimates the gas movement state in the near and far directions corresponding to the received gas distribution video using an estimation model that has been machine-learned using as training data a combination of a teacher gas distribution video and the gas movement state in the near and far directions in the teacher gas distribution video.

[0073] According to a gas movement estimation device, a gas movement estimation method, and a program according to an aspect of the present disclosure, the state of gas movement in the near and far direction is estimated based on the characteristics of the gas region in the gas distribution video. Therefore, by appropriately designing the training data, it is possible to identify whether the gas is moving toward or away from the imaging position.

[0074] (2) In a gas movement estimation device according to one aspect of the present disclosure, the gas movement estimation unit may use a relative perspective velocity, which indicates the gas movement speed in the perspective direction as a relative value to the movement speed in the field of view direction, as the gas movement state in the perspective direction in the training data.

[0075] With the above configuration, even if the imaging conditions, such as the distance to the gas and the field of view of the imaging device, are different between the gas distribution video whose movement state is to be estimated and the teacher gas distribution video, it is possible to estimate the movement state of the gas in the near and far directions.

[0076] (3) In a gas movement estimation device according to one aspect of the present disclosure, the gas movement estimation unit may output the gas movement speed in the near and far direction in the gas distribution video received by the image input unit as the gas movement state in the near and far direction.

[0077] With the above configuration, the speed of the gas in the direction from the imaging viewpoint toward the gas can be obtained, allowing for a more detailed investigation into whether or not a person can approach while avoiding the gas.

[0078] (4) In a gas movement estimation device according to one aspect of the present disclosure, the gas movement estimation unit may output, as the state of gas movement in the near and far directions, a probability distribution of the gas movement speed in the near and far directions in the gas distribution video received by the image input unit.

[0079] With the above configuration, the range of possible gas speeds in the direction from the imaging viewpoint toward the gas can be obtained, making it possible to determine with increased safety whether or not people can approach.

[0080] (5) In a gas movement estimation device according to one aspect of the present disclosure, the image input unit may include an imaging means for detecting infrared light, and the gas region may be an image of a gas or water vapor that absorbs infrared light.

[0081] With the above configuration, one aspect of the present disclosure can be applied to a gas that can be detected using infrared light or a gas whose presence can be estimated using the range of presence of the gas.

[0082] (6) In a gas movement estimation device according to one aspect of the present disclosure, the image input unit may include an imaging means for detecting visible light, and the gas region may be an image of a gas or water vapor that absorbs visible light.

[0083] With the above configuration, one aspect of the present disclosure can be applied to a gas that can be detected using visible light, or a gas whose presence can be estimated using the range of presence of the gas.

[0084] (7) In the gas movement estimation device according to one aspect of the present disclosure, the image input unit may receive as input a gas distribution video in which specific frequency components are extracted from a video captured of a space.

[0085] The above configuration enables machine learning and gas movement estimation by removing high-frequency noise and low-frequency noise, thereby improving the probability of making a correct estimation.

[0086] (8) A gas movement estimation device according to one aspect of the present disclosure may further include an image display unit that displays the gas movement state in the near and far directions superimposed on the gas distribution video received by the image input unit.

[0087] With the above configuration, facility managers and the like can easily grasp the state of gas movement, improving usability.

[0088] (9) In the gas movement estimation device according to one aspect of the present disclosure, the image display unit may display at least one of the presence or absence of gas movement in the near and far directions, the direction of movement, and the speed of movement using a color.

[0089] With the above configuration, facility managers and the like can easily grasp the state of gas movement based on the color, improving usability.

[0090] (10) In a gas movement estimation device according to one aspect of the present disclosure, the image display unit may display at least one of the presence or absence, direction, and speed of gas movement in the near and far directions using the length of a line or arrow.

[0091] With the above configuration, facility managers and the like can easily grasp whether gas is moving, the direction of movement, the speed of movement, etc., thereby improving usability.

