Error correction method, system, device and medium for full tensor magnetic gradient probe

Abstract

The present application provides an error correction method for a full-tensor magnetic gradient probe, the method comprising: obtaining chip error data of the full-tensor magnetic gradient probe; the chip error data comprising the full-tensor magnetic gradient of the full-tensor magnetic gradient probe and the gradient of a planar gradiometer; the full-tensor magnetic gradient probe being provided with at least one planar gradiometer; each planar gradiometer being provided with the chip; obtaining the error angle of each planar gradiometer based on the full-tensor magnetic gradient and the gradient of each planar gradiometer; performing chip angle error correction on the full-tensor magnetic gradient based on the error angle of each planar gradiometer to obtain the corrected full-tensor magnetic gradient. The present application obtains the error angle of each planar gradiometer by comparing the full-tensor magnetic gradient of the full-tensor magnetic gradient probe with the gradient of each planar gradiometer, thereby completing the correction of the chip angle error of the full-tensor magnetic gradient probe and improving the accuracy of the full-tensor magnetic gradient data.

Description

Technical Field

[0001] The present application belongs to the technical field of full tensor magnetic gradient probes, and in particular relates to an error correction method, system, device and medium for a full tensor magnetic gradient probe. Background Art

[0002] Full-tensor magnetic gradient measurement is an emerging technology in the field of airborne magnetic surveying. It can simultaneously measure the gradient information of the spatial magnetic field vector in three directions, with a total of nine components. Compared with traditional magnetic surveying techniques, full-tensor magnetic gradient measurement offers significant advantages and is particularly suitable for ore body exploration and the precise location of magnetic targets. This technology not only provides directional information on the magnetic field but also demonstrates insensitivity to changes in the flight platform's attitude, even in environments where the background magnetic field gradient is much smaller than the magnetic anomaly gradient, making it easier to achieve high-precision measurements.

[0003] The low-temperature superconducting full-tensor magnetic gradient measurement system combines a superconducting quantum interference device (SQUID) with airborne magnetic measurement technology, and is a culmination of current international cutting-edge technologies. The system replaces the traditional two-sensor differential method with a SQUID-based planar gradiometer, significantly improving the sensitivity and accuracy of magnetic field gradient measurements. Common low-temperature superconducting full-tensor magnetic gradient probe configurations include regular pentahedron, regular hexagonal pyramid, and cross, among which the regular hexagonal pyramid configuration is particularly prominent. Its design enables the output of each planar gradiometer to include five independent components (Bxx, Bxy, Bxz, Byy, Byz) of the nine components of the full magnetic gradient field tensor, thereby providing good redundancy and reliability for the system.

[0004] The full-tensor magnetic gradient probe, in the form of a regular hexagonal pyramid, consists of six planar gradiometers and a top-mounted SQUID triaxial magnetometer. The six planar gradiometers, mounted on the six sides of the module, measure gradient components, while the top triaxial magnetometer performs common-mode compensation. While this design offers high redundancy and high precision, it still faces certain technical challenges in practical application. Mechanical errors are inevitable during the fabrication, packaging, and assembly of the planar gradiometers. These errors cause the actual mounting position of the chip to deviate from the ideal design position, leading to angular errors such as tilt, offset, and roll between the chip's sensitive axis and the module's plane sensitive axis. These errors are added to the gradiometer output, reducing the accuracy of the full-tensor magnetic gradient data. For example, a 1° error in the tilt angle of one of the planar gradiometers can result in a deviation of up to 2.3% in the invariant of the full-tensor magnetic gradient in the measurement results. This error has a significant impact on the overall accuracy of the measurement system, especially in application scenarios requiring high sensitivity and high precision. The existence of this error will seriously reduce the accuracy of the full tensor magnetic gradient data. Summary of the Invention

[0005] The present application provides an error correction method, system, device, and medium for a full-tensor magnetic gradient probe, which are used to address the problem that existing full-tensor magnetic gradient probes containing planar gradiometers have angular errors such as tilt angle, offset angle, and roll angle between the sensitive axis of the planar gradiometer chip and the sensitive axis of the module plane, thereby reducing the accuracy of the full-tensor magnetic gradient data.

[0006] In a first aspect, the present application provides an error correction method for a full-tensor magnetic gradient probe, the method comprising: obtaining chip error data of the full-tensor magnetic gradient probe; the chip error data comprising the full-tensor magnetic gradient of the full-tensor magnetic gradient probe and the gradient of a planar gradiometer; the full-tensor magnetic gradient probe being provided with at least one planar gradiometer; each planar gradiometer being provided with the chip; obtaining an error angle of each planar gradiometer based on the full-tensor magnetic gradient and the gradient of each planar gradiometer; performing chip angle error correction on the full-tensor magnetic gradient based on the error angle of each planar gradiometer to obtain a corrected full-tensor magnetic gradient.

