CN114858062A - Detection signal processing method, device, medium, equipment and grating ruler - Google Patents

Detection signal processing method, device, medium, equipment and grating ruler Download PDF

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CN114858062A
CN114858062A CN202210659766.5A CN202210659766A CN114858062A CN 114858062 A CN114858062 A CN 114858062A CN 202210659766 A CN202210659766 A CN 202210659766A CN 114858062 A CN114858062 A CN 114858062A
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paths
signals
interference
orthogonal signals
determining
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CN114858062B (en
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郭朋军
贾星宇
李洪鹏
涂川
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Tanway Technology Co ltd
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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
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques
    • G01B11/02—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
    • G01P3/36—Devices characterised by the use of optical means, e.g. using infrared, visible, or ultraviolet light
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2218/00—Aspects of pattern recognition specially adapted for signal processing

Abstract

The disclosure relates to a detection signal processing method, a device, a medium, equipment and a grating ruler applied to the technical field of precision measurement, wherein the method comprises the following steps: controlling the reading head to move at any speed; acquiring three paths of interference signals acquired by a reading head in a motion state of any speed; the phases of the three interference signals are unknown; determining two paths of orthogonal signals by utilizing a phase compensation algorithm based on the three paths of interference signals; and determining the displacement and/or the speed of the measured target based on the two orthogonal signals. By acquiring interference signals of a non-solid fixed phase and utilizing a phase compensation algorithm, processing of detection signals can be completed without depending on the initial phase of the interference signals, so that the problems of complex installation and debugging process, severe requirements on production and manufacturing processes and the like of a grating ruler are solved, and the problem of harsh requirements on a calibration environment for solving the initial phase of the interference signals of a calibration algorithm is solved; meanwhile, the measurement precision of the grating ruler is improved.

Description

Detection signal processing method, device, medium, equipment and grating ruler
Technical Field
The present disclosure relates to the field of precision measurement technologies, and in particular, to a method, an apparatus, a medium, a device, and a grating scale for processing a detection signal applied to the grating scale.
Background
The grating ruler is a precise displacement measuring device which utilizes the optical principle of the grating, has nanoscale measurement precision, sub-nanoscale resolution and extremely high measurement stability, and is mainly applied to displacement measurement of various measuring mechanisms, instruments, numerical control machines and automation mechanisms.
In the related art, the measurement principle of the grating ruler is to determine the orthogonal signal with displacement information by obtaining the initial phase information of the interference signal and calculating according to the accurate initial phase information of the interference signal. Usually, through the design of a light path, interference signals with fixed phases are collected, and the displacement of a target to be measured is determined through calculation; however, the method has the problem of difficult realization due to the complex mechanical structure of the grating scale, and has extremely strict requirements on production and manufacturing conditions, and it is difficult to ensure that the detection signal is at the corresponding phase position, thereby resulting in poor measurement accuracy. In the related technology, high-precision initial phase solving can be carried out on the single-frequency signal according to a calibration algorithm; however, the calibration algorithm requires that the grating ruler must be provided with a high-precision electric displacement table, otherwise, the grating ruler cannot work normally, the calibration algorithm has great limitation, and the limitation on the scene causes great difficulty in the normal use of the grating ruler.
Disclosure of Invention
In order to solve the technical problem or at least partially solve the technical problem, the present disclosure provides a method, an apparatus, a medium, a device, and a grating scale for processing a detection signal applied to the grating scale.
In a first aspect, the present disclosure provides a method for processing a detection signal applied to a grating ruler, including:
controlling the reading head to move at any speed;
acquiring three paths of interference signals acquired by a reading head in a motion state of any speed; the phases of the three paths of interference signals are unknown;
determining two paths of orthogonal signals by utilizing a phase compensation algorithm based on the three paths of interference signals;
and determining the displacement and/or the speed of the measured target based on the two paths of orthogonal signals.
Optionally, the phase compensation algorithm is a fitting compensation algorithm based on a pearson correlation coefficient method and a nonlinear least square method;
wherein, the determining two paths of orthogonal signals by using a phase compensation algorithm based on the three paths of interference signals comprises:
determining the phase difference of the three-way interference signals by utilizing the Pearson correlation coefficient method based on the three-way interference signals; the three-path interference signal comprises a first path of interference signal, a second path of interference signal and a third path of interference signal, and the phase difference of the three-path interference signal comprises the phase difference of the second path of interference signal and the first path of interference signal and the phase difference of the third path of interference signal and the first path of interference signal;
determining two paths of orthogonal signals to be optimized by using a three-step phase shifting method based on the phase difference of the three paths of interference signals;
determining the compensation quantity of the orthogonal signals by utilizing a nonlinear least square method based on the two paths of orthogonal signals to be optimized;
and determining the two paths of orthogonal signals after optimization based on the two paths of orthogonal signals to be optimized and the compensation quantity of the orthogonal signals.
Optionally, the determining, based on the three-way interference signal and by using the pearson correlation coefficient method, a phase difference of the three-way interference signal includes:
calculating respective bias and amplitude for each path of interference signal in the three paths of interference signals;
determining the phase difference of the three paths of interference signals by utilizing a Pearson correlation coefficient method based on the bias and the amplitude;
the determining two paths of orthogonal signals to be optimized by using a three-step phase shifting method based on the phase difference of the three paths of interference signals comprises the following steps:
determining the two paths of orthogonal signals to be optimized by using a three-step phase shifting method based on the phase difference of the three paths of interference signals and combining the corresponding interference signal intensity;
in the correlation between the intensity of the first path of interference signal and the phase difference, the phase difference value is 0;
the method for determining the compensation quantity of the orthogonal signals by utilizing the nonlinear least square method based on the two paths of orthogonal signals to be optimized comprises the following steps:
obtaining the compensation quantity of the orthogonal signals with the phase difference between two paths of orthogonal signals to be optimized and completely orthogonal signals by utilizing a nonlinear least square method and through target matrix operation; wherein the compensation amount of the quadrature signal comprises a quadrature phase compensation amount, an amplitude compensation amount and a bias compensation amount;
the determining the two paths of orthogonal signals after optimization based on the two paths of orthogonal signals to be optimized and the compensation quantity of the orthogonal signals comprises:
and compensating the two paths of orthogonal signals to be optimized by using the compensation quantity of the orthogonal signals to obtain the two paths of optimized orthogonal signals.
