Magnetic field adjustment system and method

Abstract

The application provides a magnetic field adjusting system and method, which comprises a measuring probe, a first-stage coil, a second-stage coil and a PID control system, wherein the second-stage coil is distributed on both sides of a uniform field area inside the first-stage coil, and the second-stage coil has a higher order than the first-stage coil; the measuring probe is arranged in a preset magnetic field adjusting area of the first-stage coil to measure the magnetic field information of the first-stage coil and the second-stage coil, or the measuring probe measures the magnetic field information of the first-stage coil and the second-stage coil and sends the information to the PID control system; and the PID control system adjusts the magnetic field of the second-stage coil based on the received magnetic field information to compensate the magnetic field of the first-stage coil. The measuring probe measures the magnetic field information of the first-stage coil and the second-stage coil, so that the PID control system can determine the current acting on the corresponding first-stage coil and second-stage coil according to the measured magnetic field information, thereby realizing real-time adjustment of the magnetic field.

Description

Technical Field

[0001] This invention relates to the field of magnetic components technology, and in particular to a magnetic field adjustment system and method. Background Technology

[0002] With the development of technology, magnetic fields are everywhere in our lives; televisions, telephones, high-voltage power lines, and many other sources generate them. However, different magnetic fields have different effects. Some magnetic fields are convenient for us; for example, the Earth's magnetic field allows us to use a compass to determine direction. But other magnetic fields bring electromagnetic noise, such as interference signals. The measures we need to take for different magnetic fields will vary. Sometimes we need to amplify the magnetic field signal, for example, amplifying some signals makes them easier to measure and analyze. More often, we need to cancel or even shield some magnetic field signals.

[0003] Current methods for adjusting the magnetic field mainly involve constructing a closed cavity using high-permeability materials to enclose the object to be protected. By controlling the permeability of the material used to build the shielding cavity, the higher the permeability and the thicker the cavity wall, the more significant the shielding effect. However, this method results in a large shielding mass, heavy weight, and optical opacity in the direction of the shielding magnetic field. Summary of the Invention

[0004] This invention provides a magnetic field adjustment system and method to solve the defect of optical opacity in the direction of shielding magnetic fields in the prior art, and to realize real-time adjustment of magnetic fields.

[0005] This invention provides a magnetic field adjustment system comprising a first-stage coil, a second-stage coil, and a PID control system. The second-stage coil is distributed on both sides of the uniform field region inside the first-stage coil, and the second-stage coil has a higher order than the first-stage coil. A measuring probe is positioned within a preset region of the magnetic field to be adjusted in the first-stage coil to measure the magnetic field information of the first-stage coil and the second-stage coil. Alternatively, the measuring probe measures the magnetic field information of the first-stage coil and the second-stage coil and sends the measured magnetic field information of the first-stage coil and the second-stage coil to the PID control system. Based on the received magnetic field information of the first-stage coil and the second-stage coil, the PID control system adjusts the magnetic field of the second-stage coil to compensate for the magnetic field of the first-stage coil.

[0006] According to a magnetic field adjustment system provided by the present invention, the step of adjusting the magnetic field of the second-stage coil to compensate the magnetic field of the first-stage coil based on received magnetic field information of a first-stage coil and magnetic field information of a second-stage coil includes: determining the current corresponding to the first-stage coil and the current of the second-stage coil according to the magnetic field information of the first-stage coil and the magnetic field information of the second-stage coil; controlling the current corresponding to the first-stage coil to be applied to the first-stage coil to compensate the magnetic field of the first-stage coil; and controlling the current corresponding to the second-stage coil to be applied to the second-stage coil to adjust the magnetic field of the second-stage coil.

[0007] According to a magnetic field adjustment system provided by the present invention, before the measuring probe measures the magnetic field information of the first-stage coil and the second-stage coil, the system comprises: fixing an adhesive layer with a preset gradient coil pattern pre-formed on one side of a transparent base plate, and winding a wire on the other side of the transparent base plate according to the preset gradient coil pattern printed on the adhesive layer and curing it to obtain a second-stage coil; or, fixing an adhesive layer with a preset gradient coil pattern pre-formed on one side of a transparent base plate, and winding a wire on one side of the adhesive layer with the preset gradient coil pattern to obtain a second-stage coil; or, printing a preset gradient coil pattern on a circuit board to obtain a second-stage coil.

