Magnetic positioning system

Abstract

The application discloses a magnetic positioning system, relates to the technical field of position detection and space positioning, and realizes high-precision positioning and dynamic tracking of a space target based on a double-shaft plus single-shaft rotating magnetic field to construct a composite magnetic signal, combined with analytical modeling and a nonlinear optimization algorithm. The system is simple and compact in structure, efficient in operation, avoids the problems of high-frequency interference and low-frequency algorithm solution difficulty of traditional electromagnetic positioning, and has the advantages of high precision, high efficiency, low power consumption, and the like. By adding a single-shaft rotating permanent magnet on the revolution shaft to change the timing characteristics of the magnetic field, the sequence difference of the magnetic field vectors corresponding to different space positions is significantly different, and the probability of multiple solutions is reduced. Through joint matching residual error judgment of the double magnetic field sources, the fuzzy solution is quickly removed, the uniqueness of positioning is improved, and the calculation efficiency is improved. The system is compact and low in power consumption as a whole, and is suitable for virtual / augmented reality, medical navigation, robot positioning and other high-precision scenes.

Description

Technical Field

[0001] This invention relates to the field of position detection and spatial positioning technology, and in particular to a magnetic positioning system based on a rotating permanent magnet. Background Technology

[0002] Position detection and spatial positioning technologies are widely used in virtual reality, augmented reality, robot navigation, medical surgical navigation, precision assembly, and motion capture. Commonly used methods include optical positioning, inertial measurement positioning, ultrasonic positioning, and magnetic field positioning. Optical positioning offers high accuracy but is easily limited by obstructions and lighting conditions; inertial measurement requires no external signal but suffers from error accumulation; ultrasonic positioning is low-cost and simple to implement, but is significantly affected by environmental noise and changes in the medium.

[0003] Magnetic field positioning technology leverages the ability of magnetic fields to penetrate non-metallic materials and remain unaffected by obstructions, enabling stable operation in complex environments and enclosed spaces. Magnetic positioning systems based on time-varying magnetic fields generated by rotating permanent magnets have attracted attention due to their stable magnetic field source, low power consumption, and compact structure. A common design involves the permanent magnet rotating simultaneously around two intersecting axes of rotation, creating a time-varying magnetic field distribution in space. Sensors measure the three components of the magnetic field, and the position can be calculated through model inversion. In such dual-axis rotating magnetic field systems, the eccentric arrangement of the permanent magnets can break the magnetic field symmetry, thereby achieving a unique three-dimensional position calculation within a certain range.

[0004] However, existing magnetic field positioning systems do not have high differentiation between magnetic field signals generated at different spatial locations, which affects the positioning accuracy. Summary of the Invention

[0005] In view of the above problems, the present invention provides a magnetic positioning system for overcoming or at least partially solving the above problems. This system utilizes a time-varying magnetic field generated by a permanent magnet rotating in multiple degrees of freedom to achieve high-precision positioning of a target sensor in space.

[0006] This invention provides the following solution:

[0007] A magnetic positioning system, comprising:

[0008] A magnetic field generator includes a dual-axis rotating permanent magnet and a single-axis rotating permanent magnet. The dual-axis rotating permanent magnet is configured to rotate around two mutually perpendicular and non-coplanar axes to generate a spatially non-uniformly varying time-varying magnetic field. The rotation axis of the single-axis rotating permanent magnet is configured to be coaxial or coupled with one of the axes of the dual-axis rotating permanent magnet's rotation structure, and it independently rotates around its own axis to generate an additional magnetic field. This additional magnetic field is used to superimpose with the time-varying magnetic field to disrupt the symmetry of the magnetic field distribution and obtain a composite time-varying magnetic field.

[0009] A magnetic field sensor is disposed inside the object to be measured, and the magnetic field sensor is used to measure the three-dimensional magnetic field component data at the target spatial location.

[0010] A computing unit is configured to execute a positioning method, the positioning method comprising:

[0011] After confirming that the dual-axis rotating permanent magnet and the single-axis rotating permanent magnet work synchronously to generate the composite time-varying magnetic field; acquire the three-component magnetic field data synchronously collected by the magnetic field sensor within the sampling period, and acquire the angle information of the dual-axis rotating permanent magnet and the single-axis rotating permanent magnet;

[0012] The candidate location set of the target is calculated based on the inverse equation of the magnetic dipole model using the three components of the magnetic field and the angle information.

