Field emitter and self-calibration method, interference detection method and anomaly detection method thereof

Abstract

The invention relates to a field emitter and a self-calibration method, an interference detection method and an anomaly detection method thereof, and the field emitter comprises a field emission unit group and a magnetic detection assembly. The field emission unit group comprises field emission units, and the space poses of the field emission units in the field emitter are fixed; the magnetic detection assembly comprises a magnetic sensor, and the spatial pose of the magnetic sensor in the field emitter is fixed; when the magnetic detection assembly works, the magnetic sensor is used for detecting a calibration magnetic field generated by the field emission unit. Through the application, the calibration parameters of each field emission unit can be updated in the magnetic field model, so that the calculation result of the magnetic field model is more accurate, and the electromagnetic navigation precision can be improved. Therefore, the problem that the electromagnetic navigation precision of the electromagnetic navigation system is reduced after the initial calibration parameter of the field emitter is mismatched with the actual state in the prior art is solved.

Description

Technical Field

[0001] The present application relates to the field of electromagnetic navigation, and particularly to a field emitter and its self-calibration method, interference detection method, and anomaly detection method. Background Art

[0002] The electromagnetic navigation system (EMTS) is one of the mainstream technical solutions for surgical navigation systems. The most typical basic principle of EMTS is to generate a time-varying magnetic field through a field emitter, and after detecting the time-varying magnetic field through a magnetic sensor, perform pose calculation of the magnetic sensor.

[0003] The accuracy of the magnetic field model is the key prerequisite for obtaining high-precision calculation results. Any processing and installation inevitably have errors, and there are also errors in electronic control, such as the control of physical quantities such as current intensity and frequency. Therefore, before high-precision navigation applications, it is necessary to calibrate the field emitter in detail and with high precision to obtain an accurate magnetic field model. However, even after detailed factory calibration, problems such as collisions, thermal expansion and contraction, mechanical fatigue, and equipment aging inevitably occur during use, resulting in a mismatch between the initial calibration parameters and the actual state of the field emitter, reducing the electromagnetic navigation accuracy.

[0004] Regarding the problem that the electromagnetic navigation accuracy of the electromagnetic navigation system is reduced after the initial calibration parameters of the field emitter in the related technology are mismatched with the actual state, no effective solution has been proposed yet. Summary of the Invention

[0005] In the present invention, a field emitter and its self-calibration method, interference detection method, and anomaly detection method are provided to solve the problem that the electromagnetic navigation accuracy of the electromagnetic navigation system is reduced after the initial calibration parameters of the field emitter in the related technology are mismatched with the actual state.

[0006] In a first aspect, the present invention provides a field emitter, the field emitter comprising: a field emission unit group and a magnetic detection component;

[0007] The field emission unit group includes field emission units, and the spatial pose of the field emission units in the field emitter is fixed;

[0008] The magnetic detection component includes magnetic sensors, and the spatial pose of the magnetic sensors in the field emitter is fixed;

[0009] When the magnetic detection component works, the magnetic sensors are used to detect the calibration magnetic field generated by the field emission units.

[0010] In some of the embodiments, the magnetic detection component further includes a circuit board, and the magnetic sensors are multiple;

[0011] A plurality of the magnetic sensors are uniformly and fixedly mounted on the circuit board.

[0012] In some embodiments thereof, the field emitter further includes: a mounting housing;

[0013] Both the field emission unit group and the magnetic detection assembly are fixedly mounted inside the mounting housing;

[0014] Alternatively, the field emission unit group is fixedly mounted inside the mounting housing, and the magnetic detection assembly is fixedly mounted outside the mounting housing.

[0015] In some embodiments thereof, the field emitter further includes: a magnetic source assembly;

[0016] The spatial pose of the magnetic source assembly in the field emitter is fixed;

[0017] When the magnetic source assembly is operating, the magnetic sensor is further configured to detect a detection magnetic field generated by the magnetic source assembly.

[0018] In some embodiments thereof, the magnetic source assembly includes a plurality of coils, and the plurality of coils are uniformly distributed on the periphery of the field emission unit group.

[0019] Second aspect, the present invention provides a self-calibration method for a field emitter, and the self-calibration method is applied to the field emitter described in the first aspect; the self-calibration method includes:

[0020] Obtaining measured calibration magnetic field data detected by the magnetic sensor for a target calibration magnetic field, and obtaining magnetic body angle information of a target field emission unit; wherein, the target field emission unit is a field emission unit to be calibrated in the field emission unit group, and the target calibration magnetic field is a calibration magnetic field generated by the target field emission unit;

[0021] Calibrating target parameters of the target field emission unit according to the measured calibration magnetic field data and the magnetic body angle information.

[0022] In some embodiments thereof, the calibrating target parameters of the target field emission unit according to the measured calibration magnetic field data and the magnetic body angle information includes:

[0023] Determining model calibration magnetic field data of the target calibration magnetic field at the magnetic sensor according to the magnetic body angle information, model parameters of the target field emission unit, and the spatial pose of the magnetic sensor;

[0024] Taking the minimization of the difference between the measured calibration magnetic field data and the model calibration magnetic field data as the optimization objective, optimize the model parameters of the target field emission unit to obtain the target parameters of the target field emission unit.

[0025] In some embodiments, the target parameters of the target field emission unit include the target spatial position of the target field emission unit.

[0026] In some embodiments, the target parameters of the target field emission unit at least include one of the following parameters:

[0027] The rotation axis geometric parameters of the target field emission unit, the target magnet zero position homogeneous transformation matrix, and the target magnetic moment intensity.

[0028] In some embodiments, taking the minimization of the difference between the measured calibration magnetic field data and the model calibration magnetic field data as the optimization objective includes:

[0029] Taking the minimization of the difference between the magnitude of the measured calibration magnetic field data and the magnitude of the model calibration magnetic field data as the optimization objective.

[0030] 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;

[0031] Taking the minimization of the difference between the measured calibration magnetic field data and the model calibration magnetic field data as the optimization objective includes:

[0032] Determine the sequence mean of the sequence of measured calibration magnetic field values and determine the sequence mean of the sequence of model calibration magnetic field values;

[0033] Subtract the sequence mean of the sequence of measured calibration magnetic field values from each magnetic field value in the sequence of measured calibration magnetic field values to obtain a first magnetic field value sequence;

[0034] Subtract the sequence mean of the sequence of model calibration magnetic field values from each magnetic field value in the sequence of model calibration magnetic field values to obtain a second magnetic field value sequence;

[0035] Taking the minimization of the difference between the first magnetic field value sequence and the second magnetic field value sequence as the optimization objective.

[0036] In a third aspect, the present invention provides a method for detecting interference of a field emitter. The interference detection method is applied to the field emitter described in the first aspect; the interference detection method includes:

[0037] Obtain the measured detected magnetic field data detected by the magnetic sensor for the detected magnetic field; wherein, the detected magnetic field is generated by the magnetic source assembly;

[0038] Determine the detection difference degree between the measured detected magnetic field data and the reference detected magnetic field data, and determine the interference detection result of the field emitter according to the detection difference degree.

[0039] In some embodiments, the determining the interference detection result of the field emitter according to the detection difference degree includes:

[0040] When the detection difference degree is greater than a first preset threshold, it is determined that there is a magnetic field interference source around the field emitter.

[0041] In some embodiments, the magnetic source assembly includes a plurality of coils for generating the detected magnetic field, and the plurality of coils are evenly distributed on the circumferential side of the field emission unit group;

[0042] The obtaining the measured detected magnetic field data detected by the magnetic sensor for the detected magnetic field includes:

[0043] Obtain the target measured detected magnetic field data detected by the magnetic sensor for the target detected magnetic field; wherein, the target detected magnetic field is the detected magnetic field generated by the target coil in the magnetic source assembly.

[0044] The determining the detection difference degree between the measured detected magnetic field data and the reference detected magnetic field data, and determining the interference detection result of the field emitter according to the detection difference degree includes:

[0045] Determine the target detection difference degree between the target measured detected magnetic field data and the target reference detected magnetic field data, and determine the interference detection result of the field emitter in the direction corresponding to the target coil according to the target detection difference degree.

[0046] In a fourth aspect, an abnormal detection method for a field emitter is provided in the present invention. The abnormal detection method is applied to the field emitter described in the first aspect; the abnormal detection method includes:

[0047] Obtain the measured operating magnetic field data detected by the magnetic sensor for the operating magnetic field generated by the field emitter;

[0048] Determine the working difference degree between the measured operating magnetic field data and the reference operating magnetic field data, and determine the operating state of the field emitter according to the working difference degree.

[0049] In some embodiments, the determining the operating state of the field emitter according to the working difference degree includes:

[0050] When the working difference degree is greater than a second preset threshold, it is determined that the operating state of the field emitter is abnormal.

[0051] Fifth aspect, in the present invention, a self-calibration device for a field emitter is provided, and the self-calibration device is applied to the field emitter described in the first aspect; the self-calibration device includes:

[0052] A first acquisition module, configured to acquire the measured calibration magnetic field data obtained by the magnetic sensor detecting a target calibration magnetic field, and acquire the magnet angle information of a target field emission unit; wherein, the target field emission unit is the field emission unit to be calibrated in the field emission unit group, and the target calibration magnetic field is the calibration magnetic field generated by the target field emission unit;

[0053] A parameter calibration module, configured to calibrate the target parameters of the target field emission unit according to the measured calibration magnetic field data and the magnet angle information.