[0007] In an implementation of the first aspect, obtaining chip error data of a full-tensor magnetic gradient probe includes: installing the full-tensor magnetic gradient probe at the center of a three-axis Maxwell coil; using a signal generator and a power amplifier to respectively supply sinusoidal currents to the three-axis Maxwell coil to obtain the full-tensor magnetic gradient of the full-tensor magnetic gradient probe; and obtaining a gradient output of each planar gradiometer in the three-axis Maxwell coil as the gradient of the planar gradiometer.

[0008] In an implementation of the first aspect, obtaining the error angle of each plane gradiometer based on the full tensor magnetic gradient and the gradient of each plane gradiometer includes: constructing an error equation of each plane gradiometer based on the full tensor magnetic gradient and the gradient of each plane gradiometer; solving the error equation of each plane gradiometer separately using the Newton iteration method to obtain the error angle of each plane gradiometer; the error angle includes the tilt angle, the offset angle and / or the roll angle.

[0009] In an implementation of the first aspect, constructing an error equation for each of the planar gradiometers based on the full tensor magnetic gradient and the gradient of each of the planar gradiometers includes: obtaining vector parameters of each of the planar gradiometers; the vector parameters include a baseline vector and a plane normal vector; and constructing an error equation for each of the planar gradiometers based on the baseline vector and the plane normal vector of each of the planar gradiometers, the full tensor magnetic gradient, and the gradient of each of the planar gradiometers.

[0010] In an implementation of the first aspect, constructing an error equation for each of the planar gradiometers based on the baseline vector and the plane normal vector of each of the planar gradiometers, the full tensor magnetic gradient, and the gradient of each of the planar gradiometers includes: Among them, gij = [gi1, gi2, gi3] is the gradient value output by the i-th SQUID planar gradiometer, G1 is the full tensor magnetic gradient of the full tensor magnetic gradient probe, is the baseline vector from the center of the lower picking ring of the i-th plane gradiometer to the center of the upper picking ring, is the plane normal vector of the i-th plane gradiometer, β 1i ,β 2i ,β 3i are the offset angle, inclination angle and roll angle of the i-th plane gradiometer, and Li is the baseline length of the i-th plane gradiometer.

[0011] In an implementation of the first aspect, the error equations of each of the plane gradiometers are solved separately using the Newton iteration method to obtain the error angle of each of the plane gradiometers, including: obtaining the initialization angle data of each of the plane gradiometers; calculating and obtaining the target equation of each of the plane gradiometers based on the initialization angle data of each of the plane gradiometers and the error equation of each of the plane gradiometers; calculating and obtaining the corresponding Jacobian matrix based on the target equation of each of the plane gradiometers; calculating and obtaining the next error angle based on the target equation and the Jacobian matrix of each of the plane gradiometers; iteratively calculating until the target equation of each of the plane gradiometers converges, and using the error angle at this time as the error angle of each of the plane gradiometers.

[0012] In an implementation of the first aspect, performing chip angle error correction on the full tensor magnetic gradient according to the error angle of each of the planar gradiometers, and obtaining the corrected full tensor magnetic gradient includes: obtaining an error angle function of each of the planar gradiometers according to the error angle calculation of each of the planar gradiometers; performing chip angle error correction calculation according to the error angle function of the planar gradiometer and the gradient of each of the planar gradiometers, and obtaining the corrected full tensor magnetic gradient.

[0013] In a second aspect, the present application provides an error correction system for a full-tensor magnetic gradient probe, the system comprising: an acquisition module configured to acquire chip error data of the full-tensor magnetic gradient probe; the chip error data comprises the full-tensor magnetic gradient of the full-tensor magnetic gradient probe and the gradient of the planar gradiometer; the full-tensor magnetic gradient probe is provided with at least one planar gradiometer; each planar gradiometer is provided with the chip; a calculation module configured to acquire the error angle of each planar gradiometer based on the full-tensor magnetic gradient and the gradient of each planar gradiometer; a correction module configured to perform chip angle error correction on the full-tensor magnetic gradient based on the error angle of each planar gradiometer, and acquire the corrected full-tensor magnetic gradient.

[0014] In a third aspect, the present application provides an electronic device, comprising: a processor and a memory; the memory is configured to store a computer program; the processor is configured to execute the computer program stored in the memory, so that the electronic device performs the error correction method of the full tensor magnetic gradient probe as described above.

[0015] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by an electronic device, implements the error correction method for the full tensor magnetic gradient probe as described above.

[0016] As described above, the error correction method, system, device, and medium for a full tensor magnetic gradient probe described in this application have the following beneficial effects:

[0017] The present application obtains chip error data of a full-tensor magnetic gradient probe; the chip error data includes the full-tensor magnetic gradient of the full-tensor magnetic gradient probe and the gradient of a planar gradiometer; the full-tensor magnetic gradient probe is provided with at least one planar gradiometer; each planar gradiometer is provided with the chip; the error angle of each planar gradiometer is obtained based on the full-tensor magnetic gradient and the gradient of each planar gradiometer; the chip angle error of the full-tensor magnetic gradient is corrected based on the error angle of each planar gradiometer to obtain the corrected full-tensor magnetic gradient. By comparing the full-tensor magnetic gradient of the full-tensor magnetic gradient probe with the gradient of each planar gradiometer, the error angle of each planar gradiometer is obtained, thereby completing the correction of the chip angle error of the full-tensor magnetic gradient probe. The advantage of the present application over traditional methods is that the magnetic field generated by the three-axis Maxwell coil is more uniform than the magnetic field generated by the dipole current, reducing its volume effect, thereby improving the correction accuracy of the chip angle error.

