A detection method and system for determining the polarity of an inductor

Abstract

The present invention discloses a detection method and system for determining the polarity of an inductor, which relates to the technical field of inductors, and includes: determining the operating frequency of the inductor as the measurement frequency; performing magnetic needle setting to form a magnetic needle test space; setting the inductor in the test space, acquiring an image of the magnetic needle distribution space, and obtaining at least one actual distribution image of the magnetic needle; performing extreme point identification on the actual distribution image of the magnetic needle to obtain a first extreme point and a second extreme point; determining the magnetic field direction of the inductor on the line connecting the first extreme point and the second extreme point, and taking the magnetic field direction of the inductor on the line connecting the first extreme point and the second extreme point as the polarity direction of the inductor. By setting a test setting module, an image acquisition module, a point recognition module, and a polarity acquisition module, the error between the result of polarity determination and the actual situation is small enough, so that it can meet the subsequent use of radio frequency inductors.

Description

Technical Field

[0001] The present invention relates to the technical field of inductors, and in particular to a detection method and system for determining the polarity of an inductor. Background Art

[0002] From the structure of the inductor, it can be seen that the difference between the two ends of the inductor is nothing more than the different properties of resistance, capacitance, inductance, etc. between the two ports, which determines that the inductor can be a polar component or a non-polar component. Ordinary inductors do not have polarity, but according to usage experience, RF inductors have polarity when used. When installed in different positions, their inductance is different. In order to ensure the use effect of RF inductors, it is necessary to determine their polarity.

[0003] However, the RF inductor has an external shell, and its coil is not symmetrically wound, so it is difficult to determine its polarity. When determining the polarity, errors are prone to occur, which affects the subsequent use of the RF inductor. Summary of the invention

[0004] In order to solve the above technical problems, a detection method and system for determining the polarity of an inductor are provided. The technical solution solves the problem that the RF inductor proposed in the above background technology has an external shell and its coil winding is not symmetrically arranged, which makes it difficult to determine its polarity. When determining the polarity, errors are prone to occur, which affects the subsequent use effect of the RF inductor.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0006] A detection method for determining the polarity of an inductor, comprising:

[0007] determining an operating frequency of the inductor as a measuring frequency, wherein when the inductor operates at the measuring frequency, the inductance of the inductor changes with a measuring position;

[0008] Magnetic needles are arranged to form a magnetic needle test space, which is composed of a test space and a magnetic needle distribution space;

[0009] The inductor is arranged in the test space, and an image of the magnetic needle distribution space is acquired to obtain at least one actual distribution image of the magnetic needles;

[0010] Perform extreme point identification on the actual distribution image of the magnetic needle to obtain the first extreme point and the second extreme point;

[0011] The direction of the magnetic field of the inductor is determined on the line connecting the first extreme point and the second extreme point, and the direction of the magnetic field of the inductor on the line connecting the first extreme point and the second extreme point is used as the polarity orientation of the inductor.

[0012] Preferably, determining the operating frequency of the inductor as the measurement frequency comprises the following steps:

[0013] Setting at least one test point on a circumference at a preset distance from the inductor;

[0014] Increasing the operating frequency of the inductor at a preset interval, and measuring the inductance of the inductor at a test point under the condition that the inductor operates according to the operating frequency to obtain at least one inductance;

[0015] Taking an average value of at least one inductance to obtain an inductance average value;

[0016] The variance formula is used to calculate the variance of the inductance. When the variance of the inductance is greater than the preset gap, the operating frequency of the inductor corresponding to the measurement condition of the inductance is used as the preprocessing measurement frequency.

[0017] One of the at least one preprocessing measurement frequencies is selected as the measurement frequency.

[0018] Preferably, measuring the inductance of the inductor at the test point comprises the following steps:

[0019] The inductance of the inductor is measured at the test point using an LCR meter to obtain the inductance at the test point.

