Laser interferometer automatic adjustment device and adjustment method thereof

Abstract

The application discloses an adjusting device and method of a laser interferometer, and provides a hardware solution for automatic adjustment of the laser interferometer by designing a laser interferometer mounting and adjusting mechanism, combining a manual adjusting mechanism and an automatic adjusting mechanism, and detecting a laser light path through a combined first PSD position sensor and a second PSD position sensor to realize quick mounting and calibration between the laser interferometer and an interference mirror. The best direction vector of outgoing light of the laser interferometer in space is solved through least square fitting analysis on the results of multi-point position detection, so that the system error of the laser measuring system itself is eliminated, and the influence of Abbe error and cosine error on the laser measuring system is reduced.

Description

Technical Field

[0001] This application relates to the field of mechanical manufacturing, and in particular to an automatic adjustment device for a laser interferometer and its adjustment method. Background Technology

[0002] As a precision instrument for CNC machine tool accuracy testing, the laser interferometer measurement system plays a crucial role in the accuracy testing and compensation of CNC machine tools, including positioning accuracy, repeatability, straightness, and perpendicularity. Achieving rapid installation and high-precision automated collimation of the laser interferometer measurement system is of significant practical importance for improving the inspection accuracy of CNC machine tools, increasing the efficiency of machine tool accuracy inspection and compensation, reducing the impact of Abbe and cosine errors on the test results, and shortening downtime during machine tool inspection. Existing laser interferometer collimation methods mainly include the following: adjusting the installation position of the laser interferometer and the target mirror (cornerstone reflector) based on experience; fine-tuning the spatial angle of the laser beam propagation by installing a collimating mirror, such as the collimating mirror developed by Renishaw for its supporting products; adjusting the laser beam collimation by adding an interferometer to assist in adjusting the mechanical structure, and using a reflector to assist in adjusting the mechanical structure; and adding a beam position sensor (such as a CCD sensor or PSD position sensor) to the laser beam path to sense the beam path and thus achieve collimation of the laser measurement beam path.

[0003] Chinese patent publication CN109141223B discloses "An Efficient and Precise Calibration Method for the Optical Path of a Laser Interferometer Based on PSD," specifically outlining the following steps: first, establishing the system optical path; then, coarsely adjusting the laser interferometer optical path; finally, obtaining the coordinate values ​​of each calibration point using a PSD two-dimensional photosensitive position sensor and calculating the offset of the measured light relative to the reference reflected light; and then precisely adjusting the laser interferometer optical path based on the offset. This invention achieves automatic calibration of the laser interferometer optical path using coordinates measured in the PSD two-dimensional photosensitive position sensor; however, it cannot achieve spatial pose identification and solution for the optical path. Summary of the Invention

[0004] The main objective of this application is to provide an adjustment device for a laser interferometer, which aims to solve the technical problems existing in the rapid and automated collimation process of the existing laser interferometer measurement system.

[0005] To achieve the above objectives, this application provides an adjustment device for a laser interferometer, including an adjustment mechanism, an adjustment platform, a first PSD position sensor, a second PSD position sensor, a first beam splitter, a second beam splitter, a first pyramidal reflector, and a second pyramidal reflector;

[0006] The adjustment platform is mounted on the adjustment mechanism. The adjustment platform has four degrees of freedom and is used to mount the main unit of the laser interferometer.

[0007] The first PSD position sensor, the second PSD position sensor, the first beam splitter, the second beam splitter, the first pyramidal reflector, and the second pyramidal reflector are all mounted on the adjustment platform, so that when the laser interferometer host is mounted on the adjustment platform, the first PSD position sensor, the second PSD position sensor, the first beam splitter, the second beam splitter, the first pyramidal reflector, and the second pyramidal reflector can be in an ideal collimated state after adjustment.

[0008] Optionally, in some embodiments of the present invention, a manual fine-tuning gimbal is further included, which is mounted on top of the adjustment platform, and the laser interferometer host is mounted on top of the manual fine-tuning gimbal.

