Alternating magnetic field generating device with adjustable radiation direction based on soft magnetic material

Abstract

The invention provides an alternating magnetic field generating device with an adjustable radiation direction based on a soft magnetic material, which relates to the technical field of electromagnetism and comprises a five-axis magnetic field radiation antenna group, an excitation voltage generating unit, an induced voltage receiving unit, a current integration control unit, a magnetic field measuring unit and a magnetic field control unit, the five-axis magnetic field radiation antenna group consists of a central antenna and four surrounding antennas which uniformly surround the central antenna and form the same angle with the central antenna, and each antenna consists of a soft magnetic material magnetic core and an antenna coil and is used for forming an alternating magnetic field of which the radiation direction can be adjusted by excitation voltage; the induced voltage receiving unit adjusts induced voltage generated by the magnetic field receiving coil and provides radiation energy together with the excitation voltage generating unit. The magnetic field measurement unit measures a radiation magnetic field, and the magnetic field control unit continuously adjusts the direction, frequency and intensity of the radiation magnetic field. The requirement for rapidly and accurately changing the magnetic field state can be met.

Description

Technical Field

[0001] The invention relates to the field of electromagnetic technology, and in particular to an alternating magnetic field generating device with adjustable radiation direction based on soft magnetic materials. Background Art

[0002] Low-frequency electromagnetic detection is a technology that detects the characteristics of objects or environments through low-frequency electromagnetic waves. The frequency of low-frequency electromagnetic waves is generally between tens of hertz and hundreds of thousands of hertz. Compared with high-frequency electromagnetic waves, low-frequency electromagnetic waves have stronger penetration ability and can penetrate the ground, water or other obstructions. Therefore, they are widely used in the field of electromagnetic detection.

[0003] The radiation of low-frequency electromagnetic waves is mainly achieved by generating an alternating magnetic field. Currently, there are methods that can generate low-frequency alternating magnetic fields, such as energized solenoids and permanent magnet mechanical antennas. The alternating magnetic field generated by energized solenoids is very weak and difficult to meet detection requirements. The magnetic field generated by permanent magnet mechanical antennas is relatively strong, but due to mechanical drive, its stability and flexibility are relatively low.

[0004] In low-frequency electromagnetic detection, it may be necessary to scan the area ahead in multiple directions. However, current direction-adjustable magnetic field generating devices generally only adjust the magnetic field vector direction in a small working area, without considering the problem of magnetic field radiation direction. Summary of the invention

[0005] In view of the above problems, the present invention provides an alternating magnetic field generating device with adjustable radiation direction based on soft magnetic materials, which solves the problems of insufficient magnetic field strength, low stability, poor directionality and low flexibility.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme:

[0007] The invention discloses an alternating magnetic field generating device with adjustable radiation direction based on soft magnetic materials, comprising a five-axis magnetic field radiation antenna group, an excitation voltage generating unit, an induced voltage receiving unit, a current integration control unit, a magnetic field measuring unit and a magnetic field control unit; the five-axis magnetic field radiation antenna group is composed of a central antenna and four surrounding antennas uniformly surrounding the central antenna and forming the same angle with the central antenna, each central antenna and surrounding antenna are composed of a soft magnetic material core and an antenna coil, each antenna coil generates an alternating magnetic dipole magnetic field after being excited by the excitation voltage generating unit, and the alternating magnetic field is vectorially superimposed in space to form an alternating magnetic field whose radiation direction can be adjusted by the excitation voltage; the magnetic field receiving coil converts the alternating magnetic field opposite to the radiation direction into an induced voltage, the induced voltage receiving unit adjusts the induced voltage, and provides radiation energy together with the excitation voltage generating unit through dynamic regulation of the current integration control unit; the magnetic field measuring unit measures the radiation magnetic field, and the magnetic field control unit continuously adjusts the direction, frequency and intensity of the radiation magnetic field.