[0008] According to a magnetic field adjustment system provided by the present invention, the circuit board is a printed PCB circuit board, and the measuring probe is a fluxgate magnetometer probe; controlling the current corresponding to the first-stage coil to be applied to the first-stage coil, and controlling the current corresponding to the second-stage coil to be applied to the second-stage coil, includes: generating the current corresponding to the first-stage coil through a low-noise power amplifier and inputting it into the first-stage coil; generating the current corresponding to the second-stage coil through a low-noise power amplifier and inputting it into the second-stage coil.

[0009] According to a magnetic field adjustment system provided by the present invention, the circuit board adopts a flexible FPC transparent circuit board, and the measuring probe adopts a giant magnetoresistive probe; controlling the current corresponding to the first-stage coil to be applied to the first-stage coil, and controlling the current corresponding to the second-stage coil to be applied to the second-stage coil, includes: generating the current corresponding to the first-stage coil through a low-noise power amplifier and applying the generated current to the first-stage coil; powering the second-stage coil by using a signal generator and a low-noise power amplifier, and changing the output current magnitude by adjusting the signal generator to shield the magnetic field gradient in the second-stage coil.

[0010] According to the magnetic field adjustment system provided by the present invention, before fixing an adhesive layer on one side of a transparent base plate with a preset gradient coil pattern, the system includes: printing the preset gradient coil pattern onto the adhesive layer based on a metal 3D printing process; the printing of the preset gradient coil pattern on the circuit board includes: printing the preset gradient coil pattern onto the circuit board based on ink or powder.

[0011] According to a magnetic field adjustment system provided by the present invention, the material of the conductor includes a capillary copper tube, and a coolant circulates within the capillary copper tube.

[0012] According to a magnetic field adjustment system provided by the present invention, the measuring probe includes a magnetic probe and a magnetic probe matrix. The magnetic probe is disposed in a preset magnetic field region to be adjusted of the first-stage coil to measure the magnetic field information of the central region of the uniform field region of the first-stage coil, and feeds back the measured magnetic field information of the first-stage coil to the PID control system. The magnetic probe matrix is ​​disposed in a preset magnetic field region to be adjusted of the second-stage coil to measure the magnetic field information of the second-stage coil gradient, and feeds back the measured magnetic field information to the PID control system.

[0013] According to a magnetic field adjustment system provided by the present invention, the measuring probe includes at least one of a fluxgate, a giant magnetoresistive, or an optically pumped magnetic sensor.

[0014] According to a magnetic field adjustment system provided by the present invention, the first-stage coil includes a Helmholtz coil and the second-stage coil includes a gradient coil.

[0015] The present invention also provides a magnetic field adjustment method, comprising: measuring the magnetic field information of a first-stage coil and a second-stage coil using a measuring probe; or, the measuring probe measuring the magnetic field information of the first-stage coil and the second-stage coil, and sending the measured magnetic field information of the first-stage coil and the second-stage coil to a PID control system; the PID control system receiving the magnetic field information of the first-stage coil and the second-stage coil sent by the measuring probe, and adjusting the magnetic field of the second-stage coil according to the magnetic field information of the first-stage coil and the second-stage coil to compensate for the magnetic field of the first-stage coil.

[0016] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of any of the above-described magnetic field adjustment methods.

[0017] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the above-described magnetic field adjustment methods.

[0018] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of any of the above-described magnetic field adjustment methods.

