CN115451828A - Laser interferometer ranging error suppression system and method - Google Patents

Abstract

The invention provides a system and a method for inhibiting a ranging error of a laser interferometer, wherein the system comprises a laser emission module, an interference ranging module, a wavelength tracking module, a light splitting module and a signal processing module; the laser emission module emits laser, the reflected light of the laser is split by the light splitting module enters the wavelength tracking module to form a first measuring signal, the transmitted light split by the light splitting module passes through the interference distance measuring module to form a second measuring signal, and the signal processing module carries out error suppression on the interference distance measuring module through the first measuring signal and the second measuring signal. The system and the method for inhibiting the distance measurement error of the laser interferometer can effectively reduce the refractive index error of the laser interferometer.

Description

Laser interferometer ranging error suppression system and method

Technical Field

The invention relates to the technical field of ultra-precise displacement measurement, in particular to a system and a method for restraining a distance measuring error of a laser interferometer.

Background

The laser interferometer has the advantages of high precision, good linearity and the like, can be used for ultra-precise measurement scenes such as geometric precision detection, dynamic monitoring of a numerical control machine tool, multi-degree-of-freedom displacement measurement of a photoetching machine and the like, and has wide application occasions.

In the actual measurement process, each application scene has higher requirements on the measurement accuracy of the laser interferometer, so that the range measurement error of the laser interferometer needs to be suppressed. The laser interferometer distance measurement errors mainly comprise cosine errors, abbe errors and measurement errors brought by the refractive index. The cosine error has high repeatability and is easy to compensate, the Abbe error influence is small, and the refractive index error is a random error with low repeatability and large error. The laser is transmitted in the air, the refractive index of the air is changed due to factors such as the temperature and the humidity of the gas, the wavelength of the laser is further changed under the influence of the refractive index of the air, the theoretical wavelength is generally used in the distance measurement calculation of the laser interferometer, and finally the distance measurement result has errors, the errors can increase along with the distance between the reflector and the interferometer, namely the propagation distance of the laser in the air, and the errors can reach hundreds of nanometers or even micron-sized under the condition of long distance or severe environmental change.

In view of the above situation, a method for effectively reducing the refractive index error of a laser interferometer is needed.

Disclosure of Invention

In view of the above problems, it is an object of the present invention to provide a system and a method for suppressing a distance measurement error of a laser interferometer, which can effectively reduce a refractive index error of the laser interferometer.

The invention provides a distance measurement error suppression system of a laser interferometer, which comprises a laser emission module, an interference distance measurement module, a wavelength tracking module, a light splitting module and a signal processing module; wherein,

the laser emitted by the laser emitting module enters the wavelength tracking module through reflected light split by the light splitting module to form a first measuring signal, transmitted light split by the light splitting module passes through the interference distance measuring module to form a second measuring signal, and the signal processing module carries out error suppression on the interference distance measuring module through the first measuring signal and the second measuring signal.

In addition, the preferable scheme is that the signal processing module comprises a phase card, a main control card and an upper computer, wherein,

the phase card respectively counts the first measuring signal and the second measuring signal to obtain wavelength tracking data and original distance measuring data, and transmits the wavelength tracking data and the original distance measuring data to the main control card;

the master control card reads the wavelength tracking data and the original distance measurement data and uploads the wavelength tracking data and the original distance measurement data to the upper computer;

and the upper computer performs error suppression on the original distance measurement data through the wavelength tracking data.

In addition, preferably, the laser interferometer distance measurement error suppression system further includes a reflection module corresponding to the position of the interference distance measurement module, and light emitted by the transmitted light entering the interference distance measurement module is reflected by the reflection module to generate the second measurement signal.

In addition, the preferred scheme is that the reflection module is arranged on a preset motion table; and also,

the distance between the reflection module and the interference distance measurement module is adjusted through the preset motion platform based on a preset servo period.

