Self-adapting temperature measurement method and device for refrigeration type temperature measurement thermal imager

Abstract

The application provides a self-adaptive temperature measurement method and device for a refrigeration type temperature measurement thermal imager, which comprises the following steps: adjusting the parameters of the temperature measurement thermal imager and obtaining the saliency region of a target; adjusting the temperature measurement thermal imager again based on the ambient temperature and collecting the target image multiple times; judging whether the temperature measurement thermal imager needs to be adjusted repeatedly based on the target image until the temperature measurement value of the interval is considered to be a reasonable temperature measurement value; and correcting the reasonable temperature measurement value to obtain the target temperature value. The application utilizes the existing photoelectric turntable equipment and the electronic control box inside the equipment, and does not need to additionally increase equipment to realize the automatic rotation of the azimuth and the pitch of the refrigeration type temperature measurement thermal imager, and realizes the temperature measurement of any target in the measurement range of the refrigeration type temperature measurement thermal imager. The application adopts the laser ranging and high-precision positioning of the measured target under the self-adaptive temperature measurement environment, corrects the temperature measurement data according to the temperature measurement distance, and greatly improves the temperature measurement precision of the measured target.

Description

Technical Field

[0001] This invention belongs to the field of non-contact temperature measurement technology, specifically relating to an adaptive temperature measurement method and device for a cooling-type thermal imager. Background Technology

[0002] Infrared temperature measurement equipment mainly includes two types of non-contact temperature measurement devices: uncooled infrared temperature measurement and cooled infrared temperature measurement. Among them, uncooled infrared thermal imagers are most widely used in the civilian field. The detector material is generally vanadium oxide, etc., and they are mainly used to measure the temperature of the human body. Their characteristics are narrow temperature measurement range and low temperature measurement accuracy. Cooled thermal imagers use imaging materials such as mercury cadmium telluride and indium gallium arsenide, and have the characteristics of wide temperature measurement range, high temperature measurement accuracy, and stable performance. They are mainly used in occasions with special temperature measurement requirements.

[0003] When analyzing the characteristics of targets in the environment, their radiation properties are generally characterized by temperature distribution. The radiation temperature field distribution of a target can be acquired using a cooled medium-wave or long-wave thermal imager. Accurate measurement of the radiation temperature field is a necessary condition for calculating the intrinsic characteristics of optical targets. Existing cooled thermal imagers, as individual temperature measuring units, are relatively large. During measurement, manual adjustment of the orientation to align with the target is required, leading to inconvenience. Different aiming points result in different temperature values, and the impact of distance on measurement accuracy also varies.

[0004] Secondly, for measurements over a wide temperature range, cooled thermal imagers are generally used, with a measurement range that can cover temperatures from -40°C to 1500°C. To ensure measurement accuracy, attenuators are typically used to ensure that the radiation of the high-temperature target matches the response curve of the thermal imager detector. Therefore, attenuators with different attenuation rates need to be switched in different temperature ranges to ensure measurement accuracy. However, relying on the subjective judgment of the measurement personnel to determine the temperature of the object being measured and manually switching attenuators will inevitably reduce the measurement efficiency of the equipment.

[0005] Therefore, it is necessary to comprehensively consider factors such as temperature measurement positioning, temperature measurement distance, and adaptive temperature measurement range in order to improve the accuracy and efficiency of temperature measurement. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing temperature measuring devices in accurately measuring significant parts of a target (i.e., the object being measured) when the temperature of the object is unknown. Instead, it provides an adaptive temperature measurement method for a cooled thermal imager. By utilizing existing photoelectric turntable equipment and its internal electronic control box, the cooled thermal imager can automatically rotate in azimuth and pitch without the need for additional equipment. This enables the cooled thermal imager to adaptively measure the temperature of any target within its measurement range.

[0007] To achieve the above objectives, the technical solution provided by this invention is:

[0008] This invention provides an adaptive temperature measurement method for a cooled thermal imager, comprising:

[0009] Step 1: Adjust the parameters of the thermal imager and obtain the salient area of ​​the target; including: ensuring the linear response of the cooled thermal imager by dividing the integration time, and rotating the filter wheel to switch the attenuator to match the calibration temperature range; and obtaining the salient area reflecting the target characteristics by analyzing the target.

[0010] Step 2: Adjust the thermal imager based on the ambient temperature and acquire target images multiple times, including: adjusting the direction of the cooling thermal imager based on the analysis results of the ambient temperature of the target, rotating the filter wheel inside the thermal imager to select a suitable attenuator, and acquiring target images multiple times after switching to obtain a suitable field of view.

