CN115307664A - Multi-turn decoding method and system based on magnetic resistance and magnetic induction element - Google Patents

Abstract

The invention relates to a multi-turn decoding method and a multi-turn decoding system of an encoder based on a magnetic resistance magnetic induction element, wherein the method comprises the following steps: 1) Determining a calibration zero point based on return difference signals of the magnetic resistance magnetic induction elements, and realizing quadrant division; 2) Acquiring initial information, wherein the initial information comprises an initial image limit value and an initial single-circle position; 3) Acquiring current information, wherein the current information comprises a current image limit value, a current single-turn position and a magnetic resistance count value; 4) Determining the multi-turn count by judging the relationship between the current image limit value and the initial image limit value and the positive and negative of the magnetic resistance count value. Compared with the prior art, the method has the advantages of accuracy, low cost and the like.

Description

Multi-turn decoding method and system based on magnetic resistance and magnetic induction element

Technical Field

The invention relates to a multi-turn decoding method, in particular to a multi-turn decoding method and a multi-turn decoding system based on a magnetic resistance magnetic induction element.

Background

The multi-turn decoding method is a key for ensuring that the absolute value encoder recovers multi-turn counting when being powered on again after power failure, and the traditional method is to decode the positions of gears at all stages by means of a multi-stage gear structure during power on so as to obtain the number of turns of the multi-turn. Later developments have counted multiple turns based on the magnetic sensing element sensing a zero crossing or periodic flag signal associated with the circumference of the rotation. The latter current methods are different from sensor to sensor, and can be mainly divided into two types: a multi-turn recording and decoding method based on a Hall magnetic induction element and a multi-turn recording method based on a magnetic resistance magnetic induction element.

The prior art mainly has the following application defects:

1) The Hall signal switches levels according to the encoding of the magnetic field intensity, but the Hall signal fluctuates when the magnetic field intensity is near a jump point, so that a plurality of circles of numerical errors are caused when decoding is carried out at the switching point, for example, the patent application CN112945283A.

2) Although the return difference characteristic of the magneto-resistive magnetic induction element has the following advantages, the level fluctuation problem of the Hall sensor is avoided:

when the magnetic field intensity in the sensitive direction of the sensor exceeds the threshold of a working point, outputting a low level;

when the magnetic field intensity in the sensitive direction of the sensor is lower than the threshold of a release point, outputting a high level;

however, the multi-turn decoding algorithm is also complicated, and at present, a multi-turn decoding method based on the magnetic resistance magnetic induction element is not available for a while. As in patent application CN107941247A only multi-turn device solutions are mentioned.

Disclosure of Invention

The present invention is directed to overcoming the above-mentioned drawbacks of the prior art and providing an accurate and low-cost multi-turn decoding method and system based on a magneto-resistive magnetic induction element.

The purpose of the invention can be realized by the following technical scheme:

a multi-turn decoding method of an encoder based on a magnetic resistance magnetic induction element comprises the following steps:

1) Determining a calibration zero point based on return difference signals of the magnetic resistance magnetic induction elements, and realizing quadrant division;

2) Acquiring initial information, wherein the initial information comprises an initial image limit value and an initial single-circle position;

3) Acquiring current information, wherein the current information comprises a current image limit value, a current single-turn position, a magnetic resistance count value and a magnetic resistance multi-turn value, and the magnetic resistance multi-turn value is equal to an integer part of a quotient obtained by dividing the magnetic resistance count value by 4;

4) Determining the multi-turn count by judging the relationship between the current image limit value and the initial image limit value and the positive and negative of the magnetic resistance count value. The calibration zero point is positioned in a region where the reluctance level signal is irrelevant to the rotation direction.

Further, the quadrant division is realized through an initialization step, which specifically includes:

101 Read the level state and single-turn position of the magneto-resistive magnetic induction element, and the rotary encoder determines the magneto-resistive level state at the zero position of the single turn as the level of a first quadrant, thereby demarcating the first quadrant;

102 Clockwise rotation encoder sequentially demarcates the second, third, and fourth quadrants according to the magnetoresistive level switching sequence.

