阅读说明：本技术 一种降低环境背景辐射噪声的红外辐射测温方法 (Infrared radiation temperature measurement method for reducing environment background radiation noise ) 是由 魏艳秀 孙晓刚 孙博君 于 2021-09-02 设计创作，主要内容包括：一种降低环境背景辐射噪声的红外辐射测温方法,涉及红外辐射测温技术,为了解决现有的红外辐射测温过程中,标定工作量大、标定耗时长以及测量精度差的问题。本发明对红外辐射测温系统进行第一组实验标定,求解出增益常数和偏置常数；对红外辐射测温系统进行第二组实验标定,得到第二组实验标定系统输出电压响应；求解第二组实验标定辐射亮度响应,判断第二组实验标定函数拟合优度是否满足预先设定阈值；进而确定拟合阶数,建立发射率模型；结合增益常数和偏置常数以及发射率模型,得到理论标定函数；根据理论标定函数,结合普朗克公式与朗伯辐射定律,求解出目标的真实温度。有益效果为降低了标定的工作量以及减少了标定耗时时间,测量精度高。(An infrared radiation temperature measurement method for reducing environmental background radiation noise relates to an infrared radiation temperature measurement technology and aims to solve the problems of large calibration workload, long calibration time consumption and poor measurement precision in the existing infrared radiation temperature measurement process. The method comprises the steps of carrying out a first group of experimental calibration on an infrared radiation temperature measurement system, and solving a gain constant and a bias constant; carrying out a second set of experiment calibration on the infrared radiation temperature measurement system to obtain output voltage response of the second set of experiment calibration system; solving the radiance response of the second group of experiment calibration, and judging whether the goodness of fit of the second group of experiment calibration functions meets a preset threshold value or not; further determining a fitting order and establishing an emissivity model; obtaining a theoretical calibration function by combining the gain constant, the bias constant and the emissivity model; and solving the real temperature of the target according to a theoretical calibration function by combining a Planck formula and a Lambert radiation law. The method has the advantages of reducing calibration workload and time consumed by calibration, and being high in measurement accuracy.)

1. An infrared radiation temperature measurement method for reducing environmental background radiation noise is characterized by comprising the following steps:

firstly, carrying out a first group of experimental calibration on an infrared radiation temperature measurement system (1) by adopting a calibration device, and solving a gain constant and a bias constant of a first group of experimental calibration functions of the infrared radiation temperature measurement system (1) based on an infrared radiation temperature measurement basic formula;

secondly, carrying out second group of experiment calibration on the infrared radiation temperature measurement system (1) by adopting a calibration device to obtain output voltage response of the second group of experiment calibration system;

step three, solving a second group of experiment calibration radiance responses according to the second group of experiment calibration system output voltage responses obtained in the step two, and judging whether the second group of experiment calibration function fitting goodness with the second group of experiment calibration radiance responses as independent variables and the second group of experiment calibration system output voltage responses as dependent variables meets a preset threshold value or not; further determining the fitting order of the second group of experimental calibration functions;

step four, establishing an emissivity model according to the fitting order of the second group of experimental calibration functions determined in the step three;

step five, combining the gain constant and the bias constant of the first group of experimental calibration functions of the infrared radiation temperature measurement system (1) solved in the step one, the second group of experimental calibration functions obtained in the step four and the emissivity model established in the step four to obtain a theoretical calibration function;

and step six, solving the real temperature of the target according to the theoretical calibration function obtained in the step five by combining a Planck formula and a Lambert radiation law.

2. The method for measuring the temperature by reducing the radiation noise of the background of the environment according to claim 1, wherein a calibration device adopted in the step one is the same as a calibration device adopted in the step two;

the calibration device adopted in the first step comprises a physical target (2), a physical target platinum resistor (3), a lifting support (4), a high-low temperature test box platinum resistor (5), a physical target PID temperature controller (6), a high-low temperature test box (7) and a high-low temperature test box PID temperature controller (8);

the physical target (2), the physical target platinum resistor (3), the lifting support (4), the high-low temperature test box platinum resistor (5) and the physical target PID temperature controller (6) are all arranged in a high-low temperature test box (7); the high-low temperature test box (7) is used for constructing a calibration experiment scene with controllable environmental temperature;

the physical target (2) comprises a target surface (2-1) and a semiconductor refrigerating sheet set (2-2); the semiconductor refrigerating sheet group (2-2) is adhered to the back of the target surface (2-1) through heat-conducting silicone grease;

the infrared radiation temperature measurement system (1) is borne on the lifting support (4) so as to adjust the height of the infrared radiation temperature measurement system (1) and enable the infrared radiation temperature measurement system (1) to be opposite to the front side of the target surface (2-1);

the physical target platinum resistor (3) is arranged in the target surface (2-1), the physical target platinum resistor (3) is connected to a physical target PID temperature controller (6), and the temperature of the physical target (2) is set through the physical target PID temperature controller (6);

the high-low temperature test box platinum resistor (5) is suspended right above the real target (2), and the high-low temperature test box platinum resistor (5) is connected with a high-low temperature test box PID temperature controller (8); the temperature in the high-low temperature test box (7) is set through a PID temperature controller (8) of the high-low temperature test box.

3. The infrared radiation temperature measurement method for reducing the radiation noise of the environment background according to claim 2, wherein the specific steps of solving the gain constant and the bias constant of the first set of experimental calibration functions of the infrared radiation temperature measurement system (1) in the step one are as follows:

step one, controlling the temperature of a real object target to be equal to that of a high-low temperature test box, and carrying out a first group of experimental calibration on an infrared radiation temperature measurement system (1);

step two, obtaining output voltage response of a first group of experiment calibration systems through a first group of experiment calibration;

step three, solving a first group of experiment calibration input temperatures by using an infrared radiation temperature measurement system (1) output radiance response formula, and solving a first group of experiment calibration radiance responses;

step four, converting an infrared radiation temperature measurement basic formula by using the condition that the temperature of a physical target is equal to the temperature of a high-low temperature test chamber to obtain a first group of experiment calibration functions;

and step one, substituting the first group of experimental calibration radiance responses obtained in the step three and the first group of experimental calibration system output voltage responses obtained in the step two into the first group of experimental calibration functions for fitting to obtain the gain constant and the bias constant of the first group of experimental calibration functions.

