Coil magnetic field enhancement method and system based on magnetic focusing array

Abstract

This invention relates to the field of magnetic field enhancement technology for electromagnetic nondestructive testing, and discloses a coil magnetic field enhancement method and system based on a magnetic focusing array. The method includes acquiring the geometric dimensions, material parameters, target uniformity index, target magnetic induction intensity, and power supply constraints of the target area; arranging coils according to the magnetic focusing array, the arrangement being determined based on the shape of the target object; connecting the coils using a connection method determination strategy; applying an excitation current to the magnetic focusing array based on initial excitation parameters; acquiring magnetic field data of the target area in real time; and adjusting the parameters corresponding to the excitation current based on the magnetic field data. This method improves the adaptability of the magnetic field to the detection scenario. Under power supply constraints, it achieves synergistic optimization of magnetic induction intensity and uniformity through connection topology selection and closed-loop parameter tuning, overcoming the problems of incomplete magnetic field coverage, energy waste, and insufficient detection accuracy in traditional technologies, thereby improving the reliability and efficiency of nondestructive testing.

Description

Technical Field

[0001] This invention relates to the field of magnetic field enhancement technology, and more specifically to a coil magnetic field enhancement method and system based on a magnetic focusing array. Background Technology

[0002] In the field of nondestructive testing (NDT), magnetic field-based testing technologies, such as electromagnetic induction testing, rely on stable, penetrating, and uniformly distributed magnetic fields to accurately identify internal defects in components. However, existing coil magnetic field systems have several limitations: traditional designs generally employ fixed arrangement structures, exciting coils only through simple series or parallel connections, resulting in poor adaptability of magnetic field characteristics to the testing scenario. For large components, the magnetic field coverage is insufficient, easily forming blind spots and affecting the completeness of defect identification; for small components, the magnetic field energy is excessively concentrated, causing energy waste and reducing testing efficiency. Furthermore, although magnetic focusing arrays have the potential for unilateral magnetic field enhancement, current technologies have failed to deeply integrate them with the physical parameters of the coils and the characteristics of the target object, resulting in limited improvement in magnetic induction intensity and difficulty in ensuring uniformity. In practical applications, this lack of adaptability often leads to problems such as decreased testing accuracy and increased repeatability, severely restricting the reliability and applicability of NDT technologies. Summary of the Invention

[0003] To address the aforementioned shortcomings of existing technologies, the present invention aims to provide a coil magnetic field enhancement method based on a magnetic focusing array, which has the advantages of improving magnetic induction intensity and uniformity, adapting to different detection scenarios, reducing energy waste, and improving detection accuracy and efficiency.

[0004] To achieve the above objectives, the present invention provides the following technical solution: A coil magnetic field enhancement method based on a magnetic focusing array, the method comprising: Obtain the geometric dimensions, material parameters, and target uniformity index U of the target region. tar Target magnetic induction intensity B tar and power supply constraints; The N coils are divided into M groups and arranged in a magnetic focusing array. N is determined based on the geometric dimensions of the target area and the effective coverage of a single coil, while M is determined based on power supply constraints, target uniformity requirements, and the total number of coils N. The arrangement method is determined based on the shape of the target object. Based on the geometric dimensions, material parameters, and target uniformity index U of the target area tar Target magnetic induction intensity B tar In addition to power supply constraints, a connection method determination strategy is adopted to connect the coils. The connection method determination strategy is used to determine the target connection method in the fully series connection method and the group series-inter-group parallel connection method.

[0005] Based on the characteristics of the target and the target uniformity index U tar Target magnetic induction intensity B tar Determine the initial excitation parameters, apply an excitation current to the magnetic focusing array based on the initial excitation parameters, collect magnetic field data of the target area in real time, and adjust the parameters corresponding to the excitation current according to the magnetic field data.

[0006] In this invention, preferably, the arrangement includes at least one of linear, rectangular, hexagonal, arc, and encircling shapes.

[0007] In this invention, preferably, the connection method determination strategy includes: Calculate the area S of the target region based on its geometric dimensions. Determine whether the area S of the target region is not less than the preset area threshold S. 0thre ; If the area S of the target region is not less than the preset area threshold S 0thre Then, further determine the target uniformity index U. tar Is it not greater than the preset uniformity index U? 0thre If yes, then the target connection method is determined to be a grouped series-inter-group parallel connection; if not, then the target magnetic induction intensity B is further determined. tar Is it not less than the preset magnetic flux density index B? 0thre ; If the target magnetic induction intensity B tar Not less than the preset magnetic induction intensity index B 0thre Then the target connection method is determined to be a fully series connection method; if the target magnetic induction intensity B tar Less than the preset magnetic induction intensity index B 0thre Then the target connection method is determined to be a grouped series-inter-group parallel connection method; If the area S of the target region is less than the preset area threshold S 0thre Then, further determine the target magnetic induction intensity B. tar Is it not less than the preset magnetic flux density index B? 0thre， If yes, then the target connection method is determined to be a fully cascaded connection method; if not, then the target uniformity index U is further determined. tar Is it not greater than the preset uniformity index U? 0thre ; If the target uniformity index U tar Is it not greater than the preset uniformity index U? 0thre Then the target connection method is determined to be a grouped series-inter-group parallel connection method, if the target uniformity index U tar Greater than the preset uniformity index U 0thre If so, the target connection method is determined to be a fully serial connection method; In this invention, preferably, the connection method determination strategy further includes: Configure switching unit; Real-time monitoring of the scene's magnetic field requirements; Determine if the current connection method meets the magnetic field requirements; If the connection method does not meet the magnetic field requirements, the series-parallel connection method between the coils is switched by the switching unit; Otherwise, maintain the current series-parallel connection method between the coils.

[0008] In this invention, preferably, the connection method of the coil includes a coil group series connection and parallel connection between groups and a coil fully series connection. The switching unit is used to switch the connection method of the coil between the coil group series connection and parallel connection between groups and the coil fully series connection.