Optionally, the compensating the two orthogonal signals to be optimized by using the compensation amount of the orthogonal signal to obtain the two optimized orthogonal signals includes:
and obtaining two optimized orthogonal signals by combining the following formulas:
Figure 589106DEST_PATH_IMAGE001
Figure 151806DEST_PATH_IMAGE002
wherein the content of the first and second substances,
Figure 745598DEST_PATH_IMAGE003
and
Figure 10226DEST_PATH_IMAGE004
represents the two paths of orthogonal signals after the optimization,
Figure 449298DEST_PATH_IMAGE003
in order to be a cosine signal, the signal,
Figure 866504DEST_PATH_IMAGE004
is a sinusoidal signal;
Figure 776339DEST_PATH_IMAGE005
and
Figure 403630DEST_PATH_IMAGE006
representing the two paths of orthogonal signals to be optimized;
Figure 521758DEST_PATH_IMAGE007
and
Figure 183684DEST_PATH_IMAGE008
representing the quadrature phase compensation amount;
Figure 243913DEST_PATH_IMAGE009
and
Figure 92920DEST_PATH_IMAGE010
representing the magnitude compensation amount;
Figure 14740DEST_PATH_IMAGE011
and
Figure 531172DEST_PATH_IMAGE012
representing the offset compensation amount; corner mark
Figure 496722DEST_PATH_IMAGE013
The representation corresponds to a cosine signal, a corner mark
Figure 833026DEST_PATH_IMAGE014
The representation corresponds to a sinusoidal signal.
Optionally, the acquiring three interference signals collected by the reading head in a motion state of any speed includes:
collecting three paths of initial interference signals in real time under the state that the reading head moves at any speed;
judging whether the three initial interference signals meet storage conditions or not;
after the three paths of initial interference signals meet the storage condition, caching the initial interference signals meeting the storage condition;
and caching at least ten periods of initial interference signals aiming at each path of interference signals to obtain the three paths of interference signals.
Optionally, the determining the displacement and the velocity of the target to be measured based on the two orthogonal signals includes:
determining a phase shift amount based on the two paths of orthogonal signals;
and determining the displacement and/or the speed of the measured target based on the phase shift amount.
In a second aspect, the present disclosure further provides a detection signal processing apparatus applied to a grating ruler, including:
the motion control module is used for controlling the reading head to move at any speed;
the signal acquisition module is used for acquiring three paths of interference signals acquired by the reading head in a motion state of any speed; the phases of the three paths of interference signals are unknown;
the first determining module is used for determining two paths of orthogonal signals by utilizing a phase compensation algorithm based on the three paths of interference signals;
and the second determining module is used for determining the displacement and/or the speed of the measured target based on the two paths of orthogonal signals.
In a third aspect, the present disclosure also provides a computer-readable storage medium storing a program or instructions for causing a computer to perform the steps of any one of the methods described above.
In a fourth aspect, the present disclosure also provides an electronic device, including: a processor and a memory;
the processor is configured to perform the steps of any of the above methods by calling a program or instructions stored in the memory.
In a fifth aspect, the present disclosure further provides a grating ruler, including a reading head, where three different positions in the reading head are respectively provided with a detector for collecting detection signals at corresponding positions to form three paths of interference signals;
the phases corresponding to the three different positions are unknown;
the grating ruler adopts the steps of any one of the methods to realize detection signal processing.
Compared with the prior art, the technical scheme provided by the embodiment of the disclosure has the following advantages:
the present disclosure provides a method, an apparatus, a medium, a device and a grating scale for processing a detection signal applied to the grating scale, wherein the method includes: controlling the reading head to move at any speed; acquiring three paths of interference signals acquired by a reading head in a motion state of any speed; the phases of the three interference signals are unknown; determining two paths of orthogonal signals by utilizing a phase compensation algorithm based on the three paths of interference signals; and determining the displacement and/or the speed of the measured target based on the two orthogonal signals. Therefore, by acquiring the interference signal of the non-solid phase fixed phase and utilizing the phase compensation algorithm, the processing of the detection signal can be completed without depending on the initial phase of the interference signal, thereby not only solving the problems of complex installation and debugging process of the grating ruler, strict requirements on production and manufacturing processes and the like, but also solving the problem of harsh requirements on calibration environment for the initial phase solution of the interference signal of the calibration algorithm; meanwhile, the measurement precision of the grating ruler is improved.
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The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure.
In order to more clearly illustrate the embodiments or technical solutions in the prior art of the present disclosure, the drawings used in the description of the embodiments or prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.
Fig. 1 is a schematic flowchart of a detection signal processing method applied to a grating scale according to an embodiment of the present disclosure;
fig. 2 is a detailed flowchart of S130 in the detection signal processing method applied to the grating ruler shown in fig. 1;
fig. 3 is a schematic flowchart of another detection signal processing method applied to a grating scale according to an embodiment of the present disclosure;
FIG. 4 is a Lissajous diagram of two orthogonal signals to be optimized;
fig. 5 is a schematic detailed flow chart of S120 in the detection signal processing method applied to the grating ruler shown in fig. 1;
fig. 6 is a detailed flowchart of S140 in the detection signal processing method applied to the grating ruler shown in fig. 1;
fig. 7 is a schematic structural diagram of a detection signal processing apparatus applied to a grating ruler according to an embodiment of the present disclosure;
fig. 8 is a schematic structural diagram of an electronic device according to an embodiment of the present disclosure.
700, a detection signal processing device applied to the grating ruler; 710. a motion control module; 710. a signal acquisition module; 730. a first determination module; 740. a second determination module; 800. an electronic device; 810. a processor; 820. a memory; s110 to S140, S231 to S234, S310 to S340, S521 to S524 and S641 to S642 are steps of a method flow.
Detailed Description
In order that the above objects, features and advantages of the present disclosure may be more clearly understood, aspects of the present disclosure will be further described below. It should be noted that the embodiments and features of the embodiments of the present disclosure may be combined with each other without conflict.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure, but the present disclosure may be practiced in other ways than those described herein; it is to be understood that the embodiments disclosed in the specification are only a few embodiments of the present disclosure, and not all embodiments.
The method is combined with the background technology part, and a fixed phase method is used for acquiring initial phase information of interference signals, so that the problems of difficulty in installation and debugging, severe production and manufacturing process and the like exist; meanwhile, it is difficult to ensure that the detection signal is at the corresponding phase position in the actual sampling, which leads to poor measurement accuracy. The calibration algorithm has great limitation, and the limitation on the scene causes great difficulty in normal use of the grating ruler.
In order to solve the technical problem or at least partially solve the technical problem, embodiments of the present disclosure provide a method, an apparatus, a medium, a device, and a grating scale for processing a probe signal applied to the grating scale, where the method includes: controlling the reading head to move at any speed; acquiring three paths of interference signals acquired by a reading head in a motion state of any speed; the phases of the three interference signals are unknown; determining two paths of orthogonal signals by using a phase compensation algorithm based on the three paths of interference signals; and determining the displacement and/or the speed of the measured target based on the two orthogonal signals. Therefore, by acquiring the interference signal of the non-solid phase fixed phase and utilizing the phase compensation algorithm, the processing of the detection signal can be completed without depending on the initial phase of the interference signal, thereby not only solving the problems of complex installation and debugging process of the grating ruler, strict requirements on production and manufacturing processes and the like, but also solving the problem of harsh requirements on calibration environment for the initial phase solution of the interference signal of the calibration algorithm; meanwhile, the measurement precision of the grating ruler is improved.