[0018] The present application obtains the error angle of each planar gradiometer by comparing the full tensor magnetic gradient of the full tensor magnetic gradient probe with the gradient of each planar gradiometer. Since there is no need to solve the error parameters during the motion process as in traditional methods, the magnetic interference caused by the motion is avoided, which may affect the error correction result. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Shown is a schematic diagram of the product equipment structure of a full-tensor magnetic gradient probe with a regular hexagonal pyramid configuration as described in an embodiment of the present application.

[0020] Figure 2 Shown is a flow chart of an error correction method for a full tensor magnetic gradient probe according to an embodiment of the present application.

[0021] Figure 3 Shown is a schematic diagram of the position of the low-temperature superconducting full-tensor magnetic gradient probe described in an embodiment of the present application in a three-dimensional Maxwell coil.

[0022] Figure 4 Shown are three schematic diagrams of installation angle errors of the SQUID planar gradiometer described in an embodiment of the present application.

[0023] Figure 5 Shown is a flow chart of an error correction method for a full tensor magnetic gradient probe according to an embodiment of the present application.

[0024] Figure 6 Shown is a schematic diagram of the process of solving the error angle using Newton iteration according to an embodiment of the present application.

[0025] Figure 7Shown is a structural schematic diagram of the error correction system of the full tensor magnetic gradient probe described in an embodiment of the present application.

[0026] Figure 8 Shown is a structural schematic diagram of an electronic device described in an embodiment of the present application.

[0027] Component number description

[0028] 11 Three-axis magnetometer

[0029] 12 Plane gradiometer

[0030] 3 Error Correction System of Full Tensor Magnetic Gradient Probe

[0031] 31 Get Module

[0032] 32 computing modules

[0033] 33 Calibration module

[0034] 4 Electronic devices

[0035] 41 Memory

[0036] 42 processors

[0037] Steps S1 to S3 DETAILED DESCRIPTION

[0038] The following describes the embodiments of the present application through specific examples. Those skilled in the art can easily understand the other advantages and effects of the present application from the content disclosed in this specification. The present application can also be implemented or applied through other different specific embodiments. The details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other unless they conflict.

[0039] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. Therefore, the illustrations only show components related to the present application and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0040] The following embodiments of the present application provide an error correction method, system, device, and medium for a full-tensor magnetic gradient probe, which solves the problem that existing full-tensor magnetic gradient probes containing planar gradiometers have angular errors such as tilt angle, offset angle, and roll angle between the sensitive axis of the planar gradiometer chip and the sensitive axis of the module plane, thereby reducing the accuracy of the full-tensor magnetic gradient data.

[0041] Figure 1 The product structure diagram of the full tensor magnetic gradient probe with a regular hexagonal pyramid configuration described in the embodiment of the present application is shown. Figure 1 As shown, this embodiment provides a product device structure for a full-tensor magnetic gradient probe in a regular hexagonal pyramid configuration. The probe consists of six planar gradiometers and a top-mounted SQUID triaxial magnetometer. The six planar gradiometers are mounted on the six sides of the module to measure gradient components, while the top triaxial magnetometer performs common-mode compensation. While this design offers high redundancy and high precision, it still faces certain technical challenges in practical application. Mechanical errors are inevitable during the fabrication, packaging, and assembly of the planar gradiometers. These errors cause the actual mounting position of the chip to deviate from the ideal design position, leading to angular errors such as tilt, offset, and roll between the chip's sensitive axis and the module's plane sensitive axis. These errors are added to the gradiometer output, reducing the accuracy of the full-tensor magnetic gradient data. For example, a 1° error in the tilt angle of one of the planar gradiometers can result in a deviation of up to 2.3% in the invariant of the full-tensor magnetic gradient in the measurement results. This error has a significant impact on the overall accuracy of the measurement system, especially in application scenarios requiring high sensitivity and high precision, where error correction becomes a critical link.

[0042] The technical solutions in the embodiments of the present application will be described in detail below with reference to the accompanying drawings in the embodiments of the present application.

[0043] like Figure 2 As shown, this embodiment provides an error correction method for a full tensor magnetic gradient probe, which includes the following steps S1 to S3.

[0044] Step S1, obtaining chip error data of a full tensor magnetic gradient probe; the chip error data includes the full tensor magnetic gradient of the full tensor magnetic gradient probe and the gradient of a planar gradiometer; the full tensor magnetic gradient probe is provided with at least one planar gradiometer; each planar gradiometer is provided with the chip.

