A fluxgate sensor and working method thereof

Abstract

The present disclosure provides a fluxgate sensor, including: a probe, an excitation module, a demodulation module and a feedback module; the probe includes three fluxgates, each fluxgate includes an excitation coil, an induction coil, two magnetic cores and a magnetic core skeleton; the two magnetic cores are wound with excitation coils, and the excitation coils wound on the two magnetic cores are connected; the induction coil is wound on the magnetic core skeleton; the magnetic core skeleton is a hollow structure, and the two magnetic cores wound with excitation coils are arranged in the hollow structure of the magnetic core skeleton, and the two magnetic cores wound with excitation coils are parallel to the axis of the magnetic core skeleton; the excitation coil is connected to the excitation module, the induction coil is connected to the demodulation module and the feedback module, and the demodulation module is connected to the feedback module. The setting method of the fluxgate of the fluxgate sensor provided by the present disclosure can reduce the volume of the probe, so that the fluxgate sensor is suitable for more measurement scenarios. The present disclosure also provides a working method of a fluxgate sensor.

Description

Technical Field

[0001] The present disclosure relates to the field of sensor technology, and in particular to a fluxgate sensor and a working method thereof. Background Art

[0002] Magnetic logging technology originated from Schlumberger in France in 1927. Due to the advantages of small size, light weight and high precision, fluxgate sensors have been widely used in continental scientific drilling projects carried out around the world in recent years. Existing borehole magnetic measurements are divided into borehole total magnetic field and magnetic three-component measurement. Single component can only measure the modulus anomaly of the total magnetic field, and it is necessary to combine multi-well magnetic measurement to measure the total magnetic field in the borehole for spatial positioning of the ore body. The three-component borehole magnetic measurement is more suitable for deep prospecting. Its advantage is that it relies on three orthogonal magnetic measuring elements to understand the spatial distribution law of magnetic anomalies of the ore body from three directions. It can not only obtain the longitudinal depth of the ore body, but also determine the direction of the ore body in a certain section. The ore body can be located only by relying on the data of a single well. With the rapid development of modernization, the demand for mineral resources is increasing. The development trend of borehole geophysical exploration is small diameter, high temperature, light weight, high precision and high sensitivity, while the existing borehole three-component magnetometer has low measurement accuracy, basically normal working temperature and large steering difference. Summary of the invention

[0003] In view of the above problems, the present disclosure provides a fluxgate sensor and a working method thereof.

[0004] According to a first aspect of the present disclosure, a fluxgate sensor is provided, comprising: a probe, an excitation module, a demodulation module and a feedback module;

[0005] The probe includes three flux gates, each of which includes an excitation coil, an induction coil, two magnetic cores and a magnetic core skeleton;

[0006] The two magnetic cores are both wound with excitation coils, and the excitation coils wound on the two magnetic cores are connected;

[0007] The induction coil is wound on the magnetic core frame;

[0008] The magnetic core frame is a hollow structure, and the two magnetic cores wound with the excitation coils are both arranged in the hollow structure of the magnetic core frame, and the two magnetic cores wound with the excitation coils are both parallel to the axis of the magnetic core frame;

[0009] The excitation coil is connected to the excitation module, the induction coil is connected to the demodulation module and the feedback module, and the demodulation module is connected to the feedback module.

[0010] Optionally, the excitation module includes: a signal generator, a frequency divider and a power amplifier;

[0011] The signal generator is used to generate a clock signal;

[0012] The input end of the frequency divider is connected to the output end of the signal generator, and the frequency divider is used to perform frequency division processing on the clock signal to obtain a frequency division signal;

[0013] The input end of the power amplifier is connected to the first output end of the frequency divider, and the output end of the power amplifier is connected to the excitation coil. The power amplifier is used to perform frequency selection and amplification processing on the frequency-divided signal to obtain the excitation signal, and transmit the excitation signal to the excitation coil.

