Multi-magnetic-target horizontal position localization method based on magnetic gradient tensor

Abstract

The present application relates to a method for horizontally positioning multiple magnetic targets based on magnetic gradient tensors. The method includes: determining multiple measurement points in a horizontal detection plane where multiple magnetic targets are located according to the magnetic field distribution characteristics of the multiple magnetic targets to be measured; obtaining the magnetic gradient tensor information of each measurement point, and determining the change rate of the vertical magnetic field component of each measurement point in three-dimensional space according to the magnetic gradient tensor information of each measurement point; performing thermal imaging according to the change rate of the vertical magnetic field component of each measurement point in three-dimensional space to obtain thermal imaging maps in different magnetic field directions; and determining the horizontal information of each magnetic target according to the thermal imaging maps in different magnetic field directions. By using this method, the detection accuracy of the horizontal information of magnetic targets is improved.

Description

Technical Field

[0001] The present application relates to the technical field of magnetic target detection, and particularly to a method for horizontally positioning multiple magnetic targets based on magnetic gradient tensors. Background Art

[0002] Magnetic target detection is a technology that uses magnetic field characteristics to detect and locate magnetic targets, and is usually used in fields such as military, geological exploration, resource exploration, and non-destructive testing. The detection of the horizontal information of multiple magnetic targets is a crucial link in magnetic target detection, and plays a key role in accurately identifying and positioning the positions, distributions, and related characteristics of multiple magnetic targets in the horizontal direction.

[0003] In the related art, when detecting the horizontal information of multiple magnetic targets, the magnetic gradient tensor information of different measurement points is usually processed to obtain the processed magnetic gradient tensor information, and the processed magnetic gradient tensor information is used to determine the horizontal information of each magnetic target.

[0004] However, in the related art, when detecting the horizontal information of magnetic targets, there is a technical problem of low detection accuracy. Summary of the Invention

[0005] Based on this, it is necessary to provide a method for horizontally positioning multiple magnetic targets based on magnetic gradient tensors to improve the detection accuracy of the horizontal information of magnetic targets in view of the above technical problems.

[0006] In a first aspect, an embodiment of the present application provides a method for horizontally positioning multiple magnetic targets based on magnetic gradient tensors, including:

[0007] Determine multiple measurement points in the horizontal detection plane where multiple magnetic targets are located according to the magnetic field distribution characteristics of the multiple magnetic targets to be measured;

[0008] Obtain the magnetic gradient tensor information of each measurement point, and determine the change rate of the vertical component of the magnetic field at each measurement point in three-dimensional space according to the magnetic gradient tensor information of each measurement point;

[0009] Perform thermal imaging according to the change rate of the vertical component of the magnetic field at each measurement point to obtain thermal imaging maps in different magnetic field directions;

[0010] Determine the horizontal information of each magnetic target according to the thermal imaging maps in different magnetic field directions.

[0011] In one embodiment, obtaining the magnetic gradient tensor information of each measurement point includes:

[0012] For any horizontal detection plane, obtain the magnetic field information collected by a single sensor at each measurement point in the horizontal detection plane;

[0013] Determine the magnetic gradient tensor information of each measurement point in the horizontal detection plane according to multiple adjacent measurement points of each measurement point and each magnetic field information.

[0014] In one embodiment, determining the magnetic gradient tensor information of each measurement point in the horizontal detection plane according to multiple adjacent measurement points of each measurement point and each magnetic field information includes:

[0015] For any measurement point, obtain the magnetic field information of each adjacent measurement point of the measurement point according to each magnetic field information;

[0016] Determine the change rate of the horizontal component of the magnetic field of the measurement point in three-dimensional space and the change rate of the vertical component of the magnetic field of the measurement point in three-dimensional space according to the magnetic field information of each adjacent measurement point;

[0017] Determine the change rate of the horizontal component of the magnetic field of the measurement point in three-dimensional space and the change rate of the vertical component of the magnetic field of the measurement point in three-dimensional space as the magnetic gradient tensor information of the measurement point.

[0018] In one embodiment, determining the change rate of the vertical component of the magnetic field of each measurement point in three-dimensional space according to the magnetic gradient tensor information of each measurement point includes:

[0019] For any horizontal detection plane, obtain the change rate of the vertical component of the magnetic field of each measurement point in the X direction, the change rate in the Y direction, and the change rate in the Z direction according to the magnetic gradient tensor information collected by each measurement point in the horizontal detection plane;

[0020] Determine the change rate of the vertical component of the magnetic field of each measurement point in the X direction, the change rate in the Y direction, and the change rate in the Z direction as the change rate of the vertical component of the magnetic field of each measurement point in three-dimensional space.

[0021] In one embodiment, perform thermal imaging according to the change rate of the vertical component of the magnetic field of each measurement point in three-dimensional space to obtain an imaging thermal map in different magnetic field directions, including:

[0022] For any horizontal detection plane, determine the arctangent value of each change rate according to the change rate of the vertical component of the magnetic field of each measurement point in the horizontal detection plane in three-dimensional space;

[0023] Perform thermal imaging in the horizontal detection plane according to each change rate and each arctangent value to obtain an imaging thermal map in different magnetic field directions.

[0024] In one embodiment, perform thermal imaging in the horizontal detection plane according to each change rate and each arctangent value to obtain an imaging thermal map in different magnetic field directions, including:

[0025] For any magnetic field direction, a thermal image is obtained by taking the change rate of the vertical component of the magnetic field at each measurement point in the direction as the abscissa and the arctangent value of the change rate of the vertical component of the magnetic field at each measurement point in the direction as the ordinate, so as to obtain an imaging thermal map of the magnetic field direction.

[0026] In one embodiment, according to the imaging thermal maps in different magnetic field directions, the horizontal information of each magnetic target is determined, including:

[0027] For any horizontal detection plane, according to the imaging thermal maps in each magnetic field direction in the horizontal detection plane, the lines with zero imaging median values in each imaging thermal map are obtained;

[0028] According to the lines with zero imaging median values in each imaging thermal map, the horizontal information of the magnetic target in the horizontal detection plane is determined.

[0029] In one embodiment, according to the lines with zero imaging median values in each imaging thermal map, the horizontal information of the magnetic target in the horizontal detection plane is determined, including:

[0030] According to the lines with zero imaging median values in each imaging thermal map, the vertical lines in the imaging thermal map in the X direction, the horizontal lines in the imaging thermal map in the Y direction, and the circular lines in the imaging thermal map in the Z direction are obtained;

[0031] According to the vertical lines, horizontal lines, and circular lines, the horizontal information of the magnetic target in the horizontal detection plane is determined.

[0032] In one embodiment, according to the vertical lines, horizontal lines, and circular lines, the horizontal information of the magnetic target in the horizontal detection plane is determined, including:

[0033] According to the vertical lines, horizontal lines, and circular lines, the intersections of the vertical lines and horizontal lines inside the circular line are obtained;

[0034] The abscissa value and ordinate value of the intersection in the horizontal detection plane are obtained;

[0035] The abscissa value and ordinate value of the intersection in the horizontal detection plane are determined as the horizontal information of the magnetic target in the horizontal detection plane.

[0036] In a second aspect, an embodiment of the present application further provides a multi-magnetic target horizontal position positioning device based on a magnetic gradient tensor, including:

[0037] A measurement point determination module, configured to determine a plurality of measurement points in a horizontal detection plane where the plurality of magnetic targets are located according to the magnetic field distribution characteristics of the plurality of magnetic targets to be measured;

[0038] A change rate determination module, configured to obtain the magnetic gradient tensor information of each measurement point and determine the change rate of the vertical component of the magnetic field of each measurement point in three-dimensional space according to the magnetic gradient tensor information of each measurement point;

[0039] A thermal imaging module, configured to perform thermal imaging according to the change rate of the vertical component of the magnetic field at each measurement point in three-dimensional space, and obtain imaging thermal maps in different magnetic field directions;

[0040] A horizontal information determination module, configured to determine the horizontal information of each magnetic target according to the imaging thermal maps in different magnetic field directions.

