Dual-mode topology magnetic leakage detection device and detection method

Abstract

The application discloses a double-mode topology magnetic flux leakage detection device and a detection method, and belongs to the technical field of magnetic variable testing. The double-mode topology magnetic flux leakage detection device comprises a magnetic flux leakage detector, and further comprises: a detection part comprising a plurality of Hall elements, the plurality of Hall elements are arranged in a matrix mode, when the plurality of Hall elements of the detection part pass through the magnetic flux leakage detector, the plurality of Hall elements form a dynamic detection area on a to-be-detected area of a steel plate, each Hall element is used for detecting a magnetic flux leakage signal of a magnetic flux leakage field of the detection area and converting the magnetic flux leakage signal into a voltage signal, and the same position of the to-be-detected area on the steel plate can be detected simultaneously by the plurality of Hall elements; a filter-amplification cooperative circuit is used for filtering and amplifying the voltage signal of the corresponding Hall element; and a signal display device generates and displays a magnetic flux leakage signal distribution of the detection area in real time. The double-mode topology magnetic flux leakage detection device can detect weak magnetic flux leakage signals on the steel plate, and ensures the accuracy of the detection result.

Description

Technical Field

[0001] This invention relates to the field of magnetic variable testing technology, specifically to a dual-mode topological magnetic flux leakage detection device and method. Background Technology

[0002] During the production and processing of steel plates, defects such as cracks, inclusions, and corrosion may appear on or near the surface of the steel plates due to various reasons, such as improper operation or equipment failure in smelting, rolling, and transportation. These defects not only reduce the mechanical properties of the steel plates but may also cause accidents that endanger human and property safety.

[0003] While traditional steel plate inspection methods such as ultrasonic testing can detect defects to some extent, they suffer from low efficiency, limited detection range, and high costs. Magnetic flux leakage (MFL) testing, on the other hand, is increasingly becoming an important tool for steel plate quality inspection due to its high efficiency, accuracy, and low cost. The principle of MFL testing is to magnetize the steel plate under test using a magnetic source. When a defect exists in the steel plate, the magnetic permeability of the defect area decreases, causing partial leakage of the magnetization field and forming a detectable magnetic flux leakage signal. By analyzing and processing the magnetic flux leakage signal, the location, size, and nature of defects in the steel plate can be accurately determined. Therefore, MFL testing technology for steel plates plays an increasingly important role in ensuring industrial production safety and improving product quality.

[0004] However, the leakage magnetic field signal is weak and easily affected by noise. When the magnetization intensity of the magnetizer is insufficient or the permeability of the steel plate itself is low, the leakage magnetic field signal becomes weak, thus increasing the difficulty of detection. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems in the prior art and provide a dual-mode topology magnetic flux leakage detection device that can detect even weak magnetic flux leakage signals on steel plates, thus ensuring the accuracy of the detection results.

[0006] This invention provides a dual-mode topological magnetic flux leakage detection device, including a magnetic flux leakage device with an arched structure, the magnetic flux leakage device being used to generate a magnetic field in the test area of ​​a steel plate, and further comprising: The detection unit is capable of passing through the leakage magnet. The detection unit includes multiple Hall elements arranged in a matrix. When the multiple Hall elements of the detection unit pass through the leakage magnet, the multiple Hall elements form a dynamic detection area on the area to be tested on the steel plate. Each Hall element is used to detect the leakage magnetic field signal of the detection area and convert it into a voltage signal. The same position of the area to be tested on the steel plate can be detected by multiple Hall elements at the same time. Multiple filtering and amplifying collaborative circuits are provided, each corresponding to a Hall element. Each filtering and amplifying collaborative circuit is electrically connected to its corresponding Hall element. The filtering and amplifying collaborative circuit is used to filter and amplify the voltage signal of its corresponding Hall element. The signal display device is electrically connected to multiple filtering and amplification collaborative circuits. The signal display device is used to receive the voltage signal after filtering and amplification by each filtering and amplification collaborative circuit, and to process the multiple filtered and amplified voltage signals to generate and display the leakage magnetic signal distribution in the detection area in real time.

