Magnetic field generator and position detection system

Abstract

The invention discloses a magnetic field generator and a position detection system, relates to the technical field of electromagnetic positioning and motion tracking, realizes three-dimensional space scanning of a magnetic field, and compared with a permanent magnet scheme, the magnetic field intensity of the generator can be dynamically adjusted to adapt to different detection distance requirements. The magnetic field can be completely closed through program control, and interference to surrounding equipment is avoided. The soft magnetic material core is adopted, the demagnetization risk of the permanent magnet does not exist, the service life is longer, the generated magnetic field waveform can be flexibly changed through programming, and various positioning algorithms are supported.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electromagnetic positioning and motion tracking, and particularly relates to a magnetic field generator and a position detection system based on electromagnets and electric slip rings. BACKGROUND

[0002] Magnetic positioning systems are widely used in virtual reality, motion capture and instrument tracking due to their advantages of no line-of-sight interference, high response sensitivity and small size. In these applications, accurate and real-time positioning is crucial, and six-degree-of-freedom pose data in three-dimensional space is obtained to assist in reconstructing the motion process of the target object.

[0003] Existing magnetic positioning technologies, such as patent CN112219089B, use permanent magnets to generate time-varying magnetic fields through complex double-axis rotation. Such systems take advantage of the fact that permanent magnets can generate stable magnetic fields without external power supply, but their magnetic field strength is fixed and cannot be adjusted, and the magnetic moment may decay over time or with changes in environmental temperature. In addition, the mechanical transmission of rotating parts is subject to wear, and if the rotating parts need to be powered or signals need to be transmitted, traditional electric slip rings have problems such as contact wear, limited service life, and easy noise interference. SUMMARY

[0004] In view of the above problems, the present application provides a magnetic field generator and a position detection system for overcoming the above problems or at least partially solving the above problems. A position detection system and a magnetic field generator are provided, which have dynamically adjustable magnetic field strength, flexible control, stable and reliable power supply and signal transmission, and no contact wear.

[0005] The present application provides the following solutions: A magnetic field generator, comprising: a bearing assembly defining a first rotation axis; a magnetic field generating assembly connected to an upper portion of the bearing assembly; the magnetic field generating assembly comprises an electromagnet assembly and a non-magnetic counterweight, the electromagnet assembly has a center and is configured to generate a dipole magnetic field after being energized; a drive assembly connected to the bearing assembly and configured to act on the bearing assembly to simultaneously rotate the electromagnet assembly around the first rotation axis and revolve the electromagnet assembly and the non-magnetic counterweight around a second rotation axis; the second rotation axis intersects the first rotation axis at a point of intersection offset from the center of the electromagnet assembly; At least two electric slip rings, at least two of the electric slip rings are arranged at the connection between the driving assembly and the bearing assembly or the rotating joint of the bearing assembly, the static part of the electric slip ring receives external electric energy and control signals through wired mode; the rotating part of the electric slip ring is electrically connected with the electromagnet assembly, for providing continuous electric energy supply and transmitting control signals to the electromagnet assembly in the rotating state.

[0006] Preferably, the bearing assembly comprises a support, the at least two electric slip rings comprise a first electric slip ring and a second electric slip ring; the driving assembly comprises a first hollow shaft motor and a second hollow shaft motor, the stator of the first hollow shaft motor is fixedly connected with the upper part of the support, the electromagnet assembly is connected with the rotor of the first hollow shaft motor; the rotor of the second hollow shaft motor is connected with the support, the stator of the second hollow shaft motor is arranged on the base; the first electric slip ring and the second electric slip ring are respectively and correspondingly arranged in the interiors of the first hollow shaft motor and the second hollow shaft motor; the static part of the first electric slip ring is connected with the rotating part of the second electric slip ring in wired mode, the rotating part of the first electric slip ring is connected with the magnetic field generating assembly, and the static part of the second electric slip ring is used for receiving external electric energy and control signals and transmitting the same to the magnetic field generating assembly.

[0007] Preferably, the lower part of the support is provided with an upper circuit board, the base is provided with a lower circuit board, the static part of the first electric slip ring and the rotating part of the second electric slip ring are connected with the upper circuit board in wired mode, the static part of the second electric slip ring is connected with the lower circuit board in wired mode, and the lower circuit board is connected with an external power line and a data line.

[0008] Preferably, the control of the magnetic field intensity is realized through the lower circuit board, and the tracking and regulation of the biaxial motion trajectory are realized through encoder feedback.

