JPWO2017086230A1 - Gas measuring device and gas measuring method - Google Patents

Abstract

The calculation unit calculates, for each pixel arranged in the direction overlapping the horizontal axis set on the infrared image, the gas concentration thickness product corresponding to each pixel. A 1st production | generation part produces | generates the 1st graph which shows distribution of the concentration thickness product of the gas on a horizontal axis using the calculated concentration thickness product. In the space where the gas is leaking, the second generation unit uses the first axis as the axis corresponding to the horizontal axis, and shows the concentration distribution of the gas on the first axis based on the first graph. 2 graphs are generated. The output unit (display unit, display control unit) outputs the second graph.

Description

  The present invention relates to a technique for remotely measuring a gas leaked into a space.

  When a gas leak occurs, a slight temperature change occurs in the space where the leaked gas is drifting. As a technique for measuring gas using this principle, remote gas measurement using an infrared camera is known.

  For example, Patent Document 1 discloses the following gas detection method. In this method, there is one infrared camera, a first filter having a transmission band including an absorption line indicating the characteristics of the gas to be searched, a transmission band similar to the transmission band of the first filter, and And a second filter that does not transmit absorption lines. This method includes detecting a radiant flux from two different temperatures with an infrared camera through a first filter, switching from the first filter to the second filter, and passing through the second filter. The step of detecting the radiant flux from these two points with an infrared camera and the step of estimating whether or not gas is present based on the detection results are provided.

  When a gas leak is measured, the risk level of the gas (eg, the possibility of explosion) needs to be determined. The risk of gas can be determined by the gas concentration in the space where the gas is drifting. However, remote gas measurement using an infrared camera cannot directly measure the gas concentration in the space where the gas is drifting, but measures the gas concentration thickness product. The gas concentration / thickness product means a value obtained by integrating the gas concentration along the depth direction of the space where the gas drifts.

  Gas drifting in space is called a gas cloud. Even with the same concentration and thickness product, the gas cloud concentration is low and the gas cloud depth direction size is large, and the gas cloud concentration is high and the gas cloud depth direction size is small. There is. The latter is more dangerous than the former.

US Pat. No. 5,306,913

  An object of the present invention is to provide a gas measuring device and a gas measuring method capable of measuring a concentration distribution of a gas in a depth direction of a space where the gas is drifting.

  A gas measurement device according to a first aspect of the present invention that achieves the above object includes an acquisition unit, a calculation unit, a first generation unit, a second generation unit, and an output unit. The acquisition unit acquires image data indicating an infrared image of space. The calculation unit is set on the infrared image, the horizontal axis is an axis indicating the horizontal direction of the space, and the pixels arranged in the direction overlapping the horizontal axis among all the pixels constituting the infrared image Based on the pixel data of each pixel included in the image data, the gas concentration / thickness product is calculated corresponding to each pixel. The first generation unit generates a first graph indicating a distribution of the concentration / thickness product on the horizontal axis using the concentration / thickness product calculated by the calculation unit. The second generation unit uses the first graph generated by the first generation unit to determine, as a reference pixel, a predetermined pixel in which the density-thickness product is zero among the pixels. , Indicating the horizontal direction of the space, an axis corresponding to the horizontal axis as a first axis, a value obtained by converting a distance between the reference pixel and each pixel into a distance in the space as a converted value, A second graph showing the concentration distribution of the gas on the first axis by dividing the concentration-thickness product corresponding to each pixel shown in one graph by the converted value corresponding to each pixel. Is generated. The output unit outputs the second graph generated by the second generation unit.

  The above and other objects, features and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings.

It is explanatory drawing explaining the relationship between the gas which drifts in the space, and the coordinate system virtually set to the space. It is a graph which shows the concentration distribution of the gas of the horizontal direction and depth direction of space. It is a graph which shows distribution of the concentration thickness product of gas. It is a block diagram which shows the structure of the gas measuring device which concerns on this embodiment. It is a block diagram which shows the hardware constitutions of the control part with which the gas measuring device shown to FIG. 4A is equipped. In an infrared imaging part, it is explanatory drawing explaining the relationship between the infrared image image | photographed in the state remove | eliminated from between the optical system and the infrared image sensor, and the background containing gas. In an infrared imaging part, it is explanatory drawing explaining the relationship between the infrared image image | photographed in the state arrange | positioned between the optical system and the infrared image sensor, and the background containing gas. It is a flowchart explaining operation | movement of the gas measuring device which concerns on this embodiment. It is an image figure which shows the infrared image displayed on the display part. It is a schematic diagram which shows the horizontal axis set on the infrared image displayed on the display part. It is the graph which shows distribution of the gas concentration thickness product computed at Step S2, and the graph which carried out Gaussian fitting of this graph. It is the graph produced | generated by step S4. It is an image figure which shows the graph which shows the infrared image and the density | concentration distribution of the gas of the depth direction of space. It is an image figure which shows the graph which shows the concentration distribution of the gas of an infrared image, a gas cloud image, and the depth direction of space.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the structure which attached | subjected the same code | symbol shows that it is the same structure, The description is abbreviate | omitted about the content which has already demonstrated the structure.

