Magnetic induction displacement encoder, displacement detection mechanism and displacement detection method

Abstract

The present invention relates to the technical field of displacement measurement, and in particular to a magnetic induction displacement encoder, a displacement detection mechanism, and a displacement detection method. The magnetic induction displacement encoder comprises: a toothed mechanism, comprising a substrate, main tooth portions, and vernier tooth portions; a magnetic induction read head, comprising a detection unit, wherein the detection unit is arranged on the side of induction teeth facing away from the substrate, and a detection gap is formed between the detection unit and the induction teeth; and a magnetic mechanism, arranged on the side of the detection unit facing away from the induction teeth, and fixed to the magnetic induction read head so as to generate a magnetic field. In the present invention, a corresponding electrical signal is generated by means of changes in the relative positions of induction teeth arranged on the main tooth portions and the vernier tooth portions, so that detection of the position of a measured object relative to the toothed mechanism is implemented, and the structure is simple and reliable; and by means of an independently provided magnetic mechanism, a strong magnetic field can be formed, thereby reducing interference from external magnetic fields.

Description

Magnetic induction displacement encoder, displacement detection mechanism and displacement detection method TECHNICAL FIELD

[0001] The present application relates to the technical field of displacement measurement, in particular to a magnetic induction displacement encoder, a displacement detection mechanism and a displacement detection method. BACKGROUND

[0002] The existing encoder is a sensor for detecting angle, position, speed and acceleration, which is a device for converting mechanical rotary angular displacement or linear displacement into electrical signal form for communication, transmission and storage, and is a precise measuring device closely combining mechanics and electronics, and is widely used in many fields such as motor, automobile, wind power and robot.

[0003] The encoder using a tunnel magnetoresistance element is a magnetic induction encoder. The traditional magnetic induction encoder is divided into relative magnetic induction encoders and absolute magnetic induction encoders according to the measurement function. The relative magnetic induction encoder can also be called an incremental value magnetic induction encoder.

[0004] Among them, the magnetic scale is a kind of linear displacement measurement magnetic induction encoder commonly used in industrial production automation machinery industry. The magnetic scale is composed of a magnetic ruler and a magnetic head. The N (north) and S (south) poles on the magnetic ruler form an electromagnetic field with different orientations. The magnetic head senses the change of the electromagnetic field during the whole stroke along the magnetic ruler and converts the change of the electromagnetic field into an analog input data signal or a digital output data signal.

[0005] Nowadays, the active suspension of a vehicle is equipped with an active shock absorber, which can adjust the height of the vehicle body according to the working condition. The height adjustment of the vehicle body is often realized by a linear motor. During the adjustment process, the real-time relative displacement between the stator and the rotor of the motor needs to be obtained by an encoder. The displacement between the stator and the rotor is caused by the change of the magnetic force generated by the magnetic element. The encoder arranged between the stator and the rotor is easily disturbed by the magnetic field, resulting in inaccurate measurement results.

[0006] In addition, since the magnetic scale can generate a weak magnetic field, it is easy to cause the measurement accuracy of the magnetic head to decrease or even fail when working in an external environment with magnetic field interference.

[0007] In addition, although the application patent application with the publication number CN117232554A discloses a magnetic induction linear displacement absolute value encoder and a data processing method and equipment thereof, the magnetic induction chip of the encoder has a small magnetic field density amplitude of the detected position in the measurement process, is easily disturbed by the external magnetic field, and further generates a large measurement error. In order to avoid the disturbance of the external magnetic field and reduce the measurement error of the magnetic induction chip, the existing encoder needs to use a larger magnetic force mechanism to generate a stronger magnetic field, but at the same time increases the volume of the encoder, and the application scene is less. SUMMARY

[0008] The purpose of the present application is to provide a magnetic induction displacement encoder capable of accurately calculating the position of the measured object, avoiding external magnetic field interference, and improving detection accuracy, as well as a displacement detection mechanism and a displacement detection method comprising the magnetic induction displacement encoder.

[0009] In order to achieve the above-mentioned purpose, the present application provides a magnetic induction displacement encoder, comprising:

[0010] A tooth mechanism, the tooth mechanism comprises a base body, a main tooth part, and a vernier tooth part for affecting a magnetic field in cooperation with the main tooth part, the main tooth part and the vernier tooth part are both arranged on the same side surface of the base body, the main tooth part and the vernier tooth part both comprise a plurality of induction teeth which are spaced and uniformly arranged along a first direction, the interval between two adjacent induction teeth of the main tooth part is J millimeters, the interval between two adjacent induction teeth of the vernier tooth part is K millimeters, and K>J;

[0011] A magnetic induction read head, the magnetic induction read head comprises a detection unit, the detection unit is arranged on the side of the induction tooth away from the base body and forms a detection gap with the induction tooth;

[0012] A magnetic force mechanism, the magnetic force mechanism is arranged on the side of the detection unit away from the induction tooth and is fixed to the magnetic induction read head for generating a magnetic field;

[0013] Wherein, the magnetic induction read head can move along the first direction with the measured object, the length of the detection gap has a corresponding relationship with the tooth height of the induction tooth, the corresponding relationship can make the detection unit generate an electric signal for obtaining the displacement of the measured object according to the magnetic induction lines of the magnetic field generated by the tooth mechanism cutting the magnetic field generated by the magnetic force mechanism, and the length of the detection gap is the vertical distance between the detection unit and the induction tooth.

[0014] In some embodiments of the present application, the magnetic force mechanism is a magnetic steel body, and the magnetic steel body has a magnetic field compensation part for uniform magnetic field distribution.

[0015] In some embodiments of the present application, the magnetic field compensation part is a groove and a protrusion formed by recessing one side of the magnetic steel body towards or away from the toothed mechanism, and the protrusion is arranged on the outer periphery of the groove.

[0016] In some embodiments of the present application, two side edges of the groove are respectively formed with the protrusions along the first direction or the second direction, and the first direction is perpendicular to the second direction.

[0017] In some embodiments of the present application, the protrusions are arranged circumferentially along the edge of the groove.

[0018] In some embodiments of the present application, the protrusion is arranged to extend upwards and outwards from the bottom surface of the groove near one side of the groove.

[0019] In some embodiments of the present application, the groove has a groove depth of h millimeters, a groove width of d millimeters, and a distance between the magnetic steel body and the induction tooth of s millimeters, and the following relationship is satisfied:

[0020] wherein h>0, d>0, and s>0.

[0021] In some embodiments of the present application, the bottom surface of the groove is smoothly connected to the peripheral plane.

[0022] In some embodiments of the present application, the main tooth part and the vernier tooth part have equal lengths in the first direction.

[0023] In some embodiments of the present application, the number of induction teeth of the main tooth part is N, and the number of induction teeth of the vernier tooth part is M.

[0024] When N-M=1, the magnetic induction displacement encoder is an absolute magnetic induction displacement encoder.

