CN115164951A - Method for subdividing moire fringe signal of photoelectric encoder - Google Patents

Method for subdividing moire fringe signal of photoelectric encoder Download PDF

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CN115164951A
CN115164951A CN202210996457.7A CN202210996457A CN115164951A CN 115164951 A CN115164951 A CN 115164951A CN 202210996457 A CN202210996457 A CN 202210996457A CN 115164951 A CN115164951 A CN 115164951A
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value
signal
subdivision
photoelectric encoder
moire
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赵长海
万秋华
于海
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Changchun Institute of Optics Fine Mechanics and Physics of CAS
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Changchun Institute of Optics Fine Mechanics and Physics of CAS
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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
    • G01D5/26—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 characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
    • G01D5/32—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 characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
    • G01D5/34—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 characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
    • G01D5/347—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 characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells using displacement encoding scales
    • G01D5/34707—Scales; Discs, e.g. fixation, fabrication, compensation
    • G01D5/34715—Scale reading or illumination devices
    • 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
    • G01D5/26—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 characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
    • G01D5/32—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 characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
    • G01D5/34—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 characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
    • G01D5/347—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 characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells using displacement encoding scales
    • G01D5/3473—Circular or rotary encoders

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Abstract

The invention provides a method for subdividing moire fringe signals of a photoelectric encoder, which corrects the moire fringe signals of the photoelectric encoder through a correction coefficient obtained by calculation, and calculates the subdivision values of the subdivided positions after correction by adopting a new subdivision value calculation formula. The invention can eliminate or reduce subdivision errors caused by unequal amplitudes of two paths of moire fringe signals and the fact that the central point of the signal is not 0, namely eliminate or reduce zero position errors and amplitude errors of the signal, can improve the subdivision accuracy of the photoelectric encoder on the whole, and further improve the measurement accuracy of the photoelectric encoder.

Description

Method for subdividing moire fringe signal of photoelectric encoder
Technical Field
The invention relates to the technical field of photoelectric encoders, and particularly provides a subdivision method of moire fringe signals of a photoelectric encoder.
Background
The photoelectric shaft angle encoder, also called photoelectric angular position sensor, is a precision digital angle measuring device integrating light, machine and electricity into one body. The photoelectric shaft-position encoder is generally composed of a shaft system, a light-emitting tube, a code disc, a slit, a receiving tube and a processing circuit, wherein a plurality of concentric code channels are arranged on a circular code disc of the photoelectric encoder along the radial direction, and each code channel is composed of a light-transmitting sector and a light-impermeable sector. On one side of the code wheel, a light-emitting element is arranged, on the other side, a photosensitive element is arranged corresponding to each code track, each light-emitting element and photosensitive element pair is called a reading head, and the reading heads are combined together to form a group of reading heads. When the light emitted by the light emitting element is irradiated on the receiving element through the code disc and the slit, a moire fringe signal is formed. When the code wheel is at different positions, each photosensitive element can output different moire fringe current signals according to the fact that whether the code wheel is illuminated or not and the intensity of illumination, the current signals are connected with resistors in series, the resistors convert the current signals into voltage signals, and the voltage signals are called as original moire fringe input signals of the photoelectric encoder.
