阅读说明：本技术 减少环境温度对比度的红外测温方法 (Infrared temperature measurement method for reducing ambient temperature contrast ) 是由 赵霞 史去非 吴健 赵子龙 于 2021-08-23 设计创作，主要内容包括：本申请公开了一种减少环境温度对比度的红外测温方法。该方法可以包括：确定一个恒定的黑体温度源T-(B)；当测量距离确定时,通过改变环境温度T-(U),得到不同环境温度下黑体温度T-(B)与环境温度T-(U)的比重关系；当环境温度确定时,通过改变测量距离,得到在不同测量距离下环境温度T-(U)与黑体温度T-(B)的比重关系；通过比例系数计算被测物体的实际温度。本发明能够有效减小环境温度对比度造成的测量误差,测量准确且可以有效的减少测量误差。(The application discloses an infrared temperature measurement method for reducing ambient temperature contrast. The method can comprise the following steps: determining a constant blackbody temperature source T B (ii) a By varying the ambient temperature T when the measured distance is determined U Obtaining the black body temperature T under different environmental temperatures B And ambient temperature T U The specific gravity relationship of (a); when the ambient temperature is determined, the ambient temperature T at different measuring distances is obtained by changing the measuring distance U Temperature T of black body B The specific gravity relationship of (a); and calculating the actual temperature of the measured object through the proportionality coefficient. The invention can effectively reduce the measurement error caused by the ambient temperature contrast, the measurement is accurate and the measurement error can be effectively reduced.)

1. An infrared temperature measurement method for reducing ambient temperature contrast is characterized by comprising the following steps:

determining a constant blackbody temperature source T_B；

By varying the ambient temperature T when the measured distance is determined_UObtaining the black body temperature T under different environmental temperatures_BAnd ambient temperature T_UThe specific gravity relationship of (a);

when the ambient temperature is determined, the ambient temperature T at different measuring distances is obtained by changing the measuring distance_UTemperature T of black body_BThe specific gravity relationship of (a);

and calculating the actual temperature of the measured object through the proportionality coefficient.

2. The infrared temperature measuring method for reducing ambient temperature contrast according to claim 1, wherein the blackbody temperature is set to T_BAmbient temperature T of thermal infrared imager detector_UTemperature T of measured object₀Related to the radiant energy T of the object to be measured₀Including the black body temperature T_BAnd the ambient temperature T_UEstablishing the temperature T of the object to be measured₀With ambient temperature Tu and black body temperature T_BThe functional relationship of (A) is as follows:

T₀＝yT_B+zT_U (1)

wherein y is the blackbody temperature T_BTemperature T received at the probe₀Z is the ambient temperature T_uTemperature T received at the probe₀The scaling factor in (1), y + z is 1, and therefore, formula (1) is:

T₀＝yT_B+(1-y)T_U (2)。

3. the infrared thermometry method of reducing ambient temperature contrast according to claim 2, wherein when the measured distance is determined, the ambient environment is not constant according to equation (2), and the ambient temperature T is changed by an equal amount_UMake it from T_U1Start to change to T_Ui(ii) a When the ambient temperature T_UWhen determining, the distance x is measured by changing by an equal amount, which in turn causes a change in the contrast of the environment, thus yielding the following equation:

4. the infrared temperature measuring method with reduced ambient temperature contrast according to claim 1, wherein when the ambient temperature is T, according to formula (3)_UiBlack body temperature T_BAnd the actual temperature of the probe is T_iWhen known, the ambient contrast coefficient at each ambient temperature can be calculated; because the non-uniform ambient temperature is non-linear to the infrared temperature measurement results, the ambient temperature T is obtained by fitting experimental data_UiContrast coefficient with environment y_iFunctional relationship of (a):

wherein, the formula (4) is a piecewise function, d is a fixed measurement distance, and di is a variable measurement distance; t is_UiTo varying ambient temperature, T_UA constant ambient temperature; according to the black body temperature T_BAmbient contrast coefficient y at ambient temperature_iObtaining a corresponding ambient temperature T_UiThe true temperature of the measured object:

Technical Field

The invention relates to the field of infrared temperature measurement, in particular to an infrared temperature measurement method for reducing ambient temperature contrast.