[0009] Preferably, the electric slip ring comprises a slip ring rotating shaft, a slip ring rotor, a slip ring stator and a rotation stopping piece.

[0010] Preferably, the electromagnet assembly comprises a coil framework, a wire wound on the coil framework and a soft magnetic material core; the material of the soft magnetic material core comprises any one of ferrite, silicon steel, permalloy, amorphous alloy and nanocrystalline alloy.

[0011] A position detection system, comprising: a base station, the base station being provided with the above-mentioned magnetic field generator and a first controller; a to-be-measured object, the to-be-measured object being provided with a magnetic field sensor and a second controller; A computer system connected to the first controller and the second controller; The magnetic field generator is configured to generate a time-varying magnetic field; The magnetic field sensor is configured to collect magnetic field intensity data of a location; The second controller is configured to transmit the magnetic field intensity data to the computer system; The first controller is configured to transmit motion state data of the magnetic field generator to the computer system; The computer system is configured to use an optimization algorithm to solve the six-degree-of-freedom pose of the object based on the magnetic field intensity data and the motion state data.

[0012] Preferably, the optimization algorithm includes An algorithm.

[0013] Preferably, any point in the solution space At any time The exact expression of the magnetic field intensity felt is:

[0014] In the formula: μ0 represents the vacuum permeability, m represents the magnetic dipole moment, r represents the position vector, n represents the unit vector.

[0015] Preferably, the optimization algorithm minimizes the magnetic field intensity difference through the following objective function:

[0016] In the formula: B represents the magnetic field intensity, r represents the position vector, B represents the measured magnetic field intensity. According to the specific embodiments provided by the present application, the following technical effects are disclosed: The magnetic field generator and the position detection system provided by the embodiments of the present application realize three-dimensional space scanning of the magnetic field. Compared with the permanent magnet scheme, the magnetic field intensity of the generator can be dynamically adjusted to adapt to different detection distance requirements. The magnetic field can be completely turned off through program control to avoid interference with surrounding equipment. The soft magnetic material core is used, and there is no risk of demagnetization of the permanent magnet, so the service life is longer. The generated magnetic field waveform can be flexibly changed through programming, and multiple positioning algorithms are supported.

[0017] Of course, implementing any product of the present application does not necessarily require all the advantages described above. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to make the technical solutions in the embodiments of the present application or the prior art clearer, the accompanying drawings needed in the embodiments will be briefly introduced. Obviously, the accompanying drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those of ordinary skill in the art without any creative effort based on these drawings.

[0019] Figure 1 is a structural schematic diagram of a magnetic field generator provided by an embodiment of the present application; Figure 2 is a three-dimensional structural schematic diagram of a magnetic field generator provided by an embodiment of the present application; Figure 3 is a schematic diagram of an electric slip ring provided by an embodiment of the present application; Figure 4 is a whole schematic diagram of a position detection system provided by an embodiment of the present application; Figure 5 is a principle diagram of a magnetic field rotating generator provided by an embodiment of the present application.

[0020] In the figure: base station 1, magnetic field generator 2, bearing assembly 21, electromagnet assembly 22, non-magnetic counterweight 23, first electric slip ring 24, second electric slip ring 25, first hollow shaft motor 26, stator 2601 of the first hollow shaft motor, rotor 2602 of the first hollow shaft motor, second hollow shaft motor 27, stator 2701 of the second hollow shaft motor, rotor 2702 of the second hollow shaft motor, base 28, upper circuit board 29, lower circuit board 210, external power supply line and data line 211, first controller 3, object to be measured 4, magnetic field sensor 5, second controller 6, computer system 7, slip ring rotating shaft 81, slip ring rotor 82, slip ring stator 83, rotation stopping piece 84. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present application.

[0022] Reference is made to Figure 1 A magnetic field generator provided by an embodiment of the present application is shown in Figure 1 The method can include: The bearing assembly 21 defines a first rotation axis 310. A magnetic field generating assembly is connected to the upper part of the bearing assembly 21; the magnetic field generating assembly comprises an electromagnet assembly 22 having a center and configured to generate a dipole magnetic field after being energized, and a non-magnetic counterweight 23; A driving assembly is connected to the bearing assembly 21 and configured to act on the bearing assembly 21 to simultaneously make the electromagnet assembly 22 rotate around a first rotation axis 310, and make the electromagnet assembly 22 and the non-magnetic counterweight 23 revolve around a second rotation axis 311; the second rotation axis 311 intersects the first rotation axis at a point of intersection offset from the center of the electromagnet assembly 22; At least two electric slip rings are provided at the connection between the driving assembly and the bearing assembly 21 or the rotation joint of the bearing assembly 21; the stationary part of the electric slip ring receives external electrical energy and control signals in a wired manner; the rotating part of the electric slip ring is electrically connected to the electromagnet assembly 22 for providing continuous electrical energy supply and transmitting control signals to the electromagnet assembly 22 in a rotating state.

