Industrial-grade magnetic ring encoder and method for detecting absolute angle of magnetic ring encoder

Abstract

The application relates to the technical field of encoders, in particular to an industrial-grade magnetic ring encoder and a detection method for the absolute angle of the magnetic ring encoder. The industrial-grade magnetic ring encoder comprises a second plurality of pairs of pole magnets, a first plurality of pairs of pole magnets, a single pair of pole magnet conductor assembly and a first group of Hall elements, a second group of Hall elements and a third group of Hall elements; the single pair of pole magnet conductor assembly has a first tooth-shaped part and a second tooth-shaped part, the first group of Hall elements and the second group of Hall elements are arranged adjacent to the first plurality of pairs of pole magnets and the second plurality of pairs of pole magnets respectively, the third group of Hall elements is arranged between the first tooth-shaped part and the second tooth-shaped part, and the three groups of Hall elements output corresponding detection signals according to the magnetic pole signals of the corresponding magnets. The application calibrates the rotation angle of the outermost ring magnet by acquiring a mechanical angle with certain precision, thereby greatly improving the measurement precision, and the application is especially suitable for meeting the actual needs of angle detection of large-diameter shaft parts.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of encoders, in particular to an industrial-grade magnetic ring encoder and a method for detecting absolute angle of the magnetic ring encoder. BACKGROUND

[0002] The magnetic ring encoder has the advantages of simple structure, high temperature resistance, oil resistance, impact resistance, small size and low cost, and has unique advantages in miniaturization and harsh environment applications.

[0003] The magnetic ring encoder mainly consists of a magnetic signal generating structure and a signal processing circuit, wherein the magnetic signal generating source is called a magnet. According to the number of magnetic poles of the magnet, the magnetic ring encoder can be divided into single-pole magnetic ring encoder and multi-pole magnetic ring encoder. The commonly used multi-pole magnetic ring encoder is a double multi-pole permanent magnet with radial inner and outer ring pole numbers being coprime. The inner multi-pole permanent magnet is the reference magnetic pole, and the outer multi-pole permanent magnet is the measurement magnetic pole. Through the coaxial rotation of the reference magnetic pole and the measurement magnetic pole, the original magnetic field signal is collected by four linear Hall elements, and then the absolute angle value calculation formula is used to obtain the absolute angle of the magnetic ring encoder according to the position relationship between the measurement magnetic pole and the reference magnetic pole, i.e. the magnetic pole position characteristic value.

[0004] In actual application process, if a higher precision magnetic ring encoder is needed, for example, the magnetic ring encoder is used on a large diameter motor shaft or a large diameter hollow rotating shaft, the number of pole pairs of the magnet needs to be increased. The more the number of pole pairs, the higher the precision. However, if several hundred pole pairs are bonded together to form a multi-pole magnet, not only the pole pairs are difficult to manufacture and bond, but also the thickness of the pole pairs will be reduced to less than 1mm, which causes the problem of easy breaking and breaking of the multi-pole magnet during bonding, so that the number of pole pairs of the multi-pole magnet cannot be greatly increased, and the measurement precision is also limited. SUMMARY

[0005] In view of this, the purpose of the present application is to provide an industrial-grade magnetic ring encoder, which aims to overcome the defects that the pole pairs are difficult to manufacture and bond to form a magnet due to the increase of the number of pole pairs for improving the precision of the magnetic ring encoder.

[0006] Another purpose of the present application is to provide a method for detecting absolute angle of an industrial-grade magnetic ring encoder, which aims to solve the problem that the precision of the magnetic ring encoder cannot be improved due to the large increase in the number of pole pairs of the multi-pole magnet.

[0007] In order to achieve the above-mentioned purposes, the technical solutions adopted by the present application are as follows:

[0008] The industrial-grade magnetic ring encoder provided by the present application comprises:

[0009] The second multiple-pole magnet coaxially arranged in sequence along the axial direction, the first multiple-pole magnet and the single-pole magnet combination, wherein the first multiple-pole magnet comprises m pairs of magnetic poles and 3≤m<23, the second multiple-pole magnet comprises n pairs of magnetic poles and 3≤n<23, m is greater than n and is a natural number relatively prime to each other, the single-pole magnet combination comprises a first annular magnet, a single-pole annular magnet and a second annular magnet coaxially arranged in sequence along the axial direction and closely fitted, and the outer ring diameter of the first annular magnet and the second annular magnet is greater than the outer ring diameter of the single-pole annular magnet, wherein the second annular magnet has a cladding part cladded on the outer circular surface of the first annular magnet, and a second tooth-shaped part and a first tooth-shaped part for forming an opening area are respectively arranged on the two surfaces of the cladding part opposite to the first annular magnet, and in this structure, the overall shape of the single-pole magnet combination tends to be closed in the radial cross section, wherein the opening direction of the opening area is consistent with the axial direction of the single-pole annular magnet, and P teeth are respectively arranged on the first tooth-shaped part and the second tooth-shaped part, and p≥100.

[0010] The first group of Hall elements comprises a first linear Hall sensor and a second linear Hall sensor, which are arranged adjacent to the first multiple-pole magnet and output a first group of detection signals according to the magnetic pole signals of the first multiple-pole magnet;

[0011] The second group of Hall elements comprises a third linear Hall sensor and a fourth linear Hall sensor, which are arranged adjacent to the second multiple-pole magnet and output a second group of detection signals according to the magnetic pole signals of the second multiple-pole magnet;

[0012] The third group of Hall elements comprises a fifth linear Hall sensor, a sixth linear Hall sensor and a seventh linear Hall sensor, which are arranged between the first tooth-shaped part and the second tooth-shaped part and output a third group of corrected detection signals according to the magnetic pole signals of the single-pole magnet combination.

[0013] Further, the output signals of the first linear Hall sensor and the second linear Hall sensor are 90 degrees out of phase; the output signals of the third linear Hall sensor and the fourth linear Hall sensor are 90 degrees out of phase; and the output signals of the fifth linear Hall sensor, the sixth linear Hall sensor and the seventh linear Hall sensor are 120 degrees out of phase.

[0014] Still further, the first linear Hall sensor, the third linear Hall sensor and the fifth linear Hall sensor are aligned at one end.

[0015] Still further, the first multiple-pole magnet is arranged between the single-pole magnet combination and the second multiple-pole magnet.

[0016] Preferably, m and n are prime numbers and mn<23×19.

[0017] More preferably, the magnetization directions of the first and second multi-pole magnets are radial or axial, and the starting pole installation positions of the first and second multi-pole magnets have an angle difference.

[0018] More preferably, the magnetization direction of the single-pole ring magnet in the single-pole magnet guide assembly is radial or axial.

[0019] In addition, the application also provides a detection method for the absolute angle of the magnetic ring encoder, which is applied to the industrial magnetic ring encoder with the above-mentioned three-ring structure. The detection method comprises the following steps:

[0020] The first group of detection signals, the second group of detection signals and the corrected third group of detection signals are obtained by the first group of Hall elements, the second group of Hall elements and the third group of Hall elements, respectively.

[0021] The first electric angle value, the second electric angle value and the third electric angle value are obtained by respectively performing angle calculation on the first group of detection signals, the second group of detection signals and the corrected third group of detection signals.