[0020] Preferably, the setting of the magnetic needle to form the magnetic needle test space comprises the following steps:

[0021] Setting a test space, the test space is composed of a support frame and leads, the test space is a range where the distance from the center of the support frame is less than a preset radius, wherein the lead is wrapped with a magnetic field shielding material;

[0022] At least one magnetic needle is evenly arranged in the three-dimensional space outside the test space, the distance between adjacent magnetic needles is a preset value, and the space covered by at least one magnetic needle is the magnetic needle distribution space;

[0023] The magnetic needle distribution space and the test space constitute the magnetic needle test space.

[0024] Preferably, the step of placing the inductor in the test space comprises the following steps:

[0025] The center of the inductor is overlapped with the center of the support frame, and the leads are connected to the inductor.

[0026] Preferably, the step of acquiring an image of the magnetic needle distribution space to obtain at least one actual magnetic needle distribution image comprises the following steps:

[0027] Conduct three-dimensional coordinate modeling of the magnetic needle distribution space;

[0028] Before the inductor operates at the measurement frequency, the position of the magnetic needle in the magnetic needle distribution space is identified to obtain the first magnetic needle coordinate;

[0029] After the inductor operates at the measurement frequency, the position of the magnetic needle in the magnetic needle distribution space is identified to obtain the second magnetic needle coordinate;

[0030] When the first magnetic needle coordinates and the second magnetic needle coordinates of the same magnetic needle are different, the magnetic needle is used as a target magnetic needle; when the first magnetic needle coordinates and the second magnetic needle coordinates of the same magnetic needle are the same, the magnetic needle is used as a non-target magnetic needle;

[0031] Removing non-target magnetism in the magnetic needle distribution space;

[0032] Generate an identification circle outside the magnetic needle distribution space, the identification circle includes the magnetic needle distribution space, and the center of the identification circle coincides with the center of the support frame;

[0033] Uniformly selecting at least one sampling point on the surface of the identification circle, generating a tangent plane at the sampling point, wherein the tangent plane is tangent to the identification circle, and the tangent point is the sampling point;

[0034] The actual distribution image of the magnetic needle is acquired at the sampling point, and the image shooting angle at the sampling point is perpendicular to the tangent plane at the sampling point.

[0035] Preferably, the step of identifying the extreme points of the actual distribution image of the magnetic needles to obtain the first extreme point and the second extreme point comprises the following steps:

[0036] Conduct coordinate modeling on the actual distribution image of magnetic needles;

[0037] uniformly selecting at least one sampling point in the actual distribution image of the magnetic needles, and generating a marking circle at the sampling point;

[0038] Pre-acquire the pixel value of the pixel point corresponding to the magnetic needle in the actual distribution image of the magnetic needle as the target pixel value;

[0039] Count the pixel points with the same value as the target pixel inside the marked circle as the target pixel points, and count the total number of target pixel points inside the marked circle as the target number;

[0040] Count the total number of pixels inside the marked circle as the number of features;

[0041] The number of targets divided by the number of features is taken as the magnetic field density of the sampling point;

[0042] Pairing and fitting the coordinates of at least one sampling point with the magnetic field density to obtain a magnetic field density fitting function, wherein the coordinates of the sampling point are independent variables and the magnetic field density is an independent variable;

[0043] Obtain the value range of the horizontal coordinate and the value range of the vertical coordinate of the pixel point in the actual distribution image of the magnetic needle, and combine them to obtain the definition domain of the magnetic field density fitting function;

[0044] In the definition domain of the magnetic field density fitting function, at least one extreme value point of the magnetic field density fitting function is obtained by derivation, and the coordinates of the extreme value point are substituted into the magnetic field density fitting function to obtain an extreme value result;

[0045] Obtain the extreme value points corresponding to the two largest extreme value results, and use them as the first estimated point and the second estimated point of the actual distribution image of the magnetic needle respectively;

[0046] Substituting the first estimated point and the second estimated point into the magnetic field density fitting function respectively and superimposing the obtained results as the characteristic value of the actual distribution image of the magnetic needle;

[0047] The actual distribution image of magnetic needles with the largest eigenvalue is obtained as the target actual distribution image of magnetic needles, and the first estimated point and the second estimated point of the target actual distribution image of magnetic needles are respectively used as the first extreme point and the second extreme point.