[0092] (11) A gas movement estimation device according to one aspect of the present disclosure may further include a three-dimensional flow estimation unit that estimates the state of gas movement in a viewing angle direction in the gas distribution video received by the image input unit and estimates the state of gas movement as three-dimensional information from the state of gas movement in the viewing angle direction and the state of gas movement in a near direction, and the image display unit may display the state of gas movement as three-dimensional information.

[0093] With the above configuration, it is possible to predict the three-dimensional movement state of gas, and therefore it is possible to examine with increased safety whether or not people can approach.

[0094] (12) A prediction model generation device according to one aspect of the present disclosure includes an image input unit that receives as input a gas distribution video consisting of multiple frames, in which the range of existence of gas leaked into space is shown as a gas region; a speed input unit that receives as input the state of gas movement in a near and far direction in the gas distribution video; and a machine learning unit that performs machine learning on a combination of the gas distribution video and the state of gas movement in a near and far direction as training data, and generates a prediction model that uses the gas distribution video as input and outputs the state of gas movement in a near and far direction.

[0095] In addition, a method for generating an estimation model according to one aspect of the present disclosure receives as input a gas distribution video consisting of multiple frames in which the range of existence of gas leaked into a space is shown as a gas region, receives as input the state of gas movement in the near and far directions in the gas distribution video, performs machine learning on the combination of the gas distribution video and the state of gas movement in the near and far directions as training data, and generates an estimation model that uses the gas distribution video as input and outputs the state of gas movement in the near and far directions.

[0096] Furthermore, a program according to one aspect of the present disclosure is a program that causes a computer to perform a prediction model generation process, in which the prediction model generation process receives as input a gas distribution video consisting of multiple frames, in which the range of existence of gas leaked into a space is shown as a gas region, receives as input the state of gas movement in a distance direction in the gas distribution video, performs machine learning on a combination of the gas distribution video and the state of gas movement in a distance direction as training data, and generates a prediction model that uses the gas distribution video as input and outputs the state of gas movement in a distance direction.

[0097] According to an embodiment of the present disclosure, an estimation model generation device, an estimation model generation method, and a program for generating an estimation model are capable of estimating the state of gas movement in the near and far directions based on the characteristics of the gas region in a gas distribution video. Therefore, by appropriately designing training data, an estimation model can be generated that identifies whether the gas is moving toward or away from the imaging position.

[0098] (13) A gas movement estimation device according to one aspect of the present disclosure includes an image input unit that receives as input a gas distribution video consisting of multiple frames, in which the range of existence of gas leaked into space is shown as a gas region; a machine learning unit that performs machine learning on a combination of a teacher gas distribution video and the gas movement state in the near and far directions in the teacher gas distribution video as teacher data, and generates an estimation model; and a gas movement estimation unit that uses the estimation model to estimate the gas movement state in the near and far directions corresponding to the gas distribution video received by the image acquisition unit.

[0099] In addition, a gas movement estimation method according to one aspect of the present disclosure receives as input a gas distribution video consisting of multiple frames, in which the range of existence of gas leaked into a space is shown as a gas region, and generates an estimation model by machine learning using a combination of a teacher gas distribution video and the gas movement state in the near and far directions in the teacher gas distribution video as training data, and uses the estimation model to estimate the gas movement state in the near and far directions corresponding to the received gas distribution video.

[0100] Furthermore, a program according to one aspect of the present disclosure is a program that causes a computer to perform a gas movement estimation process, in which the gas movement estimation process receives as input a gas distribution video consisting of multiple frames, in which the range of existence of gas that has leaked into a space is shown as a gas region, performs machine learning using a combination of a teacher gas distribution video and the gas movement state in the near and far directions in the teacher gas distribution video as teacher data to generate an estimation model, and uses the estimation model to estimate the gas movement state in the near and far directions corresponding to the received gas distribution video.