  FIG. 1 is an explanatory diagram for explaining the relationship between a gas drifting in space and a coordinate system virtually set in the space. In the space, there is a gas leak monitoring target (for example, a place where gas transport pipes are connected). A gas leaking point P is generated at that location, and the gas leaked from the gas leaking point P is drifting through the space.

  An axis indicating a direction (vertical direction) directly above the gas leaking point P is taken as a y-axis. The x1, x2, and x3 axes are axes that are orthogonal to the y axis and indicate the horizontal direction. The z1 axis is orthogonal to the x1 axis and the y axis, and is an axis indicating the depth direction in the coordinate system of the x1 axis, the y axis, and the z1 axis. The z2 axis is orthogonal to the x2 axis and the y axis, and is an axis indicating the depth direction in the coordinate system of the x2, y, and z2 axes. The z3 axis is orthogonal to the x3 axis and the y axis, and indicates the depth direction in the coordinate system of the x3 axis, the y axis, and the z3 axis. The plane PL1 is a plane defined by the x1 axis and the z1 axis. The plane PL2 is a plane defined by the x2 axis and the z2 axis. The plane PL3 is a plane defined by the x3 axis and the z3 axis.

  In the space, the axis indicating the direction directly above the gas leakage point P is the second axis (y-axis), the axis orthogonal to the second axis and the horizontal direction is the first axis (x1 axis, x2 axis) , X3 axis), and the axes orthogonal to the second axis and the first axis and indicating the depth direction are the third axes (z1, z2, and z3 axes). The first axis corresponds to the horizontal axis (FIG. 9) set on the infrared image, as will be described later. Since the leaked gas spreads evenly in the horizontal direction and the depth direction of the space, the gas concentration distribution on the first axis indicating the horizontal direction of the space and the gas on the third axis indicating the depth direction of the space Can be considered to be equal.

  This will be described with reference to the drawings. FIG. 2 is a graph showing the gas concentration distribution in the horizontal and depth directions of the space. Referring to FIGS. 1 and 2, when the horizontal direction is the x1 axis, the depth direction is the z1 axis. When the horizontal direction is the x2 axis, the depth direction is the z2 axis. When the horizontal direction is the x3 axis, the depth direction is the z3 axis. The gas concentration decreases as the distance from the gas leaking point P increases. When the maximum value V1 of the gas concentration is compared between the x1 axis and the z1 axis, the x2 axis and the z2 axis, the x3 axis and the z3 axis, the maximum value in the case of the x1 axis and the z1 axis. Value V1> maximum value in the case of x2 axis and z2 axis> maximum value V1 in the case of x3 axis and z3 axis.

  In the present embodiment, the shape of the graph indicating the concentration distribution of the gas on the x-axis and the shape of the graph indicating the concentration distribution of the gas on the z-axis can be regarded as the shape of the graph of the normal distribution, and the same coordinates In the case of the system, it is assumed that the gas concentration distribution on the x-axis and the gas concentration distribution on the z-axis are the same. That is, the gas concentration distribution on the x-axis is expressed by equation (1), and the gas concentration distribution on the z-axis is expressed by equation (2).

  c indicates the concentration distribution of the gas. σ indicates a standard deviation, that is, gas spread. y shows the distance to the gas leak location P. a represents an index. As the distance from the gas leaking point P increases, the gas spreads and the concentration decreases.

  For example, the gas concentration distribution on the x1 axis and the gas concentration distribution on the z1 axis are the same, the gas concentration distribution on the x2 axis and the gas concentration distribution on the z2 axis are the same, and the x3 axis The concentration distribution of the upper gas is the same as the concentration distribution of the gas on the z3 axis.

  FIG. 3 is a graph showing a distribution of gas concentration thickness product. With reference to FIG.1 and FIG.3, the graph 1 shows distribution of the concentration thickness product of the gas on x1 axis | shaft. Graph 2 shows the distribution of the concentration thickness product of the gas on the x2 axis. Graph 3 shows the distribution of the concentration thickness product of the gas on the x3 axis. In the present embodiment, the shape of these graphs is regarded as the shape of a normal distribution graph. As can be seen from the graphs 1, 2, and 3, the gas concentration-thickness product decreases as the distance from the gas leakage point P increases, and the spread in the horizontal direction (x 1 axis, x 2 axis, x 3 axis) increases.