[0011] Step 3: Determine whether the thermal imager needs to be repeatedly adjusted based on the target image until the temperature value in the range is considered to be a reasonable temperature value; this includes: obtaining the grayscale value in the temperature measurement area based on the target image, and selecting whether to repeatedly adjust the attenuator and the integration time based on the judgment result of whether the current temperature value is reasonable, until the current temperature value reaches the temperature measurement range corresponding to the linear response of Step 1, thus obtaining the temperature value of the target image that is adapted to the cooling thermal imager and the temperature measurement is correct;

[0012] Step 4: Correct the reasonable temperature measurement value to obtain the target temperature value; including: adjusting the corresponding reasonable temperature measurement range of the thermal imager based on Step 3, performing laser ranging on the target, and correcting the temperature measurement value according to the measurement distance obtained by the laser ranging to obtain the corresponding target temperature value of the measured target.

[0013] Furthermore, step one specifically includes:

[0014] Step 11: Adjust the radiation intensity according to the temperature measurement range designed for the cooled thermal imager, and determine the spectral transmittance of the infrared optical lens; set the integration time of the thermal imager according to the high and low temperature measurements corresponding to the temperature measurement range to ensure that the spectral response curve is consistent and within its linear temperature measurement range.

[0015] Step 12: The temperature measurement linear range of the cooled thermal imager is calibrated into different temperature measurement intervals. Different intervals correspond to attenuation plates with different attenuation rates to adjust the incident radiation intensity of the thermal imager detector, thereby reducing the light energy input to the thermal imager detector.

[0016] Step 13: Before adaptive temperature measurement, use a visible light television as an imaging device to image the center of the field of view of the reference imaging device for the target under test, and determine the type of the target under test through target detection analysis, and then analyze the approximate temperature range of the target under test and the significant area of ​​the target under test characteristics.

[0017] Furthermore, step two specifically involves:

[0018] Step 21: Based on the target type obtained from the analysis of the target in Step 1, obtain the basic temperature of the target under the ambient temperature and send it to the cooling thermal imager. Then, finely adjust the photoelectric turret according to the salient area of ​​the current target so that the thermal imager is aligned with the salient area of ​​the target.

[0019] Step 22: Based on the imaging and analysis of the target by the visible light television, obtain the target type, calculate the pixel size occupied by the target in the entire image of the visible light television, determine the target imaging distance and imaging range, and adjust the target imaging range by changing the field of view until the accurate temperature measurement conditions are achieved.

[0020] Step 23: Rotate the filter wheel of the cooled thermal imager to select the appropriate attenuator corresponding to multiple temperature measurement segments based on the target type, and then switch the thermal imager to the appropriate field of view. While keeping the above settings unchanged, continuously acquire images of the target being measured multiple times.

[0021] Furthermore, step three specifically involves:

[0022] Step 31: In step two, the approximate temperature range of the target is obtained through target detection and knowledge graph. Under the condition that the attenuator and field of view remain unchanged, the histogram distribution in the temperature measurement area in the center of the image is calculated for multiple images acquired in succession, and the gray value of the peak position of the image histogram distribution in the temperature measurement area is calculated to obtain the accurate temperature of the target.

[0023] Step 32: Determine whether the current temperature measurement value is within a reasonable temperature measurement range based on the grayscale value ratio, including: (1) If the grayscale peak values ​​calculated multiple times are all within the preset range, the current temperature measurement range is considered reasonable, and there is no need to switch the attenuator. The temperature measurement value in this range is a reasonable temperature measurement value; (2) If the grayscale value at the location of the peak value of the image histogram calculated multiple times is less than the preset grayscale range, the current temperature measurement range of the cooling thermal imager is considered to be highly saturated. While further improving the temperature measurement linear range, the position of the attenuator of the rotating filter wheel is moved to a higher level. (2) The position of the attenuator with the attenuation rate is selected, and the integration time corresponding to the attenuator is selected. The judgment is continued until the requirements of step (1) are met. (3) If the gray value of the peak value of the image histogram calculated multiple times exceeds the preset gray value range, it is considered that the temperature measurement range of the cooled thermal imager is currently low saturation. While further reducing the temperature measurement linear range, the position of the filter wheel attenuator is rotated to the position of the attenuator with the lower attenuation rate. At the same time, the integration time corresponding to the attenuator is selected. The judgment is continued until the requirements of step (1) are met.

[0024] This invention also provides an adaptive temperature measurement device for a cooled infrared thermal imager, based on the aforementioned adaptive temperature measurement method for a cooled infrared thermal imager, comprising: a photoelectric turret, a cooled infrared thermal imager, a laser rangefinder, an electronic control box, a display control terminal, and a visible light television; wherein:

[0025] A cooled infrared thermal imager, a visible light television, and a laser rangefinder are installed and fixed inside the optical bench of the photoelectric turret.

[0026] A cooled infrared thermal imager, a visible light television, and a laser rangefinder are connected to an electronic control box. Data from the electronic control box is transmitted to a display control terminal, and the photoelectric turret rotates horizontally and in pitch.

