Magnetic gathering type fluxgate sensor probe

Abstract

The invention discloses a magnetism gathering type fluxgate sensor probe which comprises a magnetic core, an exciting coil, a pickup coil, a pickup coil framework, a feedback coil and a feedback coil framework, the magnetic core is dumbbell-shaped, the exciting coil is wound on the dumbbell-shaped magnetic core, a groove matched with the magnetic core in shape is machined in the pickup coil framework, and the feedback coil framework is arranged in the groove. And the dumbbell-shaped magnetic core wound with the excitation coil is arranged in the groove. The fluxgate probe can be configured to be a single-axis or three-axis fluxgate probe, a pair of pickup coil skeletons is arranged in each axial direction of the three-axis fluxgate probe, and the three pairs of pickup coil skeletons 4 along the X axis, the Y axis and the Z axis are perpendicular to one another and are placed in a feedback coil skeleton in a spatial # shape. The magnetic measurement sensitivity and precision of the fluxgate probe can be effectively improved, the X-axis, Y-axis and Z-axis parts can work independently, and the problem of mutual interference when the X, Y and Z components of a magnetic field are measured is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of fluxgate magnetic field detection, and in particular to a magnetic fluxgate sensor probe, comprising a magnetic fluxgate single-axis magnetic fluxgate sensor probe and a magnetic fluxgate tri-axis magnetic fluxgate sensor probe. Background Art

[0002] The fluxgate sensor probe is usually composed of a magnetic core of different shapes, an excitation coil and a pickup coil wound on the core, and a feedback coil is added to form a closed-loop system. At present, the three-axis fluxgate sensor probe mainly adopts a ring-shaped or runway-shaped magnetic tape structure. These two core structures still have the problem of low pickup sensitivity, which restricts the measurement accuracy of the fluxgate sensor. In addition, the core of the three-axis fluxgate sensor probe with a ring-shaped or runway-shaped core is usually a whole. The X-axis, Y-axis, and Z-axis cannot work independently. There is a certain mutual interference when measuring the X, Y, and Z components of the magnetic field, and the measurement accuracy will be affected. The single-axis fluxgate sensor probe also has the problem of low measurement sensitivity. Summary of the invention

[0003] The object of the present invention is to provide a magnetic fluxgate sensor probe capable of improving the sensitivity and accuracy of magnetic measurement in view of the deficiencies of the prior art.

[0004] The objective of the present invention is achieved through the following technical solutions:

[0005] A magnetic concentrating single-axis fluxgate sensor probe comprises a magnetic core, an excitation coil, a pickup coil and a pickup coil frame, wherein the excitation coil is wound on the magnetic core, and the pickup coil is wound on the pickup coil frame. The magnetic core is dumbbell-shaped and is formed by a magnetic conductive sheet. Grooves matching the shape of the magnetic core are formed on both sides of the pickup coil frame. Two dumbbell-shaped magnetic cores wound with the excitation coils are respectively installed in the grooves. The magnetic axes of the two dumbbell-shaped magnetic cores are parallel to each other and the structures are symmetrical. The pickup coil is wound on the outside of the middle part of the pickup coil frame.

[0006] Furthermore, the dumbbell-shaped magnetic core is formed by stacking a plurality of magnetic conductive sheets.

[0007] Furthermore, the pickup coil frame is also in a dumbbell shape, and the pickup coil is wound around the outside of the middle elongated portion of the pickup coil frame.

[0008] A magnetic concentrating three-axis fluxgate sensor probe comprises a magnetic core, an excitation coil, a pickup coil, a pickup coil frame, a feedback coil and a feedback coil frame, wherein a multi-turn excitation coil is wound on the magnetic core, a pickup coil is wound on the pickup coil frame, and a single-turn feedback coil is wound on the feedback coil frame. The magnetic core is dumbbell-shaped, a groove matching the shape of the magnetic core is processed on the pickup coil frame, the dumbbell-shaped magnetic core wound with the excitation coil is installed in the groove, the pickup coil is wound on the outside of the middle part of the pickup coil frame, and the dumbbell-shaped magnetic core and the pickup coil frame are concentrically arranged; a pair of pickup coil frames are respectively arranged in each axial direction, the two pickup coil frames of each axis are parallel to each other and symmetrically arranged, the three pairs of pickup coil frames 4 along the X, Y and Z axes are perpendicular to each other and are placed in the feedback coil frame in a spatial tic-tac-toe pattern, and the pickup coil frame 4 is coaxial with the X, Y and Z axes of the feedback coil frame 6.

