KR19990052844A - Method of measuring radiation temperature in non-contact temperature distribution measuring device - Google Patents

Abstract

The present invention relates to a method for measuring radiation temperature in a non-contact temperature distribution measuring apparatus which can perform radiation temperature measurement at a high speed by significantly reducing the amount of data to be processed in the non-contact temperature distribution measuring apparatus using a one-dimensional array of infrared sensors. It is about.

According to the present invention, a novel radiation temperature calculation method has been proposed that can easily calculate the radiation temperature distribution without having a separate device for processing a large amount of data as in a radiation thermometer using a conventional one-dimensional array infrared sensor. In this method, since the radiation temperature value of another sensor is calculated from the information of the sensor located in the center of the one-dimensional array infrared sensor, the radiation temperature distribution can be calculated without a separate high speed signal processing device.

Description

Method of measuring radiation temperature in non-contact temperature distribution measuring device

The present invention relates to a method of measuring radiation temperature in a non-contact temperature distribution measuring apparatus using an infrared sensor in a one-dimensional array, and in particular, by significantly reducing the amount of data to be processed in a non-contact temperature distribution measuring apparatus using an infrared sensor in a one-dimensional array, The present invention relates to a method for measuring radiation temperature in a non-contact temperature distribution measuring apparatus capable of performing radiation temperature measurement at high speed.

1 is a configuration diagram of a radiation temperature measuring apparatus in a conventional non-contact temperature distribution measuring apparatus. Referring to FIG. 1, a non-contact temperature distribution measuring apparatus using a conventional one-dimensional array of infrared sensors may use a signal output from an infrared sensor. When calculating the radiation temperature, use the blackbody furnace for each one-dimensional array sensor to find the correlation between the blackbody radiation temperature and the sensor output, and then store the correlation between the blackbody radiation temperature and the sensor output for each sensor. I had to store it in and then load it one by one for every measurement and calculate the temperature. In addition, it also had to have information about the change in output with respect to the change in distance, and had to reflect it every time the temperature was calculated.

However, in the related art, when calculating the radiant temperature by using a signal output from an infrared sensor in a non-contact temperature distribution measuring device, the output change for the correlation and distance change between the blackbody radiant temperature and the sensor output for each one-dimensional array sensor each time Because the information about is retrieved from its own storage and the temperature is calculated for each sensor, a huge amount of information must be processed each time. Therefore, this method requires a long time to calculate the temperature because a large amount of data must be processed each time, and thus there is a problem that a separate high-speed signal processing device must be provided.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and therefore, an object of the present invention is to reduce the amount of data to be processed in a non-contact temperature distribution measuring apparatus using a one-dimensional array of infrared sensors, thereby speeding up radiant temperature measurement. The present invention provides a method of measuring radiation temperature in a non-contact temperature distribution measuring apparatus that can be performed.

1 is a block diagram of a radiation temperature measuring apparatus in a conventional non-contact temperature distribution measuring apparatus.

2 is a block diagram of a radiation temperature measuring apparatus in a non-contact temperature distribution measuring apparatus according to the present invention.

3 is a conceptual diagram for explaining a radiation temperature measuring method according to the present invention.

4 is an explanatory view of the correlation between the output and the sensor position of the one-dimensional array sensor according to the present invention.

5 is an explanatory diagram of the correlation between the output of one-dimensional array sensor and the measurement distance according to the present invention.

6 is a flowchart illustrating a method of measuring radiation temperature in a non-contact temperature distribution measuring apparatus according to the present invention.

Explanation of symbols on the main parts of the drawings

1: radiant temperature measuring object 11: camera

12: A / D converter 13: Video memory

14 microprocessor 15 D / A converter

16: graphics card 17: monitor

18: controller 19: power supply

20: drive unit 21: temperature compensation LUT

22: compensation LUT 23: dark current compensation unit

24: non-uniform compensation part

32: radiated energy propagated from one edge of the measurement object

33: radiant energy propagated from the center of measurement object

34: radiant energy propagated from the position of the other edge of the measurement object

35: Optical system of temperature distribution measuring device

36: infrared sensor in one-dimensional array

As a technical means for achieving the above object of the present invention, the method of the present invention comprises a first step of receiving data on the radiant energy for the measurement object through the camera and the A / D converter; A second step of compensating the attenuation ratio of the radiant energy with respect to the measurement distance with respect to the data corresponding to the radiant energy input in the first step; A third step of compensating the output attenuation rate according to each position of the data of each sensor based on data corresponding to the center of the measurement object among the data whose radiation attenuation rate is compensated in the second step; A fourth step of compensating the radiant energy decay rate and the output decay rate of the sensor in the second and third steps, and then calculating the output of the blackbody radiation temperature of each sensor based on the data output corresponding to each sensor; A fifth step of finally obtaining the radiation temperature of each sensor from the output of the blackbody radiation temperature of each sensor obtained in the fourth step, and outputting the radiation temperature; Characterized in that made.

Hereinafter, a configuration of an apparatus for performing a radiation temperature measuring method in a non-contact temperature distribution measuring apparatus according to the present invention will be described with reference to the accompanying drawings.

