A method and device for determining the sensitivity of sample identification based on infrared detection

Abstract

The application discloses a kind of based on infrared detection sample identification sensitivity determination method and device, method includes: obtaining background environment temperature, determine the light source threshold temperature of infrared light source and give the light source temperature of at least one infrared light source;Infrared detector, sample and infrared light source are constructed into infrared detection system;Obtain sample group and based on each light source temperature, using infrared light source to each sample is irradiated, corresponding thermogram of each sample is collected, corresponding thermogram group of each light source temperature is formed;The irradiance of each to be identified area in thermogram is analyzed, and the irradiance difference and emissivity difference corresponding to each thermogram are given;Based on the pre-constructed sample identification sensitivity function, the irradiance difference and emissivity difference corresponding to each thermogram are combined, and the sensitivity series is given, the sample identification sensitivity of infrared detection is determined, and the detection capability of infrared detector to the sample including different to be identified area is improved.

Description

Technical Field

[0001] This invention belongs to the field of materials testing technology, specifically relating to a method and apparatus for determining sample identification sensitivity based on infrared detection. Background Technology

[0002] Infrared detection technology is a key technology that utilizes the radiation characteristics of objects in the infrared band for imaging, identification, or measurement, and is widely used in military reconnaissance, gas detection, human-computer interaction, biomedicine, and other fields. In practical applications, the radiation intensity of a target object is not only related to its temperature but also significantly affected by its surface emissivity. Because the emissivity of many objects in nature varies only slightly and is easily affected by background interference, traditional infrared imaging systems have limited sensitivity when detecting subtle differences in emissivity, making it difficult to achieve high-precision identification and dynamic response. Currently, to improve the response capability of infrared imaging systems to minute differences in emissivity, the main approach is to enhance detector performance, such as using highly sensitive cooled detectors, optimizing image processing algorithms, or constructing complex multispectral imaging systems. While these methods improve detection sensitivity to some extent, they generally suffer from problems such as system complexity, high cost, high power consumption, and poor real-time performance.

[0003] Patent CN108490029A discloses a method for detecting hollow areas in exterior wall cladding, including: (1) using infrared temperature gradient images to locate suspected locations with defects; (2) for situations with poor detection conditions, using laser irradiation to heat the surface as an auxiliary technique to amplify the surface temperature difference for defect detection; and (3) for suspected areas with abnormal temperatures, using a comparison of temperature difference changes during heating and cooling processes to identify and determine whether hollow areas in the cladding exist. Patent application CN115575449A discloses an active infrared thermal imaging detection device and method for detecting internal defects in fruit. The device includes a control and data processing analysis module, and connected to it an infrared thermal imaging acquisition module, a power supply, and a fruit heating module. The power supply is also connected to other modules to provide the necessary power. The infrared thermal imaging acquisition module acquires infrared thermal images of the fruit sample before and after thermal excitation. The fruit heating module applies controllable thermal excitation to the fruit sample. The control and data processing analysis module compares and analyzes the infrared thermal images before and after thermal excitation, and then compares them with a set temperature difference threshold to obtain the coordinate positions of fruit samples with internal defects and fruit samples without internal defects. By identifying and classifying the infrared thermal images acquired by the infrared thermal imaging acquisition module, low-quality fruit with intact exteriors but internal defects can be identified.

[0004] Currently, most research on infrared detection and imaging focuses on performance optimization at the detector end, while less attention is paid to the control of the light source end. In the existing technologies mentioned above, auxiliary light sources are only used for difference identification in specific fields, without fully utilizing the influence of auxiliary light sources on the detection performance of infrared detectors. How to improve the detection performance of infrared detectors through auxiliary light sources is a problem that needs to be solved. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method and apparatus for determining sample identification sensitivity based on infrared detection. The method includes: acquiring the background ambient temperature and determining the light source threshold temperature of an infrared light source; based on the light source threshold temperature, determining the light source temperature of at least one infrared light source; constructing an infrared detection system comprising an infrared detector, a sample, and an infrared light source; acquiring a sample group, wherein the sample group includes at least two samples, each sample including at least two types of regions to be identified; irradiating each sample with an infrared light source based on the light source temperature, acquiring a thermal image corresponding to each sample, forming a thermal image group corresponding to each light source temperature; analyzing the irradiance of each region to be identified in the thermal images, and providing the irradiance difference and emissivity difference corresponding to each thermal image; based on a pre-constructed sample identification sensitivity function, combined with the irradiance difference and emissivity difference corresponding to each thermal image, providing a sensitivity series, and determining the sample identification sensitivity of infrared detection. By determining the light source temperature of the infrared light source based on the determined background ambient temperature and light source threshold temperature, the detection effect of the infrared detector on each region to be identified in the sample is guaranteed when using an infrared light source, improving the detection capability of the infrared detector for samples including different regions to be identified.

[0006] In a first aspect, the present invention provides a method for determining sample identification sensitivity based on infrared detection, specifically including the following steps: Obtain the background ambient temperature and determine the light source threshold temperature of the infrared light source; Based on the light source threshold temperature, give the light source temperature of at least one infrared light source; Construct an infrared detection system consisting of an infrared detector, a sample, and an infrared light source; Obtain a sample set, wherein the sample set includes at least two samples, and each sample includes at least two types of regions to be identified; Based on the temperature of each light source, each sample is irradiated with an infrared light source, and a thermal image corresponding to each sample is acquired to form a thermal image group corresponding to the temperature of each light source. Analyze the irradiance of each region to be identified in the thermal images, and provide the irradiance difference and emissivity difference for each thermal image; Based on a pre-constructed sample identification sensitivity function, combined with the irradiance difference and emissivity difference corresponding to each thermal image, a sensitivity series is given to determine the sample identification sensitivity of infrared detection.