[0009] Furthermore, the dumbbell-shaped magnetic core is formed by stacking a plurality of magnetic conductive sheets.

[0010] Furthermore, the pickup coil frame is also in a dumbbell shape, and the pickup coil is wound around the outside of the middle elongated portion of the pickup coil frame.

[0011] Furthermore, the feedback coil skeleton is in a cubic shape, and a plurality of wire grooves are engraved on the feedback coil skeleton along the X-axis, Y-axis, and Z-axis directions and are orthogonal to each other. The feedback coil is wound in the wire grooves, and a through-hole groove is opened on the feedback coil skeleton along the X-axis, Y-axis, and Z-axis directions. The pickup coil skeleton installed with a dumbbell-shaped magnetic core and wound with the pickup coil is placed into the feedback coil skeleton through the through-hole groove and supported by the plane at the end face of the through-hole groove. After the pickup coil skeleton is placed in, it is arranged in a spatial tic-tac-toe shape in the feedback coil skeleton.

[0012] Furthermore, each group of the feedback coils includes three coils, and the three coils are evenly spaced.

[0013] Compared with the prior art, the present invention has the following effects:

[0014] (1) The fluxgate probe of the present invention adopts a dumbbell-shaped magnetic core, which has higher sensitivity and accuracy than fluxgate probes adopting racetrack-shaped and toroidal magnetic cores.

[0015] (2) The three-axis fluxgate probe of the present invention adopts an independently wound pickup coil, which improves the sensitivity of the probe magnetic measurement, and each part of the X, Y, and Z axes can work independently, avoiding the problem of mutual interference when measuring the X, Y, and Z components of the magnetic field.

[0016] (3) The magnetic core of the three-axis fluxgate probe of the present invention is in a stable spatial tic-tac-toe structure within the feedback coil frame. When the fluxgate probe is subjected to impact or temperature changes during use, the fluxgate probe can be prevented from introducing stray or erroneous signals when responding.

[0017] (4) The magnetic field generated by the feedback coil of the three-axis fluxgate probe of the present invention has a high uniformity and a large uniform range, which is beneficial to improving the accuracy and stability of magnetic measurement by the magnetic probe;

[0018] (5) The fluxgate probe of the present invention has a simple structure, is easy to use, and has high measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the three-axis fluxgate probe of the present invention;

[0020] Figure 2 It is a schematic diagram of the structure and layout of the magnetic core of the three-axis fluxgate probe of the present invention;

[0021] Figure 3 for Figure 2 The schematic diagram of the structure of the magnetic core with the excitation coil and the pickup coil shown;

[0022] Figure 4 Schematic diagram of the selected cross section for the pickup coil magnetic flux variation;

[0023] Figure 5 for Figure 3 The schematic diagram of the structure after the magnetic core is added with the pickup coil skeleton;

[0024] Figure 6 for Figure 1 A schematic diagram of the three-dimensional structure of the feedback coil skeleton of the three-axis fluxgate probe shown;

[0025] Figure 7 A top view of a feedback coil frame with a pickup coil frame installed;

[0026] Figure 8 for Figure 7 AA section diagram;

[0027] Fig. 9 Schematic diagram of magnetic force line distribution of the magnetic core of the present invention under the influence of an external field, wherein Figure a is a schematic diagram of magnetic force line distribution when the magnetic core is in a saturated state, and Figure b is a schematic diagram of magnetic force line distribution when the magnetic core is in a conducting state;

[0028] Fig.10 Schematic diagram of the magnetic field distribution generated by the feedback coil of the three-axis fluxgate probe of the present invention, wherein Figure a is a distribution diagram of the magnetic induction intensity of the feedback coil on the XOY plane, and Figure b is a line diagram of the feedback magnetic field deviation rate of the three axes X, Y, and Z;

[0029] Fig.11 It is a structural schematic diagram of a single-axis fluxgate probe of the present invention;

[0030] Fig.12It is a schematic diagram of the working principle of the three-axis fluxgate probe of the present invention.

