Three-dimensional orthogonal magnetic gradient sensor

Abstract

The three-dimensional orthogonal magnetic gradient sensor comprises a three-dimensional coil framework, a magnetic core, an exciting coil, a receiving coil and a signal processing circuit, the three-dimensional coil framework comprises a middle framework and a coil framework, and the coil framework comprises an X-axis coil framework, a Y-axis coil framework and a Z-axis coil framework which are mutually orthogonal. The coil framework is provided with a cavity in the axial direction, a magnetic core is arranged in the cavity, two exciting coils wound in the clockwise direction and two receiving coils wound in the opposite directions are arranged on the coaxial coil framework, and the exciting coils and the receiving coils are connected with a signal processing circuit. According to the utility model, a spatial three-dimensional orthogonal structure is adopted, so that the resolution and the stability of magnetic gradient detection are improved.

Description

Technical Field

[0001] The utility model relates to the field of space physics detection, in particular to a three-dimensional orthogonal magnetic gradient sensor. Background Art

[0002] Traditional fluxgate gradiometers are sensitive to temperature changes, which may lead to inaccurate measurement results and require temperature compensation. They have a limited dynamic range and insufficient sensitivity, making it difficult to detect weak magnetic field changes, which can easily cause information loss during physical detection. They are also easily interfered by environmental noise, which may mask the true signal.

[0003] Existing magnetic gradient detection technology optimizes traditional magnetic gradiometers, allowing the fluxgate to operate in zero magnetic field, reducing temperature sensitivity, increasing dynamic range, and improving measurement accuracy and sensitivity. However, most of these efforts focus on innovative optimization by adding signal conditioning circuits and changing sensor materials, rather than optimizing the structure. Utility Model Content

[0004] In order to solve the problem that existing magnetic gradient detection technology has not structurally optimized the interference of environmental factors such as temperature and noise of traditional magnetic gradiometers, the utility model proposes a three-dimensional orthogonal magnetic gradient sensor to improve the resolution and stability of magnetic gradient detection, which helps to ensure that false detection and signal loss will not occur during detection, thereby solving the above-mentioned problem.

[0005] A three-dimensional orthogonal magnetic gradient sensor includes a three-dimensional coil skeleton, a magnetic core, an excitation coil, a receiving coil, and a signal processing circuit. The three-dimensional coil skeleton includes an intermediate skeleton (B) and a coil skeleton. The coil skeleton includes a mutually orthogonal X-axis coil skeleton, a Y-axis coil skeleton, and a Z-axis coil skeleton. The coil skeleton is provided with a cavity along the axial direction, and a magnetic core is provided in the cavity. Two excitation coils with the same number of turns and two receiving coils with the same number of turns and opposite winding directions are wound in a clockwise direction on the coaxial coil skeleton. The excitation coil and the receiving coil are connected to the signal processing circuit.

[0006] Preferably, the X-axis coil frame, the Y-axis coil frame and the Z-axis coil frame are all centrally symmetrical about the center point of the middle frame along their respective axes.

[0007] Preferably, the three-dimensional coil skeleton adopts a dielectric constant greater than 2.0 and a conductivity less than 10 -8 S / m, insulating non-magnetic material with relative magnetic permeability less than 1.05.

[0008] Preferably, the X-axis coil skeleton, the Y-axis coil skeleton and the Z-axis coil skeleton are all provided with cavities in the positive half axis and the negative half axis along the axial direction, and magnetic cores are provided in the cavities;

[0009] The two magnetic cores in the positive and negative half axes of the X-axis coil frame, the two magnetic cores in the positive and negative half axes of the Y-axis coil frame, and the two magnetic cores in the positive and negative half axes of the Z-axis coil frame are all symmetrical about the center point of the middle frame.

[0010] Preferably, the magnetic core is made of a magnetic core material with a relative magnetic permeability greater than 10,000.

