Flame temperature measurement method, device, equipment and medium based on radiation self-calibration

Abstract

The present invention provides a flame temperature measurement method, device, equipment and medium based on radiation self-calibration, and the method includes: obtaining color images of a calibrated temperature source at different temperatures based on a camera with a built-in color stripe filter, and extracting red and green channel pixel values; obtaining the dynamic range response curve of the camera based on the radiation self-calibration of the camera; obtaining the red and green channel irradiance values ​​of the color image based on the red and green channel pixel values ​​and the dynamic range response curve; calculating the camera instrument factor based on a two-color temperature measurement method combined with the real temperature corresponding to the color image and the red and green channel irradiance values; obtaining a flame image based on the camera, determining the red and green channel irradiance values ​​of the flame image, and obtaining the flame temperature distribution of each pixel point of the flame image based on the two-color temperature measurement method and combined with the red and green channel irradiance values ​​of the flame image and the camera instrument factor. The flame temperature measurement method based on radiation self-calibration provided by the present invention can take into account measurement cost, convenience and accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of flame temperature measurement, and in particular to a flame temperature measurement method, device, equipment and medium based on radiation self-calibration. Background Art

[0002] Combustion flames are widely used in various industrial processes such as metal smelting, military aviation, energy and power, chemical production, etc. Many engineering technologies have high requirements for temperature control and flame combustion. At the same time, the temperature of the flame directly affects the flame characteristics such as the height, width, and type of the flame. It is one of the most important characteristic parameters of the flame that is closely related to the performance of the combustion device. The needs of various industries are driving the development of flame combustion diagnostic technology, especially flame temperature diagnostic technology.

[0003] In order to measure and monitor the flame temperature, many technologies for measuring flame temperature have been developed in the past, which can be divided into two categories: invasive and non-invasive measurement. Invasive measurement, such as contact measurement methods using physical probes (such as thermocouples, resistance thermometers, and gas-filled probes), is easy to implement, but has obvious disadvantages: the temperature data obtained are limited and cannot fully reproduce the full picture of the flame temperature field; the high-temperature flame has a limited measurement range due to the material melting point requirements; the physical and chemical reactions generated when the probe contacts the flame interfere with the flame combustion conditions, affecting the flame flow field and measurement accuracy. Non-invasive measurement is not subject to this limitation. Commonly used non-invasive technologies include infrared pyrometers, laser-based technologies, and acoustic methods, but they are expensive and have limited conditions for use. The temperature measurement method using hyperspectral images and systems requires multiple hyperspectral cameras, spectroscopes, or liquid crystal tunable filters with different imaging bands to build a complex temperature measurement system. The measurement method using light field cameras and layered imaging technology requires high optical path requirements for the imaging system, and the layered imaging algorithm is complex. As for the image-based two-color temperature measurement method, the existing two-color temperature measurement method using narrow-band filters requires replacing filters and taking multiple shots. The two-color temperature measurement method based on a dual optical path structure to obtain monochromatic radiation intensity at different wavelengths requires the construction of a dual optical path structure, which has high requirements for the optical path and a complex imaging system. The above technologies all require the construction of a complex temperature measurement imaging system, which has additional requirements for cameras and optical paths, high costs, and complex designs. In addition, a two-color temperature measurement based on the pixel intensity ratio of flame images has been developed. This method only uses the grayscale output of the image to calculate the temperature, ignoring the relationship between the image pixel intensity and the flame radiation intensity, which increases the temperature measurement error.

[0004] In summary, the flame temperature measurement in the prior art cannot take into account the measurement cost, measurement convenience and measurement accuracy. Summary of the invention

[0005] In view of this, it is necessary to provide a flame temperature measurement method, device, equipment and medium based on radiation self-calibration to solve the technical problem that the flame temperature measurement in the prior art cannot take into account the measurement cost, measurement convenience and measurement accuracy.

[0006] In order to solve the above technical problems, on the one hand, the present invention provides a flame temperature measurement method based on radiation self-calibration, comprising:

[0007] Acquire color images of the calibrated temperature source at different temperatures based on a camera with a built-in color stripe filter, and extract red and green channel pixel values ​​of the color image;

[0008] Determine a camera response function of the camera based on radiometric self-calibration of the camera, and obtain a dynamic range response curve of the camera through the camera response function;

[0009] Acquire red and green channel irradiance values ​​of the color image based on red and green channel pixel values ​​and a dynamic range response curve of the color image;

[0010] The camera instrument factor is calculated based on a two-color temperature measurement method in combination with the real temperature of the calibration temperature source corresponding to the color image and the irradiance values ​​of the red and green channels;

[0011] A flame image is acquired based on the camera, and the red and green channel irradiance values ​​of the flame image are determined according to the red and green channel pixel values ​​of the flame image and a dynamic range response curve. Based on a two-color temperature measurement method and in combination with the red and green channel irradiance values ​​of the flame image and a camera instrument factor, the flame temperature distribution of each pixel point of the flame image is obtained.

