阅读说明：本技术 一种非制冷红外热像仪及获取温度信息的方法 (Uncooled thermal infrared imager and method for acquiring temperature information ) 是由 郭得福 张书强 宋洁 王鹏 闫福文 于 2021-09-27 设计创作，主要内容包括：本申请提供一种非制冷红外热像仪,包括红外光学镜头、非制冷红外探测器以及图像处理模块,非制冷红外探测器的第一端与红外光学镜头连接,第二端与图像处理模块连接。还包括：补偿黑体,补偿黑体位于红外光学镜头上,补偿黑体用于切入红外光学镜头和非制冷红外探测器之间的光路,图像处理模块用于在补偿黑体切入红外光学镜头和非制冷红外探测器之间的光路时,采集补偿黑体的响应灰度数据,以作为被测目标响应灰度数据的补偿源。这样,在补偿黑体切入光路时,将补偿黑体的响应灰度数据作为被测目标响应灰度数据的补偿源,达到补偿环境辐射因素影响的目的,减小环境辐射对被测目标的图像灰度信息的影响,提高温度测量的精度和稳定性。(The application provides an uncooled thermal infrared imager, which comprises an infrared optical lens, an uncooled infrared detector and an image processing module, wherein a first end of the uncooled infrared detector is connected with the infrared optical lens, and a second end of the uncooled infrared detector is connected with the image processing module. Further comprising: the compensation black body is positioned on the infrared optical lens and used for cutting in a light path between the infrared optical lens and the uncooled infrared detector, and the image processing module is used for collecting response gray data of the compensation black body when the compensation black body is cut in the light path between the infrared optical lens and the uncooled infrared detector so as to serve as a compensation source of the response gray data of the measured target. Therefore, when the compensation black body is switched into the light path, the response gray data of the compensation black body is used as a compensation source of the response gray data of the measured target, the purpose of compensating the influence of environmental radiation factors is achieved, the influence of environmental radiation on the image gray information of the measured target is reduced, and the accuracy and the stability of temperature measurement are improved.)

1. An uncooled thermal infrared imager, comprising: the system comprises an infrared optical lens, an uncooled infrared detector and an image processing module; the first end of the uncooled infrared detector is connected with the infrared optical lens, the second end of the uncooled infrared detector is connected with the image processing module, and the uncooled thermal infrared imager further comprises:

the compensation black body is positioned on the infrared optical lens;

the compensation black body is used for cutting into a light path between the infrared optical lens and the uncooled infrared detector;

the image processing module is used for collecting the response gray data of the compensation black body when the compensation black body is switched into the light path so as to be used as a compensation source of the response gray data of the detected target.

2. The uncooled thermal infrared imager of claim 1, wherein the infrared optical lens comprises a main lens barrel and an optical system arranged in the main lens barrel, the optical system comprises a first lens, a second lens, a third lens, a diaphragm, a fourth lens and a fifth lens which are sequentially arranged along a first direction, the first lens, the second lens and the fifth lens are meniscus germanium positive lenses with convex surfaces facing a second direction, the third lens is a meniscus chalcogenide negative lens with a convex surface facing the first direction, the fourth lens is a biconvex germanium positive lens with a convex surface facing the first direction, the first direction and the second direction are opposite, and the first direction is a light incidence direction.

3. The uncooled thermal infrared imager of claim 1, wherein the image processing module includes: the device comprises an analog-to-digital conversion circuit, an image processing circuit and a cache circuit; the image processing circuit includes: the device comprises an image filtering unit, a non-uniform correction unit, a blind pixel replacement unit, a temperature compensation algorithm unit and a compensation black body gray level data acquisition unit;

the first end of the analog-to-digital conversion circuit is connected with the second end of the uncooled infrared detector, the second end of the analog-to-digital conversion circuit is connected with the first end of the image filtering unit, the second end of the image filtering unit is connected with the first end of the non-uniform correction unit, and the second end of the non-uniform correction unit is connected with the first end of the blind pixel replacement unit; the second end of the blind pixel replacing unit is connected with the first end of the temperature compensation algorithm unit, and the second end of the temperature compensation algorithm unit is connected with the cache circuit; the first end of the compensation black body gray data acquisition unit is connected with the first end of the image filtering unit, and the second end of the compensation black body gray data acquisition unit is connected with the first end of the non-uniform correction unit and the first end of the temperature compensation algorithm unit;

the temperature compensation algorithm unit is used for calculating actual gray data of the compensation target according to the response gray data of the detected target, the response gray data of the compensation black body and the gray compensation variation of the detected target caused by the temperature variation of the compensation black body, and converting the actual gray data into temperature information.

4. The uncooled thermal infrared imager of claim 3, wherein the temperature compensation algorithm unit is specifically configured to obtain response gray data of the target to be measured within a current preset time interval output by the blind pixel replacement unit and average gray data of the compensation black body within the current preset time interval and a previous preset time interval output by the compensation black body gray data acquisition unit;

the gray compensation amount of each frame of image in the current preset time interval is calculated according to the average gray data and the number of the image frames;

and the system is also used for calculating the actual gray data of the measured target according to the response gray data of the measured target in the current preset time interval, the gray compensation amount of each frame of image and the gray compensation variation amount of the measured target caused by the temperature variation of the compensation black body, and converting the actual gray data into temperature information.

5. The uncooled thermal infrared imager of claim 1, wherein the infrared optical lens includes a two-dimensional motion mechanism, the compensation black body is located on the two-dimensional motion mechanism, and the two-dimensional motion mechanism drives the compensation black body to move so that the compensation black body cuts into a light path between the infrared optical lens and the uncooled infrared detector.

6. The uncooled thermal infrared imager of claim 3, wherein the compensating black body gray data collecting unit is specifically configured to collect response gray data of the compensating black body when the compensating black body is switched into a light path between the infrared optical lens and the uncooled infrared detector at a preset time interval, and calculate average gray data of the compensating black body within each preset time interval according to the response gray data.

