Rotating magnet unit, field emitter, and control method for field emitter

Abstract

Embodiments of the invention provide a rotating magnet unit. The rotating magnet unit comprises: a driving assembly, a magnet and a self-detection assembly. The driving assembly is connected to the magnet and is used for driving the magnet to rotate. The self-detection assembly is used for detecting a magnetic field signal generated in the rotating process of the magnet.

Description

Rotating magnet unit, field transmitter, and control method of field transmitter Cross-references

[0001] This specification claims priority to the Chinese application with application number 202311648640.9 and filing date on December 1, 2023, the Chinese application with application number 202311645150.3 and filing date on December 1, 2023, and the Chinese application with application number 202311655768.8 and filing date on December 1, 2023, and the entire contents of the above applications are incorporated into this specification by reference. Technical Field

[0002] This specification relates to the field of electromagnetic navigation, and in particular to a rotating magnet unit, a field transmitter, and a control method for the field transmitter. Background Art

[0003] The electromagnetic transient simulator (EMTS) is one of the mainstream surgical navigation system technologies. The most typical EMTS principle is to generate a time-varying magnetic field using a field transmitter, detect this time-varying field using a magnetic sensor, and then calculate the position of the magnetic sensor. The field transmitter is one of the core components of this system. There are two most common methods for generating a time-varying magnetic field: one is to use an electromagnetic coil to pass an alternating current to generate a time-varying magnetic field, and the other is to generate a time-varying magnetic field through the rotation of a magnet. Compared to electromagnetic coils, magnets generate a stronger magnetic field of the same volume, consume less power, and do not have to worry about heat generation, thus offering unique advantages. Summary of the Invention

[0004] One or more embodiments of the present specification provide a rotating magnet unit, which includes: a drive component, a magnet and a self-test component; the drive component is connected to the magnet to drive the magnet to rotate; the self-test component is used to detect the magnetic field signal generated during the rotation of the magnet.

[0005] In some embodiments, the self-test component includes three annular coils whose normal vectors are orthogonal to each other; the three annular coils are respectively located on three sides of the magnet; and the normal vector of one of the annular coils coincides with the rotation axis of the magnet.

[0006] In some embodiments, the self-test component includes a magnetic sensor; the magnetic sensor is located on a side of the driving component away from the magnet.

[0007] In some embodiments, the rotation axis of the magnet is: not parallel to the magnetic moment direction of the magnet; or, not parallel to the magnetic moment direction of the magnet, and passes through the center of mass of the magnet; or, perpendicular to the magnetic moment direction of the magnet; or, perpendicular to the magnetic moment direction of the magnet, and passes through the center of mass of the magnet.

[0008] In some embodiments, the driving assembly includes a motor, a reduction mechanism, and an absolute position encoder; the output shaft of the motor is connected to the magnet through the reduction mechanism, and the absolute position encoder is used to collect angular position information of the magnet.

[0009] In some embodiments, the drive assembly includes a transmission device, and the motor drives the magnet to rotate through the transmission device.

[0010] In some embodiments, the rotating magnet unit further includes: a mounting shell; the drive component, the magnet and the self-test component are all mounted inside the mounting shell; the mounting shell is provided with a functional interface, which connects the drive component and the self-test component.

[0011] In some embodiments, the rotating magnet unit further includes: a locking assembly; the locking assembly is used to lock the angular position of the magnet.

[0012] One or more embodiments of this specification provide a field transmitter, wherein the field transmitter includes at least one rotating magnet unit, and the at least one rotating magnet unit is the rotating magnet unit described in any of the above embodiments.

[0013] One or more embodiments of the present specification provide an electromagnetic navigation system, which includes a processor, a receiving device and the field transmitter described in any of the above embodiments, wherein the receiving device is used to detect the time-varying magnetic field generated by the field transmitter, and the processor is used to control the operation of the field transmitter and determine the real-time position of the receiving device in the time-varying magnetic field based on the magnetic field detection data of the receiving device.

[0014] One or more embodiments of the present specification provide a self-test method for a rotating magnet unit, which is applied to a rotating magnet unit such as any of the above embodiments; the self-test method for the rotating magnet unit includes: controlling the driving component to drive the magnet to rotate at a preset speed; obtaining a current time-varying magnetic field signal of the magnet; wherein the current time-varying magnetic field signal is obtained by the self-test component detecting a magnetic field signal generated by the magnet during rotation; determining a signal difference between the current time-varying magnetic field signal of the magnet and a reference time-varying magnetic field signal, and determining a self-test result of the rotating magnet unit based on the signal difference.

[0015] In some embodiments, the reference time-varying magnetic field signal is obtained by detecting, by the self-test component, a magnetic field signal generated when the magnet rotates at the preset speed in the initial state of the rotating magnet unit.

[0016] In some embodiments, determining the signal difference between the current time-varying magnetic field signal of the magnet and the reference time-varying magnetic field signal, and determining the self-test result of the rotating magnet unit based on the signal difference includes: determining the current magnetic field strength based on the current time-varying magnetic field signal, and the proportional relationship between each component in the current time-varying magnetic field signal; determining the intensity difference between the current magnetic field strength and the reference magnetic field strength, wherein the reference magnetic field strength is determined based on the reference time-varying magnetic field signal; determining the proportional difference between the proportional relationship between each component in the current time-varying magnetic field signal and the proportional relationship between each component in the reference time-varying magnetic field signal; and determining the self-test result of the rotating magnet unit based on the intensity difference and the proportional difference.

[0017] One or more embodiments of the present specification provide a self-test system for a rotating magnet unit, and the system is applied to a rotating magnet unit such as any of the above embodiments; the system includes: a drive module, used to control the drive component to drive the magnet to rotate at a preset speed; a first signal acquisition module, used to acquire the current time-varying magnetic field signal of the magnet; wherein the current time-varying magnetic field signal is obtained by the self-test component detecting the magnetic field signal generated by the magnet during rotation; a first self-test result determination module, used to determine the signal difference between the current time-varying magnetic field signal of the magnet and a reference time-varying magnetic field signal, and determine the self-test result of the rotating magnet unit based on the signal difference.

[0018] One or more embodiments of this specification provide a self-test device for a rotating magnet unit, including a processor, wherein the processor is configured to execute the self-test method for a rotating magnet unit as described in any of the above embodiments.

[0019] One or more embodiments of this specification provide a computer-readable storage medium that stores computer instructions. When a computer reads the computer instructions in the storage medium, the computer executes the self-test method of the rotating magnet unit as described in any of the above embodiments.

[0020] One or more embodiments of the present specification provide a self-test method for a field transmitter, which is applied to the above-mentioned field transmitter; the self-test method for the field transmitter comprises: determining a target rotating magnet unit to be self-tested in the field transmitter, and locking the angular position of the magnet of a non-target rotating magnet unit; controlling the drive component to drive the magnet of the target rotating magnet unit to rotate at a preset speed; obtaining a current time-varying magnetic field signal of the magnet; wherein the current time-varying magnetic field signal is obtained by the self-test component detecting a magnetic field signal generated by the magnet during rotation; determining a signal difference between the current time-varying magnetic field signal of the magnet and a reference time-varying magnetic field signal, and determining a self-test result of the rotating magnet unit based on the signal difference.

[0021] One or more embodiments of the present specification provide a self-test system for a field transmitter, the system being applied to the above-mentioned field transmitter; the system comprising: a locking module for determining a target rotating magnet unit to be self-tested in the field transmitter and locking the angular position of the magnet of a non-target rotating magnet unit; a rotation control module for controlling the drive component to drive the magnet of the target rotating magnet unit to rotate at a preset speed; a second signal acquisition module for acquiring a current time-varying magnetic field signal of the magnet; wherein the current time-varying magnetic field signal is obtained by the self-test component detecting a magnetic field signal generated by the magnet during rotation; and a second self-test result determination module for determining a signal difference between the current time-varying magnetic field signal of the magnet and a reference time-varying magnetic field signal, and determining a self-test result of the rotating magnet unit based on the signal difference.

[0022] One or more embodiments of the present specification provide a self-test device for a rotating magnet unit, including a processor, wherein the processor is configured to execute the self-test method for the rotating magnet unit as described above.

[0023] One or more embodiments of this specification provide a computer-readable storage medium, wherein the storage medium stores computer instructions. When a computer reads the computer instructions in the storage medium, the computer executes the self-test method of the rotating magnet unit as described above.

[0024] One or more embodiments of the present specification provide an electromagnetic navigation method, which is applied to the electromagnetic navigation system; the electromagnetic navigation method includes: performing a self-test on the field transmitter to obtain a self-test result of each rotating magnet unit in the field transmitter, including: determining a target rotating magnet unit to be self-tested in the field transmitter, and locking the angular position of the magnet of the non-target rotating magnet unit; controlling the drive component to drive the magnet of the target rotating magnet unit to rotate at a preset speed; obtaining a current time-varying magnetic field signal of the magnet; wherein the current time-varying magnetic field signal is obtained by the self-test component detecting a magnetic field signal generated by the magnet during rotation; determining a signal difference between the current time-varying magnetic field signal of the magnet and a reference time-varying magnetic field signal, and determining a self-test result of the rotating magnet unit based on the signal difference; for any rotating magnet unit, determining a target magnetic moment strength of the rotating magnet unit based on the self-test result of the rotating magnet unit.

[0025] In some embodiments, the electromagnetic navigation method further includes: obtaining magnetic field data of the time-varying magnetic field generated by the field transmitter; wherein the magnetic field data of the time-varying magnetic field is obtained by the receiving device detecting the time-varying magnetic field; and determining the real-time posture of the receiving device in the time-varying magnetic field based on the magnetic field data of the time-varying magnetic field and the time-varying characteristics of the time-varying magnetic field.

[0026] In some embodiments, the time-varying characteristics of the time-varying magnetic field include the time-varying characteristics of the magnetic moment of each rotating magnet unit in the field transmitter in the field transmitter coordinate system, and the time-varying characteristics of the magnetic moment include the time-varying characteristics of the magnetic moment direction and the magnetic moment intensity.

[0027] In some embodiments, determining the real-time posture of the receiving device in the time-varying magnetic field based on the magnetic field data of the time-varying magnetic field and the time-varying characteristics of the time-varying magnetic field includes: calculating the posture of the receiving device in the time-varying magnetic field in real time based on the magnetic field data of the time-varying magnetic field and the time-varying characteristics of the time-varying magnetic field within a real-time time window; wherein the window width of the real-time time window is determined according to the real-time requirements of the posture calculation of the receiving device.

[0028] In some embodiments, the method further includes: obtaining real-time detection results obtained by the self-test components of each of the rotating magnet units detecting the time-varying magnetic field generated by the field transmitter; determining the difference between the real-time detection results of the self-test components of each of the rotating magnet units and their corresponding reference detection results; and determining the real-time operating status of the field transmitter based on the result difference.

[0029] One or more embodiments of the present specification provide an electromagnetic navigation device, which is applied to the electromagnetic navigation system; the electromagnetic navigation device includes: a self-test module, which is used to: perform a self-test on the field transmitter to obtain a self-test result of each rotating magnet unit in the field transmitter, including: determining a target rotating magnet unit to be self-tested in the field transmitter, and locking the angular position of the magnet of the non-target rotating magnet unit; controlling the drive component to drive the magnet of the target rotating magnet unit to rotate at a preset speed; obtaining a current time-varying magnetic field signal of the magnet; wherein the current time-varying magnetic field signal is obtained by the self-test component detecting a magnetic field signal generated by the magnet during rotation; determining a signal difference between the current time-varying magnetic field signal of the magnet and a reference time-varying magnetic field signal, and determining the self-test result of the rotating magnet unit based on the signal difference; a correction module, which is used to determine, for any of the rotating magnet units, the target magnetic moment strength of the rotating magnet unit based on the self-test result of the rotating magnet unit.

[0030] One or more embodiments of this specification provide an electromagnetic navigation device, including a processor, wherein the processor is configured to execute the electromagnetic navigation method as described in any of the above embodiments.

[0031] One or more embodiments of this specification provide a computer-readable storage medium that stores computer instructions. When a computer reads the computer instructions in the storage medium, the computer executes the electromagnetic navigation method described in any of the above embodiments.

[0032] One or more embodiments of the present specification provide a control method for a field transmitter, which is applied to the field transmitter, wherein the field transmitter includes at least one rotating magnet unit, at least one of which includes a drive assembly and a magnet. The method includes: for each rotating magnet unit in the field transmitter, determining an interaction torque exerted on the magnet of the rotating magnet unit from magnets of other rotating magnet units; using the interaction torque exerted on the magnet of the rotating magnet unit as a feedforward input for its own drive to determine a drive current corresponding to the rotating magnet unit; and controlling the drive assembly to drive the rotating magnet unit to rotate based on the drive current to generate a time-varying magnetic field.

[0033] In some embodiments, determining the interaction torque exerted on the magnet of the rotating magnet unit by the magnets of other rotating magnet units includes: determining one of the rotating magnet units in the field transmitter as a first target rotating magnet unit; determining the target magnetic field time-varying characteristics of the resultant magnetic field at the magnet of the first target rotating magnet unit, wherein the resultant magnetic field is jointly generated by the non-first target rotating magnet units in the field transmitter; determining the target magnetic moment time-varying characteristics of the magnet of the first target rotating magnet unit; and determining the time-varying characteristics of the interaction torque exerted on the magnet of the first target rotating magnet unit based on the target magnetic field time-varying characteristics and the target magnetic moment time-varying characteristics.

[0034] One or more embodiments of the present specification provide a control system for a field transmitter, which is applied to the field transmitter, wherein the field transmitter includes at least one rotating magnet unit, at least one of which includes a drive assembly and a magnet. The system includes: a torque determination module, configured to determine, for each rotating magnet unit in the field transmitter, an interaction torque exerted on the magnet of the rotating magnet unit from the magnets of other rotating magnet units; a torque processing module, configured to use the interaction torque exerted on the magnet of the rotating magnet unit as a feedforward input for its own drive to determine a drive current corresponding to the rotating magnet unit; and, based on the drive current, control the drive assembly to drive the rotating magnet unit to rotate, thereby generating a time-varying magnetic field.

[0035] One or more embodiments of this specification provide a control device for a field transmitter, including a processor, wherein the processor is configured to execute the control method for the field transmitter as described in any of the above embodiments.

[0036] One or more embodiments of this specification provide a computer-readable storage medium that stores computer instructions. When a computer reads the computer instructions in the storage medium, the computer executes the field transmitter control method described in any of the above embodiments.

[0037] One or more embodiments of this specification provide a control method for a field transmitter, which is applied to the field transmitter. The field transmitter includes at least one rotating magnet unit, and at least one of the rotating magnet units includes a drive assembly and a magnet. The method includes: controlling the magnets of the rotating magnet units with the same initial magnetic moment direction to produce different rotational speeds.

[0038] In some embodiments, the method further comprises: controlling the magnets of the rotating magnet unit having different initial magnetic moment directions to generate the same rotational speed.

[0039] One or more embodiments of this specification provide a control system for a field transmitter, which is applied to the field transmitter. The field transmitter includes at least one rotating magnet unit, at least one of which includes a drive assembly and a magnet. The system includes a speed control module for controlling the magnets of the rotating magnet units with the same initial magnetic moment direction to produce different speeds.

[0040] One or more embodiments of this specification provide a control device for a field transmitter, including a processor, wherein the processor is configured to execute the control method for the field transmitter as described in any of the above embodiments.

[0041] One or more embodiments of this specification provide a computer-readable storage medium that stores computer instructions. When a computer reads the computer instructions in the storage medium, the computer executes the field transmitter control method described in any of the above embodiments.

[0042] One or more embodiments of the present specification provide a field transmitter, comprising: a field transmitter group and a magnetic detection component; the field transmitter group comprises at least one rotating magnet unit; the magnetic detection component is used to detect a calibration magnetic field generated by the rotating magnet unit.

[0043] In some embodiments, the magnetic detection component further includes a circuit board, and the magnetic detection component includes a plurality of magnetic sensors; the plurality of magnetic sensors are evenly mounted on the circuit board.

[0044] In some embodiments, the field transmitter further includes: a mounting shell; the field transmission unit group and the magnetic detection component are both mounted inside the mounting shell; or, the field transmission unit group is mounted inside the mounting shell, and the magnetic detection component is mounted outside the mounting shell.

[0045] In some embodiments, the field transmitter further includes: a magnetic source component; the spatial position of the magnetic source component in the field transmitter is fixed; when the magnetic source component is working, the magnetic detection component is also used to detect the detection magnetic field generated by the magnetic source component.

[0046] In some embodiments, the magnetic source assembly includes a plurality of coils, and the plurality of coils are evenly distributed around the periphery of the field emission unit group.

[0047] One or more embodiments of the present specification provide a self-calibration method for a field transmitter, which is applied to the field transmitter described in any of the above embodiments; the self-calibration method includes: obtaining measured calibration magnetic field data obtained by the magnetic detection component detecting a target calibration magnetic field, wherein the target calibration magnetic field is a calibration magnetic field generated by a target rotating magnet unit, and the target rotating magnet unit is a rotating magnet unit to be calibrated in the field transmitting unit group; obtaining magnet angle information of the target rotating magnet unit; and determining target calibration parameters of the target rotating magnet unit based on the measured calibration magnetic field data and the magnet angle information.

[0048] In some embodiments, determining the target calibration parameters of the target rotating magnet unit based on the measured working magnetic field data and the magnet angle information includes: determining the model calibration magnetic field data of the target calibration magnetic field at the magnetic detection component based on the magnet angle information, the model parameters of the target rotating magnet unit and the spatial posture of the magnetic detection component; optimizing the model parameters of the target rotating magnet unit with the optimization goal of minimizing the difference between the measured calibration magnetic field data and the model calibration magnetic field data to obtain the target calibration parameters of the target rotating magnet unit.

[0049] In some embodiments, the optimization goal of minimizing the difference between the measured working magnetic field data and the model calibration magnetic field data includes: minimizing the difference between the modulus value of the measured calibration magnetic field data and the modulus value of the model calibration magnetic field data as the optimization goal.

[0050] In some embodiments, the measured calibration magnetic field data includes a measured calibration magnetic field value sequence, and the model calibration magnetic field data includes a model calibration magnetic field value sequence; the optimization goal is to minimize the difference between the measured calibration magnetic field data and the model calibration magnetic field data, including: determining the sequence mean of the measured calibration magnetic field value sequence, and the sequence mean of the model calibration magnetic field value sequence; subtracting the sequence mean of the measured calibration magnetic field value sequence from each magnetic field value in the measured calibration magnetic field value sequence to obtain a first magnetic field value sequence; subtracting the sequence mean of the model calibration magnetic field value sequence from each magnetic field value in the model calibration magnetic field value sequence to obtain a second magnetic field value sequence; minimizing the difference between the first magnetic field value sequence and the second magnetic field value sequence as the optimization goal.

[0051] One or more embodiments of the present specification provide a self-calibration system for a field transmitter, the system being applied to a field transmitter as described in any of the above embodiments; the self-calibration system comprising: a magnetic field data acquisition module for acquiring measured calibration magnetic field data obtained by the magnetic detection component detecting a target calibration magnetic field, wherein the target calibration magnetic field is a calibration magnetic field generated by a target rotating magnet unit, and the target rotating magnet unit is a rotating magnet unit to be calibrated in the field transmitter unit group; an angle information acquisition module for acquiring magnet angle information of the target rotating magnet unit; and a target calibration parameter determination module for determining target calibration parameters of the target rotating magnet unit based on the measured calibration magnetic field data and the magnet angle information.

[0052] One or more embodiments of this specification provide a self-calibration device for a field transmitter, including a processor, wherein the processor is configured to execute the self-calibration method for a field transmitter as described in any of the above embodiments.

[0053] One or more embodiments of this specification provide a computer-readable storage medium that stores computer instructions. When a computer reads the computer instructions in the storage medium, the computer executes the self-calibration method for a field transmitter as described in any of the above embodiments.

[0054] One or more embodiments of the present specification provide a field transmitter, comprising: a field transmitter group and a magnetic source assembly; the field transmitter group includes at least one rotating magnet unit; the spatial position of the magnetic source assembly in the field transmitter is fixed; when the field transmitter group stops working, the magnetic source assembly generates a detection magnetic field for performing interference detection on the field transmitter.

[0055] In some embodiments, the magnetic source assembly includes a plurality of coils, and the plurality of coils are evenly distributed around the periphery of the field emission unit group.

[0056] One or more embodiments of the present specification provide an interference detection method for a field transmitter, which is applied to the field transmitter described in any of the above embodiments; the interference detection method includes: controlling all rotating magnet units in the field transmitter to stop; controlling the magnetic source component to generate the detection magnetic field; obtaining measured detection magnetic field data obtained by the magnetic detection component detecting the detection magnetic field; determining a detection difference between the measured detection magnetic field data and a reference detection magnetic field data; and determining an interference detection result of the field transmitter based on the detection difference.

[0057] In some embodiments, the magnetic source component includes multiple coils, and the multiple coils are evenly distributed around the field emission unit group; the obtaining of the measured detection magnetic field data obtained by the magnetic sensor detecting the detection magnetic field includes: obtaining the target measured detection magnetic field data obtained by the magnetic detection component detecting the target detection magnetic field; wherein, the target detection magnetic field is the detection magnetic field generated by the target coil in the magnetic source component; the determining of the detection difference between the measured detection magnetic field data and the reference detection magnetic field data, and determining the interference detection result of the field transmitter according to the detection difference includes: determining the target detection difference between the target measured detection magnetic field data and the target reference detection magnetic field data, and determining the interference detection result of the field transmitter in the corresponding direction of the target coil according to the target detection difference.

[0058] One or more embodiments of the present specification provide an interference detection system for a field transmitter, which is applied to the field transmitter described in any of the above embodiments; the interference detection system includes: a first control module, used to control all rotating magnet units in the field transmitter to stop rotating; a second control module, used to control the magnetic source assembly to generate the detection magnetic field; a first acquisition module, used to obtain measured detection magnetic field data obtained by the magnetic detection assembly detecting the detection magnetic field; a second acquisition module, used to determine a detection difference between the measured detection magnetic field data and reference detection magnetic field data; and a first determination module, used to determine an interference detection result of the field transmitter based on the detection difference.

[0059] One or more embodiments of this specification provide an interference detection device for a field transmitter, including a processor, wherein the processor is configured to execute the interference detection method for a field transmitter as described in any of the above embodiments.

[0060] One or more embodiments of this specification provide a computer-readable storage medium that stores computer instructions. When a computer reads the computer instructions in the storage medium, the computer executes the interference detection method for a field transmitter as described in any of the above embodiments.

[0061] One or more embodiments of the present specification provide a method for detecting an abnormality of a field transmitter, which is applied to the field transmitter described in any of the above embodiments; the abnormality detection method includes: obtaining measured working magnetic field data obtained by detecting the working magnetic field generated by the field transmitter by the magnetic detection component; determining an operating difference between the measured working magnetic field data and reference working magnetic field data, and determining the operating status of the field transmitter based on the operating difference.

[0062] In some embodiments, the field transmitter further includes: a magnetic source component; determining the operating state of the field transmitter based on the operating difference includes: in response to determining that the operating difference is less than or equal to an operating difference threshold, determining that the field transmitter is in a normal operating state; in response to determining that the operating difference is greater than the operating difference threshold, controlling all rotating magnet units in the field transmitter to stop; controlling the magnetic source component to generate a detection magnetic field; obtaining measured detection magnetic field data obtained by the magnetic detection component detecting the detection magnetic field; determining a detection difference between the measured detection magnetic field data and a reference detection magnetic field data; and determining an interference detection result of the field transmitter based on the detection difference.

[0063] In some embodiments, the abnormality detection method further includes: after performing the interference detection on the field transmitter, in response to determining that the detection difference is greater than a detection difference threshold, determining that the field transmitter is in an abnormal operating state; in response to determining that the detection difference is less than or equal to the detection difference threshold, obtaining measured calibration magnetic field data obtained by the magnetic detection component detecting the target calibration magnetic field, wherein the target calibration magnetic field is a calibration magnetic field generated by a target rotating magnet unit, and the target rotating magnet unit is a rotating magnet unit to be calibrated in the field transmitting unit group; obtaining magnet angle information of the target rotating magnet unit; and determining target calibration parameters of the target rotating magnet unit based on the measured calibration magnetic field data and the magnet angle information.

[0064] In some embodiments, the method further includes: after performing the self-calibration on the field transmitter, determining the calibration difference between the target calibration parameters and the initial calibration parameters; in response to determining that the calibration difference is greater than a calibration difference threshold, determining that the field transmitter is in an abnormal operating state; in response to determining that the calibration difference is less than or equal to the calibration difference threshold, determining that the field transmitter is in a normal operating state; and updating the target parameters of the field transmitter to the target calibration parameters.

[0065] One or more embodiments of the present specification provide an electromagnetic navigation system, which includes a processor, a receiving device and a field transmitter of any of the above embodiments, wherein the receiving device is used to detect the time-varying magnetic field generated by the field transmitter, and the processor is used to control the operation of the field transmitter and determine the real-time position of the receiving device in the time-varying magnetic field based on the magnetic field detection data of the receiving device.

[0066] One or more embodiments of this specification provide a field transmitter anomaly detection system, which is applied to the field transmitter described in any of the above embodiments; the anomaly detection system includes:

[0067] a second magnetic field data acquisition module, configured to acquire measured working magnetic field data obtained by the magnetic detection component detecting the working magnetic field generated by the field transmitter;

[0068] The operating state determination module is used to determine the operating difference between the measured operating magnetic field data and the reference operating magnetic field data, and determine the operating state of the field transmitter according to the operating difference.

[0069] One or more embodiments of this specification provide a field transmitter abnormality detection device, including a processor, wherein the processor is configured to execute the field transmitter abnormality detection method as described in any of the above embodiments.

[0070] One or more embodiments of this specification provide a computer-readable storage medium that stores computer instructions. When a computer reads the computer instructions in the storage medium, the computer executes the field transmitter anomaly detection method as described in any of the above embodiments.

