Dangerous gas leakage intelligent monitoring method based on gas cloud imaging

Abstract

The invention discloses an intelligent monitoring method for dangerous gas leakage based on gas cloud imaging, and relates to the field of data analysis, the method comprises the following steps: calculating a temperature anomaly index J, a gas diffusion velocity V, a color shift index RGB and a gas diffusion index L based on infrared gas cloud image data and optical gas cloud image data, and solving the problem that temperature fluctuation exists in a natural environment, and a gas diffusion index L cannot be obtained. Whether gas leakage occurs or not is judged only through a single temperature characteristic, and misjudgment is easily caused; the gas leakage degree is judged according to the leakage degree evaluation index K and the leakage degree threshold set, and the problems that the gas leakage degree cannot be quantified, and the gas leakage condition cannot be visually known are solved. According to the scheme, the accuracy and reliability of hazardous gas leakage detection are effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of data analysis and hazardous gas detection, and in particular to an intelligent monitoring method for hazardous gas leakage based on gas cloud imaging. Background Art

[0002] As the scale of the chemical industry continues to expand and the complexity increases, the safety requirements for the production process are becoming higher and higher. Dangerous gas leakage is a major safety hazard in the chemical industry. By monitoring the leakage of dangerous gases, it is possible to warn of dangers in a timely manner, effectively ensure the safety of personnel, and avoid property losses.

[0003] The working principle of the traditional intelligent monitoring method for hazardous gas leaks is: by installing infrared detectors for real-time scanning and monitoring, when hazardous gas leaks, due to the physical properties of the gas and the temperature difference with the surrounding environment, a specific temperature abnormality area will appear in the infrared image. When an abnormal temperature change area is detected, a warning signal will be issued.

[0004] The existing technology still has the following shortcomings: temperature fluctuations exist in the natural environment, and judging whether a gas leak occurs only by a single temperature feature is prone to misjudgment. At the same time, it is impossible to quantify the degree of gas leakage and cannot intuitively understand the gas leakage situation. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the shortcomings of the prior art, the present invention provides an intelligent monitoring method for hazardous gas leakage based on gas cloud imaging, which calculates the temperature anomaly index J, gas diffusion velocity V, color shift index RGB and gas diffusion index L based on infrared gas cloud image data and optical gas cloud image data, thereby solving the problem that temperature fluctuations exist in the natural environment and whether a gas leakage occurs is easily misjudged by only judging whether a gas leakage occurs by a single temperature feature; by judging the degree of gas leakage according to the leakage degree assessment index K and the leakage degree threshold set, the problem that the degree of gas leakage cannot be quantified and the gas leakage situation cannot be intuitively understood is solved.

[0007] (II) Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions: a method for intelligent monitoring of dangerous gas leakage based on gas cloud imaging, comprising the following steps:

[0009] Based on infrared imaging technology and optical imaging technology, hazardous gas monitoring is carried out in chemical parks and infrared gas cloud image data and optical gas cloud image data are generated;

[0010] Calculation of horizontal temperature gradient A based on infrared gas cloud image data x(x, y) and vertical temperature gradient B x (x, y), and further calculate the temperature gradient amplitude AB(x, y); preset the temperature gradient amplitude threshold CH; determine the infrared leakage area range S according to the temperature gradient amplitude threshold CH and the temperature gradient amplitude AB(x, y); calculate the temperature anomaly index J based on the infrared gas cloud image;

[0011] Use image processing algorithms to identify the image boundary of the infrared leakage area S and obtain the coordinates of the boundary points (x h ,y h ); According to the boundary point coordinates (x h ,y h ) Calculate the coordinates of the center of mass (E m , F m ), and further calculate the gas diffusion velocity V;

[0012] Based on the infrared gas cloud image and optical gas cloud image data, the coordinates of the boundary points of the optical gas cloud image (c h , d h ); Statistical optical gas cloud image boundary point coordinates (c h , d h ) and the coordinates of all pixels within the boundary point constitute the optical leakage area range U; the red discreteness σ is calculated based on the optical gas cloud image data R , green dispersion σ G and the blue dispersion σ B , and further calculate the color shift index RGB;

[0013] According to the coordinates of the boundary points of the optical gas cloud image (c h , d h ) Calculate the perimeter b of the leakage area and further calculate the gas diffusion index L;

[0014] Calculate the leakage degree assessment index K according to the temperature anomaly index J, gas diffusion speed V, color shift index RGB and color gas diffusion index L; preset the leakage degree threshold set; judge the gas leakage degree according to the leakage degree assessment index K and the leakage degree threshold set; determine the remedial measures according to the gas leakage degree.

[0015] In the preferred embodiment of the intelligent monitoring method for dangerous gas leakage based on gas cloud imaging, the method for calculating the temperature gradient amplitude AB(x, y) is:

[0016] The infrared gas cloud image data at least includes infrared pixel points (x, y) and temperature T (x, y);

[0017] Calculate the horizontal temperature gradient A according to the temperature T(x, y) x (x, y), the formula is:

[0018] A x (x, y) = T (x + 1, y) - T (x, y)

[0019] Among them, A x (x, y) is the temperature gradient in the horizontal direction of the pixel point (x, y) in the infrared gas cloud image data; T(x, y) is the temperature value of the pixel point (x, y) in the infrared gas cloud image data; T(x+1, y) is the temperature value of the pixel point (x+1, y) in the infrared gas cloud image data;

[0020] Calculate the vertical temperature gradient B based on the temperature T(x, y) x (x, y), the formula is:

[0021] B x (x, y) = T (x, y + 1) - T (x, y)

[0022] Among them, B x (x, y) is the temperature gradient in the vertical direction of the pixel point (x, y) in the infrared gas cloud image data; T(x, y+1) is the temperature value of the pixel point (x, y+1) in the infrared gas cloud image data;

[0023] According to the horizontal temperature gradient A x (x, y) and vertical temperature gradient B x (x, y) to calculate the temperature gradient amplitude AB(x, y), based on the formula:

[0024]

[0025] Wherein, AB(x, y) is the temperature gradient amplitude of the pixel point (x, y) in the infrared gas cloud image data.