[0023] The magnetic field generator provided by the embodiment of the present application uses an electric slip ring as an adapter for electrical energy and signal transmission, which can realize efficient and stable transmission of electrical energy and signals without affecting the normal rotation of the rotating part. In specific implementation, the bearing assembly 21 comprises a support, and the at least two electric slip rings comprise a first electric slip ring 24 and a second electric slip ring 25; the driving assembly comprises a first hollow shaft motor 26 and a second hollow shaft motor 27; the stator 2601 of the first hollow shaft motor 26 is fixedly connected to the upper part of the support, and the electromagnet assembly 22 is connected to the rotor 2602 of the first hollow shaft motor 26; the rotor 2702 of the second hollow shaft motor 27 is connected to the support, and the stator 2701 of the second hollow shaft motor 27 is arranged on a base 28; the first electric slip ring 24 and the second electric slip ring 25 are respectively and correspondingly arranged in the interiors of the first hollow shaft motor 26 and the second hollow shaft motor 27; the stationary part of the first electric slip ring 24 is connected to the rotating part of the second electric slip ring 25 in a wired manner, the rotating part of the first electric slip ring 24 is connected to the magnetic field generating assembly, and the stationary part of the second electric slip ring 25 is used to receive external electrical energy and control signals and transmit them to the electromagnet assembly.

[0024] To further facilitate connection, this embodiment of the invention can provide an upper circuit board 29 disposed below the bracket, a lower circuit board 210 disposed inside the base 28, the stationary portion of the first slip ring 24 and the rotating portion of the second slip ring 25 being wired to the upper circuit board 29, the stationary portion of the second slip ring 25 being wired to the lower circuit board 210, and the lower circuit board 210 being connected to an external power supply line and a data line 211.

[0025] The magnetic field strength is controlled by the lower circuit board 210; the dual-axis motion trajectory is tracked and controlled by encoder feedback.

[0026] The electric slip ring includes a slip ring rotating shaft 81, a slip ring rotor 82, a slip ring stator 83, and an anti-rotation plate 84. The electromagnet assembly 22 includes a coil frame, wires wound on the coil frame, and a soft magnetic material core; the material of the soft magnetic material core includes any one of ferrite, silicon steel, permalloy, amorphous alloy, and nanocrystalline alloy.

[0027] The magnetic field generator provided by this invention will be described in detail below.

[0028] Magnetic field generator 2, configured to generate a time-varying magnetic field, includes: The carrier component 21 defines a first rotation axis 310 and includes an electromagnet component 22 having a center and being configured to generate a dipole magnetic field when energized. A drive assembly is connected to the support assembly 21 and configured to act on the support assembly 21 to cause the electromagnet assembly 22 to rotate simultaneously about the first rotation axis 310 and the second rotation axis 311, the second rotation axis 311 intersecting the first rotation axis 310 at a point off-center from the center of the electromagnet assembly 22. An electric slip ring is disposed at the connection between the drive assembly and the support assembly 21 or at the rotating joint of the support assembly 21. The stationary part of the electric slip ring receives external power and control signals via a wired connection, and its rotating part is electrically connected to the electromagnet assembly 22. It is used to provide a continuous power supply to the electromagnet assembly 22 and transmit control signals in the rotating state.

[0029] The electromagnet assembly 22 includes a coil frame, wires wound around it, and a soft magnetic material core.

[0030] In an optional embodiment, the soft magnetic core of the electromagnet assembly 22 can be made of various materials depending on the application scenario, including but not limited to ferrite, silicon steel, permalloy, amorphous alloy, or nanocrystalline alloy. The permeability, saturation magnetization, and coercivity of the soft magnetic core can be selected according to actual needs, which enables the system to adapt to application scenarios with different frequencies and different magnetic field strength requirements, demonstrating its high versatility in core material selection.

[0031] The slip ring is also configured to transmit data signals bidirectionally between the stationary portion and the rotating portion, the data signals including drive control signals for the electromagnet assembly 22 and / or feedback signals from monitoring sensors disposed on the rotating portion.