[0054] Sixth aspect, in the present invention, an interference detection device for a field emitter is provided, and the interference detection device is applied to the field emitter described in the first aspect; the interference detection device includes:

[0055] A second acquisition module, configured to acquire the measured detection magnetic field data obtained by the magnetic sensor detecting a detection magnetic field; wherein, the detection magnetic field is generated by a magnetic source assembly;

[0056] An interference analysis module, configured to determine the detection difference degree between the measured detection magnetic field data and the reference detection magnetic field data, and determine the interference detection result of the field emitter according to the detection difference degree

[0057] Seventh aspect, in the present invention, an anomaly detection device for a field emitter is provided, and the anomaly detection device is applied to the field emitter described in the first aspect; the anomaly detection device:

[0058] A third acquisition module, configured to acquire the measured working magnetic field data obtained by the magnetic sensor detecting the working magnetic field generated by the field emitter;

[0059] An anomaly analysis module, configured to determine the working difference degree between the measured working magnetic field data and the reference working magnetic field data, and determine the operating state of the field emitter according to the working difference degree.

[0060] Eighth aspect, in the present invention, an electronic device is provided, including a memory, a processor, and a computer program stored on the memory and executable on the processor, and when the processor executes the computer program, it implements the self-calibration method of the field emitter described in the second aspect above, or the interference detection method of the field emitter described in the third aspect, or the anomaly detection method of the field emitter described in the third and fourth aspects.

[0061] Fourthly, the present invention provides a storage medium, on which a computer program is stored. When the program is executed by a processor, it implements the self-calibration method of the field emitter described in the second aspect above, or the interference detection method of the field emitter described in the third aspect, or the anomaly detection method of the field emitter described in the third and fourth aspects.

[0062] Compared with the related art, for the field emitter, its self-calibration method, interference detection method and anomaly detection method provided in the present invention, by setting a magnetic detection component on the field emitter, based on the magnetic field detection data of the magnetic detection component, the calibration parameters of each field emission unit can be updated in the magnetic field model. The updated calibration parameters are more in line with the actual state of the field emission unit, and then the calculation result of the magnetic field model is more accurate, so that the electromagnetic navigation accuracy can be improved. Therefore, the present invention solves the problem that the electromagnetic navigation accuracy of the electromagnetic navigation system is reduced after the initial calibration parameters of the field emitter in the related art are mismatched with the actual state.

[0063] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more concise and understandable. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments and descriptions thereof are used to explain the present application and do not constitute an improper limitation of the present application. In the drawings:

[0065] Figure 1 is a top view of the field emitter in the first embodiment of the present invention;

[0066] Figure 2 is a side view of the field emitter in the first embodiment of the present invention;

[0067] Figure 3 is a schematic structural diagram of the field emitter in the second embodiment of the present invention;

[0068] Figure 4 is a schematic structural diagram of the magnetic detection component in the second embodiment of the present invention;

[0069] Figure 5 is a flowchart of the self-calibration method of the field emitter provided by the present invention;

[0070] Figure 6 is a flowchart of the interference detection method of the field emitter provided by the present invention;

[0071] Figure 7 is a flowchart of the anomaly detection method of the field emitter provided by the present invention;

[0072] Figure 8It is a schematic structural diagram of a field emission unit in a specific embodiment of the present invention;

[0073] Figure 9 It is a flowchart of a self-calibration method of a field emitter in a specific embodiment of the present invention;

[0074] Figure 10 It is a flowchart of an interference detection method of a field emitter in a specific embodiment of the present invention;

[0075] Figure 11 It is a flowchart of a usage method of a field emitter in a specific embodiment of the present invention;

[0076] Figure 12 It is a structural block diagram of a self-calibration device of a field emitter provided by the present invention;

[0077] Figure 13 It is a structural block diagram of an interference detection device of a field emitter provided by the present invention;

[0078] Figure 14 It is a structural block diagram of an anomaly detection device of a field emitter provided by the present invention. Detailed Embodiments

[0079] To more clearly understand the purpose, technical solution, and advantages of the present application, the present application is described and illustrated below with reference to the accompanying drawings and embodiments.

[0080] Unless otherwise defined, technical terms or scientific terms involved in this application shall have the general meanings understood by those with ordinary skills in the technical field to which this application belongs. In this application, words such as "a", "an", "one kind", "the", "these", etc. do not indicate a limitation in quantity, and they can be singular or plural. The terms "include", "comprise", "have" and any variants thereof involved in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product or device including a series of steps or modules (units) is not limited to the listed steps or modules (units), but may include unlisted steps or modules (units), or may include other steps or modules (units) inherent in these processes, methods, products or devices. The words such as "connect", "be connected", "couple" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether directly connected or indirectly connected. The "plurality" involved in this application means two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, and B exists alone. Usually, the character " / " indicates that the objects associated before and after are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific order for the objects.

[0081] In the present invention, a field emitter is provided. Figure 1 is a top view of the field emitter in the first embodiment of the present invention, Figure 2 is a side view of the field emitter in the first embodiment of the present invention, Figure 3 is a schematic structural diagram of the field emitter in the second embodiment of the present invention, Figure 4 is a schematic structural diagram of the magnetic detection component in the second embodiment of the present invention.

[0082] Referring to Figure 1 、 Figure 2 and Figure 3 According to the present invention, the provided field emitter includes: a field emission unit group 100 and a magnetic detection component 110; the field emission unit group 100 includes field emission units 101, and the spatial postures of the field emission units 101 in the field emitter are fixed; the magnetic detection component 110 includes magnetic sensors 111, and the spatial postures of the magnetic sensors 111 in the field emitter are fixed; when the magnetic detection component 110 works, the magnetic sensors 111 are used to detect the calibrated magnetic field generated by the field emission units 101.

[0083] The field emitter provided by the present invention mainly consists of two parts: a field emission unit group 100 and a magnetic detection component 110. Among them, the field emission unit group 100 is the main working unit of the field emitter. During the electromagnetic navigation process, the field emission unit group 100 is used to generate a time-varying working magnetic field, which is detected by the magnetic sensor in the receiving device to be positioned.

[0084] The field emission unit group 100 includes a plurality of field emission units 101 with relatively fixed pose relationships. The field emission unit 101 can also be called a rotating magnet unit. The core component of the field emission unit 101 is a rotatable magnet. The magnet can be a permanent magnet, an electromagnetic coil, etc. When the field emission unit 101 is working, the internal motor drives the magnet to rotate, and the rotation position is recorded in real time by an absolute position encoder. Different field emission units 101 have different working frequencies, such as 10 Hz to 100 Hz. In the field emission unit 101, the center of mass of the magnet can be on the motor shaft or not. When the center of mass of the magnet is located on the motor shaft, the mechanical structure stability of the entire field emission unit 101 is relatively high.

[0085] The plurality of field emission units 101 are installed in the field emitter in a preset configuration. The pose relationships between the field emission units 101 are known and fixed, so as to generate a suitable working magnetic field in the working space to meet the positioning accuracy requirements. The accurate pose relationships are also helpful for estimating the interaction torque between the magnets, which is convenient for the speed control of the motor.

[0086] The spatial pose of the magnetic detection component 110 in the field emitter is relatively fixed, which means that the centroid position and attitude of the magnetic detection component 110 in the field emitter are fixed. Furthermore, the spatial pose of the magnetic detection component 110 in the field emitter can be pre-calibrated. Similarly, the spatial pose of the field emission unit group 100 in the field emitter is also relatively fixed and can be pre-calibrated.

[0087] Specifically, the field emitter will undergo strict calibration before leaving the factory to determine the corresponding calibration parameters, such as the position coordinates of the magnet center of each field emission unit 101 in the body coordinate system of the field emitter, the magnetic moment intensity, and other magnet-related parameters. However, due to inevitable problems such as collisions, thermal expansion and contraction, mechanical fatigue, and equipment aging during the use of the field emitter, the magnet-related parameters will inevitably change compared with the calibration parameters. If the electromagnetic navigation positioning algorithm continues to use the initial calibration parameters, the positioning accuracy will decrease.

[0088] To solve the above problems, compared with the existing field emitters, the field emitter provided by the present invention is additionally provided with a magnetic detection component 110, and the pose relationship between the magnetic detection component 110 and the field emission unit group 100 is relatively fixed. The magnetic detection component 110 includes at least one magnetic sensor 111. When the magnetic detection component 110 is working, the magnetic sensor 111 is used to detect the calibrated magnetic field generated by the field emission unit 101. The magnetic sensor 111 can be any type of magnetic field sensor, such as a uniaxial or triaxial induction coil, and a triaxial MEMS (Micro Electro Mechanical System) magnetic sensor, etc.

[0089] When calibrating the parameters of any field emission unit 101 in the field emitter, it is necessary to operate the target field emission unit to be calibrated while turning off other non-target field emission units, and the non-target field emission units will not generate a time-varying magnetic field. Among them, operating the field emission unit 101 means making the field emission unit 101 in a working state. For example, the permanent magnet is driven to rotate by the internal motor of the field emission unit 101, and at this time, the field emission unit 101 will generate a time-varying magnetic field. Turning off the field emission unit 101 means making the field emission unit 101 in a non-working state. For example, locking the internal permanent magnet to prevent it from rotating, and at this time, the field emission unit 101 will not generate a time-varying magnetic field. The target field emission unit operates alone to generate a time-varying calibrated magnetic field, and the magnetic sensor 111 in the magnetic detection component 110 detects the calibrated magnetic field to obtain the measured calibrated magnetic field data of the calibrated magnetic field at the magnetic sensor 111. Since the pose relationship between the magnetic sensor 111 and the target field emission unit is known and fixed, the model calibrated magnetic field data of the calibrated magnetic field at the magnetic sensor 111 can be calculated through the magnetic field model of the target field emission unit.

[0090] If all the magnet-related parameters in the magnetic field model accurately conform to the current actual state of the target field emission unit, the measured calibrated magnetic field data and the model calibrated magnetic field data should be consistent. If there is an error between the measured calibrated magnetic field data and the model calibrated magnetic field data, it means that the magnet-related parameters in the magnetic field model do not conform to the current actual state of the target field emission unit. This means that the target field emission unit has undergone a state change during operation, and it is necessary to re-calibrate the magnet-related parameters of the target field emission unit. Specifically, the calibration method is to minimize the error between the measured calibrated magnetic field data and the model calibrated magnetic field data as the optimization goal, continuously optimize and adjust the magnet-related parameters of the target field emission unit, and finally obtain the calibration parameters that conform to the current actual state of the target field emission unit.

