Position calculation method and system of multi-turn magnetic encoder based on cursor combination

Abstract

The present invention belongs to the technical field of encoders, and specifically relates to a method and system for solving the position of a multi-turn magnetic encoder based on a cursor combination. The method comprises the following steps: S1, constructing a multi-level magnetic cursor group structure; S2, upgrading and combining the multi-level magnetic cursor group structure based on the minimum number of overlapping teeth; S3, determining the parameters of the multi-level magnetic cursor group structure according to the gear tooth number matching method; S4, constructing a two-level magnetic cursor group structure that saves gears. The present invention has better universality and simplicity in expanding the detection range, while retaining the advantages of high precision and high efficiency of formula solving in terms of solving ability, which can effectively reduce the hardware cost of the decoding IC, and has the characteristics of high reliability based on the cursor combination.

Description

Technical Field

[0001] The invention belongs to the technical field of encoders, and in particular relates to a position calculation method and system for a multi-turn magnetic encoder based on a cursor combination. Background Art

[0002] In rotary motion control systems, shaft angle and position detection sensors (encoders) are key components for motion control and displacement measurement. Although incremental encoders or single-turn absolute encoders can be used in many places and can complete long-distance position measurement tasks, the device application experience is very different when different types of encoders are selected.

[0003] Using an incremental encoder or a single-turn absolute encoder can realize multi-turn position detection and recording functions, but it requires an additional counting module or power-off memory module to ensure that multi-turn data will not be lost in unexpected situations such as abnormal control program operation, disconnection of the electrical connection between the system and the encoder, equipment failure or power failure. At this time, if a multi-turn absolute encoder with mechanical memory can be used, it is more likely to avoid interruptions or delays in the position measurement process caused by electrical reasons such as power failures and signal open circuits in the equipment system, thereby improving production efficiency. Therefore, multi-turn encoders with multi-turn detection ranges have received attention and research at home and abroad.

[0004] At present, multi-turn encoders can be divided into two categories according to their application principles: electronic multi-turn encoders and mechanical multi-turn encoders. Mechanical multi-turn encoders are also commonly called gear multi-turn encoders. Their respective characteristics are as follows:

[0005] 1. The electronic multi-turn encoder is composed of an additional turn counting sensor and a power supply system. It is small in size and has a large detection range. In theory, as long as the power supply system is not disconnected, it can count to the maximum memory available to the decoding IC. However, this also makes it very sensitive to power supply stability. Once the system loses power, all counting data will be lost.

[0006] In addition, this type of encoder generally does not have mechanical memory and power-off position recognition functions. When the electrical system is powered off and restarted, or in worse cases, such as when the position changes during a power outage, it is impossible to memorize or re-acquire the new multi-turn absolute position.

[0007] 2. The gear-type multi-turn encoder is an encoder with mechanical memory and mechanical recognition that combines a gear structure with a photoelectric code disk or a magnetic sensing system. When the shaft rotates, the photoelectric code disk or magnetic sensing system on each gear will also rotate, and the sensor above it will obtain the information of these changes, and process the information in the decoding IC, and finally convert it into multi-turn position information.

[0008] This type of encoder has the characteristics of mechanical memory. Even if the system loses power, you only need to power it back on to obtain the current absolute multi-turn position information of the motor shaft, and there will be no loss of position information. Even if the position moves during a power outage, the current number of turns and absolute angle position value can be re-identified when the power system is restored.

[0009] However, the current gear-type multi-turn encoders also have some limitations. For example, the conventional structure has a small detection range. When the detection range is expanded, it will lead to problems such as complex structure, large size, and complex position solution methods.

[0010] Therefore, based on the conventional magnetic cursor algorithm, the present invention proposes a magnetic cursor group encoding and decoding method with a multi-level structure, and studies its combination and parameter selection process. The magnetic cursor group encoding and decoding method with a multi-level structure can realize the expansion of the multi-turn encoding detection range with a multi-axis structure, and retain the high efficiency advantage of formula solution, and it is easier to carry out targeted parameter selection in the design stage. Summary of the invention

[0011] The present invention aims to overcome the problems in the prior art that the conventional structure of the current gear-type multi-turn encoder has a small detection range, and when the detection range is expanded, it will lead to a complex structure, a large volume, and a complex position solution method. It provides a method and system for position solution of a multi-turn magnetic encoder based on a cursor combination, which has better universality and simplicity in expanding the detection range, while retaining the advantages of high precision and high efficiency of formula solution in terms of solution capability, can effectively reduce the hardware cost of the decoding IC, and has high reliability.

