Detection module and electromagnetic navigation system

Abstract

The invention relates to a detection module and an electromagnetic navigation system, and the detection module comprises a magnetic sensor and a magnetic core. The magnetic sensor and the magnetic core are oppositely arranged, and the projection of the induction center of the magnetic sensor in the measuring axis direction of the magnetic sensor is located on the magnetic core. And the magnetic core is used for enhancing the signal intensity in the measuring axis direction of the magnetic sensor after being magnetized in the magnetic field. According to the magnetic sensor, the problems that eddy current is caused due to the fact that the magnetic field frequency needs to be improved, the device is more sensitive to metal interference, and the equivalent magnetic field intensity is affected are solved, and after the arranged magnetic core is magnetized in the magnetic field, the signal intensity of the magnetic sensor in the measuring axis direction is enhanced.

Description

Technical Field

[0001] The present application relates to the technical field of electromagnetic navigation systems, and particularly to a detection module and an electromagnetic navigation system. Background Art

[0002] An electromagnetic tracking system (EMTS) is one of the mainstream technical solutions for surgical navigation systems and is widely used. The most typical basic working principle of an EMTS is as follows: a time-varying magnetic field is generated by a field emitter, and after the time-varying magnetic field is detected by a magnetic sensor, pose calculation is performed. Since the magnetic field strength decays with the cube of the distance, after a certain distance from the field emitter, the magnetic field signal strength will rapidly weaken, resulting in a decrease in the signal-to-noise ratio, which directly affects the navigation accuracy and precision. Therefore, increasing the signal strength is one of the key methods to improve the signal-to-noise ratio.

[0003] Currently, the solution for enhancing the signal is to increase the magnetic field frequency to increase the rate of change of magnetic flux in the receiving coil, thereby increasing the signal strength. However, the disadvantage of this solution is that high-frequency magnetic fields will cause significant eddy currents in metals, making the device more sensitive to metal interference. In addition, due to the inductive reactance of the transmitting coil, increasing the magnetic field signal frequency will also result in a decrease in the equivalent magnetic field strength.

[0004] Regarding the problem in the related art that increasing the magnetic field frequency will cause eddy currents, making the device more sensitive to metal interference and affecting the equivalent magnetic field strength, no effective solution has been proposed yet. Summary of the Invention

[0005] In this embodiment, a detection module and an electromagnetic navigation system are provided to solve the problem in the related art that increasing the magnetic field frequency will cause eddy currents, making the device more sensitive to metal interference and affecting the equivalent magnetic field strength.

[0006] In a first aspect, in this embodiment, a detection module is provided, including: a magnetic sensor and a magnetic core;

[0007] The magnetic sensor and the magnetic core are arranged opposite to each other, and the projection of the induction center of the magnetic sensor along the measurement axis direction of the magnetic sensor is located on the magnetic core;

[0008] The magnetic core is used to enhance the signal strength in the measurement axis direction of the magnetic sensor after being magnetized in the magnetic field where it is located.

[0009] In some of these embodiments, the measurement axis of the magnetic sensor coincides with the axis of the magnetic core.

[0010] In some of these embodiments, the magnetic sensor is a one-axis sensor, a two-axis sensor or a three-axis sensor; and / or, the magnetic core is a magnetic core with high magnetic permeability.

[0011] In some of these embodiments, the detection module further includes a circuit board; the magnetic sensor and the magnetic core are disposed on the circuit board.

[0012] In some of these embodiments, the number of the magnetic sensors is one, and the number of the magnetic cores is two; the magnetic sensor is disposed between the two magnetic cores.

[0013] In some of these embodiments, the axes of the two magnetic cores coincide with the measurement axis of the magnetic sensor.

[0014] In some of these embodiments, the number of the magnetic sensors is two, and the number of the magnetic cores is one; the magnetic core is disposed between the two magnetic sensors.

[0015] In some of these embodiments, the measurement axes of the two magnetic sensors coincide with the axis of the magnetic core.

[0016] In some of these embodiments, the magnetic core has a cube structure, and the number of the magnetic sensors is greater than or equal to three; each of the magnetic sensors is disposed opposite to a different surface of the magnetic core.

[0017] In some of these embodiments, the measurement axes of the magnetic sensors coincide with the central normal lines of the corresponding surfaces of the magnetic core respectively.

[0018] In some of these embodiments, the detection module further includes an induction coil, and the induction coil is wound around the periphery of the magnetic core.