[0007] Preferably, the leakage magnet includes a first magnetic source transmitter, a second magnetic source transmitter, and a magnetic yoke. The first and second magnetic source transmitters are respectively disposed on both sides of the test position on the steel plate. The bottom of the first and second magnetic source transmitters are both in contact with the steel plate. The two ends of the magnetic yoke are respectively connected to the top of the first and second magnetic source transmitters. The multiple Hall elements of the detection unit can pass through the area between the first and second magnetic source transmitters.

[0008] Preferably, when the multiple Hall elements of the detection unit pass through the area between the first magnetic source transmitter and the second magnetic source transmitter, a gap 1 is left between the Hall element on one side of the detection unit and the first magnetic source transmitter, and a gap 2 is left between the Hall element on the other side of the detection unit and the second magnetic source transmitter.

[0009] Preferably, the second magnetic source transmission element is arranged in parallel with the first magnetic source transmission element.

[0010] Preferably, the filter-amplification coordinated circuit includes a first amplification component, a filter component, and a second amplification component. The inverting input terminal of the first amplification component is electrically connected to the Hall element, the output terminal of the first amplification component is electrically connected to one input terminal of the signal display device and the input terminal of the filter component, the non-inverting input terminal of the second amplification component is electrically connected to the output terminal of the filter component, and the output terminal of the second amplification component is electrically connected to the other input terminal of the signal display device.

[0011] Preferably, the detection unit includes nine Hall elements arranged in a 3×3 square array.

[0012] The present invention also provides a dual-mode topological magnetic flux leakage detection method, wherein the method is applied to the dual-mode topological magnetic flux leakage detection device as described in any one of claims 1-3, and includes the following steps: The first and second magnetic source transmission components of the leakage magnet are placed against both sides of the area to be tested on the steel plate to generate a leakage magnetic field in the area to be tested on the steel plate. Multiple Hall elements of the detection unit are passed through the area between the first magnetic source transmitter and the second magnetic source transmitter, and a gap one is maintained between the Hall element on one side of the detection unit and the first magnetic source transmitter, and a gap two is maintained between the Hall element on the other side of the detection unit and the second magnetic source transmitter. Multiple Hall elements detect the leakage magnetic field signal of the detection area and output a voltage signal. Each filtering and amplification circuit filters and amplifies the voltage signal output by its corresponding Hall element. The signal display device receives filtered and amplified voltage signals and processes the filtered and amplified voltage signals to display the distribution of leakage magnetic signals in the detection area. The location of the defect is determined based on the distribution of magnetic flux leakage signals in the detection area.

[0013] Preferably, when the multiple Hall elements of the detection unit pass through the area between the first magnetic source transmission member and the second magnetic source transmission member, it needs to be done multiple times, and the multiple Hall elements maintain a constant speed each time they pass through, and the detection areas formed by the multiple Hall elements when they pass through twice in succession partially overlap.

[0014] Preferably, methods for determining the location of defects based on the distribution of magnetic flux leakage signals in the detection area include: The plurality of Hall elements are arranged in a square array; A coordinate system is established with the position coordinates of the Hall element at the center of the square array as the origin. The multiple Hall elements in the square array are divided into multiple groups, and the independent regions formed by the Hall elements in each group do not overlap. The independent region where the defect is located on the steel plate is determined based on the distribution of leakage magnetic signal in the independent region formed by each group of Hall elements, and the group of Hall elements corresponding to the independent region is determined based on the independent region where the defect is located. Based on the coordinates of the Hall element with the strongest detected magnetic leakage signal distribution within that group, and the coordinates of the Hall element with the second strongest detected magnetic leakage signal distribution, the coordinates of the defect are determined.