[0012] In some possible implementations, the camera based on the built-in color stripe filter acquires a color image of the calibration temperature source, and extracts red and green channel pixel values ​​of the color image, including:

[0013] A Bayer pattern color filter array is coated on the sensor surface of the camera, wherein the Bayer pattern color filter array includes filters of three different colors: red, green, and blue;

[0014] The camera coated with the Bayer pattern color filter array stores the acquired image of the calibration temperature source in RAW mode and then converts it into an RGB color image;

[0015] Pixel values ​​of the red channel and the green channel are extracted from the color image.

[0016] In some possible implementations, determining a camera response function based on radiation self-calibration of the camera, and obtaining a dynamic range response curve of the camera through the camera response function includes:

[0017] Using the camera to acquire multiple images of the same static scene with different exposure times;

[0018] Based on the optical reciprocity of the imaging system, the camera response function between the digital pixel intensity and the exposure amount of the image is solved by singular value decomposition using the multiple images with different exposure times;

[0019] The dynamic range response curve of the camera is obtained through the camera response function, and the dynamic range response curve reflects the relationship between the target radiance and the pixel intensity.

[0020] In some possible implementations, the obtaining the red and green channel irradiance values ​​of the color image based on the red and green channel pixel values ​​and the dynamic range response curve of the color image includes:

[0021] Obtaining corresponding red and green channel exposures in a dynamic range response curve according to red and green channel pixel values ​​of the color image;

[0022] The red and green channel exposure values ​​of the color image are obtained by dividing the red and green channel exposure values ​​by the exposure time corresponding to the color image.

[0023] In some possible implementations, obtaining the real temperature of the calibration temperature source corresponding to the color image includes:

[0024] The brightness temperature and emissivity corresponding to the color image of the calibration temperature source at the different temperatures are obtained, and the real temperature of the calibration temperature source is determined according to the brightness temperature and emissivity of the calibration temperature source to obtain the real temperature of the calibration temperature source corresponding to the color image.

[0025] In some possible implementations, the camera instrument factor is calculated based on the two-color temperature measurement method in combination with the real temperature of the calibration temperature source corresponding to the color image and the irradiance values ​​of the red and green channels, including:

[0026] Determine the relationship between the monochromatic radiation power of the color image and the real temperature of the calibration temperature source based on Planck's radiation law and the emissivity, wherein the monochromatic radiation power includes the monochromatic radiation power at the central wavelength of the red channel and the monochromatic radiation power at the central wavelength of the green channel;

[0027] Based on paraxial geometric optics and the relationship between the monochromatic radiation power and the real temperature of the calibration temperature source, the irradiance values ​​of the red and green channels are compared to obtain the irradiance ratio of the red and green channels, and based on the irradiance ratio of the red and green channels, a two-color temperature measurement formula at the real temperature of the calibration temperature source is obtained;

[0028] The camera instrument factor is calculated based on the two-color temperature measurement formula, the irradiance ratio of the red and green channels, and the real temperature of the calibration temperature source.

[0029] In some possible implementations, the flame temperature distribution of each pixel of the flame image is obtained based on the two-color temperature measurement method and combined with the red and green channel irradiance values ​​of the flame image and the camera instrument factor, including:

[0030] Acquire the irradiance ratio of the red channel and the green channel of the flame image according to the irradiance values ​​of the red and green channels of the flame image;

[0031] The camera instrument factor and the irradiance ratio of the red and green channels of the flame image are substituted into the two-color temperature measurement formula to calculate the flame temperature distribution of each pixel of the flame image.

[0032] On the other hand, the present invention also provides a flame temperature measurement device based on radiation self-calibration, comprising:

[0033] An image acquisition module, used for acquiring color images of the calibrated temperature source at different temperatures based on a camera with a built-in color stripe filter, and extracting red and green channel pixel values ​​of the color image;

[0034] A response association module, used to determine a camera response function of the camera based on radiometric self-calibration of the camera, and obtain a dynamic range response curve of the camera through the camera response function;

[0035] An irradiance calculation module, used for obtaining irradiance values ​​of the red and green channels of the color image based on the red and green channel pixel values ​​and the dynamic range response curve of the color image;

[0036] A relationship building module, for calculating a camera instrument factor based on a two-color temperature measurement method in combination with a real temperature of a calibration temperature source corresponding to the color image and irradiance values ​​of red and green channels;

[0037] The target measurement module is used to obtain a flame image based on the camera, determine the red and green channel irradiance values ​​of the flame image according to the red and green channel pixel values ​​of the flame image and the dynamic range response curve, and obtain the flame temperature distribution of each pixel point of the flame image based on a two-color temperature measurement method and in combination with the red and green channel irradiance values ​​of the flame image and a camera instrument factor.

[0038] On the other hand, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the flame temperature measurement method based on radiation self-calibration described in the above implementation is implemented.

[0039] Finally, the present invention also provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the flame temperature measurement method based on radiation self-calibration described in the above implementation manner is implemented.