[0009] Optionally, in some embodiments of the present invention, the aforementioned manual fine-tuning gimbal and adjustment platform are connected via a quick-connect coupling.

[0010] Optionally, in some embodiments of the present invention, the above-mentioned adjustment mechanism includes a two-degree-of-freedom planar adjustment mechanism and a two-degree-of-freedom swing angle adjustment mechanism;

[0011] The two-degree-of-freedom swing angle adjustment mechanism is installed on the two-degree-of-freedom plane adjustment mechanism, and the adjustment platform is installed on the two-degree-of-freedom swing angle adjustment mechanism.

[0012] In addition, to achieve the above objectives, this application also provides an adjustment method for the adjustment device of a laser interferometer, including responding to a collimation start signal, acquiring a first detection signal from a first PSD position sensor, calculating the yaw angle deviation between the laser interferometer host and the first pyramidal reflector based on the first detection signal, and calibrating the yaw deviation based on the yaw angle deviation.

[0013] The first detection signal includes a first position signal that the laser is detected when the first PSD position sensor is in a first position and a second position signal that the laser is detected when the first PSD position sensor is in a second position.

[0014] In response to the collimation start signal, the second detection signal of the first PSD position sensor is acquired. Based on the second detection signal, the pitch angle deviation between the laser interferometer host and the first pyramidal reflector is calculated, and the pitch deviation is calibrated based on the pitch angle deviation.

[0015] The second detection signal includes a third position signal when the first PSD position sensor is in the third position and a fourth position signal when the first PSD position sensor is in the fourth position.

[0016] After the first PSD position sensor is reset, it is moved along the direction of the laser beam to obtain the values ​​of the distance between the laser and the first PSD position sensor in the quadrant axis parallel to the direction of the laser beam and the distance between the first PSD position sensor and the quadrant axis perpendicular to the direction of the laser beam.

[0017] The target spatial vector direction of the laser interferometer's outgoing light is obtained by performing least squares fitting on multiple sets of corresponding horizontal and vertical distance values.

[0018] Based on the target spatial vector direction, the offset deviation between the target spatial vector direction and the laser emission direction is obtained, and the laser emission direction is adjusted according to the offset deviation.

[0019] Optionally, in some embodiments of the present invention, the invention includes:

[0020] Based on the first position signal of the laser position detected when the first PSD position sensor is in the first position, the distance P1 between the detection signal and the coordinate axis perpendicular to the first PSD position sensor is obtained;

[0021] Control the first PSD position sensor to move to the second position along the axial direction away from the adjustment platform, and record the moving distance of the first PSD position sensor as the first moving distance D;

[0022] Based on the second position signal of the laser position detected when the first PSD position sensor is in the second position, the distance P2 between the detection signal and the coordinate axis perpendicular to the first PSD position sensor is obtained;

[0023] Based on distances P1 and P2 and the first moving distance D, the yaw angle deviation between the laser interferometer host and the first pyramidal reflector is calculated.

[0024] Optionally, in some embodiments of the present invention, the invention includes:

[0025] Based on the following set of equations, the yaw angle deviation between the laser interferometer host and the first pyramidal reflector is calculated according to the distances P1 and P2 and the first moving distance D.

[0026]

[0027] Wherein, P1 is the distance between the first position signal of the laser position detected by the first PSD position sensor when it is in the first position and the coordinate axis perpendicular to the first PSD position sensor;

[0028] P2 is the distance between the second position signal of the laser position detected by the first PSD position sensor when it is in the second position and the coordinate axis perpendicular to the first PSD position sensor;

[0029] D is the first moving distance of the first PSD position sensor when it moves from the first position to the second position;

[0030] θ represents the yaw angle deviation.

[0031] Optionally, in some embodiments of the present invention, the invention includes:

[0032] Based on the third position signal of the laser position detected when the first PSD position sensor is in the third position, the distance P3 between the detection signal and the coordinate axis perpendicular to the first PSD position sensor is obtained.