[0013] The additional magnetic field sequence introduced by the single-axis rotating permanent magnet is used to superimpose the matching degree judgment of the additional magnetic field sequence in the solution, so as to eliminate the solutions that do not conform to the joint timing characteristics of the two magnetic fields; by comparing the residuals of the theoretical magnetic field response and the measured response of several initial estimates in the candidate location set under the two sets of magnetic field sources through the residual function, the unique solution with the smallest residual and the highest consistency is selected as the unique positioning result.

[0014] The unique positioning result is output, and smoothing and dynamic tracking are performed based on the temporal correlation of continuous measurements.

[0015] Preferably, the residual function is expressed by the following formula:

[0016]

[0017] In the formula: Indicates the residual comparison value. middle This represents a magnetic field vector, where the superscript indicates the corresponding magnetic field source, and the subscript indicates the magnetic field vector. This represents the theoretical value. This represents the measured value.

[0018] Preferably, the initial estimate is obtained by inverse solving the following formula:

[0019]

[0020]

[0021]

[0022] In the formula: , , These represent the three-axis components of the magnetic field. Represents the permeability of free space. , , This represents the vector from the dual-axis rotating permanent magnet to the magnetic field sensor. This represents the vector from the single-axis rotating permanent magnet to the magnetic field sensor. Represents auxiliary variables. This indicates the axial height of a single-axis rotating permanent magnet.

[0023] Preferably, the unique solution with the smallest residual and the highest consistency is selected as the unique localization result by using time series dynamic consistency judgment and nonlinear optimization algorithm.

[0024] Preferably, the nonlinear optimization algorithm includes: The algorithm, the The algorithm is used to refine the initial estimate using a six-degree-of-freedom solution.

[0025] Preferably, the rotation axis of the single-axis rotating permanent magnet coincides with one of the rotation axes of the dual-axis rotating permanent magnet.

[0026] Preferably, both the dual-axis rotating permanent magnet and the single-axis rotating permanent magnet are connected to an angle encoder, which is used to acquire the angle information.

[0027] Preferably, the system further includes a control unit, which drives the rotation of the permanent magnet and synchronously acquires magnetic field and angle information; the control unit, the magnetic field sensor, and the angle encoder are time-synchronized using a timestamp synchronization method.

[0028] Preferably, the magnetic field generator further includes a mounting base and a drive motor. A first bevel gear is provided on the mounting base. The output shaft of the drive motor extends through the mounting base and the first bevel gear to the top of the first bevel gear. The dual-axis rotating permanent magnet is connected to the second bevel gear and the third bevel gear respectively. The second bevel gear and the third bevel gear are rotatably connected to the fixed connecting shaft respectively. The fixed connecting shaft is connected to the output shaft in an axially perpendicular manner through a bushing. The single-axis rotating permanent magnet is connected to the top of the output shaft.

[0029] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0030] This application provides a magnetic positioning system that constructs a composite magnetic signal based on a dual-axis plus a single-axis rotating magnetic field. Combined with analytical modeling and nonlinear optimization algorithms, it achieves high-precision positioning and dynamic tracking of spatial targets. The system has a simple and compact structure and high computational efficiency, avoiding the problems of high-frequency interference and low-frequency algorithm difficulty inherent in traditional electromagnetic positioning. By adding a single-axis rotating permanent magnet to the revolution axis to alter the temporal characteristics of the magnetic field, the magnetic field vector sequences corresponding to different spatial locations are significantly differentiated, reducing the probability of multiple solutions. Through joint matching of residuals using dual magnetic field sources, fuzzy solutions are quickly eliminated, improving positioning uniqueness and computational efficiency. The system maintains a compact design and low power consumption, making it suitable for high-precision scenarios such as virtual / augmented reality, medical navigation, and robot positioning.

[0031] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0033] Figure 1 This is a schematic diagram of the magnetic positioning system provided in an embodiment of the present invention;

[0034] Figure 2 This is an assembly diagram of the magnetic field generator provided in an embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram of an exemplary mathematical model of the magnetic positioning system provided in an embodiment of the present invention;

[0036] Figure 4 This is an algorithm flowchart provided in an embodiment of the present invention.

