A magneto-optical imaging integrated probe and its parameter self-adjustment method

Abstract

The present invention belongs to the technical field of oil and gas device detection, and particularly relates to a magneto-optical imaging integrated probe and a method for self-adjusting its parameters. The magneto-optical imaging integrated probe has a vertical "injection-production" optical path and a small sensing gap, with higher defect imaging clarity and device integrated layout; in addition, a method for self-adjusting the probe parameters is also provided, which can adapt to the detection requirements of various chemical working conditions and effectively improve the self-adaptability of the probe. A method for self-adjusting the parameters of a magneto-optical imaging integrated probe includes the following steps: obtaining the maximum leakage magnetic field intensity at the defect of the workpiece to be measured; constructing a three-dimensional simulation model of the magneto-optical imaging integrated probe; setting the optical physical field for the geometric structures of each part of the three-dimensional simulation model; performing differential grid meshing on the three-dimensional simulation model; setting the scanning parameters of the three-dimensional simulation model and calculating the values of each variable in the three-dimensional simulation model; and drawing a simulated magneto-optical image.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil and gas device detection, and particularly relates to a magneto-optical imaging integrated probe and a method for self-adjusting its parameters. Background Art

[0002] As important equipment in the oil and gas field, oil and gas pipelines and storage tanks play an indispensable role in the process of transporting, transferring, and storing oil and natural gas. The inventor found that the working environment of the above-mentioned equipment is harsh and vulnerable to factors such as mechanical impact and medium corrosion, resulting in defects such as cracks, deformations, and corrosion. Therefore, technicians need to conduct regular inspections and maintenance on them, so as to implement effective intervention measures before accidents occur and avoid causing significant economic losses and casualties.

[0003] The existing oil and gas device detection methods mainly include the following categories: ray method, eddy current method, ultrasonic method, magnetic flux leakage method, etc. However, further research found that the above existing oil and gas device detection methods have a series of limitations such as low efficiency, insufficient sensitivity, and poor intuitiveness; and the detection process more relies on manual experience, and the stability of its detection results is poor. Therefore, it is urgent for technicians in this field to develop a detection device with high imaging clarity, high integration, and intelligent parameter adjustment function, so as to provide reliable technical support for the detection of oil and gas equipment defects. Summary of the Invention

[0004] The present invention provides a magneto-optical imaging integrated probe and a method for self-adjusting its parameters. The magneto-optical imaging integrated probe has a vertical "input - acquisition" optical path and a smaller sensing gap, thus having higher defect imaging clarity and more integrated equipment layout; in addition, a method for self-adjusting the probe parameters is also provided, which can adapt to the detection requirements of various chemical working conditions and effectively improve the self-adaptability of the probe.

[0005] To solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A magneto-optical imaging integrated probe, which is composed of a linearly polarized light emitting unit, a linearly polarized light modulating unit, a linearly polarized light imaging unit, and a clamping mechanism;

[0007] The clamping mechanism is composed of an inner housing and an outer housing; wherein, a linearly polarized light passage is also provided between the inner housing and the outer housing;

[0008] The linearly polarized light emitting unit includes an LED light source, a light guide plate, and a polarizer; wherein, the LED light source is fixedly installed on the side wall of the inner housing; the light guide plate is fixedly installed inside the inner housing and is used to modulate the light output by the LED light source into parallel light in the horizontal direction; the polarizer is fixedly installed inside the inner housing and is arranged perpendicular to the direction of the parallel light, and is used to modulate the parallel light into linearly polarized light;

[0009] The linear polarization light modulation unit includes a magneto-optic sensing module, a beam splitter, a silicon steel yoke, and a neodymium iron boron magnet; wherein, the magneto-optic sensing module is fixedly installed inside the inner housing directly below the linear polarization light path; the beam splitter is fixedly installed inside the inner housing and is used to reflect the linearly polarized light modulated by the polarizer to the position of the magneto-optic sensing module; the neodymium iron boron magnet and the silicon steel yoke are sequentially installed on the periphery of the linear polarization light path and are used to form a closed magnetic field loop;

[0010] The linear polarization light imaging unit includes a camera, an analyzer, a camera driver board, and a Lemo connector; wherein, the analyzer is fixedly installed on the top of the outer housing directly above the linear polarization light path and is used to receive the linearly polarized light modulated by the leakage magnetic field; the camera, the camera driver board, and the Lemo connector are sequentially connected to the analyzer and are used to convert the optical signal captured by the analyzer into an electrical signal and transmit it to an external display device.