7. The uncooled thermal infrared imager of claim 3, wherein the temperature compensation algorithm unit is specifically configured to calculate a difference between average gray data according to the average gray data of the compensation black body in the current preset time interval and the previous preset time interval, calculate an average gray change rate of each frame of image in the previous preset time interval according to the difference between the average gray data and the number of frames of image in the previous preset time interval, and calculate a gray compensation amount of each frame of image in the current preset time interval according to the average gray change rate and the number of frames of image in the current preset time interval.

8. The uncooled thermal infrared imager of claim 3, wherein the thermal imager further comprises: the temperature sensor is connected with the first end of the temperature compensation algorithm unit;

the temperature sensor is used for acquiring the temperature value of the compensation black body when the calibration black body has two temperatures;

the temperature compensation algorithm unit is used for acquiring response gray scale data of the calibration black body at two temperatures and the temperature value of the compensation black body output by the temperature sensor, and calculating the difference value of the temperature value of the compensation black body and the difference value of the response gray scale data of the calibration black body, and calculating the gray level compensation change rate of the calibration black body caused by the temperature change of the compensation black body according to the difference value of the temperature values and the difference value of the response gray level data of the calibration black body, and calculating the gray compensation variation of the calibration black body caused by the temperature change of the compensation black body in the current preset time interval according to the temperature variation of the compensation black body in the current preset time interval and the gray compensation variation rate, and taking the gray compensation variation of the calibration black body as the gray compensation variation of the measured target.

9. The uncooled thermal infrared imager of claim 3, wherein the temperature compensation algorithm unit is specifically configured to collect actual gray data of the calibration black body at different temperatures of the calibration black body, fit a corresponding relationship between the temperature of the calibration black body and the actual gray data, and input the actual gray data of the target to be measured into the corresponding relationship to obtain the temperature information of the target to be measured.

10. A method of obtaining temperature information, comprising:

when a compensation black body is cut into a light path between an infrared optical lens and an uncooled infrared detector, collecting response gray data of the compensation black body;

and taking the response gray data of the compensation black body as a compensation source of the response gray data of the measured target to obtain the actual gray data of the measured target so as to convert the actual gray data into temperature information.

11. The method according to claim 10, wherein the taking the response gray scale data of the compensation black body as a compensation source of the response gray scale data of the target to be measured to obtain the actual gray scale data of the target to be measured specifically comprises:

and calculating the actual gray data of the measured target according to the response gray data of the measured target, the response gray data of the compensation black body and the gray compensation variation of the measured target caused by the temperature variation of the compensation black body.

12. The method according to claim 11, wherein calculating the actual gray scale data of the target under test according to the response gray scale data of the target under test, the response gray scale data of the compensation black body, and the gray scale compensation variation of the target under test caused by the temperature variation of the compensation black body comprises:

calculating the gray compensation amount of each frame of image in the current preset time interval according to the average gray data and the image frame number of the compensation black body in the current preset time interval and the last preset time interval;

acquiring response gray data of the measured target in the current preset time interval and gray compensation variation of the measured target caused by temperature variation of the compensation black body;

and calculating actual gray data of the measured target according to the response gray data of the measured target in the current preset time interval, the gray compensation amount of each frame of image and the gray compensation variation amount of the measured target caused by the temperature variation of the compensation black body.

13. The method as claimed in claim 12, wherein before calculating the gray compensation amount of each frame of image in the current preset time interval according to the average gray data of the compensating black body in the current preset time interval and the last preset time interval and the number of frames of the image, the method further comprises:

and calculating the average gray data of the compensation black body in each preset time interval according to the response gray data of the compensation black body so as to obtain the average gray data of the compensation black body in the current preset time interval and the last preset time interval.

14. The method according to claim 12, wherein the calculating the gray compensation amount of each frame of image in the current preset time interval according to the average gray data of the compensation black body in the current preset time interval and the previous preset time interval and the number of frames of the image comprises:

calculating the difference value of the average gray data according to the average gray data of the compensation black body in the current preset time interval and the last preset time interval;

calculating the average gray level change rate of each frame of image in the last preset time interval according to the difference value of the average gray level data and the number of image frames in the last preset time interval;

and calculating the gray compensation quantity of each frame of image in the current preset time interval according to the average gray change rate and the number of image frames in the current preset time interval.

15. The method according to claim 12, wherein the obtaining a gray compensation variation of the target to be measured caused by a temperature variation of the compensation black body within a current preset time interval specifically comprises:

the method comprises the steps of obtaining a temperature value of a compensation black body and response gray scale data of the calibration black body when the calibration black body is at two temperatures;

calculating the difference value of the temperature values of the compensation black bodies and the difference value of the response gray data;

calculating the gray level compensation change rate of the calibration black body caused by the temperature change of the compensation black body according to the difference value of the temperature values and the difference value of the gray level data;

calculating the gray compensation variation of the calibration black body caused by the temperature variation of the compensation black body according to the gray compensation variation rate and the temperature variation of the compensation black body within the current preset time interval;

and taking the gray compensation variation of the calibration black body as the gray compensation variation of the measured target.

16. The method according to claim 11, wherein the converting the actual gray scale data into temperature information specifically comprises:

acquiring actual gray data of the calibration black body at different temperatures;

fitting a corresponding relation between the temperature of the calibration black body and the actual gray data;

and inputting the actual gray data of the measured target into the corresponding relation to obtain the temperature information of the measured target.

Technical Field

The application relates to the technical field of optics, in particular to an uncooled thermal infrared imager and a method for acquiring temperature information.