[0091] In one embodiment, for multiple field emission units 101 in a field emitter, the above method can be sequentially adopted to calibrate the parameters of the field emission units 101. Only one field emission unit 101 is operated for each parameter calibration, that is, only one field emission unit 101 is determined as the target field emission unit each time. Since the relevant data of each field emission unit 101 are collected separately, the data processing can be simplified. Correspondingly, in another embodiment, for multiple field emission units 101 in a field emitter, the above method can be adopted to calibrate the parameters of multiple or all field emission units 101 simultaneously. Multiple or all field emission units 101 are operated for each parameter calibration, that is, multiple or all field emission units 101 are determined as the target field emission units.

[0092] Therefore, for the field emitter provided by the present invention, since the magnetic detection component 110 is provided and the pose relationship between the magnetic detection component 110 and the field emission unit group 100 is relatively fixed, the calibration magnetic field generated by the field emission unit 101 can be detected by the magnetic sensor 111 in the magnetic detection component 110. Further, the parameters related to the magnet of the corresponding field emission unit 101 can be calibrated by using the measured calibration magnetic field data output by the magnetic sensor 111, and the calibration parameters conforming to the actual state of the field emission unit 101 can be obtained. By updating the calibration parameters of each field emission unit 101 in the magnetic field model to make the calculation result of the magnetic field model more accurate, the electromagnetic navigation accuracy can be improved. Therefore, the present invention solves the problem that the electromagnetic navigation accuracy of the electromagnetic navigation system is reduced after the initial calibration parameters of the field emitter in the related art are mismatched with the actual state.

[0093] In some of these embodiments, the magnetic detection component 110 further includes a circuit board 112, and there are multiple magnetic sensors 111; the multiple magnetic sensors 111 are uniformly and fixedly installed on the circuit board 112.

[0094] In this embodiment, there are multiple magnetic sensors 111, and there is a certain interval between the multiple magnetic sensors 111, and they are fixedly installed on the circuit board 112 as evenly as possible. The transmission control circuit of the magnetic sensor 111 can be integrated on the circuit board 112 to facilitate the data output of the magnetic sensor 111.

[0095] During the calibration process of the field emission unit 101, multiple magnetic sensors 111 simultaneously detect the calibration magnetic field generated by the target field emission unit and output their respective measured calibration magnetic field data. Through the magnetic field model, the model calibration magnetic field data of the working magnetic field at each magnetic sensor 111 can be calculated. At this time, the errors between the measured calibration magnetic field data and the model calibration magnetic field data corresponding to the same spatial position can be calculated respectively, and then, with the goal of minimizing the cumulative error or the mean value of the magnetic field data at multiple spatial positions, the magnet-related parameters of the target field emission unit are continuously optimized and adjusted, and finally the calibration parameters that conform to the current actual state of the target field emission unit are obtained.

[0096] The magnetic detection component 110 uses multiple magnetic sensors 111. Compared with using a single magnetic sensor 111, since there is more data available for reference during the optimization process, the parameter calibration of the field emission unit 101 is finally more accurate.

[0097] In some of the embodiments, the field emitter further includes: a mounting housing 130; the field emission unit group 100 is fixedly installed inside the mounting housing 130. The mounting housing 130 functions to protect and isolate the internal structure. Preferably, the mounting housing 130 is made of a non-metal, and the mounting housing 130 as a whole can be a rectangular structure. Further, the body coordinate system of the field emitter can be constructed with the mounting housing 130 as a reference. Since the field emission unit group 100 is fixed relative to the mounting housing 130, the spatial pose of the field emission unit group 100 in the body coordinate system of the field emitter is fixed.

[0098] Further, referring to Figure 1 and Figure 2 , in one of the embodiments, the magnetic detection component 110, like the field emission unit group 100, is fixedly installed inside the mounting housing 130. Specifically, the field emission unit group 100 can be fixedly installed in the middle of the mounting housing 130, and the magnetic detection component 110 can be installed on the inner side wall of the mounting housing 130. For example, when the magnetic detection component 110 includes a circuit board 112 and a magnetic sensor 111 installed on the circuit board 112, the circuit board 112 can be directly fixedly installed on the inner side wall of the mounting housing 130. If there are two groups of magnetic detection components 110, the two groups of magnetic detection components 110 can be respectively fixedly installed on the top wall and the bottom wall of the mounting housing 130.

[0099] Correspondingly, referring to Figure 3, in another embodiment, the magnetic detection component 110 is fixedly installed outside the installation housing 130. Specifically, the magnetic detection component 110 can be installed above the installation housing 130 through corresponding connecting and fixing parts. At this time, in order to ensure that the installation position of the magnetic detection component 110 is the same as the designed position, corresponding positioning grooves can be provided on the installation housing 130, and the magnetic detection component 110 is provided with positioning protrusions that cooperate with the positioning grooves. Through the matching of the positioning grooves and the positioning protrusions, after the magnetic detection component 110 is installed, its relative pose with respect to the installation housing 130 meets the design requirements and is fixed.

[0100] In the above two embodiments, whether the magnetic detection component 110 is installed inside or outside the installation housing 130, the spatial pose of the magnetic detection component 110 relative to the installation housing 130 is fixed. Therefore, the spatial pose of the magnetic detection component 110 in the field emitter body coordinate system is relatively fixed.

[0101] In some of the embodiments, the field emitter further includes: a magnetic source component; the spatial pose of the magnetic source component in the field emitter is fixed; when the magnetic source component is operating, the magnetic sensor 111 is further configured to detect the detection magnetic field generated by the magnetic source component.

[0102] In this embodiment, the magnetic source component is used to provide a detection magnetic field, and the spatial pose of the magnetic source component in the field emitter body coordinate system is relatively fixed. Therefore, when the detection magnetic field provided by the magnetic source component remains unchanged, the magnetic field signal obtained by the magnetic sensor 111 detecting the detection magnetic field should be unchanged. If the magnetic field data obtained by the magnetic sensor 111 detecting the detection magnetic field changes compared with the reference detection magnetic field data, it indicates that there is a magnetic field interference source around the field emitter. Among them, the reference detection magnetic field data refers to the magnetic field data that the magnetic sensor 111 should obtain when detecting the detection magnetic field in an environment without interference sources. The interference source will affect the self-calibration and electromagnetic navigation accuracy of the field emitter, so it is necessary to promptly eliminate the interference source around the field emitter.

[0103] Furthermore, in some of the embodiments, the magnetic source component includes a plurality of coils 120, and the plurality of coils 120 are evenly distributed on the periphery of the field emission unit group 100.

[0104] In this embodiment, the magnetic source assembly adopts a plurality of coils 120. The coils 120 have the characteristic of controllable magnetic field. When energized, they generate a detection magnetic field, and when de-energized, they do not generate a detection magnetic field. Therefore, when interference detection is required, the coils 120 are turned on to generate a detection magnetic field, and at other times, the coils 120 are turned off so that they do not generate a detection magnetic field, avoiding the influence of the detection magnetic field on other functions of the field emitter. Here, turning on the coils 120 means energizing the coils 120, and turning off the coils 120 means de-energizing the coils 120. At the same time, there are a plurality of coils 120, and the plurality of coils 120 are evenly distributed on the periphery of the field emission unit group 100. For example, they can be fixedly installed on the respective sides of the installation housing 130 of the field emitter. Considering that the influence of a smaller magnetic field source on the magnetic field of the field emitter is local, for example, it only affects the magnetic field of the field emitter in a certain direction. Therefore, the coils 120 are arranged in a plurality and distributed around the field emitter, respectively used to detect whether there is an interference source in the corresponding direction. During detection, detection signals are generated one by one and the same phase comparison detection is performed, so as to more comprehensively detect the situation around the field emitter.

[0105] As described above, the first type of field emitter provided by the present invention at least includes a magnetic detection assembly 110. In some embodiments, the field emitter further includes a magnetic source assembly. Correspondingly, the field emitter may also not include the magnetic detection assembly 110.

[0106] Therefore, the present invention also provides a field emitter. Referring to Figure 1 and Figure 2 , the field emitter includes: a magnetic source assembly; the spatial pose of the magnetic source assembly in the field emitter is fixed; when the magnetic source assembly works, the magnetic sensor 111 is further used to detect the detection magnetic field generated by the magnetic source assembly.

[0107] In this embodiment, the magnetic source assembly is used to provide a detection magnetic field, and the spatial pose of the magnetic source assembly in the body coordinate system of the field emitter 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 111 detecting the detection magnetic field should be unchanged. If the magnetic field data obtained by the magnetic sensor 111 detecting the detection magnetic field changes compared with the reference detection magnetic field data, it indicates that there is a magnetic field interference source around the field emitter. Here, the reference detection magnetic field data refers to the magnetic field data that the magnetic sensor 111 should obtain when detecting the detection magnetic field in an environment without interference sources. The interference source will affect the self-calibration and electromagnetic navigation accuracy of the field emitter. Therefore, it is necessary to timely eliminate the interference source around the field emitter.

[0108] In some of these embodiments, the magnetic source assembly includes a plurality of coils 120, and the plurality of coils 120 are evenly distributed on the periphery of the field emission unit group 100.

[0109] In this embodiment, the magnetic source assembly employs multiple coils 120. The coils 120 have the characteristic of controllable magnetic field. When energized, they generate a detection magnetic field, and when de-energized, they do not generate a detection magnetic field. Therefore, when interference detection is required, the coils 120 are turned on to generate a detection magnetic field, and at other times, the coils 120 are turned off so that they do not generate a detection magnetic field, avoiding the influence of the detection magnetic field on other functions of the field emitter. Here, turning on the coils 120 means energizing the coils 120, and turning off the coils 120 means de-energizing the coils 120. At the same time, there are multiple coils 120, and the multiple coils 120 are evenly distributed around the field emission unit group 100. For example, they can be fixedly installed on the respective sides of the installation housing 130 of the field emitter. Considering that the influence of a smaller magnetic source on the magnetic field of the field emitter is local, for example, it only affects the magnetic field of the field emitter in a certain direction. Therefore, the coils 120 are arranged in multiple numbers and distributed around the field emitter to respectively detect whether there are interference sources in the corresponding directions. During detection, 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 emitter.