[0011] Preferably, the magneto-optic sensing module is composed of a magneto-optic thin film, a mirror coating, and a protective coating; wherein, the magneto-optic thin film is used to induce the magneto-optical rotation effect of the linearly polarized light, the mirror coating is used to reflect the linearly polarized light, and the protective coating is used to protect the magneto-optic thin film and the mirror coating.

[0012] On the other hand, the present invention also provides a method for self-adjusting the parameters of a magneto-optic imaging integrated probe, including the following steps:

[0013] Step 1: Obtain the maximum leakage magnetic field intensity at the defect of the workpiece to be measured;

[0014] Step 2: Construct a three-dimensional simulation model of the magneto-optic imaging integrated probe;

[0015] Step 3: Set the optical physical field for the geometric structures of each part of the three-dimensional simulation model constructed in Step 2;

[0016] Step 4: Perform differential grid meshing on the three-dimensional simulation model processed in Step 3;

[0017] Step 5: Set the scanning parameters for the three-dimensional simulation model processed in Step 4, calculate the values of each variable in the three-dimensional simulation model; draw a simulated magneto-optic image.

[0018] Preferably, it further includes the following steps:

[0019] Step 6: Analyze the simulated magneto-optic image obtained in Step 5 to determine the optimal values of the variable values in the three-dimensional simulation model.

[0020] Preferably, Step 1 is specifically described as:

[0021] Place the magneto-optic imaging integrated probe directly above the defect of the workpiece to be measured to excite a leakage magnetic field;

[0022] Using a teslameter, measure the maximum leakage magnetic field intensity B at the defect of the component under test.

[0023] More preferably, step two is specifically described as:

[0024] Using the COMSOL model developer, construct a three-dimensional simulation model of the magneto-optical imaging integrated probe; wherein, the constructed three-dimensional simulation model at least includes the simulation of the geometric simplified structures of the LED light source, polarizer, magneto-optical thin film, mirror coating, beam splitter, camera, analyzer, and light-blocking surface.

[0025] More preferably, step three is specifically described as:

[0026] Set the LED light source to emit uniform unpolarized light based on grid cells, and set its light source power to W, then the emitted light intensity I0 satisfies: (1);

[0027] In formula (1), l and b are respectively the length and width of the light-emitting surface of the LED light source;

[0028] Set the polarizer, magneto-optical thin film, and analyzer as linear polarizers, then the transmission axis of the polarizer is defined as: (2);

[0029] In formula (2), v p is the direction vector of the transmission axis of the polarizer, v px , v py and v pz are respectively the projections of v p on the x-axis, y-axis, and z-axis, c p is a constant, γ is the angle between v p and the horizontal direction; after the parallel light passes through the polarizer, its light intensity becomes I0 / 2;

[0030] The deflection angle θ of the linearly polarized light when passing through the magneto-optical thin film satisfies: (3);

[0031] In formula (3), V is the Verdet constant, and T is the thickness of the magneto-optical thin film;

[0032] The transmission axis of the magneto-optical thin film is defined as: (4);

[0033] In formula (4), v m is the direction vector of the transmission axis of the magneto-optical thin film, v mx , v my and v mz are respectively the projections of v m on the x-axis, y-axis, and z-axis, c m is a constant;

[0034] The transmission axis of the analyzer is defined as: (5);

[0035] In formula (5), v d is the direction vector of the transmission axis of the analyzer, v dx , v dy and v dz are the projections of v d on the x-axis, y-axis and z-axis respectively, and c d is a constant;

[0036] Set the reflectivity of the beam splitter to r, the transmittance to 1 - r, and the reflection coefficient of the mirror coating to 1. After the linearly polarized light passes through the analyzer, its light intensity I D , satisfies:

[0037] (6).