[0031] Markings in the figure: 1, dumbbell-shaped magnetic core; 2, excitation coil; 3, pickup coil; 4, pickup coil frame; 5, feedback coil; 6, feedback coil frame; 61, wire slot; 62, through-hole slot. DETAILED DESCRIPTION

[0032] The magnetic fluxgate sensor probe provided by the present invention can be configured as a single-axis fluxgate probe or a three-axis fluxgate probe as needed, including a dumbbell-shaped magnetic core 1, an excitation coil 2, a pickup coil 3, a pickup coil skeleton 4, a feedback coil 5 and a feedback coil skeleton 6. The excitation coil 2 is wrapped around the entire dumbbell-shaped magnetic core 1 to form a closed magnetic circuit, and the pickup coil 3 is wound on the pickup coil skeleton 4. The feedback coil skeleton 6 used in the three-axis fluxgate probe is in the shape of a cube, on which a plurality of mutually orthogonal wire grooves 61 are engraved, and the feedback coil 5 is wound in the wire grooves 61. According to the single-axis or three-axis fluxgate probe, the feedback coil 5 can be configured in different ways. The present invention only describes the feedback coil 5 of the three-axis fluxgate probe, and the feedback coil 5 of the three-axis fluxgate probe is obtained based on the optimized design of the Helmholtz coil.

[0033] The dumbbell-shaped magnetic core 1 is designed based on the optimization of the racetrack-shaped magnetic core. After testing, the dumbbell-shaped magnetic core has higher sensitivity than the racetrack-shaped and ring-shaped magnetic cores. The design of the three-axis fluxgate probe needs to take into account the possible mutual influence between multiple magnetic cores, including selecting appropriate magnetic core shapes and arrangement layouts to ensure that each magnetic core can work effectively within its design range without being affected by adjacent magnetic cores. In order to reduce the flux shunting and coupling effects between the magnetic cores, the three-axis fluxgate probe designed in the present invention includes three pairs of parallel dumbbell-shaped magnetic cores 1, using a three-component bulk magnetic core structure. According to the designed spatial tic-tac-toe layout, the three groups of magnetic cores are arranged on mutually perpendicular XX, YY and ZZ planes, their magnetic axes are perpendicular to each other, and the magnetic core structure is highly symmetrical. A uniform external environmental magnetic field of B=5000nT along the Z-axis is created in the simulation software, and the change in magnetic flux at the Z-axis pickup coil 3 when the magnetic core switches from the magnetic conduction state to the magnetic saturation state under the two structures is calculated respectively. The cross-section of the selected pickup coil 3 is as follows: Figure 4 As shown, the results show that the detla*le-8 value of the racetrack type magnetic core is 10.9, and the detla*le-8 value of the dumbbell type magnetic core is 15.3, which proves that the design and layout of the dumbbell type magnetic core of the present invention can make the magnetic flux change value larger. According to Faraday's law of electromagnetic induction, it can be known that the pulse amplitude of the induced electromotive force generated at the pickup coil 3 is also stronger, thereby improving the measurement accuracy.

[0034] Example 1: Magnetic-focusing three-axis fluxgate sensor probe

[0035] like Figure 1-Figure 10 As shown, the magnetic concentrating triaxial fluxgate sensor probe provided in this embodiment includes a dumbbell-shaped magnetic core 1, an excitation coil 2, a pickup coil 3, a pickup coil frame 4, a feedback coil 5 and a feedback coil frame 6. The magnetic core is dumbbell-shaped. Compared with the runway-shaped magnetic core, the dumbbell-shaped magnetic core 1 has widened two end portions. In this embodiment, the dumbbell-shaped magnetic core 1 is made of a plurality of Permalloy magnetic conductive sheets, each of which has the same thickness and size. The dumbbell-shaped magnetic core 1 is wound with a plurality of turns of the excitation coil 2. In the state of magnetic conduction, the magnetic conductive sheets of the dumbbell-shaped magnetic core 1 gather the magnetic lines of force of the environmental magnetic field, so that the magnetic concentrating effect of the dumbbell-shaped magnetic core 1 is stronger, and the magnetic induction intensity in the pickup coil 3 is also stronger. In the state of magnetic saturation, the dumbbell-shaped magnetic core 1 diffuses the magnetic lines of force of the environmental magnetic field along the edge of the magnetic core, so that the magnetic dispersion effect of the dumbbell-shaped magnetic core 1 is stronger, and the magnetic induction intensity in the pickup coil 3 is also weaker.