[0071] One or more embodiments of the present specification provide a field transmitter, comprising at least one rotating magnet unit. Each rotating magnet unit has a reference axis defined therein. The rotating magnet unit includes a magnet capable of rotating about the reference axis, and the magnetic moment of the magnet is non-parallel to the reference axis. When there are multiple rotating magnet units, the reference axes of at least two of the multiple rotating magnet units are non-parallel.

[0072] In some embodiments, at least one of the rotating magnet units includes a self-detection component for detecting a magnetic field signal generated during rotation of the magnet.

[0073] In some embodiments, the multiple rotating magnet units include a first rotating magnet unit and a second rotating magnet unit; the first rotating magnet unit includes a first motor and a first magnet, the second rotating magnet unit includes a second motor and a second magnet, the first motor is used to drive the first magnet to rotate, and the second motor is used to drive the second magnet to rotate; or, the first magnet unit includes a first motor and a first magnet, the second magnet unit includes a first transmission assembly and a second magnet, the first motor is used to drive the first magnet to rotate, and the first motor is also used to drive the second magnet to rotate by driving the first transmission assembly.

[0074] In some embodiments, for each of the rotating magnet units, a reference axis is defined in the rotating magnet unit, and the rotating magnet unit includes a magnet capable of rotating around the reference axis, and the magnetic moment direction of the magnet is perpendicular to the reference axis; wherein: the reference axes of at least two of the multiple rotating magnet units are perpendicular to each other; or, the number of the multiple rotating magnet units is four, the reference axes of the four rotating magnet units are in the same plane, and the reference axes of any adjacent two of the four rotating magnet units are perpendicular to each other; or, the number of the multiple rotating magnet units is three, and the reference axes of the three rotating magnet units are perpendicular to each other.

[0075] In some embodiments, the magnet is installed at ends of any two of the plurality of rotating magnet units that are away from each other.

[0076] In some embodiments, the field transmitter further includes a mounting body, wherein the mounting body is provided with a plurality of mounting positions, and the plurality of mounting positions are used to mount at least one of the rotating magnet units.

[0077] This specification provides a field transmitter that requires only two rotating magnet units. The combined magnetic moments of these two rotating magnet units can sweep across three orthogonal spatial directions, meeting the field transmitter's operational requirements. Therefore, this specification provides a simple and effective field transmitter configuration that can be constructed using only two rotating magnet units. This addresses the current problem of a lack of a simple and effective specific configuration for field transmitters, forcing technicians to build based on their own experience, resulting in complex field transmitter configurations that do not meet operational standards.

[0078] This specification provides a control method for a field transmitter. When the field transmitter is operating, each rotating magnet unit operates simultaneously and generates a single, time-varying magnetic field. The single, time-varying magnetic field generated by each rotating magnet unit affects the other rotating magnet units. Therefore, the driving load of each rotating magnet unit when operating simultaneously differs from the driving load when operating individually. To ensure that the magnets of each rotating magnet unit can stably rotate at a preset speed during operation of the field transmitter, the driving current of each rotating magnet unit must be modulated. In this specification, the interaction torque exerted on the magnets of each rotating magnet unit by the magnets of other rotating magnet units is calculated during operation of the field transmitter. For each rotating magnet unit, the interaction torque exerted on its magnets is used as a feedforward input to its own drive assembly. The drive current can then be modulated based on the time-varying characteristics of the interaction torque. For example, when the interaction torque is large, creating significant resistance to the magnet's rotation, the driving current intensity can be increased. Therefore, the drive control method for a field transmitter provided in this specification enables each rotating magnet unit in the field transmitter to adjust the drive current in a timely manner based on the interaction torque, significantly improving the rotational control precision of the magnets and ensuring more stable operation of the motor in the drive assembly. This solves the problem of low rotational control precision of the magnets by each rotating magnet unit in existing field transmitters.

[0079] This specification provides a control method for a field transmitter. By controlling the magnets of rotating magnet units with different initial magnetic moment directions to produce the same rotational speed, and controlling the magnets of rotating magnet units with the same initial magnetic moment direction to produce different rotational speeds, this method facilitates data decoupling, maintains positioning accuracy, and reduces the complexity of speed control.

[0080] This specification provides a rotating magnet unit and a self-test method for the rotating magnet unit. The rotating magnet unit includes a self-test component. Before the rotating magnet unit operates, the self-test component can detect the magnetic field signal generated by the magnet, and by comparing the current time-varying magnetic field signal of the magnet with the reference time-varying magnetic field signal, it can be determined whether the rotating magnet unit has any abnormal use. The self-test component can be used to perform a self-test before each use. Through self-test, any problems can be discovered in a timely manner, preventing the field transmitter from generating a time-varying magnetic field that deviates from the standard during operation, and ultimately ensuring the positioning accuracy of the magnetic sensor.

[0081] This specification provides a field transmitter and a self-calibration method for the field transmitter. The field transmitter includes a magnetic detection component. By setting up the magnetic detection component, the field transmitter can update the calibration parameters of each rotating magnet unit in the magnetic field model based on the magnetic field detection data of the magnetic detection component. The updated calibration parameters are more consistent with the actual state of the rotating magnet unit, thereby making the calculation results of the magnetic field model more accurate, thereby improving the accuracy of electromagnetic navigation. The magnetic detection component can also detect the real-time working magnetic field generated by the field transmitter during operation. By comparing the current time-varying magnetic field signal obtained by the detection with the reference time-varying magnetic field signal, it can be determined whether the field transmitter has any abnormal use, so that abnormalities can be discovered in a timely manner during the use of the field generator.

[0082] This specification provides a field transmitter and an interference detection method for the field transmitter. The field transmitter includes a magnetic source assembly. The method involves obtaining measured magnetic field data obtained by the detection assembly from detecting a detection magnetic field generated by the magnetic source assembly, determining a detection difference between the measured magnetic field data and reference magnetic field data, and determining an interference detection result for the field transmitter based on the detection difference. This method allows for detecting whether an interfering magnetic field exists around the field transmitter, thereby promptly eliminating the interfering magnetic field and preventing it from affecting electromagnetic navigation. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] This specification will be further described in the form of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting, and in these embodiments, like numbers represent like structures, wherein:

[0084] FIG1 is a schematic diagram of an application scenario of an electromagnetic navigation system according to some embodiments of this specification;

[0085] FIG2 is a top view of an exemplary structure of a field emitter according to some embodiments of the present specification;

[0086] FIG3 is a side view of an exemplary structure of a field transmitter according to some embodiments of the present specification;

[0087] FIG4 is a top view of an exemplary structure of a field emitter according to other embodiments of the present specification;

[0088] FIG5 is a side view of an exemplary structure of a field transmitter according to other embodiments of the present specification;

[0089] FIG6 is a top view of an exemplary structure of a magnetic detection assembly according to some embodiments of the present specification;

[0090] FIG7 is a side view of an exemplary structure of a magnetic detection assembly according to some embodiments of the present specification;

[0091] 8 and 9 are exemplary structural diagrams of a rotating magnet unit according to some embodiments of the present specification;

[0092] FIG10 is an exemplary flow chart of a method for controlling a field transmitter according to some embodiments of this specification;

[0093] FIG11 is an exemplary flow chart of determining a time-varying characteristic according to some embodiments of the present specification;

[0094] FIG12 is an exemplary flow chart of a method for controlling a field transmitter according to some embodiments of this specification;

[0095] FIG13 is an exemplary flow chart of a self-test method of a rotating magnet unit according to some embodiments of this specification;

[0096] FIG14 is an exemplary flow chart of determining a self-test result according to some embodiments of this specification;

[0097] FIG15 is an exemplary flow chart of a self-test method for a field transmitter according to other embodiments of this specification;

[0098] FIG16 is an exemplary flow chart of determining a target magnetic moment strength according to some embodiments of this specification;

[0099] FIG17 is an exemplary flow chart of determining the real-time operating status of a field transmitter according to some embodiments of the present specification;

[0100] FIG18 is an exemplary flow chart of a self-calibration method for a field transmitter according to some embodiments of this specification;

[0101] FIG19 is an exemplary flowchart of determining an optimization target according to some embodiments of this specification;

[0102] FIG20 is an exemplary flow chart of a method for detecting interference of a field transmitter according to some embodiments of this specification;

[0103] FIG21 is an exemplary flowchart of an anomaly detection method according to some embodiments of this specification;

[0104] FIG22 is an exemplary flowchart of an abnormality detection method according to other embodiments of this specification;

[0105] FIG23 is an exemplary flowchart of an anomaly detection method according to other embodiments of this specification;

[0106] FIG24 is an exemplary flowchart of an abnormality detection method according to other embodiments of this specification;

[0107] FIG25 is an exemplary flow chart of a method for using a field transmitter according to some embodiments of the present specification;

[0108] FIG26 is an exemplary flow chart of real-time positioning of a field transmitter according to some embodiments of the present specification;

[0109] FIG27 is an exemplary flow chart of a self-calibration method for a field transmitter according to other embodiments of this specification;

[0110] FIG28 is an exemplary flow chart of an interference detection method for a field transmitter according to other embodiments of this specification;

[0111] 29 and 30 are exemplary schematic diagrams of another field emitter structure according to some embodiments of the present specification;

[0112] FIG31 is a schematic diagram of a configuration of a field transmitter according to some embodiments of the present specification;

[0113] FIG32 is a schematic diagram of the interaction torque of each rotating magnet unit according to some embodiments of this specification;

[0114] FIG33 is a schematic diagram of data acquisition when a mid-field transmitter performs real-time positioning in this specification;

[0115] FIG34 is a schematic structural diagram of a rotating magnet unit according to some embodiments of this specification;

[0116] FIG35 is an exemplary module diagram of a self-test system for a rotating magnet unit according to some embodiments of the present specification;

[0117] FIG36 is an exemplary module diagram of a self-test system for a field transmitter according to some embodiments of the present specification;

[0118] FIG37 is an exemplary module diagram of an electromagnetic navigation device according to some embodiments of the present specification;

[0119] FIG38 is an exemplary block diagram of a control system for a field transmitter according to some embodiments of the present specification;

[0120] FIG39 is an exemplary block diagram of a control system for a field transmitter according to some embodiments of the present specification;

[0121] FIG40 is an exemplary module diagram of a self-calibration system for a field transmitter according to some embodiments of the present specification;

[0122] FIG41 is an exemplary module diagram of an interference detection system for a field transmitter according to some embodiments of the present specification;

[0123] FIG42 is an exemplary module diagram of an anomaly detection system for a field transmitter according to some embodiments of the present specification. DETAILED DESCRIPTION

[0124] To more clearly illustrate the technical solutions of the embodiments of this specification, the following briefly describes the drawings required for describing the embodiments. Obviously, the drawings described below are merely examples or embodiments of this specification. Those skilled in the art can apply this specification to other similar scenarios based on these drawings without inventive effort. Unless otherwise apparent from the context or otherwise noted, the same reference numerals in the figures represent the same structure or operation.

[0125] It should be understood that the terms "system," "device," "unit," and / or "module" used herein are a method for distinguishing different components, elements, parts, portions, or assemblies at different levels. However, if other terms can achieve the same purpose, the terms may be replaced by other expressions.

[0126] As used in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not refer to the singular but also include the plural. Generally speaking, the terms "comprises" and "include" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0127] Flowcharts are used throughout this specification to illustrate the operations performed by systems according to embodiments of this specification. It should be understood that preceding or following operations do not necessarily need to be performed in exact order. Instead, the steps may be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0128] Current field transmitters lack a simple and effective specific configuration. Field transmitters typically consist of at least two rotating magnet units, each containing a rotatable magnet. During use, the magnets can lose strength, or the rotating magnet units can become loose or deformed, causing the magnetic moment direction of the magnets to shift. These issues can cause the field transmitter to generate a time-varying magnetic field that deviates from the standard during operation, ultimately reducing the positioning accuracy of the magnetic sensor.

[0129] On the other hand, when calculating the position and posture of magnetic sensors, an accurate magnetic field model is a key prerequisite for achieving high-precision results. Errors are inevitable in any processing and installation process, as are errors in electronic control, such as in the control of physical quantities like current intensity and frequency. Therefore, before implementing high-precision navigation applications, detailed and high-precision calibration of the field transmitter is required to obtain an accurate magnetic field model. However, even with detailed factory calibration, problems such as collisions, thermal expansion and contraction, mechanical fatigue, and equipment aging inevitably occur during use, leading to a mismatch between the initial calibration parameters and the actual state of the field transmitter, reducing electromagnetic navigation accuracy. Currently, no effective solution has been proposed to address these issues.

[0130] FIG1 is a schematic diagram of an application scenario of an electromagnetic navigation system according to some embodiments of this specification.

[0131] As shown in FIG1 , an application scenario 10 of an electromagnetic navigation system may include a field transmitter 11 , a receiving device (receiver) 12 , a processor 13 and a memory 14 .

[0132] The field transmitter 11 is one of the core components of the electromagnetic navigation system. The field transmitter 11 can be used to generate a precise and stable magnetic field, through which a tracker (for example, a small coil or sensor) inside or outside the target object senses the magnetic field. By analyzing the magnetic field signal sensed by the tracker, the position and direction of the tracker in three-dimensional space can be determined. This positioning and tracking can be used in medical scenarios such as minimally invasive surgery and catheter insertion, and can also be applied to other scenarios. In some embodiments, the field transmitter 11 can be installed in an operating room, for example, it can be located next to a bed in an operating room.

[0133] The receiving device 12 can be used to receive the magnetic field signal emitted by the field transmitter 11. The receiving device 12 can include a magnetic sensor or an induction coil. In some embodiments, the receiving device 12 can be installed in a surgical device, for example, a surgical instrument (such as a probe or a catheter).

[0134] The processor 13 can process data and / or information obtained from the field transmitter 11, the receiving device 12, the memory 14 or other components of the application scenario 10 of the electromagnetic navigation system. For example, the processor 13 can analyze and process the time-varying magnetic field generated by the field transmitter 11. In some embodiments, the processor 13 can be local or remote, for example, the processor 12 can be integrated in the receiving device or transmitter, or exist as an independent unit. When existing as an independent unit, the processor 13 can access information and / or data from the field transmitter 11, the receiving device 12 and / or the storage device 14 through the network. Exemplarily, the processor 13 can process the magnetic field signal received from the receiving device 12 in real time to calculate the accurate position of the receiving device 12 in three-dimensional space and convert it into an image coordinate system. In some embodiments, the processor 13 can be one or more (only one is shown in Figure 1). The processor 13 may include but is not limited to a microprocessor MCU or a programmable logic device FPGA.

[0135] In a typical application scenario, a field transmitter 11 emits a magnetic field signal and establishes a connection with a receiving device 12 via a processor 13. The receiving device can be mounted on a surgical instrument or probe. When the surgeon approaches the surgical instrument near the patient or inserts it into the patient's body, the receiving device 12 receives the electromagnetic waves emitted by the field transmitter and returns the received magnetic field signal to the processor 13. The processor 13 processes the magnetic field signal received from the receiving device 12. For example, it can calculate the position of the receiving device 12 in real time based on changes in the magnetic field signal and convert this position data into a position in the image coordinate system. The real-time position of the receiving device can then be displayed on a display. In some embodiments, through integration with an imaging system, the spatial position of the receiving device 12 can be superimposed on the patient's real-time scan image. The real-time image provided by the navigation system and the position information of the receiving device 12 enable surgeons to perform surgical procedures more accurately. For example, during brain surgery, surgeons can precisely guide surgical instruments to the site of a brain tumor while avoiding damage to surrounding healthy brain tissue. In spinal surgery, electromagnetic navigation can help surgeons precisely implant screws, ensuring accurate screw positioning and reducing surgical risks. In some embodiments, the real-time position of the receiving device may be displayed without being superimposed on the real-time scan image of the patient.

[0136] The memory 14 can be used to store data. The memory 14 can store computer programs, data and / or information generated by other components of the electromagnetic navigation system application scenario 10, and the like. For example, software programs and modules of application software, such as the computer program corresponding to the field transmitter drive control method provided in the present invention, can be stored. The processor 13 can execute various functional applications and data processing by running the computer programs stored in the memory 14, thereby implementing the aforementioned method. The memory 14 can include high-speed random access memory (RAM) and non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 14 may further include memory remotely located from the processor 13, which can be connected to the terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0137] In some embodiments, the application scenario 10 of the electromagnetic navigation system may further include a terminal device 16. The terminal device 16 may implement user instructions, operation input, or positioning output of the tracker (receiving device 12). In some embodiments, the user may input control requests through the terminal device 16. In the embodiments of this specification, the terminal device 16 may include a mobile device 16-1, a tablet computer 16-2, a laptop computer 16-3, a display device, or any combination thereof. In this specification, the user may be an operator of a medical device, such as a doctor, researcher, engineer, etc.

[0138] In some embodiments, the electromagnetic navigation system application scenario 10 may further include an imaging device 17. Imaging device 17 may be used to provide real-time anatomical images. The position of receiving device 12 may be superimposed on the image and displayed on a display. Imaging device 17 may be a single-modality or multi-modality imaging device. For example, single-modality imaging devices may include CT devices, MRI devices, X-ray devices, PET devices, etc., while multi-modality imaging devices may include CT-MRI devices, CT-PET devices, etc. Imaging device 17 may also be omitted in the electromagnetic navigation system application scenario 10.

[0139] In some embodiments, the application scenario 10 of the electromagnetic navigation system may further include a network 15. The network 15 may include any suitable network capable of facilitating information and / or data exchange. In some embodiments, at least one component of the application scenario 10 of the electromagnetic navigation system (e.g., the field transmitter 11, the receiving device 12, the processor 13, the terminal device 16, the memory 14, the imaging device 17, etc.) may exchange information and / or data with at least one other component of the application scenario 10 of the system via the network 15.

[0140] It should be noted that the application scenario 10 of the electromagnetic navigation system is provided for illustrative purposes only and is not intended to limit the scope of this specification. Those skilled in the art will appreciate that various modifications and variations can be made based on the description of this specification. For example, the application scenario 10 of the electromagnetic navigation system may further include a database. For another example, the application scenario 10 of the electromagnetic navigation system may implement similar or different functions on other devices. However, such variations and modifications do not deviate from the scope of this specification.

[0141] FIG. 2 is a top view of an exemplary structure of a field emitter according to some embodiments of the present specification, and FIG. 3 is a side view of an exemplary structure of a field emitter according to some embodiments of the present specification.

[0142] In some embodiments, the field transmitter includes at least one rotating magnet unit 100. A reference axis 300 is defined within each rotating magnet unit 100. The rotating magnet unit includes a magnet capable of rotating about the reference axis 300, and the direction of the magnet's magnetic moment is non-parallel to the reference axis. When there are multiple rotating magnet units, the reference axes of at least two of the multiple rotating magnet units are non-parallel.

[0143] The rotating magnet unit is one of the basic components of a field transmitter. It has a rotating magnet. The magnet can be a permanent magnet made of neodymium iron boron or an electromagnet, such as an electromagnetic coil. The rotating magnet can provide a single, time-varying magnetic field. The reference axis of the rotating magnet unit is the rotation axis of the magnet itself. The reference axis of the magnet can be perpendicular to the direction of the magnet's magnetic moment. When the magnet rotates, its magnetic moment can sweep across two spatial directions, thereby defining a magnetic moment rotation plane. Furthermore, the reference axes of at least two rotating magnet units are perpendicular to each other, and the magnetic moment rotation planes of these two rotating magnet units are perpendicular. This allows the magnetic moments of the multiple magnets in the field transmitter to be combined to sweep across three orthogonal spatial directions, meeting the requirements for the use of the field transmitter.

[0144] In some embodiments, the relationship between the rotation axis of the magnet and the direction of the magnetic moment of the magnet can be various. For example, the rotation axis of the magnet can be non-parallel to the direction of the magnetic moment of the magnet; or the rotation axis of the magnet can be non-parallel to the direction of the magnetic moment of the magnet and pass through the center of mass of the magnet; or the rotation axis of the magnet can be perpendicular to the direction of the magnetic moment of the magnet; or the rotation axis of the magnet can be perpendicular to the direction of the magnetic moment of the magnet and pass through the center of mass of the magnet. The center of mass of the magnet can be located on the motor shaft. When the center of mass of the magnet is located on the motor reference axis, the mechanical structure stability of the entire unit is higher. When the center of mass of the magnet is not located on the motor shaft, the center of mass of the magnet deviates from the motor shaft. At this time, the rotation axis of the magnet is not parallel to the direction of the magnetic moment of the magnet.

[0145] The above examples illustrate the relationship between the rotation axis and the magnetic moment direction of various magnets. In practice, the rotation axis (reference axis) of the magnet is preferably perpendicular to the magnetic moment direction. The magnetic moment direction of a magnet is from the south pole (S) to the north pole (N). When the reference axis of the magnet is perpendicular to the magnetic moment direction, the magnetic moment direction of the magnet can be varied within a fixed plane, facilitating data processing during subsequent electromagnetic navigation.

[0146] In some embodiments, a field transmitter may comprise only a single rotating magnet unit, wherein the magnet in this rotating magnet unit can simultaneously revolve and rotate, thereby generating a time-varying magnetic field. For example, the simultaneous revolving and rotating of the magnet can be achieved through a motor and a transmission assembly. The transmission assembly can be a gear set, such as a helical gear set or a bevel gear set. The revolving axis and the rotating axis can intersect, for example, at a location offset from the magnet's center of mass. The revolving and rotating axes can also be non-coplanar, although this is not a limitation in this embodiment. In some embodiments, a field transmitter can be comprised of as few as two rotating magnet units, and the combined magnetic moments of the magnets of these two rotating magnet units can sweep across three orthogonal spatial directions to meet the operational requirements of the field transmitter.

[0147] The magnetic moments of the rotating magnet units, when combined, should be as balanced as possible across the three orthogonal spatial directions they can scan. That is, the number of magnetic moments sweeping across the three orthogonal spatial directions should be as close or even identical as possible. For example, the three orthogonal spatial directions can be divided into the X, Y, and Z directions. The number of magnetic moments sweeping across the X, Y, and Z directions should be close or identical. This allows the individual magnetic moment directions to be combined to form multiple "XYZ orthogonal pairs," meaning that from the temporal sequence of magnetic moment directions, at least one magnetic moment combination pointing in the X, Y, and Z directions can always be combined. At each point in the rotation process, the magnetic moments corresponding to the multiple rotating magnet units can cover the three directions of X, Y, and Z (that is, the magnetic moments do not need to fall exactly in the X, Y, and Z directions; the directions of the magnetic moments can also be in other directions, as long as their components in the X, Y, and Z directions cover all three directions). As shown in Figure 2, an orthogonal coordinate system can be established, with the direction of the reference axis of one of the rotating magnet units in the field transmitter serving as one of the X, Y, and Z directions.

[0148] In some embodiments, the rotating magnet units in the field transmitter can each use different rotational speeds, such as 10 Hz, 20 Hz, 30 Hz, and 40 Hz, and can also be adjusted according to actual usage scenarios and needs, so that the differences in the time-varying magnetic field over time and space can meet usage requirements.

[0149] In some embodiments, ends of any two rotating magnet units among the plurality of rotating magnet units that are away from each other are ends on which magnets are installed.

[0150] The field transmitter is composed of multiple rotating magnet units, and its configuration has a certain impact on electromagnetic navigation. Each rotating magnet unit houses a rotating magnet. The spacing between the magnets within each rotating magnet unit should be as large as possible to minimize the interaction force between the magnets. This ultimately reduces the drive load of each rotating magnet unit and makes the rotational drive of the magnets more stable.

[0151] For example, referring to FIG. 2 , in the two opposite rotating magnet units in FIG. 2 , the end in the direction opposite to the arrow is the end where the magnet is installed.

[0152] In some embodiments, the number of the plurality of rotating magnet units is four, and reference axes of the four rotating magnet units are in the same plane.

[0153] Since the magnetic moment direction of the magnet in each rotating magnet unit is perpendicular to the reference axis, the magnetic moments of the four rotating magnet units sweep across the YZ, XZ, YZ, and XZ planes respectively (see Figure 2). Because the rotation speeds of the rotating magnet units are different, the magnetic field signals generated by the four rotating magnet units can be decoupled (this is an inherent characteristic, and in actual processing, it is not necessary to actually perform decoupling calculations). Therefore, within a certain period of time, all the magnetic moment directions at each moment are extracted, and multiple groups of "XYZ orthogonal pairs" can be formed. These magnetic moment directions and the magnetic field data measured at the corresponding time are used for positioning. After simulation and experimental verification, better positioning results can be obtained.

[0154] In some embodiments, the reference axes of any two adjacent rotating magnet units of the four rotating magnet units are perpendicular to each other. Because the reference axes of each rotating magnet unit in this field transmitter configuration are in the same plane, the field transmitter as a whole has a flat structure. Compared to field transmitters in which the reference axes of each rotating magnet unit are distributed in three dimensions, the field transmitter in this embodiment is smaller in size, has a simpler structure, and does not take up too much space. For example, the reference axes of the four rotating magnet units are generally in the shape of a cross, meaning that the centers of mass of the four rotating magnet units are distributed in a circle, and the reference axes of the four rotating magnet units intersect at the same point. When this configuration is adopted, the field transmitter configuration is highly symmetrical, and positioning uniformity is improved during electromagnetic navigation positioning.

[0155] The relative positions of the rotating magnet units in the field transmitter follow certain design principles: the rotation axes of at least two rotating magnet units are perpendicular to each other, so that the magnetic moment can sweep through the three orthogonal directions of X, Y, and Z, and be distributed as evenly as possible.

[0156] FIG31 is a schematic diagram of a field transmitter configuration according to some embodiments of this specification. Referring to FIG31 , different permanent magnets scan in different planes, and when combined, they can form multiple "XYZ orthogonal pairs." That is, from the temporal sequence of the permanent magnet scans, multiple combinations of magnetic moments pointing in the X, Y, and Z directions can be generated. In the figure, w1, w2, w3, and w4 represent the directions of the rotation axes (reference axes of the rotating magnet units) of the four permanent magnets. The magnetic moments of the permanent magnets in each rotating magnet unit are perpendicular to their respective rotation axes. Therefore, the magnetic moments of the permanent magnets of the four rotating magnet units sweep through the YZ, XZ, YZ, and XZ planes, respectively. Because the permanent magnets rotate at different speeds, the magnetic field signals generated by them can, in principle, be decoupled to a certain extent (this is an inherent characteristic; in actual processing, decoupling calculations are not necessarily required). Therefore, within a certain period of time, all the magnetic moment directions at each moment can be extracted to form multiple groups of "XYZ orthogonal pairs", and positioning can be performed using these magnetic moment directions and the magnetic field data measured at the corresponding time. After simulation and experimental verification, better positioning effects can be obtained.