The photoelectric shaft-position encoder is divided into an absolute type and an incremental type, signals of the absolute type photoelectric encoder are divided into a coarse code signal and a fine code signal, the incremental type photoelectric encoder only has the fine code signal, and the precision of the photoelectric encoder depends on the subdivision precision of the fine code signal regardless of the absolute type photoelectric encoder or the incremental type photoelectric encoder. The original moire fringe signals of a group of fine code reading heads of the photoelectric shaft angle encoder are generally divided into four paths, recorded as C0, C90, C180 and C270, which are approximate sine wave signals with the phase difference of 90 degrees. The phase difference between the C0 and the C180 is 180 degrees, and sine wave signals obtained after the C0 and the C180 signals enter a differential amplifier for amplification and shaping are marked as SIN signals; the phase difference between the C90 and the C270 is 180 degrees, the C90 and the C270 signals enter the differential amplifier to be amplified and shaped to obtain sine wave signals which are recorded as COS signals, and the phase difference between the SIN signals and the COS signals is 90 degrees. Calculating a subdivision angle value theta of one fine code period of the photoelectric encoder according to the numerical values of the SIN signal and the COS signal, wherein the formula is as follows:
Figure BDA0003805715800000021
since a negative value appears in the actual calculation of the formula (4), a certain angle is added to the theta value according to the quadrant in the actual calculation, so that the component value is guaranteed to be positive and continuous in one period of the moire fringe signal.
When the formula (4) is adopted to calculate the subdivision angle of the photoelectric encoder, the two amplified moire fringe signals output by the default photoelectric encoder are centered at 0, the amplitude of the SIN signal is consistent with that of the COS signal, and the error of the calculated subdivision angle value is small. However, because the photoelectric encoder has errors in the assembling and manufacturing processes, a certain error exists between the two moire fringe signals amplified by the reading head of the photoelectric encoder and the standard sine wave signal, the amplitudes of the two moire fringe signals may have inconsistency, and the central points of the two moire fringe signals are not necessarily 0, if the formula (4) is still used for calculating the subdivision angle of the moire fringe signals, a large error may be generated, and the wrong code of the photoelectric encoder may be caused when the error is large to a certain degree, so that the photoelectric encoder cannot be used.
Disclosure of Invention
In order to solve the problems, the invention provides a subdivision method of a moire fringe signal of a photoelectric encoder, which effectively improves the precision of the photoelectric encoder.
The invention provides a subdivision method of a moire fringe signal of a photoelectric encoder, which corrects the moire fringe signal of the photoelectric encoder by a correction coefficient obtained by calculation and calculates a subdivision value of a subdivision position after correction by adopting a new subdivision value calculation formula (1), and comprises the following steps:
s1, calculating three correction coefficients a for moire fringe signal subdivision 0 、b 0 And c 0 Wherein a is 0 Is the central value of the SIN signal, b 0 Is the center value of the COS signal, c 0 Is the ratio of the amplitude of the COS signal and the SIN signal;
s2, collecting a numerical value of a moire fringe signal;
s3, correcting the moire fringe signal by adopting the correction coefficient, calculating and outputting the corrected subdivision value of the subdivision position
Figure BDA0003805715800000022
The calculation formula is as follows:
Figure BDA0003805715800000023
where S denotes a voltage value of the SIN signal whose moire signal is not corrected, C denotes a voltage value of the COS signal whose moire signal is not corrected, S 'denotes a voltage value of the SIN signal at the division position after the moire signal is corrected, and C' denotes a voltage value of the COS signal at the division position after the moire signal is corrected.
Preferably, the correction factor a 0 、b 0 And c 0 The calculation process of (2) is as follows:
step S11, a subdivision error measurement system is built, the motor, the high-precision reference photoelectric encoder and the detected photoelectric encoder are coaxially connected, data of n sampling points in one period of moire fringe signals of the detected photoelectric encoder are collected, n is a positive integer, and the data of the ith sampling point comprises: voltage value S of SIN signal of ith sampling point i Voltage value C of COS signal at ith sampling point i Angular value θ of reference photoelectric encoder i ，i＝1，2，3...n；
Step S12, in the value combination, a group of correction coefficients are taken, the refined values after the n sampling points are corrected are calculated by using a formula (1), and the refined values in the formula (1)
Figure BDA0003805715800000031
Is replaced by
Figure BDA0003805715800000032
Represents the corrected subdivision value of the ith sampling point, and S is replaced by S i Replacement of C by C i Obtaining n subdivision values in total;
s13, calculating the subdivision errors of the n acquisition points, wherein the formula is as follows:
Figure BDA0003805715800000033
wherein the content of the first and second substances,
Figure BDA0003805715800000034
a subdivision value e representing the ith sample point calculated in step S12 i The subdivision error of the ith sampling point is represented, namely the difference between the subdivision value of the detected photoelectric encoder of the ith sampling point and the subdivision value of the reference photoelectric encoder;
step S14, calculating the mean square error sigma of n subdivision errors, wherein the formula is as follows:
Figure BDA0003805715800000035
wherein, the first and the second end of the pipe are connected with each other,
Figure BDA0003805715800000036
represents the average of n refinement errors;
step S15, repeating the steps S12 to S14 until the mean square error sigma of all the combinations of the correction coefficients in the value combination is calculated, and taking the a when the mean square error is minimum 0 、b 0 And c 0 As the final correction factor.