4. The method of claim 3, wherein the ambient background radiation noise is reduced by the infrared radiation thermometry,

in the step one, the temperature of the physical target is set by a physical target PID temperature controller (6) to be the temperature of the physical target (2), and the temperature of the high-low temperature test box is set by a high-low temperature test box PID temperature controller (8) to be the temperature in a high-low temperature test box (7);

the specific process of obtaining the output voltage response of the first group of experimental calibration systems in the second step is as follows: in the temperature range (T) of the working environment of the infrared radiation temperature measurement system (1)_{u_lower},T_{u_upper}) Taking i temperature points with an inner equal step length, wherein T_{u_lower}Is the lowest temperature T of the working environment of the infrared radiation temperature measurement system (1)_{u_upper}Setting the step length as j for the highest temperature of the working environment of the infrared radiation temperature measurement system (1), wherein j satisfies (T)_upper-T_lower) The/j is an integer, the first group of experimental calibration acquisition temperature points are respectively (T)₁₁，T₁₂，…，T_1i) (ii) a The temperature of the object target and the temperature of the high-low temperature test chamber are set to be T₁₁The infrared radiation temperature measurement system (1) acquires the corresponding first group of experiment calibration system output voltage responses asSetting by temperature points to finish T₁₂To T_1iThe output voltage response of the first group of experiment calibration systems is acquired to obtain the output voltage response of all the first group of experiment calibration systems

The specific process of solving the first group of experimental calibration radiance responses in the first step and the third step is as follows:

the infrared radiation temperature measurement system (1) outputs a radiation brightness response formula as follows:

wherein, Delta lambda represents the spectral response bandwidth of the infrared radiation temperature measurement system (1),is the spectral responsivity, L, of the detector_λ(T₀) Representing the spectral radiance; f (T)₀) For operation in a spectral response range of (lambda)_lower,λ_upper) The input temperature of the internal infrared radiation temperature measurement system (1) is T₀A radiance response of the temporal output;

according to the Planck formula and the Lambert radiation law, a radiation brightness response formula output by the infrared radiation temperature measuring system (1) is converted into:

wherein lambda is the spectral wavelength of the light received by the infrared radiation temperature measurement system (1), c₁Is a first radiation constant, c₁＝3.7415×10⁸(W·μm⁴/m²)，c₂Is a second radiation constant, c₂＝1.43879×10⁴(μm·K)；

Input temperature (T) was calibrated for a first set of experiments using equation (6)₁₁，T₁₂，...，T_1i) And solving to obtain a first group of experimental calibration radiance responses as follows: (f (T)₁₁)，f(T₁₂)，...，f(T_1i))；

The specific process of obtaining the first group of experimental calibration functions in the first step and the fourth step is as follows:

the basic formula of infrared radiation temperature measurement is as follows:

v＝K¹{τ_a[εf(T_o)+(1-α)f(T_u)]+ε_af(T_a)}+K⁰ (7)

wherein, K¹Is a gain constant, K⁰Is a bias constant, τ_aIs the atmospheric transmittance, epsilon is the emissivity of the target to be measured, alphaIs the absorption rate of the measured object, epsilon_aTo atmospheric emissivity, T_oTarget temperature for object, T_uIs the temperature of the high-low temperature test chamber, T_aIs at atmospheric temperature;

because the real target (2) and the atmosphere both meet the gray body approximation, epsilon is alpha, epsilon_a＝1-τ_αAnd during close range measurements τ_aIf the approximation is 1, equation (7) is transformed into:

v＝K¹[εf(T_o)+(1-ε)f(T_u)]+K⁰ (8)

and due to the temperature T of the target in the object_oTemperature T of high-low temperature test chamber_uEqual, so equation (8) is expressed as:

v＝K¹f(T_o)+K⁰ (9)

formula (9) is the temperature T of the target in the object_oTemperature T of high-low temperature test chamber_uUnder the equal condition, the calibration function of the infrared radiation temperature measurement system (1), namely a first group of experimental calibration functions;

the specific process of obtaining the gain constant and the bias constant of the first group of experimental calibration functions in the first and fifth steps is as follows:

radiance response (f (T) is scaled with a first set of experiments₁₁)，f(T₁₂)，...，f(T_1i) ) as independent variable, a first set of experiments calibrates the system output voltage responseAs dependent variable, performing first-order fitting by using least square method to obtain gain constant K of first group of experimental calibration functions¹And a bias constant K⁰。

5. The method for measuring temperature by infrared radiation for reducing radiation noise of an environment background according to claim 4, wherein the specific process for obtaining the output voltage response of the second set of the experimental calibration system in the second step is as follows:

controlling the temperature of the high-low temperature test chamber to be T_u1Then, the infrared radiation temperature measuring system (1) is calibrated by a second group of experiments,at the same time, T_u1∈(T_{u_lower},T_{u_upper})；

The specific process of the second group of experimental calibration is as follows: in the temperature measuring range (T)_lower,T_upper) Taking m temperature points with an inner equal step length, setting the step length as n, and satisfying (T)_upper-T_lower) N is an integer, and the second set of experimental calibration collection temperature points are respectively (T)₂₁，T₂₂，...，T_2m) (ii) a Setting the temperature of the target to T₂₁The infrared radiation temperature measurement system (1) acquires the corresponding secondary experiment calibration system output voltage response asSetting by temperature points to finish T₂₂To T_2mThe output voltage response of the second group of experiment calibration systems is acquired, and the obtained output voltage response of the second group of experiment calibration systems is as follows:

6. the method of claim 5, wherein the step three of determining the fitting order of the second set of calibration functions comprises:

calibrating input temperature (T) according to a second set of experiments₂₁，T₂₂，…，T_2m) A second set of experiments to solve for the corresponding temperature point by Planck's law and Lambert's radiation law, equation (6), calibrates the radiance response (f (T)₂₁),f(T₂₂),…,f(T_2m) ); scaling radiance response with a second set of experimentsAs independent variable, the output voltage response of the system is calibrated by a second group of experimentsFitting by least square method for dependent variableCombining, wherein the fitting order is from first order to high order, judging whether the goodness of fit reaches a preset target threshold after each fitting is finished, and selecting the current order as the temperature T of the high-low temperature test box after the goodness of fit reaches the target threshold_u1Then, the fitting order of the second set of experimental calibration functions.