[0041] In a third aspect, the present application further provides a computer device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the steps of the method in any one of the embodiments in the first aspect are implemented.

[0042] In a fourth aspect, the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method in any one of the embodiments in the first aspect are implemented.

[0043] In a fifth aspect, the present application further provides a computer program product, including a computer program. When the computer program is executed by a processor, the steps of the method in any one of the embodiments in the first aspect are implemented.

[0044] The method for positioning the horizontal positions of multiple magnetic targets based on magnetic gradient tensors provided by the embodiments of the present application first determines multiple measurement points in the horizontal detection plane where the multiple magnetic targets to be measured are located according to the magnetic field distribution characteristics of the multiple magnetic targets to be measured, and then obtains the magnetic gradient tensor information of each measurement point, and determines the change rate of the vertical component of the magnetic field at each measurement point in three-dimensional space according to the magnetic gradient tensor information of each measurement point. Then, thermal imaging is performed according to the change rate of the vertical component of the magnetic field at each measurement point in three-dimensional space to obtain imaging thermal maps in different magnetic field directions. Then, according to the imaging thermal maps in different magnetic field directions, the horizontal information of each magnetic target is determined. In this method, first, multiple measurement points in the horizontal detection plane where each magnetic target to be measured is located are determined, and the magnetic gradient tensor information of each measurement point is obtained, so as to obtain the change rate of the vertical component of the magnetic field at each measurement point in three-dimensional space from the magnetic gradient tensor information of each measurement point. Thus, thermal imaging is performed based on these original information to obtain imaging thermal maps in different magnetic field directions. By processing each imaging thermal map, the horizontal information of each magnetic target is obtained. Equivalently, imaging is directly performed based on the original data in the magnetic gradient tensor information of each measurement point, so as to obtain the horizontal information of each magnetic target, making the obtained horizontal information of the magnetic target more accurate and improving the detection accuracy of the horizontal information of the magnetic target. Description of the Drawings

[0045] To more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the related art. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0046] Figure 1 It is the internal structure diagram of a computer device in an embodiment;

[0047] Figure 2 It is the flowchart of a method for horizontally positioning multiple magnetic targets based on magnetic gradient tensors in an embodiment;

[0048] Figure 3 It is the schematic diagram of horizontally detecting the information of multiple magnetic targets in an embodiment;

[0049] Figure 4 It is the flowchart of a method for obtaining magnetic gradient tensor information in an embodiment;

[0050] Figure 5 It is the schematic diagram of measuring points in the horizontal detection plane in an embodiment;

[0051] Figure 6 It is the flowchart of a method for determining magnetic gradient tensor information in an embodiment;

[0052] Figure 7 It is the schematic diagram of measuring points participating in calculation and imaging in an embodiment;

[0053] Figure 8 It is the flowchart of a method for determining the change rate of the vertical component of the magnetic field of each measuring point in three-dimensional space in an embodiment;

[0054] Figure 9 It is the flowchart of a method for obtaining an imaging thermal map in different magnetic field directions in an embodiment;

[0055] Figure 10 It is the schematic diagram of an imaging thermal map in an embodiment;

[0056] Figure 11 It is the schematic diagram of an imaging thermal map in another embodiment;

[0057] Figure 12 It is the schematic diagram of an imaging thermal map in another embodiment;

[0058] Figure 13 It is the flowchart of a method for determining the horizontal information of magnetic targets in an embodiment;

[0059] Figure 14Schematic diagram of the process for determining the horizontal information of a magnetic target in another embodiment;

[0060] Figure 15 Schematic diagram of the horizontal information of a magnetic target in one embodiment;

[0061] Figure 16 Schematic diagram of the position information of a magnetic target in one embodiment;

[0062] Figure 17a Schematic diagram of an imaging thermal map in another embodiment;

[0063] Figure 17b Schematic diagram of an imaging thermal map in another embodiment;

[0064] Figure 17c Schematic diagram of an imaging thermal map in another embodiment;

[0065] Figure 18 Schematic diagram of the horizontal information of a magnetic target in another embodiment;

[0066] Figure 19a Schematic diagram of an imaging thermal map in another embodiment;

[0067] Figure 19b Schematic diagram of an imaging thermal map in another embodiment;

[0068] Figure 19c Schematic diagram of an imaging thermal map in another embodiment;

[0069] Figure 20 Schematic diagram of the horizontal information of a magnetic target in another embodiment;

[0070] Figure 21 Schematic diagram of the structure of a multi - magnetic - target horizontal position positioning device based on magnetic gradient tensor in one embodiment. Detailed implementation manners

[0071] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0072] The technical background of the embodiments of the present application will be described below first.

[0073] Magnetic target detection is a technique that uses magnetic field characteristics to detect and locate magnetic targets, and is commonly used in fields such as military, geological exploration, resource exploration, and non-destructive testing. In magnetic target detection operations, magnetic gradient tensor information can provide more in-depth additional magnetic field information and has the advantage of higher spatial resolution. Therefore, magnetic target positioning methods usually select magnetic gradient tensor data for positioning calculations. Currently, it is usually based on the Euler inversion method or an improvement of the Euler inversion method to achieve the positioning of magnetic targets. Before detection, it is usually necessary to correct the magnetic sensor itself and the sensor array. Since the positioning method of Euler inversion approximates the non-linear inversion problem as the solution of a linear equation system, the requirement for the calibration accuracy of the magnetic sensor is relatively high. Moreover, for the number of magnetic targets, it needs to be determined before optimization and clustering, but in most cases, the number of magnetic targets is unknown. In addition, when the magnetic moments and buried depths of different magnetic targets vary greatly, the solution of the Euler equation will be biased towards the magnetic target that affects the measurement point data the most, that is, the magnetic target with a larger magnetic moment or a shallower buried depth.

[0074] The horizontal information detection of multiple magnetic targets is a crucial link in magnetic target detection, and it plays a key role in accurately identifying and locating the positions, distributions, and related characteristics of multiple magnetic targets in the horizontal direction. In related technologies, when detecting the horizontal information of multiple magnetic targets, the magnetic gradient tensor information of different measurement points is usually processed to obtain the processed magnetic gradient tensor information, and the processed magnetic gradient tensor information is used to determine the horizontal information of each magnetic target. However, in related technologies, there are technical problems of low detection accuracy when detecting the horizontal information of magnetic targets.

[0075] Based on this, the embodiments of the present application provide a method for positioning the horizontal positions of multiple magnetic targets based on magnetic gradient tensors. First, multiple measurement points on the horizontal detection plane where each magnetic target to be measured is located are determined, and the magnetic gradient tensor information of each measurement point is obtained, so as to obtain the change rate of the vertical component of the magnetic field at each measurement point in three-dimensional space from the magnetic gradient tensor information of each measurement point. Then, based on these original information, thermal imaging is performed to obtain imaging thermal maps in different magnetic field directions. By processing each imaging thermal map, the horizontal information of each magnetic target is obtained. Equivalently, imaging is directly performed based on the original data in the magnetic gradient tensor information of each measurement point, so as to obtain the horizontal information of each magnetic target, making the obtained horizontal information of the magnetic target more accurate and improving the detection accuracy of the horizontal information of the magnetic target. Of course, the technical solutions provided in the embodiments of the present application are not limited to only solving the above problems, and there are other technical effects, which can be specifically seen in the following embodiments.

[0076] It should be noted that the beneficial effects or technical problems solved by the embodiments of the present application are not limited to this one, and there may also be other implicit or related problems, which can be specifically seen in the description of the following embodiments.