[0045] Specifically, the full-tensor magnetic gradient probe described in this application is described using a low-temperature superconducting full-tensor magnetic gradient probe containing six SQUID planar gradiometers as an example. In this application, the angular installation error between the SQUID planar gradiometers and the plane of the hexagonal pyramid module is measured in this low-temperature superconducting full-tensor magnetic gradient probe containing six SQUID planar gradiometers.

[0046] In one embodiment of the present application, obtaining chip error data of a full tensor magnetic gradient probe includes the following steps S11 to S13 .

[0047] Step S11: Install the full tensor magnetic gradient probe at the center of the three-axis Maxwell coil.

[0048] Step S12: Using a signal generator and a power amplifier to respectively pass sinusoidal currents into the three-axis Maxwell coils to obtain the full tensor magnetic gradient of the full tensor magnetic gradient probe.

[0049] Step S13: Obtain the gradient output of each planar gradiometer in the three-axis Maxwell coil as the gradient of the planar gradiometer.

[0050] Specifically, Figure 3 This is a schematic diagram showing the position of the low-temperature superconducting full-tensor magnetic gradient probe in the three-dimensional Maxwell coil according to an embodiment of the present application. Figure 4 Shown are three schematic diagrams of the installation angle errors of the SQUID planar gradiometer described in the embodiment of the present application. Figure 3-4 As shown, the present invention installs a low-temperature superconducting full-tensor magnetic gradient probe containing 6 SQUID planar gradiometers at the center of the three-axis Maxwell coil, wherein in the low-temperature superconducting full-tensor magnetic gradient probe coordinate system o-XYZ, the six plane coordinate systems of the hexagonal pyramid are p i -X i Y i Z i (i=1~6), the plane coordinate systems of the i-th SQUID plane gradiometer are pi-X i 'Y i 'Z i '(i=1~6), the normal direction of the sensitive axis of the pick-up ring of the i-th SQUID plane gradiometer is the same as the Z i 'Parallel, the baseline vector direction of the two pick rings is parallel to the X i ' direction is parallel, the tilt angle of the hexagonal pyramid module is α, and the angle between the plane where the SQUID plane gradiometer is located and the X axis is β1, β2, and β3 are the offset angle, tilt angle, and roll angle of the SQUID planar gradiometer, respectively.

[0051] To be more specific, the present application first uses a signal generator and a power amplifier to respectively pass sinusoidal currents into the three axes of the three-axis Maxwell coil to obtain the full tensor magnetic gradients [Bxxi, Bxyi, Bxzi, Byyi, Byzi] with three known parameters to form a coefficient matrix G1 (as shown in formula (1)).

[0052]

[0053] Where k represents the gradient constant, for example, k = 0.83; μ0 represents the vacuum permeability, for example, μ0 = 4π×10 -7; a represents the side length of the coil, for example a = 3m; N represents the number of turns of the coil, for example N = 19 turns; I represents the coil input current, for example I = 3A.

[0054] Secondly, the gradient outputs [g1i, g2i, g3i, g4i, g5i, g6i] of the six SQUID planar gradiometers in the three-axis Maxwell coil are obtained to form the measured gradient value matrix G2 (as shown in formula (2)).

[0055] G2=[g11,g21,g31,g41,g51,g61,...,g1j,g2j,g3j,g4j,g5j,g6j]j=1,2,3 Formula (2)

[0056] Step S2: Obtain the error angle of each planar gradiometer according to the full tensor magnetic gradient and the gradient of each planar gradiometer.

[0057] In one embodiment of the present application, obtaining the error angle of each planar gradiometer according to the full tensor magnetic gradient and the gradient of each planar gradiometer includes the following steps S21 to S22.

[0058] Step S21 : constructing an error equation of each planar gradiometer according to the full tensor magnetic gradient and the gradient of each planar gradiometer.

[0059] Step S22: Solve the error equations of the planar gradiometers using the Newton iteration method to obtain the error angles of the planar gradiometers; the error angles include the tilt angle, the offset angle, and / or the roll angle.

[0060] In one embodiment of the present application, constructing the error equation of each planar gradiometer according to the full tensor magnetic gradient and the gradient of each planar gradiometer includes the following steps S211 to S212.

[0061] Step S211 , obtaining vector parameters of each of the plane gradiometers; the vector parameters include a baseline vector and a plane normal vector.

[0062] Step S212: constructing an error equation for each of the planar gradiometers according to the baseline vector and the plane normal vector of each of the planar gradiometers, the full tensor magnetic gradient, and the gradient of each of the planar gradiometers.

[0063] In one embodiment of the present application, the error equation of each planar gradiometer is constructed according to the baseline vector and plane normal vector of each planar gradiometer, the full tensor magnetic gradient, and the gradient of each planar gradiometer, including the following formula.

[0064]

[0065] Among them, gij = [gi1, gi2, gi3] is the gradient value output by the i-th SQUID planar gradiometer, G1 is the full tensor magnetic gradient of the full tensor magnetic gradient probe, is the baseline vector from the center of the lower picking ring of the i-th plane gradiometer to the center of the upper picking ring, is the plane normal vector of the i-th plane gradiometer, β 1i ,β 2i ,β 3i are the offset angle, inclination angle and roll angle of the i-th plane gradiometer, and Li is the baseline length of the i-th plane gradiometer.

