Observation window deformation imaging measurement system

Abstract

The invention relates to the technical field of optical measurement, in particular to an observation window deformation imaging measurement system, which is characterized in that an environment simulation group is connected with a mounting surface of a to-be-measured optical observation window and is used for simulating a high-pressure environment for the optical observation window; the optical measurement group comprises a plurality of fluorescence mark points, a fluorescence excitation light source, an imaging measurement camera and a signal processing center, the plurality of fluorescence mark points are arranged on the measurement surface of the optical observation window, and the fluorescence mark points generate fluorescence signals after being irradiated and excited by the fluorescence excitation light source; a fluorescence signal enters the imaging measurement camera for imaging, and the signal processing center calculates the deformation quantity of the optical observation window according to the imaging result of the imaging measurement camera. According to the invention, the characteristics of fluorescence labeling are ingeniously utilized, and a test method of a single-camera visual image is combined, so that a simple, low-cost and high-precision test effect is realized.

Description

Technical Field

[0001] This invention belongs to the field of optical measurement technology, and in particular relates to an observation window deformation imaging measurement system. Background Technology

[0002] Deep-sea submersibles and land-based high-pressure simulation devices (such as land cold seep simulation devices) are tasked with research on the physics, biology, chemistry, geography, and energy aspects of the deep-sea environment or simulated high-pressure environment. In their specific structure, the optical observation window serves as a key channel for visual observation, imaging, and in-situ online operation and visual monitoring, and it is subjected to extreme internal or external pressure and harsh environmental conditions.

[0003] Optical observation windows are typically made of high-strength optical materials and are exposed to high-pressure environments for extended periods. Therefore, varying degrees of deformation are unavoidable, potentially posing safety hazards over time. For example, during deep-sea submersible descent, increased water pressure can cause the window to compress, bend, or undergo other forms of deformation, affecting the field of view, image clarity, and the accuracy of measurement results. Furthermore, fatigue life and unexpected impacts can lead to breakage and leakage. In land-based cold seep simulation devices, windows also need to withstand pressures ranging from tens to hundreds of megapascals. Under such high pressure, condition monitoring and regular measurements of surface deformation are equally crucial.

[0004] Currently, various testing methods exist for optical observation window deformation, including mechanical sensor methods, optical interferometry, and image testing and analysis methods. Mechanical sensor methods utilize strain gauges and pressure sensors to monitor the strain on the window surface or glass material, enabling real-time data acquisition. However, this method typically requires direct sensor mounting on the window, and the relatively large volume of these sensors can interfere with the visualization of the window. Furthermore, the number of sensors that can be mounted is limited, and it cannot achieve complete or high spatial resolution detection of the entire window. Optical interferometry detects minute deformations on the window surface through phase changes of light waves, suitable for accurately measuring minute deformations. However, it has limitations in monitoring large-area windows and measuring under environmental interference, and it also faces high costs. Image testing and analysis methods utilize high-precision optical vision image acquisition equipment to infer window deformation by analyzing changes in the window surface in the image, providing a non-contact, global detection method. However, traditional image analysis methods still have certain accuracy and efficiency issues in monitoring minute deformations and large-scale window deformations under high pressure environments. One major reason is that the surface of the window under test is smooth and flat, exhibiting high transparency and low reflectivity, which poses a challenge to traditional visual image testing and analysis methods, preventing their effective engineering applications. Currently, the development, use, and maintenance of various high-voltage equipment urgently require a low-cost, easy-to-operate, efficient, and high-precision testing device and method. Summary of the Invention

[0005] In view of this, the present invention aims to provide an observation window deformation imaging measurement system that utilizes the pattern features of fluorescent markers and combines a single-camera visual image testing method to achieve a simple, low-cost, and high-precision testing effect.

[0006] To achieve the above objectives, the technical solution created by this invention is implemented as follows: An imaging measurement system for viewing window deformation includes: an environmental simulation group, which is connected to the mounting surface of the optical viewing window to be measured, for simulating a high-pressure environment for the optical viewing window; and an optical measurement group, which is used to measure the deformation of the optical viewing window under high-pressure environment, including multiple fluorescent markers, a fluorescent excitation light source, an imaging measurement camera, and a signal processing center, wherein: the multiple fluorescent markers are arranged on the measurement surface of the optical viewing window, and the fluorescent markers generate fluorescent signals after being excited by the fluorescent excitation light source; the fluorescent signals are imaged in the imaging measurement camera, and the signal processing center calculates the deformation of the optical viewing window based on the imaging results of the imaging measurement camera.