Preferably, the correction factor a 0 Has a minimum value of MIN Maximum value of a MAX Each time a is calculated 0 Has a variation of Δ a, then a 0 The number of values of (a) is 1+ (a) MAX -a MIN )/Δa；
Correction factor b 0 Minimum value of b MIN Maximum value of b MAX Each time b is calculated 0 Has a variation of Δ b, then b 0 The number of values of (a) is 1 +/(b) MAX -b MIN )/Δb；
Correction factor c 0 Minimum value of c MIN Maximum value of c MAX Each time c is calculated 0 When the variation of (c) is Δ c, c is measured 0 The number of values of (c) is 1+ (c) MAX -c MIN ) At a correction factor of a,/Δ c 0 、b 0 And c 0 In the calculation process of (A), c is guaranteed 0 If the value of (A) is greater than 0, then a 0 、b 0 And c 0 The number of value combinations of (a) is (1 + (a) MAX -a MIN )/Δa)*(1+(b MAX -b MIN )/Δb)*(1+(c MAX -c MIN ) And/deltac).
Preferably, the manner of selecting the final correction coefficient further includes:
taking the correction coefficient when the error average value is minimum as the final correction coefficient;
the correction coefficient when the peak-to-valley value of the subdivision error is the smallest is taken as the final correction coefficient.
An angular displacement measuring device uses a method of subdividing a moire fringe signal of a photoelectric encoder.
A linear displacement measuring device uses a method of subdividing a moire fringe signal of a photoelectric encoder.
Compared with the prior art, the invention can obtain the following beneficial effects:
the invention can eliminate or reduce subdivision errors caused by unequal amplitudes of two paths of moire fringe signals and the fact that the central point of the signal is not 0, namely, eliminate or reduce zero errors and amplitude errors of the signal, and can improve the subdivision precision of the photoelectric encoder on the whole, thereby improving the measurement precision of the photoelectric encoder.
Drawings
FIG. 1 is a flow chart of a subdivision method provided according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a subdivision error measurement system provided in accordance with an embodiment of the present invention;
fig. 3 is a flowchart for calculating a correction coefficient according to an embodiment of the present invention.
Wherein the reference numerals include: the photoelectric encoder to be detected 1, the reference photoelectric encoder 2, the data acquisition and processing system 3 and the computer 4.
Detailed Description
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same reference numerals are used for the same blocks. In the case of the same reference numerals, their names and functions are also the same. Therefore, detailed description thereof will not be repeated.
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention.
Fig. 1 shows a flow chart of a subdivision method provided according to an embodiment of the present invention.
As shown in fig. 1, the method for subdividing a moire fringe signal of an optical-electrical encoder includes the following steps:
s1, in the embodiment, three correction coefficients a for moire signal subdivision need to be calculated firstly 0 、b 0 And c 0 A is a value of 0 Is the central value of the SIN signal, b 0 Is the center value of the COS signal, c 0 Is the ratio of the magnitudes of the COS signal and the SIN signal.
