Multi-magnetic target positioning method, device, equipment and medium based on magnetic gradient tensor

Abstract

The present application proposes a method, device, equipment and medium for positioning multiple magnetic targets based on magnetic gradient tensor, which relates to the field of magnetic target positioning technology. A single sensor is used to obtain the direction resolution signal of each measuring point in two horizontal detection planes, and the direction resolution signal with the same horizontal position is differentiated to obtain its change in the z direction; horizontal detection data is obtained and imaged according to the change, and horizontal information of multiple magnetic targets is obtained; a single sensor is used to obtain the magnetic gradient tensor G of each measuring point in the depth detection plane, and the depth detection data of each measuring point is obtained and imaged; the depth information of multiple magnetic targets is obtained according to the y-axis coordinate values ​​and imaging results of multiple magnetic targets. The above method is to perform imaging processing on the measured magnetic field information on the basis of the magnetic gradient tensor G to determine the position of the magnetic target. This method has low requirements on the correction accuracy of the magnetic sensor array and is less affected by environmental noise.

Description

Technical Field

[0001] The present application relates to the field of magnetic target positioning technology, and in particular to a method, device, equipment and medium for positioning multiple magnetic targets based on a magnetic gradient tensor. Background Art

[0002] In magnetic target detection operations, magnetic gradient tensor information can provide additional information about the magnetic field at a deeper level and has the advantage of higher spatial resolution. Therefore, magnetic target positioning methods usually select magnetic gradient tensor data for positioning calculations. However, traditional magnetic target positioning methods are usually based only on the measurement data of a single magnetic target, and the positioning method of a single magnetic target is difficult to be effectively used for the detection of multiple magnetic targets.

[0003] At present, the positioning method for multiple magnetic targets is improved on the basis of the Euler inversion method. After obtaining a large amount of magnetic target position data through the Euler inversion method, some methods use the K-means clustering algorithm to cluster these initial position data to determine the position of each magnetic target in three-dimensional space; some methods use grid data to collect magnetic field gradient tensor data, derive the Euler equations for multi-point joint inversion, propose a fast and accurate method to find the optimal solution, and optimize the inversion optimal solution through genetic algorithms; some methods use the FCM clustering algorithm (Fuzzy C-Means Clustering Algorithm) to cluster the initial positions obtained by the Euler inversion method to determine the number and position of magnetic targets. However, the above methods have problems such as high requirements for correction accuracy, uncertainty in the number of detected magnetic targets, and positioning results biased towards the magnetic targets that have the greatest impact on the measurement points.

[0004] Based on this, a new magnetic target positioning method is urgently needed for positioning multiple magnetic targets. Summary of the invention

[0005] The present application provides a multi-magnetic target positioning method, device, equipment and medium based on magnetic gradient tensor to solve the above-mentioned problems existing in the existing magnetic target positioning method.

[0006] In a first aspect of an embodiment of the present application, a multi-magnetic target positioning method based on a magnetic gradient tensor is proposed, the method comprising:

[0007] Use a single sensor to obtain the directional resolution signals Ax, Ay and Az of each measuring point in two horizontal detection planes;

[0008] Differentiating the direction-analyzed signals Ax, Ay and Az corresponding to the same horizontal position of the two horizontal detection planes to obtain the variation of the direction-analyzed signals Ax, Ay and Az in the z direction;

[0009] According to the variation of the directional resolution signals Ax, Ay and Az of each measuring point in the z direction, horizontal detection data of each measuring point is obtained, and imaging is performed on the XOY plane to obtain horizontal information of multiple magnetic targets, wherein the horizontal information of the multiple magnetic targets includes x-axis coordinate values ​​and y-axis coordinate values ​​of the multiple magnetic targets;

[0010] Using the single sensor to obtain a magnetic gradient tensor G of each measuring point in a depth detection plane;

[0011] According to the magnetic gradient tensor G of each measuring point in the depth detection plane, the depth detection data of each measuring point is obtained, and imaging is performed on the YOZ plane;

[0012] According to the y-axis coordinate values ​​of the multiple magnetic targets and the imaging results on the YOZ plane, the depth information of the multiple magnetic targets is obtained, and the depth information of the multiple magnetic targets includes the z-axis coordinate values ​​of the multiple magnetic targets.

[0013] In an optional embodiment of the present application, a single sensor is used to obtain direction-analyzed signals Ax, Ay, and Az of each measuring point in each horizontal detection plane, including:

[0014] Use the single sensor to measure the magnetic field information of each measuring point in each horizontal detection plane, the magnetic field information of each measuring point is the three components of the magnetic field of four measuring points adjacent to the measuring point in the east, west, south and north directions, and the three components of the magnetic field are the components on the three axes of X-axis, Y-axis and Z-axis facing the geographic east, geographic north and vertically upward respectively;

[0015] The magnetic gradient tensor information G of each measuring point is obtained based on the three components of the magnetic field of the four measuring points adjacent to each measuring point in the east-west, south-north direction;

[0016] According to the magnetic gradient tensor information G of each measuring point, the direction analysis signals Ax, Ay and Az of each measuring point are obtained.

[0017] In an optional embodiment of the present application, the two horizontal detection planes include a horizontal detection plane 1 and a horizontal detection plane 2, with a height difference of L meters, and the height of the horizontal detection plane 1 in the z-axis direction is higher than the height of the horizontal detection plane 2 in the z-axis direction.

[0018] In an optional embodiment of the present application, the direction-resolved signals Ax, Ay and Az corresponding to the same horizontal position on the two horizontal detection planes are differentiated to obtain the change amount of the direction-resolved signals Ax, Ay and Az in the z direction, and the calculation formula used is as follows:

[0019]

[0020] In the formula, A xzis the change of the direction analysis signal Ax in the z direction, A yz is the change of the direction analysis signal Ay in the z direction, A zz is the change of the direction analysis signal Az in the z direction. On the horizontal detection plane 1, A 1x A is the directional analytical signal of the measuring point in the x direction. 1y A is the directional analytical signal of the measuring point in the y direction. 1z is the directional analytical signal of the measuring point in the z direction; on the horizontal detection plane 2, A 2x A is the directional analytical signal of the measuring point in the x direction. 2y A is the directional analytical signal of the measuring point in the y direction. 2z The direction analysis signal of the measuring point in the z direction.