[0015] Compared with existing technologies, the advantages of this invention are as follows: This invention provides a dual-mode topology magnetic flux leakage detection device. A magnetic flux leakage magnetizer magnetizes the area to be tested on a steel plate. The detection unit then passes through the magnetizer. The magnetic flux leakage signals detected by multiple Hall elements in the detection unit are processed by a filtering, amplification, and collaborative circuit before being output. Finally, the location of the defect is determined based on the output results of each Hall element. This dual-mode topology magnetic flux leakage detection device can detect defects on a steel plate by using multiple Hall elements during their movement. Multiple Hall elements can detect the same location, and the processing of the magnetic flux leakage signals detected by the Hall elements by the filtering, amplification, and collaborative circuit ensures that even weak magnetic flux leakage signals can be detected, guaranteeing the accuracy of the detection results. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the leakage magnetic field device disposed on the steel plate according to an embodiment of this application; Figure 2 The magnetic flux density vector field diagram of the steel plate and the leakage magnet provided in the embodiments of this application Figure 3 The magnetization flow line diagram of the steel plate and the leakage magnet provided in the embodiments of this application; Figure 4 A cross-sectional view of the magnetic scalar potential of the steel plate and the leakage magnet provided in the embodiments of this application; Figure 5 The leakage magnetic field upper surface magnetic flux density map of the steel plate provided in the embodiments of this application; Figure 6 This is a schematic diagram of the detection device provided in the embodiments of this application; Figure 7 A schematic diagram showing that the detection area provided in this application embodiment is divided into four groups; Figure 8 This is a schematic diagram of the structure of the filter-amplifier collaborative circuit provided in the embodiments of this application; Figure 9 A flowchart of a dual-mode topology magnetic flux leakage detection method provided in an embodiment of this application.

[0017] Reference numerals: 100, Leaking magnet; 110, First magnetic source transmission component; 120, Second magnetic source transmission component; 130, Magnetic yoke; 200, Steel plate; 300, Detection section; 310, Hall element; 320, Detection area; 400, Filtering and amplification coordination circuit; 410, First amplification component; 411, First amplifier; 412, First resistor; 413, Second resistor; 414, First variable resistor; 420, Second amplification component; 421, Second amplifier; 422, First capacitor; 423, Second variable resistor; 430, Filtering component; 431, Filtering resistor; 432, Filtering capacitor; 500, Signal display device. Detailed Implementation

[0018] The following is in conjunction with the appendix Figures 1-9 The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0019] like Figures 1-9As shown, the present invention provides a dual-mode topology magnetic flux leakage detection device, including a magnetic flux leakage device 100, which has an arched structure. The magnetic flux leakage device 100 is used to generate a magnetic field in the test area of ​​a steel plate 200. It also includes a detection unit 300, a signal display device 500, and multiple filtering and amplification coordination circuits 400. The detection unit 300 can pass through the magnetic flux leakage device 100 and includes multiple Hall elements 310 arranged in a matrix. When the multiple Hall elements 310 of the detection unit 300 pass through the magnetic flux leakage device 100, the multiple Hall elements 310 form a dynamic detection area 320 on the test area of ​​the steel plate 200. Each Hall element 310 is used to detect the magnetic flux leakage signal of the detection area 320 and convert it into a voltage signal. The same location in the test area on the steel plate 200 can be simultaneously detected by multiple Hall elements 310; multiple filtering and amplification coordination circuits 400, each corresponding to one Hall element 310, are electrically connected to their corresponding Hall element 310. The filtering and amplification coordination circuit 400 is used to filter and amplify the voltage signal of its corresponding Hall element 310; a signal display device 500 is electrically connected to all of the multiple filtering and amplification coordination circuits 400. The signal display device 500 is used to receive the filtered and amplified voltage signal from each filtering and amplification coordination circuit 400, and to process the multiple filtered and amplified voltage signals to generate and display the leakage magnetic signal distribution of the detection area 320 in real time.