[0007] Furthermore, the background ambient temperature is obtained through the following steps: Obtain standard samples, wherein the standard samples include at least two types of regions to be identified; Based on the preset first background temperature, the standard sample temperature is determined, and the standard sample is subjected to temperature excitation treatment until the intrinsic temperature of each region to be identified in the standard sample is equal to the standard sample temperature. Obtain the first thermal image of the standard sample, collect the highest and lowest temperature values ​​in the first thermal image, and give the temperature difference value of the first thermal image. Based on the temperature difference, the first background temperature is adjusted, and the process of temperature excitation processing and acquisition of the first thermal image is repeated. If the temperature difference reaches the preset requirement, the first background temperature will be determined as the background ambient temperature.

[0008] Furthermore, the threshold temperature of the light source is determined through the following steps: Obtain the preset irradiance difference threshold and the minimum resolution difference value of the infrared detector; Determine the irradiance of the background environment based on the background ambient temperature; Based on the preset irradiance difference threshold and the minimum resolution difference of the infrared detector, combined with the irradiance of the background environment, the threshold temperature of the light source is obtained.

[0009] Furthermore, based on a preset irradiance difference threshold and the minimum resolution difference of the infrared detector, combined with the irradiance of the background environment, the light source threshold temperature is obtained, specifically including: Calculate the ratio of the irradiance difference threshold to the minimum resolution difference of the infrared detector to determine the irradiance difference value; By fusing the irradiance difference and the irradiance of the background environment, the minimum irradiance of the infrared light source is obtained; The minimum irradiance of the infrared light source is analyzed to obtain the threshold temperature of the light source.

[0010] Furthermore, an infrared detection system consisting of an infrared detector, a sample, and an infrared light source is constructed, specifically including: The maximum shooting distance is determined based on the shooting range of the infrared detector, the size of each sample in the sample group, and the coverage of the infrared light source. Determine the minimum shooting distance based on the focal length of the infrared detector; By combining the minimum and maximum shooting distances, the distance range can be determined. The distances between the infrared detector, the infrared light source, and the sample are set according to the distance range to form an infrared detection system. The infrared detector and the infrared light source are set symmetrically about the normal of the sample, and the angle between the infrared detector and the normal of the sample is within a preset angle range.

[0011] Furthermore, the irradiance of each region to be identified in the thermal images is analyzed, and the irradiance difference and emissivity difference corresponding to each thermal image are given. This includes the following steps: Based on each thermal image in the thermal image group, the apparent temperature of each region to be identified in the thermal image is obtained, and the irradiance of the corresponding region to be identified is determined by combining the radiation wavelength of the infrared light source. Calculate the difference in irradiance between the regions to be identified in each thermal image to obtain the irradiance difference corresponding to each thermal image; Based on the emissivity of each region to be identified in the thermal image, the emissivity difference between the corresponding regions to be identified is calculated, and the emissivity difference corresponding to each thermal image is determined.

[0012] Furthermore, the irradiance difference values ​​corresponding to each thermal image are obtained through the following steps: Obtain the temperature value sequence of each region to be identified in the thermal image, and calculate the mean of the temperature value sequence to determine the apparent temperature of the region; By combining the apparent temperature of the region with the radiation wavelength of the infrared light source, the irradiance of each region to be identified is obtained. The differences in irradiance of each region to be identified in the sample are analyzed, and the difference in irradiance of each region to be identified is calculated to obtain the irradiance difference corresponding to each thermal image.

[0013] Furthermore, the emissivity of each region to be identified in the thermal image is obtained through the following steps: Obtain the built-in emissivity and detection wavelength range of the infrared detector; Based on the built-in emissivity and detection wavelength range of the infrared detector, and combined with the apparent temperature of the region in the thermal image, the total emitted energy term is obtained. By combining the regional excitation temperature with the regional emissivity and the detection wavelength range, the sample reflection energy term is given, where the regional excitation temperature is the intrinsic temperature of the corresponding region to be identified after being irradiated by an infrared light source. The environmental reflection energy term is given by combining the background ambient temperature with the regional emissivity and the detection wavelength range; By integrating the total emission energy term, the sample reflection energy term, and the environmental reflection energy term, an energy conservation equation is formed, and the emissivity of the corresponding region to be identified is obtained. The process of forming the energy conservation equation and obtaining the emissivity of the region to be identified is repeated to obtain the emissivity of each region to be identified in each thermal image, and to determine the emissivity distribution of the corresponding thermal image of each sample.

[0014] Furthermore, based on the pre-constructed sample identification sensitivity function, and combined with the irradiance difference and emissivity difference corresponding to each thermal image, a sensitivity series is given to determine the sample identification sensitivity of infrared detection. This specifically includes the following steps: Substitute the difference in radiance and the difference in emissivity corresponding to each thermal image into the sample identification sensitivity function to obtain the sensitivity value corresponding to each thermal image. Based on the light source temperature of each infrared light source, the sensitivity values ​​of the corresponding thermal image groups are fused to form a sensitivity sequence; The sample recognition sensitivity of the infrared detector is determined by using a sensitivity sequence.