[0019] In a second aspect, an electromagnetic navigation system is provided in this embodiment, including: a field emitter and the detection module as described in the first aspect above.

[0020] Compared with the related art, in the detection module and the electromagnetic navigation system provided in this embodiment, the detection module includes: a magnetic sensor and a magnetic core; the magnetic sensor and the magnetic core are disposed opposite to each other, and the projection of the induction center of the magnetic sensor along the direction of the measurement axis of the magnetic sensor is located on the magnetic core; the magnetic core is used to enhance the signal intensity in the direction of the measurement axis of the magnetic sensor after being magnetized in the magnetic field where it is located, solving the problems that increasing the magnetic field frequency will cause eddy currents, making the device more sensitive to metal interference, and affecting the equivalent magnetic field intensity. By using the provided magnetic core to be magnetized in the magnetic field where it is located, the signal intensity of the magnetic sensor in the direction of the measurement axis is enhanced.

[0021] Details of one or more embodiments of the present application are set forth in the following drawings and description, so that other features, objects, and advantages of the present application will become more clearly understood. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings described herein are used to provide a further understanding of the present application and form a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0023] Figure 1 is a schematic structural diagram of a detection module provided by an embodiment of the present application;

[0024] Figure 2 is a schematic structural diagram of a unidirectional one-way enhanced detection module provided by an embodiment of the present application;

[0025] Figure 3 is a schematic structural diagram of a unidirectional two-way enhanced detection module provided by Embodiment 1 of the present application;

[0026] Figure 4 is a schematic structural diagram of a unidirectional two-way enhanced detection module provided by Embodiment 2 of the present application;

[0027] Figure 5 is a schematic structural diagram of a bilateral three-way enhanced detection module provided by an embodiment of the present application;

[0028] Figure 6 is a schematic structural diagram of a detection module provided by a preferred embodiment of the present application;

[0029] Figure 7 is a schematic structural diagram of a detection module provided by another preferred embodiment of the present application.

[0030] In the figure: 10, magnetic sensor; 20, magnetic core; 30, circuit board; 40, induction coil. Detailed implementation manners

[0031] To understand the purpose, technical solution and advantages of the present application more clearly, the present application will be described and explained below in conjunction with the accompanying drawings and embodiments.

[0032] 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 that includes 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 terms "connected", "coupled", etc. involved in this application do not limit to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "plurality" involved in this application means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" may mean: 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 only distinguish similar objects and do not represent a specific order for the objects.

[0033] In this embodiment, a detection module is provided. Figure 1 It is a schematic structural diagram of the detection module of this embodiment, as Figure 1 shown. The detection module includes:

[0034] A magnetic sensor 10 and a magnetic core 20;

[0035] The magnetic sensor 10 and the magnetic core 20 are arranged opposite to each other, and the projection of the induction center of the magnetic sensor 10 along the measurement axis direction of the magnetic sensor 10 is located on the magnetic core 20.

[0036] The magnetic core 20 is used to enhance the signal intensity in the measurement axis direction of the magnetic sensor 10 after being magnetized in the magnetic field where it is located.

[0037] Specifically, the detection module includes a magnetic sensor 10 and a magnetic core 20.

[0038] The induction center of the magnetic sensor 10 is the center of the induction range of the magnetic sensor 10; in some embodiments, the induction range may be a two-dimensional plane range, and the center of this two-dimensional plane range is the induction center; the induction range may also be a three-dimensional solid range, and the geometric center of this three-dimensional solid range is the induction center. In other embodiments, a magnetic field sensitive unit is provided inside the magnetic sensor 10, and the magnetic field sensitive unit is used to convert the magnetic field signal in the area where it is located into an electrical signal. The induction range may be the size range of the induction surface of the sensitive unit, and the center of the induction range is the center of the induction surface of the sensitive unit; the induction range may also be the size range of the sensitive unit, and the center of the induction range is the geometric center of the sensitive unit.

[0039] The measurement axis of the magnetic sensor 10 passes through the induction center of the magnetic sensor 10 and is perpendicular to the induction surface of the magnetic field sensitive unit of the magnetic sensor 10. The direction of the measurement axis is the direction in which the measurement axis extends. The measurement axis of the magnetic sensor 10 is like Figure 1 the axis corresponding to Z in the figure, where Z represents the schematic direction of the measurement axis and does not limit the direction of the measurement axis of the magnetic sensor 10.