7. The method according to claim 6, wherein the emissivity model established in the fourth step is divided into a constant model, a linear model and a high-order model;

the constant model is specifically as follows: controlling the temperature of the high-low temperature test chamber to be T_u1Then, the fitting order of the second group of experimental calibration functions is first order, and the target emissivity is a constant epsilon in the temperature measurement range;

the linear model is specifically as follows: controlling the temperature of the high-low temperature test chamber to be T_u1Then, the fitting order of the second group of experimental calibration functions is second order, and the target emissivity is in linear relation with the target radiation energy in the temperature measurement range, namely

ε＝k₁f(T_o)+k₀ (10)

In the formula, k₁Is a first order coefficient factor of emissivity, k₀Is a constant coefficient factor of emissivity;

the high-order model is specifically as follows: controlling the temperature of the high-low temperature test chamber to be T_u1Then, the fitting order of the second group of experimental calibration functions is N +1 order, N is an integer greater than 1, and the target emissivity is in an N-order relation with the target radiation energy in the temperature measurement range, namely

ε＝k_Nf(T_o)^N+k_N-1f(T_o)^N-1+…+k₀ (11)

In the formula, k_NCoefficient factor of the order N, k, of emissivity_N-1Coefficient factor of order N-1, k, of emissivity₀Is a constant coefficient factor of emissivity.

8. The infrared radiation temperature measurement method for reducing the radiation noise of the environment background according to claim 7, wherein when the emissivity model is a constant model, the specific process of obtaining the theoretical calibration function is as follows:

controlling the temperature of the high-low temperature test chamber to be T_u1Then, the radiance response (f (T)) is scaled with a second set of experiments₂₁),f(T₂₂),…,f(T_2m) ) as independent variable, a second set of experiments calibrates the system output voltage responsePerforming first-order fitting by using a least square method as a dependent variable; obtaining the temperature of the high-low temperature test chamber as T_u1The second set of experimental calibration functions, which are the experimental calibration functions of time, are:

wherein the content of the first and second substances,for the second set of experimental calibration function first order coefficients,calibrating function constant coefficients for a second set of experiments;

because the physical target (2) and the atmosphere both meet the gray body approximation and tau is measured in a close distance_aCan be considered approximately as 1, then it can be obtained according to equation (8):

v＝K¹εf(T_o)+K¹f(T_u)-K¹εf(T_u)+K⁰ (13)

wherein, K¹Obtaining a gain constant for the first set of experimental calibrations; k⁰Bias constants obtained from the first set of experimental calibrations;

order:

then:

the formula (15) indicates that the temperature of the high-low temperature test chamber is T_uThe theoretical calibration function of the time-of-flight,in order to be a theoretical output voltage response,as a first order coefficient of the theoretical calibration function,function constant coefficients are theoretically calibrated;

the temperature in the high-low temperature test chamber is T_u1The theoretical calibration function is then:

at high and low temperature test chamber temperature T_u1The theoretical calibration function coefficients are expressed as:

9. the infrared radiation temperature measurement method for reducing the radiation noise of the environment background according to claim 7, wherein when the emissivity model is a linear model, the specific process of obtaining the theoretical calibration function is as follows:

controlling the temperature of the high-low temperature test chamber to be T_u1Then, the radiance response (f (T)) is scaled with a second set of experiments₂₁),f(T₂₂),…,f(T_2m) ) as independent variable, a second set of experiments calibrates the system output voltage responseShould be takenPerforming second-order fitting by using a least square method as a dependent variable; obtaining the temperature of the high-low temperature test chamber as T_u1The second set of experimental calibration functions in time is:

wherein the content of the first and second substances,for the second set of second order coefficients of the experimental calibration function,for the second set of experimental calibration function first order coefficients,calibrating function constant coefficients for a second set of experiments;

substituting (10) into (8) yields:

v＝K¹k₁f(T_o)²+f(T_o)(K¹k₀-K¹k₁f(T_u))+K¹f(T_u)-K¹k₀f(T_u)+K⁰ (20)

order:

equation (20) can be expressed as

The formula (22) is called the high-low temperature test chamber temperatureT_uThe theoretical calibration function of the time-of-flight,for the second order coefficient of the theoretical calibration function,as a first order coefficient of the theoretical calibration function,function constant coefficients are theoretically calibrated;

test chamber temperature T at high and Low temperatures according to equation (21)_u1The theoretical calibration function is then:

at high and low temperature test chamber temperature T_u1The theoretical calibration function coefficients are expressed as:

10. the infrared radiation temperature measurement method for reducing the radiation noise of the environment background according to claim 7, wherein when the emissivity model is a high-order model, the specific process of obtaining the theoretical calibration function is as follows:

controlling the temperature of the high-low temperature test chamber to be T_u1Then, the radiance response (f (T)) is scaled with a second set of experiments₂₁),f(T₂₂),…,f(T_2m) ) as independent variable, a second set of experiments calibrates the system output voltage responseAs a dependent variable, performing N +1 order fitting by using a least square method to obtain the temperature T of the high-low temperature test box_u1A second set of experimental calibration functions;substituting the emissivity model into the formula (8) to obtain the high-low temperature test box with the temperature T_u1The theoretical calibration function of time.

Technical Field

The invention relates to an infrared radiation temperature measurement technology.

Background

The infrared radiation temperature measurement technology is widely applied to the fields of aircraft thermal tests, foundation observation, space infrared detection, roadbed temperature detection and the like due to the advantages of non-contact, high response speed and no damage to a target temperature field; the infrared detector receives infrared radiation from a detected target, converts radiation information into an electric signal, and obtains radiation temperature information of the target after calibration by adopting a black body target and data processing.

In the process of measuring temperature by using an infrared radiation temperature measurement technology, the temperature of a high-low temperature test box of a measurement scene and the temperature of a high-low temperature test box of a calibration scene are often different, environmental background radiation energy and target radiation energy are overlapped together, so that an error exists between a measurement result and the real temperature of a target, and particularly when the background temperature is higher than the target temperature, the measurement result is misaligned, and the accuracy of infrared radiation temperature measurement is seriously influenced.