[0011] Preferably, the X-axis coil frame, the Y-axis coil frame and the Z-axis coil frame are respectively provided with two winding slots on the positive half-axis and the negative half-axis of their respective axial directions. The coil frame of each axial direction has an excitation coil with the same number of turns wound in a clockwise direction in the two winding slots close to the middle frame (B), and two receiving coils with the same number of turns wound in opposite directions in the two winding slots away from the middle frame (B).

[0012] Preferably, the two excitation coils on the X-axis coil frame, the two excitation coils on the Y-axis coil frame, and the two excitation coils on the Z-axis coil frame are connected in series in the same direction;

[0013] The two receiving coils on the X-axis coil frame, the two receiving coils on the Y-axis coil frame, and the two receiving coils on the Z-axis coil frame are connected in reverse series.

[0014] Preferably, the signal processing circuit includes a driving module, a processing circuit module and an analog operation module, and the processing circuit module includes an amplifier, a demodulator and a filter connected in sequence;

[0015] Preferably, the excitation coil on the X-axis coil frame, the excitation coil on the Y-axis coil frame, and the excitation coil on the Z-axis coil frame are respectively connected to a driving module of a signal processing circuit.

[0016] Preferably, the two receiving coils on the X-axis coil frame, the two receiving coils on the Y-axis coil frame, and the two receiving coils on the Z-axis coil frame are respectively connected to a processing circuit module of a signal processing circuit.

[0017] Beneficial effects of the utility model:

[0018] (1) The utility model adopts a three-dimensional orthogonal structure in space, which can generate a uniform magnetic gradient in space. When conducting space physical detection, the spatial material information can be obtained in real time by monitoring the changes in the uniform magnetic gradient. Due to its high resolution, it can not only ensure the accuracy of detection and avoid data loss and false detection, but also can be used for the detection of small deformations, bends and defects in pipelines.

[0019] (2) The excitation signals for generating the three-axis magnetic gradient in the space of the utility model are asynchronous, which ensures that the three-axis magnetic gradient field maintains a relatively stable state, avoids mutual interference between the three-axis magnetic gradients, and facilitates correction.

[0020] (3) The three-dimensional structure of the present invention is orthogonal in the X-axis, Y-axis, and Z-axis, thus avoiding errors caused by incomplete orthogonality in the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic structural diagram of a three-dimensional orthogonal magnetic gradient sensor according to an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the three-dimensional coil skeleton structure of an embodiment of the utility model;

[0023] Figure 3 This is a schematic diagram of an orthogonal cross-section of a three-dimensional orthogonal magnetic gradient sensor according to an embodiment of the present invention in the XY plane;

[0024] Figure 4 This is a schematic diagram of the structure of a signal processing circuit according to an embodiment of the present utility model;

[0025] Figure 5 This is a schematic diagram of the X-axis coil skeleton structure of an embodiment of the present utility model;

[0026] Figure 6 Schematic diagram of the spatial magnetic field distribution of a three-dimensional orthogonal magnetic gradient sensor according to an embodiment of the present invention.

[0027] The reference numerals are as follows:

[0028] B-middle skeleton, O-center point of the middle skeleton, X1-first coil skeleton, X2-second coil skeleton, Y1-third coil skeleton, Y2-fourth coil skeleton, Z1-fifth coil skeleton, Z2-sixth coil skeleton, Mx1-first magnetic core, Mx2-second magnetic core, My1-third magnetic core, My2-fourth magnetic core, Mz1-fifth magnetic core, Mz2-sixth magnetic core, Lxm1-first excitation coil, Lxm2-second excitation coil, Lym1-third excitation coil, Lym2-fourth excitation coil, Lzm1-fifth excitation coil excitation coil, Lzm2-sixth excitation coil, Lxc1-first receiving coil, Lxc2-second receiving coil, Lyc1-third receiving coil, Lyc2-fourth receiving coil, Lzc1-fifth receiving coil, Lzc2-sixth receiving coil, Lxt1-first excitation coil external input interface, Lxt2-second excitation coil external input interface, Lxt3-first excitation coil internal interface, Lxt4-second excitation coil internal interface, Lxr1-first receiving coil output interface, Lxr2-second receiving coil output interface, Lxr3-internal interface of the first receiving coil, Lxr4-output interface of the second receiving coil, Lyt1-external input interface of the third excitation coil, Lyt2-external input interface of the fourth excitation coil, Lyt3-internal interface of the third excitation coil, Lyt4-internal interface of the fourth excitation coil, Lyr1-output interface of the third receiving coil, Lyr2-output interface of the fourth receiving coil, Lyr3-internal interface of the third receiving coil, Lyr4-output interface of the fourth receiving coil. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of this application more clear, the application is further described in detail below with reference to the accompanying drawings and examples.