[0037] In the figure: Magnetic field generator 1, dual-axis rotating permanent magnet 11, single-axis rotating permanent magnet 12, mounting base 13, drive motor 14, first bevel gear 15, second bevel gear 16, third bevel gear 17, fixed connecting shaft 18, magnetic field sensor 2, object to be measured 3, computing unit 4, control unit 5, base station module 6, orbital trajectory 7. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0039] See Figure 1 This is a magnetic positioning system provided in an embodiment of the present invention, such as... Figure 1 As shown, the system may include:

[0040] A magnetic field generator 1 includes a dual-axis rotating permanent magnet 11 and a single-axis rotating permanent magnet 12. The dual-axis rotating permanent magnet 11 is configured to rotate around two mutually perpendicular and non-coplanar axes to generate a spatially non-uniformly varying time-varying magnetic field. The rotation axis of the single-axis rotating permanent magnet 12 is configured to be coaxial or coupled with one of the axes of the rotation structure of the dual-axis rotating permanent magnet 11, and it independently rotates around its own axis to generate an additional magnetic field. The additional magnetic field is used to superimpose with the time-varying magnetic field to disrupt the symmetry of the magnetic field distribution and obtain a composite time-varying magnetic field. The purpose of disrupting the symmetry of the magnetic field is to improve the uniqueness of the magnetic vector in space, enhance the distinguishability of the magnetic response sequence between different locations, and effectively eliminate the mirror ambiguity caused by symmetry.

[0041] In a specific implementation, the embodiments of this application may provide that the rotation axis of the single-axis rotating permanent magnet 12 coincides with one of the rotation axes of the dual-axis rotating permanent magnet 11. Both the dual-axis rotating permanent magnet 11 and the single-axis rotating permanent magnet 12 are connected to an angle encoder with a resolution of not less than 0.1°, and the angle encoder is used to acquire the angle information.

[0042] A magnetic field sensor 2 is disposed inside the object to be measured 3. The magnetic field sensor 2 is used to measure the three-dimensional magnetic field component data at the target spatial location. The measurement range of the magnetic field sensor 2 covers ±1000µT.

[0043] The magnetic field generator 1 provided in this application embodiment can adopt various structural forms. For example, in one example, the magnetic field generator 1 can also include a mounting base 13 and a drive motor 14. A first bevel gear 15 is provided on the mounting base 13. The output shaft of the drive motor 14 extends through the mounting base 13 and the first bevel gear 15 to the top of the first bevel gear 15. The dual-axis rotating permanent magnet 11 is connected to the second bevel gear 16 and the third bevel gear 17 respectively. The second bevel gear 16 and the third bevel gear 17 are rotatably connected to the fixed connecting shaft 18 respectively. The fixed connecting shaft 18 is connected to the output shaft in an axially perpendicular manner through a bushing. The single-axis rotating permanent magnet 12 is connected to the top of the output shaft.

[0044] To further achieve time synchronization, this application embodiment may also provide the control unit 5 for driving the rotation of the permanent magnet and synchronously collecting magnetic field and angle information; the control unit 5, the magnetic field sensor 2, and the angle encoder are time-synchronized using a timestamp synchronization method.

[0045] Calculation unit 4, the calculation unit 4 being used to execute a positioning method, the positioning method including:

[0046] After confirming that the dual-axis rotating permanent magnet 11 and the single-axis rotating permanent magnet 12 work synchronously to generate the composite time-varying magnetic field; acquire the three-component magnetic field data synchronously collected by the magnetic field sensor 2 within the sampling period, and acquire the angle information of the dual-axis rotating permanent magnet 11 and the single-axis rotating permanent magnet 12;

[0047] The candidate location set of the target is calculated based on the inverse equation of the magnetic dipole model using the three components of the magnetic field and the angle information.

[0048] Using the additional magnetic field sequence introduced by the single-axis rotating permanent magnet 12, the matching degree judgment of the additional magnetic field sequence is superimposed in the solution so as to eliminate the solutions that do not conform to the joint timing characteristics of the two magnetic fields; by comparing the residuals of the theoretical magnetic field response and the measured response of several initial estimates in the candidate position set under the two sets of magnetic field sources through the residual function, the unique solution with the smallest residual and the highest consistency is selected as the unique positioning result.

[0049] The unique positioning result is output, and smoothing and dynamic tracking are performed based on the temporal correlation of continuous measurements.

