Focal length adjusting method and device based on primary and secondary mirror temperature optical focusing system
By using a primary and secondary mirror temperature-controlled optical focusing system, combined with image quality assessment and multi-objective optimization algorithms, high-precision, wide-range focal length adjustment of the optical system under aerospace payload environments was achieved. This solved the mechanical complexity and temperature sensitivity problems of traditional methods, enabling autonomous and precise focal length control.
Patent Information
- Application Number
- CN202511717662.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-21
- Publication Date
- 2026-02-03
AI Technical Summary
Existing optical systems suffer from problems such as mechanical wear, complexity, slow response speed, high cost, and temperature sensitivity in high-precision optical equipment. They lack autonomous, direct, and precise focal length control capabilities, and it is especially difficult to achieve high-precision, wide-range adjustment in aerospace payload environments.
An optical focusing system based on the temperature of the primary and secondary mirrors is adopted. Through image quality assessment, multi-objective optimization algorithm and temperature-focal length model, the temperature of the primary and secondary mirrors is autonomously adjusted. A closed-loop system of image quality assessment, intelligent temperature decision-making and automatic temperature control execution is established, and the focal length is adjusted by utilizing the principle of thermal expansion and contraction.
It achieves high-precision, wide-range focus adjustment under aerospace payload environment, breaking through the limitations of traditional reliance on manual intervention, realizing the transformation from passive temperature control to active image control, and ensuring the best imaging state.
Smart Images
Figure CN121454732A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of optical precision instruments, and in particular to a focal length adjustment method and device based on a primary-secondary mirror temperature optical focusing system. BACKGROUND
[0002] In high-precision optical systems such as astronomical telescopes, remote sensing cameras, lithography machines, and long focal distance laser communication systems, the stability and adjustability of focal length are crucial. Traditional methods for adjusting the focal length of optical systems mainly include mechanical displacement, liquid lens, and adaptive optics. Among them, the mechanical displacement method changes the optical path by moving the secondary mirror or lens group through precise mechanical structure shafts such as stepper motors and piezoelectric ceramic drivers, thereby achieving focusing. However, this method has problems such as mechanical wear, vibration, complex structure, slow response speed, and reduced reliability in harsh environments such as high vacuum and extreme temperature. The liquid lens method changes the focal length by changing the curvature of the liquid droplet or the pressure of the liquid cavity. However, this method has limitations such as small optical aperture, poor optical pixels, sensitivity to gravity, and narrow working temperature range, although it has no mechanical moving parts. The adaptive optics method corrects wavefront errors through deformable mirrors, and its main purpose is to correct dynamic aberrations such as atmospheric turbulence. Although this method can indirectly affect the focal length, the system is extremely complex and costly, making it uneconomical for large-scale and pure focal length adjustment.
[0003] To address the above problems, researchers have proposed a temperature focusing system that adjusts the lens focal length by monitoring the camera temperature changes in real time to compensate for optical distortion caused by temperature changes. In existing technology, general camera temperature focusing does not have autonomous control function, and manual open-loop control of primary and secondary mirror temperature levels is used for focusing, lacking autonomous, direct, and accurate control ability for the optical parameter of focal length. For example, in a long focal length camera temperature focusing structure and method, according to the corresponding relationship between the thermal ring temperature and the focal plane position displacement, the thermal ring is expanded or contracted along the radial direction by adjusting the thermal ring temperature, which drives one end of the secondary mirror seat outer frame to expand or contract, thereby moving the secondary mirror position to adjust the focal plane position. However, this method requires obtaining a limited number of corresponding relationships between temperature and focal plane position displacement in advance, and cannot perform closed-loop control or control the primary and secondary mirror temperature levels. In an optical load structure and focusing method using secondary mirror temperature control focusing, the temperature control resolution and secondary mirror focusing range are obtained by calibrating the optical system. However, this method also cannot achieve closed-loop control, and the structure connecting the secondary mirror assembly and the primary mirror is complex, and temperature changes can easily introduce structural errors at the connection.
[0004] To address the above problems, we urgently need a primary-secondary mirror temperature optical focusing system that is suitable for space payload environments and can achieve high-precision and large-range focal length adjustment. SUMMARY
[0005] The application provides a focal length adjustment method and device based on a primary and secondary mirror temperature optical focusing system.
[0006] To achieve the above-mentioned purpose, the application adopts the following technical scheme: In a first aspect, the application provides a focal length adjustment method based on a primary and secondary mirror temperature optical focusing system, which includes the following steps: Obtaining a target imaging image under an initial temperature state, and determining a comprehensive quality score result of the target imaging image in combination with an imaging index of the obtained target imaging image; Determining a focal length demand amount according to a deviation amount between the comprehensive quality score result and a preset target quality demand; According to a pre-determined temperature-focal length model of the primary and secondary mirror temperature optical focusing system, determining an optimal target temperature combination based on a multi-objective optimization algorithm, with a total amount of a primary mirror temperature adjustment amount and a secondary mirror temperature adjustment amount being a target function of the focal length demand amount; the temperature-focal length model is a quantitative relationship between a primary mirror temperature, a secondary mirror temperature and a system effective focal length, which is established based on the thermal expansion and contraction principle of the primary and secondary mirror temperature optical focusing system; the optimal target temperature combination includes a primary mirror target temperature and a secondary mirror target temperature; the primary mirror temperature adjustment amount is determined by a deviation amount between an initial primary mirror temperature under an initial temperature state and the primary mirror target temperature, and the secondary mirror temperature adjustment amount is determined by a deviation amount between an initial secondary mirror temperature under the initial temperature state and the secondary mirror target temperature; According to the optimal target temperature combination, adjusting the temperatures of the primary mirror and the secondary mirror of the primary and secondary mirror temperature optical focusing system.
