CN114754685B - Detection signal processing method, device, medium, equipment and grating ruler - Google Patents
Detection signal processing method, device, medium, equipment and grating ruler Download PDFInfo
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Abstract
The disclosure relates to a detection signal processing method, device, medium, equipment and a grating ruler, wherein the method comprises the following steps: acquiring three interference signals collected by a reading head in a moving state with a fixed speed, wherein the phases of the three interference signals are unknown; determining the phase difference of three-way interference signals based on the three-way interference signals, wherein the three-way interference signals comprise a first-way interference signal, a second-way interference signal and a third-way interference signal, and the phase difference of the three-way interference signals comprises the phase difference of the second-way interference signal and the first-way interference signal and the phase difference of the third-way interference signal and the first-way interference signal; determining two paths of orthogonal signals based on the phase difference of the three paths of interference signals; and determining the displacement and/or the speed of the measured target based on the two orthogonal signals. Because the non-fixed phase is adopted to collect the interference signal, no requirement is made on the corresponding phase of the detection position, the realization difficulty and the requirement of a mechanical structure are reduced, and the measurement accuracy is favorably improved.
Description
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 nanometer-scale measuring precision, sub-nanometer-scale resolution and extremely high measuring stability, and is mainly applied to displacement measurement of various measuring mechanisms, instruments, numerical control machines and automation mechanisms.
In the related technology, the grating ruler takes grating distance as a measurement reference, the internal optical path is short, and the requirements on light source stability and environmental fluctuation are not high; the displacement of the measured target is obtained through calculation based on the interference signal with the fixed phase by acquiring the interference signal with the fixed phase. However, the mechanical structure of the grating ruler is complex, and the problem of high difficulty in implementation exists; and the requirements on production and manufacturing conditions are extremely strict, and the detection signals are difficult to ensure at corresponding phase positions, so that the measurement accuracy is poor.
Disclosure of Invention
In order to solve the technical problems or at least partially solve the technical problems, the present disclosure provides a method, an apparatus, a medium, a device, and a grating ruler for processing a detection signal.
In a first aspect, the present disclosure provides a method for processing a detection signal applied to a grating ruler, where the method includes:
acquiring three paths of interference signals collected by a reading head in a moving state at a fixed speed; the phases of the three paths of interference signals are unknown;
determining the phase difference of the three-way interference signals 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 based on the phase difference of 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 acquiring three-way interference signals collected by the reading head in a moving state with a fixed speed includes:
collecting three paths of initial interference signals in real time under the moving state of the reading head at a fixed speed;
judging whether the three initial interference signals meet a stable condition or not;
after the three initial interference signals meet the stable condition, caching the initial interference signals meeting the stable 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 three interference signals have different initial phases and the same frequency.
Optionally, the determining a phase difference of the three-way interference signal 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;
and 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.
Optionally, the determining two orthogonal signals based on the phase difference of the three interference signals includes:
determining the two paths of orthogonal signals 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.
Optionally, the determining the displacement and/or 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 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, where the apparatus includes:
the signal acquisition module is used for acquiring three paths of interference signals acquired by the reading head in a moving state at a fixed speed; the phases of the three interference signals are unknown;
the first determining module is used for determining the phase difference of the three paths of interference signals based on the three paths of interference signals; the three-path interference signals comprise 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 signals 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 second determining module is used for determining two paths of orthogonal signals based on the phase difference of the three paths of interference signals;
and the third 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;
wherein, 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 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: acquiring three paths of interference signals collected by a reading head in a moving state at a fixed speed; the phases of the three interference signals are unknown; determining the phase difference of the three interference signals based on the three 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 based on the phase difference of 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, because the non-fixed phase is adopted to collect the interference signal, no requirement is provided for the corresponding phase of the detection position, the realization difficulty of the mechanical mechanism of the grating ruler is reduced, the problems of high requirements on production, manufacturing, installation and debugging are solved, and meanwhile, the improvement of the measurement accuracy is facilitated.
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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 schematic detailed flow chart of S110 in the method for processing a detection signal applied to a grating ruler shown in fig. 1;
fig. 3 is a schematic detailed flow chart of S120 in the method for processing a detection signal applied to a grating ruler shown in fig. 1;
fig. 4 is a schematic flowchart of another detection signal processing method applied to a grating scale according to an embodiment of the present disclosure;
fig. 5 is a schematic detailed flowchart of S140 in the method for processing a detection signal applied to a grating ruler shown in fig. 1;
fig. 6 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. 7 is a schematic structural diagram of an electronic device according to an embodiment of the present disclosure.