  In the present embodiment, the gas concentration distribution on the x-axis is obtained based on the gas concentration-thickness product on the x-axis, and this is regarded as the gas concentration distribution on the z-axis.

  FIG. 4A is a block diagram illustrating a configuration of the gas measurement device 1 according to the present embodiment. The gas measuring device 1 includes an infrared imaging unit 2, a control unit 3, a display unit 4, and an input unit 5.

  The infrared imaging unit 2 takes a space in which gas drifts (in other words, a background including gas) as a subject, captures an infrared image of the subject, and generates image data indicating the infrared image. The infrared imaging unit 2 is an infrared camera, and includes an optical system 20, a filter 21, an infrared image sensor 22, and a signal processing unit 23.

  The optical system 20 forms a thermal image of the space where the gas is drifting on the infrared image sensor 22. The gas to be measured is, for example, methane. In the space, there is a gas leak monitoring target (for example, a place where gas transport pipes are connected).

  The filter 21 cuts the absorption line of the gas to be measured. The filter 21 is disposed between the optical system 20 and the infrared image sensor 22 in a state (first state) removed from between the optical system 20 and the infrared image sensor 22 by a switching mechanism (not shown). Switching to the state (second state) is enabled.

  The infrared image sensor 22 has a structure in which a plurality of sensor pixels capable of detecting infrared rays are two-dimensionally arranged. The infrared image sensor 22 receives infrared rays that have passed through the optical system 20 in the first state, and receives infrared rays that have passed through the optical system 20 and the filter 21 in the second state.

  The signal processing unit 23 converts the analog signal output from the infrared image sensor 22 into a digital signal, and performs known image processing. This digital signal becomes image data D1.

  The display unit 4 displays an infrared image taken by the infrared imaging unit 2. The display unit 4 is realized by a liquid crystal display, for example.

  The input unit 5 is realized by a keyboard or a touch panel provided on the display unit 4, and various inputs related to gas measurement are performed.

  The control unit 3 includes a display control unit 30, a calculation unit 31, a first generation unit 32, a second generation unit 33, a setting unit 34, and an acquisition unit 35 as functional blocks. The control unit 3 is realized by a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disk Drive), and the like.

  The acquisition unit 35 is a communication interface that communicates with a communication unit (not shown) of the infrared imaging unit 2. The acquisition unit 35 acquires moving image data D1 (image data indicating an infrared image of space) transmitted from the communication unit of the infrared imaging unit 2.

  The display control unit 30 causes the display unit 4 to display an infrared image or the like indicated by the moving image data D1 acquired by the acquisition unit 35. The display control unit 30 and the display unit 4 function as an output unit. The output unit outputs a graph (third graph) indicating the gas concentration distribution in the depth direction of the space.

  The calculation unit 31 calculates the concentration / thickness product of the gas floating in the space. The calculation of the concentration thickness product will be described. FIG. 5 is an explanatory diagram for explaining a relationship between an infrared image taken in a state where the filter 21 is removed from between the optical system 20 and the infrared image sensor 22 and a background containing gas in the infrared imaging unit 2. is there. FIG. 6 is an explanatory diagram for explaining a relationship between an infrared image captured in a state where the filter 21 is disposed between the optical system 20 and the infrared image sensor 22 and a background including gas in the infrared imaging unit 2. is there. The gas is leaking from the gas leak monitoring object and drifting through the space. The infrared image is configured by two-dimensionally arranging M (plural) pixels from the first to the Mth. The infrared image is composed of, for example, 128 horizontal pixels × 96 vertical pixels. In this case, the number of pixels M is 128 × 96. Image data D1 indicating an infrared image includes M pixel data. The pixel data indicates the background temperature of the area corresponding to the pixel.

  The background is virtually divided into M areas from the first to the M-th corresponding to each of the M pixels. For example, the first pixel corresponds to the first region, and the pixel data of the first pixel indicates the background temperature of the first region. The Jth pixel corresponds to the Jth region, and the pixel data of the Jth pixel indicates the background temperature of the Jth region.

  In order to calculate the concentration-thickness product of the gas located in a certain area, the background temperature of that area when there is gas in that area (background temperature with gas), and the area when there is no gas in that area Background temperature (background temperature without gas) is required. For example, in order to calculate the concentration thickness product of the gas located in the Jth region, the background temperature with gas in the Jth region and the background temperature without gas in the Jth region are required.

  In the present embodiment, first, an infrared image is taken with the filter 21 removed from between the optical system 20 and the infrared image sensor 22 (FIG. 5). Next, an infrared image is taken with the filter 21 disposed between the optical system 20 and the infrared image sensor 22 (FIG. 6). In the latter state, since the gas absorption line is cut by the filter 21, the same case as when there is no gas is realized. This realizes a case where there is gas in a certain area (for example, the Jth area) and a case where there is no gas in that area (Jth area).

