Magnetic beacon based on swinging permanent magnet type mechanical antenna array and cross-domain magnetic positioning method

Abstract

The invention discloses a magnetic beacon based on a swinging permanent magnet type mechanical antenna array and a cross-domain magnetic positioning method, and belongs to the technical field of magnetic positioning. An architecture of a magnetic beacon includes a signal generator module, a power amplifier module, and a magnetic beacon antenna. The magnetic beacon antenna is composed of four swing permanent magnet type mechanical antenna arrays of orthogonal cross structures. And each swinging permanent magnet type mechanical antenna with the orthogonal cross structure consists of two groups of swinging permanent magnet type mechanical antenna units with different resonant frequencies. The positioning method comprises the following steps: constructing a magnetic field distribution model of a magnetic beacon; acquiring magnetic field information of a detection point based on a three-axis magnetic sensor; and determining a fitness function, and solving the position of the magnetic source by using a particle swarm algorithm. The magnetic beacon provided by the invention is compact in structure and low in power consumption, and meanwhile, the pose of the magnetic beacon can be solved through one-time measurement at a single position by using a single three-axis magnetic sensor, so that the operation is greatly simplified, and the practical magnetic positioning application is facilitated.

Description

Technical Field

[0001] The present invention belongs to the technical field of magnetic positioning, and in particular relates to a magnetic beacon based on a swinging permanent magnet mechanical antenna array and a cross-domain magnetic positioning method. Background Art

[0002] In complex environments such as underground or under seawater, traditional positioning methods based on radio frequency electromagnetic waves or the steady-state magnetic field of the earth are difficult to achieve high-precision positioning. However, positioning methods based on artificial low-frequency alternating magnetic fields can provide high-precision positioning services in these scenarios. Low-frequency electromagnetic fields / electromagnetic waves have low attenuation in high-loss media such as land and seawater, and can be transmitted across domains well. Since the wavelength of ultra-low frequency electromagnetic fields (30~300Hz) reaches 10 6 ~10 7 Meters, it is difficult for traditional coils to generate strong low-frequency magnetic fields in a small volume, resulting in a short effective positioning distance. Mechanical antenna is a new type of low-frequency electromagnetic wave transmitting antenna, which directly uses the mechanical movement of magnetic dipoles or electric dipoles to generate time-varying electromagnetic fields. It usually works at kHz and below, and can generate strong radiation magnetic fields in a smaller volume. At present, permanent magnets are commonly used as magnetic sources, which generate magnetic field signals with the same frequency as the movement of permanent magnets. The existing positioning system based on rotating permanent magnets, due to the symmetry of the rotational motion of permanent magnets, has a uniform and symmetrical distribution of magnetic fields in the motion plane, which will not be able to fully obtain the posture information of the magnetic beacon. At the same time, a motor is used for driving, and the beacon magnetic source antenna structure is large. The magnetic beacon and cross-domain magnetic positioning method based on a swinging permanent magnet mechanical antenna array proposed in the present invention have the advantages of simple structure, compact size, low power consumption, long positioning distance, and high positioning accuracy. Summary of the invention

[0003] In order to solve the problems of complex positioning operation and short positioning distance in the existing magnetic field positioning technology. The present invention proposes a magnetic beacon and a cross-domain magnetic positioning method based on a swinging permanent magnet mechanical antenna array. The magnetic beacon generates a specific spatial magnetic field distribution. The three-axis magnetic field sensor collects the magnetic field signal generated by the magnetic beacon, performs fast Fourier transform on the collected signal, and solves the amplitude corresponding to the different frequency signals. The magnetic positioning target function is constructed using the amplitude value and the position of the three-axis magnetic field sensor. The position and posture of the magnetic beacon can be obtained by solving the target function.

[0004] In order to achieve the above object, the present invention is implemented by adopting the following technical solutions: The magnetic beacon based on the swinging permanent magnet mechanical antenna array comprises a signal generator module, a power amplifier module and a magnetic beacon antenna; the signal generator generates a sinusoidal wave signal, which is transmitted to the power amplifier module for power amplification and then transmitted to the magnetic beacon antenna for magnetic field radiation.