[0025] When N-M≥2, the magnetic induction displacement encoder is a relative magnetic induction displacement encoder.

[0026] In some embodiments of the present application, the base body, the main tooth part, and the vernier tooth part are integrally formed.

[0027] In some embodiments of the present application, the induction tooth is an involute tooth.

[0028] In some embodiments of the present application, the toothed mechanism is a straight rack.

[0029] In some embodiments of the present application, the toothed mechanism is a circular gear or an end face toothed disc.

[0030] In some embodiments of the present application, the tooth height of the induction tooth is H millimeters, the length of the detection gap is C millimeters, and 0.8≤H / C≤5, wherein 0.3≤C≤1.2.

[0031] In some embodiments of the present application, the thickness of the base is T millimeters, and 0.5≤T≤5.

[0032] In some embodiments of the present application, the magnetic induction reading head further comprises a housing, the housing is formed with a receiving cavity, the detection unit and the magnetic force mechanism are both arranged in the receiving cavity, and the magnetic force mechanism is arranged on the side of the detection unit away from the toothed mechanism.

[0033] In some embodiments of the present application, the housing is made of a non-magnetic conductive material.

[0034] In some embodiments of the present application, the side of the housing facing the toothed mechanism is provided with a detection window in communication with the receiving cavity, and the detection unit is arranged opposite to the toothed mechanism through the detection window.

[0035] In some embodiments of the present application, the side of the housing away from the toothed mechanism is provided with an opening in communication with the receiving cavity, and the opening is provided with a cover.

[0036] In some embodiments of the present application, the cover is made of a magnetic conductive material.

[0037] In some embodiments of the present application, a magnetic conductive sheet is arranged between the magnetic force mechanism and the detection unit.

[0038] In some embodiments of the present application, the two sides of the magnetic conductive sheet are respectively attached to the detection unit and the magnetic force mechanism.

[0039] In some embodiments of the present application, the thickness of the magnetic conductive sheet is A millimeters, and 0.1≤A≤1.

[0040] In some embodiments of the present application, the projection of the magnetic conductive sheet along the direction in which the toothed mechanism approaches the magnetic force mechanism coincides with the side of the magnetic force mechanism facing the toothed mechanism.

[0041] In some embodiments of the present application, a magnetic shielding mechanism made of a high magnetic permeability material is further included, at least one side of the toothed mechanism is provided with the magnetic shielding mechanism along the first direction, and the magnetic shielding mechanism is arranged extending along the first direction.

[0042] In some embodiments of the present application, both sides of the toothed mechanism are provided with the magnetic shielding mechanism along the first direction.

[0043] In some embodiments of the present application, the magnetic field strength generated by the magnetic force mechanism is B millitesla, and 10≤B≤500.

[0044] Based on the above invention purpose, the application further provides a displacement detection mechanism comprising the above magnetic induction displacement encoder.

[0045] Based on the above invention purpose, the application further provides a displacement detection method based on the above displacement detection mechanism, comprising the following steps:

[0046] S1: cutting the induced magnetic force lines according to the tooth profile mechanism, generating a corresponding number of first sine and cosine quadrature differential signals, and correcting and compensating the direct current bias error, amplitude error and quadrature phase error of the first sine and cosine quadrature differential signals in real time to obtain second sine and cosine quadrature differential signals;

[0047] S2: generating the relative position values of the main tooth part and the cursor tooth part with respect to the power-on time according to the second sine and cosine quadrature differential signals, respectively;

[0048] S3: analyzing the phase and phase difference of the second sine and cosine quadrature differential signals according to the cursor solving principle, and calculating the current displacement position of the measured object.

[0049] The embodiments of the application have the following technical effects:

[0050] The independent magnetic force mechanism is provided, a strong magnetic field is generated by the magnetic force mechanism, when the magnetic induction reader moves along the first direction of the main tooth part and the cursor tooth part, the magnetic field generated by the magnetic force mechanism is affected, and since the distance J between the adjacent two sensing teeth of the main tooth part and the distance K between the adjacent two sensing teeth of the cursor tooth part are different, when the main tooth part and the cursor tooth part are relatively arranged, the sensing teeth of the main tooth part and the sensing teeth of the cursor tooth part gradually offset in the first direction, so that the detection unit can detect the different magnetic field strengths generated by the magnetic force mechanism at different positions relative to the main tooth part and the cursor tooth part, and generate corresponding electrical signals, so as to calculate the position of the magnetic induction reader on the tooth profile mechanism;

[0051] And since the independent magnetic force mechanism can be provided and a strong magnetic field can be generated, when the detection unit detects the change of the magnetic field of the magnetic force mechanism relative to the tooth profile mechanism during movement, the interference of the external magnetic field can be reduced, thereby improving the reliability of the detection of the detection unit, and further more accurately calculating the position of the measured object connected to the magnetic induction reader relative to the tooth profile mechanism;

[0052] Finally, by making the length of the detection gap correspond to the tooth height of the sensing teeth, the magnetic field density amplitude of the detection position of the detection unit can be relatively large, thereby improving the accuracy of the magnetic field change when the detection unit obtains the magnetic field lines of the magnetic field generated by the tooth-shaped structure cutting magnetic force mechanism, reducing the possibility of external magnetic field interference and measurement error; and can reduce the loss of the magnetic field strength generated by the magnetic force mechanism, reduce the volume of the used magnetic force mechanism, and be suitable for more scenarios where the volume requirement of the encoder is higher. BRIEF DESCRIPTION OF DRAWINGS

[0053] The application is described in more detail below with the help of the drawings. Without being dependent on a specific combination of technical features, the technical features shown in the drawings and / or described below are generally technical features of the application and improve the application accordingly.

[0054] It should be noted that the same reference numerals in different drawings represent the same or approximately the same components.

[0055] FIG. 1 is a structural schematic diagram of a magnetic induction displacement encoder according to a preferred embodiment of the application;

[0056] FIG. 2 is a top view of a magnetic induction displacement encoder according to a preferred embodiment of the application;

[0057] FIG. 3 is a structural schematic diagram of a magnetic induction read head according to a preferred embodiment of the application;

[0058] FIG. 4 is an exploded schematic diagram of a magnetic induction read head, a magnetic force mechanism, and a magnetic conducting sheet according to a preferred embodiment of the application;

[0059] FIG. 5 is a sectional view of I-I in FIG. 2;

[0060] FIG. 6 is an enlarged schematic diagram of II in FIG. 5;

[0061] FIG. 7 is a sectional view of a tooth-shaped mechanism according to a preferred embodiment of the application;

[0062] FIG. 8 is a structural schematic diagram of a housing according to a preferred embodiment of the application;

[0063] FIG. 9 is a structural schematic diagram of a cover according to a preferred embodiment of the application;

[0064] FIG. 10 is a structural schematic diagram of a magnetic force mechanism according to a preferred embodiment of the application;

[0065] FIG. 11 is a right view of a magnetic force mechanism according to a preferred embodiment of the application;

[0066] FIG. 12 is a top view of a magnetic force mechanism according to a preferred embodiment of the application;

[0067] FIG. 13 is a strength curve of a magnetic field generated by a magnetic steel body in the Y direction according to the prior art;

[0068] Fig. 14 is a curve of the strength of the magnetic field generated by the magnetic steel body in the Y direction according to the preferred embodiment of the present application.