When the moire fringe signal output by the photoelectric encoder is a standard sine-cosine signal, the correction coefficient a 0 And b 0 Has a value of 0,c 0 The value of (2) is 1. However, in actual testing, because the photoelectric encoder has errors in the assembling, adjusting and manufacturing processes, a certain error exists between the two amplified moire fringe signals output by the reading head of the photoelectric encoder and the standard sine wave signals, the amplitudes of the two moire fringe signals may have inconsistency, and the central points of the two moire fringe signals are not necessarily 0. Therefore, the three correction coefficients are uniformly grouped in the range of the available value, each group of values is added with a variable quantity, and then each group of correction coefficients is subjected to error measurement.
Selecting a correction coefficient a 0 Has a minimum value of MIN Maximum value of a MAX Each time a is calculated 0 Has a variation of Δ a, then a 0 The number of values of (a) is 1+ (a) MAX -a MIN ) A,/Δ a; correction factor b 0 Minimum value of b MIN Maximum value of b MAX Each time b is calculated 0 Has a variation of Δ b, then b 0 The number of values of (a) is 1 +/(b) MAX -b MIN ) A,/Δ b; correction factor c 0 Minimum value of c MIN Maximum value of c MAX Each time c is calculated 0 When the variation of (c) is Δ c, c is measured 0 The number of values of (a) is 1+ (c) MAX -c MIN ) At a correction factor of a,/Δ c 0 、b 0 And c 0 In the calculation process of (A), c is guaranteed 0 If the value of (A) is greater than 0, then a 0 、b 0 And c 0 The number of the value combinations of (a) is (1 + (a) MAX -a MIN )/Δa)*(1+(b MAX -b MIN )/Δb)*(1+(c MAX -c MIN ) And/deltac).
In the embodiment, a is solved by adopting a contrast method and a successive approximation method 0 、b 0 And c 0 The numerical value of (c).
Fig. 2 illustrates a subdivision error measurement system provided in accordance with an embodiment of the present invention.
As shown in fig. 2:
s11, building a subdivision error measurement system, wherein the subdivision error measurement system comprises: the system comprises a photoelectric encoder 1 to be detected, a reference photoelectric encoder 2, a data acquisition and processing system 3, a computer 4, a motor and a motor driving system. The motor, the high-precision reference photoelectric encoder 2 and the photoelectric encoder 1 to be detected are coaxially connected, during measurement, the motor driving system drives the motor to rotate, the computer 4 collects moire fringe signals of the photoelectric encoder 1 to be detected and angle data of the reference photoelectric encoder 2 through the data collecting and processing system 3, and the difference between the subdivision value of the photoelectric encoder 1 to be detected and the subdivision value of the reference photoelectric encoder 2 is subdivision errors at the subdivision points.
The angular value of one complete moire fringe signal period of the photoelectric encoder 1 to be detected is theta all Acquiring data of n sampling points of a Moire fringe signal of a detected photoelectric encoder 1 in a period, wherein n is a positive integer, and the angle interval of every two adjacent sampling points is theta all And/n, wherein the data of the ith sampling point comprises: voltage value S of SIN signal at sampling point i Voltage value C of COS signal of sampling point i Angular value theta of reference photoelectric encoder 2 i ，i＝1，2，3...n；
Fig. 3 shows a flow of calculating a correction coefficient provided according to an embodiment of the present invention.
As shown in fig. 3:
s12, the computer 4 takes a group of correction coefficients in the value combination through the data acquisition and processing system 3, which is beneficial toCalculating and storing the corrected component values of the n sampling points by using a formula (1), wherein the formula (1) is
Figure BDA0003805715800000061
Is replaced by
Figure BDA0003805715800000062
Represents the corrected subdivision value of the ith sampling point, and S is replaced by S i Replacement of C by C i Obtaining n subdivision values in total; equation (1) is as follows:
Figure BDA0003805715800000063
wherein S represents a voltage value of the SIN signal whose moire signal is not corrected, C represents a voltage value of the COS signal whose moire signal is not corrected, S 'represents a voltage value of the SIN signal at the division position after the moire signal is corrected, and C' represents a voltage value of the COS signal at the division position after the moire signal is corrected.