[0005] In one embodiment, the magnetic beacon antenna includes a swinging permanent magnet mechanical antenna array arranged in a cross structure in a certain order, which are an x-axis array and a z-axis array respectively; the operating frequency of the x-axis antenna is f1, and the operating frequency of the z-axis antenna is f2 (f1≠f2).

[0006] In one embodiment, each layer of the cross-structure antenna in the magnetic beacon antenna includes a swinging permanent magnet mechanical antenna unit arranged in a specific direction according to four initial magnetic moments; The mechanical antenna unit comprises: a radiation permanent magnet, a coil and a bias permanent magnet; The positions of the coil and the bias permanent magnet are fixed, and the radiation permanent magnet swings around the y-axis at the center of the cylinder; The magnetic beacon antenna includes multiple layers of cross-structure antenna units along the y-axis to increase the number of antenna units.

[0007] In one scheme, the magnetic beacon antenna is divided into multiple layers along the y-axis, and the initial magnetic moments of the four antenna units in each layer of the cross-structure antenna are oriented alternately in the following order: counterclockwise → clockwise → counterclockwise → clockwise, or clockwise → counterclockwise → clockwise → counterclockwise, so that the moment couples of the facing swinging permanent magnet mechanical antenna units in each layer during movement will cancel each other out. The moment couples during the movement of the swinging permanent magnet mechanical antenna units between different layers along the y-axis will also cancel each other out.

[0008] On the other hand, a cross-domain magnetic positioning method is provided, wherein the positioning method is based on the magnetic beacon, and the method comprises: Construct a magnetic field distribution model of the magnetic beacon; Magnetic beacon positioning is performed by constructing a magnetic field distribution model of the magnetic beacon.

[0009] In one embodiment, the magnetic field distribution model of the magnetic beacon is: The geometric center point of the magnetic beacon is taken as the center of the magnetic beacon. Assuming that the center position coordinates of the magnetic beacon are (x0, y0, z0), the four orthogonal swing permanent magnet mechanical antenna arrays of the magnetic beacon can be divided into the x-axis direction and the z-axis direction. The x-axis direction is The swing permanent magnet mechanical antenna units are arranged in a certain order, and the z-axis direction is The swing permanent magnet type mechanical antenna units are arranged in a certain order, and the driving current of the driving coil of each swing permanent magnet type mechanical antenna unit is , is the total magnitude of the current, I The magnitude of the current that drives the radiating permanent magnet to swing is is the current size corresponding to the magnetic moment of the driving coil to radiate the magnetic field outward, The size is much smaller thanI The size of the swing permanent magnet type mechanical antenna unit is driven by a parallel drive method; The magnetic moments of the two orthogonal swinging permanent magnet mechanical antenna arrays of the magnetic beacon radiate the magnetic field in a simple harmonic change, which can be recorded as: in, is the magnetic moment of the radiation permanent magnet of a single swing permanent magnet mechanical antenna unit, and are the swing angles of the radiation permanent magnet of the single swing permanent magnet type mechanical antenna in the x-axis direction and the z-axis direction respectively, and are the radiation magnetic moments contributed by the driving coil of a single swing permanent magnet mechanical antenna in the x-axis direction and the z-axis direction, respectively, where: , is the number of coil turns, , is the coil area, , is the current magnitude corresponding to the magnetic moment of the driving coil radiating the magnetic field outward; the magnitude of the radiation magnetic moment in the x-axis direction is recorded as , the resonant frequency is recorded as f1; the magnitude of the radiation magnetic moment in the z-axis direction is recorded as , the resonant frequency is recorded as f2; The vector representing the radiation magnetic moment of the swinging permanent magnet mechanical antenna array in the x-axis direction, At any point P(x,y,z) in space The distance between the magnetic beacon and the point in the area hour, , is the maximum linear dimension of the magnetic beacon; Considering the magnetic beacon as a magnetic dipole, the magnetic fields generated in the x-axis, y-axis, and z-axis directions at this point are: (1) The vector representing the radiation magnetic moment of the swinging permanent magnet mechanical antenna array in the z-axis direction, the magnetic fields generated in the x-axis, y-axis, and z-axis directions at the midpoint P(x, y, z) in space are: (2) Therefore, the total magnetic field generated by the magnetic beacon at any point P(x,y,z) in space in the x-axis, y-axis, and z-axis directions is: (3) Where, μ0 = 4π × 1 0 -7 N.A -2 is the magnetic permeability in vacuum.