FIG. 2 is a configuration diagram of a radiation temperature measuring apparatus in a non-contact temperature distribution measuring apparatus according to the present invention. Referring to FIG. 2, a radiation temperature measuring apparatus for performing the present invention is a radiation for a radiation temperature measuring object 1. To the camera 11 for photographing energy, the A / D converter (16 bits) 12 for converting the analog signal from the camera 11 into digital, and the digital data from the A / D converter 12. A dark current compensator 23 for compensating for the dark current, a nonuniform compensator 24 for compensating for the uniformity of the dark current compensated digital data, and a video memory 13 for storing the compensated digital data; A controller for the operation of the camera 11 and the compensation LUT 22 storing the compensation data referred to by the uneven compensation part 24, the temperature compensation LUT 21 storing data to be referred to for the temperature compensation, and the camera 11. (18) to control the temperature compensation LUT 21 The microprocessor 14 which compensates the data stored in the video memory 13 with reference to temperature and controls various blocks in the radiation temperature measuring device, and the camera 11 under the control of the controller 18. A driving unit 20 for operating a power source, a power supply unit 19 for supplying power to the camera 11, a D / A converter 15 for converting digital data from the microprocessor 14 to analog, and The graphics card 16 supports the graphics output of the monitor under the control of the microprocessor 14, and the monitor 17 outputs the data through the graphics card 16 to the screen.

3 is a conceptual diagram illustrating a method of measuring radiation temperature according to the present invention, and FIG. 4 is an explanatory diagram of a correlation between an output of a one-dimensional array sensor and a sensor position according to the present invention, and FIG. 5 is according to the present invention. An explanatory diagram of the correlation between the output of one-dimensional array sensor and the measurement distance. 6 is a flowchart showing a radiation temperature measuring method in a non-contact temperature distribution measuring apparatus according to the present invention.

Operation according to the present invention configured as described above will be described in detail below based on the accompanying drawings.

Before describing the radiation temperature measuring method in the non-contact temperature distribution measuring apparatus according to the present invention with reference to FIGS. 2 to 6, the operation of the apparatus for performing the present invention will be briefly described. When power is supplied to the camera 11 at the same time, the microprocessor 14 commands the operation of the camera to the controller 18, the controller 18 operates the camera 11 through the drive unit 20. When the camera 11 provides the radiant energy for the radiation temperature measuring object 1 to the A / D converter 12 photographed by the camera 11, the A / D converter 12 is connected to the camera 11. The analog signal from the digital signal is converted into a digital signal, and the converted digital data is compensated for the unevenness by referring to the compensation LUT 22 in the nonuniformity compensator 24 after compensating the dark current through the dark current compensator 23. Then stored in the video memory 13. For the digital data stored in the video memory 13, the microprocessor 14 calculates the radiation temperature according to the method of the present invention and outputs it to the monitor 17 through the D / A converter 15 and the graphics card 16. The method of the present invention is described in detail below.

In the non-contact temperature distribution measuring apparatus using a one-dimensional array infrared sensor as shown in FIG. 2 to be proposed in the present invention, first, the radiant energy emitted from a measuring object and the output of the one-dimensional array infrared sensor are described. You must understand the correlation between them. In the following Equation 1 will be described the correlation between the radiant energy emitted from the measuring object and the output of the infrared sensor of the one-dimensional array.

V _i = G _i × S _i [ε _ti (ε _bi (T _ti )) + (1-ε _ti ) × E _bi (T _bi )]

here V _i = I-th output of the infrared sensor in one-dimensional array [V]

ε _ti = emissivity of the measuring object corresponding to the i-th sensor

(1-ε _ti ) = ρ _ti = i Reflectance of the measuring object corresponding to the first sensor

E _bi (T _ti ) = i Black body radiation of the measuring object corresponding to the first sensor

E _bi (T _bi ) = i Black body radiation energy of the ambient background corresponding to the first sensor

S _i = i Sensitivity of the first sensor

G _i = i Of the first sensor output

Looking at Equation 1, it can be seen that the output of the infrared sensor of the one-dimensional array is changed depending on the emissivity of the measuring object, the sensitivity of the sensor, the gain of the sensor output, the black body radiation energy of the measuring body, and the black body radiation energy of the surrounding background. have.

Here, the sensitivity of the sensor is a value that depends on the wavelength of the optical filter selected when designing the radiation thermometer and the infrared sensor of the one-dimensional array, so that the optical system is determined once, and is a fixed value. And since this value plays the same role as the proportional constant when converting the radiant energy into an electrical signal, it can be included in the radiant energy.

In addition, other variables such as emissivity of the measuring object and black body radiation energy of the surrounding background, which can be determined from the temperature of the surrounding background, are designated and inputted before the measurement of the radiant temperature from the outside of the measuring device and stored in its own internal device.

The gain of the sensor output, another variable, is known in advance and can be designed according to the measured temperature range. Therefore, it can be seen that the output of the infrared sensor in the one-dimensional array is finally changed depending on the black body radiation energy of the measuring object.