[0038] More preferably, step six is specifically described as:

[0039] Calculate the average gray level of the simulated magneto - optical image , the maximum gray level value of the simulated magneto - optical image and the minimum gray level value of the simulated magneto - optical image ;

[0040] Among them, the average gray level of the simulated magneto - optical image satisfies: (8);

[0041] In formula (8), M and N respectively represent the height and width of the simulated magneto - optical image, represents the gray level value of the pixel point ;

[0042] The maximum gray level value of the simulated magneto - optical image satisfies: (9);

[0043] The minimum gray level value of the simulated magneto - optical image satisfies: (10);

[0044] Construct an evaluation function ; Among them, the evaluation function satisfies: (11);

[0045] Calculate the value of E under different variable conditions; when the value of E is the largest, the corresponding values of each variable in the three - dimensional simulation model are the optimal values.

[0046] The present invention provides a magneto-optical imaging integrated probe and a method for self-adjusting its parameters. Among them, the method for self-adjusting parameters includes the following steps: Step 1: Obtain the maximum leakage magnetic field intensity at the defect of the workpiece to be measured; Step 2: Construct a three-dimensional simulation model of the magneto-optical imaging integrated probe; Step 3: Set the optical physical field for each part of the geometric structure of the three-dimensional simulation model constructed in Step 2; Step 4: Perform differential grid meshing on the three-dimensional simulation model processed in Step 3; Step 5: Set the scanning parameters for the three-dimensional simulation model processed in Step 4, calculate the values of each variable in the three-dimensional simulation model, and draw a simulated magneto-optical image.

[0047] The magneto-optical imaging integrated probe and the method for self-adjusting its parameters with the above technical features have a higher imaging clarity of defects and a more integrated layout of the device by configuring a vertical "projection-acquisition" optical path and a smaller sensing gap. At the same time, the present invention also provides a method for self-adjusting the probe parameters, which can adapt to the detection requirements of diverse working conditions. Compared with the prior art, the technical solution of the present invention has at least the following technical advantages:

[0048] (1) The integration degree of the device structure is higher, and the defocus phenomenon is less, which can effectively improve the imaging clarity of defect detection;

[0049] (2) It makes up for the deficiency of empirical parameter adjustment in the prior art, enhances the applicability of the magneto-optical imaging integrated probe, and enables it to adapt to different working conditions through precise parameter adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention, and do not constitute a limitation to the present invention. In the following drawings:

[0051] Figure 1 is a schematic structural diagram of the magneto-optical imaging integrated probe provided by the present invention;

[0052] Figure 2 is a schematic structural diagram of the magneto-optical sensing module;

[0053] Figure 3 is a schematic flow diagram of the method for self-adjusting the parameters of the magneto-optical imaging integrated probe provided by the present invention;

[0054] Figure 4 is a schematic diagram of the three-dimensional simulation model of the magneto-optical imaging integrated probe constructed by the method for self-adjusting the parameters of the magneto-optical imaging integrated probe.

[0055] Reference numerals:

[0056] 1. LED light source; 2. Light guide plate; 3. Polarizer; 4. PET tape; 5. Magneto-optical sensing module; 501. Magneto-optical thin film; 502. Mirror coating; 503. Protective coating; 6. Beam splitter; 7. Inner housing; 8. Silicon steel yoke; 9. Neodymium iron boron magnet; 10. Camera; 11. Analyzer; 12. Camera driver board; 13. Lemo connector; 14. Outer housing. Detailed implementation manner

[0057] The present invention provides a magneto-optical imaging integrated probe and a method for self-adjusting its parameters. The magneto-optical imaging integrated probe has a vertical "projection - acquisition" optical path and a small sensing gap, thus having higher defect imaging clarity and device integration layout; in addition, a method for self-adjusting the probe parameters is also provided, which can adapt to the detection requirements of diverse working conditions and effectively improve the self-adaptability of the probe.