[0010] In one embodiment, the The process of determining the size of is as follows: S1, only equips the mechanical antenna array with a swinging permanent magnet in the x-axis direction, and measures the attenuation curve of the magnetic field with distance at the x-axis facing the center of the antenna. , d is the distance between the measurement point and the swing permanent magnet mechanical antenna array, according to Reverse deduction , and obtain the magnitude of the radiation magnetic dipole moment in the x-axis direction; S2, only equips with a swinging permanent magnet mechanical antenna array in the z-axis direction, and measures the attenuation curve of the magnetic field with distance at the z-axis facing the center of the antenna. , d is the distance between the measurement point and the swing permanent magnet mechanical antenna array, according to Reverse deduction , and obtain the magnitude of the radiation magnetic dipole moment in the z-axis direction.

[0011] In one embodiment, the magnetic beacon positioning includes: The position (x, y, z) of the three-axis magnetic field sensor at point P is a known quantity. The attitude change of the magnetic beacon relative to the coordinate axis of the three-axis magnetic field sensor is (α, β, γ), where α is the angle between the x-axis of the magnetic beacon and the x-axis of the coordinate system of the magnetic field sensor, β is the angle between the y-axis of the magnetic beacon and the y-axis of the coordinate system of the magnetic field sensor, and γ is the angle between the z-axis of the magnetic beacon and the z-axis of the coordinate system of the magnetic field sensor. The relationship between the magnetic field generated by the magnetic beacon and the three-axis magnetic field received by the magnetic field sensor is constructed. Using fast Fourier transform, we can get the amplitude-frequency graph of the signal; The nonlinear equation group is constructed by combining the magnetic field distribution model, the relationship between the three-axis magnetic field and the amplitude of the three-axis components corresponding to the frequency. The nonlinear equation group is solved by the optimization algorithm to obtain the position and posture of the magnetic beacon.

[0012] Beneficial effects of the present invention: (1) The magnetic beacon proposed in the present invention has a compact structure and low power consumption. The antenna used in the magnetic beacon of the present invention is a swinging permanent magnet mechanical antenna, which is directly driven by a coil. Compared with the rotating permanent magnet solution, it also has lower power consumption; (2) The positioning method proposed in the present invention can achieve fast and accurate positioning. Through two orthogonal swinging permanent magnet mechanical antenna arrays with different resonant frequencies, a single three-axis sensor can be used to obtain the six unknowns of the position and attitude of the magnetic beacon in one positioning. The traditional rotating permanent magnet solution requires two three-axis sensors to position once or a single three-axis sensor to position twice at different positions to achieve this.

[0013] (3) The initial arrangement of the magnetic moments of the antenna units in the magnetic beacon antenna proposed in the present invention can solve the vibration problem of the magnetic beacon during operation, ensure the stability of its position, and thus improve the positioning accuracy.

[0014] The present invention has the advantages of simple structure and convenient and fast operation. It can use a single three-axis magnetic sensor to locate at a single position once to solve the position and posture of the magnetic beacon, which greatly improves the portability of the magnetic beacon positioning system in complex scenarios such as urban pipeline corridors and underground mines. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present invention, and together with the description are used to explain the principles of the present invention, and do not constitute improper limitations of the present invention.

[0016] Figure 1 It is a structural schematic diagram of the magnetic beacon of the present invention; Figure 2 It is a schematic diagram of a front view of a magnetic beacon antenna of the present invention; Figure 3 It is a schematic side view of the magnetic beacon antenna of the present invention; Figure 4 It is a schematic front view of the arrangement of the initial magnetic moments of four antenna units in each layer of the magnetic beacon antenna of the present invention; Figure 5 It is a schematic side view of the arrangement of the initial magnetic moments of four antenna units in each layer of the magnetic beacon antenna of the present invention; Figure 6 A schematic diagram of the positions of the magnetic beacon and the three-axis sensor when positioning is performed for the present invention; Figure 7 This is a flow chart of the positioning method of the present invention.