[0040] It should be noted that the induction range, the center of the induction range, the measurement axis, and the direction of the measurement axis of the magnetic sensor 10 are all determined by the relevant parameters of the magnetic sensor 10 device itself, and no special description is given for this.

[0041] The relative setting of the magnetic sensor 10 and the magnetic core 20 means that there is a correlation between the induction center of the magnetic sensor 10 and the magnetic core 20. Specifically: the projection of the induction center of the magnetic sensor 10 along the direction of the measurement axis of the magnetic sensor 10 is located on the magnetic core 20. For example: the minimum distance between the projection of the induction center on the magnetic core 20 and the measurement axis of the magnetic sensor 10 is less than or equal to a preset distance threshold, and this distance threshold may be less than or equal to half of the size of the magnetic sensor 10. Further, this distance threshold is determined by the measurement accuracy of the detection module and is not limited here.

[0042] Among them, the magnetic sensor 10 refers to a sensor that measures the magnetic flux density and can convert the magnetic field signal into an electrical signal. The magnetic sensor 10 includes but is not limited to magnetoresistive sensors, Hall sensors, etc. Among them, the magnetic core 20 has a magnetic permeability. When the magnetic core 20 is located in a magnetic field, it will be magnetized; then after magnetization, the magnetic core 20 will generate a magnetic field increment in the same direction along the direction of the measurement axis of the magnetic sensor 10, thereby enhancing the signal intensity of the magnetic sensor 10 in the direction of the measurement axis.

[0043] In the related art, the magnetic flux change rate in the receiving coil is increased by increasing the magnetic field frequency, thereby increasing the signal strength. To do this, the magnetic field frequency needs to be increased first, and the high-frequency magnetic field will cause significant eddy currents in the metal, making the device more sensitive to metal interference. In addition, due to the inductive reactance of the transmitting coil, increasing the magnetic field signal frequency will also result in a decrease in the equivalent magnetic field strength.

[0044] The detection module of the present application includes a magnetic sensor 10 and a magnetic core 20; the magnetic sensor 10 and the magnetic core 20 are arranged opposite to each other, and the projection of the induction center of the magnetic sensor 10 along the measurement axis direction of the magnetic sensor 10 is located on the magnetic core 20; the magnetic core 20 is used to enhance the signal strength in the measurement axis direction of the magnetic sensor 10 after being magnetized in the magnetic field it is in. It can be considered that after the magnetic core 20 provided in the present application is magnetized in the magnetic field it is in, it will generate a magnetic field increment in the same direction along the measurement axis direction of the magnetic sensor 10, thereby enhancing the signal strength of the magnetic sensor 10 in the measurement axis direction; and there is no need to change the original magnetic field frequency, thereby solving the problems of eddy currents caused by the need to increase the magnetic field frequency, making the device more sensitive to metal interference, and affecting the equivalent magnetic field strength; moreover, the magnetic core 20 and the magnetic sensor 10 in the present application can be directly combined and used, and the structure of the magnetic sensor 10 itself does not need to be improved, thereby reducing the production cost.

[0045] In some of the embodiments, the measurement axis of the magnetic sensor 10 coincides with the axis of the magnetic core 20.

[0046] Specifically, in order to reduce the difficulty of subsequent processing of the measurement signal, the measurement axis of the magnetic sensor 10 coincides with the axis of the magnetic core 20; for example, Figure 1 the measurement axis of the magnetic sensor 10 and the axis of the magnetic core 20 both coincide with the axis corresponding to Z.

[0047] The axis of the magnetic core 20 can divide the magnetic core 20 into symmetric parts. For example: the magnetic core 20 is a cylinder, and the axis of the magnetic core 20 passes through the geometric center of the magnetic core 20 and is perpendicular to the upper and lower surfaces of the magnetic core 20. For the axes of magnetic cores 20 with other configurations, the principle is similar and will not be repeated here.

[0048] In some of the embodiments, the magnetic sensor 10 is a one-axis sensor, a two-axis sensor or a three-axis sensor; and / or, the magnetic core 20 is a magnetic core 20 with high magnetic permeability.

[0049] Specifically, a one-axis sensor is also called a single-axis sensor, which has only one measurement axis and can only measure the magnetic field component in the direction of this measurement axis; a two-axis sensor has two mutually perpendicular measurement axes and can measure the magnetic field components in two mutually perpendicular directions; a three-axis sensor has three mutually perpendicular measurement axes and can measure the magnetic field components in three mutually perpendicular directions.