[0026] In the preferred embodiment of the intelligent monitoring method for dangerous gas leakage based on gas cloud imaging, the method for determining the infrared leakage area range S is:

[0027] The infrared leakage area range S is determined according to the temperature gradient amplitude threshold CH and the temperature gradient amplitude AB (x, y), and the specific method is as follows:

[0028] S={(x,y)|L(x,y)=1}

[0029]

[0030] In the preferred embodiment of the intelligent monitoring method for dangerous gas leakage based on gas cloud imaging, the method for calculating the temperature anomaly index J is:

[0031] The infrared gas cloud image data also includes the average temperature of the infrared leakage area S Temperature standard deviation σ of infrared leakage area S T and the average temperature of the area not affected by the leak

[0032] According to the average temperature Temperature standard deviation σ of infrared leakage area S T and average temperature The specific method for calculating the temperature anomaly index J is as follows:

[0033]

[0034] In the preferred embodiment of the intelligent monitoring method for dangerous gas leakage based on gas cloud imaging, the centroid coordinates (E m , F m ) is:

[0035] According to the boundary point coordinates (x h ,y h ) Calculate the coordinates of the center of mass (E m , F m ), the specific method is:

[0036]

[0037] Among them, (x h ,y h ) is the coordinate of the hth point on the boundary of the infrared leakage area; (x h ,y h )∈S; h is the serial number of different points on the boundary of the infrared leakage area, and its value is [1, g]; g is the total number of boundary points, and g is a positive integer; (E m , F m ) is the centroid coordinate of the infrared leakage area at time m; m is the serial number corresponding to different time points, and its value is a positive integer; w h is the boundary point (x h ,y h ) is located.

[0038] In the preferred embodiment of the intelligent monitoring method for dangerous gas leakage based on gas cloud imaging, the method for calculating the gas diffusion velocity V is:

[0039] According to the centroid coordinates (E m , F m ) Calculate the gas diffusion velocity V, the specific method is:

[0040]

[0041] Among them, (E m+k , F m+k) is the centroid coordinate of the leakage area at time m+k; Δt is the time interval; k is the number of frames in the time interval.

[0042] In the preferred embodiment of the above-mentioned intelligent monitoring method for hazardous gas leakage based on gas cloud imaging, the method for calculating the optical leakage area range U is:

[0043] The infrared gas cloud image data also includes the infrared imaging system coordinates (X IR , Y IR ), focal length f of infrared imaging system IR , infrared imaging horizontal resolution M IR And the vertical resolution of infrared imaging N IR ;

[0044] The optical gas cloud image data at least includes the optical imaging system coordinates (X O , Y O ), focal length f of optical imaging system O , optical imaging horizontal resolution M O and the optical imaging vertical resolution N O ;

[0045] According to the infrared imaging system coordinates (X IR , Y IR ), focal length f of infrared imaging system IR , infrared imaging horizontal resolution M IR , infrared imaging vertical resolution N IR , boundary point coordinates (x h ,y h ), optical imaging system coordinates (X O , Y O ), focal length f of optical imaging system O , optical imaging horizontal resolution M O and the optical imaging vertical resolution N O Calculate the coordinates of the boundary points of the optical gas cloud image (c h , d h ), the specific method is:

[0046]

[0047] Among them, (c h , d h ) is the optical gas cloud image coordinate corresponding to the hth point on the boundary of the infrared leakage area; the coordinates of the boundary points of the optical gas cloud image (c h , d h ) and the coordinates of all pixel points within the boundary point constitute the optical leakage area range U.

[0048] In the preferred embodiment of the intelligent monitoring method for dangerous gas leakage based on gas cloud imaging, the method for calculating the color shift index RGB is:

[0049] The optical gas cloud image data also includes the number of pixels p in the optical leakage area U, the red value Red a , Green value Green a and Blue a ;

[0050] According to the red value Red a Calculate the red dispersion σ R :

[0051]

[0052] Among them, Red a is the red value of the ath pixel in the optical leakage area U; a is the serial number corresponding to different pixels in the optical leakage area U, and its value is [1, p]; p is the total number of pixels in the optical leakage area U, and its value is a positive integer;

[0053] According to the green value Green a Calculate the green dispersion σ G :

[0054]

[0055] Among them, Green a is the green value of the ath pixel in the optical leakage area U;

[0056] According to the blue value Blue a Calculate the blue dispersion σ B :

[0057]

[0058] Among them, Blue a is the blue value of the a-th pixel in the optical leakage area U;

[0059] According to the red dispersion σ R , green dispersion σ G and the blue dispersion σ B Calculate the color shift indicator RGB:

[0060]

[0061] In the preferred embodiment of the intelligent monitoring method for dangerous gas leakage based on gas cloud imaging, the method for calculating the gas diffusion index L is:

[0062] According to the coordinates of the boundary points of the optical gas cloud image (c h , d h ) Calculate the perimeter b of the leakage area in the following way:

[0063] c min =min{c h |c h ∈(c h , d h )}

[0064] c max =max{c h |c h ∈(c h , d h )}

[0065] d min =min{d h |d h ∈(c h , d h )}

[0066] d max =max{d h |d h ∈(c h , d h )}

[0067] b=[(c max -c min )+(d max -d min )]×2

[0068] Among them, c min is the minimum horizontal coordinate of the boundary point coordinates of the optical gas cloud image; c max is the maximum horizontal coordinate of the boundary point coordinates of the optical gas cloud image; d min is the minimum ordinate of the boundary point coordinates of the optical gas cloud image; d max is the maximum ordinate of the boundary point coordinates of the optical gas cloud image;

[0069] Calculate the gas diffusion index L based on the number of pixels p and the perimeter b:

[0070]

