Miniature rotary encoder calibration device based on double-grating interference

Abstract

The utility model discloses a miniature rotary encoder calibration device based on double-grating interference, which comprises a double-grating homodyne interference calibration system, a micro-vibration displacement table, a miniature rotary encoder and a receiving system, the double-grating homodyne interference calibration system comprises a single-frequency laser light source, two self-tracing grating interference light paths and a photoelectric receiving device, the two self-tracing grating interference light paths are arranged on the two sides of the micro-vibration displacement table respectively, a mechanical vibration module provided with two grating adjusting devices is arranged in the middle of a displacement base of the micro-vibration displacement table, and a micro rotary encoder is arranged between two gratings. The grating adjusting devices are spliced with one grating adjusting device and are in circuit connection with the single-chip microcomputer control module, and the single-chip microcomputer control module receives target parameter information input by an upper computer to control the rotary encoder, drives the micro-vibration displacement table to continuously vibrate in the vector direction and drives the grating to rotate by a set angle, so that high-precision calibration of the micro rotary encoder is realized; the method can be traced to the definition of'meter ', and is high in stability, short in traceability chain and high in robustness.

Description

Technical Field

[0001] This utility model relates to a calibration device for rotary encoders, and in particular discloses a micro rotary encoder calibration device based on dual grating interference, which is specifically applied in the field of optical precision calibration. Background Technology

[0002] A rotary encoder is a mechanical device that converts angular displacement into electrical signals. It is widely used in various automated servo motors, such as moving parts on industrial automation production lines, robotic arms in medical equipment, and turbine control systems in aerospace vehicles. With the continuous miniaturization of integrated circuit characteristic parameters and the size of machined parts, as well as the integration of ultra-precision instruments, rotary encoders are also gradually becoming miniaturized and more precise. Accurate angular displacement calibration of miniature rotary encoders is crucial to ensuring their high precision and reliability. However, there are currently no clear and fixed standards for the calibration of miniature rotary encoders. Therefore, the availability of devices with high-precision online calibration capabilities and corresponding calibration methods remain unresolved technical issues. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention provides a micro rotary encoder calibration device based on dual-grating interference. By combining a dual-grating zero-difference interference calibration system with a micro-vibration displacement stage, it achieves precise calibration of the micro rotary encoder. This not only ensures calibration accuracy but also reduces production costs. Furthermore, it can be applied to other equipment requiring high-precision displacement calibration.

[0004] This invention is implemented as follows: A micro rotary encoder calibration device based on dual-grating interference includes a dual-grating zero-difference interference calibration system, a micro-vibration displacement stage, a micro rotary encoder, and a receiving system. The dual-grating zero-difference interference calibration system includes a single-frequency laser source, a first self-traceable grating interference optical path and a second self-traceable grating interference optical path positioned on either side of the micro-vibration displacement stage, and a photoelectric receiving device for receiving signals from the two self-traceable grating interference optical paths. The light source, after passing through the transmission and reflection surfaces of a polarizing beam splitter, forms the incident light source for the two self-traceable grating interference optical paths. The photoelectric receiving device described above is used to convert the received optical signal into a digital signal. A mechanical vibration module is provided at the middle position of the displacement base of the micro-vibration displacement stage. Two grating adjustment devices are provided above the mechanical vibration module. Each grating adjustment device includes a grating fixing frame installed on the grating adjustment frame. The grating fixing frame is used to clamp the grating. The grating adjustment frame is used to adjust the position and posture of the grating. The micro rotary encoder and the micro rotary encoder in the receiving system are located between the two gratings and are spliced ​​with one of the two grating adjustment devices. They are also connected to the single-chip microcomputer control module circuit. The single-chip microcomputer control module is connected to the host computer via a universal serial bus.

[0005] The microcontroller control module is used to receive target parameter information input from the host computer and then control the rotary encoder, and drive the micro-vibration displacement stage to vibrate continuously along the vector direction. The micro-vibration displacement stage drives the grating to rotate perpendicular to the movement direction of the micro-vibration displacement stage by a set angle. The host computer is used to synchronously display and record the actual rotation cosine angle measurement value of the grating, and compare it with the standard value of the rotary encoder's engraving angle to determine whether the calibration of the micro rotary encoder is completed if it meets the standard value range.

[0006] The single-frequency laser source includes a driving power supply, a single-frequency laser, an optical fiber patch cord, and an optical fiber connector. One end of the optical fiber patch cord is connected to the corresponding interface of the single-frequency laser, and the other end is inserted into the matching optical fiber connector and locked. The single-frequency laser outputs 405 nm linearly polarized light, which is coupled to the optical fiber connector via the optical fiber patch cord. The optical fiber connector is used to provide the light source with a multi-degree-of-freedom propagation direction and is mounted on an optical air-bearing platform using a connecting rod.

[0007] The photoelectric receiving device includes two photodetectors, a data acquisition card and a signal processing system connected to the two photodetectors in a circuit. The photodetectors are used to convert the received optical interference signal into an electrical signal in real time and transmit it to the signal processing system through the data acquisition card.