[0050] For a magnetic sensor 10 with multiple measurement axes, the direction of signal enhancement can be selected by changing the set position of the magnetic core 20. For example, for a triaxial sensor, one measurement axis of the magnetic sensor 10 is defined as the target measurement axis, and the target measurement axis of the magnetic sensor 10 is arranged opposite to the magnetic core 20. It can be considered that the projection of the induction center of the magnetic sensor 10 along the direction of the target measurement axis of the magnetic sensor 10 is located on the magnetic core 20; such an arrangement can enhance the signal in the direction of the target measurement axis of the magnetic sensor 10, thereby enabling flexible adaptation to various magnetic sensors 10.

[0051] Among them, the magnetic core 20 can be made of a soft magnetic material with high magnetic permeability, so that the magnetic core 20 has high magnetic permeability. The high magnetic permeability of the magnetic core 20 means that the magnetic permeability of the magnetic core 20 is above 100, and it has characteristics such as a large saturation magnetic induction intensity, a high resistance, a low loss, and good stability. Examples of high magnetic permeability materials are not given here.

[0052] In some embodiments, the length of the magnetic core 20 is in the order of millimeters to centimeters, that is, the length of the magnetic core 20 can range from a few millimeters to a few centimeters. The specific length can be determined by the measurement accuracy of the detection module. The length of the magnetic core 20 can determine the signal enhancement effect, but an overly long length will cause the magnetic core 20 to span different magnetic fields, resulting in a reduction in the measurement accuracy of the detection module. Therefore, the length of the magnetic core 20 can be selected according to different usage requirements.

[0053] In some embodiments, the detection module further includes a circuit board 30; the magnetic sensor 10 and the magnetic core 20 are arranged on the circuit board 30. The circuit board 30 supplies power to the magnetic sensor 10 and fixes the magnetic sensor 10 and the magnetic core 20, thereby reasonably arranging and setting the detection module.

[0054] The signal enhancement principle of the detection module is described below:

[0055] As Figure 2 shown, Figure 2 For the single-sided unidirectional enhancement type detection module shown, it includes a magnetic sensor 10, a magnetic core 20, and a circuit board 30; the magnetic sensor 10 and the magnetic core 20 are arranged on the circuit board 30. Z represents the direction of the measurement axis of the magnetic sensor 10; the position of the magnetic sensor 10 is z = z0; the position of the magnetic core 20 is z = (z1 + z2) / 2. z1 represents the upper boundary position of the magnetic core 20; z2 represents the lower boundary position of the magnetic core 20. The upper boundary of the magnetic core 20 needs to be as close as possible to the magnetic sensor 10. Preferably, the upper boundary of the magnetic core 20 can be in contact with the magnetic sensor 10. Assume that the external magnetic field where the magnetic core 20 is located is B, and its direction is arbitrary. B is divided into a component along the direction of the measurement axis of the magnetic sensor 10 (in the same direction as the Z measurement axis direction in the figure) component B z, and the component B in the r direction orthogonal to the Z measurement axis direction r . If the magnetic core 20 is slender, then the two external magnetic field components along the Z measurement axis direction can be expressed as: B z (z) and B r (z). Under the action of B z (z) and B r (z), the magnetic core 20 is magnetized.

[0056] At the position of the magnetic sensor 10: Along the Z measurement axis direction, a magnetic field increment ΔB in the same direction is generated z ; along the r direction, a magnetic field increment ΔB in the opposite direction is generated r (the dipole model can be referred to). It can be considered that they are the comprehensive effects of the excitation magnetic fields at various positions on the entire magnetic core 20. Therefore, the magnetic field in the Z measurement axis direction is enhanced, and this enhancement can be expressed as: B z ′(z0) = B z (z0) + ΔB z ; where B z (z0) represents the magnetic field component of the external magnetic field at the position z0 (as Figure 2 shown, its direction is upward); while in the r direction, the magnetic field is canceled, and this cancellation can be expressed as: B r ′(z0) = B r (z0) + ΔB r ; where B r (z0) represents the magnetic field component of the external magnetic field at the position z0 (as Figure 2 shown, its direction is to the left). Then, the signal intensity in the Z measurement axis direction of the magnetic sensor 10 is enhanced.