[0040] The beneficial effects of adopting the above-mentioned embodiment are as follows: the flame temperature measurement method based on radiation self-calibration provided by the present invention, on the one hand, uses a color camera with a built-in color stripe filter to measure temperature in combination with the camera dynamic range response curve and the red and green channel data of the color image, thereby avoiding the error of calculating the temperature value through the image grayscale output; on the other hand, the camera factor is obtained by calibrating the temperature source, and then the flame temperature distribution of the flame image is determined according to the camera factor and the red and green channel irradiance ratio of the flame image, thereby simplifying the complex method required for obtaining monochromatic irradiation intensity by using narrow-band filters or multi-light path settings and hyperspectral measurement or light field measurement. system; the flame temperature measurement method based on radiation self-calibration provided by the present invention only needs to use a measuring camera and a calibration temperature source to obtain a camera factor, and then the flame image is obtained through the camera, and the temperature distribution of the flame image can be obtained based on the obtained camera factor combined with a two-color temperature measurement method, which has the characteristics of low cost and high convenience; temperature measurement is performed by combining the camera dynamic range response curve and the red and green channel data of the color image, thereby avoiding the error of calculating the temperature value through the image grayscale output and improving the measurement accuracy; therefore, the flame temperature measurement method based on radiation self-calibration provided by the present invention can take into account the measurement cost, measurement convenience and measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0042] Figure 1 A schematic flow chart of an embodiment of a flame temperature measurement method based on radiation self-calibration provided by the present invention;

[0043] Figure 2 The present invention provides Figure 1 A schematic diagram of a flow chart of an embodiment of step S104;

[0044] Figure 3 A schematic diagram of an embodiment of the relationship between the current and the brightness temperature of a tungsten filament lamp provided by the present invention;

[0045] Figure 4 A schematic diagram of a flow chart of an embodiment of a flame temperature measurement device based on radiation self-calibration provided by the present invention;

[0046] Figure 5 A schematic structural diagram of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0048] It should be understood that the schematic drawings are not drawn to scale. The flow chart used in the present invention shows the operations implemented according to some embodiments of the present invention. It should be understood that the operations of the flow chart can be implemented out of order, and the steps without logical context can be reversed or implemented simultaneously. In addition, those skilled in the art can add one or more other operations to the flow chart under the guidance of the content of the present invention, and can also remove one or more operations from the flow chart.

[0049] Some of the block diagrams shown in the accompanying drawings are functional entities that do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor systems and / or microcontroller systems.

[0050] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0051] Before describing the embodiments, the following definitions are given for the relevant terms:

[0052] Surface emissivity: The surface emissivity of an object describes the ability of an object to radiate energy. It is defined as the ratio of the radiated energy value A of the object to the radiated energy value B of a black body at the same temperature: emissivity = A / B, so this value is between 0-1.

[0053] Radiant illuminance: Radiant illuminance characterizes the amount of radiant energy received per unit area per unit time on the surface illuminated by radiant energy, that is, the radiation flux density on the illuminated surface.

[0054] Brightness temperature: Brightness temperature refers to the temperature of a black body with the same radiation intensity as the object being measured, or the black body temperature when the spectral radiation intensity of the object at the same wavelength is equal to the spectral radiation intensity of the black body.

[0055] True temperature: True temperature refers to the temperature of the object itself. Brightness temperature is usually lower than the true temperature of the object.

[0056] Based on the description of the above technical terms, the existing technology for measuring and monitoring flame temperature is divided into two categories: invasive and non-invasive measurement. The contact measurement method using physical probes (such as thermocouples, resistance thermometers and gas-filled probes) is easy to implement, but has obvious disadvantages: the temperature data obtained are limited and cannot fully reproduce the full picture of the flame temperature field; the high-temperature flame has a limited measurement range due to the requirement of the melting point of the material; the physical and chemical reactions generated when the probe contacts the flame interfere with the flame combustion condition, affecting the flame flow field and measurement accuracy. Non-invasive measurement is not limited by this. Commonly used non-invasive technologies include infrared pyrometers, laser-based technologies and acoustic methods. Infrared pyrometers are based on detecting thermal radiation in the infrared spectrum. The system requires an understanding of the emissivity of the object. In addition, the use of infrared spectra requires consideration of the influence of wall reflection in the case of flame temperature in confined spaces (such as combustion chambers). Laser-based technologies, such as Rayleigh scattering, require understanding of pressure and gas composition in a small control volume for detecting temperature. In addition, the huge investment and complex settings required limit the application of this technology in academic research institutions. In recent years, image-based temperature measurement has developed with the development of electronic components and computer technology. Such as dynamic flame measurement methods based on hyperspectral images, temperature measurement methods based on light field cameras, temperature measurement methods based on dual optical path systems, etc. Image-based temperature measurement is a non-invasive measurement technology developed in recent years that avoids the shortcomings of invasive temperature measurement. At the same time, compared with infrared temperature measurement, it does not require the exact emissivity of the object and is not affected by wall reflection. Compared with laser-based temperature measurement technology, the system setup based on camera sensors is simpler and more economical, and does not require pressure and gas composition.