[0021] In an optional embodiment of the present application, the horizontal detection data of each measuring point is obtained according to the change amount of the directional analysis signals Ax, Ay and Az of each measuring point in the z direction, and the calculation formula used is as follows:

[0022]

[0023] In the formula, A xz is the change of the direction analysis signal Ax in the z direction, A yz is the change of the direction analysis signal Ay in the z direction, A zz is the change of the direction analysis signal Az in the z direction.

[0024] In an optional embodiment of the present application, the depth detection data of each measuring point is obtained according to the magnetic gradient tensor G of each measuring point in the depth detection plane, and the calculation formula used is as follows:

[0025]

[0026] Where Bxx is the rate of change of the magnetic field component Bx in the x direction, Bxy is the rate of change of the magnetic field component Bx in the y direction, and Bxz is the rate of change of the magnetic field component Bx in the z direction.

[0027] In an optional embodiment of the present application, the imaging on the XOY plane and the imaging on the YOZ plane are implemented based on red-blue imaging, and the horizontal information and depth information of each measuring point are normalized. The closer the normalized value is to 1, the closer the imaging color corresponding to the measuring point is to red, and the closer the normalized value is to 0, the closer the imaging color corresponding to the measuring point is to blue.

[0028] The method of obtaining depth information of the multiple magnetic targets according to the y-axis coordinate values ​​of the multiple magnetic targets and the imaging results on the YOZ plane includes:

[0029] Based on the horizontal information of the multiple magnetic targets, obtaining y-axis coordinate values ​​of the multiple magnetic targets;

[0030] The intersection of the y-axis coordinate value and the dark blue band in the imaging result on the YOZ plane is determined as the z-axis coordinate value of the multiple magnetic targets.

[0031] In a second aspect of an embodiment of the present application, a multi-magnetic target positioning device based on a magnetic gradient tensor is proposed, the device comprising:

[0032] A horizontal detection module, used to obtain direction analysis signals Ax, Ay and Az of each measuring point in two horizontal detection planes using a single sensor;

[0033] A differential module, used for differentiating the direction-analyzed signals Ax, Ay and Az corresponding to the same horizontal positions of the two horizontal detection planes to obtain the variation of the direction-analyzed signals Ax, Ay and Az in the z direction;

[0034] A horizontal information acquisition module is used to obtain horizontal detection data of each measuring point according to the change amount of the directional analytical signals Ax, Ay and Az of each measuring point in the z direction, and to perform imaging on the XOY plane to obtain horizontal information of multiple magnetic targets, wherein the horizontal information of the multiple magnetic targets includes x-axis coordinate values ​​and y-axis coordinate values ​​of the multiple magnetic targets;

[0035] A depth detection module, used to obtain a magnetic gradient tensor G of each measuring point in a depth detection plane using the single sensor;

[0036] A depth imaging module, used to obtain the depth detection data of each measuring point according to the magnetic gradient tensor G of each measuring point in the depth detection plane, and perform imaging on the YOZ plane;

[0037] The depth information acquisition module is used to obtain the depth information of multiple magnetic targets according to the y-axis coordinate values ​​of the multiple magnetic targets and the imaging results on the YOZ plane, wherein the depth information of the multiple magnetic targets includes the z-axis coordinate values ​​of the multiple magnetic targets.

[0038] In a third aspect of an embodiment of the present application, an electronic device is proposed, comprising a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the multi-magnetic target positioning method based on magnetic gradient tensor as described in any one of the first aspects above.

[0039] In a fourth aspect of an embodiment of the present application, a computer-readable storage medium is proposed, on which a computer program / instruction is stored. When the computer program / instruction is executed by a processor, the multi-magnetic target positioning method based on magnetic gradient tensor as described in any one of the first aspects above is implemented.

[0040] The present application includes the following advantages: The present application proposes a multi-magnetic target positioning method, device, equipment and medium based on magnetic gradient tensor, using a single sensor to obtain direction-resolved signals Ax, Ay and Az of each measuring point in two horizontal detection planes; the direction-resolved signals Ax, Ay and Az of the corresponding measuring points with the same horizontal position on the two horizontal detection planes are differentiated to obtain the change amount of the direction-resolved signals Ax, Ay and Az in the z direction; according to the change amount of the direction-resolved signals Ax, Ay and Az of each measuring point in the z direction, the horizontal detection data of each measuring point is obtained, and the horizontal detection data of each measuring point is obtained in XO Imaging is performed on the Y plane to obtain the horizontal information of multiple magnetic targets, and the horizontal information of the multiple magnetic targets includes the x-axis coordinate values ​​and y-axis coordinate values ​​of the multiple magnetic targets; the magnetic gradient tensor G of each measuring point in a depth detection plane is obtained using the single sensor; according to the magnetic gradient tensor G of each measuring point in the depth detection plane, the depth detection data of each measuring point is obtained, and imaging is performed on the YOZ plane; according to the y-axis coordinate values ​​of multiple magnetic targets and the imaging results on the YOZ plane, the depth information of multiple magnetic targets is obtained, and the depth information of the multiple magnetic targets includes the z-axis coordinate values ​​of multiple magnetic targets. The method proposed in this application is to perform imaging processing on the measured magnetic field information based on the magnetic gradient tensor G to determine the position of the magnetic target. Compared with traditional mathematical solution methods such as Euler inversion, this method has lower requirements on the correction accuracy of the magnetic sensor array and is less affected by environmental noise. On the premise of keeping the sensor array structure unchanged, the number of sensors required for detecting each detection plane is successfully reduced from 4 to 1, reducing the workload of data processing and non-alignment correction of the sensor array. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0042] Figure 1 It is a flowchart of the steps of a multi-magnetic target positioning method based on magnetic gradient tensor proposed in an embodiment of the present application;