[0027] Images acquired by the cooled infrared thermal imager and the visible light television are processed by the electronic control box and then transmitted to the display control terminal, which transmits the real-time measurement data to the data processing platform.

[0028] Furthermore, the electronic control box is located in the middle of the photoelectric turret, and the photoelectric turret is equipped with a servo motor, which adjusts the orientation and pitch of the photoelectric turret based on the display control terminal;

[0029] The cooled infrared thermal imager, based on the display control terminal and the data processing platform, is able to measure the temperature of targets and objects and output image data.

[0030] The laser rangefinder, based on the display control terminal, can measure the distance between the target and the object, and output the measured distance obtained by the laser rangefinder to the data processing platform to correct the temperature measurement value.

[0031] Furthermore, the deep learning processing board inside the electronic control box can detect and identify the target under test, determine the target type, and provide the salient area of ​​the target or object under test.

[0032] The servo drive module inside the electronic control box controls the rotation of the servo motor inside the photoelectric turret.

[0033] The display control terminal displays an image of the target being measured and marks the temperature measurement at a specified location.

[0034] The visible light television imagers the target and object being measured and output image data.

[0035] The advantages of this invention are:

[0036] 1. This invention utilizes existing photoelectric turntable equipment and its internal electronic control box to achieve automatic azimuth and pitch rotation of the cooled thermal imager without the need for additional equipment. This enables the cooled thermal imager to measure the temperature of any target within its measurement range, and has the advantages of wide applicability and strong versatility.

[0037] 2. By linking a cooled thermal imager to a data processing platform, this invention can detect and identify the target being measured, and perform accurate temperature measurement on the target based on the detected target type, thereby improving the adaptive and accurate temperature detection under high temperature conditions.

[0038] 3. This invention uses laser ranging to measure the target under adaptive temperature measurement environment, thereby achieving high-precision positioning of the target. Then, the temperature measurement data obtained by the cooling thermal imager is corrected according to the temperature measurement distance, which further greatly improves the temperature measurement accuracy.

[0039] 4. This invention enables simultaneous real-time temperature measurement of multiple targets by adaptively adjusting the cooled thermal imager to a suitable field of view, thus achieving advantages such as high measurement efficiency, fast response speed, and high reliability of temperature measurement results.

[0040] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0041] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0042] Figure 1 The present invention provides a flowchart of an adaptive temperature measurement method for a cooled thermal imager.

[0043] Figure 2 The present invention provides a schematic diagram of an adaptive temperature measurement device for a refrigerated thermal imager.

[0044] Figure 3 The present invention provides a flowchart of a method for temperature measurement using an adaptive temperature measurement device of a cooling-type thermal imager;

[0045] Figure 4 The present invention provides an installation diagram of the filter wheel and attenuator.

[0046] Figure 5 The flowchart of the automatic adjustment of the temperature measurement range of the cooled thermal imager provided by this invention;

[0047] Attached reference numerals: 11-Photoelectric turret; 12-Cooled infrared thermal imager; 13-Laser rangefinder; 14-Data cable; 15-Electronic control box; 16-Display control terminal; 17-Visible light television. Detailed Implementation

[0048] The embodiments of the present invention are described in detail below. These embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0049] See Figure 1 This invention discloses an adaptive temperature measurement method for a cooled thermal imager, comprising:

[0050] Step 1: Adjust the parameters of the thermal imager and obtain the salient area of ​​the target, including: ensuring the linear response of the cooled thermal imager by dividing the integration time, and rotating the filter wheel to switch the attenuator to match the calibration temperature range; and obtaining the salient area reflecting the target characteristics by analyzing the target.

[0051] Furthermore, in this embodiment of the invention, step one specifically includes steps 11 to 13:

[0052] Step 11: Based on the temperature measurement range (preferably -20℃ to 1200℃) designed for the cooled thermal imager, determine the spectral transmittance of the infrared optical lens. This spectral transmittance should be consistent with the spectral response curve of the thermal imager detector. For low-temperature measurements, a high spectral transmittance allows more radiation to reach the thermal imager detector, and a longer integration time is set to ensure the low-temperature response curve of the cooled thermal imager remains within its linear range, ensuring the reception of more target radiation and reducing measurement errors. For high-temperature measurements, even with a short integration time for the thermal imager detector, excessive incident radiation can cause detector output saturation or damage. Therefore, this embodiment of the invention attenuates the incident radiation according to the temperature measurement range during high-temperature measurements, achieving attenuation of a specific range of incident radiation.