[0015] Secondly, the present invention also provides an apparatus for determining sample identification sensitivity based on infrared detection, employing any one of the above-described methods for determining sample identification sensitivity based on infrared detection, comprising: A temperature configuration unit is used to acquire the background ambient temperature, determine the light source threshold temperature of the infrared light source, and, based on the light source threshold temperature, provide the light source temperature of at least one infrared light source. The system building unit is used to construct an infrared detection system consisting of an infrared detector, a sample, and an infrared light source; A sample acquisition unit is used to acquire a sample group, wherein the sample group includes at least two samples, and each sample includes at least two types of regions to be identified; The thermal imaging acquisition unit is used to irradiate each sample with an infrared light source based on the temperature of each light source, acquire thermal images corresponding to each sample, and form a group of thermal images corresponding to the temperature of each light source. The thermal imaging analysis unit is used to analyze the irradiance of each region to be identified in the thermal image and to provide the irradiance difference and emissivity difference corresponding to each thermal image. The sensitivity determination unit is used to determine the sample identification sensitivity of infrared detection by providing a sensitivity series based on a pre-constructed sample identification sensitivity function, combined with the irradiance difference and emissivity difference corresponding to each thermal image.

[0016] The present invention provides a method and apparatus for determining sample identification sensitivity based on infrared detection, which has at least the following beneficial effects: (1) By determining the background ambient temperature and the light source threshold temperature, the light source temperature of the infrared light source is given, which ensures the detection effect of each region to be identified in the sample when the infrared light source is used, and improves the detection capability of the infrared detector for samples including regions to be identified with different emissivity.

[0017] (2) By detecting the sample at the light source temperature of multiple infrared light sources, the infrared signals measured by the different emissivity differences of the sample have a greater contrast, thereby improving the infrared detector's ability to identify material samples with small emissivity differences and realizing simple, fast and highly sensitive detection of sample infrared emissivity differences.

[0018] (3) By pairing an infrared detector with an infrared light source, the difference between the different regions to be identified in the sample is enhanced, thereby enabling the infrared detector to detect the difference in emissivity of the sample and determine the sensitivity of sample identification. Attached Figure Description

[0019] Figure 1 A flowchart illustrating a method for determining sample identification sensitivity based on infrared detection, provided as an embodiment of the present invention; Figure 2 A schematic diagram of a thermal image provided in an embodiment of the present invention; Figure 3 A graph showing the relationship between the difference in irradiance and the difference in emissivity of different regions to be identified in a sample under conditions where a human hand at 37°C is used as an infrared light source, provided for an embodiment of the present invention. Figure 4 A graph showing the relationship between the difference in irradiance and the difference in emissivity of different regions to be identified in a sample under the condition of using an 80°C heating element as an infrared light source, provided for an embodiment of the present invention. Figure 5 This is a structural block diagram of a sample identification sensitivity determination device based on infrared detection, provided in an embodiment of the present invention.

[0020] Among them, 201 is the temperature configuration unit; 202 is the system construction unit; 203 is the sample acquisition unit; 204 is the thermal image acquisition unit; 205 is the thermal image analysis unit; and 206 is the sensitivity determination unit. Detailed Implementation

[0021] To better understand the above technical solutions, a detailed description of the solutions will be provided below in conjunction with the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0022] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms, and “multiple” generally includes at least two unless the context clearly indicates otherwise.

[0023] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device that includes said element.

[0024] like Figure 1 As shown in the figure, this embodiment of the invention provides a method for determining sample identification sensitivity based on infrared detection, and the specific steps are as follows: S101: Obtain the background ambient temperature and determine the light source threshold temperature of the infrared light source.

[0025] Furthermore, the background ambient temperature is obtained through the following steps: Obtain standard samples, wherein the standard samples include at least two types of regions to be identified; Based on the preset first background temperature, the standard sample temperature is determined, and the standard sample is subjected to temperature excitation treatment until the intrinsic temperature of each region to be identified in the standard sample is equal to the standard sample temperature. Obtain the first thermal image of the standard sample, collect the highest and lowest temperature values ​​in the first thermal image, and give the temperature difference value of the first thermal image. Based on the temperature difference, the first background temperature is adjusted, and the process of temperature excitation processing and acquisition of the first thermal image is repeated. If the temperature difference reaches the preset requirement, the first background temperature will be determined as the background ambient temperature.

[0026] It's important to understand that by setting a background ambient temperature, the temperature difference in the thermal image is minimized due to the emissivity differences among the various regions to be identified in the standard sample. Since the background ambient temperature varies depending on factors such as the material, size, thickness of the standard sample, actual ambient temperature, and emissivity differences among the regions to be identified, a debugging and verification process is necessary to determine the final background ambient temperature.

[0027] The emissivity of each type of region to be identified is different, and the difference in thermal conductivity between these regions is within a threshold range. That is, while the emissivity of each type of region in the sample differs, their thermal conductivity is almost identical or very similar, falling within a preset threshold range. The threshold setting is related to factors such as the sample material; therefore, no specific numerical limit is specified here.

