Thermal infrared imager separation blade correction system and method with continuously variable temperature

Abstract

The invention provides a thermal infrared imager separation blade correction system and method with continuously variable temperature, the system comprises a rotating seat connected with a rotating mechanism and an infrared light window arranged on the rotating seat, one side of the infrared light window is opposite to an optical path of a thermal infrared imager, and the other side of the infrared light window is connected with a refrigeration assembly provided with a temperature sensor. The rotating seat is provided with a heat dissipation assembly connected with the refrigeration assembly in a matched mode. High-reliability single-point correction and two-point correction on a certain position on an optical path of the thermal infrared imager are realized, non-uniform correction on the thermal infrared imager is realized without opening a cover, the maintenance cost of the thermal infrared imager is effectively reduced, and the calibration efficiency of the thermal infrared imager is improved. According to the invention, internal single-point correction and two-point correction can be carried out on the thermal infrared imager at different working temperatures, and the problem of image non-uniformity caused by performance degradation after long-time working and long-time storage of the thermal infrared imager is solved.

Description

Technical Field

[0001] The invention relates to a correction system and method, in particular to a correction system and method for a baffle of an infrared thermal imager with continuously variable temperature, belonging to the technical field of infrared thermal imaging. Background Art

[0002] Cooled infrared detectors are the core components of infrared thermal imagers and are widely used in military, high-end civilian products and other fields. Due to the differences in manufacturing processes and readout circuit channels, there is serious non-uniformity in the imaging of infrared thermal imagers. Therefore, non-uniformity correction is required before leaving the factory, during long-term storage, and after long-term startup to maintain the high-performance working state of the infrared thermal imager.

[0003] At present, in various infrared imaging applications, a calibration method combining two-point calibration and single-point calibration is usually used. Two-point calibration mainly uses two reference sources of different radiation intensities to make the linear gain change rate and bias of each pixel in the focal plane consistent for the same incident radiation intensity. Single-point calibration uses a uniform radiation background as a reference source to update the bias. Two-point calibration generally uses a black body for calibration, and the infrared thermal imager needs to be removed from the original equipment and the objective lens is placed close to the black body target for calibration. Single-point calibration generally uses an internal baffle as a reference source for calibration.

[0004] With the diversified development of infrared thermal imagers' application fields, traditional two-point correction and single-point correction methods are difficult to adapt to the non-uniform correction requirements of modern products with high efficiency, high feasibility and high reliability. For example: due to the mismatch between the longer storage time requirement of infrared thermal imagers and the manufacturing process of domestic infrared detectors, the photoelectric conversion performance of the detector chip deteriorates after long-term storage, and it is difficult to re-correct the non-uniformity of the equipment without opening the cover. With the increasing integration of optoelectronic systems, the maintenance cost of removing the infrared part separately or returning it to the factory for recalibration is high, and the feasibility is low. The operating temperature requirements of infrared thermal imagers have been increased. When the single-point correction baffle is inserted, if the temperature is higher or lower than the linear region of the two-point correction coefficient, it will seriously affect the single-point correction effect. Therefore, it is necessary to improve the existing technology. Summary of the invention

[0005] In order to solve the problems of great difficulty in non-uniformity correction, high maintenance cost, low feasibility, etc. in the existing infrared thermal imager correction system and method, the present invention provides an infrared thermal imager baffle correction system and method with continuously variable temperature.

[0006] The present invention is completed through the following technical scheme: a temperature-continuously variable infrared thermal imager baffle correction system, characterized in that it includes a rotating seat connected to a rotating mechanism, an infrared light window arranged on the rotating seat, one side of the infrared light window is opposite to the infrared thermal imager optical path, and the other side is connected to a refrigeration component on which a temperature sensor is arranged, and a heat dissipation component matched with the refrigeration component is arranged on the rotating seat, so that the detected temperature information is fed back to a controller through the temperature sensor, and then the refrigeration component is controlled to perform cooling or heating. When the refrigeration component reaches the target temperature, the rotating seat is driven to rotate by the rotating mechanism, so that the infrared light window on it is inserted into or cut out of the infrared thermal imager optical path, so as to realize the non-uniform correction of the infrared thermal imager without opening the cover, effectively reduce the maintenance cost of the infrared thermal imager, and improve the calibration efficiency of the infrared thermal imager.