[0009] In this invention, preferably, the target region magnetic field data includes magnetic induction intensity values ​​at multiple sampling points in the target region, and the real-time acquisition of the target region magnetic field data and adjustment of the parameters corresponding to the excitation current based on the magnetic field data includes: The actual magnetic induction intensity B of multiple sampling points in the target area was collected. i实 , i≥1; According to the actual magnetic induction intensity B i实 Calculate the average magnetic flux density B ave And calculate the uniformity index U based on the set of sampling points; If the average magnetic induction intensity B ave With the target magnetic induction intensity B tar If the difference exceeds the preset magnetic induction intensity, the amplitude A of the excitation current is adjusted. If the uniformity index U is the same as the target uniformity index U tar The difference exceeds the preset uniformity threshold U thre In this case, it is preferable to switch the connection method of the coil and / or adjust the grouping parameter M to improve the uniformity of magnetic induction intensity distribution in the target area.

[0010] In this invention, preferably, the real-time acquisition of magnetic field data of the target area and the adjustment of the parameters corresponding to the excitation current based on the magnetic field data further include: If the average magnetic induction intensity B ave With the target magnetic induction intensity B tar The difference did not exceed the preset magnetic induction intensity threshold B thre And the uniformity index U is the same as the target uniformity index U. tar The difference did not exceed the preset uniformity threshold U threAt that time, the need for surface or deep action is determined according to the magnetic field requirements. If it is surface action, the excitation frequency of the excitation current is increased to concentrate the magnetic field on the object surface by utilizing the skin effect. If it is deep action, the excitation frequency of the excitation current is decreased to reduce the eddy current shielding effect and increase the magnetic field penetration depth.

[0011] In this invention, preferably, the diameter and length of the coil are matched with the size of the object being acted upon.

[0012] In this invention, preferably, the characteristics of the target object include magnetic permeability, electrical conductivity, and thickness, and the initial excitation parameters include excitation current amplitude and excitation frequency, based on the characteristics of the target object and the target uniformity index U. tar Target magnetic induction intensity B tar Determine the initial excitation parameters: Based on the aforementioned material parameters, thickness, target depth of action, and target uniformity index U tar Target magnetic induction intensity B tar Consult the preset parameter mapping table or call the simulation calibration model to determine the initial excitation parameters.

[0013] A coil magnetic field enhancement system based on a magnetic focusing array, the system comprising: Parameter acquisition module: used to acquire the geometric dimensions, material parameters, and target uniformity index U of the object under action. tar Target magnetic induction intensity B tar and power supply constraints; The determination module is used to determine N based on the geometric dimensions of the target area and the effective coverage size of a single coil; to determine the grouping parameters M based on power supply constraints, target uniformity requirements, and the total number of coils N; and to determine the arrangement of the coil magnetic focusing array based on the shape of the target object. The connection module is used to determine the geometric dimensions, material parameters, and target uniformity index U of the target area. tar Target magnetic induction intensity B tar In addition to power supply constraints, a connection method determination strategy is adopted to connect the coils. The connection method determination strategy is used to determine the target connection method in the fully series connection method and the group series-inter-group parallel connection method. The adjustment module is used to determine the initial excitation parameters based on the characteristics of the target object; The driving module is used to generate a controlled time-varying excitation current based on the initial excitation parameters; The magnetic field acquisition module is used to acquire multi-point magnetic induction intensity data of the target area through a magnetic sensor array after the time-varying excitation current is applied to the magnetic focusing array. The adjustment module is also used to adjust the parameters corresponding to the time-varying excitation current based on the magnetic field data.

[0014] Compared with the prior art, the beneficial effects of the present invention are: The method of this invention arranges N coils in a magnetic focusing array that matches the shape of the target object, and determines the target area's geometric dimensions, material parameters, and target uniformity index U. tar Target magnetic induction intensity B tar In addition to power supply constraints, a connection method is used to determine the connection strategy for the coils, effectively improving the adaptability of the magnetic field to the detection scenario. Simultaneously, by applying excitation current to the magnetic focusing array based on initial excitation parameters, real-time magnetic field data of the target area is collected, and the parameters corresponding to the excitation current are adjusted according to the magnetic field data. This improves the adaptability of the magnetic field to the detection scenario. Under power supply constraints, the coordinated optimization of magnetic induction intensity and uniformity is achieved through connection topology selection and closed-loop parameter tuning, overcoming the problems of incomplete magnetic field coverage, energy waste, and insufficient detection accuracy in traditional technologies, thus improving the reliability and efficiency of non-destructive testing. Attached Figure Description

[0015] Figure 1 This is a schematic flowchart of a coil magnetic field enhancement method based on a magnetic focusing array according to the present invention.

[0016] Figure 2 This is a schematic diagram of the coil arrangement described in this invention.

[0017] Figure 3 This is a flowchart illustrating the connection method determination strategy in a preferred embodiment of the present invention.

[0018] Figure 4 This is a flowchart illustrating the connection method determination strategy in another preferred embodiment of the present invention.

[0019] Figure 5 This is a flowchart illustrating the process of adjusting the parameters corresponding to the applied excitation current in a preferred embodiment of the present invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] Please see Figure 1 A preferred embodiment of the present invention provides a coil magnetic field enhancement method based on a magnetic focusing array, the method comprising: S1. Obtain the geometric dimensions, material parameters, and target uniformity index U of the target area. tar Target magnetic induction intensity B tar And power supply constraints.

[0023] S2. Divide the N coils into M groups and arrange them according to the magnetic focusing array. The arrangement method is determined according to the shape of the target object. N is determined according to the geometric size parameters of the target area and the effective coverage size of a single coil, and M is determined according to the power supply constraints, target uniformity requirements and the total number of coils N.