[0069] BRIEF DESCRIPTION OF DRAWINGS 1, tooth mechanism, 11, base body, 12, main tooth part, 13, vernier tooth part, 14, sensing tooth 2, magnetic sensing read head, 21, detection unit, 211, magnetic sensing chip, 212, interface circuit, 22, housing, 221, accommodating cavity, 222, detection window, 223, hook groove, 224, positioning groove, 225, wire hole, 23, cover body, 231, clamping hook; 3, magnetic force mechanism, 31, magnetic steel body, 32, groove, 33, protrusion; 4, magnetic conducting sheet; 5, magnetic shielding mechanism. DETAILED DESCRIPTION

[0070] The specific embodiments of the present application will be further described in conjunction with the drawings and examples. The following examples are used to illustrate the application, but are not used to limit the scope of the application.

[0071] First of all, it should be noted that the top, bottom, upward, downward, and other orientations mentioned in this document are defined with respect to the directions in the various drawings, they are relative concepts, and therefore can change according to different positions and different use states, so these or other orientations should not be used to understand as restrictive language. At the same time, the term "comprising" does not exclude other elements or steps, and "one" or "a" does not exclude plural.

[0072] In addition, it should also be noted that for any single technical feature described or implied in the embodiments herein, or any single technical feature shown or implied in the drawings, combinations between these technical features (or their equivalents) can still be continued, thereby obtaining other embodiments of the present application which are not directly mentioned in this document.

[0073] In addition, it should also be understood that the terms "first", "second" and the like are used herein to describe various information, but these information should not be limited to these terms, these terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the "first" information can also be referred to as "second" information, and similarly, the "second" information can also be referred to as "first" information.

[0074] In the embodiment, a displacement detection mechanism is provided, wherein the displacement detection mechanism comprises a magnetic induction displacement encoder. Specifically, referring to FIG. 1 and FIG. 2, the magnetic induction displacement encoder in the embodiment comprises a toothed mechanism 1, a magnetic induction read head 2 and a magnetic force mechanism 3. The displacement detection mechanism in the embodiment is used for an active suspension of a vehicle, and the toothed mechanism 1 can be fixedly installed with a stator of a linear motor in the active suspension, the magnetic induction read head 2 can be fixedly installed with a rotor of the linear motor, and when the stator and the rotor of the linear motor are relatively displaced, the displacement detection mechanism can be used to detect the relative displacement and the relative position between the rotor and the stator of the linear motor.

[0075] Further, the toothed mechanism 1 comprises a base body 11, a main tooth portion 12 and a vernier tooth portion 13, the main tooth portion 12 and the vernier tooth portion 13 are arranged on the same side of the base body 11, and the main tooth portion 12 and the vernier tooth portion 13 each comprise a plurality of induction teeth 14 which are spaced apart and uniformly arranged along a first direction, the interval between two adjacent induction teeth 14 of the main tooth portion 12 is J millimeters, the interval between two adjacent induction teeth 14 of the vernier tooth portion 13 is K millimeters, and K > J.

[0076] The magnetic induction read head 2 comprises a detection unit 21 which is arranged on the side of the induction teeth 14 away from the base body 11 and forms a detection gap with the induction teeth 14, and the magnetic force mechanism 3 is arranged on the side of the detection unit 21 away from the induction teeth 14 and is fixed to the magnetic induction read head 2 to generate a magnetic field.

[0077] The magnetic induction read head 2 can move along the first direction with a measured object (the rotor of the linear motor in the active suspension of the vehicle), and the detection unit 21 generates a corresponding electrical signal according to the magnetic induction of the magnetic field generated by the toothed mechanism 1 cutting the magnetic lines of force of the magnetic force mechanism 3, so as to obtain the displacement of the measured object. Specifically, the magnetic induction read head 2 can be fixedly connected with the measured object by means of bolt connection, welding or adhesion.

[0078] In this way, the magnetic induction displacement encoder in the embodiment can generate a strong magnetic field by arranging an independent magnetic force mechanism 3. When the magnetic induction read head 2 moves along the first direction along the plurality of induction teeth 14 of the main tooth portion 12 and the vernier tooth portion 13, the magnetic field generated by the magnetic force mechanism 3 is affected, and because the distance J between two adjacent induction teeth of the main tooth portion 12 and the distance K between two adjacent induction teeth 14 of the vernier tooth portion 13 are different, when the main tooth portion 12 and the vernier tooth portion 13 are relatively arranged, the relative positions of the induction teeth 14 of the main tooth portion 12 and the induction teeth 14 of the vernier tooth portion 13 gradually shift along the first direction, so that the detection unit 21 can detect that the magnetic field generated by the magnetic force mechanism 3 is different at different positions relative to the main tooth portion 12 and the vernier tooth portion 13, and generate a corresponding electrical signal, so as to calculate the position of the magnetic induction read head 2 on the toothed mechanism 1.

[0079] And, since the independent magnetic force mechanism 3 can be set and a strong magnetic field can be generated, when the detection unit 21 detects the change in the magnetic field of the magnetic force mechanism 3 relative to the movement of the toothed mechanism 1, the interference of the external magnetic field can be reduced, thereby improving the reliability of the detection of the detection unit 21, and further, the position of the measured object connected to the magnetic induction read head 2 relative to the toothed mechanism 1 can be more accurately calculated.

[0080] Referring to FIGS. 1, 2, 5 and 7, further, in the present embodiment, the toothed mechanism 1 is a straight rack, wherein the first direction in the present embodiment is the length direction of the straight rack, specifically, the sensing teeth 14 of the main tooth portion 12 and the vernier tooth portion 13 in the present embodiment are involute teeth, it should be noted that the straight rack is a special gear, the gear radius is infinite, the "graduation circle" of the rack becomes a graduation line, which is a straight line, because the standard gear pressure angle is 20°, the tooth profile curvature radius of the rack "graduation circle" is infinite, so the tooth profile presents a trapezoidal shape.

[0081] In other embodiments, the toothed mechanism 1 can be a circular gear or an end face toothed disc.