[0057] It should be noted that different from the coil containing the magnetic core 20, the positions of the magnetic core 20 and the magnetic sensor 10 are different. The magnetic core 20 is excited by the magnetic field in the [z1, z2] interval, thereby affecting the signal of the magnetic sensor 10 at the position z0 (while for the coil containing the magnetic core 20, the measurement space of the coil coincides with the magnetic core 20). Since the magnetic field is continuous, when the size of the detection module is small (that is, ||z0 - z2|| is small), the magnetic field difference between each part of the magnetic core 20 and the magnetic sensor 10 is not large. Therefore, the enhanced magnetic field intensity can be considered to be only related to the local magnetic field intensity, that is, B z ′(z0) = f(B z (z0)). This intensity relationship is a non-linear relationship and can be obtained through calibration. For example: By using a Helmholtz coil system to generate a known magnetic field and recording the output signal of the detection module, several input-output pairs are generated, and then the relationship between the two is fitted, or a look-up table is formed.

[0058] If the length of the magnetic core 20 in the detection module is slightly longer, the uniformity of the magnetic field within the region where the magnetic core 20 is located will decrease, which will lead to a decrease in the accuracy of the measurement results. That is, when the change of the magnetic core 20 within the magnetic field range cannot be ignored, it is difficult to completely obtain the enhanced magnetic field intensity and the local magnetic field intensity through calibration. For example, when the position of the magnetic sensor 10 is kept unchanged and the detection module is rotated around the induction center, the magnetic field intensity sensed by the magnetic core 20 changes with the pose, and its influence on the magnetic field where the magnetic sensor 10 is located also changes, which will be difficult to represent with a simple calibration function or look-up table.

[0059] Therefore, two solutions for the unidirectional bilateral enhanced detection module are proposed below to weaken this asymmetry.

[0060] In some of the embodiments, as Figure 3 shown, it is a solution for one of the unidirectional bilateral enhanced detection modules. The number of magnetic sensors 10 in this detection module is one, and the number of magnetic cores 20 is two; the magnetic sensor 10 is arranged between the two magnetic cores 20.

[0061] In this embodiment, the magnetic sensor 10 and the magnetic core 20 are also arranged oppositely, and the projection of the induction center of the magnetic sensor 10 along the measurement axis direction of the magnetic sensor 10 is located on the magnetic core 20. For the specific form of the opposite arrangement, reference can be made to the embodiments of the above detection module, and no repeated description will be given here.

[0062] Specifically, Figure 3 for the detection module shown in, the axes of the two magnetic cores 20 coincide with the measurement axis of the magnetic sensor 10. In other embodiments, the distance between the axis and the measurement axis is less than a preset distance threshold. The difference between whether the axes of the two magnetic cores 20 coincide with the measurement axis of the magnetic sensor 10 is that if they do not coincide, it is difficult to determine the signal enhancement result using a calibration function or look-up table, and a more complex calculation method is required.

[0063] Both of the two magnetic cores 20 will be magnetized by the magnetic field where they are located. After being magnetized, the signal enhancement direction of the magnetic core 20 located above the magnetic sensor 10 is the Z measurement axis direction; after being magnetized, the signal enhancement direction of the magnetic core 20 located below the magnetic sensor 10 is also the Z measurement axis direction; both of the two magnetic cores 20 will enhance the signal intensity of the magnetic sensor 10 in the measurement axis direction. The specific signal enhancement principle will not be repeated here.

[0064] The magnetic sensor 10 is located in the middle of these two magnetic cores 20. When the length of the magnetic core 20 is small and the magnetic field is continuous, the enhancement effects of the magnetic cores 20 on both sides of the magnetic sensor 10 at the magnetic sensor 10 are averaged, so that the magnetic field intensity relationship B z ′(z0) = f(B zThe accuracy of (z0) is further improved.

[0065] In some of these embodiments, such as Figure 4 As shown, it is another solution for a unidirectional bilateral enhanced detection module. The number of magnetic sensors 10 of this detection module is two, and the number of magnetic cores 20 is one; the magnetic core 20 is arranged between the two magnetic sensors 10.

[0066] In this embodiment, the magnetic sensors 10 and the magnetic core 20 are also arranged opposite to each other, and the projection of the induction center of the magnetic sensor 10 along the measurement axis direction of the magnetic sensor 10 is located on the magnetic core 20. For the specific form of the opposite arrangement, reference can be made to the embodiments of the above detection module, which will not be repeated here.

