CN113028975B - Inductive encoder - Google Patents
Inductive encoder Download PDFInfo
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- CN113028975B CN113028975B CN202110254639.2A CN202110254639A CN113028975B CN 113028975 B CN113028975 B CN 113028975B CN 202110254639 A CN202110254639 A CN 202110254639A CN 113028975 B CN113028975 B CN 113028975B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
- G01B7/30—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring angles or tapers; for testing the alignment of axes
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
- G01B7/003—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring position, not involving coordinate determination
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
- G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
- G01D5/142—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices
- G01D5/145—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices influenced by the relative movement between the Hall device and magnetic fields
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
- G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
- G01D5/20—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
- H02K11/20—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection for measuring, monitoring, testing, protecting or switching
- H02K11/21—Devices for sensing speed or position, or actuated thereby
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
- H02K11/20—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection for measuring, monitoring, testing, protecting or switching
- H02K11/21—Devices for sensing speed or position, or actuated thereby
- H02K11/215—Magnetic effect devices, e.g. Hall-effect or magneto-resistive elements
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- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
- Transmission And Conversion Of Sensor Element Output (AREA)
Abstract
The invention discloses an inductive encoder, which comprises an incremental encoding module, an absolute encoding module and a processor, wherein the processor encodes an electrical angle period output by the incremental encoding module based on a digital signal output by the absolute encoding module, so that after determining the specific positions of each part in the respective electrical angle period after motor shaft subdivision, the processor can determine the encoding of the electrical angle period, and absolute mechanical position data of the motor shaft can be determined in a full range without rotating the motor shaft to pass through a zero point.
Description
Technical Field
The invention relates to the field of encoders, in particular to an inductive encoder.
Background
In the prior art, an inductive encoder is usually an incremental encoder, an incremental coil is arranged in the incremental encoder, when the pole pair number of the incremental coil is a plurality of, the mechanical angle of 360 degrees on a motor shaft can be subdivided, when the motor shaft rotates one circle, the incremental encoder can output sine signals and cosine signals with the cycle number of the electric angle cycle equal to the pole pair number of the incremental coil, and by calculating the angle position data of each electric angle cycle, the angle position data of each part in each electric angle cycle after the motor shaft is subdivided can be determined, however, the position of each electric angle cycle relative to the zero point can be determined only when the motor rotates through the zero point, so that the absolute mechanical position data of each point on the motor shaft can be determined, however, when the motor shaft does not rotate through the zero point, the position of each electric angle cycle relative to the zero point cannot be determined, namely the absolute mechanical position data of each point on the motor shaft cannot be determined in the full range, and the angle position data of each part in each electric angle cycle can only be determined after the motor shaft is subdivided.
Disclosure of Invention
The invention aims to provide an inductive encoder which can determine the codes of the electrical angle periods of the motor shaft after determining the specific positions of the parts of the motor shaft in the electrical angle periods of the motor shaft after subdivision, and can determine the absolute mechanical position data of the motor shaft in the full range without rotating the motor shaft to pass through a zero point.
In order to solve the above technical problems, the present invention provides an inductive encoder, including:
the incremental coding module is used for outputting angle position data of an electrical angle period when the motor shaft rotates for a preset angle, and the electrical angle period number of the angle position data output when the motor shaft rotates for one circle is equal to the pole logarithm of an incremental coil arranged by the incremental coding module;
the absolute coding module is used for outputting a digital signal corresponding to the electrical angle period of the angle position data output by the incremental coding module when the motor shaft rotates by the preset angle;
the digital signals output by the absolute coding module correspond to the electric angle periods of the angle position data output by the incremental coding module one by one when the motor shaft rotates for each circle;
the first input end is connected with the output end of the incremental coding module, the second input end is connected with the processor of the output end of the absolute coding module and used for coding each electric angle period of the angle position data output by the incremental coding module based on the digital signal, so that the absolute mechanical position data of the motor shaft are determined based on the coded electric angle period and the corresponding angle position data.
Preferably, the method further comprises:
the output end is connected with the power input end of the increment coding module, the power input end of the absolute coding module and the power supply connected with the power input end of the processor, and is used for supplying power to the increment coding module, the absolute coding module and the processor.
