Single-channel absolute magnetic encoder based on partition cursor principle and solution method

Abstract

The present invention relates to the field of magnetic encoder technology, and provides a single-track absolute magnetic encoder based on the partition cursor principle and a solution method, including a main component, wherein the main component includes a PCB carrier, a magnetoresistive sensor, a single-chip microcomputer, a Hall sensor, a magnetic grid, a rotating shaft, a substrate, a magnetic pole, an A zone, a B zone, an N-pole signal sensor, and an S-pole signal sensor; the magnetic pole is arranged on the rear surface of the magnetic grid. The present invention sets the magnetic grid into two parts, an A zone and a B zone, with different numbers of magnetic poles. When the rotating shaft rotates, the magnetic grid drives the magnetic pole and the N-pole signal sensor and the S-pole signal sensor, and the magnetic field received by the magnetoresistive sensor and the Hall sensor undergoes periodic changes. Under the solution method provided by the present invention, the purpose of realizing the solution of the absolute position on the single-track magnetic ring is achieved, the resolution of the single-track magnetic encoder is improved, the cost and production difficulty of the absolute magnetic encoder are reduced, and the influence of the installation tolerance is weakened to a certain extent.

Description

Technical Field

[0001] The present invention relates to a magnetic encoder and a method, in particular to a single-code channel absolute magnetic encoder and a solution method based on a partition cursor principle, belonging to the technical field of magnetic encoders. Background Art

[0002] The magnetic encoder is a widely used angle measurement sensor, which can be mainly divided into incremental and absolute magnetic encoders. Incremental encoders cannot calculate absolute position, and their application field is relatively narrow, while absolute magnetic encoders can output absolute position, so they have great application advantages. For absolute magnetic encoders, their main technical indicators include accuracy, resolution, anti-interference ability, etc. At present, the absolute magnetic encoder is mainly a dual-track magnetic grating type magnetic encoder, while the single-track magnetic grating is mainly used to realize incremental type. At present, few technical means can realize the absolute position calculation on the single-track magnetic grating, while it is fully comparable to the accuracy, resolution and anti-interference ability of the dual-track, and the single-track magnetic grating can achieve lower production costs and smaller volume.

[0003] The dual-track magnetic encoder is based on the dual-track magnetic grating as the core component, and realizes the measurement of absolute position by introducing the vernier principle solution. As the name implies, the dual-track magnetic grating has two magnetic rings. The main problem is that, first of all, the production cost of the dual-track magnetic grating is bound to be higher than that of the single-track magnetic ring, which is mainly reflected in the more stringent requirements on the number of consumables and the production process; secondly, each magnetic grating of the dual-track magnetic grating requires a corresponding magnetic sensor, and there may be interference in the magnetic field between adjacent tracks; at the same time, the dual-track magnetic encoder is more susceptible to eccentricity error and installation tolerance than the single-track magnetic encoder. Now, the absolute position solution can be realized on the single-track magnetic grating in the form of random magnetization, but it has a large volume while ensuring a certain resolution; secondly, the high price and cost have greatly limited its large-scale application; finally, it often requires more Hall or other types of magnetic sensors to achieve it. For this reason, a single-track absolute magnetic encoder and solution method based on the partitioned vernier principle are proposed. Summary of the invention

[0004] In view of this, the present invention hopes to provide a single-track absolute magnetic encoder and a solution method based on the partition cursor principle to solve or alleviate the technical problems existing in the prior art and at least provide a beneficial choice.

[0005] The technical solution of the embodiment of the present invention is implemented as follows: a method for solving a single-track absolute magnetic encoder based on the partition vernier principle includes a main component, wherein the main component includes a PCB carrier, a magnetoresistive sensor, a single-chip microcomputer, a Hall sensor, a magnetic grid, a rotating shaft, a substrate, a magnetic pole, an A zone, a B zone, an N-pole signal sensor, and an S-pole signal sensor;

[0006] The magnetic poles are arranged on the rear surface of the magnetic grid, and the left and right parts of the magnetic grid are provided with area A and area B. The number of magnetic poles in area A is greater than the number of magnetic poles in area B. The front surface of the magnetic grid is installed on the rear surface of the substrate, and the front surface of the substrate is fixedly connected to the rear end of the rotating shaft. The magnetoresistive sensor, the single-chip microcomputer and the Hall sensor are all installed on the front surface of the PCB carrier board, the N-pole signal sensor is installed on one side of the rear surface of the magnetic grid, and the S-pole signal sensor is installed on the other side of the rear surface of the magnetic grid.