[0157] FIG4 is a top view of an exemplary structure of a field emitter according to other embodiments of the present specification, and FIG5 is a side view of an exemplary structure of a field emitter according to other embodiments of the present specification.

[0158] As shown in Figures 4 and 5, the field transmitter is equipped with four rotating magnet units, with the reference axes of any two adjacent rotating magnet units perpendicular to each other, and the reference axes of the four rotating magnet units are not located in the same plane. The difference between the field transmitters shown in Figures 2 and 4 is that the reference axes of the rotating magnet units in Figure 2 are all located in the same plane, while the reference axes of the four rotating magnet units in the field transmitter shown in Figure 4 are not located in the same plane.

[0159] In some embodiments, the number of rotating magnet units is three, and the reference axes of the three rotating magnet units are perpendicular to each other. The field transmitter employs three rotating magnet units, and the rotation planes of the magnetic moments of any two rotating magnet units are perpendicular to each other, such that each of the three orthogonal spatial directions can be exactly swept by the magnetic moments of the two magnets.

[0160] In some embodiments, after the field transmitter is installed, at least one relative position calibration is required to determine the relative positions of the rotating magnet units in the field transmitter. The magnetic detection assembly and self-calibration method used for self-calibration are described below.

[0161] After the relative positions of the rotating magnet units are determined, the interaction torque can be calculated as the feedforward input of the motor drive control loop. When the relative distance of the rotating magnet units exceeds several times the magnet size (such as 4 times), the Dipole model can be used to approximate the interaction torque. For example, in a field transmitter composed of 4 rotating magnet units, when calculating the interaction torque on the magnet of the first rotating magnet unit, first calculate the combined magnetic field time series B(t) generated by the other three rotating magnet units at the permanent magnet of the first rotating magnet unit, then calculate the magnetic moment sequence m(t) of the first rotating magnet unit based on the absolute position encoder data of the first rotating magnet unit; finally, calculate the interaction torque sequence T(t) on the permanent magnet of the first rotating magnet unit. The calculation formula (1) is as follows: T(t) = m(t) × B(t) (1)

[0162] By multiplying the resultant magnetic field and the magnetic moment at the same moment, we can get the interaction torque at the same moment. Performing the same calculation on the data at each moment will give us the interaction torque sequence.

[0163] Figure 32 is a schematic diagram of the interaction torque of each rotating magnet unit according to some embodiments of this specification. When the magnetic strength of the permanent magnet is large, the interaction torque is relatively strong, which can reach 10~10 2 mN·m, and the torque waveforms of permanent magnets at different speeds are different. Referring to Figure 32, the interaction torque is a time-varying strong load, which will cause a certain burden on the motor drive control. However, if the load is modeled more accurately and input into the control loop as a feedforward model, the drive module can adjust the drive current in a timely manner, thereby significantly improving the corresponding speed and accuracy of the control and making the motor run more stably. The modulation method of the drive current is a well-known technology in the field of motor control. After determining the time-varying characteristics of the motor load, the time-varying characteristics can be input into the existing motor drive current modulation algorithm to obtain the modulated motor drive current.

[0164] When the field emitter is small and the permanent magnet is large, the Dipole model is not accurate enough. In this case, finite element analysis (FEA) can be used for simulation (such as Comsol, MatLab and other software).

[0165] The above embodiments describe two specific field transmitter configurations, both of which can be used to construct a field transmitter. It should be noted that other field transmitter configurations are also possible, as long as the reference axes of at least two rotating magnet units are perpendicular to each other. When more rotating magnet units are used, additional rotating magnet units can be added to the two configurations described above.

[0166] Figures 2 to 5 show two field transmitter configurations. In practice, 2, 3, 5, or other numbers of rotating magnet units 100 can also be used (4 to 5 are preferred). In the field transmitter, the rotation speed of each rotating magnet unit 100 is different, such as 10Hz, 20Hz, 30Hz, 40Hz, or 10Hz, 10Hz, 20Hz, 20Hz, etc. Among them, the initial magnetic moment directions of rotating magnet units with the same rotation speed are different, for example, they differ by 90°. Accordingly, the number and rotation speed of each rotating magnet unit 100 can also be adjusted according to the actual usage scenario and needs, so that the magnetic field has a higher degree of variability over time and space.

[0167] The field transmitter may further include a drive assembly. In some embodiments, the drive assembly may include a motor, a speed reduction mechanism, and an absolute position encoder. The output shaft of the motor is connected to the magnet via the speed reduction mechanism, and the absolute position encoder is used to collect angular position information of the magnet.

[0168] In some embodiments, the drive assembly may further include a transmission device, through which the motor drives the magnet to rotate. The transmission device may be a transmission shaft, a transmission belt, a transmission chain, a gear, etc. This embodiment does not limit the specific form of the transmission device, as long as it can achieve the transmission function. The transmission device may be connected to the motor at one end and to the reduction mechanism at the other end.

[0169] The motor is the primary driver, rotating the magnet through a reduction gear mechanism. An absolute position encoder collects the magnet's angular position information in real time and records the motor's operating status. This provides a basis for determining the time-varying magnetic field state during subsequent electromagnetic navigation, thereby determining the magnetic field state model value at the magnetic sensor.

[0170] In some embodiments, for a field transmitter, one of the multiple rotating magnet units may include a motor and a transmission device, while the other rotating magnet units may include a transmission device but no motor. For example, a single motor may be used to simultaneously drive the rotation of the magnets in multiple rotating magnet units. The magnets in one rotating magnet unit may be directly connected to the motor via a transmission shaft / reduction mechanism, while the other rotating magnet units may be connected to the motor via a transmission device, such as a transmission shaft or a transmission belt (which may also include a reduction mechanism). This allows a single motor to drive the rotation of the magnets in multiple rotating magnet units, and the rotational speeds of the magnets in the multiple rotating magnet units may be the same or different.

[0171] For example, each rotating magnet unit may include a transmission device, and a motor may be installed outside the rotating magnet unit and located inside the field transmitter. The motor may be used to drive the magnets of all rotating magnet units to rotate.

[0172] In some embodiments, for a field transmitter, each of the plurality of rotating magnet units may include a motor and a transmission device. For example, the magnets of each rotating magnet unit are driven to rotate by a single motor.

[0173] Exemplarily, the motor of each rotating magnet unit may be installed inside the rotating magnet unit, or may be installed outside the rotating magnet unit and located inside the field transmitter.

[0174] The above-mentioned driving component can be applied to all field transmitters involved in this specification, for example, the field transmitters of Figures 2 to 5, including the field transmitter of the self-test component, the field transmitter including the magnetic detection component (see description below), the field transmitter including the magnetic source component (see description below), etc.

[0175] As shown in Figures 8 and 9, Figures 8 and 9 are exemplary structural diagrams of rotating magnet units according to some embodiments of this specification. This specification provides a rotating magnet unit. The rotating magnet unit may include a drive component 101, a magnet 102, and a self-test component. A field transmitter may include multiple rotating magnet units, at least one of which may be the rotating magnet unit in this embodiment. In other words, among the multiple rotating magnet units in the field transmitter, at least one rotating magnet unit may also include a self-test component. The relative positions of the multiple rotating magnet units in the field transmitter are not limited. For example, the relative positions of the multiple rotating magnet units in the field transmitter can be described in Figures 2-5.

[0176] The drive assembly is connected to the magnet and is used to drive the magnet to rotate. In some embodiments, the drive assembly may include a motor and a transmission assembly. Among the multiple rotating magnet units, at least one rotating magnet unit includes a motor. For example, among the multiple rotating magnet units, one rotating magnet unit includes a motor, and the remaining rotating magnet units do not include motors.

[0177] Exemplarily, the plurality of rotating magnet units include a first rotating magnet unit and a second rotating magnet unit. The first rotating magnet unit includes a first motor and a first magnet, and the second rotating magnet unit includes a second motor and a second magnet. The first motor is used to drive the first magnet to rotate, and the second motor is used to drive the second magnet to rotate. Alternatively, the first magnet unit includes a first motor and a first magnet, and the second magnet unit includes a first transmission assembly and a second magnet. The first motor is used to drive the first magnet to rotate, and the first motor is also used to drive the second magnet to rotate by driving the first transmission assembly. For more information about the drive assembly, please refer to the relevant description above.

[0178] The self-test component is used to detect the magnetic field signal generated during the rotation of the magnet.

[0179] The self-test component is a component within the rotating magnet unit that detects the magnetic field generated by the rotating magnet unit. In some embodiments, in addition to detecting the magnetic field signal generated by the magnet of the rotating magnet unit, the self-test component can also perform other functions, such as detecting interfering magnetic fields in the field transmitter environment. In some embodiments, the spatial position of the self-test component remains fixed within the rotating magnet unit, that is, the spatial position of the self-test component relative to the rotating magnet unit remains fixed.

[0180] In the initial state of the rotating magnet unit, the magnetic field signal generated when the magnet rotates at a preset speed can be detected by the self-test component to obtain a reference time-varying magnetic field signal. The initial state of the rotating magnet unit can be the factory state, and the rotating magnet unit will undergo strict strength and magnetic moment direction calibration before leaving the factory. During subsequent use, the magnetic field signal generated when the magnet rotates at a preset speed can be detected again by the self-test component to obtain the current time-varying magnetic field signal of the magnet. By comparing the current time-varying magnetic field signal of the magnet with the reference time-varying magnetic field signal, it can be determined whether the rotating magnet unit has any abnormal use.

[0181] Exemplarily, the current magnetic field strength can be determined based on the current time-varying magnetic field signal, and the proportional relationship of each component in the current time-varying magnetic field signal (for example, the proportional relationship of the x component, the y component and the z component) can be determined. If the current magnetic field strength is significantly decreased compared to the reference magnetic field strength (the magnetic field strength corresponding to the reference time-varying magnetic field signal), such as a decrease of 5%, it is fully explained that the magnetic strength in the rotating magnet unit has degraded by 5%, and then the magnetic moment strength value of the rotating magnet unit needs to be corrected in the subsequent positioning algorithm model. If the proportional relationship of each component in the current time-varying magnetic field signal is significantly changed compared to the proportional relationship of each component in the reference time-varying magnetic field signal, it may be that the magnetic moment direction of the magnet has changed, the mechanical structure has become loose, or there is interference around it (such as ferromagnetic materials, other time-varying magnetic fields, etc.), then it is necessary to perform interference detection on the environment around the magnet, or take out the rotating magnet unit for shutdown and maintenance. For the interference detection method, please refer to the relevant description below.

[0182] In some embodiments, the field transmitter can perform a self-test before use using a self-test component within the rotating magnet unit. During the self-test, the field transmitter first identifies the rotating magnet unit to be self-tested, then locks the magnets of the other rotating magnet units. For the rotating magnet unit to be self-tested, the drive component rotates the magnet at a preset speed, while the self-test component detects the magnetic field signal generated by the magnet to obtain the current time-varying magnetic field signal of the magnet during the self-test. After obtaining the current time-varying magnetic field signal, it is compared with a reference time-varying magnetic field signal to determine the signal difference between the two. The self-test result of the rotating magnet unit is determined based on this signal difference. The reference time-varying magnetic field signal is the time-varying magnetic field signal that the self-test component should detect when the rotating magnet unit is operating normally and rotating at a preset speed. For example, it can be a time-varying magnetic field signal obtained by simulating a normal rotating magnet unit, or it can be a time-varying magnetic field signal detected by the self-test component when the rotating magnet unit leaves the factory. The principle is that, in the absence of anomalies, the current time-varying magnetic field signal and the reference time-varying magnetic field signal should be identical. If the signal difference exceeds the threshold, it indicates that there is an abnormality in the corresponding rotating magnet unit. If the self-test results are normal or the abnormality has been resolved (such as adjusting the magnet strength or eliminating the interference source), the field transmitter can be used normally.

[0183] In some embodiments, when the field transmitter includes a single rotating magnet unit, this rotating magnet unit is used as the target rotating magnet unit during self-test. Since the field transmitter does not contain any other rotating magnet units besides the target rotating magnet unit, there is no need to lock the other rotating magnet units. Subsequently, the self-test can be performed according to the self-test method described in the above embodiments.

[0184] For a detailed description of the self-test process, please refer to the descriptions in Figures 10 to 15.

[0185] In some embodiments, the self-test assembly includes three annular coils 103 with normal vectors orthogonal to each other; the three annular coils 103 are located on three sides of the magnet. The normal vector of one of the annular coils coincides with the rotation axis 109 of the magnet, and the normal vectors of the other two annular coils are perpendicular to the rotation axis 109 of the magnet.

[0186] In this embodiment, three annular coils with orthogonal normal vectors are used to detect the magnetic field signal generated by the magnet. Specifically, the three annular coils are located on three sides of the magnet, and one of the annular coils can be located on the side of the magnet away from the drive assembly. When the magnet rotates, the three annular coils can generate corresponding induced voltages. The induced voltages of each annular coil indirectly reflect the strength of the magnet at the location of the corresponding annular coil, so that the magnetic field signal generated by the magnet can be determined based on the induced voltages of the annular coils.

[0187] It should be noted that, in some other embodiments, the number of annular coils may not be limited to three, and the relative posture relationship in which the normal vectors are orthogonal to each other may not be satisfied. Among them, the self-test component needs to detect the signal components of the magnetic field signal in three spatial dimensions. Therefore, the use of three annular coils with normal vectors orthogonal to each other is a preferred embodiment. The three annular coils can respectively detect the signal components of the magnetic field signal in three spatial dimensions. In other embodiments, it is only necessary to ensure that the normal vectors of the multiple annular coils are not in the same plane. At this time, the signal components of the magnetic field signal in three spatial dimensions can be obtained by decoupling the detection signals of the multiple annular coils.

[0188] In some embodiments, the self-test component may further include a magnetic sensor 104. The magnetic sensor 104 is located on a side of the drive component away from the magnet. For example, the self-test component may collect magnetic field signals through the magnetic sensor and then perform self-test.

[0189] In this embodiment, the self-test component uses a magnetic sensor to detect the magnetic field signal generated by the magnet. The magnetic sensor can be a MEMS (Micro Electro Mechanical System) magnetic sensor or the like. The MEMS magnetic sensor can be a Hall sensor, an anisotropic magnetoresistance (AMR) sensor, a tunnel magnetoresistance (TMR) sensor or the like. Preferably, the magnetic sensor can be arranged on the side of the driving component away from the magnet, so that the distance between the magnetic sensor and the magnet is large, which can effectively avoid saturation of the magnetic sensor. Preferably, the magnetic sensor uses a three-axis digital sensor, so that the magnetic field signal generated by the magnet can be detected more accurately.

[0190] The self-test component can be used to perform a self-test on each rotating magnet unit in the field transmitter in sequence, for example, one rotating magnet unit at a time. Before each use of the field transmitter, the user can perform a self-test on each rotating magnet unit using the internal self-test component. This self-test can promptly identify problematic rotating magnet units, preventing the field transmitter from generating a time-varying magnetic field that deviates from the standard during operation, ultimately ensuring the positioning accuracy of the magnetic sensor. This solves the problem that existing field transmitters lack a self-test function, preventing abnormalities in rotating magnet units from being detected in a timely manner through self-test, resulting in the field transmitter generating a time-varying magnetic field that deviates from the standard during operation, ultimately reducing the positioning accuracy of the magnetic sensor.

[0191] In this embodiment, the magnetic field signal generated by the magnet can be detected through a self-test component. By comparing the current time-varying magnetic field signal of the magnet with a reference time-varying magnetic field signal, it can be determined whether the rotating magnet unit has experienced any abnormality in use. Therefore, the rotating magnet unit provided in this specification can be self-tested using the self-test component before each use, promptly identifying any problems with the unit, preventing the field transmitter from generating a time-varying magnetic field that deviates from the standard during operation, and ultimately ensuring the positioning accuracy of the magnetic sensor. This solves the problem that, when an abnormality occurs in the existing rotating magnet unit, the field transmitter generates a time-varying magnetic field that deviates from the standard during operation, ultimately reducing the positioning accuracy of the magnetic sensor.

[0192] Furthermore, since the rotating magnet unit provided in this specification has a self-test function, the field transmitter in this embodiment also has a self-test function. Before each use of the field transmitter, the user can perform a self-test on each rotating magnet unit using the internal self-test component. This self-test can promptly identify problematic rotating magnet units, preventing the field transmitter from generating a time-varying magnetic field that deviates from the standard during operation, ultimately ensuring the positioning accuracy of the magnetic sensor. This solves the problem that existing field transmitters lack a self-test function, preventing abnormalities in rotating magnet units from being promptly detected through self-test, resulting in the field transmitter generating a time-varying magnetic field that deviates from the standard during operation, ultimately reducing the positioning accuracy of the magnetic sensor.

[0193] In some embodiments, the self-test component can also be used to perform real-time interference detection. During the positioning process of magnetic navigation, the self-test component of each rotating magnet unit can capture the magnetic field waveform in real time. This function is different from the self-test of the rotating magnet unit. In the self-test of the rotating magnet unit, only one rotating magnet unit works at a time, and the other rotating magnet units are locked. When the interference detection function is executed, the field transmitter is in a normal positioning working state, and all rotating magnet units are rotating. Therefore, the magnetic field waveform captured by the magnetic detection at this time is different from that obtained in the self-test of the rotating magnet unit. During the interference detection process, if the environment is stable and there is no interference, the waveforms captured by each self-test component are also known. When the self-test signal captured by the self-test component changes beyond the limit, it is very likely that there is magnetic field interference in the surrounding area (such as interference from ferromagnetic materials), and the problem needs to be investigated.

[0194] In some embodiments, the rotating magnet unit further comprises a mounting housing 105. The driving assembly, the magnet, and the self-test assembly are all mounted inside the mounting housing 105; the mounting housing 105 is provided with a functional interface 106, which connects the driving assembly and the self-test assembly.

[0195] The mounting housing is a mounting carrier for the components in the rotating magnet unit, and serves to fix and protect the internal components. In order not to affect the time-varying magnetic field, the mounting housing is preferably made of non-metal. A fixing member 108 for the magnet 102 is provided in the mounting housing 105. At the same time, in order to realize data transmission and power transmission, a functional interface can also be provided on the mounting housing for connecting to an external interface 107. Through this functional interface, the encoder data in the drive component can be output, the detection data of the self-test component can also be output, or the drive component can be connected to an external power supply.

[0196] In some embodiments, the mounting housing can be a rectangular structure. The field transmitter body coordinate system can be constructed using the mounting housing as a reference. The rotating magnet unit is fixed relative to the mounting housing, and the spatial position of the rotating magnet unit in the field transmitter body coordinate system is fixed.

[0197] The upper and lower surfaces of the mounting housing may also be provided with magnetic detection components, for which details please refer to the following description.

[0198] In some embodiments, the field transmitter further includes a mounting body 200 having a plurality of mounting positions 201 for mounting a plurality of rotating magnet units, for example, each of the plurality of mounting positions is used to mount one rotating magnet unit.

[0199] The mounting body is a mounting carrier for each rotating magnet unit. In some embodiments, the dimensions of each mounting body can be the same. If the field transmitter uses a mounting body of the same size, the configuration center of the field transmitter configuration shown in Figures 2 and 3 needs to be set at the center of the mounting body, while in the configuration of the field transmitter shown in Figures 4 and 5, the intersection of the reference axes of the three rotating magnet units can be set at the corners of the mounting body, thereby increasing the spacing between the magnets in each rotating magnet unit and ultimately reducing the interaction force between the magnets.

[0200] In some embodiments, the mounting body is provided with at least two mounting locations, which can be groove-shaped structures provided on the surface of the mounting body, the location of the groove-shaped structures matching the configuration of the field transmitter, and the rotating magnet unit is installed in the corresponding groove-shaped structures.

[0201] At the same time, a power supply is also provided inside the installation body, and a functional interface for cooperating with the rotating magnet unit can be provided on the installation position. After the rotating magnet unit is installed, the functional interface on the installation position is connected to the functional interface on the rotating magnet unit to realize power supply and data transmission.

[0202] In some embodiments, the field transmitter mounting body 200 is further provided with an indicator slot 202, which is used to mark the XY plane of the field transmitter's body coordinate system. The Z axis is perpendicular to the XY plane and points outward from the surface. Four mounting positions are used to mount the rotating magnet unit. Internally, corresponding fixtures and power and data interfaces (not shown) are provided for connection to the functional interfaces of the rotating magnet unit. Once installed, the rotating magnet units are fixed relative to each other.

[0203] In some embodiments, the mounting orientation differs from the previous configuration. By comparison, the magnets of the rotating magnet units are spaced farther apart, resulting in less interaction between them. This reduces the motor load on each rotating magnet unit during rotation, making drive more stable. The previous configuration, with its axisymmetric structure, results in more uniform positioning.

[0204] In some embodiments, the rotating magnet unit further includes a locking assembly. The locking assembly is used to lock the magnet of the rotating magnet unit so that the magnet does not rotate. For example, the locking assembly can be used to lock the angular position of the magnet. Each rotating magnet unit can include a locking assembly.

[0205] In some embodiments, since the field transmitter is composed of multiple rotating magnet units, when performing self-test on the target rotating magnet unit, it is necessary to avoid the influence of other rotating magnet units on the target rotating magnet unit, that is, it is necessary that the magnets in other rotating magnet units do not rotate. Therefore, the rotating magnet unit may further include a locking assembly, by which the angular position of the magnet can be locked. Exemplarily, the locking assembly may adopt a clamping structure, which clamps the magnet so that it cannot rotate under a large friction force. The locking assembly may also adopt a snap-fit ​​structure, in which case a slot that cooperates with the snap-fit ​​structure may be provided on the surface of the magnet. When the snap-fit ​​structure extends into the slot, the rotation of the magnet can be restricted.

[0206] The target rotating magnet unit refers to a magnet unit that performs self-test among the plurality of rotating magnet units.

[0207] The above-mentioned mounting housing, mounting body and locking assembly can be applied to all field transmitters involved in this specification, for example, the field transmitters of Figures 2 to 5, the field transmitter including the self-test assembly, the field transmitter including the magnetic detection assembly (see description below), the field transmitter including the magnetic source assembly (see description below), etc.

[0208] FIG6 is a top view of an exemplary structure of a magnetic detection assembly according to some embodiments of the present specification, and FIG7 is a side view of an exemplary structure of a magnetic detection assembly according to some embodiments of the present specification.

[0209] In some embodiments, the magnetic detection assembly can be used to detect magnetic field signals generated by each of the plurality of rotating magnet units. In some embodiments, the spatial position of the magnetic detection assembly remains fixed within the field transmitter, that is, the spatial position of the magnetic detection assembly relative to the field transmitter remains fixed.

[0210] In some embodiments, a field transmitter may include a field transmitter unit group and a magnetic detection assembly 110; the field transmitter unit group includes multiple rotating magnet units; and the magnetic detection assembly 110 is configured to detect a calibration magnetic field generated by the rotating magnet units. In this embodiment, the field transmitter may not include a self-test assembly, or at least one of the multiple rotating magnet units in the field transmitter may further include a self-test assembly. The relative positions of the multiple rotating magnet units in the field transmitter are not limited. For example, the relative positions of the multiple rotating magnet units in the field transmitter can be described in Figures 2-5.

[0211] In some embodiments, the magnetic detection component 110 may include a plurality of magnetic sensors 111 and a circuit board 112, and the plurality of magnetic sensors 111 may be evenly mounted on the circuit board 112. There may be a certain interval between the plurality of magnetic sensors, and they may be fixedly mounted on the circuit board as evenly as possible. The transmission control circuit of the magnetic sensor may be integrated on the circuit board to facilitate the data output of the magnetic sensor. When the magnetic detection component adopts multiple magnetic sensors, compared with adopting a single magnetic sensor, more data can be referenced during the optimization process, which ultimately makes the parameter calibration of the rotating magnet unit more accurate.

[0212] 6 and 7 , in some embodiments, the field emission unit group and the magnetic detection assembly can be installed (e.g., fixedly installed) inside the mounting shell. Specifically, the field emission unit group can be fixedly installed in the middle of the mounting shell, and the magnetic detection assembly can be installed on the inner side wall of the mounting shell. For example, when the magnetic detection assembly includes a circuit board and a magnetic sensor mounted on the circuit board, the circuit board can be directly fixedly installed on the inner side wall of the mounting shell. If there are two groups of magnetic detection assemblies, the two groups of magnetic detection assemblies can be fixedly installed on the top wall and bottom wall of the mounting shell, respectively.

[0213] Accordingly, referring to Figures 29 and 30, Figures 29 and 30 are exemplary schematic diagrams of another field transmitter structure shown in some embodiments of this specification. In some embodiments, the field emission unit group is installed inside the mounting shell, and the magnetic detection component is detachably or non-detachably installed on the outside of the mounting shell. The magnetic detection component can be installed above the mounting shell through corresponding connecting fixtures. At this time, in order to ensure that the installation position of the magnetic detection component is the same as the design position, a corresponding positioning groove can be provided on the mounting shell, and the magnetic detection component is provided with a positioning protrusion that matches the positioning groove. Through the matching of the positioning groove and the positioning protrusion, after the magnetic detection component is installed, its relative posture with the mounting shell meets the design requirements and is fixed.

[0214] In the above embodiment, regardless of whether the magnetic detection assembly is installed inside or outside the mounting housing, the spatial position of the magnetic detection assembly relative to the mounting housing is fixed. Therefore, the spatial position of the magnetic detection assembly in the field transmitter body coordinate system is relatively fixed.