[0007] In a possible implementation manner, the imaging index includes model prediction, definition, contrast and signal-to-noise ratio; the step of obtaining a target imaging image under an initial temperature state and determining a comprehensive quality score result of the target imaging image in combination with an imaging index of the obtained target imaging image specifically includes the following steps: Obtaining a target imaging image under an initial temperature state, and determining a predicted image quality score of the target imaging image through a deep learning quality evaluation model trained by historical samples; the historical samples include historical imaging images and corresponding real image quality scores; Performing weighted summation on the definition, contrast and signal-to-noise ratio of the obtained target imaging image to determine an index image quality score of the target imaging image; Determining a comprehensive quality score result of the target imaging image according to the predicted image quality score and the index image quality score.
[0008] In a possible implementation, before the acquired target imaging image is weighted and summed in terms of sharpness, contrast and signal-to-noise ratio to determine the index image quality score of the target imaging image, the method further includes: The sharpness of the target imaging image is calculated according to a first formula, and the first formula is specifically: ; Wherein, represents the sharpness, represents the target imaging image The horizontal Sobel gradient of the pixel point , represents the target imaging image The vertical Sobel gradient of the pixel point .
[0009] In a possible implementation, before the acquired target imaging image is weighted and summed in terms of sharpness, contrast and signal-to-noise ratio to determine the index image quality score of the target imaging image, the method further includes: The contrast of the target imaging image is calculated according to a second formula, and the second formula is specifically: ; Wherein, represents the contrast, represents the image mean, represents the total number of pixels.
[0010] In a possible implementation, before the acquired target imaging image is weighted and summed in terms of sharpness, contrast and signal-to-noise ratio to determine the index image quality score of the target imaging image, the method further includes: The signal-to-noise ratio of the target imaging image is calculated according to a third formula, and the third formula is specifically: ; Wherein, represents the signal-to-noise ratio, represents the noise standard deviation.
[0011] In a possible implementation, the method further includes a monitoring control process, after the primary mirror and the secondary mirror of the primary-secondary mirror temperature optical focusing system are temperature adjusted according to the optimal target temperature combination, the monitoring control process includes: After monitoring that the temperature fluctuation of the primary mirror temperature and the secondary mirror temperature of the primary-secondary mirror temperature optical focusing system is less than a preset fluctuation threshold, a new imaging image in a temperature state after focusing is acquired, and a comprehensive quality score result of the new imaging image is determined; When the deviation between the comprehensive quality score result of the target imaging image and the comprehensive quality score result of the new imaging image does not satisfy a preset quality evaluation threshold, the focusing process is repeatedly performed.
[0012] In a possible implementation, the monitoring control process further includes monitoring a number of repeated executions of the focusing process, and terminating the repeated execution of the focusing process when the number of repeated executions satisfies a preset maximum iteration number.
[0013] In a second aspect, the present application provides a focal length adjustment device based on a primary-secondary mirror temperature optical focusing system, which comprises: An image quality intelligent evaluation module is configured to acquire a target imaging image under an initial temperature state, and determine a comprehensive quality score result of the target imaging image in combination with an imaging index of the acquired target imaging image; A focusing demand confirmation module is configured to determine a focusing demand amount according to a deviation between the comprehensive quality score result and a preset target quality demand; A temperature control strategy generation module is configured to determine an optimal target temperature combination based on a multi-objective optimization algorithm, taking a total amount of a primary mirror temperature adjustment amount and a secondary mirror temperature adjustment amount and a focusing demand amount as an objective function, according to a preset temperature-focal length model of the primary-secondary mirror temperature optical focusing system; the temperature-focal length model is a quantitative relationship between a primary mirror temperature, a secondary mirror temperature and a system effective focal length, which is established based on a thermal expansion and contraction principle of the primary-secondary mirror temperature optical focusing system; the optimal target temperature combination includes a primary mirror target temperature and a secondary mirror target temperature; the primary mirror temperature adjustment amount is determined by a deviation between an initial primary mirror temperature under an initial temperature state and the primary mirror target temperature, and the secondary mirror temperature adjustment amount is determined by a deviation between an initial secondary mirror temperature under the initial temperature state and the secondary mirror target temperature; A temperature control execution module is configured to adjust temperatures of the primary mirror and the secondary mirror of the primary-secondary mirror temperature optical focusing system according to the optimal target temperature combination.
[0014] In a possible implementation, the imaging index includes model prediction, definition, contrast and signal-to-noise ratio; the image quality intelligent evaluation module is specifically configured to acquire a target imaging image under an initial temperature state, and determine a predicted image quality score of the target imaging image by a deep learning quality evaluation model trained by historical samples; perform weighted summation on definition, contrast and signal-to-noise ratio of the acquired target imaging image to determine an index image quality score of the target imaging image; determine a comprehensive quality score result of the target imaging image according to the predicted image quality score and the index image quality score.
[0015] In a possible implementation, before the acquired clarity, contrast and signal-to-noise ratio of the target imaging image are weighted and summed, and the index image quality score of the target imaging image is determined, the image quality intelligent evaluation module is further configured to perform: The clarity of the target imaging image is calculated according to a first formula, and the first formula is specifically: ; Wherein, Indicates the clarity, Indicates the target imaging image The horizontal Sobel gradient of the pixel point , Indicates the target imaging image The vertical Sobel gradient of the pixel point .