[0007] Further preferably, the N-pole signal sensor and the S-pole signal sensor are symmetrically located at two ends of the diameter of the magnetic grid.

[0008] Further preferably, the position of the Hall sensor corresponds to the position of the magnetic grid.

[0009] Further preferably, the position of the magnetoresistive sensor corresponds to the position of the magnetic grid.

[0010] Further preferably, two bearings are symmetrically mounted on the outer side wall of the rotating shaft, and a housing assembly is mounted on the outer side wall of the bearing, wherein the housing assembly comprises a housing, a connector, four studs and an end cover;

[0011] The rotating shaft is rotatably connected to the inner side wall of the end cover through a bearing.

[0012] Further preferably, the four studs are symmetrically threadedly connected to the inside of the PCB carrier, and the PCB carrier is fixedly connected to the inner front wall of the shell through the four studs.

[0013] Further preferably, the connector is mounted on an outer side wall of the shell, the end cover is fixedly connected to the shell, and the substrate and the magnetic grid are both located inside the shell.

[0014] In addition, the present invention also provides a method for solving a single-track absolute magnetic encoder based on the partition cursor principle, comprising the following steps:

[0015] Step 1: By using the zoning method, the single code channel magnetic grid is divided into two parts, zone A and zone B. The number of magnetic poles in the two parts is different. The vernier principle is introduced, and one zone is used as the main code channel while the other zone is used as the vernier code channel;

[0016] Step 2: Use the Hall sensor or magnetoresistive sensor to collect the magnetic field strength signal, and then send the signal to the microcontroller for calculation;

[0017] Step 3: Rotate the shaft by a certain angle and obtain the maximum absolute value of the collected values ​​in the single chip microcomputer;

[0018] Step 4: Determine the partitions where the N-pole signal sensor and the S-pole signal sensor are located by the maximum absolute value, and then use the single-chip microcomputer to calculate the direction of their respective curves, that is, the positive or negative of the derivative;

[0019] Step 5: When the N-pole signal sensor is in area A and the S-pole signal sensor is in area B, since the number of magnetic pole pairs in area A is greater than that in area B, the phase value collected in area A should be ahead of that in area B, that is, the phase collected by the N-pole signal sensor is ahead of that by the S-pole signal sensor;

[0020] Step 6: When the shaft rotates halfway, the N-pole signal sensor enters area B, and the S-pole signal sensor enters area A. The current accumulated phase difference is 2π, and with the subsequent rotation, this phase difference will continue to decrease until it reaches 0;

[0021] Step 7: The absolute position of any point on the entire magnetic grid is calculated.

[0022] Further preferably, in step three, the rotation angle of the rotating shaft is greater than the width of a magnetic pole.

[0023] Further preferably, in the step 1, the magnetic grating alternately becomes a main code channel and a vernier code channel during the rotation process to resolve the absolute position.

[0024] Since the embodiment of the present invention adopts the above technical solution, it has the following advantages: the present invention sets the magnetic grid into two parts, area A and area B, with different numbers of magnetic poles, and sets the N-pole signal sensor and the S-pole signal sensor at both ends of the diameter of the magnetic grid. When the shaft rotates, the magnetic grid drives the magnetic poles and the N-pole signal sensor and the S-pole signal sensor, and the magnetic field received by the magnetoresistive sensor and the Hall sensor changes periodically. Under the solution method provided by the present invention, the purpose of realizing the solution of absolute position on the single-track magnetic ring is achieved, the resolution of the single-track magnetic encoder is improved, the cost and production difficulty of the absolute magnetic encoder are reduced, and the influence of the installation tolerance is weakened to a certain extent.