[0024] S3. Based on the geometric dimensions, material parameters, and target uniformity index U of the target area. tar Target magnetic induction intensity B tar In addition to power supply constraints, a connection method determination strategy is adopted to connect the coils. The connection method determination strategy is used to determine the target connection method in the fully series connection method and the group series-inter-group parallel connection method.

[0025] S4. Based on the characteristics of the target and the target uniformity index U tar Target magnetic induction intensity B tar Determine the initial excitation parameters, apply an excitation current to the magnetic focusing array based on the initial excitation parameters, collect magnetic field data of the target area in real time, and adjust the parameters corresponding to the excitation current according to the magnetic field data.

[0026] The geometric dimensions of the target area are obtained to participate in the calculation of other parameters. These parameters can be determined in various ways. For example, image recognition technology can be used to scan and analyze the target object to obtain precise dimensional information of the target area; alternatively, they can be obtained through preset parameters, manual user input, or sensor measurement. A magnetic focusing array refers to a coil combination that uses a specific arrangement to superimpose and enhance the magnetic field generated by multiple coils within a specific region, thereby forming a focusing effect. This array can achieve unilateral enhancement of the magnetic field or form a high-intensity, highly uniform magnetic field within a specific region. The initial excitation parameters are the driving parameters P0, pre-set based on the known characteristics of the target object, when the magnetic field enhancement method is started. P0 = {amplitude A0, frequency f0}. These parameters serve as the starting point for system operation, used to generate an initial magnetic field, and can be adjusted subsequently based on real-time feedback. The excitation current refers to the controlled time-varying current output by the drive module, which is supplied to the magnetic focusing array coils. It is preferably a pulsed square wave / rectangular pulse or alternating current, and its amplitude and pulse waveform parameters (pulse width, rise time, repetition frequency) and / or AC frequency affect the magnetic induction intensity and depth of action. Magnetic field uniformity is preferably achieved by switching the coil connection topology and / or adjusting the grouping parameter M. Target area magnetic field data refers to the magnetic field-related information collected in real time within the target area under the action of the magnetic focusing array. This data can include magnetic induction intensity, magnetic field uniformity, magnetic field direction, etc., and is used to assess the current magnetic field state and guide subsequent parameter adjustments.

[0027] Specifically, N coils are arranged in a magnetic focusing array, the arrangement of which is determined by the shape of the object being acted upon. For example, for an object with a long and slender shape, the coils can be arranged in a linear array extending along its length. For an object with a large flat surface, the coils can be arranged in a linear, rectangular, or hexagonal grid array to cover the entire plane when moved. For an object with a cylindrical or ring-shaped shape, the coils can be arranged in an arc or encircling array to accommodate its curved surface structure. In this way, the geometric layout of the coil array can be matched with the physical shape of the object being acted upon, thereby optimizing the distribution and focusing effect of the magnetic field in the target area.

[0028] Based on the geometric dimensions, material parameters, and target uniformity index U of the target area tar Target magnetic induction intensity B tarIn addition to power supply constraints, a connection method determination strategy is adopted to connect the coils. This strategy determines the target connection method between a fully series connection and a grouped series-inter-group parallel connection. For example, given power supply constraints, single coil impedance parameters, and target magnetic field parameters, a choice can be made between a fully series connection and a grouped series-inter-group parallel connection. For scenarios with a small target area and high local magnetic induction intensity requirements, a fully series connection is preferred; for scenarios with a large target area and high uniformity requirements, a grouped series-inter-group parallel connection is preferred to expand the magnetic field coverage and improve the uniformity of magnetic induction intensity distribution within the target area, combined with array arrangement. In a preferred embodiment, the driving power supply is a constant current source and the parameters of each branch are basically the same. In this case, a fully series connection is more conducive to increasing the single coil current, while a grouped series-inter-group parallel connection is more conducive to large area coverage.

[0029] Based on the characteristics of the target and the target uniformity index U tar Target magnetic induction intensity B tar Determine the initial excitation parameters. The characteristics of the target object can include its material type, size, geometry, or operating temperature. For example, for materials with high permeability, different initial excitation current values ​​are required to achieve the target magnetic flux density. For targets with thick walls, a higher initial excitation frequency may be needed to ensure the magnetic field penetration depth. After determining the initial excitation parameters, an excitation current is applied to the magnetic focusing array according to these parameters. After the excitation current is applied, magnetic field data of the target area is acquired in real time. This magnetic field data can be obtained by magnetic sensors placed within the target area, for example, measuring the magnetic flux density and magnetic field direction, and calculating a uniformity index based on the measured magnetic flux density. Subsequently, the parameters corresponding to the excitation current are adjusted based on the acquired magnetic field data. For example, if the acquired magnetic flux density is lower than the expected target value, the amplitude of the excitation current can be increased. If the magnetic field uniformity does not meet the requirements, the coil connection topology can be switched and / or the grouping parameter M can be adjusted. Adjustments to the pulse waveform parameters can also be made to compensate for and optimize the magnetic field distribution, ensuring that the required intensity and uniformity of the magnetic field are obtained within the target area.

[0030] Please see Figure 2In a preferred embodiment, the arrangement includes at least one of linear, rectangular, hexagonal, arc-shaped, and spiral arrangements. The appropriate coil arrangement is selected based on the shape of the object being acted upon. For example, for planar objects, such as flat plate components, a linear or rectangular arrangement can be used; for columnar objects, such as pipes and shafts, polygonal arrangements, such as hexagonal or octagonal arrangements, are often used; for specific local areas, such as welds or joints, an arc-shaped coil arrangement is used; and for spherical objects or objects requiring magnetic fields to be applied from multiple directions, a closed or semi-closed spiral arrangement is used. By providing various specific coil arrangement methods, the coils of the magnetic focusing array can adapt to objects of different shapes. The introduction of linear, rectangular, hexagonal, arc-shaped, and spiral arrangements allows for the selection of the most suitable arrangement structure based on the actual geometry of the object and the required magnetic field when arranging N coils in a magnetic focusing array. This not only improves the coverage and uniformity of the magnetic field on the target object, avoiding magnetic field blind spots or energy waste caused by improper arrangement, but also enables more effective magnetic field focusing and enhancement, thereby improving the efficiency and effectiveness of the entire magnetic field enhancement method.