[0012] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0013] The position calculation method of a multi-turn magnetic encoder based on a cursor combination includes the following steps:

[0014] S1, construct a multi-level magnetic cursor group structure;

[0015] S2, based on the minimum number of overlapping teeth, the multi-level magnetic cursor group structure is upgraded and combined;

[0016] S3, determining the parameters of the multi-level magnetic cursor group structure according to the gear tooth number ratio method;

[0017] S4, construct a two-stage magnetic travel group structure that saves gears.

[0018] Preferably, step S1 comprises the following steps:

[0019] S11, the solution cycle angle of the known magnetic cursor algorithm The output signal of the magnetic encoder is SigM and θ SigAThe same change rule is used, and the detection angle changes from 0° to 360° with the rotation of the detection axis. Then another set of cursors, namely the secondary cursors, is set, and the calculation cycle angle of the secondary cursors is The calculated cycle angle with the initial primary cursor All meet the conditions of the cursor algorithm and are used to construct a cursor group;

[0020] S12, according to the cursor group, the detection range of the detection axis is expanded, and the following results are obtained according to the cursor solution algorithm:

[0021]

[0022]

[0023]

[0024] in, is the calculated period angle of the secondary magnetic cursor; θ d2 is the difference angle, T MAX is the maximum multi-turn detection range of the secondary magnetic cursor; Z 2m1m ,Z 2m1v ,Z 2v1m ,Z 2v1v is the number of gear teeth in each of the two sets of primary cursors, Circle M is the number of rotations of the detection axis under the two-stage magnetic cursor structure, and n is a natural number greater than 1.

[0025] Preferably, step S2 comprises the following steps:

[0026] S21, according to the number of teeth of each gear constituting the current level cursor group, by calculating the number of overlapping teeth of the cursor group

[0027] S22, according to the number of overlapping teeth Z of the higher level cursor group to be constructed C(Num) , and the number of overlapping teeth of an existing lower-level cursor group Calculate the number of overlapping teeth of another lower-level magnetic cursor group required

[0028] S23, based on the possible multiple combinations of overlapping tooth numbers, the number of gears and the number of teeth of the entire system are matched, analyzed and selected to construct a multi-stage magnetic cursor system.

[0029] Preferably, step S22 includes the following steps:

[0030] S221, taking the secondary magnetic cursor as an example, if the relationship between the calculated periodic angle signals output by the two lower-level cursor groups satisfies the higher-level magnetic cursor algorithm, then when the number of overlapping teeth of the current primary cursor group is known to be In this case, the number of overlapping teeth of another primary cursor group combined with the primary cursor group is satisfy:

[0031]

[0032] in, is the greatest common divisor of the number of overlapping teeth of the two cursor groups; f m With f n They are and A factor of ;

[0033] When f n =f m When -1, formula (5) holds, and we get:

[0034]

[0035] S222, due to the number of overlapping teeth for a known cursor group There are multiple factors other than 1, indicating that there are multiple different options for the parameters of the magnetic cursor group that is to be selected as the lower level of the secondary magnetic cursor, so the set is defined:

[0036]

[0037] Then we get:

[0038]

[0039] Among them, F m Represents the known number of overlapping teeth of the lower level cursor group The set of all factors except 1; f x is a factor in the set.