[0053] Step 12: Calibrate the temperature measurement linear range of the cooled thermal imager into 5 intervals: low temperature, normal temperature, medium temperature, high temperature, and ultra-high temperature. Simultaneously, design 5 corresponding filter attenuators. Four of these filter attenuators have different attenuation rates, corresponding to different temperature measurement intervals from normal to ultra-high temperature. The low temperature interval is completely transparent without any attenuators. Attenuators with different attenuation rates reduce the light energy input to the detector by reflecting the incident light, thus preventing detector saturation. Rotating the filter wheel allows switching between attenuators with different attenuation rates, matching the thermal imager to different temperature measurement intervals according to its temperature measurement linear range.

[0054] Step 13: Before adaptive temperature measurement, use a visible light television as an imaging device to image the target and perform target detection analysis. Use the YOLO deep learning target detection algorithm to determine the type of the target. After determining the target type, analyze the knowledge graph to give the approximate temperature range of the target and the significant area that can reflect the target characteristics. When multiple targets are detected and identified, the target pointed to by the center of the field of view is the first choice target. The target types of the remaining targets are determined in turn and the significant areas of their target characteristics are given.

[0055] It should be noted that the core idea behind dividing the integration time in steps one and 11 of the present invention is to match an optimal integration time for different target temperature ranges so that the signal intensity falls within the linear response range of the detector.

[0056] Step 2: Adjust the thermal imager based on the ambient temperature and acquire target images multiple times. This includes: adjusting the direction of the cooled thermal imager based on the ambient temperature analysis results of the target, rotating the filter wheel to select a suitable attenuator, and acquiring target images multiple times after switching to obtain a suitable field of view.

[0057] Furthermore, in this embodiment of the invention, step two specifically includes steps 21 to 22:

[0058] Step 21: Based on the target type obtained from the target analysis in Step 1, automatically analyze the basic temperature of the target's ambient temperature and send the temperature information to the cooled thermal imager; finely adjust the direction of the photoelectric turret according to the analyzed target salient area, and the thermal imager mounted on the photoelectric turret will change its direction accordingly to align with the salient area of ​​the target obtained in Step 1; when there are multiple targets, the target pointed to by the center of the field of view is the first target for temperature measurement. After the test is completed, adjust the direction of the photoelectric turret to measure the temperature of the other detected targets in turn until all temperature measurements are completed.

[0059] Step 22: Based on the imaging and analysis of the target by the visible light television in Step 1, determine the target type, calculate the pixel size occupied by the target in the entire image of the visible light television, and determine the target imaging distance and target imaging range accordingly (wherein, when the percentage of the target's imaging pixel size is lower than the threshold P, it is considered that the current target imaging distance is too far and the target imaging range is too small, and the conditions for accurate temperature measurement are not met).

[0060] The field of view is changed to adjust the target imaging range (specifically, a field of view reduction command is sent to the thermal imager to reduce its field of view, thereby increasing the target imaging range; when there are multiple targets, the target contained in the center of the field of view is used as the adjustment reference) until the accurate temperature measurement conditions are achieved.

[0061] Step 23: Rotate the filter wheel of the cooled thermal imager to a suitable attenuator. The selection of the attenuator is based on the target type and knowledge graph obtained from the analysis, which indicates its approximate temperature characteristics and provides the target's typical temperature range. Attenuators corresponding to different temperature ranges are selected based on this range. Then, following the adjustment commands for the filter wheel and attenuator in Step 22, the field of view is switched to a suitable range and kept stable. Multiple images of the target are continuously acquired. Preferably, three images of the target are acquired consecutively.

[0062] Step 3: Based on the target image, determine whether the temperature measuring thermal imager needs to be repeatedly adjusted until the temperature value in this range is considered to be a reasonable temperature value. This includes: obtaining the grayscale value in the temperature measuring area based on the target image; and selecting whether to repeatedly adjust the attenuator and integration time based on the judgment result of whether the current temperature value is reasonable, until the current temperature value reaches the temperature measuring range corresponding to the linear response of Step 1, thus obtaining the temperature value of the target image that is compatible with the cooling type temperature measuring thermal imager and the temperature measurement is correct.

[0063] Specifically, step three in this embodiment of the invention includes steps 31 to 32:

[0064] Step 31: Based on the approximate temperature range of the target obtained through target detection and knowledge graph in Step 2, calculate the histogram distribution in the temperature measurement area in the center of the image for multiple images (preferably three images) acquired in succession while keeping the attenuator and field of view unchanged, and calculate the gray value at the peak position of the image histogram distribution in the temperature measurement area to obtain the accurate temperature of the target.