[0110] As described above, the second field emitter provided by the present invention includes at least a magnetic source assembly.

[0111] The present invention also provides a self-calibration method for a field emitter, and the self-calibration method is applied to the first field emitter provided by the present invention.

[0112] Figure 5 It is a flowchart of the self-calibration method for the field emitter provided by the present invention. Referring to Figure 5 , the self-calibration method for the field emitter includes:

[0113] Step S210, obtaining the measured calibration magnetic field data detected by the magnetic sensor for the target calibration magnetic field, and obtaining the magnet angle information of the target field emission unit; wherein, the target field emission unit is the field emission unit to be calibrated in the field emission unit group, and the target calibration magnetic field is the calibration magnetic field generated by the target field emission unit;

[0114] Step S220, calibrating the target parameters of the target field emission unit according to the measured working magnetic field data and the magnet angle information.

[0115] Specifically, the self-calibration method for the field emitter provided by the present invention can perform calibration detection on the field emission units in the field emitter. Among them, in order to improve the calibration accuracy and simplify the subsequent data processing process, usually each field emission unit is calibrated separately. Correspondingly, multiple or all field emission units can also be calibrated simultaneously.

[0116] Therefore, it is first necessary to determine the target field emission unit(s) to be calibrated in the field emission unit group, and operate the target field emission unit to generate a time-varying target calibration magnetic field. To avoid the influence of other field emission units on the calibration result of the target field emission unit, it is also necessary to turn off the non-target field emission units. After the field emission units are turned off, no time-varying magnetic field will be 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 field emission unit is obtained; among them, the magnet angle information refers to the angle information of the rotation axis of the drive motor of the magnet, and the magnetic moment direction of the magnet can be determined through this angle information. Finally, the target parameters of the target field emission unit can be calibrated according to the measured calibration magnetic field data and the magnet angle information. The target parameters are calibration parameters that conform to the actual state of the field emission unit.

[0117] Through the self-calibration method of the field emitter provided by the present invention, the calibration parameters of each field emission unit can be updated in the magnetic field model, making the calculation result of the magnetic field model more accurate, and thus the electromagnetic navigation accuracy can be improved. Therefore, the present invention solves the problem that the electromagnetic navigation accuracy of the electromagnetic navigation system will be reduced after the initial calibration parameters of the field emitter in the related art are mismatched with the actual state.

[0118] Further, in step S230, calibrating the target parameters of the target field emission unit according to the measured calibration 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 sensor according to the magnet angle information, the model parameters of the target field emission unit, and the spatial pose of the magnetic sensor; taking minimizing the difference between the measured calibration magnetic field data and the model calibration magnetic field data as the optimization goal, and optimizing the model parameters of the target field emission unit to obtain the target parameters of the target field emission unit.

[0119] Specifically, the model parameters of the target field emission unit refer to the current parameters of the target field emission unit in the magnetic field model. The current parameters can be calibrated when the field emitter leaves the factory or can be obtained from the last self-calibration of the field emitter. With the use of the field emitter, the usage states of each field emission unit change, making the model parameters of the target field emission unit may not conform to the actual state of the target field emission unit. Therefore, it is necessary to optimize and calibrate it to obtain the target parameters that conform to the actual state of the target field emission unit.

[0120] Among them, since the pose relationship of the magnetic sensor in the body coordinate system of the field emitter is relatively fixed, the model calibration magnetic field data of the target calibration magnetic field at the magnetic sensor can be calculated through the magnetic field model based on the magnetic angle information, the model parameters of the target field emission unit, and the spatial pose of the magnetic sensor. Among them, the dipole magnetic field model can be used as the magnetic field model. If the model calibration magnetic field data is the same as the measured calibration magnetic field data, it indicates that the model parameters of the target field emission unit conform to the actual state of the target field emission unit; if the model calibration magnetic field data is different from the measured calibration magnetic field data, it indicates that the model parameters of the target field emission unit do not conform to the actual state of the target field emission unit, and the model parameters of the target field emission unit need to be calibrated and corrected. At this time, the difference between the measured calibration magnetic field data and the model calibration magnetic field data can be minimized as the optimization goal, and the model parameters of the target field emission unit can be iteratively optimized, and the finally obtained model parameters are used as the target parameters.

[0121] It should be noted that in the embodiment where the magnetic detection component includes multiple magnetic sensors, the measured calibration magnetic field data and the model calibration magnetic field data corresponding to different magnetic sensors are different; in addition, since the calibration magnetic field generated by the field emission unit is a time-varying magnetic field, the measured calibration magnetic field data and the model calibration magnetic field data corresponding to different times are different. Therefore, when minimizing the difference between the measured calibration magnetic field data and the model calibration magnetic field data as 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 different times can be calculated first, and minimizing the above difference mean value can be used as the optimization goal.

[0122] In one of the embodiments, the target parameters of the target field emission unit include the target spatial position of the target field emission unit.

[0123] Specifically, first, according to the magnetic angle information, the magnetic moment of the target field emission unit is determined; then, according to the magnetic moment of the target field emission unit, the model spatial position of the target field emission 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 the goal of minimizing the difference between the measured calibration magnetic field data and the model calibration magnetic field data, the model spatial position of the target field emission unit is optimized to obtain the target spatial position of the target field emission unit. Among them, the magnetic moment of the target field emission unit refers to the magnetic moment of the magnet in the target field emission unit, including the magnetic moment direction and the magnetic moment intensity, and the model spatial position of the target field emission unit refers to the spatial position of the magnet center of the target field emission unit. Specifically, the optimization formula is as follows:

[0124]

[0125] Among them, f(x) is the magnetic field model, M(t) is the magnetic moment vector of the target field emission unit at time t, and P TxU is the model position coordinate of the magnet center of the target field emission unit in the emitter body coordinate system; P ci is the position coordinate of the i-th magnetic sensor in the magnetic detection component in the emitter 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 field emission 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.

[0126] In another embodiment thereof, the target parameters of the target field emission unit at least include one of the following parameters:

[0127] The target rotation axis geometric parameter, the target magnet zero position homogeneous transformation matrix, and the target magnetic moment intensity of the target field emission unit.

[0128] Specifically, the rotation axis geometric parameter refers to the geometric parameter related to the rotation axis. Exemplarily, it includes the rotation axis screw, and the rotation axis screw characterizes the offset of the magnet centroid from the rotation axis. The magnet zero position homogeneous transformation matrix refers to the pose transformation between the actual zero position direction of the magnet magnetic moment and the target zero position direction. For example, in the standard design, the magnet centroid needs to be on its own rotation axis, and the actual zero position direction of the magnet magnetic moment is the target zero position direction. However, in the actual field emitter, there are errors in the above design requirements, and the errors are characterized by the rotation axis screw and the magnet zero position homogeneous transformation matrix. In the magnetic field model, it is necessary to calibrate the target rotation axis geometric parameter and the magnet zero position homogeneous transformation matrix to improve the electromagnetic navigation accuracy.

[0129] First, according to the model rotation axis geometric parameter, the model magnet zero position homogeneous transformation matrix, and the model magnetic moment intensity of the target field emission unit, as well as the magnet angle information and the spatial position of the magnetic sensor, determine the model calibration magnetic field data of the target calibration magnetic field at the magnetic sensor; then, with the goal of minimizing the difference between the measured calibration magnetic field data and the model calibration magnetic field data, optimize the model rotation axis geometric parameter, the model magnet zero position homogeneous transformation matrix, and the model magnetic moment intensity of the target field emission unit to obtain the target rotation axis geometric parameter, the target magnet zero position homogeneous transformation matrix, and the target magnetic moment intensity of the target field emission unit.

[0130] It should be noted that the above multiple parameters can be calibrated simultaneously, or only one or two of them can be calibrated.

[0131] Further, with the optimization objective of minimizing the difference between the measured calibrated magnetic field data and the model calibrated magnetic field data, it includes: taking the minimization of the difference between the modulus of the measured calibrated magnetic field data and the modulus of the model calibrated magnetic field data as the optimization objective.

[0132] Specifically, considering that when the magnetic sensor in the magnetic detection component is installed, its position accuracy is relatively easy to ensure, but its attitude accuracy is relatively difficult to ensure. Therefore, when calculating the difference between the measured calibrated magnetic field data and the model calibrated magnetic field data, if the vector difference between the two sets of magnetic field data is calculated, uncertain errors may be introduced. Since the modulus of the magnetic field data is independent of the attitude of the magnetic sensor and only related to the position of the magnetic sensor, calculating the scalar difference between the two sets of magnetic field data, that is, the modulus difference between the two sets of magnetic field data, can improve the calibration accuracy.

[0133] Specifically, when the target parameters of the target field emission unit include the target rotation axis screw of the target field emission unit, the target magnet zero position homogeneous transformation matrix, and the target magnetic moment intensity, its optimization formula is as follows:

[0134]

[0135] Among them, T 0 is the model magnet zero position homogeneous transformation matrix of the target field emission unit, θ(n) is the angle of the magnet rotation axis of the target field emission unit at t = nΔT s moment, S is the model rotation axis screw of the target field emission unit, e [S]θ(n) is the exponential expression of the homogeneous transformation matrix, then T n = e [S]θ(n) T 0 represents the real-time homogeneous transformation matrix of the model magnet of the target field emission unit at t = nΔT s moment, ΔT s is the sampling interval of the sensor, such as 1ms - 10ms; |m| is the magnet intensity of the target field emission unit, P ai is the position coordinate of the i-th magnetic sensor in the field emitter body coordinate system in the magnetic detection component; ||f(e [S]θ(n) T 0 ,|m|,P ai )|| represents the modulus of the model calibrated magnetic field data of the magnet of the target field emission unit at P s at t = nΔT ai moment; || b B i (n)|| is the modulus of the measured calibrated magnetic field data measured by the i-th magnetic sensor in the magnetic detection component at t = nΔT s moment.