[0036] The pickup coil skeleton 4 is processed with a groove matching the shape of the dumbbell-shaped magnetic core 1, and the dumbbell-shaped magnetic core 1 wound with the excitation coil 2 is installed in the groove. The shape of the pickup coil skeleton 4 corresponds to the shape of the dumbbell-shaped magnetic core 1, which is also large at both ends and thin in the middle. The pickup coil 3 is wound on the outside of the slender part in the middle of the pickup coil skeleton 4, and the pickup coil skeleton 4 and the dumbbell-shaped magnetic core 1 are concentrically arranged. The slender structure of the middle part of the pickup coil skeleton 4 can increase the number of turns of the pickup coil 3, thereby effectively improving the sensitivity of the sensor to weak signals, improving the signal-to-noise ratio, and increasing the measurement range of the sensor.

[0037] The three-axis fluxgate sensor probe of the present invention is respectively provided with a pair of pickup coil skeletons 4 (with dumbbell-shaped magnetic cores 1 installed and pickup coils 3 wound thereon) along each axis of the X-axis, Y-axis and Z-axis. The two pickup coil skeletons 4 of each axis are parallel to each other and symmetrically arranged. The three pairs of pickup coil skeletons 4 along the X-axis, Y-axis and Z-axis are perpendicular to each other, placed in a spatial tic-tac-toe pattern in a feedback coil skeleton 6 and are concentric with the feedback coil skeleton 6. The feedback coil skeleton 6 is in the shape of a cube, and a plurality of wire grooves 61 are engraved on the feedback coil skeleton 6 along the X-axis, Y-axis, and Z-axis directions and mutually orthogonal. The feedback coil 5 is wound in the wire grooves. The feedback coil skeleton 6 is also provided with through-hole grooves 62 along the X-axis, Y-axis, and Z-axis directions. The pickup coil skeleton 4, which is equipped with a dumbbell-shaped magnetic core 1 and wound with the pickup coil 3, is placed into the feedback coil skeleton 6 through the through-hole grooves 62 and supported by the plane at the end face of the through-hole grooves 62. Three pairs of mutually perpendicular pickup coil skeletons 4 along the X-axis, Y-axis, and Z-axis directions are placed in a stable spatial tic-tac-toe pattern in the feedback coil skeleton 6. The X-axis, Y-axis, and Z-axis of the pickup coil skeleton 4 and the feedback coil skeleton 6 are coaxial. The feedback coil 5 of the present invention is based on the optimized design of the Helmholtz coil. Each group of the traditional Helmholtz coil consists of only two coils. Under the limited volume of the fluxgate sensor, the uniform magnetic field space generated by it cannot meet the requirements in terms of uniformity or range. The present invention maximizes the uniform area of ​​the field by adding a new coil between the two coils and adjusting the ampere-turn ratio of the three coil groups. The feedback coil 5 uses a single-turn coil to avoid the influence of uncontrollable factors such as capacitance and coil winding method, making the induction pulse collected by the pickup coil 3 more ideal, thereby improving the accuracy of magnetic measurement.

[0038] The pickup coil 3 and dumbbell-shaped magnetic core 1 of the present invention are coaxially placed, and each axis pickup coil 3 is independently wound along the middle slender part of the dumbbell-shaped magnetic core 1, which can reduce the mutual inductance between the pickup coils 3, reduce signal interference and thus improve the magnetic measurement accuracy and fluxgate probe sensitivity. The traditional three-axis fluxgate probe composed of six annular magnetic cores usually installs the pickup coil and the feedback coil in the same direction as the magnetic core in a manner of being surrounded by a rectangular coil as a whole. The use of such a combination will cause certain defects in the accuracy, sensitivity and linearity of the sensor probe, and will also occupy part of the space of the feedback coil. The present invention adopts a method of independently winding six pickup coils 3, which not only improves the sensitivity of the magnetic probe magnetic measurement, but also saves space for the winding of the feedback coil 5, and is more suitable for miniaturized fluxgate sensors.

[0039] Fig. 9The magnetic field distribution inside the triaxial dumbbell-shaped core under the influence of an external magnetic field is shown. When the core is in a saturated state, the magnetic permeability of the core is close to that of the air, and the magnetic lines of force spread out from the core; when the core is in a conducting state, the magnetic permeability of the core is high, and the magnetic concentration effect of the core is obvious. The closed magnetic flux path of the dumbbell-shaped core 1 can reduce magnetic noise, stray fields, and offset errors compared to the toroidal core. After testing, the dumbbell-shaped core 1 has an increase of about 31% in the flux change at the pickup coil 3 compared to the runway-shaped core of the same size. Therefore, the four induction pulse signals generated by the pickup coil 3 are stronger and more accurate, further improving the accuracy of the ambient magnetic field measurement.