[0016] In a possible implementation, before the acquired clarity, contrast and signal-to-noise ratio of the target imaging image are weighted and summed, and the index image quality score of the target imaging image is determined, the image quality intelligent evaluation module is further configured to perform: The contrast of the target imaging image is calculated according to a second formula, and the second formula is specifically: ; Wherein, Indicates the contrast, Indicates the image mean, Indicates the total number of pixels.
[0017] In a possible implementation, before the acquired clarity, contrast and signal-to-noise ratio of the target imaging image are weighted and summed, and the index image quality score of the target imaging image is determined, the image quality intelligent evaluation module is further configured to perform: The signal-to-noise ratio of the target imaging image is calculated according to a third formula, and the third formula is specifically: ; Wherein, Indicates the signal-to-noise ratio, Indicates the noise standard deviation.
[0018] In a possible implementation, the device further comprises a monitoring module, after the primary mirror and the secondary mirror of the primary-secondary mirror temperature optical focusing system are temperature adjusted according to the optimal target temperature combination, the monitoring module is configured to perform: After monitoring that the temperature fluctuation of the primary mirror temperature and the secondary mirror temperature of the primary-secondary mirror temperature optical focusing system is less than a preset fluctuation threshold, a new imaging image in a temperature state after focusing is acquired, and a comprehensive quality score result of the new imaging image is determined. When the deviation amount of the comprehensive quality score result of the target imaging image and the comprehensive quality score result of the new imaging image does not satisfy a preset quality evaluation threshold, the focusing process is repeatedly executed.
[0019] In a possible implementation, the monitoring module is further configured to perform: The number of repeated executions of the focusing process is monitored, and after the number of repeated executions satisfies a preset maximum iteration number, the repeated execution of the focusing process is terminated.
[0020] In a third aspect, the present application provides a primary-secondary mirror temperature optical focusing system, comprising a primary mirror, a primary mirror seat, a secondary mirror, a secondary mirror barrel, a temperature control plate, a secondary mirror truss, a temperature control barrel, a correction mirror group, a correction mirror barrel, a detector, a control box and a temperature controller. The primary mirror is flexibly installed on the primary mirror seat, the temperature control barrel is arranged on the outer periphery of the primary mirror, the secondary mirror is installed on the secondary mirror barrel, and the secondary mirror and the primary mirror are arranged in sequence to form a reflective optical system; the temperature control plate is arranged on the side of the secondary mirror away from the primary mirror; thin film heaters and temperature control sensors are uniformly arranged on the primary mirror seat and the temperature control plate; one end of the secondary mirror truss is connected with the secondary mirror barrel, and the other end is connected with the temperature control barrel. The correction mirror barrel is arranged through the center of the primary mirror and the primary mirror seat, the correction mirror group is installed in the correction mirror barrel, and the detector, the control box and the temperature controller are arranged in sequence on the side of the primary mirror seat away from the secondary mirror.
[0021] In a fourth aspect, the present application provides an electronic device, which comprises a processor and a memory, and the memory stores at least one instruction, at least one program, a code set or an instruction set, which are loaded and executed by the processor to implement the focusing adjustment method based on the primary-secondary mirror temperature optical focusing system according to any one of the above aspects.
[0022] In a fifth aspect, the present application provides a computer readable storage medium, which stores at least one instruction, at least one program, a code set or an instruction set, which are loaded and executed by a processor to implement the focusing adjustment method based on the primary-secondary mirror temperature optical focusing system according to any one of the above aspects.
[0023] The focal length adjustment method based on the primary and secondary mirror temperature optical focusing system provided by the embodiment of the present application is suitable for the space load environment, and can realize high-precision and large-range focal length adjustment based on the temperature optical focusing system without mechanical movement and with relatively simple structure.
[0024] The focal length adjustment method based on the primary and secondary mirror temperature optical focusing system provided by the embodiment of the present application can understand the standard of image quality, and autonomously drive the temperature of each component of the primary and secondary mirror temperature optical focusing system to the optimal temperature to maintain the best imaging state. BRIEF DESCRIPTION OF DRAWINGS
[0025] Figure 1 The embodiment of the present application provides a whole structure schematic diagram of the primary and secondary mirror temperature optical focusing system; Figure 2 The embodiment of the present application provides a step flow chart of the focal length adjustment method based on the primary and secondary mirror temperature optical focusing system; Figure 3 The embodiment of the present application provides a structure block diagram of the focal length adjustment device based on the primary and secondary mirror temperature optical focusing system.
[0026] Mark and description: 11, primary mirror; 12, primary mirror seat; 13, secondary mirror; 14, secondary mirror barrel; 15, temperature control plate; 16, secondary mirror truss; 17, temperature control barrel; 18, correction lens group; 19, correction lens barrel; 110, detector; 111, control box; 112, temperature controller. DETAILED DESCRIPTION
[0027] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.
[0028] Hereinafter, the terms "first", "second", "third", etc. are used only for the purpose of description, and cannot be understood as indicating or implying relative importance or implying the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise stated, the meaning of "a plurality of" is two or more. In addition, the use of "based on" or "according to" means open and inclusive, because the process, step, calculation or other action based on one or more stated conditions or values can be based on additional conditions or values beyond those stated in practice.
[0029] The embodiment of the present application provides a focal length adjusting method and device based on a primary and secondary mirror temperature optical focusing system, which is suitable for space load environment and can realize high-precision and large-range focal length adjustment based on the primary and secondary mirror temperature optical focusing system.