The following describes, with reference to fig. 1 to fig. 8, a method, an apparatus, a medium, a device, and a grating scale for processing a detection signal applied to the grating scale according to an embodiment of the present disclosure.
Fig. 1 is a schematic flowchart of a detection signal processing method applied to a grating scale according to an embodiment of the present disclosure. Referring to fig. 1, the method includes:
and S110, controlling the reading head to move at any speed.
The moving speed of the reading head may be a constant speed or a non-constant speed, which is not limited herein.
And S120, acquiring three interference signals collected by the reading head in a motion state of any speed.
When a semiconductor Laser (LD) emits parallel light to pass through the reference grating and the measurement grating, the parallel light can be diffracted and interfered, and interference signals are formed at a detector end by + 1-1 order diffraction light; by utilizing the characteristic that the phase change directions of + 1-order and-1-order diffraction light are opposite when the reference grating and the measurement grating move relatively, two movement signal periods correspond to one grating pitch, and the double subdivision of the signal periods is realized; meanwhile, through the design of 0-level diffraction efficiency of the grating, interference signals under the combined interference of + 1-level diffraction light and-1-level diffraction light of different groups of reference gratings and measurement gratings are subjected to phase shift to generate three paths of interference signals with different initial phases and the same frequency; the phases of the three interference signals are unknown.
Wherein, one of the reference grating and the measurement grating is arranged in the reading head, and the other one is arranged in the measured target; when the reading head moves relative to the measured target, the relative movement of the reference grating (such as a transmission grating) and the measurement grating is realized, so that an interference signal is obtained; because the reading head moves at any speed, the collected three-way interference signals are in an unstable state.
And S130, determining two paths of orthogonal signals by utilizing a phase compensation algorithm based on the three paths of interference signals.
Specifically, according to the three interference signals in an unstable state, calculating initial phases of the three interference signals, and performing quadrature conversion on the three interference signals to obtain two paths of quadrature signals; because the acquired interference signal is in an unstable state, the orthogonality of the two orthogonal signals obtained is poor, and if the displacement of the target to be measured is determined by taking the two orthogonal signals as a basis, the accuracy of the measurement result is low. Therefore, the two paths of orthogonal signals with poor orthogonality are compensated and optimized by using a phase compensation algorithm, the problem of poor orthogonality of the orthogonal signals is solved, and the measurement accuracy of the grating ruler is improved.
Wherein, the two orthogonal signals represent that the two sinusoidal signals optimized by the phase compensation algorithm are intersected, the phase difference between the two sinusoidal signals is 90 degrees, therefore, the two orthogonal signals substantially comprise one sinusoidal signal
Figure 292957DEST_PATH_IMAGE015
And a path of cosine signal
Figure 54109DEST_PATH_IMAGE016
。
And S140, determining the displacement and/or the speed of the measured target based on the two orthogonal signals.
Wherein the amount of phase shift is known
Figure 65927DEST_PATH_IMAGE017
The relationship to the quadrature signal is:
Figure 30472DEST_PATH_IMAGE018
；
by the above formula, the phase shift amount can be obtained
Figure 153149DEST_PATH_IMAGE017
。
According to the relation between the displacement and the phase shift quantity, the relative displacement between the reference grating and the measurement grating, namely the displacement of the measured target, can be obtained through the following formula.
Figure 37316DEST_PATH_IMAGE019
；
Wherein the content of the first and second substances,
Figure 220035DEST_PATH_IMAGE020
is displacement;
Figure 406297DEST_PATH_IMAGE017
is the amount of phase shift;
Figure 332665DEST_PATH_IMAGE021
is the pitch of the grating.
It should be noted that, the speed of the target to be measured can also be determined by combining the displacement and the corresponding duration of the target to be measured; the index may be determined to be the displacement and/or the speed of the measured object according to the requirement of the detection signal processing method for the grating ruler, which is not limited herein.
The embodiment of the disclosure provides a detection signal processing method applied to a grating ruler, which comprises the following steps: controlling the reading head to move at any speed; acquiring three paths of interference signals acquired by a reading head in a motion state of any speed; the phases of the three interference signals are unknown; determining two paths of orthogonal signals by utilizing a phase compensation algorithm based on the three paths of interference signals; and determining the displacement and/or the speed of the measured target based on the two orthogonal signals. Therefore, by acquiring the interference signal of the non-solid phase fixed phase and utilizing the phase compensation algorithm, the processing of the detection signal can be completed without depending on the initial phase of the interference signal, thereby not only solving the problems of complex installation and debugging process of the grating ruler, strict requirements on production and manufacturing processes and the like, but also solving the problem of harsh requirements on calibration environment for the initial phase solution of the interference signal of the calibration algorithm; meanwhile, the measurement precision of the grating ruler is improved.
In one embodiment, as shown in fig. 2, a detailed flowchart of S130 in the method for processing a detection signal applied to a grating ruler shown in fig. 1 is shown. Referring to fig. 2, the phase compensation algorithm is a fitting compensation algorithm based on a pearson correlation coefficient method and a nonlinear least square method; wherein, S130 "determining two orthogonal signals based on the three interference signals by using a phase compensation algorithm" includes:
s231, determining the phase difference of the three interference signals by utilizing a Pearson correlation coefficient method based on the three interference signals.
The three-path interference signal comprises a first path interference signal, a second path interference signal and a third path interference signal, and the phase difference of the three-path interference signal comprises the phase difference of the second path interference signal and the first path interference signal and the phase difference of the third path interference signal and the first path interference signal. The phase difference of the three paths of interference signals is obtained by taking the first path of interference signal as a reference signal and comparing the second path of interference signal and the third path of interference signal with the first path of interference signal respectively; the phase difference of the three paths of interference signals comprises the phase difference of a second path of interference signal and a first path of interference signal
Figure 68408DEST_PATH_IMAGE022
And the phase difference between the third path of interference signal and the first path of interference signal is
Figure 297396DEST_PATH_IMAGE023
(ii) a The actual number of phase differences of the three paths of interference signals is two; in order to equalize the number of phase differences and the number of interference signals, the first path of interference signal may be compared with a reference signal (i.e., the first path of interference signal), i.e., the first path of interference signal and the first path of interference signal have a phase difference of
Figure 95587DEST_PATH_IMAGE024
And is and
Figure 950280DEST_PATH_IMAGE024
is 0.
It should be noted that, the embodiment of the present disclosure only exemplarily shows that the first path of interference signal is used as the reference signal, but does not constitute a limitation on the method for processing the detection signal applied to the grating ruler provided in the embodiment of the present disclosure. In other embodiments, the reference signal may be set as any one of three interference signals according to requirements of a detection signal processing method applied to the grating ruler, and is not limited herein.