[0019] The magnetic field adjustment system and method provided by this invention measures the magnetic field information of a first-stage coil and a second-stage coil located on both sides of a uniform field area inside the first-stage coil using a measuring probe. This allows a PID control system to determine the current applied to the corresponding second-stage coil based on the measured magnetic field information. By adjusting the current in the second-stage coil, the magnetic field of the second-stage coil is adjusted, thereby compensating for the magnetic field of the first-stage coil and achieving real-time adjustment of the magnetic field. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the magnetic field adjustment system provided by the present invention;

[0022] Figure 2 This is a schematic diagram of the Gzx gradient coil and the Gzy gradient coil provided by the present invention;

[0023] Figure 3 This is one of the measurement and detection results provided by the present invention;

[0024] Figure 4 This is a schematic diagram of the environmental magnetic field test results before the first-stage coil control provided by the present invention;

[0025] Figure 5 This is one of the schematic diagrams of the magnetic field test results after the first-stage coil control provided by the present invention;

[0026] Figure 6 This is a schematic diagram of the first-order gradient of the magnetic field in the X and Y directions for testing the fluxgate probe matrix provided by the present invention;

[0027] Figure 7 This is a schematic diagram of the control data results in the X and Y directions of the second-stage coil after gradient compensation provided by the present invention;

[0028] Figure 8 This is the second schematic diagram of the measurement and detection structure provided by the present invention;

[0029] Figure 9 This is the second schematic diagram of the magnetic field test results after the first-stage coil control provided by the present invention;

[0030] Figure 10 This is a schematic diagram of the magnetoresistive probe matrix provided by the present invention for testing the first-order gradient of the magnetic field in the X and Y directions;

[0031] Figure 11 This is a schematic diagram of the control data results in the X and Y directions of the second-stage coil after gradient compensation provided by the present invention;

[0032] Figure 12 This is a flowchart illustrating the magnetic field adjustment method provided by the present invention;

[0033] Figure 13 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0035] Figure 1 A schematic diagram of a magnetic field adjustment system is shown. The system includes a measuring probe, a first-stage coil, a second-stage coil, and a PID control system, wherein:

[0036] The second-stage coil is distributed on both sides of the uniform field region inside the first-stage coil, and the order of the second-stage coil is higher than that of the first-stage coil.

[0037] The measuring probe is set in the preset magnetic field region to be adjusted of the first-stage coil to measure the magnetic field information of the first-stage coil and the second-stage coil, or the measuring probe measures the magnetic field information of the first-stage coil and the second-stage coil, and sends the measured magnetic field information of the first-stage coil and the second-stage coil to the PID control system.

[0038] The PID control system adjusts the magnetic field of the second-stage coil based on the received magnetic field information of the first-stage coil and the magnetic field information of the second-stage coil to compensate for the magnetic field of the first-stage coil.

[0039] In one alternative embodiment, the measurement probe includes at least one of a fluxgate, a giant magnetoresistive, or an optically pumped magnetic sensor.

[0040] In one optional embodiment, the first-stage coil includes a Helmholtz coil, and the second-stage coil includes a gradient coil. It should be noted that the Helmholtz coil can be a triaxial Helmholtz coil, with an overall length, width, and height of 150*150*150cm. The three sets of coils are orthogonal to each other and do not conduct electricity. The main frame can be constructed using aluminum profiles, with wires wound along the frame, forming the main body of the magnetic field shielding system. Furthermore, the first-order gradient coil consists of multiple planar coils distributed on both sides of the uniform field region inside the triaxial Helmholtz coil.

[0041] In one optional embodiment, before the first-stage coil and the second-stage coil respectively form closed circuits, the process includes: forming the second-stage coil using a wire winding and curing process, a printing process, or an etching process. Specifically, forming the second-stage coil includes: fixing an adhesive layer with a pre-formed preset gradient coil pattern to one side of a transparent base plate, and winding wires according to the preset gradient coil pattern printed on the adhesive layer on the other side of the transparent base plate and curing them to obtain the second-stage coil; or, fixing an adhesive layer with a pre-formed preset gradient coil pattern to one side of a transparent base plate, and winding wires on one side of the adhesive layer with the pre-formed gradient coil pattern to obtain the second-stage coil. It should be noted that the transparent base plate includes acrylic sheets, etc.

[0042] Furthermore, before fixing the adhesive layer with the pre-formed gradient coil pattern to one side of the transparent base plate, the process includes: printing the pre-formed gradient coil pattern onto the adhesive layer using a metal 3D printing process.

[0043] In an alternative embodiment, the second-stage coil can be wound with 0.2mm enameled wire.

[0044] In one alternative embodiment, the conductor material includes a capillary copper tube, and coolant is circulated within the capillary copper tube. In other words, a second-stage coil is wound using a capillary copper tube, and the cooling capacity of the coil under high current is increased by circulating coolant within the capillary copper tube.