[0030] As shown in Figure 1 The embodiment of the present application provides a primary and secondary mirror temperature optical focusing system 1, which comprises a primary mirror 11, a primary mirror seat 12, a secondary mirror 13, a secondary mirror barrel 14, a temperature control plate 15, a secondary mirror truss 16, a temperature control barrel 17, a correction mirror group 18, a correction mirror barrel 19, a detector 110, a control box 111 and a temperature controller 112.
[0031] The primary mirror 11 is flexibly installed on the primary mirror seat 12, the temperature control barrel 17 is arranged on the outer periphery of the primary mirror 11, the secondary mirror 13 is installed on the secondary mirror barrel 14, and the secondary mirror 13 and the primary mirror 11 are arranged in sequence to form a reflective optical system.
[0032] The temperature control plate 15 is arranged on the side of the secondary mirror 13 away from the primary mirror 11; thin film heaters and temperature control sensors are uniformly arranged on the primary mirror seat 12 and the temperature control plate 15; one end of the secondary mirror truss 16 is connected with the secondary mirror barrel 14, and the other end is connected with the temperature control barrel 17.
[0033] The correction mirror barrel 19 is arranged through the center of the primary mirror 11 and the primary mirror seat 12, the correction mirror group 18 is installed in the correction mirror barrel 19, and the detector 110, the control box 111 and the temperature controller 112 are arranged in sequence on the side of the primary mirror seat 12 away from the secondary mirror 13.
[0034] Among them, the primary mirror 11 and the secondary mirror 13 are made of materials with known thermal expansion coefficients such as microcrystalline glass and silicon carbide. The primary mirror 11 is installed on the primary mirror seat 12 through a flexible joint.
[0035] Wherein, the elastic elements such as spring, silica gel and shape memory alloy are used to replace the traditional rigid connection, the main mirror seat 12 is made of aluminum-based silicon carbide and other materials with good heat conduction performance, and the main mirror seat 12 is arranged with a thin film heater and a temperature control sensor. The secondary mirror 13 is installed in the secondary mirror barrel 14, and the temperature control plate 15 is arranged on the side of the secondary mirror 13 away from the main mirror 11, and the thin film heater and the temperature control sensor are also arranged on the temperature control plate 15. The secondary mirror barrel 14 and the secondary mirror truss 16 are carbon fiber integrated structures, and are connected with the main mirror seat 12 through a titanium alloy heat insulation pad. The four secondary mirror trusses 16 are arranged at equal intervals, and each of the four secondary mirror trusses 16 is arranged with a thin film heater and a temperature control sensor, and the secondary mirror barrel 14 is arranged with two thin film heaters and temperature control sensors, and the thin film heater and the temperature control sensor are also arranged on the circumference of the correction mirror barrel 19, and the detector 110 is installed between the main mirror seat 12 and the main mirror seat 12 through the titanium alloy heat insulation pad. The real-time temperature collection of the main mirror 11 and the secondary mirror 13 is realized through the temperature control sensor, and the temperature control of the main mirror 11 and the secondary mirror 13 is realized through the thin film heater. All the thin film heaters and temperature sensors are connected to the control box 111 and the temperature controller 112 through cables.
[0036] As shown in Figure 2 The embodiment of the present application also provides a focal length adjusting method based on the primary and secondary mirror temperature optical focusing system, which comprises a focusing process, and the focusing process comprises: Step 201, obtaining a target imaging image under an initial temperature state, and determining a comprehensive quality score result of the target imaging image in combination with an imaging index of the obtained target imaging image.
[0037] Wherein, the imaging index mainly includes core parameters such as definition, color restoration, dynamic range, noise control, focusing accuracy, distortion control, dark corner and dispersion, which comprehensively reflect the performance and image quality of the imaging equipment.
[0038] The comprehensive quality score result of the target imaging image is the comprehensive evaluation result of the core imaging index such as image definition, color restoration and noise control through quantitative multiple imaging indexes and subjective evaluation. The comprehensive quality score system of the target imaging image usually includes objective imaging indexes such as resolution, color deviation and dynamic range, and subjective score of user's image reality.
[0039] Step 202, determining a focusing demand amount according to the deviation amount of the comprehensive quality score result and the preset target quality demand.
[0040] Specifically, the target imaging image under the initial temperature state is obtained through the primary and secondary mirror temperature optical focusing system, the comprehensive quality score result under the initial temperature state is calculated through the controller and the image processing unit of the camera, and is represented as Y; the preset target quality demand is represented as Y0. The focusing demand amount is represented as D. Specifically, it is determined using the following formula: .
[0041] Step 203: Based on the pre-determined temperature-focal length model of the primary and secondary mirror temperature optical focusing system, and using a multi-objective optimization algorithm, determine the optimal target temperature combination with the objective function of minimizing the total amount of focusing demand and the temperature adjustment of the primary and secondary mirrors.
[0042] The temperature-focal length model is based on the principle of thermal expansion and contraction in the primary and secondary lens temperature-controlled optical focusing system, establishing a quantitative relationship between the primary lens temperature, secondary lens temperature, and the effective focal length of the system. The optimal target temperature combination includes the primary lens target temperature and the secondary lens target temperature; the primary lens temperature adjustment is determined by the deviation between the initial primary lens temperature and the primary lens target temperature under the initial temperature conditions, and the secondary lens temperature adjustment is determined by the deviation between the initial secondary lens temperature and the secondary lens target temperature under the initial temperature conditions.