[0043] Figure 2 It is a schematic diagram of horizontal position detection of multiple magnetic targets provided in an embodiment of the present application;

[0044] Figure 3 It is a schematic diagram of obtaining direction analysis signals of each measuring point in the prior art;

[0045] Figure 4 It is a schematic diagram of detecting a measuring point in a horizontal detection plane in a multi-magnetic target positioning method based on a magnetic gradient tensor proposed in an embodiment of the present application;

[0046] Figure 5 It is a schematic diagram of imaging results on the XOY plane in a multi-magnetic target positioning method based on magnetic gradient tensor proposed in an embodiment of the present application;

[0047] Figure 6 It is a schematic diagram of a depth detection plane in a multi-magnetic target positioning method based on magnetic gradient tensor proposed in an embodiment of the present application;

[0048] Figure 7 It is a schematic diagram of detecting a measuring point in a depth detection plane in a multi-magnetic target positioning method based on a magnetic gradient tensor proposed in an embodiment of the present application;

[0049] Figure 8 It is a schematic diagram of imaging results on the YOZ plane in a multi-magnetic target positioning method based on magnetic gradient tensor proposed in an embodiment of the present application;

[0050] Fig. 9 This is a schematic diagram of the result of a multi-magnetic target positioning method based on magnetic gradient tensor proposed in an embodiment of the present application being interfered by noise;

[0051] Fig.10 It is an architecture diagram of a multi-magnetic target positioning device based on magnetic gradient tensor provided in an embodiment of the present application;

[0052] Fig.11 It is a schematic diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0054] In magnetic target detection operations, magnetic gradient tensor information can provide additional information about the magnetic field at a deeper level and has the advantage of higher spatial resolution. Therefore, magnetic target positioning methods usually select magnetic gradient tensor data for positioning calculations. The main positioning method for a single magnetic target is the Euler inversion method. The advantage of this method is that it simplifies the nonlinear inversion problem into a linear equation system, making the calculation easier and faster. However, traditional magnetic target positioning methods are usually based only on the measurement data of a single magnetic target, and the positioning method for a single magnetic target is difficult to be effectively used for the detection of multiple magnetic targets.

[0055] At present, the positioning method for multiple magnetic targets is improved on the basis of the Euler inversion method. After obtaining a large amount of magnetic target position data through the Euler inversion method, some methods use the K-means clustering algorithm to cluster these initial position data to determine the position of each magnetic target in three-dimensional space; some methods use grid data to collect magnetic field gradient tensor data, derive the Euler equations for multi-point joint inversion, propose a fast and accurate method to find the optimal solution, and optimize the inversion optimal solution through genetic algorithms; some methods use the FCM clustering algorithm (Fuzzy C-Means Clustering Algorithm) to cluster the initial positions obtained by the Euler inversion method to determine the number and position of magnetic targets. However, the above methods have the following problems:

[0056] (1) Before detection, the magnetic sensor itself and the sensor array need to be calibrated. Since the Euler inversion positioning method approximates the nonlinear inversion problem as the solution of a linear equation system, this method has high requirements on the calibration accuracy of the magnetic sensor.

[0057] (2) The number of magnetic targets needs to be determined before optimization and clustering, but in most cases, the number of magnetic targets is unknown.

[0058] (3) When the magnetic moments and burial depths of different magnetic targets are quite different, the solution of the Euler equation will tend to favor the magnetic target that has the greatest impact on the measured point data, that is, the magnetic target with a larger magnetic moment or a shallower burial depth.

[0059] Based on this, this application proposes a multi-magnetic target positioning method, which uses the multi-dimensional information of the magnetic gradient tensor to optimize the weight distribution of different components, thereby improving the resolution of magnetic targets at different magnetic moments and depths, and visualizes the final magnetic field information to achieve precise positioning of multiple magnetic targets.

[0060] See also Figure 1 , Figure 1 : is a flowchart of a multi-magnetic target positioning method based on magnetic gradient tensor proposed in an embodiment of the present application, the method comprising the following steps:

[0061] Step 101: using a single sensor to obtain direction analysis signals Ax, Ay and Az of each measuring point in two horizontal detection planes;

[0062] Step 102: Differentiate the direction-analyzed signals Ax, Ay and Az corresponding to the same horizontal positions of the two horizontal detection planes to obtain the variation of the direction-analyzed signals Ax, Ay and Az in the z direction;

[0063] Step 103: obtaining horizontal detection data of each measuring point according to the variation of the directional resolution signals Ax, Ay and Az of each measuring point in the z direction, and performing imaging on the XOY plane to obtain horizontal information of multiple magnetic targets, wherein the horizontal information of the multiple magnetic targets includes x-axis coordinate values ​​and y-axis coordinate values ​​of the multiple magnetic targets;

[0064] Step 104: using the single sensor to obtain a magnetic gradient tensor G of each measuring point in a depth detection plane;

[0065] Step 105: obtaining depth detection data of each measuring point according to the magnetic gradient tensor G of each measuring point in the depth detection plane, and performing imaging on a YOZ plane;

[0066] Step 106: Obtain depth information of the multiple magnetic targets according to the y-axis coordinate values ​​of the multiple magnetic targets and the imaging results on the YOZ plane, wherein the depth information of the multiple magnetic targets includes the z-axis coordinate values ​​of the multiple magnetic targets.

[0067] When step 101 is specifically implemented, the directional analytical signal is obtained by introducing the concept of complex analytical signal into the magnetic anomaly data processing. The analytical signal is a complex function, the real part of which is the original signal, and the imaginary part is the Hilbert transform of the original signal. In magnetic anomaly detection, by calculating the analytical signal of magnetic anomaly data, important information about the source of the magnetic anomaly field can be extracted. Figure 2 , Figure 2 It is a schematic diagram of horizontal position detection of multiple magnetic targets provided in an embodiment of the present application. A single sensor is used on two horizontal detection planes to obtain direction-resolved signals Ax, Ay and Az of each measuring point, and the same sensor is used on two horizontal detection planes to obtain direction-resolved signals.