[0215] In some embodiments, the magnetic detection assembly includes multiple magnetic sensors (e.g., eight) distributed inside the mounting housing of the field transmitter. The multiple magnetic sensors are spaced a certain distance apart so as to be as evenly distributed as possible within the mounting housing. The multiple magnetic sensors are fixedly connected to the mounting housing of the field transmitter (after the magnetic sensors are installed, they can be fixed with glue) and jointly define a coordinate system {s}, which is the coordinate system of the field transmitter body. Therefore, the position of each magnetic sensor within the coordinate system {s} is fixed. The magnetic sensor can be any type of magnetic sensor, such as a single-axis or three-axis induction coil, a three-axis MEMS sensor, etc. The side of the mounting housing of the field transmitter also has several coils (e.g., four) for interference detection. These coils constitute a magnetic source assembly, with one coil provided on each side surface of the mounting housing. The coils are used to generate a designed magnetic field signal, such as a sinusoidal signal or a square wave signal, which can be detected by the magnetic sensor.

[0216] In some embodiments, the field transmitter includes a magnetic source assembly 120 , and the spatial position of the magnetic source assembly 120 in the field transmitter is fixed.

[0217] The magnetic source component can generate a detection magnetic field when it is in operation. When the magnetic source component is in operation, the magnetic detection component is also used to detect the detection magnetic field generated by the magnetic source component. For example, the magnetic detection component includes a magnetic sensor, and the magnetic sensor can be used to detect the detection magnetic field generated by the magnetic source component. In some embodiments, when the field transmitter includes a magnetic source component but does not include a magnetic detection component, the detection magnetic field generated by the magnetic source component can also be received by other detection components. For example, when the field transmitter includes a self-detection component, the detection magnetic field generated by the magnetic source component can also be received by the self-detection component. For another example, the detection magnetic field generated by the magnetic source component can also be received by other detection components other than the field transmitter.

[0218] Detecting the magnetic field can be used to detect whether there is magnetic field interference in the working environment of the field transmitter, for example, interference detection.

[0219] In some embodiments, the magnetic source assembly includes a plurality of coils, and the plurality of coils are evenly distributed around the circumference of the plurality of rotating magnet units.

[0220] In this embodiment, the magnetic source assembly utilizes multiple coils with controllable magnetic fields. These coils generate a detection magnetic field when powered on and do not generate one when powered off. Therefore, when interference detection is required, the coils are turned on to generate a detection magnetic field, while at other times, they are turned off to prevent the detection magnetic field from impacting other functions of the field transmitter. Turning on a coil refers to energizing the coil, while turning off a coil refers to de-energizing the coil. Furthermore, multiple coils are evenly distributed around the rotating magnet unit assembly, for example, they can be fixedly mounted on the sides of the field transmitter's mounting housing 130. Considering that smaller magnetic field sources can have a localized effect on the field transmitter's magnetic field, for example, affecting the field transmitter's magnetic field only in a specific direction, multiple coils are provided, distributed around the field transmitter, each used to detect the presence of an interference source in a corresponding direction. During detection, each coil generates a detection signal and performs a phase comparison test, thereby providing a more comprehensive understanding of the conditions surrounding the field transmitter.

[0221] In this embodiment, the magnetic source assembly is used to provide a detection magnetic field, and the spatial position of the magnetic source assembly in the coordinate system of the field transmitter is relatively fixed. Therefore, when the detection magnetic field provided by the magnetic source assembly remains unchanged, the magnetic field signal obtained by the magnetic sensor detecting the detection magnetic field should remain unchanged. If the magnetic field data obtained by the magnetic sensor detecting the detection magnetic field changes compared to the reference detection magnetic field data, it means that there is a magnetic field interference source around the field transmitter. Among them, the reference detection magnetic field data refers to the magnetic field data that should be obtained by the magnetic sensor detecting the detection magnetic field in an environment without interference sources. The interference source will affect the self-calibration of the field transmitter and the accuracy of electromagnetic navigation, so it is necessary to promptly eliminate the interference source around the field transmitter.

[0222] The spatial position of the magnetic detection assembly within the field transmitter is relatively fixed. For example, the center of mass and orientation of the magnetic detection assembly within the field transmitter are fixed. The spatial position of the magnetic detection assembly within the field transmitter can be pre-calibrated. Similarly, the spatial position of the rotating magnet unit assembly within the field transmitter is also relatively fixed and can be pre-calibrated.

[0223] Typically, field transmitters undergo rigorous calibration before leaving the factory to determine the corresponding calibration parameters, such as the position coordinates of the magnet center of each rotating magnet unit in the field transmitter's body coordinate system, the magnetic moment strength, and other magnet-related parameters. However, due to the inevitable impact of collisions, thermal expansion and contraction, mechanical fatigue, and equipment aging during use, field transmitters will cause the magnet-related parameters to change compared to the calibration parameters. If the electromagnetic navigation positioning algorithm continues to use the initial calibration parameters, positioning accuracy will decrease.

[0224] To address the above issues, the present specification provides a position magnetic detection assembly between the magnetic detection assembly and the rotating magnet unit in the field transmitter, including at least one magnetic sensor. When the magnetic detection assembly is in operation, the magnetic sensor is used to detect the calibration magnetic field generated by the rotating magnet unit. The magnetic sensor can be any type of magnetic field sensor, such as a single-axis or three-axis induction coil, a three-axis MEMS (Micro Electro Mechanical System) magnetic sensor, or the like.

[0225] When calibrating the parameters of any rotating magnet unit in the field transmitter, it is necessary to operate the target rotating magnet unit to be calibrated, while shutting down other non-target rotating magnet units. Non-target rotating magnet units will not generate a time-varying magnetic field. Operating a rotating magnet unit means putting the rotating magnet unit in an operating state, such as by driving the permanent magnet to rotate through its internal motor. At this time, the rotating magnet unit will generate a time-varying magnetic field. Shutting down a rotating magnet unit means putting the rotating magnet unit in a non-operating state, such as by locking its internal permanent magnet so that it cannot rotate. At this time, the rotating magnet unit will not generate a time-varying magnetic field. The target rotating magnet unit operates alone to generate a time-varying calibration magnetic field, and the magnetic sensor in the magnetic detection component detects this calibration magnetic field to obtain the measured calibration magnetic field data of the calibration magnetic field at the magnetic sensor. Since the positional relationship between the magnetic sensor and the target rotating magnet unit is known and fixed, the model calibration magnetic field data of the calibration magnetic field at the magnetic sensor can be calculated using the magnetic field model of the target rotating magnet unit.

[0226] If all the magnet-related parameters in the magnetic field model are accurate in accordance with the current actual state of the target rotating magnet unit, then the measured calibration magnetic field data and the model calibration magnetic field data should be consistent. If there is an error between the measured calibration magnetic field data and the model calibration magnetic field data, it means that the various magnet-related parameters in the magnetic field model do not conform to the current actual state of the target rotating magnet unit. This means that the target rotating magnet unit has undergone a state change during operation, and the magnet-related parameters of the target rotating magnet unit need to be recalibrated. Specifically, the calibration method is to minimize the error between the measured calibration magnetic field data and the model calibration magnetic field data as the optimization goal, continuously optimize and adjust the magnet-related parameters of the target rotating magnet unit, and finally obtain calibration parameters that conform to the current actual state of the target rotating magnet unit.

[0227] In some embodiments, for multiple rotating magnet units in a field transmitter, the above-described method can be used to sequentially perform parameter calibration on the rotating magnet units, with only one rotating magnet unit being run for each parameter calibration, that is, only one rotating magnet unit is determined as the target rotating magnet unit at a time. Since the relevant data of each rotating magnet unit is collected separately, data processing can be simplified. Accordingly, in other embodiments, for multiple rotating magnet units in a field transmitter, the above-described method can be used to simultaneously perform parameter calibration on multiple or all rotating magnet units, with multiple or all rotating magnet units being run for each parameter calibration, that is, multiple or all rotating magnet units are determined as the target rotating magnet units.

[0228] Because a magnetic detection assembly is provided, the calibration magnetic field generated by the rotating magnet unit can be detected by the magnetic sensor within the assembly. Furthermore, the measured calibration magnetic field data output by the magnetic sensor can be used to calibrate the magnet-related parameters of the corresponding rotating magnet unit, obtaining calibration parameters that match the actual state of the rotating magnet unit. Updating the calibration parameters of each rotating magnet unit in the magnetic field model makes the calculated results of the magnetic field model more accurate, thereby improving the accuracy of electromagnetic navigation.

[0229] During the calibration process of the rotating magnet unit, multiple magnetic sensors simultaneously detect the calibration magnetic field generated by the target rotating magnet unit (the rotating magnet unit being calibrated) and output their respective measured calibration magnetic field data. The magnetic field model can be used to calculate the model calibration magnetic field data of the working magnetic field at each magnetic sensor. At this time, the error between the measured calibration magnetic field data and the model calibration magnetic field data corresponding to the same spatial position can be calculated separately. Then, with the minimization of the cumulative error or error mean of the magnetic field data at multiple spatial positions as the optimization goal, the magnet-related parameters of the target rotating magnet unit are continuously optimized and adjusted, and finally the calibration parameters that meet the current actual state of the target rotating magnet unit are obtained.

[0230] Some embodiments of this specification provide rotating magnet units and field transmitters including these units, as well as their configurations and methods of use. This field transmitter is a time-varying magnetic field transmitter based on rotating magnet units and can be used in various scenarios, including surgical navigation. The field transmitter includes at least one rotating magnet unit (TxU), which offers the advantages of simplicity and stability. Rotating magnet units can be combined into more complex field transmitters using pre-defined combination principles. The field transmitter has good scalability and is easy to calibrate, maintain, and replace.

[0231] FIG10 is an exemplary flow chart of a method for controlling a field transmitter according to some embodiments of this specification. In some embodiments, the process 1000 shown in FIG10 may be executed by a processing device (e.g., processor 13). In some embodiments, the process 1000 may include the following operations.

[0232] In some embodiments, the field transmitter used to implement process 1000 includes multiple rotating magnet units, at least one of which includes a magnet and a drive assembly, the drive assembly being connected to the magnet for driving the magnet to rotate. For each rotating magnet unit in the field transmitter, the operations shown in the following steps 1002-1006 can be performed to generate a time-varying magnetic field. Process 1000 can be applied to all field transmitters provided in this specification, such as the field transmitters shown in Figures 2 to 5, field transmitters including self-test components, field transmitters including magnetic detection components, field transmitters including magnetic source components, and the like.

[0233] Step 1002: Determine the interaction torque exerted on the magnet of the rotating magnet unit from the magnets of other rotating magnet units.

[0234] Interaction torque refers to the torque generated between two or more magnets due to the interaction of their magnetic fields.

[0235] In some embodiments, calculating the interaction torque exerted on the magnet of each rotating magnet unit in the field transmitter by the magnets of other rotating magnet units may include: determining the target rotating magnet unit to be calculated in the field transmitter; calculating the target magnetic field time-varying characteristics of the resultant magnetic field at the magnet of the target rotating magnet unit, and calculating the target magnetic moment time-varying characteristics of the magnet of the target rotating magnet unit; wherein the resultant magnetic field is jointly generated by non-target rotating magnet units in the field transmitter; and determining the time-varying characteristics of the interaction torque exerted on the magnet of the target rotating magnet unit based on the target magnetic field time-varying characteristics and the target magnetic moment time-varying characteristics.

[0236] The combined magnetic field is the magnetic field formed by the superposition of the individual magnetic fields generated by multiple rotating magnet units. For example, when the relative distance between the rotating magnet units exceeds several times the magnet size (e.g., 4 times), the interaction torque can be approximated using the dipole model.

[0237] It should be noted that, for a field transmitter including only a single rotating magnet unit, the other rotating magnet units here may be rotating magnet units from other field transmitters (eg, field transmitters located in the same space as the field transmitter).

[0238] The process of determining the interaction torque exerted on the magnet of the target rotating magnet unit includes: first calculating the time-varying characteristics of the magnetic field of the resultant magnetic field generated by other rotating magnet units at the magnet of the target rotating magnet unit; then calculating the time-varying characteristics of the magnetic moment of the magnet of the target rotating magnet unit based on the absolute position encoder data of the target rotating magnet unit; and finally calculating the time-varying characteristics of the interaction torque exerted on the magnet of the target rotating magnet unit.

[0239] The time-varying characteristics of each physical quantity can be characterized sequentially. This involves multiplying the magnetic field vector of the resultant magnetic field at each moment by the magnetic moment vector of the magnet. This vector product is the interaction torque experienced by the magnet at that moment. The time-varying characteristics of the interaction torque experienced by the magnet include the interaction torque experienced by the magnet at each moment.

[0240] When the field transmitter is small and the magnet is large, the Dipole model is not accurate enough and finite element analysis (FEA) may be needed for simulation. Therefore, in some embodiments, the time-varying characteristics of the interaction torque to which the magnets of each rotating magnet unit are subjected can be determined by simulation. Specifically, the field transmitter structure is modeled in simulation software, and the operating parameters of each component are set, such as the rotation speed, magnet strength, and magnetic moment direction of each rotating magnet unit. The interaction torque between the magnets of each rotating magnet unit is calculated by simulation software.

[0241] In some embodiments, before determining the interaction torque between the magnets of each rotating magnet unit, the relative positions of the rotating magnet units can also be determined. Specifically, the coordinate information of each rotating magnet unit in the field transmitter coordinate system can be determined.

[0242] Step 1004 : Using the interaction torque exerted on the magnet of the rotating magnet unit as a feedforward input of its own drive, and determining the drive current of the drive component.

[0243] When the field transmitter is operating, each rotating magnet unit operates simultaneously and generates a single, time-varying magnetic field. The single, time-varying magnetic field generated by each rotating magnet unit affects the other rotating magnet units. Therefore, the driving load of each rotating magnet unit when operating simultaneously differs from the driving load when operating individually. To ensure that the magnets of each rotating magnet unit can stably rotate at a preset speed during field transmitter operation, the driving current of each rotating magnet unit must be modulated. In this specification, the interaction torque exerted on the magnets of each rotating magnet unit by the magnets of other rotating magnet units is calculated during field transmitter operation. For each rotating magnet unit, the interaction torque exerted on its magnets is used as a feedforward input to its own drive assembly. The driving current can then be modulated based on the time-varying characteristics of the interaction torque. For example, when the interaction torque is large, creating significant resistance to the magnet's rotation, the driving current intensity can be increased.

[0244] Step 1006 : Control the driving component to drive the rotating magnet unit to rotate according to the driving current, thereby generating a time-varying magnetic field.

[0245] When the driving component applies a driving current to rotate the rotating magnet unit, the relative position of the magnet in space changes continuously, causing the magnetic field it generates to change accordingly.

[0246] In this embodiment, each rotating magnet unit in the field transmitter can adjust the drive current in a timely manner based on the interaction torque, significantly improving the rotational control precision of the magnets and making the motor in the drive assembly more stable. This solves the problem of low rotational control precision of the magnets by each rotating magnet unit in existing field transmitters.

[0247] FIG11 is an exemplary flow chart for determining a time-varying characteristic according to some embodiments of this specification. In some embodiments, process 1100 shown in FIG11 may be performed by a processing device (e.g., processor 13) or an electromagnetic navigation system. As shown in FIG11 , process 1100 may include the following operations.

[0248] In some embodiments, a field transmitter for implementing process 1100 includes a plurality of rotating magnet units, at least one of which includes a magnet and a drive assembly, the drive assembly being coupled to the magnet for driving the magnet to rotate. For each rotating magnet unit in the field transmitter, process 1100 can be executed to generate a time-varying magnetic field. Process 1100 can be applied to all field transmitters provided herein, such as the field transmitters of Figures 2 through 5, field transmitters including self-test components, field transmitters including magnetic detection components, field transmitters including magnetic source components, and the like.

[0249] Step 1102: Determine one of the rotating magnet units in the field transmitter as a first target rotating magnet unit.

[0250] In some embodiments, the processor may designate a rotating magnet unit in the field transmitter as the first target rotating magnet unit, or may randomly determine one of the multiple rotating magnet units in the field transmitter as the first target rotating magnet unit.

[0251] Step 1104 : Determine the time-varying characteristics of the target magnetic field of the resultant magnetic field at the magnet of the first target rotating magnet unit.

[0252] In some embodiments, the resultant magnetic field is jointly generated by the non-first target rotating magnet units in the field transmitter. The time-varying characteristics of the target magnetic field of the resultant magnetic field at the magnet of the first target rotating magnet unit can be detected by a magnetic sensor.

[0253] Step 1106 : Determine the time-varying characteristics of the target magnetic moment of the magnet of the first target rotating magnet unit.

[0254] The target magnetic moment time-varying characteristic refers to the time-varying property of the magnet of the first target rotating magnet unit.

[0255] In some embodiments, the time-varying characteristics of the target magnetic moment can also be detected by a magnetic sensor.

[0256] Step 1108 : Determine the time-varying characteristics of the interaction torque acting on the magnet of the first target rotating magnet unit according to the time-varying characteristics of the target magnetic field and the time-varying characteristics of the target magnetic moment.

[0257] As described above, the time-varying characteristics of each target magnetic field and target magnetic moment can be characterized sequentially. The magnetic field vector of the resultant magnetic field at each moment is then multiplied by the magnetic moment vector of the first target rotating magnet unit to obtain a vector product. This vector product represents the interaction torque experienced by the magnet of the first target rotating magnet unit at that moment. The time-varying characteristics of this interaction torque can then be determined through simulation.

[0258] The interaction torque exerted on the magnets of each rotating magnet unit in the field transmitter can be obtained through process 1000 and process 1100 .

[0259] FIG12 is an exemplary flow chart of a method for controlling a field transmitter according to some embodiments of this specification. In some embodiments, process 1200 shown in FIG12 can be executed by a processing device (e.g., processor 13) or an electromagnetic navigation system. As shown in FIG12, process 1200 can include the following operations.

[0260] The control method for a field transmitter disclosed in this embodiment can be applied to a field transmitter that may include multiple rotating magnet units, at least one of which includes a drive assembly and a magnet. Process 1200 can be applied to all field transmitters provided in this specification, such as the field transmitters shown in Figures 2 through 5 , field transmitters including self-test assemblies, field transmitters including magnetic detection assemblies, and field transmitters including magnetic source assemblies.

[0261] Step 1202 : Control the magnets of the rotating magnet unit with the same initial magnetic moment direction to generate different rotational speeds.

[0262] In some embodiments, when there are rotating magnet units with the same initial magnetic moment direction, the magnets of the rotating magnet units with the same initial magnetic moment direction can be controlled to generate different rotational speeds.

[0263] The magnetic moment direction of the rotating magnet is the magnetic moment direction of the magnet itself, and the initial magnetic moment direction of the rotating magnet is the magnetic moment direction of the rotating magnet before the drive control method is executed. When a field transmitter includes multiple rotating magnet units, the initial magnetic moment directions of the multiple rotating magnet units can be the same or different. For rotating magnet units with different initial magnetic moment directions, the rotational speeds of the magnets during operation can be the same or different.

[0264] Step 1204 : Control the magnets of the rotating magnet unit with different initial magnetic moment directions to generate the same rotation speed.

[0265] In some embodiments, some field transmitters may include rotating magnet units with the same initial magnetic moment direction. During operation, the magnets of these rotating magnet units need to be controlled to produce different rotational speeds to facilitate decoupling of the field transmitter's operating status data during data processing. It should be noted that the magnets in the rotating magnet units are typically driven by a motor, so the magnet's rotational speed can be controlled by controlling the operating current or voltage of the corresponding motor.

[0266] Different magnets use different rotational speeds to facilitate data decoupling. Therefore, in some embodiments, the rotational speeds of the magnets of multiple rotating magnet units are different. In addition, data decoupling can also be performed using the direction of the magnetic moment, that is, there is a phase difference between the directions of the magnetic moments of different rotating magnet units. Therefore, the magnets of rotating magnet units with different initial magnetic moment directions can use the same rotational speed, and data decoupling can be performed using the phase difference in the direction of the magnetic moment. In this way, the drive control of the field transmitter can be simplified. For example, for a field transmitter including four rotating magnet units, it is assumed that the initial magnetic moment directions of the first three rotating magnet units are perpendicular to each other, and the initial magnetic moment direction of the last rotating magnet unit is the same as the initial magnetic moment direction of any other rotating magnet unit. Then the magnets of the first three rotating magnet units can use the same rotational speed (such as 20 Hz), and the magnets of the last rotating magnet unit can use another rotational speed (such as 10 Hz).

[0267] It should be noted that when the motor cannot achieve a higher speed, such as when the maximum speed is only 20Hz. If the speeds of the magnets of different rotating magnet units are different, the speed difference between different magnets will be relatively small, which is not conducive to data decoupling between rotating magnet units with the same initial magnetic moment direction, and the complexity of speed control is relatively high. Controlling the magnets of rotating magnet units with different initial magnetic moment directions to produce the same speed, and controlling the magnets of rotating magnet units with the same initial magnetic moment direction to produce different speeds, can facilitate data decoupling, maintain positioning accuracy, and reduce the complexity of speed control.

[0268] It should be noted that before the field transmitter is operational, the initial magnetic moment directions of each rotating magnet unit can be adjusted so that some rotating magnet units have different initial magnetic moment directions. This allows the magnets of rotating magnet units with different initial magnetic moment directions to be controlled to produce the same rotational speed during operation, simplifying the drive control of the field transmitter.

[0269] In some embodiments, different initial magnetic moment directions refer to the initial magnetic moment directions being perpendicular to each other. Thus, in this embodiment, the magnets of the rotating magnet units with the initial magnetic moments directions being perpendicular to each other can be controlled to generate the same rotational speed.

[0270] It should be noted that there is no necessary relationship between step 1202 and step 1204, and step 1202 and step 1204 can be performed independently.

[0271] FIG13 is an exemplary flow chart of a self-test method for a rotating magnet unit according to some embodiments of this specification. In some embodiments, process 1300 shown in FIG13 can be performed by a processing device (e.g., processor 13) or an electromagnetic navigation system. As shown in FIG13 , process 1300 can include the following operations.

[0272] The self-test method of the rotating magnet unit disclosed in this embodiment can be applied to the rotating magnet unit including the self-test component described above.

[0273] Step 1302: Control the driving assembly to drive the magnet to rotate at a preset speed.

[0274] In some embodiments, a driving control signal may be sent to a driving component of the field transmitter so that the driving component drives the magnet to rotate at a preset speed to generate a rated magnetic field.

[0275] Step 1304: Acquire the current time-varying magnetic field signal of the magnet.

[0276] Current Time-Varying Magnetic Field Signal The current time-varying magnetic field signal can be obtained by the self-detection component detecting the magnetic field signal generated by the magnet during rotation.

[0277] Step 1306 : Determine the signal difference between the current time-varying magnetic field signal of the magnet and the reference time-varying magnetic field signal, and determine the self-test result of the rotating magnet unit according to the signal difference.

[0278] The reference time-varying magnetic field signal is the time-varying magnetic field signal that the self-test component should detect when the rotating magnet unit is operating normally and the magnet rotates at a preset speed. The reference time-varying magnetic field signal can be obtained by detecting the magnetic field signal generated when the magnet rotates at a preset speed using the magnetic detection component in the initial state of the rotating magnet unit. For example, it can be a time-varying magnetic field signal obtained by simulating a normal rotating magnet unit; it can also be a time-varying magnetic field signal detected by the self-test component when the rotating magnet leaves the factory.

[0279] In some embodiments, the reference time-varying magnetic field signal can be obtained by detecting the magnetic field signal generated when the magnet rotates at the preset speed through the self-test component in the initial state of the rotating magnet unit (it is necessary to ensure that only the magnetic field generated by the rotation of the magnet of the rotating magnet unit is present without other interfering magnetic fields).

[0280] In some embodiments, the signal difference between the current time-varying magnetic field signal of the magnet and the reference time-varying magnetic field signal can be obtained in the following manner.

[0281] For example, the preset speed can be between 10Hz and 100Hz. The self-test process mainly involves rotating the magnet through the drive component. During the magnet's rotation, the self-test component detects the magnetic field signal generated by the magnet to obtain the current time-varying magnetic field signal of the magnet during this self-test process. The current time-varying magnetic field signal reflects the time-varying characteristics of the magnetic field generated by the current magnet at the self-test component. After obtaining the current time-varying magnetic field signal, it is compared with the reference time-varying magnetic field signal to determine the signal difference between the two. Then, the self-test result of the rotating magnet unit can be determined based on this signal difference.

[0282] In some embodiments, the operating state of the field transmitter can be determined based on the self-test result of the rotating magnet unit determined by the signal difference, for example, normal operating state, abnormal operating state, etc.

[0283] In this embodiment, a specific determination method of the reference time-varying magnetic field signal is provided. The initial state of the rotating magnet unit refers to the state after strict strength and magnetic moment direction calibration, which can usually be the factory state. The rotating magnet unit will undergo strict strength and magnetic moment direction calibration when leaving the factory. At this time, the self-test is performed by the magnetic detection component, and the reference time-varying magnetic field signal obtained has a good reference significance. The reference time-varying magnetic field signal corresponds to the calibration characteristics of the rotating magnet unit (the calibration strength and magnetic moment direction of the magnet). If the subsequent time-varying magnetic field signal changes compared to the reference time-varying magnetic field signal, it means that the real-time characteristics of the rotating magnet unit have changed compared to the calibration characteristics. In some cases, the characteristic changes of the rotating magnet unit can be determined based on the changes in the time-varying magnetic field signal.

[0284] In this embodiment, the magnetic field signal generated by the magnet can be detected by a self-test component. By comparing the current time-varying magnetic field signal of the magnet with a reference time-varying magnetic field signal, it can be determined whether the rotating magnet unit has experienced any abnormal usage. This method can be used to self-test the rotating magnet unit before each use, or it can be used to self-test the rotating magnet unit regularly or irregularly. This self-test can promptly identify problems with the rotating magnet unit, preventing the field transmitter from generating a time-varying magnetic field that deviates from the standard during operation, ultimately ensuring the positioning accuracy of the receiving device. This solves the problem that, when an abnormality occurs in the existing rotating magnet unit, the field transmitter generates a time-varying magnetic field that deviates from the standard during operation, ultimately reducing the positioning accuracy of the receiving device.