[0050] The magnetic positioning system provided in this application aims to achieve highly reliable and accurate six-degree-of-freedom position and attitude measurement. The system comprises a magnetic field generator, an additional rotation unit, a magnetic field measurement unit, and a computer. The magnetic field generator employs a dual-axis rotation mechanism, driving permanent magnets to rotate around two intersecting axes to form a dynamically changing dual-axis magnetic field distribution. Simultaneously, a single-axis rotating permanent magnet 12 is positioned on the revolution axis to generate additional magnetic field disturbances, enhancing the uniqueness of the positioning features. To improve the accuracy of the system's calculations, this invention proposes a calculation algorithm combining dual-source magnetic fields. Using triaxial magnetic field data and rotation angle information collected by magnetic sensors, filtering, candidate position calculation, and fuzzy resolution steps are performed, ultimately outputting a unique positioning result with optimal consistency.

[0051] The magnetic positioning method provided in this application, based on magnetic field sequence feature modeling, introduces auxiliary information by adding an additional magnetic field, which effectively improves the ability to determine multiple solutions. At the same time, the system has a compact structure, supports periodic, low-frequency magnetic field working mode, has strong anti-interference performance, and is suitable for precise positioning tasks in complex spatial environments such as virtual / augmented reality, medical navigation, and robot end-effector positioning.

[0052] The magnetic positioning system and positioning method provided in this application will be described in detail below.

[0053] A space positioning system based on dual rotating permanent magnets includes a dual-axis rotating magnetic field generating unit and a single-axis rotating permanent magnet 12 on the revolution axis. It is coupled with a solution algorithm to eliminate ambiguity in magnetic field positioning, achieving high-precision analysis of the target position in three-dimensional space. By combining the dual-axis rotating magnetic field with the single-axis rotating permanent magnet 12 on the revolution axis, the system alters the magnetic field distribution characteristics, resulting in higher distinguishability of magnetic field signals generated at different spatial locations, thereby improving the reliability and accuracy of positioning calculations. The system includes:

[0054] The magnetic field generator 1 consists of a support component and a drive component. The support component defines a first rotation axis and houses a first permanent magnet. The drive component drives the first permanent magnet to rotate simultaneously around the first rotation axis and a second rotation axis intersecting with it, forming a dual-axis rotating time-varying magnetic field. A single-axis rotating permanent magnet 12 is disposed on the second rotation axis. This permanent magnet rotates around its own axis, generating an additional time-varying magnetic field, which superimposes on the dual-axis rotating magnetic field, changing the temporal characteristics of the magnetic field vector.

[0055] The dual-axis rotating permanent magnet 11 is configured to rotate around two mutually perpendicular axes to generate a spatially non-uniformly varying magnetic field; the dual-axis rotating permanent magnet 11 rotates around two mutually perpendicular and non-coplanar rotation axes to form a non-periodic magnetic field.

[0056] The single-axis rotating permanent magnet 12 has its rotation axis set to be coaxial or coupled with a certain axis of the first permanent magnet rotation structure, and can rotate independently around its own axis to superimpose additional time-varying magnetic field signals; the rotation axis of the single-axis rotating permanent magnet coincides with one of the rotation axes of the first permanent magnet of the dual-axis rotating permanent magnet 11, and the magnetic field generated is used to modulate the frequency domain characteristics of the original magnetic field.

[0057] The single-axis rotating permanent magnet 12 is used to introduce specific frequency and phase modulation information, thereby destroying the symmetry of the magnetic field distribution, improving the uniqueness of the magnetic vector in space, enhancing the distinguishability of magnetic response sequences between different locations, and effectively eliminating the mirror ambiguity caused by symmetry.

[0058] An angle encoder, configured on the permanent magnet, is used to collect the angle information and magnetic moment direction of each rotating magnet in real time; the angle encoder includes a capacitive or photoelectric rotary encoder with a resolution of not less than 0.1°.

[0059] Magnetic field sensor 2 is used to measure the three-dimensional magnetic field component data at the target spatial location; the magnetic field sensor 2 adopts the AMR or TMR type, has triaxial measurement capability, and the measurement range covers ±1000µT.

[0060] The control unit 5 is used to drive the rotation of the permanent magnet and synchronously collect magnetic field and angle information; the control unit 5, the magnetic field sensor 2, and the angle encoder are synchronized by timestamp to ensure that the data corresponds one-to-one.

[0061] The following describes a specific implementation method for system deployment.

[0062] The system includes a magnetic field generator 1, a controller, a magnetic field sensor 2, an angle encoder, a computing unit 4, and a power supply and drive module. The magnetic field generator 1 is driven by a stepper motor and carries a dual-axis rotating magnet and an additional single-axis rotating permanent magnet module 12 to generate a composite low-frequency magnetic field signal. The controller is responsible for driving the magnet rotation, controlling the measurement process, and simultaneously acquiring signals from the magnetic field sensor 2. The magnetic field sensor 2 measures the three-axis magnetic field vector, while the angle encoder records the magnet's angular position information. The computing unit 4 processes the data in real time, calculates the target position and attitude, and outputs a six-degree-of-freedom prediction result.