The method comprises the following specific steps:
(1) calculating the average value of the calibration data of each path of interference signal to be used as the bias of the path of interference signal; the first path of signal offset is obtained through calculation
Figure 150317DEST_PATH_IMAGE025
Second path signal bias
Figure 815785DEST_PATH_IMAGE026
And third path signal bias
Figure 101272DEST_PATH_IMAGE027
。
(2) Calculating the amplitude of the calibration data by using offset, wherein the amplitude of each path of interference signal is equal to the total standard deviation of each path of interference signalMultiplication by
Figure 759656DEST_PATH_IMAGE028
(ii) a Calculated amplitude of signal to first path
Figure 814199DEST_PATH_IMAGE029
The amplitude of the second path signal
Figure 384989DEST_PATH_IMAGE030
And third path signal amplitude
Figure 545056DEST_PATH_IMAGE031
。
(3) Calculating the phase difference between the second path of interference signal and the first path of signal by using a Pearson correlation coefficient method and combining the obtained amplitude value and bias
Figure 616918DEST_PATH_IMAGE032
And the phase difference between the second path of interference signal and the first path of signal
Figure 401334DEST_PATH_IMAGE033
。
And S232, determining two paths of orthogonal signals to be optimized by using a three-step phase shifting method based on the phase difference of the three paths of interference signals.
Wherein, the two orthogonal signals represent that the two sinusoidal signals are crossed, the phase difference between the two sinusoidal signals is 90 degrees, therefore, the two orthogonal signals substantially comprise one sinusoidal signal
Figure 533238DEST_PATH_IMAGE034
And a path of cosine signal
Figure 652373DEST_PATH_IMAGE035
。
Specifically, there is a certain correspondence between the interference signal intensity and the phase difference, and the interference signal intensity can be represented by the phase difference; using three-step phase shifting method to combine and solve the intensity expressions of three interference signals to obtain phase shift quantity containing phase difference
Figure 527925DEST_PATH_IMAGE017
The expression of (1); the phase shift quantity obtained according to the trigonometric function calculation relationship and the three-step phase shift algorithm
Figure 432427DEST_PATH_IMAGE017
And determining two paths of orthogonal signals to be optimized.
Because the acquired interference signal is in an unstable state, the orthogonality of the two orthogonal signals obtained is poor, and if the displacement of the target to be measured is determined by taking the two orthogonal signals as a basis, the accuracy of the measurement result is low, so that the two orthogonal signals to be optimized need to be optimized.
And S233, determining the compensation quantity of the orthogonal signals by utilizing a nonlinear least square method based on the two paths of orthogonal signals to be optimized.
The factors influencing the orthogonality of the two paths of orthogonal signals at least comprise a non-orthogonal error angle, an amplitude error and a bias error, and corresponding compensation quantities are calculated by using a nonlinear least square method and are respectively an orthogonal phase compensation quantity, an amplitude compensation quantity and a bias compensation quantity.
And S234, determining two paths of optimized orthogonal signals based on the two paths of orthogonal signals to be optimized and the compensation quantity of the orthogonal signals.
In particular, two orthogonal signals to be optimized are combined
Figure 735232DEST_PATH_IMAGE034
And
Figure 341663DEST_PATH_IMAGE035
compensating the orthogonal signals, eliminating the error influence caused by the orthogonal error angle, the amplitude error and the offset error, obtaining two optimized orthogonal signals
Figure 755327DEST_PATH_IMAGE015
And
Figure 779915DEST_PATH_IMAGE016
。
in an embodiment, as shown in fig. 3, a schematic flow chart of another detection signal processing method applied to a grating scale is provided for the embodiment of the present disclosure. Referring to fig. 3, in the method:
and S310, controlling the reading head to move at any speed.
The step is the same as S110, and for details, refer to the explanation at S110, which is not described herein again.
S320, acquiring three interference signals collected by the reading head in a motion state of any speed.
The step is the same as S120, and for details, refer to the explanation at S120, which is not described herein again.
The method for determining the phase difference of the three-way interference signals by using the Pearson correlation coefficient method based on the three-way interference signals comprises the following steps:
s3311, calculating respective offset and amplitude for each path of the three paths of interference signals.
Calculating the average value of the calibration data of each path of interference signal as the bias of the path of interference signal to obtain the bias of the first path of signal
Figure 378255DEST_PATH_IMAGE025
Second path signal bias
Figure 347348DEST_PATH_IMAGE026
And third path signal bias
Figure 440069DEST_PATH_IMAGE027
(ii) a The offset of each interference signal can be calculated by the following formula:
Figure 178218DEST_PATH_IMAGE036
；
wherein the content of the first and second substances,
Figure 950389DEST_PATH_IMAGE037
representing a channel sequence of the three-path interference signal, and taking values from 1 to 3;
Figure 406778DEST_PATH_IMAGE038
representing the number of the interference signals containing calibration data;
Figure 37611DEST_PATH_IMAGE039
calibration data representing the interference signal path;
Figure 161425DEST_PATH_IMAGE040
representing the variable in the calculation process, and the variation range is 0-N.
Calculating the amplitude by using the obtained bias, specifically: by multiplying the total standard deviation of each path of interference signal by
Figure 835989DEST_PATH_IMAGE028
Obtaining the amplitude of the channel signal
Figure 779674DEST_PATH_IMAGE041
Calculating to obtain the amplitude of the first path signal according to the following formula
Figure 479777DEST_PATH_IMAGE029
The amplitude of the second path signal
Figure 317151DEST_PATH_IMAGE030
And third path signal amplitude
Figure 303562DEST_PATH_IMAGE042
：
Figure 344330DEST_PATH_IMAGE043
。
S3312, determining the phase difference of the three paths of interference signals by using a Pearson correlation coefficient method based on the bias and the amplitude.
Specifically, the phase difference between the second path of interference signal and the first path of signal is calculated by using a Pearson correlation coefficient method and combining the obtained amplitude value and bias
Figure 707179DEST_PATH_IMAGE032
And the phase difference between the second path of interference signal and the first path of signal
Figure 664639DEST_PATH_IMAGE033
(ii) a The calculation formula is as follows:
Figure 821951DEST_PATH_IMAGE044
；
Figure 350015DEST_PATH_IMAGE045
。
the method for determining two paths of orthogonal signals to be optimized by using a three-step phase shifting method based on the phase difference of three paths of interference signals comprises the following steps:
and S332, determining two paths of orthogonal signals to be optimized by using a three-step phase shifting method based on the phase difference of the three paths of interference signals and combining the corresponding interference signal intensity.
And in the correlation between the intensity of the first path of interference signal and the phase difference, the phase difference value is 0. The phase difference of the three paths of interference signals is obtained by taking the first path of interference signal as a reference signal and comparing the second path of interference signal and the third path of interference signal with the first path of interference signal respectively; the phase difference between the second path of interference signal and the first path of interference signal is
Figure 250975DEST_PATH_IMAGE046
And the phase difference between the third path of interference signal and the first path of interference signal is
Figure 325592DEST_PATH_IMAGE047
(ii) a The actual number of phase differences of the three paths of interference signals is two; in order to equalize the number of phase differences and the number of interference signals, the first path of interference signal may be compared with a reference signal (i.e., the first path of interference signal), i.e., the first path of interference signal and the first path of interference signal have a phase difference of
Figure 529171DEST_PATH_IMAGE024
And is and
Figure 669166DEST_PATH_IMAGE024
is 0.