[0071] In the preferred embodiment of the intelligent monitoring method for hazardous gas leakage based on gas cloud imaging, the method for judging the degree of gas leakage according to the leakage degree evaluation index K and the leakage degree threshold set is:

[0072] The leakage evaluation index K is calculated based on the temperature anomaly index J, gas diffusion velocity V, color shift index RGB and gas diffusion index L. The standard is:

[0073] K=β1×J+β2×V+β3×RGB+β4×L

[0074] Among them, β1 is the weight coefficient of the temperature anomaly index J, which is 0.2-0.4; β2 is the weight coefficient of the gas diffusion velocity V, which is 0.3-0.4; β3 is the weight coefficient of the color shift index RGB, which is 0.2-0.3; β4 is the weight coefficient of the gas diffusion index L, which is 0.1-0.3; and β1+β2+β3+β4=1;

[0075] The leakage degree threshold set includes a severe leakage threshold KZ and a mild leakage threshold KQ;

[0076] The gas leakage degree is judged according to the leakage degree assessment index K and the leakage degree threshold set, and the formula is as follows:

[0077]

[0078] (III) Beneficial effects

[0079] The present invention provides an intelligent monitoring method for dangerous gas leakage based on gas cloud imaging, which has the following beneficial effects:

[0080] (1) Based on infrared imaging technology and optical imaging technology, hazardous gas monitoring in chemical parks and generating infrared gas cloud image data and optical gas cloud image data are helpful to more accurately determine whether gas leakage has occurred. The information obtained by the two imaging methods can complement each other and improve the accuracy and reliability of monitoring.

[0081] (2) Determining the infrared leakage area range S based on the temperature gradient amplitude threshold CH and the temperature gradient amplitude AB (x, y) can more accurately locate the temperature anomaly area near the leakage source, which helps to timely discover potential leakage points; calculating the temperature anomaly index J based on the infrared gas cloud image can quantify the degree of temperature change caused by gas leakage. By calculating the gas diffusion velocity V, the diffusion process of gas leakage can be dynamically tracked. By calculating the color shift index RGB, the distribution of leaked gas can be reflected from the perspective of color characteristics. By calculating the gas diffusion index L, the dynamic characteristics of the leakage can be better understood. These quantitative indicators provide intuitive data support for staff;

[0082] (3) The leakage degree assessment index K is calculated based on the temperature anomaly index J, gas diffusion velocity V, color shift index RGB and color gas diffusion index L. It can comprehensively measure the severity of gas leakage from multiple key dimensions, avoid the limitation of single factor judgment, and solve the problem of misjudgment caused by judging whether gas leakage occurs only by a single temperature feature; judge the degree of gas leakage based on the leakage degree assessment index K and the leakage degree threshold set; determine the remedial measures based on the degree of gas leakage, so that the staff can take targeted measures according to the specific leakage degree, thereby enhancing the accuracy of emergency decision-making. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0084] Figure 1 A schematic diagram of the working steps of an intelligent monitoring method for dangerous gas leakage based on gas cloud imaging according to the present invention;

[0085] Figure 2 A schematic diagram of a framework of an intelligent monitoring system for hazardous gas leakage based on gas cloud imaging is provided for an embodiment of the present invention. DETAILED DESCRIPTION

[0086] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0087] See also Figure 1 The present invention provides an intelligent monitoring method for dangerous gas leakage based on gas cloud imaging, comprising the following steps:

[0088] Step 1: Monitor hazardous gases in chemical parks based on infrared imaging technology and optical imaging technology and generate infrared gas cloud image data and optical gas cloud image data.

[0089] According to step 1:

[0090] Based on infrared imaging technology and optical imaging technology, hazardous gas monitoring in chemical parks and generating infrared gas cloud image data and optical gas cloud image data are helpful to more accurately determine whether gas leakage has occurred. The information obtained by the two imaging methods can complement each other and improve the accuracy and reliability of monitoring.

[0091] Step 2: Calculate the horizontal temperature gradient A based on infrared gas cloud image data x (x, y) and vertical temperature gradient B x (x, y), and further calculate the temperature gradient amplitude AB(x, y); preset the temperature gradient amplitude threshold CH; determine the infrared leakage area range S according to the temperature gradient amplitude threshold CH and the temperature gradient amplitude AB(x, y); calculate the temperature anomaly index J based on the infrared gas cloud image.

[0092] Use image processing algorithms to identify the image boundary of the infrared leakage area S and obtain the coordinates of the boundary points (x h ,y h ); According to the boundary point coordinates (x h ,y h ) Calculate the coordinates of the center of mass (E m , F m ), and further calculate the gas diffusion velocity V.

[0093] Based on the infrared gas cloud image and optical gas cloud image data, the coordinates of the boundary points of the optical gas cloud image (c h , d h ); Coordinates of boundary points of statistical optical gas cloud image (c h , d h ) and the coordinates of all pixels within the boundary point constitute the optical leakage area range U; the red discreteness σ is calculated based on the optical gas cloud image data R , green dispersion σ G and the blue dispersion σ B , and further calculate the color shift index RGB.

[0094] According to the coordinates of the boundary points of the optical gas cloud image (c h , d h ) Calculate the perimeter b of the leakage area and further calculate the gas diffusion index L.

[0095] Step 201: The method for calculating the temperature gradient amplitude AB(x, y) is:

[0096] The infrared gas cloud image data at least includes infrared pixel points (x, y) and temperature T(x, y).

[0097] It should be noted that the infrared pixel point (x, y) is the coordinate of each pixel point in the infrared gas cloud image. The origin of the infrared gas cloud image coordinate is in the upper left corner, the right is the positive direction of the x-axis, and the downward is the positive direction of the y-axis. The temperature T (x, y) is obtained through the temperature measurement function of the infrared imaging system.