[0285] FIG14 is an exemplary flow chart of determining a self-test result according to some embodiments of this specification. In some embodiments, process 1400 shown in FIG14 can be performed by a processing device (e.g., processor 13) or an electromagnetic navigation system. As shown in FIG14, process 1400 may include the following operations.

[0286] In some embodiments, determining the signal difference between the current time-varying magnetic field signal of the magnet and the reference time-varying magnetic field signal may include the following operations.

[0287] Step 1402: Determine the current magnetic field strength and the proportional relationship between the components of the working magnetic field based on the current time-varying magnetic field signal.

[0288] Step 1404: Determine the intensity difference between the current magnetic field intensity and the reference magnetic field intensity.

[0289] The reference magnetic field strength may be determined based on a reference time-varying magnetic field signal.

[0290] Step 1406 : Determine the proportional difference between the proportional relationship of each component in the current time-varying magnetic field signal and the proportional relationship of each component in the reference time-varying magnetic field signal.

[0291] The difference between the current time-varying magnetic field signal and the reference time-varying magnetic field signal includes the intensity difference and the ratio difference.

[0292] Step 1408 : Determine a self-test result of the rotating magnet unit according to the intensity difference and the ratio difference.

[0293] During the implementation of the above steps, the current time-varying magnetic field signal output by the self-test component can first be obtained. The sampling rate of the self-test component can be 100Hz to 1000Hz. For example, the current time-varying magnetic field signal is a magnetic field vector waveform (Bx(t), By(t), Bz(t)), which has corresponding components Bx(t), By(t), and Bz(t) in three orthogonal directions. The current magnetic field strength and the proportional relationship between the components are then calculated based on the current time-varying magnetic field signal. If the measured current magnetic field strength decreases significantly relative to the reference magnetic field strength (the magnetic field strength corresponding to the reference time-varying magnetic field signal), such as a 5% decrease (the ratio of the difference between the current magnetic field strength and the reference magnetic field strength to the reference magnetic field strength), this fully indicates a 5% degradation in magnetic strength. Therefore, the magnetic moment strength value |M| of the rotating magnet unit needs to be corrected in the subsequent navigation and positioning algorithm model. The proportional relationship between the components is Bx(t):By(t):Bz(t). Each component includes multiple frequency components, and the proportional relationship between the components includes the proportional relationship between at least one frequency component of the same frequency component of each component. For example, an information sequence over a period of time can be selected and analyzed using a fast Fourier transform to obtain the intensity values ​​of the main frequency components or the stronger frequency components of each component: Bx1, Bx2…, By1, By2,… and Bz1, Bz2,…. The proportional relationship between the different frequency components of each component is then obtained: Bx1:By1:Bz1, Bx2:By2:Bz2,…. For comparison, the ratio of the frequency components of each component in the current time-varying magnetic field signal is compared with the ratio of the corresponding frequency components of each component in the reference time-varying magnetic field signal. If the proportional relationship between the components of the self-test magnetic field changes beyond the limit, it may be due to a change in the magnetic moment direction of the magnet, looseness of the mechanical structure, or surrounding interference (such as ferromagnetic materials, other time-varying magnetic fields, etc.), and the rotating magnet unit needs further inspection. Among them, when the ratio relationship of at least one frequency component of each component in the current time-varying magnetic field signal exceeds the limit, it can be determined that there is an abnormality in the rotating magnet unit. In some embodiments, for each sampling time point, a first comparison result of the current magnetic field intensity and the reference magnetic field intensity is determined, as well as a second comparison result of the ratio relationship of each frequency component of each component in the current time-varying magnetic field signal and the ratio relationship of the corresponding frequency component of each component in the reference time-varying magnetic field signal. Then, a first mean of the first comparison result of all sampling points and a second mean of the second comparison result are determined. If at least one of the first mean and the second mean exceeds the limit, it can be determined that there is an abnormality in the rotating magnet unit. For example, when the mean of the ratio relationship of at least one frequency component of each component at all sampling time points exceeds the limit, it can be determined that there is an abnormality in the rotating magnet unit.

[0294] It should be noted that the above self-test process is an example of comparing the strength values ​​of the current time-varying magnetic field signal and the reference time-varying magnetic field signal. In some embodiments, the strength value and magnetic field direction of the current time-varying magnetic field signal can also be compared.

[0295] FIG15 is an exemplary flow chart of a self-test method for a field transmitter according to other embodiments of this specification. In some embodiments, process 1500 shown in FIG15 can be executed by a processing device (e.g., processor 13) or an electromagnetic navigation system. As shown in FIG15 , process 1500 may include the following operations.

[0296] The field transmitter self-test method disclosed in this embodiment can be applied to a field transmitter in which at least one rotating magnet unit includes a driving component, a magnet, and a self-test component.

[0297] Step 1502: Determine a target rotating magnet unit to be self-checked in the field transmitter, and lock (for example, using a locking assembly) the angular position of the magnet of the non-target rotating magnet unit.

[0298] In some embodiments, before controlling at least one of the rotating magnet units to rotate at the preset speed, one of the rotating magnet units in the field transmitter is determined to be a non-target rotating magnet unit; and the angular position of the magnet of the non-target rotating magnet unit is locked.

[0299] Step 1504: Control the driving assembly to drive the magnet of the target rotating magnet unit to rotate at a preset speed.

[0300] Step 1506: Acquire the current time-varying magnetic field signal of the magnet.

[0301] The current time-varying magnetic field signal is obtained by the self-detection component detecting a magnetic field signal generated by the magnet during rotation.

[0302] Step 1508 : Determine a signal difference between the current time-varying magnetic field signal of the magnet and a reference time-varying magnetic field signal corresponding to the preset rotation speed, and determine a self-test result of the rotating magnet unit according to the signal difference.

[0303] Specifically, when a field transmitter utilizes the rotating magnet unit provided in this specification, the self-test method for rotating magnet units provided in this specification can also be used to self-test each rotating magnet unit in the field transmitter. That is, any embodiment of the self-test method for rotating magnet units described above can be used to self-test each rotating magnet unit in the field transmitter. When performing a self-test on a target rotating magnet unit, it is necessary to eliminate interference from other magnetic fields. Therefore, it is necessary to disable non-target rotating magnet units in the field transmitter, i.e., lock the angular position of the magnets of the non-target rotating magnet units. The self-test method for rotating magnet units provided in this specification is then used to self-test the target rotating magnet unit.

[0304] Through the above method, each rotating magnet unit in the field transmitter is self-tested in sequence. Before each use of the field transmitter, the user can perform a self-test on each rotating magnet unit using the internal self-test component. This self-test promptly identifies problematic rotating magnet units, preventing the field transmitter from generating a time-varying magnetic field that deviates from the standard during operation, and ultimately ensuring the positioning accuracy of the self-test component. This solves the problem that existing field transmitters lack a self-test function, preventing abnormalities in rotating magnet units from being detected promptly through self-test, resulting in the field transmitter generating a time-varying magnetic field that deviates from the standard during operation, ultimately reducing the positioning accuracy of the self-test component.

[0305] It should be noted that, when the field transmitter includes only one rotating magnet unit, the self-test result of each rotating magnet unit is also the self-test result of the rotating magnet unit.

[0306] For more details about steps 1502 to 1504 , please refer to the relevant description of FIG. 13 .

[0307] Some embodiments of this specification also disclose an electromagnetic navigation system, which includes a processor, a receiving device and a field transmitter including a drive component, a magnet and a self-test component. The receiving device is used to detect the time-varying magnetic field generated by the field transmitter, and the processor is used to control the operation of the field transmitter and determine the real-time position of the receiving device in the time-varying magnetic field based on the magnetic field detection data of the receiving device.

[0308] FIG16 is an exemplary flow chart of determining a target magnetic moment strength according to some embodiments of this specification. In some embodiments, process 1600 shown in FIG16 can be performed by a processing device (e.g., processor 13) or an electromagnetic navigation system. As shown in FIG16, process 1600 can include the following operations.

[0309] In some embodiments, the electromagnetic navigation method may include performing a self-test on the field transmitter to obtain self-test results of each rotating magnet unit in the field transmitter, for example, to determine the target magnetic moment strength of the rotating magnet unit. Exemplarily, the method may include the following operations.

[0310] Step 1602: Determine a target rotating magnet unit to be self-checked in the field transmitter, and lock the angular position of the magnets of non-target rotating magnet units.

[0311] Step 1604: Control the driving assembly to drive the magnet of the target rotating magnet unit to rotate at a preset speed.

[0312] Step 1606: Acquire the current time-varying magnetic field signal of the magnet.

[0313] The current time-varying magnetic field signal is obtained by the self-detection component detecting a magnetic field signal generated by the magnet during rotation.

[0314] Step 1608 : Determine the signal difference between the current time-varying magnetic field signal of the magnet and the reference time-varying magnetic field signal, and determine the self-test result of the rotating magnet unit according to the signal difference.

[0315] Steps 1602 to 1608 are similar to the self-test process described above and will not be repeated here.

[0316] Step 1610: For any of the rotating magnet units, determine the target magnetic moment strength of the rotating magnet unit according to the self-test result of the rotating magnet unit.

[0317] In some embodiments, the field transmitter can be self-tested using the field transmitter self-test method provided herein to obtain self-test results for each rotating magnet unit in the field transmitter. For any rotating magnet unit, the target magnetic moment strength of the rotating magnet unit can be determined based on the operating state of the rotating magnet unit.

[0318] Specifically, for an abnormal operating state of any rotating magnet, the related problem can be solved by correcting the magnetic moment strength of the rotating magnet unit.

[0319] For example, for any rotating magnet unit, if the measured current magnetic field strength decreases significantly relative to the reference magnetic field strength, the magnetic moment strength of the corresponding rotating magnet unit is corrected in the navigation and positioning algorithm. If the decrease is 5%, it fully indicates that the magnetic strength has degraded by 5%. In this case, the magnetic moment strength value |M| of the rotating magnet unit needs to be corrected in the navigation and positioning algorithm model. For example, the magnetic moment strength is reduced by 5%, and the corrected magnetic moment strength is the target magnetic moment strength. Correspondingly, if the measured current magnetic field strength is the same as or similar to the reference magnetic field strength, that is, the decrease is less than the threshold, then there is no need to correct the magnetic moment strength of the rotating magnet unit, and the original magnetic moment strength is the target magnetic moment strength.

[0320] The field transmitter in the electromagnetic navigation system provided in this manual has a self-test function. Before the system locates the receiving device, the user can perform a self-test on each rotating magnet unit in the field transmitter through its internal self-test component. The self-test can promptly detect rotating magnet units with problems and correct the magnetic moment strength of the corresponding rotating magnet unit to keep the actual value of the time-varying magnetic moment characteristic consistent with the model value, thereby avoiding the field transmitter from generating a time-varying magnetic field that deviates from the standard during operation, and ultimately ensuring the positioning accuracy of the self-test component.

[0321] In some embodiments, determining the real-time position of the receiving device in the time-varying magnetic field (electromagnetic navigation method) includes: acquiring magnetic field data of the time-varying magnetic field generated by the field transmitter; wherein the magnetic field data of the time-varying magnetic field is obtained by the receiving device detecting the time-varying magnetic field; and determining the real-time position of the receiving device in the time-varying magnetic field based on the magnetic field data of the time-varying magnetic field and the time-varying characteristics of the time-varying magnetic field.

[0322] A receiving device refers to a magnetic sensor or a device containing a magnetic sensor. During operation, the electromagnetic navigation system generates a time-varying magnetic field from a field transmitter, and the receiving device moves within this field. The magnetic field data detected by the magnetic sensor and the time-varying characteristics of the field can be used to determine the receiving device's position in real time.

[0323] In some embodiments, the time-varying characteristics of the time-varying magnetic field include the time-varying characteristics of the magnetic moment of each rotating magnet unit in the field transmitter in the field transmitter coordinate system, and the time-varying characteristics of the magnetic moment include the time-varying characteristics of the magnetic moment direction and the magnetic moment intensity.

[0324] The electromagnetic navigation process is essentially a real-time positioning process for a receiving device. During real-time positioning, each rotating magnet unit rotates at a different frequency, and each receiving device to be positioned collects magnetic field data in real time. The receiving device is a magnetic sensor or a device containing a magnetic sensor.

[0325] Typically, positioning algorithms require two data inputs: magnetic field data from each receiving device within a time window, and angular data sequences from the absolute position encoders of each rotating magnet unit. The angular data sequences are used to determine the time-varying characteristics of the time-varying magnetic field; these characteristics include the time-varying magnetic moment characteristics of each rotating magnet unit in the field transmitter's coordinate system.

[0326] The time-varying characteristics of the magnetic moment mainly include the time-varying characteristics of the magnetic moment direction and the magnetic moment intensity. The magnetic moment intensity remains unchanged by default within the time window, and the angle data sequence of the absolute position encoder can determine the time-varying characteristics of the magnetic moment direction.

[0327] After the two data are input, the clocks of the two data are aligned. That is, the algorithm requires the magnetic field data at each moment and the magnetic moment direction of each rotating magnet unit at that moment. These two data can be input into a nonlinear optimization solver or a Kalman filter for solution. The objective function of the optimization solution is shown in formula (2):

[0328] Among them, M i (t) and P i (t) are the magnetic moment vector and position coordinates of the i-th rotating magnet unit 100 in the field transmitter body coordinate system at time t; P x is the position coordinate of the magnetic sensor in the field transmitter body coordinate system; R x B is the rotation matrix of the magnetic sensor relative to the field transmitter body coordinate system; x (t) is the expression of the resultant magnetic field vector collected by the magnetic sensor in its own coordinate system. Therefore, the above optimization goal is to determine the optimal sensor position P x and Posture R x , so that the difference between the magnetic field model and the measured magnetic field is minimized.

[0329] It should be noted that the above solution algorithm does not require separation of the magnetic field, and can directly use the combined magnetic field measurement value and the combined magnetic field model.

[0330] In some embodiments, the real-time posture of the receiving device in the time-varying magnetic field is determined based on the magnetic field data of the time-varying magnetic field and the time-varying characteristics of the time-varying magnetic field, including: calculating the posture of the receiving device in the time-varying magnetic field in real time based on the magnetic field data of the time-varying magnetic field and the time-varying characteristics of the time-varying magnetic field within a real-time time window; wherein the window width of the real-time time window is determined based on the real-time requirements of the posture calculation of the receiving device.

[0331] Specifically, the navigation and positioning algorithm requires data within a real-time time window to locate the receiving device, but there is no quantitative relationship between the width of this time window and the rotation period of the rotating magnet unit. The window width can be adjusted according to the actual signal-to-noise ratio and real-time requirements. When the real-time requirements are not high, the width of the sliding real-time time window can be longer, so that the signal-to-noise ratio of the solution is higher; when the real-time requirements are relatively high, the width of the sliding real-time time window needs to be shortened, which may cause a certain degree of "jitter" in the positioning results. The reason is that the data signal-to-noise ratio is reduced, and the stronger noise leads to a larger variance in the positioning results.

[0332] The speed of the rotating magnet unit can also be adjusted. Higher-frequency, time-varying magnetic fields are more likely to induce eddy currents in metals, affecting the surrounding magnetic field and reducing positioning accuracy. Therefore, the speed can be appropriately reduced to improve the system's anti-interference capabilities. However, in scenarios with high real-time requirements, the speed should not be too low, otherwise the positioning speed will be reduced.

[0333] FIG17 is an exemplary flow chart for determining the real-time operational status of a field transmitter according to some embodiments of this specification. In some embodiments, process 1700 shown in FIG17 can be performed by a processing device (e.g., processor 13) or an electromagnetic navigation system. As shown in FIG17 , process 1700 can include the following operations.

[0334] Step 1702 : Acquire a real-time detection result obtained by the self-detection component of each of the rotating magnet units detecting the time-varying magnetic field generated by the field transmitter.

[0335] In some embodiments, when electromagnetic navigation is performed on the receiving device, each rotating magnet unit operates at its own rotation frequency. During this process, the self-detection component of each rotating magnet unit can detect and obtain magnetic field signals in real time, thereby obtaining the measured magnetic field data of each detection component.

[0336] Step 1704 : Determine the difference between the real-time detection result of the self-detection component of each rotating magnet unit and the corresponding reference detection result.

[0337] Since the operating characteristics of each rotating magnet unit are known, such as the relative positions between the rotating magnet units, and the time-varying characteristics of the magnetic moment strength and direction of each rotating magnet unit, the reference detection magnetic field data of each magnetic detection component can be calculated and determined in advance. If the measured detection magnetic field data of each component differs significantly from its respective reference detection magnetic field data and exceeds the preset threshold, it is very likely that magnetic field interference has occurred in the surrounding area (such as interference from ferromagnetic materials), and troubleshooting is required.

[0338] In some embodiments, several sets of operating parameters of the field transmitter may be set before shipment, for example, each set of parameters includes the operating rotation frequency of each magnet. For each set of parameters, a reference detection result is determined.

[0339] Step 1706: Determine the real-time operating status of the field transmitter according to the result difference.

[0340] The real-time operating status can be the current operating status of the field transmitter. The field transmitter includes multiple rotating magnet units, each having its own result difference. In some embodiments, as long as the result difference of one of the rotating magnet units exceeds a preset threshold, the field transmitter can be determined to be in an abnormal operating state. Accordingly, the result differences of each rotating magnet unit can be compared using the same preset threshold, or different preset result difference thresholds can be set for each rotating magnet unit.

[0341] It should be noted that the detection process in the above steps is different from the field transmitter's self-test process (e.g., the self-test method in Figure 15 ). The field transmitter's self-test is performed before real-time positioning of the receiving device, and a single rotating magnet unit is self-tested simultaneously, while the other rotating magnet units are deactivated. The detection in the above steps is performed during electromagnetic navigation of the receiving device, with each rotating magnet unit operating and its respective self-test components simultaneously acquiring magnetic field signals.

[0342] In Figure 15, the difference between the current time-varying magnetic field signal and the reference time-varying magnetic field signal corresponding to the preset speed is expressed by signal difference, while in Figure 17, result difference is used. The two differences are obtained in the same way, and the only difference is the difference in expression. Therefore, for more explanation of Figure 17, please refer to the relevant description of Figure 15. For example, for the real-time detection results, please refer to the description of the current time-varying magnetic field signal in Figure 15, and for the reference detection results, please refer to the description of the reference time-varying magnetic field signal in Figure 15.

[0343] FIG18 is an exemplary flow chart of a method for self-calibration of a field transmitter according to some embodiments of this specification. In some embodiments, process 1800 shown in FIG18 can be performed by a processing device (e.g., processor 13) or an electromagnetic navigation system. As shown in FIG18 , process 1800 can include the following operations.

[0344] The self-calibration method for a field transmitter disclosed in this embodiment can be applied to a field transmitter including a field transmitter unit group and a magnetic detection component. In some embodiments, the self-calibration method for a field transmitter can include the following operations.

[0345] Step 1802: Acquire measured calibration magnetic field data obtained by the magnetic detection component detecting the target calibration magnetic field.

[0346] Wherein, the target calibration magnetic field is a calibration magnetic field generated by a target rotating magnet unit, and the target rotating magnet unit is a rotating magnet unit to be calibrated in the field emission unit group;

[0347] Step 1804: Acquire magnet angle information of the target rotating magnet unit.

[0348] Step 1806: Determine target calibration parameters of the target rotating magnet unit based on the measured calibration magnetic field data and the magnet angle information.

[0349] In some embodiments, in order to improve calibration accuracy and simplify subsequent data processing, each rotating magnet unit can be calibrated separately, that is, a single rotating magnet unit can be calibrated in turn, or multiple or all rotating magnet units can be calibrated at the same time.

[0350] For example, the target rotating magnet unit to be calibrated can be first determined in the rotating magnet unit group, and the target rotating magnet unit is operated to generate a time-varying target calibration magnetic field. In order to prevent other rotating magnet units from affecting the calibration result of the target rotating magnet unit, the non-target rotating magnet unit needs to be turned off. After the rotating magnet unit is turned off, no time-varying magnetic field is generated. Then, the target calibration magnetic field is detected by the magnetic sensor in the magnetic detection component to obtain the corresponding measured calibration magnetic field data, and the magnet angle information output by the absolute position encoder in the target rotating magnet unit is obtained; wherein, the magnet angle information refers to the angle information of the reference axis of the driving motor of the magnet, and the magnetic moment direction of the magnet can be determined by this angle information. Finally, the target parameters of the target rotating magnet unit can be calibrated according to the measured calibration magnetic field data and the magnet angle information to obtain the target calibration parameters. The target calibration parameters are calibration parameters that conform to the actual state of the rotating magnet unit.

[0351] It should be noted that when the rotating magnet unit group includes only one rotating magnet unit, this rotating magnet unit is the target rotating magnet unit to be calibrated. During the self-calibration process, since there are no non-target rotating magnet units, there is no need to turn off the non-target rotating magnet units. The other steps for calibrating the target rotating magnet unit can be the same as described above.

[0352] In some embodiments, determining the target calibration parameters of the target rotating magnet unit based on the current time-varying magnetic field signal and the magnet angle information includes: determining the model calibration magnetic field data of the target calibration magnetic field at the magnetic detection component based on the magnet angle information, the model parameters of the target rotating magnet unit and the spatial posture of the magnetic detection component; optimizing the model parameters of the target rotating magnet unit with the optimization goal of minimizing the difference between the measured calibration magnetic field data and the model calibration magnetic field data to obtain the target calibration parameters of the target rotating magnet unit.

[0353] The model parameters of the target rotating magnet unit refer to the current parameters of the target rotating magnet unit in the magnetic field model. These current parameters can be obtained by factory calibration of the field transmitter or by the field transmitter's last self-calibration. As the field transmitter is used, the operating status of each rotating magnet unit changes, causing the model parameters of the target rotating magnet unit to potentially not match the actual status of the target rotating magnet unit. Therefore, these parameters need to be optimized and calibrated to obtain target calibration parameters that match the actual status of the target rotating magnet unit.

[0354] Among them, the model calibration magnetic field data of the target calibration magnetic field at the magnetic detection component can be obtained by calculating the magnetic field model based on the magnet angle information, the model parameters of the target rotating magnet unit and the spatial posture of the magnetic detection component. Among them, the magnetic field model can adopt the Dipole magnetic field model. If the model calibration magnetic field data is the same as the measured calibration magnetic field data, it means that the model parameters of the target rotating magnet unit are consistent with the actual state of the target rotating magnet unit; if the model calibration magnetic field data is different from the measured calibration magnetic field data, it means that the model parameters of the target rotating magnet unit are inconsistent with the actual state of the target rotating magnet unit, and the model parameters of the target rotating magnet unit need to be calibrated and corrected. At this time, minimizing the difference between the measured calibration magnetic field data and the model calibration magnetic field data can be used as the optimization goal, and the model parameters of the target rotating magnet unit are continuously iteratively optimized, and the final model parameters are used as the target parameters.

[0355] It should be noted that in embodiments where the magnetic detection assembly includes multiple magnetic sensors, the measured calibration magnetic field data and the model calibration magnetic field data corresponding to different magnetic sensors are different. Furthermore, because the calibration magnetic field generated by the rotating magnet unit is a time-varying magnetic field, the measured calibration magnetic field data and the model calibration magnetic field data corresponding to different moments are different. Therefore, when minimizing the difference between the measured calibration magnetic field data and the model calibration magnetic field data is the optimization goal, the difference between the measured calibration magnetic field data and the model calibration magnetic field data corresponding to different magnetic sensors and at different moments can be first calculated, and minimizing the mean of these differences can be used as the optimization goal.

[0356] In some embodiments, the target parameter of the target rotating magnet unit includes a target spatial position of the target rotating magnet unit.

[0357] For example, first, the magnetic moment of the target rotating magnet unit is determined based on the magnet angle information; then, based on the magnetic moment of the target rotating magnet unit, the model spatial position of the target rotating magnet unit and the spatial position of the magnetic sensor, the model calibration magnetic field data of the target calibration magnetic field at the magnetic sensor is determined; finally, with minimizing the difference between the measured calibration magnetic field data and the model calibration magnetic field data as the optimization goal, the model spatial position of the target rotating magnet unit is optimized to obtain the target spatial position of the target rotating magnet unit. Among them, the magnetic moment of the target rotating magnet unit refers to the magnetic moment of the magnet in the target rotating magnet unit, including the magnetic moment direction and magnetic moment intensity, and the model spatial position of the target rotating magnet unit refers to the spatial position of the magnet center of the target rotating magnet unit. Specifically, the optimization formula (3) is as follows:

[0358] Where f(x) is the magnetic field model, M(t) is the magnetic moment vector of the target rotating magnet unit at time t, and P TxU P is the model position coordinate of the magnet center of the target rotating magnet unit in the transmitter body coordinate system; ci is the position coordinate of the i-th magnetic sensor in the magnetic detection assembly in the field transmitter body coordinate system; then f(M(t),P TxU ,P ci ) is the model calibration magnetic field data (model magnetic field vector) of the target rotating magnet unit at the i-th magnetic sensor; B c (i, t) is the measured calibration magnetic field data (measured magnetic field vector) measured by the i-th magnetic sensor in the magnetic detection component at time t.

[0359] In some embodiments, the target parameters of the target rotating magnet unit include at least one of the following parameters: a target reference axis geometric parameter of the target rotating magnet unit, a target magnet zero position homogeneous transformation matrix, and a target magnetic moment strength.

[0360] Specifically, the reference axis geometric parameters refer to geometric parameters related to the reference axis, illustratively, they include the reference axis spin, which characterizes the offset of the magnet's center of mass from the reference axis. The magnet zero-position homogeneous transformation matrix refers to the posture transformation between the actual zero-position direction of the magnet's magnetic moment and the target zero-position direction. For example, under the standard design, the magnet's center of mass needs to be on its own reference axis, and the actual zero-position direction of the magnet's magnetic moment is the target zero-position direction. However, in actual field transmitters, the above design requirements have errors, and the errors are characterized by the reference axis spin and the magnet zero-position homogeneous transformation matrix. In the magnetic field model, it is necessary to calibrate the target reference axis geometric parameters and the magnet zero-position homogeneous transformation matrix to improve the accuracy of electromagnetic navigation.