[0043] Among them, the primary mirror target temperature is It indicates that the target temperature of the secondary mirror is... In other words, the effective focal length is... The core mathematical expression of the temperature-focal length model is: ; in, Indicates temperature The predicted focal length of the system is as follows; Indicates at reference temperature The system design focal length is as follows; , These represent the focal length temperature coefficients (unit: μm / °C) of the primary and secondary mirrors, respectively, and their signs and magnitudes are determined by material properties and optomechanical structure. Indicates the reference temperature of the primary mirror. The reference temperature of the secondary mirror is indicated by a standard laboratory temperature, such as 20°C.
[0044] This temperature-focal length model shows that the change in focal length has a linear superposition relationship with the deviations of the primary and secondary mirrors from the reference temperature. Its core parameter is the focal length temperature coefficient. , The model was calibrated and verified through systematic temperature control experiments and focus measurement data. As a forward prediction model for the primary and secondary mirror temperature-based optical focusing system, this model provides crucial information for multi-objective optimization algorithms to solve for the optimal temperature combination.
[0045] Specifically, based on the temperature-focal length model, the primary and secondary lens temperature-based optical focusing system uses a multi-objective optimization algorithm to solve for the optimal combination of target temperatures. The specific objective function is as follows: ; wherein, , respectively are initial primary mirror temperature, initial secondary mirror temperature, , is a temperature adjustment cost weight, used to balance the focusing effect and energy consumption, stability. represents the total amount of focusing demand and primary mirror temperature adjustment amount, secondary mirror temperature adjustment amount, used to guide the system to find a best trade-off point, which can significantly improve the image quality to the target level, and ensure that the temperature adjustment process is smooth, energy-saving and fast enough.
[0046] Step 204, adjusting the primary mirror and the secondary mirror of the primary-secondary mirror temperature optical focusing system according to the optimal target temperature combination.
[0047] Specifically, the temperature controller adjusts the primary mirror and the secondary mirror temperature to the target value according to the optimal target temperature combination determined in the previous step.
[0048] The focal length adjustment method based on the primary-secondary mirror temperature optical focusing system provided by the embodiment of the application is based on a temperature optical focusing system without mechanical movement and relatively simple structure, is suitable for space load environment, and can realize high-precision and large-range focal length adjustment. The focal length adjustment method establishes an image quality evaluation-intelligent temperature decision-automatic temperature control execution temperature focusing technology, which breaks through the limitation of traditional temperature adjustment system relying on manual intervention, and realizes a fundamental change from "passive temperature control" to "active image control".
[0049] The focal length adjustment method based on the primary-secondary mirror temperature optical focusing system provided by the embodiment of the application can understand the standard of image quality, and autonomously drive the temperature of each component of the primary-secondary mirror temperature optical focusing system to the optimal temperature to maintain the best imaging state.
[0050] Further, the imaging indicators include model prediction, sharpness, contrast, and signal-to-noise ratio.
[0051] The target imaging image under the initial temperature state is acquired, and the comprehensive quality score result of the target imaging image is determined in combination with the imaging indicators of the acquired target imaging image, specifically including: The target imaging image under the initial temperature state is acquired, and the predicted image quality score of the target imaging image is determined through the deep learning quality evaluation model trained by the historical samples.
[0052] Wherein, the historical samples include historical imaging images and corresponding real image quality scores; the real image quality score can be a subjective score of the user on the image reality.
[0053] The sharpness, contrast, and signal-to-noise ratio of the acquired target imaging image are weighted and summed to determine the indicator image quality score of the target imaging image.
[0054] determine a comprehensive quality score result of the target imaging image according to the predicted image quality score and the index image quality score.
[0055] In the embodiments of the present application, the sharpness is calculated by using a gradient function, the contrast is represented by an image gray standard deviation, and the signal-to-noise ratio is measured in a uniform area; the index image quality score is defined as a weighted comprehensive evaluation function of the sharpness, the contrast, and the signal-to-noise ratio, and is specifically as follows: are weight coefficients, and
[0056] The deep learning quality evaluation model adopts a CNN structure or a Transformer structure, the model takes the target imaging image as input, and outputs a predicted image quality score corresponding to the image .
[0057] The predicted image quality score is fused with the index image quality score to obtain a comprehensive quality score result , and the specific calculation formula is as follows: indicates a fusion weight, which can be adjusted according to actual application.
[0058] Further, before the sharpness, the contrast, and the signal-to-noise ratio of the obtained target imaging image are weighted and summed to determine the index image quality score of the target imaging image, the method further includes: The sharpness of the target imaging image is calculated according to a first formula, and the first formula is specifically as follows: indicates the sharpness, indicates a horizontal Sobel gradient of the target imaging image at a pixel point . indicates a vertical Sobel gradient of the target imaging image at a pixel point .
[0059] Further, before the sharpness, the contrast, and the signal-to-noise ratio of the obtained target imaging image are weighted and summed to determine the index image quality score of the target imaging image, the method further includes: The contrast of the target imaging image is calculated according to a second formula, and the second formula is specifically: ; Wherein, represents the contrast, represents the image mean, represents the total number of pixels.
[0060] Further, before the clarity, contrast and signal-to-noise ratio of the obtained target imaging image are weighted and summed to determine the index image quality score of the target imaging image, the method further comprises: The signal-to-noise ratio of the target imaging image is calculated according to a third formula, and the third formula is specifically: ; Wherein, represents the signal-to-noise ratio, represents the noise standard deviation.