However, in the temperature distribution measuring apparatus using the infrared sensor of the one-dimensional array, the black body radiant energy appears differently as shown in FIG. 4 according to the position of the infrared sensor which measures the black body of the same temperature.

This can be seen in the figure shown in Figure 3, the radiant energy radiated from the measurement object (1) will appear different depending on the position of the measurement object. In other words, the radiant energy 33 radiated from the center of the measuring body and the radiant energy 32,34 radiated from the edge of the measuring body appear differently for the same temperature.

This is because in a temperature distribution measuring device using a wide angle, the radiant energy at the center of the measuring object and the edge of the measuring object radiated from the same area is changed due to different distances to the sensor. The mathematical definition of this can be explained by introducing the following solid angle concept as shown in equation (2).

here Ω = Solid angle

A _n = Element area perpendicular to the incident angle of the measuring body

R = Distance between measuring object and sensor

Solid angle in Equation 2 Ω The larger the temperature is for the same measuring object, the larger the radiated energy. Therefore, in FIG. 3, the radiant energy radiated from the center and the radiant energy radiated from the edge of the radiant energy are changed due to the difference in solid angle.

Therefore, in the conventional radiation temperature calculation, a correlation between the blackbody radiation temperature and the output of each sensor must be obtained by using a blackbody path for each one-dimensional array sensor in order to compensate for these different values.

However, in the method proposed in the present invention, first, the correlation between the output of the one-dimensional array sensor and the position of the measuring sensor is shown in FIG. 4 using the blackbody furnace under the same measurement conditions, that is, the same blackbody radiation temperature and measuring distance. Obtain as At this time, it can be seen that the distribution of the sensor output with respect to the obtained sensor position is symmetrically distributed about the same temperature with respect to the center of the one-dimensional array sensor as shown in FIG. 4. In other words, the relationship shown in Equation 3 below is satisfied.

V = f (X _center -1) = f (X _center +1)

Therefore, if you know the information on one side with respect to the center of the one-dimensional array sensor, the information on the other side can be known automatically. Equation 3 gives information on the decay rate of the output of each sensor with respect to the central sensor output.

Secondly, when the relational expression in FIG. 4 is obtained, the correlation with the sensor output with respect to the black body radiation temperature is obtained using the black body furnace for the sensor located in the center of the one-dimensional array sensor. As shown in Equation 4 below, a relational expression can be obtained for a black body having an emissivity of 1.

V _center = f (T _t.center )

Third, by fixing the temperature in the black body and changing the measurement distance, the correlation between the output of each one-dimensional array sensor and the measurement distance is calculated as a function of the measurement distance as shown in FIG.

V _i = f _i (D)

Using Equation 5 above, the radiation attenuation rate of each sensor in the one-dimensional array for the same temperature can be determined according to the measurement distance. In this way, when the relations are determined as in Equations 4 and 5, the temperature distribution can be easily calculated using the above relations.

Referring to FIG. 6, a method of obtaining a radiant temperature from data on radiant energy measured based on the above theory and equation is described. First, in a first step 61, 62, 63, 64, the camera 11 is used. And the A / D converter 12 receives the data on the radiant energy for the measurement object (1).

In the second steps 65 and 66, the radiation attenuation rate with respect to the measurement distance is first compensated using Equation 5 from the output of each sensor in the one-dimensional array.

In the third steps 67 and 68, the attenuation rate of the output of each sensor with respect to the output from the central sensor is compensated for by using the relational expression of Equation (3).

In the fourth step 69, when all the processes of the compensation through the second steps 65 and 66 and the third steps 67 and 68 are completed, the black body radiation of each sensor is expressed using the equation (1) from the output of each sensor. Find the output for temperature.

Finally, in the fifth step (70, 71), the radiation temperature of each sensor is finally obtained by using the relational expression of Equation 4 from the output of the blackbody radiation temperature of each sensor obtained above, and outputs this value.

According to the present invention as constant, a novel radiation temperature calculation method is proposed which can easily calculate the radiation temperature distribution without having a separate device for processing a large amount of data as in a radiation thermometer using a conventional one-dimensional array infrared sensor. did.

In this method, since the radiation temperature value of another sensor is calculated from the information of the sensor located in the center of the one-dimensional array infrared sensor, the radiation temperature distribution can be calculated without a separate high speed signal processing device.

Claims (1)

A first step of receiving data on radiant energy for the measurement object 1 through the camera 11 and the A / D converter 12; A second step of compensating the attenuation ratio of the radiant energy with respect to the measurement distance with respect to the data corresponding to the radiant energy input in the first step; A third step of compensating the output attenuation rate according to each position of the data of each sensor based on data corresponding to the center of the measurement object (1) among the data whose radiation energy attenuation rate is compensated in the second step; A fourth step of compensating the radiant energy decay rate and the output decay rate of the sensor in the second and third steps, and then calculating the output of the blackbody radiation temperature of each sensor based on the data output corresponding to each sensor; A fifth step of finally obtaining the radiation temperature of each sensor from the output of the blackbody radiation temperature of each sensor obtained in the fourth step, and outputting the radiation temperature; Radiation temperature measurement method in a non-contact temperature distribution measuring device, characterized in that consisting of.