Step S13, the computer 4 calculates and stores the subdivision errors of the n acquisition points through the data acquisition and processing system 3, and the formula is as follows:
Figure BDA0003805715800000064
wherein, the first and the second end of the pipe are connected with each other,
Figure BDA0003805715800000065
a subdivision value e representing the ith sample point calculated in step S12 i A subdivision error of the ith sampling point is represented, namely the difference between the subdivision value of the detected photoelectric encoder 1 of the ith sampling point and the subdivision value of the reference photoelectric encoder 2;
step S14, the computer 4 calculates and stores the mean square error sigma of the n subdivision errors through the data acquisition and processing system 3, and the formula is as follows:
Figure BDA0003805715800000071
wherein the content of the first and second substances,
Figure BDA0003805715800000072
represents the average of n refinement errors;
step S15, the steps S12 to S14 are repeatedly executed until the mean square deviation sigma of the combination of all the correction coefficients in the value combination is calculated, and the a with the minimum mean square deviation is taken 0 、b 0 And c 0 As the final correction factor.
In the present embodiment, a group of correction coefficients a whose mean square error of the subdivision error is smallest is selected 0 、b 0 And c 0 As final correction factors and stored in the data acquisition and processing system 3, it is also possible to use the mean value of the subdivided errors, the peak-to-valley value or the characteristic values of other parameters as a basis for selecting the final correction factors. The photoelectric encoder calculates the correction coefficient a when actually calculating the correction coefficient 0 、b 0 And c 0 The value range and the variation of the method can also be adjusted according to parameters such as precision indexes of the photoelectric encoder, and the like, and a proper range is selected so as to meet the precision requirement and avoid overlarge calculated amount. The number n of sampling points in one moire fringe signal period can be adjusted according to the requirement, and a proper numerical value is selected, so that the accuracy requirement can be met, and the calculated amount cannot be too large.
S2, after the correction coefficient of the photoelectric encoder is calculated, the stored correction coefficient a is read firstly when the photoelectric encoder actually runs 0 、b 0 And c 0 And then collecting two paths of moire fringe signals.
S3, correcting the moire fringe signal by adopting the correction coefficient, calculating and outputting the subdivision value of the corrected subdivision position by using the formula (1)
Figure BDA0003805715800000073
The invention can be used on an angular displacement measuring device, such as an axial angle photoelectric encoder, and can also be used on a linear displacement measuring device, such as a grating ruler, and the working principles of the invention are the same.
While embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are exemplary and should not be taken as limiting the invention. Variations, modifications, substitutions and changes to the embodiments described above will occur to those skilled in the art and are intended to be within the scope of the present invention.
The above embodiments of the present invention should not be construed as limiting the scope of the present invention. Any other corresponding changes and modifications made according to the technical idea of the present invention should be included in the protection scope of the claims of the present invention.

Claims (6)

1. A method for subdividing a moire fringe signal of an optical-to-electrical encoder, comprising the steps of:
s1, calculating three correction coefficients a for moire fringe signal subdivision 0 、b 0 And c 0 Wherein a is 0 Is the central value of the SIN signal, b 0 Is the center value of the COS signal, c 0 Is the ratio of the amplitude of the COS signal and the SIN signal;
s2, collecting the numerical value of the moire fringe signal;
s3, correcting the moire fringe signal by adopting the correction coefficient, calculating and outputting a subdivision value of a corrected subdivision position
Figure FDA0003805715790000011
The calculation formula is as follows:
Figure FDA0003805715790000012
wherein S represents a voltage value of the SIN signal whose moire signal is not corrected, C represents a voltage value of the COS signal whose moire signal is not corrected, S 'represents a voltage value of the SIN signal at the division position after the moire signal is corrected, and C' represents a voltage value of the COS signal at the division position after the moire signal is corrected.