[0033] Control the first PSD position sensor to move to the fourth position along the normal direction of the laser measurement plane, and record the moving distance of the first PSD position sensor as the second moving distance T;

[0034] Based on the fourth position signal of the laser position detected by the first PSD position sensor when it is in the fourth position, the distance P4 between the fourth position signal and the coordinate axis perpendicular to the first PSD position sensor is obtained.

[0035] Based on distances P3 and P4 and the second moving distance T, the pitch angle deviation between the laser interferometer host and the first pyramidal reflector is calculated.

[0036] Optionally, in some embodiments of the present invention, the method includes: calculating the pitch angle deviation between the laser interferometer host and the first pyramidal reflector based on the following equations, according to distance P3, distance P4 and the second moving distance T;

[0037] Wherein, P3 is the distance between the third position signal of the laser position detected by the first PSD position sensor when it is in the third position and the coordinate axis perpendicular to the first PSD position sensor;

[0038] P4 is the distance between the fourth position signal of the laser position detected by the first PSD position sensor when it is in the fourth position and the coordinate axis perpendicular to the first PSD position sensor.

[0039] T is the first moving distance of the first PSD position sensor when it moves from the third position to the fourth position;

[0040] φ represents the pitch angle deviation.

[0041] Optionally, in some embodiments of the present invention, the invention includes:

[0042] Establish a coordinate system with the center of the first PSD position sensor plane.

[0043] Control the first PSD position sensor to move along the direction of the laser beam, select n points during the movement, and obtain the third detection signal of the laser at each point where the first PSD position sensor is located;

[0044] Based on multiple third detection signals, the perpendicular distances between these signals and the quadrant axis parallel to the laser beam direction are arranged sequentially, and the values ​​of these perpendicular distances are obtained as H1, H2, H3, ..., H... n ;

[0045] Based on multiple fourth detection signals, the perpendicular distances between these signals and the quadrant axis parallel to the laser beam direction are arranged sequentially, and the values ​​of the perpendicular distances between these third detection signals and the quadrant axis parallel to the laser beam direction are obtained as V1, V2, V3, ..., V n .

[0046] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects:

[0047] The present application provides an adjustment device and method for a laser interferometer, which, by designing a laser interferometer mounting and adjustment mechanism and combining manual and automatic adjustment mechanisms, provides a hardware solution for the automated adjustment of the laser interferometer.

[0048] By combining a first PSD position sensor and a second PSD position sensor, the laser optical path is detected, enabling rapid installation and calibration between the laser interferometer and the interferometer mirror.

[0049] By running a predetermined detection path and combining the optical path position information from the first PSD position sensor and the second PSD position sensor, the spatial position and attitude of the laser optical path are identified and calculated, and corresponding adjustment parameters are given.

[0050] By performing least squares fitting analysis on the results of multi-point position detection, the optimal direction vector of the laser interferometer's output light in space is solved, eliminating the systematic error of the laser measurement system itself and reducing the influence of Abbe error and cosine error on the laser measurement system. Attached Figure Description

[0051] Figure 1 A flowchart illustrating the collimation adjustment process of a laser interferometer measurement system provided in an embodiment of the present invention;

[0052] Figure 2 This is a schematic diagram of the automatic collimation adjustment mechanism of the laser interferometer measurement system provided in an embodiment of the present invention;

[0053] Figure 3 This is a schematic diagram illustrating the adjustment and calibration principle of the laser interferometer host provided in an embodiment of the present invention.

[0054] Figure 4 This is a schematic diagram of laser interferometer movement error adjustment provided in an embodiment of the present invention;

[0055] Figure 5 This is a schematic diagram of laser interferometer yaw error adjustment provided in an embodiment of the present invention;

[0056] Figure 6 This is a schematic diagram of the elevation error adjustment of a laser interferometer provided in an embodiment of the present invention.