[0032] The design strategy can employ two motors with different speeds. By selecting different speeds, the magnetic field motion becomes non-repetitive, and the generated magnetic field signal exhibits quasi-periodicity, ensuring that each point in space has a unique magnetic field fingerprint, thereby accurately matching a unique position.

[0033] See Figure 1 The rotor 2702 of the second hollow shaft motor 27 is fixedly mounted on the rotor base 28 via an interference fit, forming the power output core of the horizontal scanning mechanism. This rotor assembly is connected to the system mounting base 28 in a back-to-back mounting configuration using a set of precision angular contact bearings. This configuration can simultaneously withstand radial and axial loads, ensuring the stability and reliability of the rotor under high-speed and long-cycle operating conditions. The rotor 2702 of the second hollow shaft motor 27 can be a permanent magnet synchronous motor (PMSM) or an AC asynchronous motor. Its function is to convert electromagnetic torque into continuous rotational motion around the second rotation axis 311 (revolution axis), providing the basic scanning drive for the system.

[0034] The bracket provided by this invention is formed using a lightweight, high-strength composite material (such as carbon fiber or aluminum alloy) through an autoclave process. Its lower end achieves a keyless connection with the rotor 2702 of the second hollow shaft motor 27 via a high-precision conical surface fit. The upper end has a standardized mounting interface to support the entire vertical scanning mechanism. This bracket undergoes topology optimization design, significantly reducing its inertia while meeting structural rigidity and dynamic balance requirements, thereby reducing system drive power consumption and improving dynamic response performance. Its core functions are to transmit torque, support precision components, and provide internal wiring channels; it is a core load-bearing and transmission structure of the system.

[0035] The second hollow shaft motor 27 adopts a frameless direct-drive design. The stator 2701 of the second hollow shaft motor 27 is fixed to the upper surface of the bracket with a high-stability adhesive. The rotor 2702 of the second hollow shaft motor 27 and the torque output shaft are manufactured using an integrated process, ensuring extremely high structural rigidity and motion accuracy. This type of motor typically belongs to the category of permanent magnet synchronous torque motors, possessing multi-pole pairs and low-speed, high-torque characteristics. It can be used with optical encoders or rotary transformers to achieve arcsecond-level positioning accuracy. Its function is to directly drive the load to perform high-precision rotary motion around the first rotation axis (rotation axis), eliminating transmission chain errors, and is a key actuator for achieving precision scanning.

[0036] Electromagnet assembly 22, serving as the system's magnetic field generating unit, is rigidly connected to the output end of the rotor 2702 of the second hollow shaft motor 27 via a rigid mounting component. Its physical center is offset from the intersection of the system's two axes by a certain distance. This assembly can employ different core materials such as soft magnetic ferrite, amorphous / nanocrystalline alloys, or silicon steel sheets to meet different frequency response and magnetic field strength requirements. Furthermore, it achieves instantaneous start / stop and intensity adjustment of the magnetic field through active current control, completely overcoming the problems of permanent magnet solutions, such as the inability to shut down the magnetic field and its susceptibility to interference with sensitive equipment. Its main function is to generate a dipole magnetic field whose intensity and direction can be dynamically controlled, and this magnetic field forms a complex time-varying distribution in space with the combined motion of the two axes.

[0037] The lower circuit board 210 provides localized drive and control functions for the system, integrating a high-precision current sampling circuit, an isolated communication interface, and a temperature monitoring unit. By employing digital isolation devices and a closed-loop PID control algorithm, precise control and protection of the excitation current of the electromagnet assembly 22 can be achieved. Such circuit boards are commonly embedded control boards based on ARM or DSP architectures. Their function is to receive control commands from the upper level, drive the electromagnet assembly 22 to operate, and provide real-time feedback on its operating status, forming the inner loop (current loop) of the system's control closed loop.

[0038] The system includes multiple types of functional cables: the power cable adopts a twisted-pair shielded structure to improve anti-interference capability and meet industrial environment safety standards; the transmission line integrates CAN bus, analog sampling, and encoder signal lines, and uses color codes for differentiation to improve assembly and maintenance efficiency. These cables are connected in an orderly manner between the fixed and rotating ends through the first slip ring 24, the second slip ring 25, and the internal cable grooves of the bracket, undertaking the power transmission and signal transmission tasks of the entire system.