2. The method for subdividing a moire signal of an optical-electrical encoder as claimed in claim 1, wherein said correction coefficient a 0 、b 0 And c 0 The calculation process of (c) is as follows:
s11, building a subdivision error measurement system, coaxially connecting a motor, a high-precision reference photoelectric encoder and a detected photoelectric encoder, and acquiring data of n sampling points of the detected photoelectric encoder in one period of a moire fringe signal, wherein n is a positive integer, and the data of the ith sampling point comprises: voltage value S of SIN signal of ith sampling point i Voltage value C of COS signal of ith sampling point i Angle value θ of the reference photoelectric encoder i ，i＝1，2，3...n；
S12, in the value combination, a group of correction coefficients is taken, and the corrected component values of the n sampling points are calculated by using a formula (1), wherein the component values in the formula (1)
Figure FDA0003805715790000013
Is replaced by
Figure FDA0003805715790000014
Represents the corrected subdivision value of the ith sampling point, and S is replaced by S i Replacement of C by C i Obtaining n subdivided values in total;
step S13, calculating the subdivision errors of the n acquisition points, wherein the formula is as follows:
Figure FDA0003805715790000015
wherein the content of the first and second substances,
Figure FDA0003805715790000016
represents the i-th subdivision value of the sampling point calculated in the step S12, e i Representing the subdivision error of the ith said sample point, i.e. of the ith sample pointA difference of the component value from the component value of the reference photoelectric encoder;
step S14, calculating the mean square error sigma of n subdivision errors, wherein the formula is as follows:
Figure FDA0003805715790000021
wherein the content of the first and second substances,
Figure FDA0003805715790000022
represents the average of n subdivision errors;
step S15, the steps S12 to S14 are repeatedly executed until the mean square error sigma of the combination of all the correction coefficients in the value combination is calculated, and the a with the minimum mean square error is taken 0 、b 0 And c 0 As the final correction factor.
3. The method for subdividing a moire signal of an optical-electrical encoder as claimed in claim 2, wherein said correction factor a 0 Has a minimum value of MIN Maximum value of a MAX Each time a is calculated 0 Has a variation of Δ a, then a 0 The number of values of (a) is 1+ (a) MAX -a MIN )/Δa；
The correction coefficient b 0 Minimum value of b MIN Maximum value of b MAX Each time b is calculated 0 Has a variation of Δ b, then b 0 The number of values of (a) is 1 +/(b) MAX -b MIN )/Δb；
The correction coefficient c 0 Minimum value of c MIN Maximum value of c MAX Each time c is calculated 0 When the variation of (c) is Δ c, c is measured 0 The number of values of (c) is 1+ (c) MAX -c MIN ) At the correction coefficient a,/Δ c 0 、b 0 And c 0 In the calculation process of (2), c is required to be guaranteed 0 If the value of (A) is greater than 0, then a 0 、b 0 And c 0 The number of the value combinations of (a) is (1 + (a) MAX -a MIN )/Δa)*(1+(b MAX -b MIN )/Δb)*(1+(c MAX -c MIN ) And/deltac).
4. The method for subdividing a moire signal for an optical-electrical encoder as claimed in claim 2, wherein said selecting said final correction factor further comprises:
taking the correction coefficient when the error average value is minimum as a final correction coefficient;
the correction coefficient when the peak-to-valley value of the subdivision error is minimum is taken as the final correction coefficient.
5. An angular displacement measuring device, characterized in that the method of subdividing a moire fringe signal of an optical-electrical encoder according to any one of claims 1 to 4 is used.
6. A linear displacement measuring device, characterized in that the method of subdividing a moir e fringe signal of an optical-electrical encoder according to any one of claims 1 to 4 is used.
CN202210996457.7A 2022-08-19 2022-08-19 Method for subdividing moire fringe signal of photoelectric encoder Pending CN115164951A (en)

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