[0082] Referring to FIGS. 2 and 3, specifically, the magnetic induction displacement encoder in the present embodiment is an absolute magnetic induction displacement encoder, wherein the detection unit 21 includes a magnetic induction chip 211 and an interface circuit 212, the magnetic induction chip 211 is electrically connected with the interface circuit 212, and the magnetic induction chip 211 is electrically connected with the external circuit through the interface circuit 212; specifically, the magnetic induction chip 211 of the present embodiment adopts the iC-MU series of magnetic off-axis absolute position encoder chip of iC-Haus Company in Germany, and the model is iC-MU200.

[0083] In order to save the space for setting the toothed mechanism 1, the lengths of the main tooth portion 12 and the vernier tooth portion 13 in the first direction are equal, and the number of the sensing teeth 14 of the main tooth portion 12 is N, and the number of the sensing teeth 14 of the vernier tooth portion 13 is M, M < N. Since the present embodiment is an absolute magnetic induction displacement encoder, the relationship between the number N of the sensing teeth 14 of the main tooth portion 12 and the number M of the sensing teeth 14 of the vernier tooth portion 13 is: N-M = 1, in this way, the main tooth portion 12 and the vernier tooth portion 13 are mirror symmetrically arranged except for the two sensing teeth 14 at both ends in the length direction, and gradually offset along the first direction between the sensing teeth 14 of the main tooth portion 12 and the vernier tooth portion 13, and the offset distances are all different, so that when the magnetic field generated by the magnetic force mechanism 3 corresponds to any two sensing teeth 14 on both sides of the first direction, the magnetic field strength detected by the detection unit 21 is different, and a unique electrical signal can be generated accordingly to determine the position of the magnetic induction read head 2 on the toothed mechanism 1.

[0084] In some other embodiments, the magnetic induction displacement encoder is a relative magnetic induction displacement encoder, N-M≥2; specifically, when N-M=2, the magnetic induction displacement encoder is a two-period displacement encoder; when N-M=3, the magnetic induction displacement encoder is a three-period displacement encoder; and so on.

[0085] Further, referring to FIG. 1, the base body 11, the main tooth portion 12 and the vernier tooth portion 13 in the embodiment are integrally formed; specifically, the base body 11, the main tooth portion 12 and the vernier tooth portion 13 in the embodiment are integrally injection molded by using a metal injection molding process; on the one hand, the stability and reliability of the tooth-shaped mechanism 1 as a whole can be improved; on the other hand, the base body 11, the main tooth portion 12 and the vernier tooth portion 13 can be integrally formed by one-time mold opening, so that the accuracy of the relative positions between the sensing teeth 14 of the main tooth portion 12 and the vernier tooth portion 13 is ensured, errors possibly caused in the assembly process are avoided, and the reliability of the detection is improved.

[0086] In some other embodiments, the base body 11, the main tooth portion 12 and the vernier tooth portion 13 can be integrally formed by using a mold pressing technology.

[0087] In order to improve the measurement accuracy and reduce the measurement error, the length of the detection gap corresponds to the tooth height of the sensing teeth 14, and the magnetic field strength at the detection position of the detection unit 21 is improved, wherein the length of the detection gap, i.e., the vertical distance between the detection unit 21 and the sensing teeth 14, the tooth height of the sensing teeth 14 is H millimeters, and the vertical distance between the detection unit 21 and the sensing teeth 14 is C millimeters, which satisfies the following relationship: 0.8≤H / C≤5, and the magnetic field directions generated by the magnetic force mechanism are X direction, Y direction and Z direction respectively, wherein since the detection unit 21 can simultaneously scan the sensing teeth 14 of the main tooth portion 12 and the vernier tooth portion 13, the vertical distance C millimeters between the detection unit 21 and the sensing teeth 14 is the vertical distance between the detection unit 21 and the sensing teeth 14 of the main tooth portion 12 or the vertical distance between the detection unit 21 and the sensing teeth 14 of the vernier tooth portion 13, wherein the X direction is the first direction described above, the Y direction is perpendicular to the X direction, the tooth-shaped mechanism 1, the detection unit 21 and the magnetic force mechanism 3 are arranged along the Z direction in sequence;

[0088] Table 1

[0089] As can be seen from Table 1, when the tooth height H of the sensing tooth 14 and the distance C between the detection unit 21 and the sensing tooth 14 satisfy 0.8≤H / C, under the action of the same magnetic mechanism 3, the magnetic field generated by the magnetic mechanism 3 has a higher amplitude of the magnetic field density in the Y direction at the position of the detection unit 21, and has a larger increase than when H / C<1, thereby enhancing the modulation of the magnetic field by the magnetic induction chip 211 when the magnetic induction read head 2 moves relative to the tooth-shaped mechanism 1, and further improving the amplitude of the sine and cosine orthogonal differential signals, which can effectively increase the ratio of the strength of the received useful signal to the strength of the received interference signal, thereby reducing the detection error. Therefore, when using the same volume of the magnetic mechanism 3, the spatial structure of the magnetic induction encoder can be optimized by the above relationship to make the space utilization of the equipment assembled with it higher, and better performance can be achieved. Under the premise that the requirement of the amplitude of the Y-direction magnetic field density is met, the problem of space occupation is considered, and a higher average value of the Y-direction magnetic field density is ensured, and H / C≤5 is set.

[0090] In addition, when 0.3≤C≤1.2, the magnetic mechanism 3 is arranged to be as close as possible to the tooth-shaped mechanism 1, thereby ensuring the magnetic field strength at the position of the tooth-shaped mechanism 1, avoiding the interference of external magnetic fields when the magnetic field generated by the magnetic mechanism 3 acts on the tooth-shaped mechanism 1, and further affecting the measurement accuracy, thereby making the detection accuracy higher and the measurement error smaller.

[0091] Further, in order to avoid the interference of external magnetic fields and improve the measurement accuracy of the detection unit 21, the magnetic field strength generated on the surface of the magnetic mechanism 3 is B millitesla (mT), and 10≤B≤500; specifically, in the embodiment, the magnetic field strength B generated on the surface of the magnetic mechanism 3 is 50 mT. In the embodiment, the tooth height H of the sensing tooth 14 is 1.4 millimeters, the vertical distance C between the detection unit 21 and the sensing tooth 14 is 0.4 millimeters, and the following relationship is satisfied: H / C=3.5. In other embodiments, the tooth height H of the sensing tooth 14 can be 1.8 millimeters, the vertical distance C between the detection unit 21 and the sensing tooth 14 can be 0.5 millimeters; the tooth height H of the sensing tooth 14 can be 1.4 millimeters, the vertical distance C between the detection unit 21 and the sensing tooth 14 can be 0.6 millimeters; the tooth height H of the sensing tooth 14 can be 0.8 millimeters, the vertical distance C between the detection unit 21 and the sensing tooth 14 can be 0.7 millimeters; and the tooth height H of the sensing tooth 14 can be 2 millimeters, the vertical distance C between the detection unit 21 and the sensing tooth 14 can be 0.4 millimeters.