[0361] Firstly, the model calibration magnetic field data of the target calibration magnetic field at the magnetic sensor are determined according to the model reference axis geometric parameters, model magnet zero-position homogeneous transformation matrix and model magnetic moment strength of the target rotating magnet unit, as well as the magnet angle information and the spatial position of the magnetic sensor. Then, with the optimization goal of minimizing the difference between the measured calibration magnetic field data and the model calibration magnetic field data, the model reference axis geometric parameters, model magnet zero-position homogeneous transformation matrix and model magnetic moment strength of the target rotating magnet unit are optimized to obtain the target reference axis geometric parameters, target magnet zero-position homogeneous transformation matrix and target magnetic moment strength of the target rotating magnet unit.

[0362] It should be noted that the above-mentioned multiple target parameters can be calibrated, or some target parameters can be calibrated in sequence. Multiple target parameters can be calibrated at the same time, or each target parameter can be calibrated in sequence.

[0363] Furthermore, minimizing the difference between the measured calibration magnetic field data and the model calibration magnetic field data is the optimization goal, including: minimizing the difference between the modulus value of the measured calibration magnetic field data and the modulus value of the model calibration magnetic field data is the optimization goal.

[0364] Specifically, considering that the positional accuracy of the magnetic sensor in the magnetic detection assembly is relatively easy to ensure during installation, its attitude accuracy is relatively difficult to ensure. Therefore, when calculating the difference between the measured calibration magnetic field data and the model calibration magnetic field data, calculating the vector difference between the two sets of magnetic field data may introduce uncertain errors. Since the modulus of the magnetic field data is independent of the magnetic sensor's attitude and only depends on its position, calculating the scalar difference between the two sets of magnetic field data—that is, the difference in the modulus values ​​of the two sets of magnetic field data—can improve calibration accuracy.

[0365] Specifically, when the target parameters of the target rotating magnet unit include the target reference axis spin of the target rotating magnet unit, the target magnet zero-position homogeneous transformation matrix and the target magnetic moment strength, the optimization formula (4) is as follows:

[0366] Where T0 is the model magnet zero position homogeneous transformation matrix of the target rotating magnet unit, θ(n) is t=nΔT s The angle of the magnet reference axis of the target rotating magnet unit at the moment S is the model reference axis rotation of the target rotating magnet unit, e [S]θ(n) is the exponential expression of the homogeneous transformation matrix, then T n =e [S]θ(n) T0 represents t=nΔT s The real-time homogeneous transformation matrix of the model magnet of the target rotating magnet unit at time ΔT sis the sampling interval of the sensor, such as 1ms to 10ms; |m| is the magnetic strength of the target rotating magnet unit, P ai is the position coordinate of the i-th magnetic sensor in the magnetic detection assembly in the field transmitter body coordinate system; ||f(e [S]θ(n) T0,|m|,P ai )|| means t=nΔT s At the moment the target rotating magnet unit's magnet is at P ai The modulus of the model calibration magnetic field data at || b B i (n)|| is the value of the i-th magnetic sensor in the magnetic detection assembly at t=nΔT s The modulus value of the measured calibration magnetic field data measured at the moment.

[0367] At the same time, it can be seen from the above optimization formula that when only one or two parameters are calibrated, it is only necessary to use the non-target parameters as fixed values ​​in the optimization formula.

[0368] After determining the target parameters, the difference between the target parameters and the reference parameters can also be determined, and it can be judged whether the difference exceeds a threshold; if so, the target rotating magnet unit corresponding to the target parameters needs to be repaired; if not, the parameters corresponding to the target rotating magnet unit are updated.

[0369] The reference parameters may be determined when the field transmitter leaves the factory. For example, parameter information in an initial state may be obtained by calibrating the field transmitter at the factory. The parameter information may be recorded and used as the reference parameters.

[0370] FIG19 is an exemplary flow chart of determining an optimization target according to some embodiments of this specification. In some embodiments, process 1900 shown in FIG19 can be performed by a processing device (e.g., processor 13) or an electromagnetic navigation system. As shown in FIG19, process 1900 may include the following operations.

[0371] In some embodiments, the measured calibration magnetic field data includes a sequence of measured calibration magnetic field values, and the model calibration magnetic field data includes a sequence of model calibration magnetic field values; the optimization goal of minimizing the difference between the measured calibration magnetic field data and the model calibration magnetic field data may include the following operations.

[0372] Step 1902: Determine the sequence mean of the measured calibration magnetic field value sequence and the sequence mean of the model calibration magnetic field value sequence.

[0373] Step 1904 : Subtract the sequence mean of the measured calibration magnetic field value sequence from each magnetic field value in the measured calibration magnetic field value sequence to obtain a first magnetic field value sequence.

[0374] Step 1906: Subtract the sequence mean of the model calibration magnetic field value sequence from each magnetic field value in the model calibration magnetic field value sequence to obtain a second magnetic field value sequence.

[0375] Step 1908 : Minimizing the difference between the first magnetic field value sequence and the second magnetic field value sequence is an optimization goal.

[0376] Considering the existence of the ambient magnetic field, the magnetic field data detected by the magnetic detection component is essentially the combined magnetic field of the calibration magnetic field and the ambient magnetic field. This embodiment removes the influence of the static ambient magnetic field during the calibration process to improve the calibration accuracy.

[0377] The calibration magnetic field provided by the rotating magnet unit can be divided into a time-varying part and a time-invariant part. Among them, the periodic mean of the time-varying part is zero, and the mean of the time-invariant part is itself. Therefore, the measured data mean of the measured calibration magnetic field data represents the measured data mean of the time-invariant part of the calibration magnetic field and the measured data mean of the ambient magnetic field. Specifically, since the data is continuously acquired, the measured calibration magnetic field data includes a measured calibration magnetic field value sequence, and the model calibration magnetic field data includes a model calibration magnetic field value sequence. The sequence mean of the measured calibration magnetic field value sequence is the measured data mean of the time-invariant part of the calibration magnetic field and the measured data mean of the ambient magnetic field, and the sequence mean of the model calibration magnetic field value sequence is the model data mean of the time-invariant part of the calibration magnetic field. After subtracting the sequence mean from each magnetic field value in the sequence, each magnetic field value is the magnetic field value of the time-varying part of the calibration magnetic field. Then, the first magnetic field value sequence is the measured data of the time-varying part of the calibration magnetic field, and the second magnetic field value sequence is the model data of the time-varying part of the calibration magnetic field. Furthermore, when calculating the difference between the first magnetic field value sequence and the second magnetic field value sequence, the influence of the ambient magnetic field is eliminated. Specifically, since the magnetic field values ​​in the first magnetic field value sequence and the second magnetic field value sequence are one-to-one corresponding (determined based on the acquisition time), the difference between the two sequences can be calculated as the difference between multiple groups of corresponding magnetic field values, and the cumulative difference is used as the difference between the two sequences.

[0378] This embodiment provides a self-calibration method for a field transmitter. The following is an explanation of the principle of the self-calibration method for a field transmitter.

[0379] Due to processing errors, installation errors, wear and collision during use, there are errors in the relevant parameters of the magnet in the field transmitter and the model parameters in the algorithm model, which will lead to a decrease in positioning accuracy.

[0380] Figure 34 is a schematic diagram of the structure of the rotating magnet unit shown in some embodiments of this specification. Referring to Figure 34, the rotating magnet unit includes a motor 341 and a permanent magnet 342. Assume that the design scheme requires that in the rotating magnet unit, the center of mass of the permanent magnet is located on the motor shaft w, and when the motor is in zero position (measured by the absolute position encoder), the direction of the magnetic moment of the magnet is along the positive direction of the Z axis (based on the coordinate system {s}). However, the actual situation may be that the center of mass of the magnet deviates from the motor shaft w, and when the motor is in zero position, the direction of the magnetic moment of the magnet deviates from the positive direction of the Z axis. The reference axis spin S and the homogeneous transformation matrix T0 of the magnet at zero position (the magnetic moment is regarded as an active vector, the starting point is the center of mass of the magnet, and the direction is the direction of the magnetic moment) are expressed in the coordinate system {s} as formula (5):

[0381] in, The unit vector representing the direction of the axis of rotation or angular velocity, R m is the rotation matrix of the magnet, P m and P s They represent the centroid of the magnet and a point on the reference axis (the point where the centroid of the magnet should be located). s ≠P m , In addition to the direction of the magnetic moment, the magnetic moment strength |m| of a magnet may also vary. Therefore, the field transmitter self-calibration method provided in this manual is designed to calibrate the offset S between the magnet's center of mass and the motor shaft w, the magnet's homogeneous transformation matrix T0 at zero position, and the magnet's magnetic moment strength |m|. Both S and T0 are six-dimensional parameters.

[0382] It should be noted that in this specification, the superscripts of all physical quantities indicate the coordinate system in which the vector is expressed. If not directly stated in the text, the coordinates, rotation matrices, vectors, etc. are all expressed in the coordinate system {s}.

[0383] Assume that there are N magnetic sensors (magnetic detection components) distributed at fixed positions in the field transmitter. Here, a 3-axis MEMS sensor is used as an example. The position P of the magnetic sensor in the coordinate system {s} is ai The error is known (e.g., ≤ 0.01 mm, significantly higher than the navigation and positioning requirements). Keep the other rotating magnet units inactive, and only rotate one rotating magnet unit at a time at a relatively low speed to generate a calibration magnetic field, such as 1 Hz to 10 Hz. The system obtains the angle information θ(t) of the absolute position encoder and the measured calibration magnetic field data of each magnetic sensor in real time. b B i (t), i=1,2,...,N. b B i(t) is the projection of the calibration magnetic field on the magnetic sensor's own coordinate system {b}. The above physical quantities to be calibrated can be solved using the optimization method through the objective function.

[0384] It should be noted that when the sensor is mounted on the patch, the position accuracy is easy to ensure, but its posture is difficult to ensure. Therefore, in this embodiment, the difference in the modulus of the magnetic field data is calculated.

[0385] It is difficult to ensure that the axis direction inside the sensor is completely parallel to the actual design direction, which results in a pose transformation between the magnetic sensor's own coordinate system {b} and the field transmitter's body coordinate system {s}, that is, b B i (n)≠ s B i (n). If a vector is used for comparison, some uncertain errors will be introduced. However, since the modulus of the magnetic field data has nothing to do with the posture of the magnetic sensor, but only with the position of the magnetic sensor, that is, || b B i (n)||=|| s B i The position of the magnetic sensor can be accurately measured using a coordinate measuring machine, so using the modulus of the magnetic field data can reduce the introduction of errors.

[0386] In order to further improve the calibration accuracy, the above objective function can be further optimized. For MEMS sensors, the measured b B i (n) is the resultant magnetic field, which is the combination of the calibration magnetic field generated by the rotating magnet unit and the ambient magnetic field. Specifically, it is shown in formula (6):

[0387] in, is the inverse of the rotation matrix of the i-th magnetic sensor, representing the transformation from coordinate system {s} to coordinate system {b}; B i-pm (n) is the magnetic field contributed by the rotating magnet unit, which can be divided into the time-varying part B i-pmac (n) and the time-invariant part B i-pmdc ; B i-g B is the environmental magnetic field, such as the geomagnetic field, and the static magnetic field generated by other materials and equipment in the environment; i-d is the zero drift parameter of the sensor, which does not change with the posture. Since the environment is complex and unknown, there are other stationary units that also contribute to the static magnetic field, so B i-g is a quantity that cannot be ignored and cannot be modeled. In this embodiment, the de-averaging method is used to remove the ambient magnetic field. Specifically, as shown in formula (7):

[0388] Among them, N Tis the number of sampling points in a fixed time. Assuming that the fixed time is 1s and the speed of 10Hz corresponds to the sampling rate of 800Hz, then 1s corresponds to 10 turns, N T =800. The above formula means that a series of magnetic field data are collected first, their mean is calculated, and then the mean is subtracted from the magnetic field data sequence one by one. Since the magnetic field contribution of the rotating magnet unit is divided into a time-varying part and a time-invariant part, the periodic mean of the time-varying part is zero, the mean of the time-invariant part is itself, and the mean of the ambient magnetic field is also itself. Therefore, after removing the mean, only the time-varying part of the magnetic field contribution of the rotating magnet unit remains. It reflects the characteristics of magnet rotation. [S]θ(n) T0,|m|,P ai ) is optimized so that after calculating the theoretical value, the mean of all theoretical values ​​is calculated, and finally the sequence mean is deducted from each theoretical value. The optimized objective function is as follows (8):

[0389] Some embodiments of this specification provide a field transmitter, which may include a field transmitter unit group and a magnetic source assembly. The field transmitter unit group includes multiple rotating magnet units; the magnetic source assembly is fixed in spatial position within the field transmitter; and when the field transmitter unit group stops operating, the magnetic source assembly generates a detection magnetic field for interference detection of the field transmitter.

[0390] The magnetic source assembly may include a plurality of coils, and the plurality of coils are evenly distributed around the periphery of the field emission unit group.

[0391] Based on the field transmitter, some embodiments of this specification also provide a method for detecting interference with the field transmitter. In addition, the method for detecting interference with the field transmitter can also be applied to the field transmitter including the magnetic source assembly disclosed above.

[0392] FIG20 is an exemplary flow chart of a method for detecting interference with a field transmitter according to some embodiments of this specification. In some embodiments, process 2000 shown in FIG20 may be performed by a processing device (e.g., processor 13) or an electromagnetic navigation system. As shown in FIG20 , process 2000 may include the following operations.

[0393] Step 2002: Control all rotating magnet units in the field transmitter to stop rotating.

[0394] Step 2004: Control the magnetic source assembly to generate the detection magnetic field.

[0395] Step 2006: Acquire actual detection magnetic field data obtained by the magnetic detection component detecting the detection magnetic field.

[0396] In some embodiments, the magnetic source assembly includes a plurality of coils for generating a detection magnetic field, and the plurality of coils are uniformly distributed around the rotating magnet unit group. Acquiring measured detection magnetic field data obtained by the magnetic detection assembly detecting the detection magnetic field includes acquiring measured detection magnetic field data obtained by the magnetic detection assembly detecting a target detection magnetic field. The target detection magnetic field is the detection magnetic field generated by a target coil among the plurality of coils in the magnetic source assembly.

[0397] In this embodiment, the magnetic source assembly utilizes multiple coils that generate a detection magnetic field when energized. The detection magnetic field generated by the coils can be a sinusoidal signal. The detection magnetic field frequency can be set slightly higher than the operating frequency of the field transmitter during electromagnetic navigation, such as 50 Hz to 100 Hz. The coils have controllable magnetic fields, generating a detection magnetic field when energized and not generating a detection magnetic field when de-energized.

[0398] Step 2008: Determine the detection difference between the measured magnetic field data and the reference magnetic field data.

[0399] Step 2010: Determine the interference detection result of the field transmitter according to the detection difference.

[0400] In some embodiments, when interference detection is required, the coil is turned on to generate a detection magnetic field, and at other times, the coil is turned off to prevent the detection magnetic field from affecting other functions of the field transmitter. For example, when the magnetic source assembly generates the detection magnetic field, the multiple rotating magnet units are turned off.

[0401] In some embodiments, the main function of the rotating magnet unit is to generate a time-varying magnetic field. In order to better detect the detection magnetic field, the rotating magnet unit in the field transmitter can be turned off during the detection process. Turning off the rotating magnet unit means stopping it from generating a time-varying magnetic field. For example, for a rotating magnet unit that uses a motor to drive a permanent magnet to rotate, turning off the rotating magnet unit means turning off the motor and locking the permanent magnet so that it cannot rotate; and for a rotating magnet unit that uses an electromagnetic coil, turning off the rotating magnet unit means turning off the electromagnetic coil.

[0402] After the rotating magnet units are turned off, the magnetic sensor in the magnetic detection assembly detects the detection magnetic field generated by the magnetic source assembly and reads the measured magnetic field data from the magnetic sensor. The measured magnetic field data is then compared with the reference magnetic field data to determine the difference between the two. Ultimately, the interference detection result of the field transmitter is determined based on the difference.

[0403] At the same time, there are multiple coils, evenly distributed around the rotating magnet unit group, for example, they can be fixedly mounted on the various sides of the field transmitter's mounting housing. Considering that the impact of smaller magnetic field sources on the field transmitter's magnetic field is localized, for example, affecting the field transmitter's magnetic field only in a certain direction, multiple coils are provided, distributed around the field transmitter, each used to detect the presence of an interference source in the corresponding direction. During detection, detection signals are generated one by one and the same phase comparison test is performed, thereby more comprehensively detecting the conditions around the field transmitter.

[0404] Therefore, during the interference detection process, each coil is selected as the target coil in turn, and the interference source is determined in the direction corresponding to the target coil. After the interference detection for the current target coil is completed, the next coil is determined as the new target coil and the interference detection steps are repeated.

[0405] In some embodiments, determining the detection difference between the measured detection magnetic field data and the reference detection magnetic field data, and determining the interference detection result of the field transmitter based on the detection difference includes: determining the target detection difference between the target measured detection magnetic field data and the target reference detection magnetic field data, and determining the interference detection result of the field transmitter in the direction corresponding to the target coil based on the target detection difference.

[0406] Among them, the detection difference is mainly used to determine whether there are other magnetic field sources in the current environment. Therefore, the reference detection magnetic field data refers to the magnetic field data that should be obtained when the magnetic detection component detects the detection magnetic field in an environment without interference sources. Specifically, the reference detection magnetic field data can be obtained by detecting the detection magnetic field through the magnetic detection component when the field transmitter is calibrated at the factory, because the calibration environment at the factory is controllable, which can ensure that there are no interference sources in the calibration environment. At the same time, the reference detection magnetic field data can also be obtained through simulation calculation when the relative position of the magnetic source component and the magnetic detection component is fixed and known.

[0407] Furthermore, the measured magnetic field data is compared with the reference detection magnetic field data, and the comparison method can be to compare the phases between the two, such as comparing peak positions, calculating correlation coefficients, etc. This comparison method can be applicable to detecting interference signals of the same frequency but different phases. Common ones, such as metal eddy currents, can produce interference signals of the same frequency but different phases. Therefore, the signal difference can be a phase difference. Correspondingly, the signal difference can also be a peak size difference. At the same time, both the measured magnetic field data and the reference detection magnetic field data contain a number of magnetic field data numbered in time sequence, and there is a one-to-one correspondence between the two. When comparing the two, the magnetic field data with the same number can be compared in turn.

[0408] In some embodiments, determining the interference detection result of a field transmitter based on a detection difference includes: determining the presence of a magnetic field interference source around the field transmitter when the detection difference is greater than a preset threshold. In this embodiment, the measured magnetic field data and the reference magnetic field data do not need to be exactly the same; typically, the presence of a magnetic field interference source around the field transmitter is determined only when the detection difference is greater than a preset threshold. Furthermore, the detected magnetic field data is typically a vector, including magnetic field component data in three spatial dimensions. Therefore, when comparing the measured magnetic field data with the reference magnetic field data, the magnetic field component data in each spatial dimension can be compared separately. For example, the presence of a magnetic field interference source around the field transmitter can be determined when the detection difference in the magnetic field component data in a particular spatial dimension is greater than a preset threshold. Correspondingly, the presence of a magnetic field interference source around the field transmitter can be determined only when the detection difference in the magnetic field component data in two or all three spatial dimensions is greater than the preset threshold.

[0409] The above description of the interference detection method uses the example of a magnetic detection component detecting the detection magnetic field generated by a magnetic source component. It is understood that the interference detection method can also be applied to other detection components (e.g., other detection components other than a self-test component or a field transmitter) to detect the detection magnetic field generated by a magnetic source component.

[0410] It should be noted that the self-calibration method, interference detection method, and anomaly detection method for the field transmitter provided in some embodiments of this specification are interrelated in use. Specifically, before each electromagnetic navigation is performed using the field transmitter, the interference detection method can be used to detect the working environment of the field transmitter to determine whether there is a magnetic field interference source around the field transmitter. If so, the interference source needs to be eliminated first. If not, or after the interference source is eliminated, the field transmitter is self-calibrated using the self-calibration method. When the model parameters of the field transmitter do not match the actual state, the model parameters of the field transmitter are updated in real time. After the self-calibration is completed, electromagnetic navigation is performed using the field transmitter, and during the electromagnetic navigation process, the operating state of the field transmitter is detected in real time using the anomaly detection method. Furthermore, after self-calibration and before electromagnetic navigation, the self-test component can be used to perform a self-test method to self-test the rotating magnet unit.

[0411] In view of this, some embodiments of this specification also provide a method for detecting abnormalities in a field transmitter.

[0412] FIG21 is an exemplary flow chart of an anomaly detection method according to some embodiments of this specification. In some embodiments, process 2100 shown in FIG21 can be performed by a processing device (e.g., processor 13) or an electromagnetic navigation system. As shown in FIG21, process 2100 can include the following operations.

[0413] The abnormality detection method for a field transmitter disclosed in this embodiment can be applied to the field transmitter comprising a field transmitter unit group and a magnetic detection component as described above. In some embodiments, the abnormality detection method can include the following operations.

[0414] Step 2102: Acquire a current time-varying magnetic field signal obtained by the magnetic detection component detecting the working magnetic field generated by the field transmitter.

[0415] Step 2104: Determine the operating difference between the current time-varying magnetic field signal and the reference time-varying magnetic field signal, and determine the operating state of the field transmitter according to the operating difference.

[0416] The field transmitter anomaly detection method provided in this embodiment can perform real-time anomaly detection on the field transmitter during electromagnetic navigation. During electromagnetic navigation, the field transmitter generates an operating magnetic field. Each rotating magnet unit in the field transmitter operates at its own operating frequency, and the combined magnetic field generated by these rotating magnet units constitutes the field transmitter's operating magnetic field.

[0417] In some embodiments, when the field transmitter includes only one rotating magnet unit, the resultant magnetic field may be the magnetic field generated by the revolution and rotation of the rotating magnet unit.

[0418] When the field transmitter generates an operating magnetic field, the magnetic sensor in the magnetic detection assembly detects the magnetic field, obtaining measured magnetic field data. The measured magnetic field data is then compared with reference magnetic field data to determine the degree of difference between the two. Ultimately, the operating status of the field transmitter is determined based on this difference.

[0419] The operating variability is primarily used to determine whether the field transmitter's operating status is abnormal. An abnormal status refers to the field transmitter generating an operating magnetic field that does not conform to the calibration value. This is primarily due to interference from other magnetic fields or the field transmitter's real-time status not matching the calibration state. Therefore, the reference operating magnetic field data refers to the magnetic field data that would be obtained by a magnetic sensor detecting the operating magnetic field in the calibrated state in an interference-free environment. Specifically, the reference operating magnetic field data can be obtained by detecting the operating magnetic field using a magnetic sensor during factory calibration of the field transmitter. In this case, the field transmitter is not only in the calibrated state, but the calibration environment is also controllable, ensuring that the calibration environment is free of interference sources. Furthermore, the reference operating magnetic field data can also be obtained through simulation calculations when the relative position of the field transmitter unit and the magnetic sensor is fixed and known.

[0420] In some embodiments, determining the operating state of the field transmitter according to the operating difference includes: when the operating difference is greater than a second preset threshold, determining that the operating state of the field transmitter is abnormal.

[0421] Specifically, the working difference can be the cumulative value or mean of the errors between the corresponding data in the measured working magnetic field data and the reference working magnetic field data. For example, the calculation formula (9) of the mean value L of the error is as follows:

[0422] in, b B i ′(n) is the measured working magnetic field data, b B i-0 (n) refers to the working magnetic field data, the symbol “||||” indicates the modulus value, N T When calculating the mean of the errors between the corresponding data, the corresponding measured working magnetic field data and the reference working magnetic field data can be substituted into the above formula at intervals according to the time series.

[0423] As described above, the abnormality detection method of the field transmitter provided by the present invention can be used to perform real-time detection on the operating status of the field transmitter during the electromagnetic navigation process of the field transmitter provided by the present invention.

[0424] FIG22 is an exemplary flow chart of an anomaly detection method according to other embodiments of this specification. In some embodiments, process 2200 shown in FIG22 can be performed by a processing device (e.g., processor 13) or an electromagnetic navigation system. As shown in FIG22, process 2200 can include the following operations.

[0425] Furthermore, in some embodiments, when the field transmitter further includes a magnetic source component, determining the operating state of the field transmitter according to the operating difference may further include the following operations.

[0426] Step 2202: In response to determining that the operating variability is less than or equal to an operating variability threshold, determine that the field transmitter is in a normal operating state.

[0427] Step 2204: In response to determining that the operating difference is greater than the operating difference threshold, all rotating magnet units in the field transmitter are controlled to stop rotating.

[0428] Step 2206: In response to determining that the operating difference is greater than the operating difference threshold, control all rotating magnet units in the field transmitter to stop rotating.

[0429] Step 2208: Acquire the actual detection magnetic field data obtained by the magnetic detection component detecting the detection magnetic field.

[0430] Step 2210: Determine the detection difference between the measured magnetic field data and the reference detection magnetic field data.

[0431] Step 2212: Determine the interference detection result of the field transmitter according to the detection difference.

[0432] Steps 2202 and 2204 are subsequent workflows required for abnormality detection of field transmitters in different operating states. For more details on steps 2206 to 2212, please refer to the relevant description of FIG. 20 and will not be repeated here.

[0433] FIG23 is an exemplary flow chart of an anomaly detection method according to other embodiments of this specification. In some embodiments, process 2300 shown in FIG23 can be performed by a processing device (e.g., processor 13) or an electromagnetic navigation system. As shown in FIG23, process 2300 can include the following operations.

[0434] In some embodiments, after performing interference detection on the field transmitter, the field transmitter abnormality detection method may further include the following operations.

[0435] Step 2302: In response to determining that the detection difference is greater than a detection difference threshold, determine that the field transmitter is in an abnormal operating state.

[0436] Step 2304 : In response to determining that the detection difference is less than or equal to the detection difference threshold, obtain measured calibration magnetic field data obtained by the magnetic detection component detecting the target calibration magnetic field.

