Infrared thermal imager detection device and detection method

Abstract

This invention discloses an infrared thermal imager testing device and method, relating to the field of infrared imaging equipment performance testing technology. The testing device includes a blackbody radiation source, an electric target wheel mechanism, an off-axis reflective collimator, a positioning and detection unit, an infrared image acquisition unit, and a control and processing unit. The electric target wheel mechanism includes a drive motor and a rotating target wheel connected by a transmission. The rotating target wheel has multiple target plate mounting positions, each housing a test target plate with different functions. The positioning and detection unit has an angle encoder, which is coaxially connected to the rotating target wheel. The infrared image acquisition unit is used to connect to the infrared thermal imager under test. The control and processing unit is connected to the blackbody radiation source, drive motor, positioning and detection unit, infrared image acquisition unit, and the infrared thermal imager under test. This testing device has a simple overall structure, automates the entire testing process, and effectively improves testing accuracy, data consistency, and testing efficiency.

Description

Technical Field

[0001] This invention relates to the field of infrared imaging equipment performance testing technology, specifically to an infrared thermal imager testing device and testing method. Background Technology

[0002] Minimum resolvable temperature difference (MRTD) and noise equivalent temperature difference (NETD) are core indicators for measuring the imaging quality and detection sensitivity of infrared thermal imagers, and are widely used in equipment factory inspection, daily calibration and performance verification.

[0003] Currently, traditional testing methods require manual disassembly and replacement of various functional target plates, resulting in cumbersome procedures and low testing efficiency. Furthermore, manual contact with the target plate surface easily causes contamination and scratches, affecting test accuracy. After target plate replacement, manual adjustment of the position is still required to align the optical path; the alignment effect is limited by the operator's experience, leading to significant human error and poor consistency of test data across different batches and operators, making standardized testing difficult. In addition, existing equipment suffers from weak integration between different operational stages; target plate switching, blackbody temperature control, image acquisition, and index determination all require manual intervention. The minimum resolvable temperature difference index relies on subjective human judgment, making fully automated operation impossible and further reducing the stability and consistency of test results.

[0004] Therefore, existing testing devices suffer from technical problems such as low testing accuracy, poor testing consistency, and insufficient testing efficiency. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose an infrared thermal imager detection device and detection method to solve the technical problems of low testing accuracy, poor testing consistency and insufficient detection efficiency in the prior art.

[0006] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides an infrared thermal imager detection device, which includes a blackbody radiation source, an electric target wheel mechanism, an off-axis reflective collimator, a positioning detection unit, an infrared image acquisition unit, and a control processing unit. The electric target wheel mechanism includes a drive motor and a rotating target wheel connected by a transmission. The rotating target wheel has multiple target plate mounting positions, and each target plate mounting position is equipped with a test target plate with different functions. The off-axis reflective collimator is used to convert the infrared radiation emitted by the blackbody radiation source into a parallel beam for the infrared thermal imager under test to acquire and image. The positioning detection unit has an angle encoder, which is coaxially connected to the rotating target wheel and is used to acquire the rotation angle signal of the rotating target wheel in real time. The infrared image acquisition unit is used to connect to the infrared thermal imager under test, and the infrared image acquisition unit acquires the infrared image of the target plate captured by the infrared thermal imager under test and transmits the image data. The control processing unit is connected to the blackbody radiation source, the drive motor, the positioning detection unit, the infrared image acquisition unit, and the infrared thermal imager under test.

[0007] In some embodiments, the rotating target wheel has a disc-shaped structure, and multiple target plate mounting positions are evenly spaced along the circumference of the rotating target wheel.

[0008] In some embodiments, the target plate mounting position includes a mounting groove and an elastic pressure plate disposed on the inner wall of the mounting groove, and the test target plate is fixed in the mounting groove by the elastic pressure plate.

[0009] In some embodiments, the rotating target wheel is made of a metal material and has an anodized layer on its surface.

[0010] In some embodiments, the drive motor is a stepper motor or a servo motor, and the positioning repeatability error of the rotating target wheel is less than or equal to ±10 arcseconds.

[0011] In some embodiments, the test target plate includes one or more of the following: a four-bar target for minimum resolvable temperature difference testing, a uniform target for noise equivalent temperature difference testing, a cross target for zero-point movement testing, and a line target for field of view testing.