Background

The infrared thermal imager comprises an infrared optical lens and an infrared detector, wherein the infrared optical lens collects infrared radiation emitted by a measured object onto the infrared detector through a lens group, the infrared detector converts the incident radiation into an electric signal to form a gray image, namely a thermal image, of the measured object, and the thermal image reflects temperature information of the measured object.

The infrared thermal imager comprises a refrigeration infrared thermal imager and an uncooled infrared thermal imager, the uncooled infrared thermal imager has fewer manufacturing steps, higher yield and longer service life, and has higher thermal radiation resolution ratio in 3um-5um medium wave infrared and 8um-14um long wave infrared, so that the uncooled infrared thermal imager outputs a gray level image of a measured object with better resolution ratio, and more accurate temperature information can be obtained.

However, the output information of the uncooled thermal infrared imager not only includes the radiation information of the target to be measured and the environmental radiation information, but also includes various influence factors such as the direct current information output by the uncooled thermal infrared imager itself, and the change of the influence factors can cause the image gray scale information output by the uncooled thermal infrared imager to be influenced, so that the precision and the stability of temperature measurement are poor.

Disclosure of Invention

The application provides an uncooled thermal infrared imager and a method for acquiring temperature information, which are used for solving the problem that the accuracy and stability of temperature measurement are poor due to the fact that image gray scale information output by the uncooled thermal infrared imager is influenced by various external factors.

In a first aspect, the present application provides an uncooled thermal infrared imager, comprising: the system comprises an infrared optical lens, an uncooled infrared detector and an image processing module; the first end of the uncooled infrared detector is connected with the infrared optical lens, the second end of the uncooled infrared detector is connected with the image processing module, and the thermal infrared imager further comprises:

the compensation black body is positioned on the infrared optical lens;

the compensation black body is used for cutting into a light path between the infrared optical lens and the uncooled infrared detector;

the image processing module is used for collecting the response gray data of the compensation black body when the compensation black body is switched into the light path so as to be used as a compensation source of the response gray data of the detected target.

Optionally, the infrared optical lens includes a main lens barrel and an optical system arranged in the main lens barrel, the optical system includes a first lens, a second lens, a third lens, a diaphragm, a fourth lens and a fifth lens which are sequentially arranged along a first direction, the first lens, the second lens and the fifth lens are meniscus germanium positive lenses with convex surfaces facing a second direction, the third lens is a meniscus chalcogenide negative lens with convex surfaces facing the first direction, the fourth lens is a biconvex germanium positive lens with convex surfaces facing the first direction, the first direction and the second direction are opposite, and the first direction is a light incidence direction.

Optionally, the image processing module includes: the device comprises an analog-to-digital conversion circuit, an image processing circuit and a cache circuit; the image processing circuit includes: the device comprises an image filtering unit, a non-uniform correction unit, a blind pixel replacement unit, a temperature compensation algorithm unit and a compensation black body gray level data acquisition unit;

the first end of the analog-to-digital conversion circuit is connected with the second end of the infrared detector, the second end of the analog-to-digital conversion circuit is connected with the first end of the image filtering unit, the second end of the image filtering unit is connected with the first end of the non-uniform correction unit, the second end of the non-uniform correction unit is connected with the first end of the blind pixel replacement unit, the second end of the blind pixel replacement unit is connected with the first end of the temperature compensation algorithm unit, and the second end of the temperature compensation algorithm unit is connected with the cache circuit;

the first end of the compensation black body gray data acquisition unit is connected with the first end of the image filtering unit, and the second end of the compensation black body gray data acquisition unit is connected with the first end of the non-uniform correction unit and the first end of the temperature compensation algorithm unit;

the temperature compensation algorithm unit is used for calculating actual gray data of the compensation target according to the response gray data of the detected target, the response gray data of the compensation black body and the gray compensation variation of the detected target caused by the temperature variation of the compensation black body, and converting the actual gray data into temperature information.

Optionally, the temperature compensation algorithm unit is configured to obtain response gray scale data of the target to be measured within a current preset time interval output by the blind pixel replacement unit and average gray scale data of the compensation black body within the current preset time interval and a previous preset time interval output by the compensation black body gray scale data acquisition unit;

the gray compensation amount of each frame of image in the current preset time interval is calculated according to the average gray data and the number of the image frames;

and the system is also used for calculating the actual gray data of the measured target according to the response gray data of the measured target in the current preset time interval, the gray compensation amount of each frame of image and the gray compensation variation amount of the measured target caused by the temperature variation of the compensation black body, and converting the actual gray data into temperature information.

Optionally, the infrared optical lens includes a two-dimensional movement mechanism, the compensation black body is located on the two-dimensional movement mechanism, and the two-dimensional movement mechanism drives the compensation black body to move, so that the compensation black body is cut into a light path between the infrared optical lens and the uncooled infrared detector.

Optionally, the compensating black body gray scale data collecting unit is specifically configured to collect response gray scale data of the compensating black body when the compensating black body is switched into a light path between the infrared optical lens and the uncooled infrared detector at a preset time interval, and calculate average gray scale data of the compensating black body within each preset time interval according to the response gray scale data.

Optionally, the temperature compensation algorithm unit is specifically configured to calculate a difference of average gray scale data according to the average gray scale data of the compensation black body in the current preset time interval and the last preset time interval, calculate an average gray scale change rate of each frame of image in the last preset time interval according to the difference of the average gray scale data and the number of frames of the image in the last preset time interval, and calculate a gray scale compensation amount of each frame of image in the current preset time interval according to the average gray scale change rate and the number of frames of the image in the current preset time interval.