[0045] In another alternative embodiment, before the first-stage coil and the second-stage coil form closed loops respectively, the method further includes: printing a preset gradient coil pattern on a circuit board to obtain the second-stage coil.

[0046] In this embodiment, the circuit board includes at least one of a printed circuit board (PCB) and a flexible flexible printed circuit board (FPC). Additionally, printing a preset gradient coil pattern on the circuit board includes: printing the preset gradient coil pattern onto the circuit board using ink or powder. The ink or powder allows for adjustment of the gradient coil shape at any time based on the actual gradient shielding results.

[0047] For example, the gradient coils are drawn on white paper using a graphite pencil, or a pre-designed gradient coil pattern is printed directly on an FPC circuit board, with a size of 140*140cm. The inner Gzx gradient coils are spaced 70cm apart, and the outer Gzy gradient coils are spaced 77cm apart. The Gzx and Gzy gradient coils serve as references. Figure 2 .

[0048] In one optional embodiment, the measuring probe includes a magnetic probe and a magnetic probe matrix. The magnetic probe is set in a preset adjustable magnetic field region of the first-stage coil to measure the magnetic field information of the central region of the uniform field region of the first-stage coil, and feeds back the measured magnetic field information of the first-stage coil to the PID control system. The magnetic probe matrix is ​​set in a preset adjustable magnetic field region of the second-stage coil to measure the magnetic field information of the gradient of the second-stage coil, and feeds back the measured magnetic field information of the second-stage coil to the PID control system.

[0049] In this embodiment, the magnetic probe is positioned within the uniform field region at the center of the triaxial Helmholtz coil to detect the internal magnetic field of the coil and feed it back to the PID control system. The PID control system generates a current based on the magnitude of the internal magnetic field and applies it to the coil to shield the magnetic field in real time. Additionally, the first-order gradient coil consists of two sets of four planar gradient coils, used to shield the first-order gradient magnetic field in the Z-axis (X) and Y-axis directions, respectively.

[0050] In addition, in this embodiment, based on the received magnetic field information of the first-stage coil and the magnetic field information of the second-stage coil, the magnetic field of the second-stage coil is adjusted to compensate the magnetic field of the first-stage coil. This includes: determining the current corresponding to the first-stage coil and the current of the second-stage coil according to the magnetic field information of the first-stage coil and the magnetic field information of the second-stage coil; controlling the current corresponding to the first-stage coil to be applied to the first-stage coil to compensate the magnetic field of the first-stage coil; and controlling the current corresponding to the second-stage coil to be applied to the second-stage coil to adjust the magnetic field of the second-stage coil.

[0051] In one possible implementation, when the circuit board is a PCB, the measurement probe is a fluxgate probe; controlling the current corresponding to the first-stage coil to be applied to the first-stage coil, and controlling the current corresponding to the second-stage coil to be applied to the second-stage coil, includes: generating the current corresponding to the first-stage coil through a low-noise power amplifier and inputting it into the first-stage coil; generating the current corresponding to the second-stage coil through a low-noise power amplifier and inputting it into the second-stage coil.

[0052] To elaborate further, the magnetic probe matrix is ​​located on one side of the magnetic probe, for example... Figure 3As shown, the fluxgate probe matrix is ​​positioned below the fluxgate probes. It should be noted that the measurement probe uses a fluxgate probe shielded by a Helmholtz coil to shield the 0th-order magnetic field. The spacing between the probes in the 5x5 fluxgate probe matrix can be 2cm to measure the 1st-order gradient field.

[0053] In actual testing, a single fluxgate probe was first fixed in the central uniform field region of a triaxial Helmholtz coil. A data acquisition system was then used to monitor the current ambient noise level. The monitored ambient noise level was then used as a reference. Figure 4 As shown; simultaneously, the magnetic field information collected by the fluxgate probe is fed back to the PID control system; the current required to shield the current magnetic field is calculated according to the PID algorithm, and the current is input to the Helmholtz coil through the power amplifier to cancel the 0th-order environmental noise, thus obtaining the magnetic field test results after the three-axis Helmholtz coil control, as shown. Figure 5 As shown. Simultaneously, the fluxgate probe matrix monitors the magnitude of the first-order gradient magnetic field in the current environment. The fluxgate probe matrix measures the first-order gradient of the magnetic field in the X and Y directions, as shown... Figure 6 As shown; then, by adjusting the input current to the gradient coil to shield the first-order gradient magnetic field, the control data results in the X and Y directions of the second-stage coil after gradient compensation are as follows. Figure 7 As shown.