[0007] The rotating seat is configured as a flat plate seat with a large end at one end and a small end at the other end. The infrared window is arranged at the large end of the flat plate seat. The small end of the flat plate seat is connected to the rotating mechanism so that various parts can be installed through the rotating seat and rotated by the rotating mechanism.

[0008] The infrared light window comprises a circular window arranged at the large end of the rotating seat, an infrared window sheet is arranged on the outer side of the circular window, inner and outer insulation rings are arranged on the inner side, and a refrigeration component is arranged between the inner and outer insulation rings so that the refrigeration component can be inserted into the optical path of the infrared thermal imager through the infrared light window as needed.

[0009] The refrigeration component includes a circular temperature-averaging baffle with a rectangular window thereon, the inner side of the temperature-averaging baffle is arranged on the inner side of the circular window through an inner insulation ring, the outer side is connected to the outer insulation ring, a semiconductor refrigeration plate clamped by inner and outer thermal conductive silicone grease is arranged in the rectangular window, the semiconductor refrigeration plate is electrically connected to the existing controller, and a slot for placing a temperature sensor is provided on one side of the rectangular window of the temperature-averaging baffle so that cooling or heating can be performed by the semiconductor refrigeration plate, and the temperature sensor is used to detect whether the temperature data of cooling or heating meets the requirements, and then the controller decides whether to insert or cut out the refrigeration component from the optical path of the infrared thermal imager.

[0010] The temperature sensor is configured as a thermistor.

[0011] The heat dissipation component includes a cover plate arranged on the inner side of the rotating seat, a heat dissipation fan is arranged between the cover plate and the small end of the rotating seat, and heat dissipation fins are arranged at the position where the cover plate connects with the heat dissipation fan, and a plurality of heat dissipation holes are arranged at the position where the cover plate connects with the refrigeration component, so that the non-working surface of the refrigeration component on the rotating seat can be heat-dissipated by the heat dissipation component, thereby ensuring the temperature control accuracy of the refrigeration component.

[0012] The rotating mechanism comprises a DC motor and a motor seat connected to the DC motor. The DC motor main shaft passes through the motor seat and is connected to the rotating seat. The DC motor is electrically connected to a controller so that the rotating mechanism is controlled by the controller to drive the rotating seat to rotate.

[0013] A limiting piece is provided between the rotating mechanism and the rotating seat to limit the rotation angle of the rotating seat.

[0014] The present invention provides a method for calibrating a temperature-continuously variable infrared thermal imager baffle, which is characterized in that it comprises the following steps:

[0015] (1) Setting the target temperature Td according to the single-point correction temperature Ts, the two-point correction low temperature TL or the two-point correction high temperature TH;

[0016] (2) Set the sampling frequency Fs, and calculate the time interval Sr between two adjacent sampling moments k and k-1 as follows:

[0017]

[0018] (3) According to the current thermistor resistance R0(k), calculate the current temperature of the temperature baffle T as follows: n (k) is:

[0019]

[0020] Where, T0 and R0 are the thermistor reference temperature and the resistance value corresponding to the reference temperature, respectively, which are usually obtained by testing at 25°C; β is the thermistor index variation coefficient, which is determined by the thermistor selection;

[0021] (4) The discrete PID temperature control quantity Y(k) is calculated as follows:

[0022] Y(k)=K p e(k)+K i Σe(k)+K d [e(k)-e(k-1)]

[0023] In the formula, K p , K i , K d They are proportional coefficient, integral coefficient and differential coefficient respectively. For the three coefficients of semiconductor refrigeration plate, the empirical coefficients obtained after multiple tests are: 1, 4, 8; e(k) is the difference between the temperature of the temperature baffle Tn(k) at the current moment and the expected temperature Td;

[0024] (5) Calculate the semiconductor cooling plate driving voltage U as follows: T (k):

[0025]

[0026] Where Y NT It is the normalized threshold value of temperature control, which affects the temperature rise and fall rate of the semiconductor refrigeration chip and is determined by the designer; Umax is the maximum driving voltage of the semiconductor refrigeration chip, which is determined by the model of the semiconductor refrigeration chip;

[0027] (6) The semiconductor cooling plate driving voltage U is set by the controller T (k) Output to the semiconductor cooling chip, driving it to heat or cool the temperature-averaging barrier to the target temperature Td.