Optionally, the thermal imager further includes: the temperature sensor is connected with the first end of the temperature compensation algorithm unit;

the temperature sensor is used for acquiring the temperature value of the compensation black body when the calibration black body has two temperatures;

the temperature compensation algorithm unit is used for acquiring response gray scale data of the calibration black body at two temperatures and the temperature value of the compensation black body output by the temperature sensor, and calculating the difference value of the temperature value of the compensation black body and the difference value of the response gray scale data of the calibration black body, and calculating the gray level compensation change rate of the calibration black body caused by the temperature change of the compensation black body according to the difference value of the temperature values and the difference value of the response gray level data of the calibration black body, and calculating the gray compensation variation of the calibration black body caused by the temperature change of the compensation black body in the current preset time interval according to the temperature variation of the compensation black body in the current preset time interval and the gray compensation variation rate, and taking the gray compensation variation of the calibration black body as the gray compensation variation of the measured target.

Optionally, the temperature compensation algorithm unit is specifically configured to collect actual gray scale data of the calibration black body at different temperatures of the calibration black body, fit a corresponding relationship between the temperature of the calibration black body and the actual gray scale data, and input the actual gray scale data of the target to be measured into the corresponding relationship, so as to obtain temperature information of the target to be measured.

In a second aspect, the present application provides a method for acquiring temperature information, including:

when a compensation black body is cut into a light path between an infrared optical lens and an uncooled infrared detector, collecting response gray data of the compensation black body;

and taking the response gray data of the compensation black body as a compensation source of the response gray data of the measured target to obtain the actual gray data of the measured target so as to convert the actual gray data into temperature information.

Optionally, the obtaining of the actual gray scale data of the measured target by using the response gray scale data of the compensation black body as a compensation source of the response gray scale data of the measured target specifically includes:

and calculating actual gray data of the measured target according to the response gray data of the measured target, the response gray data of the compensation black body and the gray compensation variation of the measured target caused by the temperature variation of the compensation black body, and converting the actual gray data into temperature information.

Optionally, calculating actual gray scale data of the measured target according to the response gray scale data of the measured target, the response gray scale data of the compensation black body, and the gray scale compensation variation of the measured target caused by the temperature variation of the compensation black body, specifically including:

calculating the gray compensation amount of each frame of image in the current preset time interval according to the average gray data and the image frame number of the compensation black body in the current preset time interval and the last preset time interval;

acquiring response gray data of the measured target in the current preset time interval and gray compensation variation of the measured target caused by temperature variation of the compensation black body;

and calculating actual gray data of the measured target according to the response gray data of the measured target in the current preset time interval, the gray compensation amount of each frame of image and the gray compensation variation amount of the measured target caused by the temperature variation of the compensation black body.

Optionally, before calculating the gray compensation amount of each frame of image in the current preset time interval according to the average gray data of the compensation black body in the current preset time interval and the previous preset time interval and the number of frames of the image, the method further includes:

when the compensation black body is cut into a light path between the infrared optical system and the infrared detector at a preset time interval, acquiring response gray data of the compensation black body;

and calculating the average gray data of the compensation black body in each preset time interval according to the response gray data of the compensation black body so as to obtain the average gray data of the compensation black body in the current preset time interval and the last preset time interval.

Optionally, the calculating a gray compensation amount of each frame of image in the current preset time interval according to the average gray data of the compensation black body in the current preset time interval and the previous preset time interval and the number of image frames specifically includes:

calculating the difference value of the average gray data according to the average gray data of the compensation black body in the current preset time interval and the last preset time interval;

calculating the average gray level change rate of each frame of image in the last preset time interval according to the difference value of the average gray level data and the number of image frames in the last preset time interval;

and calculating the gray compensation quantity of each frame of image in the current preset time interval according to the average gray change rate and the number of image frames in the current preset time interval.

Optionally, the obtaining of the gray compensation variation of the measured target caused by the temperature change of the compensation black body within the current preset time interval specifically includes:

the method comprises the steps of obtaining a temperature value of a compensation black body and response gray scale data of the calibration black body when the calibration black body is at two temperatures;

calculating the difference value of the temperature values of the compensation black bodies and the difference value of the response gray data;

calculating the gray level compensation change rate of the calibration black body caused by the temperature change of the compensation black body according to the difference value of the temperature values and the difference value of the gray level data;

calculating the gray compensation variation of the calibration black body caused by the temperature variation of the compensation black body according to the gray compensation variation rate and the temperature variation of the compensation black body within the current preset time interval;

and taking the gray compensation variation of the calibration black body as the gray compensation variation of the measured target.

Optionally, the converting the actual gray scale data into the temperature information specifically includes:

acquiring actual gray data of the calibration black body at different temperatures;

fitting a corresponding relation between the temperature of the calibration black body and the actual gray data;

and inputting the actual gray data of the measured target into the corresponding relation to obtain the temperature information of the measured target.

The application provides an uncooled thermal infrared imager, including infrared optical lens, uncooled infrared detector and image processing module, uncooled infrared detector's first end is connected with infrared optical lens, and the second end is connected with image processing module. Further comprising: the compensation black body is positioned on the infrared optical lens and used for cutting in a light path between the infrared optical lens and the uncooled infrared detector, and the image processing module is used for collecting response gray data of the compensation black body when the compensation black body is cut in the light path between the infrared optical lens and the uncooled infrared detector so as to serve as a compensation source of the response gray data of the measured target. Therefore, when the compensation black body is switched into the light path, the response gray data of the compensation black body is used as a compensation source of the response gray data of the measured target, the purpose of compensating the influence of environmental radiation factors is achieved, the influence of environmental radiation on the image gray information of the measured target is reduced, and the accuracy and the stability of temperature measurement are improved.

Drawings

In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings needed for the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an uncooled thermal infrared imager according to an embodiment of the present application;

FIG. 2 is a schematic structural view of an uncooled thermal infrared imager according to another embodiment of the present application;

fig. 3 is a schematic structural diagram of an optical system of an infrared optical lens according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of an image processing module according to an embodiment of the present application;

fig. 5-9 are flowcharts illustrating a method for acquiring temperature information according to an embodiment of the present disclosure.