[0014] Optionally, the excitation module includes a frequency divider for generating a frequency-divided signal, and the demodulation module includes: a detection circuit, a demodulation circuit, a filtering circuit and an integration circuit;

[0015] The input end of the detection circuit is connected to the output end of the induction coil, and the detection circuit is used to receive the induction signal output by the induction coil and adjust the phase of the induction signal to obtain a first output signal;

[0016] A first input end of the demodulation circuit is connected to an output end of the detection circuit, a second input end of the demodulation circuit is connected to a second output end of the frequency divider, the demodulation circuit is used to receive a first output signal output by the detection circuit, and a frequency-divided signal output by the frequency divider, and use the frequency-divided signal to demodulate the first output signal to a baseband frequency to obtain a second output signal;

[0017] The input end of the filter circuit is connected to the output end of the demodulation circuit, and the filter circuit is used to receive the second output signal output by the demodulation circuit and filter the second output signal to obtain a third output signal;

[0018] The input end of the integration circuit is connected to the output end of the filtering circuit. The integration circuit is used to receive the third output signal output by the filtering circuit and integrate the third output signal to obtain a measurement value.

[0019] Optionally, the input end of the feedback module is connected to the output end of the integration circuit, and the output end of the feedback module is connected to the input end of the induction coil. The feedback module is used to receive the measurement value and output the measurement value to the induction coil so that the induction coil generates a feedback magnetic field in the opposite direction to the measured magnetic field.

[0020] Optionally, three fluxgates are equidistantly arranged on any axis of the fluxgate sensor, and the three fluxgates are installed orthogonally.

[0021] Optionally, centers of the three flux gates are located in the same horizontal plane.

[0022] Optionally, the wire diameter of the excitation coil is 0.035 mm to 0.1 mm, and the number of turns of the excitation coil is 200 to 2000 turns;

[0023] The wire diameter of the induction coil is 0.05 mm to 0.2 mm, and the number of turns of the induction coil is 800 to 3000 turns.

[0024] Optionally, the magnetic core has a thickness of 3 to 30 mm, a length of 10 to 30 mm, and a width of 1 to 5 mm.

[0025] Optionally, it also includes: a power supply module, which is connected to the excitation module, the demodulation module and the feedback module, and is used to supply power to the excitation module, the demodulation module and the feedback module.

[0026] According to a second aspect of the present disclosure, a working method of the fluxgate sensor as described above is provided, the method comprising:

[0027] Using the excitation module to generate an excitation signal and a frequency division signal;

[0028] All the excitation coils in the probe are driven by the excitation signal so that the magnetic cores wound with the excitation coils are all in an excitation saturation state;

[0029] Using the magnetic core in the excitation saturation state, all the induction coils in the probe generate induction signals;

[0030] Using the demodulation module to obtain the measured value according to the frequency division signal and the sensing signal;

[0031] The feedback module is used to input the measured values ​​into all the induction coils in the probe so that all the induction coils generate a feedback magnetic field in the opposite direction to the measured magnetic field. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0033] Figure 1 The schematic diagram of the structure of a fluxgate sensor provided by an embodiment of the present disclosure is shown;

[0034] Figure 2 The structure diagram of a fluxgate of a fluxgate sensor provided by an embodiment of the present disclosure is schematically shown;

[0035] Figure 3 A schematic diagram of the detailed structure of a fluxgate sensor provided by an embodiment of the present disclosure is shown;

[0036] Figure 4A schematic diagram of a circuit structure of a fluxgate sensor provided by an embodiment of the present disclosure is shown schematically;

[0037] Figure 5A and Figure 5B A schematic diagram of the three-dimensional structure of a probe of a fluxgate sensor provided by an embodiment of the present disclosure is shown;

[0038] Figure 6 A schematic diagram of the packaging of a probe of a fluxgate sensor provided by an embodiment of the present disclosure is shown schematically; and

[0039] Figure 7 A flow chart of a fluxgate sensor working method provided by an embodiment of the present disclosure is schematically shown.

[0040] Description of reference numerals:

[0041] 10 probe; 11 flux gate; 12 excitation coil; 13 induction coil; 14 magnetic core; 15 magnetic core skeleton; 20 excitation module; 21 signal generator; 22 frequency divider; 23 power amplifier; 30 demodulation module; 31 detection circuit; 32 demodulation circuit; 33 filtering circuit; 34 integration circuit; 40 feedback module; 50 power supply module. DETAILED DESCRIPTION

[0042] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0043] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0044] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0045] In the case of using expressions such as "at least one of A, B, and C, etc.", it should generally be interpreted in accordance with the meaning of the expression generally understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but not be limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.). In the case of using expressions such as "at least one of A, B, or C, etc.", it should generally be interpreted in accordance with the meaning of the expression generally understood by those skilled in the art (for example, "a system having at least one of A, B, or C" should include but not be limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.). Those skilled in the art should also understand that any transitional conjunctions and / or phrases that substantially indicate two or more optional items, whether in the specification, claims, or drawings, should be understood to give the possibility of including one of these items, either of these items, or both of these items. For example, the phrase "A or B" should be understood to include the possibilities of "A" or "B", or "A and B".