[0022] According to the pole pair number m of the first multi-pole magnet, the pole pair number n of the second multi-pole magnet, the first electric angle value and the second electric angle value, the magnetic pole position characteristic value corresponding to the first multi-pole magnet is obtained.

[0023] According to the magnetic pole position characteristic value, the first magnetic pole interval in which the first electric angle value is currently located is determined.

[0024] According to the first magnetic pole interval, the pole pair number m of the first multi-pole magnet and the first electric angle value, the initial mechanical angle θ formed by the first multi-pole magnet and the second multi-pole magnet is determined. _single

[0025] According to the initial mechanical angle, the tooth number interval in which the third electric angle value is currently located is calibrated.

[0026] The absolute angle of the magnetic ring encoder is determined by using the determined tooth number interval, the tooth number p of the single-pole magnet guide assembly and the third electric angle value.

[0027] Further, the first group of detection signals comprises the first detection signal and the second detection signal output by the first linear Hall sensor and the second linear Hall sensor according to the magnetic pole signal of the first multi-pole magnet.

[0028] The second group of detection signals comprises the third detection signal and the fourth detection signal output by the third linear Hall sensor and the fourth linear Hall sensor according to the magnetic pole signal of the second multi-pole magnet.

[0029] ​The modified third group of detection signals include: fifth linear Hall sensors, sixth linear Hall sensors and seventh linear Hall sensors output d-axis and q-axis detection signals according to magnetic pole signals of a single pair of pole magnet assembly.

[0030] Further, the fifth linear Hall sensors, the sixth linear Hall sensors and the seventh linear Hall sensors output d-axis and q-axis detection signals according to magnetic pole signals of a single pair of pole magnet assembly, specifically including:

[0031] The fifth linear Hall sensors, the sixth linear Hall sensors and the seventh linear Hall sensors collect magnetic pole signals of a single pair of pole magnet assembly to obtain original three-phase Hall signals, which are the fifth detection signal, the sixth detection signal and the seventh detection signal.

[0032] The d-axis and q-axis detection signals are output after zero drift processing of the obtained original three-phase Hall signals.

[0033] Further, the d-axis and q-axis detection signals are output after zero drift processing of the obtained original three-phase Hall signals, specifically including:

[0034] The collected original three-phase Hall signals are subjected to zero drift processing according to the following formula (1);

[0035] The third group of d-axis and q-axis detection signals are output according to the following formula (2):

[0036]

[0037]

[0038] In the formula, U1, U2 and U3 are original three-phase Hall signals; U is signal drift; U'1, U'2 and U'3 are three-phase Hall voltage signals after removing the drift; α is the included angle between the detection signal electric angle of any one linear Hall sensor in the third group of Hall elements and the horizontal direction, and U and U are output two-phase Hall voltage signals. shift d q

[0039] Further, the first group of detection signals, the second group of detection signals and the modified third group of detection signals are respectively angle-solved to obtain first electric angle values, second electric angle values and third electric angle values, specifically including:

[0040] The first group of detection signals, the second group of detection signals and the modified third group of detection signals are subjected to A / D conversion to obtain first group of voltage values, second group of voltage values and third group of voltage values.

[0041] ​​​According to the positive and negative of the voltage values in the first, second and third groups of voltage values and the magnitude of the voltage values, the angle interval in which the first group of detection signals, the second group of detection signals and the third group of detection signals are located is obtained;

[0042] According to the angle interval, the first, second and third electric angle values are obtained by using the arctangent algorithm on the first, second and third groups of voltage values.

[0043] Further, according to the number of magnetic pole pairs m of the first multi-pole magnet, the number of magnetic pole pairs n of the second multi-pole magnet, the first electric angle value and the second electric angle value, a magnetic pole position characteristic value corresponding to the first multi-pole magnet is obtained, specifically including:

[0044] The magnetic pole position characteristic value λ is calculated according to the following formula:

[0045]

[0046] In the formula, θ m is the obtained first electric angle value, and θ n is the obtained second electric angle value.

[0047] Further, according to the first magnetic pole interval, the number of magnetic pole pairs m of the first multi-pole magnet and the first electric angle value, an initial mechanical angle θ _single formed by the first multi-pole magnet and the second multi-pole magnet is determined, specifically including:

[0048] The initial mechanical angle θ _single is calculated according to the following formula:

[0049] θ _single = N m × 360° / m + θ m / m

[0050] In the formula, N m is the magnetic pole interval number in which the first electric angle value θ m is currently located, and N m ∈ [0, m-1].

[0051] Further, according to the initial mechanical angle, the tooth number interval in which the third electric angle value is currently located is calibrated, and then the absolute angle of the magnetic ring encoder is determined by using the determined tooth number interval, the tooth number p of the single-pole magnet combination and the third electric angle value, specifically including:

[0052] According to the obtained initial mechanical angle, the tooth number interval in which the third electric angle value is currently located is calibrated by looking up the table index;

[0053] The absolute angle of the magnetic ring encoder is determined according to the following formula by using the determined tooth number interval, the tooth number p of the single-pair-pole magnet combination assembly and the third electric angle value:

[0054] θ = N p × 360° / p + θ p / p

[0055] In the formula, θ is the absolute angle output by the magnetic ring encoder, N p is the third electric angle value θ p is the tooth number interval number currently located, N p ∈ [0, p-1].

[0056] The beneficial effects of the present application are as follows: in the present application, a surface of the first annular magnet of the single-pair-pole magnet combination assembly is provided with a first tooth-shaped part, a surface of the second annular magnet is provided with a second tooth-shaped part, and the two are kept in an opposite state; when the single-pair-pole magnet combination assembly rotates coaxially for one revolution, the number of periods in the detection signal collected by the Hall element corresponds to the tooth number of the first tooth-shaped part or the second tooth-shaped part, that is, the first tooth-shaped part and the second tooth-shaped part both correspond to P teeth to obtain a detection signal containing P periods, which is exactly the same as the detection signal collected by the Hall element of the multi-pole magnet with P pole pairs. At this time, the single-pair-pole magnet combination assembly can be equivalent to a multi-pole magnet with P pole pairs.

[0057] On this basis, one multi-pole magnet with P pole pairs is axially added to the original two-ring multi-pole magnet, and due to the increase in the number of pole pairs, the multi-pole magnet will have problems in manufacturing and bonding of the pole pairs. The single-pair-pole magnet combination assembly used in the present application can perfectly avoid this defect. The first tooth-shaped part with P teeth can be easily machined on the first annular magnet, and the second tooth-shaped part with P teeth can be easily machined on the second annular magnet, and the teeth on the first tooth-shaped part correspond to the teeth on the second tooth-shaped part one by one. In this way, the number of pole pairs of the multi-pole magnet is greatly increased, thereby greatly improving the measurement accuracy of the encoder, and at the same time, it can also meet the actual needs of angle detection of large-diameter shaft parts. BRIEF DESCRIPTION OF DRAWINGS

[0058] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0059] Figure 1 The cross-sectional view of the industrial-grade magnetic ring encoder structure of the embodiment of the present application is shown.