[0092] Further, the detection unit 21 in the embodiment has a detection plane, which is parallel to the tooth top plane of the sensing teeth 14 of the main tooth part 12 and the cursor tooth part 13, so that when the magnetic induction read head 2 moves along the first direction, the position of the detection plane has good magnetic field uniformity in the Y direction, which helps to reduce the measurement error; thus, in the embodiment, the detection plane is the side of the detection unit 21 facing the tooth-shaped mechanism 1, that is, the vertical distance C between the detection unit 21 and the sensing teeth 14 is the vertical distance between the detection plane and the sensing teeth 14 of the main tooth part 12 or the cursor tooth part 13.

[0093] Further, with reference to FIG. 7, along the first direction, the tooth spacing between the adjacent two sensing teeth 14 in the embodiment is L, the tooth root spacing between the adjacent two sensing teeth 14 is L1, and the tooth top width of the sensing teeth 14 is L2, wherein L1:L2:L = 1:1:(2.8-3.2), so as to meet the machining precision requirement and ensure the resolution and sensitivity of the detection unit to obtain the magnetic field change when moving relative to the tooth-shaped mechanism 1; specifically, since the relationship between the number N of the sensing teeth 14 of the main tooth part 12 and the number M of the sensing teeth 14 of the cursor tooth part 13 is N-M = 1, and the magnetic induction chip 211 in the embodiment is the iC-MU series magnetic off-axis absolute position encoder chip of iC-Haus Company in Germany, the model is iC-MU200, therefore, the number N of the sensing teeth 14 of the main tooth part 12 is set to 32, the number M of the sensing teeth 14 of the cursor tooth part 13 is set to 31, and the distance between the two sensing teeth 14 at the two ends of the main tooth part 12 along the first direction and the distance between the two sensing teeth 14 at the two ends of the cursor tooth part 13 along the first direction are the same, that is, the distance between the adjacent two sensing teeth 14 of the main tooth part 12 is less than the distance between the adjacent two sensing teeth 14 of the cursor tooth part 13, further, in the embodiment, the tooth spacing L of the main tooth part 12 is 4±0.03mm, the tooth top width L2 is 1.345±0.03mm, and the tooth root spacing L1 is 1.345±0.03mm; the tooth spacing L of the cursor tooth part 13 is 4.129±0.03mm, the tooth top width L2 is 1.345±0.03mm, and the tooth root spacing L1 is 1.345±0.03mm.

[0094] The thickness of the base body 11 in the embodiment is T mm, 0.5≤T≤5, on the one hand, through the base body 11 with the thickness, a good shielding effect of external magnetic field can be formed, the influence of the external magnetic field on the magnetic field generated by the magnetic force mechanism 3 is reduced, thereby improving the accuracy of the detection unit 21; on the other hand, the base body 11 smaller than the above thickness cannot effectively shield the external magnetic interference, thereby reducing the detection accuracy of the detection unit 21, and the base body 11 larger than the above thickness is easy to cause a large space to be occupied during installation, thereby reducing the space utilization; specifically, T = 1mm in the embodiment.

[0095] Further, referring to FIG. 2, FIG. 8 and FIG. 9, the magnetic induction reading head 2 in the embodiment further comprises a shell 22, the shell 22 is provided with screw holes, the shell 22 is fixed with the measured object through screws to follow the movement of the measured object, a containing cavity 221 is formed in the shell 22, the detection unit 21 is arranged in the containing cavity 221, and the magnetic force mechanism 3 is arranged on the side of the detection unit 21 away from the toothed mechanism 1; specifically, the magnetic force mechanism 3 is also arranged in the containing cavity 221 and is arranged close to the side of the detection unit 21 away from the induction tooth 14.

[0096] Specifically, since the detection unit 21 comprises a magnetic induction chip 211 and an interface circuit 212, the interface circuit 212 is in the form of a circuit board, in order to make the magnetic induction chip 211 better detect the change of the magnetic field caused by the toothed mechanism 1, the magnetic induction chip 211 is installed on the side of the interface circuit 212 away from the magnetic force mechanism 3 and is arranged towards the toothed mechanism 1; further, the magnetic force mechanism 3, the magnetic conducting sheet 4 and the detection unit 21 are all fixed in the containing cavity 221 of the shell 22 by epoxy resin encapsulation, so that the relative positions of the magnetic force mechanism 3, the magnetic conducting sheet 4 and the detection unit 21 are fixed, and the decrease of detection accuracy caused by relative movement is avoided; specifically, the shell 22 in the embodiment is made of non-magnetic material, which can avoid the magnetic field generated by the magnetic force mechanism 3 from being affected, so that the magnetic lines of force generated by the magnetic field of the magnetic force mechanism 3 can penetrate the shell 22 to reach the detection unit 21.

[0097] Further, referring to FIG. 8, the side of the shell 22 towards the toothed mechanism 1 is provided with a detection window 222 in communication with the containing cavity 221, and the detection unit 21 is arranged opposite to the toothed mechanism 1 through the detection window 222, so as to avoid the problem of decrease of detection accuracy caused by the blocking of the detection unit 21 by other objects and improve the detection reliability; specifically, the detection unit 21 is installed on the interface circuit 212 and protrudes towards the toothed mechanism 1 and is embedded in the detection window 222, so that the detection unit 21 can be as close to the toothed mechanism 1 as possible and the accuracy of magnetic field induction is improved.

[0098] In addition, the side of the shell 22 away from the toothed mechanism 1 is provided with an opening in communication with the containing cavity 221, and a cover body 23 is arranged on the opening, the cover body 23 can be made of magnetic or non-magnetic material; specifically, the cover body 23 in the embodiment is made of magnetic material, which can effectively block the interference of the external magnetic field from the side of the containing cavity 221 away from the cover body 23 and improve the stability of the magnetic field generated by the magnetic force mechanism 3 and the detection accuracy of the detection unit 21.

[0099] As shown in FIGS. 8 and 9, the cover 23 is fixed to the shell 22 by a buckle structure. Specifically, the two side edges of the side of the cover 23 opposite to the shell 22 are respectively provided with a clasp 231, and the two clasps 231 have hook portions. The hook portions of the two clasps 231 are oppositely arranged. The two side walls of the shell 22 are respectively provided with a hook groove 223. When the cover 23 is fixed to the shell 22, the clasps 231 can be embedded in the hook grooves 223 and hooked to the inner side walls of the hook grooves 223.

[0100] Further, the inner side wall of the shell 22 is provided with a positioning groove 224, which penetrates the side of the shell 22 facing the cover 23. When the cover 23 is arranged on the shell 22, the cover 23 can be embedded in the positioning groove 224, so as to improve the reliability and efficiency of the installation of the cover 23 and the shell 22.

[0101] The side wall of the shell 22 is provided with a wire hole 225. The wire from the outside can pass through the wire hole 225 and be electrically connected with the interface circuit 212 in the shell 22, so as to realize the conduction and data transmission between the magnetic induction chip 211 and the interface circuit 212 and the external device.