[0057] The temperature measurement method using hyperspectral images and systems requires multiple hyperspectral cameras, spectroscopes or liquid crystal tunable filters with different imaging bands to build a complex temperature measurement system. The measurement method using light field cameras and layered imaging technology requires high optical path requirements for the imaging system, and the layered imaging algorithm is complex. As for the image-based two-color temperature measurement method, the existing two-color temperature measurement method using narrow-band filters requires the replacement of filters and multiple shots. The two-color temperature measurement method based on a dual optical path structure to obtain monochromatic radiation intensity at different wavelengths requires the construction of a dual optical path structure, which has high optical path requirements and a complex imaging system. The above technologies all require the construction of a complex temperature measurement imaging system, which has additional requirements for cameras and optical paths, high costs, and complex designs. In addition, the two-color temperature measurement based on the pixel intensity ratio of the flame image has been developed. This method only uses the grayscale output of the image to calculate the temperature, ignoring the relationship between the image pixel intensity and the flame radiation intensity, which increases the temperature measurement error.

[0058] The present invention aims to propose a flame temperature measurement method that can take into account measurement cost, measurement convenience and measurement accuracy.

[0059] The specific embodiments are described in detail below. It should be noted that the description order of the following embodiments is not intended to limit the preferred order of the embodiments.

[0060] The embodiments of the present invention provide a flame temperature measurement method, device, equipment and medium based on radiation self-calibration.

[0061] like Figure 1 As shown, Figure 1 The present invention provides a flame temperature measurement method based on radiation self-calibration according to an embodiment of the present invention. The flame temperature measurement method based on radiation self-calibration includes:

[0062] S101, acquiring color images of a calibrated temperature source at different temperatures based on a camera with a built-in color stripe filter, and extracting red and green channel pixel values ​​of the color image;

[0063] S102, determining a camera response function of the camera based on radiation self-calibration of the camera, and obtaining a dynamic range response curve of the camera through the camera response function;

[0064] S103, acquiring red and green channel irradiance values ​​of the color image based on the red and green channel pixel values ​​of the color image and a dynamic range response curve;

[0065] S104, calculating a camera instrument factor based on a two-color temperature measurement method in combination with the real temperature of the calibration temperature source corresponding to the color image and the irradiance values ​​of the red and green channels;

[0066] S105. Acquire a flame image based on the camera, determine the red and green channel irradiance values ​​of the flame image according to the red and green channel pixel values ​​of the flame image and a dynamic range response curve, and obtain the flame temperature distribution of each pixel point of the flame image based on a two-color temperature measurement method in combination with the red and green channel irradiance values ​​of the flame image and a camera instrument factor.

[0067] Compared with the prior art, the flame temperature measurement method based on radiation self-calibration provided in the embodiment of the present invention, on the one hand, uses a color camera with a built-in color stripe filter to measure temperature in combination with the camera dynamic range response curve and the red and green channel data of the color image, thereby avoiding the error of calculating the temperature value through the image grayscale output; on the other hand, the camera factor is obtained by calibrating the temperature source, and then the flame temperature distribution of the flame image is determined according to the camera factor and the red and green channel irradiance ratio of the flame image, thereby simplifying the complex system required for obtaining monochromatic irradiation intensity using narrow-band filters or multi-optical path settings and hyperspectral measurement or light field measurement. ; The flame temperature measurement method based on radiation self-calibration provided by the present invention only needs to use a measuring camera and a calibration temperature source to obtain a camera factor, and then the flame image is obtained through the camera. Based on the obtained camera factor and a two-color temperature measurement method, the temperature distribution of the flame image can be obtained, which has the characteristics of low cost and high convenience; by combining the camera dynamic range response curve and the red and green channel data of the color picture to measure the temperature, the error of calculating the temperature value through the image grayscale output is avoided, and the measurement accuracy is improved; therefore, the flame temperature measurement method based on radiation self-calibration provided by the present invention can take into account the measurement cost, measurement convenience and measurement accuracy.

[0068] It should be noted that the calibration temperature source used in the embodiment of the present invention is a calibrated tungsten filament lamp with a known emissivity. The current passing through the tungsten filament lamp can be changed to take photos of the tungsten filament lamp at different temperatures.

[0069] Optionally, in some embodiments of the present invention, in step S101,

[0070] A Bayer pattern color filter array is coated on the sensor surface of the camera, wherein the Bayer pattern color filter array includes filters of three different colors: red, green, and blue;

[0071] The camera coated with the Bayer pattern color filter array stores the acquired image of the calibration temperature source in RAW mode and then converts it into an RGB color image;

[0072] Pixel values ​​of the red channel and the green channel are extracted from the color image.