[0060] Figure 2 A perspective view of the structure of an industrial-grade magnetic ring encoder according to an embodiment of this application is shown;

[0061] Figure 3 This diagram illustrates a flowchart of an absolute angle detection method for a magnetic ring encoder according to an embodiment of this application.

[0062] Figure 4 This invention illustrates the signal detection principle of two linear Hall sensors in an embodiment of this application.

[0063] Figure 5 This illustration shows a schematic diagram of two linear Hall elements detecting signals in an embodiment of this application.

[0064] Figure 6 This invention illustrates the signal detection principle of three linear Hall sensors in an embodiment of this application.

[0065] Figure 7 This illustration shows a schematic diagram of the signals detected by three linear Hall sensors in an embodiment of this application.

[0066] Figure 8 This diagram illustrates the principle of eliminating zero-point drift using three Hall signals in an embodiment of this application.

[0067] Figure 9 A schematic diagram illustrating the principle of synthesizing two-phase Hall signals in an embodiment of this application is shown;

[0068] Figure 10 Show Figures 1-2 There is an angular difference θ between the initial magnetic pole installation positions of the second multi-pole magnet and the first multi-pole magnet. x A schematic diagram;

[0069] Figure 11 This diagram illustrates the number of magnetic pole position feature values ​​in an embodiment of this application. Detailed Implementation

[0070] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided to make the invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted.

[0071] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of the invention.

[0072] It should be understood that although the terms first, second, third, etc. can be used herein to describe various components, these components should not be limited by these terms. These terms are only used to distinguish one component from another. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0073] Those skilled in the art can understand that the drawings are only schematic views of the example embodiments. The modules or flows in the drawings are not necessarily essential for implementing the present application, and therefore cannot be used to limit the protection scope of the present application.

[0074] In the actual application process of the existing two-ring multi-pole magnetic ring encoder with coprime pole pairs, the situation of a large-diameter shaft will inevitably be encountered. In this case, for the two-ring multi-pole magnet set on the large-diameter shaft, it is necessary to correspondingly increase the pole pair number of the magnet itself. In the ideal case, that is, under the condition that there is no installation error and no noise influence of the two-ring multi-pole magnet, the two-ring multi-pole magnetic ring encoder with coprime pole pairs can completely measure the rotation angle of the large-diameter shaft part, but the applicant's technical personnel find that in the actual application process, when the pole pair number of the two-ring multi-pole magnet is increased to a certain number, the detection signal obtained through the Hall element will be completely consistent in a certain angle interval, which will cause the two-ring multi-pole magnetic ring encoder with coprime pole pairs to be unable to measure the rotation angle of the large-diameter shaft part, thereby causing the measurement accuracy of the magnetic ring encoder to fail.

[0075] In theory, axially adding a multi-pole magnet with a large pole pair number to the existing two-ring multi-pole magnet can obtain the actual rotation angle of the encoder, thereby meeting the detection needs of the large-diameter shaft workpiece.

[0076] However, a large increase in the pole pair number of the magnet will cause the thickness of the pole pair to be sharply reduced to within 1 mm, and several hundred pole pairs need to be bonded together to form a magnet. First, the process of manufacturing the pole pair is difficult to implement, and the bonding process is also very difficult. Finally, the multi-pole magnet formed is also easy to break and break, and ultimately the large increase in the pole pair number of the multi-pole magnet cannot be realized, and the measurement accuracy is also limited.

[0077] In order to solve the above problems, the application provides an industrial-grade magnetic ring encoder, which comprises a single-pair-pole magnet assembly. In the single-pair-pole magnet assembly, a surface of a first annular magnet is provided as a first tooth-shaped part, a surface of a second annular magnet is provided as a second tooth-shaped part, and the first tooth-shaped part and the second tooth-shaped part are kept opposite to each other. When the single-pair-pole magnet assembly rotates coaxially for one revolution, the number of periods in the detection signal collected by the Hall element is in one-to-one correspondence with the number of teeth of the first tooth-shaped part or the second tooth-shaped part, that is, the first tooth-shaped part and the second tooth-shaped part both correspond to P teeth to obtain a detection signal containing P periods, which is exactly the same as the detection signal collected by the Hall element from a multi-pair-pole magnet with P pole pairs. At this time, the single-pair-pole magnet assembly can be equivalent to a multi-pair-pole magnet with P pole pairs.

[0078] Furthermore, the single-pair-pole magnet assembly can perfectly avoid the defects of difficult processing and difficult bonding. The first tooth-shaped part with P teeth can be easily machined on the first annular magnet, and the second tooth-shaped part with P teeth can be easily machined on the second annular magnet, and the teeth on the first tooth-shaped part and the teeth on the second tooth-shaped part are in one-to-one correspondence, so that the number of pole pairs of the multi-pair-pole magnet is greatly increased, thereby greatly improving the measurement accuracy of the encoder, and also meeting the actual needs of angle detection of large-diameter shaft parts.

[0079] The technical solutions of the application will be described in detail below with reference to the drawings.

[0080] Figure 1 A cross-sectional view of the structure of the industrial-grade magnetic ring encoder of the embodiment of the application is shown.

[0081] Figure 2 A perspective view of the structure of the industrial-grade magnetic ring encoder of the embodiment of the application is shown.

[0082] As Figure 1 , Figure 2As shown, the application provides an industrial-grade magnetic ring encoder 100, which comprises a second plurality of pairs of magnetic poles 120, a first plurality of pairs of magnetic poles 110 and a single pair of magnetic pole magnet conductor assembly 130 arranged coaxially and sequentially in a first spatial plane, the single pair of magnetic pole magnet conductor assembly 130 comprises a first annular magnetic conductor 135, a single pair of annular magnetic pole 134 and a second annular magnetic conductor 136 arranged coaxially and sequentially in close contact, and the outer ring diameter of the first annular magnetic conductor 135 and the second annular magnetic conductor 136 is greater than the outer ring diameter of the single pair of annular magnetic pole 134, wherein the second annular magnetic conductor 136 has a cladding part covering the outer circular surface of the first annular magnetic conductor 135, and a second tooth-shaped part and a first tooth-shaped part for forming an opening area are respectively arranged on the two surfaces of the cladding part opposite to the first annular magnetic conductor 135, under this structure, the overall shape of the single pair of magnetic pole magnet conductor assembly 130 tends to be closed in its radial cross-section, wherein the opening direction of the opening area is consistent with the axial direction of the single pair of annular magnetic pole 134, and P teeth are respectively formed on the first tooth-shaped part and the second tooth-shaped part, and p≥100.

[0083] The first plurality of pairs of magnetic poles 110 comprises m pairs of magnetic poles and 3≤m<23, the second plurality of pairs of magnetic poles 120 comprises n pairs of magnetic poles and 3≤n<23, m is greater than n and mn<23×19, and the number of teeth p of the single pair of magnetic pole magnet conductor assembly 130 can be 100, 200, 300, 400, 500, 600, 700, 800 or even more, and the more the number of P, the higher the accuracy of the final magnetic ring encoder. For example, according to some embodiments, m and n are prime numbers and relatively prime to each other. As Figure 1 、 2 As shown, in this embodiment, m is 5, n is 3, and p is 100, but the application is not limited to this.