600, a detection signal processing device applied to the grating ruler; 610. a signal acquisition module; 620. a first determination module; 630. a second determination module; 640. a third determination module; 700. an electronic device; 710. a processor; 720. a memory; s110 to S140, S211 to S214, S321 to S322, S410 to S440 and S541 to S542 are all steps of the 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.
In combination with the background technology part, the problems of difficult installation and debugging, severe production and manufacturing process and the like exist due to the complex mechanical structure of the grating ruler; meanwhile, it is difficult to ensure that the detection signal is at the corresponding phase position in the actual sampling, which results in poor measurement accuracy.
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: acquiring three paths of interference signals collected by a reading head in a moving state at a fixed speed; the phases of the three interference signals are unknown; determining the phase difference of the three interference signals based on the three 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 based on the phase difference of 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, because the non-fixed phase is adopted to collect the interference signal, no requirement is provided for the corresponding phase of the detection position, the realization difficulty of the mechanical mechanism of the grating ruler is reduced, the problem of high requirements on production, manufacturing, installation and debugging is solved, and meanwhile, the improvement of the measurement accuracy is facilitated.
The following describes, with reference to fig. 1 to fig. 7, a detection signal processing method, an apparatus, a medium, a device, and a grating scale 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:
s110, acquiring three interference signals collected by the reading head in a moving state with a fixed 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 (for example, transmission grating) and the measurement grating is realized, so that an interference signal is obtained.
And S120, determining the phase difference of the three interference signals 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.
Wherein, the phase difference of the three interference signals is the firstThe path interference signal is a reference signal, and the second path interference signal and the third path interference signal are respectively compared with the first path interference signal to obtain the second path interference signal and the third path interference signal; 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
And the phase difference between the third path of interference signal and the first path of interference signal is
(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
And is and
is 0.
It should be noted that, the embodiment of the present disclosure only exemplarily shows that the first path interference signal is used as the reference signal, but does not constitute a limitation to the method for processing the detection signal applied to the grating ruler provided by 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.
And S130, determining two paths of orthogonal signals based on the phase difference of the three paths of interference signals.
The interference signal intensity and the phase difference have a certain corresponding relation, and the phase difference is subjected to orthogonal conversion to obtain two paths of orthogonal signals; the two orthogonal signals represent the intersection of two sinusoidal signals, the phase difference between the two sinusoidal signals is 90 degrees, and therefore, the two orthogonal signals substantially comprise one sinusoidal signal
And a cosine signal
。
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
The relationship to the quadrature signal is:
by the above formula, the phase shift amount can be obtained
。
According to the relation between the displacement and the phase shift quantity, the relative displacement between the reference grating and the measuring grating, namely the displacement of the measured target, can be obtained through the following formula.
Wherein the content of the first and second substances,
is displacement;
is the amount of phase shift;
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 includes: acquiring three paths of interference signals collected by a reading head in a moving state at a fixed speed; wherein, the phases of the three interference signals are unknown; determining the phase difference of the three interference signals based on the three 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 based on the phase difference of 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, because the non-fixed phase is adopted to collect the interference signal, no requirement is provided for the corresponding phase of the detection position, the realization difficulty of the mechanical mechanism of the grating ruler is reduced, the problem of high requirements on production, manufacturing, installation and debugging is solved, and meanwhile, the improvement of the measurement accuracy is facilitated.
In one embodiment, as shown in fig. 2, a detailed flowchart of S110 in the method for processing a detection signal applied to a grating ruler shown in fig. 1 is shown. Referring to fig. 2, S110 "acquiring three interference signals collected by the reading head in a moving state with a fixed speed" includes:
s211, collecting three paths of initial interference signals in real time under the moving state of the reading head at a fixed speed.
The movable grating ruler reading head moves in a fixed speed in a single direction, the detector end generates equal-period initial interference signals, and the initial interference signals are collected in real time.
S212, judging whether the three initial interference signals meet the stable 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 a stable condition is judged; the stable condition includes that a difference between periods of two adjacent digital interference signals is smaller than a preset period difference threshold, that is, the periods of the digital interference signals are as close as possible, for example, the preset period difference threshold is zero, that is, the periods of the digital interference signals are stable or stable within a certain range, so as to ensure signal stability.
And S213, caching the initial interference signals meeting the stable condition after the three initial interference signals meet the stable condition.
After the stable condition is met, the three paths of digital interference signals meeting the stable condition are cached.
S214, 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 interference signals with stable at least ten periods; when the data with more than ten interference signal periods in the buffer data is detected, the next step is executed.