[0046] The present disclosure provides a fluxgate sensor, including: a probe, an excitation module, a demodulation module and a feedback module; the probe includes three fluxgates, each fluxgate includes an excitation coil, an induction coil, two magnetic cores and a magnetic core skeleton; the two magnetic cores are wound with excitation coils, and the excitation coils wound on the two magnetic cores are connected; the induction coil is wound on the magnetic core skeleton; the magnetic core skeleton is a hollow structure, the two magnetic cores wound with excitation coils are arranged in the hollow structure of the magnetic core skeleton, and the two magnetic cores wound with excitation coils are parallel to the axis of the magnetic core skeleton; the excitation coil is connected to the excitation module, the induction coil is connected to the demodulation module and the feedback module, and the demodulation module is connected to the feedback module. The setting method of the fluxgate of the fluxgate sensor provided by the present disclosure can reduce the volume of the probe, so that the fluxgate sensor is suitable for more measurement scenarios. At the same time, the feedback module in the fluxgate sensor adopted by the present disclosure uses the induction coil to realize the feedback effect, and does not use a separate feedback coil, which further reduces the volume of the fluxgate sensor.

[0047] The fluxgate sensor is a vector magnetic sensor that measures weak static or low-frequency alternating magnetic fields. It uses a strong alternating magnetic field to excite the soft magnetic material to a saturated state, and uses the nonlinear effect of the saturated state of the magnetic material to modulate the measured magnetic field to the excitation magnetic field and its harmonic components. Finally, the measured magnetic field in the induced electromotive force is extracted through a demodulation circuit. In essence, it is a magnetic sensor based on the nonlinear effect of materials and Faraday's law of electromagnetic induction.

[0048] The following will be passed Figure 1 to Figure 6A fluxgate sensor according to an embodiment of the present disclosure is described in detail to help those skilled in the art to more clearly understand the technical solution of the present disclosure.

[0049] Figure 1 The schematic diagram shows the structure of a fluxgate sensor provided by an embodiment of the present disclosure. Figure 2 The schematic diagram shows the structure of a fluxgate of a fluxgate sensor provided by an embodiment of the present disclosure. Figure 5A and Figure 5B The three-dimensional structural diagram of a probe of a fluxgate sensor provided in an embodiment of the present disclosure is schematically shown. Figure 6 The package diagram of a probe of a fluxgate sensor provided by an embodiment of the present disclosure is schematically shown.

[0050] refer to Figure 1 to Figure 2 as well as FIG. 5A to FIG. 6 In one embodiment of the present disclosure, the fluxgate sensor includes: a probe 10, an excitation module 20, a demodulation module 30 and a feedback module 40; the probe 10 includes three fluxgates 11, each fluxgate 11 includes an excitation coil 12, an induction coil 13, two magnetic cores 14 and a magnetic core skeleton 15; the two magnetic cores 14 are each wound with an excitation coil 12, and the excitation coils 12 wound on the two magnetic cores 14 are connected; the induction coil 13 is wound on the magnetic core skeleton 15; the magnetic core skeleton 15 is a hollow structure, the two magnetic cores 14 wound with the excitation coils 12 are both arranged in the hollow structure of the magnetic core skeleton 15, and the two magnetic cores 14 wound with the excitation coils 12 are both parallel to the axis of the magnetic core skeleton 15; the excitation coil 12 is connected to the excitation module 20, the induction coil 13 is connected to the demodulation module 30 and the feedback module 40, and the demodulation module 30 is connected to the feedback module 40.