[0020] The working principle of the above embodiments is briefly described below: The leakage magnetic flux 100 is placed against both sides of the test area on the steel plate 200 to generate a leakage magnetic field in the test area of ​​the steel plate 200. The detection unit 300 passes through the leakage magnetic flux 100, and gap one and gap two are respectively between the leakage magnetic flux 100 and the first magnetic source transmission member 110 and between the leakage magnetic flux 100 and the second magnetic source transmission member 120. Figure 6 As shown, the detection unit 300 includes a plurality of Hall elements 310, and a rectangular array of the plurality of Hall elements 310 forms a detection area 320. Figure 6 The area inside the dashed box is the detection area 320. Multiple Hall elements 310 detect defects in the steel plate 200 during movement. Multiple Hall elements 310 can detect the same location, avoiding the omission of weak magnetic leakage signals on the steel plate 200.

[0021] Among them, the Hall element 310 can be the HX6639-D model, which has high-speed and low-noise output characteristics and can detect leakage magnetic signal characteristics.

[0022] The dual-mode topology magnetic flux leakage detection device of the present invention uses multiple filtering and amplification collaborative circuits 400 and multiple Hall elements 310 connected one-to-one with them. Each filtering and amplification circuit can receive the magnetic flux leakage signal of the corresponding Hall element 310, and filter and amplify the magnetic flux leakage signal of the Hall element 310, thereby reducing the influence of noise on the detection results and amplifying the weak magnetic flux leakage signal, so that the weak magnetic flux leakage signal can also be detected, thus ensuring the accuracy of the detection results.

[0023] Based on the above embodiments, in order to reduce magnetic leakage of the leakage magnet 100 and improve magnetic circuit efficiency.

[0024] like Figure 1 As shown, the leakage magnet 100 includes a first magnetic source transmission element 110, a second magnetic source transmission element 120, and a magnetic yoke 130. The first magnetic source transmission element 110 and the second magnetic source transmission element 120 are respectively disposed on both sides of the test position on the steel plate 200. The bottom of the first magnetic source transmission element 110 and the bottom of the second magnetic source transmission element 120 are both in contact with the steel plate 200. The two ends of the magnetic yoke 130 are respectively connected to the top of the first magnetic source transmission element 110 and the top of the second magnetic source transmission element 120. The multiple Hall elements 310 of the detection unit 300 can pass through the area between the first magnetic source transmission element 110 and the second magnetic source transmission element 120.

[0025] Specifically, the first magnetic source transmission element 110 and the second magnetic source transmission element 120 are used to generate a magnetic field, and the magnetic yoke 130 is used to transmit magnetic field lines. Exemplarily, the first magnetic source transmission element 110 and the second magnetic source transmission element 120 can be neodymium iron boron magnets, and the material of the magnetic yoke 130 can be soft iron, A3 steel, or a soft magnetic alloy, etc. (Refer to...) Figures 2 to 5 As shown, Figure 2 The magnetic flux density vector field diagram is shown for the steel plate 200 and the leakage magnet 100. Figure 3 The diagram shows the streamlines of magnetization intensity for the steel plate 200 and the leakage magnet 100. Figure 4 This is a cross-sectional view of the magnetic scalar potential of steel plate 200 and leakage magnet 100. Figure 5 This is a magnetic flux density diagram of the upper surface of the leakage magnetic field of steel plate 200. Magnetic yoke 130 is a device made of high-permeability materials (such as silicon steel and permalloy), whose main function is to guide and concentrate the magnetic field, reduce leakage magnetic field, and improve magnetic circuit efficiency.

[0026] As a preferred option, such as Figure 6As shown, when the multiple Hall elements 310 of the detection unit 300 pass through the region between the first magnetic source transmission member 110 and the second magnetic source transmission member 120, a gap 1 is left between the Hall element 310 on one side of the detection unit 300 and the first magnetic source transmission member 110, and a gap 2 is left between the Hall element 310 on the other side of the detection unit 300 and the second magnetic source transmission member 120. Gap 1 and gap 2 can significantly reduce the influence of the leakage magnet 100 on the detection unit 300.

[0027] As a preferred option, such as Figure 1 As shown, the second magnetic source transmission element 120 is arranged parallel to the first magnetic source transmission element 110. Arranging the second magnetic source transmission element 120 and the first magnetic source transmission element 110 in parallel enables a uniform, stable, and directional magnetic field to be formed inside the steel plate 200 to be tested. This magnetic field, together with the magnetic yoke 130 and the steel plate 200 to be tested, forms a closed magnetic circuit, maximizing the leakage magnetic signal.