Background

In many fields such as electric power, chemical industry, transportation machinery, medical treatment, it is necessary to know the temperature of equipment, products and parts in time. Due to the non-contact characteristic of the infrared temperature measurement system, the infrared temperature measurement system has the advantages of long measurement distance, short response time, wide measurement range, high sensitivity, high accuracy, no influence on temperature field distribution and the like. The thermal infrared imager needs to be calibrated before leaving a factory, namely, the thermal infrared imager has the highest temperature measurement precision when measuring the calibrated distance. When the detection distance is very far away, the target occupies fewer pixel points in the image and has weaker brightness (generally called as an infrared weak target), and the target is difficult to detect; meanwhile, many complex backgrounds often exist in the field of view of the detector, and the target is easily submerged. In addition, in many cases, due to the influence of background environment temperature factors, an error exists between the temperature displayed by the temperature measurement system and the actual temperature of the object. For example, when the outdoor temperature in winter is very low, and the temperature difference between day and night in Xinjiang, Tibet and the like is very large, the environmental temperature is the most main reason for influencing the infrared temperature measurement, and the temperature measurement accuracy of the thermal infrared imager is very poor, so that the research on the infrared temperature measurement method in the extreme environment is very important. Although Cao Xinrong and the like research the influence of the environmental background temperature on the precision of the infrared temperature measurement system, Tianchang and the like analyze the influence on target detection from the atmospheric angle. But measurement errors due to ambient background temperature and ambient temperature contrast caused by changes in measurement distance are not systematically analyzed and compensated for.

Therefore, there is a need to develop an infrared thermometry method that reduces ambient temperature contrast.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

The invention provides an infrared temperature measurement method for reducing ambient temperature contrast, which can effectively reduce measurement errors caused by the ambient temperature contrast, is accurate in measurement and can effectively reduce the measurement errors.

The infrared temperature measurement method for reducing the contrast of the ambient temperature comprises the following steps:

determining a constant blackbody temperature source T_B；

By varying the ambient temperature T when the measured distance is determined_UObtaining the black body temperature T under different environmental temperatures_BAnd ambient temperature T_UThe specific gravity relationship of (a);

when the ambient temperature is determined, the ambient temperature T at different measuring distances is obtained by changing the measuring distance_UTemperature T of black body_BThe specific gravity relationship of (a);

and calculating the actual temperature of the measured object through the proportionality coefficient.

Preferably, the black body temperature is set to T_BAmbient temperature T of thermal infrared imager detector_UTemperature T of measured object₀Related to the radiant energy T of the object to be measured₀Including the black body temperature T_BAnd the ambient temperature T_UEstablishing the temperature T of the object to be measured₀With ambient temperature Tu and black body temperature T_BThe functional relationship of (A) is as follows:

T₀＝yT_B+zT_U (1)

wherein y is the blackbody temperature T_BTemperature T received at the probe₀Z is the ambient temperature T_uTemperature T received at the probe₀The scaling factor in (1), y + z is 1, and therefore, formula (1) is:

T₀＝yT_B+(1-y)T_U (2)。

preferably, according to equation (2), when the measured distance is determined, the ambient environment is not constant, the ambient temperature T is changed by an equal amount_UMake it from T_U1Start to change to T_Ui(ii) a When the ambient temperature T_UWhen determining, the distance x is measured by changing by an equal amount, which in turn causes a change in the contrast of the environment, thus yielding the following equation:

preferably, according to equation (3), when the ambient temperature is T_UiBlack body temperature T_BAnd the actual temperature of the probe is T_iWhen known, the ambient contrast coefficient at each ambient temperature can be calculated; the result of infrared temperature measurement isNon-linear, ambient temperature T being obtained by fitting experimental data_UiContrast coefficient with environment y_iFunctional relationship of (a):

wherein, the formula (4) is a piecewise function, d is a fixed measurement distance, and di is a variable measurement distance; t is_UiTo varying ambient temperature, T_UA constant ambient temperature; according to the black body temperature T_BAmbient contrast coefficient y at ambient temperature_iObtaining a corresponding ambient temperature T_UiThe true temperature of the measured object:

the beneficial effects are that: when the temperature of the black body is constant, the environment temperature is changed equivalently and gradually at the same measuring distance, a functional relation of environment temperature contrast is established according to data of different environment temperatures and the black body temperature, or the measuring distance is changed equivalently and gradually at the same environment temperature, and finally the functional relation of an environment contrast coefficient and the environment temperature can be obtained, so that the real temperature of the measured object at the environment temperature is obtained.