[0073] In a specific embodiment of the present invention, a camera having a Bayer pattern color filter array coated on the sensor surface is used. The sensor consists of a repeating unit of square pixels, including three different color filters: red (R), green (G), and blue (B), which selectively allow only radiation of specific colors to reach the sensor.

[0074] Images of the calibrated temperature source are taken at different temperatures. The camera stores the images in RAW mode, eliminates white balance and gamma correction, converts the images stored in RAW format into color images stored in the RGB color system with 8 bits per channel, and extracts the pixel values ​​of the red channel and the green channel from the color images.

[0075] The embodiment of the present invention achieves the effect of eliminating white balance and gamma correction by storing images in RAW mode, thereby improving image imaging quality and ensuring the accuracy of subsequent processing calculations of the image.

[0076] Optionally, in some embodiments of the present invention, step S102 includes: using the camera to acquire multiple images of the same static scene with different exposure times;

[0077] Based on the optical reciprocity of the imaging system, the camera response function between the digital pixel intensity and the exposure amount of the image is solved by singular value decomposition using the multiple images with different exposure times;

[0078] The dynamic range response curve of the camera is obtained through the camera response function, and the dynamic range response curve reflects the relationship between the target radiance and the pixel intensity.

[0079] In a specific embodiment of the present invention, the camera is used to take multiple photos of the same static scene with different exposure times. Based on the optical reciprocity of the imaging system, the pixel intensity of the image is a function of exposure. The function is defined to be monotonic, and after taking the logarithm to linearize the equation and introducing a smoothing term, N pixels are taken at the same position of each image, and the camera response function is solved by singular value decomposition. Then, the dynamic range response curve of the camera is obtained through the camera response function, and the x-axis of the dynamic response curve is (ln exposure value) (exposure value = irradiance value E*Δt), and the y-axis is pixel intensity.

[0080] Optionally, in some embodiments of the present invention, step S103 includes: acquiring corresponding red and green channel exposures in a dynamic range response curve according to red and green channel pixel values ​​of the color image;

[0081] The red and green channel exposure values ​​of the color image are obtained by dividing the red and green channel exposure values ​​by the exposure time corresponding to the color image.

[0082] In a specific embodiment of the present invention, a lookup table between digital pixel intensity and exposure is established through a dynamic range response curve, and the corresponding red and green channel exposures are looked up according to the red and green channel pixel values ​​of the color image. The exposure is divided by the camera exposure time to obtain the red and green channel irradiance values ​​of the color image.

[0083] Optionally, in some embodiments of the present invention, in step S104, by acquiring the brightness temperature and emissivity corresponding to the color image of the calibration temperature source at different temperatures, the actual temperature of the calibration temperature source is determined according to the brightness temperature and emissivity of the calibration temperature source, and the actual temperature of the calibration temperature source corresponding to the color image is obtained.

[0084] like Figure 2 As shown, Figure 2 The present invention provides Figure 1 The flowchart of step S104 in an embodiment is shown in FIG. 1 , wherein step S104 includes:

[0085] S201, determining the relationship between the monochromatic radiation power of the color image and the real temperature of the calibration temperature source based on Planck's radiation law and the emissivity, wherein the monochromatic radiation power includes the monochromatic radiation power at the central wavelength of the red channel and the monochromatic radiation power at the central wavelength of the green channel;

[0086] S202, based on paraxial geometric optics and the relationship between the monochromatic radiation power and the real temperature of the calibration temperature source, the irradiance values ​​of the red and green channels are compared to obtain the irradiance ratio of the red and green channels, and based on the irradiance ratio of the red and green channels, a two-color temperature measurement formula at the real temperature of the calibration temperature source is obtained;

[0087] S203: Calculate the camera instrument factor according to the irradiance ratio of the two-color temperature measurement system and the real temperature of the calibration temperature source.

[0088] In a specific embodiment of the present invention, the calibration temperature source used is a calibrated tungsten filament lamp with a known emissivity. The manufacturer provides the relationship between the current and the brightness temperature of the calibrated tungsten filament lamp, such as Figure 3 As shown, Figure 3 This is a schematic diagram of an embodiment of the relationship between the current and brightness temperature of a tungsten filament lamp provided by the present invention. The current passing through the tungsten filament lamp is changed, and pictures of the tungsten filament lamp are taken at different currents. The real temperature T and the brightness temperature The correlation between the two can be regarded as the emissivity of the tungsten lamp The function can be expressed as:

[0089] (1)

[0090] Emissivity of tungsten lamps The wavelength He Zhenwen Function:

[0091] (2)

[0092] Based on the selected red and green wavelengths, the actual temperature and emissivity corresponding to the brightness temperature of the tungsten filament lamp can be calculated according to formula (1) and formula (2).

[0093] Based on Planck's radiation law and true surface emissivity Constructing Monochromatic Radiant Power The relationship between the actual temperature T and When , the Wien approximation is performed to obtain the monochromatic radiation power formula:

[0094] (3)

[0095] In the formula is the first radiation constant, is the second radiation constant.