[0063] The system mainly includes the following parts:

[0064] Magnetic field generator 1: Built into base station module 6, it generates a time-varying magnetic field signal that can simulate geomagnetic disturbances and enhance the solvability of the positioning system. This magnetic field is a low-frequency composite magnetic field, which can be superimposed on the natural geomagnetic field and detected by the receiver.

[0065] Control Unit 5: Also integrated in Base Station Module 6, it is responsible for driving and controlling the magnetic field generator 1, coordinating the rotation rhythm of the magnet, triggering the measurement process, and transmitting data synchronously with the computing system through the interface.

[0066] Magnetic sensor: Embedded inside the object under test 3, used to collect external magnetic field vector data. This sensor has the ability to measure three-axis magnetic field components and can operate stably in environments with varying magnetic fields and geomagnetic fields.

[0067] Object 3 under test: This is the target requiring real-time localization, and it contains a magnetic sensor. The object's position and orientation are described using Cartesian coordinates and Euler angles, denoted as (…). ).

[0068] Variable magnetic field: dynamically generated by magnetic field generator 1, covering a preset three-dimensional spatial area, and forming a combined field with the natural geomagnetic field to enhance positioning accuracy and spatial information identification.

[0069] Computer system: Receives data from magnetic sensors, communicates through interface modules, calls the internal processor to perform data parsing tasks, runs the positioning program to model and calculate the collected magnetic field data, and outputs the six-degree-of-freedom spatial information of the target object.

[0070] Base station module 6: Integrating magnetic field generator 1 and control unit 5, it is the core of the system's magnetic source and control logic. Its structural design features excellent electromagnetic shielding performance and high-frequency response characteristics.

[0071] In actual operation, the magnetic field generator 1 generates a changing magnetic field according to a preset control law. The magnetic sensor collects the magnetic field vector after coupling with the Earth's magnetic field in real time and transmits it to the computing system via wired or wireless means. The latter is based on a known magnetic source motion model and sensor position model, combined with the magnetic moment direction. Orbital radius Displacement between sensor and magnetic source Parameters such as these are used to calculate the spatial position and orientation of the target object in the global coordinate system using an inversion algorithm.

[0072] Calculation unit 4 includes:

[0073] The magnetic field modeling module is used to construct a theoretical model of a dual-source composite magnetic field. The magnetic field modeling module constructs a mathematical model of the dual-source magnetic field based on the magnetic dipole theory and calibrates the model parameters using experimental calibration.

[0074] The data filtering module is used to filter out background noise and non-target frequency magnetic signals; the data filtering module adopts a bandpass filter with a center frequency matching the rotation frequency of the permanent magnet, and is used to remove geomagnetic DC interference and high-frequency noise.

[0075] The initial value inversion module is used to solve for the initial estimate of the target position based on the magnetic dipole model;

[0076] The fuzzy solution elimination module, based on a residual consistency judgment strategy under dual magnetic field sources, combines the composite magnetic field characteristics of the dual-axis rotating permanent magnet 11 and the single-axis rotating permanent magnet 12. It calculates the residual consistency of different solutions in the candidate solution set under the dual magnetic field response, eliminating solutions that do not conform to the coupling law of the dual magnetic field response. The fuzzy solution elimination module constructs a residual function under dual magnetic field sources, calculates the sum of errors for each candidate solution, and selects the solution with the minimum residual as the final positioning result.

[0077] The system further introduces time series dynamic consistency judgment and nonlinear optimization algorithm to select the solution with the smallest residual and the strongest consistency across time in the multi-frame magnetic field measurement sequence as the final unique localization solution, thereby effectively avoiding the problem of multiple solutions caused by the geometric symmetry of the magnetic field.

[0078] It further includes a nonlinear optimization module that uses the Levenberg-Marquardt algorithm to refine the initial value with a six-degree-of-freedom solution.

[0079] The positioning system supports a wireless communication module, which transmits the calculation results to the terminal device in real time via Wi-Fi. The overall power consumption of the system is less than 500mW, making it suitable for portable positioning devices.