[0084] According to the example embodiments of the application, the first plurality of pairs of magnetic poles 110 is between the single pair of magnetic pole magnet conductor assembly 130 and the second plurality of pairs of magnetic poles 120. The number of pole pairs m of the first plurality of pairs of magnetic poles 110 is greater than the number of pole pairs n of the second plurality of pairs of magnetic poles 120. This is because the diameter of the first plurality of pairs of magnetic poles 110 is greater than the diameter of the second plurality of pairs of magnetic poles 120, in order to make the size of the magnetic poles uniform, the number of magnetic pole pairs of the first plurality of pairs of magnetic poles 110 is greater than the number of magnetic pole pairs of the second plurality of pairs of magnetic poles 120.

[0085] In the application, the number of pole pairs m of the first plurality of pairs of magnetic poles 110 and the number of pole pairs n of the second plurality of pairs of magnetic poles 120 are defined, which is to obtain effective detection signals in actual application and avoid the coincidence of detection signals in a certain angle range.

[0086] According to some embodiments of the application, the magnetization direction of the first plurality of pairs of magnetic poles 110 can be radial or axial. In Figure 1 、2 In the illustrated embodiment, the magnetization direction of the first multi-pole magnet 110 is set to be axial. The magnetization direction of the second multi-pole magnet 120 can also be radial or axial. Figure 1 、 2 In the illustrated embodiment, the magnetization direction of the second multi-pole magnet 120 is set to be axial. Similarly, the magnetization direction of the single-pole magnet guide magnet assembly 130 can also be radial or axial. Figure 1 、 2 In the illustrated embodiment, the magnetization direction of the single-pole ring magnet 134 is set to be axial. The application does not limit the magnetization direction.

[0087] The first multi-pole magnet 110 and the second multi-pole magnet 120 can be formed by adhering a plurality of magnetic poles, but are not limited thereto. According to the embodiment of the application, the magnets can be made of neodymium iron boron permanent magnet material, directly attached to the shaft, or fixed on the shaft, and there is an angle difference in the installation of the starting magnetic poles of the first multi-pole magnet 110 and the second multi-pole magnet 120 when installed and fixed.

[0088] As shown in Figure 1 、 2 The industrial-grade magnetic ring encoder 100 further includes a first group of Hall elements, a second group of Hall elements, and a third group of Hall elements for detecting the magnetic signals generated by the multi-pole magnets.

[0089] The first group of Hall elements includes a first linear Hall sensor 111 and a second linear Hall sensor 112, which are arranged adjacent to the first multi-pole magnet 110 and output a first group of detection signals according to the magnetic pole signals of the first multi-pole magnet 110. The output signals of the first linear Hall sensor 111 and the second linear Hall sensor 112 are 90 degrees out of phase.

[0090] The second group of Hall elements includes a third linear Hall sensor 121 and a fourth linear Hall sensor 122, which are arranged adjacent to the second multi-pole magnet 120 and output a second group of detection signals according to the magnetic pole signals of the second multi-pole magnet 120. The output signals of the third linear Hall sensor 121 and the fourth linear Hall sensor 122 are 90 degrees out of phase.

[0091] The third group of Hall elements includes a fifth linear Hall sensor 131, a sixth linear Hall sensor 132, and a seventh linear Hall sensor 133, which are arranged between the first tooth-shaped portion and the second tooth-shaped portion and output a third group of detection signals according to the magnetic pole signals of the single-pole magnet guide magnet assembly 130. The output signals of the fifth linear Hall sensor 131, the sixth linear Hall sensor 132, and the seventh linear Hall sensor 133 are 120 degrees out of phase.

[0092] It should be noted that the third group of Hall elements will collect three kinds of original detection signals after the single-pair-pole magnet assembly 130 rotates one revolution around the shaft, and the number of periods in each original detection signal is exactly the same as the number of teeth of the first tooth-shaped portion in the first annular magnet 135 or the second tooth-shaped portion in the second annular magnet 136. That is, the number of teeth P of the first tooth-shaped portion or the second tooth-shaped portion coincides with the number of periods in the detection signal, and therefore, the single-pair-pole magnet assembly 130 with the first annular magnet 135 and the second annular magnet 136 both having P teeth can be considered as a multi-pair-pole magnet with a pole pair number of P.

[0093] According to the tooth-shaped structure, it can be seen that each tooth contains a tooth top and a tooth recess. According to the distance between the tooth top and the tooth recess of the tooth on the first tooth-shaped portion and the tooth top and the tooth recess of the tooth on the second tooth-shaped portion corresponding thereto, the change of the magnetic field strength can be reflected, that is, according to the characteristics of the magnetic field, in the case that the distance between the two tooth tops is obviously smaller than the distance between the two tooth recesses, the magnetic field strength between the two tooth tops is obviously greater than the magnetic field strength between the two tooth recesses.

[0094] According to some embodiments, in the above-mentioned encoder structure, the first linear Hall sensor 111, the third linear Hall sensor 121, and the fifth linear Hall sensor 131 are aligned at one end; and when the above-mentioned encoder is working, the first multi-pair-pole magnet 110, the second multi-pair-pole magnet 120, and the single-pair-pole magnet assembly 130 rotate together with the shaft, and the three groups of Hall elements remain stationary.

[0095] Figure 3 A flowchart of an absolute angle detection method of a magnetic ring encoder according to an embodiment of the present application is shown.

[0096] The present application also provides an absolute angle detection method of the above-mentioned magnetic ring encoder, as shown in Figure 3 The method comprises the following steps:

[0097] In step S310, a first group of detection signals, a second group of detection signals, and a third group of detection signals are obtained by the first group of Hall elements, the second group of Hall elements, and the third group of Hall elements, respectively.

[0098] The magnetic ring encoder provided by the present application comprises a second multi-pair-pole magnet 120, a first multi-pair-pole magnet 110, and a single-pair-pole magnet assembly 130, wherein the pole pair number of the second multi-pair-pole magnet 120 and the first multi-pair-pole magnet 110 are coprime, and the three groups of magnets are isolated by an isolation means to prevent magnetic field coupling. The magnetic field around the three groups of multi-pair-pole magnets presents a sinusoidal distribution in the circumferential direction.

[0099] Two linear Hall sensors in the first group of Hall elements and the second group of Hall elements corresponding to the first multi-pole magnet 110 and the second multi-pole magnet 120 are arranged at an included angle of 90° in electric angle. The following will be introduced in combination with Figure 4 , 5 The principle of detecting the magnetic signal of the second multi-pole magnet 120 or the first multi-pole magnet 110 by using two linear Hall sensors is introduced.

[0100] Figure 4 The principle diagram of signal detection of two linear Hall sensors in the embodiment of the application is shown.

[0101] Figure 5 The schematic diagram of signal detection of two linear Hall elements in the embodiment of the application is shown.