[0098] Calculate the horizontal temperature gradient A according to the temperature T(x, y) x (x, y), the specific method is:

[0099] A x (x, y) = T (x + 1, y) - T (x, y)

[0100] It should be noted that this formula calculates the temperature difference between adjacent pixels in the horizontal direction to obtain the horizontal temperature gradient A. x (x, y).

[0101] Among them, A x (x, y) is the horizontal temperature gradient of the pixel point (x, y) in the infrared gas cloud image data; T(x, y) is the temperature value of the pixel point (x, y) in the infrared gas cloud image data; T(x+1, y) is the temperature value of the pixel point (x+1, y) in the infrared gas cloud image data.

[0102] Calculate the vertical temperature gradient B based on the temperature T(x, y) x (x, y), the specific method is:

[0103] B x (x, y) = T (x, y + 1) - T (x, y)

[0104] It should be noted that this formula calculates the temperature difference between adjacent pixels in the vertical direction to obtain the vertical temperature gradient B. x (x, y).

[0105] Among them, B x (x, y) is the temperature gradient in the vertical direction of the pixel point (x, y) in the infrared gas cloud image data; T(x, y+1) is the temperature value of the pixel point (x, y+1) in the infrared gas cloud image data.

[0106] According to the horizontal temperature gradient A x (x, y) and vertical temperature gradient B x (x, y) calculates the temperature gradient amplitude AB(x, y) as follows:

[0107]

[0108] It should be noted that this formula is based on the principle of spatial difference operation, and the temperature gradient amplitude AB (x, y) is obtained by performing comprehensive operations on the temperature gradients in the horizontal and vertical directions.

[0109] Wherein, AB(x, y) is the temperature gradient amplitude of the pixel point (x, y) in the infrared gas cloud image data.

[0110] Step 202: The method for determining the infrared leakage area range S is:

[0111] The infrared leakage area range S is determined according to the temperature gradient amplitude threshold CH and the temperature gradient amplitude AB (x, y), and the specific method is as follows:

[0112] S={(x,y)|L(x,y)=1}

[0113]

[0114] It should be noted that the operating principle of this formula is: at the junction of the leakage area and the surrounding environment, the temperature will quickly transition from the temperature of the leaking gas to the ambient temperature. By detecting this sudden change in temperature gradient, the temperature gradient amplitude AB (x, y) exceeding the temperature gradient amplitude threshold CH is marked as 1 and counted to determine the boundary of the suspected leakage area, thereby obtaining the infrared leakage area range S.

[0115] The method for determining the temperature gradient amplitude threshold CH is as follows: in a laboratory environment, various gas leakage scenarios that may occur in a chemical park are simulated, and the temperature data of the infrared imaging system is collected under different gas leakage rates, leakage gas types, and environmental conditions. The collected data is analyzed to determine the temperature gradient amplitude threshold CH that can distinguish between normal temperature fluctuations and temperature changes caused by gas leakage.

[0116] Step 203: The method for calculating the temperature anomaly index J is:

[0117] The infrared gas cloud image data also includes the average temperature of the infrared leakage area S Temperature standard deviation σ of infrared leakage area S T and the average temperature of the area not affected by the leak

[0118] It should be noted that the average temperature of the infrared leakage area S It reflects the average temperature of all pixels in the area and represents the overall temperature condition of the leakage area. It is determined by adding the temperature values ​​of all pixels in the leakage area and then dividing it by the total number of pixels. The temperature standard deviation σ of the infrared leakage area range S T It is used to measure the discrete degree of temperature distribution in the infrared leakage area. The calculation method is: for each pixel in the infrared leakage area, calculate its temperature and the average temperature The squares of the differences are added together and then divided by the total number of pixels to get the average squared temperature difference. The square root of the average squared temperature difference is the temperature standard deviation σ. T The average temperature of the area not affected by the leak It refers to the average temperature of all pixels in the area not affected by the gas leak. It is used as a reference value to compare with the temperature of the infrared leak area in order to more accurately determine the leak and assess the impact of the leak on the ambient temperature. It is obtained by adding the temperature values ​​of all pixels in the unaffected area and then dividing it by the total number of pixels.

[0119] According to the average temperature Temperature standard deviation σ of infrared leakage area S T and average temperature Calculate the temperature anomaly index J in the following way:

[0120]

[0121] It should be noted that this formula takes into account the average temperature of the leakage area. The difference from the ambient temperature and the degree of temperature dispersion. When the leaked gas causes the regional temperature to be significantly higher than the ambient temperature and the temperature distribution is more concentrated, the temperature anomaly index J value will be larger.

[0122] Step 204: Calculate the centroid coordinates (E m , F m ) is:

[0123] According to the boundary point coordinates (x h ,y h ) Calculate the coordinates of the center of mass (E m , F m ), the specific method is:

[0124]

[0125] It should be noted that the working principle of this formula is: the center of mass is the central position of the mass distribution of an object. For a system composed of multiple particles, the position of the center of mass is related to the mass of each particle. In the gas cloud image, the position of the center of mass is measured by the area of ​​each particle. The horizontal coordinate of the centroid is determined by multiplying the value of the horizontal coordinate of each point on the boundary of the leakage area by the area and then dividing it by the total area, and according to the proportion of the area of ​​the small area where each point is located to the whole area. The vertical coordinate of the centroid is determined by multiplying the vertical coordinate value of each point on the boundary of the leakage area by the area and then dividing it by the total area, and the vertical coordinate of the centroid is determined according to the proportion of the area of ​​the small area where each point is located to the whole area.

[0126] Among them, (xh ,y h ) is the coordinate of the hth point on the boundary of the infrared leakage area; (x h ,y h )∈S; h is the serial number of different points on the boundary of the infrared leakage area, and its value is [1, g]; g is the total number of boundary points, and g is a positive integer; (E m , F m ) is the centroid coordinate of the infrared leakage area at time m; m is the serial number corresponding to different time points, and its value is a positive integer; w h is the boundary point (x h ,y h ) is calculated based on the parameters of the imaging device and the corresponding relationship between the actual size of the shooting scene and the pixels.