[0061] Further, the method further comprises a monitoring control process, after the primary mirror and the secondary mirror of the primary-secondary mirror temperature optical focusing system are adjusted in temperature according to the optimal target temperature combination, the monitoring control process comprises: After monitoring that the temperature fluctuations of the primary mirror temperature and the secondary mirror temperature of the primary-secondary mirror temperature optical focusing system are less than the preset fluctuation threshold, a new imaging image under the temperature state after focusing is obtained, and a comprehensive quality score result of the new imaging image is determined.
[0062] When the deviation amount of the comprehensive quality score result of the target imaging image and the comprehensive quality score result of the new imaging image does not meet the preset quality evaluation threshold, the focusing process is repeatedly executed.
[0063] Further, the monitoring control process further comprises monitoring the number of repeated executions of the focusing process, and terminating the repeated execution of the focusing process when the number of repeated executions meets the preset maximum iteration number.
[0064] Specifically, the temperature controller adjusts the primary mirror temperature and the secondary mirror temperature to the target value according to the optimal target temperature combination. After the temperature fluctuations of the primary mirror temperature and the secondary mirror temperature are less than the preset fluctuation threshold, that is, after the primary mirror temperature and the secondary mirror temperature are stable, a new imaging image is re-acquired, and a comprehensive quality score result of the new imaging image is evaluated If the comprehensive quality score result of the new imaging image meets , the primary-secondary mirror temperature optical focusing system enters a stable running state, and the image quality is continuously monitored, and if the requirement is not met. The above focusing process is repeated until the imaging quality meets the requirement, or the focusing process reaches the maximum iteration number.
[0065] Wherein, represents the preset quality evaluation threshold.
[0066] After the system enters a stable running state, the system periodically acquires images and evaluates the comprehensive quality score of the images, and if it is monitored that the result of the comprehensive quality score decreases by more than a set tolerance due to environmental changes, the focusing process is restarted.
[0067] The system can also update the temperature-focal length model and the deep learning quality evaluation model according to historical focusing data, to achieve long-term adaptive optimization of the system.
[0068] The present application establishes a full-automatic closed-loop temperature focusing system of "image quality evaluation-intelligent decision-making-temperature control execution-effect verification", breaks through the limitation of traditional temperature focusing systems relying on manual intervention, and realizes a fundamental change from "passive temperature control" to "active image control". The intelligent temperature control technology of the present application can understand the standard of image quality and automatically drive the temperature of each component of the optical system to the target value, and maintain the best imaging state of the system.
[0069] The intelligent and autonomous temperature focusing of the present application utilizes the principle of thermal expansion and contraction, controls the temperature level of the primary and secondary mirrors through the temperature control components arranged on each component, adjusts the distance between the primary and secondary mirrors and the focal plane position of the detector, thereby realizing the adjustment of the focal length, and further adjusting the imaging quality of the imaging device. Through the evaluation of the imaging quality, feedback is given to the temperature controller, forming a closed-loop temperature and focal length focusing system.
[0070] As shown in Figure 3 The present application also provides a focal length adjusting device based on the primary and secondary mirror temperature optical focusing system, which comprises: An image quality intelligent evaluation module 301 is used to acquire a target imaging image under an initial temperature state, and determine the comprehensive quality score result of the target imaging image in combination with the imaging indicators of the acquired target imaging image.
[0071] A focusing demand confirmation module 302 is used to determine the focusing demand amount according to the deviation amount of the comprehensive quality score result from the preset target quality demand.
[0072] A temperature control strategy generation module 303 is used to determine the optimal target temperature combination based on a multi-objective optimization algorithm, taking the minimum total amount of the focusing demand amount, the primary mirror temperature adjusting amount and the secondary mirror temperature adjusting amount as the objective function, according to the temperature-focal length model of the primary and secondary mirror temperature optical focusing system.
[0073] The temperature-focal length model is a quantitative relationship between the primary mirror temperature, the secondary mirror temperature and the effective focal length of the system, which is established based on the thermal expansion and contraction principle of the primary and secondary mirror temperature optical focusing system.
[0074] The optimal target temperature combination includes the target temperature of the primary mirror and the target temperature of the secondary mirror.
[0075] The primary mirror temperature adjustment amount is determined by the deviation amount of the initial primary mirror temperature in the initial temperature state from the primary mirror target temperature.
[0076] The secondary mirror temperature adjustment amount is determined by the deviation amount of the initial secondary mirror temperature in the initial temperature state from the secondary mirror target temperature.
[0077] The temperature control execution module 304 is configured to adjust the primary mirror and secondary mirror temperatures of the primary and secondary mirror temperature optical focusing system according to the optimal target temperature combination.
[0078] Further, the imaging indicators include model prediction, sharpness, contrast, and signal-to-noise ratio; and the image quality intelligent evaluation module 301 is specifically configured to perform: Obtain a target imaging image in an initial temperature state, and determine a predicted image quality score of the target imaging image by using a deep learning quality evaluation model trained by historical samples.
[0079] The historical samples include historical imaging images and corresponding real image quality scores.
[0080] Weighted sum the sharpness, contrast, and signal-to-noise ratio of the obtained target imaging image to determine an indicator image quality score of the target imaging image.
[0081] Determine a comprehensive quality score result of the target imaging image according to the predicted image quality score and the indicator image quality score.