[0065] Step 32: Determine whether the current temperature measurement value is within a reasonable temperature measurement range based on the grayscale value ratio, including: (1) If the grayscale peak value calculated multiple times (preferably 3 times) is within a preset range (e.g., between 5% and 95%), then the current temperature measurement range is considered reasonable, and there is no need to switch the attenuator. The temperature measurement value in this range is a reasonable temperature measurement value; (2) If the grayscale value at the location of the peak value of the image histogram calculated multiple times is below 5% of the grayscale range, then the current temperature measurement range of the cooled thermal imager is considered to be highly saturated. It is necessary to further improve the temperature measurement linear range while rotating the filter wheel attenuator. The position is moved to the position of the attenuator with a higher attenuation rate, and the integration time corresponding to the attenuator is selected. The judgment is continued until the requirements of step (1) are met. (3) If the gray value of the peak value of the image histogram calculated multiple times exceeds 95% of the preset gray value range, it is considered that the current temperature measurement range of the cooled thermal imager is low saturation. While further reducing the temperature measurement linear range, the position of the filter wheel attenuator is rotated to the position of the attenuator with a lower attenuation rate, and the integration time corresponding to the attenuator is selected. The judgment is continued until the requirements of step (1) are met.

[0066] Step 4: Correct the reasonable temperature measurement value to obtain the target temperature value, including: adjusting the corresponding reasonable temperature measurement range of the thermal imager based on Step 3; when the temperature measurement reaches the reasonable temperature measurement range, performing laser ranging on the target; and further correcting the temperature measurement value based on the laser ranging distance to obtain the corresponding target temperature value of the measured target.

[0067] See Figure 2 This invention also discloses a cooled infrared thermal imager adaptive temperature measurement device, based on the aforementioned disclosed cooled infrared thermal imager adaptive temperature measurement method, comprising: a photoelectric turret 11, a cooled infrared thermal imager 12, a laser rangefinder 13, a data cable 14, an electronic control box 15, a display control terminal 16, and a visible light television 17; wherein:

[0068] (1) The infrared cooled infrared thermal imager 12, the visible light television 17, and the laser rangefinder 13 are installed and fixed in the optical bench of the photoelectric turret 11; specifically: the photoelectric turret 11 has a two-axis, two-frame structure and can rotate on the azimuth and pitch axes, driven by a servo motor inside, and the motor drive module is integrated in the electronic control box 1-5. When the electronic control box 15 receives a rotation command, it drives the servo motor to rotate in the corresponding azimuth; the photoelectric turret 11 contains one optical bench on the left and one on the right, where the mid-wave cooled infrared thermal imager 12 is installed in the optical bench on the left and is powered by the photoelectric turret 11. The image data it collects is transmitted to the electronic control box 1-5 through the data cable 14; the optical bench on the right is equipped with sensors such as the laser rangefinder 13 and the visible light television 17, and the data output by them is also transmitted to the electronic control box 15.

[0069] (2) The cooled infrared thermal imager 12, the visible light television 17, and the laser rangefinder 13 are connected to the electronic control box 15. The data from the electronic control box 15 is transmitted to the display control terminal 16, and the photoelectric turret 11 rotates horizontally and in pitch. Furthermore, the electronic control box 15 is located in the middle of the photoelectric turret 11, and the photoelectric turret 11 has a servo motor inside. The azimuth and pitch attitude of the photoelectric turret 11 are adjusted based on the display control terminal 16. Furthermore, the cooled infrared thermal imager 12 can measure the temperature of the target and object and output image data based on the display control terminal 16 and the data processing platform. Furthermore, the laser rangefinder 13 can measure the distance between the target and object based on the display control terminal 16 and output the measured distance obtained by the laser rangefinder 13 to the data processing platform to correct the temperature value. The display control terminal 16 is linked to the data processing platform. Furthermore, the deep learning processing board inside the electronic control box 15 can detect and identify the target under test, determine the object's attributes, and provide the salient area of ​​the target or object under test; furthermore, the servo drive module inside the electronic control box 15 controls the rotation of the servo motor inside the photoelectric turret 11.

[0070] Specifically, the electronic control box 15 includes a servo control board, a deep learning processing board, and a data fusion board. The servo control board mainly drives and controls the orientation motor and the pitch motor, driving the photoelectric turret 11 to rotate according to the instructions. The deep learning processing board mainly collects image data from the cooled infrared thermal imager 12 and the visible light television 17. The image collected by the visible light television 17 is processed by the deep learning processing board to detect and identify the target, determine the category of the target, and automatically adjust the turret's direction to the target position based on the detection results. The data fusion board is mainly responsible for distributing and switching temperature measurement image data, laser rangefinder data, visible light television image data, serial communication data, etc.

[0071] (3) The images acquired by the cooled infrared thermal imager 12 and the visible light television 17 are processed by the electronic control box 15 and then transmitted to the display control terminal 16, which transmits the real-time measurement data to the data processing platform. Furthermore, the display control terminal 16 displays the image of the target being measured and marks the temperature measurement at the specified location; furthermore, the visible light television 17 images the target and the object being measured and outputs the image data.