[0127] Step 205: The method for calculating the gas diffusion velocity V is:

[0128] According to the centroid coordinates (E m , F m ) Calculate the gas diffusion velocity V, the specific method is:

[0129]

[0130] It should be noted that this formula is based on the velocity formula, that is, velocity is equal to the ratio of displacement to time, and the center of mass coordinates (E m , F m ) in the x-axis and y-axis directions, thereby obtaining the gas diffusion velocity V.

[0131] Among them, (E m+k , F m+k ) is the centroid coordinate of the leakage area at time m+k. According to the centroid coordinate (E m , F m ) calculation formula. Δt is the time interval; k is the number of frames in the time interval, which is determined by the settings of the image acquisition device and can usually be obtained in the parameter configuration of the device.

[0132] Step 206: The method for calculating the optical leakage area range U is:

[0133] The infrared gas cloud image data also includes the infrared imaging system coordinates (X IR , Y IR ), infrared imaging system focal length f IR , infrared imaging horizontal resolution M IR And the vertical resolution of infrared imaging N IR .

[0134] The optical gas cloud image data at least includes the optical imaging system coordinates (X O , YO ), focal length f of optical imaging system O , optical imaging horizontal resolution M O and the optical imaging vertical resolution N O .

[0135] It should be noted that the infrared imaging system coordinates (X IR , Y IR ) and the optical imaging system coordinates (X O , Y O ) are the coordinate values ​​of the origin of the infrared gas cloud image coordinate system and the origin of the optical gas cloud image coordinate system in actual space, which are determined by measurement and positioning during equipment installation and calibration. The focal length of the infrared imaging system f IR , infrared imaging horizontal resolution M IR , infrared imaging vertical resolution N IR , focal length of optical imaging system f O , optical imaging horizontal resolution M O and the optical imaging vertical resolution N O Determined by the hardware parameters of the imaging system and determined by consulting the technical specifications of the device.

[0136] According to the infrared imaging system coordinates (X IR , Y IR ), infrared imaging system focal length f IR , infrared imaging horizontal resolution M IR , infrared imaging vertical resolution N IR , boundary point coordinates (x h ,y h ), optical imaging system coordinates (X O , Y O ), focal length f of optical imaging system O , optical imaging horizontal resolution M O and the optical imaging vertical resolution N O Calculate the coordinates of the boundary points of the optical gas cloud image (c h , d h ), the specific method is:

[0137]

[0138] It should be noted that this formula is based on the principle of similar triangles. is the horizontal scaling factor in the optical imaging system, To consider the horizontal position adjustment value after the boundary point coordinates in the infrared imaging system, finally subtract X O This position is converted from the coordinate system of the infrared imaging system to the coordinate system of the optical imaging system to obtain the horizontal coordinate c under the optical imaging system. h . is the scaling factor in the vertical direction of the optical imaging system, To consider the vertical position adjustment value after the boundary point coordinates in the infrared imaging system, subtract Y O This position is converted from the coordinate system of the infrared imaging system to the coordinate system of the optical imaging system to obtain the vertical coordinate d under the optical imaging system. h .

[0139] Among them, (c h , d h ) is the optical gas cloud image coordinate corresponding to the hth point on the boundary of the infrared leakage area; the coordinates of the boundary points of the optical gas cloud image (c h , d h ) and the coordinates of all pixel points within the boundary point constitute the optical leakage area range U.

[0140] Step 207: The method for calculating the color shift index RGB is:

[0141] The optical gas cloud image data also includes the number of pixels p in the optical leakage area U, the red value Red a , Green value Green a and Blue a .

[0142] It should be noted that the red value Red a Refers to the intensity of red in the pixel, and the green value Green a Refers to the intensity of green in the pixel, blue value Blue a Refers to the intensity of blue in the pixel. The number of pixels p in the optical leakage area range U, the red value Red a , Green value Green a and Blue a The images were extracted using image processing software.

[0143] According to the red value Red a Calculate the red dispersion σ R :

[0144]

[0145] It should be noted that the operating principle of this formula is: The red dispersion σ is obtained by calculating the sum of the difference between the red value of each pixel in the optical leakage area U and the average value and dividing it by the total number of pixels. R .

[0146] Among them, Red ais the red value of the ath pixel in the optical leakage area U; a is the serial number corresponding to different pixels in the optical leakage area U, and its value is p1, p]; p is the total number of pixels in the optical leakage area U, and its value is a positive integer;

[0147] According to the green value Green a Calculate the green dispersion σ G :

[0148]

[0149] It should be noted that the operating principle of this formula is: The green dispersion σ is obtained by calculating the sum of the difference between the green value of each pixel in the optical leakage area U and the average value and dividing it by the total number of pixels. G .

[0150] Among them, Green a is the green value of the ath pixel in the optical leakage area U;

[0151] According to the blue value Blue a Calculate the blue dispersion σ B :

[0152]

[0153] It should be noted that the operating principle of this formula is: The blue dispersion σ is obtained by calculating the sum of the differences between the blue value of each pixel in the optical leakage area U and the average value and dividing it by the total number of pixels. B .

[0154] Among them, Blue a It is the blue value of the a-th pixel in the optical leakage area U.

[0155] According to the red dispersion σ R , green dispersion σ G and the blue dispersion σ B Calculate the color shift index RGB as follows:

[0156]

[0157] It should be noted that this formula takes into account the red dispersion σ R , green dispersion σ G and the blue dispersion σ B, and obtain the color shift index RGB. The larger the color shift index RGB is, the higher the color shift is, and the more serious the gas leakage is.