[0082] Further, before the weighted sum of the sharpness, contrast, and signal-to-noise ratio of the obtained target imaging image to determine the indicator image quality score of the target imaging image, the image quality intelligent evaluation module 301 is further configured to perform: Calculate the sharpness of the target imaging image according to a first formula, and the first formula is specifically: ; Wherein, represents the sharpness, represents the target imaging image The horizontal Sobel gradient of the pixel point The vertical Sobel gradient of the pixel point represents the target imaging image The vertical Sobel gradient of the pixel point
[0083] Further, before the weighted sum of the sharpness, contrast, and signal-to-noise ratio of the obtained target imaging image to determine the indicator image quality score of the target imaging image, the image quality intelligent evaluation module 301 is further configured to perform: Calculate the contrast of the target imaging image according to a second formula, and the second formula is specifically: ; wherein, denotes the contrast, denotes the image mean, denotes the total number of pixels.
[0084] Further, before the acquired target imaging image is weighted and summed in terms of the definition, the contrast and the signal-to-noise ratio to determine the index image quality score of the target imaging image, the image quality intelligent evaluation module 301 is further configured to perform: According to a third formula, the signal-to-noise ratio of the target imaging image is calculated, and the third formula is specifically: ; wherein, denotes the signal-to-noise ratio, denotes the noise standard deviation.
[0085] Further, the device further comprises a monitoring module, after the primary mirror and the secondary mirror of the primary-secondary mirror temperature optical focusing system are temperature adjusted according to the optimal target temperature combination, the monitoring module is configured to perform: After monitoring that the temperature fluctuations of the primary mirror temperature and the secondary mirror temperature of the primary-secondary mirror temperature optical focusing system are less than the preset fluctuation threshold, a new imaging image in the temperature state after focusing is acquired, and a comprehensive quality score result of the new imaging image is determined; When the deviation amount of the comprehensive quality score result of the target imaging image and the comprehensive quality score result of the new imaging image does not satisfy the preset quality evaluation threshold, the focusing process is repeatedly executed.
[0086] Further, the monitoring module is further configured to perform: The number of repeated executions of the focusing process is monitored, and after the number of repeated executions satisfies the preset maximum iteration number, the repeated execution of the focusing process is terminated.
[0087] The focal length adjustment device based on the primary-secondary mirror temperature optical focusing system provided by the embodiment of the application is used to execute the focal length adjustment method based on the primary-secondary mirror temperature optical focusing system, and therefore the same effect as the focal length adjustment method based on the primary-secondary mirror temperature optical focusing system can be achieved.
[0088] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the system, the device and the unit described above can refer to the corresponding processes in the foregoing method embodiments, which will not be described herein.
[0089] The embodiment of the present application further provides an electronic device, which comprises a processor and a memory, and the memory stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by the processor to realize the focal length adjustment method based on the primary and secondary mirror temperature optical focusing system in the embodiment of the present application.
[0090] The embodiment of the present application further provides a computer readable storage medium, which stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by the processor to realize the focal length adjustment method based on the primary and secondary mirror temperature optical focusing system in the embodiment of the present application.
[0091] In the above embodiment, the implementation can be achieved by software, hardware, firmware or any combination thereof, in whole or in part. When implemented by software, the implementation can be achieved in the form of a computer program product, in whole or in part. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the flow or function according to the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network or other programmable device. The computer instructions can be stored in a computer readable storage medium or transferred from one computer readable storage medium to another, for example, the computer instructions can be transferred from one website, computer, server or data center to another by wire (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.). The computer readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. integrated with one or more available media. The available media can be magnetic media (such as floppy disk, hard disk, magnetic tape), optical media (such as DVD) or semiconductor media (such as solid state disk (SSD)) and the like.
[0092] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any change or replacement within the technical scope disclosed by the present application should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.
Claims
1. A focal length adjustment method based on a primary and secondary mirror temperature-based optical focusing system, characterized in that, This includes a focusing process, which includes: Acquire a target imaging image under the initial temperature condition, and combine the imaging indicators of the acquired target imaging image to determine the comprehensive quality score result of the target imaging image; The focusing requirement is determined based on the deviation between the comprehensive quality score and the preset target quality requirement. Based on the predetermined temperature-focal length model of the primary and secondary mirror temperature-based optical focusing system, and using a multi-objective optimization algorithm, the optimal target temperature combination is determined with the objective function of minimizing the total amount of focusing demand and the adjustment amounts of the primary and secondary mirror temperatures. The temperature-focal length model establishes a quantitative relationship between the primary mirror temperature, the secondary mirror temperature, and the effective focal length of the system based on the principle of thermal expansion and contraction of the primary and secondary mirror temperature-based optical focusing system. The optimal target temperature combination includes the primary mirror target temperature and the secondary mirror target temperature. The primary mirror temperature adjustment amount is determined by the deviation between the initial primary mirror temperature and the primary mirror target temperature under the initial temperature conditions, and the secondary mirror temperature adjustment amount is determined by the deviation between the initial secondary mirror temperature and the secondary mirror target temperature under the initial temperature conditions. The primary and secondary mirrors of the primary and secondary mirror temperature optical focusing system are adjusted according to the optimal target temperature combination.
2. The focal length adjustment method based on the primary and secondary mirror temperature-based optical focusing system according to claim 1, characterized in that, The imaging metrics include model prediction, sharpness, contrast, and signal-to-noise ratio; acquiring the target imaging image at the initial temperature state, and combining the acquired imaging metrics of the target imaging image to determine the comprehensive quality score of the target imaging image, specifically includes: The target imaging image is acquired under the initial temperature condition, and the predicted image quality score of the target imaging image is determined by a deep learning quality assessment model trained on historical samples; the historical samples include historical imaging images and their corresponding real image quality scores. The sharpness, contrast, and signal-to-noise ratio of the acquired target imaging image are weighted and summed to determine the index image quality score of the target imaging image; The comprehensive quality score of the target imaging image is determined based on the predicted image quality score and the index image quality score.