[0048] Preferably, determining the magnetic field direction of the inductor on the line connecting the first extreme point and the second extreme point comprises the following steps:

[0049] The sampling points of the actual distribution image of the target magnetic needle are obtained as the target sampling points;

[0050] A target plane is made through the center of the inductor and is parallel to the tangent plane of the target sampling point. The position of the target magnetic needle actual distribution image is set in the target plane. The inductor in the target magnetic needle actual distribution image is satisfied to coincide with the actual inductor. The positions of the first extreme point and the second extreme point in the target plane are used to determine the polarity.

[0051] An induction coil is sheathed outside the inductor, and the direction of the coil is along the connection direction of the first extreme point and the second extreme point;

[0052] A closed loop is formed for the induction coil to obtain the direction of the induced current in the induction coil. Based on the right-hand rule and the direction of the induced current, the direction of the magnetic field on the line connecting the first extreme point and the second extreme point is determined and used as the magnetic field direction of the inductor.

[0053] A detection system for determining the polarity of an inductor, used to implement the above-mentioned detection method for determining the polarity of an inductor, comprising:

[0054] A frequency determination module, wherein the frequency determination module determines an operating frequency of the inductor as a measurement frequency, wherein when the inductor operates at the measurement frequency, the inductance of the inductor changes with a measurement position;

[0055] A test setting module, wherein the test setting module performs magnetic needle setting to form a magnetic needle test space, wherein the magnetic needle test space is composed of a test space and a magnetic needle distribution space;

[0056] An image acquisition module, wherein the image acquisition module sets the inductor in the test space, acquires an image of the magnetic needle distribution space, and obtains at least one actual distribution image of the magnetic needles;

[0057] A point recognition module, wherein the point recognition module recognizes extreme points of the actual distribution image of the magnetic needle to obtain a first extreme point and a second extreme point;

[0058] A polarity acquisition module determines the magnetic field direction of the inductor on the line connecting the first extreme point and the second extreme point, and uses the magnetic field direction of the inductor on the line connecting the first extreme point and the second extreme point as the polarity orientation of the inductor.

[0059] Compared with the prior art, the present invention has the following beneficial effects:

[0060] By setting up a test setting module, an image acquisition module, a point recognition module and a polarity acquisition module, when the coil of the RF inductor is wrapped by a shell and the coil is unevenly wound, the magnetic field outside the RF inductor can be modeled through the coordination of the magnetic needle setting and external measurement, and the polarity of the RF inductor can be determined based on the modeling result. Since multiple points are used for fitting, the fitting accuracy meets the requirements. Therefore, the error between the result of polarity determination and the actual situation is small enough, and thus can meet the subsequent use of the RF inductor. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 is a schematic flow chart of a detection method for determining the polarity of an inductor according to the present invention;

[0062] Figure 2 A schematic diagram of a process for determining the operating frequency of an inductor as a measurement frequency according to the present invention;

[0063] Figure 3 A schematic diagram of the process of setting a magnetic needle and forming a magnetic needle test space according to the present invention;

[0064] Figure 4 A schematic diagram of a process of acquiring an image of a magnetic needle distribution space to obtain at least one actual magnetic needle distribution image according to the present invention;

[0065] Figure 5 A schematic diagram of the process of identifying the extreme points of the actual distribution image of the magnetic needle to obtain the first extreme point and the second extreme point of the present invention;

[0066] Figure 6It is a schematic diagram of a flow chart of determining the magnetic field direction of an inductor on a line connecting a first extreme point and a second extreme point of the present invention. DETAILED DESCRIPTION

[0067] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.