[0058] The present invention provides a magneto-optical imaging integrated probe, as Figure 1 shown, the magneto-optical imaging integrated probe is composed of a linearly polarized light emitting unit, a linearly polarized light modulating unit, a linearly polarized light imaging unit and a clamping mechanism.

[0059] Specifically, the clamping mechanism is composed of an inner housing 7 and an outer housing 14. It should be noted that the inner housing 7 is used to provide an installation space for structural units such as the LED light source 1, the light guide plate 2, the polarizer 3, the magneto-optical sensing module 5, and the beam splitter 6; the outer housing 14 is used to provide an installation space for structural units such as the camera 10, the analyzer 11, and the camera driver board 12. In addition, a linearly polarized light path is also provided between the inner housing 7 and the outer housing 14.

[0060] The linearly polarized light emitting unit includes an LED light source 1, a light guide plate 2, and a polarizer 3. Among them, the LED light source 1 is fixedly installed on the side wall of the inner housing 7 and is used to provide a natural light source. In this embodiment, the selected LED light source 1 has a green natural light with an output wavelength of 520 - 530 nm, a light emitting surface size of 15 mm × 15 mm, and the power W is determined according to different light source models. The light guide plate 2 is fixedly installed inside the inner housing 7 and is used to modulate the light output by the LED light source 1 into parallel light in the horizontal direction; the polarizer 3 is fixedly installed inside the inner housing 7 and is arranged perpendicular to the parallel light direction (by screening specific polarization components in the parallel natural light) and is used to modulate the parallel light into linearly polarized light.

[0061] The linearly polarized light modulating unit includes a magneto-optical sensing module 5, a beam splitter 6, a silicon steel yoke 8, and a neodymium iron boron magnet 9. Among them, the beam splitter 6 is fixedly installed inside the inner housing 7 and is used to reflect the linearly polarized light modulated by the polarizer 3 to the position of the magneto-optical sensing module 5. The magneto-optical sensing module 5 is fixedly installed inside the inner housing 7 directly below the linearly polarized light path through the PET tape 4.

[0062] As a more preferred embodiment of the present invention, as Figure 2 shown, the magneto - optical sensing module 5 is composed of a magneto - optical thin film 501, a mirror coating 502, and a protective coating 503. Among them, the magneto - optical thin film 501 (the thickness T of the magneto - optical thin film is selected to be 0.05 mm, and the Verdet constant V is 1.04×10⁶ rad / mT) is used to induce the magneto - optical rotation effect on linearly polarized light, the mirror coating 502 is used to reflect linearly polarized light, and the protective coating 503 is used to protect the magneto - optical thin film 501 and the mirror coating 502.

[0063] Moreover, the neodymium - iron - boron magnet 9 and the silicon - steel magnetic yoke 8 are sequentially installed on the periphery of the linearly polarized light path. The silicon - steel magnetic yoke 8 and the neodymium - iron - boron magnet 9 are used to form a closed magnetic - field loop, so as to generate a leakage magnetic field directly above the defect of the test piece.

[0064] The linearly polarized light imaging unit includes a camera 10, a polarizer 11, a camera driver board 12, and a Lemo connector 13. Among them, the polarizer 11 is fixedly installed on the top of the outer housing 14 directly above the linearly polarized light path, and is used to receive the linearly polarized light modulated by the leakage magnetic field. The camera 10 (the performance parameters of the camera can be referred to as follows: 1280×720 pixels, frame rate of 120 frames, pixel size of 3m×3m, lens focal length of 12 mm, and external dimensions of 8mm×8mm×5mm), the camera driver board 12, and the Lemo connector 13 are sequentially connected to the polarizer 11, and are used to convert the optical signal captured by the polarizer 11 into an electrical signal and transmit it to an external display device.