[0028] As a preferred option, such as Figure 8 As shown, the filter-amplification coordination circuit 400 includes a first amplification component 410, a filter component 430, and a second amplification component 420. The inverting input terminal of the first amplification component 410 is electrically connected to the Hall element 310, and the output terminal of the first amplification component 410 is electrically connected to one input terminal of the signal display device 500 and the input terminal of the filter component 430. The non-inverting input terminal of the second amplification component 420 is electrically connected to the output terminal of the filter component 430, and the output terminal of the second amplification component 420 is electrically connected to the other input terminal of the signal display device 500.

[0029] The filter component 430 includes a filter resistor 431 and a filter capacitor 432; the filter resistor 431 has a first terminal and a second terminal; one end of the filter capacitor 432 is connected to the second terminal of the filter resistor 431, and the other end of the filter capacitor 432 is grounded.

[0030] The first amplification component 410 includes a first amplifier 411, a first resistor 412, a second resistor 413, and a first variable resistor 414. The output terminal of the first amplifier 411 is connected to the first terminal of the filter resistor 431 and the signal display device 500; and the output terminal of the first amplifier 411 is connected to the inverting input terminal of the first amplifier 411 through the first resistor 412, forming a feedback network for the first amplifier 411; the non-inverting input terminal of the first amplifier 411 is grounded through the second resistor 413 to ensure the DC potential of the first amplifier 411 is stable; the two ends of the first variable resistor 414 are respectively connected to the first pin and the eighth pin of the first amplifier 411 for zero biasing the first amplifier 411; the fourth pin and the seventh pin of the first amplifier 411 are respectively connected to a DC power supply, with the DC power supply connected to the fourth pin being -12V and the DC power supply connected to the seventh pin being +12V.

[0031] The second amplification component 420 includes a second amplifier 421, a first capacitor 422, and a second variable resistor 423. The positive input terminal of the second amplifier 421 is connected to the second terminal of the filter resistor 431, and the output terminal of the second amplifier 421 is connected to the signal display device 500. One end of the first capacitor 422 is connected to the output terminal and the inverting input terminal of the second amplifier 421, and the other end of the first capacitor 422 is connected to the first terminal of the filter resistor 431. The two ends of the second variable resistor 423 are respectively connected to the first pin and the eighth pin of the second amplifier 421 for zero-biasing the second amplifier 421.

[0032] The first amplifier 411 of the first amplification component 410 and the second amplifier 421 of the second amplification component 420 are both electrically connected to the signal display device 500, enabling the original magnetic leakage signal to be displayed on the oscilloscope and compared with the amplified and filtered magnetic leakage signal to verify the circuit's filtering and amplification effect.

[0033] The first amplifier 411 and the second amplifier 421 can be OP07CP chips. The OP07CP chip has the characteristics of low noise and no chopping, and can be used stably for a long time. The filter amplification coordination circuit 400 combines the filtering function with the amplification function. While saving costs, it can better process the characteristics of leakage magnetic signals and has a stronger noise suppression capability.

[0034] As a preferred option, such as Figure 6 and Figure 7As shown, the detection unit 300 includes nine Hall elements 310 arranged in a 3×3 matrix. The arrangement of the nine Hall elements 310 in the 3×3 matrix ensures that when the detection unit 300 passes through the magnetic flux leakage detector 100, the detection areas 320 of adjacent movements partially overlap, avoiding missed detections within the magnetized area and improving the efficiency of magnetic flux leakage detection.