Specifically, the key parameters were calculated using the following formula
Figure 232871DEST_PATH_IMAGE048
、
Figure 774711DEST_PATH_IMAGE049
、
Figure 414771DEST_PATH_IMAGE050
、
Figure 42061DEST_PATH_IMAGE051
And Amp:
Figure 409457DEST_PATH_IMAGE052
；
Figure 805804DEST_PATH_IMAGE053
；
Figure 351186DEST_PATH_IMAGE054
；
Figure 855985DEST_PATH_IMAGE055
；
Figure 902439DEST_PATH_IMAGE056
；
due to the fact that
Figure 28658DEST_PATH_IMAGE057
Then, then
Figure 869575DEST_PATH_IMAGE058
；
Figure 599021DEST_PATH_IMAGE059
。
The data obtained by the calculation is subjected to real-time normalization algorithm processing, which specifically comprises the following steps: subtracting the corresponding offset from the three interference signal values, and dividing by the corresponding amplitude to obtain the preprocessed signal
Figure 183586DEST_PATH_IMAGE060
、
Figure 695470DEST_PATH_IMAGE061
And
Figure 707288DEST_PATH_IMAGE062
：
Figure 921101DEST_PATH_IMAGE063
；
Figure 184723DEST_PATH_IMAGE064
；
Figure 410168DEST_PATH_IMAGE065
；
wherein the content of the first and second substances,
Figure 983101DEST_PATH_IMAGE066
representing a first path of digital interference signal which is converted by an analog-to-digital converter in real time;
Figure 293996DEST_PATH_IMAGE067
representing the digital interference signal of the second path after being converted by the analog-to-digital converter in real time;
Figure 95730DEST_PATH_IMAGE068
representing the third path of digital interference signals which are converted by the analog-to-digital converter in real time.
Then, two paths of orthogonal signals to be optimized are obtained by utilizing an orthogonal preprocessing algorithm
Figure 441261DEST_PATH_IMAGE069
And
Figure 919515DEST_PATH_IMAGE070
the expression of the two orthogonal signals to be optimized is as follows:
Figure 717707DEST_PATH_IMAGE071
；
Figure 323132DEST_PATH_IMAGE072
；
wherein the content of the first and second substances,
Figure 788748DEST_PATH_IMAGE073
representing orthogonal signals to be optimized obtained by three-step phase shifting;
Figure 434975DEST_PATH_IMAGE035
representing the orthogonal cosine signal to be optimized obtained by three-step phase shifting. The phase difference of three interference signals
Figure 720463DEST_PATH_IMAGE022
And
Figure 863999DEST_PATH_IMAGE074
and substituting the formula to obtain an orthogonal signal and an orthogonal cosine signal to be optimized.
The method for determining the compensation quantity of the orthogonal signals by utilizing the nonlinear least square method based on two paths of orthogonal signals to be optimized comprises the following steps:
s333, obtaining the compensation quantity of the orthogonal signal of the phase difference between the two paths of orthogonal signals to be optimized and the completely orthogonal signal through target matrix operation by utilizing a nonlinear least square method.
The compensation amount of the quadrature signal includes a quadrature phase compensation amount, an amplitude compensation amount, and a bias compensation amount.
FIG. 4 is a Lissajous diagram of two orthogonal signals to be optimized; wherein, the axis of abscissa is Sin signal, and the axis of ordinate is Cos signal. As shown in fig. 4, L1 is the correspondence of two orthogonal signals in an ideal state, and is circular as a whole; l2 is the corresponding relation of two paths of orthogonal signals to be optimized, and the whole is elliptic; the orthogonality of the two orthogonal signals to be optimized is poor, and the reasons influencing the orthogonality include non-orthogonal error angle, amplitude error and offset error, so the two orthogonal signals to be optimized can also be expressed as:
Figure 308756DEST_PATH_IMAGE075
；
Figure 269759DEST_PATH_IMAGE076
；
wherein the content of the first and second substances,
Figure 917909DEST_PATH_IMAGE077
representing an error angle;
Figure 724191DEST_PATH_IMAGE078
and
Figure 23454DEST_PATH_IMAGE079
representing an amplitude error;
Figure 889779DEST_PATH_IMAGE080
and
Figure 290804DEST_PATH_IMAGE081
representing the bias error.
Thus, an error angle is calculated
Figure 900777DEST_PATH_IMAGE077
Amplitude error
Figure 54547DEST_PATH_IMAGE078
And
Figure 357352DEST_PATH_IMAGE079
offset error of
Figure 714515DEST_PATH_IMAGE080
And
Figure 521322DEST_PATH_IMAGE081
and obtaining two paths of optimized orthogonal signals by corresponding compensation amount.
Further, on the basis of fig. 4, a parametric equation of cartesian coordinate system is fitted by using a nonlinear least square method, which is expressed as follows, and corresponds to the equation of the ellipse in fig. 4:
Figure 404964DEST_PATH_IMAGE082
；
and furthermore, coefficients a, b, c, d and e of the parameter equation are solved.
Then, the coefficients and error angles are calculated according to the parametric equation
Figure 754037DEST_PATH_IMAGE077
Amplitude error
Figure 723130DEST_PATH_IMAGE078
And
Figure 65119DEST_PATH_IMAGE079
offset error of
Figure 68847DEST_PATH_IMAGE080
And
Figure 588821DEST_PATH_IMAGE081
to calculate the amount of quadrature phase compensation
Figure 45210DEST_PATH_IMAGE083
And
Figure 925310DEST_PATH_IMAGE084
amplitude compensation amount
Figure 517965DEST_PATH_IMAGE009
And
Figure 474420DEST_PATH_IMAGE010
and an offset compensation amount
Figure 542739DEST_PATH_IMAGE011
And
Figure 101897DEST_PATH_IMAGE012
the calculation formula is as follows:
Figure 690004DEST_PATH_IMAGE085
；
Figure 410835DEST_PATH_IMAGE086
；
Figure 986958DEST_PATH_IMAGE087
；
Figure 349806DEST_PATH_IMAGE088
；
Figure 57999DEST_PATH_IMAGE089
；
Figure 949732DEST_PATH_IMAGE090
；
Figure 992643DEST_PATH_IMAGE091
；
wherein, the corner mark
Figure 893603DEST_PATH_IMAGE013
The representation corresponds to a cosine signal, a corner mark
Figure 456303DEST_PATH_IMAGE014
The representation corresponds to a sinusoidal signal.
"determining two paths of optimized orthogonal signals based on the compensation quantity of two paths of orthogonal signals to be optimized and orthogonal signals" includes:
and S334, compensating the two orthogonal signals to be optimized by using the compensation quantity of the orthogonal signals to obtain the two optimized orthogonal signals.