[0017] Numbers in the figure: 1. Magnetic beacon; 2. Signal generator module; 3. Power amplifier module; 4. Magnetic beacon antenna; 5. Swinging permanent magnet mechanical antenna unit; 6. Radiating permanent magnet; 7. Coil; 8. Bias permanent magnet. DETAILED DESCRIPTION

[0018] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Typical embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described in the present invention. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0019] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meanings as those understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0020] Embodiment 1 like Figure 1 As shown, the structure of a magnetic beacon 1 of a swinging permanent magnet mechanical antenna array of the present invention includes: a signal generator module 2, a power amplifier module 3 and a magnetic beacon antenna 4. When working, the signal generator 2 generates a sine wave signal of a certain frequency, which is transmitted to the power amplifier module 3 for power amplification, and then transmitted to the magnetic beacon antenna 4 to radiate a magnetic field outward. Preferably, the signal generator module 2 and the power amplifier module 3 are both powered by batteries.

[0021] In the above scheme, if Figure 2 The magnetic beacon antenna 4 includes a plurality of swinging permanent magnet mechanical antenna units 5 arranged in a cross structure in a certain order, and each of the swinging permanent magnet mechanical antenna units 5 includes: a radiating permanent magnet 6, a coil 7 and a bias permanent magnet 8, wherein the positions of the coil 7 and the bias permanent magnet 8 are fixed, and the radiating permanent magnet 6 can rotate around the center y-axis of the cylinder. Figure 2 The magnetic beacon antenna 4 is shown to include multiple layers of cross-structure antennas along the y-axis to increase the number of antenna units.

[0022] In the above scheme, if Figure 3 , the antenna unit of each cross structure in the magnetic beacon antenna 4 has an x-axis antenna operating frequency of f1 and a z-axis antenna operating frequency of f2 (f1≠f2). In order to reduce the vibration of the magnetic beacon antenna during operation, which causes the problem of amplitude fluctuation and unstable posture of the magnetic beacon signal, the following initial magnetic moment direction arrangement of the swing permanent magnet mechanical antenna unit 5 is proposed, such as Figure 4 , 5 As shown. The magnetic beacon antenna is divided into multiple layers along the y-axis, and the initial magnetic moment arrangement of the swing permanent magnet type mechanical antenna unit 5 of each layer is as follows: counterclockwise → clockwise → counterclockwise → clockwise, or clockwise → counterclockwise → clockwise → counterclockwise, with the orientation changing alternately; under this arrangement, the moment couples of the swing permanent magnet type mechanical antenna unit 5 facing each other during the movement of each layer will cancel each other out. Similarly, the moment couples of the swing permanent magnet type mechanical antenna unit 5 between different layers along the y-axis during the movement will also cancel each other out. Based on this, the vibration suppression and posture stabilization of the magnetic beacon antenna 4 during operation are achieved.