[0028] The present invention also provides a method for correcting non-uniformity of a baffle of an infrared thermal imager with continuously variable temperature, which is characterized by comprising the following steps:

[0029] (1) When receiving the serial port command from the computer, decode the serial port command to obtain the calibration method and calibration temperature information, and select the following single-point calibration mode or two-point calibration mode;

[0030] (1-1) When the single-point calibration mode is selected, the controller drives the DC motor to drive the rotating seat to rotate and insert it into the infrared thermal imager optical path to complete the baffle cutting; the controller controls the semiconductor refrigeration plate to cool or heat according to the temperature information fed back by the temperature sensor, so as to heat or cool the temperature-averaging baffle to reach the single-point calibration temperature Ts, and then synchronously controls the infrared thermal imager to perform single-point calibration;

[0031] (1-11) Synchronously control the infrared thermal imager to determine whether the single-point calibration result is valid. When the infrared thermal imager returns a single-point calibration completion instruction, drive the DC motor to drive the rotating seat to rotate and leave the infrared thermal imager optical path, complete the baffle cutting, and stop the semiconductor refrigeration film from working; when the infrared thermal imager returns a single-point calibration invalid instruction, re-perform the single-point calibration; when the single-point calibration is performed three times and the result is still judged to be invalid, report the system to issue a fault instruction;

[0032] (1-2) When the two-point calibration mode is selected, the low-temperature calibration is completed first. The controller drives the DC motor to drive the rotating seat to rotate and insert it into the infrared thermal imager optical path to complete the baffle cutting. The controller controls the semiconductor refrigeration plate to cool or heat through the temperature information fed back by the temperature sensor to heat or cool the temperature-averaging baffle to reach the two-point calibration low-temperature temperature TL, and then synchronously controls the infrared thermal imager to perform the two-point calibration low-temperature calibration. After obtaining the low-temperature acquisition completion instruction returned by the infrared thermal imager, the two-point calibration low-temperature calibration is continued.

[0033] (1-3) After the two-point calibration is completed at low temperature, high temperature calibration is performed; the controller controls the semiconductor refrigeration plate to cool or heat through the temperature information fed back by the temperature sensor, so as to heat or cool the temperature-averaging baffle to reach the two-point calibration high temperature TH; after reaching the temperature, the infrared thermal imager is synchronously controlled to perform the two-point calibration at high temperature;

[0034] (1-4) Synchronously control the infrared thermal imager to determine whether the two-point calibration result is valid. When the infrared thermal imager returns a two-point calibration completion instruction, the DC motor is driven to drive the rotating seat to rotate and leave the infrared thermal imager optical path, complete the baffle cutting, and stop the semiconductor refrigeration film from working; when the infrared thermal imager returns a two-point calibration invalid instruction, the two-point calibration operation is performed again; when the single-point calibration is performed three times and the result is still judged to be invalid, the reporting system sends a fault instruction.

[0035] The present invention has the following advantages and effects: by adopting the above scheme, high-reliability single-point calibration and two-point calibration can be realized at a certain position on the optical path of the infrared thermal imager, and non-uniform calibration of the infrared thermal imager can be realized without opening the cover, which effectively reduces the maintenance cost of the infrared thermal imager and improves the calibration efficiency of the infrared thermal imager. The present invention can realize internal single-point calibration and two-point calibration of the infrared thermal imager at different working temperatures, and solve the image non-uniformity problem caused by the performance degradation of the infrared thermal imager after long-term operation and long-term storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a system structure diagram of the present invention;