[0066] In one embodiment of the present application, the Newton iteration method is used to solve the error equations of the planar gradiometers respectively to obtain the error angles of the planar gradiometers, including the following steps S221 to S225.

[0067] Step S221: Obtain initialization angle data of each of the planar gradiometers.

[0068] Step S222: Calculate and obtain a target equation for each of the plane gradiometers based on the initialization angle data of each of the plane gradiometers and the error equation of each of the plane gradiometers.

[0069] Step S223: Calculate and obtain the corresponding Jacobian matrix according to the target equation of each plane gradiometer.

[0070] Step S224: Calculate and obtain the next error angle according to the target equation and Jacobian matrix of each plane gradiometer.

[0071] Step S225 : Iterate the calculation until the target equation of each plane gradiometer converges, and use the error angle at this time as the error angle of each plane gradiometer.

[0072] Specifically, Figure 5 1 is a flow chart showing an error correction method for a full tensor magnetic gradient probe according to an embodiment of the present application. Figure 6 The figure shows the process flow of Newton iteration to solve the error angle according to the embodiment of the present application. Figure 5-6 As shown, the present application first constructs the angle error [β] by combining the full tensor magnetic gradient matrix G1 of the three-dimensional Maxwell coil and the measured gradient value matrix G2 output by the i-th SQUID planar gradiometer. 1i ,β 2i ,β 3i ] nonlinear equation, β 1i The i-th SQUID plane gradiometer rotates around the plane coordinate system Z i Counterclockwise rotation angle, β 2i The i-th SQUID plane gradiometer rotates around the plane coordinate system Yi Counterclockwise rotation angle, β 3i The i-th SQUID plane gradiometer rotates around the plane coordinate system X i The counterclockwise rotation angle is then used to obtain the baseline vector of the i-th SQUID planar gradiometer after the angle error rotation. and the plane normal vector Among them, the baseline vector of the i-th SQUID plane gradiometer is and the rotated plane coordinate system X i ' is parallel to the direction of the normal vector of the i-th SQUID plane gradiometer and the rotated plane coordinate system Z i ' direction. Among them, the baseline vector of the i-th SQUID plane gradiometer is The plane normal vector of the i-th SQUID plane gradiometer is calculated by formula (3): Calculated by formula (4).

[0073]

[0074] Among them, β 1i ,β 2i ,β 3i are the offset angle, tilt angle and roll angle of the i-th SQUID planar gradiometer respectively.

[0075] Taking the first SQUID planar gradiometer as an example, the specific method of constructing the error equation is shown in the following formula (5).

[0076]

[0077] Among them, g1j = [g11, g12, g13] is the gradient value output by the first SQUID planar gradiometer, G1 is the full tensor magnetic gradient value after the three-axis Maxwell coil applies sinusoidal current on the three axes respectively, is the baseline vector from the center of the lower pick-up ring of the first SQUID planar gradiometer to the center of the upper pick-up ring, is the plane normal vector of the first SQUID plane gradiometer, β 11 ,β 21 ,β 31 are the offset angle, tilt angle and roll angle of the first SQUID plane gradiometer, and L1 is the baseline length of the first plane gradiometer.

[0078] Then the full tensor magnetic gradient matrix G1 of the three-dimensional Maxwell coil and the gradient value g1 output by the first SQUID planar gradiometer are constructed to determine the relationship between β 11 ,β 21 ,β 31The nonlinear equation is constructed as shown in the following formula (6).

[0079]

[0080] in, represents the baseline vector of the first SQUID planar gradiometer, represents the plane normal vector of the first SQUID planar gradiometer, [x11, x21, x31, x41, x51] represents the nonlinear function of the first SQUID planar gradiometer with respect to β1, β2, and β3, g11 represents the output of the first planar gradiometer when a sinusoidal current is applied to the X-axis of the three-dimensional Maxwell coil, g12 represents the output of the first planar gradiometer when a sinusoidal current is applied to the Y-axis of the three-dimensional Maxwell coil, and g13 represents the output of the first planar gradiometer when a sinusoidal current is applied to the Z-axis of the three-dimensional Maxwell coil. g11(β) represents the theoretically calculated value of the first planar gradiometer when a sinusoidal current is applied to the X-axis of the three-dimensional Maxwell coil, g12(β) represents the theoretically calculated value of the first planar gradiometer when a sinusoidal current is applied to the Y-axis of the three-dimensional Maxwell coil, and g13(β) represents the theoretically calculated value of the first planar gradiometer when a sinusoidal current is applied to the Z-axis of the three-dimensional Maxwell coil.

[0081] Finally, the Newton iteration method is used to solve the inclination angle β1, offset angle β2 and roll angle β3 of the 6-piece SQUID planar gradiometer, as shown in the following example: Figure 6 The specific iterative process is shown in the following formula (7).