[0023] Embodiment 2: like Figure 7As shown, based on the swing permanent magnet type mechanical antenna array of the first embodiment, a positioning method based on the swing permanent magnet type mechanical antenna array is constructed. It includes: 1. Construct the magnetic field distribution model of the magnetic beacon The geometric center point of the magnetic beacon is taken as the center of the magnetic beacon. Assuming that the center position coordinates of the magnetic beacon are (x0, y0, z0), the four orthogonal swing permanent magnet mechanical antenna arrays of the magnetic beacon can be divided into the x-axis direction and the z-axis direction. The x-axis direction is The swing permanent magnet mechanical antenna units are arranged in a certain order, and the z-axis direction is The swing permanent magnet type mechanical antenna units are arranged in a certain order, and the driving current of the driving coil of each swing permanent magnet type mechanical antenna unit is , is the total magnitude of the current, I The magnitude of the current that drives the radiating permanent magnet to swing is is the current size corresponding to the magnetic moment of the driving coil to radiate the magnetic field outward, The size is much smaller than I The size of the swing permanent magnet type mechanical antenna unit is driven by a parallel drive method; The magnetic moments of the two orthogonal swinging permanent magnet mechanical antenna arrays of the magnetic beacon radiate the magnetic field in a simple harmonic change, which can be recorded as: in, is the magnetic moment of the radiation permanent magnet of a single swing permanent magnet mechanical antenna unit, and are the swing angles of the radiation permanent magnet of the single swing permanent magnet type mechanical antenna in the x-axis direction and the z-axis direction respectively, and are the radiation magnetic moments contributed by the driving coil of a single swing permanent magnet mechanical antenna in the x-axis direction and the z-axis direction, respectively, where: , is the number of coil turns, , is the coil area, , is the current magnitude corresponding to the magnetic moment of the driving coil radiating the magnetic field outward; the magnitude of the radiation magnetic moment in the x-axis direction is recorded as , the resonant frequency is recorded as f1; the magnitude of the radiation magnetic moment in the z-axis direction is recorded as , the resonant frequency is recorded as f2; The vector representing the radiation magnetic moment of the swinging permanent magnet mechanical antenna array in the x-axis direction, at any point in space P(x,y,z) , the distance between the magnetic beacon and the point hour, , is the maximum linear dimension of the magnetic beacon. The magnetic beacon can be regarded as a magnetic dipole. At this point, the magnetic fields generated in the x-axis, y-axis, and z-axis directions are: (1) The vector representing the radiation magnetic moment of the swinging permanent magnet mechanical antenna array in the z-axis direction, the magnetic fields generated in the x-axis, y-axis, and z-axis directions at the midpoint P(x, y, z) in space are: (2) Therefore, the total magnetic field generated by the magnetic beacon at any point P(x,y,z) in space in the x-axis, y-axis, and z-axis directions is: (3) Where, μ0 = 4π × 1 0 -7 N.A -2 is the magnetic permeability in vacuum.

[0024] like Figure 7 As shown, The process of determining the size of is as follows: S1, only equips the mechanical antenna array with a swinging permanent magnet in the x-axis direction, and measures the attenuation curve of the magnetic field with distance at the x-axis facing the center of the antenna. , d is the distance between the measurement point and the swing permanent magnet mechanical antenna array, according to Reverse deduction , and obtain the magnitude of the radiation magnetic dipole moment in the x-axis direction; S2, only equips with a swinging permanent magnet mechanical antenna array in the z-axis direction, and measures the attenuation curve of the magnetic field with distance at the z-axis facing the center of the antenna. , d is the distance between the measurement point and the swing permanent magnet mechanical antenna array, according to Reverse deduction , and obtain the magnitude of the radiation magnetic dipole moment in the z-axis direction; In order to ensure the accuracy of the magnetic dipole moment of the magnetic beacon as much as possible, multiple points and multiple measurements are carried out, and the result with the smallest variance is taken.

[0025] 2. The magnetic beacon positioning method is to perform magnetic beacon positioning by constructing a magnetic field distribution model of the magnetic beacon.

[0026] Assuming that the position of the three-axis magnetic field sensor is known at (x, y, z), the attitude change of the magnetic beacon relative to the coordinate axis of the three-axis magnetic field sensor is (α, β, γ), where α is the angle between the x-axis of the magnetic beacon and the x-axis of the coordinate system of the magnetic field sensor, β is the angle between the y-axis of the magnetic beacon and the y-axis of the coordinate system of the magnetic field sensor, and γ is the angle between the z-axis of the magnetic beacon and the z-axis of the coordinate system of the magnetic field sensor. The magnetic field generated by the magnetic beacon and the three-axis magnetic field received by the magnetic field sensor have the following relationship: (4) remember for ; In short:

[0027] Among them, V x , V y , V z The magnetic field components received by the three axes of the magnetic field sensor are obtained by fast Fourier transform to obtain the spectrum of the signal. The corresponding amplitudes of the three-axis components are , , , there are the following relations: (5) frequency The corresponding three-axis component amplitudes , , , there are the following relations: (6) Combining equation (5) and equation (6) can obtain 6 nonlinear equations. Preferably, the nonlinear equations are solved using an optimization algorithm.

[0028] The fitness value function of the optimization algorithm is: , , , , , , (7) In the above scheme, the optimization problem is: , find its minimum value on the domain.

[0029] In the above scheme, if Figure 6, assuming that the position of the three-axis sensor is known, the position of the magnetic beacon is in the area The position and posture of the magnetic beacon can be calculated based on the three-axis output of the three-axis sensor.