[0030] The embodiment of the present application discloses a three-dimensional orthogonal magnetic gradient sensor, which includes a three-dimensional coil skeleton, a high-permeability magnetic core, an excitation coil, a receiving coil, and a signal processing circuit.

[0031] In this embodiment, the three-dimensional coil skeleton adopts a dielectric constant greater than 2.0 and a conductivity less than 10 -8 S / m, insulating non-magnetic material with a relative magnetic permeability lower than 1.05, such as polyetheretherketone, polytetrafluoroethylene, epoxy resin or polystyrene. The three-dimensional coil skeleton includes an intermediate skeleton B and a coil skeleton, and the coil skeleton includes mutually orthogonal X-axis coil skeleton, Y-axis coil skeleton and Z-axis coil skeleton. The X-axis coil skeleton, Y-axis coil skeleton and Z-axis coil skeleton are all symmetrical about the center point O of the intermediate skeleton B along their respective axes. Specifically, Figure 1 and Figure 2As shown, the X-axis coil bobbin includes a first coil bobbin X1 along the positive half axis of the X-axis, and a second coil bobbin X2 along the negative half axis of the X-axis, with the center point O of the intermediate bobbin B as the origin. The first coil bobbin X1 and the second coil bobbin X2 are centrosymmetric about the center point O of the intermediate bobbin B. The Y-axis coil bobbin includes a third coil bobbin Y1 along the positive half axis of the Y-axis, and a fourth coil bobbin Y2 along the negative half axis of the Y-axis, with the center point O of the intermediate bobbin B as the origin. The third coil bobbin Y1 and the fourth coil bobbin Y2 are centrosymmetric about the center point O of the intermediate bobbin B. The Z-axis coil bobbin includes a fifth coil bobbin Z1 along the positive half axis of the Z-axis, and a sixth coil bobbin Z2 along the negative half axis of the Z-axis, with the center point O of the intermediate bobbin B as the origin. The fifth coil bobbin Z1 and the sixth coil bobbin Z2 are centrosymmetric about the center point O of the intermediate bobbin B.

[0032] The coil skeleton is provided with a cavity along the axial direction, and a magnetic core is provided in the cavity. Specifically, the X-axis coil skeleton, the Y-axis coil skeleton and the Z-axis coil skeleton are all provided with a cavity in the positive and negative half axes along the axial direction, and a magnetic core is provided in the cavity. The two magnetic cores in the positive and negative half axes of the X-axis coil skeleton, the two magnetic cores in the positive and negative half axes of the Y-axis coil skeleton and the two magnetic cores in the positive and negative half axes of the Z-axis coil skeleton are all symmetrical about the center point O of the middle skeleton B, and the center lines of the six magnetic cores intersect at the center point O of the middle skeleton B, that is, at the origin O of the three-dimensional space coordinate axis system. The six magnetic cores have the same material, shape and length, and the magnetic core material uses a magnetic core material with a relative magnetic permeability greater than 10,000, such as: Permalloy core or amorphous nano-magnetic core.