[0025] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present invention will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is a structural diagram of the present invention;

[0028] Figure 2 It is a magnetic grid structure diagram of the present invention;

[0029] Figure 3 It is a shell structure diagram of the present invention;

[0030] Figure 4 It is a structural diagram of the main components of the present invention;

[0031] Figure 5 It is a flow chart of the steps of the solution method in the present invention.

[0032] Figure numerals: 101, main assembly; 11, PCB carrier board; 12, magnetoresistive sensor; 13, single-chip microcomputer; 14, Hall sensor; 15, magnetic grid; 16, bearing; 17, rotating shaft; 18, substrate; 19, magnetic pole; 21, area A; 22, area B; 23, N-pole signal sensor; 24, S-pole signal sensor; 301, shell assembly; 31, shell; 32, connector; 33, stud; 34, end cover. DETAILED DESCRIPTION

[0033] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0034] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0035] like Figure 1-5 As shown, the embodiment of the present invention provides a method for solving a single-track absolute magnetic encoder based on the partition cursor principle, including a main component 101, the main component 101 includes a PCB carrier board 11, a magnetoresistive sensor 12, a single-chip computer 13, a Hall sensor 14, a magnetic grid 15, a rotating shaft 17, a substrate 18, a magnetic pole 19, an A area 21, a B area 22, an N-pole signal sensor 23 and an S-pole signal sensor 24;

[0036] The magnetic poles 19 are arranged on the rear surface of the magnetic grid 15, and the left and right parts of the magnetic grid 15 are provided with area A 21 and area B 22. The number of magnetic poles 19 in area A 21 is greater than the number of magnetic poles 19 in area B 22. The front surface of the magnetic grid 15 is installed on the rear surface of the substrate 18, and the front surface of the substrate 18 is fixedly connected to the rear end of the rotating shaft 17. The magnetoresistive sensor 12, the single-chip microcomputer 13 and the Hall sensor 14 are all installed on the front surface of the PCB carrier board 11. The N-pole signal sensor 23 is installed on one side of the rear surface of the magnetic grid 15, and the S-pole signal sensor 24 is installed on the other side of the rear surface of the magnetic grid 15.

[0037] In one embodiment, the N-pole signal sensor 23 and the S-pole signal sensor 24 are symmetrically located at both ends of the diameter of the magnetic grid 15, the position of the Hall sensor 14 corresponds to the position of the magnetic grid 15, and the position of the magnetoresistive sensor 12 corresponds to the position of the magnetic grid 15. Then, when the shaft 17 rotates, the shaft 17 rotates in the end cover 34 through the bearing 16, the shaft 17 drives the substrate 18 to rotate, the substrate 18 drives the magnetic grid 15, and the magnetic grid 15 drives the magnetic pole 19 and the N-pole signal sensor 23 and the S-pole signal sensor 24. At this time, the magnetoresistive sensor 12 can receive the periodic changes in the magnetic field intensity, and the Hall sensor 14 also receives the periodic changes in the magnetic field. The signal output end of the Hall sensor 14 is connected to the signal input end of the single-chip microcomputer 13, and the signal output end of the magnetoresistive sensor 12 is connected to the signal input end of the single-chip microcomputer 13. Then, the direction of the N-pole signal sensor 23 and the S-pole signal sensor 24 can be calculated by the single-chip microcomputer 13.

[0038] In one embodiment, two bearings 16 are symmetrically mounted on the outer side wall of the rotating shaft 17, and a housing assembly 301 is mounted on the outer side wall of the bearing 16. The housing assembly 301 includes a housing 31, a connector 32, four studs 33 and an end cover 34;

[0039] The rotating shaft 17 is rotatably connected to the inner wall of the end cover 34 via the bearing 16 , and the bearing 16 can reduce the resistance when the rotating shaft 17 rotates.