[0136] Meanwhile, as can be seen from the above optimization formula, when calibrating only one or two of the parameters, it is only necessary to regard the non-target parameters as fixed values in the optimization formula.

[0137] Further, in some of the 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. Taking minimizing the difference between the measured calibration magnetic field data and the model calibration magnetic field data as the optimization objective includes: determining the sequence mean of the sequence of measured calibration magnetic field values, and determining the sequence mean of the sequence of model calibration magnetic field values; subtracting each magnetic field value in the sequence of measured calibration magnetic field values from the sequence mean of the sequence of measured calibration magnetic field values to obtain a first magnetic field value sequence; subtracting each magnetic field value in the sequence of model calibration magnetic field values from the sequence mean of the sequence of model calibration magnetic field values to obtain a second magnetic field value sequence; taking minimizing the difference between the first magnetic field value sequence and the second magnetic field value sequence as the optimization objective.

[0138] Specifically, considering the existence of the ambient magnetic field, the magnetic field data detected by the magnetic sensor is essentially the combined magnetic field of the calibration magnetic field and the ambient magnetic field. In this embodiment, the influence of the static ambient magnetic field is removed during the calibration process to improve the calibration accuracy.

[0139] The calibration magnetic field provided by the field emission 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 sequence of measured calibration magnetic field values, and the model calibration magnetic field data includes a sequence of model calibration magnetic field values. The sequence mean of the sequence of measured calibration magnetic field values 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 sequence of model calibration magnetic field values 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. Furthermore, 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 brought by 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 in one-to-one correspondence (determined based on the acquisition time), the difference between the two sequences can be the differences between multiple sets of corresponding magnetic field values respectively, and the cumulative difference is used as the difference between the two sequences.

[0140] As described above, this is the self-calibration method of the field emitter provided by the present invention, which is used to perform self-calibration on the field emitter provided by the present invention.

[0141] In addition, the present invention also provides a method for detecting interference of a field emitter, which is applied to any field emitter provided by the present invention and is used to detect whether there are other magnetic field sources around the field emitter.

[0142] Figure 6 It is a flowchart of the method for detecting interference of the field emitter provided by the present invention. Refer to Figure 6 , the method for detecting interference of the field emitter includes the following steps:

[0143] Step S310, obtain the measured detected magnetic field data detected by the magnetic sensor for the detected magnetic field; wherein, the detected magnetic field is generated by the magnetic source assembly;

[0144] Step S320, determine the detection difference degree between the measured detected magnetic field data and the reference detected magnetic field data, and determine the interference detection result of the field emitter according to the detection difference degree.

[0145] Specifically, the main function of the field emission unit is to generate a time-varying magnetic field. In order to better detect the detected magnetic field, the field emission unit in the field emitter can be turned off during the detection process. Turning off the field emission unit means making it stop generating a time-varying magnetic field. For example, for a field emission unit that uses a motor to drive a permanent magnet to rotate, turning off the field emission unit means turning off the motor and locking the permanent magnet so that it cannot rotate; while for a field emission unit that uses electromagnetic coils, turning off the field emission unit means making the electromagnetic coils in a power-off state.

[0146] After all the field emission units are turned off, the magnetic sensor in the magnetic detection assembly is used to detect the detected magnetic field generated by the magnetic source assembly, and the measured detected magnetic field data of the magnetic sensor is read. Then the measured detected magnetic field data is compared with the reference detected magnetic field data to determine the detection difference degree between the two. Finally, the interference detection result of the field emitter is determined according to the detection difference degree.

[0147] Among them, the detection difference degree is mainly used to judge whether there are other magnetic field sources in the current environment. Therefore, the reference detected magnetic field data refers to the magnetic field data that should be obtained when the magnetic sensor detects the detected magnetic field in an environment without interference sources. Specifically, the reference detected magnetic field data can be obtained by the magnetic sensor detecting the detected magnetic field during the factory calibration of the field emitter, because the calibration environment during factory production is controllable, which can ensure that there are no interference sources in the calibration environment. At the same time, the reference detected magnetic field data can also be obtained through simulation calculation when the relative pose of the magnetic source assembly and the magnetic sensor is fixed and known.

[0148] Further, the measured detected magnetic field data is compared with the reference detected magnetic field data. The comparison method can be to compare the phases between the two, such as comparing the peak positions and calculating the correlation coefficient. This comparison method can be applied to detect interference signals with the same frequency but different phases. Commonly, metal eddy currents can generate interference signals with the same frequency but different phases. Therefore, the signal difference degree can be the phase difference degree. Correspondingly, the signal difference degree can also be the peak value difference degree. At the same time, both the measured detected magnetic field data and the reference detected magnetic field data contain a number of magnetic field data numbered according to time sequence, and there is a one-to-one correspondence between them. When comparing the two, the magnetic field data with the same number is compared in sequence.

[0149] In one embodiment, determining the interference detection result of the field emitter according to the detection difference degree includes: when the detection difference degree is greater than the first preset threshold, it is determined that there is a magnetic field interference source around the field emitter. In this embodiment, it is not necessary for the measured detected magnetic field data and the reference detected magnetic field data to be exactly the same. Usually, when the detection difference degree is greater than the first preset threshold, it is determined that there is a magnetic field interference source around the field emitter. Further, the detected magnetic field data is usually a vector, which includes the magnetic field component data in three spatial dimensions. Therefore, when comparing the measured detected magnetic field data with the reference detected magnetic field data, the magnetic field component data in each spatial dimension can be compared separately. Exemplarily, when the detection difference degree of the magnetic field component data in a certain spatial dimension is greater than the first preset threshold, it is determined that there is a magnetic field interference source around the field emitter. Correspondingly, it can also be determined that there is a magnetic field interference source around the field emitter only when the detection difference degrees of the magnetic field component data in two or three spatial dimensions are both greater than the first preset threshold.

[0150] In some of these embodiments, the magnetic source assembly includes a plurality of coils, and the coils are used to generate the detected magnetic field. The plurality of coils are evenly distributed on the periphery of the field emission unit group.

[0151] Step S310, obtaining the measured detected magnetic field data detected by the magnetic sensor for the detected magnetic field, includes: obtaining the target measured detected magnetic field data detected by the magnetic sensor for the target detected magnetic field; wherein, the target detected magnetic field is the detected magnetic field generated by the target coil in the magnetic source assembly.

[0152] Step S320, determining the detection difference degree between the measured detected magnetic field data and the reference detected magnetic field data, and determining the interference detection result of the field emitter according to the detection difference degree, includes: determining the target detection difference degree between the target measured detected magnetic field data and the target reference detected magnetic field data, and determining the interference detection result of the field emitter in the direction corresponding to the target coil according to the target detection difference degree.

[0153] In this embodiment, the magnetic source component adopts a coil. After the coil is energized, a detection magnetic field can be generated. The detection magnetic field generated by the coil can be a sine signal. The frequency of the detection magnetic field can be set slightly higher than the operating frequency of the field emitter during electromagnetic navigation, such as 50 Hz to 100 Hz. The coil has the characteristic of controllable magnetic field. When energized, it generates a detection magnetic field, and when de-energized, it does not generate a detection magnetic field. Therefore, 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 so that it does not generate a detection magnetic field, avoiding the influence of the detection magnetic field on other functions of the field emitter.

[0154] Meanwhile, there are multiple coils, and the multiple coils are evenly distributed on the periphery of the field emission unit group. For example, they can be fixedly installed on each side of the installation housing of the field emitter. Considering that the influence of a smaller magnetic source on the magnetic field of the field emitter is local, for example, it only affects the magnetic field of the field emitter in a certain direction. Therefore, multiple coils are provided and distributed around the field emitter, respectively used to detect whether there is an interference source in the corresponding direction. During detection, detection signals are generated one by one and the same phase comparison detection is performed, so as to more comprehensively detect the situation around the field emitter.

[0155] Therefore, during the interference detection process, each coil is sequentially used as the target coil, and it is judged whether there is an interference source 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 step is repeated.

[0156] As described above, this is the interference detection method for the field emitter provided by the present invention, which is used to perform interference detection on the field emitter provided by the present invention.

[0157] In the present invention, an abnormal detection method for a field emitter is also provided. It is applied to the first field emitter provided by the present invention and is used to perform abnormal detection on the field emitter.

[0158] Figure 7 This is the flowchart of the abnormal detection method for the field emitter provided by the present invention. Referring to Figure 7 , the abnormal detection method for the field emitter includes the following steps:

[0159] Step S410, obtaining the measured working magnetic field data detected by the magnetic sensor for the working magnetic field generated by the field emitter;

[0160] Step S420, determining the working difference degree between the measured working magnetic field data and the reference working magnetic field data, and determining the operating state of the field emitter according to the working difference degree.

[0161] Specifically, the method for detecting anomalies of the field emitter provided by the present invention can perform real-time anomaly detection on the field emitter during electromagnetic navigation. During electromagnetic navigation, the field emitter generates a working magnetic field. At this time, each field emission unit in the field emitter operates according to its own working frequency, and the combined magnetic field generated by each field emission unit together is the working magnetic field of the field emitter.

[0162] When the field emitter generates a working magnetic field, the magnetic sensor in the magnetic detection component is used to detect the working magnetic field, so as to obtain the measured working magnetic field data output by the magnetic sensor. Then, the measured working magnetic field data is compared with the reference working magnetic field data to determine the working difference degree between the two. Finally, the operating state of the field emitter is determined according to the working difference degree.