[0102] As shown in FIGS. 5 and 6, in the embodiment, the thickness of the magnetic conductive sheet 4 is A=0.1 mm. The magnetic conductive sheet 4 is made of a high magnetic permeability material, such as a silicon steel sheet. On the one hand, the magnetic conductive sheet 4 can shield the residual magnetism and stray magnetic field generated by the outside world, so as to avoid the interference of the residual magnetism and stray magnetic field generated by the outside world on the detection unit 21. On the other hand, the magnetic conductive sheet 4 can guide the magnetic field generated by the magnetic force mechanism 3. Since the magnetic force line is always perpendicular to the surface of the ferromagnetic material, the magnetic force line is closed and curved at the edge of the ferromagnetic material. In the parallel plane at a certain distance in the middle, it is equivalent to a parallel magnetic field. The magnetic conductive sheet 4 made of a high magnetic permeability material is arranged on the side of the magnetic steel facing the toothed mechanism 1. The magnetic conductive sheet 4 can increase the emission area of the magnetic pole, increase the area of the uniform parallel magnetic field, and improve the uniformity of the magnetic field in a certain sensing area, so as to improve the detection accuracy. It can be understood that the magnetic conductive sheet 4 is a rectangular body. The projection of the rectangular magnetic conductive sheet 4 along the direction of the toothed mechanism 1 approaching the magnetic force mechanism 3 is substantially coincided with the side of the magnetic force mechanism 3 facing the toothed mechanism 1.

[0103] Specifically, the thickness A of the magnetic conductive sheet 4 can be 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.6 mm, 0.8 mm, or 1 mm in different embodiments.

[0104] Further, referring to FIG. 1, the embodiment further comprises a magnetic shielding mechanism made of high magnetic permeability material, at least one side of the tooth-shaped mechanism 1 is provided with the magnetic shielding mechanism 5 along the first direction; specifically, both sides of the tooth-shaped mechanism 1 are provided with the magnetic shielding mechanism 5, the length of the magnetic shielding mechanism 5 extending along the first direction is basically the same as that of the tooth-shaped mechanism 1, and the magnetic shielding mechanism 5 is close to the two side surfaces of the tooth-shaped mechanism 1, which can shield the external stray magnetic field from entering the tooth-shaped mechanism 1 and absorb the external interference electromagnetic wave, thereby avoiding the magnetic field generated by the magnetic force mechanism 3 from being disturbed by the external magnetic field, and further solving the problem that the magnetic grating ruler cannot work in a strong magnetic environment; specifically, the magnetic shielding mechanism 5 can be a rectangular body made of high magnetic permeability material, one side surface of which is attached to the side surface of the tooth-shaped mechanism 1.

[0105] Further, the magnetic force mechanism 3 of the embodiment is a magnetic steel body 31, because the magnetic field generated by the magnetic steel body 31 gradually starts to diffuse in the X and / or Y direction as it gets closer to the edge, resulting in a gradual decrease in the magnetic field strength generated by the magnetic steel body 31 in the X and / or Y direction, a magnetic field bias is generated, thereby causing the magnetic field strength generated by the magnetic steel body 31 to have poor uniformity, and thus when the magnetic field strength uniformity of the detection plane of the magnetic induction chip 211 is poor, the X and / or Y direction magnetic field bias cannot be eliminated, and residual bias separation will be introduced into the calculation process, resulting in a large calculation error;

[0106] Therefore, the magnetic steel body 31 has a magnetic field compensation part for uniform magnetic field distribution, specifically, the magnetic field compensation part is a groove 32 and a protrusion 33 formed on one side of the magnetic steel body 31 facing or away from the tooth-shaped mechanism, and the protrusion 33 is arranged on the outer periphery of the groove 32, in this way, because the thickness P of the magnetic steel body 31 with the protrusion 33 in the Z direction is greater than the thickness Q of the magnetic steel body 31 at the position where the groove 32 is formed, the magnetic field strength at the edge of the magnetic plane can be increased, the magnetic field is uniformly distributed, and thus the magnetic field strength uniformity of the plane where the magnetic induction chip 211 is located is good, the error generated when the magnetic induction chip 211 measures is reduced, and the detection precision is improved; further, along the X direction (first direction) or Y direction (second direction), the two side edges of the magnetic plane are respectively provided with the protrusion 33, or the protrusion 33 is circumferentially arranged along the edge of the groove 32, in this way, the uniformity of the magnetic field in the X and Y directions can be improved at the same time;

[0107] Specifically, referring to FIGS. 4, 5, 10-12, in the embodiment, one side of the magnetic steel body 31 away from the tooth-shaped mechanism 1 is formed with a magnetic field compensation part, wherein the two side edges of the magnetic steel body 31 in the Y direction of the groove 32 are provided with the protrusion 33.

[0108] Further, the protrusion 33 is arranged to extend upward and outward from the side of the groove 32 close to the bottom surface of the groove 32, so that the position of the protrusion 33 corresponds to the gradually increasing thickness P of the magnetic steel body 31, and the corresponding generated magnetic field strength is also gradually increased. The closer to the edge of the magnetic steel body 31, the greater the offset, which corresponds to mutual compensation, further improving the uniformity of the magnetic steel body 31 in the detection plane Y direction or X direction of the magnetic induction chip 211.

[0109] Further, the bottom surface of the groove 32 is smoothly connected with the surrounding plane, avoiding the distortion of the periodic change signal sensed by the magnetic induction chip 211, further improving the uniformity of the magnetic field generated by the magnetic steel body 31 in the detection plane of the magnetic induction chip 211, and reducing the measurement error.

[0110] Referring to FIG. 13, FIG. 13 is a schematic diagram of the strength of the magnetic field generated by the magnetic steel body without protrusion in the Y direction. As can be seen from FIG. 13, the distance of the uniform magnetic field generated by the magnetic steel body without protrusion in the Y direction is about 6.5-14 of the horizontal axis value in FIG. 13, i.e. the length of the uniform magnetic field generated by the magnetic steel body without groove in the Y direction is 7.5;

[0111] Referring to FIG. 14, FIG. 14 is a magnetic steel body 31 of the present embodiment. As can be seen from FIG. 14, the distance of the uniform magnetic field generated by the magnetic steel body 31 of the present embodiment provided with protrusion 33 in the Y direction is about 3-17 of the horizontal axis value, i.e. the length of the uniform magnetic field generated by the magnetic steel body 31 of the present embodiment provided with protrusion 33 in the Y direction is 14, which is much larger than the area of the uniform magnetic field that can be generated by the magnetic steel body without protrusion 33.