[0068] Compared with the prior art, see Figure 3 , Figure 3 The schematic diagram of obtaining the direction analysis signal of each measuring point in the prior art is shown in FIG. 1 . In the prior art, a cross-shaped sensor array is used to obtain the direction analysis signal of each measuring point. That is, when detecting each measuring point, a cross-shaped sensor array is placed. Figure 3The sensor array shown in part (a) is placed at the center O of the sensor array at the measuring point to detect data. In this application, in order to improve the utilization rate of the measuring point data and reduce the influence of the sensor calibration accuracy on the experiment, Figure 3 As shown in part (b), only a single sensor is needed to measure the magnetic field information of each measuring point, and the magnetic field information of the four measuring points adjacent to the central measuring point O1 (the measuring points located in the east, west, south and north of the central measuring point O1) is used as the measurement value of the four sensors of the cross-shaped sensor array at the central measuring point O1. The magnetic field data detected by the measuring point O3 located between the measuring points O1 and O2 can be used as the magnetic field value measured by the sensor 3 of the cross-shaped sensor array at the point O1, and can also be used as the value measured by the sensor 1 of the cross-shaped sensor array at the point O2.

[0069] In an optional embodiment of the present application, a single sensor is used to obtain direction-resolved signals Ax, Ay, and Az of each measuring point in each horizontal detection plane, including the following method: first, the single sensor is used to measure the magnetic field information of each measuring point in each of the horizontal detection planes, the magnetic field information of each measuring point is the three components of the magnetic field of four measuring points adjacent to the measuring point in the east-west, south-north directions, and the three components of the magnetic field are components on the three axes of the X-axis, the Y-axis, and the Z-axis facing the geographic east, the geographic north, and the vertical upward; according to the three components of the magnetic field of the four measuring points adjacent to the measuring point in the east-west, south-north directions, the magnetic gradient tensor information G of each measuring point is obtained; wherein the magnetic gradient tensor information G of each measuring point can be expressed as follows:

[0070]

[0071] Wherein, 2d is the baseline distance of the magnetic sensor array, that is, the distance between two sensors in the horizontal direction or the distance between two sensors in the vertical direction in the magnetic sensor array, Bx, By and Bz are the magnetic field components of each measuring point in the X-axis, Y-axis and Z-axis respectively, B1x and B3x are the magnetic field components of the measuring points of the single sensor on the west and east sides of the measuring point in the X-axis respectively, B1y, B2y, B3y and B4y are the magnetic field components of the measuring points of the single sensor on the west, north, east and south sides of the measuring point in the y-axis respectively, B1z, B2z, B3z and B4z are the magnetic field components of the measuring points of the single sensor on the west, north, east and south sides of the measuring point in the Y-axis respectively. The magnetic field components of the measuring points on the left, right, north, east and south sides on the z-axis; Bxx is the rate of change of the magnetic field component Bx in the x-direction, Bxy is the rate of change of the magnetic field component Bx in the y-direction, Bxz is the rate of change of the magnetic field component Bx in the z-direction, Byx is the rate of change of the magnetic field component By in the x-direction, Byy is the rate of change of the magnetic field component By in the y-direction, Byz is the rate of change of the magnetic field component By in the z-direction, Bzx is the rate of change of the magnetic field component Bz in the x-direction, Bzy is the rate of change of the magnetic field component Bz in the y-direction, and Bzz is the rate of change of the magnetic field component Bz in the z-direction.

[0072] According to the above expression, the magnetic gradient tensor information G can be expressed as a matrix, and the modulus of each row of magnetic gradient data in the matrix G is used as the directional analytical signals Ax, Ay and Az of each measuring point, which can be expressed as follows:

[0073]

[0074] Wherein, Bxx is the rate of change of the magnetic field component Bx in the x direction, Bxy is the rate of change of the magnetic field component Bx in the y direction, Bxz is the rate of change of the magnetic field component Bx in the z direction, Byy is the rate of change of the magnetic field component By in the y direction, Byz is the rate of change of the magnetic field component By in the z direction, and Bzz is the rate of change of the magnetic field component Bz in the z direction, where Bxx, Bxy, Bxz, Byy, Byz and Bzz are calculated by the matrix G, and their expressions can be expressed as follows:

[0075]

[0076] When step 102 is specifically implemented, after obtaining the direction-resolved signals Ax, Ay and Az of each measuring point on each horizontal detection plane, the direction-resolved signals Ax, Ay and Az of the corresponding measuring points at the same horizontal position on the two horizontal detection planes are differentiated to obtain the changes in the direction-resolved signals Ax, Ay and Az in the z direction.

[0077] In an optional embodiment of the present application, if Figure 2 As shown, the two horizontal detection planes include a horizontal detection plane 1 and a horizontal detection plane 2, and the height difference L between the two horizontal detection planes is determined based on actual needs. The horizontal detection plane 1 and the horizontal detection plane are both XOY planes, and the height of the horizontal detection plane 1 in the z-axis direction is higher than the height of the horizontal detection plane 2 in the z-axis direction.

[0078] The two horizontal detection planes are detected in the same way, see Figure 4 , Figure 4 Schematic diagram of detecting a measuring point in a horizontal detection plane in a multi-magnetic target positioning method based on magnetic gradient tensor proposed in an embodiment of the present application. There is an N×N detection square array in the horizontal detection plane. The interval between each measuring point in the detection square array is d meters, which is the same as the distance d between each sensor and the center point in the sensor array. Figure 4 In the example, the distance d between each measuring point is 0.1 meters. Then, a sensor is used to measure the magnetic field information of each measuring point, and the magnetic field information of the four measuring points adjacent to each measuring point in the east, west, south and north directions is used as the four sensor measurement values ​​of the cross-shaped sensor array at the measuring point. Through the above processing method, the magnetic gradient tensor G and direction resolution signals Ax, Ay and Az at each measuring point in each horizontal detection plane are obtained.