[0037] Figure 2 for Figure 1 sectional view of

[0038] Figure 3 It is a system principle block diagram of the present invention;

[0039] Figure 4 is a flow chart of the correction method of the present invention;

[0040] Figure 5 This is an application effect diagram of Example 1 of the present invention. DETAILED DESCRIPTION

[0041] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0042] Example 1

[0043] The temperature-continuously variable infrared thermal imager baffle correction system provided by the present invention comprises: a rotating seat 4 connected to a rotating mechanism, an infrared light window arranged on the rotating seat 4, one side of the infrared light window is opposite to the infrared thermal imager optical path, and the other side of the infrared light window is connected to a refrigeration component on which a temperature sensor 13 is arranged, and a heat dissipation component matched with the refrigeration component is arranged on the rotating seat 4;

[0044] The rotating seat 4 is configured as a flat plate seat with a large end at one end and a small end at the other end. The infrared light window is provided at the large end of the flat plate seat. The small end of the flat plate seat is connected to the rotating mechanism so that various components can be installed through the rotating seat 4 and rotated by the rotating mechanism.

[0045] The infrared light window comprises a circular window 14 arranged at the large end of the rotating seat 4, an infrared window sheet 15 is arranged on the outer side of the circular window 14, and inner and outer heat insulation rings 6 and 11 are sleeved on the inner side, and a refrigeration component is arranged between the inner and outer heat insulation rings 6 and 11, so that the refrigeration component can be inserted into the optical path of the infrared thermal imager through the infrared light window as needed;

[0046] The refrigeration component includes a circular temperature-averaging baffle 7 with a rectangular window thereon, the inner side of the temperature-averaging baffle 7 is arranged on the inner side of the circular window 14 through an inner insulation ring 6, the outer side of the temperature-averaging baffle 7 is connected to an outer insulation ring 11, a semiconductor refrigeration sheet 9 clamped by inner and outer thermal conductive silicone greases 8 and 10 is arranged in the rectangular window on the temperature-averaging baffle 7, the semiconductor refrigeration sheet 9 is electrically connected to an existing controller, and a card slot for placing a temperature sensor 13 is arranged on one side of the rectangular window of the temperature-averaging baffle 7, so that cooling or heating can be performed through the semiconductor refrigeration sheet 9, and the detected cooling or heating temperature data is sent to the controller through the temperature sensor 13 to determine whether the requirements are met, and then the refrigeration component is inserted into or cut out of the infrared thermal imager optical path through the control of the controller;

[0047] The temperature sensor 13 is set as a thermistor;

[0048] The heat dissipation component includes a cover plate 12 arranged on the inner side of the rotating seat 4, a heat dissipation fan 5 is arranged between the cover plate 12 and the small end of the rotating seat 4, and a heat dissipation fin is arranged at the position where the cover plate 12 is connected to the heat dissipation fan 5, and a plurality of heat dissipation holes are arranged at the position where the cover plate 12 is connected to the refrigeration component, so that the non-working surface of the refrigeration component on the rotating seat 4 is heat-dissipated by the heat dissipation component, thereby ensuring the temperature control accuracy of the refrigeration component;

[0049] The rotating mechanism includes a DC motor 1 and a motor base 2 connected to the DC motor 1. The main shaft of the DC motor 1 passes through the motor base 2 and is connected to a rotating base 4. The DC motor 1 is electrically connected to a controller so that the rotating mechanism is controlled by the controller to drive the rotating base to rotate.

[0050] A limit plate 3 is provided between the rotating mechanism and the rotating seat 4 to limit the rotation angle of the rotating seat 4 .