[0054] In this embodiment, taking the Z-axis as an example, the ambient DC magnetic field is 40220 nT, the AC fluctuating magnetic field is 160 nT, and the DC magnetic field after shielding the Helmholtz coil is 0-10 nT, while the AC magnetic field is 5-10 nT. Data acquisition is based on these parameters. Additionally, the fluxgate detector's detection sensitivity range is: DC-1000 Hz, 100 mV / μT.

[0055] In another possible implementation, when the circuit board uses a flexible FPC transparent circuit board, a giant magnetoresistive (GMR) probe is used for the measurement. The circuit board uses a flexible FPC transparent circuit board, and the measurement probe uses a GMR probe. Controlling the application of current to the first-stage coil and the application of current to the second-stage coil includes: generating current to the first-stage coil using a low-noise amplifier and applying the generated current to the first-stage coil; powering the second-stage coil using a signal generator and a low-noise amplifier, and adjusting the signal generator to change the output current magnitude to shield the magnetic field gradient within the second-stage coil. It should be noted that adjusting the signal generator to change the output current magnitude shields the first-order magnetic field gradient within the second-stage coil to avoid additional noise from the DC power supply.

[0056] Furthermore, the giant magnetoresistive probe matrix can be arranged around the giant magnetoresistive probe, for example... Figure 8As shown, a giant magnetoresistive (GMR) probe matrix is ​​arranged around the GMR probe. It should be noted that the GMR probe measures the 0th-order magnetic field, while the 5x5 GMR probe matrix measures the first-order gradient magnetic field, with a probe-matrix spacing of 2 cm.

[0057] In one optional embodiment, the triaxial Helmholtz coil has a size of 150*150*150cm, the FPC transparent circuit board gradient coil has a size of 140*140cm, the gradient coil is suspended at the center of the uniform field region of the triaxial Helmholtz coil, the Gzx gradient coil is spaced 70cm apart, and the Gzy gradient coil is spaced 77cm apart, which are used to shield the first-order gradient fields in the Z-axis X direction and Y direction, respectively.

[0058] Specifically, the giant magnetoresistive (GMR) probe is positioned at the center of the triaxial Helmholtz coil to provide feedback to the PID control system on the current ambient magnetic field and monitor the shielded ambient noise. A matrix of GMR probes is placed directly below each individual GMR probe to measure the first-order gradient magnetic field in the Z-axis (X and Y directions).

[0059] In actual testing, the three-axis Helmholtz coil active control system was first activated to cancel out the 0th-order environmental noise, and the results were as follows: Figure 9 As shown; activate the giant magnetoresistive probe matrix to obtain the magnitude of the first-order gradient magnetic field in two directions. The magnetoresistive probe matrix measures the first-order gradient of the magnetic field in the X and Y directions as follows. Figure 10 As shown; a suitable current is applied to the gradient coil through a low-noise power amplifier to cancel the first-order gradient magnetic field. After gradient compensation, the control data results in the X and Y directions of the second-stage coil are as follows. Figure 11 As shown.

[0060] In this embodiment, taking the Z-axis as an example, the ambient DC magnetic field is 42000 nT, the AC fluctuating magnetic field is 160 nT, and the DC magnetic field after shielding the Helmholtz coil is 0-10 nT, and the AC magnetic field is 5-10 nT. Data acquisition is based on these parameters. Additionally, the fluxgate detector's detection sensitivity range is: DC-1000Hz, 80mV / μT.

[0061] In summary, this embodiment of the invention measures the magnetic field information of the first-stage coil and the second-stage coil located on both sides of the uniform field area inside the first-stage coil using a measuring probe. This allows the PID control system to determine the current applied to the corresponding second-stage coil based on the measured magnetic field information. By adjusting the current in the second-stage coil, the magnetic field of the second-stage coil is adjusted, thereby compensating for the magnetic field of the first-stage coil and achieving real-time adjustment of the magnetic field.