[0012] In some embodiments, the control processing unit includes a memory and an arithmetic circuit. The memory stores an automatic reading program for the minimum resolvable temperature difference and an automatic calculation program for the noise equivalent temperature difference. The arithmetic circuit is used to run the automatic reading program for the minimum resolvable temperature difference and the automatic calculation program for the noise equivalent temperature difference, and to perform image feature extraction, noise statistics and parameter calculation.

[0013] In some embodiments, the testing device further includes a human-machine interaction unit, which is signal-connected to the control processing unit and is used for parameter input, project selection, result display, and test report generation and export.

[0014] Secondly, the present invention also provides an infrared thermal imager detection method applicable to the aforementioned detection device. The detection method includes: controlling the detection device to complete initialization, calibrating the reference temperature of the blackbody radiation source, and controlling the infrared image acquisition unit to complete preheating and parameter setting; controlling the drive motor to rotate the rotating target wheel and switch to the target test target plate; acquiring rotation angle signals through an angle encoder to position the rotating target wheel, aligning the center of the target plate with the center of the test optical path; setting the blackbody radiation source temperature according to the current target plate type, and acquiring infrared images of the target plate after the temperature stabilizes; processing the acquired infrared image data to obtain various test index results; completing the detection and outputting the test data.

[0015] In some embodiments, the rotation angle signal is acquired by an angle encoder to position the rotating target wheel so that the center of the target plate is aligned with the center of the test optical path. This includes: acquiring the rotation angle signal by an angle encoder to perform preliminary positioning of the rotating target wheel; acquiring a calibration image to verify the alignment accuracy; if the deviation of the alignment accuracy exceeds a preset threshold, adjusting the angle of the rotating target wheel until the center of the target plate is aligned with the center of the test optical path.

[0016] Compared with existing technologies, this invention provides an infrared thermal imager detection device that integrates a blackbody radiation source, an electric target wheel mechanism, an off-axis reflective collimator, a positioning and detection unit, an infrared image acquisition unit, and a control and processing unit. The various functional components work together to automatically complete the entire process of target switching, angle positioning, image acquisition, and data transmission. The device has a compact overall structure and high integration, requiring no manual assistance and achieving fully automated operation of the detection process, effectively improving testing accuracy, data consistency, and detection efficiency. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of an infrared thermal imager detection device provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the electric target wheel mechanism provided in the embodiments of the present invention. Figure 1 ; Figure 3 yes Figure 2 A magnified schematic diagram of part A in the middle section; Figure 4 This is a schematic diagram of the structure of the electric target wheel mechanism provided in the embodiments of the present invention. Figure 2 ; Figure 5 This is a flowchart illustrating an infrared thermal imager detection method provided in an embodiment of the present invention. Figure 1 ; Figure 6 This is a flowchart illustrating an infrared thermal imager detection method provided in an embodiment of the present invention. Figure 2 .

[0018] Explanation of reference numerals in the attached figures: 100. Detection device; 110. Blackbody radiation source; 120. Electric target wheel mechanism; 121. Drive motor; 122. Rotating target wheel; 123. Target plate mounting position; 1231. Mounting groove; 1232. Elastic pressure plate; 124. Test target plate; 130. Off-axis reflective collimator; 140. Positioning detection unit; 141. Angle encoder; 150. Infrared image acquisition unit; 160. Control and processing unit; 170. Human-machine interaction unit; 200. The infrared thermal imager to be tested; 300. Detection methods. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0020] Minimum resolvable temperature difference and noise-equivalent temperature difference are two core indicators for evaluating the imaging quality and detection sensitivity of infrared thermal imagers. Traditional detection methods rely on manual disassembly and replacement of different functional target plates, which is cumbersome and inefficient. Even after the target plate is in place, manual adjustment is still required to align the optical path. Therefore, existing detection devices suffer from low testing accuracy, poor testing consistency, and insufficient detection efficiency.

[0021] To address the technical problems of low testing accuracy, poor testing consistency, and insufficient detection efficiency, this invention provides an infrared thermal imager detection device. This detection device has a simple overall structure, automates the entire detection process, and effectively improves testing accuracy, data consistency, and detection efficiency.