[0163] Among them, the working difference degree is mainly used to judge whether the operating state of the field emitter is abnormal. An abnormal state means that the field emitter generates a working magnetic field that does not conform to the calibration value. The main reasons are the existence of other magnetic field interferences or the real-time state of the field emitter does not match the calibrated state. Therefore, the reference working magnetic field data refers to the magnetic field data that should be obtained by the magnetic sensor when detecting the working magnetic field in the calibrated state in an environment without interference sources. Specifically, the reference working magnetic field data can be obtained by the magnetic sensor detecting the working magnetic field during the factory calibration of the field emitter. At this time, the field emitter is not only in the calibrated state, but also the calibration environment at the time of factory production is controllable, which can ensure that there is no interference source in the calibration environment. At the same time, the reference working magnetic field data can also be obtained through simulation calculation when the relative pose of the field emission unit group and the magnetic sensor is fixed and known.

[0164] In one of the embodiments, step S420, determining the operating state of the field emitter according to the working difference degree, includes: when the working difference degree is greater than the second preset threshold, determining that the operating state of the field emitter is abnormal.

[0165] Specifically, the working difference degree can be the cumulative value or the average value of the errors between the corresponding data in the measured working magnetic field data and the reference working magnetic field data. Exemplarily, the formula for calculating the average value L of the error is as follows:

[0166]

[0167] Among them, b B′ i (n) is the measured working magnetic field data, b B i-0 (n) is the reference working magnetic field data, and the symbol "|| ||" represents taking the modulus value, N Tis the number of data for which difference calculation is performed. When calculating the mean value of the errors between corresponding data, the measured working magnetic field data and the reference working magnetic field data corresponding to each other can be substituted into the above formula for calculation at time intervals according to the time sequence.

[0168] As described above, the abnormal detection method of the field emitter provided by the present invention can perform real-time detection on the operating state of the field emitter during the electromagnetic navigation process of the field emitter provided by the present invention.

[0169] It should be noted that the self-calibration method, interference detection method, and abnormal detection method of the field emitter provided by the present invention have usage relevance. Specifically, before each electromagnetic navigation using the field emitter, the interference detection method can be first used to detect the working environment of the field emitter to determine whether there is a magnetic field interference source around the field emitter. If there is, the interference source needs to be excluded first. If not or after the interference source is excluded, the field emitter is self-calibrated by the self-calibration method, and when the model parameters of the field emitter are mismatched with the actual state, the model parameters of the field emitter are updated in real time. After the self-calibration is completed, electromagnetic navigation is performed through the field emitter, and during the electromagnetic navigation process, the abnormal detection method is used to perform real-time detection on the operating state of the field emitter.

[0170] As follows, the technical solutions in the present application are described in detail through some specific embodiments.

[0171] Refer to Figure 1 and Figure 2 , in a specific embodiment, a field emitter in an electromagnetic positioning system is provided. The field emitter is used to generate a specific time-varying magnetic field, and the time-varying magnetic field is detected by a magnetic sensor at the receiving end. The magnetic sensor at the receiving end can be an induction coil, a MEMS magnetic sensor, etc. The MEMS magnetic sensor can be a Hall sensor, an anisotropic magnetoresistive (AMR) sensor, a tunneling magnetoresistive (TMR) sensor, etc. The field emitter can generate a time-varying magnetic field through one or more field emission units, and each field emission unit includes a rotatable permanent magnet. When the field emitter is working, each field emission unit has a different rotation frequency, such as 10 Hz to 100 Hz. Each field emission unit is composed of a permanent magnet, a motor, and corresponding transmission components. The centroid of the permanent magnet can be located on the motor shaft or deviate from the motor shaft. When the centroid of the permanent magnet is located on the motor rotation axis, the mechanical structure stability of the entire unit is relatively high.

[0172] The upper and lower surfaces of the installation housing 130 are also provided with a magnetic detection component 110, and the magnetic detection component 110 includes a plurality of magnetic sensors 111 for self-calibration and its circuit board 112. The magnetic detection component 110 contains a plurality of magnetic sensors 111 (such as 8), which are distributed inside the installation housing 130 of the field emitter. The plurality of magnetic sensors 111 are separated by a certain distance so as to be as evenly distributed as possible inside the installation housing 130. The plurality of magnetic sensors 111 are fixedly connected to the installation housing 130 of the field emitter (after the magnetic sensors 111 are installed, they can be fixed with glue), and together determine a coordinate system {s}, and the coordinate system {s} is the body coordinate system of the field emitter. Therefore, the positions of the magnetic sensors 111 in the coordinate system {s} are determined. The magnetic sensors 111 can be any type of magnetic sensors, such as single-axis or three-axis induction coils, three-axis MEMS sensors, etc. There are also several coils 120 (such as 4) for interference detection inside the side surface of the installation housing 130 of the field emitter, and these coils 120 constitute a magnetic source component, and one is provided on each side surface of the installation housing 130. The coils 120 are used to generate designed magnetic field signals, such as sine signals, square wave signals, etc., and the magnetic field signals can be detected by the magnetic sensors 111.

[0173] In this specific embodiment, a self-calibration method for the field emitter is also provided, and the following is the principle explanation of the self-calibration method for the field emitter.

[0174] Due to processing errors, installation errors, wear and tear, collisions, etc. during use, there are errors in the relevant parameters of the magnet in the field emitter and the model parameters in the algorithm model, which will lead to a decrease in positioning accuracy.

[0175] Figure 8 It is a schematic structural diagram of the field emission unit in a specific embodiment of the present invention. Refer to Figure 8 , the field emission unit includes a motor 141 and a permanent magnet 142. Assume that the design scheme requires that the magnetic center of mass of the permanent magnet 142 in the field emission unit is located on the motor shaft w, and when the motor 141 is in the zero position (measured by an absolute position encoder), the magnetic moment direction of the magnet is along the positive direction of the Z axis (based on the coordinate system {s}). However, in actual situations, the magnetic center of mass may deviate from the motor shaft w, and when the motor is in the zero position, the magnetic moment direction of the magnet deviates from the positive direction of the Z axis. The rotation axis screw S and the homogeneous transformation matrix T of the magnet at the zero position 0 (regarding the magnetic moment as an active vector, with the starting point at the magnetic center of mass and the direction being the magnetic moment direction) are expressed in the coordinate system {s} as follows:

[0176]

[0177]

[0178] Among them, A unit vector indicating the axis direction or angular velocity, R m is the rotation matrix of the magnet, P m and P s respectively represent the centroid of the magnet and a point on the rotation axis (the position where the centroid of the magnet should be). From the above error description, it can be seen that at this time P s ≠P m , In addition to the direction of the magnetic moment, the magnetic moment strength |m| of the magnet may also change. Therefore, the self-calibration method of the field emitter provided by the present invention is to calibrate the offset S between the centroid of the magnet and the motor shaft w, the homogeneous transformation matrix T of the magnet at zero position 0 and the magnetic moment strength |m| of the magnet. Among them, S and T 0 are both six-dimensional parameters.

[0179] It should be noted that in the present invention, the upper left superscript of all physical quantities represents the coordinate system in which the vector expression is located. If not directly shown in the text, the coordinates, rotation matrix, vector, etc. are all expressed in the coordinate system {s}.

[0180] Assume that there are N magnetic sensors (magnetic detection components) distributed at fixed positions in the field emitter. Here, a 3-axis MEMS sensor is taken as an example. The position P of the magnetic sensor in the coordinate system {s} ai is known (such as the error ≤0.01 mm, significantly higher than the navigation and positioning requirements). Keep other field emission units not working, and each time only one field emission unit rotates at a low speed to generate a calibration magnetic field, such as 1 Hz to 10 Hz. The system obtains the angular 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 self-coordinate system {b} of the magnetic sensor. The physical quantities to be calibrated above can be solved by the following objective function using an optimization method:

[0181]

[0182] Among them, θ(n) is the angle of the magnet rotation axis of the field emission unit at t = nΔT s moment, e [S]θ(n) is the exponential expression of the homogeneous transformation matrix, then T n = e [S θ(n) T 0 represents the real-time homogeneous transformation matrix of the magnet of the field emission unit at t = nΔT s moment, ΔT s ​ΔT is the sampling interval of the sensor, such as 1 ms to 10 ms; |m| is the magnetic moment intensity of the magnet in the field emission unit, and P ai is the position coordinate of the i-th magnetic sensor in the body coordinate system of the field emitter; ||f(e [S]θ(n) T 0 , |m|, P ai )|| represents the magnitude of the model-calibrated magnetic field data of the magnet of the field emission unit at the position P s at the moment t = nΔT ai ; || b B i (n)|| is the magnitude of the measured calibrated magnetic field data measured by the i-th magnetic sensor at the moment t = nΔT s .

[0183] It should be noted that when the sensor is patch-mounted, the position accuracy is easy to ensure, but its attitude is difficult to ensure. Therefore, in this embodiment, the difference in the magnitude of the magnetic field data is calculated.

[0184] It is difficult to ensure that the axial direction inside the sensor is completely parallel to the actual design direction, resulting in a pose transformation between the body coordinate system {b} of the magnetic sensor and the body coordinate system {s} of the field emitter, that is b B i (n) ≠ s B i (n). If vectors are used for comparison, some uncertain errors will be introduced. However, since the magnitude of the magnetic field data is independent of the attitude of the magnetic sensor and only related to the position of the magnetic sensor, that is || b B i (n)|| = || s B i (n)||. The position of the magnetic sensor can be accurately measured by a three-coordinate measuring instrument. Therefore, using the magnitude of the magnetic field data can reduce the introduction of errors.