[0102] The magnetic field at any point in the space where the magnet is located changes regularly as the magnet rotates with the rotating shaft. The change can be converted into a cosine electric signal by using two linear Hall sensors with an included angle of 90° in electric angle, and the frequency of the electric signal change is the same as the frequency of the magnetic pole rotation. As shown in Figure 4 , 5 For the second multi-pole magnet 120 with three magnetic poles, the third linear Hall sensor 121 and the fourth linear Hall sensor 122 respectively detect three periods of sine and cosine signals, i.e., a group of detection signals, as the magnet rotates one round. The first group of detection signals can be obtained by the first group of Hall elements arranged by the first multi-pole magnet 110. The second group of detection signals can be obtained by the second group of Hall elements arranged by the second multi-pole magnet 120.

[0103] In actual process, the two-Hall arrangement is often arranged at an included angle of 90° in electric angle. However, the two-Hall method is difficult to eliminate the error caused by processing or assembly, and it is also difficult to suppress the harmonic error existing in the magnetic field. Increasing the number of Hall or symmetrically arranging the Hall mainly reduces the mechanical error by using symmetric cancellation, and also cancels the harmonic component. Therefore, the three-Hall arrangement is arranged between the first tooth-shaped part and the second tooth-shaped part of the single-pole magnet combination 130, and a higher calculation precision can be obtained when the electric angle of the three Hall is 120°.

[0104] The third group of Hall elements is arranged between the first tooth-shaped part and the second tooth-shaped part, and the three linear Hall sensors are arranged at an included angle of 120° in electric angle. The following will be introduced in combination with Figures 6-9 The principle of detecting the magnetic signal of the single-pole magnet combination 130 by using three linear Hall sensors is introduced.

[0105] Figure 6 The principle diagram of signal detection of three linear Hall sensors in the embodiment of the application is shown.

[0106] Figure 7 This diagram illustrates the signal detection of three linear Hall sensors in an embodiment of this application.

[0107] Figure 8 This diagram illustrates the principle of eliminating zero-point drift using three Hall signals in an embodiment of this application.

[0108] Figure 9 The schematic diagram of synthesizing two-phase Hall signals in the embodiments of this application is shown.

[0109] Based on the above principle, it is easy to see that this magnetic field change can also be converted into sine and cosine electrical signals using three linear Hall sensors with electrical angles differing by 120°. For example... Figure 6 , 7 As shown, for a single-pole magnetic conductor assembly 130, which is a group of multi-pole magnets with six pole pairs, when the magnet rotates one revolution, the fifth linear Hall sensor 131, the sixth linear Hall sensor 132, and the seventh linear Hall sensor 133 detect six cycles of sine and cosine signals, i.e., the original three-phase Hall signals. The original three-phase Hall signals here... Figure 8 The signals are represented by U1, U2, and U3 respectively, with U1 corresponding to the detection signal of the fifth linear Hall sensor 131; U2 corresponding to the detection signal of the sixth linear Hall sensor 132; and U3 corresponding to the detection signal of the seventh linear Hall sensor 133.

[0110] Due to issues with Hall effect placement and mechanical assembly, the original three-phase Hall signals U1, U2, and U3 are superimposed with some error signals, affecting the component U of the synthesized two-phase 90° phase difference. d U q At that time, there is a high probability that the zero point will drift.

[0111] Therefore, it is necessary to perform zero-point drift processing on the acquired raw three-phase Hall signals, such as... Figure 8 As shown, the calculation is performed according to the following formula:

[0112]

[0113] In the formula, U1, U2, and U3 are the original three-phase Hall signals; U shift U′1, U′2, and U′3 are the signal drift amounts; U′1, U′2, and U′3 are the three-phase Hall voltage signals after removing the drift amounts.

[0114] Then, the three-phase Hall voltage signals, after removing zero-point drift, are synthesized into a two-phase U with a 90° phase difference. d U q Signals, such as Figure 9 As shown, the conversion is performed using the following formula:

[0115]

[0116] In the formula, α is the angle between the electrical angle of the detection signal of any linear Hall sensor in the third group of Hall elements and the horizontal direction, and U d U q The output two-phase Hall voltage signals are the corrected third set of detection signals.

[0117] At this point, the third set of detection signals with a corrected two-phase phase difference of 90° can be approximated as sine and cosine detection signals acquired by two linear Hall sensors. For the convenience of subsequent textual explanation, this application approximates the third set of Hall elements as two linear Hall sensors arranged at an electrical angle of 90°.

[0118] Of course, the second multi-pair magnet 120 and the first multi-pair magnet 110 of this application can also be arranged in the form of a three-Hall sensor to improve the measurement accuracy, and then the above formula can be used to convert the acquired detection signal into a detection signal with a two-phase phase difference of 90°.

[0119] In step S320, angle calculations are performed on the first group of detection signals, the second group of detection signals, and the corrected third group of detection signals to obtain the first electrical angle value, the second electrical angle value, and the third electrical angle value, respectively.

[0120] After obtaining sine and cosine signals using a linear Hall sensor, a digital voltage value with a certain number of bits can be obtained through an A / D conversion circuit. That is, the first, second, or corrected third set of detection signals are converted to digital values ​​using an A / D converter to obtain the first, second, or third set of voltage values. While the digital voltage value at this point is related to the encoder's measured angle, it is not the encoder's measured angle value and requires angle calculation.

[0121] For each pair of magnetic poles, the two linear Hall sensors are spatially 90° apart, causing their output sine and cosine signals to be 90° out of phase. The signal with the leading phase can be considered a sine signal, and the signal with the lagging phase a cosine signal. Dividing the sine signal by the cosine signal yields the tangent of the signal at that point. Then, performing an arctangent operation on this tangent yields the electrical angle value at that point.

[0122] Since the tangent function's interval is [-90°, 90°], directly calculating the angle using the above process will lead to an error in the angle calculation interval. Therefore, it is necessary to solve the interval error problem by dividing the intervals, that is, obtaining the electrical angle interval of the first group of detection signals, the second group of detection signals, or the corrected third group of detection signals based on the sign and magnitude of the voltage values ​​in the first group of voltage values, the second group of voltage values, or the corrected third group of voltage values.

[0123] Taking the angle resolution of a group of magnetic poles as an example, 360° of the group of magnetic poles can be divided into 8 equal length intervals at intervals of 45°. The position of the Hall signal at this time is determined by judging the size and sign of the voltage values detected by the two linear Hall elements, and the implementation principle of the interval arctangent algorithm is shown in Table 1. VA and VB are linear Hall detection signals with a phase difference of 90°.

[0124] Table 1 Angle interval division

[0125]

[0126] Through the above angle interval division, the conversion of the signal collected by the Hall element to the angle signal can be realized, and the converted electrical angle interval range is [0°, 360°].

[0127] For the magnetic ring encoder of the present application, according to the sign and value of the voltage values in the first group of voltage values, the second group of voltage values and the third group of voltage values, the angle interval of the first group of detection signals, the second group of detection signals and the corrected third group of detection signals can be obtained. According to the angle interval, the first electrical angle value, the second electrical angle value and the third electrical angle value can be obtained by using the arctangent algorithm on the first group of voltage values or the second group of voltage values or the third group of voltage values according to Table 1. The electrical angle value here refers to the electrical angle value of a single pair of magnetic pole period, simply referred to as single period electrical angle value.