[0057] Icons: 1-Two-degree-of-freedom plane adjustment mechanism, 2-Two-degree-of-freedom swing angle adjustment mechanism, 3-Adjustment platform, 4-Manual fine-tuning gimbal, 5-Laser interferometer host, 6-First PSD position sensor, 7-Second PSD position sensor, 8-First beam splitter, 9-Second beam splitter, 10-First pyramidal reflector, 11-Second pyramidal reflector.

[0058] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0059] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0060] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0061] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0062] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0063] Reference Figure 2 The first embodiment of the present invention provides an adjustment device for a laser interferometer, including an adjustment mechanism, an adjustment platform 3, a first PSD position sensor 6, a second PSD position sensor 7, a first beam splitter 8, a second beam splitter 9, a first pyramidal reflector 10, and a second pyramidal reflector 11;

[0064] It also includes a manual fine-tuning gimbal 4, which is mounted on top of the adjustment platform 3, and the laser interferometer main unit 5 is mounted on top of the manual fine-tuning gimbal 4;

[0065] The adjustment mechanism includes a two-degree-of-freedom planar adjustment mechanism 1 and a two-degree-of-freedom swing angle adjustment mechanism 2.

[0066] In this embodiment, the two-degree-of-freedom plane adjustment mechanism 1 is placed on the bottom surface or other platform, and the two-degree-of-freedom swing angle adjustment mechanism 2 is fixedly installed on the top of the two-degree-of-freedom plane adjustment mechanism 1. The adjustment platform 3 is installed on the top of the two-degree-of-freedom swing angle adjustment mechanism 2, and the laser interferometer host 5 is fixedly installed on the top of the adjustment platform 3. The two-degree-of-freedom plane adjustment mechanism 1 controls the adjustment platform 3 to drive the laser interferometer host 5 to calibrate the swing deviation, and the two-degree-of-freedom swing angle adjustment mechanism 2 controls the adjustment platform 3 to drive the laser interferometer host 5 to calibrate the pitch deviation.

[0067] The first beam splitter 8 and the second beam splitter 9 are also installed on the top of the adjustment platform 3. The first beam splitter 8 and the first pyramidal reflector 10 are arranged sequentially along the direction of the laser emitted by the laser interferometer host 5. The first pyramidal reflector 10 is installed on the machine tool and can move along the direction of the laser emitted by the laser interferometer host 5. The second beam splitter 9 is installed above the first beam splitter 8. The second PSD position sensor 7 is installed above the second beam splitter 9. The first PSD position sensor 6 is installed below the first beam splitter 8.

[0068] The first PSD position sensor 6, the second PSD position sensor 7, the first beam splitter 8, the second beam splitter 9, the first pyramidal reflector 10, and the second pyramidal reflector 11 can be in an ideal collimated state after adjustment. That is, the position signal collected by the first PSD position sensor 6 is at the origin of the optical target of the first PSD position sensor 6, and the position signal collected by the second PSD position sensor 7 is at the origin of the optical target of the second PSD position sensor 7.

[0069] Optionally, in this embodiment, the angle of the corner bevel reflector is 90°, and the beam splitter is installed at an angle of 45° to the ideal laser beam path. This facilitates the calculation of the propagation path of the laser beam path and the beam path position information detected by the first PSD position sensor 6 and the second PSD position sensor 7 based on the angle parameters of the laser interferometer mirror group.

[0070] As an optional implementation method, refer to Figure 2 The second embodiment of the present invention provides a specific structure of an adjustment device for a laser interferometer, comprising:

[0071] The manual gimbal is installed on the adjustment platform 3. The manual fine-tuning gimbal 4 is connected to the adjustment platform 3 through a quick-connect coupling. The quick-connect coupling enables the manual fine-tuning gimbal 4 to be quickly connected, and the positioning surface on the quick-connect coupling enables the installation and positioning of the manual fine-tuning gimbal 4.