[0035] For example, the Hall elements 310 are spaced 1 mm laterally and 2 mm vertically. When a defect is located at the center of the Hall element 310 in the detection area 320, the defect is equidistant from the other eight Hall elements 310. The larger the distance between the Hall element 310 and the first magnetic source transmitter 110 and the second magnetic source transmitter 120, the smaller the influence of the leakage magnet 100 on the detection unit 300. The first magnetic source transmitter 110 and the second magnetic source transmitter 120 are spaced 40 mm apart. When the detection unit 300 performs detection on the left side of the magnetized area, it is 6 mm away from the left side of the first magnetic source transmitter 110, forming a first blank area. When the detection unit 300 performs detection on the right side of the magnetized area, it is 6 mm away from the right side of the second magnetic source transmitter 120, forming a second blank area. The first blank area and the second blank area can reduce the influence of the first magnetic source transmitter 110 and the second magnetic source transmitter 120. After removing the two first blank areas and the second blank area, the lateral width of the magnetized area is 28mm, and the width of the detection part 300 is 14mm. During the detection, the detection part 300 can pass through the leakage magnet 100 more than three times. The detection areas 320 of two adjacent movements partially overlap, which avoids the situation of missed detection in the magnetized area and improves the working efficiency of leakage detection.

[0036] By establishing a coordinate system with the central Hall element 310 as the origin (0, 0), the coordinates of the other eight Hall elements 310 can be determined. After obtaining the output leakage magnetic signal of each filter amplification coordination circuit 400, the direction of the Hall element 310 at the center of the defect is determined based on the Hall element 310 corresponding to the strongest leakage magnetic signal and the Hall element 310 corresponding to the second strongest leakage magnetic signal, thus determining the location of the defect. Except for the Hall element 310 at the center, when any one of the other eight Hall elements 310 is in the state of strongest leakage magnetic signal, the three Hall elements 310 around it must have a leakage magnetic signal second only to the strongest, narrowing the detection range and further accurately determining the direction of the defect.

[0037] The present invention also provides a dual-mode topological magnetic flux leakage detection method, which is applied to a dual-mode topological magnetic flux leakage detection device and includes the following steps: The first magnetic source transmission element 110 and the second magnetic source transmission element 120 of the leakage magnetic device 100 are brought into contact with both sides of the area to be tested on the steel plate 200 to generate a leakage magnetic field in the area to be tested on the steel plate 200. The multiple Hall elements 310 of the detection unit 300 pass through the area between the first magnetic source transmission member 110 and the second magnetic source transmission member 120, and maintain a gap one between the Hall element 310 on one side of the detection unit 300 and the first magnetic source transmission member 110, and a gap two between the Hall element 310 on the other side of the detection unit 300 and the second magnetic source transmission member 120. Multiple Hall elements 310 detect the leakage magnetic field signal of the leakage magnetic field in the detection area 320 and output a voltage signal. Each filter amplification coordination circuit 400 filters and amplifies the voltage signal output by its corresponding Hall element 310. The signal display device 500 receives the filtered and amplified voltage signal and processes the filtered and amplified voltage signal to display the leakage magnetic signal distribution in the detection area 320. The location of the defect is determined based on the distribution of the magnetic flux leakage signal in the detection area 320.

[0038] As a preferred option, such as Figure 7 As shown, when the multiple Hall elements 310 of the detection unit 300 pass through the area between the first magnetic source transmission member 110 and the second magnetic source transmission member 120, it needs to be done multiple times, and the multiple Hall elements 310 maintain a constant speed each time they pass through, and the detection area 320 formed when the multiple Hall elements 310 pass through two adjacent times partially overlaps.

[0039] As a preferred option, such as Figure 9 As shown, the method for determining the location of the defect based on the distribution of the magnetic flux leakage signal in the detection area 320 includes: The plurality of Hall elements 310 are arranged in a square array; A coordinate system is established with the position coordinates of the Hall element 310 at the center of the square array as the origin. The multiple Hall elements 310 in the square array are divided into multiple groups, and the independent regions formed by the Hall elements 310 in each group do not overlap. The independent region where the defect is located on the steel plate 200 is determined based on the distribution of leakage magnetic signal in the independent region formed by each group of Hall elements 310, and the group of Hall elements 310 corresponding to the independent region is determined based on the independent region where the defect is located. The location coordinates of the defect are determined based on the coordinates of the Hall element 310 with the strongest leakage magnetic signal distribution detected in this group and the coordinates of the Hall element 310 with the second strongest leakage magnetic signal distribution detected.