[0007] Furthermore, the environmental simulation group includes a cabin, a pressurized liquid, and a pressure controller. The optical observation window is mounted on the cabin, the pressurized liquid is placed inside the cabin, and the mounting surface of the optical observation window faces the pressurized liquid. The pressure controller controls the hydraulic pressure of the pressurized liquid in the cabin, thereby simulating a high-pressure environment for the optical observation window.

[0008] Furthermore, an active fluorescent liquid is used to coat fluorescent markers in an array on the measurement surface of the optical observation window, forming a semi-hidden fluorescent marker array.

[0009] Furthermore, the signal processing center divides the region according to the array arrangement of multiple fluorescent markers, and uses a feature matching algorithm to process the images acquired by the imaging measurement camera. By analyzing the changes in fluorescent markers in each region, the deformation of different regions on the measurement surface of the optical observation window is calculated. The deformation of different regions is fitted to obtain the continuous deformation of the measurement surface.

[0010] Furthermore, the optical measurement assembly also includes a filter wheel diaphragm and a multi-channel filter wheel. The filter wheel diaphragm and the multi-channel filter wheel are arranged sequentially between the fluorescence excitation source and the imaging measurement camera along the direction of fluorescence signal propagation, for filtering the fluorescence signal at different wavelengths. The multi-channel filter wheel includes a turntable, a rotating structure, and multiple filters. The multiple filters are arranged circumferentially on the turntable, which is located at the moving end of the rotating structure. The filter wheel diaphragm has light-transmitting holes that match the size of the filters. The rotating structure drives the turntable to rotate, causing the filters of the appropriate wavelengths to rotate to the light-transmitting holes. After passing through the light-transmitting holes, the fluorescence signal is filtered by the corresponding filters before entering the imaging measurement camera.

[0011] Furthermore, the optical measurement group also includes a laser rangefinder placed at the imaging measurement camera. The laser emitted by the laser rangefinder passes through the filter wheel, the light shield, and the multi-channel filter wheel in sequence to illuminate the surface of the optical observation window, measuring the distance between the optical observation window and the imaging measurement camera.

[0012] Furthermore, the measurement system also includes a displacement control group, which includes a support frame, a transverse electric displacement stage, and a longitudinal electric displacement stage. The support frame is integrated with the filter wheel shading plate and the multi-channel filter wheel, and supports the imaging measurement camera. The transverse electric displacement stage drives the support frame to move laterally, and the longitudinal electric displacement stage drives the support frame to move longitudinally.

[0013] Compared with the prior art, the present invention can achieve the following beneficial effects: (1) The observation window deformation imaging measurement system created by the present invention combines fluorescent markers, laser ranging auxiliary technology of laser rangefinders, and feature matching algorithms in signal processing center to form an integrated optical image measurement and analysis device, thereby realizing the accurate detection of the small deformation of the optical observation window after pressure, and thus providing effective protection for the safety of the optical observation window of deep-sea submersibles and land-based high-pressure fidelity simulation devices. (2) The observation window deformation imaging measurement system created by the present invention cleverly utilizes the pattern features of fluorescent markers to provide semi-hidden regular coding marks for smooth, low-reflection weak feature surfaces. Combined with the single-camera visual image testing method, it achieves a simple, low-cost, and high-precision testing effect. In addition, it integrates multiple dimensions of testing advantages, including the ring-shaped uniform non-interference arrangement of the illumination source, the multi-wavelength selection detection of the filter wheel, the dual precise positioning and calibration of the laser rangefinder, and the geometric regular calibration of the translation imaging of the electric displacement stage. Attached Figure Description

[0014] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 A schematic diagram of the structure of the observation window deformation imaging measurement system described in the embodiment of the present invention; Figure 2 A simplified schematic diagram of the observation window deformation imaging measurement system described in an embodiment of the present invention in an underwater environment; Figure 3 A schematic diagram of the arrayed layout of fluorescent markers as described in the embodiments of the present invention; Figure 4 A schematic diagram showing the relative positions of the imaging measurement camera and the optical observation window as described in an embodiment of the present invention; Figure 5 A simulation diagram illustrating the local deformation measurement effect of the optical observation window described in an embodiment of the present invention; Figure 6 This is a simulation diagram of the surface morphology of the optical observation window described in an embodiment of the present invention.