[0072] Quick-connect couplings are a broad term for industrial product accessories, categorized into hydraulic pipeline quick-connect couplings and excavator quick-connect couplings. Excavator quick-connect couplings, also known as fast connectors or quick couplings, allow for the rapid installation of various components (buckets, rippers, breakers, hydraulic shears, etc.) on excavators, expanding their application range, saving time, and improving efficiency.

[0073] Based on the hardware environment of the foregoing embodiments, embodiments of this application provide an adjustment method for the adjustment device of a laser interferometer, such as... Figure 1 As shown, the method includes:

[0074] First, install the automatic adjustment platform 3 for fixing the laser interferometer. After completing the installation and calibration of the laser interferometer main unit 5, install and fix the second fixed pyramidal reflector on the end face of the machine tool spindle.

[0075] The position of the automatic adjustment platform 3 or the machine tool coordinate axis can be manually adjusted to ensure that both PSD sensors have position detection signals. Once both the first PSD position sensor 6 and the second PSD position sensor 7 have light position detection signals input, the automatic alignment mode can be activated.

[0076] Specifically, when both the first PSD position sensor 6 and the second PSD position sensor 7 receive light position detection signals, the specific implementation method of this step is as follows: Figure 3 As shown, the laser interferometer host 5 emits an incident laser. After passing through the first beam splitter 8, the incident laser is split into a first refracted laser perpendicular to the incident laser direction and a second incident laser moving along the incident laser direction. The second incident laser hits the first pyramidal reflector 10 and is reflected by the first pyramidal reflector 10 to form the first reflected laser. The first reflected laser passes through the first beam splitter 8 again and is split into a second refracted laser and a third reflected laser. The second refracted laser hits the first PSD position sensor 6 and activates the first PSD position sensor. When the device 6 detects the position signal, the third reflected laser is reflected back to the laser interferometer host 5. The first refracted laser moves along a direction perpendicular to the incident laser, passes through the second beam splitter 9, is reflected by the second pyramidal reflector 11 to form the second reflected laser, and is reflected back to the second beam splitter 9. The second beam splitter 9 splits the laser into the third reflected laser and the third refracted laser. The third refracted laser hits the second PSD position sensor 7 and makes the second PSD position sensor 7 detect the position signal. The third reflected laser is irradiated by the first beam splitter 8 and then merges with the third reflected laser and is reflected back to the laser interferometer host 5.

[0077] Figure 4 This is a schematic diagram of adjusting the movement error of a laser interferometer. When an error is found during the calibration of the laser interferometer, the first pyramidal reflector 10 is moved to the optimal position so that the reflected light can be sent back to the laser receiving component of the laser interferometer host 5. At this time, the movement error of the laser interferometer can be adjusted according to the detection signal of the first PSD position sensor 6.

[0078] In response to the collimation start signal, the first detection signal of the first PSD position sensor 6 is acquired. Based on the first detection signal, the yaw angle deviation between the laser interferometer host 5 and the first pyramidal reflector 10 is calculated, and the yaw deviation is calibrated based on the yaw angle deviation.

[0079] In the specific implementation of the yaw deviation calibration, when there is a yaw angle deviation in the laser interferometer's light path, the schematic diagram of the incident and outgoing light rays of the first pyramidal reflector 10 is as follows: Figure 5 As shown, the specific implementation process for adjusting the yaw angle deviation is as follows:

[0080] S1: When the first pyramidal reflector 10 is in the first position, the detection signal of the first PSD position sensor 6 is recorded as the first position P1;

[0081] S2: Move the first pyramidal reflector 10 on the spindle end face backward a certain distance to the second position P2, ensuring that the detection signal of the first PSD position sensor 6 is not lost during the machine tool movement. Record the moving distance between P1 and P2 and the detection signal of the first PSD position sensor 6 at the first position as the second position P2;

[0082] Among them, the distance between P1 and P2 should be as small as possible. Specifically, the minimum moving distance can be determined based on the positional accuracy and resolution of the PSD sensor.

[0083] S3: Based on the geometric relationship of the light propagation path, at the two positions, the difference in the path length of the laser light path in the target mirror in the plane perpendicular to the measurement plane is: (P2-P1) / cos2θ, where θ is the yaw angle deviation.