[0040] Preferably, step S3 comprises the following steps:

[0041] S31, calculate the number of overlapping teeth of the derived x-level secondary cursor group The set of all factors of And determine whether the input factor set exists to satisfy |f v1 -f v2 |=1 condition, if yes, proceed to the next step;

[0042] S32, construct multiple existence factor pairs, according to different factor pairs (f v1 , f v2), perform deconstruction calculation to find the number of overlapping teeth of the lower main cursor group Number of teeth overlapping with the auxiliary cursor group

[0043] S33, calculate the number of overlapping teeth of the main cursor group The set of all factors of Find the number of overlapping teeth of the secondary cursor group The set of all factors of

[0044] Preferably, step S4 comprises the following steps:

[0045] S41, when three gears with consecutive numbers of teeth form a secondary magnetic cursor, the details are as follows:

[0046] If the number of teeth of the three gears contains two even numbers, that is, the number of teeth of the three gears Z a , Z b , Z c Respectively expressed as

[0047]

[0048] Where k∈N is a natural number set, then the number of overlapping teeth of the two primary magnetic cursor groups composed of three gears is Z ab and Z bc for:

[0049] Z ab =Z a *Z b (10)

[0050] Z bc =Z b *Z c (11)

[0051] The overlap gear ratio of the two primary magnetic cursor groups is obtained as follows:

[0052]

[0053] The two primary magnetic cursors are used to construct a secondary magnetic cursor of a higher level, and if the number of teeth is Z a The gear is used as the detection axis, and the maximum multi-turn detection range of the secondary magnetic cursor is:

[0054]

[0055] Preferably, in step S41, when the number of teeth of the three gears includes two odd numbers, then

[0056]

[0057] And it is concluded

[0058]

[0059] At this time, the factor pair formed by the overlapping tooth number ratio of the two primary magnetic cursor groups is not composed of continuous natural numbers and cannot be combined into a higher-level magnetic cursor group.

[0060] The present invention also provides a multi-turn magnetic encoder position resolution system based on a cursor combination, comprising:

[0061] A multi-level magnetic cursor group construction module is used to construct a multi-level magnetic cursor group structure;

[0062] An upgrade combination module is used to upgrade and combine the multi-level magnetic cursor group structure based on the minimum number of overlapping teeth;

[0063] A parameter determination module is used to determine the parameters of the multi-level magnetic cursor group structure according to the gear tooth number ratio method;

[0064] A special two-stage magnetic travel group structure building module is used to build a two-stage magnetic travel group structure that saves gears.

[0065] Compared with the prior art, the present invention has the following beneficial effects: (1) when the method of the present invention is used to realize the position detection of a multi-turn magnetic encoder with a differential tooth structure, the output signal of the magnetic encoder can be directly calculated by a multi-level cursor formula, without converting the signal value into the number of teeth or building a table for query; (2) the present invention can realize the expansion of the detection range of the multi-turn encoder by multi-axis expansion of the gear structure; (3) using the analysis method of the present invention, it is easier to carry out targeted multi-level magnetic cursor group structure parameter selection in the design stage; (4) the present invention has better universality and simplicity in expanding the detection range, while retaining the advantages of high precision and high efficiency of formula solution in terms of solution capability, which can effectively reduce the hardware cost of the decoding IC and has high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 A schematic diagram of the vernier solution algorithm;

[0067] Figure 2 A schematic diagram envisioned for a primary magnetic cursor combination;

[0068] Figure 3 A schematic diagram of calculating the period angle of the secondary magnetic cursor generated by combining the primary magnetic cursors;

[0069] Figure 4 A schematic diagram of the multi-level cursor group architecture and its naming rules;

[0070] Figure 5 A schematic diagram of a two-stage magnetic cursor multi-turn encoding gear and sensor system;

[0071] Figure 6 T for different secondary magnetic cursors MAX A data diagram of size;

[0072] Figure 7 A flow chart of a cursor group combination method based on the multi-level magnetic cursor principle in the present invention;

[0073] Figure 8 A flow chart of the secondary stage cursor gear ratio indexing method derived in the present invention;

[0074] Fig. 9 Different embodiments of the present invention provide The factor of the secondary axis Z 2a1m , Z 2a1a A data diagram of a relationship. DETAILED DESCRIPTION

[0075] In order to more clearly illustrate the embodiments of the present invention, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other accompanying drawings and other implementation methods can be obtained based on these accompanying drawings without creative work.