[0051] In this embodiment, the fluxgate sensor includes a probe 10, an excitation module 20, a demodulation module 30 and a feedback module 40. Figure 5A and Figure 5B As shown, the probe 10 in this embodiment includes three fluxgates 11, which are equidistantly arranged on any axis of the fluxgate sensor, and the three fluxgates 11 are orthogonally installed. In addition, the centers of the three fluxgates 11 are located in the same horizontal plane. Figure 2As shown, each fluxgate 11 includes an excitation coil 12, an induction coil 13, a magnetic core 14 and a magnetic core skeleton 15, wherein each fluxgate 11 includes two magnetic cores 14, on which the excitation coil 12 is wound, and the excitation coils 12 wound on the two magnetic cores 14 are connected end to end, and on the magnetic core skeleton 15 is wound the induction coil 13. In this embodiment, the wire diameter of the excitation coil 12 is 0.035mm-0.1mm, the number of turns of the excitation coil 12 is 200-2000 turns, the wire diameter of the induction coil 13 is 0.05mm-0.2mm, the number of turns of the induction coil 13 is 800-3000 turns, and the thickness of the magnetic core 14 can be 3-30μm, the length is 10-30mm, and the width is 1-5mm. The magnetic core skeleton 15 in this embodiment is a hollow structure, and the magnetic core 14 is arranged in the hollow structure, so that the structure of the fluxgate is compact and the volume is small. The probe 10 in this embodiment can be adopted Figure 6 The probe is packaged in the form shown, and the diameter range of the packaged probe is 35mm to 80mm, and the length range is 100mm to 200mm. In addition, the magnetic core 14 in this embodiment can also be made of cobalt-based amorphous strip, whose composition is: CoFeMoSiB (cobalt iron molybdenum silicon boron). This type of material has the characteristics of high magnetic permeability, low coercive force and good rectangular loop. This type of material is easily magnetized by a magnetic field and easily demagnetized. The hysteresis loop is narrow and has extremely low hysteresis loss. Therefore, the fluxgate sensor designed with it as the magnetic core has the characteristics of high sensitivity and low noise. The method for setting the fluxgate of the fluxgate sensor provided in the present disclosure can reduce the volume of the probe, making the fluxgate sensor suitable for more measurement scenarios.

[0052] It should be noted that the above description of the size, material, etc. of each component in the fluxgate sensor is only exemplary to facilitate those skilled in the art to understand the solution of the present disclosure, and is not intended to limit the scope of protection of the present disclosure. In some other embodiments, the size, material, etc. of each component in the above fluxgate sensor can be selected according to actual conditions and are not limited here.

[0053] It is mentioned above that the fluxgate sensor provided by the present invention includes not only a probe, but also electrical modules such as an excitation module, a demodulation module and a feedback module. The design of the electrical module of the fluxgate sensor needs to adapt to the output characteristics of the probe (including signals and noise, etc.). The role of the electrical module is not only filtering and signal conversion, but also to make up for the intrinsic defects of the probe. When designing the electrical module, it is necessary to consider making up for the defects of the probe, because the probe signal is very weak and is often submerged by noise, and the probe signal stability is extremely poor, and there are nonlinear errors. In addition, the fluxgate sensor must rely on the magnetic field formed by the compensation and feedback circuit to ensure the upper limit of measurement. The following will be Figure 3 and Figure 4The electrical modules of a fluxgate sensor according to an embodiment of the present disclosure are described in detail to help those skilled in the art to more clearly understand the technical solution of the present disclosure.

[0054] Figure 3 A detailed structural diagram of a fluxgate sensor provided in an embodiment of the present disclosure is schematically shown. Figure 4 A schematic diagram of the circuit structure of a fluxgate sensor provided in an embodiment of the present disclosure is schematically shown.

[0055] refer to Figure 3 and Figure 4 In one embodiment of the present disclosure, the excitation module 20 of the above-mentioned fluxgate sensor includes: a signal generator 21, a frequency divider 22 and a power amplifier 23; the signal generator 21 is used to generate a clock signal; the input end of the frequency divider 22 is connected to the output end of the signal generator 21, and the frequency divider 22 is used to divide the clock signal to obtain a divided frequency signal; the input end of the power amplifier 23 is connected to the first output end of the frequency divider 22, and the output end of the power amplifier 23 is connected to the excitation coil 12, and the power amplifier 23 is used to select and amplify the divided frequency signal to obtain an excitation signal, and transmit the excitation signal to the excitation coil 12.