Further, the initialization step is performed at a first power-on of the main power supply.

Further, the determining the multi-turn count by judging the relationship between the current image limit value and the initial image limit value and the positive and negative of the magnetic resistance count value specifically comprises:

401 Judging whether the current image limit value is the same as the initial image limit value, if so, obtaining multi-turn counting through a sub-process 0, and if not, executing a step 402);

402 Whether the magnetic resistance count value is larger than 0 or not is judged, if yes, multi-turn counting is obtained through a sub-process 1, and if not, multi-turn counting is obtained through a sub-process 2.

Further, the sub-process 0 specifically includes the following steps:

001 Judging whether the initial image limit value is the first quadrant, if so, executing a step 002), and if not, taking the magnetic resistance multi-turn value as multi-turn counting;

002 Judging whether the initial single-turn position is 180 degrees or not and the current single-turn position is less than 180 degrees, if so, taking the magnetic resistance multi-turn value +1 as multi-turn counting, and if not, executing a step 003);

003 Whether the initial single-turn position is less than 180 degrees and the current single-turn position is greater than 180 degrees is judged, if yes, the magnetic resistance multi-turn value-1 is used as multi-turn counting, and if not, the magnetic resistance multi-turn value is used as multi-turn counting.

Further, the sub-process 1 specifically includes the following steps:

101 Let the angle α between the starting position and the zero position equal to the maximum value of a single turn-the starting single turn position, and the angle β between the starting position and the current position equal to the current single turn position-the starting single turn position;

102 Judging whether beta <0 exists, if so, executing step 103) after the beta is equal to the alpha + single-circle maximum value, and if not, directly executing step 103);

103 Whether alpha < beta exists is judged, if yes, the magnetic resistance multi-turn value +1 is used as multi-turn counting, and if not, the magnetic resistance multi-turn value is used as multi-turn counting.

Further, the sub-process 2 specifically includes the following steps:

201 Let the negative angle γ between the starting position and the zero point equal the starting single-turn position, and the negative angle δ between the starting position and the current position equal the starting single-turn position-the current single-turn position;

202 Judging whether delta <0 exists, if yes, executing step 203) after delta is equal to gamma + single-circle maximum value, and if not, directly executing step 203);

203 Whether gamma < delta) exists or not is judged, if yes, the magnetic resistance multi-turn value-1 is used as multi-turn counting, and if not, the magnetic resistance multi-turn value is used as multi-turn counting.

The invention also provides an encoder multi-turn decoding system based on the magnetic resistance magnetic induction element, which comprises:

the single-turn decoding unit is used for acquiring a starting single-turn position and a current single-turn position;

the magnetic resistance counting unit is used for acquiring an initial magnetic resistance level and a current magnetic resistance level, further correspondingly acquiring an initial image limit value and a current image limit value and acquiring a magnetic resistance counting value according to a magnetic resistance level signal;

the multi-turn decoding unit is used for decoding to obtain a final multi-turn position according to the output of the single-turn decoding unit and the output of the magnetic resistance counting unit so as to obtain multi-turn counting;

a data backup unit for backing up the initial single-turn position and the initial reluctance level;

the magnetoresistive counting unit is always in an operating state under the operating condition of the encoder.

Furthermore, the magnetic resistance counting unit comprises magnetic steel fixedly connected with the rotating shaft and two magnetic resistance magnetic induction elements which are orthogonally arranged on a concentric circle taking the rotating shaft as a circle center.

Compared with the prior art, the invention has the following beneficial effects:

1) The invention is realized based on a magnetic resistance and magnetic induction element, thereby avoiding the level fluctuation problem of the Hall sensor;

2) The multi-turn decoding scheme of the invention can accurately acquire multi-turn counting and has the advantage of low cost.