  In the present embodiment, the so-called second site method is used to calculate the gas concentration / thickness product. In this method, the amount of infrared rays in each of the two regions where the leaked gas is drifting and the background temperature is different is obtained. The two areas are any of the M areas, and are hereinafter referred to as area A and area B. In the second site method, the concentration / thickness product ct is calculated by the following equation, and the concentration / thickness product ct at which both sides of the following equation are the same is obtained as the gas concentration / thickness product ct in the region A and region B.

Here, _{P A} is the amount of infrared rays are observed by infrared imaging unit 2 in the region _{A, B (T back_A, λ} ) is the background radiation amount of infrared rays in the region _{A (T} back_A the background in the area A P _B is the amount of infrared observed by the infrared imaging unit 2 in region B, and B (T _{back —} B, λ) is the amount of background radiation infrared in region B ( T _{back —} B is the background temperature in region B), S (λ) is the optical system transmittance, ct is the gas thickness product (c is the concentration, and t is the thickness), Each of ε and α (λ) is a parameter (coefficient). The integration is performed over the observed infrared wavelength range.

  The amount of infrared rays in the region A is obtained based on the pixel data of the pixels corresponding to the region A among the M pixels. The amount of infrared rays in the region B is obtained based on the pixel data of the pixels corresponding to the region B among the M pixels. Thus, the gas concentration thickness product of a certain region is obtained based on the pixel data of the pixel corresponding to that region. The calculation unit 31 calculates the gas concentration thickness product in association with each of the M regions (M pixels).

  The first generation unit 32, the second generation unit 33, and the setting unit 34 will be described in the operation of the gas measurement device 1.

  FIG. 4B is a block diagram illustrating a hardware configuration of the control unit 3. The control unit 3 includes a CPU 10a, a RAM 10b, a ROM 10c, an HDD 10d, and a bus 10e that connects them. In the HDD 10d (the ROM 10c may be used instead of the HDD 10d), the display control unit 30, the calculation unit 31, the first generation unit 32, the second generation unit 33, the setting unit 34, and the acquisition unit 35 illustrated in FIG. A program for realizing each of these functional blocks is stored. The CPU 10a reads these programs from the HDD 10d, expands them in the RAM 10b, and executes the expanded programs to realize these functional blocks. A flowchart of these programs executed by the CPU 10a is shown in FIG.

  The operation of the gas measuring device 1 according to this embodiment will be described. FIG. 7 is a flowchart for explaining this operation. With reference to FIG. 4A and FIG. 7, the display control part 30 displays the infrared image image | photographed by the infrared imaging part 2 on the display part 4 (step S1). FIG. 8 is an image diagram showing an infrared image displayed on the display unit 4.

  An operator (measuring person) of the gas measuring device 1 operates the input unit 5, and in the infrared image displayed on the display unit 4, the position of the gas leak point (for example, the gas leak point P shown in FIG. 1). Is specified by the cursor 100. That is, in the infrared image displayed on the display unit 4, the position where the operator pays attention is set as the focus position, and the operator operates the input unit 5 to input the focus position. The setting unit 34 sets, on the infrared image, a horizontal axis that passes through the gas leak point (attention position) designated by the cursor 100. The horizontal axis is an axis indicating the horizontal direction of the space where the leaked gas is drifting. FIG. 9 is a schematic diagram showing the horizontal axis set on the infrared image displayed on the display unit 4. The horizontal axis is set to the Jth line of the infrared image. In FIG. 9, for simplification, the number of pixels in each row is seven. However, in the case of an infrared image having a horizontal width of 128 pixels, the number of pixels in each row is 128. The horizontal axis corresponds to an axis indicating the horizontal direction of the space indicated by the x axis (for example, the x1, x2, and x3 axes) in FIG.

  The calculation unit 31 includes pixel data of each pixel included in the image data D1 indicating the infrared image for each pixel arranged in the direction overlapping the horizontal axis among all the pixels constituting the infrared image displayed on the display unit 4. Based on the above, a gas concentration thickness product is calculated corresponding to each pixel (step S2). Referring to FIG. 9, the calculation unit 31 includes pixels arranged in the direction overlapping the horizontal axis (the J−3th pixel, the J−2th pixel, the J−1th pixel, the Jth pixel, and the J + 1th pixel). , J + 2 pixel, J + 3 pixel) based on the pixel data of each pixel included in the image data D1 indicating the infrared image, the gas concentration thickness product is calculated corresponding to each pixel. .