[0051] Example 2

[0052] The method for calibrating a baffle of an infrared thermal imager with continuously variable temperature provided by the present invention comprises the following steps:

[0053] (1) Setting the target temperature Td according to the single-point correction temperature Ts, the two-point correction low temperature TL or the two-point correction high temperature TH;

[0054] (2) Set the sampling frequency Fs, and calculate the time interval Sr between two adjacent sampling moments k and k-1 as follows:

[0055]

[0056] (3) According to the current thermistor resistance R0(k), calculate the current temperature of the temperature baffle T as follows: n (k) is:

[0057]

[0058] Where, T0 and R0 are the thermistor reference temperature and the resistance value corresponding to the reference temperature, respectively, which are usually obtained by testing at 25°C; β is the thermistor index variation coefficient, which is determined by the thermistor selection;

[0059] (4) The discrete PID temperature control quantity Y(k) is calculated as follows:

[0060] Y(k)=K p e(k)+K i Σe(k)+K d [e(k)-e(k-1)]

[0061] In the formula, K p , K i , K d They are proportional coefficient, integral coefficient and differential coefficient respectively. For the three coefficients of semiconductor refrigeration plate, the empirical coefficients obtained after multiple tests are: 1, 4, 8; e(k) is the difference between the temperature of the temperature baffle Tn(k) at the current moment and the expected temperature Td;

[0062] (5) Calculate the semiconductor cooling plate driving voltage U as follows: T (k):

[0063]

[0064] Where Y NT It is the normalized threshold value of temperature control, which affects the temperature rise and fall rate of the semiconductor refrigeration chip and is determined by the designer; U max is the maximum driving voltage of the semiconductor refrigeration chip, which is determined by the model of the semiconductor refrigeration chip;

[0065] (6) The semiconductor cooling plate driving voltage U is set by the controller T (k) Output to the semiconductor cooling chip, driving it to heat or cool the temperature-averaging barrier to the target temperature Td.

[0066] The method for non-uniform correction of a baffle of an infrared thermal imager with continuously variable temperature provided by the present invention comprises the following steps:

[0067] (1) When receiving the serial port command from the computer, decode the serial port command to obtain the calibration method and calibration temperature information, and select the following single-point calibration mode or two-point calibration mode;

[0068] (1-1) When the single-point calibration mode is selected, the controller drives the DC motor 1 to drive the rotating seat 4 to rotate and insert it into the infrared thermal imager optical path to complete the baffle cutting; the controller controls the semiconductor refrigeration plate 9 to cool or heat through the temperature information fed back by the temperature sensor 13, and transmits the heating or cooling temperature to the temperature-averaging baffle 7 to make it reach the single-point calibration temperature Ts, and then synchronously controls the infrared thermal imager to perform single-point calibration;

[0069] (1-11) Synchronously control the infrared thermal imager to determine whether the single-point calibration result is valid: when the infrared thermal imager returns a single-point calibration completion instruction, drive the DC motor 1 to drive the rotating seat 4 to rotate and leave the infrared thermal imager optical path, complete the baffle cutting, and stop the semiconductor cooling plate 9 from working; when the infrared thermal imager returns a single-point calibration invalid instruction, re-perform the single-point calibration; when the single-point calibration is performed three times and the result is still judged to be invalid, report the system to issue a fault instruction;

[0070] (1-2) When the two-point calibration mode is selected, the low-temperature calibration is first completed. The controller drives the DC motor 1 to drive the rotating seat 4 to rotate and insert it into the infrared thermal imager optical path to complete the baffle cutting. The controller controls the semiconductor refrigeration plate 9 to cool or heat through the temperature information fed back by the temperature sensor 13, and transmits the heating or cooling temperature to the temperature-averaging baffle 7 to make it reach the two-point calibration low-temperature temperature TL, and then synchronously controls the infrared thermal imager to perform the two-point calibration low-temperature calibration. After obtaining the low-temperature acquisition completion instruction returned by the infrared thermal imager, the two-point calibration low-temperature calibration is continued.

[0071] (1-3) After the two-point calibration is completed at low temperature, high temperature calibration is performed; the controller controls the semiconductor refrigeration plate 9 to cool or heat through the temperature information fed back by the temperature sensor 13, and transmits the heating or cooling temperature to the temperature-averaging baffle 7 to make it reach the two-point calibration high temperature TH; then the infrared thermal imager is synchronously controlled to perform the two-point calibration at high temperature;

[0072] (1-4) Synchronously control the infrared thermal imager to determine whether the two-point calibration result is valid: when the two-point calibration completion instruction is returned by the infrared thermal imager, drive the DC motor 1 to drive the rotating seat 4 to rotate and leave the infrared thermal imager optical path, complete the baffle cutting, and stop the semiconductor cooling plate 9; when the two-point calibration invalid instruction is returned by the infrared thermal imager, perform the two-point calibration operation again; when the single-point calibration is performed three times and the result is still judged to be invalid, report the system to issue a fault instruction.