[0065] It should be noted that the linearly polarized light modulated by the leakage magnetic field can be used to reflect the defect of the test piece; therefore, by analyzing the output electrical signal, the specific defect existing in the test piece can be finally determined.

[0066] On the other hand, the present invention also provides a method for self - adjusting the parameters of a magneto - optical imaging integrated probe, as Figure 3 shown. The method for self - adjusting the parameters of this magneto - optical imaging integrated probe specifically includes the following steps:

[0067] Step 1: Obtain the maximum leakage magnetic - field intensity at the defect of the test piece.

[0068] As a more preferred embodiment of the present invention, step 1 can be specifically described as follows:

[0069] Place the magneto - optical imaging integrated probe directly above the defect of the test piece to excite a leakage magnetic field;

[0070] Use a teslameter to measure the maximum leakage magnetic - field intensity B at the defect of the test piece.

[0071] Step 2: Construct a three - dimensional simulation model of the magneto - optical imaging integrated probe;

[0072] On the basis of completing Step 1, further construct a three-dimensional simulation model of the magneto-optical imaging integrated probe. As a relatively preferred embodiment of the present invention, this Step 2 can be specifically described and referred to as follows:

[0073] Use the COMSOL model developer to select the interface of the specific three-dimensional space dimension and the optical physical field, and construct a three-dimensional simulation model of the magneto-optical imaging integrated probe. It should be noted that the constructed three-dimensional simulation model at least includes the simulation of the LED light source 1, the polarizer 3, the magneto-optical thin film 501, the mirror coating 502, the beam splitter 6, the camera 10, the analyzer 11, and the geometric simplified structure of the light blocking surface. Specifically, it can be referred to as Figure 4 shown.

[0074] Step 3: Set the optical physical field for each part of the geometric structure of the three-dimensional simulation model constructed in Step 2.

[0075] On the basis of completing Step 2, further set the optical physical field for each part of the geometric structure of the three-dimensional simulation model. As a relatively preferred embodiment of the present invention, this Step 3 mainly sets the optical physical field of the geometric structures of the LED light source 1, the polarizer 3, the magneto-optical thin film 501, and the analyzer 11, and the beam splitter 6, the camera 10, and the light blocking surface are briefly described.

[0076] First, set the LED light source 1 to emit uniform unpolarized light based on the grid unit, and set its light source power to W. Then the outgoing light intensity I0 satisfies: (1); in the formula (1), l and b are respectively the length and width of the light-emitting surface of the LED light source 1.

[0077] Specifically, according to the design selection of the aforementioned magneto-optical imaging integrated probe, that is . Therefore, the outgoing light intensity obtained from formula (1) is .

[0078] Then, set the polarizer 3, the magneto-optical thin film 501, and the analyzer 11 as linear polarizers.

[0079] Among them, the transmission axis of the polarizer 3 is defined as: (2);

[0080] In the formula (2), v p is the direction vector of the transmission axis of the polarizer 3, v px , v py and v pz are respectively the projections of v p on the x-axis, y-axis, and z-axis, c p is a constant, and γ is v pThe angle with the horizontal direction; after the parallel light passes through the polarizer 3, its light intensity becomes I0 / 2.

[0081] The deflection angle θ of the linearly polarized light when passing through the magneto-optical thin film 501 satisfies: (3);

[0082] In the formula (3), V is the Verdet constant, and T is the thickness of the magneto-optical thin film 501.

[0083] It should be added that since the transmission axis of the polarizer 3 is set along the horizontal direction, satisfying , so the direction vector obtained from formula (2) is , and the rotation angle of formula (3) satisfies , where B is the maximum leakage magnetic field intensity at the defect of the test piece measured by the teslameter in step one.

[0084] The transmission axis of the magneto-optical thin film 501 is defined as: (4);

[0085] In the formula (4), v m is the direction vector of the transmission axis of the magneto-optical thin film 501, v mx , v my and v mz are the projections of v m on the x-axis, y-axis and z-axis respectively, and c m is a constant.

[0086] Substituting the aforementioned calculated values, the direction vector calculated by formula 4 is .