[0082] β k+1 =β k -J -1 (β k )·F(β k ) Formula (7)

[0083]

[0084] Among them, β k =[β1,β2,β3] is a variable vector, k=1, 2, F(β k )=[F1(β k ),F2(β k ),F3(β k )] is the target equation group (as shown in formula (8)), J(β k ) is the Jacobian matrix (as shown in formula (9)), J -1 (β k )The inverse of the Jacobian matrix.

[0085] First initialize β k=[β1,β2,β3], and then calculate F(β k ), J -1 (β k ) and update β k+1 , and finally when F(β k ) or the variable changes meet the convergence conditions, which are shown in the following formula (10).

[0086] ||F(β k )||2<tol or||Δβ k ||2<tol formula (10)

[0087] Among them, ||·||2 represents the 2-norm (i.e., the Euclidean norm), ||Δβ k || represents the parameter change in the current iteration, and tol represents the tolerance. If one of the above convergence conditions is met, the algorithm terminates and returns the current solution β and the number of iterations.

[0088] Step S3: performing chip angle error correction on the full tensor magnetic gradient according to the error angle of each planar gradiometer to obtain a corrected full tensor magnetic gradient.

[0089] In one embodiment of the present application, performing chip angle error correction on the full tensor magnetic gradient according to the error angle of each planar gradiometer, and obtaining the corrected full tensor magnetic gradient includes the following steps S31 to S32.

[0090] Step S31: Calculate the error angle function of each plane gradiometer according to the error angle of each plane gradiometer.

[0091] Step S32: performing chip angle error correction calculation according to the error angle function of the planar gradiometer and the gradient of each planar gradiometer to obtain a corrected full tensor magnetic gradient.

[0092] Specifically, the present application performs chip angle error correction on the independent components of the full magnetic gradient tensor, including: the outputs of the six SQUID planar gradiometers are g1, g2, g3, g4, g5, and g6, respectively. The five independent components of the full magnetic gradient tensor after chip angle error correction are shown in the following formula (11).

[0093]

[0094] Among them, [x1i,x2i,x3i,x4i,x5i] represents the β of the i-th SQUID plane gradiometer 1i ,β 2i ,β 3iThe unknown quantity of the angle error (as shown in formula (12)) is substituted into formula (12) and formula (11) to obtain the corrected full tensor magnetic gradient G1' = [Bxx, Bxy, Bxz, Byy, Byz].

[0095] In this application, the plane coordinate systems p of the six SQUID planar gradiometers are obtained by comparing the magnetic gradient tensor values ​​with known parameters generated by three-dimensional Maxwell coils with the actual measured values ​​of the SQUID planar gradiometer. i -X i Y i Z i The six plane coordinate systems p of the hexagonal pyramid i -X i Y i Z i The angular error between them is reduced, thereby completing the correction of the angular error of the low-temperature superconducting full-tensor magnetic gradient probe chip. The advantage of the technical solution of the present application over the traditional method is that, on the one hand, the magnetic field generated by the three-axis Maxwell coil is more uniform than the magnetic field generated by the dipole current, reducing its volume effect, thereby improving the correction accuracy of the chip angular error; on the other hand, since the present application does not need to solve the error parameters during the movement process like the traditional method, it avoids the influence of magnetic interference caused by the movement on the error correction result.

[0096] The protection scope of the error correction method for the full tensor magnetic gradient probe described in the embodiment of the present application is not limited to the execution order of the steps listed in this embodiment. All solutions implemented by adding, subtracting, or replacing steps in the prior art based on the principles of the present application are included in the protection scope of the present application.

[0097] The embodiments of the present application also provide an error correction system for a full-tensor magnetic gradient probe. The error correction system for the full-tensor magnetic gradient probe can implement the error correction method for the full-tensor magnetic gradient probe described in the present application. However, the device for implementing the error correction method for the full-tensor magnetic gradient probe described in the present application includes, but is not limited to, the structure of the error correction system for the full-tensor magnetic gradient probe listed in the present embodiment. Any structural variations and replacements in the prior art made according to the principles of the present application are included within the scope of protection of the present application.

[0098] like Figure 7 As shown, this embodiment provides an error correction system for a full tensor magnetic gradient probe, and the system includes: an acquisition module 31 , a calculation module 32 and a correction module 33 .

[0099] The acquisition module 31 is configured to acquire chip error data of a full tensor magnetic gradient probe; the chip error data includes the full tensor magnetic gradient of the full tensor magnetic gradient probe and the gradient of a planar gradiometer; the full tensor magnetic gradient probe is provided with at least one planar gradiometer; each planar gradiometer is provided with the chip;

[0100] The calculation module 32 is configured to obtain the error angle of each planar gradiometer according to the full tensor magnetic gradient and the gradient of each planar gradiometer;

[0101] The correction module 33 is configured to perform chip angle error correction on the full tensor magnetic gradient according to the error angle of each planar gradiometer to obtain a corrected full tensor magnetic gradient.

[0102] It should be noted that the functions or operations of the acquisition module 31, the calculation module 32 and the correction module 33 described in the embodiment of the present disclosure correspond one-to-one to the steps in the above-mentioned data transmission method for the bus, and therefore will not be repeated here.