Preferably, the power source includes an external power source and a battery;
the external power supply is used for supplying power to the incremental coding module, the absolute coding module and the processor when the motor works, and is powered off when the motor stops working;
the battery is used for supplying power to one of the Hall switch chips and the processor when the external power supply is powered off.
Preferably, the processor is further configured to determine whether the motor is currently powered by the battery, conduct the hall switch chip powered by the battery with only a port connected to the hall switch chip, and count when receiving a digital signal jump output by the hall switch chip, so as to calculate the number of rotations of the motor shaft.
Preferably, the incremental encoding module includes:
an excitation coil connected with the processor through a capacitor and used for resonating with the capacitor so as to form a resonance magnetic field inside the self coil;
the output end of the incremental coil is connected with the low-pass filter and is used for outputting resonance induction electromotive force after sensing the resonance magnetic field;
the delta coils of each pole pair comprise a lead delta coil and a lag delta coil, the lag delta coil being positioned to lag the lead delta coil by one quarter of the electrical angle period;
the conducting metal is arranged between the incremental coils and rigidly connected with the motor shaft and is used for changing the amplitude of the resonance induction electromotive force output by the incremental coils when rotating along with the motor shaft and passing through the incremental coils so as to enable the amplitude of the resonance induction electromotive force output by the hysteresis incremental coils in the incremental coils of each pole pair to fluctuate according to a sine curve waveform; the amplitude of the resonance induction electromotive force output by the lead increment coil fluctuates according to the waveform of a cosine curve;
the output end of the low-pass filter is connected with the processor;
the low-pass filter is used for carrying out demodulation filtering processing on the resonance induction electromotive force with the amplitude value which is output by the increment coil and fluctuates according to the waveform of the sine curve and the resonance induction electromotive force with the amplitude value which fluctuates according to the waveform of the cosine curve;
the analog-to-digital converter is used for converting the resonance induction electromotive force after demodulation and filtering into sine signals and cosine signals of corresponding digital quantity;
the subdivision unit is used for subdividing and decoding the sine signals and the cosine signals of the digital quantity so as to output angle position data of an electrical angle period when the motor shaft rotates for a preset angle, and the number of the electrical angle period output when the motor shaft rotates for one circle is equal to the pole pair number of the increment coil arranged by the motor shaft.
Preferably, the conductive metal is fan-shaped and has an inner diameter smaller than an outer diameter;
the absolute encoding module includes:
the magnet is arranged at the center of the circle of the conductive metal, the outer diameter of the magnet is smaller than the inner diameter of the conductive metal, and the magnet is rigidly connected with the motor shaft and is used for rotating along with the motor shaft;
the plurality of Hall switch chips are correspondingly arranged on the incremental coils and are used for outputting digital signals corresponding to the electrical angle periods of the angle position data output by the incremental coding module based on magnetic fluxes passing through the Hall switch chips when the magnet rotates by the preset angle along with the motor shaft;
and when the motor shaft rotates for every circle, a plurality of digital signals output by the Hall switch chip correspond to each electrical angle period of the angle position data output by the incremental coding module one by one.
Preferably, the hall switch chip includes:
the Hall sensor is correspondingly arranged with the increment coil and is used for outputting a sine voltage signal based on magnetic flux passing through the Hall sensor when the magnet rotates by the preset angle along with the motor shaft;
the input end of the comparator is connected with the Hall sensor, and the output end of the comparator is connected with the processor and is used for converting the sinusoidal voltage signal into a square wave signal;
the square wave signal is a first level when the sine voltage signal is in the range of 0-pi in one period; the square wave signal is of a second level when the sine voltage signal is in the range of pi-2 pi in one period;
the digital signals are formed by the levels output by the Hall switch chips at the same time, and the digital signals output by the Hall switch chips correspond to the electric angle periods of the angle position data output by the incremental coding module one by one when the magnet follows the motor shaft to rotate for each circle.