[0068] Reference Figure 1 As shown, a detection method for determining the polarity of an inductor includes:

[0069] determining an operating frequency of the inductor as a measuring frequency, wherein when the inductor operates at the measuring frequency, the inductance of the inductor changes with a measuring position;

[0070] Magnetic needles are arranged to form a magnetic needle test space, which is composed of a test space and a magnetic needle distribution space;

[0071] The inductor is arranged in the test space, and an image of the magnetic needle distribution space is acquired to obtain at least one actual distribution image of the magnetic needles;

[0072] Perform extreme point identification on the actual distribution image of the magnetic needle to obtain the first extreme point and the second extreme point;

[0073] The direction of the magnetic field of the inductor is determined on the line connecting the first extreme point and the second extreme point, and the direction of the magnetic field of the inductor on the line connecting the first extreme point and the second extreme point is used as the polarity orientation of the inductor.

[0074] Reference Figure 2 As shown, determining the operating frequency of the inductor as the measurement frequency includes the following steps:

[0075] Setting at least one test point on a circumference at a preset distance from the inductor;

[0076] Increasing the operating frequency of the inductor at a preset interval, and measuring the inductance of the inductor at a test point under the condition that the inductor operates according to the operating frequency to obtain at least one inductance;

[0077] Taking an average value of at least one inductance to obtain an inductance average value;

[0078] The variance formula is used to calculate the variance of the inductance. When the variance of the inductance is greater than the preset gap, the operating frequency of the inductor corresponding to the measurement condition of the inductance is used as the preprocessing measurement frequency.

[0079] One of the at least one preprocessing measurement frequencies is selected as the measurement frequency.

[0080] The purpose of obtaining the measurement frequency is that when the frequency is low, the polarity is usually not obvious. Therefore, the error generated during testing is relatively large. Therefore, when using the measurement frequency, the polarity is more obvious. When measuring at different positions, there will be a large difference in the inductance, which makes it easier to determine the polarity.

[0081] Measuring the inductance of an inductor at a test point includes the following steps:

[0082] The inductance of the inductor is measured at the test point using an LCR meter to obtain the inductance at the test point.

[0083] Reference Figure 3 As shown, setting the magnetic needle to form a magnetic needle test space includes the following steps:

[0084] A test space is set up. The test space is composed of a support frame and leads. The test space is a range where the distance from the center of the support frame is less than a preset radius. The lead is wrapped with a magnetic field shielding material. When current passes through the lead, a magnetic field is generated, which interferes with the magnetic field of the inductor. Therefore, the magnetic field shielding material is used to avoid such interference.

[0085] At least one magnetic needle is evenly arranged in the three-dimensional space outside the test space, the distance between adjacent magnetic needles is a preset value, and the space covered by at least one magnetic needle is the magnetic needle distribution space;

[0086] The magnetic needle distribution space and the test space constitute the magnetic needle test space.

[0087] The setting of the magnetic needle is mainly to visualize the magnetic field of the inductor, because the polarity of the inductor is synchronized with the magnetic field of the inductor. When its magnetic field is symmetrically distributed, the inductor has no polarity. When its magnetic field is unevenly distributed and the degree of unevenness is large, the inductor has polarity. Therefore, the polarity of the inductor is analyzed by visualizing the magnetic field.

[0088] Setting up the inductor in the test space involves the following steps:

[0089] The center of the inductor is overlapped with the center of the support frame, and the leads are connected to the inductor.

[0090] Reference Figure 4 As shown, acquiring an image of the magnetic needle distribution space to obtain at least one actual magnetic needle distribution image includes the following steps:

[0091] Conduct three-dimensional coordinate modeling of the magnetic needle distribution space;

[0092] Before the inductor operates at the measurement frequency, the position of the magnetic needle in the magnetic needle distribution space is identified to obtain the first magnetic needle coordinate;

[0093] After the inductor operates at the measurement frequency, the position of the magnetic needle in the magnetic needle distribution space is identified to obtain the second magnetic needle coordinate;