[0101] According to an embodiment of the present disclosure, a prediction model generation device, a prediction model generation method, and a program for generating a prediction model are capable of predicting the state of gas movement in the near and far directions based on the characteristics of the gas region in a gas distribution video. Therefore, by appropriately designing training data, a prediction model can be generated that identifies whether the gas is moving toward or away from the imaging position, and then the determination can be made. [Industrial Applicability]

[0102] The gas leak location identification device, gas leak location identification method, and program disclosed herein can estimate the state of gas movement from an image captured from a single viewpoint, and are useful as a system for people to safely investigate and work on site. [Explanation of symbols]

[0103] 100, 101, 200 Gas Detection Systems 10 Image generation unit 20, 41, 42 Gas detection devices 201 Image acquisition unit 211 Gas Region Video Extraction Unit 212 Gas region video acquisition unit 213 Perspective velocity acquisition section 214, 224 Near and far direction velocity estimator 2141 Machine Learning Department 2142 Learning Model Storage Unit 215 Judgment result output unit 271 Screen direction speed estimator 275 Speed ​​synthesis section 21, 26, 27 Gas velocity estimator 24 Display section 30 Learning data creation device

Claims

1. an image input unit that receives as input a gas distribution video consisting of a plurality of frames, in which the range of existence of gas leaked into space is shown as a gas region; a gas movement estimation unit that estimates a gas movement state in a near-far direction corresponding to the gas distribution video received by the image input unit, using an estimation model that is machine-learned using a combination of a teacher gas distribution video and a gas movement state in a near-far direction in the teacher gas distribution video as teacher data; Equipped with The gas movement estimation unit uses a relative perspective speed, which indicates the gas movement speed in the perspective direction as a relative value to the movement speed in the viewing angle direction, as the gas movement state in the perspective direction in the teacher data. Gas migration estimation device.

2. The gas movement estimation unit outputs the gas movement speed in the near and far direction in the gas distribution video received by the image input unit as the gas movement state in the near and far direction. The gas movement prediction device according to claim 1.

3. The gas movement estimation unit outputs a probability distribution of gas movement speeds in the near and far directions in the gas distribution video received by the image input unit as a state of gas movement in the near and far directions. The gas movement prediction device according to claim 1.

4. The image input unit includes an imaging means for detecting infrared light, and the gas region is an image of a gas or water vapor that absorbs infrared light. The gas movement estimation device according to any one of claims 1 to 3.

5. The image input unit includes an imaging means for detecting visible light, and the gas region is an image of a gas or water vapor that absorbs visible light. The gas movement estimation device according to any one of claims 1 to 3.

6. The image input unit receives as input a gas distribution video in which specific frequency components are extracted from a video captured of a space. The gas movement estimation device according to any one of claims 1 to 5.

7. The image display unit may further include an image display unit that displays the gas movement state in the near and far directions superimposed on the gas distribution video received by the image input unit. The gas movement estimation device according to any one of claims 1 to 6.

8. The image display unit displays, in color, at least one of the presence or absence of gas movement in the near and far directions, the direction of movement, and the speed of movement. The gas movement prediction device according to claim 7.

9. The image display unit displays at least one of the presence or absence of gas movement in the near and far directions, the direction of movement, and the speed of movement by the length of a line or an arrow. The gas movement prediction device according to claim 7.

10. a three-dimensional flow estimation unit that estimates a gas movement state in a viewing angle direction in the gas distribution video received by the image input unit, and infers a gas movement state as three-dimensional information from the gas movement state in the viewing angle direction and the gas movement state in a near direction; The image display unit displays the gas movement state as three-dimensional information. The gas movement estimation device according to any one of claims 7 to 9.

11. an image input unit that receives as input a gas distribution video consisting of a plurality of frames, in which the range of existence of gas leaked into space is shown as a gas region; a velocity input unit that receives as input the state of gas movement in the near and far directions in the gas distribution video; a machine learning unit that performs machine learning using a combination of the gas distribution video and the gas movement state in the near and far directions as training data, and generates an estimation model that inputs the gas distribution video and outputs the gas movement state in the near and far directions; Equipped with As the movement state of gas in the near and far direction in the training data, the relative near and far speed, which indicates the movement speed of gas in the near and far direction relative to the movement speed in the viewing angle direction, is used. Inference model generator.