[0079] In an optional embodiment of the present application, the direction-resolved signals Ax, Ay and Az corresponding to the same horizontal position on the two horizontal detection planes are differentiated to obtain the change in the z direction of the direction-resolved signals Ax, Ay and Az. The calculation formula used is as follows:

[0080]

[0081] In the formula, A xz is the change of the direction analysis signal Ax in the z direction, A yz is the change of the direction analysis signal Ay in the z direction, A zz is the change of the direction analysis signal Az in the z direction. On the horizontal detection plane 1, A 1x A is the directional analytical signal of the measuring point in the x direction. 1y A is the directional analytical signal of the measuring point in the y direction. 1z is the directional analytical signal of the measuring point in the z direction; on the horizontal detection plane 2, A 2x A is the directional analytical signal of the measuring point in the x direction. 2y A is the directional analytical signal of the measuring point in the y direction. 2z The direction analysis signal of the measuring point in the z direction.

[0082] When step 103 is specifically implemented, the horizontal detection data of each measuring point is obtained based on the change in the z direction of the directional resolution signals Ax, Ay and Az of each measuring point on the horizontal detection plane. The horizontal detection data of each measuring point is obtained by calculating the change in the z direction of the directional resolution signals Ax, Ay and Az of each measuring point, thereby optimizing the weight distribution method of the directional resolution signals Ax, Ay and Az in the z direction, and improving the resolution capability of magnetic targets with smaller magnetic moments or deeper buried.

[0083] In an optional embodiment of the present application, the horizontal detection data of each measuring point is obtained according to the change amount of the directional analysis signals Ax, Ay and Az of each measuring point in the z direction, and the calculation formula used is as follows:

[0084]

[0085] In the formula, A xz is the change of the direction analysis signal Ax in the z direction, A yz is the change of the direction analysis signal Ay in the z direction, A zz is the change of the direction analysis signal Az in the z direction.

[0086] See also Figure 5 , Figure 5This is a schematic diagram of the imaging results on the XOY plane in a multi-magnetic target positioning method based on magnetic gradient tensor proposed in an embodiment of the present application. After obtaining the horizontal detection data of each measuring point, the horizontal detection data of each measuring point is used to image on the XOY plane, and the horizontal information of multiple magnetic targets is obtained through the imaging results. The horizontal information of the multiple magnetic targets includes the x-axis coordinate values ​​and y-axis coordinate values ​​of the multiple magnetic targets. Imaging on the XOY plane using the horizontal detection data of each measuring point is achieved based on the red-blue imaging method. The horizontal information and depth information of each measuring point are normalized. The closer the normalized value is to 1, the closer the imaging color corresponding to the measuring point is to red. The closer the normalized value is to 0, the closer the imaging color corresponding to the measuring point is to blue.

[0087] When step 104 is specifically implemented, after obtaining the horizontal information of multiple magnetic targets, a single sensor is used to detect the depth detection plane, see Figure 6 , Figure 6 Schematic diagram of a depth detection plane in a multi-magnetic target positioning method based on magnetic gradient tensor proposed in an embodiment of the present application. The magnetic gradient tensor G of each measuring point in a depth detection plane is obtained using the above single sensor. Figure 7 , Figure 7 Schematic diagram of detecting a measuring point in a depth detection plane in a multi-magnetic target positioning method based on magnetic gradient tensor proposed in an embodiment of the present application. There is an N×N detection square array in the depth detection plane. The interval between each measuring point in the detection square array is d meters, which is the same as the distance d between each sensor and the center point in the sensor array. Figure 7 In the example, the distance d between each measuring point is 0.1 meters. A sensor is used to measure the magnetic field information of each measuring point, and the magnetic field information of the four measuring points adjacent to each measuring point is used as the four sensor measurement values ​​of the cross-shaped sensor array at the measuring point. Through the above processing method, the magnetic gradient tensor G at each measuring point can be obtained.

[0088] In an optional embodiment of the present application, the magnetic gradient tensor is calculated from the three components of the magnetic field, and the magnetic gradient tensor G can be expressed as:

[0089]

[0090] In the formula, the meaning of each letter is the same as the above, and will not be repeated here.

[0091] When step 105 is specifically implemented, the depth detection data of each measuring point is calculated based on the magnetic gradient tensor G obtained at each measuring point in the above-mentioned depth detection plane.

[0092] In an optional embodiment of the present application, the depth detection data of each measuring point is obtained according to the magnetic gradient tensor G of each measuring point in the depth detection plane, and the calculation formula used is as follows:

[0093]

[0094] Where Bxx is the rate of change of the magnetic field component Bx in the x direction, Bxy is the rate of change of the magnetic field component Bx in the y direction, and Bxz is the rate of change of the magnetic field component Bx in the z direction. Among them, Bxx, Bxy, and Bxz are calculated by the matrix G, and their expressions can be expressed as follows:

[0095]

[0096] After the depth detection data of each measuring point is obtained, imaging is performed on the YOZ plane using the depth detection data of each measuring point to obtain an imaging result on the YOZ plane.

[0097] When implementing step 106, refer to Figure 8 , Figure 8 This is a schematic diagram of imaging results on the YOZ plane in a multi-magnetic target positioning method based on magnetic gradient tensor proposed in an embodiment of the present application. After obtaining the imaging results on the YOZ plane, the depth information of the multiple magnetic targets is obtained according to the y-axis coordinate values ​​of the multiple magnetic targets and the imaging results on the YOZ plane. The depth information of the multiple magnetic targets includes the z-axis coordinate values ​​of the multiple magnetic targets. Among them, imaging on the YOZ plane is realized based on red-blue imaging, and the depth information of each measuring point is normalized. The closer the normalized value is to 1, the closer the imaging color corresponding to the measuring point is to red, and the closer the normalized value is to 0, the closer the imaging color corresponding to the measuring point is to blue.