[0094] When the first magnetic needle coordinates and the second magnetic needle coordinates of the same magnetic needle are different, the magnetic needle is used as a target magnetic needle; when the first magnetic needle coordinates and the second magnetic needle coordinates of the same magnetic needle are the same, the magnetic needle is used as a non-target magnetic needle;

[0095] Removing non-target magnetism in the magnetic needle distribution space;

[0096] Generate an identification circle outside the magnetic needle distribution space, the identification circle includes the magnetic needle distribution space, and the center of the identification circle coincides with the center of the support frame;

[0097] Uniformly selecting at least one sampling point on the surface of the identification circle, generating a tangent plane at the sampling point, wherein the tangent plane is tangent to the identification circle, and the tangent point is the sampling point;

[0098] The actual distribution image of the magnetic needle is acquired at the sampling point, and the image shooting angle at the sampling point is perpendicular to the tangent plane at the sampling point.

[0099] Since the magnetic field distribution of the inductor is not uniform, when you want to obtain the points with the strongest magnetic field intensity on both sides, you need to analyze at various angles to get the points with the strongest magnetic field intensity. This is because the point with the strongest magnetic field in the actual distribution image of the magnetic needle at a certain viewing angle may have a stronger magnetic field than the point in the actual distribution image of the magnetic needle at other viewing angles. Therefore, it is necessary to identify the magnetic field in all cases. In this solution, image acquisition is performed at at least one sampling point, so that all situations can be approximated, and the error between the obtained result and the actual situation is within the allowable range.

[0100] Reference Figure 5 As shown, the extreme point identification of the actual distribution image of the magnetic needle to obtain the first extreme point and the second extreme point includes the following steps:

[0101] Conduct coordinate modeling on the actual distribution image of magnetic needles;

[0102] uniformly selecting at least one sampling point in the actual distribution image of the magnetic needles, and generating a marking circle at the sampling point;

[0103] Pre-acquire the pixel value of the pixel point corresponding to the magnetic needle in the actual distribution image of the magnetic needle as the target pixel value;

[0104] Count the pixel points with the same value as the target pixel inside the marked circle as the target pixel points, and count the total number of target pixel points inside the marked circle as the target number;

[0105] Count the total number of pixels inside the marked circle as the number of features;

[0106] The number of targets divided by the number of features is taken as the magnetic field density of the sampling point;

[0107] Pairing and fitting the coordinates of at least one sampling point with the magnetic field density to obtain a magnetic field density fitting function, wherein the coordinates of the sampling point are independent variables and the magnetic field density is an independent variable;

[0108] Obtain the value range of the horizontal coordinate and the value range of the vertical coordinate of the pixel point in the actual distribution image of the magnetic needle, and combine them to obtain the definition domain of the magnetic field density fitting function;

[0109] In the definition domain of the magnetic field density fitting function, at least one extreme value point of the magnetic field density fitting function is obtained by derivation, and the coordinates of the extreme value point are substituted into the magnetic field density fitting function to obtain an extreme value result;

[0110] Obtain the extreme value points corresponding to the two largest extreme value results, and use them as the first estimated point and the second estimated point of the actual distribution image of the magnetic needle respectively;

[0111] Substituting the first estimated point and the second estimated point into the magnetic field density fitting function respectively and superimposing the obtained results as the characteristic value of the actual distribution image of the magnetic needle;

[0112] The actual distribution image of magnetic needles with the largest eigenvalue is obtained as the target actual distribution image of magnetic needles, and the first estimated point and the second estimated point of the target actual distribution image of magnetic needles are respectively used as the first extreme point and the second extreme point.

[0113] In order to obtain the first extreme point and the second extreme point, the magnetic field strength of the points in the actual distribution image of the magnetic needles is calculated. By setting sampling points in the actual distribution image of the magnetic needles, the density of the magnetic needles near the sampling points is used to estimate the magnetic field at the sampling points, and then the magnetic field density fitting function is obtained according to the sampling points. When the distance between the sampling points is small enough, the error between the result of the magnetic field density fitting function and the actual situation is within the allowable range.