Specifically, the optimized two orthogonal signals can be obtained through back-stepping calculation by combining the expression of the two orthogonal signals to be optimized obtained in step S332 and the compensation amount obtained through calculation in step S333; the two paths of optimized orthogonal signals have better orthogonality, and the orthogonal error of the two paths of optimized orthogonal signals is smaller than a preset orthogonal error threshold; the value range of the orthogonal error threshold can be flexibly set according to the requirements of the detection signal processing method applied to the grating ruler, for example, 0.1-1 degree, and is not limited herein.
And S340, determining the displacement and/or the speed of the measured target based on the two orthogonal signals.
The steps are the same as S140, and refer to the explanation at S140 for details, which are not described herein.
In one embodiment, the compensating for the two orthogonal signals to be optimized by using the compensation amount of the orthogonal signals to obtain the two optimized orthogonal signals includes:
and obtaining two optimized orthogonal signals by combining the following formulas:
Figure 909150DEST_PATH_IMAGE092
Figure 49144DEST_PATH_IMAGE002
wherein the content of the first and second substances,
Figure 629161DEST_PATH_IMAGE003
and
Figure 171001DEST_PATH_IMAGE004
represents the two paths of orthogonal signals after being optimized,
Figure 794749DEST_PATH_IMAGE003
in order to be a cosine signal, the signal,
Figure 422039DEST_PATH_IMAGE004
is a sinusoidal signal;
Figure 805747DEST_PATH_IMAGE005
and
Figure 202094DEST_PATH_IMAGE006
representing two paths of orthogonal signals to be optimized;
Figure 999673DEST_PATH_IMAGE093
and
Figure 114259DEST_PATH_IMAGE008
represents the amount of quadrature phase compensation;
Figure 36079DEST_PATH_IMAGE009
and
Figure 677145DEST_PATH_IMAGE010
representing an amplitude compensation amount;
Figure 518062DEST_PATH_IMAGE011
and
Figure 995311DEST_PATH_IMAGE012
representing an offset compensation amount; corner mark
Figure 845455DEST_PATH_IMAGE013
The representation corresponds to a cosine signal, a corner mark
Figure 341027DEST_PATH_IMAGE014
The representation corresponds to a sinusoidal signal.
Specifically, the expression of the two orthogonal signals to be optimized obtained in S332 and the compensation amount calculated in S333 are substituted into the above formula, and the optimized two orthogonal signals can be obtained through calculation
Figure 352846DEST_PATH_IMAGE003
And
Figure 51811DEST_PATH_IMAGE004
further calculating the amount of phase shift
Figure 440067DEST_PATH_IMAGE017
(ii) a And finally determining the displacement and/or the speed of the measured target based on the phase shift amount.
According to the detection signal processing method applied to the grating ruler, the compensation quantity of the two orthogonal signals is accurately calculated by using a nonlinear least square method, the two intersecting sinusoidal signals to be optimized are optimized, the two orthogonal signals after optimization have high orthogonality, the problem that the orthogonality of the two orthogonal signals to be optimized is poor is solved, the measurement precision of the grating ruler is improved, and the grating ruler can reach the nanometer level.
In some embodiments, as shown in fig. 5, a detailed flowchart of S120 in the detection signal processing method applied to the grating ruler shown in fig. 1 is shown. Referring to fig. 5, S120 "acquiring three interference signals collected by the reading head in a motion state with any speed" includes:
and S521, collecting three paths of initial interference signals in real time under the condition that the reading head moves at any speed.
And S522, judging whether the three initial interference signals meet the storage condition.
The amplifying circuit amplifies the 3 paths of initial interference signals, so that the voltage amplitude of the interference signals reaches a sampling interval of an Analog-to-Digital Converter (ADC), the ADC converts the Analog interference signals into Digital interference signals, and whether the converted Digital interference signals meet storage conditions is judged; the storage conditions include that the amplitude of the digital interference signal is stable within a range corresponding to the speed of the readhead to ensure that the signal to noise ratio is high. For example, when the reading head does not move, the signal amplitude is 0, and after the reading head starts moving, when the signal amplitude is greater than 0.5V, it is determined that the storage condition is satisfied.
And S523, after the three paths of initial interference signals meet the storage condition, caching the initial interference signals meeting the storage condition.
After the storage condition is met, the three paths of digital interference signals meeting the storage condition are cached.
And S524, caching at least ten periods of initial interference signals aiming at each path of interference signals to obtain three paths of interference signals.
Wherein each path of interference signal comprises at least ten interference signals with stable periods; when the data with more than ten interference signal periods in the buffer data is detected, the next step is executed.
In some embodiments, as shown in fig. 6, it is a detailed flowchart of S140 in the detection signal processing method applied to the grating ruler shown in fig. 1. Referring to fig. 6, S140 "determining the displacement and the velocity of the measured target based on two orthogonal signals" includes:
and S641, determining a phase shift amount based on the two paths of orthogonal signals.
Wherein the amount of phase shift is known
Figure 790146DEST_PATH_IMAGE017
The relationship with the two optimized orthogonal signals is as follows:
Figure 113811DEST_PATH_IMAGE018
；
calculating to obtain the phase shift amount by the formula
Figure 690286DEST_PATH_IMAGE017
。
And S642, determining the displacement and/or the speed of the measured target based on the phase shift amount.
According to the relationship between the displacement and the phase shift amount, the relative displacement between the reference grating and the measurement grating can be obtained by the following formula:
Figure 738358DEST_PATH_IMAGE019
；
wherein the content of the first and second substances,
Figure 818309DEST_PATH_IMAGE020
is displacement;
Figure 312876DEST_PATH_IMAGE017
is the amount of phase shift;
Figure 111067DEST_PATH_IMAGE021
is the pitch of the grating.
It should be noted that, the speed of the target to be measured can also be determined by combining the displacement and the corresponding duration of the target to be measured; the index may be determined to be the displacement and/or the speed of the measured object according to the requirement of the detection signal processing method for the grating ruler, which is not limited herein.
Based on the same inventive concept, the embodiments of the present disclosure further provide a device for processing a detection signal applied to a grating ruler, where the device can perform any one of the steps of the method for processing a detection signal applied to a grating ruler provided in the embodiments of the present disclosure, and has functional modules and beneficial effects corresponding to the method for performing, and thus, for avoiding repeated descriptions, details are not repeated herein. The device can be realized by adopting software and/or hardware, and can be integrated on any terminal equipment such as a server or a computer with computing capability.
Fig. 7 is a detection signal processing apparatus applied to a grating ruler according to an embodiment of the present disclosure. Referring to fig. 7, the detection signal processing apparatus 700 applied to the grating ruler includes: the motion control module 710 is used for controlling the reading head to move at any speed; the signal acquisition module 720 is used for acquiring three paths of interference signals acquired by the reading head in a motion state at any speed; the phases of the three interference signals are unknown; a first determining module 730, configured to determine two paths of orthogonal signals by using a phase compensation algorithm based on the three paths of interference signals; and the second determining module 740 is configured to determine the displacement and/or the velocity of the target to be measured based on the two orthogonal signals.