[0067] Specifically, Figure 4 For the detection module shown in, the measurement axes of the two magnetic sensors 10 coincide with the axis of the magnetic core 20. In other embodiments, the distance between the measurement axis and the axis is less than or equal to a preset distance threshold. The difference between whether the measurement axes of the two magnetic sensors 10 coincide with the axis of the magnetic core 20 is that if they do not coincide, it is difficult to use a calibration function or a look-up table to determine the result of signal enhancement, and a more complex calculation method is required.

[0068] Among them, the magnetic core 20 will be magnetized by the magnetic field where it is located, and the direction of signal enhancement after magnetization is the Z measurement axis direction; since the measurement axes of the two magnetic sensors 10 coincide with the axis of the magnetic core 20, the signal intensities of the magnetic sensor 10 above the magnetic core 20 and the magnetic sensor 10 below the magnetic core 20 in the Z measurement axis direction will both be enhanced. The specific signal enhancement principle will not be repeated here.

[0069] The magnetic core 20 is located in the middle of these two magnetic sensors 10. When the length of the magnetic core 20 is small and the magnetic field is continuous, the mean value of the measurement signals of the two magnetic sensors 10 can be approximately expressed as: That is, it is determined by the excitation magnetic field at the center position of the magnetic core 20 ( Figure 4 z0 in).

[0070] In the detection module of this embodiment, the influence of the non-uniform magnetic field distribution on the measured magnetic field strength in a certain direction at a certain point is reduced. Moreover, two measurement data can be provided, and through the comparison or screening of these two measurement data, the measurement accuracy of the detection module can be further improved.

[0071] The detection module in the above example enhances the signal of a single axis and can only obtain magnetic field information of 5 degrees of freedom (DOF), that is, it cannot know the attitude information of the detection module rotating around its own Z axis. Here, a single-sided three-way enhanced or double-sided three-way enhanced detection module is provided, which can simultaneously measure three components of the magnetic field, so as to calculate the pose information of 6 DOF.

[0072] In other embodiments, the numbers of the magnetic core 20 and the magnetic sensor 10 can also adopt other forms, such as: two magnetic cores 20 and three magnetic sensors 10, etc.; the magnetic cores 20 and the magnetic sensors 10 are arranged at intervals, and the corresponding measurement axes and axes are set correspondingly, etc. No examples are given here.

[0073] In some of these embodiments, the magnetic core 20 has a cube structure, and the number of magnetic sensors 10 is greater than or equal to three; each magnetic sensor 10 is disposed opposite to a different surface of the magnetic core 20.

[0074] In this embodiment, the magnetic sensor 10 and the magnetic core 20 are also disposed opposite to each other, and the projection of the induction center of the magnetic sensor 10 along the measurement axis direction of the magnetic sensor 10 is located on the magnetic core 20. For the specific form of the opposite setting, reference can be made to the embodiment of the above detection module, and no repeated description is given here.

[0075] Specifically, the number and setting position of the magnetic sensors 10 determine the type of the detection module with several sides and several directions of enhancement. The detection module is divided into an X measurement axis direction, a Y measurement axis direction, and a Z measurement axis direction. Since the magnetic core 20 has a cube structure, there are corresponding two surfaces in each measurement axis direction.

[0076] When the number of magnetic sensors 10 is one; it is set on the surface of the magnetic core 20 in any Z measurement axis direction, and it is a single-way single-sided enhanced detection module, which enhances the signal intensity in the Z measurement axis direction; it is set on the surface of the magnetic core 20 in any X measurement axis direction, and it is a single-way single-sided enhanced detection module, which enhances the signal intensity in the X measurement axis direction; it is set on the surface of the magnetic core 20 in any Y measurement axis direction, and it is a single-way single-sided enhanced detection module, which enhances the signal intensity in the Y measurement axis direction.

[0077] When the number of magnetic sensors 10 is two; when the two magnetic sensors 10 are respectively arranged on two faces of the magnetic core 20 in the X measurement axis direction, it is a unidirectional bilateral enhanced detection module, and the signal intensity in the X measurement axis direction is enhanced. Other types of unidirectional bilateral enhanced detection modules are not exemplified one by one here. When one magnetic sensor 10 is arranged on the face of the magnetic core 20 in the X measurement axis direction, and the other magnetic sensor 10 is arranged on the face of the magnetic core 20 in the Y measurement axis direction, it is a unilateral bidirectional enhanced detection module, and the signal intensities in the X measurement axis direction and the Y measurement axis direction are enhanced. Other types of unilateral bidirectional enhanced detection modules are not exemplified one by one here.