[0033] The specific structure is as Figure 1 As shown, a first cavity is axially provided in the first coil bobbin X1, in which a first magnetic core Mx1 is disposed. A second cavity is axially provided in the second coil bobbin X2, in which a second magnetic core Mx2 is disposed. The first magnetic core Mx1 and the second magnetic core Mx2 are symmetrical about the center point O of the intermediate bobbin B. A third cavity is axially provided in the third coil bobbin Y1, in which a third magnetic core My1 is disposed. A fourth cavity is axially provided in the fourth coil bobbin Y2, in which a fourth magnetic core My2 is disposed. The third magnetic core My1 and the fourth magnetic core My2 are symmetrical about the center point O of the intermediate bobbin B. A fifth cavity is axially provided in the fifth coil bobbin Z1, in which a fifth magnetic core Mz1 is disposed. A sixth cavity is axially provided in the sixth coil bobbin Z2, in which a sixth magnetic core Mz2 is disposed. The fifth magnetic core Mz1 and the sixth magnetic core Mz2 are symmetrical about the center point O of the intermediate bobbin B. Each magnetic core has the same distance from the center. If the distance between the magnetic core and the center point O of the middle frame B is d, then the distance between the two axially symmetrical magnetic cores is 2d.

[0034] The X-axis coil frame, Y-axis coil frame and Z-axis coil frame are respectively provided with two winding slots on the positive half-axis and negative half-axis of their respective axial directions. The coil frame of each axial direction has an excitation coil with the same number of turns wound in a clockwise direction in the two winding slots close to the middle frame B, and two receiving coils with the same number of turns in opposite directions are wound in the two winding slots away from the middle frame B.

[0035] The specific structure is as Figure 1 As shown, the first coil bobbin X1 is provided with two winding slots. The first excitation coil Lxm1 is wound clockwise in the winding slot near the middle bobbin B, while the first receiving coil Lxc1 is wound clockwise in the winding slot away from the middle bobbin B. The second coil bobbin X2 is provided with two winding slots. The second excitation coil Lxm2 is wound clockwise in the winding slot near the middle bobbin B, while the second receiving coil Lxc2 is wound counterclockwise in the winding slot away from the middle bobbin B. The first excitation coil Lxm1 and the second excitation coil Lxm2 have the same number of turns and are at the same distance from the center point O of the middle bobbin B. The first receiving coil Lxc1 and the second receiving coil Lxc2 have the same number of turns and are at the same distance from the center point O of the middle bobbin B.

[0036] The third coil bobbin Y1 is provided with two winding slots. The third excitation coil Lym1 is wound clockwise in the winding slot closest to the middle bobbin B, while the third receiving coil Lyc1 is wound clockwise in the winding slot further from the middle bobbin B. The fourth coil bobbin Y2 is provided with two winding slots. The fourth excitation coil Lym2 is wound clockwise in the winding slot closest to the middle bobbin B, while the fourth receiving coil Lyc2 is wound counterclockwise in the winding slot further from the middle bobbin B. The third excitation coil Lym1 and the fourth excitation coil Lym2 have the same number of turns and are located at the same distance from the center point O of the middle bobbin B. The third receiving coil Lyc1 and the fourth coil Lyc2 have the same number of turns and are located at the same distance from the center point O of the middle bobbin B.

[0037] The fifth coil bobbin Z1 is provided with two winding slots. The fifth excitation coil Lzm1 is wound clockwise in the winding slot near the middle bobbin B, and the fifth receiving coil Lzc1 is wound clockwise in the winding slot away from the middle bobbin B. The sixth coil bobbin Z2 is provided with two winding slots. The sixth excitation coil Lzm2 is wound clockwise in the winding slot near the middle bobbin B, and the sixth receiving coil Lzc2 is wound counterclockwise in the winding slot away from the middle bobbin B. The fifth excitation coil Lzm1 and the sixth excitation coil Lzm2 have the same number of turns and are at the same distance from the center point O of the middle bobbin B. The fifth receiving coil Lzc1 and the sixth receiving coil have the same number of turns and are at the same distance from the center point O of the middle bobbin B.