[0076] Example:

[0077] The present invention provides a multi-turn magnetic encoder position solution method based on a cursor combination, comprising the following steps:

[0078] S1, construct a multi-level magnetic cursor group structure;

[0079] S2, based on the minimum number of overlapping teeth, the multi-level magnetic cursor group structure is upgraded and combined;

[0080] S3, determining the parameters of the multi-level magnetic cursor group structure according to the gear tooth number ratio method;

[0081] S4, constructing a two-stage magnetic travel group structure without gears

[0082] Step S1 specifically includes the following steps:

[0083] S11, the solution cycle angle of the known magnetic cursor algorithm The output signal of the magnetic encoder is SigM and θ SigA The same change rule is used, and the detection angle changes from 0° to 360° with the rotation of the detection axis. Then another set of cursors, namely the secondary cursors, is set, and the calculation cycle angle of the secondary cursors is The calculated cycle angle with the initial primary cursor All meet the conditions of the cursor algorithm and are used to construct a cursor group, such as Figure 2 and Figure 3 As shown, Figure 2 and Figure 3 In the calculation cycle angle of the secondary cursor, there is and There are two cases; according to their relationship in period, we can and or and Pair them and substitute them into the formula of the cursor solution algorithm to obtain the solution cycle angle of a cursor combination, such as Figure 3 shown and

[0084] S12, according to the cursor group, the detection range of the detection axis is expanded, and the following results are obtained according to the cursor solution algorithm:

[0085]

[0086]

[0087]

[0088]

[0089] in, is the calculated period angle of the secondary magnetic cursor; θ d2 is the difference angle, T MAX is the maximum multi-turn detection range of the secondary magnetic cursor; Z 2m1m ,Z 2m1v ,Z 2v1m ,Z 2v1v is the number of gear teeth in each of the two sets of primary cursors, Circle M is the number of rotations of the detection axis under the two-stage magnetic cursor structure, and n is a natural number greater than 1.

[0090] The vernier solution algorithm is an absolute position measurement method that can achieve both high precision and a large range. For rotation angle measurement, only two periodic signals are required to meet the period ratio of (n is a natural number greater than 1), the solution cycle angle in the range of 0°-360° corresponding to the movement distance can be calculated:

[0091]

[0092]

[0093] The magnetic encoder can output a signal that meets the above conditions by using only two gears with a tooth number difference of 1. m =10, the number of countershaft teeth is Z a =9 as an example, the period angle is calculated as Figure 1 shown. Figure 1 In, θ SigM To detect the output signal angle of the shaft encoder, θ SigA is the output signal angle of the secondary shaft; is the solution cycle angle corresponding to the cursor algorithm. Figure 1 It can be seen that a resolution cycle angle of 0°-360° corresponds to the output signal angles of 9 detection shaft encoders. Therefore, the number of any turns of the detection shaft within the range of 9 turns can be calculated according to the following formula.

[0094]

[0095]

[0096] In the above formula, Circle M To detect the number of revolutions of the shaft; MCM[Z m ,Z a ] is the least common multiple of the detection shaft gear and the pinion A, which is called the overlapping teeth number in the present invention; T MAX is the maximum detection range of the detection axis, and Angle is the rotation angle of the detection axis at the current number of turns. It can be seen that the magnetic cursor algorithm has the same ability to solve the direct formula of the number of turns and position as the difference algorithm, but similarly, its detection range is directly related to the number of gear teeth. Similarly, the more teeth there are, the larger the detection range is, and the larger the encoder size is.

[0097] Furthermore, the cursor combination can be extended to any level, such as Figure 4 As shown in the figure, the left part indicates the level of the current cursor group, which represents the number of cursor groups in the overall structure. The box expresses the role of this cursor group in the overall cursor group. For example, if the overall structure is a three-level cursor group MVG[3], there are two second-level cursor groups MVG[3]m[2] and MVG[3]n[2]. Similarly, the two second-level cursor groups each contain two first-level cursor groups MVG[3]m[2]m[1], MVG[3]m[2]n[1], MVG[3]n[2]m[1], MVG[3]n[2]n[1], and so on. For any k-th-layer MVG, the combination of magnetic cursors can be upgraded according to the same method as above to achieve a wider range of circle detection.