[0087] The transmission axis of the analyzer 11 is defined as: (5);

[0088] In the formula (5), v d is the direction vector of the transmission axis of the analyzer 11, v dx , v dy and v dz are the projections of v d on the x-axis, y-axis and z-axis respectively, and c d is a constant.

[0089] Substituting the aforementioned calculated values, the direction vector calculated by formula (5) is .

[0090] Furthermore, setting the reflectivity of the beam splitter 6 as r and the transmittance as 1 - r, and the reflection coefficient of the mirror coating 502 as 1, then after the linearly polarized light passes through the analyzer 11, its light intensity I D , satisfies:

[0091] (6).

[0092] Substituting the aforementioned calculated values, it can be obtained that the light intensity calculated by Equation (6) satisfies: .

[0093] Finally, set the wall condition of the light-blocking surface to disappear to delete the redundant light rays reflected and transmitted by the beam splitter 6 (for the purpose of saving computing power). Then, set the wall condition of the camera 10 to be frozen, so as to ensure that the camera 10 can capture and save the position and light intensity information of the corresponding linearly polarized light rays.

[0094] Step Four: Perform differential grid meshing on the three-dimensional simulation model processed in Step Three.

[0095] On the basis of completing Step Three, further perform differential grid meshing on the three-dimensional simulation model. Specifically, in order to ensure both the accuracy of the simulation and a relatively fast running speed of the calculation process; here, for the light source 1, the magneto-optical thin film 501, and the camera 10 with relatively high requirements for calculation accuracy, set smaller cells (for example, set the side length of the grid unit of the cell to 0.01 mm); while for other structures with relatively low requirements for calculation accuracy, relatively larger unit grids can be selected (for example, set the side length of the grid unit of the cell to 0.05 mm).

[0096] Step Five: Set the scanning parameters for the three-dimensional simulation model processed in Step Four, calculate the values of various variables in the three-dimensional simulation model; draw the simulated magneto-optical image.

[0097] On the basis of completing Step Four, further perform calculations and solutions on the three-dimensional simulation model in order to draw the simulated magneto-optical image. It should be noted that in order to solve for the variables W, α, and r that have an important impact on the imaging effect, first set the scanning parameters for the three-dimensional simulation model, so as to assign values to the above variables.

[0098] The specific variables satisfy:

[0099] (7);

[0100] where range is the name of a built-in function in COMSOL, and i W , s W , f W are respectively the initial value, step size, and final value of the variable W, and i α , s α , f α are respectively the initial value, step size, and final value of the variable α, and i r , s r , f rThey are respectively the initial value, step size, and final value of the variable r. Substitute the above three variables into formula (6), and call the solver of the three-dimensional simulation model for calculation, then the simulated magneto-optical image of camera 10 when W, α, and r take corresponding values can be plotted.

[0101] Furthermore, a method for self-adjusting parameters of a magneto-optical imaging integrated probe provided by the present invention further includes the following steps:

[0102] Step Six: Analyze the simulated magneto-optical image obtained in Step Five to determine the optimal values of each variable in the three-dimensional simulation model.

[0103] On the basis of completing Step Five, further analyze the simulated magneto-optical image. As a relatively preferred embodiment of the present invention, this Step Six is specifically described as:

[0104] First, calculate the average gray level of the simulated magneto-optical image , the maximum gray level value of the simulated magneto-optical image, and the minimum gray level value of the simulated magneto-optical image.

[0105] Among them, the average gray level of the simulated magneto-optical image satisfies: (8);

[0106] In formula (8) thereof, M and N respectively represent the height and width of the simulated magneto-optical image, represents the gray level value of pixel point ;

[0107] The maximum gray level value of the simulated magneto-optical image satisfies: (9);

[0108] The minimum gray level value of the simulated magneto-optical image satisfies: (10).

[0109] Then, construct an evaluation function ; among them, the evaluation function satisfies: (11). Calculate the E value under different variable conditions. When the E value is the largest, the corresponding values of each variable in the three-dimensional simulation model are the optimal values (when each variable takes the optimal value, the detection effect of the magneto-optical imaging integrated probe is the best).