[0437] The target calibration magnetic field is a calibration magnetic field generated by a target rotating magnet unit, and the target rotating magnet unit is a rotating magnet unit to be calibrated in the field emission unit group.

[0438] Step 2306: Acquire the magnet angle information of the target rotating magnet unit.

[0439] Step 2308: Determine target calibration parameters of the target rotating magnet unit based on the measured calibration magnetic field data and the magnet angle information.

[0440] Steps 2302 and 2304 are the subsequent workflows required for detecting anomalies in the field emitter when the detected difference is greater than the detection difference threshold and less than the detection difference threshold, respectively. For more details on steps 2306-2308, please refer to the relevant descriptions of Figures 18 and 19 and will not be repeated here.

[0441] FIG24 is an exemplary flow chart of an anomaly detection method according to other embodiments of this specification. In some embodiments, process 2400 shown in FIG24 can be performed by a processing device (e.g., processor 13) or an electromagnetic navigation system. As shown in FIG24, process 2400 can include the following operations.

[0442] In some embodiments, after the field transmitter is self-calibrated, the field transmitter anomaly detection method may further include the following operations.

[0443] Step 2402: Determine the calibration difference between the target calibration parameters and the initial calibration parameters.

[0444] Step 2404: In response to determining that the calibration difference is greater than a calibration difference threshold, determine that the field transmitter is in an abnormal operating state.

[0445] Step 2406: In response to determining that the calibration difference is less than or equal to the calibration difference threshold, determine that the field transmitter is in a normal operating state.

[0446] Step 2408: Update the target parameters of the field transmitter to the target calibration parameters.

[0447] The calibration difference refers to the difference between the target calibration parameters and the initial calibration parameters. Steps 2404 and 2406 are the subsequent workflows required for field transmitter anomaly detection when the calibration difference is greater than or less than the calibration difference threshold. For more details on steps 2406-2408, please refer to the descriptions of Figures 18 and 19 and are not repeated here.

[0448] It should be noted that FIG. 22 to FIG. 24 taken together can constitute a complete embodiment of the abnormality detection method of the field emitter disclosed in the embodiments of this specification.

[0449] On the other hand, some embodiments of this specification also disclose the use process of the field transmitter. For details on the use process of the field transmitter, please refer to the detailed description in other parts of this specification based on the contents of Figures 21 to 24.

[0450] FIG25 is an exemplary flow chart of a method for using a field transmitter according to some embodiments of this specification. Referring to FIG26 , the method for using a field transmitter includes: a pre-shipment detection stage 2510, a real-time anomaly detection stage 2520, an on-site interference detection stage 2530, and an on-site self-calibration stage 2540.

[0451] During the pre-shipment inspection phase 2510 of the field transmitter, interference detection, anomaly detection, and self-calibration are performed. The interference detection reference signal, anomaly detection reference signal, and initial calibration parameters are recorded. Interference detection, anomaly detection, and self-calibration can all be performed using the corresponding methods described in this specific embodiment. After the field transmitter leaves the factory, it is put into use.

[0452] The real-time anomaly detection phase 2520 is the electromagnetic navigation phase of the field transmitter. During this phase, the field transmitter operates and performs real-time anomaly detection using the anomaly detection method of this embodiment. The transmitter's measured operating magnetic field signal is recorded, compared with the anomaly detection reference signal, and the error is calculated. If the error is within the specified limit, the transmitter continues to operate; if the error exceeds the specified limit, the transmitter proceeds to the on-site interference detection phase 2530.

[0453] In the on-site interference detection phase 2530, on-site interference detection is performed using the interference detection method of this embodiment. The measured magnetic field signal generated by the interference detection coil is recorded. The measured magnetic field signal is compared with the interference detection reference signal and the error is calculated. If the error is within the limit, the on-site self-calibration phase begins. If the error is beyond the limit, interference elimination is required. After the interference is eliminated, the error between the measured working magnetic field signal and the anomaly detection reference signal is recalculated to determine whether it exceeds the limit.

[0454] In the on-site self-calibration stage 2540, the self-calibration method of this embodiment is used to perform on-site self-calibration. The real-time calibration parameters of each rotating magnet unit are recorded, compared with the initial calibration parameters, and the error is calculated. If the error is within the limit, the calibration parameters are updated and continued use is performed. If the error is beyond the limit, the field transmitter is returned to the factory for repair.

[0455] It should be noted that some of the above processes do not need to be executed every time the field transmitter is used. For example, the relative position calibration between the various rotating magnet units only needs to be performed regularly according to a certain period. The calculation of the interaction torque between the magnets of each rotating magnet unit does not need to be repeatedly calculated when the system parameters (such as the rotational speed) remain unchanged. Preferably, the field transmitter system pre-records the interaction torque data under various speed configurations, which can be searched after the parameters are adjusted. The self-test of the rotating magnet unit can be performed when the field transmitter leaves the factory, or it can be performed once before each startup. The self-test before startup is the startup test.

[0456] In the above description, in response to determining that the working difference is greater than the working difference threshold, it is indicated that the working state of the field transmitter is abnormal, and then interference detection and self-calibration are performed in sequence to eliminate the cause of the abnormality. For example, interference detection is performed first. If it is found that there is no interfering magnetic field, self-calibration is performed to determine whether there is a deviation in the posture of the rotating magnet unit in the field transmitter. In some embodiments, in response to determining that the working difference is greater than the working difference threshold, self-calibration can also be performed first. If it is found that the calibration parameter error is within the limit, interference detection can be performed again. In some embodiments, in response to determining that the working difference is greater than the working difference threshold, a self-test component can also be used to perform a self-test to determine whether the magnetic strength has attenuated or the direction of the magnetic moment of the magnet has changed. The order of interference detection, self-calibration, and self-test is not limited.

[0457] Based on the same inventive concept, some embodiments of this specification also provide an electromagnetic navigation system, which includes a processor, a receiving device and the transmitter including the magnetic detection component mentioned above, wherein the receiving device is used to detect the time-varying magnetic field generated by the field transmitter, and the processor is used to control the operation of the field transmitter and determine the real-time posture of the receiving device in the time-varying magnetic field based on the magnetic field detection data of the receiving device.

[0458] The electromagnetic navigation method provided in this specification can be applied to the electromagnetic navigation system provided in this specification. Since the field transmitter in the electromagnetic navigation system provided in this specification has a self-test function, the user can perform a self-test on each rotating magnet unit in the field transmitter through its internal self-test component before the system locates the receiving device. The self-test can promptly detect rotating magnet units with problems and correct the magnetic moment strength of the corresponding rotating magnet unit so that the actual value of the time-varying characteristic of the magnetic moment is consistent with the model value, thereby avoiding the field transmitter from generating a time-varying magnetic field that deviates from the standard during operation, and ultimately ensuring the positioning accuracy of the magnetic sensor.

[0459] FIG26 is an exemplary flow chart of real-time positioning of a field transmitter according to some embodiments of the present specification. Referring to FIG26 , real-time positioning includes the following steps:

[0460] Step 2602: Each rotating magnet unit operates at a different set frequency;

[0461] Step 2604: collecting signals from each magnetic sensor and each absolute position encoder;

[0462] Step 2606, various signal time synchronization;

[0463] Step 2608, 6DoF positioning solution.

[0464] Specifically, during real-time positioning, each rotating magnet unit rotates at a different frequency, and each receiving device to be positioned (including a three-axis magnetic field sensor) collects magnetic field data in real time. The positioning algorithm requires two data inputs: the magnetic field data of each receiving device within a time window and the angular data sequence of the absolute position encoder of each rotating magnet unit; then the clocks of the two data are aligned, that is, the algorithm requires the magnetic field data at each moment and the orientation of the magnetic moment in each rotating magnet unit at that moment; finally, these two data can be input into a nonlinear optimization solver or a Kalman filter for solution. The objective function of the optimization solution is shown in the above formula (4).

[0465] It should be noted that the above solution algorithm does not need to separate the time-varying magnetic field, and can directly use the combined magnetic field measurement value and the combined magnetic field model.

[0466] FIG33 is a schematic diagram of data acquisition when the field transmitter performs real-time positioning in this specification. Referring to FIG33 , the positioning algorithm requires data within a real-time time window, but there is no quantitative relationship between the width of the real-time time window and the rotation period of the rotating magnet unit. The width of the real-time time window can be adjusted according to the actual signal-to-noise ratio and real-time requirements. When the real-time requirements are not high, the width of the sliding real-time time window can be longer, so that the signal-to-noise ratio of the solution is higher; when the real-time requirements are relatively high, the width of the sliding real-time time window needs to be shortened, which may cause a certain degree of "jitter" in the positioning results. The reason is that the data signal-to-noise ratio is reduced, and stronger noise causes the variance of the positioning results to increase.

[0467] The rotational speed of the rotating magnet unit can also be adjusted. Higher-frequency, time-varying magnetic fields are more likely to induce eddy currents in metals, affecting the surrounding magnetic field and reducing positioning accuracy. Therefore, the rotational speed can be appropriately reduced to improve the field transmitter system's anti-interference capabilities. However, in scenarios with high real-time requirements, the rotational speed should not be too low, otherwise positioning speed will be insufficient.

[0468] FIG27 is an exemplary flow chart of a self-calibration method for a field transmitter according to another embodiment of the present disclosure. Referring to FIG27 , the self-calibration method for a field transmitter includes the following steps:

[0469] Step 2702, determining the target rotating magnet unit to be calibrated;

[0470] Step 2704, keeping the motor of the non-target rotating magnet unit stopped;

[0471] Step 2706, recording the magnetic field data measured by the magnetic sensor;

[0472] Step 2708, recording the position information output by the absolute position encoder in the target rotating magnet unit;

[0473] Step 2710: calibrate the target rotating magnet unit according to the magnetic field data and position information.

[0474] Specifically, the above steps S530 and S540 can be performed simultaneously. For all rotating magnet units in the field transmitter, the above steps are performed one by one for calibration. For a detailed description of the self-calibration method, please refer to the description of Figures 18 and 19.

[0475] In this specific embodiment, an interference detection method for a field transmitter is also provided. The following is an explanation of the principle of the interference detection method for a field transmitter.

[0476] Field transmitters are also calibrated at the factory, following a similar process to the self-calibration process described above. However, factory calibration is conducted in a more controlled environment. For example, the calibration environment can be controlled to be free of other magnetic field sources, large metal masses, and ferromagnetic materials. On-site calibration, however, presents many uncertainties, such as the presence of various interference sources that can distort the measured magnetic field. Calibrating the field transmitter directly can introduce significant errors. To eliminate this interference, an interference detection coil is incorporated into the field transmitter. Together with the magnetic sensor in the magnetic detection assembly, both are secured to the field transmitter's mounting housing (e.g., a seal). This ensures a stable relative position between the interference detection coil and the magnetic sensor.

[0477] FIG28 is an exemplary flow chart of an interference detection method for a field transmitter according to another embodiment of the present disclosure. Referring to FIG28 , the interference detection method for a field transmitter includes the following steps:

[0478] Step 2802, keeping the motors of all rotating magnet units in the field transmitter stopped;

[0479] Step 2804, activating the target interference detection coil to be detected;

[0480] Step 2806 , the magnetic sensor in the magnetic detection assembly records the magnetic field generated by the target interference detection coil;

[0481] Step 2808: Compare the detection signal of the magnetic sensor with the reference signal.

[0482] Specifically, for all interference detection coils in the field transmitter, the above steps are performed one by one to perform detection.

[0483] The detection signal generated by the coil can be a sinusoidal signal, and in order to ensure the cleanliness of the navigation working frequency band, the detection signal frequency can be set slightly higher than the working frequency of electromagnetic navigation, such as 50Hz~100Hz. During the detection, all rotating magnet units are stopped to eliminate all known time-varying magnetic field sources. The magnetic sensor collects the signal b B′ ij-e(n) and compared with the reference signal recorded in a clean environment at the factory b B ij-e (n) for comparison, where b B ij-e (n) represents the magnetic field signal generated by the jth interference detection coil recorded by the i-th magnetic sensor. The comparison method can be phase-based, such as comparing peak positions, calculating correlation coefficients, etc. (it is known that interferences such as metal eddy currents are interference signals of the same frequency but different phases). The disturbance of the magnetic field by some small interference sources is usually local, so the interference detection coils are set to be multiple and distributed around the field transmitter. During detection, the detection signals are generated one by one and the same phase comparison detection is performed, so as to more comprehensively detect the conditions around the field transmitter and ensure that the self-calibration process is in an environment without magnetic field interference. When the interference detection finds that there is perceptible interference in the surrounding area (such as the phase difference exceeds a certain limit), the field transmitter will not start the self-calibration program and prompt the user that there is interference. At this time, the user can independently eliminate the interference source. If no interference is perceived, the self-calibration program can be started.

[0484] It should be noted that b B ij-e (n) with b B′ ij-e (n) Obviously they are not measured at the same time, but n is used to represent the sequence number. n ranges from 0 to N T Marking, where n = 0 represents the start time of the signal, so b B ij-e (n) with b B′ ij-e (n) Although not measured simultaneously, a one-to-one comparison can still be performed.

[0485] In this specific embodiment, a method for detecting anomalies of a field transmitter is also provided. The following is an explanation of the principle of the method for detecting anomalies of a field transmitter.

[0486] When the field transmitter is used in the field, the magnetic sensor in the magnetic detection component will continuously record the magnetic field value during navigation b B i '(n), and periodically (e.g. 1s) compared with the reference magnetic field value in the record b B i ′(n), as shown in Formula (3), which is not repeated here. Any changes in intensity or phase will be reflected in the error L(Err0). When the value of L is within a certain limit, the system is considered normal and can continue to be used. If it exceeds the limit, the system will stop navigation and enter the "interference detection" phase.

[0487] It should be noted that the magnetic field measured by the magnetic sensor during real-time anomaly detection b Bi ′(n) is the same as the one measured in the self-calibration process above. b B i (n) is different. Measurement b B i '(n), the field transmitter is in the "navigation state", at which time all the rotating magnet units are working normally. b B i (n), only one rotating magnet unit works at a time, and the other rotating magnet units do not work. For a detailed description of the interference detection method, please refer to the description of FIG. 20 .

[0488] In some embodiments, the self-calibration method, interference detection method, and real-time anomaly detection method performed using a magnetic detection component can be replaced by being performed using a self-test component. For example, the field transmitter includes a self-test component, but does not include a magnetic detection component. The self-test component detects the calibration magnetic field of the rotating magnet unit, the detection magnetic field generated by the magnetic source component, and the real-time working magnetic field generated by the field transmitter during the electromagnetic navigation process. The structure and configuration of the self-test component are as described above. In the method for determining the real-time operating status of the field transmitter using the self-test component (Figure 17) and the real-time anomaly detection method using the magnetic detection component (Figure 21) described above, the devices for detecting the real-time working magnetic field of the field transmitter are different (the self-test component and the magnetic detection component, respectively), but the detection methods are similar.

[0489] FIG35 is an exemplary module diagram of a self-test system for a rotating magnet unit according to some embodiments of this specification. The system is applied to the rotating magnet unit described in some embodiments of this specification. The self-test system for the rotating magnet unit can be implemented in the processor 13 in the form of hardware or software. As shown in FIG35 , the self-test system 3500 includes the following modules:

[0490] A driving module 3510 is used to control the driving assembly to drive the magnet to rotate at a preset speed;

[0491] A first signal acquisition module 3520 is configured to acquire a current time-varying magnetic field signal of the magnet; wherein the current time-varying magnetic field signal is obtained by the self-detection component detecting a magnetic field signal generated by the magnet during rotation;

[0492] The first self-test result determination module 3530 is configured to determine a signal difference between a current time-varying magnetic field signal of the magnet and a reference time-varying magnetic field signal, and determine a self-test result of the rotating magnet unit according to the signal difference.

[0493] The self-test system 3500 can execute the self-test method of the rotating magnet unit in this specification using the driving module 3510, the first signal acquisition module 3520, and the first self-test result determination module 3530. The self-test method of the rotating magnet unit is described above in detail.

[0494] FIG36 is an exemplary block diagram of a self-test system for a field transmitter according to some embodiments of this specification. The system is applied to the field transmitters described in some embodiments of this specification. The transmitter self-test system can be implemented in the processor 13 in the form of hardware or software. As shown in FIG36 , the self-test system 3600 includes the following modules:

[0495] a locking module 3610 for determining a target rotating magnet unit to be self-checked in the field transmitter and locking the angular position of the magnets of non-target rotating magnet units;

[0496] The rotation control module 3620 is configured to control the driving assembly to drive the magnet of the target rotating magnet unit to rotate at a preset speed;

[0497] The second signal acquisition module 3630 is configured to acquire a current time-varying magnetic field signal of the magnet; wherein the current time-varying magnetic field signal is obtained by the self-detection component detecting a magnetic field signal generated by the magnet during rotation;

[0498] The second self-test result determination module 3640 is configured to determine a signal difference between a current time-varying magnetic field signal of the magnet and a reference time-varying magnetic field signal, and determine a self-test result of the rotating magnet unit according to the signal difference.

[0499] The self-test system 3600 can execute the field transmitter self-test method of this specification using the locking module 3610, the rotation control module 3620, the second signal acquisition module 3630, and the second self-test result determination module 3640. For details about the field transmitter self-test method, please refer to the above description.

[0500] FIG37 is an exemplary block diagram of an electromagnetic navigation device according to some embodiments of this specification. The electromagnetic navigation device can be implemented in the processor 13 in the form of hardware or software. As shown in FIG37 , the electromagnetic navigation device 3700 includes:

[0501] A self-test module 3710 is configured to: perform a self-test on the field transmitter to obtain self-test results of each rotating magnet unit in the field transmitter, including: determining a target rotating magnet unit to be self-tested in the field transmitter, and locking the angular position of the magnets of non-target rotating magnet units; controlling the drive component to drive the magnet of the target rotating magnet unit to rotate at a preset speed; obtaining a current time-varying magnetic field signal of the magnet; wherein the current time-varying magnetic field signal is obtained by the self-test component detecting a magnetic field signal generated by the magnet during rotation; determining a signal difference between the current time-varying magnetic field signal of the magnet and a reference time-varying magnetic field signal, and determining a self-test result of the rotating magnet unit based on the signal difference;

[0502] The correction module 3720 is configured to determine, for any of the rotating magnet units, a target magnetic moment strength of the rotating magnet unit according to a self-test result of the rotating magnet unit.

[0503] The electromagnetic navigation device 3700 can execute the electromagnetic navigation method described in this specification using the self-checking module 3710 and the correction module 3720. For details about the electromagnetic navigation method, please refer to the above description.

[0504] FIG38 is an exemplary block diagram of a control system for a field transmitter according to some embodiments of this specification. The system is applied to a field transmitter comprising at least one rotating magnet unit, wherein at least one rotating magnet unit includes a drive assembly and a magnet. The control system for the field transmitter can be implemented in the processor 13 in the form of hardware or software. The control system 3800 includes the following modules:

[0505] A torque determination module 3810 is configured to determine, for at least one rotating magnet unit in the field transmitter, an interaction torque exerted on the magnet of the rotating magnet unit by magnets of other rotating magnet units;

[0506] The torque processing module 3820 is used to: use the interaction torque exerted on the magnet of the rotating magnet unit as the feedforward input of its own drive to determine the driving current corresponding to the rotating magnet unit; and control the driving component to drive the rotating magnet unit to rotate according to the driving current to generate a time-varying magnetic field.

[0507] The control system 3800 of the field transmitter can use the torque determination module 3810 and the torque processing module 3820 to execute the control method of the field transmitter in this specification. For details about the control method of the field transmitter, please refer to the above description.

[0508] FIG39 is an exemplary block diagram of a control system for a field transmitter according to some embodiments of this specification. The field transmitter includes at least one rotating magnet unit, each of which includes a drive assembly and a magnet. The field transmitter control system can be implemented in processor 13 in hardware or software. The control system 3900 includes a rotational speed control module.

[0509] The rotation speed control module 3910 is used to control the magnets of the rotating magnet unit with the same initial magnetic moment direction to produce different rotation speeds.

[0510] The control system 3900 of the field transmitter can use the rotation speed control module 3910 to execute the control method of the field transmitter in this specification. The control method of the field transmitter is described in detail above.

[0511] FIG40 is an exemplary block diagram of a self-calibration system for a field transmitter according to some embodiments of this specification. The self-calibration system for a field transmitter is applied to the field transmitters described in some embodiments of this specification. The self-calibration system for a field transmitter can be implemented in the processor 13 in the form of hardware or software. The self-calibration system 4000 includes the following modules:

[0512] A magnetic field data acquisition module 4010 is configured to acquire measured calibration magnetic field data obtained by the magnetic detection assembly detecting a target calibration magnetic field, wherein the target calibration magnetic field is a calibration magnetic field generated by a target rotating magnet unit, which is a rotating magnet unit to be calibrated in the field emission unit group;

[0513] An angle information acquisition module 4020, used to acquire magnet angle information of the target rotating magnet unit;

[0514] The target calibration parameter determination module 4030 is configured to determine target calibration parameters of the target rotating magnet unit according to the measured calibration magnetic field data and the magnet angle information.

[0515] The field transmitter self-calibration system 4000 can execute the field transmitter self-calibration method described in this specification using the magnetic field data acquisition module 4010, the angle information acquisition module 4020, and the target calibration parameter determination module 4030. For details about the field transmitter self-calibration method, please refer to the previous description.

[0516] FIG41 is an exemplary block diagram of an interference detection system for a field transmitter according to some embodiments of this specification. The interference detection system is applied to the field transmitter described in some embodiments of this specification. The interference detection system for a field transmitter can be implemented in the processor 13 in the form of hardware or software. The interference detection system 4100 includes the following modules:

[0517] A first control module 4110 is configured to control all rotating magnet units in the field transmitter to stop rotating;

[0518] A second control module 4120 is configured to control the magnetic source assembly to generate the detection magnetic field;

[0519] A first acquisition module 4130 is configured to acquire actual detection magnetic field data obtained by the magnetic detection component detecting the detection magnetic field;

[0520] The second acquisition module 4140 is configured to determine a detection difference between the measured magnetic field data and the reference magnetic field data;

[0521] The first determining module 4150 is configured to determine an interference detection result of the field transmitter according to the detection difference.

[0522] The interference detection system 4100 for a field transmitter can implement the interference detection method for a field transmitter described herein using a first control module 4110, a second control module 4120, a first acquisition module 4130, a second acquisition module 4140, and a first determination module 4150. The interference detection method for a field transmitter is described above for details.

[0523] FIG42 is an exemplary module diagram of a field transmitter anomaly detection system according to some embodiments of this specification. The anomaly detection system is applied to the field transmitters described in some embodiments of this specification. The field transmitter anomaly detection system can be implemented in the processor 13 in the form of hardware or software. The anomaly detection system includes the following modules:

[0524] The second magnetic field data acquisition module 4210 is used to acquire the measured working magnetic field data obtained by the magnetic detection component detecting the working magnetic field generated by the field transmitter;

[0525] The operating state determining module 4220 is configured to determine an operating difference between the measured operating magnetic field data and the reference operating magnetic field data, and determine an operating state of the field transmitter according to the operating difference.

[0526] The field transmitter abnormality detection system 4200 can use the second magnetic field data acquisition module 4210 and the operation status determination module 4220 to execute the field transmitter abnormality detection method described in this specification. Detailed description of the field transmitter abnormality detection method is provided above.

[0527] While the basic concepts have been described above, it will be apparent to those skilled in the art that the detailed disclosure is merely illustrative and does not limit this specification. Although not explicitly stated herein, various modifications, improvements, and revisions to this specification may be made by those skilled in the art. Such modifications, improvements, and revisions are suggested in this specification and remain within the spirit and scope of the exemplary embodiments of this specification.

[0528] This specification also uses specific terms to describe the embodiments of this specification. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a feature, structure, or characteristic associated with at least one embodiment of this specification. Therefore, it should be emphasized and noted that references to "one embodiment," "an embodiment," or "an alternative embodiment" two or more times in different locations in this specification do not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of this specification may be appropriately combined.

[0529] In addition, unless expressly stated in the claims, the order of the processing elements and sequences, the use of alphanumeric characters, or the use of other names described in this specification are not intended to limit the order of the processes and methods of this specification. Although the above disclosure discusses some of the invention embodiments currently considered useful through various examples, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the spirit and scope of the embodiments of this specification. For example, although the system components described above can be implemented by hardware devices, they can also be implemented only by software solutions, such as installing the described system on an existing server or mobile device.

[0530] Similarly, it should be noted that, in order to simplify the presentation of this specification and thus facilitate understanding of one or more embodiments of the invention, the foregoing descriptions of the embodiments of this specification sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not imply that the subject matter of this specification requires more features than those recited in the claims. In fact, an embodiment may have fewer features than all of the features of a single disclosed embodiment.

[0531] In some embodiments, numbers are used to describe the quantity of components and attributes. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise stated, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the description and claims are approximate values, which may change according to the required characteristics of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of this specification are approximate values, in specific embodiments, the settings of such numerical values ​​are as accurate as possible within the feasible range.

[0532] Each patent, patent application, patent application publication, and other materials, such as articles, books, specifications, publications, and documents, cited in this specification is hereby incorporated by reference in its entirety. This includes application history documents that are inconsistent with or conflict with the content of this specification, as well as documents (currently or subsequently attached to this specification) that limit the broadest scope of the claims of this specification. It should be noted that if the descriptions, definitions, and / or terminology used in the accompanying materials are inconsistent or conflicting with the content of this specification, the descriptions, definitions, and / or terminology used in this specification will control.

[0533] Finally, it should be understood that the embodiments described in this specification are intended only to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, by way of example and not limitation, alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly described and illustrated in this specification.

Claims

1. A rotating magnet unit, comprising: drive assembly, magnet and self-test assembly; The driving assembly is connected to the magnet and is used to drive the magnet to rotate; The self-test component is used to detect the magnetic field signal generated during the rotation of the magnet.