[0128] In the process of angle measurement, the three groups of multi-pair pole magnets rotate simultaneously with the shaft, and the linear Hall element remains stationary for receiving the changing magnetic field signal generated by the magnetic pole in the rotation process. The induction signal of the linear Hall is processed by the above-mentioned arctangent lookup table method, and the electrical angle value of a single pair of magnetic pole period of the measured magnet can be obtained. After determining the single period electrical angle value, the magnetic pole interval where the single period electrical angle value is located is determined, and finally the tooth number interval on the single pair of pole magnet group assembly 130 is determined, so that the absolute angle value detected by the magnetic ring encoder can be finally obtained.

[0129] In the absolute angle detection method of the magnetic ring encoder provided in the present application, first, an initial mechanical angle with a certain accuracy is determined according to the two groups of detection signals of the second multi-pair pole magnet 120 and the first multi-pair pole magnet 110, and then the initial mechanical angle is used to calibrate which specific tooth number interval the single period electrical angle value of the single pair of pole magnet group assembly 130 is currently in. Finally, the mechanical angle value is calculated by using the calculation formula of the mechanical angle value to calculate the mechanical angle of the magnetic ring encoder. The mechanical angle mentioned in the present application is also called absolute angle.

[0130] Next, the application will describe in detail how to obtain the initial mechanical angle with certain accuracy.

[0131] In the application, the calculation of the initial mechanical angle can be calculated according to the following formula:

[0132] θ _single = N m × 360° / m + θ m / m formula (3) wherein, N m ∈ [0, m-1] or

[0133] θ _single = (N m -1) × 360° / m + θ m / m formula (4) wherein, N m ∈ [1, m]

[0134] In the formula, θ _single is the initial mechanical angle, θ m is the single cycle electric angle value measured by the linear Hall sensor on the first multi-pole magnet 110, N m is the first magnetic pole interval where θ m is located; m is the number of magnetic pole pairs of the first multi-pole magnet 110. Here, θ m is also called the first electric angle value.

[0135] For the encoder shown in Figures 1-2 , the second multi-pole magnet 120 and the starting magnetic pole installation position of the first multi-pole magnet 110 have an angle difference θ x , as shown in Figure 10 , then the initial mechanical angle can also be represented as:

[0136] θ _single = N n × 360° / n + θ n / n + θ x formula (5) wherein, N n ∈ [0, n-1] or

[0137] θ _single = (N n -1) × 360° / n + θ n / n + θ x formula (6) wherein, N n ∈ [1, n]

[0138] In the formula, θ _single is the initial mechanical angle, θ n is the single cycle electric angle value measured by the linear Hall sensor on the second multi-pole magnet 120, N n is the first magnetic pole interval where θ nThe second magnetic pole interval in which the second pair of pole magnets 120 is located; n is the number of pole pairs of the second pair of pole magnets 120. θ n Also referred to as the second electrical angle value.

[0139] Therefore, on the basis of having obtained the first electrical angle value or the second electrical angle value, as long as the corresponding magnetic pole interval is determined, the initial mechanical angle value can be calculated according to the above formula (3) - formula (6).

[0140] In step S330, according to the number of pole pairs m of the first pair of pole magnets 110, the number of pole pairs n of the second pair of pole magnets 120, the first electrical angle value, and the second electrical angle value, the first magnetic pole interval corresponding to the first electrical angle value is determined.

[0141] When the linear Hall sensor on the first pair of pole magnets 110 measures the same single-period electrical angle value twice, the two single-period electrical angle values measured by the linear Hall sensor on the second pair of pole magnets 120 are different, so that the magnetic pole interval in which the first pair of pole magnets 110 single-period electrical angle is currently located can be distinguished.

[0142] For the magnetic ring encoder magnet structure provided in the present application, in the case that the greatest common divisor of the number of pole pairs m and n of the first pair of pole magnets 110 and the second pair of pole magnets 120 is 1, that is, they are co-prime, each pair of poles of the first pair of pole magnets 110 has a corresponding non-repeated magnetic pole part of the second pair of pole magnets 120. The following is proved by reductio ad absurdum.

[0143] Suppose there are positive integers N m1 , N m2 , N n1 , N n2 , N m1 ≠N m2 , such that:

[0144] (N m1 -1)×360° / m+θ m / m=(N n1 -1)×360° / n+θ n / n+θ x

[0145] (N m2 -1)×360° / m+θ m / m=(N n2 -1)×360° / n+θ n / n+θ x Formula (7)

[0146] Where θ m is the single-period electrical angle value measured by the linear Hall sensor on the first pair of pole magnets 110, Nm1 , N m2 ∈ [1, m], θ m corresponds to the first magnetic pole interval; θ n is a single period electric angle value measured by the linear Hall sensor on the second multi-pole magnet 120, N n1 , N n2 ∈ [1, n], θ n corresponds to the second magnetic pole interval; θ x is the installation angle difference of a pair of magnetic pole start points in the two groups of magnets.

[0147] Subtracting the two formulas in formula (7), we get:

[0148]

[0149] Since m and n are coprime, and N m1 -N m2 ∈ [1, m-1], formula (8) is always not true, that is, formula (7) is always not true.

[0150] From formula (8), we further get:

[0151]

[0152] Formula (9) is not true for any different N m and its corresponding N n . That is, formula (9) is not true for different magnetic pole pairs in the first multi-pole magnet 110 and the corresponding magnetic pole pairs in the second multi-pole magnet 120. Thus it can be proved that when the linear Hall sensor on the first multi-pole magnet 110 measures the same single period electric angle value, the two single period electric angle values measured by the linear Hall sensor on the second multi-pole magnet 120 are different. In this way, the magnetic pole interval where the first angle value is currently located can be distinguished through the positional relationship between the first multi-pole magnet 110 and the second multi-pole magnet 120.

[0153] From formula (3) and formula (5), we get:

[0154]

[0155] It can be seen that the value on the right side of the expression is a single period electric angle value that does not contain the current sampling point, and its value only depends on the magnetic pole interval number of the second multi-pole magnet 120 and the first multi-pole magnet 110. In the case where the magnetic pole interval number group (N m , N n ) is fixed, its value is a constant, and this constant is the characteristic value of the mapping interval number group.

[0156] Set and define it as the pole position characteristic value. As can be seen from equation (10), when the number of pole pairs of the first multi-pair pole magnet 110 and the second multi-pair pole magnet 120 is constant, the pole position characteristic value is constant. When at least one of them changes, the pole position characteristic value will also change, otherwise equation (9) is true, which contradicts the premise that the number of pole pairs is co-prime. Thus, the magnetic pole interval in which the current electrical angle is located can be determined by calculating the pole position characteristic value.

[0157] When θ x ≠ 0, that is, the starting points of some pole pairs of the second multi-pair pole magnet 120 and the first multi-pair pole magnet 110 do not coincide, and it is also impossible to make them coincide by changing the coordinate starting point, the pole position characteristic value λ has m+n different values. As shown in Figure 11 .

[0158] Figure 11 A schematic diagram of the number of values of the pole position characteristic value of the embodiment of the application is shown.