The utility model provides an inductive encoder, including increment coding module, absolute coding module and treater, the treater carries out the coding to the electrical angle cycle of increment coding module output based on the digital signal of absolute coding module output to can confirm the code of its place electrical angle cycle again after the concrete position of each part in the electrical angle cycle that each place is located after confirming the motor shaft subdivision, need not the motor shaft rotation and passes through the zero point, can confirm the absolute mechanical position data of motor shaft in the full range.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required in the prior art and the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of an inductive encoder according to the present invention;
FIG. 2 is a schematic diagram of a single period inductive encoder according to the present invention;
FIG. 3 is a schematic diagram of a multi-cycle inductive encoder according to the present invention;
FIG. 4 is a schematic diagram of a signal waveform output by an incremental coil according to the present invention;
FIG. 5 is a schematic diagram of a filtered signal waveform provided by the present invention;
FIG. 6 is a schematic diagram illustrating an embodiment of an inductive encoder according to the present invention;
fig. 7 is a schematic diagram of a corresponding arrangement relationship between a hall sensor and a magnet according to the present invention.
Detailed Description
The invention provides an inductive encoder, which can determine the specific position of each part in the electrical angle period of each motor shaft after the motor shaft is subdivided, then determine the code of the electrical angle period of each part, and determine the absolute mechanical position data of the motor shaft in the full range without rotating the motor shaft to pass through a zero point.
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Referring to fig. 1, fig. 1 is a schematic structural diagram of an inductive encoder according to the present invention, where the inductive encoder includes:
the incremental coding module 1 is used for outputting angle position data of an electrical angle period when the motor shaft rotates by a preset angle, and the electrical angle period number of the angle position data output when the motor shaft rotates by one circle is equal to the pole logarithm of an incremental coil arranged by the incremental coding module;
an absolute encoding module 2 for outputting a digital signal corresponding to an electrical angle period of the angular position data output by the incremental encoding module 1 every time the motor shaft rotates by a preset angle;
the digital signals output by the absolute coding module 2 and the electric angle periods of the angle position data output by the incremental coding module 1 correspond to each other one by one when the motor shaft rotates for one time;
the first input end is connected with the output end of the incremental coding module 1, the second input end is connected with the processor 3 of the output end of the absolute coding module 2, and the processor is used for coding each electric angle period of the angle position data output by the incremental coding module 1 based on the digital signal, so that the absolute mechanical position data of the motor shaft is determined based on the coded electric angle period and the corresponding angle position data.
In this embodiment, the applicant considers that the incremental encoder of the prior art can determine the position of each electrical angle cycle output by itself with respect to the zero point only when the rotation passes the zero point, thereby determining the absolute mechanical position data of the motor shaft based on the angular position data of each electrical angle cycle. If the motor shaft does not pass through the zero point when rotating, the incremental encoder cannot determine the relative positions of each electrical angle period and the zero point, that is, cannot determine the absolute mechanical position data of each point on the motor shaft, but only can determine the position data in each part of the motor shaft after the incremental coil in the incremental encoding module 1 subdivides the motor shaft, that is, only can determine the position data in an electrical angle period through the angular position data of one electrical angle period output in a subdivided part, but cannot determine the specific position of the electrical angle period on the motor shaft, so that the absolute mechanical position data of the motor shaft cannot be determined.
In order to solve the technical problem, an incremental coding module 1 and an absolute coding module 2 are arranged in the inductive encoder in the application, the incremental coding module 1 outputs angle position data of an electrical angle period when a motor shaft rotates by a preset angle, and the electrical angle period number of the angle position data output when the motor shaft rotates by one circle is equal to the pole pair number of an incremental coil arranged by the incremental encoder. In order to determine the absolute mechanical position on the motor shaft corresponding to the angular position data of each electrical angular period output by the incremental encoding module 1, the absolute encoding module 2 in the application can synchronously output digital signals corresponding to each electrical angular period of the angular position data output by the incremental encoding module 1, and the processor 3 encodes each electrical angular period of the angular position data output by the incremental encoding module 1 based on the digital signals, so that the specific position corresponding to the angular position data of each electrical angular period on the motor shaft, namely, the absolute mechanical position data of each point on the motor shaft can be determined.
It should be noted that, the motor shaft in the present application does not need zero crossing when rotating, and the sine signal or the cosine signal output by the incremental coding module 1 can be coded when rotating by a preset angle, so as to determine the specific position on the corresponding motor shaft.