[0040] In one embodiment, four studs 33 are symmetrically threadedly connected to the inside of the PCB carrier 11, and the PCB carrier 11 is fixedly connected to the inner front wall of the shell 31 through the four studs 33, so that the position of the PCB carrier 11 can be fixed by the studs 33, and the positions of the magnetoresistive sensor 12, the single-chip computer 13 and the Hall sensor 14 can be limited by the PCB carrier 11, so that the overall structure is stable.

[0041] In one embodiment, the connector 32 is installed on the outer wall of the shell 31, the end cover 34 is fixedly connected to the shell 31, the substrate 18 and the magnetic grid 15 are both located inside the shell 31, and the signal output end of the microcontroller 13 is connected to the signal input end of the connector 32, and then the data in the microcontroller 13 is transmitted to the outside through the connector 32.

[0042] In addition, the present invention also provides a method for solving a single-track absolute magnetic encoder based on the partition cursor principle, comprising the following steps:

[0043] Step 1: By using the zoning method, the single code channel magnetic grid is divided into two parts, zone A and zone B. The number of magnetic poles in the two parts is different. The vernier principle is introduced, and one zone is used as the main code channel while the other zone is used as the vernier code channel;

[0044] Step 2: Use the Hall sensor or magnetoresistive sensor to collect the magnetic field strength signal, and then send the signal to the microcontroller for calculation;

[0045] Step 3: Rotate the shaft to a certain angle, and obtain the maximum absolute value of the collected values ​​in the single-chip microcomputer. Let this leading value be K1, then K1 should be:

[0046] K1=ΦN-ΦS (ΦN-ΦS>0) or K1=ΦN-ΦS+2π (ΦN-ΦS<0);

[0047] Assume the absolute position is Ki, then:

[0048] Ki=floor(X·K1 / 2π)·π / X+ΦN / 2X;

[0049] That is, the current absolute position is solved;

[0050] Step 4: Determine the partitions where the N-pole signal sensor and the S-pole signal sensor are located by the maximum absolute value, and then use the single-chip microcomputer to calculate the direction of their respective curves, that is, the positive or negative of the derivative;

[0051] Step 5: When the N-pole signal sensor is in area A and the S-pole signal sensor is in area B, since the number of magnetic pole pairs in area A is greater than that in area B, the phase value collected in area A should be ahead of that in area B, that is, the phase collected by the N-pole signal sensor is ahead of that by the S-pole signal sensor;

[0052] Step 6: When the shaft rotates halfway, the N-pole signal sensor enters area B, and the S-pole signal sensor enters area A. The current accumulated phase difference is 2π, and with the subsequent rotation, this phase difference will continue to decrease until it reaches 0. The value of this compensated phase difference is the rear leading phase K2, then:

[0053] K2=ΦS-ΦN (ΦS-ΦN>0) or K1=ΦS-ΦN+2π (ΦS-ΦN<0);

[0054] Then the absolute position Ki is:

[0055] Ki=floor(Y·K2 / 2π)·2π / Y+ΦN / 2Y+π;

[0056] Step 7: The absolute position of any point on the entire magnetic grid is calculated.

[0057] In one embodiment, in step three, the rotation angle of the shaft is greater than the width of a magnetic pole. In step one, the magnetic grating alternately becomes the main code channel and the cursor code channel to solve the absolute position during the rotation process, and then the maximum absolute value of the collected value can be obtained in the single-chip microcomputer.