[0062] The magnetic field adjustment method provided by the present invention is described below. The magnetic field adjustment method described below can be referred to in correspondence with the magnetic field adjustment system described above.

[0063] Figure 12A flowchart of a magnetic field adjustment method is shown, which uses any of the magnetic field adjustment systems described above. The method includes:

[0064] S121, the measuring probe measures the magnetic field information of the first-stage coil and the second-stage coil, or, the measuring probe measures the magnetic field information of the first-stage coil and the second-stage coil, and sends the measured magnetic field information of the first-stage coil and the second-stage coil to the PID control system;

[0065] S122, the PID control system receives the magnetic field information of the first-stage coil and the magnetic field information of the second-stage coil sent by the measurement probe, and adjusts the magnetic field of the second-stage coil according to the magnetic field information of the first-stage coil and the second-stage coil to compensate for the magnetic field of the first-stage coil.

[0066] In one alternative embodiment, the first-stage coil includes a triaxial Helmholtz coil, and the second-stage coil includes a gradient coil.

[0067] Optionally, before measuring the magnetic field information of the first-stage coil and the second-stage coil with the measuring probe, the process includes: forming the second-stage coil. Specifically, forming the second-stage coil includes: fixing an adhesive layer with a preset gradient coil pattern pre-formed on one side of a transparent substrate, and winding a wire around the preset gradient coil pattern printed on the adhesive layer on the other side of the transparent substrate and curing it to obtain the second-stage coil; or, fixing an adhesive layer with a preset gradient coil pattern pre-formed on one side of a transparent substrate, and winding a wire around the adhesive layer with the preset gradient coil pattern pre-formed on one side to obtain the second-stage coil; or, printing the preset gradient coil pattern on a circuit board to obtain the second-stage coil.

[0068] In one alternative embodiment, before fixing the adhesive layer on one side of the transparent base plate with the pre-formed gradient coil pattern, the method includes: printing the pre-formed gradient coil pattern onto the adhesive layer based on a metal 3D printing process.

[0069] In one alternative embodiment, printing a preset gradient coil pattern on a circuit board includes: printing the preset gradient coil pattern on the circuit board based on ink or powder.

[0070] In addition, in this embodiment, based on the received magnetic field information of the first-stage coil and the magnetic field information of the second-stage coil, the magnetic field of the second-stage coil is adjusted to compensate the magnetic field of the first-stage coil. This includes: determining the current corresponding to the first-stage coil and the current of the second-stage coil according to the magnetic field information of the first-stage coil and the magnetic field information of the second-stage coil; controlling the current corresponding to the first-stage coil to be applied to the first-stage coil to compensate the magnetic field of the first-stage coil; and controlling the current corresponding to the second-stage coil to be applied to the second-stage coil to adjust the magnetic field of the second-stage coil.

[0071] Furthermore, when the circuit board uses a PCB circuit board, the PID control system determines the current of the corresponding level coil based on the magnetic field information, controls the current corresponding to the first level coil to be applied to the first level coil, and controls the current corresponding to the second level coil to be applied to the second level coil, including: generating the current corresponding to the first level coil through a low-noise power amplifier and inputting it into the first level coil; generating the current corresponding to the second level coil through a low-noise power amplifier and inputting it into the second level coil.

[0072] When the circuit board uses an FPC transparent circuit board, the measurement probe uses a giant magnetoresistive probe; controlling the current corresponding to the first-stage coil to be applied to the first-stage coil, and controlling the current corresponding to the second-stage coil to be applied to the second-stage coil, includes: generating the current corresponding to the first-stage coil through a low-noise power amplifier and applying the generated current to the first-stage coil; powering the second-stage coil by using a signal generator and a low-noise power amplifier, and adjusting the signal generator to change the output current magnitude to shield the magnetic field gradient in the second-stage coil.