[0159] Figure 11 In the figure, the first multi-pair pole magnet 110 is m pairs of poles, and m is 5, so five boxes are used to represent the planar development of the five pairs of poles. The second multi-pair pole magnet 120 is n pairs of poles, and n is 3. After being planarly developed, it is equivalent to introducing three vertical lines in the five boxes. Since θ x ≠ 0, there are m+n+1 lines in total, which are divided into m+n parts. That is, for an encoder with five pairs of poles and three pairs of poles, the position characteristic value has eight different values. By analogy, for an encoder with two pairs of poles and nineteen pairs of poles, the pole position characteristic value has forty-two different values.

[0160] After the installation of the second multi-pair pole magnet 120 and the first multi-pair pole magnet 110 is completed, the value of θ x is determined, and then the m+n different values are also determined. According to the number of pole pairs m of the first multi-pair pole magnet 110 and the number of pole pairs n of the second multi-pair pole magnet 120, as well as the first electrical angle value and the second electrical angle value, the pole position characteristic value corresponding to the first multi-pair pole magnet 110 can be determined. For example, Figure 10 , when θ x = 40°, the rotation direction of the magnet is clockwise, and the pole position characteristic value obtained by calibration and the corresponding magnetic pole interval on the first multi-pair pole magnet 110 are shown in Table 2.

[0161] Correspondence between λ value and first multi-pair pole magnet magnetic pole interval

[0162]

[0163] By the correspondence between the λ and the magnetic pole interval in Table 2, the identification of the magnetic pole position can be completed, i.e. according to the magnetic pole position characteristic value, the first electric angle value currently located in the first magnetic pole interval is calculated.

[0164] In step S340, according to the first magnetic pole interval, the number of magnetic pole pairs m of the first multi-pole magnet 110, and the first electric angle value, the initial mechanical angle θ formed by the first multi-pole magnet 110 and the second multi-pole magnet 120 is determined. _single .

[0165] After the first electric angle value and the first magnetic pole interval where the electric angle value is located are determined, the initial mechanical angle formed by the first multi-pole magnet 110 and the second multi-pole magnet 120 can be obtained according to formula (3).

[0166] In step S350, according to the initial mechanical angle, the tooth number interval where the third electric angle value is currently located is calibrated.

[0167] On the premise that the initial mechanical angle is obtained, the initial mechanical angle can be used to calibrate the tooth number interval where the third electric angle value of the single-pole magnet guide magnet assembly 130 is currently located.

[0168] In this application, the tooth number interval N p and the initial mechanical angle have the following correspondence:

[0169] N p = INT(θ _single × p / 360), N p ∈ [0, p-1]

[0170] Therefore, the index table of the correspondence between the initial mechanical angle and the tooth number interval is established, the first column of the index table is the value of the initial mechanical angle, and the second column is the interval number of the tooth number interval corresponding to the initial mechanical angle. Since the initial mechanical angle is an absolute angle, its value range is [0°, 360°], so the first column of the first row is the number 0, and the last column of the first row is the number 360.

[0171] For example, assuming that the tooth number P of the single-pole magnet guide magnet assembly 130 is 5, the initial mechanical angle obtained by calibration and the corresponding tooth number interval are shown in Table 3.

[0172] Table 3 Index table of the correspondence between the initial mechanical angle and the tooth number interval in the single-pole magnet guide magnet assembly

[0173] initial mechanical angle θ _single ]]> Tooth number interval P 0 0 1 0 2 0 3 … … 3 358 3 359 4 360 4

[0174] Therefore, only the initial mechanical angle degree needs to be determined, and the tooth number interval value can be obtained from the table. However, it should be noted that when the table is prepared, the number of rows in the initial mechanical angle column should be set to be much larger than the pole pair number of the single-pole magnet combination assembly 130, i.e. the tooth number P, so as to greatly improve the accuracy of the magnetic ring encoder.

[0175] For example, in Table 3, the number of rows in the initial mechanical angle column is 360, and the tooth number P of the single-pole magnet combination assembly 130 is 5, which satisfies the requirement of being much larger than the tooth number P of the single-pole magnet combination assembly 130.

[0176] Suppose the tooth number P of the single-pole magnet combination assembly 130 is 360, the number of rows in the initial mechanical angle column can be set to 360, i.e. each degree of the initial mechanical angle corresponds to a tooth number interval of the single-pole magnet combination assembly 130; similarly, the number of rows in the initial mechanical angle column can also be set to 3600, so that each 0.1 degree of the initial mechanical angle corresponds to a tooth number interval of the single-pole magnet combination assembly 130, and the accuracy of the magnetic ring encoder is improved by 10 times. Correspondingly, the accuracy can also be improved by 20 times, 30 times, or even 100 times or more, which is the significance of the number of rows being much larger than the pole pair number.

[0177] In step S360, the absolute angle of the magnetic ring encoder is determined according to the following formula by using the determined tooth number interval, the tooth number P of the single-pole magnet combination assembly 130, and the third electric angle value:

[0178] θ = N p × 360° / P + θ p / P

[0179] In the formula, θ is the absolute angle output by the magnetic ring encoder, N p is the third electric angle value θ p , the tooth number interval number in which the single-pole magnet combination assembly 130 currently locates, N p ∈ [0, P-1].

[0180] Finally, it should be noted that the above description is only for the preferred embodiments of the present application and is not used to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or make equivalent replacements to some technical features, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. An industrial-grade magnetic ring encoder, characterized in that, include: A second multi-pole magnet, a first multi-pole magnet, and a single-pole magnetic conductor assembly are arranged coaxially and sequentially. The first multi-pole magnet includes m pairs of magnetic poles and 3 ≤ m < 23. The second multi-pole magnet includes n pairs of magnetic poles and 3 ≤ n < 23, where m is greater than n and is a natural number that is coprime to each other. The single-pole magnetic conductor assembly includes a first annular magnetic conductor, a single-pole annular magnet, and a second annular magnetic conductor that are coaxially and sequentially tightly fitted together. The outer ring diameters of the first and second annular magnetic conductors are larger than the outer ring diameter of the single-pole annular magnet. The second annular magnetic conductor has a covering portion that covers the outer circular surface of the first annular magnetic conductor. On the two surfaces of the covering portion opposite to the first annular magnetic conductor, a second toothed portion and a first toothed portion are respectively provided for forming an opening region. The opening direction of the opening region is consistent with the axial direction of the single-pole annular magnet, and P teeth are correspondingly opened on both the first and second toothed portions, where p ≥ 100. The first group of Hall elements, including a first linear Hall sensor and a second linear Hall sensor, is arranged adjacent to the first multiple pairs of pole magnets and outputs a first group of detection signals based on the magnetic pole signals of the first multiple pairs of pole magnets. The second group of Hall elements, including the third linear Hall sensor and the fourth linear Hall sensor, is arranged adjacent to the second multiple pairs of pole magnets and outputs the second group of detection signals according to the magnetic pole signals of the second multiple pairs of pole magnets. The third group of Hall elements includes a fifth linear Hall sensor, a sixth linear Hall sensor, and a seventh linear Hall sensor, and is disposed between the first toothed portion and the second toothed portion, and outputs a corrected third group of detection signals based on the magnetic pole signals of the single-pair magnetic conductor assembly.