[0096] In paraxial geometric optics, according to the transmittance of the optical system , relative aperture , spectral response and monochromatic radiant power Get the irradiance value :

[0097] (4)

[0098] Combining formula (3) and (4), the irradiance values ​​under red and green wavelengths are compared to obtain the two-color temperature measurement formula of the actual temperature T:

[0099] (5)

[0100] In the formula is the second radiation constant ; is the central wavelength of the camera’s red channel, is the center wavelength of the camera's green channel; The irradiance value corresponding to the red channel pixel of the tungsten light captured by the camera. The irradiance value corresponding to the green channel pixel of the tungsten lamp; is the camera instrument factor; is the emissivity of the tungsten lamp at the central wavelength of the red channel, Emissivity of a tungsten lamp at the center wavelength of the green channel.

[0101] The red and green channel irradiance values ​​corresponding to the real temperature are obtained through the tungsten lamp photos and the response function. The camera instrument factor is calculated from the real temperature and the red and green channel irradiance ratio of each tungsten lamp photo.

[0102] Optionally, in some embodiments of the present invention, step S105 includes: obtaining an irradiance ratio of the red and green channels of the flame image according to the irradiance values ​​of the red and green channels of the flame image;

[0103] The camera instrument factor and the irradiance ratio of the red and green channels of the flame image are substituted into the two-color temperature measurement formula to calculate the flame temperature distribution of each pixel of the flame image.

[0104] It should be noted that the method for obtaining the red and green channel irradiance values ​​and the irradiance ratio of the red and green channels of the flame image in step S105 is the same as the method used in steps S101 to S104, so it is not repeated here.

[0105] In a specific embodiment of the present invention, the temperature distribution is calculated based on the red-green channel irradiance ratio of the flame image and the camera instrument factor calculated by calibrating the temperature source, and the two-color temperature measurement formula of the real temperature T is substituted into the temperature distribution distribution:

[0106] (6)

[0107] In the formula The irradiance value corresponding to the red channel pixel of the flame image taken by the camera, is the irradiance value corresponding to the green channel pixel of the flame image; the central wavelengths of the selected red and green channels are close enough, and the emissivity ratio under the two wavelengths is approximately 1, so , the flame temperature distribution of each pixel of the flame image is obtained by calculation.

[0108] The embodiment of the present invention uses a color camera with a built-in color stripe filter, combines the camera dynamic range response curve and the red and green channel data of the color image to measure the temperature, avoids the error of calculating the temperature value through the image grayscale output, and then obtains the camera factor by calibrating the temperature source, and then determines the flame temperature distribution of the flame image according to the camera factor and the red and green channel irradiance ratio of the flame image, simplifies the complex system required for obtaining the monochromatic irradiation intensity by using narrow-band filters or multi-light path settings and hyperspectral measurement or light field measurement. The flame temperature measurement method based on radiation self-calibration provided by the present invention can take into account the measurement cost, measurement convenience and measurement accuracy.

[0109] In order to better implement the flame temperature measurement method based on radiation self-calibration in the embodiment of the present invention, on the basis of the flame temperature measurement method based on radiation self-calibration, the embodiment of the present invention also provides a flame temperature measurement device based on radiation self-calibration, such as Figure 4 As shown, the flame temperature measurement device 400 based on radiation self-calibration includes:

[0110] An image acquisition module 401 is used to acquire color images of a calibrated temperature source at different temperatures based on a camera with a built-in color stripe filter, and extract red and green channel pixel values ​​of the color image;

[0111] A response association module 402 is used to determine a camera response function of the camera based on radiometric self-calibration of the camera, and obtain a dynamic range response curve of the camera through the camera response function;

[0112] The amplitude calculation module 403 is used to obtain the red and green channel irradiance values ​​of the color image based on the red and green channel pixel values ​​and the dynamic range response curve of the color image;

[0113] A relationship building module 404 is used to calculate the camera instrument factor based on a two-color temperature measurement method in combination with the real temperature of the calibration temperature source corresponding to the color image and the irradiance values ​​of the red and green channels;

[0114] The target measurement module 405 is used to obtain a flame image based on the camera, determine the red and green channel irradiance values ​​of the flame image according to the red and green channel pixel values ​​of the flame image and the dynamic range response curve, and obtain the flame temperature distribution of each pixel point of the flame image based on a two-color temperature measurement method in combination with the red and green channel irradiance values ​​of the flame image and a camera instrument factor.

[0115] The flame temperature measurement device 400 based on radiation self-calibration provided in the above embodiment can implement the technical solution described in the above embodiment of the flame temperature measurement method based on radiation self-calibration. The specific implementation principles of the above modules or units can refer to the corresponding contents in the above embodiment of the flame temperature measurement method based on radiation self-calibration, which will not be repeated here.

[0116] like Figure 5 As shown, the present invention also provides an electronic device 500. The electronic device 500 includes a processor 501, a memory 502 and a display 503. Figure 5 Only some components of the electronic device 500 are shown, but it should be understood that it is not required to implement all of the components shown, and more or fewer components may be implemented instead.