[0040] The feedback coil winding method adopted in the present invention enables the magnetic measurement system to form a closed-loop system. The feedback winding 5 generates a uniform feedback magnetic field, which enables the dumbbell-shaped magnetic core 1 to work in a zero-field state, thereby improving the linearity and stability of the magnetic measurement. Fig.10 Figure 1 is the uniform magnetic field generated by the three-axis feedback coil. Figure a shows the distribution of the magnetic induction intensity of the feedback coil 5 on the XOY plane. The magnetic field distributions on the XOZ and YOZ planes are very similar to those on the XOY plane. Figure B shows the uniformity of the X, Y, and Z three-axis feedback magnetic fields along the core axis. The black vertical dotted line is the boundary of the feedback coil 5. Fig.10 It can be seen that there is an inflection point in the uniformity near the boundary. Within the boundary of the feedback coil 5, the maximum magnetic field deviation rate does not exceed 1.5%, indicating that the feedback coil 5 can generate a uniform magnetic field within a certain range, and the closer to the center, the better the uniformity.

[0041] Please refer to the working principle and working process of the present invention. Fig.12 Specifically, when performing weak magnetic field detection, the sensor probe of the present invention is placed in the magnetic field environment to be detected, and the excitation coil is excited by a square wave voltage of a certain frequency, so that the magnetic permeability of the dumbbell-shaped magnetic core 1 is periodically changed between the two states of magnetic conduction and magnetic saturation. In the magnetic conduction state, the magnetic permeability of the dumbbell-shaped magnetic core 1 is relatively high, the magnetic lines of force gather at the dumbbell-shaped magnetic core 1, and the magnetic induction intensity in the pickup coil 3 becomes stronger. In the magnetic saturation state, the magnetic permeability of the dumbbell-shaped magnetic core 1 is close to the magnetic permeability of the air, and the magnetic lines of force spread from the dumbbell-shaped magnetic core 1, so that the magnetic induction intensity in the pickup coil 3 becomes weaker. In one excitation cycle of the square wave voltage, the magnetic induction intensity in the pickup coil 3 changes four times, so that the pickup coil 3 generates four induction pulses: Pickup1, Pickup2, Pickup3, and Pickup4, and the amplitudes of the four induction pulses depend on the environmental magnetic field. The induction pulses collected by the pickup coil 3 along the X-axis, Y-axis and Z-axis are amplified and processed by the phase-sensitive rectification circuit, and the processed voltage value is used as the feedback current of the feedback coil 4 along the X-axis, Y-axis and Z-axis. The magnetic field generated by the feedback coil 5 can offset the ambient magnetic field, and the voltage value of the feedback coil 5 determines the size of the ambient magnetic field.

[0042] Example 2: Magnetic-focusing single-axis fluxgate sensor probe

[0043] like Fig.11 As shown, the magnetic-concentrating uniaxial fluxgate sensor probe provided in this embodiment includes a dumbbell-shaped magnetic core 1, an excitation coil 2, a pickup coil 3 and a pickup coil skeleton. Different from the existing uniaxial fluxgate sensor probe, the magnetic core of the uniaxial fluxgate sensor probe of the present invention adopts a dumbbell-shaped magnetic core 1, which is made of a plurality of Permalloy magnetic conductive sheets, each of which has the same thickness and size, and a plurality of turns of the excitation coil 2 are wound on the dumbbell-shaped magnetic core 1. In the state of magnetic conduction, the magnetic conductive sheets of the dumbbell-shaped magnetic core 1 gather the magnetic lines of force of the environmental magnetic field, so that the magnetic concentration effect of the dumbbell-shaped magnetic core 1 is stronger, and the magnetic induction intensity in the pickup coil 3 is also stronger. In the state of magnetic saturation, the dumbbell-shaped magnetic core 1 diffuses the magnetic lines of force of the environmental magnetic field along the edge of the magnetic core, so that the magnetic dispersion effect of the dumbbell-shaped magnetic core 1 is stronger, and the magnetic induction intensity in the pickup coil 3 is also weaker.

[0044] The two sides of the pickup coil skeleton 4 are processed with grooves matching the shape of the dumbbell-shaped magnetic core 1, and two dumbbell-shaped magnetic cores 1 with excitation coils 2 are respectively installed in the grooves. The structures of the two dumbbell-shaped magnetic cores 1 are symmetrical and the magnetic axes are parallel to each other. The shape of the pickup coil skeleton 4 corresponds to the shape of the dumbbell-shaped magnetic core 1, which is also large at both ends and thin in the middle. The pickup coil 3 is wound on the outside of the middle slender part of the pickup coil skeleton 4. The slender structure of the middle part of the pickup coil skeleton 4 can increase the number of turns of the pickup coil 3, thereby effectively improving the sensitivity of the sensor to weak signals, improving the signal-to-noise ratio, and increasing the measurement range of the sensor.