In one embodiment, the phase compensation algorithm is a fitting compensation algorithm based on the Pearson correlation coefficient method and the nonlinear least squares method; the first determining module is used for determining two paths of orthogonal signals by utilizing a phase compensation algorithm based on the three paths of interference signals, and comprises the following steps: the first determining submodule is used for determining the phase difference of the three paths of interference signals by utilizing a Pearson correlation coefficient method based on the three paths of interference signals; the three-path interference signal comprises a first path of interference signal, a second path of interference signal and a third path of interference signal, and the phase difference of the three-path interference signal comprises the phase difference of the second path of interference signal and the first path of interference signal and the phase difference of the third path of interference signal and the first path of interference signal; the second determining submodule is used for determining two paths of orthogonal signals to be optimized by using a three-step phase shifting method based on the phase difference of the three paths of interference signals; the third determining submodule is used for determining the compensation quantity of the orthogonal signals by utilizing a nonlinear least square method based on the two paths of orthogonal signals to be optimized; and the fourth determining submodule is used for determining the two paths of optimized orthogonal signals based on the two paths of orthogonal signals to be optimized and the compensation quantity of the orthogonal signals.
In one embodiment, the first determining sub-module is configured to determine the phase difference of the three-way interference signal by using a pearson correlation coefficient method based on the three-way interference signal, and includes: calculating respective bias and amplitude for each of the three interference signals, and determining phase differences of the three interference signals by using a Pearson correlation coefficient method based on the bias and amplitude.
The second determining submodule is used for determining two paths of orthogonal signals to be optimized by using a three-step phase shifting method based on the phase difference of the three paths of interference signals, and comprises the following steps of: determining two paths of orthogonal signals to be optimized by using a three-step phase shifting method based on the phase difference of the three paths of interference signals and combining the corresponding interference signal intensity; and in the correlation relationship between the intensity of the first path of interference signal and the phase difference, the phase difference value is 0.
The third determining submodule is used for determining the compensation quantity of the orthogonal signals by utilizing a nonlinear least square method based on two paths of orthogonal signals to be optimized, and comprises the following steps: obtaining the compensation quantity of orthogonal signals with the phase difference between two paths of orthogonal signals to be optimized and completely orthogonal signals by utilizing a nonlinear least square method and through target matrix operation; the compensation amount of the quadrature signal includes a quadrature phase compensation amount, an amplitude compensation amount, and a bias compensation amount.
The fourth determining submodule is used for determining the two paths of optimized orthogonal signals based on the compensation quantity of the two paths of orthogonal signals to be optimized and the orthogonal signals, and comprises the following steps: and compensating the two paths of orthogonal signals to be optimized by using the compensation quantity of the orthogonal signals to obtain the two paths of optimized orthogonal signals.
In one embodiment, the fourth determining submodule is configured to compensate the two orthogonal signals to be optimized by using the compensation amount of the orthogonal signal, and obtain the two optimized orthogonal signals, and includes: and obtaining two optimized orthogonal signals by combining the following formulas:
Figure 965760DEST_PATH_IMAGE092
Figure 165797DEST_PATH_IMAGE002
wherein the content of the first and second substances,
Figure 831265DEST_PATH_IMAGE003
and
Figure 116752DEST_PATH_IMAGE004
represents the two paths of orthogonal signals after being optimized,
Figure 509557DEST_PATH_IMAGE003
in order to be a cosine signal, the signal,
Figure 564100DEST_PATH_IMAGE004
is a sinusoidal signal;
Figure 666048DEST_PATH_IMAGE005
and
Figure 297887DEST_PATH_IMAGE006
representing two paths of orthogonal signals to be optimized;
Figure 369748DEST_PATH_IMAGE093
and
Figure 419744DEST_PATH_IMAGE008
represents the amount of quadrature phase compensation;
Figure 551648DEST_PATH_IMAGE009
and
Figure 939291DEST_PATH_IMAGE010
representing an amplitude compensation amount;
Figure 549264DEST_PATH_IMAGE011
and
Figure 453766DEST_PATH_IMAGE012
representing an offset compensation amount; corner mark
Figure 490992DEST_PATH_IMAGE013
The representation corresponds to a cosine signal, a corner mark
Figure 628582DEST_PATH_IMAGE014
The representation corresponds to a sinusoidal signal.
In one embodiment, the signal acquiring module is configured to acquire three interference signals collected by the reading head in a state of performing a motion at an arbitrary speed, and includes: collecting three paths of initial interference signals in real time under the state that the reading head moves at any speed; judging whether the three initial interference signals meet storage conditions or not; after the three initial interference signals meet the storage condition, caching the initial interference signals meeting the storage condition; and caching at least ten periods of initial interference signals aiming at each path of interference signals to obtain three paths of interference signals.
In one embodiment, the second determining module is configured to determine the displacement and the velocity of the measured target based on the two orthogonal signals, and includes: determining a phase shift amount based on the two paths of orthogonal signals; and determining the displacement and/or the speed of the measured target based on the phase shift amount.
On the basis of the above embodiment, the embodiment of the present disclosure further provides an electronic device. As shown in fig. 8, the electronic device 800 includes: a processor 810 and a memory 820; processor 810 achieves corresponding benefits by invoking programs or instructions stored by memory 820 for performing the steps of any of the methods described above.
Processor 810 may be, among other things, a Central Processing Unit (CPU) or other form of Processing Unit having data computing capabilities and/or instruction execution capabilities, and may control other components in electronic device 800 to perform desired functions. Memory 820 may include one or more computer program products that may include various forms of computer-readable storage media, such as volatile memory and/or non-volatile memory, among others. The volatile memory may include, for example, Random Access Memory (RAM), cache memory (cache), and/or the like. The non-volatile memory may include, for example, Read Only Memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium and executed by the processor 810 to implement the detection signal processing method applied to the grating ruler provided by the embodiments of the present disclosure described above, and/or other desired functions. Various contents such as an input signal, a signal component, a noise component, etc. may also be stored in the computer-readable storage medium
On the basis of the foregoing embodiments, the embodiments of the present disclosure further provide a computer-readable storage medium, which may be the computer-readable storage medium included in the apparatus in the foregoing embodiments; or it may be a separate computer readable storage medium not incorporated into the device. The computer-readable storage medium stores computer-executable instructions, which, when executed by a computing device, can be used to implement the method for processing a detection signal applied to a grating ruler, described in any embodiment of the present disclosure.