[0077] The application environment of the multi-magnetic target horizontal position positioning method based on magnetic gradient tensor provided in the embodiments of the present application will be described below. It can be applied to a computer device. The computer device can be a server, and its internal structure diagram can be as Figure 1 shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, it implements a multi-magnetic target horizontal position positioning method based on magnetic gradient tensor. Those skilled in the art can understand that Figure 1 the structure shown in

[0078] merely represents the block diagram of some structures related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. A specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0079] In an exemplary embodiment, as Figure 2 shown, a multi-magnetic target horizontal position positioning method based on magnetic gradient tensor is provided. Taking the method applied to the Figure 1 computer device in

[0080] S101, according to the magnetic field distribution characteristics of multiple magnetic targets to be measured, determine multiple measurement points in the horizontal detection plane where the multiple magnetic targets are located.

[0081] The magnetic field distribution characteristics of a magnetic target are a comprehensive manifestation of the physical attributes (such as magnetic moment, shape, structure) and spatial position of the magnetic target, which directly affect the measurement point layout of the magnetic detection system.

[0082] When setting the measurement points, the measurement points can be designed based on the magnetic field distribution characteristics of the magnetic targets. For example, for areas with a sharp magnetic field gradient, such as the target edge and the near-field area, dense measurement points are designed to avoid spatial aliasing; for areas with a gentle gradient, sparse measurement points are designed.

[0083] As Figure 3 shown, it is a schematic diagram of horizontal information detection of multiple magnetic targets provided by an embodiment of the present application. Among them, after dividing the grid on a 2m×2m horizontal detection plane, measurement points are set at the grid nodes, and these measurement points are evenly distributed. A1, A2, A3, and A4 are four of the measurement points.

[0084] S102. Obtain the magnetic gradient tensor information of each measurement point, and determine the change rate of the vertical magnetic field component of each measurement point in three-dimensional space according to the magnetic gradient tensor information of each measurement point.

[0085] The magnetic gradient tensor information is used to describe the change rate of the magnetic field, and is applied to quantify the change of the magnetic field in space and provide a measure that is highly sensitive to the magnetic field distribution. The magnetic gradient tensor information is composed of multiple components, and each component represents the change rate of the magnetic field in the corresponding coordinate axis direction.

[0086] In one embodiment, magnetic sensors are set at the measurement points to collect the magnetic field data at each measurement point, and then the magnetic field data of each measurement point is substituted into the magnetic gradient tensor calculation formula to obtain the magnetic gradient tensor information of each measurement point.

[0087] In another embodiment, the magnetic gradient tensor information of each measurement point is stored in a database, and when in use, the magnetic gradient tensor information of each measurement point that has been pre-stored can be directly obtained from the database.

[0088] The magnetic gradient tensor information includes nine elements, namely B xx , B yx , B zx , B xy , B yy , B zy , B xz , B yz , B zz . Among them, B xz , B yz , B zz are the change rates of the vertical magnetic field component (B z ) in three-dimensional space; B xx , B yx , B zx are the change rates of the horizontal magnetic field component (B x ) in three-dimensional space; B xy , B yy , Bzy is the rate of change of the horizontal component of the magnetic field (B y ) in three-dimensional space. Based on this, the rate of change of the vertical component of the magnetic field at each measurement point in three-dimensional space can be directly obtained from the magnetic gradient tensor information of each measurement point, that is, for any measurement point, B xz , B yz , and B zz among the three elements are obtained from the magnetic gradient tensor information of the measurement point, and these three elements are the rate of change of the vertical component of the magnetic field at the measurement point in three-dimensional space.

[0089] S103, perform thermal imaging according to the rate of change of the vertical component of the magnetic field at each measurement point in three-dimensional space to obtain thermal imaging maps in different magnetic field directions.

[0090] In the embodiment of the present application, after obtaining the rate of change of the vertical component of the magnetic field at each measurement point in three-dimensional space, thermal imaging is performed on the corresponding horizontal detection plane based on the rate of change of the vertical component of the magnetic field at these measurement points in three-dimensional space, so as to obtain thermal imaging maps in different magnetic field directions for each horizontal detection plane. The thermal imaging map includes a thermal imaging map in the X direction, which can be obtained by imaging based on the rate of change of the vertical component of the magnetic field in the X direction, and also includes a thermal imaging map in the Y direction, which can be obtained by imaging based on the rate of change of the vertical component of the magnetic field in the Y direction, and further includes a thermal imaging map in the Z direction, which can be obtained by imaging based on the rate of change of the vertical component of the magnetic field in the Z direction.

[0091] S104, determine the horizontal information of each magnetic target according to the thermal imaging maps in different magnetic field directions.

[0092] Based on the above-obtained thermal imaging maps in different magnetic field directions, determine the horizontal information of each magnetic target. For example, image processing can be performed on the thermal imaging maps in different magnetic field directions and input them into a pre-trained horizontal information prediction model. The horizontal information prediction model analyzes and processes the thermal imaging maps in each magnetic field direction and outputs the horizontal information of each magnetic target.

[0093] In the multi-magnetic target horizontal position positioning method based on magnetic gradient tensor provided by the embodiments of the present application, first, according to the magnetic field distribution characteristics of multiple magnetic targets to be measured, multiple measurement points in the horizontal detection plane where the multiple magnetic targets are located are determined. Then, the magnetic gradient tensor information of each measurement point is obtained, and the change rate of the vertical magnetic field component of each measurement point in three-dimensional space is determined according to the magnetic gradient tensor information of each measurement point. After that, thermal imaging is performed according to the change rate of the vertical magnetic field component of each measurement point in three-dimensional space to obtain imaging thermal maps in different magnetic field directions. Then, according to the imaging thermal maps in different magnetic field directions, the horizontal information of each magnetic target is determined. In this method, first, multiple measurement points in the horizontal detection plane where each magnetic target to be measured is located are determined, and the magnetic gradient tensor information of each measurement point is obtained, so as to obtain the change rate of the vertical magnetic field component of each measurement point in three-dimensional space from the magnetic gradient tensor information of each measurement point. Thus, based on these original information, thermal imaging is performed to obtain imaging thermal maps in different magnetic field directions. By processing each imaging thermal map, the horizontal information of each magnetic target is obtained. Equivalently, imaging is directly performed based on the original data in the magnetic gradient tensor information of each measurement point, so as to obtain the horizontal information of each magnetic target, making the obtained horizontal information of the magnetic target more accurate and improving the detection accuracy of the horizontal information of the magnetic target.

[0094] Based on the above embodiments, an embodiment for the process of obtaining the magnetic gradient tensor information is provided for description.

[0095] In an exemplary embodiment, as Figure 4 shown, obtaining the magnetic gradient tensor information of each measurement point includes:

[0096] S201, for any horizontal detection plane, obtain the magnetic field information collected by a single sensor at each measurement point in the horizontal detection plane.

[0097] In the embodiments of the present application, a single sensor is used to collect the magnetic field information of each measurement point. As Figure 5 shown in b of, it is a schematic diagram of the measurement points of a horizontal detection plane. When collecting the magnetic field information of each measurement point, the single sensor can be placed at each measurement point in turn to collect the magnetic field information of each measurement point.

[0098] S202, according to multiple adjacent measurement points of each measurement point and each magnetic field information, determine the magnetic gradient tensor information of each measurement point in the horizontal detection plane.

[0099] Based on the obtained magnetic field information of each measurement point, combined with the four adjacent measurement points of each measurement point in the east, west, south, and north directions, calculate the magnetic field gradient tensor information of each measurement point in the horizontal detection plane.