[0114] Reference Figure 6 As shown, on the line connecting the first extreme point and the second extreme point, determining the magnetic field direction of the inductor includes the following steps:

[0115] The sampling points of the actual distribution image of the target magnetic needle are obtained as the target sampling points;

[0116] A target plane is made through the center of the inductor and is parallel to the tangent plane of the target sampling point. The position of the target magnetic needle actual distribution image is set in the target plane. The inductor in the target magnetic needle actual distribution image is satisfied to coincide with the actual inductor. The positions of the first extreme point and the second extreme point in the target plane are used to determine the polarity.

[0117] An induction coil is sheathed outside the inductor, and the direction of the coil is along the connection direction of the first extreme point and the second extreme point;

[0118] A closed loop is formed for the induction coil to obtain the direction of the induced current in the induction coil. Based on the right-hand rule and the direction of the induced current, the direction of the magnetic field on the line connecting the first extreme point and the second extreme point is determined and used as the magnetic field direction of the inductor.

[0119] The line connecting the first extreme point and the second extreme point is the polarity direction of the inductor, but the line connecting the first extreme point and the second extreme point has two directions. Therefore, it is necessary to further determine the direction of the magnetic field between the first extreme point and the second extreme point. The polarity direction is consistent with the direction of the magnetic field. Since the magnetic field between the first extreme point and the second extreme point can generate an induced current, the direction of the magnetic field between the first extreme point and the second extreme point can be determined according to the right-hand rule. Although the line connecting the first extreme point and the second extreme point can determine the direction, there are countless straight lines parallel to the direction. Therefore, before determining the actual positions of the first extreme point and the second extreme point, the polarity cannot be finally determined. Therefore, a target plane is made, and the target plane is used to determine the actual positions of the first extreme point and the second extreme point, and then the polarity is determined.

[0120] A detection system for determining the polarity of an inductor, used to implement the above-mentioned detection method for determining the polarity of an inductor, comprising:

[0121] A frequency determination module, wherein the frequency determination module determines an operating frequency of the inductor as a measurement frequency, wherein when the inductor operates at the measurement frequency, the inductance of the inductor changes with a measurement position;

[0122] A test setting module, wherein the test setting module performs magnetic needle setting to form a magnetic needle test space, wherein the magnetic needle test space is composed of a test space and a magnetic needle distribution space;

[0123] An image acquisition module, wherein the image acquisition module sets the inductor in the test space, acquires an image of the magnetic needle distribution space, and obtains at least one actual distribution image of the magnetic needles;

[0124] A point recognition module, wherein the point recognition module recognizes extreme points of the actual distribution image of the magnetic needle to obtain a first extreme point and a second extreme point;

[0125] A polarity acquisition module determines the magnetic field direction of the inductor on the line connecting the first extreme point and the second extreme point, and uses the magnetic field direction of the inductor on the line connecting the first extreme point and the second extreme point as the polarity orientation of the inductor.

[0126] Furthermore, the present solution also proposes a storage medium on which a computer-readable program is stored. When the computer-readable program is called, the above-mentioned detection method for determining the polarity of an inductor is executed.

[0127] It is understandable that the storage medium may be a magnetic medium, such as a floppy disk, a hard disk, or a magnetic tape; an optical medium, such as a DVD; or a semiconductor medium, such as a solid state drive (SSD).

[0128] In summary, the advantages of the present invention are: by setting a test setting module, an image acquisition module, a point recognition module and a polarity acquisition module, when the coil of the RF inductor is wrapped by a shell and the coil is unevenly wound, the magnetic field outside the RF inductor can be modeled through the cooperation of the magnetic needle setting and external measurement, and the polarity of the RF inductor can be determined based on the modeling result. Since multiple points are used for fitting, the fitting accuracy meets the requirements. Therefore, the error between the result of polarity determination and the actual situation is small enough, so it can meet the subsequent use of the RF inductor.