The method of the present invention has other features and advantages which will be apparent from or are set forth in detail in the accompanying drawings and the following detailed description, which are incorporated herein, and which together serve to explain certain principles of the invention.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent by describing in more detail exemplary embodiments thereof with reference to the attached drawings, in which like reference numerals generally represent like parts.

Fig. 1 shows a schematic diagram of the infrared thermometry principle according to one embodiment of the present invention.

FIG. 2 shows a schematic diagram of a distance compensation experiment according to one embodiment of the invention.

FIG. 3 shows a schematic diagram of ambient temperature versus ambient temperature contrast according to one embodiment of the present invention.

FIG. 4 shows a schematic diagram of distance versus ambient temperature contrast according to one embodiment of the present invention.

Detailed Description

Preferred embodiments of the present invention will be described in more detail below. While the following describes preferred embodiments of the present invention, it should be understood that the present invention may be embodied in various forms and should not be limited by the embodiments set forth herein.

Fig. 1 shows a schematic diagram of the infrared thermometry principle according to one embodiment of the present invention.

When the object is measured by the thermal infrared imager, the thermal imager and the measured object can be divided into three parts. As shown in fig. 1, when the measured distance is equal to the calibration position, the measurement accuracy is highest; when the measuring distance is smaller than the calibration position, the influence of the ambient temperature on the measuring accuracy is minimal and can be ignored. When the measuring distance is larger than the calibration distance, the ratio of the radiation area received by the measured object to the environmental background area changes along with the change of the distance, which indicates that the environmental contrast is changed due to the difference of the measuring distance. In the second case, when the measurement distance is constant, the ambient temperature changes greatly, and a large ambient contrast is also generated, so the measurement accuracy is also greatly affected.

In order to solve the problems caused by the two situations, the invention aims to provide a method for reducing the measurement error caused by the ambient temperature contrast, and the method is simple, convenient to use and simple and clear in implementation stepsA method of measurement is provided. The invention idea is as follows: using black body as a constant temperature source T_BBy varying the ambient background temperature T at a given distance measurement_UObtaining the temperature T of the black body under different environmental temperatures_BAnd ambient temperature T_UThe specific gravity relationship of (a); when the environment temperature is constant, different measuring distances are changed to obtain the environment temperature T under different measuring distances_UTemperature T of black body_BAnd finally obtaining the actual temperature of the final measured object through the proportionality coefficient.

The technical scheme adopted by the invention for solving the technical problems is as follows:

firstly setting the temperature of the black body to be T_BAmbient background radiation energy T of thermal infrared imager detector_URadiant energy T with the object to be measured₀Related to the radiant energy T of the object to be measured₀Including the black body temperature T_BAnd the ambient temperature T_UThus, establishing the temperature T of the object to be measured₀With ambient temperature Tu and black body temperature T_BThe functional relationship of (a) is as follows:

T₀＝yT_B+zT_U (1)

wherein y is the blackbody temperature T_BTemperature T received at the probe₀Z is the ambient temperature T_uTemperature T received at the probe₀The proportionality coefficient of (1). y + z is 1, so the above formula can be written as follows:

T₀＝yT_B+(1-y)T_U (2)。

according to the formula (2), when the measured distance is constant and the surrounding environment is not constant, the ambient temperature T is changed by the same amount_UMake it from T_U1Start to change to T_Ui. When the ambient temperature T_UAt a certain time, the distance x is measured by an equal change, which in turn causes a change in the ambient contrast. The following formula can thus be obtained:

according to the formula (3), when the ambient temperature is T_UiBlack body temperature T_BAnd the actual temperature of the probe is T_iWhen known, the ambient contrast ratio at each ambient temperature can be obtained. Because the non-uniform ambient temperature is non-linear to the infrared temperature measurement results, the ambient temperature T is obtained by fitting experimental data_UiContrast coefficient with environment y_iThe functional relationship of (a).