[0045] The single-axis fluxgate sensor probe is configured with a feedback coil and a feedback coil frame when in use, and the structure of the feedback coil frame is not described here.

[0046] The above description is only a preferred implementation manner of the present invention, but the protection scope of the present invention is not limited thereto, and any modification and replacement based on the technical solution and inventive concept provided by the present invention should be included in the protection scope of the present invention.

Claims

1. A magnetic concentrating single-axis fluxgate sensor probe, comprising a magnetic core, an excitation coil, a pickup coil and a pickup coil frame, wherein the excitation coil is wound on the magnetic core, and the pickup coil is wound on the pickup coil frame, characterized in that: The magnetic core is dumbbell-shaped and is formed by a magnetic conductive sheet. Two grooves matching the shape of the magnetic core are processed on both sides of the pickup coil skeleton. Two dumbbell-shaped magnetic cores with excitation coils are respectively installed in the grooves. The structures of the two dumbbell-shaped magnetic cores are symmetrical and their magnetic axes are parallel to each other. The pickup coil is wound on the outside of the middle part of the pickup coil skeleton.

2. The magnetic field-concentrating single-axis fluxgate sensor probe according to claim 1, characterized in that: The dumbbell-shaped magnetic core is made of multiple magnetic conductive sheets stacked together.

3. The magnetic field-concentrating single-axis fluxgate sensor probe according to claim 1, characterized in that: The pickup coil frame is also in a dumbbell shape, and the pickup coil is wound around the outside of the middle elongated part of the pickup coil frame.

4. A magnetic concentrating three-axis fluxgate sensor probe, comprising a magnetic core, an excitation coil, a pickup coil, a pickup coil frame, a feedback coil and a feedback coil frame, wherein the multi-turn excitation coil is wound on the magnetic core, the pickup coil is wound on the pickup coil frame, and the single-turn feedback coil is wound on the feedback coil frame, characterized in that: The magnetic core is in a dumbbell shape, and a groove matching the shape of the magnetic core is processed on the pickup coil skeleton. The dumbbell-shaped magnetic core with an excitation coil is installed in the groove, and the pickup coil is wound on the outside of the middle part of the pickup coil skeleton. The dumbbell-shaped magnetic core and the pickup coil skeleton are concentrically arranged; a pair of pickup coil skeletons are respectively arranged in each axial direction, and the two pickup coil skeletons of each axis are parallel to each other and symmetrically arranged. The three pairs of pickup coil skeletons 4 along the X, Y, and Z axes are perpendicular to each other and are placed in a spatial tic-tac-toe pattern in the feedback coil skeleton. The pickup coil skeleton 4 is coaxial with the X, Y, and Z axes of the feedback coil skeleton 6.

5. The magnetic field focusing three-axis fluxgate sensor probe according to claim 4, characterized in that: The dumbbell-shaped magnetic core is made of multiple magnetic conductive sheets stacked together.

6. The magnetic field-concentrating three-axis fluxgate sensor probe according to claim 4, characterized in that: The pickup coil frame is also in a dumbbell shape, and the pickup coil is wound around the outside of the middle elongated part of the pickup coil frame.

7. The magnetic field-concentrating three-axis fluxgate sensor probe according to claim 4, characterized in that: The feedback coil skeleton is in a cubic shape, and a plurality of wire grooves are engraved on the feedback coil skeleton along the X-axis, Y-axis, and Z-axis directions and are orthogonal to each other. The feedback coil is wound in the wire grooves, and a through-hole groove is opened on the feedback coil skeleton along the X-axis, Y-axis, and Z-axis directions. The pickup coil skeleton installed with a dumbbell-shaped magnetic core and wound with a pickup coil is placed into the feedback coil skeleton through the through-hole groove and supported by the plane at the end face of the through-hole groove. After being placed in, the pickup coil skeleton is arranged in a spatial tic-tac-toe shape in the feedback coil skeleton.

8. The magnetic field-concentrating three-axis fluxgate sensor probe according to claim 4, characterized in that: Each group of the feedback coils includes three coils, and the three coils are evenly spaced.

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