In the existing infrared radiation temperature measurement technology, an infrared radiation temperature measurement system adopts a calibration function when a real target is calibrated:

v＝Kf(T_o)+B (1)

f(T_o) For operation in the wavelength range (lambda)_lower,λ_upper) Internal infrared radiation thermometry system, input temperature T_oRadiance response of time output:

wherein, Delta lambda represents the spectral response bandwidth of the infrared radiation temperature measurement system,is the spectral responsivity, L, of an infrared detector_λ(T) represents the spectral radiance.

According to the Planck formula and the Lambert radiation law, the radiance response of an infrared radiation temperature measurement system can be expressed as follows:

wherein, c₁Is a first radiation constant, c₁＝3.7415×10⁸(W·μm⁴/m²)；c₂Is a second radiation constant, c₂＝1.43879×10⁴(μm·K)；

In the temperature range of the working environment of the infrared radiation temperature measurement system, the temperature of the high-low temperature test box is controlled by adjusting the PID temperature controller of the high-low temperature test box so as to realize the adjustment of the environmental temperature of the infrared radiation temperature measurement system, and the temperature is respectively adjusted at the ith environmental temperature T_uiThen, carrying out calibration experiments to obtain calibration functions at different environmental temperatures;

during the measurement, according to the ambient temperature T_uSelecting corresponding calibration function to carry out target temperature T_oIf the ambient temperature T is calculated_uIf there is no corresponding calibration function, selecting the calibration function at the most similar ambient temperature to calculate the temperature, and if the ambient temperature T is not the same as the temperature_u＝(T_ui+T_u(i-1)) A high temperature point T is selected_uiAnd calculating the temperature by the time calibration function.

The calibration is carried out at different environmental temperatures, the influence of the environmental temperature on the measurement error is considered, however, in the actual operation process, a plurality of environmental temperature points are calibrated by selecting proper temperature intervals according to the working environmental temperature range of the infrared radiation temperature measurement system, the calibration workload is large, and the calibration time is long.

When the calibration of multiple environmental temperature points is carried out, the environmental temperature points corresponding to the calibration function can not be continuous, and in the measurement process, the environmental temperature T which is not measured_uWhen the corresponding calibration function is used, the current ambient temperature T is selected_uThe closest calibration function performs the target temperature calculation, thereby introducing measurement errors.

Disclosure of Invention

The invention aims to solve the problems of large calibration workload, long calibration time consumption and poor measurement precision caused by environment background radiation noise in the existing infrared radiation temperature measurement process, and provides an infrared radiation temperature measurement method for reducing the environment background radiation noise.

The invention relates to an infrared radiation temperature measurement method for reducing environmental background radiation noise, which comprises the following steps:

firstly, carrying out a first group of experimental calibration on an infrared radiation temperature measurement system by adopting a calibration device, and solving a gain constant and a bias constant of a first group of experimental calibration functions of the infrared radiation temperature measurement system based on an infrared radiation temperature measurement basic formula;

step two, carrying out a second group of experiment calibration on the infrared radiation temperature measurement system by adopting a calibration device to obtain output voltage response of the second group of experiment calibration system;

step three, solving a second group of experiment calibration radiance responses according to the second group of experiment calibration system output voltage responses obtained in the step two, and judging whether the second group of experiment calibration function fitting goodness with the second group of experiment calibration radiance responses as independent variables and the second group of experiment calibration system output voltage responses as dependent variables meets a preset threshold value or not; further determining the fitting order of the second group of experimental calibration functions;

step four, establishing an emissivity model according to the fitting order of the second group of experimental calibration functions determined in the step three;

combining the gain constant and the bias constant of the first group of experimental calibration functions of the infrared radiation temperature measurement system solved in the step one, the second group of experimental calibration functions obtained in the step four and the emissivity model established in the step four to obtain a theoretical calibration function;

and step six, solving the real temperature of the target according to the theoretical calibration function obtained in the step five by combining a Planck formula and a Lambert radiation law.

The invention has the beneficial effects that: under the condition that the emissivity of a measured target does not need to be known, the environmental background radiation noise can be reduced only by performing two groups of calibration experiments, the efficiency is greatly improved compared with the existing method for performing multiple groups of calibration experiments at multiple environmental temperature points in a temperature measurement range, the calibration workload is reduced, and the time consumed by calibration is shortened; compared with the existing method in which the environmental temperature covered by a calibration function of multiple environmental temperature points is discontinuous, the method needs to approximately select the calibration function to calculate the target temperature, and has higher measurement precision.

Drawings

FIG. 1 is a flowchart illustrating a method for reducing ambient background radiation noise according to a first embodiment of the present invention;

FIG. 2 is a schematic diagram of a three-dimensional structure of a calibration apparatus according to a first embodiment;

FIG. 3 is a front view of a physical target according to one embodiment;

FIG. 4 is a side view of a physical target according to one embodiment;

FIG. 5 is a graph of spectral responsivity of a mid-IR detector in accordance with one embodiment.

Detailed Description

The first embodiment is as follows: the present embodiment is described with reference to fig. 1 to 5, and the infrared radiation temperature measurement method for reducing the ambient background radiation noise according to the present embodiment includes the following steps:

firstly, carrying out a first group of experimental calibration on the infrared radiation temperature measurement system 1 by adopting a calibration device, and solving a gain constant and a bias constant of a first group of experimental calibration functions of the infrared radiation temperature measurement system 1 based on an infrared radiation temperature measurement basic formula;

secondly, carrying out a second group of experiment calibration on the infrared radiation temperature measurement system 1 by adopting a calibration device to obtain output voltage response of the second group of experiment calibration system;

step three, solving a second group of experiment calibration radiance responses according to the second group of experiment calibration system output voltage responses obtained in the step two, and judging whether the second group of experiment calibration function fitting goodness with the second group of experiment calibration radiance responses as independent variables and the second group of experiment calibration system output voltage responses as dependent variables meets a preset threshold value or not; further determining the fitting order of the second group of experimental calibration functions;

step four, establishing an emissivity model according to the fitting order of the second group of experimental calibration functions determined in the step three;

step five, combining the gain constant and the bias constant of the first group of experimental calibration functions of the infrared radiation temperature measurement system 1 solved in the step one, the second group of experimental calibration functions obtained in the step four and the emissivity model established in the step four to obtain a theoretical calibration function;

and step six, solving the real temperature of the target according to the theoretical calibration function obtained in the step five by combining a Planck formula and a Lambert radiation law.