[0100] In one embodiment, as Figure 6As shown, according to multiple adjacent measuring points of each measuring point and each magnetic field information, the magnetic gradient tensor information of each measuring point in the horizontal detection plane is determined, including:

[0101] S301. For any measuring point, according to each magnetic field information, obtain the magnetic field information of each adjacent measuring point of the measuring point.

[0102] For any measuring point, if the magnetic field information of each measuring point includes the magnetic field information of the adjacent measuring points of the measuring point, first determine which adjacent measuring points of the measuring point are, and then obtain the magnetic field information of the multiple adjacent measuring points from the magnetic field information of each measuring point. Continue to refer to Figure 5 In b, for the measuring point O1, its four adjacent measuring points in the east, west, south, and north directions are O3, C1, C3, and C2 respectively. Then obtain the magnetic field information of O3, C1, C3, and C2 from the magnetic field information of each measuring point, which is the magnetic field information of the adjacent measuring points of the measuring point O1.

[0103] It should be noted that since the magnetic gradient tensor information needs to be calculated based on the four adjacent measuring points in the east, south, west, and north directions of the measuring point, and for Figure 5 In b, the outermost measuring points have only two or three adjacent measuring points, so the outermost measuring points do not participate in the calculation and imaging of the magnetic gradient tensor information. The specific part participating in the calculation and imaging is as shown in Figure 7 the gray part shown.

[0104] S302. According to the magnetic field information of each adjacent measuring point, determine the change rate of the horizontal component of the magnetic field in three-dimensional space and the change rate of the vertical component of the magnetic field in three-dimensional space.

[0105] S303. Determine the change rate of the horizontal component of the magnetic field in three-dimensional space and the change rate of the vertical component of the magnetic field in three-dimensional space of the measuring point as the magnetic gradient tensor information of the measuring point.

[0106] As described above, the change rate of the horizontal component of the magnetic field in three-dimensional space includes B xx 、B yx 、B zx 、B xy 、B yy 、B zy , and the change rate of the vertical component of the magnetic field in three-dimensional space includes B xz 、B yz 、B zz . In the embodiment of the present application, substitute the magnetic field information of each adjacent measuring point of the measuring point into the magnetic gradient tensor information calculation formula (1) to obtain the change rate of the horizontal component of the magnetic field in three-dimensional space of the measuring point and the change rate of the vertical component of the magnetic field in three-dimensional space of the measuring point.

[0107] (1)

[0108] where d is the distance between two adjacent measurement points; B x , B y and B z are the magnetic field components of each measurement point on the X-axis, Y-axis and Z-axis respectively; B 1x , B 3x are the magnetic field components on the X-axis of the adjacent measurement points on the west side and the east side of the single sensor at this measurement point respectively; B 1y , B 2y , B 3y , B 4y are the magnetic field components on the y-axis of the adjacent measurement points on the west side, north side, east side and south side of the single sensor at this measurement point respectively; B 1z , B 2z , B 3z and B 4z are the magnetic field components on the z-axis of the adjacent measurement points on the west side, north side, east side and south side of the single sensor at this measurement point respectively.

[0109] As shown in a of Figure 5 , the adjacent measurement points on the west side, north side, east side and south side are represented by (1), (2), (3) and (4), and the subscripts 1, 2, 3 and 4 in the above formula are the labels of the four adjacent measurement points in a of Figure 5 . Taking the measurement point O1 in b of Figure 5 as an example, B 1x , B 3x are the magnetic field components on the X-axis of the single sensor at the adjacent measurement points C1 and O3 respectively; B 1y , B 2y , B 3y , B 4y are the magnetic field components on the y-axis of the single sensor at the adjacent measurement points C1, C2, O3 and C3 respectively; B 1z , B 2z , B 3z and B 4z are the magnetic field components on the z-axis of the single sensor at the adjacent measurement points C1, C2, O3 and C3 respectively.

[0110] Generally, a cross-shaped sensor is used to collect magnetic field information in the prior art. In the embodiments of the present application, in order to improve the utilization rate of measurement point data and reduce the influence of sensor calibration accuracy on the experiment. Taking the measurement point O1 as an example, the magnetic field information of the four adjacent measurement points of the measurement point O1 is used as the measurement values of the four sensors of the cross-shaped sensor array at the central measurement point O1. The magnetic field information detected by the measurement point O3 located in the middle of the measurement point O1 and the measurement point O2 can be used as the magnetic field value measured by the right sensor in the cross-shaped sensor array at the point O1, or as the magnetic field value measured by the left sensor in the cross-shaped sensor array at the point O2.

[0111] In the multi-magnetic target horizontal position positioning method based on magnetic gradient tensor provided by the embodiments of the present application, for any horizontal detection plane, the magnetic field information collected by a single sensor at each measurement point in the horizontal detection plane is obtained, and then, based on multiple adjacent measurement points of each measurement point and the respective magnetic field information, the magnetic gradient tensor information of each measurement point in the horizontal detection plane is determined. In this method, the magnetic field information at each measurement point is sequentially measured by a single sensor, and based on the magnetic field information of each measurement point, calculations are performed in combination with the adjacent measurement points of each measurement point, so as to obtain the magnetic gradient tensor information of each measurement point. In this process, there is no need to calibrate the sensor, which reduces the influence of the sensor calibration accuracy on the measurement result, improves the measurement accuracy of the magnetic field information, and thus improves the accuracy of the magnetic gradient tensor information.

[0112] Based on the above embodiments, an embodiment is provided to illustrate the process of determining the change rate of the vertical component of the magnetic field of each measurement point in three-dimensional space.

[0113] In an exemplary embodiment, as Figure 8 shown, determining the change rate of the vertical component of the magnetic field of each measurement point in three-dimensional space according to the magnetic gradient tensor information of each measurement point includes:

[0114] S401, for any horizontal detection plane, according to the magnetic gradient tensor information collected at each measurement point in the horizontal detection plane, obtain the change rate of the vertical component of the magnetic field of each measurement point in the X direction, the change rate in the Y direction, and the change rate in the Z direction.

[0115] Among them, the change rate of the vertical component of the magnetic field in the X direction is B xz , the change rate of the vertical component of the magnetic field in the Y direction is B yz , and the change rate of the vertical component of the magnetic field in the Z direction is B zz . That is to say, the change rate of the vertical component of the magnetic field of each measurement point in the X direction, the change rate in the Y direction, and the change rate in the Z direction are the three elements in the last column of the magnetic gradient tensor information.

[0116] Based on this, in the embodiments of the present application, after obtaining the magnetic field gradient tensor information of each measurement point, the values in the last column of each magnetic gradient tensor information are respectively obtained from the magnetic field gradient tensor information of each measurement point, and the values in the last column of the magnetic gradient tensor information of each measurement point are determined as the change rate of the vertical component of the magnetic field of each measurement point in the X direction, the change rate in the Y direction, and the change rate in the Z direction.

[0117] S402, determine the change rate of the vertical component of the magnetic field of each measurement point in the X direction, the change rate in the Y direction, and the change rate in the Z direction as the change rate of the vertical component of the magnetic field of each measurement point in three-dimensional space.

[0118] The rates of change of the vertical magnetic field components at each measurement point in the X direction, Y direction, and Z direction obtained above are determined as the rates of change of the vertical magnetic field components at each measurement point in three-dimensional space.

[0119] In the multi-magnetic target horizontal position positioning method based on the magnetic gradient tensor provided in the embodiments of the present application, for any horizontal detection plane, according to the magnetic gradient tensor information collected at each measurement point in the horizontal detection plane, the rates of change of the vertical magnetic field components at each measurement point in the X direction, Y direction, and Z direction are obtained, and the rates of change of the vertical magnetic field components at each measurement point in the X direction, Y direction, and Z direction are determined as the rates of change of the vertical magnetic field components at each measurement point in three-dimensional space. In this method, the rates of change of the vertical magnetic field components in three-dimensional space include the rates of change of the vertical magnetic field components in the X direction, Y direction, and Z direction. Based on this, the last column value is obtained from the magnetic gradient tensor information of each measurement point, and the last column value in the magnetic gradient tensor information of each measurement point is determined as the rate of change of the vertical magnetic field components at each measurement point in three-dimensional space, providing a data basis for thermal imaging, thereby improving the detection accuracy of the horizontal information of the magnetic target.