[0117] In some embodiments, the processor 501 may be a central processing unit (CPU), a microprocessor or other data processing chip, used to run program codes or process data stored in the memory 502, such as the flame temperature measurement program based on radiation self-calibration in the present invention.

[0118] In some embodiments, the processor 501 may be a single server or a server group. The server group may be centralized or distributed. In some embodiments, the processor 501 may be local or remote. In some embodiments, the processor 501 may be implemented in a cloud platform. In one embodiment, the cloud platform may include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an internal cloud, a multi-cloud, etc., or any combination thereof.

[0119] In some embodiments, the memory 502 may be an internal storage unit of the electronic device 500, such as a hard disk or memory of the electronic device 500. In other embodiments, the memory 502 may also be an external storage device of the electronic device 500, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the electronic device 500.

[0120] Furthermore, the memory 502 may include both an internal storage unit of the electronic device 500 and an external storage device. The memory 502 is used to store application software installed in the electronic device 500 and various data.

[0121] In some embodiments, the display 503 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, an OLED (Organic Light-Emitting Diode) touch device, etc. The display 503 is used to display information on the electronic device 500 and to display a visual user interface. The components 501-503 of the electronic device 500 communicate with each other via a system bus.

[0122] In one embodiment, when the processor 501 executes the flame temperature measurement program based on radiation self-calibration in the memory 502, the following steps may be implemented:

[0123] Acquire color images of the calibrated temperature source at different temperatures based on a camera with a built-in color stripe filter, and extract red and green channel pixel values ​​of the color image;

[0124] Determine a camera response function of the camera based on radiometric self-calibration of the camera, and obtain a dynamic range response curve of the camera through the camera response function;

[0125] Acquire red and green channel irradiance values ​​of the color image based on red and green channel pixel values ​​and a dynamic range response curve of the color image;

[0126] The camera instrument factor is calculated based on a two-color temperature measurement method in combination with the real temperature of the calibration temperature source corresponding to the color image and the irradiance values ​​of the red and green channels;

[0127] A flame image is acquired based on the camera, and the red and green channel irradiance values ​​of the flame image are determined according to the red and green channel pixel values ​​of the flame image and a dynamic range response curve. Based on a two-color temperature measurement method and in combination with the red and green channel irradiance values ​​of the flame image and a camera instrument factor, the flame temperature distribution of each pixel point of the flame image is obtained.

[0128] It should be understood that: when the processor 501 executes the flame temperature measurement program based on radiation self-calibration in the memory 502, in addition to the above functions, other functions may also be implemented, and details may refer to the description of the corresponding method embodiments above.

[0129] Furthermore, the embodiment of the present invention does not specifically limit the type of the electronic device 500 mentioned, and the electronic device 500 may be a portable electronic device such as a mobile phone, a tablet computer, a personal digital assistant (PDA), a wearable device, a laptop computer, etc. Exemplary embodiments of portable electronic devices include but are not limited to portable electronic devices equipped with IOS, Android, Microsoft or other operating systems. The above-mentioned portable electronic devices may also be other portable electronic devices, such as a laptop computer with a touch-sensitive surface (e.g., a touch panel). It should also be understood that in some other embodiments of the present invention, the electronic device 500 may not be a portable electronic device, but a desktop computer with a touch-sensitive surface (e.g., a touch panel).

[0130] Accordingly, an embodiment of the present application also provides a computer-readable storage medium, which is used to store computer-readable programs or instructions. When the program or instructions are executed by a processor, the steps or functions of the flame temperature measurement method based on radiation self-calibration provided in the above-mentioned method embodiments can be implemented.

[0131] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware (such as a processor, a controller, etc.) through a computer program, and the computer program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0132] The flame temperature measurement method, device, equipment and medium based on radiation self-calibration provided by the present invention are introduced in detail above. Specific examples are used in this article to illustrate the principle and implementation mode of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A flame temperature measurement method based on radiation self-calibration, characterized in that: include: Acquire color images of the calibrated temperature source at different temperatures based on a camera with a built-in color stripe filter, and extract red and green channel pixel values ​​of the color image; Determine a camera response function of the camera based on radiometric self-calibration of the camera, and obtain a dynamic range response curve of the camera through the camera response function; Acquire red and green channel irradiance values ​​of the color image based on red and green channel pixel values ​​and a dynamic range response curve of the color image; The camera instrument factor is calculated based on a two-color temperature measurement method in combination with the real temperature of the calibration temperature source corresponding to the color image and the irradiance values ​​of the red and green channels; A flame image is acquired based on the camera, and the red and green channel irradiance values ​​of the flame image are determined according to the red and green channel pixel values ​​of the flame image and a dynamic range response curve. Based on a two-color temperature measurement method and in combination with the red and green channel irradiance values ​​of the flame image and a camera instrument factor, the flame temperature distribution of each pixel point of the flame image is obtained.