In the embodiment, the calibration device comprises a physical target 2, a physical target platinum resistor 3, a lifting bracket 4, a high-low temperature test box platinum resistor 5, a physical target PID temperature controller 6, a high-low temperature test box 7 and a high-low temperature test box PID temperature controller 8;

the physical target 2, the physical target platinum resistor 3, the lifting support 4, the high-low temperature test box platinum resistor 5 and the physical target PID temperature controller 6 are all arranged in a high-low temperature test box 7; the high-low temperature test box 7 is used for constructing a calibration experiment scene with controllable environmental temperature;

the physical target 2 comprises a target surface 2-1 and a semiconductor refrigerating sheet group 2-2; the semiconductor refrigerating sheet group 2-2 is adhered to the back of the target surface 2-1 through heat-conducting silicone grease;

the infrared radiation temperature measurement system 1 is carried on the lifting support 4 so as to adjust the height of the infrared radiation temperature measurement system 1, and the infrared radiation temperature measurement system 1 is opposite to the front side of the target surface 2-1;

the physical target platinum resistor 3 is arranged in the target surface 2-1, the physical target platinum resistor 3 is connected to a physical target PID temperature controller 6, and the temperature of the physical target 2 is set through the physical target PID temperature controller 6; (ii) a

The test box platinum resistor 5 is suspended right above the real object target 2, and the test box platinum resistor 5 is connected with a high-low temperature test box PID temperature controller 8; the temperature in the high-low temperature test box 7 is set through the PID temperature controller 8 of the high-low temperature test box.

In the calibration process, a plate with the same material as a measurement target is selected to manufacture a target surface 2-1 of the physical target 2, the semiconductor refrigerating sheet group 2-2 is adhered to the target surface 2-1 through heat-conducting silicone grease, and a physical target platinum resistor 3 is arranged in the target surface 2-1; the semiconductor refrigerating sheet set 2-2 and the physical target platinum resistor 3 are connected to a physical target PID temperature controller 6, and the temperature of the physical target 2 is set through a panel of the physical target PID temperature controller 6; the physical target 2 realizes the refrigeration and heating of the physical target 2 by changing the current direction of the semiconductor refrigerating sheet set 2-2; (ii) a The real object target 2 is adopted for calibration, so that the problem of measurement error caused by the fact that the emissivity of the surface source black body target and the measured target is inconsistent in the existing calibration process is effectively solved.

The infrared radiation temperature measurement system 1 and the object target 2 are placed in a high-low temperature test box 7, the high-low temperature test box 7 has good temperature uniformity, and the lens of the infrared radiation temperature measurement system 1 and the effective radiation surface of the object target 2 are concentric and can be full of the visual field of the infrared radiation temperature measurement system 1 by adjusting the lifting support 4.

The infrared radiation temperature measurement system 1 has a temperature control function, and aims to ensure that the working temperature of an infrared detector in the infrared radiation temperature measurement system 1 is constant and avoid measurement errors caused by changes of spectral responsivity of the infrared detector due to changes of the internal environment temperature of the infrared radiation temperature measurement system 1; the internal temperature of the infrared radiation temperature measurement system 1 is set as the temperature value when the infrared detector performs spectral responsivity calibration.

In this embodiment, the specific steps of solving the gain constant and the bias constant of the first set of experimental calibration functions of the infrared radiation temperature measurement system 1 in the first step are as follows:

step one, controlling the temperature of a real object target to be equal to that of a high-low temperature test box, and carrying out a first group of experimental calibration on an infrared radiation temperature measurement system 1;

step two, obtaining output voltage response of a first group of experiment calibration systems through a first group of experiment calibration;

solving a first group of experiment calibration input temperatures by using a radiance response formula output by the infrared radiation temperature measuring system 1, and solving a first group of experiment calibration radiance responses;

step four, converting an infrared radiation temperature measurement basic formula by using the condition that the temperature of a physical target is equal to the temperature of a high-low temperature test chamber to obtain a first group of experiment calibration functions;

substituting the first group of experimental calibration radiance responses obtained in the first step and the second step and the first group of experimental calibration system output voltage responses obtained in the second step into the first group of experimental calibration functions for fitting to obtain the gain constant and the bias constant of the first group of experimental calibration functions;

in the step one, the temperature of the physical target is set to be the temperature of the physical target 2 through a physical target PID temperature controller 6, and the temperature of the high-low temperature test box is set to be the temperature in a high-low temperature test box 7 through a high-low temperature test box PID temperature controller 8;

the specific process of obtaining the output voltage response of the first group of experimental calibration systems in the second step is as follows: in the temperature range (T) of the working environment of the infrared radiation temperature measurement system 1_{u_lower},T_{u_upper}) Taking i temperature points with an inner equal step length, wherein T_{u_lower}Is the lowest temperature T of the working environment of the infrared radiation temperature measurement system 1_{u_upper}Setting the step length as j for the highest temperature of the working environment of the infrared radiation temperature measurement system 1, wherein j satisfies (T)_upper-T_lower) The/j is an integer, the first group of experimental calibration acquisition temperature points are respectively (T)₁₁，T₁₂，…，T_1i) (ii) a The temperature of the object target and the temperature of the high-low temperature test chamber are set to be T₁₁The output voltage response of the first set of experiment calibration system collected by the infrared radiation temperature measurement system 1 isSetting by temperature points to finish T₁₂To T_1iThe output voltage response of the first group of experiment calibration systems is acquired to obtain the output voltage response of all the first group of experiment calibration systems

The specific process of solving the first group of experimental calibration radiance responses in the first step and the third step is as follows:

the infrared radiation temperature measurement system 1 outputs a radiation brightness response formula as follows:

wherein, Delta lambda represents the spectral response bandwidth of the infrared radiation temperature measurement system 1,is the spectral responsivity, L, of the detector_λ(T₀) Representing the spectral radiance; f (T)₀) For operation in the wavelength range (lambda)_lower,λ_upper) The input temperature of the internal infrared radiation temperature measurement system 1 is T₀A radiance response of the temporal output;

according to the Planck formula and the Lambert radiation law, the radiation brightness response formula output by the infrared radiation temperature measurement system 1 is converted into:

wherein λ is the spectral wavelength of light received by the infrared radiation temperature measurement system 1, c₁Is a first radiation constant, c₁＝3.7415×10⁸(W·μm⁴/m²)，c₂Is a second radiation constant, c₂＝1.43879×10⁴(μm·K)；