[0072] The deep learning processing board described above in this embodiment of the invention mainly realizes mid-wave infrared thermometry image acquisition, target detection and recognition, and image transmission. Its hardware platform is based on the Hi3559AV100 processor, and the data processing platform is based on deep learning theory. Utilizing the YOLOv5 deep learning model, large-scale sample acquisition and training were initially conducted on typical targets such as vehicles, aircraft, and pedestrians. The YOLOv5 model was developed and deployed in a Linux environment, enabling the detection and recognition of these targets. Based on the recognition results and combined with the knowledge database, the salient regions of different targets are automatically determined, i.e., the parts that require key attention for target characteristic acquisition and radiation thermometry. The detection results are then sent to the servo drive module, which drives the photoelectric turret to point to this salient region.

[0073] Since the task of acquiring target characteristics is a non-real-time task, the temperature measurement process does not have high real-time requirements. After the photoelectric turret 11 points to the target and remains stationary, the laser rangefinder 13 performs a distance measurement every minute and transmits the data to the medium-wave cooled infrared thermal imager 12 via the electronic control box 15 for temperature measurement accuracy correction.

[0074] Continue reading Figure 2 When using the adaptive temperature measurement device of the cooled infrared thermal imager in this embodiment of the invention to measure the temperature of a target in the environment, the photoelectric turret 11 is first powered on. After the system self-test is normal, the mid-wave cooled infrared thermal imager 12, visible light television 17, laser rangefinder 13 and other sensors work normally. The display control terminal 16 displays the image collected by the cooled infrared thermal imager 12, and the image screen displays the temperature value of any target or background. Simultaneously, the deep learning processing board performs target detection and recognition algorithms based on the images acquired by the visible light television 17, and marks and classifies the identified targets. After marking various targets, the operator manually adjusts the direction of the photoelectric turret 11 so that the crosshairs in the image are aimed at the target object to be measured, and measures the temperature of the target. The rotating filter wheel of the cooled infrared thermal imager 12 is adjusted in real time to select a suitable attenuator, and laser ranging is performed by the laser rangefinder 13. The measured distance is used to further correct the temperature value. Alternatively, according to the identified target type, the targets are sorted in sequence, and the photoelectric turret 11 is automatically driven to point to the salient area of ​​the target. The rotating filter wheel of the cooled infrared thermal imager 12 is adjusted in real time to select a suitable attenuator, and the temperature value of the measured target is given synchronously until the temperature and distance of all salient targets are measured. During this period, the laser ranging corrects the temperature value of the measured target.

[0075] See Figure 3As shown, the process of temperature measurement using an adaptive temperature measurement device in a cooled thermal imager is as follows: Power on the photoelectric turret – self-test of the adaptive temperature measurement system – visible light television image acquisition – target identification and classification – determination of automatic or manual measurement; if automatic measurement is performed, targets are classified and sorted sequentially, and the system automatically aims at the salient areas of each target in turn – adjustment of the filter wheel and selection of the attenuator – measurement of target temperature – laser marking of target distance – output of adaptive temperature measurement results after all temperature measurements are completed. Specifically, if manual measurement is performed, the process is as follows: specify the target location – turret aims at the target – measure the target temperature – laser marking of target distance – output of measurement results.

[0076] See Figure 4 As shown, the filter wheel consists of five circular holes, each corresponding to an attenuator with a different attenuation rate. Different attenuators are installed for the room temperature range (attenuation rate a), medium temperature range (attenuation rate b), high temperature range (attenuation rate c), and ultra-high temperature range (attenuation rate d). No attenuator is installed for the low temperature range. The filter wheel is installed in front of the thermal imager detector. When selecting different attenuators, the filter wheel is rotated to align the corresponding attenuator with the detector, achieving the purpose of attenuating the incident radiation. The ultra-high temperature range has the highest attenuation rate, while the low temperature range does not require an attenuator, and the incident radiation reaches the detector directly.

[0077] See Figure 5 As shown, based on the linear range of the response of the cooled infrared thermal imager, the integration time is adjusted and the temperature measurement range is calibrated. The temperature measurement range is divided into low temperature zone, normal temperature zone, medium temperature zone, high temperature zone and ultra-high temperature zone. The current target is measured and three consecutive frames of images are collected. (1) If the peak gray value of the three consecutive frames is between 5% and 95%, the temperature measurement range is reasonable. (2) If the peak gray value of the three consecutive frames is below 5% of the gray level, the current target is measured again after reducing the temperature measurement range, adjusting the integration time and adjusting the attenuator. The temperature measurement range is considered reasonable when the peak gray value of the three consecutive frames is between 5% and 95%. (3) If the peak gray value of the three consecutive frames is above 95% of the gray level, the current target is measured again after increasing the temperature measurement range, adjusting the integration time and adjusting the attenuator. The temperature measurement range is considered reasonable when the peak gray value of the three consecutive frames is between 5% and 95%. The temperature value of the target is output when the temperature measurement range of the three consecutive frames is reasonable.