[0008] Beneficial effects:

[0009] The present invention can continuously generate a composite alternating magnetic field in a specified direction in the half space in front of the device. The frequency of the generated composite magnetic field can be continuously adjusted in the range of 0 to 100 kHz. Under the same volume, the radiation magnetic field intensity can reach 1 / 3 of that of a neodymium iron boron magnet. The switching speed of different frequencies, intensities and directions can reach milliseconds, and it has high stability, which can meet the needs of quickly changing the radiation frequency, intensity and direction of the alternating magnetic field in low-frequency electromagnetic detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural schematic diagram of an alternating magnetic field generating device with adjustable radiation direction based on soft magnetic materials according to an embodiment of the present invention;

[0011] Figure 2 This is a functional principle block diagram of an alternating magnetic field generating device with adjustable radiation direction based on soft magnetic materials according to an embodiment of the present invention.

[0012] Among them, the figure markings are: the first axis magnetic field radiation antenna group 1-1, the second axis magnetic field radiation antenna group 1-2, the third axis magnetic field radiation antenna group 1-3, the fourth axis magnetic field radiation antenna group 1-4, the fifth axis magnetic field radiation antenna group 1-5, the first measuring coil 7-1, the second measuring coil 7-2, the third measuring coil 7-3, the fourth measuring coil 7-4, the fifth measuring coil 7-5, the receiving plate 8, the first receiving coil 9-1, the second receiving coil 9-2, the third receiving coil 9-3, the fourth receiving coil 9-4, the fifth receiving coil 9-5, the sixth receiving coil 9-6, the seventh receiving coil 9-7, the eighth receiving coil 9-8, the ninth receiving coil 9-9, and the shell 10. DETAILED DESCRIPTION

[0013] In order to make the specific structure, technical solutions and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0014] like Figure 1 , Figure 2 As shown, an alternating magnetic field generating device with adjustable radiation direction based on soft magnetic materials according to an embodiment of the present invention is functionally divided into a five-axis magnetic field radiation antenna group, an excitation voltage generating unit, an induced voltage receiving unit, a current integration control unit, a magnetic field measuring unit and a magnetic field control unit.

[0015] The five-axis magnetic field radiation antenna group includes a first-axis magnetic field radiation antenna group 1-1, a second-axis magnetic field radiation antenna group 1-2, a third-axis magnetic field radiation antenna group 1-3, a fourth-axis magnetic field radiation antenna group 1-4, and a fifth-axis magnetic field radiation antenna group 1-5, that is, it consists of a central antenna (the first-axis magnetic field radiation antenna group 1-1) and four surrounding antennas uniformly surrounding it and forming the same angle with the same end of the central antenna. Each antenna is composed of a soft magnetic material core and an antenna coil to form an antenna array.

[0016] The excitation voltage generating unit generates five alternating voltages with the same frequency and phase. After each antenna coil of the five-axis magnetic field radiation antenna group is excited by the alternating voltage (i.e. Figure 2 The excitation voltage in the antenna generates an alternating magnetic dipole magnetic field, which is enhanced by the magnetization of the soft magnetic material core. The magnetic fields generated by the five antennas are vector-superimposed in three-dimensional space to form an alternating magnetic field whose radiation direction can be adjusted by the amplitude of the five excitation voltages.

[0017] The induced voltage receiving unit converts the alternating magnetic field in the opposite direction of the radiation into an induced voltage through a magnetic field receiving coil located behind the alternating magnetic field generating device, and provides radiation energy together with the excitation voltage generating unit through dynamic regulation of the current integration control unit.

[0018] The magnetic field measurement unit can measure the radiated magnetic field through the magnetic field measurement coil, and the magnetic field control unit can send the required current signal to the current integration control unit based on the measurement result, and then continuously adjust the direction, frequency and intensity of the radiated magnetic field, which can meet the needs of quickly and accurately changing the magnetic field state.