2. The industrial-grade magnetic ring encoder according to claim 1, characterized in that: The output signals of the first and second linear Hall sensors are 90 degrees out of phase; the output signals of the third and fourth linear Hall sensors are 90 degrees out of phase; and the output signals of the fifth, sixth, and seventh linear Hall sensors are 120 degrees out of phase.

3. The industrial-grade magnetic ring encoder according to claim 1, characterized in that: The first linear Hall sensor, the third linear Hall sensor, and the fifth linear Hall sensor are aligned at one end.

4. The industrial-grade magnetic ring encoder according to claim 1, characterized in that: The first multiple pairs of pole magnets are located between the single pair of pole conductor assembly and the second multiple pairs of pole magnets.

5. The industrial-grade magnetic ring encoder according to claim 1, characterized in that: m and n are prime numbers and mn < 23 × 19.

6. The industrial-grade magnetic ring encoder according to claim 1, characterized in that: The magnetization directions of the first and second pairs of pole magnets are radial or axial, and there is an angular difference between the initial pole installation positions of the first and second pairs of pole magnets.

7. The industrial-grade magnetic ring encoder according to claim 1, characterized in that: The magnetization direction of the single-pole annular magnet in the single-pole magnetic conductor assembly is radial or axial.

8. A method for detecting the absolute angle of a magnetic ring encoder, characterized in that, The detection method, applied in any one of claims 1-7, comprises: The first group of detection signals, the second group of detection signals, and the corrected third group of detection signals are obtained by the first group of Hall elements, the second group of Hall elements, and the third group of Hall elements, respectively. Angle calculations are performed on the first group of detection signals, the second group of detection signals, and the corrected third group of detection signals to obtain the first electrical angle value, the second electrical angle value, and the third electrical angle value, respectively. Based on the number of magnetic pole pairs m of the first multi-pole magnet, the number of magnetic pole pairs n of the second multi-pole magnet, the first electrical angle value, and the second electrical angle value, obtain the magnetic pole position characteristic value corresponding to the first multi-pole magnet; Based on the magnetic pole position characteristic value, the first magnetic pole interval where the first electrical angle value is currently located is determined; The initial mechanical angle θ formed by the first and second pairs of pole magnets is determined based on the first magnetic pole region, the number of pole pairs m of the first multi-pole magnet, and the first electrical angle value. _single ; Based on the initial mechanical angle, the tooth count range in which the third electrical angle value currently falls is calibrated; The absolute angle of the magnetic ring encoder is determined by using the defined tooth count range, the number of teeth p of the single pair of pole conductor magnet assembly, and the third electrical angle value.

9. The method for detecting the absolute angle of a magnetic ring encoder according to claim 8, characterized in that: The first set of detection signals includes: a first detection signal and a second detection signal output by a first linear Hall sensor and a second linear Hall sensor based on the magnetic pole signals of the first multi-pair magnet; The second set of detection signals includes: a third detection signal and a fourth detection signal output by a third linear Hall sensor and a fourth linear Hall sensor based on the magnetic pole signals of the second multi-pair magnet; The modified third set of detection signals includes: d-axis and q-axis detection signals output by the fifth, sixth, and seventh linear Hall sensors based on the magnetic pole signals of the single-pair magnetic conductor assembly.

10. The method for detecting the absolute angle of a magnetic ring encoder according to claim 9, characterized in that: The fifth, sixth, and seventh linear Hall sensors output d-axis and q-axis detection signals based on the magnetic pole signals of the single-pair magnetic conductor assembly, specifically including: The fifth, sixth, and seventh linear Hall sensors acquire the magnetic pole signals of the single-pair magnetic conductor assembly to obtain the original three-phase Hall signals, which are the fifth detection signal, the sixth detection signal, and the seventh detection signal. After zero-point drift processing of the obtained raw three-phase Hall signals, the detection signals of the d-axis and q-axis are output.

11. The method for detecting the absolute angle of a magnetic ring encoder according to claim 10, characterized in that: After zero-point drift processing of the obtained raw three-phase Hall signals, the d-axis and q-axis detection signals are output, specifically including: The original three-phase Hall signal is processed for zero-point drift according to the following formula (1); The third set of detection signals for the d-axis and q-axis is output according to the following formula (2): In the formula, U1, U2, and U3 are the original three-phase Hall signals; U shift U'1, U'2, and U'3 are the three-phase Hall voltage signals after removing the drift; α is the angle between the electrical angle of the detection signal of any linear Hall sensor in the third group of Hall elements and the horizontal direction. d U q The output is the two-phase Hall voltage signal.

12. The method for detecting the absolute angle of a magnetic ring encoder according to claim 11, characterized in that: Angle calculations are performed on the first group of detection signals, the second group of detection signals, and the corrected third group of detection signals to obtain the first electrical angle value, the second electrical angle value, and the third electrical angle value, specifically including: The first group of detection signals, the second group of detection signals, and the corrected third group of detection signals are converted by A / D to obtain the first group of voltage values, the second group of voltage values, and the third group of voltage values; Based on the sign and magnitude of the voltage values ​​in the first, second, and third sets of voltage values, the angle ranges of the first, second, and corrected third sets of detection signals are obtained. Based on the angle range, the first electrical angle value, the second electrical angle value, and the third electrical angle value are obtained by using the arctangent algorithm on the first group of voltage values, the second group of voltage values, and the third group of voltage values.

13. The method for detecting the absolute angle of a magnetic ring encoder according to claim 12, characterized in that: Based on the number of pole pairs m of the first multi-pole magnet, the number of pole pairs n of the second multi-pole magnet, the first electrical angle value, and the second electrical angle value, the magnetic pole position characteristic value corresponding to the first multi-pole magnet is obtained, specifically including: The characteristic value λ of the magnetic pole position is calculated using the following formula: In the formula, θ m To obtain the first electrical angle value, θ n This is the second electrical angle value obtained.

14. The method for detecting the absolute angle of a magnetic ring encoder according to claim 13, characterized in that: The initial mechanical angle θ formed by the first and second pairs of pole magnets is determined based on the first magnetic pole region, the number of pole pairs m of the first multi-pole magnet, and the first electrical angle value. _single Specifically, it includes: Calculate the initial mechanical angle θ using the following formula. _single : i _single =N m ×360° / m+θ m / m In the formula, N m The first electrical angle value θ m The current magnetic pole zone number, N m ∈[0, m-1].

15. The method for detecting the absolute angle of a magnetic ring encoder according to claim 14, characterized in that: Based on the initial mechanical angle, the tooth count range in which the third electrical angle value currently falls is calibrated; Then, using the determined tooth count range, the tooth count p of the single-pole magnetic conductor assembly, and the third electrical angle value, the absolute angle of the magnetic ring encoder is determined, specifically including: Based on the obtained initial mechanical angle, the tooth count range where the third electrical angle value currently falls can be determined by referring to the index table; The absolute angle of the magnetic ring encoder is determined using the defined tooth count range, the tooth count p of the single-pole magnetic conductor assembly, and the third electrical angle value, according to the following formula: θ=N p ×360° / p+θ p / p In the formula, θ is the absolute angle output by the magnetic ring encoder, and N p The third electrical angle value θ p The current tooth count range number, N p ∈[θ,p-1].

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