[0098] In an optional embodiment of the present application, the depth information of the multiple magnetic targets is obtained according to the y-axis coordinate values ​​of the multiple magnetic targets and the imaging results on the YOZ plane, including: obtaining the y-axis coordinate values ​​of the multiple magnetic targets based on the horizontal information of the above-mentioned multiple magnetic targets; and determining the intersection of the above-mentioned y-axis coordinate value and the dark blue band in the imaging result on the YOZ plane as the z-axis coordinate value of the multiple magnetic targets.

[0099] by Figure 5 and Figure 8 For example, the height of horizontal detection plane 1 in the z-axis direction is 0.5 meters, the height of horizontal detection plane 2 in the z-axis direction is 1 meter, the size of the horizontal detection plane is 2 meters × 2 meters, and the distance between each measuring point is set to 0.1 meters. Then each horizontal detection plane has 400 (20 × 20) detection points. The horizontal detection data of each measuring point is imaged on the XOY plane. The result is as follows Figure 5 As shown, it can be clearly distinguished that the horizontal positions of magnetic target 1 and magnetic target 2 are (0.55, 0.25) and (1.40, 1.10) respectively.

[0100] The size of the depth detection plane is 2 meters × 2 meters, and the distance between each measuring point is set to 0.1 meters. The depth detection plane has 400 (20 × 20) detection points. A sensor is used to measure the depth information of each measuring point and image it in the YOZ plane. According to the horizontal information, the y coordinate values ​​of magnetic target 1 and magnetic target 2 are 0.25 and 1.10 respectively. According to the y coordinate value and the YOZ imaging result, the depth information z coordinate value of magnetic target 1 is -0.30 and the depth information z coordinate value of magnetic target 2 is -0.50. The results are as follows: Figure 8 As shown in the figure, by integrating the horizontal information and depth information of multiple magnetic targets, the final position information of multiple magnetic targets is (0.55, 0.25, -0.30) and (1.40, 1.10, -0.50) respectively.

[0101] In order to evaluate the influence of noise interference on the multi-magnetic target positioning method based on magnetic gradient tensor proposed in the embodiment of the present application, in the comparative experiment, noise with a mean of 10 and conforming to Gaussian distribution was added to the generation process of magnetic field information. The experimental results are shown in Fig. 9 , Fig. 9 This is a schematic diagram of the results of a multi-magnetic target positioning method based on magnetic gradient tensor proposed in the embodiment of the present application being interfered by noise. Compared with the traditional multi-magnetic target positioning method, this method does not need to use mathematical formulas to solve the position information, but uses magnetic field data imaging to identify magnetic targets, so it is less affected by environmental noise. Fig. 9 As shown, Fig. 9 Part (a) is a noise-free horizontal detection image obtained by using a multi-magnetic target positioning method based on magnetic gradient tensor. Fig. 9 Part (b) is a horizontal detection image with noise interference obtained by using a multi-magnetic target positioning method based on magnetic gradient tensor. After adding noise interference, it does not have a significant impact on the detection results and detection effects of this application.

[0102] The present application proposes a multi-magnetic target positioning method based on magnetic gradient tensor, which uses a single sensor to obtain direction-resolved signals Ax, Ay and Az of each measuring point in two horizontal detection planes; the direction-resolved signals Ax, Ay and Az of the corresponding measuring points with the same horizontal position on the two horizontal detection planes are differentiated to obtain the variation of the direction-resolved signals Ax, Ay and Az in the z direction; the horizontal detection data of each measuring point is obtained according to the variation of the direction-resolved signals Ax, Ay and Az of each measuring point in the z direction, and imaging is performed on the XOY plane. The horizontal information of multiple magnetic targets is obtained, and the horizontal information of the multiple magnetic targets includes the x-axis coordinate values ​​and y-axis coordinate values ​​of the multiple magnetic targets; the magnetic gradient tensor G of each measuring point in a depth detection plane is obtained using the single sensor; according to the magnetic gradient tensor G of each measuring point in the depth detection plane, the depth detection data of each measuring point is obtained, and imaging is performed on the YOZ plane; according to the y-axis coordinate values ​​of multiple magnetic targets and the imaging results on the YOZ plane, the depth information of multiple magnetic targets is obtained, and the depth information of the multiple magnetic targets includes the z-axis coordinate values ​​of multiple magnetic targets. The method proposed in the present application is to perform imaging processing on the measured magnetic field information based on the magnetic gradient tensor G to determine the position of the magnetic target. Compared with traditional mathematical solution methods such as Euler inversion, this method has lower requirements on the correction accuracy of the magnetic sensor array and is less affected by environmental noise. On the premise of keeping the sensor array structure unchanged, the number of sensors required for detecting each detection plane is successfully reduced from 4 to 1, reducing the workload of data processing and non-alignment correction of the sensor array.

[0103] In a second aspect of the embodiment of the present application, a multi-magnetic target positioning device based on a magnetic gradient tensor is proposed, see Fig.10 , Fig.10 : is an architecture diagram of a multi-magnetic target positioning device based on magnetic gradient tensor provided in an embodiment of the present application, the device comprising:

[0104] The horizontal detection module 1001 is used to obtain the directional analysis signals Ax, Ay and Az of each measuring point in two horizontal detection planes using a single sensor;

[0105] A differential module 1002 is used to differentiate the direction-analyzed signals Ax, Ay and Az corresponding to the same horizontal position of the two horizontal detection planes to obtain the variation of the direction-analyzed signals Ax, Ay and Az in the z direction;

[0106] The horizontal information acquisition module 1003 is used to obtain the horizontal detection data of each measuring point according to the change amount of the directional analytical signals Ax, Ay and Az of each measuring point in the z direction, and perform imaging on the XOY plane to obtain the horizontal information of multiple magnetic targets, wherein the horizontal information of the multiple magnetic targets includes the x-axis coordinate values ​​and the y-axis coordinate values ​​of the multiple magnetic targets;

[0107] A depth detection module 1004 is used to obtain a magnetic gradient tensor G of each measuring point in a depth detection plane using the single sensor;

[0108] A depth imaging module 1005 is used to obtain depth detection data of each measuring point according to the magnetic gradient tensor G of each measuring point in the depth detection plane, and perform imaging on a YOZ plane;

[0109] The depth information acquisition module 1006 is used to obtain the depth information of the multiple magnetic targets according to the y-axis coordinate values ​​of the multiple magnetic targets and the imaging results on the YOZ plane, wherein the depth information of the multiple magnetic targets includes the z-axis coordinate values ​​of the multiple magnetic targets.