  More specifically, the calculation unit 31 is based on the pixel data of the J-3th pixel, and the gas concentration / thickness product corresponding to the J-3th pixel (the gas concentration / thickness product of the J-3th region). ) And the gas concentration / thickness product corresponding to the J−2th pixel (the gas concentration / thickness product of the J−2th region) is calculated based on the pixel data of the J−2th pixel. Based on the pixel data of the J-1th pixel, the gas concentration / thickness product corresponding to the J-1th pixel (the gas concentration / thickness product of the J-1th region) is calculated, and the Jth Based on the pixel data of the pixel, the gas concentration / thickness product corresponding to the Jth pixel (the gas concentration / thickness product of the Jth region) is calculated. Based on the pixel data of the J + 1th pixel, J + 1 Calculate the gas concentration thickness product corresponding to the 1st pixel (the gas concentration thickness product of the J + 1th region) Based on the pixel data of the J + 2 pixel, the gas concentration / thickness product corresponding to the J + 2 pixel (the gas concentration / thickness product of the J + 2 region) is calculated, and the pixel data of the J + 3 pixel is used as the basis. Then, the gas concentration / thickness product corresponding to the J + 3rd pixel (the gas concentration / thickness product of the J + 3rd region) is calculated.

  The first generation unit 32 generates a graph (first graph) showing the distribution of the concentration / thickness product of the gas on the horizontal axis shown in FIG. 9 using the concentration / thickness product calculated in step S2 (step 1). S3). FIG. 10 is a graph showing the distribution of the gas concentration / thickness product calculated in step S2, and a graph obtained by Gaussian fitting of this graph. The former graph is a line indicated by ct (actual measurement), and the latter graph is a line indicated by ct (calculation). The horizontal axis of the graph indicates the order of pixels (order of pixels from 0th to 127th). For example, in the case of the Jth row, the order of the pixels from the 0th to the 127th pixel in the Jth row is shown. The vertical axis of the graph represents the gas concentration thickness product.

  The first generation unit 32 generates a ct (actual measurement) graph, that is, a graph (fourth graph) indicating the distribution of the concentration and thickness product of the gas calculated in step S2. Then, the first generation unit 32 fits the ct (actual measurement) graph using the least square method so as to have a normal distribution shape, and the ct (calculation) graph from the ct (measurement) graph. Is generated. The graph of ct (calculation) is the first graph. In the present embodiment, the ct (calculation) graph is the first graph, but the ct (actual measurement) graph may be the first graph.

  The second generation unit 33 uses the graph (first graph) generated in step S3 to perform a predetermined gas concentration / thickness product from zero to 127th pixels (each pixel). Are determined as reference pixels. Referring to FIG. 10, the ct (calculation) graph as the first graph has a zero concentration-thickness product corresponding to the 0th to 32nd pixels and a gas corresponding to the 33rd pixel. It is assumed that the concentration thickness product of is greater than zero. The second generation unit 33 determines, as a reference pixel, the 32nd pixel that is a pixel in which the gas concentration thickness product is switched from zero to a value greater than zero.

  The second generation unit 33 indicates the horizontal direction of the space, the axis corresponding to the horizontal axis (FIG. 9) is the first axis, and the distance between the reference pixel and each pixel (pixels from 0th to 127th) A converted value is a value obtained by converting a distance into a space, and a gas concentration thickness product corresponding to each pixel (0th to 127th pixels) shown in the first graph is set to each pixel (0th to 127). A graph (second graph) indicating the gas concentration distribution on the first axis is generated by dividing by the converted value corresponding to the first pixel) (step S4). The first axis is, for example, the x1 axis, the x2 axis, or the x3 axis in FIG.

  More specifically, the order of the reference pixels is 32 among the pixels arranged in the direction overlapping the horizontal axis (FIG. 9). A value obtained by converting the size of one pixel into a distance in space is 1 meter. The gas concentration thickness product corresponding to the 50th pixel shown in the ct (calculation) graph is 500. The concentration of the gas corresponding to the 50th pixel is 500 ÷ (50−32) × 1. The second generation unit 33 calculates the gas concentration for each pixel.

  FIG. 11 is a graph (second graph) generated in step S4. The horizontal axis of the graph indicates the order of pixels (order of pixels from 0th to 127th). For example, in the case of the Jth row, the order of the pixels from the 0th to the 127th pixel in the Jth row is shown. The vertical axis of the graph indicates the gas concentration.

  The display control unit 30 causes the display unit 4 to display the graph (second graph) generated in step S4 as a graph (third graph) indicating the gas concentration distribution in the depth direction of the space (step S5). . FIG. 12 is an image diagram showing an infrared image and a graph 101 (third graph) showing a gas concentration distribution in the depth direction of the space. The graph 101 is displayed on the display unit 4 so as to overlap the infrared image of FIG.

  In the present embodiment, the concentration distribution of the gas on the axes indicating the depth direction (for example, z1, z2, and z3 axes) is obtained from the position of the origin shown in FIG. The general formula for obtaining this is as follows.