[0084] S4: At two different positions, the difference between the distance between the laser's landing point on the target mirror and the distance between the center of the target mirror on the measurement plane is: (P2-P1) / cos2θ×cos(pi / 4+θ).

[0085] S5: Based on the geometric relationship of the light propagation path, we know that: The deviation of the yaw angle can be calculated based on the above equation.

[0086] Wherein, P1 is the distance between the first position signal of the laser position detected by the first PSD position sensor 6 when it is in the first position and the coordinate axis perpendicular to the first PSD position sensor 6;

[0087] P2 is the distance between the second position signal of the laser position detected by the first PSD position sensor 6 when it is in the second position and the coordinate axis perpendicular to the first PSD position sensor 6;

[0088] D is the first moving distance of the first PSD position sensor 6 when it moves from the first position to the second position;

[0089] θ represents the yaw angle deviation.

[0090] S6: After the automatic adjustment platform 3 adjusts the corresponding yaw angle according to the calculated yaw angle deviation, the adjustment platform 3 translates along the direction perpendicular to the laser beam so that the position signal of the first PSD position sensor 6 returns to the quadrant axis parallel to the laser beam direction, thus completing the calibration of the yaw deviation.

[0091] After the yaw deviation calibration of the laser interferometer is completed, record the position coordinates of the initial position (first position) in the CNC machine tool coordinate system.

[0092] In response to the collimation start signal, the second detection signal of the first PSD position sensor 6 is acquired. Based on the second detection signal, the pitch angle deviation between the laser interferometer host 5 and the first pyramidal reflector 10 is calculated, and the pitch deviation is calibrated based on the pitch angle deviation.

[0093] In the specific implementation of pitch deviation calibration, when there is a pitch angle deviation in the laser interferometer's light path, the schematic diagram of the incident and outgoing light rays of the first pyramidal reflector 10 is as follows: Figure 6 As shown, the specific implementation process for adjusting the pitch angle deviation is as follows:

[0094] S1: When the first pyramidal reflector 10 is in the third position (which can coincide with the first position), record the detection signal of the first PSD position sensor 6 as the third position P3;

[0095] S2: Control the CNC machine tool to move the first pyramidal reflector 10 along the normal direction of the laser measurement plane until the position detected by the first PSD position sensor 6 reaches the preset point. This preset point is regarded as the fourth position. At this time, the laser beam shines directly on the center of the first pyramidal reflector 10. Record the moving distance T of the CNC machine tool. The detection signal of the first PSD position sensor 6 at the fourth position is the fourth position P4.

[0096] S3: Based on the geometric relationship of the light propagation path, we know that: The pitch angle deviation φ can be calculated using the above equation.

[0097] Wherein, P3 is the distance between the third position signal of the laser position detected by the first PSD position sensor 6 when it is in the third position and the coordinate axis perpendicular to the first PSD position sensor 6.

[0098] P4 is the distance between the fourth position signal of the laser position detected by the first PSD position sensor 6 when it is in the fourth position and the coordinate axis perpendicular to the first PSD position sensor 6.

[0099] T is the first moving distance of the first PSD position sensor 6 when it moves from the third position to the fourth position;

[0100] φ represents the pitch angle deviation.

[0101] S4: After the automatic adjustment platform 3 adjusts the pitch angle according to the calculated pitch angle deviation, the automatic adjustment platform 3 translates along the direction of the vertical laser beam so that the position signal detected by the first PSD position sensor 6 returns to the quadrant axis of the direction of the vertical laser beam, thus completing the calibration of the pitch deviation.

[0102] In this embodiment, the order of adjusting the yaw deviation or the pitch deviation can be interchanged.

[0103] After the first PSD position sensor 6 is reset, it is moved along the direction of the laser beam to obtain the values ​​of the horizontal distance and the vertical distance between the laser and the vertical quadrant axis of the first PSD position sensor 6.