In addition, for example, when the incremental encoding module 1 is provided with four pairs of incremental coils, that is, the motor shaft can be subdivided into four parts, and the motor shaft rotates once, the incremental encoding module 1 can output angular position data of four electrical angular periods, the absolute encoding module 2 can output digital signals corresponding to the four electrical angular periods one by one, for example, the digital signals are 00, 01, 11 and 10 in sequence, and the electrical angular period of the angular position data output by the incremental coils of the first pair corresponds to 00, the electrical angular period of the angular position data output by the incremental coils of the second pair corresponds to 01, the electrical angular period of the angular position data output by the incremental coils of the third pair corresponds to 11, the electrical angular period of the angular position data output by the incremental coils of the fourth pair corresponds to 10, and the electrical angular period of the angular position data output by the incremental coils of any one pair can correspond to the respective digital signals, that is, the absolute mechanical position data of the motor shaft can be determined in the full range.
It should be noted that the inductive encoder in the application also has the characteristics of interference resistance, dirt resistance, small temperature drift, strong tolerance in severe environment and high performance consistency.
In summary, the inductive encoder in the application can determine the specific position of each part of the motor shaft within the respective electrical angle period after determining the subdivision of the motor shaft, and then determine the code of the electrical angle period, so that absolute mechanical position data of the motor shaft can be determined within the full range without rotating the motor shaft to pass through the zero point.
Based on the above embodiments:
as a preferred embodiment, further comprising:
the output end is connected with the power input end of the increment coding module 1, the power input end of the absolute coding module 2 and the power supply connected with the power input end of the processor 3, and is used for supplying power to the increment coding module 1, the absolute coding module 2 and the processor 3.
The power supply in this embodiment can supply power to the incremental encoding module 1, the absolute encoding module 2 and the processor 3, so as to ensure the normal operation of the inductive encoder, and of course, the power supply in this application may be, but is not limited to, an external main power supply or a battery.
As a preferred embodiment, the power source includes an external power source and a battery;
the external power supply is used for supplying power to the incremental coding module 1, the absolute coding module 2 and the processor 3 when the motor works and for cutting off the power when the motor stops working;
the battery is used for supplying power to one of the hall switch chips and the processor 3 when the external power supply is powered off.
In this embodiment, the applicant considers that the motor may still rotate due to the reason of false touch when the motor is powered off, that is, the main power supply is powered off, but the inductive encoder is not powered on and cannot calculate the number of turns of the motor shaft, so in the prior art, the inductive encoder is usually powered by the battery, however, the electric energy of the battery is limited, the incremental encoding module 1, the absolute encoding module 2 and the processor 3 are all arranged in the inductive encoder, the battery is required to supply the electric energy, the electric energy in the battery is consumed soon, and the workload of the user is increased by frequent battery replacement.
In order to solve the technical problem, when the main power supply is powered off, the battery supplies power for one of the Hall switch chips and the processor 3, so that the Hall switch chips and the processor 3 can record the number of turns of the motor after the motor is powered off.
As a preferred embodiment, the processor 3 is further configured to determine whether the motor is currently powered by a battery, conduct only the battery-powered hall switch chip with its own connected port when determining that the motor is powered by the battery, and count when receiving a jump of the digital signal output from the hall switch chip, thereby calculating the number of rotations of the motor shaft.
In this embodiment, when the processor 3 determines that the battery is currently powered, only the hall switch chip powered by the battery is turned on to the port connected to itself, and the ports connected to the output terminals of the other hall switch chips are turned off, thereby reducing power consumption. In addition, when the battery is powered, the battery supplies power to only one hall switch chip, and the digital signal output by the hall switch chip during one rotation of the motor shaft can include a half-turn high level and a half-turn low level, so that the processor 3 can determine the number of turns of the motor shaft according to whether the digital signal output by the hall switch chip is jumped or not, thereby realizing multi-turn counting, and saving the calculated numerical value.
In addition, when the digital signal output by the hall switch chip is not hopped, the processor 3 is in a low power consumption state, i.e., a sleep state, thereby further reducing power consumption.