[0078] In practical applications, according to Figure 3 As shown, for an image with a pixel count of grayscale range is The image makes Indicates the first One gray level, In the image The number of pixels that appear, then histogram distribution for Mark histogram distribution The gray value where the peak is located When the cooled infrared thermal imager 12 measures temperature, the histogram distribution of three consecutive frames... The gray value where the peak is located When the histogram distribution is between 5% and 95%, it is determined that the current image shows a large range between high and low temperature values. Therefore, the temperature measurement range is considered reasonable, and the temperature of the target being measured falls within this range. The temperature value of the target can then be directly output. When the histogram distribution of three consecutive frames... The gray value where the peak is located When the temperature is below 5%, the current temperature measurement range of the cooled infrared thermal imager 12 is considered to be highly saturated. It is necessary to further increase the temperature measurement range by rotating the filter wheel attenuator to a lower attenuation rate position and simultaneously adjusting the corresponding integration time of the cooled infrared thermal imager 12. The process continues until the temperature measurement range is met. Only when a reasonable temperature measurement range is reached can the correct temperature value be output. (When the histogram...) grayscale value at the location of the peak If the grayscale range is above 95%, then the current temperature measurement range of the cooled infrared thermal imager 12 is considered to be low-saturated, and the temperature measurement range needs to be further increased. This requires rotating the filter wheel attenuator to a higher attenuation rate position and simultaneously adjusting the corresponding integration time of the thermal imager. The system continues to make judgments until the temperature measurement range requirements are met. Only when the reasonable temperature measurement range is reached can the correct temperature value be output.

[0079] Taking vehicle measurement as an example, when the cooled infrared thermal imager's adaptive temperature measurement system detects a vehicle as the target, the target is labeled as a certain type of vehicle. Based on a machine learning database, the system identifies the engine area as the region with significant radiative heat generation. This area is a key focus for the measurement target's characteristics. The system automatically adjusts the direction of the photoelectric turret 11, locking onto the engine area with crosshairs and providing the real-time measured temperature value of the engine area. Furthermore, during this measurement process, the laser rangefinder periodically measures the detected target, transmitting this distance value from the electronic control box 15 to the cooled infrared thermal imager 12. The cooled infrared thermal imager 12 corrects the temperature measurement function based on this distance to eliminate measurement errors caused by distance. This embodiment of the invention can also simultaneously perform real-time temperature measurements on multiple engines by adaptively adjusting the cooled infrared thermal imager 12 to a suitable field of view. The vehicle measurement example described above has the advantages of high measurement efficiency, fast response speed, and high reliability of temperature measurement results.

[0080] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the scope of the technology disclosed in the present invention, and such modifications or substitutions should all be covered within the scope of protection of the present invention.

Claims

1. An adaptive temperature measurement method for a cooled thermal imager, characterized in that, include: Step 1: Adjust the parameters of the thermal imager and obtain the salient area of ​​the target, including: ensuring the linear response of the cooled thermal imager by dividing the integration time, and rotating the filter wheel to switch the attenuator to match the calibration temperature range; and obtaining the salient area reflecting the target characteristics by analyzing the target. Step 2: Adjust the thermal imager based on the ambient temperature and acquire target images multiple times, including: adjusting the direction of the cooled thermal imager based on the analysis results of the ambient temperature of the target, rotating the filter wheel to select a suitable attenuator, and acquiring target images multiple times after switching to obtain a suitable field of view. Step 3: Based on the target image, determine whether the temperature measuring thermal imager needs to be repeatedly adjusted until the temperature value in the range is considered to be a reasonable temperature value. This includes: obtaining the grayscale value in the temperature measuring area based on the target image; selecting whether to repeatedly adjust the attenuator and the integration time based on the judgment result of whether the current temperature value is reasonable, until the current temperature value reaches the temperature measuring range corresponding to the linear response of Step 1, and obtaining the temperature value of the target image that is adapted to the cooling type temperature measuring thermal imager and the temperature measurement is correct. Step 4: Correcting the reasonable temperature measurement value to obtain the target temperature value, including: adjusting the corresponding reasonable temperature measurement range of the thermal imager based on Step 3, performing laser ranging on the target, and correcting the temperature measurement value according to the measurement distance obtained by the laser ranging to obtain the corresponding target temperature value of the measured target.

2. The adaptive temperature measurement method for a cooled thermal imager according to claim 1, characterized in that, Step one specifically involves: Step 11: Adjust the radiation intensity according to the temperature measurement range designed for the cooled thermal imager, and determine the spectral transmittance of the infrared optical lens; set the integration time of the thermal imager according to the high and low temperature measurements corresponding to the temperature measurement range to ensure that the spectral response curve is consistent and within its linear temperature measurement range. Step 12: The temperature measurement linear range of the cooled thermal imager is calibrated into different temperature measurement intervals. Different intervals correspond to attenuation plates with different attenuation rates to adjust the incident radiation intensity of the thermal imager detector, thereby reducing the light energy input to the thermal imager detector. Step 13: Before adaptive temperature measurement, use a visible light television as an imaging device to image the center of the field of view of the reference imaging device for the target under test, and determine the type of the target under test through target detection analysis, and then analyze the approximate temperature range of the target under test and the significant area of ​​the target under test characteristics.