[0129] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A detection method for determining the polarity of an inductor, characterized in that: include: determining an operating frequency of the inductor as a measuring frequency, wherein when the inductor operates at the measuring frequency, the inductance of the inductor changes with a measuring position; Magnetic needles are arranged to form a magnetic needle test space, which is composed of a test space and a magnetic needle distribution space; The inductor is arranged in the test space, and an image of the magnetic needle distribution space is acquired to obtain at least one actual distribution image of the magnetic needles; Perform extreme point identification on the actual distribution image of the magnetic needle to obtain the first extreme point and the second extreme point; The direction of the magnetic field of the inductor is determined on the line connecting the first extreme point and the second extreme point, and the direction of the magnetic field of the inductor on the line connecting the first extreme point and the second extreme point is used as the polarity orientation of the inductor.

2. A detection method for determining the polarity of an inductor according to claim 1, characterized in that: Determining the operating frequency of the inductor as the measurement frequency comprises the following steps: Setting at least one test point on a circumference at a preset distance from the inductor; Increasing the operating frequency of the inductor at a preset interval, and measuring the inductance of the inductor at a test point under the condition that the inductor operates according to the operating frequency to obtain at least one inductance; Taking an average value of at least one inductance to obtain an inductance average value; The variance formula is used to calculate the variance of the inductance. When the variance of the inductance is greater than the preset gap, the operating frequency of the inductor corresponding to the measurement condition of the inductance is used as the preprocessing measurement frequency. One of the at least one preprocessing measurement frequencies is selected as the measurement frequency.

3. A detection method for determining the polarity of an inductor according to claim 2, characterized in that: Measuring the inductance of the inductor at the test point comprises the following steps: The inductance of the inductor is measured at the test point using an LCR meter to obtain the inductance at the test point.

4. A detection method for determining the polarity of an inductor according to claim 3, characterized in that: The magnetic needle arrangement to form a magnetic needle test space comprises the following steps: Setting a test space, the test space is composed of a support frame and leads, the test space is a range where the distance from the center of the support frame is less than a preset radius, wherein the lead is wrapped with a magnetic field shielding material; At least one magnetic needle is evenly arranged in the three-dimensional space outside the test space, the distance between adjacent magnetic needles is a preset value, and the space covered by at least one magnetic needle is the magnetic needle distribution space; The magnetic needle distribution space and the test space constitute the magnetic needle test space.

5. A detection method for determining the polarity of an inductor according to claim 4, characterized in that: The step of placing the inductor in the test space comprises the following steps: The center of the inductor is overlapped with the center of the support frame, and the leads are connected to the inductor.

6. A detection method for determining the polarity of an inductor according to claim 5, characterized in that: The method of acquiring an image of the magnetic needle distribution space to obtain at least one actual magnetic needle distribution image comprises the following steps: Conduct three-dimensional coordinate modeling of the magnetic needle distribution space; Before the inductor operates at the measurement frequency, the position of the magnetic needle in the magnetic needle distribution space is identified to obtain the first magnetic needle coordinate; After the inductor operates at the measurement frequency, the position of the magnetic needle in the magnetic needle distribution space is identified to obtain the second magnetic needle coordinate; When the first magnetic needle coordinates and the second magnetic needle coordinates of the same magnetic needle are different, the magnetic needle is used as a target magnetic needle; when the first magnetic needle coordinates and the second magnetic needle coordinates of the same magnetic needle are the same, the magnetic needle is used as a non-target magnetic needle; Removing non-target magnetism in the magnetic needle distribution space; Generate an identification circle outside the magnetic needle distribution space, the identification circle includes the magnetic needle distribution space, and the center of the identification circle coincides with the center of the support frame; Uniformly selecting at least one sampling point on the surface of the identification circle, generating a tangent plane at the sampling point, wherein the tangent plane is tangent to the identification circle, and the tangent point is the sampling point; The actual distribution image of the magnetic needle is acquired at the sampling point, and the image shooting angle at the sampling point is perpendicular to the tangent plane at the sampling point.