[0015] Explanation of reference numerals in the attached figures: 1. Optical observation window; 2. Fluorescent marker; 3. Fluorescent excitation source; 4. Imaging measurement camera; 5. Signal processing center; 6. Cabin; 7. Pressurized liquid; 8. Pressure controller; 9. Filter wheel and light shield; 10. Multi-channel filter wheel; 11. Laser rangefinder; 12. Support frame; 13. Lateral electric displacement stage; 14. Longitudinal electric displacement stage; 15. Electrical control module. Detailed Implementation

[0016] 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 specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0018] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] like Figure 1As shown, the observation window deformation imaging measurement system of this invention includes an environmental simulation group and an optical measurement group. The environmental simulation group is connected to the mounting surface of the optical observation window 1 to be measured and is used to simulate a high-pressure environment for the optical observation window 1. The optical measurement group is used to measure the deformation of the optical observation window 1 under high-pressure environment and includes multiple fluorescent markers 2, a fluorescent excitation light source 3, an imaging measurement camera 4, and a signal processing center 5. The multiple fluorescent markers 2 are arranged on the measurement surface of the optical observation window 1. After being excited by the fluorescent excitation light source 3, the fluorescent markers 2 generate a fluorescent signal, which is then imaged in the imaging measurement camera 4. The signal processing center 5 calculates the deformation of the optical observation window 1 based on the imaging result of the imaging measurement camera 4.

[0022] In this embodiment of the invention, the imaging measurement camera 4 employs a highly sensitive research-grade camera with a high signal-to-noise ratio, good response to weak fluorescence signals, and stable imaging, but at a slightly higher cost. Alternatively, an industrial-grade commercial camera can be used, which has a slightly lower signal-to-noise ratio, but noise interference can be reduced and the testing effect improved through multiple exposures and inter-frame averaging. When selecting parameters for the imaging measurement camera 4, factors such as image plane size and pixel count need to be considered. Based on the triangulation relationship of optical imaging, the determination of the size of the surface to be measured and the actual deformation of the optical observation window 1 depends on the size of the image plane and the number of pixels of the imaging measurement camera 4. This is especially true when measuring small deformations or displacements of the fluorescent marker point 2; generally, a larger pixel count results in higher accuracy for the smallest measurable deformation and displacement. Sub-pixel algorithms can also be used to achieve sub-pixel level interpolation calculations and analysis. Besides the image sensor, the camera lens is another crucial parameter in the imaging measurement camera 4. It needs to be specifically matched to the testing scenario, including the fixed position, the size of the measurement area, and the influence of ambient light, which correspond to key optical parameters such as the lens's focal length, field of view, depth of field, and light transmission.

[0023] In some embodiments, the environmental simulation group is presented as a land-based high-pressure simulation fidelity device, such as a cold seep simulation device, specifically including a chamber 6, a pressurized liquid 7, and a pressure controller 8. An optical observation window 1 is mounted on the chamber 6, the pressurized liquid 7 fills the chamber 6, and the mounting surface of the optical observation window 1 faces the pressurized liquid 7. The pressure controller 8 controls the hydraulic pressure of the pressurized liquid 7 within the chamber 6, thereby simulating a high-pressure environment for the optical observation window 1. In this embodiment, the optical observation window 1 adopts a cylindrical trapezoidal structure. The side with the larger diameter of the optical observation window 1 is the mounting surface, facing the pressurized liquid 7, while the side with the smaller diameter of the optical observation window 1 is the measuring surface, coated with fluorescent markers 2. The outer side of the chamber 6 is equipped with a protective shell for temperature control and external thermal insulation. In other embodiments, the system provided by this invention can perform deformation measurement of the optical observation window 1 in an underwater environment, such as... Figure 2As shown, since the system itself is already in an underwater pressurized environment, there is no longer a need for the pressurized liquid 7 and pressure controller 8. However, the optical measurement group needs to be placed in the cabin 6. Since the high pressure brought by the seawater in the deep sea is from the outside of the cabin 6 to the inside of the cabin 6, the installation direction of the optical observation window 1 on the cabin 6 is opposite to the installation direction in the land environment. That is, the measurement surface of the optical observation window 1 faces the inside of the cabin 6, and the installation surface of the optical observation window 1 faces the external water environment.