3. The adaptive temperature measurement method for a cooled thermal imager according to claim 1, characterized in that, Step two specifically involves: Step 21: Based on the target type obtained from the analysis of the target in Step 1, obtain the basic temperature of the target under the ambient temperature and send it to the cooling thermal imager. Then, finely adjust the photoelectric turret according to the salient area of ​​the current target so that the thermal imager is aligned with the salient area of ​​the target. Step 22: Based on the imaging and analysis of the target by the visible light television, obtain the target type, calculate the pixel size occupied by the target in the entire image of the visible light television, determine the target imaging distance and imaging range, and adjust the target imaging range by changing the field of view until the accurate temperature measurement conditions are achieved. Step 23: Rotate the filter wheel of the cooled thermal imager to select the appropriate attenuator corresponding to multiple temperature measurement segments based on the target type, and then switch the thermal imager to the appropriate field of view. While keeping the above settings unchanged, continuously acquire images of the target being measured multiple times.

4. The adaptive temperature measurement method for a cooled thermal imager according to claim 1, characterized in that, Step three specifically involves: Step 31: In step two, the approximate temperature range of the target is obtained through target detection and knowledge graph. Under the condition that the attenuator and field of view remain unchanged, the histogram distribution in the temperature measurement area in the center of the image is calculated for multiple images acquired in succession, and the gray value of the peak position of the image histogram distribution in the temperature measurement area is calculated to obtain the accurate temperature of the target. Step 32: Determine whether the current temperature measurement value is within a reasonable temperature measurement range based on the grayscale value ratio, including: (1) If the grayscale peak values ​​calculated multiple times are all within the preset range, the current temperature measurement range is considered reasonable, and there is no need to switch the attenuator. The temperature measurement value in this range is a reasonable temperature measurement value; (2) If the grayscale value at the location of the peak value of the image histogram calculated multiple times is less than the preset grayscale range (e.g., below 5%), the current temperature measurement range of the cooling thermal imager is considered to be highly saturated. It is necessary to further improve the temperature measurement linear range while rotating the filter wheel attenuator. (2) Move the filter to the position of the attenuator with a higher attenuation rate, and select the integration time corresponding to the attenuator. Continue to make judgments until the requirements of step (1) are met. (3) If the gray value of the peak value of the image histogram calculated multiple times exceeds the preset gray value range, it is considered that the temperature measurement range of the cooled thermal imager is currently low saturation. While further reducing the temperature measurement linear range, rotate the filter wheel attenuator to the position of the attenuator with a lower attenuation rate, and select the integration time corresponding to the attenuator. Continue to make judgments until the requirements of step (1) are met.

5. An adaptive temperature measurement device for a cooled thermal imager, based on the adaptive temperature measurement method for a cooled thermal imager according to any one of claims 1-4, characterized in that, include: Photoelectric turret, cooled infrared thermal imager, laser rangefinder, electronic control box, display and control terminal, and visible light television; among which: A cooled infrared thermal imager, a visible light television, and a laser rangefinder are installed and fixed inside the optical bench of the photoelectric turret. A cooled infrared thermal imager, a visible light television, and a laser rangefinder are connected to an electronic control box. Data from the electronic control box is transmitted to a display control terminal, and the photoelectric turret rotates horizontally and in pitch. Images acquired by the cooled infrared thermal imager and the visible light television are processed by the electronic control box and then transmitted to the display control terminal, which transmits the real-time measurement data to the data processing platform.

6. The adaptive temperature measurement device for a cooling-type thermal imager according to claim 5, characterized in that, The electronic control box is located in the middle of the photoelectric turret. The photoelectric turret is equipped with a servo motor, which adjusts the orientation and pitch of the photoelectric turret based on the display control terminal. The cooled infrared thermal imager measures the temperature of the target and outputs image data based on the display control terminal and the data processing platform. The laser rangefinder, based on the display control terminal, can measure the distance between the target and the object, and output the measured distance obtained by the laser rangefinder to the data processing platform to correct the temperature measurement value.

7. The adaptive temperature measurement device for a cooled thermal imager according to claim 5 or 6, characterized in that, The deep learning processing board inside the electronic control box can detect and identify the target under test, determine the target type, and provide the salient area of ​​the target or object under test. The servo drive module inside the electronic control box controls the rotation of the servo motor inside the photoelectric turret. The display control terminal displays an image of the target being measured and marks the temperature measurement at a specified location. The visible light television imagers the target under test and analyze it to determine the target type.

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