Input temperature (T) was calibrated for a first set of experiments using equation (6)₁₁，T₁₂，…，T_1i) And solving to obtain a first group of experimental calibration radiance responses as follows: (f (T)₁₁)，f(T₁₂)，…，f(T_1i))；

The specific process of obtaining the first group of experimental calibration functions in the first step and the fourth step is as follows:

the basic formula of infrared radiation temperature measurement is as follows:

v＝K¹{τ_a[εf(T_o)+(1-α)f(T_u)]+ε_af(T_a)}+K⁰ (7)

wherein, K¹Is a gain constant, K⁰Is a bias constant, τ_aIs the atmospheric permeability, epsilon is the emissivity of the measured target, alpha is the absorptivity of the measured target, epsilon_aTo atmospheric emissivity, T_oTarget temperature for object, T_uIs the temperature of the high-low temperature test chamber, T_aIs at atmospheric temperature;

because the real object target 2 and the atmosphere both satisfy the gray body approximation, epsilon is alpha, epsilon_a＝1-τ_αAnd during close range measurements τ_aIf the approximation is 1, equation (7) is transformed into:

v＝K¹[εf(T_o)+(1-ε)f(T_u)]+K⁰ (8)

and due to the temperature T of the target in the object_oTemperature T of high-low temperature test chamber_uEqual, so equation (8) is expressed as:

v＝K¹f(T_o)+K⁰ (9)

formula (9) is the temperature T of the target in the object_oTemperature T of high-low temperature test chamber_uUnder the equal condition, the calibration function of the infrared radiation temperature measurement system 1 is the first group of experimental calibration functions;

the specific process of obtaining the gain constant and the bias constant of the first group of experimental calibration functions in the first and fifth steps is as follows:

radiance response (f (T) is scaled with a first set of experiments₁₁)，f(T₁₂)，…，f(T_1i) ) as independent variable, a first set of experiments calibrates the system output voltage responseAs dependent variable, performing first-order fitting by using least square method to obtain gain constant K of first group of experimental calibration functions¹And a bias constant K⁰。

The working wavelength range of the infrared radiation temperature measurement system 1 is 8-11 μm, the working environment temperature range is-20-40 ℃, and the temperature measurement range is-20-60 ℃. Under the condition of 20 ℃, the spectral responsivity curve of the infrared detector is shown in fig. 5, wherein the internal temperature of the infrared detector 1 is set to 20 ℃, and the infrared detector can be obtained according to the spectral responsivity curve of the infrared detectorSpectral responsivity of

Within the temperature range of-20 ℃ to 40 ℃ of the working environment of the infrared radiation temperature measurement system 1, taking 7 temperature points at equal intervals with the step length of 10 ℃; setting the temperature T of a physical target 2_oTemperature T of 7 ℃ of high-low temperature test chamber_uThe system output voltage responses of 7 temperature points within-20 to 40 ℃ are obtained through sequential acquisition, and the real target temperature T is obtained_oAnd ambient temperature T_uThe calibration function of the infrared radiation temperature measurement system under the same condition is as follows: 0.04582f (T)_o) 1.71001, i.e. gain constant K¹0.04582, bias constant K⁰＝-1.71001。

In this embodiment, the specific process of obtaining the system output voltage response of the second set of experimental calibration functions in the second step is as follows:

controlling the temperature of the high-low temperature test chamber to be T_u1Then, the second set of experimental calibration is performed on the infrared radiation temperature measurement system 1, and simultaneously, T is performed_u1∈(T_{u_lower},T_{u_upper})；

The specific process of the second group of experimental calibration is as follows: in the temperature measuring range (T)_lower,T_upper) Taking m temperature points with an inner equal step length, setting the step length as n, and satisfying (T)_upper-T_lower) N is an integer, and the second set of experimental calibration collection temperature points are respectively (T)₂₁，T₂₂，…，T_2m) (ii) a Setting the temperature of the target to T₂₁The output voltage response of the corresponding secondary experiment calibration system collected by the infrared radiation temperature measurement system 1 isSetting by temperature points to finish T₂₂To T_2mThe output voltage response of the second group of experimental calibration systems is acquired, and the system output voltage response of the obtained second group of experimental calibration functions is as follows:

setting the temperature of the high-low temperature test chamber to be 10 ℃; taking 9 temperature points at equal intervals with step length of 10 ℃ within the temperature measuring range of-20-60 ℃, and measuring the temperature T of the real target_oRespectively setting the values to the 9 temperature points to obtain the output voltage response of the infrared radiation temperature measurement system as follows:

in this embodiment, the specific process of determining the fitting order of the second set of experimental calibration functions in step three is as follows:

calibrating input temperature (T) according to a second set of experiments₂₁，T₂₂，…，T_2m) A second set of experiments to solve for the corresponding temperature point by Planck's law and Lambert's radiation law, equation (6), calibrates the radiance response (f (T)₂₁),f(T₂₂),…,f(T_2m) ); the radiance response (f (T) is scaled with a second set of experiments₂₁),f(T₂₂),…,f(T_2m) ) as independent variable, the output voltage response of the system is calibrated by a second set of experimentsFitting by using a least square method for a dependent variable, wherein the fitting order is from first order to high order, judging whether the goodness of fit reaches a preset target threshold after each fitting is finished, and selecting the current order as the temperature T of the high-low temperature test box after the goodness of fit reaches the target threshold_u1Then, the fitting order of the second set of experimental calibration functions.

In the embodiment, the emissivity model established in the fourth step is divided into a constant model, a linear model and a high-order model;

the constant model is specifically as follows: controlling the temperature of the high-low temperature test chamber to be T_u1Then, the fitting order of the second group of experimental calibration functions is first order, and the target emissivity is a constant epsilon in the temperature measurement range;

the linear model is specifically as follows: controlling the temperature of the high-low temperature test chamber to be T_u1Then, the fitting order of the second group of experimental calibration functions is second order, and the target emissivity is in the temperature measurement range and the targetThe radiant energy being linear, i.e.