On the basis of the above embodiment, the embodiment of the present disclosure further provides a grating ruler. The grating ruler comprises a reading head, wherein detectors are respectively arranged at three different positions in the reading head and are used for acquiring detection signals at corresponding positions to form three paths of interference signals; the phases corresponding to the three different positions are unknown; the grating ruler adopts the steps of any one of the methods to realize detection signal processing, has corresponding beneficial effects, and is not repeated herein in order to avoid repeated description.
It is noted that, in this document, relational terms such as "first" and "second," and the like, may be 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. Also, 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 an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The foregoing are merely exemplary embodiments of the present disclosure, which enable those skilled in the art to understand or practice the present disclosure. 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 disclosure. Thus, the present disclosure 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 (10)

1. A detection signal processing method applied to a grating ruler is characterized by comprising the following steps:
controlling the reading head to move at any speed;
acquiring three paths of interference signals acquired by a reading head in a motion state of any speed; the phases of the three paths of interference signals are unknown;
determining two paths of orthogonal signals by utilizing a phase compensation algorithm based on the three paths of interference signals;
and determining the displacement and/or the speed of the measured target based on the two orthogonal signals.
2. The method of claim 1, wherein the phase compensation algorithm is a fitting compensation algorithm based on the Pearson correlation coefficient method and the nonlinear least squares method;
wherein, the determining two paths of orthogonal signals by using a phase compensation algorithm based on the three paths of interference signals comprises:
determining the phase difference of the three-way interference signals by utilizing the Pearson correlation coefficient method based on the three-way interference signals; the three-path interference signal comprises a first path of interference signal, a second path of interference signal and a third path of interference signal, and the phase difference of the three-path interference signal comprises the phase difference of the second path of interference signal and the first path of interference signal and the phase difference of the third path of interference signal and the first path of interference signal;
determining two paths of orthogonal signals to be optimized by using a three-step phase shifting method based on the phase difference of the three paths of interference signals;
determining the compensation quantity of the orthogonal signals by utilizing a nonlinear least square method based on the two paths of orthogonal signals to be optimized;
and determining the two paths of orthogonal signals after optimization based on the two paths of orthogonal signals to be optimized and the compensation quantity of the orthogonal signals.
3. The method of claim 2, wherein:
the determining the phase difference of the three-way interference signal by using the pearson correlation coefficient method based on the three-way interference signal includes:
calculating respective bias and amplitude for each path of interference signal in the three paths of interference signals;
determining the phase difference of the three paths of interference signals by utilizing a Pearson correlation coefficient method based on the bias and the amplitude;
determining two paths of orthogonal signals to be optimized by using a three-step phase shifting method based on the phase difference of the three paths of interference signals, wherein the two paths of orthogonal signals to be optimized comprise:
determining the two paths of orthogonal signals to be optimized by using a three-step phase shifting method based on the phase difference of the three paths of interference signals and combining the corresponding interference signal intensity;
in the correlation between the intensity of the first path of interference signal and the phase difference, the phase difference value is 0;
the method for determining the compensation quantity of the orthogonal signals by utilizing the nonlinear least square method based on the two paths of orthogonal signals to be optimized comprises the following steps:
obtaining the compensation quantity of the orthogonal signals with the phase difference between two paths of orthogonal signals to be optimized and completely orthogonal signals by utilizing a nonlinear least square method and through target matrix operation; wherein the compensation amount of the quadrature signal comprises a quadrature phase compensation amount, an amplitude compensation amount and a bias compensation amount;
the determining the two paths of orthogonal signals after optimization based on the two paths of orthogonal signals to be optimized and the compensation quantity of the orthogonal signals comprises:
and compensating the two paths of orthogonal signals to be optimized by using the compensation quantity of the orthogonal signals to obtain the two paths of optimized orthogonal signals.
4. The method according to claim 3, wherein the compensating the two orthogonal signals to be optimized by using the compensation amount of the orthogonal signals to obtain the two optimized orthogonal signals comprises:
and obtaining two optimized orthogonal signals by combining the following formulas:
Figure 802447DEST_PATH_IMAGE001
Figure 975940DEST_PATH_IMAGE002
wherein the content of the first and second substances,
Figure 314517DEST_PATH_IMAGE003
and
Figure 548052DEST_PATH_IMAGE004
represents the two paths of orthogonal signals after the optimization,
Figure 847447DEST_PATH_IMAGE003
is a signal that is a cosine signal of,
Figure 559051DEST_PATH_IMAGE004
is a sinusoidal signal;
Figure 784758DEST_PATH_IMAGE005
and
Figure 923615DEST_PATH_IMAGE006
representing the two paths of orthogonal signals to be optimized;
Figure 507043DEST_PATH_IMAGE007
and
Figure 225601DEST_PATH_IMAGE008
represents the quadrature phase compensation amount;
Figure 476453DEST_PATH_IMAGE009
and
Figure 114108DEST_PATH_IMAGE010
representing the magnitude compensation amount;
Figure 388095DEST_PATH_IMAGE011
and
Figure 441501DEST_PATH_IMAGE012
representing the offset compensation amount; corner mark
Figure 546861DEST_PATH_IMAGE014
The representation corresponds to a cosine signal, a corner mark
Figure 355417DEST_PATH_IMAGE015
The representation corresponds to a sinusoidal signal.
5. The method of any one of claims 1-4, wherein obtaining the three-way interference signal collected by the reading head during any speed of motion comprises:
collecting three paths of initial interference signals in real time under the condition that the reading head moves at any speed;
judging whether the three initial interference signals meet storage conditions or not;
after the three paths of initial interference signals meet the storage condition, caching the initial interference signals meeting the storage condition;
and caching at least ten periods of initial interference signals aiming at each path of interference signals to obtain the three paths of interference signals.
6. The method according to any one of claims 1-4, wherein the determining the displacement and the velocity of the measured object based on the two orthogonal signals comprises:
determining a phase shift amount based on the two paths of orthogonal signals;
and determining the displacement and/or the speed of the measured target based on the phase shift amount.
7. A detection signal processing device applied to a grating ruler is characterized by comprising:
the motion control module is used for controlling the reading head to move at any speed;
the signal acquisition module is used for acquiring three paths of interference signals acquired by the reading head in a motion state of any speed; the phases of the three paths of interference signals are unknown;
the first determining module is used for determining two paths of orthogonal signals by utilizing a phase compensation algorithm based on the three paths of interference signals;
and the second determining module is used for determining the displacement and/or the speed of the measured target based on the two paths of orthogonal signals.
8. A computer-readable storage medium, characterized in that it stores a program or instructions for causing a computer to perform the steps of the method according to any one of claims 1-6.
9. An electronic device, comprising: a processor and a memory;
the processor is configured to perform the steps of the method of any one of claims 1-6 by calling a program or instructions stored in the memory.
10. A grating ruler is characterized by comprising a reading head, wherein detectors are respectively arranged at three different positions in the reading head and used for collecting detection signals at corresponding positions to form three paths of interference signals;
the phases corresponding to the three different positions are unknown;
the grating ruler realizes detection signal processing by adopting the steps of the method of any one of claims 1 to 6.
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