In addition, it is preferable that the interferometric ranging module includes a first interferometer and a second interferometer, the light reflecting module includes a first reflecting mirror and a second reflecting mirror, and the beam splitting module includes a first beam splitter and a second beam splitter; wherein,

the first reflector and the second reflector are respectively arranged on an X-axis guide rail and a Y-axis guide rail of the preset motion table to slide, the first interferometer corresponds to the first reflector in position, and the second interferometer corresponds to the second reflector in position;

laser emitted by the laser emitting module is split by the first beam splitter to form first transmitted light and first reflected light; the light emitted by the first transmitted light after entering the first interferometer is reflected by the second reflector to form a Y-axis signal of the second measurement signal; the first reflected light forms second transmitted light and second reflected light after passing through the second spectroscope, wherein the light emitted by the second transmitted light after entering the second interferometer forms an X-axis signal of the second measurement signal after being reflected by the first reflector, and the second reflected light enters the wavelength tracking module to form the first measurement signal.

In addition, it is preferable that a reference signal of the laser emission module is connected to a reference axis of the phase card, the first measurement signal is connected to a first measurement axis of the phase card, and the second measurement signal is connected to a second measurement axis of the phase card.

On the other hand, the invention also provides a laser interferometer ranging error suppression method, which utilizes the laser interferometer ranging error suppression system to suppress the error of the interference ranging module: the method comprises the following steps:

the laser emission module emits laser to the light splitting module, reflected light split by the light splitting module enters the wavelength tracking module to form a first measurement signal, and transmitted light split by the light splitting module passes through the interference distance measuring module to form a second measurement signal;

error suppression is performed on the interferometric ranging module by the signal processing module based on the first measurement signal and the second measurement signal.

In addition, the preferable scheme is that n groups of the first measurement signal and the second measurement signal are arranged, wherein n is an integer and is more than or equal to 10; and the performing, by the signal processing module, error mitigation on the interferometric ranging module based on the first measurement signal and the second measurement signal comprises:

respectively acquiring a data value c of the first measuring signal and a data value d of the second measuring signal of each group through the signal processing module;

performing linear fitting on the data values c and d of each group to obtain n fitting coefficients A = [ A1, A2, \ 8230;, an ];

carrying out linear fitting on preset actual distance data X = [ X1, X2, \8230;, xn ] and A to obtain a fitting equation A = f (X);

and obtaining a measurement distance optimization data value d1= d-f (X) c of the interference ranging module based on the fitting equation A = f (X).

In addition, it is preferable that the data value d of the second measurement signal is a measurement distance between the interferometric ranging module and the transmitting module, and the actual distance data X is an actual distance between the interferometric ranging module and the transmitting module; wherein,

the reflection module is arranged on a preset motion table, and n groups of measured distance data values and n groups of actual distance data values X = [ X1, X2, \8230;, xn ] are obtained by adjusting the position of the reflection module on the preset motion table.

In addition, preferably, n groups of the first measurement signal and the second measurement signal are provided, wherein n is an integer and is more than or equal to 10, and the second measurement signal comprises an X-axis signal and a Y-axis signal; and the performing, by the signal processing module, error suppression on the interferometric ranging module based on the first measurement signal and the second measurement signal comprises:

respectively acquiring a data value c of the first measuring signal, an X-axis data value dx of the X-axis signal and a Y-axis data value dy of the Y-axis signal of each group through the signal processing module;

respectively carrying out linear fitting on the X-axis measurement data value dx and the Y-axis measurement data value dy of each group and the data value c to obtain two paths of fitting coefficients Ax = [ Ax1, ax2, \8230;, axn ], ay = [ Ay1, ay2, \8230;, ayn ];

carrying out linear fitting on preset actual distance data X = [ X1, X2, \8230;, xn ] and Ax to obtain a fitting equation Ax = f (X), and carrying out linear fitting on preset actual distance data Y = [ Y1, Y2, \8230;, yn ] and Ay to obtain a fitting equation Ay = f (Y);

based on the fitting equation Ax = f (X) and the fitting equation Ay = f (Y), the X-axis measured distance optimized data value dx1= dx-f (X) c and the Y-axis measured distance optimized data value dy1= dy-f (Y) c of the interferometric ranging module are obtained.

Compared with the prior art, the ranging error suppression system of the laser interferometer has the following beneficial effects:

the laser interferometer ranging error suppression system provided by the invention can suppress errors generated by the change of environmental factors in the laser interferometer ranging, so that the laser interferometer ranging result is more accurate, different compensation coefficients are used according to the distance between the laser interferometer and the measured object, the system can be applied to the large-stroke ranging occasion, a single-axis interferometer is used as an example in the schematic diagram, and the system is also applied to an angle interferometer, a three-axis interferometer, a five-axis interferometer and the like, the technology is easy to implement, and the applicable occasion is wide.