[0112] Specifically, the magnetic steel body 31 in the present embodiment is made of N40UH material, which has high magnetic performance and can form a strong magnetic field, avoiding the interference of external magnetic field. The size of the magnetic steel body 31 is: length (along X direction)-10 mm, width (along Y direction)-15 mm, and height (along Z direction)-4 mm.

[0113] Further, in order to make the detection unit obtain the change of the magnetic field of the magnetic steel body 31 under the influence of the toothed mechanism 1, it is necessary to make the magnetic field generated by the magnetic steel body 31 have good magnetic field uniformity in the detection plane Y direction of the magnetic induction chip 211, i.e. the proportion of the length of the Y direction uniform magnetic field generated by the magnetic steel body 31 in the detection plane Y direction of the magnetic induction chip 211, so that the detection plane of the magnetic induction chip 211 can be accommodated in the uniform magnetic field as much as possible, avoiding the measurement error of the magnetic induction chip 211. Therefore, in order to increase the length of the Y direction uniform magnetic field generated by the magnetic steel body 31, in the present embodiment, the groove depth of the groove 32 is h mm, the groove width of the groove 32 is d mm, and the distance between the magnetic steel body 31 and the induction tooth 14 is s mm, so that:

[0114] Wherein, 4>h>0, 15>d>0, s>0; preferably, 0.5≤Q / P≤0.95, Q=P-h, so that the length E of the uniform magnetic field in the Y direction generated by the magnetic steel body 31 accounts for the length F of the Y direction of the detection plane of the magnetic induction chip 211, so that the detection plane of the magnetic induction chip 211 can be in the uniform magnetic field as much as possible, which helps to reduce the measurement error of the magnetic induction chip 211.

[0115] In the embodiment, the grade of the magnetic steel body 31 is N40UH; the size of the magnetic steel body 31 is 10mm in length, 15mm in width, and 4mm in height; by setting grooves with different size parameters on the magnetic steel body 31 and measuring, the length of the uniform magnetic field in the Y direction of the detection plane of the magnetic induction chip 211 accounts for the length of the Y direction of the detection plane of the magnetic induction chip 211, the following table can be obtained:

[0116] Table 2

[0117] Based on Table 2, it can be known that when the groove depth h of the groove 32, the groove width d of the groove 32, and the distance s between the magnetic steel body 31 and the induction tooth 14 satisfy the relationship:

[0118] The length of the uniform magnetic field in the Y direction generated by the magnetic steel body 31 accounts for the length of the Y direction of the detection plane of the magnetic induction chip 211, which is greater than 50%, so that the magnetic induction chip 211 can be in a magnetic field environment with good uniformity as much as possible, thereby improving the detection precision and reducing the detection error.

[0119] Further, based on the above displacement detection mechanism, the measured object is fixedly connected with the magnetic induction reader, so that the displacement detection method of the measured object comprises the following steps:

[0120] S1: The magnetic induction displacement encoder applies the rack induction magnetic force line working principle to non-contact scan the main tooth part 12 and the vernier tooth part 13 whose number difference is 1, the detection unit 21 cuts the induction magnetic force line according to the tooth shape mechanism 1, generates a corresponding number of high-reliability first sine and cosine quadrature differential signals, and real-time corrects and compensates the direct current bias error, amplitude error and quadrature phase error of the first sine and cosine quadrature differential signals to obtain second sine and cosine quadrature differential signals, and realizes high-precision correction and subdivision of the sine and cosine quadrature differential signals.

[0121] S2: The detection unit 21 generates two relative position values of two tracks (i.e. the second cosine and sine quadrature differential signals) of the main tooth part 12 and the vernier tooth part 13 relative to two code channels (the code channel formed by the main tooth part 12 and the code channel formed by the vernier tooth part 13) at the power-on time;

[0122] S3: The phase and phase difference between the two tracks (i.e. the second cosine and sine quadrature differential signals) are analyzed according to the vernier calculation principle. In this embodiment, N-M=1, so the phase and phase difference within one stroke are fixed and unique, and the magnetic induction displacement encoder can calculate the absolute position and absolute displacement of the measured object relative to the tooth mechanism 1 through the relative position of the two code channels.

[0123] In this way, in this embodiment, when the magnetic induction chip 211 moves to different positions of the tooth mechanism 1 during movement, the magnetic induction chip 211 generates corresponding cosine and sine quadrature differential signals according to the different influences of the two relative sensing teeth 14 of the main tooth part 12 and the vernier tooth part 13 and the position changes therebetween on the magnetic field generated by the magnetic steel body 31, and the magnetic induction chip 211 can calculate the absolute displacement of the measured object relative to the tooth mechanism 1 through tangent operation on the original cosine and sine quadrature differential signals and the vernier calculation algorithm.

[0124] In summary, the displacement detection mechanism of this embodiment, the magnetic induction displacement encoder sets up an independent magnetic force mechanism, generates a strong magnetic field through the magnetic force mechanism, and when the magnetic induction read head moves along the first direction of the main tooth part and the vernier tooth part The sensing teeth arranged by the measured object, due to the change of the relative position of the sensing teeth of the main tooth part and the vernier tooth part, the magnetic field generated by the magnetic force mechanism is affected, and the detection unit can detect the change of the magnetic field generated by the magnetic force mechanism at different positions relative to the tooth mechanism, and generate corresponding electrical signals, so as to calculate the position of the magnetic induction read head in the tooth mechanism;

[0125] And because an independent magnetic force mechanism can be set up and a strong magnetic field can be generated, when the detection unit detects the change of the magnetic field of the magnetic force mechanism relative to the tooth mechanism during movement, the interference of the external magnetic field can be reduced, thereby improving the reliability of the detection of the detection unit, and the position of the measured object connected to the magnetic induction read head relative to the tooth mechanism can be more accurately calculated.

[0126] Finally, the uniformity of the magnetic field generated by the magnetic force mechanism can be optimized to reduce the error of the detection unit.

[0127] In addition, the displacement detection method based on the above displacement detection mechanism provided by this embodiment can accurately obtain the position and displacement of the measured object relative to the tooth mechanism, and improve the detection accuracy.

[0128] The present specification discloses the present application in reference to the drawings and also enables one of ordinary skill in the art to practice the present application, including making and using any devices or systems, employing appropriate materials, and using any incorporated methods. The scope of the present application is defined by the claims, and includes other examples that occur to persons of ordinary skill in the art. Such other examples are deemed to be within the scope of the present application as determined by the claims and equivalents thereof. Such other examples should be considered to be within the scope of the present application as determined by the claims and equivalents thereof whenever such other examples include structural elements not materially different from the literal language of the claims, or include equivalent structural elements to those of the literal language of the claims.

Claims

1. A magnetic inductive displacement encoder, characterized in that The application relates to a magnetic induction displacement encoder. The magnetic induction displacement encoder comprises a toothed mechanism and a magnetic induction read head. The toothed mechanism comprises a base body, a main tooth part and a vernier tooth part which cooperates with the main tooth part to affect a magnetic field. The main tooth part and the vernier tooth part are arranged on the same side of the base body. The main tooth part and the vernier tooth part each comprise a plurality of induction teeth which are spaced and arranged uniformly along a first direction.