[0019] Furthermore, the soft magnetic material core of each axis magnetic field radiation antenna of the five-axis magnetic field radiation antenna group is cylindrical in shape and is placed in a cylindrical antenna coil frame. The antenna coil is wound on the antenna coil frame, and the outer periphery of the antenna coil is wrapped by a cylindrical protective shell.

[0020] Furthermore, the central antenna is along the positive direction of the Z axis, and the other four surrounding antennas are evenly distributed in the XZ plane and the YZ plane. All surrounding antennas have the same angle with the positive direction of the Z axis, the bottom ends of all antennas are at the same distance from the coordinate origin, and all antennas are wound in the same way.

[0021] Furthermore, the magnetic field receiving coils are placed on a receiving plate 8 shaped as a half ellipsoid, and the area of ​​each magnetic field receiving coil is substantially the same and covers the entire receiving plate, leaving no gaps between the magnetic field receiving coils.

[0022] Furthermore, the center of the receiving plate 8 of the ellipsoid coincides with the coordinate origin and is entirely located below the XY plane, and the semi-axis length of the ellipsoid in the X-axis direction is equal to the semi-axis length in the Y-axis direction.

[0023] Furthermore, the magnetic field measurement coils of the magnetic field measurement unit are respectively located at one end of the five-axis magnetic field radiation antenna group away from the coordinate origin, are coaxial with each antenna and have a certain distance therefrom, and are wrapped by a protective shell.

[0024] Furthermore, the excitation voltage generating unit, the induced voltage receiving unit, the current integration control unit, the magnetic field measuring unit, and the magnetic field control unit are all located behind the ellipsoidal receiving plate, and all modules are fixed by a supporting structure.

[0025] Furthermore, the soft magnetic material core is a high magnetic permeability and high resistivity soft magnetic material, and the cylindrical antenna coil frame, the protective shell of the antenna coil, the ellipsoidal receiving plate 8 and all supporting structures are low magnetic permeability (μ r ≈1) High hardness non-metallic materials.

[0026] The magnetic field control unit, the current integration control unit and the control parts of other units are all programmably controlled by a micro control unit (MCU).

[0027] like Figure 2 As shown, the magnetic field control unit calculates the effective value of the current that each antenna coil should reach by inputting the expected magnetic field strength, direction, and frequency. Due to the nonlinearity of the magnetic permeability of the soft magnetic material, in order to make the alternating magnetic field radiated by the antenna sinusoidal and without high-frequency components, the specific current waveform of each antenna coil in one cycle is calculated based on the BH curve and hysteresis characteristics of the magnetic core material used, and is transmitted to the current integration control unit.

[0028] Furthermore, the magnetic field control unit receives in real time the actual magnetic field waveform (i.e. Figure 2 The measured radiated magnetic field waveform in the image is used as a feedback signal to dynamically adjust the desired current waveform transmitted to the current integration control unit.

[0029] The current integration control unit receives the current frequencies of the five antenna coils sent from the magnetic field control unit, as well as the current change waveform of each antenna coil within one cycle, converts them into a voltage change waveform within one cycle according to the impedance characteristics of the antenna coil, and transmits the desired excitation voltage waveform to the excitation voltage generating unit.

[0030] Furthermore, the current integration control unit monitors the current waveform of the antenna coil in real time (i.e. Figure 2 The measured antenna coil current waveform is used as a feedback signal to dynamically adjust the desired excitation voltage waveform transmitted to the excitation voltage generating unit.

[0031] The excitation voltage generating unit includes a signal generating module, a digital-to-analog conversion module, a power amplifying module, a filtering module and an output isolation module.

[0032] Furthermore, the signal generation module is implemented by an MCU, and the waveform samples to be output are stored in RAM or Flash. The MCU realizes the generation of arbitrary waveforms by reading the stored data and passing it to the digital-to-analog conversion module.

[0033] Furthermore, the digital-to-analog conversion module is implemented by a resistor divider (R-2R) DAC, which converts the input digital signal into an analog voltage signal through a series of precise resistors.