[0073] Application Examples

[0074] The temperature-continuously variable infrared thermal imager baffle correction system of the present invention is applied to a medium-wave 640×512 refrigerated infrared photoelectric system. The baffle is installed 1 mm in front of the infrared detector window. The infrared thermal imager is turned on and the baffle correction is performed according to the steps of Examples 2 and 3. Specifically, two-point correction is performed. After the two-point correction is completed, the non-uniformity of the output image is reduced, so that the quality of the infrared image is significantly improved. Figure 5 Comparison before and after correction is shown.

Claims

1. A temperature-continuously variable infrared thermal imager baffle correction system, characterized in that It includes a rotating seat connected to a rotating mechanism, an infrared light window arranged on the rotating seat, one side of the infrared light window is opposite to the optical path of the infrared thermal imager, and the other side is connected to a refrigeration component with a temperature sensor arranged thereon, and a heat dissipation component matched with the refrigeration component is arranged on the rotating seat.

2. The temperature-continuously variable infrared thermal imager baffle correction system according to claim 1, characterized in that: The rotating seat is configured as a flat plate seat with a large end at one end and a small end at the other end. The infrared light window is arranged at the large end of the flat plate seat, and the small end of the flat plate seat is connected to the rotating mechanism.

3. The temperature-continuously variable infrared thermal imager barrier correction system according to claim 1, characterized in that: The infrared light window comprises a circular window arranged at the large end of the rotating seat, an infrared window sheet is arranged on the outer side of the circular window, inner and outer heat insulation rings are sleeved on the inner side of the circular window, and a refrigeration component is arranged between the inner and outer heat insulation rings.

4. The temperature-continuously variable infrared thermal imager baffle correction system according to claim 1, characterized in that: The refrigeration component includes a circular temperature-averaging baffle with a rectangular window thereon. The inner side of the temperature-averaging baffle is arranged on the inner side of the circular window through an inner insulation ring, and the outer side is connected to the outer insulation ring. A semiconductor refrigeration plate clamped by inner and outer thermal conductive silicone grease is arranged in the rectangular window. The semiconductor refrigeration plate is electrically connected to the existing controller, and a slot for placing a temperature sensor is provided on one side of the rectangular window of the temperature-averaging baffle.

5. The temperature-continuously variable infrared thermal imager barrier correction system according to claim 1, characterized in that: The heat dissipation component includes a cover plate arranged on the inner side of the rotating seat, a heat dissipation fan is arranged between the cover plate and the small end of the rotating seat, and heat dissipation fins are arranged at the position where the cover plate connects with the heat dissipation fan, and a plurality of heat dissipation holes are arranged at the position where the cover plate connects with the refrigeration component.

6. The temperature-continuously variable infrared thermal imager baffle correction system according to claim 1, characterized in that: The rotating mechanism comprises a DC motor and a motor seat connected to the DC motor. The DC motor main shaft passes through the motor seat and is connected to the rotating seat. The DC motor is electrically connected to the controller.

7. The temperature-continuously variable infrared thermal imager barrier correction system according to claim 1, characterized in that: A limiting piece is arranged between the rotating mechanism and the rotating seat.