[0039] When the system is running, the stator 2701 of the second hollow shaft motor 27 generates a rotating magnetic field, which drives the rotor 2702 of the second hollow shaft motor 27 and the upper overall structure to perform uniform or variable speed scanning motion around the second axis (revolution axis). At the same time, the control command is transmitted to the lower circuit board 210 through the first slip ring 24 and the second slip ring 25, which precisely drives the electromagnet assembly 22 to work. The stator 2601 and rotor of the first hollow shaft motor 26 drive the electromagnet assembly 22 to perform high-precision directional rotation around the first axis (rotation axis).

[0040] The system employs a dual closed-loop control strategy: the inner loop is a current loop, which achieves precise control of the magnetic field strength through the lower circuit board 210; the outer loop is a position loop, which uses encoder feedback to accurately track and control the dual-axis motion trajectory. Throughout the process, the first slip ring 24 and the second slip ring 25 continuously provide energy and signal paths to the rotating electromagnet assembly 22, the hollow shaft motor, and the sensors through their sliding contact between the rotor and stator, thereby ensuring the reliability of power supply and communication during 360° continuous rotation.

[0041] Figure 2 The diagram illustrates a three-dimensional structure of an embodiment of the magnetic field generator of the present invention, mainly including a first hollow shaft motor 26, a second hollow shaft motor 27, a rotor 2702 portion of the second hollow shaft motor 27, a first slip ring 24, an electromagnet assembly 22, a second slip ring 25, and a non-magnetic counterweight 23. In this example, the mounting base is fixed to the rotor 2702 of the second hollow shaft motor 27, thereby the second hollow shaft motor 27 drives the first hollow shaft motor 26, the electromagnet assembly 22, and the non-magnetic counterweight 23 above to rotate horizontally; the first hollow shaft motor 26 drives the electromagnet assembly 22 to rotate in a second mode, the direction of which depends on the mounting angle of the first hollow shaft motor 26, for example, the rotation can be vertical (…). Figure 1 (as shown), it can be either horizontal or inclined; Figure 2 The electromagnet assembly 22 is a cylindrical winding with an iron core in the middle, but other winding shapes can also be used. The iron core enhances the magnetic field strength generated by the electromagnet, but it is not a necessary feature. The power supply cable of the electromagnet assembly 22 passes through the first slip ring 24. The non-magnetic counterweight 23 has no shape limit; its purpose is to better balance the rotation, and this part is not a necessary feature of this invention. The first hollow shaft motor 26 and the second hollow shaft motor 27 are hollow shaft motors, allowing the energized wires to be connected to the circuit board module below through the central through hole. Specifically, this is achieved by using the first slip ring 24 and the second slip ring 25 to prevent the cable from twisting during rotation.

[0042] See Figure 3The electric slip ring mentioned in this invention mainly solves the problem of wire entanglement and breakage during rotation. It is mainly composed of components such as slip ring rotating shaft 81, slip ring rotor 82, slip ring stator 83 and anti-rotation plate 84.

[0043] The slip ring rotating shaft 81 serves as the core rotational power carrier of the entire assembly, and it is rotatably supported on the fixed base 28 or bearing of the equipment. One end of the slip ring rotating shaft 81 is used to be fixedly connected to an external rotary actuator (such as a turntable or robotic arm joint) to receive and transmit torque, thereby driving the integrated slip ring rotor 82 on it to rotate synchronously.

[0044] An electric slip ring rotor 82 is fixedly mounted on the slip ring rotating shaft 81 and rotates with it. Multiple concentric conductive rings are precision-machined or embedded on the radial outer circumference of the slip ring rotor 82. An electric slip ring stator 83 is sleeved on the outer circumference of the slip ring rotor 82 and maintains constant sliding contact with the conductive rings on the slip ring rotor 82 through multiple elastic brush assemblies (such as precious metal brushes or graphite brushes) carried internally. The stator itself is designed to be absolutely stationary relative to the equipment housing and is connected to the control system, power supply, and signal processing unit at the fixed end via wires. When the slip ring rotor 82 rotates, current or signals are transmitted unrestricted and continuously from the rotating side to the fixed side through the "conductive ring-brush" sliding contact pair.

[0045] To ensure that the slip ring stator 83 does not undergo circumferential displacement during equipment operation or vibration, the anti-rotation plate 84 is preferably a rigid metal plate. One end of the plate is reliably connected to the end of the slip ring stator 83 via a fastener, while the other end extends and is fitted into a specific positioning groove or mounting hole in the equipment housing. This structure effectively restricts the rotational freedom of the slip ring stator 83, ensuring its absolute static state. This is a crucial guarantee for achieving stable electrical transmission and preventing wire breakage or contact failure due to the rotation of the slip ring stator 83.