[0024] Since common fluorescent materials absorb wavelengths including violet and blue light, as well as other visible light bands, and generally have a narrow absorption peak, requiring a specific wavelength light source for excitation, they do not produce significant fluorescence absorption and excitation under indoor lighting, sunlight, or ambient visible light. Therefore, this invention preferably uses fluorescence for deformation detection in the optical observation window 1, effectively avoiding the influence of ambient light. Furthermore, the fluorescence emission wavelength of the fluorescent labeling material is also flexibly selectable; it can choose either narrow-band fluorescence or relatively broadband luminescent fluorescent materials. Since this invention achieves land-based simulation, the embodiments of this invention preferably use labeling materials with narrow-band visible light wavelength fluorescence emission.

[0025] In some embodiments, an active fluorescent liquid is used to coat fluorescent markers 2 in an array on the measurement surface of the optical observation window 1, forming a semi-hidden fluorescent marker array. That is, the fluorescent markers 2 are approximately colorless and transparent in the non-illumination excitation state, and can remain on the measurement surface of the optical observation window 1 for easy observation at any time. In this embodiment of the invention, a protective isolation cover 9 is also provided on one side of the measurement surface of the observation window 1 to protect the optical observation window 1 and the fluorescent markers 2 thereon.

[0026] In this embodiment of the invention, during the process of applying the active fluorescent liquid to the measurement surface of the optical observation window 1 to form a fluorescent marker array, a mask is needed to ensure that the formed fluorescent marker array has a good image observation effect while minimizing the visual observation optical effect of the optical observation window 1. Specifically, this embodiment of the invention uses laser etching to prepare the mask, allowing for flexible design of the layout, size, and spacing of the fluorescent markers 2. The specific parameters of the mask directly correspond to these parameters. After the design of the fluorescent markers 2 is completed, the parameters are input into a laser micro-nano etching machine to etch the corresponding array pores onto the mask material, thus completing the mask preparation. During the mask preparation process, this embodiment of the invention appropriately adds random serrated textures to the array edges to increase the specificity and randomness of the markers and improve the speckle tendency of the pattern. Meanwhile, this embodiment of the invention does not use completely speckled fluorescent markers. On the one hand, this would make the surface pattern of the observation window too fragmented and messy, reducing the visualization effect. On the other hand, it would also be easy to resemble the pattern formed by surface dust pollution, frost, fog, etc., resulting in a deterioration of the test effect. In contrast, array-type markers are relatively regular, which facilitates image recognition and reading. Furthermore, due to the blank space between the points, there is less visual interference. At the same time, it is easier to be recognized and judged by the image when there are multiple reflections on the front and back surfaces, reducing feature matching misjudgments during measurement and reducing measurement errors. Therefore, in this embodiment of the invention, by using a mask to block the light and by spraying or brushing, the active fluorescent liquid is applied to the measurement surface of the optical observation window 1 to form an array of fluorescent markers 2.

[0027] The active fluorescent liquid used in this invention can be various fluorescent coatings, fluorescent adhesives, or other types of fluorescent liquids. Considering long-term reliability and optical stability, this embodiment of the invention preferably uses fluorescent adhesive to coat the surface of the optical observation window 1 to form fluorescent markers 2. When measurement is not required, the fluorescent markers 2 can be wiped off at any time without affecting the surface smoothness of the window. Similarly, for accidentally applied or unwanted fluorescent markers 2, they can be selectively wiped off. Before the adhesive solidifies, they can be wiped off with a wet wipe; after the adhesive solidifies, they can be dissolved and wiped off with organic solvents such as alcohol without affecting the surface smoothness and flatness of the optical observation window 1. If the requirements of short-term continuous observation are met, and the subsequent application is flexible, the active fluorescent liquid can be replaced with quick-drying fluorescent markers or fluorescent stickers to form the fluorescent markers 2.

[0028] The array layout of fluorescent marker 2 can adopt a common rectangular array, such as... Figure 3 As shown in (a) in the figure, or the staggered matrix layout, as... Figure 3 As shown in (b), and considering further reducing the area of ​​the surface coating and increasing the area of ​​the blank gaps, several typical areas can also be selected for dot matrix marking, such as... Figure 3 As shown in (c) and (d). The overall deformation can also be approximately recovered by fitting the surface under test in the later stage.