[0080] The magnetic positioning method of the present invention includes the following steps:

[0081] Magnetic field generation: The dual-axis rotating permanent magnet 11 and the single-axis rotating permanent magnet 12 are controlled to work synchronously to generate a composite time-varying magnetic field, ensuring that the rich characteristics of the spatial magnetic field vector are obtained within one magnetic field cycle.

[0082] Data acquisition and preprocessing: During the sampling period, magnetic field sensor 2 synchronously acquires three components of magnetic field data and records the angle information of each rotating unit; a bandpass filter is used to eliminate DC components and high-frequency noise.

[0083] Preliminary position calculation: The measured magnetic field data is compared with the magnetic field model, and the candidate position set of the target is calculated using the inversion algorithm, which is based on the inverse equation of the magnetic dipole model. The candidate position set contains several initial estimates.

[0084] Fuzzy Solution Judgment and Elimination: In traditional dual-axis rotational positioning, similar magnetic field vector sequences may be generated at different spatial locations, leading to multiple iterative solutions (fuzzy solutions). This invention utilizes an additional magnetic field sequence introduced by an additional single-axis rotating permanent magnet 12. The matching degree of this additional magnetic field sequence is superimposed during the solution calculation to eliminate solutions that do not conform to the joint temporal characteristics of the dual magnetic fields. By comparing the residuals of the theoretical magnetic field response and the measured response of the candidate solutions under the two sets of magnetic field sources, the unique solution with the smallest residual and the highest consistency is selected.

[0085] Results Output and Updates: Output unique localization results and perform smoothing and dynamic tracking based on the temporal correlation of continuous measurements.

[0086] The magnetic positioning system provided by this invention is mainly used in high-precision positioning scenarios in a small three-dimensional space, and is applicable to, but not limited to, medical navigation, robot end-effector tracking, special training systems, etc.

[0087] Specific positioning methods are as follows Figure 1 The magnetic positioning system shown is used as an example for explanation.

[0088] like Figure 2 As shown, the magnetic field generating structure device of the present invention includes:

[0089] Dual-axis rotating permanent magnet 11: used to achieve compound rotational motion around two perpendicular rotation axes (X-axis and Y-axis) to form the first time-varying magnetic field;

[0090] Stepper motor (drive motor 14) and bearing assembly: drive the dual-axis magnet to rotate, provide stable power, and ensure controllable rotation frequency;

[0091] Single-axis rotating permanent magnet 12: Installed above or on the side of the dual-axis magnet device, it generates a second additional magnetic field by rotating independently along the axis, which, together with the main magnetic field source, improves the uniqueness of the solution.

[0092] Bevel gear drive structure: used to transmit power between different rotating shafts to achieve multi-axis linkage;

[0093] Fixed connecting shaft 18: As the core structure of the rotating shaft, it connects each magnet to the motor assembly;

[0094] Structural fasteners and mounting base 13: provide stable support for the device, integrate various mechanical components, and ensure system rigidity and precision.

[0095] The specific connection method includes a first bevel gear 15 provided on the mounting base 13, the output shaft of the drive motor 14 passing through the mounting base 13 and the first bevel gear 15 and extending above the first bevel gear 15, the dual-axis rotating permanent magnet 11 being connected to the second bevel gear 16 and the third bevel gear 17 respectively, the second bevel gear 16 and the third bevel gear 17 being rotatably connected to the fixed connecting shaft 18 respectively, the fixed connecting shaft 18 being connected to the output shaft in an axially perpendicular manner through a bushing, and the single-axis rotating permanent magnet 12 being connected to the top of the output shaft.

[0096] like Figure 3 As shown, the exemplary mathematical model diagram of the magnetic positioning device illustrates the geometric and motion relationships of the present invention in a space magnetic field positioning system. This system includes the following main components:

[0097] Rotating permanent magnet: its magnetic moment direction is represented by It indicates that it is installed on a rotating structure, and its revolution angular velocity is... With rotational angular velocity Under the combined action of these factors, a stable space magnetic field excitation is achieved. The magnetic field generated constitutes the main excitation signal source.

[0098] Revolutionary trajectory 7: This is the path of the permanent magnet's circular motion around its central axis. Figure 3 The path is represented by a dashed line. The radius of this path is set as a known quantity. With the center of the trajectory set as the origin, a right-handed Cartesian coordinate system is established. ), used as a global reference coordinate system.