[0158] Step 208: The method for calculating the gas diffusion index L is:

[0159] According to the coordinates of the boundary points of the optical gas cloud image (c h , d h ) Calculate the perimeter b of the leakage area in the following way:

[0160] c min =min{c h |c h ∈(c h , d h )}

[0161] c max =max{c h |c h ∈(c h , d h )}

[0162] d min =min{d h |d h ∈(c h , d h )}

[0163] d max =max{d h |d h ∈(c h , d h )}

[0164] b=[(c max -c min )+(d max -d min )]×2

[0165] It should be noted that the operating principle of this formula is: the leakage area is equivalent to a rectangle, and by traversing the coordinates of the pixel points in the leakage area, the minimum value of the horizontal coordinate, the maximum value of the horizontal coordinate, the minimum value of the vertical coordinate, and the maximum value of the vertical coordinate are found. The difference between the maximum value of the horizontal coordinate and the minimum value of the horizontal coordinate is the width of the equivalent rectangle, and the difference between the maximum value of the vertical coordinate and the minimum value of the vertical coordinate is the length of the equivalent rectangle. According to the rectangle perimeter formula, the perimeter b of the leakage area is obtained.

[0166] Among them, c min is the minimum horizontal coordinate of the boundary point coordinates of the optical gas cloud image; c max is the maximum horizontal coordinate of the boundary point coordinates of the optical gas cloud image; d min is the minimum ordinate of the boundary point coordinates of the optical gas cloud image; dmax is the maximum ordinate of the boundary point coordinates of the optical gas cloud image;

[0167] The gas diffusion index L is calculated based on the number of pixels p and the perimeter b of the leakage area. The specific method is:

[0168]

[0169] It should be noted that this formula is based on the concept of circularity, and the gas diffusion index L is obtained according to the ratio of the number of pixels p and the square of the perimeter b of the leakage area. The gas diffusion index L is used to measure the gas diffusion range. The larger the gas diffusion index L, the larger the gas diffusion range.

[0170] Combined with the contents of step 201 to step 208:

[0171] Determining the infrared leakage area range S based on the temperature gradient amplitude threshold CH and the temperature gradient amplitude AB (x, y) can more accurately locate the temperature anomaly area near the leakage source, which helps to find potential leakage points in time; calculating the temperature anomaly index J based on the infrared gas cloud image can quantify the degree of temperature change caused by gas leakage. By calculating the gas diffusion velocity V, the diffusion process of gas leakage can be dynamically tracked. By calculating the color shift index RGB, the distribution of leaked gas can be reflected from the perspective of color characteristics. By calculating the gas diffusion index L, the dynamic characteristics of the leakage can be better understood. These quantitative indicators provide intuitive data support for staff.

[0172] Step 3: Calculate the leakage degree assessment index K according to the temperature anomaly index J, the gas diffusion velocity V, the color shift index RGB and the color gas diffusion index L; preset the leakage degree threshold set; judge the gas leakage degree according to the leakage degree assessment index K and the leakage degree threshold set; determine the remedial measures according to the gas leakage degree.

[0173] Step 301: The method for determining the gas leakage degree according to the leakage degree assessment index K and the leakage degree threshold set is:

[0174] The leakage evaluation index K is calculated based on the temperature anomaly index J, gas diffusion velocity V, color shift index RGB and gas diffusion index L. The standard is:

[0175] K=β1×J+β2×V+β3×RGB+β4×L

[0176] It should be noted that the formula comprehensively considers the influence of the temperature anomaly index J, the gas diffusion velocity V, the color shift index RGB and the gas diffusion index L according to the weighted formula, thereby obtaining the leakage degree assessment index K. The larger the leakage degree assessment index K is, the more serious the leakage is.

[0177] Among them, β1 is the weight coefficient of the temperature anomaly index J, and its value is 0.2~0.4, which is determined according to the influence of the temperature anomaly index J on the leakage degree assessment index K. β2 is the weight coefficient of the gas diffusion velocity V, and its value is 0.3~0.4, which is determined according to the influence of the gas diffusion velocity V on the leakage degree assessment index K. β3 is the weight coefficient of the color shift index RGB, and its value is 0.2~0.3, which is determined according to the influence of the color shift index RGB on the leakage degree assessment index K. β4 is the weight coefficient of the gas diffusion index L, and its value is 0.1~0.3, which is determined according to the influence of the gas diffusion index L on the leakage degree assessment index K. And β1+β2+β3+β4=1;

[0178] The leakage degree threshold set includes a severe leakage threshold KZ and a mild leakage threshold KQ.

[0179] The degree of gas leakage is determined based on the leakage degree assessment index K and the leakage degree threshold set. The specific method is as follows:

[0180]

[0181] It should be noted that the method for determining the severe leakage threshold KZ and the mild leakage threshold KQ is to collect records of hazardous gas leakage accidents that occurred in chemical parks, factories or other relevant places in the past, including accident reports, monitoring data, on-site photos and videos, etc. Organize these data, calculate the historical leakage degree assessment index according to the above method, and further calculate the median, mean and standard deviation of the historical leakage degree assessment index. The severe leakage threshold KZ is determined by referring to the smaller value of the median and the mean, and the mild leakage threshold KQ is determined by referring to the value of the mean minus the standard deviation.

[0182] Combined with the content of step 301:

[0183] The leakage degree assessment index K is calculated based on the temperature anomaly index J, gas diffusion rate V, color shift index RGB and color gas diffusion index L. It can comprehensively measure the severity of gas leakage from multiple key dimensions, avoid the limitation of single factor judgment, and solve the problem of misjudgment caused by judging whether gas leakage occurs only by a single temperature feature; judge the degree of gas leakage based on the leakage degree assessment index K and the leakage degree threshold set; determine the remedial measures based on the degree of gas leakage, so that the staff can take targeted measures according to the specific degree of leakage, thereby enhancing the accuracy of emergency decision-making.