[0029] Typically, the wavelength requirements for the fluorescent excitation source 3 are not overly stringent; it does not require ultra-narrow wavelengths or ultra-short pulses like narrow-linewidth lasers. However, it needs to ensure stable local power output, good environmental stability, and good consistency during repeated switching operations. Since the fluorescent excitation source 3 functions as an energy supply, and fluorescent marking materials typically have a certain fluorescence lifetime and relaxation time, a certain degree of transient jitter is permissible. Under continuous excitation, this will not affect the fluorescent marking signal or the image detection performance of the imaging measurement camera 4. To achieve uniform illumination, constrained by the imaging measurement camera 4, this embodiment preferably employs a ring-shaped fluorescent excitation source 3 that provides stable and continuous excitation light output. The window's direct viewing area can be appropriately extended to ensure that the excitation illumination light does not directly enter the chamber. Simultaneously, it can excite the fluorescent marking on the surface of the window under test without causing other impacts on measurement and actual operating conditions. It is important to note that the fluorescent excitation source 3 should undergo specific lighting angle control and spatial placement adjustments to avoid prolonged and high-power direct illumination of the imaging measurement camera 4 by the light emitted from the fluorescent excitation source 3.

[0030] In some embodiments, the optical measurement assembly further includes a filter wheel shading stop 10 and a multi-channel filter wheel 11. The filter wheel shading stop 10 and the multi-channel filter wheel 11 are arranged sequentially between the fluorescence excitation source 3 and the imaging measurement camera 4 along the propagation direction of the fluorescence signal, for filtering the fluorescence signal at different wavelengths. The multi-channel filter wheel 11 includes a turntable, a rotating structure, and multiple filters. The multiple filters are arranged circumferentially on the turntable, which is located at the moving end of the rotating structure. The filter wheel shading stop 10 has a light-transmitting hole that matches the size of the filter. The rotating structure drives the turntable to rotate, so that the filter with a specific filtering wavelength rotates to the light-transmitting hole. After the fluorescence signal passes through the light-transmitting hole, it is filtered by the corresponding filter and then enters the imaging measurement camera 4. The imaging measurement camera 4 captures image information of fluorescent markers 2 on the optical observation window 1 by taking pictures. With the cooperation of the filter wheel shading 10 and the multi-channel filter wheel 11, it can avoid the interference of ambient stray light and the influence of uneven distribution of fluorescence signal intensity.

[0031] In some embodiments, the optical measurement group further includes a laser rangefinder 12 placed at the imaging measurement camera 4, which provides accurate distance data for the measurement area in the optical observation window 1. Specifically, the laser emitted by the laser rangefinder 12 passes sequentially through the filter wheel shackle 10 and the multi-channel filter wheel 11 to illuminate the surface of the optical observation window 1, measuring the distance between the optical observation window 1 and the imaging measurement camera 4. Specifically, in this embodiment of the invention, mechanical openings are made at the center of the filter wheel shackle 10 and the center of the turntable in the multi-channel filter wheel 11, so that the central axis of the lens in the imaging measurement camera 4 and the light emission direction of the laser rangefinder 12 are relatively parallel and far apart, and ensure that the laser rangefinder 12 can avoid the front obstruction of the filter wheel shackle 10 and the multi-channel filter wheel 11.

[0032] To fix the position between the imaging measurement camera 4 and the laser rangefinder 12, it is necessary to determine the accurate target surface position in the imaging measurement camera 4 and the relative position of its external packaging structure. This can be provided by the instruction manual of the imaging measurement camera 4, or by calibrating the laser rangefinder 12. That is, the laser rangefinder 12 is used to measure the position of the target surface of the imaging measurement camera 4, and then the relative position of the imaging measurement camera 4 and the laser rangefinder 12 is determined during actual test deployment.