ε＝k₁f(T_o)+k₀ (10)

In the formula, k₁Is a first order coefficient factor of emissivity, k₀Is a constant coefficient factor of emissivity;

the high-order model is specifically as follows: controlling the temperature of the high-low temperature test chamber to be T_u1Then, the fitting order of the second group of experimental calibration functions is N +1 order, N is an integer greater than 1, and the target emissivity is in an N-order relation with the target radiation energy in the temperature measurement range, namely

ε＝k_Nf(T_o)^N+k_N-1f(T_o)^N-1+…+k₀ (11)

In the formula, k_NCoefficient factor of the order N, k, of emissivity_N-1Coefficient factor of order N-1, k, of emissivity₀Is a constant coefficient factor of emissivity.

In this embodiment, if the emissivity model is a constant model, the specific process of obtaining the theoretical calibration function is as follows:

controlling the temperature of the high-low temperature test chamber to be T_u1Then, the radiance response (f (T)) is scaled with a second set of experiments₂₁),f(T₂₂),…,f(T_2m) ) as independent variable, a second set of experiments calibrates the system output voltage responsePerforming first-order fitting by using a least square method as a dependent variable; obtaining the temperature of the high-low temperature test chamber as T_u1The second set of experimental calibration functions, which are the experimental calibration functions of time, are:

wherein the content of the first and second substances,for the second set of experimental calibration function first order coefficients,calibrating function constant coefficients for a second set of experiments;

because the physical target 2 and the atmosphere both satisfy the gray body approximation and tau is measured in a short distance_aCan be considered approximately as 1, then it can be obtained according to equation (8):

v＝K¹εf(T_o)+K¹f(T_u)-K¹εf(T_u)+K⁰ (13)

wherein, K¹Obtaining a gain constant for the first set of experimental calibrations; k⁰Bias constants obtained from the first set of experimental calibrations;

order:

then:

the formula (15) indicates that the temperature of the high-low temperature test chamber is T_uThe theoretical calibration function of the time-of-flight,in order to be a theoretical output voltage response,as a first order coefficient of the theoretical calibration function,function constant coefficients are theoretically calibrated;

then the temperature T of the high-low temperature test chamber_u1The theoretical calibration function is then:

at high and low temperature test chamber temperature T_u1The theoretical calibration function coefficients are expressed as:

at high and low temperature test chamber temperature T_u1Time, theoretically, the theoretical output voltage responseShould equal the second set of experimental calibration function output responsesNamely, the existence of:

two emissivity values are obtained according to equation (18), the average of which is taken as the optimum value, i.e.

In this embodiment, if the emissivity model is a linear model, the specific process of obtaining the theoretical calibration function is as follows:

controlling the temperature of the high-low temperature test chamber to be T_u1Then, the radiance response (f (T)) is scaled with a second set of experiments₂₁),f(T₂₂),…,f(T_2m) ) as independent variable, a second set of experiments calibrates the system output voltage responsePerforming second-order fitting by using a least square method as a dependent variable; obtaining the temperature of the high-low temperature test chamber as T_u1The second set of experimental calibration functions in time is:

wherein the content of the first and second substances,for the second set of second order coefficients of the experimental calibration function,for the second set of experimental calibration function first order coefficients,calibrating function constant coefficients for a second set of experiments;

substituting (10) into (8) yields:

v＝K¹k₁f(T_o)²+f(T_o)(K¹k₀-K¹k₁f(T_u))+K¹f(T_u)-K¹k₀f(T_u)+K⁰ (20)

order:

equation (20) can be expressed as

The formula (22) is called that the temperature of the high-low temperature test chamber is T_uThe theoretical calibration function of the time-of-flight,for the second order coefficient of the theoretical calibration function,as a first order coefficient of the theoretical calibration function,function constant coefficients are theoretically calibrated;

controlling the temperature of the high-low temperature test chamber according to the formula (21)Is T_u1The theoretical calibration function coefficients are expressed as:

then, the temperature T of the high-low temperature test chamber_u1The theoretical output voltage response is expressed as:

at a high and low temperature test chamber temperature of T_u1Time, theoretically, the theoretical output voltage responseShould equal the output response of the calibration function of the second experimentAt this time, the first order coefficient factor k of the emissivity obtainable by solving equation (22), equation (23), equation (24)₁And constant coefficient factor k₀(ii) a But in actual practice the first order coefficient factor k₁And constant coefficient factor k₀The solving process belongs to a constrained multivariate nonlinear optimization problem, and adopts an optimization mode to solve a first-order coefficient factor k of emissivity₁And constant coefficient factor k₀And (6) solving.

In this embodiment, if the emissivity model is a high-order model, the specific process of obtaining the theoretical calibration function is as follows:

controlling the temperature of the high-low temperature test chamber to be T_u1Then, the radiance response (f (T)) is scaled with a second set of experiments₂₁),f(T₂₂),…,f(T_2m) ) as independent variable, a second set of experiments calibrates the system output voltage responseAs a dependent variable, performing N +1 order fitting by using a least square method to obtain the temperature T of the high-low temperature test box_u1Second group of timesCarrying out an experiment calibration function; substituting the emissivity model into the formula (8) to obtain the high-low temperature test box with the temperature T_u1A theoretical calibration function of time; further obtaining the temperature T of the high-low temperature test chamber_u1Time of day, theoretical output voltage responseAt high and low temperature test chamber temperature T_u1Time, theoretically, the theoretical output voltage responseEqual to the output response of the calibration function of the second experimentAt this time, the analog emissivity is a linear model, that is, the coefficient factors of each order of emissivity are solved in an optimization mode.