[0110] Wherein, the level detection module comprises:

[0111] A measurement submodule, used to use the single sensor to measure the magnetic field information of each measuring point in each of the horizontal detection planes, wherein the magnetic field information of each measuring point is the three components of the magnetic field of four measuring points adjacent to the measuring point in the east, west, south and north directions, and the three components of the magnetic field are the components on the three axes of the X-axis, the Y-axis and the Z-axis facing the geographic east, the geographic north and the vertical upward direction respectively;

[0112] The magnetic gradient tensor information G acquisition submodule is used to obtain the magnetic gradient tensor information G of each measuring point according to the three components of the magnetic field of four measuring points adjacent to each measuring point in the east-west, south-north directions;

[0113] The direction resolution signal acquisition submodule is used to obtain the direction resolution signals Ax, Ay and Az of each measuring point according to the magnetic gradient tensor information G of each measuring point.

[0114] Among them, the two horizontal detection planes in the horizontal detection module include horizontal detection plane 1 and horizontal detection plane 2, with a height difference of L meters, and the height of horizontal detection plane 1 in the z-axis direction is higher than the height of horizontal detection plane 2 in the z-axis direction.

[0115] The calculation formula used in the differential module is as follows:

[0116]

[0117] In the formula, A xz is the change of the direction analysis signal Ax in the z direction, A yz is the change of the direction analysis signal Ay in the z direction, A zz is the change of the direction analysis signal Az in the z direction. On the horizontal detection plane 1, A 1x A is the directional analytical signal of the measuring point in the x direction. 1yA is the directional analytical signal of the measuring point in the y direction. 1z is the directional analytical signal of the measuring point in the z direction; on the horizontal detection plane 2, A 2x A is the directional analytical signal of the measuring point in the x direction. 2y A is the directional analytical signal of the measuring point in the y direction. 2z The direction analysis signal of the measuring point in the z direction.

[0118] The calculation formula used in the horizontal information acquisition module is as follows:

[0119]

[0120]

[0121] In the formula, A xz is the change of the direction analysis signal Ax in the z direction, A yz is the change of the direction analysis signal Ay in the z direction, A zz is the change of the direction analysis signal Az in the z direction.

[0122] The calculation formula used in the depth imaging module is as follows:

[0123]

[0124] Where Bxx is the rate of change of the magnetic field component Bx in the x direction, Bxy is the rate of change of the magnetic field component Bx in the y direction, and Bxz is the rate of change of the magnetic field component Bx in the z direction.

[0125] The horizontal information acquisition module and the depth imaging module also include an imaging submodule, which is implemented based on red and blue imaging. The horizontal information and depth information of each measuring point are normalized. The closer the normalized value is to 1, the closer the imaging color corresponding to the measuring point is to red. The closer the normalized value is to 0, the closer the imaging color corresponding to the measuring point is to blue.

[0126] The depth information acquisition module includes:

[0127] A y-axis coordinate value acquisition submodule, used to acquire y-axis coordinate values ​​of multiple magnetic targets based on the horizontal information of the multiple magnetic targets;

[0128] The z-axis coordinate value determination submodule is used to determine the intersection of the y-axis coordinate value and the dark blue band in the imaging result on the YOZ plane as the z-axis coordinate values ​​of multiple magnetic targets.

[0129] Based on the same application concept, the embodiment of the present application discloses an electronic device in a third aspect. Fig.11 A schematic diagram of an electronic device disclosed in an embodiment of the present application is shown. Fig.11 As shown, the electronic device 100 includes: a memory 110 and a processor 120, the memory of the electronic device is not less than 12G, the main frequency of the processor is not less than 2.4GHz, the memory 110 and the processor 120 are connected via a bus communication, and a computer program is stored in the memory 110. The computer program can be run on the processor 120 to implement a multi-magnetic target positioning method based on a magnetic gradient tensor disclosed in an embodiment of the present application.

[0130] Based on the same application concept, the fourth aspect of the embodiment of the present application discloses a computer-readable storage medium, on which a computer program / instruction is stored. When the computer program / instruction is executed by a processor, a multi-magnetic target positioning method based on magnetic gradient tensor disclosed in the embodiment of the present application is implemented.

[0131] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0132] The embodiments of the present application are described with reference to the flowcharts and / or block diagrams of the methods, apparatuses, electronic devices, and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing terminal device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0133] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing terminal device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0134] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal device so that a series of operating steps are executed on the computer or other programmable terminal device to produce a computer-implemented process, thereby providing instructions for executing on the computer or other programmable terminal device to implement the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0135] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present application.

[0136] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0137] The above is a detailed introduction to the multi-magnetic target positioning method, device, equipment and medium based on magnetic gradient tensor provided by the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for general technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A multi-magnetic target positioning method based on magnetic gradient tensor, characterized in that: The method comprises: Use a single sensor to obtain the directional resolution signals Ax, Ay and Az of each measuring point in two horizontal detection planes; Differentiating the direction-analyzed signals Ax, Ay and Az corresponding to the same horizontal position of the two horizontal detection planes to obtain the variation of the direction-analyzed signals Ax, Ay and Az in the z direction; According to the variation of the directional resolution signals Ax, Ay and Az of each measuring point in the z direction, horizontal detection data of each measuring point is obtained, and imaging is performed on the XOY plane to obtain horizontal information of multiple magnetic targets, wherein the horizontal information of the multiple magnetic targets includes x-axis coordinate values ​​and y-axis coordinate values ​​of the multiple magnetic targets; Using the single sensor to obtain a magnetic gradient tensor G of each measuring point in a depth detection plane; According to the magnetic gradient tensor G of each measuring point in the depth detection plane, the depth detection data of each measuring point is obtained, and imaging is performed on the YOZ plane; According to the y-axis coordinate values ​​of the multiple magnetic targets and the imaging results on the YOZ plane, the depth information of the multiple magnetic targets is obtained, and the depth information of the multiple magnetic targets includes the z-axis coordinate values ​​of the multiple magnetic targets.