Drawings

FIG. 1 is a flowchart illustrating the overall operation of the decoding method of the present invention;

FIG. 2 is a graph of output signals of a magneto-resistive magnetic sensing element signal as a function of magnetic field strength;

FIG. 3 is a switching diagram of two orthogonal magnetic resistance signals moving in the forward direction and outputting level signals along with the change of magnetic field intensity;

FIG. 4 is a diagram of return difference signal state switching and quadrant division;

FIG. 5 is a flowchart illustrating a decoding method according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of sub-process 0 of FIG. 5;

FIG. 7 is a schematic diagram of sub-process 1 of FIG. 5;

FIG. 8 is a schematic diagram of sub-process 2 of FIG. 5;

FIG. 9 is a block diagram of a decoding system according to the present invention.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

Example 1

The embodiment provides an encoder multi-turn decoding method based on a magnetic resistance magnetic induction element, which comprises the following steps: 1) Determining a calibration zero point based on return difference signals of the magnetic resistance magnetic induction elements, and realizing quadrant division; 2) Acquiring initial information, wherein the initial information comprises an initial image limit value and an initial single-circle position; 3) Acquiring current information, wherein the current information comprises a current image limit value, a current single-turn position, a magnetic resistance count value and a magnetic resistance multi-turn value; 4) And determining the multi-turn count by judging the relationship between the current image limit value and the initial image limit value and the positive and negative of the magnetic resistance count value.

The method realizes a simpler multi-turn decoding algorithm based on the magneto-resistance magnetic induction element, has high reliability, can effectively ensure that the absolute value encoder recovers accurate multi-turn counting when being electrified again after power failure, and realizes multi-turn decoding and correction of multi-turn recording.

As shown in fig. 1, the multi-turn decoding method of the encoder is mainly divided into two stages, an initialization stage and a normal operation stage. The method comprises the steps of performing zero point calibration and quadrant division in an initialization stage, performing accurate multi-turn counting of power-on again after power-off in a normal operation stage, and executing a multi-turn decoding algorithm to output a multi-turn value according to backup and current signal data when the multi-turn value is calculated after a main power supply is powered on after the normal operation stage is started.

As shown in fig. 2-4, which are schematic diagrams illustrating the output level variation of the signal of the magneto-resistive and magnetic-inductive element along with the magnetic field strength and quadrant division in the circumference, it can be seen that the high-low switching points are not mapped on the same magnetic field strength point on the circumference as the state overlap interval, and therefore, in the initialization stage of the method, the determined calibration zero point should be located in the area where the magneto-resistive level signal is not related to the rotation direction.

The quadrant division of the initialization stage is realized through an initialization step, the initialization step is executed when a main power supply is powered on for the first time, and the initialization step specifically comprises the following steps:

101 Read the level state and single-turn position of the magneto-resistive magnetic sensing element, and the rotary encoder determines the magneto-resistive level state at the zero position of the single turn as the level of a first quadrant, thereby defining the first quadrant;

102 Clockwise rotation encoder sequentially demarcates the second, third, and fourth quadrants according to the magnetoresistive level switching sequence.

As shown in fig. 3, in this embodiment, when the first quadrant magnetoresistance level state is 01, and the first sensor magnetoresistance signal release point threshold position is reached (clockwise), the magnetoresistance level state is switched to 11, and the second quadrant is entered, at this time, the count value is increased by 1, and so on, the count value is increased by 1 for each switching state; the level switching state in the reverse rotation is as follows: 01- > 00- > 10- > 11- >01, decrementing the state count by 1 per switch, where the reluctance multi-turn value = integer part of the quotient of reluctance count value/4.

As shown in fig. 5, the determination of the multi-turn count by determining the relationship between the current image limit value and the initial image limit value and the positive and negative of the magnetic resistance count value is specifically as follows:

401 Judging whether the current image limit value is the same as the initial image limit value, if so, obtaining multi-turn counting through a sub-process 0, and if not, executing a step 402);

402 Whether the magnetic resistance count value is larger than 0 or not is judged, if yes, multi-turn counting is obtained through a sub-process 1, and if not, multi-turn counting is obtained through a sub-process 2.