[0028] In one specific implementation, a standard sample is obtained, comprising at least two types of regions to be identified. First, a preset first background temperature is obtained, and the standard sample temperature is determined. The standard sample is then subjected to temperature excitation processing until the intrinsic temperature of each region to be identified in the standard sample reaches the standard sample temperature. The first background temperature and the standard sample temperature are the same, or there may be a certain temperature difference, but the temperature difference between the first background temperature and the standard sample temperature must not exceed the resolution of the infrared detector; that is, the temperature difference between the first background temperature and the standard sample temperature cannot be detected by the infrared detector. The standard sample is then subjected to temperature excitation processing based on its temperature, i.e., heated or cooled, until the intrinsic temperature of each region to be identified in the standard sample reaches the standard sample temperature. At this point, a first thermal image of the standard sample is obtained using an infrared detector. The highest and lowest temperature values ​​in the first thermal image are collected, and the temperature difference value of the first thermal image is given. If the temperature difference is 0, the current first background temperature can be used as the background ambient temperature. Conversely, if the temperature difference is greater than or less than zero, the first background temperature needs to be adjusted according to the actual situation. The standard sample needs to be re-excited and the first thermal image after temperature excitation needs to be acquired. This process continues until the temperature difference of the first thermal image reaches the preset requirement. The first background temperature is then determined as the background ambient temperature for subsequent processing of the sample group. In this example, the preset requirement is a temperature difference of zero. In other examples, the preset requirement may be adjusted according to the differences between the areas to be identified in the standard sample or the actual environment. This is not limited. The intrinsic temperature is the actual temperature of the material sample, which satisfies Planck's blackbody radiation law and is independent of external factors such as surface emissivity, environmental reflection, and atmospheric path. The intrinsic temperature can be measured by setting a contact temperature measuring device on the material sample, or other methods may be used. This is not limited.

[0029] Furthermore, the threshold temperature of the light source is determined through the following steps: Obtain the preset irradiance difference threshold and the minimum resolution difference value of the infrared detector; Determine the irradiance of the background environment based on the background ambient temperature; Based on the preset irradiance difference threshold and the minimum resolution difference of the infrared detector, combined with the irradiance of the background environment, the threshold temperature of the light source is obtained.

[0030] Furthermore, based on a preset irradiance difference threshold and the minimum resolution difference of the infrared detector, combined with the irradiance of the background environment, the light source threshold temperature is obtained, specifically including: Calculate the ratio of the irradiance difference threshold to the minimum resolution difference of the infrared detector to determine the irradiance difference value; By fusing the irradiance difference and the irradiance of the background environment, the minimum irradiance of the infrared light source is obtained; The minimum irradiance of the infrared light source is analyzed to obtain the threshold temperature of the light source.

[0031] It's important to understand that when the infrared light source temperature reaches its threshold temperature, the differences between the various regions to be identified in the sample begin to appear in the infrared detector. By calculating the threshold temperature, the infrared light source temperature can be configured accordingly to improve the detection efficiency of the infrared detector for each region to be identified in the sample, thus ensuring effective detection.

[0032] In one specific implementation, a preset irradiance difference threshold and the minimum resolution difference of the infrared detector are first obtained. The irradiance difference threshold is set according to the actual situation. When the irradiance difference between any two regions to be identified in the sample exceeds the irradiance difference threshold, it indicates that the infrared detector can detect the corresponding two regions; otherwise, it cannot detect them. The minimum resolution difference of the infrared detector is the minimum difference in resolution that the infrared detector can recognize different regions to be identified based on the device configuration. That is, when the resolution of any two regions to be identified is not less than the minimum resolution difference, the infrared detector can recognize the corresponding two regions to be identified. Then, based on the background ambient temperature where the infrared detector is located, the irradiance of the background environment can be obtained. Next, the ratio of the irradiance difference threshold to the minimum resolution difference of the infrared detector is calculated to determine the irradiance difference. Then, the irradiance difference and the irradiance of the background environment are fused to obtain the minimum irradiance of the infrared light source. Finally, the minimum irradiance of the infrared light source is analyzed using Planck's radiation law to obtain the light source threshold temperature. The minimum irradiance is specifically expressed as:

[0033] Among them, L(T) 2,thr ) min T represents the minimum irradiance of an infrared light source. 2,thr The threshold temperature of the light source. The threshold for difference in radiance. L(T1) is the minimum resolution difference of the infrared detector, T1 is the background ambient temperature, L(T1) is the irradiance of the background environment, λ1 is the minimum radiation wavelength of the infrared detector, λ2 is the maximum radiation wavelength of the infrared detector, h is Planck's constant, c is the speed of light in vacuum, k is Boltzmann's constant, λ is the radiation wavelength, and e is a constant.

[0034] S102: Based on the light source threshold temperature, provide the light source temperature of at least one infrared light source.

[0035] By determining the threshold temperature of the infrared light source, it can be seen that when the temperature of the infrared light source exceeds the threshold temperature, the infrared detector can detect the difference between two regions to be identified in the sample. However, it is important to note that the temperature of the infrared light source must not damage the sample itself. For example, if the threshold temperature of the light source is 20℃ and the maximum irradiation temperature the sample can withstand is 100℃, it means that irradiating the sample with an infrared light source above 100℃ may cause some damage. Therefore, the temperature of the infrared light source can be any temperature between 20℃ and 100℃. Depending on the actual detection needs, one or more infrared light source temperatures can be selected; there is no limitation on this.

[0036] S103: Construct an infrared detection system consisting of an infrared detector, a sample, and an infrared light source.

[0037] Furthermore, an infrared detection system consisting of an infrared detector, a sample, and an infrared light source is constructed, specifically including: The maximum shooting distance is determined based on the shooting range of the infrared detector, the size of each sample in the sample group, and the coverage of the infrared light source. The minimum shooting distance is determined based on the focal length of the infrared detector; By combining the minimum and maximum shooting distances, the distance range can be determined. The distances between the infrared detector, the infrared light source, and the sample are set according to the distance range to form an infrared detection system. The infrared detector and the infrared light source are set symmetrically about the normal of the sample, and the angle between the infrared detector and the normal of the sample is within a preset angle range.