[0184] In another embodiment, the present invention further discloses an intelligent monitoring system for hazardous gas leakage based on gas cloud imaging, which may include the following main modules:

[0185] An image data generation module, which can monitor hazardous gases in chemical parks based on infrared imaging technology and optical imaging technology and generate infrared gas cloud image data and optical gas cloud image data;

[0186] The index calculation module can calculate the horizontal temperature gradient A based on the infrared gas cloud image data x (x, y) and vertical temperature gradient B x (x, y), and further calculate the temperature gradient amplitude AB(x, y); preset the temperature gradient amplitude threshold CH; determine the infrared leakage area range S according to the temperature gradient amplitude threshold CH and the temperature gradient amplitude AB(x, y); calculate the temperature anomaly index J based on the infrared gas cloud image;

[0187] Use image processing algorithms to identify the image boundary of the infrared leakage area S and obtain the coordinates of the boundary points (x h ,y h ); According to the boundary point coordinates (x h ,y h ) Calculate the coordinates of the center of mass (E m , F m ), and further calculate the gas diffusion velocity V;

[0188] Based on the infrared gas cloud image and optical gas cloud image data, the coordinates of the boundary points of the optical gas cloud image (c h , d h ); Coordinates of boundary points of statistical optical gas cloud image (c h , d h ) and the coordinates of all pixels within the boundary point constitute the optical leakage area range U; the red discreteness σ is calculated based on the optical gas cloud image data R , green dispersion σ G and the blue dispersion σ B , and further calculate the color shift index RGB;

[0189] According to the coordinates of the boundary points of the optical gas cloud image (c h , d h ) Calculate the perimeter b of the leakage area and further calculate the gas diffusion index L;

[0190] The judgment module can calculate the leakage degree assessment index K according to the temperature anomaly index J, the gas diffusion speed V, the color shift index RGB and the color gas diffusion index L; preset the leakage degree threshold set; judge the gas leakage degree according to the leakage degree assessment index K and the leakage degree threshold set; determine the remedial measures according to the gas leakage degree.

[0191] Furthermore, in the present system, various functional modules can work in coordination with each other to execute the method for intelligent monitoring of hazardous gas leakage as described in the above embodiments.

[0192] Furthermore, the system may also include an alarm module to interact with remote terminals (such as personal digital terminals, mobile phones, remote control centers, etc.) in a wired or wireless manner, send or upload monitoring data in a timely manner, and send alarm signals after leaks are detected, so as to promptly remind monitoring personnel to take emergency measures.

[0193] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination thereof. When implemented using software, the above embodiments may be implemented in whole or in part in the form of a computer program product. A person of ordinary skill in the art may appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein may be implemented in electronic hardware or in combination with computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution.

[0194] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0195] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. An intelligent monitoring method for hazardous gas leakage based on gas cloud imaging, characterized in that: The following steps are involved: Based on infrared imaging technology and optical imaging technology, hazardous gas monitoring is carried out in chemical parks and infrared gas cloud image data and optical gas cloud image data are generated; Calculation of horizontal temperature gradient A based on infrared gas cloud image data x (x, y) and vertical temperature gradient B x (x, y), and further calculate the temperature gradient amplitude AB(x, y); preset the temperature gradient amplitude threshold CH; determine the infrared leakage area range S according to the temperature gradient amplitude threshold CH and the temperature gradient amplitude AB(x, y); Calculate temperature anomaly index J based on infrared gas cloud images; Use image processing algorithms to identify the image boundary of the infrared leakage area S and obtain the coordinates of the boundary points (x h ,y h ); According to the boundary point coordinates (x h ,y h ) Calculate the coordinates of the center of mass (E m , F m ), and further calculate the gas diffusion velocity V; Based on the infrared gas cloud image and optical gas cloud image data, the coordinates of the boundary points of the optical gas cloud image (c h , d h ); Coordinates of boundary points of statistical optical gas cloud image (c h , d h ) and the coordinates of all pixels within the boundary point constitute the optical leakage area range U; the red discreteness σ is calculated based on the optical gas cloud image data R , green dispersion σ G and the blue dispersion σ B , and further calculate the color shift index RGB; According to the coordinates of the boundary points of the optical gas cloud image (c h , d h ) Calculate the perimeter b of the leakage area and further calculate the gas diffusion index L; Calculate the leakage degree assessment index K according to the temperature anomaly index J, gas diffusion speed V, color shift index RGB and color gas diffusion index L; preset the leakage degree threshold set; judge the gas leakage degree according to the leakage degree assessment index K and the leakage degree threshold set; determine the remedial measures according to the gas leakage degree.

2. The intelligent monitoring method for dangerous gas leakage based on gas cloud imaging according to claim 1 is characterized by: The method for calculating the temperature gradient amplitude AB(x, y) is: The infrared gas cloud image data at least includes infrared pixel points (x, y) and temperature T (x, y); Calculate the horizontal temperature gradient A according to the temperature T(x, y) x (x, y), the formula is: A x (x,y)=T(x+1,y)-T(x,y) Among them, A x (x, y) is the temperature gradient in the horizontal direction of the pixel point (x, y) in the infrared gas cloud image data; T(x, y) is the temperature value of the pixel point (x, y) in the infrared gas cloud image data; T(x+1, y) is the temperature value of the pixel point (x+1, y) in the infrared gas cloud image data; Calculate the vertical temperature gradient B based on the temperature T(x, y) x (x, y), the formula is: B x (x,y)=T(x,y+1)-T(x,y) Among them, B x (x, y) is the temperature gradient in the vertical direction of the pixel point (x, y) in the infrared gas cloud image data; T(x, y+1) is the temperature value of the pixel point (x, y+1) in the infrared gas cloud image data; According to the horizontal temperature gradient A x (x, y) and vertical temperature gradient B x (x, y) to calculate the temperature gradient amplitude AB(x, y), based on the formula: Wherein, AB(x, y) is the temperature gradient amplitude of the pixel point (x, y) in the infrared gas cloud image data.