[0031] Please see Figure 3 In a preferred embodiment, the connection method determination strategy includes: S11. Calculate the area S of the target region based on the geometric dimensions of the target region; S12. Determine whether the area S of the target region is not less than the preset area threshold S. 0thre ; S13. If the target area S is not less than the preset area threshold S 0thre Then, further determine the target uniformity index U. tar Is it not greater than the preset uniformity index U? 0thre ; S14. If yes, then the target connection method is determined to be a grouped series-inter-group parallel connection method; if not, then the target magnetic induction intensity B is further determined. tar Is it not less than the preset magnetic flux density index B? 0thre ; S15, if the target magnetic induction intensity B tar Not less than the preset magnetic induction intensity index B 0thre Then the target connection method is determined to be a fully series connection method; if the target magnetic induction intensity B tar Less than the preset magnetic induction intensity index B 0thre Then the target connection method is determined to be a grouped series-inter-group parallel connection method; S16. If the target area S is less than the preset area threshold S 0thre Then, further determine the target magnetic induction intensity B.tar Is it not less than the preset magnetic flux density index B? 0thre ; S17. If yes, then determine that the target connection method is a fully series connection method; if not, then further determine the target uniformity index U. tar Is it not greater than the preset uniformity index U? 0thre ; S18, If the target uniformity index U tar Not greater than the preset uniformity index U 0thre Then the target connection method is determined to be a grouped series-inter-group parallel connection method, if the target uniformity index U tar Greater than the preset uniformity index U 0thre If so, the target connection method is determined to be a fully serial connection method; Specifically, when implementing this connection method determination strategy, the target area must first be calculated based on the acquired geometric parameters. After obtaining the area, the process proceeds to the judgment process. The preset area threshold in the process is pre-set or dynamically adjusted according to the specific application scenario, the required magnetic field characteristics, and the physical characteristics of the coil array. For example, this threshold can be determined based on empirical values, simulation results, or experimental data to distinguish between scenarios requiring wide-area coverage and scenarios requiring high-intensity focusing. This judgment process is typically completed by the controller or processing unit performing logical comparison operations.

[0032] Determine whether the area S of the target region is not less than the preset area threshold S. 0thre ; If so, then further determine the target uniformity index U. tar Is it not greater than the preset uniformity index U? 0thre , If yes, then the target connection method is determined to be a grouped series-inter-group parallel connection; if not, then the target magnetic induction intensity B is further determined. tar Is it not less than the preset magnetic flux density index B? 0thre ; If yes, then the target connection method is determined to be a fully series connection; if not, then the target connection method is determined to be a grouped series-inter-group parallel connection. If not, then further determine the target magnetic induction intensity B. tar Is it not less than the preset magnetic flux density index B? 0thre ; If yes, then the target connection method is determined to be a fully cascaded connection method; if not, then the target uniformity index U is further determined. tar Is it not greater than the preset uniformity index U? 0thre ; If yes, then the target connection method is determined to be a grouped series-inter-group parallel connection method; otherwise, the target connection method is determined to be a fully series connection method. The series and parallel connection of the coils is dynamically adjusted according to the target area of ​​the object, thereby optimizing the magnetic field distribution. When the target area is large, given the power supply constraints, single coil impedance parameters, and target magnetic field specifications, using a grouped series connection with parallel connections between groups can provide a wider magnetic field coverage and better uniformity. When the target area is small, using a fully series connection can achieve higher magnetic induction intensity and more precise focusing effect. This adaptive connection strategy enables the magnetic focusing array to more efficiently and accurately meet the magnetic field enhancement needs of target areas of different sizes, improves energy utilization efficiency, and ensures that the magnetic field can accurately act on the target object, thus significantly improving the overall performance and applicability of the magnetic field enhancement method.

[0033] Please see Figure 4 In a preferred embodiment, the connection method determination strategy further includes: S19, Configuration switching unit; S20, Real-time monitoring of scene magnetic field requirements; S21. Determine whether the current connection method meets the magnetic field requirements; S22. If the connection method does not meet the magnetic field requirements, the series-parallel connection method between the coils is switched by the switching unit; otherwise, the current series-parallel connection method between the coils is maintained.

[0034] Specifically, a switching unit is an electrical device used to change the circuit connection state. It can be composed of relays, solid-state switches, or semiconductor devices, and is configured to physically switch the series or parallel connection of N coils according to control commands, such as a switching unit consisting of a PLC controller and relay switches. For example, when switching from a fully series mode to a grouped series-parallel mode, the switching unit will correspondingly close or open specific circuit paths to reconfigure the coil connection method. The real-time monitoring of the scene's magnetic field requirements refers to continuously acquiring the target uniformity index U through sensors. tar Target magnetic induction intensity B tar Alternatively, it can receive instructions from an external control system to understand the required magnetic field strength, uniformity, or depth of action for the current application. This requirement data reflects real-time changes in the target object or application scenario. Whether the current connection method meets the magnetic field requirements is determined by comparing the currently monitored magnetic field requirements with preset values ​​or the actual magnetic field parameters from the previous moment. If a difference exists between the two, and this difference exceeds a preset threshold, the current connection method is deemed not to meet the magnetic field requirements. This judgment process is typically completed by a control module with a built-in logical judgment algorithm capable of identifying trends or patterns in magnetic field requirements.