[0038] Understandably, the infrared detector's position should ensure a clear and complete thermal image of the sample. Larger samples can be placed further away, while smaller detectors can be placed closer. The infrared light source should cover the entire area of ​​the sample to be identified. It's crucial that the distance between the infrared detector and the sample is greater than the detector's focal length; the focal length should be used as the minimum shooting distance to guarantee a clear thermal image. Furthermore, the infrared light source and detector should be symmetrically positioned about the sample's normal axis, ensuring that the infrared light emitted by the light source is reflected from the sample before reaching the detector. In a specific example, with a 25cm focal length, the minimum shooting distance is 25cm. Based on the detector's shooting range, the size of each sample in the sample group, and the coverage of the infrared light source, the maximum shooting distance is determined to be 60cm. This corresponds to a distance range of 25cm-60cm. For instance, if the distance between the infrared detector and the sample is set to 40cm, the angle between the infrared light source and the sample's normal direction is 10 degrees, and the positions of the infrared light source and detector are symmetrically distributed about the sample's normal axis.

[0039] In the embodiments provided by this invention, the infrared light source includes artificial infrared light sources and natural infrared light sources, such as artificial infrared light sources like infrared LEDs, laser illuminators, and infrared incandescent lamps, and natural infrared light sources like the human body. The selection of the infrared light source is not limited. The preset angle range is determined based on the reflection of infrared light emitted by the infrared light source by the sample, and is not limited thereto.

[0040] S104: Obtain a sample set, wherein the sample set includes at least two samples, and each sample includes at least two types of regions to be identified. The emissivity of each type of region to be identified is different, and the difference in thermal conductivity between the types of regions to be identified is within a threshold range. That is, the emissivity of the various types of regions to be identified in the sample differs, but the thermal conductivity of the various types of regions to be identified is almost the same, or the difference is very small, within a preset threshold range. The threshold setting is related to factors such as the material of the sample; no specific numerical limit is specified here.

[0041] A sample group may include multiple samples, each of which includes two or more types of regions to be identified with different emissivity. Alternatively, a sample group may include samples with several types of regions to be identified, with each pair of regions to be identified corresponding to one sample in the sample group. There is no limitation on this.

[0042] In one embodiment, the emissivity of various types of regions to be identified is different, but the difference in emissivity between various types of regions to be identified is less than the difference threshold. That is, the difference in emissivity between the regions to be identified is small and they are not easy to identify. Therefore, an infrared light source is added to achieve a better identification effect.

[0043] In one specific implementation, the various regions to be identified in the sample are made of materials with different infrared emissivity, and these regions emit infrared rays of different energies. For example, the material can be a metal with low infrared emissivity, such as Pt, or a polymer with high infrared emissivity, such as PMMA. The material can also be one or more multilayer film materials with different absorption or reflection properties for infrared rays, and different multilayer film materials have different film thicknesses. The materials of each region to be identified include metals and alloys, inorganic non-metallic materials, polymer materials, composite materials, etc., and different materials have different infrared emissivity.

[0044] In one specific example, the sample consists of a mask with a "YES" pattern covering a portion of the surface of a PMMA substrate. Metallic Pt is deposited on the substrate using a high-vacuum evaporation system. Different thicknesses of metallic Pt are obtained by adjusting the deposition time. After deposition, the mask is removed to obtain a sample with varying emissivity. In other examples, the material in each region of the sample to be identified may also interact with infrared light, including one or more of reflection, diffraction, interference, absorption, and transmission.

[0045] S105: Based on the temperature of each light source, each sample is irradiated with an infrared light source, and a thermal image corresponding to each sample is acquired to form a thermal image group corresponding to the temperature of each light source.

[0046] After completing the position and corresponding parameter settings of the sample, infrared detector, and infrared light source, turn on the infrared light source and irradiate each sample with the infrared light source. When the infrared light source is stable, the infrared detector collects thermal images of the sample. Each sample corresponds to a thermal image, forming a thermal image group.

[0047] S106: Analyze the irradiance of each region to be identified in the thermal image, and give the irradiance difference and emissivity difference corresponding to each thermal image.

[0048] Furthermore, the irradiance of each region to be identified in the thermal images is analyzed, and the irradiance difference and emissivity difference corresponding to each thermal image are given. This includes the following steps: Based on each thermal image in the thermal image group, the apparent temperature of each region to be identified in the thermal image is obtained, and the irradiance of the corresponding region to be identified is determined by combining the radiation wavelength of the infrared light source. Calculate the difference in irradiance between the regions to be identified in each thermal image to obtain the irradiance difference corresponding to each thermal image; Based on the emissivity of each region to be identified in the thermal image, the emissivity difference between the corresponding regions to be identified is calculated, and the emissivity difference corresponding to each thermal image is determined.

[0049] Furthermore, the difference in irradiance is obtained through the following steps: Obtain the temperature value sequence of each region to be identified in the thermal image, and calculate the mean of the temperature value sequence to determine the apparent temperature of the region; Based on Planck's radiation law, and combined with the apparent temperature of the region and the radiation wavelength of the infrared light source, the irradiance of each region to be identified is obtained. The differences in irradiance of each region to be identified in the sample are analyzed, and the difference in irradiance of each region to be identified is calculated to obtain the irradiance difference corresponding to each thermal image.

[0050] The difference in irradiance is specifically expressed as:

[0051] Among them, L(T) area T represents the irradiance of the area to be identified. area The apparent temperature of the region to be identified. T represents the difference in irradiance. area1 T represents the apparent temperature of region 1 to be identified. area2 Let L(T) be the apparent temperature of region 2 to be identified.area1 L(T) represents the irradiance of the region to be identified, where T is the irradiance of the region to be identified area2 ) represents the irradiance of the region to be identified 2, λ1 represents the minimum radiation wavelength of the infrared detector, λ2 represents the maximum radiation wavelength of the infrared detector, h represents Planck's constant, c represents the speed of light in a vacuum, k represents Boltzmann's constant, λ represents the radiation wavelength, and e represents a constant.