[0104] After adjusting the yaw and pitch deviations, the first PSD position sensor 6 is returned to its initial position, i.e., the first position. Using the machine tool coordinate system as the reference coordinate system, it moves along the laser beam direction, selecting n points to record multiple detection signals from the first PSD position sensor 6. These multiple detection signals are then arranged sequentially, and the vertical distances between the multiple detection signals and the quadrant axis parallel to the laser beam direction are obtained as H1, H2, H3, ..., H... n The vertical distances between the multiple detection signals and the quadrant axis perpendicular to the laser beam direction are V1, V2, V3, ..., V n .

[0105] For H1, H2, H3, ..., H n and V1, V2, V3, ..., V n By matching one-to-one and performing least squares fitting, the optimal spatial vector direction of the laser interferometer's output light is obtained by SVD decomposition of the combined yaw and pitch deviations.

[0106] After the vector direction of the laser emitted by the laser interferometer host 5 is adjusted, the automatic adjustment platform 3 is moved in two directions perpendicular to the laser beam to bring the position signal of the first PSD position sensor 6 back to the quadrant axis of the first PSD position sensor 6, thus completing the initial calibration and the collimation calibration of the laser interferometer.

[0107] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. An adjustment device for a laser interferometer, characterized in that: It includes an adjustment mechanism, an adjustment platform, a first PSD position sensor, a second PSD position sensor, a first beam splitter, a second beam splitter, a first pyramidal reflector, and a second pyramidal reflector; The adjustment platform is movably mounted on the adjustment mechanism, which includes a two-degree-of-freedom planar adjustment mechanism and a two-degree-of-freedom swing angle adjustment mechanism. The two-degree-of-freedom swing angle adjustment mechanism is mounted on the two-degree-of-freedom planar adjustment mechanism, and the adjustment platform is mounted on the two-degree-of-freedom swing angle adjustment mechanism. The adjustment platform has four degrees of freedom and is used to mount the laser interferometer main unit. The first PSD position sensor, the second PSD position sensor, the first beam splitter, the second beam splitter, the first pyramidal reflector, and the second pyramidal reflector are all mounted on the adjustment platform. The two PSD sensors are used to detect position signals. After light position detection signals are input to both the first PSD position sensor and the second PSD position sensor, the automatic collimation mode is activated, so that when the laser interferometer host is mounted on the adjustment platform, the first PSD position sensor, the second PSD position sensor, the first beam splitter, the second beam splitter, the first pyramidal reflector, and the second pyramidal reflector can be in an ideal collimated state after adjustment.

2. The adjustment device for a laser interferometer as described in claim 1, characterized in that: It also includes a manually adjustable gimbal, which is mounted on top of the adjustment platform, and the laser interferometer main unit is mounted on top of the manually adjustable gimbal.

3. The adjustment device for a laser interferometer as described in claim 2, characterized in that: The manual fine-tuning gimbal is connected to the adjustment platform via a quick-connect coupling.

4. An adjustment method for the adjustment device of a laser interferometer according to any one of claims 1-3, characterized in that, The method includes: In response to the collimation start signal, the first detection signal of the first PSD position sensor is acquired. Based on the first detection signal, the yaw angle deviation between the laser interferometer host and the first corner cube reflector is calculated, and the yaw deviation is calibrated based on the yaw angle deviation. The first detection signal includes a first position signal when the first PSD position sensor is located at a first position and a second position signal when the first PSD position sensor is located at a second position. In response to the collimation start signal, the second detection signal of the first PSD position sensor is acquired. Based on the second detection signal, the pitch angle deviation between the laser interferometer host and the first corner cube reflector is calculated, and the pitch deviation is calibrated based on the pitch angle deviation. The second detection signal includes a third position signal when the first PSD position sensor is in the third position and a fourth position signal when the first PSD position sensor is in the fourth position. After the first PSD position sensor is reset, it is moved along the laser beam direction to obtain the values ​​of the distance between the laser and the first PSD position sensor in the quadrant axis parallel to the laser beam direction and the distance between the first PSD position sensor and the quadrant axis perpendicular to the laser beam direction. The target spatial vector direction of the laser interferometer's outgoing light is obtained by performing least squares fitting on multiple sets of corresponding horizontal and vertical distance values. Based on the target spatial vector direction, the offset deviation between the target spatial vector direction and the laser emission direction is obtained, and the laser emission direction is adjusted according to the offset deviation.