[0110] The present invention provides a magneto-optical imaging integrated probe and a method for self-adjusting its parameters. Among them, the method for self-adjusting parameters includes the following steps: Step 1: Obtain the maximum leakage magnetic field intensity at the defect of the workpiece to be measured; Step 2: Construct a three-dimensional simulation model of the magneto-optical imaging integrated probe; Step 3: Set the optical physical field for each part of the geometric structure of the three-dimensional simulation model constructed in Step 2; Step 4: Perform differential grid meshing on the three-dimensional simulation model processed in Step 3; Step 5: Set the scanning parameters for the three-dimensional simulation model processed in Step 4, calculate the values of each variable in the three-dimensional simulation model, and draw a simulated magneto-optical image.

[0111] The magneto-optical imaging integrated probe and the method for self-adjusting its parameters with the above technical features have a higher defect imaging clarity and a more integrated device layout by configuring a vertical "projection-acquisition" optical path and a smaller sensing gap. At the same time, the present invention also provides a method for self-adjusting the probe parameters, which can adapt to the detection requirements of diverse working conditions. Compared with the prior art, the technical solution of the present invention has at least the following technical advantages:

[0112] (1) The integration degree of the device structure is higher, and the defocus phenomenon is less, which can effectively improve the clarity of defect detection imaging;

[0113] (2) It makes up for the deficiency of empirical parameter adjustment in the prior art, enhances the applicability of the magneto-optical imaging integrated probe, and enables it to adapt to different working condition environments through precise parameter adjustment.

[0114] As described above, the above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claimed rights.

Claims

1. A method for self-adjusting parameters of a magneto-optical imaging integrated probe, wherein the method for self-adjusting parameters of the magneto-optical imaging integrated probe adopts the magneto-optical imaging integrated probe described below; The magneto-optical imaging integrated probe is composed of a linearly polarized light emitting unit, a linearly polarized light modulation unit, a linearly polarized light imaging unit and a clamping mechanism; The clamping mechanism is composed of an inner shell (7) and an outer shell (14); wherein: A linearly polarized light path is also provided between the inner housing (7) and the outer housing (14); The linearly polarized light emitting unit comprises an LED light source (1), a light guide plate (2) and a polarizer (3); wherein the LED light source (1) is fixedly mounted on the side wall of an inner shell (7); the light guide plate (2) is fixedly mounted inside the inner shell (7) and is used to modulate the light output by the LED light source (1) into parallel light in a horizontal direction; the polarizer (3) is fixedly mounted inside the inner shell (7) and is arranged perpendicular to the direction of the parallel light and is used to modulate the parallel light into linearly polarized light; The linear polarization light modulation unit comprises a magneto-optical sensor module (5), a beam splitter (6), a silicon steel yoke (8) and a neodymium iron boron magnet (9); wherein the magneto-optical sensor module (5) is fixedly installed inside an inner shell (7) directly below the linear polarization light path; the beam splitter (6) is fixedly installed inside the inner shell (7) and is used to reflect the linear polarization light modulated by the polarizer (3) to the position of the magneto-optical sensor module (5); the neodymium iron boron magnet (9) and the silicon steel yoke (8) are sequentially arranged and installed on the periphery of the linear polarization light path to form a closed magnetic field loop; The linear polarized light imaging unit comprises a camera (10), an analyzer (11), a camera driving board (12) and a Lemo connector (13); wherein the analyzer (11) is fixedly mounted on the top of an outer shell (14) directly above the linear polarized light path, and is used to receive linear polarized light modulated by a leakage magnetic field; the camera (10), the camera driving board (12) and the Lemo connector (13) are sequentially connected to the analyzer (11), and are used to convert the optical signal captured by the analyzer (11) into an electrical signal, and transmit the electrical signal to an external display device; It is characterized by comprising the following steps: Step 1: Obtain the maximum leakage magnetic field intensity at the defect of the test piece; The step 1 is specifically described as: Place the magneto-optical imaging integrated probe just above the defect of the test piece to stimulate the leakage magnetic field; Use a Tesla meter to measure the maximum leakage magnetic field intensity B at the defect of the test piece; Step 2: Construct a three-dimensional simulation model of the magneto-optical imaging integrated probe; Step 3: Setting the optical physical field for each geometric structure of the three-dimensional simulation model constructed in step 2; Step 4: Perform differential meshing on the three-dimensional simulation model processed in step 3; Step 5: setting scanning parameters for the three-dimensional simulation model processed in step 4, calculating the values ​​of various variables in the three-dimensional simulation model; and drawing a simulated magneto-optical image; Step six: Analyze the simulated magneto-optical image obtained in step five to determine the optimal value of each variable in the three-dimensional simulation model.