To the accomplishment of the foregoing and related ends, one or more aspects of the invention comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative aspects of the invention. These aspects are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Further, the present invention is intended to include all such aspects and their equivalents.

Drawings

Other objects and results of the present invention will become more apparent and readily appreciated as the same becomes better understood by reference to the following description and appended claims, taken in conjunction with the accompanying drawings. In the drawings:

FIG. 1 is a schematic diagram of a first configuration of a laser interferometer range error mitigation system in accordance with an embodiment of the invention;

FIG. 2 is a diagram of a second configuration of a laser interferometer range error mitigation system according to an embodiment of the invention.

Reference numerals: the system comprises an upper computer 1, a VME case 2, a back plate 3, a VME main control card 4, a phase card 5, a first optical fiber 6, a laser emission module 7, a light splitting module 8, a wavelength tracking module 9, a reflection module 10, a second optical fiber 11, a third optical fiber 12, an interference distance measuring module 13, an X-axis guide rail 15, a first reflective mirror 16, a second reflective mirror 17, a positioning table 18, a Y-axis guide rail 19, a first interferometer 20, a first dichroic mirror 21, a dual-frequency laser 22, a wavelength tracker 23, a second dichroic mirror 24 and a second interferometer 25.

The same reference numbers in all figures indicate similar or corresponding features or functions.

Detailed Description

In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It may be evident, however, that such embodiment(s) may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing one or more embodiments.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention; the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; furthermore, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, as they may be fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The structure of the laser interferometer ranging error suppression system provided by the invention is described in detail below, and fig. 1 is a schematic diagram of a first structure of the laser interferometer ranging error suppression system according to the embodiment of the invention.

As can be seen from fig. 1 in conjunction with the figure, the ranging error suppression system of the laser interferometer provided by the present invention mainly includes a laser emitting module 7 for emitting measurement laser, an interference ranging module 13 for ranging, a wavelength tracking module 9 for measuring laser, a light splitting module 8 for splitting laser, and a signal processing module for processing the measured information; the laser emitted by the laser emitting module 7 enters the wavelength tracking module 9 through reflected light split by the light splitting module 8 to form a first measurement signal (which is a wavelength measurement signal), the transmitted light split by the light splitting module 8 forms a second measurement signal (which is a distance measurement signal) through the interference distance measuring module 13, and the signal processing module performs error suppression on the interference distance measuring module 13 through the first measurement signal and the second measurement signal.

Specifically, to implement the ranging function of the interferometric ranging module 13, the laser interferometer ranging error suppression system further includes a reflection module 10 corresponding to the position of the interferometric ranging module 13, and the light emitted from the transmitted light entering the interferometric ranging module 13 is reflected by the reflection module 10 to generate a second measurement signal (i.e., a distance measurement signal between the interferometric ranging module 13 and the reflection module 10).

More specifically, in order to realize the digital acquisition of the first measurement signal and the second measurement signal by the signal processing module, the signal processing module includes a phase card 5, a master control card and an upper computer 1, wherein the phase card 5 respectively counts the digital values of the first measurement signal and the second measurement signal to obtain wavelength tracking data (i.e., a data value c) and original distance measurement data (i.e., a data value d), and transmits the wavelength tracking data and the original distance measurement data to the master control card (preferably, the VME master control card 4); the master control card reads the wavelength tracking data and the original distance measurement data and uploads the wavelength tracking data and the original distance measurement data to the upper computer 1; and the upper computer 1 performs error suppression on the original distance measurement data through the wavelength tracking data.

In the actual device connection process, a reference signal of a dual-frequency laser 22 in the laser emission module 7 is accessed to a reference axis of the phase card 5 through the first optical fiber 6, the light emitted from the dual-frequency laser 22 enters the wavelength tracking module 9 through the reflected light of the light splitting module 8, the transmitted light passing through the light splitting module 8 enters the interference ranging module 13, the light emitted from the interference ranging module 13 is reflected by the reflection module 10 to generate a second measurement signal, and the second measurement signal is transmitted to a second measurement axis of the phase card 5 through the third optical fiber 12. At the same time, the first measurement signal generated by the wavelength tracking module 9 is transmitted to the first measurement axis of the phase card 5 via the second optical fiber 11. The phase card 5 and the VME main control card 4 are connected to the back plate 3 of the VME case 2 and can communicate with each other, the phase card 5 counts two measurement signals and transmits the two measurement signals to the VME main control card 4, the VME main control card 4 reads and records measurement data of the phase card 5 in each preset servo period and uploads the measurement data to the upper computer 1, and finally the upper computer 1 stores and analyzes the data.