[0056] In this embodiment, the excitation module 20 includes a signal generator 21, a frequency divider 22 and a power amplifier 23, wherein the signal generator 21 is used to generate a clock signal, wherein the frequency of the clock signal is generally higher than the frequency of the excitation signal and the frequency division signal of the probe. When the fluxgate sensor is used for measurement, a suitable excitation signal frequency is usually selected according to the parameters of the probe. Figure 3 to Figure 4 The frequency divider 22 in this embodiment receives the clock signal transmitted by the signal generator 21 and performs frequency division processing on it to obtain a frequency division signal, and transmits the frequency division signal to the power amplifier 23. The power amplifier 23 performs frequency division processing on the frequency division signal again to obtain a two-frequency division signal, and performs frequency selection amplification and power amplification on the two-frequency division signal to finally obtain an excitation signal, and transmits the excitation signal to the excitation coil 12.

[0057] refer to Figure 3 and Figure 4In one embodiment of the present disclosure, the excitation module 20 of the fluxgate sensor includes a frequency divider 22 for generating a frequency division signal, and the demodulation module 30 of the fluxgate sensor includes: a detection circuit 31, a demodulation circuit 32, a filter circuit 33 and an integration circuit 34; the input end of the detection circuit 31 is connected to the output end of the induction coil 13, and the detection circuit 31 is used to receive the induction signal output by the induction coil 13 and adjust the phase of the induction signal to obtain a first output signal; the first input end of the demodulation circuit 32 is connected to the output end of the detection circuit 31, and the second input end of the demodulation circuit 32 is connected to the second output end of the frequency divider 22, The demodulation circuit 32 is used to receive the first output signal output by the detection circuit 31, and the divided signal output by the divider 22, and use the divided signal to demodulate the first output signal to the baseband frequency to obtain the second output signal; the input end of the filter circuit 33 is connected to the output end of the demodulation circuit 32, the filter circuit 33 is used to receive the second output signal output by the demodulation circuit 32, and filter the second output signal to obtain the third output signal; the input end of the integration circuit 34 is connected to the output end of the filter circuit 33, the integration circuit 34 is used to receive the third output signal output by the filter circuit 33, and integrate the third output signal to obtain a measurement value.

[0058] In this embodiment, the demodulation module 30 includes a detection circuit 31, a demodulation circuit 32, a filter circuit 33 and an integration circuit 34. The output end of the induction coil 13 is connected to the detection circuit 31. The detection circuit 31, the demodulation circuit 32, the filter circuit 33 and the integration circuit 34 are connected in series in sequence. When the fluxgate sensor is used to measure the magnetic field, the excitation signal generated by the excitation module 20 puts the magnetic core 14 in an excitation saturation state. At this time, the induction coil 13 generates an induced electromotive force, that is, an induction signal. The detection circuit 31 adjusts the phase of the induction signal. The demodulation circuit 32 is also connected to the frequency divider 22 of the excitation module 20, and uses the frequency division signal output by the frequency divider 22 to demodulate the first output signal output by the detection circuit 31 to the baseband frequency, and then uses the filter circuit 33 and the integration circuit 34 to filter and integrate it, and finally obtains the measured value.

[0059] In one embodiment of the present disclosure, the input end of the feedback module 40 is connected to the output end of the integration circuit 34, and the output end of the feedback module 40 is connected to the input end of the induction coil 13. The feedback module 40 is used to receive the measurement value and output the measurement value to the induction coil 13, so that the induction coil 13 generates a feedback magnetic field in the opposite direction to the measured magnetic field.

[0060] refer to Figure 3 and Figure 4In this embodiment, the integration circuit 34 in the demodulation module 30 is connected to the feedback module 40. After receiving the measurement value output by the integration circuit 34, the feedback module 40 transmits it to the induction coil 13, so that the induction coil 13 generates a feedback magnetic field opposite to the direction of the measured magnetic field. Here, the feedback magnetic field generated by the induction coil 13 is not only opposite to the direction of the measured magnetic field, but also the magnetic field strength of the feedback magnetic field is the same as the measured magnetic field. The feedback magnetic field and the measured magnetic field offset each other, so that the magnetic core 14 is close to the zero magnetic space. The fluxgate sensor provided by the present disclosure adopts closed-loop feedback, which can effectively improve the stability of the system, expand the dynamic range, and reduce the nonlinearity of the system. At the same time, the compensation circuit is adopted to eliminate the zero-position signal or false signal caused by the asymmetry of the probe.