5. The adjustment method of the adjustment device for a laser interferometer as described in claim 4, characterized in that, The step of calculating the yaw angle deviation between the laser interferometer host and the first pyramidal reflector based on the first detection signal includes: Based on the first position signal of the laser position detected when the first PSD position sensor is in the first position, the distance P1 between the detection signal and the coordinate axis perpendicular to the first PSD position sensor is obtained; The first PSD position sensor is controlled to move to a second position along an axial direction away from the adjustment platform, and the moving distance of the first PSD position sensor is recorded as the first moving distance D; Based on the second position signal of the laser position detected when the first PSD position sensor is in the second position, the distance P2 between the detection signal and the coordinate axis perpendicular to the first PSD position sensor is obtained; Based on the distances P1 and P2 and the first moving distance D, the yaw angle deviation between the laser interferometer host and the first pyramidal reflector is calculated.

6. The adjustment method of the adjustment device for a laser interferometer as described in claim 5, characterized in that, The step of calculating the pitch angle deviation between the laser interferometer host and the first pyramidal reflector based on the distance P1, the distance P2 and the first moving distance D includes: Based on the following set of equations, the yaw angle deviation between the laser interferometer host and the first pyramidal reflector is calculated according to the distance P1, the distance P2 and the first moving distance D; Wherein, P1 is the distance between the first position signal of the laser position detected by the first PSD position sensor when it is in the first position and the coordinate axis perpendicular to the first PSD position sensor; P2 is the distance between the second position signal of the laser position detected by the first PSD position sensor when it is in the second position and the coordinate axis perpendicular to the first PSD position sensor; D is the first moving distance of the first PSD position sensor when it moves from the first position to the second position; This refers to the deviation in the yaw angle.

7. The adjustment method of the adjustment device for a laser interferometer as described in claim 4, characterized in that, The step of calculating the pitch angle deviation between the laser interferometer host and the first pyramidal reflector based on the second detection signal includes: Based on the third position signal of the laser position detected when the first PSD position sensor is in the third position, the distance P3 between the detection signal and the coordinate axis perpendicular to the first PSD position sensor is obtained. The first PSD position sensor is controlled to move to the fourth position along the normal direction of the laser measurement plane, and the moving distance of the first PSD position sensor is recorded as the second moving distance T; Based on the fourth position signal of the laser position detected when the first PSD position sensor is in the fourth position, the distance P4 between the fourth position signal and the coordinate axis perpendicular to the first PSD position sensor is obtained. Based on the distances P3 and P4 and the second moving distance T, the pitch angle deviation between the laser interferometer host and the first pyramidal reflector is calculated.

8. The adjustment method of the adjustment device for a laser interferometer as described in claim 7, characterized in that, The step of calculating the pitch angle deviation between the laser interferometer host and the first pyramidal reflector based on the distance P3, the distance P4, and the second moving distance T includes: Based on the following equations, the pitch angle deviation between the laser interferometer host and the first pyramidal reflector is calculated according to the distance P3, the distance P4 and the second moving distance T; Wherein, P3 is the distance between the third position signal of the laser position detected by the first PSD position sensor when it is in the third position and the coordinate axis perpendicular to the first PSD position sensor; P4 is the distance between the fourth position signal of the laser position detected by the first PSD position sensor when it is in the fourth position and the coordinate axis perpendicular to the first PSD position sensor. T is the first moving distance of the first PSD position sensor when it moves from the third position to the fourth position; This refers to the pitch angle deviation.

Images