[0035] When magnetic field requirements change, the strategy of determining the connection method allows for timely judgment and dynamic adjustment of the series and parallel connections of the coils using switching units. This enables the magnetic focusing array to move beyond a single fixed connection mode and flexibly switch according to actual operating conditions, providing optimal or near-optimal magnetic field enhancement effects under different magnetic field ranges and intensity requirements. For example, one connection method can be used when a large-scale uniform magnetic field is needed, while another connection method can be switched when a high-intensity local magnetic field is required. This dynamic adaptability significantly improves the system's versatility, flexibility, and energy efficiency, ensuring the continued effectiveness of the magnetic field enhancement method in diverse application scenarios and avoiding performance degradation or resource waste caused by changes in requirements.

[0036] In a preferred embodiment, the coil connection method includes a coil group series connection and parallel connection between groups and a coil fully series connection. The switching unit is used to switch the coil connection method between the coil group series connection and parallel connection between groups and the coil fully series connection.

[0037] Specifically, the coil grouping and parallel connection method refers to dividing N coils into M branches, with several coils within each branch connected in series sequentially, and different branches connected in parallel. This connection method is suitable for scenarios with a large target area and high requirements for the uniformity of magnetic induction intensity distribution. Given power supply constraints, single coil impedance parameters, and target magnetic induction intensity and uniformity indicators, this connection method, combined with the spatial arrangement of the magnetic focusing array, can expand the magnetic field coverage of the target area and improve the uniformity of magnetic induction intensity distribution within the target area. The value of M can be determined based on the total number of coils N, the geometric dimensions of the target area, the target uniformity indicators, and the output capability of the drive module.

[0038] A fully series connection refers to connecting N coils end-to-end to form a single loop. This connection method is suitable for scenarios with a small target area and high local magnetic flux density requirements. Given power supply constraints, single-coil impedance parameters, and target magnetic field specifications, a fully series connection helps ensure consistent current flow through each coil and creates a more concentrated magnetic flux density distribution within a smaller target area. Due to the relatively large total series impedance, the drive module preferably provides an output voltage that matches it. This connection method is preferred for applications such as local re-inspection and precise defect location.

[0039] The aforementioned switching unit is used to switch between preset connection methods. This switching unit can be composed of a relay, a solid-state switch, or a combination thereof, and changes the electrical connection topology of the coil under the instruction of the control module. Preferably, the switching action occurs between different detection stages and / or when the average magnetic flux density or uniformity index of the target area does not meet preset requirements. For example, in the full-area scanning stage, a grouped series connection with parallel connections between groups can be used to balance coverage and uniformity; in the local re-inspection or defect location stage, a fully series connection can be switched to improve the magnetic flux density of the local target area.

[0040] By using preset and switchable connection methods, the system avoids arbitrary topology reconstruction for each change in operating conditions. Instead, it selects from a limited pool of candidate connection methods, thereby improving control feasibility, response efficiency, and adaptability to different nondestructive testing scenarios. The system can select the appropriate connection method based on the geometry, material parameters, target magnetic induction intensity, and uniformity requirements of the object being tested, to optimize the magnetic field enhancement effect and improve detection reliability.

[0041] Please see Figure 5 In a preferred embodiment, the target region magnetic field data includes magnetic induction intensity B and uniformity index U. The real-time acquisition of the target region magnetic field data and the adjustment of parameters corresponding to the excitation current based on the magnetic field data include: The actual magnetic induction intensity B of multiple sampling points in the target area was collected. i实 , i≥1; According to the actual magnetic induction intensity B i实 Calculate the average magnetic flux density B ave And calculate the uniformity index U based on the set of sampling points; If the average magnetic induction intensity B ave With the target magnetic induction intensity B tar The difference exceeds the preset magnetic induction intensity threshold B thre Then adjust the amplitude A of the excitation current; If the uniformity index U is the same as the target uniformity index U tar The difference exceeds the preset uniformity threshold U thre In this case, it is preferable to switch the connection method of the coil and / or adjust the grouping parameter M to improve the uniformity of magnetic induction intensity distribution in the target area.

[0042] Specifically, magnetic flux density (B) is a physical quantity that measures the strength of a magnetic field, while the uniformity index (U) is used to assess the uniformity of the magnetic field distribution within a target area. The actual magnetic flux density (B) is collected from multiple sampling points in the target area. i实This forms the basis for magnetic field manipulation. Multiple magnetic field sensors can be deployed within the target area, measuring the magnetic flux density at various points in real-time or near real-time. The system processes this measurement data to calculate the average magnetic flux density B of the target area. ave As the actual magnetic induction intensity, and based on the magnetic induction intensity B at each point i实 With average B ave The deviation is used to calculate the actual uniformity U. For example, the standard deviation of the magnetic flux density B within the target area can be calculated and compared with the average magnetic flux density B. ave A comparison is made to obtain the actual uniformity index. This collected data will serve as the basis for subsequent adjustments to the excitation current parameters. When the actual magnetic flux density reaches or exceeds the preset target magnetic flux density, it indicates that the current excitation current may be too large or already sufficient. At this point, the excitation current needs to be adjusted. Adjustment methods may include reducing the amplitude of the excitation current to avoid energy waste or causing unnecessary excessive magnetic field effects on the target object. Specific adjustment algorithms can employ PID controllers or other closed-loop control strategies, based on the actual magnetic flux density B. ave With the target magnetic induction intensity B tar The difference between the actual uniformity and the target uniformity index U is used to dynamically adjust the output of the excitation current. When the actual uniformity fails to meet the preset requirements, i.e., when the uniformity index U < the target ... tar The difference exceeds the preset uniformity threshold U thre This indicates a non-uniform magnetic field distribution, requiring fine-tuning. At this point, the system analyzes and identifies weak magnetic field regions with relatively low magnetic flux density within the target area based on data collected by each magnetic field sensor. Once the weak magnetic field region is located, it determines which coils contribute most significantly to the magnetic field in that region. Subsequently, by switching the coil connection topology and / or adjusting the grouping parameter M, and possibly by adjusting the excitation amplitude A or pulse waveform parameters for compensation optimization, the superposition effect of the magnetic fields generated by these coils in the weak magnetic field region is altered, thereby specifically enhancing the magnetic flux density in that region and improving the overall magnetic field uniformity of the target area. For example, by adjusting the grouping parameter M, its magnetic field can form constructive interference with the magnetic fields of adjacent coils in the weak magnetic field region, locally enhancing the magnetic field and thus improving overall uniformity.