[0038] The two excitation coils on the X-axis coil frame, the two excitation coils on the Y-axis coil frame, and the two excitation coils on the Z-axis coil frame are connected in series in the same direction. That is, taking the connection method of the two excitation coils on the X-axis coil frame as an example, Figure 3 As shown, Figure 3 The Lxt3 point of the first excitation coil Lxm1 is connected to the Lxt4 point of the second excitation coil Lxm2. The two receiving coils on the X-axis coil frame, the two receiving coils on the Y-axis coil frame, and the two receiving coils on the Z-axis coil frame are connected in reverse series. That is: Figure 3 The point Lxr3 of the first receiving coil Lxc1 is connected to the point Lxr4 of the second receiving coil Lxc2. Similarly, the connection method of the two excitation coils on the Y-axis coil frame and the connection method of the two excitation coils on the Z-axis coil frame are the same as the connection method of the two excitation coils on the X-axis coil frame.

[0039] like Figure 4 As shown, the signal processing circuit includes a driver module, a processing circuit module, and an analog operation module. The processing circuit module includes an amplifier, a demodulator, and a filter connected in sequence. The signal processing circuit excites the sensor excitation coil, processes the output signal of the sensor receiving coil, and converts the gradient magnetic field into voltage.

[0040] The two excitation coils on the X-axis coil bobbin, the two excitation coils on the Y-axis coil bobbin, and the two excitation coils on the Z-axis coil bobbin are each connected to a driver module in a signal processing circuit. The driver module is responsible for providing excitation signals to the sensor coils and chip and processing the output signals from the sensor receiving coils. The two receiving coils on the X-axis coil bobbin, the two receiving coils on the Y-axis coil bobbin, and the two receiving coils on the Z-axis coil bobbin are each connected to an amplifier in a processing circuit module in the signal processing circuit.

[0041] In a specific embodiment, an IPS2550 chip is used as a signal processing circuit. The IPS2550 chip integrates the driving module, processing circuit module and analog operation module of the signal processing circuit disclosed in this application, and can realize the corresponding functions of each module. Specifically, taking the connection between the excitation coil and the receiving coil on the X-axis coil skeleton and the IPS2550 chip as an example, the excitation pins of the IPS2550 chip are respectively connected to Figure 5 The Lxt1 point of the first excitation coil Lxm1 and the Lxt2 point of the second excitation coil Lxm2 are connected. The receiving pins of the IPS2550 chip are respectively connected to Figure 5The first receiving coil Lxc1 is connected to the second receiving coil Lxc2 at point Lxr1, where the signal is amplified, filtered, and demodulated. Analog operations are then performed to generate output signals Outx+ and Outx-. Analog operations involve using analog circuits to perform signal addition, subtraction, multiplication, division, or exponential operations, such as the THP210 fully differential operational amplifier.

[0042] Similarly, the connection method of the excitation coil and the receiving coil on the Y-axis coil frame and the Z-axis coil frame is the same as that of the excitation coil and the receiving coil on the X-axis coil frame. The excitation coils are respectively connected to the excitation pins of the IPS2550 chip, and the receiving coils are respectively connected to the receiving pins of the IPS2550 chip.

[0043] The IPS2550 chip used above can be any chip with the same function, including but not limited to IPS2550, THP210 and other chips.

[0044] like Figure 6 Figure 2 shows a schematic diagram of the spatial magnetic field distribution of a three-dimensional orthogonal magnetic gradient sensor disclosed in an embodiment of this application. A pattern was constructed based on the structure disclosed in this embodiment, and data was collected on its magnetic field distribution. The diagram shows that the magnetic field strength is equal at two points symmetrical about the X, Y, and Z axes.

[0045] This application utilizes a three-dimensional orthogonal structure to optimize and offset interference from environmental factors such as temperature and noise directly within the probe structure, significantly improving the uniformity and stability of the magnetic gradient, and significantly enhancing its resolution and sensitivity. This provides an effective device with high precision, high resolution, and high sensitivity for space physics exploration, and offers a new approach to magnetic gradiometer detection.