[0098] The cursor combination inherits the advantages of the simple and efficient magnetic cursor algorithm, which enables it to be effectively used in low-cost decoding ICs, greatly reducing the cost of multi-turn encoders. At the same time, when expanding the detection range of multi-turn encoders, it abandons the disadvantage of simply expanding the number of gear teeth. It only needs to pair multiple gears with a small number of teeth to achieve the expansion of the detection range, which effectively reduces the structural volume of the encoder. The combined magnetic cursor can also achieve multiple expansions, which is more flexible in application.

[0099] According to the cursor combination principle, a secondary magnetic cursor group can be constructed, such as Figure 5 shown.

[0100] Figure 5 In it, two primary cursor groups are included, wherein the secondary main cursor is known in the above principle, and the secondary auxiliary cursor is conceived according to the magnetic cursor combination principle.

[0101] The gear-type multi-turn magnetic encoding scheme is composed of a gear structure with permanent magnets that transmit each other, and a magnetic sensor chip outputs the corresponding basic signal. In this way, a coupling relationship is established between the number of teeth rotated by the gear and the angle signal output by the magnetic sensor chip.

[0102] In the multi-stage magnetic vernier method, the highest-level magnetic vernier resolves the periodic angle signal and the number of teeth turned by the gear, which requires a reasonable combination and matching of the gear systems at all levels. According to the vernier combination principle, a two-stage magnetic vernier can be constructed.

[0103] Under the premise of satisfying the gear meshing structure, for any level, another vernier group of the same level that can match the current vernier group can be found to form a higher level magnetic vernier group. In order to find and realize this suitable combination, we can start from the number of overlapping teeth of the current vernier group.

[0104] Specifically, step S2 includes the following steps:

[0105] S21, according to the number of teeth of each gear constituting the current level cursor group, by calculating the number of overlapping teeth of the cursor group

[0106] S22, according to the number of overlapping teeth Z of the higher level cursor group to be constructed C(Num) , and the number of overlapping teeth of an existing lower-level cursor group Calculate the number of overlapping teeth of another lower-level magnetic cursor group required

[0107] S23, based on the possible multiple combinations of overlapping tooth numbers, the number of gears and the number of teeth of the entire system are matched, analyzed and selected to construct a multi-stage magnetic cursor system.

[0108] Specifically, step S22 includes the following steps:

[0109] S221, taking the secondary magnetic cursor as an example, if the relationship between the calculated periodic angle signals output by the two lower-level cursor groups satisfies the higher-level magnetic cursor algorithm, then when the number of overlapping teeth of the current primary cursor group is known to be In this case, the number of overlapping teeth of another primary cursor group combined with the primary cursor group is satisfy:

[0110]

[0111] in, is the greatest common divisor of the number of overlapping teeth of the two cursor groups; f m With f n They are and A factor of ;

[0112] When f n =f m When -1, formula (5) holds, and we get:

[0113]

[0114] S222, due to the number of overlapping teeth for a known cursor group There are multiple factors other than 1, indicating that there are multiple different options for the parameters of the magnetic cursor group that is to be selected as the lower level of the secondary magnetic cursor, so the set is defined:

[0115]

[0116] Then we get:

[0117]

[0118] Among them, F m Represents the known number of overlapping teeth of the lower level cursor group The set of all factors except 1; f x is a factor in the set.

[0119] For example, when Figure 5 The number of gear teeth Z of the primary cursor group in the structure shown 2m1m and Z 2m1a When they are 16 and 15 respectively, the number of overlapping teeth of the primary cursor group is beg The factor set is:

[0120] F m ={2,3,4,5,6,···,240}

[0121] Therefore, according to formula (8), The possible values ​​of are:

[0122]

[0123] Different combinations of secondary magnetic cursors can be obtained. The number of overlapping teeth of these secondary magnetic cursor groups may be:

[0124] Z C(2) =240,480,···,57360

[0125] According to formula (4), the maximum number of encoding circles of these two-level magnetic cursor groups is

[0126]

[0127] The maximum multi-turn detection range is as follows: Figure 6 shown.

[0128] Figure 6 Analysis shows that even if the parameters of a lower-level cursor group have been determined (such as in the above example Determined), when realizing the multi-level magnetic cursor combination, according to the different f of the known lower level magnetic cursor group x There are different multi-turn detection ranges for different values, and there are more choices when designing multi-level multi-turn encoding schemes.