[0058] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of various changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for solving a single-track absolute magnetic encoder based on the partition cursor principle, comprising a main component (101), characterized in that: The main body component (101) comprises a PCB carrier board (11), a magnetoresistive sensor (12), a single chip computer (13), a Hall sensor (14), a magnetic grid (15), a rotating shaft (17), a substrate (18), a magnetic pole (19), an A region (21), a B region (22), an N-pole signal sensor (23) and an S-pole signal sensor (24); The magnetic poles (19) are arranged on the rear surface of the magnetic grid (15); the left and right parts of the magnetic grid (15) are provided with an A zone (21) and a B zone (22); the number of magnetic poles (19) in the A zone (21) is greater than the number of magnetic poles (19) in the B zone (22); the front surface of the magnetic grid (15) is mounted on the rear surface of the substrate (18); the front surface of the substrate (18) is fixedly connected to the rear end of the rotating shaft (17); the magnetoresistive sensor (12), the single-chip computer (13) and the Hall sensor (14) are all mounted on the front surface of the PCB carrier (11); the N-pole signal sensor (23) is mounted on one side of the rear surface of the magnetic grid (15); and the S-pole signal sensor (24) is mounted on the other side of the rear surface of the magnetic grid (15); The solution method comprises the following steps: Step 1: By using the zoning method, the single code channel magnetic grid is divided into two parts, zone A and zone B. The number of magnetic poles in the two parts is different. The vernier principle is introduced, and one zone is used as the main code channel while the other zone is used as the vernier code channel; Step 2: Use the Hall sensor or magnetoresistive sensor to collect the magnetic field strength signal, and then send the signal to the microcontroller for calculation; Step 3: Rotate the shaft by a certain angle and obtain the maximum absolute value of the collected values ​​in the single chip microcomputer; Step 4: Determine the partitions where the N-pole signal sensor and the S-pole signal sensor are located by the maximum absolute value, and then use the single-chip microcomputer to calculate the direction of their respective curves, that is, the positive or negative of the derivative; Step 5: When the N-pole signal sensor is in area A and the S-pole signal sensor is in area B, since the number of magnetic pole pairs in area A is greater than that in area B, the phase value collected in area A should be ahead of that in area B, that is, the phase collected by the N-pole signal sensor is ahead of that by the S-pole signal sensor; Step 6: When the shaft rotates halfway, the N-pole signal sensor enters area B, and the S-pole signal sensor enters area A. The current accumulated phase difference is 2π, and with the subsequent rotation, this phase difference will continue to decrease until it reaches 0; Step 7: The absolute position of any point on the entire magnetic grid is calculated.

2. The method for solving the single-track absolute magnetic encoder based on the partition cursor principle according to claim 1 is characterized in that: The N-pole signal sensor (23) and the S-pole signal sensor (24) are symmetrically located at two ends of the diameter of the magnetic grid (15).

3. The method for solving the single-track absolute magnetic encoder based on the partition cursor principle according to claim 1 is characterized in that: The position of the Hall sensor (14) corresponds to the position of the magnetic grid (15).

4. The method for solving the single-track absolute magnetic encoder based on the partition cursor principle according to claim 1 is characterized in that: The position of the magnetoresistive sensor (12) corresponds to the position of the magnetic grid (15).

5. The method for solving the single-track absolute magnetic encoder based on the partition cursor principle according to claim 1 is characterized in that: Two bearings (16) are symmetrically mounted on the outer side wall of the rotating shaft (17), and a housing assembly (301) is mounted on the outer side wall of the bearing (16). The housing assembly (301) comprises a housing (31), a connector (32), four studs (33) and an end cover (34); The rotating shaft (17) is rotatably connected to the inner wall of the end cover (34) via a bearing (16).

6. The method for solving the single-track absolute magnetic encoder based on the partition cursor principle according to claim 5 is characterized in that: The four studs (33) are symmetrically threadedly connected to the inside of the PCB carrier (11), and the PCB carrier (11) is fixedly connected to the inner front wall of the housing (31) via the four studs (33).

7. The method for solving the single-track absolute magnetic encoder based on the partition cursor principle according to claim 5 is characterized in that: The connector (32) is mounted on the outer wall of the housing (31), the end cover (34) is fixedly connected to the housing (31), and the substrate (18) and the magnetic grid (15) are both located inside the housing (31).

8. The method for solving the single-track absolute magnetic encoder based on the partition cursor principle according to claim 1 is characterized in that: In the step three, the rotation angle of the rotating shaft is greater than the width of a magnetic pole.

9. The method for solving the single-track absolute magnetic encoder based on the partition cursor principle according to claim 1 is characterized in that: In the step 1, the magnetic grid alternately becomes a main code track and a vernier code track during the rotation process to resolve the absolute position.

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