[0120] Based on the above embodiments, an embodiment is provided to illustrate the process of obtaining the thermal imaging maps in different magnetic field directions.

[0121] In an exemplary embodiment, as Figure 9 shown, thermal imaging is performed according to the rates of change of the vertical magnetic field components at each measurement point in three-dimensional space to obtain thermal imaging maps in different magnetic field directions, including:

[0122] S501, for any horizontal detection plane, according to the rates of change of the vertical magnetic field components at each measurement point in the horizontal detection plane in three-dimensional space, determine the arctangent values of the respective rates of change.

[0123] The arctangent values of the rates of change of the vertical magnetic field components at each measurement point in three-dimensional space are determined by the following formulas (2)-(4).

[0124] (2)

[0125] (3)

[0126] (4)

[0127] Wherein, is the arctangent value of the rate of change of the vertical magnetic field component at each measurement point in the X direction; is the arctangent value of the rate of change of the vertical magnetic field component at each measurement point in the Y direction; It is the arctangent value of the rate of change of the vertical component of the magnetic field at each measurement point in the Z direction.

[0128] S502. Based on each rate of change and each arctangent value, perform thermal imaging on the horizontal detection plane to obtain an imaging thermal map in different magnetic field directions.

[0129] In one embodiment, for any magnetic field direction, use the rate of change of the vertical component of the magnetic field at each measurement point in this direction as the abscissa, and use the arctangent value of the rate of change of the vertical component of the magnetic field at each measurement point in this direction as the ordinate to perform thermal imaging, and obtain an imaging thermal map of the magnetic field direction.

[0130] In the embodiment of the present application, imaging the magnetic field-related information (each rate of change and each arctangent value) on the horizontal detection plane is achieved based on the red-blue imaging method. Among all the measurement points, the larger the magnetic field information data at the measurement point, the closer the corresponding imaging color is to red, and the smaller the value, the closer the imaging color corresponding to this measurement point is to blue.

[0131] For the magnetic field X direction, use the rate of change of the vertical component of the magnetic field at each measurement point in the X direction as the abscissa, and use the arctangent value of the rate of change of the vertical component of the magnetic field at each measurement point in the X direction as the ordinate, and perform thermal imaging on the horizontal detection plane to obtain an imaging thermal map in the magnetic field X direction. As Figure 10 shown, the left figure is information imaging, where there is a vertical line with a value of 0 passing through the magnetic target. The color at this vertical line is green, the left side of the vertical line is red, the right side of the vertical line is blue, and the corresponding color information decreases from top to bottom beside it, and the color transitions from red to blue. The right figure is the B xz imaging contour map. When the center point of the sensor array is located on the vertical line where the magnetic target is located, the positions of sensor 1 and sensor 3 in the sensor array are on the contour line. Therefore, the B z components measured by sensor 1 and sensor 3 at this position are the same. Furthermore, the B xz at this position is 0. Thus, the value at this measurement point is 0. Therefore the imaging thermal map will have a vertical line passing through the magnetic target. The colors from the outside to the inside in the right figure are blue, green, yellow, red, and dark red in turn.

[0132] For the magnetic field Y direction, use the rate of change of the vertical component of the magnetic field at each measurement point in the Y direction as the abscissa, and use the arctangent value of the rate of change of the vertical component of the magnetic field at each measurement point in the Y direction as the ordinate, and perform thermal imaging on the horizontal detection plane to obtain an imaging thermal map in the magnetic field Y direction. As Figure 11 shown, the left figure is Information imaging, where there is a horizontal line with a value of 0 passing through the magnetic target. The color at this vertical line is green, blue above the vertical line, and red below the vertical line. The right figure is B yz Imaging contour map. When the center point of the sensor array is located on the horizontal line where the magnetic target is located, the positions of sensor 2 and sensor 4 in the sensor array are on the contour line. Therefore, the B measured by sensor 2 and sensor 4 at this position z components are the same. Furthermore, the B at this position yz is 0. Thus, the value at this measurement point is 0. Therefore the imaging thermal map will have a horizontal line passing through the magnetic target. In the right figure, the colors from the outside to the inside are blue, green, yellow, red, and dark red in turn.

[0133] For the Z direction of the magnetic field, taking the change rate of the vertical component of the magnetic field at each measurement point in the Z direction as the abscissa, and taking the arctangent value of the change rate of the vertical component of the magnetic field at each measurement point in the Z direction as the ordinate, thermal imaging is performed on the horizontal detection plane to obtain the imaging thermal map in the Z direction of the magnetic field. As Figure 12 shown, the left figure is information imaging, where there is a circular line surrounding the magnetic target. The color at this circular line is green, blue inside the circular line, and red outside the circular line. The right figure is B zz Imaging contour map, where there is a circle of B around the position where the magnetic target is located zz with a value of 0, that is, area E, whose color is green. The B in area D zz is greater than zero, and the color is red. The B in area F zz is less than zero, and the color is blue.

[0134] In the method for horizontally positioning multiple magnetic targets based on magnetic gradient tensors provided in the embodiments of the present application, for any horizontal detection plane, according to the change rate of the vertical component of the magnetic field at each measurement point in the three-dimensional space in the horizontal detection plane, the arctangent value of each change rate is determined. Furthermore, according to each change rate and each arctangent value, thermal imaging is performed on the horizontal detection plane to obtain the imaging thermal maps in different magnetic field directions. In this method, by solving the arctangent function of the change rate of the vertical component of the magnetic field at each measurement point in the three-dimensional space, the arctangent value of each change rate is obtained. Then, using each change rate and each arctangent value as the abscissa and ordinate respectively, thermal imaging is performed on the horizontal detection plane, thereby obtaining the imaging thermal maps in different magnetic field directions. In this process, directly using the original data in the magnetic gradient tensor information as the imaging data for imaging improves the imaging accuracy, thereby improving the detection accuracy of the horizontal information of the magnetic target.

[0135] Based on the above embodiments, an embodiment is provided to illustrate the process of determining the horizontal information of the magnetic target.

[0136] In an exemplary embodiment, as Figure 13 shown, according to the imaging heat maps in different magnetic field directions, the horizontal information of each magnetic target is determined, including:

[0137] S601. For any horizontal detection plane, according to the imaging heat maps in each magnetic field direction in the horizontal detection plane, obtain the lines with an imaging median value of zero in each imaging heat map.

[0138] Based on the foregoing embodiment, after color imaging based on the magnetic field information in different magnetic field directions, there is a line with an imaging value of 0 in each imaging heat map. Therefore, in the embodiments of the present application, the lines with an imaging median value of zero are directly obtained from the imaging heat maps in different magnetic field directions for determining the horizontal information of the magnetic target.

[0139] S602. According to the lines with an imaging median value of zero in each imaging heat map, determine the horizontal information of the magnetic target in the horizontal detection plane.

[0140] Exemplarily, according to the lines with an imaging median value of zero in each imaging heat map, obtain the vertical lines in the imaging heat map in the X direction, the horizontal lines in the imaging heat map in the Y direction, and the circumferential lines in the imaging heat map in the Z direction; according to the vertical lines, horizontal lines, and circumferential lines, determine the horizontal information of the magnetic target in the horizontal detection plane.