[0034] Furthermore, the power amplification module is implemented by a power amplifier, which amplifies the generated low-amplitude signal to a required voltage and power range, suitable for driving a load.

[0035] Furthermore, the filtering module is implemented by a high-order low-pass filter to remove high-frequency noise and harmonic components in the signal to ensure the purity of the output waveform frequency.

[0036] Furthermore, the output isolation module is implemented by a low-power voltage follower, whose characteristics of high input impedance and low output impedance keep the output voltage waveform stable, avoid voltage fluctuations caused by load changes, and effectively isolate the mutual influence between the load and the signal source.

[0037] The output end of each magnetic field receiving coil is connected to a digital potentiometer, whose resistance range can be adjusted within a certain range. A low-power operational amplifier voltage follower is connected at both ends of the digital potentiometer. The outputs of the voltage followers of all magnetic field receiving coils are connected in series to merge the induced voltages of the magnetic field receiving coils.

[0038] Furthermore, the resistance of each digital potentiometer is regulated by the current integration control unit. When the resistance of the digital potentiometer of a magnetic field receiving coil is 0, the voltage follower input is 0, and the entire induced voltage of the magnetic field receiving coil is used to generate an induced current. According to Lenz's law, a magnetic field in the opposite direction to the antenna radiation magnetic field is generated, thereby weakening the alternating magnetic field intensity behind the radiation direction and improving the directionality of the radiation magnetic field.

[0039] Furthermore, when the digital potentiometer resistance of a magnetic field receiving coil is +∞, the voltage follower input is the total induced voltage generated by the magnetic field receiving coil. When the digital potentiometer resistance of a magnetic field receiving coil is between 0 and +∞, its resistance value determines the energy distribution of the two groups of actions.

[0040] Furthermore, the induced voltage receiving unit includes a phase adjustment module, a filtering module and an output isolation module. The phase adjustment module is implemented by a digital phase shifter and is controlled by the MCU. It adjusts the phase of the combined induced voltage to be the same as the phase of the excitation voltage. The filtering module and the output isolation module are similar to the excitation voltage generating unit.

[0041] Furthermore, the current integration control unit monitors the induced voltage waveform (i.e. Figure 2 The measured induced voltage waveform is obtained by connecting the phase-adjusted induced voltage to the antenna coil with the largest voltage demand through a digital switching circuit to replenish energy for the excitation voltage generating unit of the antenna coil.

[0042] Furthermore, the current integration control unit subtracts the voltage waveform required by the antenna coil with the largest voltage demand within one cycle from the induced voltage waveform adjusted by the induced voltage receiving unit, and corrects the voltage waveform that the excitation voltage generating unit of the antenna coil needs to generate, that is, the energy of the antenna coil with the largest voltage demand is provided jointly by the induced voltage receiving unit and the excitation voltage generating unit.

[0043] Example:

[0044] An alternating magnetic field generating device with adjustable radiation direction based on soft magnetic materials according to an embodiment of the present invention is divided into the following structures: Figure 1 As shown, it includes a five-axis magnetic field radiation antenna group, an excitation voltage generating unit, an induced voltage receiving unit, a current integration control unit, a magnetic field measuring unit, a magnetic field control unit, a magnetic field measuring coil, a receiving plate 8, a magnetic field receiving coil, and a shell 10.

[0045] Each radiating antenna of the five-axis magnetic field radiation antenna group includes a soft magnetic material core and an antenna coil. The soft magnetic material core is a high magnetic permeability manganese-zinc ferrite material with a diameter of 30 mm and a length of 200 mm. The inner diameter of the antenna coil frame is 30 mm, the thickness of the antenna coil in the radial direction is 10 mm, and the diameter of the cylindrical protective shell is 50 mm. All antennas have the same size and the same winding method. The central antenna is along the positive direction of the Z axis, and all surrounding antennas are evenly distributed in the XZ plane and the YZ plane. The angle between all surrounding antennas and the positive direction of the Z axis is 60°, and the distance between all antennas and the coordinate origin is 45 mm.

