Infrared calibration temperature measurement method based on multi-component insulating gas multispectral imaging device

Abstract

The invention discloses an infrared calibration temperature measurement method based on a multi-component insulating gas multispectral imaging device, belongs to the technical field of electric power safety detection, and solves the problem of how to improve the temperature measurement precision of electric power equipment. The non-uniformity correction calibrates the response and bias of each pixel to the same numerical value, the temperature correction eliminates the influence of the lens temperature and the movement temperature on the received electric signal, the shading shutter correction ensures the accuracy and consistency of the shutter or the shading system, the radiation calibration is adopted to convert the measured blackbody voltage value into the temperature value, and the temperature value is converted into the temperature value. The real temperature of the surface of the detected electrical equipment is calculated by combining the temperature value after radiometric calibration conversion, the influence of the atmospheric environment on temperature measurement is eliminated, and the temperature measurement function of the electrical equipment based on an infrared multispectral imaging detector for insulating gas leakage in a complex environment can be realized. And a foundation is laid for further forming portable power multifunctional monitoring.

Description

Technical Field

[0001] The present invention belongs to the technical field of power safety detection, and relates to an infrared calibration temperature measurement method based on a multi-component insulating gas multi-spectral imaging device. Background Art

[0002] For power equipment in substations, such as transformers, switchgear, etc., monitoring their temperature changes is crucial for ensuring the safe operation of the equipment and is an important means to ensure the safe operation of the equipment and prevent failures. Monitoring the temperature changes of power equipment can timely detect overheating of the equipment to avoid damage or fire; through temperature control, the aging of the equipment can be slowed down and potential failures can be detected in advance. The existing temperature measurement methods mainly use infrared thermometers and infrared thermal imagers to measure the temperature of power equipment. This method is greatly interfered by environmental factors, has low measurement accuracy for power equipment with complex surfaces, and cannot meet the requirements of the current power system for higher and higher power equipment condition monitoring and fault diagnosis scenarios. Summary of the Invention

[0003] The technical solution of the present invention is used to solve the problem of how to improve the accuracy of temperature measurement of power equipment.

[0004] The present invention solves the above technical problems through the following technical solutions:

[0005] The present invention provides an infrared calibration temperature measurement method based on a multi-component insulating gas multi-spectral imaging device, including:

[0006] S1 Measure the infrared original voltage value of the power scene. After non-uniformity correction, temperature correction, and shading shutter correction, the measured infrared original voltage value of the power scene is converted into a temperature value by radiation calibration;

[0007] S2 Perform infrared temperature measurement on the power equipment, and calculate the true temperature of the surface of the measured power equipment in combination with the temperature value after radiation calibration. The calculation formula is as follows:

[0008]

[0009] Assume that the power equipment is a gray body, then ε = α, the atmospheric emissivity ε a = 1 - τ a , the atmospheric temperature is equal to the ambient temperature, that is, T a = T0, then there is:

[0010]

[0011] Among them, ε is the surface emissivity, T u is the true temperature of the power equipment, τ a is the atmospheric transmittance, α is the absorptivity of the surface of the power equipment to environmental radiation, T0 is the ambient temperature, ε ais the atmospheric emissivity, and T a is the atmospheric temperature, and n is the infrared band parameter.

[0012] Furthermore, the multi-component insulating gas multi-spectral imaging device includes: a visible light camera (11), a laser ranging module (12), an infrared imaging lens (13), a multi-spectral filter wheel (14), an infrared imaging detector (15), a signal processing board (16), a lithium battery (17), and a flip-up display screen (18); the visible light camera (11) is used to collect video images of the power scene, providing a visible light scene background map for infrared detection of insulating gas leakage on the one hand and expanding the multi-functional video monitoring function of the power scene on the other hand; the laser ranging module (12) is used to measure the distance between the device and the power equipment; the infrared imaging lens (13) is used to adjust the infrared imaging field of view of the insulating gas; multiple broadband filters are installed on the multi-spectral filter wheel (14) for extracting the infrared characteristics of the multi-component insulating gas; the infrared imaging detector (15) is used to collect infrared images of the power scene of the multi-component insulating gas; the signal processing board (16) is used to process the data of the infrared imaging of the multi-component insulating gas; the lithium battery (17) is used to supply power to the device; and the flip-up display screen (18) is used to display the imaging result.