[0033] When fixing and placing the imaging measuring camera 4 and the laser rangefinder 12, special attention should be paid to whether the central axis of the lens of the imaging measuring camera 4 and the light emission direction of the laser rangefinder 12 are perpendicular to the measurement surface of the optical observation window 1 (e.g., Figure 4 (as shown in (a)) or arranged at a certain angle (such as...) Figure 4 As shown in (b)). On the one hand, the specific working conditions of the window deformation test need to ensure that the fixation of this equipment does not interfere with other surrounding structures, while also being unaffected by particularly harsh factors such as large vibrations and high heat dissipation of other equipment; on the other hand, it is necessary to consider the geometric correspondence of the images measured by the imaging measurement camera 4 when the optical observation window 1 deforms, and the imaging optical lens of the imaging measurement camera 4 (excluding the telecentric lens) has the problem of near-large and far-small (e.g. Figure 4 (a) After the test surface ABCa moves forward to the position AABBCCaa, the field of view increases, the original position of B becomes BB, replacing the original position of A in the image, and the magnification increases by AC / BC times. This is something that will occur regardless of the camera's angle of placement. The central axis of the lens in the imaging measurement camera 4 is tilted at a small angle to the measurement surface of the optical observation window 1. This is beneficial for testing the movement or deformation of the lens relative to the vertically placed optical observation window 1, because the tilted state of the imaging measurement camera 4 manifests as a translation of the optical observation window 1 on the imaging plane. Figure 4As shown in (b), when the optical observation window 1 moves vertically a distance dz relative to the imaging measurement camera 4, it will correspondingly translate dx on the image plane of the imaging measurement camera 4, where dx = dz × sinα, and α represents the tilt angle of the image plane of the imaging measurement camera 4 relative to the vertical optical observation window 1. This makes the imaging measurement camera 4 more sensitive to vertical displacement and temporarily ignores the size transformation problem of near-large and far-small. In addition, tilting the imaging measurement camera 4 also allows the imaging measurement camera 4 to capture a wider fluorescence image of the optical observation window 1 at the same distance, with the same camera target surface and number of pixels. That is, the actual measurement size corresponding to a unit pixel in the target surface of the imaging measurement camera 4 becomes larger (e.g., ...). Figure 4 In (b), at the same object distance, the measurable width Lt increases to Ls, and Lt = cosα × Ls), which is theoretically unfavorable for improving the deformation measurement limit. In summary, improving the deformation measurement effect and breaking the limit of the window surface requires a trade-off between several factors. In this embodiment of the invention, the central axis of the lens of the imaging measurement camera 4 is preferably arranged perpendicular to the surface of the optical observation window 1.

[0034] In some embodiments, the signal processing center 5 divides the region according to the array arrangement of multiple fluorescent markers 2, and processes the image acquired by the imaging measurement camera 4 using a feature matching algorithm. By analyzing the changes in the fluorescent markers 2 in each region, the deformation of different regions on the measurement surface of the optical observation window 1 is calculated, such as... Figure 5 As shown, Figure 5 R1 to R6 in the figure are the feature region numbers; the deformation of different regions is fitted to obtain the continuous deformation of the measurement surface. Specifically, the feature matching algorithm, based on the displacement and deformation of the fluorescent marker 2 in the image acquired by the imaging measurement camera 4, combined with the fitting algorithm, calculates the minute deformation of the measurement surface of the optical observation window 1, forming a continuous surface morphology result. The simulation results are as follows: Figure 6As shown. In this embodiment of the invention, the processing of images acquired by the imaging measurement camera 4 using a feature matching algorithm includes: combining region matching based on feature points (such as the center position of fluorescent markers, or the position of edge grayscale gradient changes at different threshold intervals) with a sub-pixel interpolation algorithm to process the images acquired by the imaging measurement camera; calculating the deformation of different regions on the measurement surface of the optical observation window by analyzing the displacement and morphological changes of fluorescent feature points in each region. Furthermore, the process of fitting the deformation of different regions in this embodiment includes: firstly, fitting the changing morphology of feature points within each feature region; specifically, in this embodiment, Gaussian surface fitting is performed on the feature points; then, cross-region fitting is performed between different feature regions, specifically by selecting the spacing at the region connection points; in this embodiment, polynomial surface fitting is used for cross-region fitting.

[0035] Considering that there is a protective glass in front of the optical observation window 1, in addition to defogging and wiping it before each test, there may also be certain contaminants, scratches and other interference features. This can be optimized by using a hardware solution that matches a lens with a small depth of field to the imaging measurement camera 4, blurring and weakening the out-of-focus surface features in the imaging measurement camera 4, and eliminating the influence with image homogenization. Alternatively, a feature removal method marked manually in the software can be used to eliminate the influence of interference from the protective glass surface. By manually removing some interference features, the accuracy of glass surface deformation and displacement recognition of the optical observation window 1 can be further improved.