[0052] Furthermore, the emissivity of each region to be identified in the thermal image is obtained through the following steps: Obtain the built-in emissivity and detection wavelength range of the infrared detector; Based on the built-in emissivity and detection wavelength range of the infrared detector, and combined with the apparent temperature of the region in the thermal image, the total emitted energy term is obtained. By combining the regional excitation temperature with the regional emissivity and the detection wavelength range, the sample reflection energy term is given, where the regional excitation temperature is the intrinsic temperature of the corresponding region to be identified after being irradiated by an infrared light source. The environmental reflection energy term is given by combining the background ambient temperature with the regional emissivity and the detection wavelength range; By integrating the total emission energy term, the sample reflection energy term, and the environmental reflection energy term, an energy conservation equation is formed, and the emissivity of the corresponding region to be identified is obtained. The process of forming the energy conservation equation and obtaining the emissivity of the region to be identified is repeated to obtain the emissivity of each region to be identified in each thermal image, and to determine the emissivity distribution of the corresponding thermal image of each sample.

[0053] The law of conservation of energy is expressed as follows:

[0054] Among them, T area T represents the apparent temperature of the region to be identified. sam T is the region excitation temperature of the area to be identified. amb ε represents the background ambient temperature. int ε is the built-in emissivity of the infrared detector. area Let λ be the emissivity of the area to be identified, λ be the radiation wavelength, and the minimum and maximum radiation wavelengths of the infrared detector constitute the detection wavelength range. Let λ1 be the minimum radiation wavelength of the infrared detector, and λ2 be the maximum radiation wavelength of the infrared detector. For the total emission energy term, This is the energy term of the sample reflection. This is the energy term reflected by the environment.

[0055] In this example, the built-in emissivity of the infrared detector is set to 1. The only unknown in the energy conservation equation is the emissivity of each region to be identified, which can be obtained by solving the energy conservation equation. It is important to understand that due to the different material compositions of each region to be identified, there are certain differences between the apparent temperature and intrinsic temperature of each region. The intrinsic temperature is measured by placing a contact temperature measuring device (such as a thermocouple) on the surface of the corresponding region to be identified.

[0056] S107: Based on the pre-constructed sample identification sensitivity function, combined with the irradiance difference and emissivity difference corresponding to each thermal image, a sensitivity series is given to determine the sample identification sensitivity of infrared detection.

[0057] Furthermore, based on the pre-constructed sample identification sensitivity function, and combined with the irradiance difference and emissivity difference corresponding to each thermal image, a sensitivity series is given to determine the sample identification sensitivity of infrared detection. This specifically includes the following steps: Substitute the difference in radiance and the difference in emissivity corresponding to each thermal image into the sample identification sensitivity function to obtain the sensitivity value corresponding to each thermal image. Based on the light source temperature of each infrared light source, the sensitivity values ​​of the corresponding thermal image groups are fused to form a sensitivity sequence; The sample recognition sensitivity of the infrared detector is determined by using a sensitivity sequence.

[0058] The sample identification sensitivity function is specifically expressed as follows:

[0059] Where Sen is the sensitivity value. The difference in irradiance. σ represents the emissivity difference, and σ is the noise of the infrared detection system. σ is obtained by calculating the standard deviation of irradiance in each thermal image.

[0060] At a specific light source temperature, an infrared detector is used to detect each sample in the sample group, obtaining the corresponding sample's sensitivity value. Each light source temperature corresponds to a set of sensitivity sequences. By fitting the emissivity difference and sensitivity value of each sample at a specific light source temperature, a fitting curve is obtained. Multiple light source temperatures can yield multiple curves, thus determining the sample recognition sensitivity of the infrared detector.

[0061] When using an infrared detector to detect samples in the future, the corresponding sensitivity value can be retrieved based on the corresponding emissivity difference. It can then be determined whether the sensitivity value has reached the set threshold. If it has, it means that the corresponding areas to be identified in the sample can be detected at the corresponding light source temperature. Otherwise, they cannot be detected, and the sensitivity values ​​at other light source temperatures need to be determined to provide a data basis for sample detection and improve the detection efficiency of infrared detectors for each sample.

[0062] In a specific example, a human hand is used as an infrared light source for detection. The temperature difference between the hand and the background environment plays a crucial role in the identification and detection of different areas to be identified. During the infrared light source illumination identification process, the infrared detector captures infrared signals from different areas of the sample to be identified. This infrared signal includes the infrared light emitted from the area to be identified and the infrared light reflected from the hand. Increased differences in the infrared signals of different areas of the sample allow for the identification of the corresponding areas, enhancing the sensitivity of emissivity difference detection. In the absence of a hand as an infrared light source (e.g.) Figure 2 As shown in the left-middle column), the low-reflectance and high-reflectance regions to be identified in the sample are in temperature equilibrium with the background. Therefore, the infrared signals of different regions to be identified are the same, and the infrared detector cannot identify the pattern. When a human hand is used as an infrared light source (e.g., Figure 2 As shown in the right column (middle), the infrared radiation from the human hand is reflected by each area to be identified in the sample. Therefore, the infrared signal of the area to be identified with high reflectivity is stronger than that of the area to be identified with low reflectivity. Thus, the infrared detector can be used to identify each area to be identified in the sample and realize the detection of differences in infrared emissivity. Figure 3 This study examines the differences in irradiance (i.e., irradiance difference) and infrared emissivity (i.e., emissivity difference) between different regions of the sample to be identified, under the condition of using a human hand at 37°C as the infrared light source. In this example, under the condition of using a human hand at 37°C as the infrared light source... The value is 11.5 W / sr, and the noise is 0.027. Therefore, the sample recognition sensitivity of the infrared detector is 0.007.