[0141] In the imaging heat maps in different magnetic field directions, the types of the lines with an imaging median value of zero are different. In the imaging heat map in the X direction of the magnetic field, the line with an imaging median value of zero is the vertical line passing through the magnetic target. In the imaging heat map in the Y direction of the magnetic field, the line with an imaging median value of zero is the horizontal line passing through the magnetic target. In the imaging heat map in the Z direction of the magnetic field, the line with an imaging median value of zero is the circumferential line surrounding the magnetic target. After obtaining the vertical lines in the imaging heat map in the X direction, the horizontal lines in the imaging heat map in the Y direction, and the circumferential lines in the imaging heat map in the Z direction, based on the vertical lines, horizontal lines, and circumferential lines, determine the horizontal information of the magnetic target in the horizontal detection plane.

[0142] In one embodiment, as Figure 14 shown, according to the vertical lines, horizontal lines, and circumferential lines, determine the horizontal information of the magnetic target in the horizontal detection plane, including:

[0143] S701. According to the vertical lines, horizontal lines, and circumferential lines, obtain the intersection points of the vertical lines and horizontal lines inside the circumferential line.

[0144] Based on the above-extracted vertical lines in the imaging heat map in the X direction, horizontal lines in the imaging heat map in the Y direction, and circumferential lines in the imaging heat map in the Z direction, combine these lines in the same coordinate system to obtain the intersection points of the vertical lines and horizontal lines inside the circumferential line, as Figure 15As shown, the intersection of the vertical line and the horizontal line inside the circumferential line is M, and this intersection M is the horizontal position of the magnetic target.

[0145] S702, obtain the abscissa value and the ordinate value of the intersection in the horizontal detection plane.

[0146] S703, determine the abscissa value and the ordinate value of the intersection in the horizontal detection plane as the horizontal information of the magnetic target in the horizontal detection plane.

[0147] After obtaining the intersection of the vertical line and the horizontal line inside the circumferential line, obtain the abscissa value and the ordinate value of this intersection in the horizontal detection plane. This abscissa value and ordinate value are the abscissa and ordinate of the magnetic target. Based on this, determine the abscissa value and the ordinate value of the intersection in the horizontal detection plane as the horizontal information of the magnetic target in the horizontal detection plane.

[0148] In the multi-magnetic target horizontal position positioning method based on magnetic gradient tensor provided by the embodiments of the present application, for any horizontal detection plane, according to the imaging heat maps in each magnetic field direction in the horizontal detection plane, obtain the lines with the imaging median value of zero in each imaging heat map. Then, according to the lines with the imaging median value of zero in each imaging heat map, determine the horizontal information of the magnetic target in the horizontal detection plane. In this method, after obtaining the imaging heat maps in different magnetic field directions, obtain the lines with the imaging median value of zero from each imaging heat map, that is, obtain the vertical lines in the imaging heat map in the X direction, the horizontal lines in the imaging heat map in the Y direction, and the circumferential lines in the imaging heat map in the Z direction. The intersection of the vertical line and the horizontal line inside the circumferential line is the horizontal position of the magnetic target. Based on this, obtain the abscissa value and the ordinate value of the intersection of the vertical line and the horizontal line inside the circumferential line, so as to obtain the horizontal information of the magnetic target, providing a reliable and fast way for the detection of the horizontal information of the magnetic target.

[0149] In addition, in an exemplary embodiment, another embodiment of the multi-magnetic target horizontal position positioning method based on magnetic gradient tensor in the embodiments of the present application is described.

[0150] S1. According to the magnetic field distribution characteristics of multiple magnetic targets to be measured, determine multiple measurement points in the horizontal detection plane where the multiple magnetic targets are located.

[0151] S2. For any horizontal detection plane, obtain the magnetic field information collected by a single sensor at each measurement point in the horizontal detection plane.

[0152] S3. For any measurement point, based on the magnetic field information, obtain the magnetic field information of each adjacent measurement point of the measurement point; based on the magnetic field information of each adjacent measurement point, determine the change rate of the horizontal component of the magnetic field of the measurement point in three-dimensional space and the change rate of the vertical component of the magnetic field in three-dimensional space; determine the change rate of the horizontal component of the magnetic field of the measurement point in three-dimensional space and the change rate of the vertical component of the magnetic field in three-dimensional space as the magnetic gradient tensor information of the measurement point.

[0153] S4. For any horizontal detection plane, based on the magnetic gradient tensor information collected by each measurement point in the horizontal detection plane, obtain the change rate of the vertical component of the magnetic field of each measurement point in the X direction, in the Y direction, and in the Z direction; determine the change rate of the vertical component of the magnetic field of each measurement point in the X direction, in the Y direction, and in the Z direction as the change rate of the vertical component of the magnetic field of each measurement point in three-dimensional space.

[0154] S5. For any horizontal detection plane, based on the change rate of the vertical component of the magnetic field of each measurement point in the horizontal detection plane in three-dimensional space, determine the arctangent value of each change rate.

[0155] S6. For any magnetic field direction, use the change rate of the vertical component of the magnetic field of each measurement point in the direction as the abscissa, and use the arctangent value of the change rate of the vertical component of the magnetic field of each measurement point in the said direction as the ordinate to perform thermal imaging, and obtain the imaging thermal map of the magnetic field direction.

[0156] S7. For any horizontal detection plane, based on the imaging thermal map of each magnetic field direction in the horizontal detection plane, obtain the lines with an imaging median value of zero in each imaging thermal map; based on the lines with an imaging median value of zero in each imaging thermal map, obtain the vertical lines in the imaging thermal map in the X direction, the horizontal lines in the imaging thermal map in the Y direction, and the circular lines in the imaging thermal map in the Z direction.

[0157] S8. Based on the vertical lines, horizontal lines, and circular lines, obtain the intersections of the vertical lines and horizontal lines inside the circular line; obtain the abscissa value and ordinate value of the intersections in the horizontal detection plane; determine the abscissa value and ordinate value of the intersections in the horizontal detection plane as the horizontal information of the magnetic target in the horizontal detection plane.

[0158] In addition, taking 11 magnetic targets with different depths and magnetic moments in the simulation experiment as examples, the process of positioning these 11 magnetic targets is described.

[0159] As Figure 16 shown, it is the position information of 11 magnetic targets; Figure 17a shown, it is the information imaging corresponding to 11 magnetic targets; Figure 17b shown, it is the information imaging corresponding to 11 magnetic targets; Figure 17cFor the information imaging corresponding to 11 magnetic targets.

[0160] After obtaining three imaging heat maps, the lines with an imaging median value of zero are respectively extracted from them and shown in the same coordinate system. The intersection points of the vertical and horizontal lines within each circular line are the horizontal positions of the 11 magnetic targets, specifically as Figure 18 shown. Among them, the labels of the 11 magnetic targets are respectively ①~ .

[0161] Furthermore, taking two magnetic targets in the on-site experiment as examples, the positioning process of these two magnetic targets will be further described.

[0162] In on-site detection, two magnetic targets are placed with horizontal positions of (0.6, 0.55) and (1.35, 1.35) respectively. After imaging the magnetic field information measured at each measurement point in the detection plane, Figure 19a as shown, it is the information imaging corresponding to 2 magnetic targets; Figure 19b as shown, it is the information imaging corresponding to 2 magnetic targets; Figure 19c It is the information imaging corresponding to 2 magnetic targets.

[0163] After obtaining three imaging heat maps, the lines with an imaging median value of zero are respectively extracted from them and shown in the same coordinate system. The intersection points of the vertical and horizontal lines within each circular line are the horizontal positions of the 2 magnetic targets, specifically as Figure 20 shown. Among them, the labels of the two magnetic targets are respectively and .