In equation (4) as a piecewise function, d is a fixed measured distance, di is a varying measured distance; t is_UiTo varying ambient temperature, T_UIs a constant ambient temperature. According to the black body temperature T_BAmbient contrast coefficient y at ambient temperature_iObtaining a corresponding ambient temperature T_UiThe true temperature of the measured object:

example 1

To facilitate understanding of the solution of the embodiments of the present invention and the effects thereof, a specific application example is given below. It will be understood by those skilled in the art that this example is merely for the purpose of facilitating an understanding of the present invention and that any specific details thereof are not intended to limit the invention in any way.

FIG. 2 shows a schematic diagram of a distance compensation experiment according to one embodiment of the invention.

Firstly, determining the calibration distance of the thermal infrared imager or the infrared detector, aligning the infrared detector to the center of the black body along the x axis as shown in figure 2, and setting the temperature of the black body to be T_BWhen the temperature is 40 ℃, the door and the window of the laboratory are closed, the ambient temperature is adjusted by an air conditioner in a closed room, or the ambient temperature T of the thermal imager is changed in a constant temperature box_UiAt 1 ℃ intervals from 0 DEG CGradually increasing to 40 deg.C, at each temperature measuring point, monitoring indoor temperature with temperature and humidity meter to keep constant, and recording temperature T of infrared detector_0iTo reduce the measurement error, three averages are recorded and then a series of blackbody temperatures T at different ambient temperatures can be obtained as shown in equation (3)_BAmbient temperature T_UiAnd the temperature T of the detector_0iIs described in (1). From the measurement results, the environmental contrast coefficients at different environmental temperatures were obtained as follows.

Environmental contrast ═ 0.4625,0.4975,0.535,0.5725,0.6075,0.6475,0.685,0.72,0.76,0.7875,0.8225,0.8475,0.865,0.879,0.895,0.91,0.926,0.943,0.958,0.969,0.976,0.983,0.987,0.99,0.995,0.995, 0.9975,0.9975,0.9975,0.9975,0.9975,0.9975,0.9975,1,1,1,1,1 ];

according to the ambient temperature contrast coefficient and the formula (3), the multivariate regression function p on the Matlab program is used to perform segmented calculation, and the functional relationship between different ambient temperatures and the ambient temperature contrast coefficient is obtained as follows:

according to the above formula, the true temperature of the measured object can be obtained as follows:

FIG. 3 shows a schematic diagram of ambient temperature versus ambient temperature contrast according to one embodiment of the present invention.

In the second case: when the ambient temperature is T_UWhen the temperature is 22 ℃, the indoor temperature is kept at 22 ℃ by an air conditioner or a thermostat, and the blackbody temperature is set to be T_B40 deg.C, aligning the infrared detector with the center of the black body along the x-axis as shown in FIG. 2, and gradually increasing the distance from the center of the black body along the x-axis from 0 meter to 20 meters every 1 meter, at each oneRecording the temperature T of the infrared detector at intervals_0iThe temperature T of the infrared detector at a series of different measuring distances can be obtained_0iAccording to a known ambient temperature T_U22 ℃ and black body temperature T_BThe ambient temperature contrast coefficients at different distances can be obtained as shown in fig. 3, with 40 ℃ and equation (3).

Ambient temperature contrast ═ [1.0166,1,0.9833,0.9666,0.9444,0.9277,0.9111,0.8888,0.85,0.8055,0.7555,0.7222,0.6888,0.6444,0.6055,0.5388,0.4777,0.4222,0.3777,0.3444,0.3055,0.2666,0.2388,0.2111,0.1777,0.1611,0.1444,0.1333,0.1222,0.1166 ];

FIG. 4 shows a schematic diagram of distance versus ambient temperature contrast according to one embodiment of the present invention.

The environmental contrast coefficient and the multivariate regression function p in the Matlab program are calculated in segments, and the functional relationship between different measured distances and the environmental temperature contrast coefficient is shown in fig. 4:

according to the above formula, the true temperature of the measured object can be obtained as follows:

it will be appreciated by persons skilled in the art that the above description of embodiments of the invention is intended only to illustrate the benefits of embodiments of the invention and is not intended to limit embodiments of the invention to any examples given.

Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.