[0043] By monitoring multiple magnetic induction intensities and calculating their uniformity, targeted adjustments can be made based on the actual conditions of both, avoiding the limitations that may arise from adjusting a single indicator. When the magnetic induction intensity meets the standard, unnecessary energy consumption can be avoided; when the magnetic field uniformity does not meet the standard, by switching the coil connection topology and / or adjusting the grouping parameter M, and supplemented by adjusting the excitation amplitude A or pulse waveform parameters, local optimization of the magnetic field distribution can be achieved, effectively improving the overall uniformity of the magnetic field. This ensures that the target object receives a stable and consistent magnetic field, improving the efficiency and effect of magnetic field enhancement, and is especially suitable for applications with strict requirements on magnetic field distribution.

[0044] In a preferred embodiment, the real-time acquisition of magnetic field data of the target area and the adjustment of the parameters corresponding to the excitation current based on the magnetic field data further include: If the average magnetic induction intensity B ave With the target magnetic induction intensity B tar The difference did not exceed the preset magnetic induction intensity threshold B thre And the uniformity index U is the same as the target uniformity index U. tar The difference did not exceed the preset uniformity threshold U thre At that time, the need for surface or deep action is determined according to the magnetic field requirements. If it is surface action, the excitation frequency of the excitation current is increased to concentrate the magnetic field on the object surface by utilizing the skin effect. If it is deep action, the excitation frequency of the excitation current is decreased to reduce the eddy current shielding effect and increase the magnetic field penetration depth.

[0045] Specifically, magnetic field requirements include the depth of magnetic field application required for the specific application scenario. For example, for surface defect detection, a surface-level effect is needed, requiring a high-frequency excitation current, thus necessitating an increased excitation current frequency. Conversely, for deep defect detection, a deep-level effect is required, corresponding to a low-frequency excitation current. When the actual magnetic induction intensity and uniformity of the target area meet the standards, the system can intelligently determine whether a surface or deep-level effect is needed based on the specific magnetic field depth. By appropriately increasing or decreasing the excitation frequency of the excitation current, the penetration depth and range of the magnetic field can be precisely controlled. This allows the magnetic field enhancement method to better adapt to the differentiated requirements for magnetic field depth in different application scenarios, avoiding the limitations of a single adjustment method. This significantly improves the targeting and effectiveness of magnetic field enhancement, ensuring that magnetic field energy can more efficiently act on a specific depth in the target area, thus optimizing the overall magnetic field enhancement effect.

[0046] In a preferred embodiment, the diameter and length of the coil are matched to the dimensions of the target object. The coil diameter refers to the cross-sectional dimension of a single coil constituting the magnetic focusing array. The choice of coil diameter directly affects the spatial distribution and penetration depth of the magnetic field it generates. A larger coil diameter can produce a wider magnetic field coverage, but may lead to decreased magnetic field uniformity or weakened focusing ability; a smaller coil diameter is beneficial for achieving finer magnetic field focusing, but the coverage is limited. The coil length refers to the axial dimension of a single coil, and for multi-turn coils, it typically refers to the axial length of the coil winding. The coil length affects the axial distribution and intensity of the magnetic field. Longer coils generally produce a more uniform axial magnetic field and may increase the penetration depth of the magnetic field; shorter coils may produce a more concentrated magnetic field in a specific area. The dimensions of the target object refer to the geometric size of the physical target object to be subjected to magnetic field enhancement treatment, such as its width, height, and depth. The dimensions of the target object are a key factor in determining the required magnetic field range, penetration depth, and uniformity. Matching means that the diameter and length of the coil should be optimized and selected according to the specific dimensions of the target object. The purpose of this matching is to ensure that the magnetic field generated by the magnetic focusing array can efficiently and accurately cover the target object, achieving the expected magnetic induction intensity and uniformity requirements. For example, for larger targets, coils with larger diameters and lengths may be needed to ensure sufficient magnetic field coverage and penetration; for smaller targets or those requiring fine focusing, coils with smaller diameters and lengths may be needed to achieve more precise magnetic field application. The matching process typically involves electromagnetic field simulation and experimental verification to determine the optimal coil geometry. Matching avoids magnetic field overflow or insufficient coverage caused by improper coil size, reduces energy loss, and ensures the accuracy and uniformity of the magnetic field application, thereby optimizing the performance of the entire magnetic field enhancement method.

[0047] In a preferred embodiment, the characteristics of the target object include magnetic permeability, electrical conductivity, and thickness; the initial excitation parameters include excitation current amplitude and excitation frequency; and the excitation parameters are determined based on the characteristics of the target object and the target uniformity index U. tar Target magnetic induction intensity B tar Determine the initial excitation parameters: Based on the aforementioned material parameters, thickness, target depth of action, and target uniformity index U tar Target magnetic induction intensity B tar Consult the preset parameter mapping table or call the simulation calibration model to determine the initial excitation parameters.

[0048] Specifically, the target depth can be selected based on three key characteristics of the target object: magnetic permeability, electrical conductivity, and thickness. Simultaneously, the target uniformity index U... tar Target magnetic induction intensity Btar The initial excitation parameters are determined by consulting a pre-defined parameter mapping table or calling a simulation calibration model. This not only meets the requirements for magnetic field enhancement but also effectively avoids unnecessary energy waste and potential oversaturation effects on the target object. This refined method of determining initial excitation parameters based on the characteristics of the target object significantly improves the adaptability of the magnetic field enhancement process, ensuring optimal magnetic field enhancement effects in different application scenarios. It also optimizes the system's energy efficiency ratio and extends the service life of both the equipment and the target object.