12. an image input unit that receives as input a gas distribution video consisting of a plurality of frames, in which the range of existence of gas leaked into space is shown as a gas region; a machine learning unit that performs machine learning on a combination of a teacher gas distribution video and a gas movement state in a near and far direction in the teacher gas distribution video as teacher data, and generates an inference model; a gas movement estimation unit that estimates a gas movement state in a near and far direction corresponding to the gas distribution video received by the image input unit using the estimation model; Equipped with As the movement state of gas in the near and far direction in the training data, the relative near and far speed, which indicates the movement speed of gas in the near and far direction relative to the movement speed in the viewing angle direction, is used. Gas migration estimation device.

13. The system accepts as input a gas distribution video consisting of multiple frames, in which the range of gas leaked into space is shown as a gas region, predicting a gas movement state in the near and far direction corresponding to the received gas distribution video using an estimation model machine-learned using a combination of a teacher gas distribution video and the gas movement state in the near and far direction in the teacher gas distribution video as training data; As the movement state of gas in the near and far direction in the training data, the relative near and far speed, which indicates the movement speed of gas in the near and far direction relative to the movement speed in the viewing angle direction, is used. Gas transport estimation method.

14. A program for causing a computer to perform gas movement estimation processing, The gas movement estimation process includes: The system accepts as input a gas distribution video consisting of multiple frames, in which the range of gas leaked into space is shown as a gas region, predicting a gas movement state in the near and far direction corresponding to the received gas distribution video using an estimation model machine-learned using a combination of a teacher gas distribution video and the gas movement state in the near and far direction in the teacher gas distribution video as training data; As the movement state of gas in the near and far direction in the training data, the relative near and far speed, which indicates the movement speed of gas in the near and far direction relative to the movement speed in the viewing angle direction, is used. program.

15. The system accepts as input a gas distribution video consisting of multiple frames, in which the range of gas leaked into space is shown as a gas region, receiving, as an input, a state of gas movement in a near and far direction in the gas distribution video; machine learning a combination of the gas distribution video and the gas movement state in the near and far directions as training data, and generating an estimation model that inputs the gas distribution video and outputs the gas movement state in the near and far directions; As the movement state of gas in the near and far direction in the training data, the relative near and far speed, which indicates the movement speed of gas in the near and far direction relative to the movement speed in the viewing angle direction, is used. Inference model generation method.

16. A program that causes a computer to perform a prediction model generation process, The estimation model generation process includes: The system accepts as input a gas distribution video consisting of multiple frames, in which the range of gas leaked into space is shown as a gas region, receiving, as an input, a state of gas movement in a near and far direction in the gas distribution video; machine learning a combination of the gas distribution video and the gas movement state in the near and far directions as training data, and generating an estimation model that inputs the gas distribution video and outputs the gas movement state in the near and far directions; As the movement state of gas in the near and far direction in the training data, the relative near and far speed, which indicates the movement speed of gas in the near and far direction relative to the movement speed in the viewing angle direction, is used. program.

17. The system accepts as input a gas distribution video consisting of multiple frames, in which the range of gas leaked into space is shown as a gas region, generating an inference model by performing machine learning using a combination of a teacher gas distribution video and the gas movement state in the near and far directions in the teacher gas distribution video as teacher data; Using the estimation model, a gas movement state in a near and far direction corresponding to the received gas distribution video is estimated; As the movement state of gas in the near and far direction in the training data, the relative near and far speed, which indicates the movement speed of gas in the near and far direction relative to the movement speed in the viewing angle direction, is used. Gas migration estimation method.

18. A program for causing a computer to perform gas movement estimation processing, The gas movement estimation process includes: The system accepts as input a gas distribution video consisting of multiple frames, in which the range of gas leaked into space is shown as a gas region, generating an inference model by performing machine learning using a combination of a teacher gas distribution video and the gas movement state in the near and far directions in the teacher gas distribution video as teacher data; Using the estimation model, a gas movement state in a near and far direction corresponding to the received gas distribution video is estimated; As the movement state of gas in the near and far direction in the training data, the relative near and far speed, which indicates the movement speed of gas in the near and far direction relative to the movement speed in the viewing angle direction, is used. program.

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