[0061] In one embodiment of the present disclosure, the above-mentioned fluxgate sensor also includes a power supply module 50, which is connected to the excitation module 20, the demodulation module 30 and the feedback module 40, and the power supply module 50 is used to supply power to the excitation module 20, the demodulation module 30 and the feedback module 40.

[0062] It should be understood that Figure 1 to Figure 6 The fluxgate sensor shown in the figure is only exemplary, so as to facilitate those skilled in the art to understand the solution of the present disclosure, and is not intended to limit the protection scope of the present disclosure. In some other embodiments, the material, size, shape, etc. of each component in the above-mentioned fluxgate magnetic field sensor can be selected according to actual conditions, and are not limited here.

[0063] Based on the above fluxgate sensor, the present disclosure also provides a working method of the fluxgate sensor.

[0064] Figure 7 A flow chart of a fluxgate sensor working method provided by an embodiment of the present disclosure is schematically shown.

[0065] like Figure 7 As shown, in one embodiment of the present disclosure, the working method includes operations S710 to S750.

[0066] In operation S710, an excitation signal and a frequency division signal are generated by using an excitation module.

[0067] In operation S720, all the excitation coils in the probe are driven by an excitation signal so that the magnetic cores wound with the excitation coils are in an excitation saturation state.

[0068] In operation S730, all the induction coils in the probe generate induction signals by utilizing the magnetic core in an excitation saturation state.

[0069] In operation S740, a measurement value is obtained according to the frequency-divided signal and the sensing signal by using a demodulation module.

[0070] In operation S750, the feedback module is used to input the measured values ​​into all the induction coils in the probe, so that all the induction coils generate a magnetic field in the opposite direction to the measured magnetic field.

[0071] When the fluxgate sensor provided by the present invention is used for measurement, after the fluxgate sensor provided by the present invention is placed in the measured magnetic field, an excitation module is used to generate an excitation signal and a frequency division signal, wherein the excitation signal is transmitted to the excitation coil, so that the magnetic core wound with the excitation coil is in an excitation saturation state, and the magnetic core in the excitation saturation state is used to make the induction coil generate an induction signal, and the demodulation module is used to process the induction signal according to the frequency division signal to obtain a measurement value, and the measurement value is transmitted to the feedback module, and then the feedback module is used to transmit the measurement value to the induction coil, so that the induction coil generates a feedback magnetic field in the opposite direction to the measured magnetic field. The feedback magnetic field is used to offset the measured magnetic field near the magnetic core, so that the magnetic core is close to the zero magnetic space, which can effectively improve the stability of the fluxgate sensor, expand the dynamic range, and reduce the nonlinearity of the fluxgate sensor.

[0072] It will be appreciated by those skilled in the art that the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways, even if such combinations and / or combinations are not explicitly described in the present disclosure. In particular, the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways without departing from the spirit and teachings of the present disclosure. All of these combinations and / or combinations fall within the scope of the present disclosure.

[0073] The embodiments of the present disclosure are described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Although the present disclosure has been shown and described with reference to specific exemplary embodiments of the present disclosure, it should be understood by those skilled in the art that various changes in form and detail may be made to the present disclosure without departing from the spirit and scope of the present disclosure as defined by the attached claims and their equivalents. Therefore, the scope of the present disclosure should not be limited to the above-mentioned embodiments, but should be determined not only by the attached claims, but also by the equivalents of the attached claims.