[0049] In one specific embodiment, when the magnetic field requirement is for circumferential weld inspection of a metal pipe, both circumferential coverage and local defect localization are needed. In this case, the coils are arranged in a hexagonal surround array with 16 coils (N) to enhance the circumferential coverage of the pipe weld. The coil diameter is determined based on the pipe's outer diameter to ensure a suitable fit and full magnetic field coverage of the weld area. When circumferential scanning begins, a series connection within a group and a parallel connection of components are used. The 16 coils are divided into 4 groups, with 4 coils in each group connected in series and the 4 groups connected in parallel to achieve full circumferential weld coverage, and a predetermined initial excitation current is applied. When entering the defect localization stage, the switching unit switches to a connection where all 16 coils are connected in series to increase the magnetic induction intensity in the defect area. Since the metal pipe is made of high-permeability steel, the excitation frequency is increased for the surface layer during circumferential scanning and decreased for the deeper layer during defect localization. For the weakened magnetic areas at the weld corners, the coil grouping parameters at the corresponding positions are adjusted to eliminate detection blind spots.

[0050] In one specific embodiment, when the magnetic field requirement is to detect deep inclusion defects inside an alloy plate of length L and width W, the required magnetic field penetration depth must be greater than the depth corresponding to the inclusion defects. The coils are arranged in a rectangular pattern, uniformly distributed along the length of the alloy plate, with the enhanced side facing the plate's detection surface to avoid edge magnetic field attenuation. During the full-area scanning phase, multiple coils are divided into several groups, connected in series within groups and in parallel between groups, to first complete the defect detection across the entire plate area. When entering the defect localization phase, if an abnormal magnetic field is detected in the central region of the plate, the connection is switched to a series connection of all coils, and the magnetic induction intensity is increased to enhance the deep defect signal. When the plate thickness exceeds a critical thickness constant, due to the deep defects, a deeper effect is required. A low-frequency excitation current frequency is used to cover the wall thickness of the alloy plate using the high penetration of the low frequency, thus avoiding signal attenuation.

[0051] In another specific embodiment, the magnetic field requirement is for an alloy shaft component with a diameter of D2 and a length of L2, where surface cracks at the shoulder transition need to be detected. In this case, an arc-shaped coil is used, with the chord length corresponding to the arc-shaped coil being twice the estimated maximum crack length constant to ensure magnetic field concentration in the crack area. During the global scanning phase, multiple coils are divided into multiple groups, with the coils connected in series within each group and in parallel between groups to complete the global scanning of the shaft circumference. During the defect localization phase, when a sudden change in the magnetic field at the shoulder is detected, the system switches to a fully series mode to increase the local magnetic induction intensity for precise crack localization.

[0052] Another preferred embodiment of the present invention provides a coil magnetic field enhancement system based on a magnetic focusing array, the system comprising: a parameter acquisition module for acquiring the geometric dimensional parameters, material parameters, and target uniformity index U of the target object. tar Target magnetic induction intensity B tar The module determines the power supply constraints; it also determines the N based on the geometric dimensions of the target area and the effective coverage size of a single coil, and the M based on the power supply constraints, target uniformity requirements, and the total number of coils N; it further determines the arrangement of the N coil magnetic focusing array based on the shape of the target object; and it connects the modules based on the geometric dimensions, material parameters, and target uniformity index U of the target area. tar Target magnetic induction intensity B tar In addition to power supply constraints, a connection method determination strategy is adopted to connect the coils. This strategy is used to determine the target connection method among a fully series connection method and a grouped series-inter-group parallel connection method. A driving module is used to generate a controlled time-varying excitation current; a magnetic field acquisition module is used to acquire multi-point magnetic induction intensity data of the target area through a magnetic sensor array. The parameter acquisition module acquires the geometric dimensions, material parameters, and target uniformity index U of the target object. tar Target magnetic induction intensity B tar The system incorporates power supply constraints to provide a foundation for subsequent parameter calls; the determination module ensures that the coil array shape matches the shape of the target object, for example, using a ring-shaped arrangement for cylindrical components to adapt to curved surfaces; the connection module flexibly judges various parameters through connection method determination strategies and intelligently switches between different connection methods; the adjustment module sets differentiated initial excitation currents based on permeability and thickness parameters, and adjusts the excitation parameters through real-time feedback closed-loop to ensure that the magnetic field data always meets the target requirements. Overall, this system, through modular collaborative design, achieves dynamic adaptation of magnetic field characteristics to the detection scenario, significantly improving the reliability and efficiency of nondestructive testing.

[0053] In some other preferred embodiments of the present invention, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, causes the processor to perform the steps of the method as described in the above embodiments.

[0054] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0055] The above description is a detailed description of the preferred embodiments of the present invention. However, the embodiments are not intended to limit the scope of the patent application of the present invention. All equivalent changes or modifications made under the technical spirit of the present invention should fall within the patent scope covered by the present invention.

Claims

1. A method for enhancing the magnetic field of a coil based on a magnetic focusing array, characterized in that, The method includes: Obtain the geometric dimensions, material parameters, target uniformity index, target magnetic induction intensity, and power supply constraints of the target region; Divide the N coils into M groups and arrange them according to the magnetic focusing array. The arrangement method is determined according to the shape of the object being acted upon. Based on the geometric dimensions, material parameters, target uniformity index, target magnetic induction intensity, and power supply constraints of the target area, a connection method determination strategy is adopted to connect the coils. The connection method determination strategy is used to determine the target connection method between a fully series connection method and a group series-inter-group parallel connection method. The initial excitation parameters are determined based on the characteristics of the target object, the target uniformity index, and the target magnetic induction intensity. An excitation current is then applied to the magnetic focusing array based on the initial excitation parameters. Magnetic field data of the target area is collected in real time, and the parameters corresponding to the excitation current are adjusted based on the magnetic field data.