Detailed Description

To make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be clearly and completely described below with reference to the drawings in the present application, and it is obvious that the described embodiments are some, but not all embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

When the uncooled thermal infrared imager is used for temperature measurement, the output information of the uncooled thermal infrared imager not only contains target radiation information and environment radiation information, but also contains various influence factors such as direct current information output by the uncooled thermal infrared imager and the like, and the change of the influence factors can change the image gray scale information output by the uncooled thermal infrared imager, so that the temperature measurement precision and stability are poor.

Assuming that the relation between the response gray data of the measured target and the temperature of the measured target is y = f ((x)), the actual output gray of the uncooled thermal infrared imager is as follows: y = f (x) + t (ring), t (ring) being the effect of ambient temperature radiation on the uncooled thermal infrared imager output gray data. Therefore, to make an accurate temperature measurement, the influence of these factors needs to be eliminated.

In order to solve the problems, the compensation black body is installed in the uncooled thermal infrared imager, the compensation black body is a solid object with uniform temperature radiation, the compensation black body can be in any shape, and the compensation black body can block a detection surface of the infrared detector after being cut into a light path between the infrared detector and the infrared optical system. After the compensation black body is switched into the light path, response gray data of the compensation black body are collected, and the response gray data of the compensation black body is used as a compensation source of response gray data of the measured target, so that the purpose of compensating the influence of environmental radiation factors is achieved, the influence of environmental radiation on image gray data of the measured target is reduced, and the accuracy and the stability of temperature measurement are improved.

The technical solution of the present application will be described in detail below with specific examples. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.

Fig. 1 and fig. 2 show schematic structural diagrams of an uncooled thermal infrared imager provided by an embodiment of the present application. Referring to fig. 1 and 2, the uncooled thermal infrared imager includes:

infrared optical lens 100, uncooled infrared detector 200 and image processing module 300, uncooled infrared detector 200's first end is connected with infrared optical lens 100, and the second end is connected with image processing module 300, and uncooled thermal infrared imager still includes:

a compensation black body 400, the compensation black body 400 being positioned on the infrared optical lens 100;

the compensation black body 400 is used for cutting into a light path between the infrared optical lens 100 and the uncooled infrared detector 200;

the image processing module 300 is configured to collect response gray data of the compensation black body 400 when the compensation black body 400 is switched into the optical path, so as to serve as a compensation source of the response gray data of the target to be measured.

The infrared optical lens 100 includes a main barrel and an optical system 500 disposed in the main barrel, the optical system 500 includes a first lens 501, a second lens 502, a third lens 503, a diaphragm 504, a fourth lens 505, a fifth lens 506, and an image plane 507, which are sequentially disposed in a first direction, as shown with reference to fig. 3. The uncooled thermal infrared imager comprising the optical system can realize large-view-field comprehensive temperature measurement screening and small-view-field local precise measurement.

The first lens 501 is a positive meniscus germanium lens with a convex surface facing the second direction, and is used for converging light. The second lens 502 is a positive meniscus germanium lens with a convex surface facing the second direction, and is used for converging light, and the second lens 502 can move along the first direction or the second direction to change the focal length of the lens. The third lens element 503 is a negative meniscus chalcogenide lens with a convex surface facing the first direction, and the third lens element 503 can also move along the first direction or the second direction to compensate the image shift of the lens caused by the movement of the second lens element 502.

It is understood that when the second lens 502 moves in the first direction, the third lens 503 also moves in the first direction to compensate for the image shift caused by the movement of the second lens 502. Accordingly, when the second lens 502 moves in the second direction, the third lens 503 also moves in the second direction. Further, the focal length between the second lens 502 and the third lens 503 may be a short focus of 10mm or a long focus of 32 mm.

The aperture 504 is used to limit the size of the light. The fourth lens 505 is a biconvex germanium positive lens with a convex surface facing the first direction, and is used for aberration correction. The fifth lens 506 is a positive meniscus germanium lens with a convex surface facing the second direction, and the fifth lens 506 can move along the first direction or the second direction to compensate image shift of the lens caused by temperature change. The first direction and the second direction are opposite directions, the first direction is a direction in which light is incident and is also a direction toward the image side, and the second direction is a direction toward the object side. The image plane 507 is a plane on which an object is clearly imaged through the lens.

The infrared optical lens 100 collects infrared radiation emitted by a measured object onto the uncooled infrared detector 200 through a lens group consisting of the first lens 501, the second lens 502, the third lens 503, the diaphragm 504, the fourth lens 505 and the fifth lens 506, and the uncooled infrared detector 200 converts the incident radiation into an electric signal to form a gray image of the measured object.

Referring to fig. 4, the image processing module 300 includes: an analog-to-digital conversion circuit 130, an image processing circuit 140, and a buffer circuit 150; the image processing circuit 140 includes: the system comprises an image filtering unit 101, a non-uniformity correction unit 102, a blind pixel replacement unit 103, a temperature compensation algorithm unit 104 and a compensation black body gray data acquisition unit 105;

a first end of the analog-to-digital conversion circuit 130 is connected with a second end of the uncooled infrared detector 200, a second end of the analog-to-digital conversion circuit 130 is connected with a first end of the image filtering unit 101, a second end of the image filtering unit 101 is connected with a first end of the non-uniform correction unit 102, a second end of the non-uniform correction unit 102 is connected with a first end of the blind pixel replacement unit 103, a second end of the blind pixel replacement unit 103 is connected with a first end of the temperature compensation algorithm unit 104, and a second end of the temperature compensation algorithm unit 104 is connected with the buffer circuit 150;

a first end of the compensation black body gray data acquisition unit 105 is connected with a first end of the image filtering unit 101, and a second end of the compensation black body gray data acquisition unit 105 is connected with a first end of the non-uniform correction unit 102 and a first end of the temperature compensation algorithm unit 104;

the temperature compensation algorithm unit 104 is configured to calculate actual gray data of the compensation black body according to the response gray data of the target, the response gray data of the compensation black body, and a gray compensation variation of the target caused by a temperature variation of the compensation black body, and convert the actual gray data into temperature information.