In order to ensure the measurement accuracy, it is usually necessary to set n (n is an integer, n.gtoreq.10) sets of the first measurement signal and the second measurement signal. In order to realize the setting of n sets of first measurement signals and second measurement signals, the reflection module 10 may be disposed on a preset motion stage; moreover, the distance between the reflection module 10 and the interferometric ranging module 13 is adjusted by a preset motion stage based on a preset servo period, and n sets of first measurement signals and second measurement signals can be formed by adjusting the distance between the reflection module 10 and the interferometric ranging module 13 for multiple times.

It should be noted that, in the actual error suppression process, the wavelength tracking module 9 and the interferometric ranging module 13 need to be arranged in the same environment with close positions, after the reflection module 10 is fixed on a preset motion platform, the VME main control card 4 collects and records the measurement wavelength data (corresponding to the first measurement signal) of the wavelength tracking module 9, the measurement distance data (corresponding to the second measurement signal) of the interferometric ranging module 13, and the actual distance data between the interferometric ranging module 13 and the reflection module 10, and then uploads these data to the upper computer 1; in order to ensure stability of the data, each data was collected for 8 hours or more. After the collection is completed, moving the reflection module 10 on a preset motion table for a certain distance, repeating the collection steps until the reflection module gradually moves to the limit position of the stroke of the preset motion table, thereby obtaining n groups of data (including n measurement data c, n measurement data d and n actual distance data x), and performing linear fitting on the data value c and the data value d of each group to obtain n fitting coefficients A = [ A1, A2, \8230;, an ]; then, performing linear fitting on preset actual distance data X = [ X1, X2, \8230;, xn ] and A to obtain a fitting equation A = f (X); finally, based on the fitting equation a = f (X), the measurement distance optimization data value d1= d-f (X) c of the interferometric ranging module 13 can be obtained.

In another preferred embodiment of the present invention, fig. 2 is a schematic diagram of a second structure of the laser interferometer ranging error suppression system according to the embodiment of the present invention. As can be seen from fig. 2, the wavelength error suppression effect is further improved. The wavelength error of the interferometric ranging module 13 can be suppressed in both directions of the X axis and the Y axis.

Specifically, the interferometric ranging module 13 comprises a first interferometer 20 and a second interferometer 25, the reflective module comprises a first reflector 16 and a second reflector 17, and the beam splitting module 8 comprises a first beam splitter 21 and a second beam splitter 24; wherein,

the first reflector and the second reflector are respectively arranged on an X-axis guide rail 15 and a Y-axis guide rail 19 of a preset motion table to slide, the first interferometer 20 corresponds to the first reflector in position, and the second interferometer 25 corresponds to the second reflector in position; laser emitted by the laser emitting module 7 is split by the first beam splitter 21 to form first transmitted light and first reflected light; wherein, the light emitted from the first transmitted light entering the first interferometer 20 is reflected by the second mirror to form a Y-axis signal of the second measurement signal; the first reflected light forms second transmitted light and second reflected light after passing through the second beam splitter 24, wherein the outgoing light of the second transmitted light entering the second interferometer 25 forms an X-axis signal of a second measurement signal after being reflected by the first reflector, and the second reflected light enters the wavelength tracking module 9 to form a first measurement signal. The reference signal of the laser emitting module 7 is connected to the reference axis of the phase card 5, the first measuring signal is connected to the first measuring axis of the phase card 5, and the second measuring signal is connected to the second measuring axis of the phase card 5.