[0046] A computer device, electrically connected to the stationary portion of the slip ring, is configured to determine the position of the sensor based on magnetic field measurements obtained by the sensor in the time-varying magnetic field. It then sends control commands to the electromagnet assembly 22 via the wired connection and the slip ring to adjust its operating current. The computer device dynamically adjusts the intensity, direction, or frequency characteristics of the time-varying magnetic field by controlling the magnitude of the current flowing through the electromagnet assembly 22. By controlling the on / off state and magnitude of the current flowing through the electromagnet assembly 22, the computer device actively controls the presence and intensity of the time-varying magnetic field. Therefore, the motor can freely control the rotation switch according to usage requirements, and its speed is adjustable. This active control characteristic allows the system to generate a magnetic field on demand and completely shut it off when no magnetic field is needed, fundamentally avoiding the potential interference and damage risks caused by the continuous static magnetic field in permanent magnet solutions. This makes it particularly suitable for applications sensitive to electromagnetic environments or where human electromagnetic exposure safety needs to be considered (such as medical environments or near wearable devices).

[0047] The magnetic field generator 2 also includes a first encoder mounted on the first hollow shaft motor 26 and a second encoder mounted on the second hollow shaft motor 27, for measuring the rotation angles around the first rotation axis 310 and the second rotation axis 311, respectively; the rotation angle data is transmitted to the computer system 7 as the motion state data.

[0048] In summary, the magnetic field generator provided by this invention enables three-dimensional spatial scanning of the magnetic field. Compared to permanent magnet solutions, the magnetic field strength of this generator can be dynamically adjusted to adapt to different detection distance requirements. The magnetic field can be completely shut off via program control, avoiding interference with surrounding equipment. Using a soft magnetic material core eliminates the risk of demagnetization associated with permanent magnets, resulting in a longer service life. The generated magnetic field waveform can be flexibly changed through programming, supporting multiple positioning algorithms.

[0049] like Figure 4 As shown, the present invention provides a position detection system, comprising: Base station 1, wherein the base station 1 is equipped with the aforementioned magnetic field generator 2 and first controller 3; The object to be tested 4 is equipped with a magnetic field sensor 5 and a second controller 6. Computer system 7, wherein each computer system 7 is connected to the first controller 3 and the second controller 6; The magnetic field generator 2 is used to generate a time-varying magnetic field; The magnetic field sensor 5 is used to collect magnetic field strength data at its location; The second controller 6 is used to transmit the magnetic field strength data to the computer system 7; The first controller 3 is used to transmit the motion state data of the magnetic field generator 2 to the computer system 7; The computer system 7 is used to calculate the six-degree-of-freedom pose of the object based on the magnetic field strength data and the motion state data using an optimization algorithm.

[0050] The optimization algorithm includes algorithm.

[0051] Solve for any point in space At any time The precise expression for the perceived magnetic field strength:

[0052] In the formula: Represents the permeability of free space. Represents magnetic dipole moment, Represents a position vector. Represents a unit vector.

[0053] The optimization algorithm minimizes the difference in magnetic field strength using the following objective function:

[0054] In the formula: Indicates magnetic field strength. Represents a position vector. This indicates the measured magnetic field strength.

[0055] The position detection system provided by this invention will be described in detail below.

[0056] The position detection system provided by this invention includes: Base station 1 includes magnetic field generator 2, base station 1 controller, electric slip ring and power supply module; The magnetic field generator 2 includes a support component 21, a first hollow shaft motor 26, a second hollow shaft motor 27, and an electromagnet assembly 22; The support component 21 defines a first rotation axis 310, and the electromagnet component 22 is mounted on the support component 21; The first hollow shaft motor 26 is connected to the bearing component 21 and is configured to drive the electromagnet component 22 to rotate around the first rotation axis 310. The second hollow shaft motor 27 is configured to drive the bearing assembly 21 and the electromagnet assembly 22 to rotate around the second rotation axis 311, which intersects the first rotation axis 310 at a position away from the center of the electromagnet assembly 22. The stator end of the electric slip ring is connected to the fixed structure of the base station 1, and the rotor end of the electric slip ring is connected to the bearing assembly 21 and rotates around the second rotation axis 311 thereafter. The power supply module is connected to the stator end of the slip ring via a wired connection, and is used to provide electrical energy to the rotating first hollow shaft motor 26 and the electromagnet assembly 22 through the slip ring; The base station 1 controller is communicatively connected to the power supply module, the first hollow shaft motor 26, the second hollow shaft motor 27 and the electric slip ring, and is configured to control the operation of the first hollow shaft motor 26 and the second hollow shaft motor 27 as well as the excitation current of the electromagnet assembly 22; An object equipped with a magnetic field sensor 5 and a sensor controller; Magnetic field sensor 5 is configured to measure time-varying magnetic field strength data generated by magnetic field generator 2; The sensor controller is configured to acquire the magnetic field strength data and transmit it externally; Computer system 7 is communicatively connected to base station 1 controller and the sensor controller; The computer system 7 is configured to receive magnetic field strength data from the magnetic field sensor 5 and motion state data from the first hollow shaft motor 26 and the second hollow shaft motor 27 of the base station 1 controller, and calculate the six-degree-of-freedom pose of the object relative to the base station 1 based on the magnetic field strength data and the motion state data through an optimization algorithm.