3. The focal length adjustment method based on the primary and secondary mirror temperature-based optical focusing system according to claim 2, characterized in that, Before determining the index image quality score of the target imaging image by weighted summation of the sharpness, contrast, and signal-to-noise ratio of the acquired target imaging image, the method further includes: The sharpness of the target image is calculated according to a first formula, which is as follows: ； in, Indicates sharpness, Represents the target imaging image At pixel Horizontal Sobel gradient, Represents the target imaging image At pixel The vertical Sobel gradient.
4. The focal length adjustment method based on the primary and secondary mirror temperature-based optical focusing system according to claim 3, characterized in that, Before determining the index image quality score of the target imaging image by weighted summation of the sharpness, contrast, and signal-to-noise ratio of the acquired target imaging image, the method further includes: The contrast of the target image is calculated according to the second formula, which is as follows: ； in, Indicates contrast. Represents the image mean. Indicates the total number of pixels.
5. The focal length adjustment method based on the primary and secondary mirror temperature-based optical focusing system according to claim 4, characterized in that, Before determining the index image quality score of the target imaging image by weighted summation of the sharpness, contrast, and signal-to-noise ratio of the acquired target imaging image, the method further includes: The signal-to-noise ratio of the target imaging image is calculated according to the third formula, which is as follows: ； in, Indicates the signal-to-noise ratio. This represents the standard deviation of noise.
6. The focal length adjustment method based on the primary and secondary mirror temperature-based optical focusing system according to claim 1, characterized in that, The method further includes a monitoring and control process. After adjusting the temperatures of the primary and secondary mirrors of the primary and secondary mirror temperature optical focusing system according to the optimal target temperature combination, the monitoring and control process includes: After monitoring that the temperature fluctuations of the primary and secondary mirror temperatures in the optical focusing system are less than a preset fluctuation threshold, a new imaging image under the temperature state after focusing is acquired, and the comprehensive quality score of the new imaging image is determined. If the deviation between the overall quality score of the target image and the overall quality score of the new image does not meet the preset quality assessment threshold, the focusing process is repeated.
7. The focal length adjustment method based on the primary and secondary mirror temperature-based optical focusing system according to claim 6, characterized in that, The monitoring and control process further includes: monitoring the number of times the focusing process is repeated, and terminating the repeated execution of the focusing process after the number of repeated executions meets the preset maximum number of iterations.
8. A focal length adjustment device based on a primary and secondary mirror temperature-based optical focusing system, characterized in that, include: The image quality intelligent assessment module is used to acquire the target imaging image under the initial temperature state, and combine the imaging index of the acquired target imaging image to determine the comprehensive quality score of the target imaging image. The focusing requirement confirmation module is used to determine the focusing requirement based on the deviation between the comprehensive quality score result and the preset target quality requirement. The temperature control strategy generation module is used to determine the optimal target temperature combination based on a pre-determined temperature-focal length model of the primary and secondary mirror temperature optical focusing system, using a multi-objective optimization algorithm with the objective function of minimizing the total amount of focusing demand and the adjustment amounts of the primary and secondary mirror temperatures. The temperature-focal length model is based on the principle of thermal expansion and contraction of the primary and secondary mirror temperature optical focusing system, establishing a quantitative relationship between the primary mirror temperature, the secondary mirror temperature, and the effective focal length of the system. The optimal target temperature combination includes the primary mirror target temperature and the secondary mirror target temperature. The primary mirror temperature adjustment amount is determined by the deviation between the initial primary mirror temperature and the primary mirror target temperature under the initial temperature state, and the secondary mirror temperature adjustment amount is determined by the deviation between the initial secondary mirror temperature and the secondary mirror target temperature under the initial temperature state. The temperature control execution module is used to adjust the temperatures of the primary and secondary mirrors of the primary and secondary mirror temperature optical focusing system according to the optimal target temperature combination.
9. A primary and secondary mirror temperature-controlled optical focusing system, characterized in that, It includes a primary mirror, primary mirror mount, secondary mirror, secondary mirror tube, temperature control plate, secondary mirror truss, temperature control tube, calibration mirror assembly, calibration mirror tube, detector, control box, and temperature controller; The primary mirror is flexibly mounted on the primary mirror mount, the temperature control cylinder is disposed on the outer periphery of the primary mirror, and the secondary mirror is mounted on the secondary mirror barrel. The secondary mirror and the primary mirror are arranged sequentially to form a reflective optical system. The temperature control plate is disposed on the side of the secondary mirror away from the primary mirror. Thin-film heaters and temperature control sensors are evenly distributed on the primary mirror mount and the temperature control plate. One end of the secondary mirror truss is connected to the secondary mirror barrel, and the other end is connected to the temperature control cylinder. The calibration tube is inserted through the center of the primary mirror and the primary mirror mount. The calibration mirror assembly is installed inside the calibration tube. The detector, the control box, and the temperature controller are sequentially arranged on the side of the primary mirror mount away from the secondary mirror.
10. An electronic device, characterized in that, The electronic device includes a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set, or an instruction set, and the at least one instruction, the at least one program, the code set, or the instruction set is loaded and executed by the processor to implement the focal length adjustment method based on the primary and secondary mirror temperature optical focusing system as described in any one of claims 1-7.