[0013] Furthermore, the formula for converting the measured voltage value to a temperature value by radiation calibration is as follows:

[0014]

[0015] where T r is the temperature value after radiation calibration conversion, and U ( ″ i ′ ,j) is the voltage value after shading shutter correction, d3, d2, and d1 are all calibration coefficients, and d0 is a constant.

[0016] Furthermore, the method of non-uniformity correction is as follows:

[0017] Under the indoor normal temperature environment, measure two blackbodies at different temperatures to obtain voltages U 1,(i,j) and U 2,(i,j) , where (i, j) represents the pixel coordinates;

[0018] Calculate the average voltage of all pixels and

[0019]

[0020] where M×N is the number of pixels set by the infrared imaging detector;

[0021] Let the original voltage measured by pixel (i, j) be U (i,j), the voltage after non-uniformity correction is U′ (i,j) , then the following relationship exists:

[0022]

[0023] Then it is obtained that:

[0024]

[0025] Furthermore, the method of temperature correction is as follows:

[0026] Establish a non-linear model formula for the voltage U ( ′ i,j) after non-uniformity correction, the lens temperature T C and the module temperature T s as follows:

[0027]

[0028] Set different ambient temperatures respectively, and obtain the lens temperature and the module temperature after the device is stable;

[0029] At the same temperature, measure the blackbody voltage values at 3 temperatures respectively;

[0030] According to the formula of the non-linear model, use the least square method to calculate the correction coefficients related to the module and the correction coefficients related to the lens;

[0031] According to the obtained correction coefficients related to the module and the correction coefficients related to the lens, and combined with the current lens temperature T C ′ and the current module temperature T s ′, calculate the voltage value U ( ″ i,j) after temperature correction, and the calculation formula is as follows:

[0032]

[0033] In the formula, a 3,(i,j) , a 2,(i,j) , a 1,(i,j) represent the correction coefficients related to the module; b 2,(i,j) , b 1,(i,j) represent the correction coefficients related to the lens, and c is a constant coefficient.

[0034] Furthermore, the method of shading shutter correction is as follows:

[0035] Turn the shutter into the field of view of the infrared imaging detector and measure the shutter voltage value;

[0036] The voltage value U ( ″ i,j), subtract the shutter voltage value to obtain the voltage value U after shading shutter correction ( ″ i ′ ,j) , and the calculation formula is as follows:

[0037] U ( ′ i ″ ,j) =U ( ″ i,j) -U sh

[0038] wherein, U sh represents the measured shutter voltage value.

[0039] The present invention also provides an electronic device, including a memory and a processor. The memory is used to store a program that supports the processor to execute the above infrared calibration temperature measurement method based on the multi-component insulating gas multi-spectral imaging device, and the processor is configured to execute the program stored in the memory.

[0040] The present invention also provides a storage medium, on which a computer program is stored. When the computer program is run by a processor, it executes the steps of the above infrared calibration temperature measurement method based on the multi-component insulating gas multi-spectral imaging device.

[0041] The beneficial effects of the present invention are as follows:

[0042] The method of the present invention measures the infrared original voltage value of the power scene, performs non-uniformity correction, temperature correction, and shading shutter correction on it. The non-uniformity correction calibrates the responses and biases of each pixel to the same value. The temperature correction eliminates the influence of the received electrical signal by the lens temperature and the movement temperature. The shading shutter correction ensures the accuracy and consistency of the shutter or the shading system. The radiation calibration is used to convert the measured infrared original voltage value of the power scene into a temperature value. Combining the temperature value after radiation calibration conversion, the true temperature of the surface of the measured power equipment is calculated, eliminating the influence of the atmospheric environment on temperature measurement. The present invention can realize the temperature measurement function of power equipment based on the infrared multi-spectral imaging detector for insulating gas leakage in a complex environment, laying a foundation for further forming a portable power multi-functional monitoring. Description of the Drawings

[0043] Figure 1 is the front three-dimensional view of the multi-component insulating gas multi-spectral imaging device in Embodiment 1 of the present invention;

[0044] Figure 2 is the rear three-dimensional view of the multi-component insulating gas multi-spectral imaging device in Embodiment 1 of the present invention;

[0045] Figure 3 is the internal structure three-dimensional view of the multi-component insulating gas multi-spectral imaging device in Embodiment 1 of the present invention;

[0046] Figure 4 It is a flowchart of the radiation calibration and correction method for the infrared calibration temperature measurement method of the multi-component insulating gas multispectral imaging device in the second embodiment of the present invention;