[0057] Computer system 7 dynamically controls the intensity and mode of the time-varying magnetic field by adjusting the current parameters output from the base station 1 controller to the electromagnet assembly 22. The optimized algorithm is... algorithm.

[0058] See Figure 5 Magnetic dipole moment Its direction and the position of its center point change drastically over time. This change in direction is due to its simultaneous participation in both rotation and revolution. We mathematically describe this composite motion using a rotation matrix. Its direction is initially around... The axis rotates by one angle Then follow the support The axis revolves at an angle Its rotation matrix is:

[0059] The change in the position of its center point is caused only by its revolution. Initial offset vector As the entire support structure rotates When the axis rotates, its trajectory is a circle. Therefore, the direction of the variable dipole moment is:

[0060] Therefore, the location of its time-varying source point is:

[0061] By substituting the above equation into the general field strength formula for a magnetic dipole, the solution can be obtained for any point in space. At any time The precise expression for the perceived magnetic field strength:

[0062] Combining quaternion rotation matrices:

[0063] Minimize the difference in magnetic field strength using the objective function:

[0064] Solve for the position and attitude quaternions: Location

[0065] attitude

[0066] Then use The algorithm is optimized so that it can quickly approach the local optimum during the solution process, and by adjusting the damping factor, it provides a good balance between convergence speed and stability, and finally outputs a six-degree-of-freedom pose.

[0067] This design is particularly suitable for applications with stringent electromagnetic environment requirements, such as medical equipment and precision instruments, providing unprecedented flexibility and safety.

[0068] The detection methods used by this system in specific applications include: First, a time-varying magnetic field is generated by operating the magnetic field generator 2; wherein the rotating electromagnet assembly 22 is powered by wire and a control signal is transmitted through the slip ring. The magnetic field strength data at the location of the object is collected by the magnetic field sensor 5. The magnetic field strength data is transmitted to the computer system 7 via the sensor controller; The motion status data of the magnetic field generator 2 is transmitted to the computer system 7 via the base station 1 controller; At computer system 7, magnetic field measurements obtained by a sensor in the time-varying magnetic field are received; and through the operation of computer system 7, the position of the sensor is determined based on the magnetic field measurements, and the current of the electromagnet assembly 22 is adjusted via a wired connection and an electric slip ring. Finally, through the operation of computer system 7, based on the magnetic field strength data and the motion state data, the six-degree-of-freedom pose of the object is calculated using an optimization algorithm.

[0069] The computer system 7 can also control the on / off state of the current in the electromagnet assembly 22 to achieve active start / stop control of the magnetic field, thereby eliminating the generation of the magnetic field during non-working periods, enhancing system safety and reducing energy consumption.

[0070] In summary, the position detection system provided in this application uses an electromagnet instead of a traditional permanent magnet in its magnetic field generator. A first hollow shaft motor and a second hollow shaft motor drive the electromagnet to rotate in a composite manner around mutually orthogonal first and second rotation axes, generating a complex time-varying magnetic field. Crucially, this invention employs an electric slip ring as the core power supply and signal transmission component. Its stator is connected to an external power source via a wired connection, while the rotor rotates along the second rotation axis, providing a continuous and stable power supply to the rotating first hollow shaft motor and electromagnet. This solves the power limitations of wireless power supply and the problem of cable entanglement in rotating components. The computer system calculates the six-degree-of-freedom pose information of the field sensor based on magnetic field data collected by the magnetic field sensor and angle data obtained by the encoder through an optimized algorithm. This invention achieves dynamic controllability of magnetic field strength and mode, and has advantages such as reliable power supply, high positioning accuracy, and strong anti-interference capability.