3. The intelligent monitoring method for dangerous gas leakage based on gas cloud imaging according to claim 1 is characterized by: The method for determining the infrared leakage area range S is: The infrared leakage area range S is determined according to the temperature gradient amplitude threshold CH and the temperature gradient amplitude AB (x, y), and the specific method is as follows: S = {(x, y) | L(x, y) = 1} 4. The intelligent monitoring method for dangerous gas leakage based on gas cloud imaging according to claim 1 is characterized by: The method for calculating the temperature anomaly index J is: The infrared gas cloud image data also includes the average temperature of the infrared leakage area S Temperature standard deviation σ of infrared leakage area S T and the average temperature of the area not affected by the leak According to the average temperature Temperature standard deviation σ of infrared leakage area S T and average temperature Calculate the temperature anomaly index J in the following way:

5. The intelligent monitoring method for dangerous gas leakage based on gas cloud imaging according to claim 1 is characterized by: Calculate the coordinates of the center of mass (E m , F m ) is: According to the boundary point coordinates (x h ,y h ) Calculate the coordinates of the center of mass (E m , F m ), the specific method is: Among them, (x h ,y h ) is the coordinate of the hth point on the boundary of the infrared leakage area; (x h ,y h )∈S; h is the serial number of different points on the boundary of the infrared leakage area, and its value is [1, g]; g is the total number of boundary points, and g is a positive integer; (E m , F m ) is the centroid coordinate of the infrared leakage area at time m; m is the serial number corresponding to different time points, and its value is a positive integer; w h is the boundary point (x h ,y h ) is located.

6. The intelligent monitoring method for hazardous gas leakage based on gas cloud imaging according to claim 1 is characterized by: The method for calculating the gas diffusion velocity V is: According to the centroid coordinates (E m , F m ) Calculate the gas diffusion velocity V, the specific method is: Among them, (E m+k , F m+k ) is the centroid coordinate of the leakage area at time m+k; Δt is the time interval; k is the number of frames in the time interval.

7. The intelligent monitoring method for hazardous gas leakage based on gas cloud imaging according to claim 1 is characterized by: The method for calculating the optical leakage area range U is: The infrared gas cloud image data also includes the infrared imaging system coordinates (X IR , Y IR ), infrared imaging system focal length f IR , infrared imaging horizontal resolution M IR And the vertical resolution of infrared imaging N IR ; The optical gas cloud image data at least includes the optical imaging system coordinates (X O , Y O ), focal length f of optical imaging system O , optical imaging horizontal resolution M O and the optical imaging vertical resolution N O ; According to the infrared imaging system coordinates (X IR , Y IR ), infrared imaging system focal length f IR , infrared imaging horizontal resolution M IR , infrared imaging vertical resolution N IR , boundary point coordinates (x h ,y h ), optical imaging system coordinates (X O , Y O ), focal length f of optical imaging system O , optical imaging horizontal resolution M O and the optical imaging vertical resolution N O Calculate the coordinates of the boundary points of the optical gas cloud image (c h , d h ), the specific method is: Among them, (c h , d h ) is the optical gas cloud image coordinate corresponding to the hth point on the boundary of the infrared leakage area; the coordinates of the boundary points of the optical gas cloud image (c h , d h ) and the coordinates of all pixel points within the boundary point constitute the optical leakage area range U.

8. The intelligent monitoring method for dangerous gas leakage based on gas cloud imaging according to claim 7 is characterized by: The method for calculating the color shift index RGB is: The optical gas cloud image data also includes the number of pixels p in the optical leakage area U, the red value Red a , Green value Green a and Blue a ; According to the red value Red a Calculate the red dispersion σ R : Among them, Red a is the red value of the ath pixel in the optical leakage area U; a is the serial number corresponding to different pixels in the optical leakage area U, and its value is [1, p]; p is the total number of pixels in the optical leakage area U, and its value is a positive integer; According to the green value Green a Calculate the green dispersion σ G : Among them, Green a is the green value of the ath pixel in the optical leakage area U; According to the blue value Blue a Calculate the blue dispersion σ B : Among them, Blue a is the blue value of the a-th pixel in the optical leakage area U; According to the red dispersion σ R , green dispersion σ G and the blue dispersion σ B Calculate the color shift indicator RGB:

9. The intelligent monitoring method for hazardous gas leakage based on gas cloud imaging according to claim 1 is characterized by: The method for calculating the gas diffusion index L is: According to the coordinates of the boundary points of the optical gas cloud image (c h , d h ) Calculate the perimeter b of the leakage area in the following way: c min =min{c h |c h ∈(c h ,d h )} c max =max{c h |c h ∈(c h ,d h )} the min =min{d h |d h ∈(c h ,d h )} d max =max{d h |[d h ∈(c h ,d h )} b=[(C max -c min )+(d max -d min )]×2 Among them, c min is the minimum horizontal coordinate of the boundary point coordinates of the optical gas cloud image; C max is the maximum horizontal coordinate of the boundary point coordinates of the optical gas cloud image; d min is the minimum ordinate of the boundary point coordinates of the optical gas cloud image; d max is the maximum ordinate of the boundary point coordinates of the optical gas cloud image; Calculate the gas diffusion index L based on the number of pixels p and the perimeter b:

10. The intelligent monitoring method for hazardous gas leakage based on gas cloud imaging according to claim 1 is characterized in that: The method for judging the degree of gas leakage according to the leakage degree assessment index K and the leakage degree threshold set is: The leakage evaluation index K is calculated based on the temperature anomaly index J, gas diffusion velocity V, color shift index RGB and gas diffusion index L. The standard is: K=β1×J+β2×V+β3×RGB+β4×L Among them, β1 is the weight coefficient of the temperature anomaly index J, which is 0.2-0.4; β2 is the weight coefficient of the gas diffusion velocity V, which is 0.3-0.4; β3 is the weight coefficient of the color shift index RGB, which is 0.2-0.3; β4 is the weight coefficient of the gas diffusion index L, which is 0.1-0.3; and β1+β2+β3+β4=1; The leakage degree threshold set includes a severe leakage threshold KZ and a mild leakage threshold KQ; The degree of gas leakage is determined based on the leakage degree assessment index K and the leakage degree threshold set, and the formula is as follows:

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