In one embodiment, the three-way interference signals have different initial phases and the same frequency.
The three-path interference signal is formed by diffraction and interference of parallel light emitted by the semiconductor laser when the parallel light passes through the reference grating and the measurement grating and is formed at the end of a detector by + 1-1 order diffraction light; through the 0-order diffraction efficiency design of the grating, interference signals under + 1-order diffraction light combination interference of different groups of reference gratings and measuring gratings are subjected to phase shift, but the frequency of the interference signals cannot be changed, namely the period cannot be changed; therefore, the three interference signals have different initial phases and the same frequency.
In an embodiment, as shown in fig. 3, a detailed flow chart of S120 in the method for processing a detection signal applied to a grating ruler in fig. 1 is shown. Referring to fig. 3, S120 "determining a phase difference of the three-way interference signal based on the three-way interference signal" includes:
s321, calculating respective bias and amplitude for each path of interference signal in the three paths of interference signals.
Wherein, the average of the calibration data of each path of interference signal is calculatedThe mean value is used as the bias of the path of signal to obtain the bias of the first path of signal
Second path signal bias
And third path signal bias
(ii) a The offset of each interference signal can be calculated by the following formula:
wherein, the first and the second end of the pipe are connected with each other,
representing a three-way signal channel sequence and taking values from 1 to 3;
representing the total number of calibration data for each interference signal;
calibration data representing the interference signal path;
and (3) representing variables in the calculation process, wherein the variation range is 0-N.
Calculating the amplitude by using the obtained bias, specifically: by multiplying the standard deviation of each path of interference signal by
Obtaining the amplitude of the channel signal
The amplitude of the first path signal is obtained by scattering according to the following formula
The amplitude of the second path signal
And third path signal amplitude
：
And S322, 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
And the phase difference between the second path of interference signal and the first path of signal
(ii) a The calculation formula is as follows:
in an embodiment, as shown in fig. 4, 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. 4, in the method:
s410, acquiring three interference signals collected by the reading head in a moving state with a fixed speed.
The step is the same as S110, and for details, refer to the explanation at S110, which is not described herein again.
And S420, determining the phase difference of the three interference signals based on the three interference signals.
The step is the same as S120, and for details, refer to the explanation at S120, which is not described herein again.
S130 "determining two orthogonal signals based on the phase difference of the three interference signals", includes:
and S430, determining two paths of orthogonal signals 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
And the phase difference between the third path of interference signal and the first path of interference signal is
(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
And is and
is 0.
Specifically, the intensity of the three-way interference signal can be represented by the calculated phase difference; the specific formula is as follows:
wherein the content of the first and second substances,
、
and
respectively representing the intensity of the three paths of interference signals;
a direct current component representing the interference signal;
representing the alternating current component of the interference signal.
The three formulas are combined, the influence of direct current components and alternating current components of interference signals on phases can be counteracted, the influence of factors such as temperature drift and light intensity drift of an electronic device is eliminated, the measurement stability and the measurement precision of the grating ruler are improved, and the expression formula obtained by combining is as follows:
parameter substitution is introduced for convenient solution:
wherein the content of the first and second substances,
representing the difference between the phase difference cosine value of the second path of interference signals and the phase difference cosine value of the third path of interference signals;
representing the difference between the phase difference sine value of the second path of interference signal and the phase difference sine value of the third path of interference signal;
the phase difference cosine value of the second path of interference signal and the phase difference cosine value of the third path of interference signal are subtracted from the phase difference cosine value of the first path of interference signal by 2 times because
Then, then
；
The phase difference sine value of the second path of interference signal and the phase difference sine value of the third path of interference signal are subtracted from the phase difference sine value of the first path of interference signal which is expressed by 2 times
Then, then
。
Will be provided with
、
、
And
the new simultaneous formula is replaced into the simultaneous formula:
by solving the simultaneous formula, the phase shift quantity can be obtained
The calculation formula of (2) is as follows:
therefore, according to the trigonometric function calculation relationship and the expression of the phase shift amount 2 omega obtained by the three-step phase shift algorithm, the expressions of the two orthogonal signals are determined as follows:
wherein the content of the first and second substances,
representing orthogonal signals obtained by three-step phase shifting;
representing the quadrature cosine signal obtained by three steps of phase shifting. The phase difference of three interference signals
And
and substituting the formula to obtain an orthogonal signal and an orthogonal cosine signal.