Gas concentration = Gas concentration / thickness product / distance (distance is the distance between the position of the gas leak point P and the position of interest)

  In the present embodiment, in the case of the same plane (for example, plane PL1), the gas concentration is obtained on the assumption that the gas concentration distribution in the depth direction is the same. That is, the gas concentration on the axis indicating the depth direction from this position at a position shifted in the horizontal direction from the origin (for example, an arbitrary position on the x1 axis) is the depth direction from the position of the origin (the origin of the x1 axis). The gas concentration is obtained by using the gas concentration distribution on the axis indicating.

  The main effects of this embodiment will be described. Referring to FIGS. 4A and 7, the first generation unit 32 is a graph (first graph) showing the distribution of the concentration thickness product of the gas on the horizontal axis set on the infrared image shown in FIG. 8. Is generated (step S3). The second generation unit 33 generates a graph (second graph) indicating the gas concentration distribution based on the first graph (step S4). The second graph is a graph showing the gas concentration distribution on the first axis when the axis corresponding to the horizontal axis is the first axis in the space where the gas is drifting. For example, when the first axis is the x1 axis shown in FIG. 1, it is a graph showing the gas concentration distribution on the x1 axis, and when the first axis is the x2 axis, the gas concentration distribution on the x2 axis is shown. FIG. 6 is a graph showing the gas concentration distribution on the x3 axis when the first axis is the x3 axis.

  The display control unit 30 causes the display unit 4 to display the second graph as a graph (third graph) indicating the gas concentration distribution in the depth direction of the space (step S5). The third graph shows the gas concentration distribution on the third axis when the third axis is the axis that is orthogonal to the first axis and that indicates the depth direction in the space. For example, when the first axis is the x1 axis shown in FIG. 1 and the third axis is the z1 axis, it is a graph showing the gas concentration distribution on the z1 axis, and the first axis is the x2 axis. When the third axis is the z2 axis, the graph shows the gas concentration distribution on the z2 axis, the first axis is the x3 axis, and the third axis is the z3 axis. It is a graph which shows concentration distribution of gas on z3 axis. Therefore, according to the gas measurement device 1 according to the present embodiment, the gas concentration distribution in the depth direction of the space can be measured.

  Further, according to the present embodiment, as shown in FIG. 12, the display control unit 30 is a graph (third graph) showing the infrared image captured by the infrared imaging unit 2 and the gas concentration distribution in the depth direction. ) Are displayed together on the display unit 4. Thereby, the operator of the gas measuring apparatus 1 can recognize the state of gas leaking from the infrared image and can recognize the gas concentration distribution in the depth direction.

  According to the present embodiment, as described in step S1, the operator designates the position of the gas leak location, and the setting unit 34 sets the horizontal axis passing through the position on the infrared image. Yes. However, the gas measuring device 1 may measure the position of the gas leak location, and the setting unit 34 may set the horizontal axis passing through the position on the infrared image.

  As shown in FIG. 12, in the present embodiment, the graph 101 is displayed on the display unit 4 as the output of the graph 101 that is the third graph. However, the graph 101 may be printed as the output of the graph 101, or the infrared image and the graph 101 shown in FIG. 12 may be printed.

  The present embodiment outputs a third graph. However, the second graph (FIG. 11) may be output. As described in step S5, the display control unit 30 causes the display unit 4 to display the second graph as a graph (third graph) indicating the gas concentration distribution in the depth direction of the space. Therefore, the data of the second graph and the data of the third graph are the same (in other words, the shape of the second graph and the shape of the third graph are the same). Therefore, the measurer can determine the gas concentration distribution in the depth direction of the space by looking at the second graph. When the second graph is output, the display control unit 30 causes the display unit 4 to display the second graph instead of the graph 101 in FIG.

  According to the present embodiment, the infrared image and the graph 101 shown in FIG. 12 are displayed on the display unit 4, but the image including the infrared image, the graph 101, and the gas cloud image 102 shown in FIG. 4 may be displayed. The gas cloud image 102 shows the spread of the gas in the horizontal direction and the vertical direction of the space where the gas is drifting. The light and shade of the gas cloud image 102 indicates the same concentration in the depth direction where the gas concentration maximum value is the same. The gas cloud image 102 shown in FIG. 13 has three regions with different shades. As the maximum value of the gas concentration increases, the concentration of the region increases. In addition, the area | region where light and shade are different is not limited to three, What is necessary is just two or more.

  If the control unit 3 of the gas measuring device 1 determines that the maximum value of the gas concentration in the depth direction exceeds a predetermined threshold (for example, a value indicating the risk of explosion), the gas measuring device 1 May be notified. For example, in the case of methane, if it exceeds 20000 ppm, there is a risk of explosion, so if the maximum value of the concentration of gas in the depth direction exceeds 20000 ppm, the gas measuring device 1 notifies it. As a notification mode, a mode in which an alarm is sounded, or a mode in which a region where the maximum gas concentration in the depth direction exceeds a predetermined threshold in the region of the gas cloud image 102 shown in FIG. 13 blinks. is there.