2. The coil magnetic field enhancement method based on a magnetic focusing array according to claim 1, characterized in that, The N is determined based on the geometric dimensions of the target area and the effective coverage size of a single coil, while the M is determined based on power supply constraints, target uniformity requirements, and the total number of coils N. The arrangement includes at least one of the following: linear, rectangular, hexagonal, arc, and encircling.

3. The coil magnetic field enhancement method based on a magnetic focusing array according to claim 2, characterized in that, The connection method determination strategy includes: Calculate the area of ​​the target region based on its geometric dimensions. Determine whether the area of ​​the target region is not less than a preset area threshold. ， If the target area is not less than a preset area threshold, then it is determined whether the target uniformity index is not greater than a preset uniformity index. If so, the target connection method is determined to be a grouped series-inter-group parallel connection method; otherwise, it is determined whether the target magnetic induction intensity is not less than a preset magnetic induction intensity index. If the target magnetic flux density is not less than the preset magnetic flux density index, the target connection method is determined to be a fully series connection method; if the target magnetic flux density is less than the preset magnetic flux density index, the target connection method is determined to be a grouped series-inter-group parallel connection method. If the target area is smaller than a preset area threshold, then determine whether the target magnetic induction intensity is not less than a preset magnetic induction intensity index. ， If yes, then the target connection method is determined to be a fully serial connection method; if not, then it is further determined whether the target uniformity index is not greater than the preset uniformity index. If the target uniformity index is not greater than the preset uniformity index, the target connection method is determined to be a grouped series-inter-group parallel connection method. If the target uniformity index is greater than the preset uniformity index, the target connection method is determined to be a fully series connection method.

4. The coil magnetic field enhancement method based on a magnetic focusing array according to claim 1, characterized in that, The connection method determination strategy also includes: Configure switching unit; Real-time monitoring of the scene's magnetic field requirements; Determine if the current connection method meets the magnetic field requirements; If the connection method does not meet the magnetic field requirements, the series-parallel connection method between the coils is switched by the switching unit; Otherwise, maintain the current series-parallel connection method between the coils.

5. The coil magnetic field enhancement method based on a magnetic focusing array according to claim 4, characterized in that, The coil connection methods include coil group series connection and parallel connection between groups and coil full series connection. The switching unit is used to switch the coil connection method between coil group series connection and parallel connection between groups and coil full series connection.

6. The coil magnetic field enhancement method based on a magnetic focusing array according to claim 1, characterized in that, The target region magnetic field data includes the magnetic induction intensity values ​​of multiple sampling points in the target region. The real-time acquisition of the target region magnetic field data and the adjustment of the parameters corresponding to the excitation current based on the magnetic field data include: Collect the actual magnetic induction intensity at multiple sampling points in the target area; The average magnetic flux density is calculated based on the actual magnetic flux density, and the uniformity index is calculated based on the set of sampling points. If the difference between the average magnetic flux density and the target magnetic flux density exceeds a preset magnetic flux density threshold, the amplitude of the excitation current is adjusted. If the difference between the uniformity index and the target uniformity index exceeds a preset uniformity threshold, it is preferable to switch the connection method of the coil and / or adjust the grouping parameter M to improve the uniformity of magnetic induction intensity distribution within the target area.

7. The coil magnetic field enhancement method based on a magnetic focusing array according to claim 6, characterized in that, If the difference between the average magnetic induction intensity and the target magnetic induction intensity does not exceed a preset magnetic induction intensity threshold, and the difference between the uniformity index and the target uniformity index does not exceed a preset uniformity threshold, then a surface-level or deep-level effect is required based on the magnetic field requirements. If it is a surface-level effect, the excitation frequency of the excitation current is increased to utilize the skin effect to concentrate the magnetic field on the object surface. If it is a deep-level effect, the excitation frequency of the excitation current is decreased to reduce the eddy current shielding effect and increase the magnetic field penetration depth.

8. The coil magnetic field enhancement method based on a magnetic focusing array according to claim 1, characterized in that, The diameter and length of the coil are matched with the size of the object being acted upon.

9. The coil magnetic field enhancement method based on a magnetic focusing array according to claim 1, characterized in that, The characteristics of the target object include magnetic permeability, electrical conductivity, and thickness. The initial excitation parameters include excitation current amplitude and excitation frequency. The initial excitation parameters are determined based on the characteristics of the target object, target uniformity index, and target magnetic induction intensity. Based on the material parameters, thickness, target depth of action, target uniformity index, and target magnetic induction intensity, the initial excitation parameters are determined by consulting a preset parameter mapping table or calling a simulation calibration model.

10. A coil magnetic field enhancement system based on a magnetic focusing array, characterized in that, The system includes: Parameter acquisition module: used to acquire the geometric dimensions, material parameters, target magnetic field parameters, and power supply constraints of the object under action; The determination module is used to determine N based on the geometric dimensions of the target area and the effective coverage size of a single coil; to determine the grouping parameters M based on power supply constraints, target uniformity requirements, and the total number of coils N; and to determine the arrangement of the coil magnetic focusing array based on the shape of the target object. The connection module is used to connect the coils according to the geometric dimensions, material parameters, target uniformity index, target magnetic induction intensity and power supply constraints of the target area, and adopts a connection method determination strategy. The connection method determination strategy is used to determine the target connection method between a fully series connection method and a group series-inter-group parallel connection method. The adjustment module is used to determine the initial excitation parameters based on the characteristics of the target object; The driving module is used to generate a controlled time-varying excitation current based on the initial excitation parameters; The magnetic field acquisition module is used to acquire multi-point magnetic induction intensity data of the target area through a magnetic sensor array after the time-varying excitation current is applied to the magnetic focusing array. The adjustment module is also used to adjust the parameters corresponding to the time-varying excitation current based on the magnetic field data.

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