[0022] It should be noted that the detection device provided by the present invention is used for, but not limited to, testing scenarios such as factory testing, daily calibration, and performance verification of infrared thermal imagers. For ease of explanation, this invention will only use the application of the detection device to the factory testing scenario of infrared thermal imagers as an example. The principle of the detection device in other testing scenarios is essentially the same as that in the factory testing scenario of infrared thermal imagers, and will not be described in detail here.

[0023] This invention provides an infrared thermal imager detection device 100, such as... Figures 1 to 4As shown, the detection device 100 includes a blackbody radiation source 110, an electric target wheel mechanism 120, an off-axis reflective collimator 130, a positioning detection unit 140, an infrared image acquisition unit 150, and a control processing unit 160. The electric target wheel mechanism 120 includes a drive motor 121 and a rotating target wheel 122 connected by a drive motor. The rotating target wheel 122 has multiple target plate mounting positions 123, and each target plate mounting position 123 is equipped with a test target plate 124 with different functions. The off-axis reflective collimator 130 is used to convert the infrared radiation emitted by the blackbody radiation source 110 into a parallel beam for use by the infrared thermal imager 2 under test. 00. Imaging acquisition; the positioning detection unit 140 has an angle encoder 141, which is coaxially connected to the rotating target wheel 122 and is used to acquire the rotation angle signal of the rotating target wheel 122 in real time; the infrared image acquisition unit 150 is used to connect with the infrared thermal imager 200 under test, and the infrared image acquisition unit 150 acquires the infrared image of the target plate captured by the infrared thermal imager 200 under test and transmits the image data; the control processing unit 160 is connected to the blackbody radiation source 110, the drive motor 121, the positioning detection unit 140, the infrared image acquisition unit 150 and the infrared thermal imager 200 under test respectively.

[0024] The blackbody radiation source 110 provides a stable and uniform thermal radiation surface, serving as a standard temperature difference reference for minimum resolvable temperature difference (MRTD) and noise equivalent temperature difference (NETD) testing. Specifically, the blackbody radiation source 110 employs a high-precision blackbody furnace with a temperature adjustment range of 0℃-125℃ and a temperature control accuracy of ±0.001℃, ensuring testing accuracy.

[0025] The electric target wheel mechanism 120 includes a drive motor 121 and a rotating target wheel 122, such as Figure 2 and Figure 3 As shown, the rotating target wheel 122 has multiple target plate mounting positions 123, which can be evenly or non-evenly spaced. The number of target plate mounting positions 123 can be determined according to actual needs, such as 6, 8, 10, 12, 15, etc. Each target plate mounting position 123 is equipped with a test target plate 124 with different functions. The drive motor 121 is connected to the rotating target wheel 122 and is used to drive the rotating target wheel 122 to rotate around its central axis, thereby realizing the switching of different test target plates 124.

[0026] For example, the test target plate 124 includes one or more of the following: a four-bar target for minimum resolvable temperature difference testing, a uniform target for noise equivalent temperature difference testing, a cross target for zero-point movement testing, and a line target for field of view testing.

[0027] For example, such as Figure 3As shown, the rotating target wheel 122 has 12 target plate mounting positions 123 along its circumference. Different test target plates 124 with different functions can be detachably installed in each of the 12 target plate mounting positions 123. Specifically, these include: 5 MRTD four-bar targets with different spatial frequencies (0.4-2.5, 0.6-1.667, 0.8-1.25, 1.2-0.883), 1 NETD uniform target, 1 cross target for zero-position movement, 1 spare target plate, 1 long strip target, 1 square target, 1 crescent target, and 2 spare targets.

[0028] The off-axis reflective collimator 130 is used to convert the infrared radiation emitted by the blackbody radiation source 110 into a parallel beam for the infrared thermal imager 200 to acquire and image.

[0029] The positioning detection unit 140 has an angle encoder 141, which is coaxially connected to the rotating target wheel 122. Specifically, the angle encoder 141 is a 24-bit absolute encoder used to acquire the rotation angle signal of the rotating target wheel 122 in real time and transmit the angle signal to the control processing unit 160 to achieve precise indexing and positioning of each test target plate 124. The positioning repeatability is not less than ±10″ (10 arcseconds), ensuring that the center of the target plate after switching is aligned with the center of the test optical path.