[0036] In some embodiments, the measurement system further includes a displacement control group, which includes a support frame 13, a lateral electric displacement stage 14, and a longitudinal electric displacement stage 15. The support frame 13 is integrally connected to the filter wheel shading 10 and the multi-channel filter wheel 11, and supports the imaging measurement camera 4. The lateral electric displacement stage 14 and the longitudinal electric displacement stage 15 are used to adjust the position of the imaging measurement camera 4 and the laser rangefinder 12 relative to the optical observation window 1. Specifically, the lateral electric displacement stage 14 drives the support frame 13 to move laterally, and the longitudinal electric displacement stage 15 drives the support frame 13 to move longitudinally. In this embodiment of the invention, the displacement control group further includes an electronic control module 16, which controls the movement of the support frame 13 driven by the lateral electric displacement stage 14 and the longitudinal electric displacement stage 15, thereby adjusting the measurement distance and left-right position of the imaging measurement camera 4 and the laser rangefinder 12. Regarding the distortion effect of the lens of the imaging measurement camera 4, the lens distortion can be calibrated in advance, such as by using a checkerboard calibration method. However, this method is relatively cumbersome and not conducive to application in real working conditions. Therefore, the displacement control group provided in this embodiment of the invention can also be used to calibrate the lens distortion in the imaging measurement camera 4. Specifically, the electronic control module 16 applies a longitudinal displacement, such as 5mm, to the longitudinal electric displacement stage 15, which can clarify the near-large and far-small mapping relationship of the imaging measurement camera 4, including the lens distortion effect in the imaging measurement camera 4. In subsequent measurements, based on this calibration result, the accurate solution of the true deformation vertical axis direction value can be directly obtained. The transverse electric displacement stage 14 can calibrate the imaging geometric change relationship in the calibration plane direction and the lens distortion effect. With the assistance of the measurement data from the laser rangefinder 12, such calibration is more accurate.

[0037] Based on the observation window distortion imaging measurement system provided by this invention, the corresponding observation window distortion imaging measurement method includes: Step 1: Based on the size of the optical observation window 1, the window surface deformation detection time, the surface deformation measurement accuracy requirements, and the degree of coating on the surface of the window to be tested, determine the array arrangement scheme of the fluorescent markers 2, including ordinary rectangular arrays, staggered matrices, annular blank arrays, and irregular shaped area blank arrays. It also includes the size of the fluorescent markers 2, the distance between two points, and the irregular serrated texture around the markers, as well as the specific material of the fluorescent paint or glue.

[0038] Step 2: Based on the arraying scheme of fluorescent marker 2 determined in Step 1, its quantitative data is input into the laser etching system to prepare a mask template for fluorescent markers or a corresponding fluorescent sticker pattern. Then, the fluorescent marker 2 is attached to the measurement surface of the optical observation window 1, and the arrayed fluorescent marker 2 is prepared by spraying, brushing, fluorescent pen application, or other methods.

[0039] Step 3: Based on the material of the fluorescent marker 2 in Step 2, determine the wavelength selection of the annular fluorescent excitation source 3 and the multiple configuration methods to ensure that the fluorescent excitation source 3 can uniformly illuminate all the fluorescent markers 2 on the measurement surface of the optical observation window 1 and will not directly enter the interior of the chamber 6; at the same time, based on the material of the fluorescent marker 2, determine the wavelength and required number of filters in the multi-channel filter wheel 11, and ensure that the configuration and installation can block the excitation source of the imaging measurement camera 4 without blocking the fluorescent markers 2.

[0040] Step 4: Based on the dimensions of the optical observation window 1, the window surface deformation detection time, the surface deformation measurement accuracy requirements, and the installation effect of the multi-channel filter wheel 11 in Step 1, determine the perpendicular or tilted relationship between the central axis of the lens in the imaging measurement camera 4 and the measurement surface of the optical observation window 1. Install the camera on the support frame 13 together with the multi-channel filter wheel 11. Adjust the pitch and height of the imaging measurement camera 4 to ensure that there is no deviation in any direction or angle except for the specified tilt relationship. Configure the wires and data transmission lines between the various components and confirm that the software program is correct. The laser rangefinder 12 is fixedly positioned above or to the left or right of the imaging measurement camera 4, with its optical axis aligned with the central axis of the lens in the imaging measurement camera 4. The laser rangefinder 12 measures the distance between the target surface of the imaging measurement camera 4 and the measurement surface of the optical observation window 1.

[0041] Step 5: After installation and confirmation in Step 4, control the horizontal electric displacement stage 14 and the vertical electric displacement stage 15 to move quantitatively in the vertical and parallel directions. During this movement, use the laser rangefinder 12 to double-calibrate the amount of movement perpendicular to the measurement surface of the optical observation window 1. The movement of the horizontal electric displacement stage 14 and the vertical electric displacement stage 15 should be 1 to 10 times the estimated maximum range of the measurement surface. Too small a movement will not achieve effective calibration, while too large a movement will introduce more mechanical errors and lens optical aberrations. The comprehensive calibration results can clarify the geometric relationships in the imaging test and the influence of lens distortion.