[0030] The positioning method of the magnetic beacon proposed in the present invention is simulated and verified. In this example simulation, the position of the three-axis magnetic sensor is (0 m, 0 m, 0 m), and the magnitude of the magnetic moment of the x-axis and z-axis is 6 A·m 2 , there is white noise of 3% of the signal amplitude in the environment, and the magnetic beacon is in the area The robot moves in the positive direction along the y-axis, collects magnetic field data from the measurement point at a sampling frequency of 1000 Hz, and then estimates the position and posture based on the magnetic field amplitude values ​​at different frequencies. The real coordinates and posture and the inverted posture are shown in Table 1.

[0031] Table 1 Comparison of pose simulation results

[0032] As shown in Table 1, under the condition of a distance of 3m, the position error is at the centimeter level, the attitude error is within 4°, and it can be achieved with a single three-axis sensor at a single location and a single measurement.

[0033] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium, and when the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM).

[0034] It should be understood that the detailed description of the technical solutions of the present invention by means of the preferred embodiments is illustrative rather than restrictive. A person skilled in the art may modify the technical solutions described in the embodiments, or replace some of the technical features by equivalents, based on reading the specification of the present invention; and these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A magnetic beacon based on a swinging permanent magnet mechanical antenna array, characterized in that: The magnetic beacon based on the swinging permanent magnet mechanical antenna array comprises: a signal generator module, a power amplifier module and a magnetic beacon antenna; The magnetic beacon antenna is composed of four swinging permanent magnet mechanical antenna arrays with orthogonal cross structures; each swinging permanent magnet mechanical antenna with orthogonal cross structure is composed of two groups of swinging permanent magnet mechanical antenna units with different resonant frequencies.

2. A magnetic beacon based on a swinging permanent magnet mechanical antenna array according to claim 1, characterized in that: The magnetic beacon antenna comprises: swing permanent magnet type mechanical antenna units arranged in sequence into a cross structure; The mechanical antenna unit comprises: a radiation permanent magnet, a coil and a bias permanent magnet; The positions of the coil and the bias permanent magnet are fixed, and the radiation permanent magnet swings around the y-axis at the center of the cylinder; The magnetic beacon antenna includes multiple layers of cross-structure antenna units along the y-axis, thereby increasing the number of antenna units.

3. The magnetic beacon based on a swinging permanent magnet mechanical antenna array according to claim 1, characterized in that: In the magnetic beacon antenna, for each layer of the cross-structured antenna unit, the operating frequency of the x-axis antenna is f1, and the operating frequency of the z-axis antenna is f2 (f1≠f2).

4. A magnetic beacon based on a swinging permanent magnet mechanical antenna array according to claim 2, characterized in that: The magnetic beacon antenna is divided into multiple layers along the y-axis, and the initial magnetic moments of the four antenna units in each layer of the cross-structure antenna are oriented alternately in the following order: counterclockwise → clockwise → counterclockwise → clockwise, or clockwise → counterclockwise → clockwise → counterclockwise; the moment pairs of the facing swinging permanent magnet mechanical antenna units in each layer cancel each other out during movement; The moment couples during the movement of the swinging permanent magnet type mechanical antenna unit between different layers along the y-axis also cancel each other out.

5. A cross-domain magnetic positioning method, the positioning method is based on the magnetic beacon of the swinging permanent magnet mechanical antenna array according to any one of claims 1 to 4, characterized in that: The cross-domain magnetic positioning method comprises: Construct a magnetic beacon magnetic field distribution model; Acquire magnetic field information of detection points based on three-axis magnetic sensor; The fitness function is determined, and the position and posture of the magnetic source are solved using an optimization algorithm.