[0046] The magnetic field receiving coil is composed of 9 receiving coils. Figure 1 9 coils are shown, namely the 1st receiving coil 9-1, the 2nd receiving coil 9-2, the 3rd receiving coil 9-3, the 4th receiving coil 9-4, the 5th receiving coil 9-5, the 6th receiving coil 9-6, the 7th receiving coil 9-7, the 8th receiving coil 9-8, and the 9th receiving coil 9-9. One of them is placed at the center of the receiving plate 8, and the other 8 are evenly placed in the 8 directions around it. The area of ​​each magnetic field receiving coil is roughly the same, and the entire receiving plate is covered, and there is no gap between the magnetic field receiving coils. The shape of the receiving plate 8 is a half ellipsoid, the center of which coincides with the origin of the coordinates, and all are located below the XY plane. The semi-axis length of the ellipsoid in the X-axis direction is equal to the semi-axis length in the Y-axis direction and is 180 mm, and the semi-axis length of the ellipsoid in the Z-axis direction is 40 mm.

[0047] The magnetic field measuring coil is composed of five measuring coils, namely the first measuring coil 7-1, the second measuring coil 7-2, the third measuring coil 7-3, the fourth measuring coil 7-4 and the fifth measuring coil 7-5, which are respectively located at the end of the five antennas away from the coordinate origin, coaxial with each antenna and at a distance of 10 mm. The diameter of the enameled wire used for all magnetic field measuring coils, antenna coils and magnetic field receiving coils is selected to be 0.5 mm.

[0048] The signal generation processing and circuit control part includes signal generation, power amplification, phase adjustment, MCU, etc. It is located behind the receiving board 8 and fixed on the shell 10 of the generating device. All coils are connected to it and are regulated by this part.

[0049] The device's housing, antenna coil frame, coil protection shell, ellipsoidal receiving plate and all supporting structures are made of organic glass material.

[0050] The above structure is composed of six main unit modules, namely a five-axis magnetic field radiation antenna group, an excitation voltage generating unit, an induced voltage receiving unit, a current integration control unit, a magnetic field measurement unit and a magnetic field control unit.

[0051] like Figure 2 As shown, the magnetic field control unit receives instructions of expected magnetic field strength, direction, and frequency from the host computer, and calculates the expected current waveforms of all antenna coils in combination with the magnetic field waveform measured by the magnetic field measurement unit.

[0052] The current integration control unit receives the desired current waveform of the antenna coil sent from the magnetic field control unit, dynamically adjusts the antenna coil to which the induced voltage is connected according to the induced voltage waveform adjusted by the induced voltage receiving unit and the measured antenna coil current waveform, and calculates the desired excitation voltage waveforms of all antenna coils.

[0053] The excitation voltage generating unit receives the desired excitation voltage waveform of the antenna coil sent by the current integration control unit, and provides the excitation voltage to the five-axis magnetic field radiation coil group through signal generation, digital-to-analog conversion, power amplification, filtering and other links.

[0054] The induced voltage receiving unit receives the phase information from the excitation voltage generating unit, and adjusts the induced voltage generated by the magnetic field receiving coil through phase adjustment, filtering and other steps to provide energy for the antenna coil with the largest voltage demand.

[0055] The magnetic field control unit and the current integration control unit are controlled by two levels: forward calculation and error feedback. Taking the magnetic field control unit as an example, when the expected magnetic field strength, direction, and frequency of the input change, the expected current waveform of each antenna coil is first calculated through the BH curve and hysteresis characteristics of manganese-zinc ferrite, and then the output result is adjusted using a PID controller based on the error between the measured radiation magnetic field waveform and the ideal sinusoidal waveform. By measuring the radiation magnetic field waveform and the antenna coil current waveform to form a two-level feedback control, the magnetic field can be controlled at a faster convergence speed.