[0078] When the number of magnetic sensors 10 is three; when the three magnetic sensors 10 are respectively arranged on the faces of the corresponding magnetic cores 20 in the X measurement axis direction, the Y measurement axis direction, and the Z measurement axis direction, it is a unilateral tri-directional enhanced detection module, and the signal intensities in the X measurement axis direction, the Y measurement axis direction, and the Z measurement axis direction are enhanced.

[0079] When the number of magnetic sensors 10 is four; when three magnetic sensors 10 are respectively arranged on the faces of the corresponding magnetic cores 20 in the X measurement axis direction, the Y measurement axis direction, and the Z measurement axis direction, and another magnetic sensor 10 is arranged on any other magnetic core 20; it is a unilateral tri-directional combined with bilateral enhanced detection module, and the signal intensities in the X measurement axis direction, the Y measurement axis direction, and the Z measurement axis direction are enhanced.

[0080] When the number of magnetic sensors 10 is five; when three magnetic sensors 10 are respectively arranged on the faces of the corresponding magnetic cores 20 in the X measurement axis direction, the Y measurement axis direction, and the Z measurement axis direction, and the other two magnetic sensors 10 are arranged on any other two magnetic cores 20; it is a unilateral tri-directional combined with bilateral enhanced detection module, and the signal intensities in the X measurement axis direction, the Y measurement axis direction, and the Z measurement axis direction are enhanced.

[0081] When the number of magnetic sensors 10 is six; when the six magnetic sensors 10 are respectively arranged on six faces of the magnetic core 20, it is a bilateral tri-directional enhanced detection module, and the signal intensities in the X measurement axis direction, the Y measurement axis direction, and the Z measurement axis direction are enhanced.

[0082] It should be noted that the above various types of detection modules are not fully exemplified, and are not exemplified one by one here. And it can be foreseen that for the implementation methods of various detection modules, the magnetic sensors 10 and the magnetic cores 20 are both arranged in a relative manner, which is not repeated here.

[0083] In some of these embodiments, the measurement axes of the respective magnetic sensors 10 coincide with the central normal of the corresponding surface of the magnetic core 20.

[0084] The difference between whether the axis coincides with the measurement axis is that if they do not coincide, it is difficult to use a calibration function or a look-up table to determine the result of signal enhancement, and a more complex calculation method is required. In other embodiments, the distance between the axis and the measurement axis is less than a preset distance threshold.

[0085] The following describes a detection module with six magnetic sensors 10 and a regular hexahedron magnetic core 20, which is a bilateral three-way enhancement type:

[0086] As Figure 5 shown, a magnetic sensor 10 is provided on each surface of the magnetic core 20 (the sensors on the occluded surface are not shown). The measurement axis of each magnetic sensor 10 coincides with the central axis of the surface where it is located, that is, the measurement axes of all magnetic sensors 10 pass through the geometric center of the hexahedron of the magnetic core 20. The directions of the measurement axes are as shown in the figure, which are the X measurement axis direction, the Y measurement axis direction, and the Z measurement axis direction respectively. This detection module can output 3D magnetic field information, and then the magnetic field intensity at the detection point (x0, y0, z0) with the geometric center position of the detection module can be obtained, that is, B′0 = g(B(x0, y0, z0)), where g represents integrating the magnetic field information collected by all magnetic sensors 10. This magnetic field intensity can also be confirmed by calibration.

[0087] In this embodiment, the bilateral three-way enhancement type detection module has a large volume and good signal enhancement effect, and is suitable for scenarios with large space and high signal intensity. The single-way enhancement type detection module is slender and has high measurement accuracy, and is suitable for scenarios with a slender space and high measurement accuracy requirements.

[0088] In some of these embodiments, the detection modules of the above embodiments further include induction coils 40;

[0089] The induction coils 40 are wound around the periphery of the magnetic core 20.

[0090] For example, taking the single-way bilateral enhancement type detection module as an example, as Figure 6 shown, a detection module of a preferred embodiment is provided. This detection module includes a magnetic sensor 10, a magnetic core 20, a circuit board 30, and an induction coil 40; the induction coil 40 is wound around the periphery of the magnetic core 20, and alternating magnetic field signals are detected through the principle of electromagnetic induction.