[0129] The cursor combination method is as follows Figure 7 As shown, the idea of ​​the cursor combination process is:

[0130] 1. When the primary vernier completes a vernier resolution cycle angle, the two gears of the detection shaft and the secondary shaft A rotate the same number of teeth, which is called the overlapping number of teeth of the primary vernier. Therefore, the overlapping number of teeth of the secondary vernier that meets the magnetic vernier algorithm can be found based on the overlapping number of teeth of the primary vernier.

[0131] 2. The number of gear teeth needs to be an integer, so the number of overlapping teeth of the secondary vernier should be derived by subdividing the factors of the overlapping teeth number of the primary vernier. For example, when the overlapping teeth number of the primary vernier is 90, there are factors such as 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, and 90. If the ratio of the overlapping teeth number of the primary vernier to the overlapping teeth number of the secondary vernier is to satisfy Therefore, the magnetic vernier algorithm is used, and the number of overlapping teeth of the secondary vernier can be 45, 60, 72, 75, 80, 81, 84, 85, 87, 88, 89, or 135, 120, 108, 105, 100, 99, 96, 95, 93, 92, 91. It can be seen that the larger the subdivision factor, the larger the least common multiple of the number of overlapping teeth of the primary vernier and the number of overlapping teeth of the secondary vernier. Therefore, the solved cycle angle of the primary vernier and the secondary vernier requires more cycles to overlap at the initial position again and complete the number of overlapping teeth of the vernier combination, which is equivalent to increasing the multi-turn detection range of the detection axis.

[0132] 3. Not all sub-stage cursors can be realized by the gear tooth ratio, so it is necessary to establish an index method for the gear tooth ratio of the sub-stage cursor.

[0133] The derived secondary cursor gear number matching indexing method of the present invention is as follows: Figure 8 As shown, the specific steps include:

[0134] S31, calculate the number of overlapping teeth of the derived x-level secondary cursor group The set of all factors of And determine whether the input factor set exists to satisfy |f v1 -f v2 |=1 condition, if yes, proceed to the next step;

[0135] S32, construct multiple existence factor pairs, according to different factor pairs (f v1 , f v2 ), perform deconstruction calculation to find the number of overlapping teeth of the lower main cursor group Number of teeth overlapping with the auxiliary cursor group

[0136] S33, calculate the number of overlapping teeth of the main cursor group The set of all factors of Find the number of overlapping teeth of the secondary cursor group The set of all factors of

[0137] The number of overlapping teeth of the derived x-level secondary cursor group If there is a condition satisfying |f v1 -f v2 |=1, the deconstruction calculation of the bottom gear can continue; otherwise, deconstruction cannot be performed.

[0138] The larger the continuity factor value, the more turns the two gears of the secondary cursor need to rotate to complete the number of overlapping teeth of the secondary cursor. This is equivalent to reducing the number of gear teeth on the two axes of the secondary cursor, thereby further reducing the size of the encoder.

[0139] Take the primary vernier with 16 teeth on the detection axis and 15 teeth on the secondary axis A as an example. At this time, the number of overlapping teeth of the secondary vernier is The relationship between the number of teeth of countershaft B and countershaft C derived from the factor pair is as follows: Fig. 9 shown.

[0140] From the above figure, we can see that for different There are many different gear combinations, and as The number of teeth of the deconstructed 0th gear will decrease. There is a special case when The tooth values ​​of the two 0th-level gears deconstructed from the value are exactly equal to the value of the secondary shaft A, which is equivalent to saving a gear in disguise, but does not affect the construction of the secondary magnetic cursor.