[0071] 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.

[0072] 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.

[0073] The embodiments in this specification are described in a progressive manner. For systems or system embodiments, since they are fundamentally similar to method embodiments, the descriptions are relatively simple; relevant details can be found in the descriptions of 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. 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.

[0074] 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 field generator, characterized in that, include: A support assembly, the support assembly defining a first rotation axis; A magnetic field generating component is connected to the upper part of the supporting component; the magnetic field generating component includes an electromagnet component and a non-magnetic counterweight, the electromagnet component having a center and being configured to generate a dipole magnetic field when energized; A drive assembly is connected to the support assembly and configured to act on the support assembly to cause the electromagnet assembly to simultaneously rotate about a first rotation axis and to cause the electromagnet assembly and the non-magnetic counterweight to revolve about a second rotation axis; the second rotation axis intersects the first rotation axis at a point off-center from the center of the electromagnet assembly. At least two slip rings are provided at the connection between the drive assembly and the support assembly or at the rotating joint of the support assembly. The stationary part of the slip ring receives external power and control signals via a wired connection. The rotating part of the slip ring is electrically connected to the electromagnet assembly to provide a continuous power supply to the electromagnet assembly and transmit control signals during rotation.

2. The magnetic field generator according to claim 1, characterized in that, The load-bearing component includes a bracket, and at least two slip rings include a first slip ring and a second slip ring; the drive component includes a first hollow shaft motor and a second hollow shaft motor, the stator of the first hollow shaft motor is fixedly connected to the upper part of the bracket, and the electromagnet assembly is connected to the rotor of the first hollow shaft motor; the rotor of the second hollow shaft motor is connected to the bracket, and the stator of the second hollow shaft motor is disposed on a base; The first slip ring and the second slip ring are respectively disposed inside the first hollow shaft motor and the second hollow shaft motor in a one-to-one correspondence; The stationary portion of the first slip ring is connected to the rotating portion of the second slip ring by a wire. The rotating portion of the first slip ring is connected to the magnetic field generating component. The stationary portion of the second slip ring is used to receive external electrical energy and control signals and transmit them to the electromagnetic generating component.

3. The magnetic field generator according to claim 2, characterized in that, An upper circuit board is provided below the bracket, and a lower circuit board is provided inside the base. The stationary part of the first electric slip ring and the rotating part of the second electric slip ring are both connected to the upper circuit board by wires. The stationary part of the second electric slip ring is connected to the lower circuit board by wires. The lower circuit board is connected to an external power supply line and a data line.

4. The magnetic field generator according to claim 3, characterized in that, The magnetic field strength is controlled by the lower circuit board; the dual-axis motion trajectory is tracked and adjusted by encoder feedback.

5. The magnetic field generator according to claim 1, characterized in that, The electric slip ring includes a slip ring rotating shaft, a slip ring rotor, a slip ring stator, and an anti-rotation plate.

6. The magnetic field generator according to claim 1, characterized in that, The electromagnet assembly includes a coil frame, a wire wound around the coil frame, and a soft magnetic material core; the soft magnetic material core is made of any one of ferrite, silicon steel, permalloy, amorphous alloy, and nanocrystalline alloy.

7. A position detection system, characterized in that, include: A base station, wherein the base station is equipped with a magnetic field generator as described in any one of claims 1 to 6 and a first controller; The object to be tested is equipped with a magnetic field sensor and a second controller. The computer systems are all connected to the first controller and the second controller; The magnetic field generator is used to generate a time-varying magnetic field; The magnetic field sensor is used to collect magnetic field strength data at its location; The second controller is used to transmit the magnetic field strength data to the computer system; The first controller is used to transmit the motion status data of the magnetic field generator to the computer system; The computer system is used to calculate the six-degree-of-freedom pose of the object based on the magnetic field strength data and the motion state data using an optimization algorithm.

8. The position detection system according to claim 7, characterized in that, The optimization algorithm includes algorithm.

9. The position detection system according to claim 7, characterized in that, Solve for any point in space At any time The precise expression for the perceived magnetic field strength: In the formula: Represents the permeability of free space. Represents magnetic dipole moment, Represents a position vector. Represents a unit vector.

10. The position detection system according to claim 7, characterized in that, The optimization algorithm minimizes the difference in magnetic field strength using the following objective function: In the formula: Indicates magnetic field strength. Represents a position vector. This indicates the measured magnetic field strength.

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