(Summary of embodiment)
The gas measurement device according to the first aspect of the present embodiment includes an acquisition unit that acquires image data indicating an infrared image of a space, and an axis that is set on the infrared image and indicates a horizontal direction of the space. For each pixel arranged in the direction overlapping with the horizontal axis among all the pixels constituting the infrared image as the axis, based on the pixel data of each pixel included in the image data, the concentration concentration product of the gas A first graph that shows a distribution of the concentration-thickness product on the horizontal axis is calculated using a calculation unit that calculates the value corresponding to each pixel and the concentration-thickness product calculated by the calculation unit. 1 generation unit and the first graph generated by the first generation unit, a predetermined pixel in which the density-thickness product is zero among the pixels is determined as a reference pixel, Indicates the horizontal direction of the space, and the horizontal axis The corresponding axis is the first axis, and the value obtained by converting the distance between the reference pixel and each pixel into the distance in the space is the converted value, and the corresponding to each pixel shown in the first graph. A second generation unit that generates a second graph indicating the concentration distribution of the gas on the first axis by dividing the concentration-thickness product by the converted value corresponding to each pixel; An output unit that outputs the second graph generated by the generation unit as a third graph indicating the concentration distribution of the gas in the depth direction of the space. As described in the embodiment, the data of the second graph and the data of the third graph are the same. Therefore, the output unit may output the second graph instead of the third graph.

  In the space, it indicates the direction directly above the portion where the gas has leaked, the axis orthogonal to the first axis is the second axis, the axis is orthogonal to the first axis and the second axis, and indicates the depth direction of the space Is the third axis. Since the leaked gas spreads evenly in the horizontal direction and the depth direction of the space, the gas concentration distribution on the first axis indicating the horizontal direction of the space and the gas on the third axis indicating the depth direction of the space Can be considered to be equal. The gas measuring device according to the first aspect of the present embodiment has been created by paying attention to this.

  A 1st production | generation part produces | generates the 1st graph which shows distribution of the concentration thickness product of the gas on the horizontal axis set on the infrared image. The second generation unit generates a second graph based on the first graph. This graph is a graph showing the gas concentration distribution on the first axis when the axis corresponding to the horizontal axis is the first axis in the space. The output unit outputs the second graph as a third graph indicating the gas concentration distribution in the depth direction of the space. This shows the gas concentration distribution on the third axis when the third axis is the axis perpendicular to the first axis and indicating the depth direction in the space. Therefore, according to the gas measurement device according to the first aspect of the present embodiment, the gas concentration distribution in the depth direction of the space can be measured.

  The output unit may display the third graph on the display unit, or may print the third graph on paper.

  In the above configuration, the third graph output by the output unit indicates a direction directly above the portion where the gas has leaked in the space, and an axis orthogonal to the first axis is a second axis. A graph of the concentration distribution of the gas at each position on the third axis, where the third axis is an axis perpendicular to the first axis and the second axis and indicating the depth direction of the space. It is.

  This configuration is an example of the coordinate system of the third graph.

  In the above configuration, the first generation unit generates a fourth graph indicating the distribution of the concentration-thickness product calculated by the calculation unit, and the fourth generation unit has a shape of a normal distribution graph. A graph is fitted to generate the first graph from the fourth graph.

  This configuration is an example of how to generate the first graph. The fourth graph itself may be the first graph.

  In the above configuration, the output unit includes a display unit, and a display control unit that causes the display unit to display the infrared image and the third graph together.

  According to this configuration, it is possible to recognize a gas leak from the infrared image and to recognize a gas concentration distribution in the depth direction. In the case where the output unit outputs the second graph, the display control unit displays the infrared image and the second graph together on the display unit.

  In the above configuration, an operator of the gas measuring device in the infrared image before the concentration-thickness product is calculated by the calculation unit and in a state where the infrared image is displayed on the display unit. Is set as a target position, and an input unit for inputting the target position by an operation of the operator, and a setting unit for setting the horizontal axis passing through the target position input to the input unit And further comprising.

  According to this configuration, the operator can set the position of the horizontal axis.