[0030] The infrared image acquisition unit 150 is connected to the infrared thermal imager 200 under test to acquire infrared images of the target plate captured by the infrared thermal imager 200 and transmit the image data to the control processing unit 160. Specifically, the infrared image acquisition unit 150 uses a high-definition infrared image acquisition card, which is connected to the video output terminal of the infrared thermal imager 200 under test. It is used to acquire infrared images of the target plate captured by the infrared thermal imager 200 under test and transmit the image data to the control processing unit 160. The image acquisition card used with the control processing unit 160 can adapt to various image acquisition resolutions to ensure the integrity and clarity of the image data.

[0031] The control processing unit 160 adopts an industrial-grade microcontroller and is connected to the blackbody radiation source 110, the drive motor 121, the positioning detection unit 140, the infrared image acquisition unit 150, and the infrared thermal imager 200 under test.

[0032] For example, the control processing unit 160 is provided with a memory and an arithmetic circuit. The memory stores an automatic reading program for the minimum resolvable temperature difference and an automatic calculation program for the noise equivalent temperature difference. The arithmetic circuit is used to run the automatic reading program for the minimum resolvable temperature difference and the automatic calculation program for the noise equivalent temperature difference, and to perform image feature extraction, noise statistics and parameter calculation.

[0033] Specifically, the control processing unit 160 has built-in automatic calculation algorithms. The MRTD automatic interpretation algorithm performs grayscale processing, contrast extraction, and threshold segmentation on the infrared image, then uses an edge detection algorithm to determine the stripe discernibility, gradually adjusting the blackbody temperature difference until the minimum discernible temperature difference is determined. The NETD automatic calculation algorithm performs spatial noise statistics (calculating the image grayscale standard deviation) and temporal noise statistics (acquiring multiple frames of images to calculate grayscale fluctuations) on the infrared image of the NETD uniform target, combined with the blackbody temperature setting, and automatically calculates the noise equivalent temperature difference according to the NETD calculation formula. ; Where ΔT is the blackbody set temperature difference; σ is the standard deviation of image noise; and μ is the average gray level of the image. The control processing unit 160 is also used to receive the angle signal from the positioning detection unit 140, control the drive motor 121 to drive the rotating target wheel 122 to switch to the designated test target plate 124 and complete the positioning, control the blackbody radiation source 110 to adjust the output temperature, receive infrared image data and process it, and output the test results.

[0034] In this embodiment, the detection device 100 integrates a blackbody radiation source 110, an electric target wheel mechanism 120, an off-axis reflective collimator 130, a positioning and detection unit 140, an infrared image acquisition unit 150, and a control and processing unit 160. These functional components work together to automatically complete the entire process of target switching, angle positioning, image acquisition, and data transmission. The device has a compact overall structure and high integration, requiring no manual assistance and achieving fully automated operation of the detection process, effectively improving testing accuracy, data consistency, and detection efficiency.

[0035] In some embodiments, such as Figure 2 and Figure 3 As shown, the rotating target wheel 122 has a disc-shaped structure, and multiple target plate mounting positions 123 are evenly spaced along the circumference of the rotating target wheel 122.

[0036] Specifically, in this embodiment, the rotating target wheel 122 adopts a metal disc structure with 12 target plate mounting positions 123 evenly spaced around its circumference. The disc structure combined with the evenly distributed mounting positions allows for the simultaneous mounting of multiple functional test target plates 124, enabling continuous testing of multiple performance indicators. Furthermore, it improves the smoothness of the rotating target wheel 122's operation when switching targets, thus ensuring consistent positioning results.

[0037] In some embodiments, such as Figure 2 and Figure 3 As shown, the target plate mounting position 123 includes a mounting groove 1231 and an elastic pressure plate 1232 disposed on the inner wall of the mounting groove 1231. The test target plate 124 is fixed in the mounting groove 1231 by the elastic pressure plate 1232.