7. A detection method for determining the polarity of an inductor according to claim 6, characterized in that: The step of identifying the extreme points of the actual distribution image of the magnetic needles to obtain the first extreme point and the second extreme point comprises the following steps: Conduct coordinate modeling on the actual distribution image of magnetic needles; uniformly selecting at least one sampling point in the actual distribution image of the magnetic needles, and generating a marking circle at the sampling point; Pre-acquire the pixel value of the pixel point corresponding to the magnetic needle in the actual distribution image of the magnetic needle as the target pixel value; Count the pixel points with the same value as the target pixel inside the marked circle as the target pixel points, and count the total number of target pixel points inside the marked circle as the target number; Count the total number of pixels inside the marked circle as the number of features; The number of targets divided by the number of features is taken as the magnetic field density of the sampling point; Pairing and fitting the coordinates of at least one sampling point with the magnetic field density to obtain a magnetic field density fitting function, wherein the coordinates of the sampling point are independent variables and the magnetic field density is an independent variable; Obtain the value range of the horizontal coordinate and the value range of the vertical coordinate of the pixel point in the actual distribution image of the magnetic needle, and combine them to obtain the definition domain of the magnetic field density fitting function; In the definition domain of the magnetic field density fitting function, at least one extreme value point of the magnetic field density fitting function is obtained by derivation, and the coordinates of the extreme value point are substituted into the magnetic field density fitting function to obtain an extreme value result; Obtain the extreme value points corresponding to the two largest extreme value results, and use them as the first estimated point and the second estimated point of the actual distribution image of the magnetic needle respectively; Substituting the first estimated point and the second estimated point into the magnetic field density fitting function respectively and superimposing the obtained results as the characteristic value of the actual distribution image of the magnetic needle; The actual distribution image of magnetic needles with the largest eigenvalue is obtained as the target actual distribution image of magnetic needles, and the first estimated point and the second estimated point of the target actual distribution image of magnetic needles are respectively used as the first extreme point and the second extreme point.

8. A detection method for determining the polarity of an inductor according to claim 7, characterized in that: Determining the magnetic field direction of the inductor on the line connecting the first extreme point and the second extreme point comprises the following steps: The sampling points of the actual distribution image of the target magnetic needle are obtained as the target sampling points; A target plane is made through the center of the inductor and is parallel to the tangent plane of the target sampling point. The position of the target magnetic needle actual distribution image is set in the target plane. The inductor in the target magnetic needle actual distribution image is satisfied to coincide with the actual inductor. The positions of the first extreme point and the second extreme point in the target plane are used to determine the polarity. An induction coil is sheathed outside the inductor, and the direction of the coil is along the connection direction of the first extreme point and the second extreme point; A closed loop is formed for the induction coil to obtain the direction of the induced current in the induction coil. Based on the right-hand rule and the direction of the induced current, the direction of the magnetic field on the line connecting the first extreme point and the second extreme point is determined and used as the magnetic field direction of the inductor.

9. A detection system for determining the polarity of an inductor, used to implement the detection method for determining the polarity of an inductor according to any one of claims 1 to 8, characterized in that: include: A frequency determination module, wherein the frequency determination module determines an operating frequency of the inductor as a measurement frequency, wherein when the inductor operates at the measurement frequency, the inductance of the inductor changes with a measurement position; A test setting module, wherein the test setting module performs magnetic needle setting to form a magnetic needle test space, wherein the magnetic needle test space is composed of a test space and a magnetic needle distribution space; An image acquisition module, wherein the image acquisition module sets the inductor in the test space, acquires an image of the magnetic needle distribution space, and obtains at least one actual distribution image of the magnetic needles; A point recognition module, wherein the point recognition module recognizes extreme points of the actual distribution image of the magnetic needle to obtain a first extreme point and a second extreme point; A polarity acquisition module determines the magnetic field direction of the inductor on the line connecting the first extreme point and the second extreme point, and uses the magnetic field direction of the inductor on the line connecting the first extreme point and the second extreme point as the polarity orientation of the inductor.

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