6. A cross-domain magnetic positioning method according to claim 5, characterized in that: The magnetic beacon magnetic field distribution model is as follows: The geometric center point of the magnetic beacon is taken as the center of the magnetic beacon. Assuming that the center position coordinates of the magnetic beacon are (x0, y0, z0), the main radiation directions of the four orthogonal swing permanent magnet mechanical antenna arrays of the magnetic beacon are divided into the x-axis direction and the z-axis direction. The x-axis direction is The swing permanent magnet mechanical antenna units are arranged in a certain order, and the z-axis direction is The swing permanent magnet type mechanical antenna units are arranged in a certain order, and the driving current of the driving coil of each swing permanent magnet type mechanical antenna unit is , is the total magnitude of the current, I The magnitude of the current that drives the radiating permanent magnet to swing is is the current size corresponding to the magnetic moment of the driving coil to radiate the magnetic field outward, The size is much smaller than I The size of the swing permanent magnet type mechanical antenna unit is driven by a parallel drive method; The magnetic moments of the two orthogonal swinging permanent magnet mechanical antenna arrays of the magnetic beacon radiate the magnetic field in a simple harmonic change, which can be recorded as: in, is the magnetic moment of the radiation permanent magnet of a single swing permanent magnet mechanical antenna unit, and are the swing angles of the radiation permanent magnet of the single swing permanent magnet type mechanical antenna in the x-axis direction and the z-axis direction respectively, and are the radiation magnetic moments contributed by the driving coil of a single swing permanent magnet mechanical antenna in the x-axis direction and the z-axis direction, respectively, where: , is the number of coil turns, , is the coil area, , is the current magnitude corresponding to the magnetic moment of the driving coil radiating the magnetic field outward; the magnitude of the radiation magnetic moment in the x-axis direction is recorded as , the resonant frequency is recorded as f1; the magnitude of the radiation magnetic moment in the z-axis direction is recorded as , the resonant frequency is recorded as f2; Represents the radiation magnetic moment vector of the swinging permanent magnet mechanical antenna array in the x-axis direction, at any point P(x,y,z) in space , the distance between the magnetic beacon and the point hour,( , is the maximum linear dimension of the magnetic beacon), and the magnetic beacon is regarded as a magnetic dipole. The three components of the magnetic field generated at this point are: (1) The radiation magnetic moment vector of the swinging permanent magnet mechanical antenna array in the z-axis direction, and the magnetic fields generated at point P (x, y, z) are: (2) Therefore, the total magnetic field of the magnetic beacon at any point P(x,y,z) in space is: (3) Where, μ0=4π×10 -7 N.A -2 is the magnetic permeability in vacuum.

7. A cross-domain magnetic positioning method according to claim 6, characterized in that: Said The process of determining the size of is as follows: S1. Only assemble the swing permanent magnet mechanical antenna array in the x-axis direction, and measure the attenuation curve of the magnetic field with distance at the x-axis facing the center of the antenna. , d is the distance between the measurement point and the swing permanent magnet mechanical antenna array, according to Reverse deduction , and obtain the magnitude of the radiation magnetic dipole moment in the x-axis direction; S2, only assemble the swing permanent magnet mechanical antenna array in the z-axis direction, measure the attenuation curve of the magnetic field with distance at the z-axis facing the center of the antenna, according to , d is the distance between the measurement point and the swing permanent magnet mechanical antenna array, according to Reverse deduction , and obtain the magnitude of the radiation magnetic dipole moment in the z-axis direction.

8. A cross-domain magnetic positioning method according to claim 5, characterized in that: The method for solving the magnetic source pose includes: The position (x, y, z) of the three-axis magnetic field sensor point P is a known quantity, and the attitude change of the magnetic beacon relative to the coordinate axis of the three-axis magnetic field sensor is (α, β, γ), where α is the angle between the x-axis of the magnetic beacon and the x-axis of the coordinate system of the magnetic field sensor, β is the angle between the y-axis of the magnetic beacon and the y-axis of the coordinate system of the magnetic field sensor, and γ is the angle between the z-axis of the magnetic beacon and the z-axis of the coordinate system of the magnetic field sensor. The relationship between the magnetic field generated by the magnetic beacon and the three-axis magnetic field received by the magnetic field sensor is constructed; Using fast Fourier transform, we can get the amplitude-frequency graph of the signal; The nonlinear equations are constructed by combining the magnetic field distribution model, the relationship between the three-axis magnetic field and the amplitudes of the three-axis components corresponding to the frequency. The nonlinear equations are solved by the optimization algorithm to obtain the position and posture of the magnetic beacon.

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