2. The magnetic induction displacement encoder of claim 1, wherein, The interval between two adjacent induction teeth of the main tooth part is J millimeters.

3. The magnetic induction displacement encoder of claim 2, wherein, The interval between two adjacent induction teeth of the vernier tooth part is K millimeters, and K>J.

4. The magnetic induction displacement encoder of claim 3, wherein, The magnetic induction read head comprises a detection unit which is arranged on the side of the induction tooth away from the base body and forms a detection gap with the induction tooth.

5. The magnetic induction displacement encoder of claim 3, wherein, A magnetic force mechanism is arranged on the side of the detection unit away from the induction tooth and is fixed to the magnetic induction read head to generate a magnetic field.

6. A magnetic induction displacement encoder according to any one of claims 3-5, characterized in that, The magnetic induction read head can move along the first direction with a measured object.

7. A magnetic inductive displacement encoder according to any one of claims 3-5, characterized in that, The groove depth is h millimeters, the groove width is d millimeters, the distance between the magnetic steel body and the induction tooth is s millimeters, and the following is true: The length of the detection gap and the tooth height of the induction tooth have a corresponding relationship.

8. The magnetic induction displacement encoder of claim 3, wherein, The corresponding relationship can make the detection unit generate an electric signal for obtaining the displacement of the measured object according to the magnetic induction lines of the magnetic field cut by the toothed mechanism.

9. The magnetic induction displacement encoder of claim 1, wherein, The length of the detection gap is the vertical distance between the detection unit and the induction tooth.

10. The magnetic induction displacement encoder of claim 1, wherein, The magnetic force mechanism is a magnetic steel body which has a magnetic field compensation part for uniform magnetic field distribution. The magnetic field compensation part is a groove and a protrusion formed on the side of the magnetic steel body facing or away from the toothed mechanism. The protrusion is arranged on the outer periphery of the groove.

11. The magnetic induction displacement encoder of claim 1, wherein, Along the first direction or a second direction, the two side edges of the groove are respectively provided with the protrusions.

12. The magnetic induction displacement encoder of claim 1, wherein, The first direction is perpendicular to the second direction.

13. The magnetic induction displacement encoder according to any of claims 1, 9-12, characterized in that, The protrusions are arranged along the edge of the groove in the circumferential direction.

14. The magnetic induction displacement encoder according to any of claims 1, 9-12, characterized in that, The side of the protrusion close to the side of the groove extends upward and outward from the bottom surface of the groove.

15. The magnetic inductive displacement encoder according to any one of claims 1, 9-12, characterized in that Wherein, h>0, d>0, s>0.

16. The magnetic induction displacement encoder of claim 1, wherein, The bottom surface of the groove is smoothly connected with the surrounding plane.

17. The magnetic induction displacement encoder of claim 1, wherein, The length of the main tooth part and the vernier tooth part in the first direction is equal.

18. The magnetic induction displacement encoder of claim 17, wherein, The number of the induction teeth of the main tooth part is N, and the number of the induction teeth of the vernier tooth part is M. When N-M=1, the magnetic induction displacement encoder is an absolute magnetic induction displacement encoder. When N-M>=2, the magnetic induction displacement encoder is a relative magnetic induction displacement encoder. The base body, the main tooth part and the vernier tooth part are integrally formed. The induction tooth is an involute tooth. The toothed mechanism is a straight toothed rack. The toothed mechanism is a circular gear or an end face toothed disc. The tooth height of the induction tooth is H millimeters, and the length of the detection gap is C millimeters. The corresponding relationship is 0.8<=H / C<=5, wherein 0.3<=C<=1.

2. The thickness of the base body is T millimeters, and 0.5<=T<=5. The magnetic induction read head further comprises a shell which forms an accommodating cavity. The detection unit and the magnetic force mechanism are arranged in the accommodating cavity. The magnetic force mechanism is arranged on the side of the detection unit away from the toothed mechanism. The shell is made of non-magnetic material.

19. The magnetic induction displacement encoder of claim 17, wherein, The shell is provided with a detection window on one side thereof facing the toothed mechanism, which is in communication with the accommodating cavity, and the detection unit is arranged opposite to the toothed mechanism through the detection window.

20. The magnetic induction displacement encoder of claim 17, wherein, The shell is provided with an opening on one side thereof facing away from the toothed mechanism, which is in communication with the accommodating cavity, and the opening is provided with a cover.

21. The magnetic induction displacement encoder of claim 20, wherein, The cover is made of a magnetic conductive material.

22. The magnetic induction displacement encoder of claim 1, wherein, A magnetic conductive sheet is arranged between the magnetic force mechanism and the detection unit.

23. The magnetic induction displacement encoder of claim 22, wherein, The two side surfaces of the magnetic conductive sheet are respectively attached to the detection unit and the magnetic force mechanism.

24. The magnetic induction displacement encoder of claim 22, wherein, The thickness of the magnetic conductive sheet is A millimeters, and 0.1≤A≤1.

25. The magnetic induction displacement encoder of claim 22, wherein, The projection of the magnetic conductive sheet along the direction in which the toothed mechanism approaches the magnetic force mechanism coincides with one side of the magnetic force mechanism facing the toothed mechanism.

26. The magnetic induction displacement encoder of claim 1, wherein, A magnetic shielding mechanism made of a high magnetic permeability material is further included, and at least one side of the toothed mechanism is provided with the magnetic shielding mechanism along the first direction, and the magnetic shielding mechanism is arranged along the first direction.

27. The magnetic induction displacement encoder of claim 26, wherein, Both sides of the toothed mechanism are provided with the magnetic shielding mechanism along the first direction.

28. The magnetic induction displacement encoder of claim 1, wherein, The magnetic field strength generated by the magnetic force mechanism is B millitesla, and 10≤B≤500.

29. A displacement detection mechanism characterized by comprising: The magnetic induction displacement encoder of any one of claims 1-28 is included.

30. A displacement detection method based on the displacement detection mechanism according to claim 29, characterized by, The following steps are included: S1: cutting the induced magnetic force lines according to the toothed mechanism to generate a corresponding number of first sine and cosine quadrature differential signals, and correcting and compensating the direct current bias error, amplitude error and quadrature phase error of the first sine and cosine quadrature differential signals in real time to obtain second sine and cosine quadrature differential signals; S2: generating the relative position values of the main tooth part and the cursor tooth part relative to the power-on time according to the second sine and cosine quadrature differential signals, respectively; S3: analyzing the phase and phase difference of the second sine and cosine quadrature differential signals according to the cursor calculation principle to calculate the current displacement position of the measured object.

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