[0040] For example, the first magnetic source transmission member 110 and the second magnetic source transmission member 120 are spaced 40mm apart, the detection part 300 has a width of 14mm, and gap one and gap two are both 6mm apart.

[0041] S902, obtain the output results of multiple filter amplification collaborative circuits 400.

[0042] The filter-amplifier co-circuit 400 combines filtering and amplification functions, enabling noise reduction and amplification of the leakage magnetic signal detected by the Hall element 310. This allows even weak leakage magnetic signals to be detected, ensuring the accuracy of the detection results. The output of multiple filter-amplifier co-circuits 400 represents the strength of the external leakage magnetic field detected by multiple Hall elements 310.

[0043] S903. Determine the location of the defect based on multiple output results.

[0044] Specifically, the closer to the defect location, the stronger the leakage magnetic field. Therefore, the Hall element 310 closest to the defect has the strongest leakage magnetic signal. Based on the multiple output results obtained in S902, the Hall element 310 with the strongest leakage magnetic signal and the Hall element 310 with the second strongest leakage magnetic signal can be identified, thereby determining the location of the defect.

[0045] In step S901, the detection unit 300 is passed through the magnetic flux leakage device 100. Specifically, this includes passing the detection unit 300 through the magnetic flux leakage device 100 multiple times at a constant speed, with the detection areas 320 of two adjacent passes through the magnetic flux leakage device 100 partially overlapping. This step avoids missed detections and ensures comprehensive detection.

[0046] like Figure 6 and Figure 7 As shown, the multiple Hall elements 310 include nine Hall elements 310, which are arranged in a 3×3 array, and a coordinate system is established with the Hall element 310 located at the center as the origin. Step S903 includes steps S1001 to S1004.

[0047] S1001. Divide the nine output results into four groups according to the positions of the multiple Hall elements 310.

[0048] like Figure 7 As shown, the detection results corresponding to the four Hall elements 310 in the upper left corner are the first group, the detection results corresponding to the four Hall elements 310 in the upper right corner are the second group, the detection results corresponding to the four Hall elements 310 in the lower left corner are the third group, and the detection results corresponding to the four Hall elements 310 in the lower right corner are the fourth group.

[0049] S1002. Establish a coordinate system with the Hall element 310 located at the center as the origin.

[0050] S1003. Judge the leakage magnetic signal of each group to obtain the group where the defect is located.

[0051] S1004. Determine the defect location by using the coordinates of the Hall element 310 with the strongest leakage magnetic signal and the coordinates of the Hall element 310 with the second strongest leakage magnetic signal.

[0052] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A dual-mode topological magnetic flux leakage detection device, comprising a magnetic flux leakage device, wherein the magnetic flux leakage device has an arched structure, and the magnetic flux leakage device is used to generate a magnetic field in the test area of ​​a steel plate, characterized in that, Also includes: The detection unit is capable of passing through the leakage magnet. The detection unit includes multiple Hall elements arranged in a matrix. When the multiple Hall elements of the detection unit pass through the leakage magnet, the multiple Hall elements form a dynamic detection area on the area to be tested on the steel plate. Each Hall element is used to detect the leakage magnetic field signal of the detection area and convert it into a voltage signal. The same position of the area to be tested on the steel plate can be detected by multiple Hall elements at the same time. Multiple filtering and amplifying collaborative circuits are provided, each corresponding to a Hall element. Each filtering and amplifying collaborative circuit is electrically connected to its corresponding Hall element. The filtering and amplifying collaborative circuit is used to filter and amplify the voltage signal of its corresponding Hall element. The signal display device is electrically connected to multiple filtering and amplification collaborative circuits. The signal display device is used to receive the voltage signal after filtering and amplification by each filtering and amplification collaborative circuit, and to process the multiple filtered and amplified voltage signals to generate and display the leakage magnetic signal distribution in the detection area in real time.