Where the starting quadrant being equal to the current quadrant encompasses the portion of the scene where the reluctance count is equal to 0 and the reluctance count is not equal to zero.

As shown in fig. 6, which is a flow chart of the sub-process 0, when the initial quadrant is equal to the current quadrant, the initial single-turn position and the current single-turn position are in one quadrant, and only one consideration needs to be given to whether a zero point exists in the quadrant, but the present invention defines the quadrant in which the zero point exists as the first quadrant, so that the multi-turn number in other quadrants is equal to the magnetic resistance turn count value, and if the initial quadrant is in the first quadrant, the three situations can be divided into three situations. The sub-process 0 specifically comprises the following steps:

001 Judging whether the initial image limit value is the first quadrant, if so, executing a step 002), and if not, taking the magnetic resistance multi-turn value as multi-turn counting;

002 Judging whether the initial single-turn position is 180 degrees or not and the current single-turn position is less than 180 degrees, if so, taking the magnetic resistance multi-turn value +1 as multi-turn counting, and if not, executing a step 003);

003 Whether the initial single-turn position is less than 180 degrees and the current single-turn position is more than 180 degrees is judged, if yes, the magnetic resistance multi-turn value-1 is used as multi-turn counting, and if not, the magnetic resistance multi-turn value is used as multi-turn counting.

As shown in fig. 7, the flow chart of the sub-process 1 specifically includes the following steps:

101 When the reluctance count is larger than zero, the included angle between the starting position and the zero point is the rotated included angle when the starting position of a single circle is taken as the starting point and the zero point rotates clockwise to the zero point, namely, the included angle alpha between the starting position and the zero point is equal to the maximum value of the single circle-the starting single circle position, and the included angle between the starting position and the current position is the rotated included angle when the starting position and the current position rotate clockwise to the current position by taking the starting position of the single circle as the starting point, namely, the included angle beta between the starting position and the current position is equal to the current position of the single circle-the starting single circle position;

102 Judging whether beta <0 exists, if so, executing step 103) after the beta is equal to the alpha + single-circle maximum value, and if not, directly executing step 103);

103 Whether alpha < beta exists or not is judged, if yes, the positive direction in a single circle is considered to pass through a zero point, the magnetic resistance multi-circle value +1 is taken as multi-circle counting, and if not, the magnetic resistance multi-circle value is taken as multi-circle counting.

As shown in fig. 8, which is a flowchart of the sub-process 2, when the magnetic resistance count is less than zero, the included angle between the starting position and the zero point is equal to the value of the starting single-turn position when the starting position and the zero point rotate counterclockwise to the zero point with the starting single-turn starting position as the starting point, the included angle between the starting position and the current position is equal to the included angle between the starting position and the current position when the starting position and the current position rotate counterclockwise to the current position with the starting single-turn starting position as the starting point, and if the included angle between the starting position and the current position is less than zero, the included angle between the starting position and the current position is equal to the negative included angle between the starting position and the current position plus the maximum value of the single-turn position. When the included angle between the initial position and the zero point is smaller than the included angle between the initial position and the current position, the negative direction in the single circle is considered to pass through the zero point, and the multi-circle counting is equal to the magnetic resistance multi-circle value of-1; otherwise, the multi-turn count equals the magnetoresistive multi-turn value. The sub-process 2 specifically comprises the following steps:

201 When the reluctance count is less than zero, the included angle between the starting position and the zero point is equal to the value of the starting single-turn position when the starting position rotates anticlockwise to the zero point with the single-turn starting position as the starting point, the included angle between the starting position and the zero point is equal to the value of the starting single-turn position, and the included angle between the starting position and the current position is equal to the included angle when the starting position rotates anticlockwise to the current position with the single-turn starting position as the starting point, namely the included angle between the starting position and the current position is equal to the value delta between the starting single-turn position and the current single-turn position;

202 Judging whether delta <0 exists, if yes, executing step 203) after delta is equal to gamma + single-circle maximum value, and if not, directly executing step 203);

203 Whether gamma < delta exists or not is judged, if yes, the negative direction in a single circle is considered to pass through a zero point, and the magnetic resistance multi-circle value-1 is taken as multi-circle counting, and if not, the magnetic resistance multi-circle value is taken as multi-circle counting.