[0063] In another specific example, an infrared camera is used as the infrared detector, and a heating element is used as the infrared light source, allowing the infrared detector to capture corresponding signal differences. The 37°C human hand is replaced with a heating element at 80°C as the infrared light source. Figure 4 This paper presents the relationship between the differences in irradiance (i.e., irradiance difference) and infrared emissivity (i.e., emissivity difference) of different regions to be identified in the sample under the condition of using an 80℃ heating element as an infrared light source. Specifically, under conditions where noise variation is small, the difference in light source temperature... The value increased from 11.5 W / sr to 20.4 W / sr. Therefore, the sample recognition sensitivity of the infrared detector increased from 0.007 to 0.004.

[0064] Reference Figure 5 This invention provides a device for determining sample identification sensitivity based on infrared detection, comprising: Temperature configuration unit 201 is used to acquire background ambient temperature, determine the light source threshold temperature of infrared light source, and provide the light source temperature of at least one infrared light source based on the light source threshold temperature. System building unit 202 is used to build an infrared detection system consisting of an infrared detector, a sample, and an infrared light source; The sample acquisition unit 203 is used to acquire a sample group, wherein the sample group includes at least two samples, and each sample includes at least two types of regions to be identified; The thermal image acquisition unit 204 is used to irradiate each sample with an infrared light source based on the temperature of each light source, acquire thermal images corresponding to each sample, and form a group of thermal images corresponding to the temperature of each light source. The thermal image analysis unit 205 is used to analyze the irradiance of each region to be identified in the thermal image and to give the irradiance difference and emissivity difference of each thermal image. The sensitivity determination unit 206 is used to determine the sample identification sensitivity of infrared detection by giving a sensitivity series based on a pre-constructed sample identification sensitivity function and combining the irradiance difference and emissivity difference corresponding to each thermal image.

[0065] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the described module can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0066] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if these modifications and variations of the invention fall within the scope of the claims and their equivalents, the invention is also intended to include these modifications and variations.

Claims

1. A method for determining sample identification sensitivity based on infrared detection, characterized in that, Specifically, the steps include the following: The background ambient temperature is obtained, and the threshold temperature of the infrared light source is determined. The threshold temperature is the lowest temperature at which the differences between the various regions to be identified in the sample begin to appear in the infrared detector. The threshold temperature is determined through the following steps: obtaining a preset irradiance difference threshold and the minimum resolution difference of the infrared detector; determining the irradiance of the background environment based on the background ambient temperature; calculating the ratio of the preset irradiance difference threshold to the minimum resolution difference of the infrared detector based on the preset irradiance difference threshold and the minimum resolution difference of the infrared detector, thus determining the irradiance difference; fusing the irradiance difference and the irradiance of the background environment to obtain the minimum irradiance of the infrared light source; and analyzing the minimum irradiance of the infrared light source using Planck's law of radiation to obtain the threshold temperature. Based on the light source threshold temperature, the light source temperatures of at least two infrared light sources are given, wherein the temperature of each light source is not lower than the light source threshold temperature; Construct an infrared detection system consisting of an infrared detector, a sample, and an infrared light source; Obtain a sample group, wherein the sample group includes at least two samples, each sample includes at least two types of regions to be identified, wherein the emissivity of each type of region to be identified is different, and the difference in thermal conductivity between each type of region to be identified is within a threshold range. Based on the temperature of each light source, each sample is irradiated with an infrared light source, and a thermal image corresponding to each sample is acquired to form a thermal image group corresponding to the temperature of each light source. Analyze the irradiance of each region to be identified in the thermal images, and provide the irradiance difference and emissivity difference for each thermal image; Substituting the irradiance difference and emissivity difference corresponding to each thermal image into the sample identification sensitivity function yields the sensitivity value corresponding to each thermal image. The sample identification sensitivity function is specifically expressed as follows: ； Where Sen is the sensitivity value, ΔL is the difference in radiance, Δε is the difference in emissivity, and σ is the noise of the infrared detection system; Based on the light source temperature of each infrared light source, the sensitivity values ​​of the corresponding thermal image groups are fused to form a sensitivity sequence; By fitting the emissivity difference and sensitivity value of each sample at each light source temperature, a fitting curve is obtained; The sample recognition sensitivity of the infrared detector was determined based on multiple fitted curves obtained from multiple light source temperatures.

2. The method for determining sample identification sensitivity based on infrared detection as described in claim 1, characterized in that, The background ambient temperature is obtained through the following steps: Obtain standard samples, wherein the standard samples include at least two types of regions to be identified; Based on the preset first background temperature, the standard sample temperature is determined, and the standard sample is subjected to temperature excitation treatment until the intrinsic temperature of each region to be identified in the standard sample is equal to the standard sample temperature. Obtain the first thermal image of the standard sample, collect the highest and lowest temperature values ​​in the first thermal image, and give the temperature difference value of the first thermal image. Based on the temperature difference, the first background temperature is adjusted, and the process of temperature excitation processing and acquisition of the first thermal image is repeated. If the temperature difference reaches the preset requirement, the first background temperature will be determined as the background ambient temperature.