As a preferred embodiment, the delta coding module 1 comprises:
an exciting coil 12 connected to the processor 3 through a capacitor for resonating with the capacitor to form a resonance magnetic field inside the own coil;
a multi-pole pair increment coil 13 with an output end connected with the low-pass filter 14 and used for outputting resonance induction electromotive force after sensing a resonance magnetic field;
the increment coils 13 of each pole pair comprise an advance increment coil 13 and a retard increment coil 13, wherein the retard increment coil 13 is placed by one quarter of an electrical angle period;
the conductive metal 11 is arranged between the incremental coils 13 and is rigidly connected with the motor shaft, and is used for changing the amplitude of the resonance induction electromotive force output by the incremental coils 13 when the motor shaft rotates along with the motor shaft and passes through the incremental coils 13 so as to enable the amplitude of the resonance induction electromotive force output by the hysteresis incremental coils 13 in the incremental coils 13 of each pole pair to fluctuate according to a sine curve waveform; the amplitude of the resonance induction electromotive force output by the lead increment coil 13 fluctuates according to the waveform of a cosine curve;
the output end of the low-pass filter 14 is connected with the processor;
the low-pass filter 14 is used for demodulating and filtering the resonance induction electromotive force with the amplitude which is output by the increment coil 13 and fluctuates according to the waveform of the sine curve and the resonance induction electromotive force with the amplitude which fluctuates according to the waveform of the cosine curve;
the analog-to-digital converter 15 is used for converting the resonance induction electromotive force after demodulation and filtering into sine signals and cosine signals of corresponding digital quantities;
the subdivision unit 16 is used for subdividing and decoding the sine signal and the cosine signal of the digital quantity to output the angle position data of one electrical angle period when the motor shaft rotates by a preset angle, and the number of the electrical angle period output when the motor shaft rotates by one circle is equal to the pole logarithm of the increment coil 13.
The incremental encoding module 1 in the present application is provided with an excitation coil 12, an incremental coil 13, a conductive metal 11, a low-pass filter 14, an analog-to-digital converter 15, and a subdivision unit 16. The exciting coil 12 and the capacitor form an LC resonant network, a resonant magnetic field is formed inside the exciting coil 12, and after the incremental coil 13 senses the resonant magnetic field, a resonant induced electromotive force is generated. The conductive metal 11 is disposed between the incremental coils 13 and rigidly connected to the motor shaft, generates eddy currents in the resonant magnetic field, and forms a magnetic field with completely opposite directions to the resonant magnetic field, thereby affecting the effective magnetic field strength of the resonant magnetic field induced by the incremental coils 13, and affecting the resonant induced electromotive force in the incremental coils 13. When the conductive metal 11 rotates along with the motor shaft and passes through the increment coil 13 of one pole pair, the amplitude of the resonance induction electromotive force output by the delay increment coil 13 in the increment coil 13 of the pole pair fluctuates according to the waveform of the sine curve for one period, the amplitude of the resonance induction electromotive force output by the lead increment coil 13 fluctuates according to the waveform of the cosine curve for one period, and corresponding sine signals and cosine signals are output after being filtered by the low-pass filter 14. The sine signal and the cosine signal are subjected to analog-digital conversion by the analog-digital converter 15, and the sine signal and the cosine signal subjected to analog-digital conversion are subjected to position decoding by the subdivision unit 16, so that the angle position information of the corresponding position on the motor shaft and the increment coil 13 of the pole pair can be obtained. Referring to fig. 2, fig. 2 is a schematic structural diagram of a single-period inductor encoder according to the present invention. Referring to fig. 3, fig. 3 is a schematic structural diagram of a multi-period inductor encoder according to the present invention. Referring to fig. 4 and 5, fig. 4 is a schematic diagram of a signal waveform output by an incremental coil according to the present invention, fig. 5 is a schematic diagram of a filtered signal waveform according to the present invention, and fig. 6 is a schematic diagram of a specific structure of an inductive encoder according to the present invention.
In the present embodiment, the position decoding means that the arctangent calculation is performed on the digital sine signal and the digital cosine signal corresponding to the incremental coil 13 of each pole pair, so that the high-resolution and high-precision angular position data of the subdivided portion on the motor shaft corresponding to the incremental coil 13 of the pole pair can be obtained.
As a preferred embodiment, the conductive metal 11 is fan-shaped and has an inner diameter smaller than an outer diameter;
the absolute encoding module 2 includes:
the magnet is arranged at the center of the conductive metal 11, has an outer diameter smaller than the inner diameter of the conductive metal 11 and is rigidly connected with the motor shaft and is used for rotating along with the motor shaft;
a plurality of hall switch chips provided corresponding to the incremental coils 13 for outputting digital signals corresponding to the electrical angle period of the angular position data output by the incremental encoding module 1 based on the magnetic flux passing through the magnet per rotation of the motor shaft by a preset angle;
the digital signals output by the Hall switch chip when the motor shaft rotates for each circle correspond to the electric angle periods of the angle position data output by the incremental coding module 1 one by one.