[0141] There is also a special structural situation when the first-level cursor group is combined and upgraded to the second-level cursor group, that is, the possibility that three gears with continuous numbers of teeth can form a second-level magnetic cursor. The specific contents are as follows:

[0142] If the number of teeth of the three gears contains two even numbers, that is, the number of teeth of the three gears Z a , Z b , Z c Expressed as

[0143]

[0144] Where k∈N is a natural number set, then the number of overlapping teeth of the two primary magnetic cursor groups composed of three gears is Z ab and Z bc for:

[0145] Z ab =Z a *Z b (10)

[0146] Z bc =Z b *Z c (11)

[0147] The overlap gear ratio of the two primary magnetic cursor groups is obtained as follows:

[0148]

[0149] The two primary magnetic cursors are used to construct a secondary magnetic cursor of a higher level, and if the number of teeth is Z a The gear is used as the detection axis, and the maximum multi-turn detection range of the secondary magnetic cursor is:

[0150]

[0151] When the number of teeth on the three gears includes two odd numbers, then

[0152]

[0153] And it is concluded

[0154]

[0155] At this time, the factor pair formed by the overlapping tooth number ratio of the two primary magnetic cursor groups is not composed of continuous natural numbers and cannot be combined into a higher-level magnetic cursor group.

[0156] The present invention also provides a multi-turn magnetic encoder position resolution system based on a cursor combination, comprising:

[0157] A multi-level magnetic cursor group construction module is used to construct a multi-level magnetic cursor group structure;

[0158] An upgrade combination module is used to upgrade and combine the multi-level magnetic cursor group structure based on the minimum number of overlapping teeth;

[0159] A parameter determination module is used to determine the parameters of the multi-level magnetic cursor group structure according to the gear tooth number ratio method;

[0160] A special two-stage magnetic travel group structure building module is used to build a two-stage magnetic travel group structure that saves gears.

[0161] The innovation of the present invention is that it proposes a method for multi-turn position calculation and detection range expansion of a multi-turn magnetic encoder with a differential gear structure, which combines the advantages of various position calculation methods of the current multi-turn magnetic encoder with a differential gear structure. It has better universality and simplicity in terms of detection range expansion, and at the same time retains the advantages of high precision and high efficiency of formula calculation in terms of calculation ability, which can effectively reduce the hardware cost of the decoding IC and has high reliability:

[0162] 1. A multi-level magnetic cursor group structure and its architecture topology are proposed;

[0163] 2. Based on the minimum number of overlapping teeth, an upgrade combination method of a multi-level magnetic cursor group is proposed;

[0164] 3. A gear tooth number ratio method for determining the parameters of a multi-level magnetic cursor group is proposed;

[0165] 4. A special construction rule for a two-stage magnetic travel group that saves gears is proposed.

[0166] The above description is only a detailed description of the preferred embodiments and principles of the present invention. For ordinary technicians in this field, according to the ideas provided by the present invention, there will be changes in the specific implementation methods, and these changes should also be regarded as the protection scope of the present invention.

Claims

1. Multi-turn magnetic encoder position calculation method based on cursor combination, It is characterized in that The following steps are involved: S1, construct a multi-level magnetic cursor group structure; S2, based on the number of overlapping teeth, the multi-level magnetic cursor group structure is upgraded and combined; the number of overlapping teeth refers to the least common multiple of the detection shaft gear and the pinion gear; S3, determining the parameters of the multi-level magnetic cursor group structure according to the gear tooth number ratio method; S4, constructing a two-stage magnetic travel group structure without gears; Step S2 includes the following steps: S21, according to the number of teeth of each gear constituting the current level cursor group, by calculating the number of overlapping teeth of the cursor group S22, according to the number of overlapping teeth Z of the higher level cursor group to be constructed C(Num) , and the number of overlapping teeth of an existing lower-level cursor group Calculate the number of overlapping teeth of another lower-level magnetic cursor group required S23, based on various combinations of overlapping tooth numbers, the number of gears and the number of teeth of the entire system are matched, analyzed and selected, and a multi-stage magnetic cursor system is constructed; Step S3 includes the following steps: S31, calculate the number of overlapping teeth of the derived x-level secondary cursor group The set of all factors of And determine whether the input factor set exists to satisfy |f v1 -f v2 |=1 condition, if yes, proceed to the next step; S32, construct multiple existence factor pairs, according to different factor pairs (f v1 , f v2 ), perform deconstruction calculation to find the number of overlapping teeth of the lower main cursor group Number of teeth overlapping with the auxiliary cursor group S33, calculate the number of overlapping teeth of the main cursor group The set of all factors of Find the number of overlapping teeth of the secondary cursor group The set of all factors of 2. The method for calculating the position of a multi-turn magnetic encoder based on a cursor combination according to claim 1, It is characterized in that Step S1 includes the following steps: S11, the solution cycle angle of the known magnetic cursor algorithm The output signal of the magnetic encoder is SigM and θ SigA The same change rule is used, and the detection angle changes from 0° to 360° with the rotation of the detection axis. Then another set of cursors, namely the secondary cursors, is set, and the calculation cycle angle of the secondary cursors is The calculated cycle angle with the initial primary cursor All meet the conditions of the cursor algorithm and are used to construct a cursor group; S12, according to the cursor group, the detection range of the detection axis is expanded, and the following results are obtained according to the cursor solution algorithm: in, is the calculated period angle of the secondary magnetic cursor; θ d2 is the difference angle, T MAX is the maximum multi-turn detection range of the secondary magnetic cursor; Z 2m1m ,Z 2m1v ,Z 2v1m ,Z 2v1v is the number of gear teeth in each of the two sets of primary cursors, Circle M is the number of rotations of the detection axis under the two-stage magnetic cursor structure, and n is a natural number greater than 1.