[0103] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices or methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of modules / units is only a logical function division. There may be other division methods in actual implementation. For example, multiple modules or units can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or modules or units, which can be electrical, mechanical or other forms.

[0104] The modules / units described as separate components may or may not be physically separate, and the components displayed as modules / units may or may not be physical modules, that is, they may be located in one place or distributed across multiple network elements. Some or all of the modules / units may be selected according to actual needs to achieve the purpose of the embodiments of the present application. For example, the functional modules / units in the various embodiments of the present application may be integrated into a processing module, or each module / unit may exist physically separately, or two or more modules / units may be integrated into a single module / unit.

[0105] Those skilled in the art should further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the composition and steps of each example according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0106] like Figure 8 As shown, this embodiment provides an electronic device, the electronic device 4 includes: a memory 41 and a processor 42;

[0107] The memory 41 is configured to store computer programs;

[0108] The processor 42 is configured to execute the computer program stored in the memory 41 so as to enable the electronic device 4 to perform the error correction method for the full tensor magnetic gradient probe as described above.

[0109] The embodiment of the present application also provides a computer-readable storage medium. Those skilled in the art will understand that all or part of the steps in the method for implementing the above embodiment can be completed by instructing the processor through a program, and the program can be stored in a computer-readable storage medium, and the storage medium is a non-transitory medium, such as a random access memory, a read-only memory, a flash memory, a hard disk, a solid-state drive, a magnetic tape, a floppy disk, an optical disc, and any combination thereof. The above storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or a data center that includes one or more available media. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a tape), an optical medium (for example, a digital video disc (DVD)), or a semiconductor medium (for example, a solid-state drive (SSD)), etc.

[0110] The embodiment of the present application may also provide a computer program product, the computer program product including one or more computer instructions. When the computer instructions are loaded and executed on a computing device, the process or function described in the embodiment of the present application is generated in whole or in part. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website, computer or data center to another website, computer or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method.

[0111] When the computer program product is executed by a computer, the computer executes the method described in the above method embodiment. The computer program product can be a software installation package. When the above method is needed, the computer program product can be downloaded and executed on the computer.

[0112] In summary, the error correction method, system, device, and medium for a full tensor magnetic gradient probe described in this application have the following beneficial effects:

[0113] The present application obtains chip error data of a full-tensor magnetic gradient probe; the chip error data includes the full-tensor magnetic gradient of the full-tensor magnetic gradient probe and the gradient of a planar gradiometer; the full-tensor magnetic gradient probe is provided with at least one planar gradiometer; each planar gradiometer is provided with the chip; the error angle of each planar gradiometer is obtained based on the full-tensor magnetic gradient and the gradient of each planar gradiometer; the chip angle error of the full-tensor magnetic gradient is corrected based on the error angle of each planar gradiometer to obtain the corrected full-tensor magnetic gradient. By comparing the full-tensor magnetic gradient of the full-tensor magnetic gradient probe with the gradient of each planar gradiometer, the error angle of each planar gradiometer is obtained, thereby completing the correction of the chip angle error of the full-tensor magnetic gradient probe. The advantage of the present application over traditional methods is that the magnetic field generated by the three-axis Maxwell coil is more uniform than the magnetic field generated by the dipole current, reducing its volume effect, thereby improving the correction accuracy of the chip angle error.

[0114] The present application obtains the error angle of each planar gradiometer by comparing the full tensor magnetic gradient of the full tensor magnetic gradient probe with the gradient of each planar gradiometer. Since there is no need to solve the error parameters during the motion process as in traditional methods, the magnetic interference caused by the motion is avoided, which may affect the error correction result.

[0115] The descriptions of the processes or structures corresponding to the above figures have different emphases. For parts that are not described in detail in a certain process or structure, please refer to the relevant descriptions of other processes or structures.

[0116] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical concepts disclosed in this application shall be covered by the claims of this application.

Claims

1. A method for error correction of a full tensor magnetic gradient probe, characterized in that: The method comprises: Acquiring chip error data of a full tensor magnetic gradient probe; the chip error data includes the full tensor magnetic gradient of the full tensor magnetic gradient probe and the gradient of a planar gradiometer; the full tensor magnetic gradient probe is provided with at least one planar gradiometer; each planar gradiometer is provided with the chip; Obtaining an error angle of each of the planar gradiometers according to the full tensor magnetic gradient and the gradient of each of the planar gradiometers; performing chip angle error correction on the full tensor magnetic gradient according to the error angle of each planar gradiometer to obtain a corrected full tensor magnetic gradient; Obtaining the error angle of each of the planar gradiometers according to the full tensor magnetic gradient and the gradient of each of the planar gradiometers includes: Constructing an error equation for each of the planar gradiometers based on the full tensor magnetic gradient and the gradient of each of the planar gradiometers; obtaining vector parameters of each of the planar gradiometers; the vector parameters including a baseline vector and a plane normal vector; constructing an error equation for each of the planar gradiometers based on the baseline vector and the plane normal vector of each of the planar gradiometers, the full tensor magnetic gradient, and the gradient of each of the planar gradiometers; Among them, gij = [gi1, gi2, gi3] is the gradient value output by the i-th SQUID planar gradiometer, G1 is the full tensor magnetic gradient of the full tensor magnetic gradient probe, is the baseline vector from the center of the lower picking ring of the i-th plane gradiometer to the center of the upper picking ring, is the plane normal vector of the i-th plane gradiometer, β 1i , β 2i , β 3i are the offset angle, tilt angle and roll angle of the i-th plane gradiometer, respectively; Li is the baseline length of the i-th plane gradiometer; The error equations of the planar gradiometers are solved respectively using the Newton iteration method to obtain the error angles of the planar gradiometers; the error angles include the tilt angle, the offset angle and / or the roll angle.