2. The flame temperature measurement method based on radiation self-calibration according to claim 1 is characterized in that: The camera based on the built-in color stripe filter acquires a color image of the calibration temperature source, and extracts red and green channel pixel values ​​of the color image, including: A Bayer pattern color filter array is coated on the sensor surface of the camera, wherein the Bayer pattern color filter array includes filters of three different colors: red, green, and blue; The camera coated with the Bayer pattern color filter array stores the acquired image of the calibration temperature source in RAW mode and then converts it into an RGB color image; Pixel values ​​of the red channel and the green channel are extracted from the color image.

3. The flame temperature measurement method based on radiation self-calibration according to claim 1, characterized in that: The step of determining a camera response function based on the radiation self-calibration of the camera and obtaining a dynamic range response curve of the camera through the camera response function includes: Using the camera to acquire multiple images of the same static scene with different exposure times; Based on the optical reciprocity of the imaging system, the camera response function between the digital pixel intensity and the exposure amount of the image is solved by singular value decomposition using the multiple images with different exposure times; The dynamic range response curve of the camera is obtained through the camera response function, and the dynamic range response curve reflects the relationship between the target radiance and the pixel intensity.

4. The flame temperature measurement method based on radiation self-calibration according to claim 3 is characterized in that: The step of obtaining the red and green channel irradiance values ​​of the color image based on the red and green channel pixel values ​​and the dynamic range response curve of the color image includes: Obtaining corresponding red and green channel exposures in a dynamic range response curve according to red and green channel pixel values ​​of the color image; The red and green channel exposure values ​​of the color image are obtained by dividing the red and green channel exposure values ​​by the exposure time corresponding to the color image.

5. The flame temperature measurement method based on radiation self-calibration according to claim 1, characterized in that: Obtaining the real temperature of the calibration temperature source corresponding to the color image, including: The brightness temperature and emissivity corresponding to the color image of the calibration temperature source at the different temperatures are obtained, and the real temperature of the calibration temperature source is determined according to the brightness temperature and emissivity of the calibration temperature source to obtain the real temperature of the calibration temperature source corresponding to the color image.

6. The flame temperature measurement method based on radiation self-calibration according to claim 5, characterized in that: The camera instrument factor is calculated based on the two-color temperature measurement method in combination with the real temperature of the calibration temperature source corresponding to the color image and the irradiance values ​​of the red and green channels, including: Determine the relationship between the monochromatic radiation power of the color image and the real temperature of the calibration temperature source based on Planck's radiation law and the emissivity, wherein the monochromatic radiation power includes the monochromatic radiation power at the central wavelength of the red channel and the monochromatic radiation power at the central wavelength of the green channel; Based on paraxial geometric optics and the relationship between the monochromatic radiation power and the real temperature of the calibration temperature source, the irradiance values ​​of the red and green channels are compared to obtain the irradiance ratio of the red and green channels, and based on the irradiance ratio of the red and green channels, a two-color temperature measurement formula at the real temperature of the calibration temperature source is obtained; The camera instrument factor is calculated based on the two-color temperature measurement formula, the irradiance ratio of the red and green channels, and the real temperature of the calibration temperature source.

7. The flame temperature measurement method based on radiation self-calibration according to claim 6 is characterized in that: The flame temperature distribution of each pixel point of the flame image is obtained based on the two-color temperature measurement method and combined with the red and green channel irradiance values ​​of the flame image and the camera instrument factor, including: Acquire the irradiance ratio of the red channel and the green channel of the flame image according to the irradiance values ​​of the red and green channels of the flame image; The camera instrument factor and the irradiance ratio of the red and green channels of the flame image are substituted into the two-color temperature measurement formula to calculate the flame temperature distribution of each pixel of the flame image.

8. A flame temperature measurement device based on radiation self-calibration, characterized in that: include: An image acquisition module, used for acquiring color images of the calibrated temperature source at different temperatures based on a camera with a built-in color stripe filter, and extracting red and green channel pixel values ​​of the color image; A response association module, used to determine a camera response function of the camera based on radiometric self-calibration of the camera, and obtain a dynamic range response curve of the camera through the camera response function; An irradiance calculation module, used for obtaining irradiance values ​​of the red and green channels of the color image based on the red and green channel pixel values ​​and the dynamic range response curve of the color image; A relationship building module, for calculating a camera instrument factor based on a two-color temperature measurement method in combination with a real temperature of a calibration temperature source corresponding to the color image and irradiance values ​​of red and green channels; The target measurement module is used to obtain a flame image based on the camera, determine the red and green channel irradiance values ​​of the flame image according to the red and green channel pixel values ​​of the flame image and the dynamic range response curve, and obtain the flame temperature distribution of each pixel point of the flame image based on a two-color temperature measurement method and in combination with the red and green channel irradiance values ​​of the flame image and a camera instrument factor.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the flame temperature measurement method based on radiation self-calibration according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the flame temperature measurement method based on radiation self-calibration according to any one of claims 1 to 7 is implemented.

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