[0038] Specifically, in this embodiment, the target plate mounting position 123 adopts an elastic clamping structure, specifically including a mounting groove 1231 and elastic pressure plates 1232. A circular mounting groove 1231 is provided on the rotating target wheel, and elastic pressure plates 1232 are fixed to the inner wall of the mounting groove 1231. The material of these pressure plates depends on actual needs; for example, the elastic pressure plates 1232 may be made of stainless steel. After the test target plate 124 is inserted into the mounting groove 1231, it can be clamped and fixed by the elastic force of the elastic pressure plates 1232 without the need for auxiliary tools, enabling quick assembly and disassembly of the target plate and facilitating maintenance. This flexible clamping method not only reliably fixes the target plate and prevents loosening and displacement during testing, but also adapts to various target plate specifications, improving structural versatility.

[0039] In some embodiments, the rotating target wheel 122 is made of a metallic material and has an anodized layer on its surface.

[0040] Specifically, in this embodiment, emissivity refers to an object's ability to spontaneously radiate infrared heat, with a value between 0 and 1. The emissivity of a blackbody is approximately 1, and the emissivity of a specular metal is approximately 0. Low emissivity means that the surface of an object radiates infrared heat very little, and it also follows the law of thermal radiation: the lower the emissivity, the higher the infrared reflectivity. The rotating target wheel 122 is made of a low-emissivity metal material, for example, a low-emissivity aluminum alloy. The surface is anodized to form an anodized layer to reduce the thermal radiation of the rotating target wheel 122 itself, reducing interference with NETD testing and improving test accuracy.

[0041] In some embodiments, the drive motor 121 is a stepper motor or a servo motor, and the positioning repeatability error of the rotating target wheel 122 is less than or equal to ±10 arcseconds.

[0042] Specifically, in this embodiment, a stepper motor or servo motor is used as the driving component. The driving control is precise, the response speed is fast, and the rotation is smooth. Combined with angle detection, the positioning repeatability error of the rotating target wheel 122 can be controlled within ±10 arcseconds. The positioning accuracy is high and the repeatability is good, which can ensure that the target accurately aligns with the test optical path each time, effectively reducing the test error caused by positioning deviation.

[0043] In some embodiments, such as Figure 1 As shown, the testing device 100 also includes a human-machine interaction unit 170, which is connected to the control processing unit 160 for parameter input, project selection, result display, and test report generation and export.

[0044] Specifically, in this embodiment, the human-computer interaction unit 170 adopts a laptop or desktop computer and works in conjunction with the control processing unit 160 to input test parameters (such as test temperature difference and number of tests) and test item selection. It can also display the test process, target status (current target type and positioning status) and test results in real time. At the same time, it supports the automatic generation and export of test reports, which facilitates the retention, traceability and archiving of test data, and effectively improves the ease of operation and overall practicality of the testing device 100.

[0045] To better understand this invention, the following is combined with... Figures 1 to 4 The technical solution of the present invention will be described in detail below: In some embodiments, the detection device 100 includes a blackbody radiation source 110, an electric target wheel mechanism 120, an off-axis reflective collimator 130, a positioning detection unit 140, an infrared image acquisition unit 150, a control processing unit 160, and a human-computer interaction unit 170.

[0046] The electric target wheel mechanism 120 includes a drive motor 121 and a rotating target wheel 122 connected by a transmission. The drive motor 121 is a stepper motor or a servo motor; the rotating target wheel 122 is a metal disc with an anodized layer on its surface, and 12 target plate mounting positions 123 are evenly spaced along the circumference of the rotating target wheel 122. Different test target plates 124 with different functions can be detachably assembled in each target plate mounting position 123; the target plate mounting position 123 includes a mounting groove 1231 and an elastic pressure plate 1232 disposed on the inner wall of the mounting groove 1231. The test target plate 124 is fixed in the mounting groove 1231 by the elastic pressure plate 1232. The positioning repeatability error of the rotating target wheel 122 is less than or equal to ±10 arcseconds. The test target plate 124 includes one or more of the following: a four-bar target for minimum resolvable temperature difference testing, a uniform target for noise equivalent temperature difference testing, a cross target for zero-point movement testing, and a single-line target for field of view testing.

[0047] The off-axis reflective collimator 130 is used to convert the infrared radiation emitted by the blackbody radiation source 110 into a parallel beam for the infrared thermal imager 200 to acquire and image.

[0048] The positioning detection unit 140 has an angle encoder 141, which is coaxially connected to the rotating target wheel 122 and is used to acquire the rotation angle signal of the rotating target wheel 122 in real time.