[0073] In summary, this embodiment of the invention measures the magnetic field information of the first-stage coil and the second-stage coil located on both sides of the uniform field area inside the first-stage coil using a measuring probe. This allows the PID control system to determine the current applied to the corresponding second-stage coil based on the measured magnetic field information. By adjusting the current in the second-stage coil, the magnetic field of the second-stage coil is adjusted, thereby compensating for the magnetic field of the first-stage coil and achieving real-time adjustment of the magnetic field.

[0074] Figure 13 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 13 As shown, the electronic device may include a processor 1310, a communication interface 1320, a memory 1330, and a communication bus 1340. The processor 1310, communication interface 1320, and memory 1330 communicate with each other via the communication bus 1340. The processor 1310 can call logic instructions in the memory 1330 to execute a magnetic field adjustment method. This method includes: measuring the magnetic field information of a first-stage coil and a second-stage coil using a measuring probe; or, the measuring probe measures the magnetic field information of the first-stage coil and the second-stage coil, and sends the measured magnetic field information of the first-stage coil and the second-stage coil to a PID control system; the PID control system receives the magnetic field information of the first-stage coil and the second-stage coil sent by the measuring probe, and adjusts the magnetic field of the second-stage coil according to the magnetic field information of the first-stage coil and the second-stage coil to compensate for the magnetic field of the first-stage coil.

[0075] Furthermore, the logical instructions in the aforementioned memory 1330 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0076] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the magnetic field adjustment method provided by the above methods. The method includes: measuring the magnetic field information of a first-stage coil and a second-stage coil with a measuring probe, or measuring the magnetic field information of the first-stage coil and the second-stage coil with a measuring probe, and sending the measured magnetic field information of the first-stage coil and the second-stage coil to a PID control system; the PID control system receives the magnetic field information of the first-stage coil and the second-stage coil sent by the measuring probe, and adjusts the magnetic field of the second-stage coil according to the magnetic field information of the first-stage coil and the second-stage coil to compensate for the magnetic field of the first-stage coil.

[0077] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the magnetic field adjustment method provided by the above methods. The method includes: measuring magnetic field information of a first-stage coil and a second-stage coil by a measuring probe, or measuring magnetic field information of a first-stage coil and a second-stage coil by a measuring probe, and sending the measured magnetic field information of the first-stage coil and the second-stage coil to a PID control system; the PID control system receives the magnetic field information of the first-stage coil and the second-stage coil sent by the measuring probe, and adjusts the magnetic field of the second-stage coil according to the magnetic field information of the first-stage coil and the second-stage coil to compensate for the magnetic field of the first-stage coil.

[0078] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0079] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A magnetic field adjustment system, characterized in that, It includes a measuring probe, a first-stage coil, a second-stage coil, and a PID control system, wherein: The second-stage coil is distributed on both sides of the uniform field region inside the first-stage coil, and the order of the second-stage coil is higher than that of the first-stage coil; The measuring probe is set in the preset magnetic field region to be adjusted of the first-stage coil to measure the magnetic field information of the first-stage coil and the second-stage coil; or, the measuring probe measures the magnetic field information of the first-stage coil and the second-stage coil and sends the measured magnetic field information of the first-stage coil and the magnetic field information of the second-stage coil to the PID control system. The PID control system adjusts the magnetic field of the second-stage coil based on the received magnetic field information of the first-stage coil and the magnetic field information of the second-stage coil, so as to compensate the magnetic field of the first-stage coil. The measuring probe includes a magnetic probe and a magnetic probe matrix. The magnetic probe is set in the preset magnetic field region to be adjusted of the first-stage coil to measure the magnetic field information of the central region of the uniform field region of the first-stage coil, and feeds back the measured magnetic field information of the first-stage coil to the PID control system. The magnetic probe matrix is ​​set in the preset adjustable magnetic field region of the second-stage coil to measure the magnetic field information of the second-stage coil and feed the measured magnetic field information of the second-stage coil back to the PID control system. The first-stage coil includes a Helmholtz coil, which is a triaxial Helmholtz coil. The second-stage coil includes a gradient coil, which consists of multiple planar coils distributed on both sides of the uniform field region inside the triaxial Helmholtz coil. The gradient coil is composed of two groups of four planar gradient coils, which are used to shield the first-order gradient magnetic field in the Z-axis X direction and Y direction, respectively. The magnetic probe is positioned within the uniform field region at the center of the triaxial Helmholtz coil, and the magnetic probe matrix is ​​located on one side of the magnetic probe.