[0047] Figure 5 It is the test effect diagram of non-uniformity correction;

[0048] Figure 6 It is the temperature measurement effect diagram of typical power equipment. Specific embodiments

[0049] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0050] The technical solutions of the present invention will be further described below in conjunction with the specification drawings and specific embodiments:

[0051] Embodiment 1

[0052] The embodiment of the present invention provides a multi-component insulating gas multispectral imaging device, as Figures 1 to 3 shown, including: visible light camera 11, laser ranging module 12, infrared imaging lens 13, multispectral filter wheel 14, infrared imaging detector 15, signal processing board 16, lithium battery 17, flip-up display screen 18; the visible light camera 11 is used to collect power scene video images, on the one hand, providing a visible light scene background map for infrared detection of insulating gas leakage, and on the other hand, expanding the multi-functional video monitoring function of the power scene; the laser ranging module 12 is used to measure the distance between the device and the power equipment; the infrared imaging lens 13 is used for adjusting the infrared imaging field of view of the insulating gas; a plurality of broadband filters are installed on the multispectral filter wheel 14 for extracting the infrared characteristics of the multi-component insulating gas; the infrared imaging detector 15 is used to collect the infrared images of the power scene of the multi-component insulating gas; the signal processing board 16 is used to process the data of the infrared imaging of the multi-component insulating gas; the lithium battery 17 is used to supply power to the device; the flip-up display screen 18 is used to display the imaging results.

[0053] Embodiment 2

[0054] The embodiment of the present invention provides an infrared calibration temperature measurement method based on the multi-component insulating gas multispectral imaging device in Embodiment 1, specifically including the following steps:

[0055] 1. Radiation calibration and correction of the device

[0056] like Figure 4 As shown, the method of radiation calibration and correction includes the following:

[0057] 1) Non-uniformity correction

[0058] The response and bias of each pixel of the infrared imaging detector are different. The image displayed directly as a voltage value will show different grayscales due to different pixels. Non-uniformity correction is to calibrate the response and bias of each pixel to the same value.

[0059] Measure the blackbody voltage at two temperatures to obtain standard values ​​of response and bias. The specific process is as follows:

[0060] Under normal indoor temperature, measure two black bodies with different temperatures and get the voltage U 1,(i,j) and U 2,(i,j) , where (i,j) represents the pixel coordinates.

[0061] Calculate the average voltage of all pixels and

[0062]

[0063] Among them, M×N is the pixel set by the infrared imaging detector,

[0064] Let the original voltage measured by pixel (i, j) be U (i,j) , the voltage after non-uniformity correction is U′ (i,j) , then the following relationship exists:

[0065]

[0066] Then we get:

[0067]

[0068] The voltage after non-uniformity correction is U ( ' i,j) As input for the next step of temperature correction.

[0069] like Figure 5 As shown, Figure 5 The five columns of images are infrared images collected by filters 1 to 5 of the multi-spectral filter wheel; Figure 5 The first row of images is the original infrared image collected by filters 1 to 5 of the multispectral filter wheel. Figure 5 The second row of images is the infrared images after the non-uniformity correction of the original infrared images collected by filters 1 to 5 of the multispectral filter wheel. It can be seen that the image consistency is improved after correction.

[0070] 2) Temperature correction

[0071] The electrical signal received by the infrared imaging detector is affected by the lens temperature and the temperature of the camera core, which causes changes in the sensitivity and dark current of the electrical signal. Temperature changes need to be corrected.

[0072] Establish the voltage U ( ′ i,j) after non-uniformity correction and the non-linear model formula with the lens temperature T C and the temperature T s of the camera core is as follows:

[0073]

[0074] The temperature correction process is as follows:

[0075] ① Set different ambient temperatures respectively, and obtain the lens temperature and the temperature of the camera core after the device stabilizes;

[0076] ② Measure the blackbody voltage values at three temperatures respectively at the same temperature;

[0077] ③ Calculate the correction coefficient related to the camera core and the correction coefficient related to the lens by using the least square method according to formula (4);

[0078] ④ According to the correction coefficient related to the camera core and the correction coefficient related to the lens obtained in step ③, and combined with the current lens temperature T C ′ and the current temperature T s ′ of the camera core, calculate the voltage value U ( ″ i,j) after temperature correction, and the calculation formula is as follows:

[0079]

[0080] In the formula, a 3,(i,j) 、a 2,(i,j) 、a 1,(i,j) represent the correction coefficients related to the camera core; b 2,(i,j) 、b 1,(i,j) represent the correction coefficients related to the lens, and c is a constant coefficient.