[0042] Step Six: After moving the transverse electric displacement stage 14 and the longitudinal electric displacement stage 15 in Step Five, both are locked in place. The imaging measurement camera 4 is controlled to continuously acquire and photograph images of the measurement surface. The number of repeated photographs is determined according to the window surface deformation detection time requirements, and the exposure time is determined according to the average gray value of the image. After acquiring the image, feature recognition is performed. The feature region division strategy is determined by combining the fluorescent marker array scheme. The divided regions are continuously identified and compared for correlation. The movement of each feature region at different times is obtained. The actual discrete movement or deformation is restored by combining the calibration results of Step Five. Finally, the continuous deformation of the measurement surface of the optical observation window 1 is obtained by fitting.

[0043] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.

[0044] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A viewing window deformation imaging measurement system, characterized by, The application relates to a measurement system for measuring the deformation of an optical observation window under high pressure, which comprises an environment simulation group, an optical measurement group and a displacement control group. The environment simulation group is arranged in contact with the mounting surface of the optical observation window to be measured and is used for simulating a high-pressure environment for the optical observation window. The optical measurement group is used for measuring the deformation of the optical observation window under the high-pressure environment and comprises a plurality of fluorescent marking points, a fluorescent excitation light source, an imaging measurement camera and a signal processing center. The plurality of fluorescent marking points are arranged on the measurement surface of the optical observation window, and the fluorescent marking points generate fluorescent signals after being excited by the fluorescent excitation light source.

2. The viewing window shape imaging measurement system of claim 1, wherein, The fluorescent signals are imaged in the imaging measurement camera, and the signal processing center calculates the deformation of the optical observation window according to the imaging results of the imaging measurement camera.

3. The viewing window shape imaging measurement system of claim 1, wherein, The environment simulation group comprises a cabin body, a pressurized liquid and a pressure controller.

4. The viewing window shape imaging measurement system of claim 3, wherein, The optical observation window is mounted on the cabin body, the pressurized liquid is arranged in the cabin body, the mounting surface of the optical observation window is in contact with the pressurized liquid, and the pressure controller controls the liquid pressure of the pressurized liquid in the cabin body, thereby simulating a high-pressure environment for the optical observation window.

5. The viewing window shape imaging measurement system of claim 1, wherein, An active fluorescent liquid is used to smear the fluorescent marking points in an array form on the measurement surface of the optical observation window, thereby forming a semi-hidden fluorescent marking point array. The signal processing center divides the array of the plurality of fluorescent marking points into regions and processes the images collected by the imaging measurement camera by using a feature matching algorithm.

6. The viewing window shape imaging measurement system of claim 5, wherein, The deformation of different regions on the measurement surface of the optical observation window is calculated by analyzing the changes of the fluorescent marking points in the regions.

7. The viewing window shape imaging measurement system of claim 5, wherein, The deformations of the different regions are fitted to obtain the continuous deformation of the measurement surface. The optical measurement group further comprises a light filter rotating wheel shutter and a multi-channel light filter rotating wheel. The light filter rotating wheel shutter and the multi-channel light filter rotating wheel are arranged in sequence between the fluorescent excitation light source and the imaging measurement camera along the propagation direction of the fluorescent signals and are used for filtering the fluorescent signals at different wavelengths. The multi-channel light filter rotating wheel comprises a rotating disc, a rotating structure and a plurality of light filters. The plurality of light filters are arranged in a circumferential direction on the rotating disc. The rotating disc is arranged at the movement end of the rotating structure. The light filter rotating wheel shutter has a light transmission hole matching the size of the light filters. The rotating structure drives the rotating disc to rotate, so that the light filters of different wavelengths are rotated to the light transmission hole. The fluorescent signals pass through the light transmission hole and then pass through the corresponding light filters to enter the imaging measurement camera. The optical measurement group further comprises a laser range finder arranged at the imaging measurement camera. The laser emitted by the laser range finder passes through the light filter rotating wheel shutter and the multi-channel light filter rotating wheel in sequence and irradiates the surface of the optical observation window. The distance between the optical observation window and the imaging measurement camera is measured. The displacement control group comprises a support frame, a horizontal electric displacement table and a vertical electric displacement table. The support frame is integrally connected with the light filter rotating wheel shutter and the multi-channel light filter rotating wheel and supports the imaging measurement camera. The horizontal electric displacement table drives the support frame to move horizontally, and the vertical electric displacement table drives the support frame to move vertically.

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