8. A method for correcting a temperature-continuously variable infrared thermal imager baffle, characterized in that It includes the following steps: (1) Setting the target temperature Td according to the single-point correction temperature Ts, the two-point correction low temperature TL or the two-point correction high temperature TH; (2) Set the sampling frequency Fs, and calculate the time interval Sr between two adjacent sampling moments k and k-1 as follows: (3) According to the current thermistor resistance R0(k), calculate the current temperature of the temperature baffle T as follows: n (k) is: Where, T0 and R0 are the thermistor reference temperature and the resistance value corresponding to the reference temperature, respectively, which are usually obtained by testing at 25°C; β is the thermistor index variation coefficient, which is determined by the thermistor selection; (4) The discrete PID temperature control quantity Y(k) is calculated as follows: Y(k)=K p e(k)+K i Σe(k)+K d [e(k)-e(k-1)] In the formula, K p , K i , K d They are proportional coefficient, integral coefficient and differential coefficient respectively. For the three coefficients of semiconductor refrigeration plate, the empirical coefficients obtained after multiple tests are: 1, 4, 8; e(k) is the difference between the temperature of the temperature baffle Tn(k) at the current moment and the expected temperature Td; (5) Calculate the semiconductor cooling plate driving voltage U as follows: T (k): Where Y NT It is the normalized threshold value of temperature control, which affects the temperature rise and fall rate of the semiconductor refrigeration chip and is determined by the designer; U max is the maximum driving voltage of the semiconductor refrigeration chip, which is determined by the model of the semiconductor refrigeration chip; (6) The semiconductor cooling plate driving voltage U is set by the controller T (k) Output to the semiconductor cooling chip, driving it to heat or cool the temperature-averaging barrier to the target temperature Td.

9. A method for correcting non-uniformity of a baffle of an infrared thermal imager with continuously variable temperature, characterized in that The following steps are involved: (1) When receiving the serial port command from the computer, decode the serial port command to obtain the calibration method and calibration temperature information, and select the following single-point calibration mode or two-point calibration mode; (1-1) When the single-point calibration mode is selected, the controller drives the DC motor to drive the rotating seat to rotate and insert it into the infrared thermal imager optical path to complete the baffle cutting; the controller controls the semiconductor refrigeration plate to cool or heat according to the temperature information fed back by the temperature sensor, so as to heat or cool the temperature-averaging baffle to reach the single-point calibration temperature Ts, and then synchronously controls the infrared thermal imager to perform single-point calibration; (1-11) Synchronously control the infrared thermal imager to determine whether the single-point calibration result is valid. When the infrared thermal imager returns a single-point calibration completion instruction, drive the DC motor to drive the rotating seat to rotate and leave the infrared thermal imager optical path, complete the baffle cutting, and stop the semiconductor refrigeration film from working; when the infrared thermal imager returns a single-point calibration invalid instruction, re-perform the single-point calibration; when the single-point calibration is performed three times and the result is still judged to be invalid, report the system to issue a fault instruction; (1-2) When the two-point calibration mode is selected, the low-temperature calibration is completed first. The controller drives the DC motor to drive the rotating seat to rotate and insert it into the infrared thermal imager optical path to complete the baffle cutting. The controller controls the semiconductor refrigeration plate to cool or heat through the temperature information fed back by the temperature sensor to heat or cool the temperature-averaging baffle to reach the two-point calibration low-temperature temperature TL, and then synchronously controls the infrared thermal imager to perform the two-point calibration low-temperature calibration. After obtaining the low-temperature acquisition completion instruction returned by the infrared thermal imager, the two-point calibration low-temperature calibration is continued. (1-3) After the two-point calibration is completed at low temperature, high temperature calibration is performed; the controller controls the semiconductor refrigeration plate to cool or heat through the temperature information fed back by the temperature sensor, so as to heat or cool the temperature-averaging baffle to reach the two-point calibration high temperature TH; after reaching the temperature, the infrared thermal imager is synchronously controlled to perform the two-point calibration at high temperature; (1-4) Synchronously control the infrared thermal imager to determine whether the two-point calibration result is valid. When the infrared thermal imager returns a two-point calibration completion instruction, the DC motor is driven to drive the rotating seat to rotate and leave the infrared thermal imager optical path, complete the baffle cutting, and stop the semiconductor refrigeration film from working; when the infrared thermal imager returns a two-point calibration invalid instruction, the two-point calibration operation is performed again; when the single-point calibration is performed three times and the result is still judged to be invalid, the reporting system sends a fault instruction.

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