Claims

1. A fluxgate sensor, characterized in that: include: A probe (10), an excitation module (20), a demodulation module (30) and a feedback module (40); The probe (10) comprises three flux gates (11), each of the flux gates (11) comprising an excitation coil (12), an induction coil (13), two magnetic cores (14) and a magnetic core skeleton (15); The excitation coil (12) is wound on each of the two magnetic cores (14), and the excitation coils (12) wound on the two magnetic cores (14) are connected; The induction coil (13) is wound on the magnetic core frame (15); The magnetic core skeleton (15) is a hollow structure, and the two magnetic cores (14) around which the excitation coils (12) are wound are both arranged in the hollow structure of the magnetic core skeleton (15), and the two magnetic cores (14) around which the excitation coils (12) are wound are both parallel to the axis of the magnetic core skeleton (15); The excitation coil (12) is connected to the excitation module (20), the induction coil (13) is connected to the demodulation module (30) and the feedback module (40), and the demodulation module (30) is connected to the feedback module (40); The excitation module (20) comprises: a signal generator (21), a frequency divider (22) and a power amplifier (23); the signal generator (21) is used to generate a clock signal; the input end of the frequency divider (22) is connected to the output end of the signal generator (21), and the frequency divider (22) is used to perform frequency division processing on the clock signal to obtain a frequency division signal; the input end of the power amplifier (23) is connected to the first output end of the frequency divider (22), the output end of the power amplifier (23) is connected to the excitation coil (12), and the power amplifier (23) is used to perform frequency selection and amplification processing on the frequency division signal to obtain an excitation signal, and transmit the excitation signal to the excitation coil (12); The demodulation module (30) comprises: a detection circuit (31), a demodulation circuit (32), a filtering circuit (33) and an integration circuit (34); an input end of the detection circuit (31) is connected to an output end of the induction coil (13); the detection circuit (31) is used to receive an induction signal output by the induction coil (13), and adjust the phase of the induction signal to obtain a first output signal; a first input end of the demodulation circuit (32) is connected to an output end of the detection circuit (31); a second input end of the demodulation circuit (32) is connected to a second output end of the frequency divider (22); the demodulation circuit (32) is used to receive the first output signal output by the detection circuit (31) output signal, and receiving the divided signal output by the frequency divider (22), and using the divided signal to demodulate the first output signal to a baseband frequency to obtain a second output signal; the input end of the filter circuit (33) is connected to the output end of the demodulation circuit (32), the filter circuit (33) is used to receive the second output signal output by the demodulation circuit (32), and filter the second output signal to obtain a third output signal; the input end of the integration circuit (34) is connected to the output end of the filter circuit (33), the integration circuit (34) is used to receive the third output signal output by the filter circuit (33), and integrate the third output signal to obtain a measurement value; The input end of the feedback module (40) is connected to the output end of the integration circuit (34), and the output end of the feedback module (40) is connected to the input end of the induction coil (13). The feedback module (40) is used to receive the measurement value and output the measurement value to the induction coil (13), so that the induction coil (13) generates a feedback magnetic field in the opposite direction to the measured magnetic field.

2. The fluxgate sensor according to claim 1, characterized in that: The three flux gates (11) are equidistantly arranged on any axis of the flux gate sensor, and the three flux gates (11) are installed orthogonally.

3. The fluxgate sensor according to claim 1, characterized in that: The centers of the three flux gates (11) are located in the same horizontal plane.

4. The fluxgate sensor according to claim 1, characterized in that: The wire diameter of the excitation coil (12) is 0.035 mm to 0.1 mm, and the number of turns of the excitation coil (12) is 200 to 2000 turns; The wire diameter of the induction coil (13) is 0.05 mm to 0.2 mm, and the number of turns of the induction coil (13) is 800 to 3000 turns.

5. The fluxgate sensor according to claim 1, characterized in that: The magnetic core (14) has a thickness of 3 to 30 mm, a length of 10 to 30 mm, and a width of 1 to 5 mm.

6. The fluxgate sensor according to claim 1, characterized in that: Also includes: A power module (50), the power module (50) being connected to the excitation module (20), the demodulation module (30) and the feedback module (40), the power module (50) being used to supply power to the excitation module (20), the demodulation module (30) and the feedback module (40).

7. A working method of a fluxgate sensor according to any one of claims 1 to 6, characterized in that: include: Using the excitation module to generate an excitation signal and a frequency division signal; Using the excitation signal to drive all the excitation coils in the probe, so that the magnetic cores wound with the excitation coils are all in an excitation saturation state; Using the magnetic core in an excitation saturation state, all the induction coils in the probe generate induction signals; Using the demodulation module to obtain a measurement value according to the frequency-divided signal and the sensing signal; The feedback module is used to input the measured value into all the induction coils in the probe, so that all the induction coils generate a feedback magnetic field in the opposite direction to the measured magnetic field.

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