[0164] In this embodiment, based on the magnetic gradient tensor, the measured magnetic field information is subjected to imaging processing to determine the positions of magnetic targets. Compared with traditional mathematical solution methods such as Euler inversion, this method does not require sensor calibration, does not require obtaining the magnetic anomaly field, and is less affected by environmental noise. Moreover, on the premise of keeping the sensor array structure unchanged, this method uses one sensor to measure the magnetic field information at each measurement point respectively, and takes the magnetic field information of the four adjacent measurement points of each measurement point as the measurement values of the four sensors of the cross-shaped sensor array at that measurement point. Through the above processing method, the number of sensors required for detecting each detection plane is reduced from 4 to 1, reducing the workload of data processing and misalignment correction of the sensor array.

[0165] It should be understood that although the steps in the flowcharts involved in the above-described embodiments are sequentially shown according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear indication in this article, there is no strict order limit for the execution of these steps, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-described embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or steps or stages in other steps.

[0166] Based on the same inventive concept, an embodiment of the present application further provides a multi-magnetic target horizontal position positioning device based on magnetic gradient tensor for implementing the above-mentioned multi-magnetic target horizontal position positioning method based on magnetic gradient tensor. The implementation solutions provided by this device to solve problems are similar to the implementation solutions described in the above method. Therefore, the specific limitations in one or more embodiments of the multi-magnetic target horizontal position positioning device based on magnetic gradient tensor provided below can refer to the limitations on the multi-magnetic target horizontal position positioning method based on magnetic gradient tensor in the above text, and will not be repeated here.

[0167] In an exemplary embodiment, as Figure 21 shown, a multi-magnetic target horizontal position positioning device 80 based on magnetic gradient tensor is provided, including: a measurement point determination module 81, a change rate determination module 82, a thermal imaging module 83, and a horizontal information determination module 84, where:

[0168] The measurement point determination module 81 is configured to determine multiple measurement points in the horizontal detection plane where multiple magnetic targets are located according to the magnetic field distribution characteristics of the multiple magnetic targets to be measured;

[0169] The change rate determination module 82 is configured to obtain the magnetic gradient tensor information of each measurement point and determine the change rate of the vertical magnetic field component of each measurement point in three-dimensional space according to the magnetic gradient tensor information of each measurement point;

[0170] The thermal imaging module 83 is configured to perform thermal imaging according to the change rate of the vertical magnetic field component of each measurement point in three-dimensional space to obtain imaging thermal maps in different magnetic field directions;

[0171] The horizontal information determination module 84 is configured to determine the horizontal information of each magnetic target according to the imaging thermal maps in different magnetic field directions.

[0172] In one of the embodiments, the above change rate determination module 82 is further configured to:

[0173] For any horizontal detection plane, acquire the magnetic field information collected by a single sensor at each measurement point in the horizontal detection plane; determine the magnetic gradient tensor information of each measurement point in the horizontal detection plane according to multiple adjacent measurement points of each measurement point and the respective magnetic field information.

[0174] In one embodiment, the above-mentioned change rate determination module 82 is further configured to:

[0175] For any measurement point, acquire the magnetic field information of each adjacent measurement point of the measurement point according to the respective magnetic field information; determine the change rate of the horizontal component of the magnetic field of the measurement point in three-dimensional space and the change rate of the vertical component of the magnetic field of the measurement point in three-dimensional space according to the magnetic field information of each adjacent measurement point; determine the change rate of the horizontal component of the magnetic field of the measurement point in three-dimensional space and the change rate of the vertical component of the magnetic field of the measurement point in three-dimensional space as the magnetic gradient tensor information of the measurement point.

[0176] In one embodiment, the above-mentioned change rate determination module 82 is further configured to:

[0177] For any horizontal detection plane, acquire the change rate of the vertical component of the magnetic field of each measurement point in the X direction, the change rate in the Y direction, and the change rate in the Z direction according to the magnetic gradient tensor information collected at each measurement point in the horizontal detection plane; determine the change rate of the vertical component of the magnetic field of each measurement point in three-dimensional space as the change rate of the vertical component of the magnetic field of each measurement point in the X direction, the change rate in the Y direction, and the change rate in the Z direction.

[0178] In one embodiment, the above-mentioned thermal imaging module 83 is further configured to:

[0179] For any horizontal detection plane, determine the arctangent value of each change rate according to the change rate of the vertical component of the magnetic field of each measurement point in three-dimensional space; perform thermal imaging on the horizontal detection plane according to each change rate and each arctangent value to obtain an imaging thermal map in different magnetic field directions.

[0180] In one embodiment, the above-mentioned thermal imaging module 83 is further configured to:

[0181] For any magnetic field direction, perform thermal imaging with the change rate of the vertical component of the magnetic field of each measurement point in the direction as the abscissa and the arctangent value of the change rate of the vertical component of the magnetic field of each measurement point in the direction as the ordinate to obtain an imaging thermal map of the magnetic field direction.

[0182] In one embodiment, the above-mentioned horizontal information determination module 84 is further configured to:

[0183] For any horizontal detection plane, according to the thermal imaging maps in each magnetic field direction in the horizontal detection plane, obtain the lines where the imaging median value is zero in each thermal imaging map; according to the lines where the imaging median value is zero in each thermal imaging map, determine the horizontal information of the magnetic target in the horizontal detection plane.

[0184] In one embodiment, the above-mentioned horizontal information determination module 84 is further configured to:

[0185] According to the lines where the imaging median value is zero in each thermal imaging map, obtain the vertical lines in the thermal imaging map in the X direction, the horizontal lines in the thermal imaging map in the Y direction, and the circumferential lines in the thermal imaging map in the Z direction; according to the vertical lines, horizontal lines, and circumferential lines, determine the horizontal information of the magnetic target in the horizontal detection plane.

[0186] In one embodiment, the above-mentioned horizontal information determination module 84 is further configured to:

[0187] According to the vertical lines, horizontal lines, and circumferential lines, obtain the intersections of the vertical lines and horizontal lines within the circumferential line;

[0188] Obtain the abscissa value and ordinate value of the intersection in the horizontal detection plane;

[0189] Determine the abscissa value and ordinate value of the intersection in the horizontal detection plane as the horizontal information of the magnetic target in the horizontal detection plane.

[0190] Each module in the above-mentioned multi-magnetic target horizontal position positioning device based on magnetic gradient tensor can be implemented in whole or in part by software, hardware, and their combination. The above-mentioned modules can be embedded in the processor of the computer device in the form of hardware or independent of it, or stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above-mentioned modules.

[0191] In an exemplary embodiment, a computer device is provided, including a memory and a processor. A computer program is stored in the memory. When the processor executes the computer program, the following steps are implemented:

[0192] According to the magnetic field distribution characteristics of multiple magnetic targets to be measured, determine multiple measurement points in the horizontal detection plane where the multiple magnetic targets are located;

[0193] Obtain the magnetic gradient tensor information of each measurement point, and determine the change rate of the magnetic field vertical component of each measurement point in three-dimensional space according to the magnetic gradient tensor information of each measurement point;

[0194] Perform thermal imaging according to the change rate of the magnetic field vertical component of each measurement point in three-dimensional space, and obtain thermal imaging maps in different magnetic field directions;

[0195] According to the thermal imaging maps in different magnetic field directions, determine the horizontal information of each magnetic target.

[0196] In the embodiments of the present application, the steps implemented by the processor have similar implementation principles and technical effects to those of the above-mentioned multi-magnetic target horizontal position positioning method based on magnetic gradient tensors, which will not be elaborated here.

[0197] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0198] According to the magnetic field distribution characteristics of multiple magnetic targets to be measured, determine multiple measurement points in the horizontal detection plane where the multiple magnetic targets are located;

[0199] Obtain the magnetic gradient tensor information of each measurement point, and determine the change rate of the vertical magnetic field component of each measurement point in three-dimensional space according to the magnetic gradient tensor information of each measurement point;

[0200] Perform thermal imaging according to the change rate of the vertical magnetic field component of each measurement point in three-dimensional space to obtain imaging thermal maps in different magnetic field directions;

[0201] According to the imaging thermal maps in different magnetic field directions, determine the horizontal information of each magnetic target.