In practical use, the device can be operated on an ultra-precise preset motion table which is of a top-bottom laminated design and comprises an X-axis guide rail 15 and a Y-axis guide rail 19, wherein the Y-axis guide rail 19 can slide on the X-axis guide rail 15 along the X-axis direction, a positioning table 18 is arranged on the Y-axis guide rail 19, the positioning table 18 can slide on the Y-axis guide rail 19 along the Y-axis direction, and a first reflective mirror 16 is arranged at one end of the Y-axis guide rail 19 (of course, on the X-axis guide rail 15) and slides along the X-axis direction along with the Y-axis guide rail 19 on the X-axis guide rail 15. The transmitted light split by the first beam splitter 21 from the light emitted from the dual-frequency laser 22 enters the first interferometer 20, and when the second mirror moves on the Y-axis guide rail 19 along with the positioning table 18, the first interferometer 20 can measure the displacement in the Y-axis direction (i.e., the distance between the first interferometer 20 and the second mirror, i.e., the Y-axis measurement signal). The reflected light from the first beam splitter 21 enters the second beam splitter 24, the transmitted light from the second beam splitter 24 enters the second interferometer 25, and when the first mirror moves in the X-axis direction along with the Y-axis guide 19, the second interferometer 25 can measure the displacement in the X-axis direction (i.e., the distance between the second interferometer 25 and the first mirror, i.e., the X-axis measurement signal). In addition, the reflected light from the second beam splitter 24 enters the wavelength tracker 23 of the wavelength tracking module 9, and the first measurement signal is obtained. And finally, transmitting the two paths of displacement measurement signals (namely the Y-axis measurement signal and the X-axis measurement signal) and the first measurement signal of the wavelength tracking module 9 into the phase card 5 through optical fiber transmission, recording and uploading the signals to the upper computer 1 through the VME main control card 4, and finishing the final error suppression calculation.

Note that, for the spectroscopic module, since the spectroscopic module includes the first spectroscope 21 and the second spectroscope 24, and since the light split by the second spectroscope 24 is output as the spectroscopic module, in order to facilitate understanding of the transmission of the optical path in the spectroscopic module, here, the light reflected by the first spectroscope 21 and transmitted by the second spectroscope 24 is referred to as the transmission light of the entire spectroscopic module, and the light reflected by the first spectroscope 21 and reflected by the second spectroscope 24 is referred to as the reflection light of the entire spectroscopic module.

To further explain the working principle of the optical interferometer ranging error suppression system provided by the present invention, the present invention further provides a laser interferometer ranging error suppression method, which utilizes the laser interferometer ranging error suppression system to perform error suppression of the interferometric ranging module 13: the method comprises the following steps:

laser is emitted to the light splitting module 8 through the laser emitting module 7, reflected light split by the light splitting module 8 enters the wavelength tracking module 9 to form a first measuring signal, and transmitted light split by the light splitting module 8 forms a second measuring signal through the interference distance measuring module 13;

the signal processing module performs error suppression on the interferometric ranging module 13 based on the first measurement signal and the second measurement signal.

Specifically, in order to improve the error suppression effect, n groups of first measurement signals and second measurement signals are arranged, wherein n is an integer and is more than or equal to 10; the signal processing module performs error suppression on the interferometric ranging module 13 based on the first measurement signal and the second measurement signal, and includes:

respectively acquiring a data value c of the first measuring signal and a data value d of the second measuring signal of each group through a signal processing module;

performing linear fitting on the data values c and d of each group to obtain n fitting coefficients A = [ A1, A2, \ 8230;, an ];

performing linear fitting on preset actual distance data X = [ X1, X2, \8230;, xn ] and A to obtain a fitting equation A = f (X);

based on the fitting equation a = f (X), the measurement distance optimization data value d1= d-f (X) c of the interferometric ranging module 13 is obtained.

It should be noted that the data value d of the second measurement signal is the measurement distance between the interferometric ranging module 13 and the transmitting module 10, and the actual distance data X is the actual distance between the interferometric ranging module 13 and the transmitting module 10; the reflection module 10 is disposed on a preset motion stage, and n sets of measured distance data values and n sets of actual distance data values X = [ X1, X2, \8230;, xn ] are obtained by adjusting a position of the reflection module 10 on the preset motion stage.