2. The dual-mode topological magnetic flux leakage detection device according to claim 1, characterized in that, The leakage magnet includes a first magnetic source transmitter, a second magnetic source transmitter, and a magnetic yoke. The first and second magnetic source transmitters are respectively disposed on both sides of the test position on the steel plate. The bottom of the first and second magnetic source transmitters are both in contact with the steel plate. The two ends of the magnetic yoke are respectively connected to the top of the first and second magnetic source transmitters. The multiple Hall elements of the detection unit can pass through the area between the first and second magnetic source transmitters.

3. The dual-mode topological magnetic flux leakage detection device according to claim 2, characterized in that, When the multiple Hall elements of the detection unit pass through the area between the first magnetic source transmitter and the second magnetic source transmitter, a gap 1 is left between the Hall element on one side of the detection unit and the first magnetic source transmitter, and a gap 2 is left between the Hall element on the other side of the detection unit and the second magnetic source transmitter.

4. The dual-mode topological magnetic flux leakage detection device according to claim 2, characterized in that, The second magnetic source transmission element is arranged in parallel with the first magnetic source transmission element.

5. The dual-mode topological magnetic flux leakage detection device according to claim 1, characterized in that, The filtering and amplification coordination circuit includes a first amplification component, a filtering component, and a second amplification component. The inverting input terminal of the first amplification component is electrically connected to the Hall element, and the output terminal of the first amplification component is electrically connected to one input terminal of the signal display device and the input terminal of the filtering component. The non-inverting input terminal of the second amplification component is electrically connected to the output terminal of the filtering component, and the output terminal of the second amplification component is electrically connected to the other input terminal of the signal display device.

6. The dual-mode topological magnetic flux leakage detection device according to claim 1, characterized in that, The detection unit includes nine Hall elements arranged in a 3×3 square array.

7. A dual-mode topological magnetic flux leakage detection method, characterized in that, The method, applied to the dual-mode topology magnetic flux leakage detection device as described in claim 3, includes the following steps: The first and second magnetic source transmission components of the leakage magnet are placed against both sides of the area to be tested on the steel plate to generate a leakage magnetic field in the area to be tested on the steel plate. Multiple Hall elements of the detection unit are passed through the area between the first magnetic source transmitter and the second magnetic source transmitter, and a gap one is maintained between the Hall element on one side of the detection unit and the first magnetic source transmitter, and a gap two is maintained between the Hall element on the other side of the detection unit and the second magnetic source transmitter. Multiple Hall elements detect the leakage magnetic field signal of the detection area and output a voltage signal. Each filtering and amplification circuit filters and amplifies the voltage signal output by its corresponding Hall element. The signal display device receives filtered and amplified voltage signals and processes the filtered and amplified voltage signals to display the distribution of leakage magnetic signals in the detection area. The location of the defect is determined based on the distribution of magnetic flux leakage signals in the detection area.

8. The detection method according to claim 7, characterized in that, When multiple Hall elements of the detection unit pass through the area between the first magnetic source transmission member and the second magnetic source transmission member, it needs to be done multiple times, and the multiple Hall elements maintain a constant speed each time they pass through, and the detection areas formed by the multiple Hall elements when they pass through twice in a row partially overlap.

9. The detection method according to claim 7, characterized in that, Methods for determining the location of defects based on the distribution of magnetic flux leakage signals in the detection area include: The plurality of Hall elements are arranged in a square array; A coordinate system is established with the position coordinates of the Hall element at the center of the square array as the origin. The multiple Hall elements in the square array are divided into multiple groups, and the independent regions formed by the Hall elements in each group do not overlap. The independent region where the defect is located on the steel plate is determined based on the distribution of leakage magnetic signal in the independent region formed by each group of Hall elements, and the group of Hall elements corresponding to the independent region is determined based on the independent region where the defect is located. The location coordinates of the defect are determined based on the coordinates of the Hall element with the strongest leakage magnetic signal distribution and the coordinates of the Hall element with the second strongest leakage magnetic signal distribution within the group.

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