The temperature compensation algorithm unit 104 is configured to collect response gray scale data of the target to be measured in the current preset time interval output by the blind pixel replacement unit 103, average gray scale data of the compensation black body in the current preset time interval and the previous preset time interval output by the compensation black body gray scale data collection unit 105, collect image frame numbers in the current preset time interval and the previous preset time interval, calculate a gray scale compensation amount of each frame of image in the current preset time interval according to the average gray scale data and the image frame numbers, and calculate actual gray scale data of the target to be measured according to the response gray scale data of the target to be measured in the current preset time interval, the gray scale compensation amount of each frame of image, and a gray scale compensation variation amount of the target to be measured caused by a temperature change of the compensation black body.

In this embodiment, the compensation black body gray level data acquisition unit 105 is used to acquire the response gray level data of the compensation black body, and the response gray level data of the compensation black body is used as a compensation source of the response gray level data of the target to be measured, so as to achieve the purpose of compensating the influence of the environmental radiation factor. Meanwhile, the temperature compensation algorithm unit 104 calculates the gray compensation amount of each frame of image within a preset time interval according to the average gray data of the compensation black body. And the gray compensation variation of the measured target caused by the temperature change of the compensation black body caused by the change of the environmental factors is used as a compensation source of response gray data of the measured target, so that the accuracy of temperature compensation is further improved. And then adding the response gray data of the measured target, the gray compensation amount of each frame of image and the gray compensation variation amount of the measured target caused by the temperature variation of the compensation black body to obtain the actual gray data of the measured target, and converting the actual gray data into temperature information to obtain the temperature information of the measured target with higher accuracy and stability.

The original digital infrared signal is processed into a uniform infrared image after sequentially passing through the image filtering unit 101, the non-uniformity correction unit 102 and the blind pixel replacement unit 103. The image filtering unit 101 is used for filtering noise in an image time domain, the non-uniformity correction unit 102 is used for correcting non-uniformity of infrared radiation response of an infrared detector focal plane pixel, and the blind pixel replacement unit 103 is used for replacing a dead pixel or an overheated pixel on a focal plane by using surrounding pixels and outputting response gray data of a detected target in real time.

The image filtering unit 101, the non-uniformity correcting unit 102, the blind pixel replacing unit 103, the temperature compensation algorithm unit 104, and the compensation black body gray scale data acquiring unit 105 form an image processing circuit 140, a first end of the image processing circuit 140 is connected to a second end of the analog-to-digital conversion circuit 130, and a second end of the image processing circuit 140 is connected to a first end of the buffer circuit 150. The analog-to-digital conversion circuit 130, the image processing circuit 140 and the buffer circuit 150 form an infrared imaging temperature measuring circuit.

The infrared optical lens 110 includes a two-dimensional moving mechanism 401, the compensation black body 400 is installed on the two-dimensional moving mechanism 401, and as shown in fig. 2, the compensation black body 400 is operated on an FPGA (Field Programmable Gate Array) platform to control the two-dimensional moving mechanism according to a preset time interval, so that the compensation black body 400 can be switched into and out of a light path between the uncooled infrared detector 200 and the infrared optical lens 100 at regular time. When the compensation black body 400 is switched into the optical path at a preset time interval, the compensation black body gray data acquisition unit 105 acquires and stores the response gray data of the compensation black body 400, calculates the average gray data of the compensation black body 400 at the preset time interval, and outputs the average gray data of the compensation black body 400. When the compensation black body 400 is cut out of the light path, the response gray data of the compensation black body 400 is used as a compensation source of the response gray data of the detected target, and non-uniform correction is executed to achieve the purpose of compensating the influence of environmental radiation factors. Specifically, the average gray data of the compensation black body 400 is input to the non-uniformity correction unit 102 for correction by the compensation black body gray data acquisition unit 105.

For example, the predetermined time interval is t₁~t₂、t₂~t₃、……、t_i~t_i+1If the preset time interval corresponds to a time t₁、t₂、t₃、……、t_i、t_i+1Compensating black body at t₁、t₂、……、t_i、t_i+1Indicating the time at which the optical path was cut. According to t₁~t₂Inner response gray data calculation t₁~t₂Average gray scale data of according to t₂~t₃Inner response gray data calculation t₂~t₃Average gray data of … …, t_i~t_i+1Inner response gray data calculation t_i~t_i+1Average gray scale data of (1).

The temperature compensation algorithm unit 104 is used for acquiring the current preset time output by the blind pixel replacement unit 103The response gray data of the target to be measured in the interval and the average gray data of the compensation black body 400 in the current preset time interval and the previous preset time interval output by the compensation black body gray data acquisition unit 105 are also used for acquiring the image frame number in the current preset time interval and the previous preset time interval. For example, the current preset time interval is t₂~t₃If the last predetermined time interval is t₁~t₂(ii) a The current preset time interval is t_i~t_i+1If the last predetermined time interval is t_i-1~t_i。

The temperature compensation algorithm unit 104 calculates the gray compensation amount of each frame of image in the current preset time interval according to the average gray data of the compensation black body 400 and the number of frames in the current preset time interval and the last preset time interval. Specifically, the difference between the average gray data of the compensation black body 400 in the current preset time interval and the average gray data of the compensation black body 400 in the previous preset time interval is calculated according to the average gray data of the compensation black body 400 in the current preset time interval and the average gray data of the compensation black body 400 in the previous preset time interval, then, the average gray change rate of each frame of image in the previous preset time interval is calculated according to the difference between the average gray data and the number of frames of the image in the previous preset time interval, and the gray compensation amount of each frame of image in the current preset time interval is calculated according to the average gray change rate of each frame of image in the previous preset time interval and the number of frames of the image in the current preset time interval.