2. The magnetic field adjustment system according to claim 1, characterized in that, The step of adjusting the magnetic field of the second-stage coil based on the received magnetic field information of the first-stage coil and the magnetic field information of the second-stage coil to compensate for the magnetic field of the first-stage coil includes: Based on the magnetic field information of the first-stage coil and the magnetic field information of the second-stage coil, determine the current corresponding to the first-stage coil and the current of the second-stage coil; The control applies the current corresponding to the first-stage coil to the first-stage coil to compensate for the magnetic field of the first-stage coil, and controls the application of the current corresponding to the second-stage coil to the second-stage coil to adjust the magnetic field of the second-stage coil.

3. The magnetic field adjustment system according to claim 2, characterized in that, Before the measuring probe measures the magnetic field information of the first-stage coil and the second-stage coil, the following steps are included: An adhesive layer with a pre-formed gradient coil pattern is fixed to one side of a transparent base plate, and wires are wound around the pre-formed gradient coil pattern printed on the adhesive layer on the other side of the transparent base plate and cured to obtain a second-stage coil; or... A second-stage coil is obtained by fixing an adhesive layer with a pre-formed gradient coil pattern to one side of a transparent base plate, and then winding a wire around the adhesive layer with the pre-formed gradient coil pattern; or, A preset gradient coil pattern is printed on the circuit board to obtain the second-stage coil.

4. The magnetic field adjustment system according to claim 3, characterized in that, The circuit board is a printed PCB circuit board, and the measuring probe is a fluxgate probe; Controlling the application of current corresponding to the first-stage coil to the first-stage coil, and controlling the application of current corresponding to the second-stage coil to the second-stage coil, includes: A low-noise power amplifier generates a current corresponding to the first-stage coil and inputs it into the first-stage coil. A low-noise power amplifier generates the current corresponding to the second-stage coil and inputs it into the second-stage coil.

5. The magnetic field adjustment system according to claim 3, characterized in that, The circuit board is a flexible FPC transparent circuit board, and the measuring probe is a giant magnetoresistive probe; Controlling the application of current corresponding to the first-stage coil to the first-stage coil, and controlling the application of current corresponding to the second-stage coil to the second-stage coil, includes: A low-noise power amplifier generates a current corresponding to the first-stage coil, and the generated current is applied to the first-stage coil. The second-stage coil is powered by a signal generator and a low-noise power amplifier. The magnetic field gradient within the second-stage coil is shielded by adjusting the signal generator to change the output current.

6. The magnetic field adjustment system according to claim 3, characterized in that, The conductor is made of capillary copper tubing, and coolant circulates within the capillary copper tubing.

7. The magnetic field adjustment system according to claim 1, characterized in that, The measurement probe includes at least one of a fluxgate, a giant magnetoresistive, or an optically pumped magnetic sensor.

8. A magnetic field adjustment method, using the magnetic field adjustment system as described in any one of claims 1-7, characterized in that, include: The measuring probe measures the magnetic field information of the first-stage coil and the second-stage coil, or the measuring probe measures the magnetic field information of the first-stage coil and the second-stage coil, and sends the measured magnetic field information of the first-stage coil and the second-stage coil to the PID control system; The PID control system receives the first-stage coil magnetic field information and the second-stage coil magnetic field information sent by the measuring probe, and adjusts the magnetic field of the second-stage coil according to the first-stage coil magnetic field information and the second-stage coil to compensate for the magnetic field of the first-stage coil. The measuring probe includes a magnetic probe and a magnetic probe matrix. The magnetic probe is set in the preset magnetic field region to be adjusted of the first-stage coil to measure the magnetic field information of the central region of the uniform field region of the first-stage coil, and feeds back the measured magnetic field information of the first-stage coil to the PID control system. The magnetic probe matrix is ​​set in the preset adjustable magnetic field region of the second-stage coil to measure the magnetic field information of the second-stage coil and feeds back the measured magnetic field information of the second-stage coil to the PID control system.

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