Example 2

The embodiment provides an encoder multi-turn decoding system based on a magnetic resistance magnetic induction element, which comprises a single-turn decoding unit, a magnetic resistance counting unit, a multi-turn decoding unit and a data backup unit, wherein the single-turn decoding unit is used for acquiring a starting single-turn position and a current single-turn position as shown in fig. 9; the magnetic resistance counting unit is used for acquiring an initial magnetic resistance level and a current magnetic resistance level, further correspondingly acquiring an initial image limit value and a current image limit value, and acquiring a magnetic resistance counting value according to a magnetic resistance level signal; the multi-turn decoding unit is used for decoding to obtain a final multi-turn position according to the output of the single-turn decoding unit and the output of the magnetic resistance counting unit to obtain multi-turn counting; the data backup unit is used for backing up the initial single-turn position and the initial magnetic resistance level.

In a specific embodiment mode, the single-turn decoding unit is a single-turn magnetic encoder module; the magnetic resistance counting unit comprises magnetic steel fixedly connected with the rotating shaft and two magnetic resistance magnetic induction elements which are orthogonally arranged on a concentric circle taking the rotating shaft as the center of circle; the data backup unit may include a backup register and a nonvolatile memory.

The multi-turn decoding working mode of the decoding system specifically comprises the following steps:

when the device is in an initialization mode, a main power supply supplies power, the single-turn decoding unit reads the absolute position of the single turn, the magnetic resistance counting unit reads the magnetic resistance level signal and stores the magnetic resistance level signal in the backup register, the interval where the zero point is located is used as a first quadrant, the zero point rotates clockwise, the interval is sequentially divided into a second quadrant and a fourth quadrant according to the magnetic resistance output level switching sequence and is stored in the nonvolatile memory. And after the initialization is finished, entering a normal working mode.

When in the normal operating mode: when the encoder initiates a multi-turn decoding signal, the multi-turn decoding unit performs multi-turn decoding output according to the current quadrant, the starting single-turn position, the current single-turn position and the magnetic resistance count value.

Whether the main power supply of the encoder is electrified or not, the magnetic resistance counting unit is always in a working mode, and the zero point of the single-turn position is in an interval divided by the magnetic resistance level signal.

The multi-turn decoding process is described with reference to example 1.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.

Claims (10)

1. A multi-turn decoding method of an encoder based on a magnetic resistance and magnetic induction element is characterized by comprising the following steps:

1) Determining a calibration zero point based on return difference signals of the magnetic resistance magnetic induction elements, and realizing quadrant division;

2) Acquiring initial information, wherein the initial information comprises an initial image limit value and an initial single-circle position;

3) Acquiring current information, wherein the current information comprises a current image limit value, a current single-turn position, a magnetic resistance count value and a magnetic resistance multi-turn value, and the magnetic resistance multi-turn value is equal to an integer part of a quotient obtained by dividing the magnetic resistance count value by 4;

4) Determining the multi-turn count by judging the relationship between the current image limit value and the initial image limit value and the positive and negative of the magnetic resistance count value.

2. The multi-turn decoding method of an encoder based on magneto-resistive magnetic induction elements according to claim 1, characterized in that the calibration zero point is located in a region where the magneto-resistive level signal is not related to the rotation direction.

3. The multi-turn decoding method for an encoder based on magneto-resistive and magnetic-inductive elements according to claim 1, wherein the quadrant division is implemented by an initialization step, and the initialization step is specifically:

101 Read the level state and single-turn position of the magneto-resistive magnetic induction element, and the rotary encoder determines the magneto-resistive level state at the zero position of the single turn as the level of a first quadrant, thereby demarcating the first quadrant;

102 Clockwise rotary encoder sequentially demarcates the second, third and fourth quadrants according to the magnetoresistive level switching sequence.