[0185] 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 combined magnetic field, that is, the combination of the calibrated magnetic field generated by the field emission unit and the ambient magnetic field. Specifically:[[]]

[0186]

[0187] Among them, is the inverse of the rotation matrix of the i-th magnetic sensor, representing the conversion from the coordinate system {s} to the coordinate system {b}; B i-pm (n) is the magnetic field contributed by the field emission unit, which can be further divided into a time-varying part B i-pmac (n) and a time-invariant part Bi-pmdc; Bi-g is the ambient magnetic field, such as the geomagnetic field, the static magnetic fields generated by other materials or devices in the environment; B i-d is the zero-drift parameter of the sensor, which does not change with the attitude. Due to the complex and unknown environment, other static units may also contribute to the static magnetic field. Therefore, B i-g is a quantity that cannot be ignored and cannot be modeled. In this embodiment, the ambient magnetic field is removed by the method of removing the mean value. Specifically:

[0188]

[0189] where N T is the number of sampling points within a fixed time. Assuming that the fixed time is 1 s and the sampling rate corresponding to a rotation speed of 10 Hz is 800 Hz, then 1 s corresponds to 10 revolutions, and N T = 800. The meaning of the above formula is to first collect a series of magnetic field data, calculate their mean value, and then subtract this mean value from the magnetic field data sequence one by one Since the magnetic field contribution of the field emission unit is divided into a time-varying part and a time-invariant part, where the periodic mean value of the time-varying part is zero and the mean value of the time-invariant part is itself, and the mean value of the ambient magnetic field is also itself. Therefore, after removing the mean value, only the time-varying part of the magnetic field contribution of the field emission unit remains which reflects the characteristics of the magnet rotation. At the same time, optimize f(e [S]θ(n) T 0 ,|m|,P ai ). After calculating the theoretical values, calculate the mean value of all the theoretical values, and finally subtract the sequence mean value from each theoretical value as well. The optimized objective function is as follows:

[0190]

[0191] Figure 9 is the flow chart of the self-calibration method of the field emitter in the specific embodiment of the present invention. Referring to Figure 9 , the self-calibration method of the field emitter includes the following steps:

[0192] Step S510, determine the target field emission unit to be calibrated currently;

[0193] Step S520, keep the motors of the non-target field emission units stopped;

[0194] Step S530, record the magnetic field data measured by the magnetic sensor;

[0195] Step S540, record the position information output by the absolute position encoder in the target field emission unit;

[0196] Step S550, calibrate the target field emission unit according to the magnetic field data and the position information.

[0197] Specifically, the above steps S530 and S540 can be performed simultaneously. For all field emission units in the field emitter, the above steps are executed one by one for calibration.

[0198] In this specific embodiment, a method for detecting interference of the field emitter is further provided. The following is an explanation of the principle of the method for detecting interference of the field emitter.

[0199] When leaving the factory, the field emitter will also be calibrated once, and its basic process is similar to the above self-calibration process. However, the environment during factory calibration is more controllable. For example, it can be controlled that there is no other magnetic field source, no large metal substances, and no ferromagnetic materials around during calibration. There are many uncertainties during on-site calibration. For example, there may be various interference sources around, causing the measured magnetic field to be distorted. If the field emitter is directly calibrated, many errors may be introduced. To eliminate this interference, an interference detection coil is also introduced inside the field emitter. Together with the magnetic sensor in the magnetic detection component, both are fixed on the installation housing of the field emitter (such as glued and sealed). Therefore, the relative positions of the interference detection coil and the magnetic sensor are stable.

[0200] Figure 10 It is a flowchart of the method for detecting interference of the field emitter in a specific embodiment of the present invention. Refer to Figure 10 , the method for detecting interference of the field emitter includes the following steps:

[0201] Step S610, keep the motors of all field emission units in the field emitter stopped;

[0202] Step S620, activate the target interference detection coil to be detected;

[0203] Step S630, the magnetic sensor in the magnetic detection component records the magnetic field generated by the target interference detection coil;

[0204] Step S640, compare the detection signal of the magnetic sensor with the reference signal.

[0205] Specifically, for all interference detection coils in the field emitter, the above steps are executed one by one for detection.

[0206] The detection signal generated by the coil can be a sine signal. And 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 50 Hz - 100 Hz. During detection, all field emission units are stopped to exclude all known time-varying magnetic field sources. The magnetic sensor collects this signal b B′ ij-e (n), and compare it with the reference signal b B ij-e (n) recorded in a clean environment when leaving the factory, whereb B ij-e (n) represents the magnetic field signal generated by the jth interference detection coil recorded by the ith magnetic sensor. The comparison method can be phase-based, such as comparing peak positions, calculating correlation coefficients, etc. (it is known that interference signals such as metal eddy currents are interference signals with the same frequency but different phases). The perturbation of the magnetic field by some small interference sources is usually local. Therefore, multiple interference detection coils are arranged around the field emitter, and detection signals are generated one by one during detection and the same phase comparison detection is performed, so as to more comprehensively detect the conditions around the field emitter and ensure that the self-calibration process is in an environment without magnetic field interference. When interference detection finds that there is detectable interference around (such as the phase difference exceeds a certain limit), the field emitter will not start the self-calibration program and will prompt the user that there is interference. At this time, the user can independently eliminate the interference source. If no interference is detected, the self-calibration program can be started.

[0207] It should be noted that b B ij-e (n) and b B′ ij-e (n) are obviously not measured simultaneously, but the serial number n is used to represent both. n is labeled from 0 to N T for annotation. Among them, n = 0 represents the starting moment of the signal. Therefore, b B ij-e (n) and b B′ ij-e (n) are not measured simultaneously, but still can be compared one by one.

[0208] In this specific embodiment, an abnormal detection method for the field emitter is also provided. The following is the principle description of the abnormal detection method for the field emitter.

[0209] When the field emitter is used on-site, the magnetic sensors in the magnetic detection component will continuously record the magnetic field values b B′ i (n) during navigation and regularly (such as every 1 s) compare them with the reference magnetic field values b B′ i (n) in the record. For example:

[0210]

[0211] Whether it is the intensity change or the phase change, it will be reflected in the error quantity L(Err0). When the value of L is within a certain limit, it is considered that the system is normal and can continue to be used; if it exceeds a certain limit, the system will stop the navigation work and enter the "interference detection" link.

[0212] It should be noted that the magnetic field measured by the magnetic sensor during real-time abnormal detection b B′ i(n) is different from that measured during the self-calibration process in the above text. b B i (n). When measuring b B′ i (n), the field emitter is in the "navigation state", and at this time all field emission units are working properly. When measuring b B i (n), only one field emission unit works each time, and other field emission units do not work.

[0213] Figure 11 is a flowchart of the usage method of the field emitter in a specific embodiment of the present invention. Referring to Figure 11 , the usage method of the field emitter includes: pre-factory detection stage 710, real-time anomaly detection stage 720, on-site interference detection stage 730, and on-site self-calibration stage 740.

[0214] In the pre-factory detection stage 710 of the field emitter, interference detection, anomaly detection, and self-calibration need to be carried out, and the interference detection reference signal, anomaly detection reference signal, and initial calibration parameters are recorded respectively. Among them, interference detection, anomaly detection, and self-calibration can all be carried out by the corresponding methods in this specific embodiment. After the field emitter leaves the factory, it is put into use.

[0215] The real-time anomaly detection stage 720 is in the electromagnetic navigation state of the field emitter. In this stage, the field emitter works, and real-time anomaly detection is carried out by the anomaly detection method in this specific embodiment, and the measured working magnetic field signal of the field emitter is recorded. The measured working magnetic field signal is compared with the anomaly detection reference signal and the error is calculated. If the error is not exceeded, it continues to be used; if the error is exceeded, the on-site interference detection stage 730 is carried out.

[0216] In the on-site interference detection stage 730, on-site interference detection is carried out by the interference detection method in this specific embodiment, and the measured detection magnetic field signal generated by the interference detection coil is recorded. The measured detection magnetic field signal is compared with the interference detection reference signal and the error is calculated. If the error is not exceeded, it enters the on-site self-calibration stage; if the error is exceeded, interference elimination is required, and after interference elimination, the error between the measured working magnetic field signal and the anomaly detection reference signal is recalculated and it is judged whether it is exceeded.

[0217] In the on-site self-calibration stage 740, on-site self-calibration is carried out by the self-calibration method in this specific embodiment, and the real-time calibration parameters of each field emission unit are recorded. The real-time calibration parameters are compared with the initial calibration parameters and the error is calculated. If the error is not exceeded, the calibration parameters are updated and it continues to be used; if the error is exceeded, the field emitter is returned to the factory for repair.

[0218] Some virtual devices are also provided in the present invention. These devices are used to implement the above-described embodiments and preferred implementation manners, and those that have been described will not be elaborated herein. The following terms "module", "unit", "sub-unit", etc. may be a combination of software and / or hardware that can achieve a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware is also possible and contemplated.

[0219] Figure 12 is a structural block diagram of the self-calibration device of the field emitter provided by the present invention. As Figure 12 shown, the device includes:

[0220] A first acquisition module 1210, configured to acquire the measured calibration magnetic field data detected by the magnetic sensor for the target calibration magnetic field, and acquire the magnet angle information of the target field emission unit; wherein, the target field emission unit is the field emission unit to be calibrated in the field emission unit group, and the target calibration magnetic field is the calibration magnetic field generated by the target field emission unit;

[0221] A parameter calibration module 1220, configured to calibrate the target parameters of the target field emission unit according to the measured calibration magnetic field data and the magnet angle information.

[0222] Through the self-calibration device of the field emitter provided by the present invention, the calibration parameters of each field emission unit can be updated in the magnetic field model, so that the calculation result of the magnetic field model is more accurate, and the electromagnetic navigation accuracy can be improved. Therefore, the present invention solves the problem that the electromagnetic navigation accuracy of the electromagnetic navigation system is reduced after the initial calibration parameters of the field emitter in the related art are mismatched with the actual state.

[0223] Figure 13 is a structural block diagram of the interference detection device of the field emitter provided by the present invention. As Figure 13 shown, the device includes:

[0224] A second acquisition module 1310, configured to acquire the measured detection magnetic field data detected by the magnetic sensor for the detection magnetic field; wherein, the detection magnetic field is generated by the magnetic source assembly;

[0225] An interference analysis module 1320, configured to determine the detection difference degree between the measured detection magnetic field data and the reference detection magnetic field data, and determine the interference detection result of the field emitter according to the detection difference degree.