[0081] 3) Shading shutter correction

[0082] The correction process is as follows:

[0083] ① Turn the shutter into the field of view of the infrared imaging detector and measure the shutter voltage value.

[0084] ② Subtract the shutter voltage value from the voltage value U ( ″ i,j) after temperature correction to obtain the voltage value U( ″ i ′ ,j) , the calculation formula is as follows:

[0085] U ( ′ i ″ ,j) = U ( ″ i,j) - U sh (6)

[0086] Wherein, U sh represents the measured shutter voltage value.

[0087] 4) Radiometric calibration

[0088] After non-uniformity correction, temperature correction, and light-shielding shutter correction, the measured voltage value of the infrared imaging detector is converted into a temperature value by radiometric calibration. The conversion formula is as follows:

[0089]

[0090] Wherein, T r is the temperature value after radiometric calibration conversion.

[0091] The process of radiometric calibration is as follows:

[0092] ① Place the blackbody at the front end of the device, set the blackbody temperature, and measure the blackbody voltage value after the device is stable;

[0093] ② Select the pixels in the blackbody area and calculate the average voltage value;

[0094] ③ Set two other different blackbody temperatures and repeat steps ① and ②;

[0095] ④ According to formula (7), calculate the calibration coefficients d3, d2, d1, where d0 is a constant.

[0096] 2. Infrared temperature measurement of power equipment

[0097] Use a multi-component insulating gas multi-spectral imaging device to perform infrared temperature measurement on power equipment, and combine the temperature value after radiometric calibration conversion to calculate the true temperature of the surface of the power equipment under test. The calculation formula is as follows:

[0098]

[0099] Assume that the power equipment is a gray body, then ε = α, and the atmospheric emissivity ε a = 1 - τ a ; The distances between the multi-component insulating gas multi-spectral imaging device and the power equipment under test from the ground are both within a dozen meters. Therefore, it is considered that the atmospheric temperature is equal to the ambient temperature, that is, T a = T0, then there is:

[0100]

[0101] where ε is the surface emissivity, T u is the true temperature of the power equipment, τ a is the atmospheric transmittance, α is the absorptivity of the surface of the power equipment to environmental radiation, T0 is the environmental temperature, ε a is the atmospheric emissivity, T a is the atmospheric temperature, and n is the infrared band parameter.

[0102] Figure 6 is the temperature measurement effect diagram of typical power equipment. The method of the present invention can realize the temperature measurement function of power equipment based on an infrared multi-spectral imaging detector for insulating gas leakage in a complex environment, laying a foundation for further forming a portable multi-functional power monitor.

[0103] Embodiment III

[0104] An embodiment of the present invention provides an electronic device, including a memory and a processor. The memory is used to store a program that supports the processor to execute the infrared calibration temperature measurement method based on the multi-component insulating gas multi-spectral imaging device in Embodiment II, and the processor is configured to execute the program stored in the memory.

[0105] Embodiment IV

[0106] An embodiment of the present invention provides a storage medium, on which a computer program is stored. When the computer program is run by a processor, it executes the steps of the infrared calibration temperature measurement method based on the multi-component insulating gas multi-spectral imaging device in Embodiment II.

[0107] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An infrared calibration temperature measurement method based on a multi-component insulating gas multi-spectral imaging device, characterized in that: include: S1 measures the infrared raw voltage value of the power scene, and after non-uniformity correction, temperature correction, and light-shielding shutter correction, uses radiation calibration to convert the measured infrared raw voltage value of the power scene into a temperature value; S2 performs infrared temperature measurement on the power equipment and calculates the real surface temperature of the tested power equipment in combination with the temperature value converted by radiation calibration. The calculation formula is as follows: Assuming the power equipment is a gray body, then ε=α, and the atmospheric emissivity ε a =1-τ a , the atmospheric temperature is equal to the ambient temperature, that is, T a =T0, then: Where ε is the surface emissivity, T u is the actual temperature of the power equipment, τ a is the atmospheric transmittance, α is the surface absorptivity of the power equipment to the ambient radiation, T0 is the ambient temperature, ε a is the atmospheric emissivity, T a is the atmospheric temperature, and n is the infrared band parameter.