In this embodiment, considering that the resonant magnetic field in the inductive encoder is easily disturbed, if the absolute encoding module is also implemented by the coil, the sine signal and the cosine signal output by the incremental coil 13 will be disturbed, so that the accuracy of the inductive encoder is reduced, and in order to solve this technical problem, the absolute encoding module 2 in this application is implemented by the hall switch chip. Specifically, the magnet in this application is disposed at the center of the conductive metal 11, and the outer diameter of the magnet is smaller than the inner diameter of the conductive metal 11, and the magnet is less in variation of the magnetic flux passing through the inside of the incremental coil 13 and the exciting coil 12 when rotating following the motor shaft, and therefore, the influence on the resonance magnetic field is also less. The hall switch chips are arranged in one-to-one correspondence with the increment coils 13 of each pole pair, so that corresponding digital signals can be output when the increment coding module 1 outputs the angle position data of any one electrical angle period, and the processor 3 can conveniently code each electrical angle period of the angle position data output by the increment coding module 1, and determine the absolute mechanical position data of each point on a motor shaft in the whole range.
The principle of the work of the Hall switch chip is that when the magnetic field of the Hall switch chip rotates and the effective magnetic flux in the positive direction of the Hall switch chip is larger than 0, the Hall switch chip outputs a high-level signal, and when the effective magnetic flux in the positive direction of the Hall switch chip is smaller than 0, the Hall switch chip outputs a low-level signal. Therefore, when the magnet rotates one circle along with the motor shaft, the Hall switch chip outputs a high-level signal of half circle and a low-level signal of half circle.
For example, a circle of the motor shaft is divided into four parts, only two hall switch chips a and B (for example, a advances by 90 ° when placed) having a phase difference of 90 ° are required, when the effective magnetic flux in the positive direction of the hall switch chip a is greater than 0 and the effective magnetic flux in the positive direction of B is not greater than 0, the digital signals output by the hall switch chips a and B are 10, when the effective magnetic fluxes in the positive direction of the hall switch chips a and B are both greater than 0, the digital signals output by the hall switch chips a and B are 11, when the effective magnetic flux in the positive direction of the hall switch chip B is greater than 0 and the effective magnetic flux in the positive direction of a is not greater than 0, the digital signals output by the hall switch chips a and B are 01, and when the effective magnetic fluxes in the positive direction of the hall switch chips a and B are both not greater than 0, the digital signals output by the hall switch chips a and B are 00. The motor shaft can be divided into 2 parts by one Hall switch chip, and four digital signals which are equal to the pole pair number of the incremental coil 13 and correspond to the pole pair number can be output, so that when the incremental coil 13 with 2X pole pairs is arranged in the incremental coding module 1, one circle can be divided into X parts, and only X/2 Hall switches are placed according to the mechanical angle of the encoder, and the mechanical angle of the encoder is equally divided into X/2 parts, so that the coding of the electrical angle period output by the incremental coil 13 can be realized. All hall switch chips are arranged on the same track, namely the radius from the center of the circle is the same. The number of pole pairs of the incremental coils 13 provided in the present invention is not limited as long as the space is sufficient.
In addition, it should be noted that the pole pair number of the incremental coil 13 in the present application needs to be set to be an even number, so that it can be ensured that when the magnet rotates along with the motor shaft, no matter where the magnet rotates, the areas of the N pole and the S pole of the magnet located inside the exciting coil 12 and the incremental coil 13 are equal, so that it can be ensured that the variation of the magnetic flux of the magnet in the exciting coil 12 and the incremental coil 13 is smaller, so as to ensure that the interference generated by the sine signal and the cosine signal output by the incremental coil 13 is smaller when the magnet rotates.
As a preferred embodiment, the hall switch chip includes:
the Hall sensor is arranged corresponding to the increment coil 13 and is used for outputting a sine voltage signal based on magnetic flux passing through the Hall sensor when the magnet follows the motor shaft to rotate for a preset angle;
the input end is connected with the Hall sensor, and the output end is connected with the comparator of the processor 3 and is used for converting the sine voltage signal into a square wave signal;
when the sine voltage signal is in the range of 0-pi in one period, the square wave signal is at a first level; when the sine voltage signal is in the range of pi-2 pi in one period, the square wave signal is at a second level;
the level that a plurality of hall switch chips output at the same time constitutes the digital signal, and a plurality of digital signals that hall switch chip output and the each electric angle cycle one-to-one of the angular position data that incremental coding module 1 output when magnet follows motor shaft every round.