2. The error correction method for a full tensor magnetic gradient probe according to claim 1, characterized in that: Obtaining chip error data for a full tensor magnetic gradient probe includes: Installing the full tensor magnetic gradient probe at the center of the three-axis Maxwell coil; Using a signal generator and a power amplifier to respectively pass sinusoidal currents into the three-axis Maxwell coils to obtain a full tensor magnetic gradient of a full tensor magnetic gradient probe; The gradient output of each planar gradiometer in the three-axis Maxwell coil is obtained as the gradient of the planar gradiometer.

3. The error correction method for a full tensor magnetic gradient probe according to claim 1, characterized in that: Solving the error equations of the planar gradiometers using the Newton iteration method to obtain the error angles of the planar gradiometers includes: Obtaining initialization angle data of each of the planar gradiometers; Obtaining a target equation for each of the plane gradiometers by calculation based on the initialization angle data of each of the plane gradiometers and the error equation of each of the plane gradiometers; Calculate and obtain the corresponding Jacobian matrix according to the target equation of each plane gradiometer; Obtaining the next error angle according to the target equation and Jacobian matrix of each plane gradiometer; Iterative calculation is performed until the target equation of each plane gradiometer converges, and the error angle at this time is used as the error angle of each plane gradiometer.

4. The error correction method for a full tensor magnetic gradient probe according to claim 1, characterized in that: Performing chip angle error correction on the full tensor magnetic gradient according to the error angle of each planar gradiometer to obtain the corrected full tensor magnetic gradient includes: Obtaining an error angle function of each of the planar gradiometers according to the error angle calculation of each of the planar gradiometers; A chip angle error correction calculation is performed according to the error angle function of the planar gradiometer and the gradient of each planar gradiometer to obtain a corrected full tensor magnetic gradient.

5. An error correction system for a full tensor magnetic gradient probe, characterized in that: The system comprises: an acquisition module configured to acquire chip error data of a full tensor magnetic gradient probe; the chip error data includes the full tensor magnetic gradient of the full tensor magnetic gradient probe and the gradient of a planar gradiometer; the full tensor magnetic gradient probe is provided with at least one planar gradiometer; each planar gradiometer is provided with the chip; a calculation module configured to obtain an error angle of each of the planar gradiometers based on the full tensor magnetic gradient and the gradient of each of the planar gradiometers; a correction module configured to perform chip angle error correction on the full tensor magnetic gradient according to the error angle of each planar gradiometer to obtain a corrected full tensor magnetic gradient; Obtaining the error angle of each of the planar gradiometers according to the full tensor magnetic gradient and the gradient of each of the planar gradiometers includes: Constructing an error equation for each of the planar gradiometers based on the full tensor magnetic gradient and the gradient of each of the planar gradiometers; obtaining vector parameters of each of the planar gradiometers; the vector parameters including a baseline vector and a plane normal vector; constructing an error equation for each of the planar gradiometers based on the baseline vector and the plane normal vector of each of the planar gradiometers, the full tensor magnetic gradient, and the gradient of each of the planar gradiometers; Among them, gij = [gi1, gi2, gi3] is the gradient value output by the i-th SQUID planar gradiometer, G1 is the full tensor magnetic gradient of the full tensor magnetic gradient probe, is the baseline vector from the center of the lower picking ring of the i-th plane gradiometer to the center of the upper picking ring, is the plane normal vector of the i-th plane gradiometer, β 1i , β 2i , β 3i are the offset angle, tilt angle and roll angle of the i-th plane gradiometer, respectively; Li is the baseline length of the i-th plane gradiometer; The error equations of the planar gradiometers are solved respectively using the Newton iteration method to obtain the error angles of the planar gradiometers; the error angles include the tilt angle, the offset angle and / or the roll angle.

6. An electronic device, characterized in that: The electronic device includes: a processor and a memory; The memory is configured to store a computer program; The processor is configured to execute the computer program stored in the memory, so as to enable the electronic device to perform the error correction method for the full tensor magnetic gradient probe according to any one of claims 1 to 4.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by an electronic device, the error correction method for a full tensor magnetic gradient probe according to any one of claims 1 to 4 is implemented.

Images