[0056] The alternating magnetic field generating device with adjustable radiation direction in this embodiment uses high magnetic permeability manganese-zinc ferrite as the antenna core, which can radiate a stronger magnetic field; uses antenna coils and current control to improve the stability of the radiated magnetic field; uses a five-axis magnetic field radiation antenna group to radiate a composite magnetic field, which can make the radiated magnetic field have a higher directionality; uses a two-stage feedback control method to improve the flexibility of the radiation magnetic field.

[0057] Therefore, on the whole, the present invention simultaneously meets the requirements of high intensity, high stability, high directionality and high flexibility of the radiated magnetic field, can continuously and accurately adjust the radiated magnetic field quickly, and can meet the need to quickly change the radiation direction of the alternating magnetic field in low-frequency electromagnetic detection.

Claims

1. An alternating magnetic field generating device with adjustable radiation direction based on soft magnetic materials, characterized in that: It comprises a five-axis magnetic field radiation antenna group, an excitation voltage generating unit, an induced voltage receiving unit, a current integration control unit, a magnetic field measurement unit and a magnetic field control unit; the five-axis magnetic field radiation antenna group comprises a central antenna and four surrounding antennas uniformly surrounding the central antenna and forming the same angle with the central antenna, each central antenna and surrounding antenna are composed of a soft magnetic material core and an antenna coil, each antenna coil generates an alternating magnetic dipole magnetic field after being excited by the excitation voltage generating unit, the alternating magnetic field is vectorially superimposed in space, and forms an alternating magnetic field whose radiation direction can be adjusted by the excitation voltage; the magnetic field receiving coil converts the alternating magnetic field opposite to the radiation direction into an induced voltage, the induced voltage receiving unit adjusts the induced voltage, and provides radiation energy together with the excitation voltage generating unit through dynamic regulation of the current integration control unit; the magnetic field measurement unit measures the radiation magnetic field, and the magnetic field control unit continuously adjusts the direction, frequency and intensity of the radiation magnetic field.

2. The alternating magnetic field generating device with adjustable radiation direction based on soft magnetic materials according to claim 1, characterized in that: The soft magnetic material core of each central antenna and surrounding antenna is cylindrical in shape and is placed in a cylindrical antenna coil frame. The antenna coil is wound on the antenna coil frame, and the outer periphery of the antenna coil is wrapped by a cylindrical protective shell.

3. The alternating magnetic field generating device with adjustable radiation direction based on soft magnetic materials according to claim 1, characterized in that: The magnetic field receiving coils are placed on a receiving plate shaped like a half ellipsoid, each magnetic field receiving coil has the same area and covers the entire receiving plate, leaving no gaps between the magnetic field receiving coils.

4. The alternating magnetic field generating device with adjustable radiation direction based on soft magnetic materials according to claim 1, characterized in that: The magnetic field measuring coils of the magnetic field measuring unit are respectively located at one end of the five-axis magnetic field radiation antenna group far away from the coordinate origin, and are coaxial with their respective corresponding antennas and have a distance therebetween.

5. The alternating magnetic field generating device with adjustable radiation direction based on soft magnetic material according to claim 1, characterized in that: The soft magnetic material core is a soft magnetic material with high magnetic permeability and high resistivity, and the cylindrical antenna coil frame, the protective shell of the antenna coil, the receiving plate and the supporting structure are non-metallic materials with low magnetic permeability and high hardness.

6. The alternating magnetic field generating device with adjustable radiation direction based on soft magnetic materials according to claim 1, characterized in that: The magnetic field control unit and the current integration control unit are both programmably controlled by a micro control unit.

7. The alternating magnetic field generating device with adjustable radiation direction based on soft magnetic material according to claim 1, characterized in that: The current integration control unit receives the current frequency of the antenna coils of the central antenna and the surrounding antennas issued by the magnetic field control unit, as well as the current change waveform of each antenna coil within one cycle, converts it into a voltage change waveform within one cycle according to the impedance characteristics of the antenna coil, and transmits the desired excitation voltage waveform to the excitation voltage generating unit.