2. The rotating magnet unit according to claim 1, wherein the self-test component comprises three annular coils whose normal vectors are orthogonal to each other; The three annular coils are respectively located on three sides of the magnet; the normal vector of one of the annular coils coincides with the rotation axis of the magnet.

3. The rotating magnet unit according to claim 1, wherein the self-test component comprises a magnetic sensor; The magnetic sensor is located on a side of the driving component away from the magnet.

4. The rotating magnet unit according to any one of claims 1 to 3, wherein the rotating axis of the magnet: is not parallel to the magnetic moment direction of the magnet; or, is not parallel to the magnetic moment direction of the magnet and passes through the center of mass of the magnet; or, perpendicular to the magnetic moment direction of the magnet; or It is perpendicular to the magnetic moment direction of the magnet and passes through the center of mass of the magnet.

5. The rotating magnet unit according to any one of claims 1 to 4, wherein the driving assembly comprises a motor, a reduction mechanism and an absolute position encoder; The output shaft of the motor is connected to the magnet through the speed reduction mechanism, and the absolute position encoder is used to collect angular position information of the magnet.

6. The rotating magnet unit according to any one of claims 1 to 5, wherein the driving assembly comprises a transmission device, and the motor drives the magnet to rotate through the transmission device.

7. The rotating magnet unit according to any one of claims 1 to 6, further comprising: Install the housing; The driving component, the magnet and the self-test component are all installed inside the installation housing; The mounting housing is provided with a functional interface, and the functional interface connects the driving component and the self-test component.

8. The rotating magnet unit according to any one of claims 1 to 7, further comprising: Locking components; The locking assembly is used to lock the angular position of the magnet.

9. A field transmitter, comprising at least one rotating magnet unit, wherein at least one rotating magnet unit is the rotating magnet unit according to any one of claims 1 to 8.

10. An electromagnetic navigation system, comprising a processor, a receiving device and the field transmitter as described in claim 9, wherein the receiving device is used to detect the time-varying magnetic field generated by the field transmitter, and the processor is used to control the operation of the field transmitter and determine the real-time position of the receiving device in the time-varying magnetic field based on the magnetic field detection data of the receiving device.

11. A self-checking method for a rotating magnet unit, the self-checking method for a rotating magnet unit being applied to the rotating magnet unit according to any one of claims 1 to 8; The self-test method of the rotating magnet unit comprises: Controlling the driving assembly to drive the magnet to rotate at a preset speed; Acquire a current time-varying magnetic field signal of the magnet; wherein the current time-varying magnetic field signal is obtained by the self-detection component detecting a magnetic field signal generated by the magnet when it rotates; A signal difference between a current time-varying magnetic field signal of the magnet and a reference time-varying magnetic field signal is determined, and a self-test result of the rotating magnet unit is determined according to the signal difference.

12. The self-test method of a rotating magnet unit according to claim 11, wherein the reference time-varying magnetic field signal is obtained by detecting, by the self-test component, a magnetic field signal generated when the magnet rotates at the preset speed in an initial state of the rotating magnet unit.

13. The self-test method of a rotating magnet unit according to claim 11 or 12, wherein determining a signal difference between a current time-varying magnetic field signal of the magnet and a reference time-varying magnetic field signal, and determining a self-test result of the rotating magnet unit according to the signal difference comprises: Determining a current magnetic field strength and a proportional relationship between components in the current time-varying magnetic field signal based on the current time-varying magnetic field signal; Determining a strength difference between the current magnetic field strength and a reference magnetic field strength, wherein the reference magnetic field strength is determined based on the reference time-varying magnetic field signal; Determine a proportional difference between a proportional relationship of each component in the current time-varying magnetic field signal and a proportional relationship of each component in the reference time-varying magnetic field signal; A self-test result of the rotating magnet unit is determined according to the intensity difference and the ratio difference.

14. A self-test system for a rotating magnet unit, the system being applied to the rotating magnet unit according to any one of claims 1 to 8; the system comprising: A driving module, used for controlling the driving assembly to drive the magnet to rotate at a preset speed; A first signal acquisition module, used to acquire a current time-varying magnetic field signal of the magnet; wherein the current time-varying magnetic field signal is obtained by the self-detection component detecting a magnetic field signal generated by the magnet when it rotates; The first self-test result determination module is used to determine the signal difference between the current time-varying magnetic field signal of the magnet and the reference time-varying magnetic field signal, and determine the self-test result of the rotating magnet unit according to the signal difference.

15. A self-checking device for a rotating magnet unit, comprising a processor, wherein the processor is used to execute the self-checking method for a rotating magnet unit according to any one of claims 11 to 13. 16 . A computer-readable storage medium storing computer instructions. When a computer reads the computer instructions in the storage medium, the computer executes the self-test method of a rotating magnet unit according to claim 11 .

17. A self-testing method for a field transmitter, the self-testing method for a field transmitter being applied to the field transmitter according to claim 9; The self-test method of the field transmitter comprises: determining a target rotating magnet unit to be self-checked in the field transmitter, and locking the angular position of the magnet of the non-target rotating magnet unit; Controlling the driving assembly to drive the magnet of the target rotating magnet unit to rotate at a preset speed; Acquire a current time-varying magnetic field signal of the magnet; wherein the current time-varying magnetic field signal is obtained by the self-detection component detecting a magnetic field signal generated by the magnet when it rotates; A signal difference between a current time-varying magnetic field signal of the magnet and a reference time-varying magnetic field signal is determined, and a self-test result of the rotating magnet unit is determined according to the signal difference.

18. A self-test system for a field transmitter, the system being applied to the field transmitter according to claim 9; The system comprises: A locking module, used to determine a target rotating magnet unit to be self-checked in the field transmitter, and to lock the angular position of the magnet of the non-target rotating magnet unit; A rotation control module, used for controlling the driving assembly to drive the magnet of the target rotating magnet unit to rotate at a preset speed; A second signal acquisition module, used to acquire a current time-varying magnetic field signal of the magnet; wherein the current time-varying magnetic field signal is obtained by the self-detection component detecting a magnetic field signal generated by the magnet when it rotates; The second self-test result determination module is used to determine the signal difference between the current time-varying magnetic field signal of the magnet and the reference time-varying magnetic field signal, and determine the self-test result of the rotating magnet unit according to the signal difference. 19 . A self-checking device for a rotating magnet unit, comprising a processor, wherein the processor is used to execute the self-checking method for a rotating magnet unit according to claim 17 . 20 . A computer-readable storage medium storing computer instructions. When a computer reads the computer instructions in the storage medium, the computer executes the self-test method of the rotating magnet unit according to claim 17 .

21. An electromagnetic navigation method, the electromagnetic navigation method being applied to the electromagnetic navigation system according to claim 10; The electromagnetic navigation method comprises: Performing a self-test on the field transmitter to obtain a self-test result of each rotating magnet unit in the field transmitter includes: determining a target rotating magnet unit to be self-checked in the field transmitter, and locking the angular position of the magnet of the non-target rotating magnet unit; Controlling the driving assembly to drive the magnet of the target rotating magnet unit to rotate at a preset speed; Acquire a current time-varying magnetic field signal of the magnet; wherein the current time-varying magnetic field signal is obtained by the self-detection component detecting a magnetic field signal generated by the magnet when it rotates; Determine a signal difference between a current time-varying magnetic field signal of the magnet and a reference time-varying magnetic field signal, and determine a self-test result of the rotating magnet unit according to the signal difference; For any of the rotating magnet units, a target magnetic moment strength of the rotating magnet unit is determined according to a self-test result of the rotating magnet unit.

22. The electromagnetic navigation method according to claim 21, further comprising: Acquiring magnetic field data of the time-varying magnetic field generated by the field transmitter; wherein the magnetic field data of the time-varying magnetic field is obtained by the receiving device detecting the time-varying magnetic field; The real-time position and posture of the receiving device in the time-varying magnetic field is determined according to the magnetic field data of the time-varying magnetic field and the time-varying characteristics of the time-varying magnetic field.

23. According to the electromagnetic navigation method of claim 22, the time-varying characteristics of the time-varying magnetic field include the time-varying characteristics of the magnetic moment of each rotating magnet unit in the field transmitter in the field transmitter coordinate system, and the time-varying characteristics of the magnetic moment include the time-varying characteristics of the magnetic moment direction and the magnetic moment intensity.

24. The electromagnetic navigation method according to claim 21 or 22, wherein determining the real-time position and posture of the receiving device in the time-varying magnetic field according to the magnetic field data of the time-varying magnetic field and the time-varying characteristics of the time-varying magnetic field comprises: Based on the magnetic field data of the time-varying magnetic field within the real-time time window and the time-varying characteristics of the time-varying magnetic field, the posture of the receiving device in the time-varying magnetic field is calculated in real time; wherein the window width of the real-time time window is determined according to the real-time requirements of the posture calculation of the receiving device.

25. The method according to any one of claims 21 to 24, further comprising: Acquiring real-time detection results of the self-detection components of each of the rotating magnet units detecting the time-varying magnetic field generated by the field transmitter; Determining the difference between the real-time detection result of the self-detection component of each of the rotating magnet units and the corresponding reference detection result; The real-time operating status of the field transmitter is determined according to the result difference.

26. An electromagnetic navigation device, applied to the electromagnetic navigation system according to claim 10; The electromagnetic navigation device comprises: Self-check module for: Performing a self-test on the field transmitter to obtain a self-test result of each rotating magnet unit in the field transmitter includes: determining a target rotating magnet unit to be self-checked in the field transmitter, and locking the angular position of the magnet of the non-target rotating magnet unit; Controlling the driving assembly to drive the magnet of the target rotating magnet unit to rotate at a preset speed; Acquire a current time-varying magnetic field signal of the magnet; wherein the current time-varying magnetic field signal is obtained by the self-detection component detecting a magnetic field signal generated by the magnet when it rotates; Determine a signal difference between a current time-varying magnetic field signal of the magnet and a reference time-varying magnetic field signal, and determine a self-test result of the rotating magnet unit according to the signal difference; The correction module is used to determine the target magnetic moment strength of any rotating magnet unit according to the self-test result of the rotating magnet unit.

27. An electromagnetic navigation device, comprising a processor, wherein the processor is used to execute the electromagnetic navigation method according to any one of claims 21-25.

28. A computer-readable storage medium, wherein the storage medium stores computer instructions. When a computer reads the computer instructions in the storage medium, the computer executes the electromagnetic navigation method according to any one of claims 21 to 25.

29. A control method for a field transmitter, applied to the field transmitter, wherein the field transmitter comprises at least one rotating magnet unit, wherein at least one rotating magnet unit comprises a driving component and a magnet; The method comprises: For each of the rotating magnet units in the field transmitter, determining the interaction torque exerted on the magnet of the rotating magnet unit by magnets of other rotating magnet units; Using the interaction torque exerted on the magnet of the rotating magnet unit as a feedforward input of its own drive to determine a drive current corresponding to the rotating magnet unit; According to the driving current, the driving component is controlled to drive the rotating magnet unit to rotate, thereby generating a time-varying magnetic field.

30. The method according to claim 29, wherein determining the interaction torque on the magnet of the rotating magnet unit from magnets of other rotating magnet units comprises: determining one of the rotating magnet units in the field transmitter as a first target rotating magnet unit; Determining a target magnetic field time-varying characteristic of a combined magnetic field at the magnet of the first target rotating magnet unit, wherein the combined magnetic field is jointly generated by non-first target rotating magnet units in the field transmitter; determining a target magnetic moment time-varying characteristic of the magnet of the first target rotating magnet unit; The time-varying characteristic of the interaction torque to which the magnet of the first target rotating magnet unit is subjected is determined according to the time-varying characteristic of the target magnetic field and the time-varying characteristic of the target magnetic moment.

31. A control system for a field transmitter, applied to a field transmitter, wherein the field transmitter comprises at least one rotating magnet unit, wherein at least one rotating magnet unit comprises a driving component and a magnet; The system comprises: A torque determination module, configured to determine, for each of the rotating magnet units in the field transmitter, an interaction torque on the magnet of the rotating magnet unit from magnets of other rotating magnet units; Torque processing module for: Using the interaction torque exerted on the magnet of the rotating magnet unit as a feedforward input of its own drive to determine a drive current corresponding to the rotating magnet unit; According to the driving current, the driving component is controlled to drive the rotating magnet unit to rotate, thereby generating a time-varying magnetic field.

32. A control device for a field transmitter, comprising a processor, wherein the processor is used to execute the control method for a field transmitter according to any one of claims 29 to 30.

33. A computer-readable storage medium, wherein the storage medium stores computer instructions. When a computer reads the computer instructions in the storage medium, the computer executes the control method of the field transmitter according to any one of claims 29 to 30.

34. A control method for a field transmitter, applied to the field transmitter, the field transmitter comprising at least one rotating magnet unit, at least one of the rotating magnet units comprising a driving component and a magnet; The method comprises: The magnets of the rotating magnet unit with the same initial magnetic moment direction are controlled to produce different rotation speeds.

35. The method of claim 34, further comprising: The magnets of the rotating magnet unit having different initial magnetic moment directions are controlled to generate the same rotation speed.

36. A control system for a field transmitter, applied to a field transmitter, the field transmitter comprising at least one rotating magnet unit, at least one of the rotating magnet units comprising a driving assembly and a magnet; The system includes a speed control module for: The magnets of the rotating magnet unit with the same initial magnetic moment direction are controlled to produce different rotation speeds.

37. A control device for a field transmitter, comprising a processor, wherein the processor is used to execute the control method for a field transmitter as claimed in any one of claims 34 to 35.

38. A computer-readable storage medium, wherein the storage medium stores computer instructions. When a computer reads the computer instructions in the storage medium, the computer executes the control method of the field transmitter according to any one of claims 34-35.

39. A field transmitter, comprising: Field emission unit group and magnetic detection assembly; The field emission unit group includes at least one rotating magnet unit; The magnetic detection component is used to detect the calibration magnetic field generated by the rotating magnet unit.

40. The field transmitter of claim 39, wherein the magnetic detection assembly further comprises a circuit board, wherein the magnetic detection assembly comprises a plurality of magnetic sensors; A plurality of magnetic sensors are evenly mounted on the circuit board.

41. The field transmitter of claim 39 or 40, further comprising: Install the housing; The field emission unit group and the magnetic detection assembly are both installed inside the installation housing; Alternatively, the field emission unit group is installed inside the installation shell, and the magnetic detection component is installed outside the installation shell.

42. The field transmitter according to any one of claims 39 to 41, further comprising: Magnetic source assembly; When the magnetic source component is working, the magnetic detection component is also used to detect the detection magnetic field generated by the magnetic source component.

43. The field transmitter according to claim 42, wherein the magnetic source assembly comprises a plurality of coils, and the plurality of coils are evenly distributed around the field emission unit group.

44. A self-calibration method for a field transmitter, the self-calibration method being applied to the field transmitter according to any one of claims 39 to 43; The self-calibration method comprises: Acquire measured calibration magnetic field data obtained by the magnetic detection component detecting a target calibration magnetic field, wherein the target calibration magnetic field is a calibration magnetic field generated by a target rotating magnet unit, and the target rotating magnet unit is a rotating magnet unit to be calibrated in the field emission unit group; Acquiring magnet angle information of the target rotating magnet unit; The target calibration parameters of the target rotating magnet unit are determined according to the measured calibration magnetic field data and the magnet angle information.

45. The self-calibration method for a field transmitter according to claim 44, wherein determining target calibration parameters of the target rotating magnet unit according to the measured working magnetic field data and the magnet angle information comprises: Determine the model calibration magnetic field data of the target calibration magnetic field at the magnetic detection component according to the magnet angle information, the model parameters of the target rotating magnet unit and the spatial posture of the magnetic detection component; Taking minimizing the difference between the measured calibration magnetic field data and the model calibration magnetic field data as the optimization goal, the model parameters of the target rotating magnet unit are optimized to obtain the target calibration parameters of the target rotating magnet unit.

46. ​​The method for self-calibration of a field transmitter according to claim 45, wherein minimizing the difference between the measured working magnetic field data and the model calibration magnetic field data is an optimization goal, comprising: The optimization goal is to minimize the difference between the modulus value of the measured calibration magnetic field data and the modulus value of the model calibration magnetic field data.

47. The self-calibration method for a field transmitter according to claim 46, wherein the measured calibration magnetic field data comprises a measured calibration magnetic field value sequence, and the model calibration magnetic field data comprises a model calibration magnetic field value sequence; The optimization goal of minimizing the difference between the measured calibration magnetic field data and the model calibration magnetic field data includes: Determining a sequence mean of the measured calibration magnetic field value sequence and a sequence mean of the model calibration magnetic field value sequence; Subtracting the sequence mean of the measured calibration magnetic field value sequence from each magnetic field value in the measured calibration magnetic field value sequence to obtain a first magnetic field value sequence; Subtracting the sequence mean of the model calibration magnetic field value sequence from each magnetic field value in the model calibration magnetic field value sequence to obtain a second magnetic field value sequence; The optimization goal is to minimize the difference between the first magnetic field value sequence and the second magnetic field value sequence.

48. A self-calibration system for a field transmitter, the system being applied to the field transmitter as claimed in any one of claims 44 to 47; The self-calibration system comprises: A magnetic field data acquisition module, used to acquire measured calibration magnetic field data obtained by the magnetic detection component detecting a target calibration magnetic field, wherein the target calibration magnetic field is a calibration magnetic field generated by a target rotating magnet unit, and the target rotating magnet unit is a rotating magnet unit to be calibrated in the field emission unit group; An angle information acquisition module, used to acquire the magnet angle information of the target rotating magnet unit; The target calibration parameter determination module is used to determine the target calibration parameters of the target rotating magnet unit according to the measured calibration magnetic field data and the magnet angle information.

49. A self-calibration device for a field transmitter, comprising a processor, wherein the processor is used to execute the self-calibration method for a field transmitter as described in any one of claims 44-47.

50. A computer-readable storage medium, wherein the storage medium stores computer instructions. When a computer reads the computer instructions in the storage medium, the computer executes the self-calibration method for a field transmitter as described in any one of claims 44-47.

51. A field transmitter, comprising: A field emission unit group and a magnetic source assembly; The field emission unit group includes at least one rotating magnet unit; When the field emission unit group stops working, the magnetic source assembly generates a detection magnetic field for performing interference detection on the field emitter.

52. The field transmitter according to claim 51, wherein the magnetic source assembly comprises a plurality of coils, and the plurality of coils are evenly distributed around the field emission unit group.

53. An interference detection method for a field transmitter, the interference detection method being applied to the field transmitter according to any one of claims 42-43 or 51-52; The interference detection method comprises: Controlling all rotating magnet units in the field transmitter to stop rotating; Controlling the magnetic source component to generate the detection magnetic field; Acquire actual detection magnetic field data obtained by the magnetic detection component detecting the detection magnetic field; Determining a detection difference between the measured detection magnetic field data and the reference detection magnetic field data; An interference detection result of the field transmitter is determined according to the detection difference.

54. The interference detection method for a field transmitter according to claim 53, wherein the magnetic source assembly comprises a plurality of coils, and the plurality of coils are evenly distributed around the field transmitting unit group; The obtaining of the measured detection magnetic field data obtained by the magnetic sensor detecting the detection magnetic field includes: Acquire the target measured detection magnetic field data obtained by the magnetic detection component detecting the target detection magnetic field; wherein the target detection magnetic field is the detection magnetic field generated by the target coil in the magnetic source component; The step of determining the detection difference between the measured magnetic field data and the reference magnetic field data, and determining the interference detection result of the field transmitter according to the detection difference, comprises: The target detection difference between the target measured detection magnetic field data and the target reference detection magnetic field data is determined, and the interference detection result of the field transmitter in the direction corresponding to the target coil is determined according to the target detection difference.

55. An interference detection system for a field transmitter, applied to a field transmitter as claimed in any one of claims 42-43 or 51-52; The interference detection system comprises: A first control module, used for controlling all rotating magnet units in the field transmitter to stop rotating; A second control module, used for controlling the magnetic source component to generate the detection magnetic field; A first acquisition module is used to acquire the actual detection magnetic field data obtained by the magnetic detection component detecting the detection magnetic field; A second acquisition module is used to determine the detection difference between the measured detection magnetic field data and the reference detection magnetic field data; The first determination module is used to determine the interference detection result of the field transmitter according to the detection difference.

56. An interference detection device for a field transmitter, comprising a processor, wherein the processor is used to execute the interference detection method for a field transmitter as described in any one of claims 53-54.

57. A computer-readable storage medium, wherein the storage medium stores computer instructions. When a computer reads the computer instructions in the storage medium, the computer executes the interference detection method for a field transmitter as described in any one of claims 53-54.

58. A method for detecting an abnormality of a field transmitter, the method for detecting an abnormality being applied to the field transmitter according to any one of claims 39 to 43; The anomaly detection method comprises: Acquire measured working magnetic field data obtained by the magnetic detection component detecting the working magnetic field generated by the field transmitter; The working difference between the measured working magnetic field data and the reference working magnetic field data is determined, and the operating state of the field transmitter is determined according to the working difference.

59. The method for detecting anomalies of a field transmitter according to claim 58, wherein the field transmitter further comprises: Magnetic source assembly; The step of determining the operating state of the field transmitter according to the operating difference comprises: In response to determining that the operating difference is less than or equal to an operating difference threshold, determining that the field transmitter is in a normal operating state; In response to determining that the working difference is greater than the working difference threshold, Controlling all rotating magnet units in the field transmitter to stop rotating; Controlling the magnetic source component to generate a detection magnetic field; Acquire actual detection magnetic field data obtained by the magnetic detection component detecting the detection magnetic field; Determining a detection difference between the measured detection magnetic field data and the reference detection magnetic field data; An interference detection result of the field transmitter is determined according to the detection difference.

60. The method for detecting anomalies of a field transmitter according to claim 59, further comprising: After performing the interference detection on the field transmitter, In response to determining that the detection difference is greater than a detection difference threshold, determining that the field transmitter is in an abnormal operating state; In response to determining that the detection difference is less than or equal to the detection difference threshold, Acquire measured calibration magnetic field data obtained by the magnetic detection component detecting a target calibration magnetic field, wherein the target calibration magnetic field is a calibration magnetic field generated by a target rotating magnet unit, and the target rotating magnet unit is a rotating magnet unit to be calibrated in the field emission unit group; Acquiring magnet angle information of the target rotating magnet unit; The target calibration parameters of the target rotating magnet unit are determined according to the measured calibration magnetic field data and the magnet angle information.

61. The method for detecting anomalies of a field transmitter according to claim 60, further comprising: After the field transmitter is self-calibrated, Determining a calibration difference between the target calibration parameters and the initial calibration parameters; In response to determining that the calibrated difference is greater than a calibrated difference threshold, determining that the field transmitter is in an abnormal operating state; In response to determining that the calibration difference is less than or equal to the calibration difference threshold, Determining that the field transmitter is in normal operating condition; The target parameters of the field transmitter are updated to the target calibration parameters.

62. An electromagnetic navigation system, comprising a processor, a receiving device and the field transmitter according to any one of claims 39-43, wherein the receiving device is used to detect the time-varying magnetic field generated by the field transmitter, and the processor is used to control the operation of the field transmitter and determine the real-time position of the receiving device in the time-varying magnetic field based on the magnetic field detection data of the receiving device.

63. A field transmitter anomaly detection system, applied to the field transmitter according to any one of claims 58 to 61; The anomaly detection system comprises: A second magnetic field data acquisition module is used to acquire measured working magnetic field data obtained by the magnetic detection component detecting the working magnetic field generated by the field transmitter; The operating state determination module is used to determine the operating difference between the measured operating magnetic field data and the reference operating magnetic field data, and determine the operating state of the field transmitter according to the operating difference.

64. An abnormality detection device for a field transmitter, comprising a processor, wherein the processor is used to execute the abnormality detection method for a field transmitter as described in any one of claims 58-61.

65. A computer-readable storage medium, wherein the storage medium stores computer instructions. When a computer reads the computer instructions in the storage medium, the computer executes the method for detecting anomalies of a field transmitter as described in any one of claims 58 to 61.

66. A field transmitter, comprising at least one rotating magnet unit, wherein a reference axis is defined in each rotating magnet unit, wherein the rotating magnet unit comprises a magnet capable of rotating around the reference axis, wherein a magnetic moment direction of the magnet is not parallel to the reference axis.

67. The field transmitter of claim 66, wherein at least one of the rotating magnet units comprises a self-detection component for detecting a magnetic field signal generated during rotation of the magnet.

68. The field transmitter of any one of claims 9, 39, 51, 66 or 67, comprising a plurality of rotating magnet units, the plurality of rotating magnet units comprising a first rotating magnet unit and a second rotating magnet unit; The first rotating magnet unit includes a first motor and a first magnet, the second rotating magnet unit includes a second motor and a second magnet, the first motor is used to drive the first magnet to rotate, and the second motor is used to drive the second magnet to rotate; or, The first magnet unit includes a first motor and a first magnet, the second magnet unit includes a first transmission assembly and a second magnet, the first motor is used to drive the first magnet to rotate, and the first motor is also used to drive the second magnet to rotate by driving the first transmission assembly.

69. The field transmitter according to any one of claims 66 to 68, wherein for each of the rotating magnet units, a reference axis is defined in the rotating magnet unit, the rotating magnet unit comprises a magnet capable of rotating around the reference axis, and a magnetic moment direction of the magnet is perpendicular to the reference axis; in, When the field transmitter comprises a plurality of rotating magnet units: The reference axes of at least two of the plurality of rotating magnet units are perpendicular to each other; or, The number of the plurality of rotating magnet units is four, the reference axes of the four rotating magnet units are in the same plane, and the reference axes of any two adjacent rotating magnet units of the four rotating magnet units are perpendicular to each other; or, The number of the plurality of rotating magnet units is three, and the reference axes of the three rotating magnet units are perpendicular to each other.

70. The field transmitter according to any one of claims 66 to 69, wherein the magnet is mounted on ends of any two of the plurality of rotating magnet units that are away from each other.

71. The field transmitter according to any one of claims 66-70, further comprising a mounting body, wherein the mounting body is provided with a plurality of mounting positions, and the plurality of mounting positions are used to mount the at least one rotating magnet unit.

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