  The gas measurement method according to the second aspect of the present embodiment includes a first step of acquiring image data indicating an infrared image of a space, and an axis that is set on the infrared image and indicates a horizontal direction of the space. The horizontal axis, and among all the pixels constituting the infrared image, for each pixel aligned in the direction overlapping the horizontal axis, the concentration of the gas based on the pixel data of each pixel included in the image data A second step of calculating a thickness product corresponding to each pixel and a first distribution thickness distribution product on the horizontal axis using the concentration thickness product calculated by the second step. And using the first graph generated by the third step as a reference pixel, a predetermined pixel having a density / thickness product of zero among the pixels is used as a reference pixel. Determine and of the space In the first graph, a horizontal direction is indicated, an axis corresponding to the horizontal axis is a first axis, a distance obtained by converting a distance between the reference pixel and each pixel into a distance in the space is a converted value, and A second graph showing the concentration distribution of the gas on the first axis is generated by dividing the concentration-thickness product corresponding to each pixel shown by the converted value corresponding to each pixel. And a fifth step of outputting the second graph generated by the fourth step.

  The gas measurement method according to the second aspect of the present embodiment has the same operational effects as the gas measurement device according to the first aspect of the present embodiment.

  This application is based on Japanese Patent Application No. 2015-223705 filed on November 16, 2015, the contents of which are included in the present application.

  In order to express the present invention, the present invention has been properly and fully described through the embodiments with reference to the drawings. However, those skilled in the art can easily change and / or improve the above-described embodiments. It should be recognized that this is possible. Therefore, unless the modifications or improvements implemented by those skilled in the art are at a level that departs from the scope of the claims recited in the claims, the modifications or improvements are not covered by the claims. To be construed as inclusive.

  According to the present invention, a gas measuring device and a gas measuring method can be provided.

Claims (7)

An acquisition unit for acquiring image data indicating an infrared image of space;
The image data is set for each pixel that is set on the infrared image and has an axis indicating the horizontal direction of the space as a horizontal axis, and is aligned in the direction overlapping the horizontal axis among all the pixels constituting the infrared image. A calculation unit that calculates the concentration thickness product of the gas corresponding to each pixel based on the pixel data of each pixel included;
A first generation unit that generates a first graph indicating a distribution of the concentration thickness product on the horizontal axis using the concentration thickness product calculated by the calculation unit;
Using the first graph generated by the first generation unit, a predetermined pixel in which the density / thickness product is zero is determined as a reference pixel from among the pixels, and the horizontal direction of the space is indicated. The axis corresponding to the horizontal axis is the first axis, the distance between the reference pixel and each pixel is converted to the distance in the space, and the converted value is used as each of the above-described values shown in the first graph. A second generation unit that generates a second graph indicating the concentration distribution of the gas on the first axis by dividing the concentration-thickness product corresponding to the pixel by the converted value corresponding to the pixel. When,
An output unit that outputs the second graph generated by the second generation unit.   The gas measurement apparatus according to claim 1, wherein the output unit outputs the second graph as a third graph indicating the concentration distribution of the gas in the depth direction of the space.   The third graph output by the output unit indicates a direction directly above the portion where the gas leaked in the space, and an axis orthogonal to the first axis is a second axis, and the first graph The gas concentration distribution graph at each position on the third axis when an axis perpendicular to the axis and the second axis and indicating the depth direction of the space is a third axis. 2. The gas measuring device according to 2.   The first generation unit generates a fourth graph indicating the distribution of the concentration-thickness product calculated by the calculation unit, and fits the fourth graph so as to have a shape of a normal distribution graph. The gas measuring device according to any one of claims 1 to 3, wherein the first graph is generated from the fourth graph. The output unit is
A display unit;
The gas measurement device according to claim 1, further comprising: a display control unit that displays the infrared image and the second graph together on the display unit. Before the calculation of the concentration-thickness product by the calculation unit, in a state where the infrared image is displayed on the display unit, a position of an operator of the gas measurement device in the infrared image And an input unit for inputting the position of interest by the operation of the operator,
The gas measurement device according to claim 5, further comprising: a setting unit that sets the horizontal axis that passes through the position of interest input to the input unit. A first step of acquiring image data indicating an infrared image of space;
The image data is set for each pixel that is set on the infrared image and has an axis indicating the horizontal direction of the space as a horizontal axis, and is aligned in the direction overlapping the horizontal axis among all the pixels constituting the infrared image. A second step of calculating a concentration thickness product of the gas corresponding to each pixel based on pixel data of each pixel included;
A third step of generating a first graph showing a distribution of the concentration-thickness product on the horizontal axis using the concentration-thickness product calculated by the second step;
Using the first graph generated by the third step, a predetermined pixel having a density / thickness product of zero among the pixels is determined as a reference pixel, and indicates the horizontal direction of the space, Each pixel shown in the first graph is a value obtained by converting an axis corresponding to the horizontal axis as a first axis, a value obtained by converting a distance between the reference pixel and each pixel into a distance in the space. A fourth step of generating a second graph showing the concentration distribution of the gas on the first axis by dividing the concentration-thickness product corresponding to, by the converted value corresponding to each pixel;
And a fifth step of outputting the second graph generated by the fourth step.

Images