[0099] Magnetic sensor: Installed in the object under test 3, it receives the changing magnetic field emitted by the rotating magnet. The triaxial magnetic field data recorded by this sensor will serve as input for attitude and position inversion. The spatial distance between the sensor and the permanent magnet is denoted as... Its position and orientation in the global coordinate system are represented by a six-dimensional vector. ) describe.

[0100] Relationship between magnetic moment direction (m) and rotation: In addition to its revolution around the sun, the permanent magnet also rotates about its own vertical axis, the direction of which is indicated by the marked double-headed arrow, and the angular velocity is... This is used to form more complex time-varying magnetic field structures and improve the uniqueness of system solutions.

[0101] The algorithm flowchart of this invention is as follows: Figure 4 As shown. The magnetic positioning method proposed in this embodiment is based on the magnetic field signal constructed by the dual-axis rotating magnet 11. By analyzing the magnetic field observation data at multiple time points, the spatial three-dimensional position and attitude parameters of the target sensor are deduced.

[0102] Exemplary mathematical models of magnetic positioning systems are as follows: Figure 3 As shown, it includes a rotating magnet located on a planar circular track. and the auxiliary magnet located at the center of the rotation axis. Its magnetic moment direction can rotate synchronously or asynchronously. The sensor is placed at any point in the far-field space. The signal is calculated after sensing the superimposed magnetic field of the two magnets.

[0103] The vectors from the two magnets to the sensor are respectively: and Due to magnet Fixed at the axial height ,according to Figure 3 The relationship between the right triangles can be obtained as follows: and ,in .

[0104] I. Magnetic field analytical modeling.

[0105] Assume a magnet , with vector The included angles are respectively Then the magnitude of the magnetic field strength sensed by the sensor is:

[0106] (1)

[0107] In the next moment The two magnets rotated respectively The corresponding magnetic field modulus is: (2)

[0108] To eliminate distance The influence of angle calculation is addressed by introducing a geometric ratio parameter: (3)

[0109] After substituting, the rewritten equations (2) and (3) are as follows:

[0110] (4)

[0111] (5)

[0112] To eliminate the scaling factor Construct a normalized angle function:

[0113] (6)

[0114] This function depends only on the angle variable. Rotation angle Magnetic moment ratio Height ratio parameters Numerical solution The unique solution is used as the initial value for localization. At a certain angle θ, the angle we are looking for is the one where the ratio of the model's predicted value to the measured value is 1. .

[0115] Analytical expansion of biaxial and triaxial components:

[0116] According to the expansion form of a magnetic dipole, the magnetic field components satisfy the following formula:

[0117] (7)

[0118] (8)

[0119] (9)

[0120] in: Used as an auxiliary variable to simplify calculation expressions.

[0121] The initial estimated value can be obtained by using equations (7) to (9), which can be used as the starting point for subsequent optimization.

[0122] III. Environmental interference and nonlinear optimization.

[0123] Actual measured value Includes geomagnetic interference Sensor rotation disturbance ,therefore:

[0124] (10)

[0125] To eliminate interference signals in non-target frequency bands, the system performs bandpass filtering on the raw data, matching the center frequency to the magnet's rotation frequency. To preserve the main signal, after filtering, an error function is constructed starting from the initial value:

[0126] (11)

[0127] in These are the six-DOF pose parameters to be estimated. The estimated solution is output after minimizing the objective function.

[0128] IV. Elimination of fuzzy solutions and selection of unique solutions.

[0129] Because the magnetic field may have mirror-image ambiguity, the system introduces a dual-source simultaneous comparison mechanism. The theoretical responses of candidate solutions under biaxial magnet and additional uniaxial magnet fields are calculated separately, and their residuals are compared.

[0130] (12)

[0131] Select The smallest value is used as the final solution to ensure uniqueness.

[0132] In summary, the magnetic positioning system provided in this application constructs a composite magnetic signal based on a dual-axis plus a single-axis rotating magnetic field. Combined with analytical modeling and nonlinear optimization algorithms, it achieves high-precision positioning and dynamic tracking of spatial targets. The system has a simple and compact structure and high computational efficiency, avoiding the problems of high-frequency interference and low-frequency algorithm difficulty inherent in traditional electromagnetic positioning. By adding a single-axis rotating permanent magnet to the revolution axis to alter the temporal characteristics of the magnetic field, the magnetic field vector sequences corresponding to different spatial locations are significantly differentiated, reducing the probability of multiple solutions. Through joint matching of residuals using dual magnetic field sources, fuzzy solutions are rapidly eliminated, improving positioning uniqueness and computational efficiency. The system maintains a compact design and low power consumption, making it suitable for high-precision scenarios such as virtual / augmented reality, medical navigation, and robot positioning.