8. The alternating magnetic field generating device with adjustable radiation direction based on soft magnetic materials according to claim 7, characterized in that: The current integration control unit monitors the current waveform of the antenna coil in real time and dynamically adjusts the desired excitation voltage waveform transmitted to the excitation voltage generating unit as a feedback signal.

9. The alternating magnetic field generating device with adjustable radiation direction based on soft magnetic materials according to claim 1, characterized in that: The excitation voltage generating unit includes a signal generating module, a digital-to-analog conversion module, a power amplifying module, a filtering module and an output isolation module; The signal generation module is implemented by MCU, and the waveform samples to be output are stored in RAM or Flash. The MCU realizes the generation of arbitrary waveforms by reading the stored data and passing it to the digital-to-analog conversion module; The digital-to-analog conversion module is implemented by a resistor-divider DAC, which converts the input digital signal into an analog voltage signal; The power amplification module is implemented by a power amplifier, which amplifies the generated low-amplitude signal to the required voltage and power range, suitable for driving the load; The filtering module is implemented by a high-order low-pass filter to remove high-frequency noise and harmonic components in the signal to ensure the purity of the output waveform frequency; The output isolation module is implemented by a low-power voltage follower, and its high input impedance and low output impedance characteristics enable the output voltage waveform to remain stable.

10. The alternating magnetic field generating device with adjustable radiation direction based on soft magnetic material according to claim 1, characterized in that: The output end of each magnetic field receiving coil is connected to a digital potentiometer, whose resistance range is adjustable within a certain range. Both ends of the digital potentiometer are connected to a low-power operational amplifier voltage follower. The outputs of the low-power operational amplifier voltage followers of all magnetic field receiving coils are connected in series to combine the induced voltages of the magnetic field receiving coils.

11. The alternating magnetic field generating device with adjustable radiation direction based on soft magnetic materials according to claim 10, characterized in that: The resistance of each digital potentiometer is regulated by the current integration control unit. When the resistance of the digital potentiometer of a magnetic field receiving coil is 0, the input of its low-power operational amplifier voltage follower is 0, and all the induced voltage of the magnetic field receiving coil is used to generate an induced current, thereby generating a magnetic field in the opposite direction to the antenna radiation magnetic field, weakening the alternating magnetic field intensity behind the radiation direction, and improving the directionality of the radiation magnetic field; when the resistance of the digital potentiometer of a magnetic field receiving coil is +∞, the input of its low-power operational amplifier voltage follower is all the induced voltage generated by the magnetic field receiving coil. When the resistance of the digital potentiometer of a magnetic field receiving coil is between 0 and +∞, its resistance determines the energy distribution of generating the induced current and the induced voltage.

12. The alternating magnetic field generating device with adjustable radiation direction based on soft magnetic material according to claim 1, characterized in that: The induced voltage receiving unit comprises a phase adjustment module, a filtering module and an output isolation module. The phase adjustment module is implemented by a digital phase shifter and is controlled by an MCU to adjust the phase of the combined induced voltage to be the same as the phase of the excitation voltage.

13. The alternating magnetic field generating device with adjustable radiation direction based on soft magnetic material according to claim 1, characterized in that: The current integration control unit monitors the induced voltage waveform adjusted by the induced voltage receiving unit in real time, and connects the phase-adjusted induced voltage to the antenna coil with the largest voltage demand through the digital switching circuit to replenish energy for the excitation voltage generating unit of the antenna coil.

14. The alternating magnetic field generating device with adjustable radiation direction based on soft magnetic material according to claim 1, characterized in that: The current integration control unit subtracts the voltage waveform required by the antenna coil with the largest voltage demand within one cycle from the induced voltage waveform adjusted by the induced voltage receiving unit, and corrects the voltage waveform that the excitation voltage generating unit of the antenna coil needs to generate, that is, the energy of the antenna coil with the largest voltage demand is provided jointly by the induced voltage receiving unit and the excitation voltage generating unit.

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