[0049] The infrared image acquisition unit 150 is used to connect to the infrared thermal imager 200 under test. The infrared image acquisition unit 150 acquires infrared images of the target plate captured by the infrared thermal imager 200 under test and transmits the image data.

[0050] The human-computer interaction unit 170 is used for parameter input, project selection, result display, and test report generation and export.

[0051] The control processing unit 160 is connected to the blackbody radiation source 110, the drive motor 121, the positioning detection unit 140, the infrared image acquisition unit 150, the human-machine interaction unit 170, and the infrared thermal imager 200 under test. The control processing unit 160 includes a memory and a processing circuit. The memory stores the minimum resolvable temperature difference automatic interpretation program and the noise equivalent temperature difference automatic calculation program; the processing circuit is used to run the minimum resolvable temperature difference automatic interpretation program and the noise equivalent temperature difference automatic calculation program, and to perform image feature extraction, noise statistics, and parameter calculation.

[0052] In this embodiment, the detection device 100 has the following beneficial effects: 1. This device integrates various test target plates such as MRTD four-bar target, NETD uniform target, and cross target into a rotating target wheel. The target wheel is rotated by a drive motor to automatically switch targets, eliminating the need for manual disassembly and assembly. This not only solves the problems of cumbersome target changing operations and low efficiency of traditional equipment, but also avoids target surface contamination and scratches caused by manual contact, effectively improving testing efficiency.

[0053] 2. The test target plate of this device adopts a detachable elastic clamping structure, and the target wheel assembly housing is provided with a window for replacing the target wheel. Damaged target plates or target plates of different specifications can be replaced individually without replacing the entire target wheel, which significantly reduces maintenance costs. At the same time, the equipment is more flexible and expandable, and can meet the various testing needs of different models of infrared thermal imagers.

[0054] 3. The device is equipped with an angle encoder to complete the precise indexing and positioning of the target wheel, ensuring that the center of the target plate is precisely aligned with the center of the test optical path. No manual alignment is required, eliminating human operation errors, improving the repeatability and consistency of test results, and achieving standardized testing.

[0055] 4. This device automates the entire process of target switching, blackbody temperature control, image acquisition, parameter calculation, and result output without requiring manual intervention. It automatically interprets and calculates MRTD and NETD parameters using built-in algorithms, overcoming biases caused by subjective human judgment and further improving testing accuracy and operational efficiency.

[0056] 5. The rotating target wheel of this device is made of low emissivity material and is anodized, which effectively reduces the interference of the target wheel's own thermal radiation on NETD testing, further improving the accuracy of NETD testing. The structural design fits the actual testing needs and is highly practical.

[0057] 6. The device has a simple overall structure, requires no complex electric adjustment mechanism, has low manufacturing cost, is easy and convenient to operate, and is suitable for large-scale factory testing and daily calibration of infrared thermal imagers, with a wide range of applications.

[0058] This invention also provides an infrared thermal imager detection method 300, applicable to the aforementioned detection device 100, such as... Figure 5 As shown, the detection method 300 includes: In step S310, the control detection device completes initialization, calibrates the reference temperature of the blackbody radiation source, and controls the infrared image acquisition unit to complete preheating and parameter setting.

[0059] Specifically, the detection device system is initialized, the reference temperature of the blackbody radiation source 110 is calibrated (set to 25℃), the infrared image acquisition unit 150 is preheated, and the image acquisition resolution is set according to the video type of the product being tested.

[0060] Step S320: Control the drive motor to drive the rotating target wheel to rotate, and switch to the target test target plate.

[0061] Specifically, for example, by selecting a test item (such as MRTD test) through the human-computer interaction unit 170 and inputting test parameters (such as test temperature difference range of 5℃-20℃), the control processing unit 160 generates a target plate switching command according to the selected MRTD test item, controls the drive motor 121 to drive the rotating target wheel 122 to rotate, and switches to the MRTD four-bar target with the specified spatial frequency.

[0062] Step S330: The rotation angle signal is acquired by the angle encoder to position the rotating target wheel so that the center of the target plate is aligned with the center of the test optical path.