4. A multi-turn decoding method for an encoder based on magneto-resistive magnetic induction elements according to claim 3, characterized in that the initialization step is performed when the main power is first turned on.

5. The multi-turn decoding method for an encoder based on magneto-resistive magnetic induction elements according to claim 1, wherein the determining the multi-turn count by determining the relationship between the current image limit value and the initial image limit value and the positive or negative of the magneto-resistive count value is specifically:

401 Judging whether the current image limit value is the same as the initial image limit value, if so, obtaining multi-turn counting through a sub-process 0, and if not, executing a step 402);

402 Whether the magnetic resistance count value is larger than 0 or not is judged, if yes, multi-turn counting is obtained through a sub-process 1, and if not, multi-turn counting is obtained through a sub-process 2.

6. The multi-turn decoding method for an encoder based on a magneto-resistive magnetic induction element according to claim 5, wherein the sub-process 0 specifically comprises the following steps:

001 Judging whether the initial image limit value is the first quadrant, if so, executing a step 002), and if not, taking the magnetic resistance multi-turn value as multi-turn counting;

002 Judging whether the initial single-turn position is 180 degrees or not and the current single-turn position is less than 180 degrees, if so, taking the magnetic resistance multi-turn value +1 as multi-turn counting, and if not, executing a step 003);

003 Whether the initial single-turn position is less than 180 degrees and the current single-turn position is greater than 180 degrees is judged, if yes, the magnetic resistance multi-turn value-1 is used as multi-turn counting, and if not, the magnetic resistance multi-turn value is used as multi-turn counting.

7. The multi-turn decoding method for the encoder based on the magneto-resistive magnetic induction element according to claim 5, wherein the sub-process 1 specifically comprises the following steps:

101 Let the angle α between the starting position and the zero position equal to the maximum value of a single turn-the starting single turn position, and the angle β between the starting position and the current position equal to the current single turn position-the starting single turn position;

102 Judging whether beta <0 exists, if so, executing step 103) after the beta is equal to the alpha + single-circle maximum value, and if not, directly executing step 103);

103 Whether alpha < beta exists or not is judged, if yes, the magnetic resistance multi-turn value +1 is used as multi-turn counting, and if not, the magnetic resistance multi-turn value is used as multi-turn counting.

8. The multi-turn decoding method for the encoder based on the magneto-resistive magnetic induction element according to claim 5, wherein the sub-process 2 specifically comprises the following steps:

201 Making a negative included angle gamma between the starting position and the zero point equal to the starting single-turn position, and making a negative included angle delta between the starting position and the current position equal to the starting single-turn position-the current single-turn position;

202 Judging whether delta <0 exists, if yes, executing step 203) after delta is equal to gamma + single-circle maximum value, and if not, directly executing step 203);

203 Is determined whether gamma < delta exists, if yes, the reluctance multi-turn value-1 is taken as the multi-turn count, and if not, the reluctance multi-turn value is taken as the multi-turn count.

9. An encoder multi-turn decoding system for implementing the encoder multi-turn decoding method based on magneto-resistive magnetic induction elements of claim 1, comprising:

the single-turn decoding unit is used for acquiring a starting single-turn position and a current single-turn position;

the magnetic resistance counting unit is used for acquiring an initial magnetic resistance level and a current magnetic resistance level, further correspondingly acquiring an initial image limit value and a current image limit value, and acquiring a magnetic resistance counting value according to a magnetic resistance level signal;

the multi-turn decoding unit is used for decoding to obtain the final multi-turn position according to the output of the single-turn decoding unit and the output of the magnetic resistance counting unit to obtain multi-turn counting;

a data backup unit for backing up the starting single-turn position and the starting magnetoresistive level;

the magnetoresistive counting unit is always in an operating state under the operating condition of the encoder.

10. The encoder multi-turn decoding system of claim 9, wherein the magneto-resistive counting unit comprises a magnetic steel fixedly connected to the rotating shaft and two magneto-resistive magnetic induction elements orthogonally disposed on a concentric circle centered on the rotating shaft.

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