2. The infrared calibration temperature measurement method based on the multi-component insulating gas multi-spectral imaging device according to claim 1 is characterized in that: The multi-component insulating gas multi-spectral imaging device comprises: a visible light camera (11), a laser ranging module (12), an infrared imaging lens (13), a multi-spectral filter wheel (14), an infrared imaging detector (15), a signal processing board (16), a lithium battery (17), and a flip-able display screen (18); the visible light camera (11) is used to collect video images of power scenes, on the one hand to provide a visible light scene base map for insulating gas leakage infrared detection, and on the other hand to expand the multi-functional video monitoring function of the power scene; the laser ranging module (12) is used to measure the distance between the device and the power equipment; the infrared imaging lens (13) is used to adjust the insulating gas infrared imaging field of view; a plurality of broadband filters are installed on the multi-spectral filter wheel (14) to extract the infrared characteristics of the multi-component insulating gas; the infrared imaging detector (15) is used to collect infrared images of the power scene of the multi-component insulating gas; the signal processing board (16) is used to process the data of the infrared imaging of the multi-component insulating gas; the lithium battery (17) is used to power the device; and the flip-able display screen (18) is used to display the imaging results.

3. The infrared calibration temperature measurement method based on the multi-component insulating gas multi-spectral imaging device according to claim 2 is characterized in that: The formula for converting the measured voltage value to temperature value using radiation calibration is as follows: Among them, T r is the temperature value after radiation calibration conversion, U ( ″ i ' ,j) is the voltage value after the light-shielding shutter is corrected, d3, d2, and d1 are all calibration coefficients, and d0 is a constant.

4. The infrared calibration temperature measurement method based on the multi-component insulating gas multi-spectral imaging device according to claim 3 is characterized in that: The method of non-uniformity correction is as follows: Under normal indoor temperature, measure two black bodies with different temperatures and get the voltage U 1,(i,j) and U 2,(i,j) , where (i, j) represents the pixel coordinates; Calculate the average voltage of all pixels and Among them, M×N is the pixels set by the infrared imaging detector; Let the original voltage measured by pixel (i, j) be U (i,j) , the voltage after non-uniformity correction is U′ (i,j) , then the following relationship exists: Then we get:

5. The infrared calibration temperature measurement method based on the multi-component insulating gas multi-spectral imaging device according to claim 4 is characterized in that: The method of temperature correction is as follows: Establish the voltage U after non-uniformity correction ( ' i,j) and lens temperature T C and movement temperature T s The formula of the nonlinear model is as follows: Set different ambient temperatures respectively, and obtain the lens temperature and movement temperature after the device is stable; At the same temperature, measure the blackbody voltage values ​​at three temperatures respectively; According to the formula of the nonlinear model, the correction coefficients related to the core and the correction coefficients related to the lens are calculated using the least square method; According to the obtained correction coefficients related to the movement and the lens, combined with the current lens temperature T C ′ and the current movement temperature T s ', calculate the voltage value U after temperature correction ( ″ i,j) , the calculation formula is as follows: In the formula, a 3,(i,j) 、a 2,(i,j) 、a 1,(i,j) Represents the correction factor related to the movement; b 2,(i,j) 、b 1,(i,j) Represents the correction coefficient related to the lens, and c is a constant coefficient.

6. The infrared calibration temperature measurement method based on the multi-component insulating gas multi-spectral imaging device according to claim 5 is characterized in that: The method of shading shutter correction is as follows: Move the shutter into the field of view of the infrared imaging detector and measure the shutter voltage value; The voltage value after temperature correction is U ( ″ i,j) , minus the shutter voltage value, to get the voltage value U after light-shielding shutter correction ( ″ i ' ,j) , the calculation formula is as follows: IN ( ′ i " ,j) =U ( " i,j) -IN sh Among them, U sh Indicates the measured shutter voltage value.

7. An electronic device, comprising a memory and a processor, characterized in that: The memory is used to store a program that supports the processor to execute the infrared calibration temperature measurement method based on the multi-component insulating gas multi-spectral imaging device as described in any one of claims 1 to 6, and the processor is configured to execute the program stored in the memory.

8. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the infrared calibration temperature measurement method based on a multi-component insulating gas multi-spectral imaging device as described in any one of claims 1 to 6 are executed.

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