[0046] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements are intended to fall within the scope of the present invention. The scope of protection claimed in this invention is defined by the appended claims and their equivalents.

Claims

1. A three-dimensional orthogonal magnetic gradient sensor, characterized in that: It includes a three-dimensional coil skeleton, a magnetic core, an excitation coil, a receiving coil and a signal processing circuit. The three-dimensional coil skeleton includes an intermediate skeleton (B) and a coil skeleton. The coil skeleton includes an X-axis coil skeleton, a Y-axis coil skeleton and a Z-axis coil skeleton that are orthogonal to each other. The coil skeleton is provided with a cavity along the axial direction, and a magnetic core is provided in the cavity. Two excitation coils wound in a clockwise direction and two receiving coils wound in opposite directions are provided on the coaxial coil skeleton. The excitation coil and the receiving coil are connected to the signal processing circuit.

2. The three-dimensional orthogonal magnetic gradient sensor according to claim 1, characterized in that: The X-axis coil frame, the Y-axis coil frame and the Z-axis coil frame are all symmetrical about the center point (O) of the middle frame (B) along their respective axes.

3. The three-dimensional orthogonal magnetic gradient sensor according to claim 2, characterized in that: The three-dimensional coil skeleton adopts a dielectric constant greater than 2.0 and a conductivity less than 10 -8 S / m, insulating non-magnetic material with relative magnetic permeability less than 1.

05.

4. The three-dimensional orthogonal magnetic gradient sensor according to claim 3, characterized in that: The X-axis coil skeleton, the Y-axis coil skeleton, and the Z-axis coil skeleton are all provided with cavities in the positive half axis and the negative half axis along the axial direction, and magnetic cores are provided in the cavities; The two magnetic cores in the positive and negative half axes of the X-axis coil frame, the two magnetic cores in the positive and negative half axes of the Y-axis coil frame, and the two magnetic cores in the positive and negative half axes of the Z-axis coil frame are all symmetrical about the center point (O) of the middle frame (B).

5. The three-dimensional orthogonal magnetic gradient sensor according to claim 4, characterized in that: The magnetic core is made of a magnetic core material with a relative magnetic permeability greater than 10,000.

6. The three-dimensional orthogonal magnetic gradient sensor according to claim 5, characterized in that: The X-axis coil frame, the Y-axis coil frame and the Z-axis coil frame are each provided with two winding slots on the positive half-axis and the negative half-axis of their respective axial directions. The coil frame of each axial direction has an excitation coil with the same number of turns wound in a clockwise direction in the two winding slots close to the middle frame (B), and two receiving coils with the same number of turns wound in opposite directions in the two winding slots away from the middle frame (B).

7. The three-dimensional orthogonal magnetic gradient sensor according to claim 6, characterized in that: The two excitation coils on the X-axis coil frame, the two excitation coils on the Y-axis coil frame, and the two excitation coils on the Z-axis coil frame are connected in series in the same direction; The two receiving coils on the X-axis coil frame, the two receiving coils on the Y-axis coil frame, and the two receiving coils on the Z-axis coil frame are connected in reverse series.

8. The three-dimensional orthogonal magnetic gradient sensor according to claim 7, characterized in that: The signal processing circuit includes a driving module, a processing circuit module and an analog operation module. The processing circuit module includes an amplifier, a demodulator and a filter connected in sequence.

9. The three-dimensional orthogonal magnetic gradient sensor according to claim 8, characterized in that: The excitation coil on the X-axis coil frame, the excitation coil on the Y-axis coil frame, and the excitation coil on the Z-axis coil frame are respectively connected to a driving module of a signal processing circuit.

10. The three-dimensional orthogonal magnetic gradient sensor according to claim 9, characterized in that: The two receiving coils on the X-axis coil frame, the two receiving coils on the Y-axis coil frame, and the two receiving coils on the Z-axis coil frame are respectively connected to a processing circuit module of a signal processing circuit.

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