The Hall switch chip is provided with the Hall sensor, the Hall sensor can output a corresponding sinusoidal voltage signal when the magnet rotates, and the sinusoidal voltage signal with one period can be output after the motor rotates once, the comparator can convert the sinusoidal voltage signal into a square wave signal by converting the sinusoidal voltage signal, the square wave signal is in a first level when corresponding to the range of 0-pi of the sinusoidal voltage signal, and the square wave signal is in a second level when corresponding to the range of pi-2 pi of the sinusoidal voltage signal. The processor 3 may determine the digital signal of the time based on the levels corresponding to the square wave signals at the same time, for example, two hall switch chips are set, the square wave signal output by the first hall switch chip at the current moment is at a high level, that is, 1, and the square wave signal output by the second hall switch chip at the current moment is at a low level, that is, 0, so that the current digital signal can be determined to be 10.
In addition, since the hall sensor outputs a corresponding square wave signal based on the magnitude of the effective magnetic flux passing through the hall sensor, the hall sensor may not be located at the center of the magnet when being arranged, and the hall sensor may be arranged as a hollow scheme, that is, the center of the hall sensor track is hollow, please refer to fig. 7, and fig. 7 is a schematic diagram of the corresponding arrangement relationship between the hall sensor and the magnet.
It should also be noted that in this specification, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (7)
1. An inductive encoder, comprising:
the incremental coding module is used for outputting angle position data of an electrical angle period when the motor shaft rotates for a preset angle, and the electrical angle period number of the angle position data output when the motor shaft rotates for one circle is equal to the pole logarithm of an incremental coil arranged by the incremental coding module;
the absolute coding module is used for outputting a digital signal corresponding to the electrical angle period of the angle position data output by the incremental coding module when the motor shaft rotates by the preset angle;
the digital signals output by the absolute coding module correspond to the electric angle periods of the angle position data output by the incremental coding module one by one when the motor shaft rotates for each circle;
the first input end is connected with the output end of the incremental coding module, the second input end is connected with the processor of the output end of the absolute coding module and used for coding each electric angle period of the angle position data output by the incremental coding module based on the digital signal, so that the absolute mechanical position data of the motor shaft are determined based on the coded electric angle period and the corresponding angle position data.
2. The inductive encoder of claim 1, further comprising:
the output end is connected with the power input end of the increment coding module, the power input end of the absolute coding module and the power supply connected with the power input end of the processor, and is used for supplying power to the increment coding module, the absolute coding module and the processor.
3. The inductive encoder of claim 2, wherein the power supply comprises an external power supply and a battery;
the external power supply is used for supplying power to the incremental coding module, the absolute coding module and the processor when the motor works, and is powered off when the motor stops working;
the battery is used for supplying power to one of the Hall switch chips and the processor when the external power supply is powered off; wherein:
the absolute encoding module includes: and the Hall switch chips are correspondingly arranged on the increment coils and are used for outputting digital signals corresponding to the electrical angle periods of the angle position data output by the increment coding module when the motor shaft rotates by the preset angle.
4. The inductive encoder of claim 3, wherein said processor is further configured to determine whether the current is being supplied by said battery, to turn on only the port to which said hall switch chip is connected when it is determined that the current is being supplied by said battery, and to count when a digital signal transition from the output of said hall switch chip is received, thereby calculating the number of revolutions of the motor shaft.