[0091] For another example, taking the bilateral three-way enhancement type detection module as an example, as Figure 7The detection module of a preferred embodiment is provided as shown. The detection module includes a magnetic sensor (not shown in the figure), a magnetic core (not shown in the figure), a circuit board (not shown in the figure), and an induction coil 40. The induction coil 40 is wound around the periphery of the magnetic core, and alternating magnetic field signals are detected through the principle of electromagnetic induction. Among them, the magnetic sensor is arranged on the side of the induction coil 40 away from the magnetic core. The setting relationship between the magnetic sensor and the magnetic core will not be repeated here.

[0092] Since sensors that directly measure magnetic field strength may be affected by strong low-frequency or static magnetic fields, such as strong background magnetic fields causing sensor saturation, etc. Coil-type sensors are not affected by direct current and can only sense alternating signals.

[0093] The detection module of this embodiment can detect DC or low-frequency magnetic field signals, and can also detect high-frequency weak magnetic field signals.

[0094] In addition, in combination with the detection module provided in the above embodiment, an electromagnetic navigation system can also be provided in this embodiment, including a field emitter and the detection module of each of the above embodiments.

[0095] Through the above electromagnetic navigation system, the problems that increasing the magnetic field frequency will cause eddy currents, making the device more sensitive to metal interference and affecting the equivalent magnetic field strength are solved. After the magnetic core is magnetized in the magnetic field, the signal strength of the magnetic sensor in the measurement axis direction is enhanced.

[0096] It should be noted that specific examples in this embodiment can refer to the examples described in the above embodiment and optional implementation manners, and will not be elaborated in this embodiment.

[0097] 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 in this application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of this application.

[0098] Obviously, the drawings are only some examples or embodiments of this application. For those of ordinary skill in the art, this application can also be applied to other similar situations based on these drawings without creative work. In addition, it can be understood that although the work done during the development process here 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 this application are only conventional technical means and should not be regarded as insufficient disclosure of this application.

[0099] As used herein, the term "embodiment" means that the specific features, structures or characteristics described in connection with the embodiments may be included in at least one embodiment of the present application. The phrase appears in various places in the specification and does not necessarily mean the same embodiment, nor does it mean independence or alternative to other embodiments and mutual exclusion. 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.

[0100] The above-described embodiments merely represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on 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 modifications and improvements can still be made, and these all belong to 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 detection module, characterized in that, Comprising: A magnetic sensor (10) and a magnetic core (20); The magnetic sensor (10) and the magnetic core (20) are arranged opposite to each other, and the projection of the induction center of the magnetic sensor (10) along the measurement axis direction of the magnetic sensor (10) is located on the magnetic core (20); The magnetic core (20) is used to enhance the signal intensity in the measurement axis direction of the magnetic sensor (10) after being magnetized in the magnetic field where it is located.

2. The detection module according to claim 1, wherein The measurement axis of the magnetic sensor (10) coincides with the axis of the magnetic core (20).

3. The detection module according to claim 1, characterized in that The magnetic sensor (10) is a one-axis sensor, a two-axis sensor or a three-axis sensor; and / or, the magnetic core (20) is a magnetic core (20) with high magnetic permeability.

4. The detection module according to claim 1, characterized in that, The detection module further includes a circuit board (30); the magnetic sensor (10) and the magnetic core (20) are arranged on the circuit board (30).

5. The detection module according to claim 1, wherein The number of the magnetic sensors (10) is one, and the number of the magnetic cores (20) is two; the magnetic sensor (10) is arranged between the two magnetic cores (20).

6. The detection module according to claim 5, wherein The axes of the two magnetic cores (20) both coincide with the measurement axis of the magnetic sensor (10).

7. The detection module according to claim 1, characterized in that, The number of the magnetic sensors (10) is two, and the number of the magnetic cores (20) is one; the magnetic core (20) is arranged between the two magnetic sensors (10).

8. The detection module according to claim 7, characterized in that, The measurement axes of the two magnetic sensors (10) both coincide with the axis of the magnetic core (20).

9. The detection module according to claim 1, wherein The magnetic core (20) is of a cube structure, and the number of the magnetic sensors (10) is greater than or equal to three; each of the magnetic sensors (10) is arranged opposite to a different surface of the magnetic core (20).

10. The detection module according to claim 9, wherein, The measurement axes of each of the magnetic sensors (10) respectively coincide with the central normal of the corresponding surface of the magnetic core (20).

11. The detection module according to claim 1, characterized in that The detection module further includes an induction coil (40), and the induction coil (40) is wound around the periphery of the magnetic core (20).

12. An electromagnetic navigation system, characterized in that, Comprising: A field emitter and the detection module according to any one of claims 1-11.

Images