3. The method for determining sample identification sensitivity based on infrared detection as described in claim 1, characterized in that, Constructing an infrared detection system comprising an infrared detector, a sample, and an infrared light source, specifically including: The maximum shooting distance is determined based on the shooting range of the infrared detector, the size of each sample in the sample group, and the coverage of the infrared light source. Determine the minimum shooting distance based on the focal length of the infrared detector; By combining the minimum and maximum shooting distances, the distance range can be determined. The distances between the infrared detector, the infrared light source, and the sample are set according to the distance range to form an infrared detection system. The infrared detector and the infrared light source are set symmetrically about the normal of the sample, and the angle between the infrared detector and the normal of the sample is within a preset angle range.

4. The method for determining sample identification sensitivity based on infrared detection as described in claim 1, characterized in that, Analyze the irradiance of each region to be identified in the thermal images, and provide the irradiance difference and emissivity difference for each thermal image. This process includes the following steps: Based on each thermal image in the thermal image group, the apparent temperature of each region to be identified in the thermal image is obtained, and the irradiance of the corresponding region to be identified is determined by combining the radiation wavelength of the infrared light source. Calculate the difference in irradiance between the regions to be identified in each thermal image to obtain the irradiance difference corresponding to each thermal image; Based on the emissivity of each region to be identified in the thermal image, the emissivity difference between the corresponding regions to be identified is calculated, and the emissivity difference corresponding to each thermal image is determined.

5. The method for determining sample identification sensitivity based on infrared detection as described in claim 4, characterized in that, The irradiance difference values ​​corresponding to each thermal image are obtained through the following steps: Obtain the temperature value sequence of each region to be identified in the thermal image, and calculate the mean of the temperature value sequence to determine the apparent temperature of the region; By combining the apparent temperature of the region with the radiation wavelength of the infrared light source, the irradiance of each region to be identified is obtained. The differences in irradiance of each region to be identified in the sample are analyzed, and the difference in irradiance of each region to be identified is calculated to obtain the irradiance difference corresponding to each thermal image.

6. The method for determining sample identification sensitivity based on infrared detection as described in claim 4, characterized in that, The emissivity of each region to be identified in the thermal image is obtained through the following steps: Obtain the built-in emissivity and detection wavelength range of the infrared detector; Based on the built-in emissivity and detection wavelength range of the infrared detector, and combined with the apparent temperature of the region in the thermal image, the total emitted energy term is obtained. By combining the regional excitation temperature with the regional emissivity and the detection wavelength range, the sample reflection energy term is given, where the regional excitation temperature is the intrinsic temperature of the corresponding region to be identified after being irradiated by an infrared light source. The environmental reflection energy term is given by combining the background ambient temperature with the regional emissivity and the detection wavelength range; By integrating the total emission energy term, the sample reflection energy term, and the environmental reflection energy term, an energy conservation equation is formed, and the emissivity of the corresponding region to be identified is obtained. The process of forming the energy conservation equation and obtaining the emissivity of the region to be identified is repeated to obtain the emissivity of each region to be identified in each thermal image, and to determine the emissivity distribution of the corresponding thermal image of each sample.

7. A device for determining sample identification sensitivity based on infrared detection, characterized in that, The method for determining sample identification sensitivity based on infrared detection as described in claim 1 specifically includes: A temperature configuration unit is used to acquire the background ambient temperature, determine the light source threshold temperature of the infrared light source, and, based on the light source threshold temperature, provide the light source temperatures of at least two infrared light sources. The light source threshold temperature is the lowest temperature at which the differences between each region to be identified in the sample begin to appear in the infrared detector. The light source threshold temperature is determined through the following steps: acquiring a preset irradiance difference threshold and the minimum resolution difference value of the infrared detector; determining the irradiance of the background environment based on the background ambient temperature; calculating the ratio of the irradiance difference threshold to the minimum resolution difference value of the infrared detector based on the preset irradiance difference threshold and the minimum resolution difference value of the infrared detector, and determining the irradiance difference value; fusing the irradiance difference value and the irradiance of the background environment to obtain the minimum irradiance of the infrared light source; analyzing the minimum irradiance of the infrared light source using Planck's radiation law to obtain the light source threshold temperature; and ensuring that each light source temperature is not lower than the light source threshold temperature. The system building unit is used to construct an infrared detection system consisting of an infrared detector, a sample, and an infrared light source; A sample acquisition unit is used to acquire a sample group, wherein the sample group includes at least two samples, each sample includes at least two types of regions to be identified, wherein the emissivity of each type of region to be identified is different, and the difference in thermal conductivity between each type of region to be identified is within a threshold range. The thermal imaging acquisition unit is used to irradiate each sample with an infrared light source based on the temperature of each light source, acquire thermal images corresponding to each sample, and form a group of thermal images corresponding to the temperature of each light source. The thermal imaging analysis unit is used to analyze the irradiance of each region to be identified in the thermal image and to provide the irradiance difference and emissivity difference corresponding to each thermal image. The sensitivity determination unit is used to substitute the irradiance difference and emissivity difference corresponding to each thermal image into the sample identification sensitivity function to obtain the sensitivity value corresponding to each thermal image. The sample identification sensitivity function is specifically expressed as follows: ； Where Sen is the sensitivity value, ΔL is the difference in radiance, Δε is the difference in emissivity, and σ is the noise of the infrared detection system; Based on the light source temperature of each infrared light source, the sensitivity values ​​of the corresponding thermal image groups are fused to form a sensitivity sequence; By fitting the emissivity difference and sensitivity value of each sample at each light source temperature, a fitting curve is obtained; The sample recognition sensitivity of the infrared detector was determined based on multiple fitted curves obtained from multiple light source temperatures.

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