[0226] Through the interference detection device of the field emitter provided by the present invention, it is possible to detect whether there are other magnetic field sources around the field emitter.

[0227] Figure 14 is a structural block diagram of the anomaly detection device of the field emitter provided by the present invention. As Figure 14As shown, the device includes:

[0228] A third acquisition module 1410, configured to acquire measured operating magnetic field data obtained by a magnetic sensor detecting an operating magnetic field generated by a field emitter;

[0229] An anomaly analysis module 1420, configured to determine an operating difference degree between the measured operating magnetic field data and reference operating magnetic field data, and determine the operating state of the field emitter according to the operating difference degree.

[0230] Through the anomaly detection device for a field emitter provided by the present invention, real-time anomaly detection can be performed on the field emitter during the implementation of electromagnetic navigation by the field emitter.

[0231] It should be noted that each of the above modules may be a functional module or a program module, and can be implemented either by software or by hardware. For the modules implemented by hardware, each of the above modules may be located in the same processor; or each of the above modules may also be located in different processors in any combination form.

[0232] In the present invention, an electronic device is further provided, including a memory and a processor. A computer program is stored in the memory, and the processor is configured to run the computer program to execute the steps in any one of the above method embodiments.

[0233] It should be noted that specific examples in this embodiment may refer to the examples described in the above embodiments and optional implementation manners, and will not be repeated in this embodiment.

[0234] In the present invention, a storage medium may also be provided to implement it. A computer program is stored on the storage medium; when the computer program is executed by a processor, any one of the self-calibration method, interference detection method, or anomaly detection method for a field emitter in the above embodiments is implemented.

[0235] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0236] It should be understood that the specific embodiments described here are only used to explain this application, rather than to limit it. According to the embodiments provided by this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of this application.

[0237] Obviously, the accompanying drawings are only some examples or embodiments of the present application. For those of ordinary skill in the art, the present application can also be applied to other similar situations based on these drawings without creative work. Additionally, it can be understood that although the work done during this development process may be complex and time-consuming, for those of ordinary skill in the art, certain design, manufacturing, or production changes based on the technical content disclosed in the present application are only conventional technical means and should not be regarded as insufficient disclosure of the present application.

[0238] The term "embodiment" in the present application means that the specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears in various positions in the specification and does not necessarily mean the same embodiment, nor does it mean being independent or alternative to other embodiments and mutually exclusive. Those of ordinary skill in the art can clearly or implicitly understand that the embodiments described in the present application can be combined with other embodiments without conflict.

[0239] The above-described embodiments merely represent several implementation manners of the present application. Their descriptions are relatively specific and detailed, but should not be construed as limiting the scope of patent protection. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several variations and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A field emitter, characterized in that, the field emitter includes: a field emission unit group (100) and a magnetic detection component (110); the field emission unit group (100) includes field emission units (101), and the spatial postures of the field emission units (101) in the field emitter are fixed; the magnetic detection component (110) includes a magnetic sensor (111), and the spatial posture of the magnetic sensor (111) in the field emitter is fixed; when the magnetic detection component (110) works, the magnetic sensor (111) is used to detect the calibrated magnetic field generated by the field emission unit (101).

2. The field emitter according to claim 1, characterized in that, the magnetic detection component (110) further includes a circuit board (112), and there are multiple magnetic sensors (111); the multiple magnetic sensors (111) are uniformly installed on the circuit board (112).

3. The field emitter according to claim 1, characterized in that, the field emitter further includes: a mounting housing (130); both the field emission unit group (100) and the magnetic detection component (110) are installed inside the mounting housing (130); alternatively, the field emission unit group (100) is installed inside the mounting housing (130), and the magnetic detection component (110) is installed outside the mounting housing (130).

4. The field emitter according to claim 1, characterized in that, the field emitter further includes: a magnetic source component; the spatial posture of the magnetic source component in the field emitter is fixed; when the magnetic source component works, the magnetic sensor (111) is further used to detect the detection magnetic field generated by the magnetic source component.

5. The field emitter according to claim 4, characterized in that, the magnetic source component includes multiple coils (120), and the multiple coils (120) are uniformly distributed on the periphery of the field emission unit group (100).

6. A self-calibration method for a field emitter, characterized in that, the self-calibration method is applied to the field emitter according to any one of claims 1-5; the self-calibration method includes: obtaining the measured calibrated magnetic field data detected by the magnetic sensor for the target calibrated magnetic field, and obtaining the magnet angle information of the target field emission unit; wherein, the target field emission unit is the field emission unit to be calibrated in the field emission unit group, and the target calibrated magnetic field is the calibrated magnetic field generated by the target field emission unit; calibrating the target parameters of the target field emission unit according to the measured calibrated magnetic field data and the magnet angle information.

7. The self-calibration method for a field emitter according to claim 6, characterized in that, the calibrating the target parameters of the target field emission unit according to the measured working magnetic field data and the magnet angle information includes: determining the model calibrated magnetic field data of the target calibrated magnetic field at the magnetic sensor according to the magnet angle information, the model parameters of the target field emission unit, and the spatial posture of the magnetic sensor. Taking the minimization of the difference between the measured calibrated magnetic field data and the model calibrated magnetic field data as the optimization objective, the model parameters of the target field emission unit are optimized to obtain the target parameters of the target field emission unit.

8. The self-calibration method of a field emitter according to claim 7, wherein, taking the minimization of the difference between the measured working magnetic field data and the model working magnetic field data as the optimization objective includes: taking the minimization of the difference between the magnitude of the measured calibrated magnetic field data and the magnitude of the model calibrated magnetic field data as the optimization objective.

9. The self-calibration method of a field emitter according to claim 7, wherein, the measured calibrated magnetic field data includes a sequence of measured calibrated magnetic field values, and the model calibrated magnetic field data includes a sequence of model calibrated magnetic field values; taking the minimization of the difference between the measured calibrated magnetic field data and the model calibrated magnetic field data as the optimization objective includes: determining the sequence mean of the sequence of measured calibrated magnetic field values and determining the sequence mean of the sequence of model calibrated magnetic field values; subtracting the sequence mean of the sequence of measured calibrated magnetic field values from each magnetic field value in the sequence of measured calibrated magnetic field values to obtain a first sequence of magnetic field values; subtracting the sequence mean of the sequence of model calibrated magnetic field values from each magnetic field value in the sequence of model calibrated magnetic field values to obtain a second sequence of magnetic field values; taking the minimization of the difference between the first sequence of magnetic field values and the second sequence of magnetic field values as the optimization objective.

10. An interference detection method for a field emitter, wherein, the interference detection method is applied to the field emitter according to claim 4 or 5; the interference detection method includes: acquiring measured detected magnetic field data obtained by the magnetic sensor detecting a detected magnetic field; wherein, the detected magnetic field is generated by a magnetic source component; determining the detection difference degree between the measured detected magnetic field data and the reference detected magnetic field data, and determining the interference detection result of the field emitter according to the detection difference degree.

11. The interference detection method for a field emitter according to claim 10, wherein, the magnetic source component includes a plurality of coils, and the plurality of coils are evenly distributed on the periphery of the field emission unit group; the acquiring the measured detected magnetic field data obtained by the magnetic sensor detecting the detected magnetic field includes: acquiring target measured detected magnetic field data obtained by the magnetic sensor detecting a target detected magnetic field; wherein, the target detected magnetic field is the detected magnetic field generated by a target coil in the magnetic source component; the determining the detection difference degree between the measured detected magnetic field data and the reference detected magnetic field data, and determining the interference detection result of the field emitter according to the detection difference degree includes: determining the target detection difference degree between the target measured detected magnetic field data and the target reference detected magnetic field data, and determining the interference detection result of the field emitter in the direction corresponding to the target coil according to the target detection difference degree.

12. An anomaly detection method for a field emitter, wherein, the anomaly detection method is applied to the field emitter according to any one of claims 1-5; the anomaly detection method includes: Obtain the measured working magnetic field data detected by the magnetic sensor for the working magnetic field generated by the field emitter; Determine the working difference degree between the measured working magnetic field data and the reference working magnetic field data, and determine the operating state of the field emitter according to the working difference degree.

13. A self-calibration device for a field emitter, characterized in that, The self-calibration device is applied to the field emitter according to any one of claims 1-5; The self-calibration device includes: A first acquisition module, configured to acquire the measured calibration magnetic field data detected by the magnetic sensor for the target calibration magnetic field, and acquire the magnet angle information of the target field emission unit; wherein, the target field emission unit is the field emission unit to be calibrated in the field emission unit group, and the target calibration magnetic field is the calibration magnetic field generated by the target field emission unit; A parameter calibration module, configured to calibrate the target parameters of the target field emission unit according to the measured calibration magnetic field data and the magnet angle information.

14. An interference detection device for a field emitter, characterized in that, The interference detection device is applied to the field emitter according to claim 4 or 5; The interference detection device includes: A second acquisition module, configured to acquire the measured detection magnetic field data detected by the magnetic sensor for the detection magnetic field; wherein, the detection magnetic field is generated by the magnetic source assembly; An interference analysis module, configured to determine the detection difference degree between the measured detection magnetic field data and the reference detection magnetic field data, and determine the interference detection result of the field emitter according to the detection difference degree.

15. An anomaly detection device for a field emitter, characterized in that, The anomaly detection device is applied to the field emitter according to any one of claims 1-5; the anomaly detection device: A third acquisition module, configured to acquire the measured working magnetic field data detected by the magnetic sensor for the working magnetic field generated by the field emitter; An anomaly analysis module, configured to determine the working difference degree between the measured working magnetic field data and the reference working magnetic field data, and determine the operating state of the field emitter according to the working difference degree.

Images