For example, the current preset time interval is t₂~t₃Last predetermined time interval is t₁~t₂Calculating t₁~t₂Average gray data sum t of₂~t₃The difference of the average gradation data of (1) is denoted as Δ s 1. Obtaining t₂~t₃And t₁~t₂The number of real-time image frames of (2) is respectively marked as n₂And n₁. Using Δ s₁Divided by n₁To obtain t₁~t₂Per frame image average gray-scale change rate k₁. At t₂~t₃By t₁~t₂Per frame image average gray-scale change rate k₁Multiplying by the distance t at the moment corresponding to each frame of image₂The number of real-time image frames between moments to obtain t₂~t₃The amount of gray scale compensation per frame of image. The current preset time interval is t_i~t_i+1Last predetermined time interval is t_i-1~t_iCalculating t_i-1~t_iAverage gray data sum t of_i~t_i+1Is recorded as Δ s_i-1. Obtaining t_i~t_i+1And t_i-1~t_iThe number of real-time image frames of (2) is respectively marked as n_iAnd n_i-1. Using Δ s_i-1Divided by n_i-1To obtain t_i-1~t_iPer frame image average gray-scale change rate k_i-1. At t_i~t_i+1By t_i-1~t_iPer frame image average gray-scale change rate k_i-1Multiplying by the distance t at the moment corresponding to each frame of image_iThe number of real-time image frames between moments to obtain t_i~t_i+1The amount of gray scale compensation per frame of image.

The temperature compensation algorithm unit 104 obtains a gray compensation amount of the target to be measured caused by the temperature change of the compensation black body 400, specifically, a calibration black body is used as a reference, a temperature sensor in the uncooled thermal infrared imager is used for obtaining temperature values of the compensation black body 400 when the calibration black body is at two different temperatures, the temperature sensor is connected with a first end of the temperature compensation algorithm unit 104, and the temperature sensor inputs the temperature values of the compensation black body 400 when the calibration black body is at two different temperatures into the temperature compensation algorithm unit 104. The temperature compensation algorithm unit 104 obtains response gray data of the calibration black body at two different temperatures and a temperature value of the compensation black body 400, calculates a difference value of the response gray data and a difference value of the temperature value, calculates a gray compensation change rate of the calibration black body caused by temperature change of the compensation black body 400 according to the difference value of the temperature value and the difference value of the response gray data of the compensation calibration black body, calculates a gray compensation change amount of the calibration black body caused by temperature change of the compensation black body 400 according to a temperature change amount of the compensation black body 400 at a current preset time interval and the gray compensation change rate of the calibration black body, and takes the gray compensation change amount of the calibration black body as a gray compensation change amount of a target to be measured.

For example, the temperature value of the compensation black body is T when the calibration black body is at different temperatures₁、T₂Calibrating the response gray scale data of the black body as S₁、S₂Calculating T₁And T₂Has a difference of Δ T, S₁And S₂The difference value of (1) is delta S, and the grey level compensation change rate of the calibration black body caused by the temperature change of the compensation black body is obtained by dividing delta S by delta T. Then, using t₂~t₃Multiplying the temperature variation of the compensation black body by the gray compensation variation rate to obtain t₂~t₃And compensating the gray compensation variable quantity of the calibration black body caused by the temperature change of the black body. Using t_i~t_i+1Multiplying the temperature variation of the compensation black body by the gray compensation variation rate to obtain t_i~t_i+1And compensating the gray compensation variable quantity of the calibration black body caused by the temperature change of the black body. Will t₂~t₃The gray compensation variable quantity of the calibration black body caused by the temperature change of the compensation black body is taken as t₂~t₃And compensating the gray compensation variation of the measured target caused by the temperature variation of the black body. Will t_i~t_i+1The gray compensation variable quantity of the calibration black body caused by the temperature change of the compensation black body is taken as t_i~t_i+1And compensating the gray compensation variation of the measured target caused by the temperature variation of the black body.

The temperature compensation algorithm unit 104 calculates actual gray data of the measured object according to the response gray data of the measured object in the current preset time interval, the gray compensation amount of each frame of image, and the gray compensation variation amount of the measured object caused by the temperature variation of the compensation black body.

For example, let t₂~t₃And adding the gray compensation quantity of each frame of image to the response gray data of the measured target, and adding the gray compensation variable quantity of the measured target caused by the temperature change of the compensation black body to obtain the actual gray data of the measured target.

The temperature compensation algorithm unit 104 is also used for converting the actual gray data of the measured object into temperature information. Specifically, the calibration black body is used as a target to be measured, the temperature of the calibration black body is adjusted for multiple times, actual gray data of the calibration black body under different temperatures of the calibration black body are collected, a corresponding relation between the temperature of the calibration black body and the actual gray data is fitted, the actual gray data of the target to be measured is input into the corresponding relation, and temperature information of the target to be measured is obtained.

Referring to fig. 1 and 2, the uncooled thermal infrared imager further includes: one end of the interface board 600 is connected to the image processing module 300, and the other end is connected to the data receiving device, so that the uncooled thermal infrared imager can output analog video signals and digital video signals to the data receiving device.

The application provides an uncooled thermal infrared imager, sets up the compensation blackbody on infrared optical lens, and the compensation blackbody is used for cutting into the light path between infrared optical lens and the uncooled infrared detector, and image processing module gathers the response grey scale data of compensation blackbody when the compensation blackbody cuts into the light path between infrared optical lens and the uncooled infrared detector to as being surveyed the compensation source of target response grey scale data. Therefore, when the compensation black body is switched into the light path, the response gray data of the compensation black body is used as a compensation source of the response gray data of the measured target, the purpose of compensating the influence of environmental radiation factors is achieved, the influence of environmental radiation on the image gray information of the measured target is reduced, and the accuracy and the stability of temperature measurement are improved.