3. The multi-turn magnetic encoder position calculation method based on cursor combination according to claim 1, It is characterized in that Step S22 includes the following steps: S221, taking the secondary magnetic cursor as an example, if the relationship between the calculated periodic angle signals output by the two lower-level cursor groups satisfies the higher-level magnetic cursor algorithm, then when the number of overlapping teeth of the current primary cursor group is known to be In this case, the number of overlapping teeth of another primary cursor group combined with the primary cursor group is satisfy: in, is the greatest common divisor of the number of overlapping teeth of the two cursor groups; f m With f n They are and A factor of ; When f n =f m When -1, formula (5) holds, and we get: S222, due to the number of overlapping teeth for a known cursor group There are multiple factors other than 1, indicating that there are multiple different options for the parameters of the magnetic cursor group that is to be selected as the lower level of the secondary magnetic cursor, so the set is defined: Then we get: (f m ∈F m ) Among them, F m Represents the known number of overlapping teeth of the lower level cursor group The set of all factors except 1; f x is a factor in the set.

4. The multi-turn magnetic encoder position calculation method based on cursor combination according to claim 1, It is characterized in that Step S4 includes the following steps: S41, when three gears with consecutive numbers of teeth form a secondary magnetic cursor, the details are as follows: If the number of teeth of the three gears contains two even numbers, that is, the number of teeth of the three gears Z a , Z b , Z c Respectively expressed as Where k∈N is a natural number set, then the number of overlapping teeth of the two primary magnetic cursor groups composed of three gears is Z ab and Z bc for: WITH ab =Z a *WITH b (10) WITH bc =Z b *WITH c (11) The overlap gear ratio of the two primary magnetic cursor groups is obtained as follows: The two primary magnetic cursors are used to construct a secondary magnetic cursor of a higher level, and if the number of teeth is Z a The gear is used as the detection axis, and the maximum multi-turn detection range of the secondary magnetic cursor is:

5. The method for calculating the position of a multi-turn magnetic encoder based on a cursor combination according to claim 4, It is characterized in that In step S41, when the number of teeth of the three gears includes two odd numbers, then And it is concluded At this time, the factor pair formed by the overlapping tooth number ratio of the two primary magnetic cursor groups is not composed of continuous natural numbers and cannot be combined into a higher-level magnetic cursor group.

6. A multi-turn magnetic encoder position resolution system based on a cursor combination, used to implement the multi-turn magnetic encoder position resolution method based on a cursor combination as described in any one of claims 1 to 5, It is characterized in that The multi-turn magnetic encoder position solving system based on cursor combination includes: A multi-level magnetic cursor group construction module is used to construct a multi-level magnetic cursor group structure; An upgrade combination module is used to upgrade and combine the multi-level magnetic cursor group structure based on the minimum number of overlapping teeth; A parameter determination module is used to determine the parameters of the multi-level magnetic cursor group structure according to the gear tooth number ratio method; The secondary magnetic travel group structure building module is used to build a secondary magnetic travel group structure that saves gears.

Images