2. The multi-magnetic target positioning method based on magnetic gradient tensor according to claim 1, characterized in that: Use a single sensor to obtain the directional resolution signals Ax, Ay and Az of each measuring point in each horizontal detection plane, including: Use the single sensor to measure the magnetic field information of each measuring point in each horizontal detection plane, the magnetic field information of each measuring point is the three components of the magnetic field of four measuring points adjacent to the measuring point in the east, west, south and north directions, and the three components of the magnetic field are the components on the three axes of X-axis, Y-axis and Z-axis facing the geographic east, geographic north and vertically upward respectively; The magnetic gradient tensor information G of each measuring point is obtained based on the three components of the magnetic field of the four measuring points adjacent to each measuring point in the east-west, south-north direction; According to the magnetic gradient tensor information G of each measuring point, the direction analysis signals Ax, Ay and Az of each measuring point are obtained.

3. The multi-magnetic target positioning method based on magnetic gradient tensor according to claim 1, characterized in that: The two horizontal detection planes include a horizontal detection plane 1 and a horizontal detection plane 2, with a height difference of L meters. The height of the horizontal detection plane 1 in the z-axis direction is higher than the height of the horizontal detection plane 2 in the z-axis direction.

4. The multi-magnetic target positioning method based on magnetic gradient tensor according to claim 3 is characterized in that: The direction-analyzed signals Ax, Ay and Az corresponding to the same horizontal position on the two horizontal detection planes are differentiated to obtain the variation of the direction-analyzed signals Ax, Ay and Az in the z direction. The calculation formula used is as follows: ， ， ， In the formula, A xz is the change of the direction analysis signal Ax in the z direction, A yz is the change of the direction analysis signal Ay in the z direction, A zz is the change of the direction analysis signal Az in the z direction. On the horizontal detection plane 1, A 1x A is the directional analytical signal of the measuring point in the x direction. 1y A is the directional analytical signal of the measuring point in the y direction. 1z is the directional analytical signal of the measuring point in the z direction; on the horizontal detection plane 2, A 2x A is the directional analytical signal of the measuring point in the x direction. 2y A is the directional analytical signal of the measuring point in the y direction. 2z The direction analysis signal of the measuring point in the z direction.

5. The multi-magnetic target positioning method based on magnetic gradient tensor according to claim 1, characterized in that: According to the change amount of the directional analytical signals Ax, Ay and Az in the z direction of each measuring point, the horizontal detection data of each measuring point is obtained, and the calculation formula used is as follows: ， In the formula, A xz is the change of the direction analysis signal Ax in the z direction, A yz is the change of the direction analysis signal Ay in the z direction, A zz is the change of the direction analysis signal Az in the z direction.

6. The multi-magnetic target positioning method based on magnetic gradient tensor according to claim 1, characterized in that: According to the magnetic gradient tensor G of each measuring point in the depth detection plane, the depth detection data of each measuring point is obtained, and the calculation formula used is as follows: ， Where Bxx is the rate of change of the magnetic field component Bx in the x direction, Bxy is the rate of change of the magnetic field component Bx in the y direction, and Bxz is the rate of change of the magnetic field component Bx in the z direction.

7. The multi-magnetic target positioning method based on magnetic gradient tensor according to claim 1, characterized in that: The imaging on the XOY plane and the imaging on the YOZ plane are implemented based on the red-blue imaging method, and the horizontal information and depth information of each measuring point are normalized. The closer the normalized value is to 1, the closer the imaging color corresponding to the measuring point is to red, and the closer the normalized value is to 0, the closer the imaging color corresponding to the measuring point is to blue; The method of obtaining depth information of the multiple magnetic targets according to the y-axis coordinate values ​​of the multiple magnetic targets and the imaging results on the YOZ plane includes: Based on the horizontal information of the multiple magnetic targets, obtaining y-axis coordinate values ​​of the multiple magnetic targets; The intersection of the y-axis coordinate value and the dark blue band in the imaging result on the YOZ plane is determined as the z-axis coordinate value of the multiple magnetic targets.

8. A multi-magnetic target positioning device based on magnetic gradient tensor, characterized in that: The device comprises: A horizontal detection module, used to obtain direction analysis signals Ax, Ay and Az of each measuring point in two horizontal detection planes using a single sensor; A differential module, used for differentiating the direction-analyzed signals Ax, Ay and Az corresponding to the same horizontal positions of the two horizontal detection planes to obtain the variation of the direction-analyzed signals Ax, Ay and Az in the z direction; A horizontal information acquisition module is used to obtain horizontal detection data of each measuring point according to the change amount of the directional analytical signals Ax, Ay and Az of each measuring point in the z direction, and to perform imaging on the XOY plane to obtain horizontal information of multiple magnetic targets, wherein the horizontal information of the multiple magnetic targets includes x-axis coordinate values ​​and y-axis coordinate values ​​of the multiple magnetic targets; A depth detection module, used to obtain a magnetic gradient tensor G of each measuring point in a depth detection plane using the single sensor; A depth imaging module, used to obtain the depth detection data of each measuring point according to the magnetic gradient tensor G of each measuring point in the depth detection plane, and perform imaging on the YOZ plane; The depth information acquisition module is used to obtain the depth information of multiple magnetic targets according to the y-axis coordinate values ​​of the multiple magnetic targets and the imaging results on the YOZ plane, wherein the depth information of the multiple magnetic targets includes the z-axis coordinate values ​​of the multiple magnetic targets.

9. An electronic device comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the multi-magnetic target positioning method based on magnetic gradient tensor according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: A computer program / instruction is stored thereon, and when the computer program / instruction is executed by a processor, the multi-magnetic target positioning method based on magnetic gradient tensor described in any one of claims 1-7 is implemented.

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