Fig. 5 is a flowchart illustrating a method for acquiring temperature information according to an embodiment of the present application. As shown in fig. 5, the method of this embodiment may include the following steps:

s101, when the compensation black body is cut into a light path between the infrared optical lens and the uncooled infrared detector, response gray scale data of the compensation black body are collected.

The compensating blackbody can be switched in and out of a light path between the uncooled infrared detector and the infrared optical lens at regular time, response gray data of the compensating blackbody is collected when the compensating blackbody is switched in the light path between the uncooled infrared detector and the infrared optical lens, and the response gray data of a detected target is collected when the compensating blackbody is switched out of the light path between the uncooled infrared detector and the infrared optical lens.

And S102, taking the response gray data of the compensation black body as a compensation source of the response gray data of the detected target to obtain actual gray data of the detected target so as to convert the actual gray data into temperature information.

In this embodiment, the actual gray scale data of the target to be measured may be calculated according to the response gray scale data of the target to be measured, the response gray scale data of the compensation black body, and the gray scale compensation variation of the target to be measured caused by the temperature variation of the compensation black body, so as to convert the actual gray scale data into the temperature information.

For example, referring to fig. 6, in S201, the gray compensation amount of each frame image in the current preset time interval is calculated according to the average gray data and the number of image frames of the current preset time interval and the last preset time interval. When the compensation black body is cut into a light path between the infrared optical system and the infrared detector at a preset time interval, acquiring response gray scale data of the compensation black body, calculating average gray scale data in the preset time interval according to the preset time interval and the response gray scale data in the preset time interval, and selecting the average gray scale data of the compensation black body in the current preset time interval and the average gray scale data of the compensation black body in the previous preset time interval from the acquired average gray scale data in each preset time interval.

In S202, response gray scale data of the target to be measured and a gray scale compensation variation of the target to be measured caused by a temperature change of the compensation black body within a current preset time interval are obtained.

In S203, the actual gray data of the target to be measured is calculated according to the response gray data of the target to be measured in the current preset time interval, the gray compensation amount of each frame of image, and the gray compensation variation amount of the target to be measured caused by the temperature variation of the compensation black body, and the actual gray data is converted into temperature information.

As an implementation manner, obtaining the gray compensation amount of each frame of image in the current preset time interval according to the response gray data of the compensation black body, as shown in fig. 7, may include:

s3011, calculating a difference value of average gray scale data according to the compensation black body average gray scale data in the current preset time interval and the previous preset time interval.

And subtracting the average gray data of the compensation black body of the last preset time interval from the average gray data of the compensation black body of the current preset time interval to obtain the difference value of the average gray data.

And S3012, calculating the average change rate of each frame of image in the last preset time interval according to the difference of the average gray scale data and the number of the image frames in the last preset time interval.

And dividing the difference value of the average gray scale data of the compensation black body in the current preset time interval and the average gray scale data of the compensation black body in the previous preset time interval by the number of the image frames in the previous preset time interval to obtain the average change rate of each frame of image in the previous preset time interval.

S3013, calculating the gray compensation amount of each frame of image in the current preset time interval according to the average gray change rate and the number of image frames in the current preset time interval.

And multiplying the average change rate of each frame of image in the last preset time interval by the number of real-time image frames between the corresponding moment of each frame of image in the current preset time interval and the current moment to obtain the gray compensation amount of each frame of image in the current preset time interval, wherein the current moment refers to the moment included in the last preset time interval and the current preset time interval, namely the coincidence moment of the last preset time interval and the current preset time interval.

As an implementation manner, acquiring a gray compensation variation of the measured target caused by a temperature variation of the compensation black body within a current preset time interval, as shown in fig. 8, may include:

s3021, when the calibration black body has two temperatures, the temperature value of the compensation black body and the response gray scale data of the calibration black body are obtained.

And S3022, calculating the difference value of the temperature values of the compensation black body and the difference value of the response gray data.

And S3023, calculating the gray level compensation change rate of the calibration black body caused by the temperature change of the compensation black body according to the difference value of the temperature values and the difference value of the response gray level data of the calibration black body.

And S3024, calculating the gray compensation variation of the calibration black body caused by the temperature variation of the compensation black body according to the gray compensation variation rate of the calibration black body and the temperature variation of the compensation black body in the current preset time interval.

And S3025, taking the gray compensation variable quantity of the calibration black body as the gray compensation variable quantity of the measured target.

After the gray compensation amount of each frame of image in the current preset time interval and the gray compensation variation of the measured target caused by the temperature variation of the compensation black body in the current preset time interval are obtained, the gray compensation amount of each frame of image in the current preset time interval, the gray compensation variation of the measured target caused by the temperature variation of the compensation black body and the response gray data of the measured target are added to obtain the actual gray data of the measured target in the current preset time interval, and then the actual gray data are converted into temperature information.

And converting the actual gray scale data into temperature information, specifically, referring to fig. 9, S1031, obtaining the actual gray scale data of the calibration black body at different temperatures of the calibration black body. S1032, fitting the corresponding relation between the temperature of the calibration black body and the actual gray scale data. And S1033, inputting the actual gray data of the measured target into the corresponding relation to obtain the temperature information of the measured target.

According to the method for acquiring the temperature information, the response gray data of the compensation black body is acquired, the response gray data of the compensation black body is used as a compensation source of the response gray data of the measured target, the purpose of compensating the influence of environmental radiation factors is achieved, and the temperature information of the measured target with high accuracy and stability is acquired.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: it is also possible to modify the solutions described in the previous embodiments or to substitute some or all of them with equivalents. And the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.