Further, the second measurement signal includes an X-axis signal and a Y-axis signal; in addition, in the process of suppressing the wavelength error of the interferometric ranging module 13 in the two directions of the X axis and the Y axis, the process of suppressing the error of the interferometric ranging module 13 by the signal processing module based on the first measurement signal and the second measurement signal includes:

equally dividing the total X/Y travel n on the preset motion table into n preset positions of the positioning table 18, and obtaining the actual position X = [ X1, X2, \8230;, xn ], Y = [ Y1, Y2, \8230;, yn ] (note that the actual position of the n preset positions can be directly read out due to the scale on the preset motion table); then fixing the moving table at each point in sequence, and collecting three signals for more than 8 hours

Fixing the positioning table 18 at each predetermined position in sequence, and collecting three signals (including an X-axis data value dx, an axis data value dy and a data value c) of each predetermined position for more than 8 hours; the specific acquisition process comprises the following steps: respectively acquiring a data value c of the first measuring signal, an X-axis data value dx of the X-axis signal and a Y-axis data value dy of the Y-axis signal of each group through a signal processing module;

respectively carrying out linear fitting on the X-axis data value dx and the Y-axis data value dy of each group and the data value c to obtain two fitting coefficients Ax = [ Ax1, ax2, \8230;, axn ], ay = [ Ay1, ay2, \8230;, ayn ];

linearly fitting preset actual distance data X = [ X1, X2, \8230;, xn ] and Ax to obtain a fitting equation Ax = f (X), and linearly fitting preset actual distance data Y = [ Y1, Y2, \8230;, yn ] and Ay to obtain a fitting equation Ay = f (Y);

based on the fitting equation Ax = f (X) and the fitting equation Ay = f (Y), the X-axis measured distance optimized data value dx1= dx-f (X) c and the Y-axis measured distance optimized data value dy1= dy-f (Y) c of the interferometric ranging module 13 are obtained.

It should be noted that the wavelength tracker 23 used in the present invention is a standard commercial wavelength tracker 23, which is composed of a single-axis interferometer, a standard cavity and a bottom plate, and can measure the wavelength variation caused by the air refractive index variation, the temperature drift of the laser itself, and the like. In addition, the mirrors used in the present invention may use a long strip mirror, a diagonal mirror, or the like as an alternative according to an application scene; the VME system for collecting the laser data can use a VPX system as an alternative scheme; the phase card 5 may use a photo detector and a voltage acquisition card as an alternative.

Laser interferometer range error suppression systems and methods according to the present invention are described above by way of example with reference to fig. 1 and 2. However, it will be appreciated by those skilled in the art that various modifications may be made to the laser interferometer ranging error suppression system and method of the present invention without departing from the spirit and scope of the invention. Therefore, the scope of the present invention should be determined by the contents of the appended claims.

Claims (10)

1. A laser interferometer ranging error suppression system is characterized by comprising a laser emission module, an interference ranging module, a wavelength tracking module, a light splitting module and a signal processing module; wherein,

the laser emitted by the laser emitting module enters the wavelength tracking module to form a first measuring signal after being split by the light splitting module, the transmitted light split by the light splitting module passes through the interference distance measuring module to form a second measuring signal, and the signal processing module carries out error suppression on the interference distance measuring module through the first measuring signal and the second measuring signal.

2. The laser interferometer range error suppression system of claim 1,

the signal processing module comprises a phase card, a main control card and an upper computer, wherein,

the phase card respectively counts the first measuring signal and the second measuring signal to obtain wavelength tracking data and original distance measuring data, and transmits the wavelength tracking data and the original distance measuring data to the main control card;

the master control card reads the wavelength tracking data and the original distance measurement data and uploads the wavelength tracking data and the original distance measurement data to the upper computer;

and the upper computer performs error suppression on the original distance measurement data through the wavelength tracking data.

3. The laser interferometer range error suppression system of claim 2,

the laser interferometer ranging error suppression system further comprises a reflection module corresponding to the position of the interference ranging module, and the transmitted light entering the interference ranging module is reflected by the reflection module to generate the second measurement signal.

4. The laser interferometer range error suppression system of claim 3,

the reflection module is arranged on a preset motion table; and,

the distance between the reflection module and the interference ranging module is adjusted through the preset motion platform based on a preset servo period.