2. The method for self-adjusting parameters of a magneto-optical imaging integrated probe according to claim 1, characterized in that: The step 2 is specifically described as: A three-dimensional simulation model of a magneto-optical imaging integrated probe is constructed using a COMSOL model developer; wherein the constructed three-dimensional simulation model at least includes simulations of an LED light source (1), a polarizer (3), a magneto-optical film (501), a mirror coating (502), a beam splitter (6), a camera (10), an analyzer (11), and a simplified geometric structure of a light-blocking surface.

3. The method for self-adjusting parameters of a magneto-optical imaging integrated probe according to claim 1, characterized in that: The step three is specifically described as: The LED light source (1) is set to emit uniform non-polarized light based on the grid unit, and its light source power is set to W. Then the output light intensity I0 satisfies: (1) ; In the formula (1), l and b are respectively the length and width of the light-emitting surface of the LED light source (1); The polarizer (3), the magneto-optical film (501) and the analyzer (11) are set as linear polarizers, and the transmission axis of the polarizer (3) is defined as: (2) ; In formula (2), v p is the direction vector of the transmission axis of the polarizer (3), v px , v py and v pz They are v p The projection on the x-axis, y-axis and z-axis, c p is a constant, γ is v p The angle with the horizontal direction; after the parallel light passes through the polarizer (3), its light intensity becomes I0 / 2; The deflection angle θ of the linearly polarized light when passing through the magneto-optical film (501) satisfies: (3) ; In the formula (3), V is the Verdet constant, T is the thickness of the magneto-optical film (501); The transmission axis of the magneto-optical film (501) is defined as: (4) ; In formula (4), v m is the direction vector of the transmission axis of the magneto-optical film (501), v mx , v my and v mz They are v m The projection on the x-axis, y-axis and z-axis, c m is a constant; The transmission axis of the polarizer (11) is defined as: (5); In formula (5), v d is the direction vector of the transmission axis of the polarizer (11), v dx , v dy and v dz They are v d The projection on the x-axis, y-axis and z-axis, c d is a constant; The reflectivity of the beam splitter (6) is set to r, the transmittance is set to 1-r, and the reflection coefficient of the mirror coating (502) is set to 1. Then, after the linearly polarized light passes through the analyzer (11), its light intensity I D ,satisfy: (6).

4. The method for self-adjusting parameters of a magneto-optical imaging integrated probe according to claim 1, characterized in that: The step six is ​​specifically described as: Calculate the average grayscale of simulated magneto-optical image , the maximum gray value of the simulated magneto-optical image and the minimum gray value of the simulated magneto-optical image ; Among them, the average grayscale of the simulated magneto-optical image ,satisfy: (8) ; In formula (8), M and N represent the height and width of the simulated magneto-optical image, respectively. Represents pixel Gray value of Maximum grayscale value of simulated magneto-optical image ,satisfy: (9) ; Minimum gray value of simulated magneto-optical image ,satisfy: (10) ; Constructing the evaluation function ; Among them, the evaluation function ,satisfy: (11) ; Calculate the E value under different variable conditions; when the E value is the largest, the corresponding value of each variable in the three-dimensional simulation model is the optimal value.

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