And S440, 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 an embodiment, as shown in fig. 5, a detailed flow chart of S140 in the method for processing a detection signal applied to a linear scale shown in fig. 1 is shown. Referring to fig. 5, S140 "determining the displacement and/or velocity of the measured target based on two orthogonal signals" includes:
and S541, determining a phase shift amount based on the two paths of orthogonal signals.
Specifically, the amount of phase shift is known
The relationship to the quadrature signal is:
expression of two orthogonal signals
And
substituting into the above formula, the amount of phase shift
The calculation formula of (2) is as follows:
calculating to obtain the phase shift quantity by the formula
。
And S542, 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:
wherein, the first and the second end of the pipe are connected with each other,
is displacement;
is the amount of phase shift;
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 with computing power, such as a server or a computer and the like.
Fig. 6 is a schematic structural diagram of a detection signal processing apparatus applied to a grating scale according to an embodiment of the present disclosure. Referring to fig. 6, the apparatus 600 includes: the signal acquisition module 610 is configured to acquire three paths of interference signals acquired by the reading head in a moving state at a fixed speed; the phases of the three interference signals are unknown; a first determining module 620, configured to determine a phase difference of the three-way interference signal based on the three-way interference signal; 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; a second determining module 630, configured to determine two paths of orthogonal signals based on the phase difference of the three paths of interference signals; and the third determining module 640 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 signal acquiring module is configured to acquire three interference signals acquired by a reading head in a moving state with a fixed speed, and includes: collecting three paths of initial interference signals in real time under the moving state of the reading head at a fixed speed; judging whether the three initial interference signals meet a stable condition or not; after the three initial interference signals meet the stable condition, caching the initial interference signals meeting the stable 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 three interference signals have different initial phases and the same frequency.
In one embodiment, the first determining module is configured to determine a phase difference of the three-way interference signal based on the three-way interference signal, and includes: calculating respective bias and amplitude for each path of interference signal in the three paths of interference signals; and 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.
In one embodiment, the second determining module is configured to determine two-way quadrature signals based on the phase difference of the three-way interference signals, and includes: determining two paths of orthogonal signals 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.
In one embodiment, the third determining module is configured to determine the displacement and/or 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 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. 7, the electronic device 700 includes: a processor 710 and a memory 720; processor 710 achieves corresponding advantages by invoking programs or instructions stored by memory 720 for performing any of the method steps described above.
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, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. 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 the 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:
acquiring three paths of interference signals collected by a reading head in a moving state at a fixed speed; the phases of the three interference signals are unknown;
determining the phase difference of the three interference signals based on the three 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 based on the phase difference of the three paths of interference signals;
determining the displacement and/or the speed of the target to be measured based on the two paths of orthogonal signals;
the three-way interference signal is generated based on the movement of a reading head relative to a measured target, the grating ruler comprises a reference grating and a measurement grating, one of the reference grating and the measurement grating is arranged in the reading head, and the other one of the reference grating and the measurement grating is arranged in the measured target.
2. The method of claim 1, wherein obtaining the three-way interference signal collected by the readhead under a fixed speed motion comprises:
collecting three paths of initial interference signals in real time under the moving state of the reading head at a fixed speed;
judging whether the three initial interference signals meet a stable condition or not;
after the three initial interference signals meet the stable condition, caching the initial interference signals meeting the stable 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.
3. The method according to claim 1 or 2, wherein the three-way interference signals have different initial phases and same frequency.
4. The method of claim 1 or 2, wherein determining the phase difference of the three-way interference signal based on the three-way interference signal comprises:
calculating respective bias and amplitude for each path of interference signal in the three paths of interference signals;
and 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.
5. The method of claim 1, wherein determining two orthogonal signals based on the phase difference of the three interfering signals comprises:
determining the two paths of orthogonal signals 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.
6. The method according to claim 1, wherein the determining the displacement and/or velocity of the target under test 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 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 signal acquisition module is used for acquiring three paths of interference signals acquired by the reading head in a moving state at a fixed speed; the phases of the three paths of interference signals are unknown;
the first determining module is used for determining the phase difference of the three-way interference signals 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;
the second determining module is used for determining two paths of orthogonal signals based on the phase difference of the three paths of interference signals;
the third determining module is used for determining the displacement and/or the speed of the measured target based on the two paths of orthogonal signals;
the three-way interference signal is generated based on the movement of a reading head relative to a measured target, the grating ruler comprises a reference grating and a measurement grating, one of the reference grating and the measurement grating is arranged in the reading head, and the other one of the reference grating and the measurement grating is arranged in the measured target.
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 of 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 adopts the steps of the method of any one of claims 1 to 6 to realize detection signal processing.
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