5. The laser interferometer range error suppression system of claim 4,

the interference distance measuring module comprises a first interferometer and a second interferometer, the light reflecting module comprises a first reflecting mirror and a second reflecting mirror, and the light splitting module comprises a first light splitting mirror and a second light splitting mirror; wherein,

the first reflector and the second reflector are respectively arranged on an X-axis guide rail and a Y-axis guide rail of the preset motion table to slide, the first interferometer corresponds to the first reflector in position, and the second interferometer corresponds to the second reflector in position;

laser emitted by the laser emission module is split by the first beam splitter to form first transmission light and first reflection light; the light emitted by the first transmitted light after entering the first interferometer is reflected by the second reflector to form a Y-axis signal of the second measurement signal; the first reflected light forms second transmitted light and second reflected light after passing through the second spectroscope, wherein the light emitted by the second transmitted light after entering the second interferometer forms an X-axis signal of the second measurement signal after being reflected by the first reflector, and the second reflected light enters the wavelength tracking module to form the first measurement signal.

6. The laser interferometer range error suppression system of any one of claims 1 to 5,

the reference signal of the laser emission module is accessed to the reference axis of the phase card, the first measurement signal is accessed to the first measurement axis of the phase card, and the second measurement signal is accessed to the second measurement axis of the phase card.

7. A laser interferometer ranging error suppression method, characterized in that the laser interferometer ranging error suppression system of any one of claims 1 to 6 is used for error suppression of an interferometric ranging module: the method comprises the following steps:

the laser emission module emits laser to the light splitting module, reflected light split by the light splitting module enters the wavelength tracking module to form a first measurement signal, and transmitted light split by the light splitting module passes through the interference distance measuring module to form a second measurement signal;

error suppression is performed on the interferometric ranging module by the signal processing module based on the first measurement signal and the second measurement signal.

8. The laser interferometer range error suppression method of claim 7,

the first measurement signal and the second measurement signal are provided with n groups, wherein n is an integer and is more than or equal to 10; and the performing, by the signal processing module, error suppression on the interferometric ranging module based on the first measurement signal and the second measurement signal comprises:

respectively acquiring a data value c of the first measuring signal and a data value d of the second measuring signal of each group through the signal processing module;

performing linear fitting on the data values c and d of each group to obtain n fitting coefficients A = [ A1, A2, \ 8230;, an ];

performing linear fitting on preset actual distance data X = [ X1, X2, \8230;, xn ] and A to obtain a fitting equation A = f (X);

obtaining a measurement distance optimization data value d of the interferometric ranging module based on the fitting equation A = f (X) ₁ ＝d-f(X)c。

9. The laser interferometer range error suppression method of claim 8,

the data value d of the second measurement signal is measurement data recorded when the interference ranging module and the transmitting module are relatively static, and the actual distance data X is the actual distance between the interference ranging module and the transmitting module; wherein,

the reflection module is arranged on a preset motion table, and n groups of measured distance data values and n groups of actual distance data values X = [ X1, X2, \8230;, xn ] are obtained by adjusting the position of the reflection module on the preset motion table.

10. The laser interferometer range error suppression method of claim 7,

the first measurement signal and the second measurement signal are provided with n groups, wherein n is an integer and is more than or equal to 10, and the second measurement signal comprises an X-axis signal and a Y-axis signal; and the performing, by the signal processing module, error suppression on the interferometric ranging module based on the first measurement signal and the second measurement signal comprises:

respectively acquiring a data value c of the first measuring signal, an X-axis measuring data value dx of the X-axis signal and a Y-axis measuring data value dy of the Y-axis signal of each group through the signal processing module;

respectively carrying out linear fitting on the X-axis measurement data value dx and the Y-axis measurement data value dy of each group and the data value c to obtain two paths of fitting coefficients Ax = [ Ax1, ax2, \8230;, axn ], ay = [ Ay1, ay2, \8230;, ayn ];

linearly fitting preset actual distance data X = [ X1, X2, \8230;, xn ] and Ax to obtain a fitting equation Ax = f (X), and linearly fitting preset actual distance data Y = [ Y1, Y2, \8230;, yn ] and Ay to obtain a fitting equation Ay = f (Y);

based on the fitting equation Ax = f (X) and the fitting equation Ay = f (Y), an X-axis measured distance optimized data value dx1= dx-f (X) c and a Y-axis measured distance optimized data value dy1= dy-f (Y) c of the interferometric ranging module are obtained.

Images