[0063] Specifically, the rotation angle signal of the rotating target wheel 122 is acquired in real time by the angle encoder 141 and transmitted to the control processing unit 160. The control processing unit 160 calculates the rotation angle of the rotating target wheel 122 based on the angle signal. When it is determined that the target MRTD four-bar target has reached the test optical path position, the drive motor 121 is controlled to finely adjust the angle of the rotating target wheel 122 so that the center of the target plate is aligned with the center of the test optical path.

[0064] Step S340: Set the blackbody radiation source temperature according to the current target plate type, and collect infrared images of the target plate after the temperature stabilizes.

[0065] Specifically, the control processing unit 160 automatically configures the output temperature of the blackbody radiation source 110 according to the current spatial frequency of the MRTD four-bar target, so that an initial set temperature difference (10℃) is formed between the blackbody radiation source 110 and the MRTD four-bar target. After the temperature of the blackbody radiation source 110 stabilizes (temperature fluctuation ≤ ±0.001℃), the infrared image acquisition unit 150 is triggered to acquire the infrared image of the MRTD four-bar target captured by the infrared thermal imager 200 under test. Three frames of images are acquired and the average value is taken to reduce image noise interference.

[0066] Step S350: The acquired infrared image data is processed to obtain the results of various test indicators.

[0067] Specifically, the infrared image acquisition unit 150 transmits the acquired infrared image data to the control processing unit 160, which processes the image data using a built-in algorithm.

[0068] For example, for MRTD testing, the control processing unit 160 processes the image data using a built-in MRTD automatic interpretation algorithm: first, the image is converted to grayscale and noise is reduced, and the contrast of the stripe area is extracted; then, it is determined whether the stripes are distinguishable. If the stripes are clear and distinguishable, the blackbody set temperature difference is gradually reduced, and steps S340 and S350 are repeated; if the stripes are not distinguishable, the blackbody set temperature difference is gradually increased, and steps S340 and S350 are repeated; until the minimum distinguishable temperature difference is determined, the MRTD test result is transmitted to the human-computer interaction unit 170 for display.

[0069] For example, for NETD testing, the NETD test item is selected through the human-computer interaction unit 170, and the control processing unit 160 controls the drive motor 121 to drive the rotating target wheel 122 to rotate, switching to the NETD uniform target, repeating steps S330-S350, controlling the blackbody radiation source 110 to maintain a constant temperature (30°C), and using the NETD automatic calculation algorithm to statistically analyze image noise, combined with the blackbody set temperature difference, automatically calculating and outputting the NETD test results.

[0070] Step S360: Complete the detection and output the test data.

[0071] Specifically, after the test is completed, the control processing unit 160 controls the drive motor 121 to drive the rotating target wheel 122 back to the zero position, shuts down the blackbody radiation source 110, infrared image acquisition unit 150 and other units, automatically generates a test report (including test parameters, test results and test time), supports export via USB flash drive, and completes the entire test process.

[0072] In this embodiment, the detection method 300 relies on the detection device 100 to achieve fully automated operation, sequentially completing system initialization, target switching, positioning and alignment, temperature control and image acquisition, data calculation and result output, with a coherent and orderly process; no manual intervention is required in the core detection links throughout the process, the detection process is standardized, and detection efficiency and consistency are effectively improved.

[0073] In some embodiments, such as Figure 6 As shown, step S330 involves acquiring rotation angle signals via an angle encoder to position the rotating target wheel, aligning the target plate center with the test optical path center, including: Step S331: The rotation angle signal is acquired by the angle encoder to perform preliminary positioning of the rotating target wheel.

[0074] Step S332: Acquire calibration images to verify alignment accuracy. If the alignment accuracy deviation exceeds the preset threshold, adjust the rotation angle of the target wheel until the center of the target plate is aligned with the center of the test optical path.

[0075] Specifically, when the target MRTD four-bar target is determined to be in the test optical path position, the drive motor 121 is controlled to stop working; the control processing unit 160 controls the infrared image acquisition unit 150 to acquire a calibration image to verify the alignment accuracy between the target center and the test optical path center. The preset threshold can be determined according to actual needs. For example, if the alignment deviation exceeds 0.05mm, the drive motor 121 is controlled to finely adjust the angle of the rotating target wheel 122 until the alignment accuracy meets the requirements and the target positioning is completed.