(1) Case of target emissivity model being constant model

At high and low temperature test chamber temperature T_uIn time, the output voltage response is collected by the infrared radiation temperature measuring system 1Known emissivityThe response of the collected output voltage of the infrared radiation temperature measurement system can be solved through the formula (13)Radiance response of time f (T)_o) The target real temperature T can be solved according to the formula (6)_o。

(2) The case that the target emissivity model is a linear model

At high and low temperature test chamber temperature T_uIn time, the output voltage response is collected by an infrared radiation temperature measuring systemFirst order coefficient factor of known emissivityk₁Constant coefficient factor k with emissivity₀The temperature T of the high-low temperature test chamber can be obtained according to the formula (21)_uCoefficient of each order of time-theoretic calibration functionThe response of the collected output voltage of the infrared radiation temperature measurement system can be solved through a formula (22)Radiance response of time f (T)_o) The target real temperature T can be solved according to the formula (6)_o。

(3) The target emissivity model is a high-order model

At high and low temperature test chamber temperature T_uIn time, the output voltage response is collected by an infrared radiation temperature measuring systemKnowing the coefficient factors of each order of emissivity, the temperature T of the high-low temperature test chamber can be obtained_uThe coefficients of the function are calibrated in time theory, and then the response of the collected output voltage of the infrared radiation temperature measurement system is solvedRadiance response of time f (T)_o) The target real temperature T can be solved according to the formula (6)_o。

The radiance response (f (T) was calibrated with a second set of experiments, setting the target goodness-of-fit threshold to be R-square 0.999₂₁),f(T₂₂),…,f(T_2m) ) is independent variable, the output voltage response of the system is calibrated by secondary experimentFitting for dependent variables, first order goodness of fit R-square<0.999, the target threshold is not reached, second-order fitting is adopted, and second-order goodness of fit R-square>And 0.999, the target threshold requirement is met, the second order is selected as the fitting order of the calibration function of the infrared radiation temperature measurement system at the ambient temperature of 10 ℃, and the emissivity model is a linear model.

Ambient temperature T_u1At 10 ℃ with (f (T)₂₁),f(T₂₂),…,f(T_2m) Is) is an independent variable, is,performing second-order fitting by using a least square method as a dependent variable; obtaining an ambient temperature of T_u1The second set of experimental calibration functions in time is:

according to equation (20), at ambient temperature T_u1The theoretical calibration function coefficient at 10 ℃ is expressed as:

then, at ambient temperature T_u1The theoretical output response of the infrared radiation thermometry system 1 at 10 ℃ is expressed as:

at an ambient temperature of 10 ℃, theoretically, the infrared radiation temperature measurement system 1 outputs response theoreticallyEqual to the experimental calibration function output responseAt this time, the first order coefficient factor k of the emissivity obtained by solving the equations (25), (26) and (27) can be obtained₁And constant coefficient factor k₀(ii) a But in actual practice the first order coefficient factor k₁And constant coefficient factor k₀The solving process belongs to a constrained multivariate nonlinear optimization problem, and adopts an optimization mode to solve a first-order coefficient factor k of emissivity₁And constant coefficient factor k₀And (6) solving.

Ambient temperature 10 ℃ and target temperature (T)₂₁，T₂₂，…，T_2m) In the case of (1), the quadratic experimental calibration function output response isWherein

Wherein

Ambient temperature 10 ℃ and target temperature (T)₂₁，T₂₂，…，T_2m) In the case of (1), the theoretical output response isWherein

Then the objective function of the optimization solution is set as:

according to the property of the real object target material, determining that the emissivity range of the real object target material is more than or equal to 0.5 and less than or equal to 1, and then, the constraint condition exists in the temperature measurement range of the infrared radiation temperature measurement system:

solving the constrained multivariate nonlinear optimization problem by adopting an optimization algorithm to obtain a first-order coefficient factor k of emissivity₁0.00507 and constant coefficient factor k₀＝0.70366。

At T_uFirst order coefficient factor k of emissivity is known at 15 ℃₁0.00507 and constant coefficient factor k₀0.70366. According to the formula (21) and the formula (22), the theoretical calibration function of the infrared radiation temperature measurement system at the ambient temperature of 15 ℃ can be obtained as follows: 0.00023f (T)_o)²+0.02778f(T_o)-1.44924。

By adjusting the set environmental temperature of the high-low temperature test box to be 15 ℃, the output voltage response of the infrared radiation temperature measurement system at the target temperature of-20 ℃, 10 ℃, 0 ℃, 10 ℃, 20 ℃, 30 ℃, 40 ℃, 50 ℃ and 60 ℃ is acquired, and the voltage response is respectively as follows:

the radiation brightness response f (T) when the infrared radiation temperature measurement system collects the output voltage response v can be solved through the theoretical calibration function of the infrared radiation temperature measurement system when the ambient temperature is 15 DEG C_o) The target real temperature measured by the method provided by the invention can be obtained according to the formula (6).

According to the existing method, in the temperature range of the working environment of the infrared radiation temperature measurement system, the environment temperature is controlled by adjusting the high-low temperature test box, calibration experiments are respectively carried out at the environment temperatures of minus 20 ℃, minus 10 ℃, 0 ℃, 10 ℃, 20 ℃, 30 ℃ and 40 ℃, and calibration functions under different environment temperatures are obtained.

In the measuring process, for convenience of comparison with the method provided by the invention, 15 ℃ is also selected as the measured environment temperature, and since the environment temperature 15 ℃ does not have a calibration function corresponding to the environment temperature, the calibration function when the environment temperature is 20 ℃ is selected for temperature calculation, and the calibration function when the environment temperature is 20 ℃ is as follows: 0.03827f (T)_o)-1.51106。

The function is calibrated by the traditional method of the infrared radiation temperature measurement system when the ambient temperature is 20 DEG CTarget radiation energy f (T) when infrared radiation temperature measurement system collects output voltage response v can be solved_o) And obtaining the target real temperature measured by the existing method according to the formula (6).

According to the experimental timing, under a certain environmental temperature, the target temperature takes 10 ℃ as a step length, and the time for carrying out one calibration experiment in the temperature measuring range of an infrared radiation temperature measuring system of-20 ℃ to 60 ℃ is about 180 minutes. In this example, the calibration according to the prior art method requires 7 sets of calibration experiments at 7 ambient temperatures in the range of-20 ℃ to 40 ℃ and takes about 1260 minutes. In the method provided by the invention, only 2 groups of calibration experiments are needed, namely the object target temperature T_oAnd ambient temperature T_uThe first group of experiment calibration is carried out on the infrared radiation temperature measurement system under the equal condition, the second group of experiment calibration is carried out on the infrared radiation temperature measurement system under the condition of 10 ℃ of the ambient temperature, the consumed time is about 360 minutes, the consumed time is 900 minutes, and the working efficiency is greatly improved. Comparing the measurement result of the method provided by the invention with the measurement result of the traditional method, the method provided by the invention has higher measurement precision.