[0202] In the embodiments of the present application, the steps implemented when the computer program is executed by the processor have similar implementation principles and technical effects to those of the above-mentioned multi-magnetic target horizontal position positioning method based on magnetic gradient tensors, which will not be elaborated here.

[0203] In one embodiment, a computer program product is provided, including a computer program. When the computer program is executed by a processor, the following steps are implemented:

[0204] According to the magnetic field distribution characteristics of multiple magnetic targets to be measured, determine multiple measurement points in the horizontal detection plane where the multiple magnetic targets are located;

[0205] Obtain the magnetic gradient tensor information of each measurement point, and determine the change rate of the vertical magnetic field component of each measurement point in three-dimensional space according to the magnetic gradient tensor information of each measurement point;

[0206] Perform thermal imaging according to the change rate of the vertical magnetic field component of each measurement point in three-dimensional space to obtain imaging thermal maps in different magnetic field directions;

[0207] According to the imaging thermal maps in different magnetic field directions, determine the horizontal information of each magnetic target.

[0208] In the embodiments of the present application, the steps implemented when the computer program is executed by the processor have similar implementation principles and technical effects to those of the above-mentioned multi-magnetic target horizontal position positioning method based on magnetic gradient tensors, which will not be elaborated here.

[0209] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data that have been authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0210] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memories. Non-volatile memories can include read-only memory (ROM), magnetic tapes, floppy disks, flash memories, optical memories, high-density embedded non-volatile memories, resistive random access memories (ReRAM), magnetoresistive random access memories (MRAM), ferroelectric random access memories (FRAM), phase change memories (PCM), graphene memories, etc. Volatile memories can include random access memory (RAM) or external cache memories, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in this application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in this application can be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, data processing logics based on quantum computing, etc., without limitation.

[0211] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0212] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A method for horizontally positioning multiple magnetic targets based on magnetic gradient tensors, characterized in that The method includes: Determining a plurality of measurement points in a horizontal detection plane where the plurality of magnetic targets are located according to the magnetic field distribution characteristics of the plurality of magnetic targets to be measured; Obtaining the magnetic gradient tensor information of each of the measurement points, and determining the change rate of the vertical magnetic field component of each measurement point in three-dimensional space according to the magnetic gradient tensor information of each of the measurement points; Performing thermal imaging according to the change rate of the vertical magnetic field component of each measurement point in three-dimensional space to obtain thermal imaging maps in different magnetic field directions; For any horizontal detection plane, obtaining the lines with an imaging median value of zero in each of the thermal imaging maps according to the thermal imaging maps in each magnetic field direction in the horizontal detection plane; Obtaining the vertical lines in the thermal imaging map in the X direction, the horizontal lines in the thermal imaging map in the Y direction, and the circular lines in the thermal imaging map in the Z direction according to the lines with an imaging median value of zero in each of the thermal imaging maps; Determining the horizontal information of the magnetic targets in the horizontal detection plane according to the vertical lines, the horizontal lines, and the circular lines; 2. The method according to claim 1, wherein The obtaining the magnetic gradient tensor information of each of the measurement points includes: For any horizontal detection plane, obtaining the magnetic field information collected by a single sensor at each measurement point in the horizontal detection plane; Determining the magnetic gradient tensor information of each measurement point in the horizontal detection plane according to the multiple adjacent measurement points of each measurement point and the magnetic field information; 3. The method according to claim 2, wherein The determining the magnetic gradient tensor information of each measurement point in the horizontal detection plane according to the multiple adjacent measurement points of each measurement point and the magnetic field information includes: For any measurement point, obtaining the magnetic field information of each adjacent measurement point of the measurement point according to the magnetic field information; Determining the change rate of the horizontal magnetic field component of the measurement point in three-dimensional space and the change rate of the vertical magnetic field component of the measurement point in three-dimensional space according to the magnetic field information of each adjacent measurement point; Determining the change rate of the horizontal magnetic field component of the measurement point in three-dimensional space and the change rate of the vertical magnetic field component of the measurement point in three-dimensional space as the magnetic gradient tensor information of the measurement point; 4. The method according to any one of claims 1 to 3, characterized in that, The determining the change rate of the vertical magnetic field component of each measurement point in three-dimensional space according to the magnetic gradient tensor information of each of the measurement points includes: For any horizontal detection plane, obtaining the change rate of the vertical magnetic field component of each measurement point in the X direction, the change rate in the Y direction, and the change rate in the Z direction according to the magnetic gradient tensor information collected at each measurement point in the horizontal detection plane; Determining the change rate of the vertical magnetic field component of each measurement point in the X direction, the change rate in the Y direction, and the change rate in the Z direction as the change rate of the vertical magnetic field component of each measurement point in three-dimensional space; 5. The method according to any one of claims 1-3, characterized in that, The performing thermal imaging according to the change rate of the vertical magnetic field component of each measurement point in three-dimensional space to obtain thermal imaging maps in different magnetic field directions includes: For any horizontal detection plane, determining the arctangent value of each of the change rates according to the change rate of the vertical magnetic field component of each measurement point in three-dimensional space in the horizontal detection plane; Performing thermal imaging in the horizontal detection plane according to each of the change rates and each of the arctangent values to obtain the thermal imaging maps in different magnetic field directions.

6. The method according to claim 5, wherein Performing thermal imaging on the horizontal detection plane according to each of the change rates and each of the arctangent values to obtain the imaging thermal maps in different magnetic field directions, including: For any magnetic field direction, performing thermal imaging with the change rate of the magnetic field vertical component of each measurement point in this direction as the abscissa and the arctangent value of the change rate of the magnetic field vertical component of each measurement point in this direction as the ordinate to obtain the imaging thermal map of this magnetic field direction.

7. The method according to any one of claims 1 to 3, characterized in that, Determining the horizontal information of the magnetic target in the horizontal detection plane according to the vertical line, the horizontal line, and the circular line, including: According to the vertical line, the horizontal line, and the circular line, obtaining the intersection points of the vertical line and the horizontal line within the circular line; Obtaining the abscissa value and the ordinate value of the intersection points in the horizontal detection plane; Determining the abscissa value and the ordinate value of the intersection points in the horizontal detection plane as the horizontal information of the magnetic target in the horizontal detection plane.

8. A multi-magnetic target horizontal position positioning device based on magnetic gradient tensor, characterized in that, The device includes: A measurement point determination module, configured to determine a plurality of measurement points in the horizontal detection plane where the plurality of magnetic targets are located according to the magnetic field distribution characteristics of the plurality of magnetic targets to be measured; A change rate determination module, configured to obtain the magnetic gradient tensor information of each measurement point, and determine the change rate of the magnetic field vertical component of each measurement point in three-dimensional space according to the magnetic gradient tensor information of each measurement point; A thermal imaging module, configured to perform thermal imaging according to the change rate of the magnetic field vertical component of each measurement point in three-dimensional space to obtain imaging thermal maps in different magnetic field directions; A horizontal information determination module, configured to, for any horizontal detection plane, obtain the lines with an imaging median value of zero in each of the imaging thermal maps according to the imaging thermal maps in each magnetic field direction in the horizontal detection plane; obtain the vertical line in the imaging thermal map in the X direction, the horizontal line in the imaging thermal map in the Y direction, and the circular line in the imaging thermal map in the Z direction according to the lines with an imaging median value of zero in each of the imaging thermal maps; and determine the horizontal information of the magnetic target in the horizontal detection plane according to the vertical line, the horizontal line, and the circular line.

9. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, the steps of the method according to any one of claims 1 to 7 are implemented.

11. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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