[0076] In this embodiment, an image verification and angle fine-tuning step is added to the target wheel positioning process. Initial positioning is completed first, and then the alignment accuracy is verified by calibrating the image. The angle is automatically corrected for out-of-tolerance situations, forming a closed-loop positioning control. This further improves the alignment accuracy between the target plate and the test optical path, thereby ensuring the final infrared image acquisition quality and the accuracy of the test data.

[0077] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An infrared thermal imager detection device, characterized in that, include: Blackbody radiation source; An electric target wheel mechanism includes a drive motor and a rotating target wheel connected by a transmission. The rotating target wheel is provided with multiple target plate mounting positions, and test target plates with different functions are assembled in each of the target plate mounting positions. An off-axis reflective collimator is used to convert the infrared radiation emitted by the blackbody radiation source into a parallel beam for the infrared thermal imager under test to acquire images. The positioning detection unit has an angle encoder, which is coaxially connected to the rotating target wheel and is used to acquire the rotation angle signal of the rotating target wheel in real time. An infrared image acquisition unit is used to connect to the infrared thermal imager under test. The infrared image acquisition unit acquires infrared images of the target plate captured by the infrared thermal imager under test and transmits the image data. The control and processing unit is connected to the blackbody radiation source, the drive motor, the positioning and detection unit, the infrared image acquisition unit, and the infrared thermal imager under test, respectively.

2. The infrared thermal imager detection device according to claim 1, characterized in that, The rotating target wheel has a disc-shaped structure, and multiple target plate mounting positions are evenly spaced along the circumference of the rotating target wheel.

3. The infrared thermal imager detection device according to claim 2, characterized in that, The target plate mounting position includes a mounting groove and an elastic pressure plate disposed on the inner wall of the mounting groove, and the test target plate is fixed in the mounting groove by the elastic pressure plate.

4. The infrared thermal imager detection device according to claim 2, characterized in that, The rotating target wheel is made of metal and has an anodized layer on its surface.

5. The infrared thermal imager detection device according to claim 1, characterized in that, The drive motor is a stepper motor or a servo motor, and the positioning repeatability error of the rotating target wheel is less than or equal to ±10 arcseconds.

6. The infrared thermal imager detection device according to claim 1, characterized in that, The test target plate includes one or more of the following: a four-bar target for minimum resolvable temperature difference testing, a uniform target for noise equivalent temperature difference testing, a cross target for zero-position movement testing, and a single-line target for field of view testing.

7. The infrared thermal imager detection device according to claim 6, characterized in that, The control processing unit is equipped with a memory and a computing circuit. The memory stores an automatic reading program for the minimum resolvable temperature difference and an automatic calculation program for the noise equivalent temperature difference. The computing circuit is used to run the automatic interpretation program for the minimum resolvable temperature difference and the automatic calculation program for the noise equivalent temperature difference, and to perform image feature extraction, noise statistics and parameter calculation.

8. The infrared thermal imager detection device according to claim 1, characterized in that, The detection device also includes a human-computer interaction unit, which is signal-connected to the control and processing unit and is used for parameter input, project selection, result display, and test report generation and export.

9. An infrared thermal imager detection method, applicable to the detection device according to any one of claims 1-8, characterized in that, The detection method includes: The detection device is controlled to complete initialization, the reference temperature of the blackbody radiation source is calibrated, and the infrared image acquisition unit is controlled to complete preheating and parameter setting. Control the drive motor to drive the rotating target wheel to rotate, and switch to the target test target plate; The rotation angle signal is acquired by the angle encoder to position the rotating target wheel so that the center of the target plate is aligned with the center of the test optical path. Set the temperature of the blackbody radiation source according to the current target plate type, and collect infrared images of the target plate after the temperature stabilizes. The collected infrared image data is processed to obtain the results of various test indicators; Complete the test and output the test data.

10. The detection method according to claim 9, characterized in that, The step of acquiring rotation angle signals through the angle encoder to position the rotating target wheel and align the center of the target plate with the center of the test optical path includes: The rotation angle signal is acquired by the angle encoder to perform preliminary positioning of the rotating target wheel; Acquire calibration images to verify alignment accuracy. If the deviation of the alignment accuracy exceeds a preset threshold, adjust the angle of the rotating target wheel until the center of the target plate is aligned with the center of the test optical path.

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