5. The inductive encoder of any of claims 1-4, wherein the incremental encoding module comprises:
an excitation coil connected with the processor through a capacitor and used for resonating with the capacitor so as to form a resonance magnetic field inside the self coil;
the output end of the incremental coil is connected with the low-pass filter and is used for outputting resonance induction electromotive force after sensing the resonance magnetic field;
the delta coils of each pole pair comprise a lead delta coil and a lag delta coil, the lag delta coil being positioned to lag the lead delta coil by one quarter of the electrical angle period;
a conductive metal disposed between the motor shaft and the incremental coils and rigidly connected to the motor shaft for changing the amplitude of the resonance-induced electromotive force output by the incremental coils while following the motor shaft rotation and passing through the incremental coils so that the amplitude of the resonance-induced electromotive force output by the hysteresis incremental coils in the incremental coils of each pole pair fluctuates in accordance with a sinusoidal waveform; the amplitude of the resonance induction electromotive force output by the lead increment coil fluctuates according to the waveform of a cosine curve;
the output end of the low-pass filter is connected with the processor;
the low-pass filter is used for carrying out demodulation filtering processing on the resonance induction electromotive force with the amplitude value which is output by the increment coil and fluctuates according to the waveform of the sine curve and the resonance induction electromotive force with the amplitude value which fluctuates according to the waveform of the cosine curve;
the analog-to-digital converter is used for converting the resonance induction electromotive force after demodulation and filtering into sine signals and cosine signals of corresponding digital quantity;
the subdivision unit is used for subdividing and decoding the sine signals and the cosine signals of the digital quantity so as to output angle position data of an electrical angle period when the motor shaft rotates for a preset angle, and the number of the electrical angle period output when the motor shaft rotates for one circle is equal to the pole pair number of the increment coil arranged by the motor shaft.
6. The inductive encoder of claim 5, wherein the conductive metal is scalloped and has an inner diameter less than an outer diameter;
the absolute encoding module includes:
the magnet is arranged at the center of the circle of the conductive metal, the outer diameter of the magnet is smaller than the inner diameter of the conductive metal, and the magnet is rigidly connected with the motor shaft and is used for rotating along with the motor shaft;
the plurality of Hall switch chips are correspondingly arranged on the incremental coils and are used for outputting digital signals corresponding to the electrical angle periods of the angle position data output by the incremental coding module based on magnetic fluxes passing through the Hall switch chips when the magnet rotates by the preset angle along with the motor shaft;
and when the motor shaft rotates for every circle, a plurality of digital signals output by the Hall switch chip correspond to each electrical angle period of the angle position data output by the incremental coding module one by one.
7. The inductive encoder of claim 6, wherein the hall switch chip comprises:
the Hall sensor is correspondingly arranged with the increment coil and is used for outputting a sine voltage signal based on magnetic flux passing through the Hall sensor when the magnet rotates by the preset angle along with the motor shaft;
the input end of the comparator is connected with the Hall sensor, and the output end of the comparator is connected with the processor and is used for converting the sinusoidal voltage signal into a square wave signal;
the square wave signal is a first level when the sine voltage signal is in the range of 0-pi in one period; the square wave signal is of a second level when the sine voltage signal is in the range of pi-2 pi in one period;
the digital signals are formed by the levels output by the Hall switch chips at the same time, and the digital signals output by the Hall switch chips correspond to the electric angle periods of the angle position data output by the incremental coding module one by one when the magnet follows the motor shaft to rotate for each circle.
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| CN114526761A (en) * | 2022-02-23 | 2022-05-24 | 成都卡诺普机器人技术股份有限公司 | Robot and detection method thereof, double encoders and system thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| GB0127491D0 (en) * | 2001-11-16 | 2002-01-09 | Trw Lucas Varity Electric | Angular position sensor |
| CN101846531B (en) * | 2010-05-28 | 2011-08-24 | 江苏斯沃特电气有限公司 | Multipole combined-type magnetic encoder |
| DE102013201241A1 (en) * | 2013-01-25 | 2014-09-11 | Schaeffler Technologies Gmbh & Co. Kg | Method and device for determining the position of the rotor in a brushless DC motor |
| JP6224349B2 (en) * | 2013-05-15 | 2017-11-01 | 株式会社アイエイアイ | Stepping motor control system and stepping motor control method |
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| DE102017200988A1 (en) * | 2017-01-23 | 2018-07-26 | Robert Bosch Gmbh | A sensor wheel arrangement and method for determining an absolute angle position and a direction of rotation |
| CN110940361A (en) * | 2019-12-04 | 2020-03-31 | 北京科技大学 | Magnetic sensitive multi-circle absolute value encoder |
| CN110986746B (en) * | 2019-12-27 | 2020-09-22 | 上海舞肌科技有限公司 | Output side absolute position detection method, output side absolute position detection device, speed reduction motor and storage medium |
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