[0133] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0134] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments of this application.

[0135] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for system or system embodiments, since they are basically similar to method embodiments, the description is relatively simple, and relevant parts can be referred to the descriptions in the method embodiments. The systems and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0136] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A magnetic positioning system, characterized in that, include: A magnetic field generator includes a dual-axis rotating permanent magnet and a single-axis rotating permanent magnet. The dual-axis rotating permanent magnet is configured to rotate around two mutually perpendicular and non-coplanar axes to generate a spatially non-uniformly varying time-varying magnetic field. The rotation axis of the single-axis rotating permanent magnet coincides with one of the rotation axes of the dual-axis rotating permanent magnet and rotates independently around its own axis to generate an additional magnetic field. This additional magnetic field is used to superimpose with the time-varying magnetic field to disrupt the symmetry of the magnetic field distribution and obtain a composite time-varying magnetic field. A magnetic field sensor is disposed inside the object to be measured, and the magnetic field sensor is used to measure the three-dimensional magnetic field component data at the target spatial location. A computing unit is configured to execute a positioning method, the positioning method comprising: After confirming that the dual-axis rotating permanent magnet and the single-axis rotating permanent magnet work synchronously to generate the composite time-varying magnetic field; acquire the three-component magnetic field data synchronously collected by the magnetic field sensor within the sampling period, and acquire the angle information of the dual-axis rotating permanent magnet and the single-axis rotating permanent magnet; The candidate location set of the target is calculated based on the inverse equation of the magnetic dipole model using the three components of the magnetic field and the angle information. The additional magnetic field sequence introduced by the single-axis rotating permanent magnet is used to superimpose the matching degree judgment of the additional magnetic field sequence in the solution, so as to eliminate the solutions that do not conform to the joint timing characteristics of the two magnetic fields; by comparing the residuals of the theoretical magnetic field response and the measured response of several initial estimates in the candidate location set under the two sets of magnetic field sources through the residual function, the unique solution with the smallest residual and the highest consistency is selected as the unique positioning result. The unique positioning result is output, and smoothing and dynamic tracking are performed based on the temporal correlation of continuous measurements. The magnetic field generator further includes a mounting base and a drive motor. A first bevel gear is provided on the mounting base. The output shaft of the drive motor extends through the mounting base and the first bevel gear to the top of the first bevel gear. The dual-axis rotating permanent magnet is connected to the second bevel gear and the third bevel gear respectively. The second bevel gear and the third bevel gear are rotatably connected to a fixed connecting shaft. The fixed connecting shaft is connected to the output shaft in an axially perpendicular manner through a bushing. The single-axis rotating permanent magnet is connected to the top of the output shaft.

2. The magnetic positioning system according to claim 1, characterized in that, The residual function is expressed by the following equation: In the formula: Indicates the residual comparison value. middle This represents a magnetic field vector, where the superscript indicates the corresponding magnetic field source, and the subscript indicates the magnetic field vector. This represents the theoretical value. This represents the measured value.

3. The magnetic positioning system according to claim 1, characterized in that, The initial estimate is obtained by inverse solving the following equation: In the formula: , , These represent the three-axis components of the magnetic field. Represents the permeability of free space. , , This represents the vector from the dual-axis rotating permanent magnet to the magnetic field sensor. This represents the vector from the single-axis rotating permanent magnet to the magnetic field sensor. Represents auxiliary variables. This indicates the axial height of a single-axis rotating permanent magnet.

4. The magnetic positioning system according to claim 3, characterized in that, By using time series dynamic consistency judgment and nonlinear optimization algorithm, the unique solution with the smallest residual and the highest consistency is selected as the unique localization result.

5. The magnetic positioning system according to claim 4, characterized in that, The nonlinear optimization algorithm includes The algorithm, the The algorithm is used to refine the initial estimate using a six-degree-of-freedom solution.

6. The magnetic positioning system according to claim 1, characterized in that, Both the dual-axis rotating permanent magnet and the single-axis rotating permanent magnet are connected to an angle encoder, which is used to acquire the angle information.

7. The magnetic positioning system according to claim 6, characterized in that, It also includes a control unit, which drives the rotation of the permanent magnet and synchronously collects magnetic field and angle information; the control unit, the magnetic field sensor and the angle encoder are time-synchronized using a timestamp synchronization method.

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