[0008] The two grating adjustment devices are used to adjust the clamped double gratings to keep them relatively parallel, while ensuring that the double gratings are parallel to the micro-vibration displacement stage along the vector motion direction.

[0009] The micro-vibration displacement stage is connected to the displacement stage drive system via a communication cable. The vibration digital signal of the target parameter information input from the host computer is converted into a voltage signal through a signal generator to drive the micro-vibration displacement stage to vibrate continuously along the vector direction.

[0010] The first self-traceable grating interference optical path sequentially includes a first half-wave plate, a second reflector, and a second polarizing beam splitter. After the second polarizing beam splitter, it splits into two paths: one path consists of a first quarter-wave plate and a fourth reflector, and the other path consists of a second quarter-wave plate and a fifth reflector. The second self-traceable grating interference optical path sequentially includes a second half-wave plate, a third reflector, and a third polarizing beam splitter. After the third polarizing beam splitter, it splits into two paths: one path consists of a third quarter-wave plate and a sixth reflector, and the other path consists of a fourth quarter-wave plate and a seventh reflector. The photoelectric receiving device includes a first photodetector and a second photodetector. The first photodetector is located outside the first self-traceable grating interference optical path and is coaxial with the second polarizing beam splitter. The second photodetector is located outside the second self-traceable grating interference optical path and is coaxial with the third polarizing beam splitter. Each component in the optical path is mounted on an optical air-bearing platform using its corresponding connecting rod and clamp.

[0011] Linearly polarized light output from a single-frequency laser is proportionally split into two beams by the transmission and reflection surfaces of a polarizing beam splitter. These beams then enter two self-traceable grating interference paths. The beam in the first self-traceable grating interference path passes sequentially through a half-wave plate, a mirror, and the polarizing beam splitter before being split into two beams again. These two beams then pass sequentially through a quarter-wave plate and a mirror before being incident on the corresponding grating surfaces and undergoing diffraction.

[0012] The second self-traceable grating interference optical path structure and beam propagation path are the same as the first self-traceable grating interference optical path. The four beams that are finally incident on the corresponding grating surface all use the Littrow angle to be incident on the grating. The diffracted light returns along the original path and merges to cause interference, and the optical interference signal is collected by the photoelectric receiving device.

[0013] The beneficial effects of this invention are as follows: This invention is a high-precision online calibration device for miniature rotary encoders. It combines a dual-grating zero-difference interferometric calibration system with a micro-vibration displacement stage, effectively achieving high-precision calibration of miniature rotary encoders. This invention can trace back to the definition of "meter" through the grating period, and features high stability, short traceability chain, and strong robustness. It provides a new solution for the development of calibration instruments and corresponding calibration methods for miniature rotary encoders. Furthermore, the overall structure of this invention adopts a modular design, with each module component designed as an independent individual placed on an optical air-bearing platform, enabling rapid disassembly and assembly of each module component, thus improving calibration efficiency. Attached Figure Description

[0014] Figure 1 This is a simplified schematic diagram of the structure of this utility model.

[0015] Figure 2 This is a three-dimensional structural schematic diagram of the present invention.

[0016] Figure 3 This is a schematic diagram of the optical path propagation of this utility model.

[0017] Figure 4 This is a schematic diagram showing the installation structure relationship between the grating adjustment device and the micro-vibration displacement stage in this utility model.

[0018] In the diagram: 1. Dual-grating zero-difference interferometry calibration system; 2. Micro-vibration displacement stage; 3. Miniature rotary encoder and receiving system; 4. Optical air-bearing stage; 5. Single-frequency laser; 6. Fiber optic patch cord; 7. Fiber optic connector; 8. First reflector; 9. Second reflector; 10. Third reflector; 11. Fourth reflector; 12. Fifth reflector; 13. Sixth reflector; 14. Seventh reflector; 15. First polarizing beam splitter; 16. Second polarizing beam splitter; 17. Third polarizing beam splitter; 18. First half-wave plate; 19. Second half-wave plate; 20. First quarter-wave plate; 21. Second quarter-wave plate; 22. Third quarter-wave plate; 23. Fourth quarter-wave plate; 24. First photodetector; 25. Second photodetector; 26. Connecting rod; 27. Gripper; 28. Fastening bolt; 29. ​​Host computer;

[0019] 101. Laser source; 102. First self-traceable grating interference optical path; 103. Second self-traceable grating interference optical path; 104. Photoelectric receiving device;

[0020] 201. Grating adjustment bracket; 202. Grating fixing bracket; 203. First self-traceable grating; 204. Second self-traceable grating; 205. Displacement base; 206. Mechanical vibration module; 207. Rectangular block; 208. Shorting rod; 209. Fixing screw; 210. Through hole; 211. Small gripper; 212. Hex bolt;

[0021] 301. Miniature rotary encoder; 302. Microcontroller control module. Detailed Implementation

[0022] The technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings.

[0023] According to the appendix Figure 1 As shown, this utility model is a micro rotary encoder calibration device based on dual grating interference, including: a dual grating zero-difference interference calibration system 1, a micro vibration displacement stage 2, and a micro rotary encoder and receiving system 3.

[0024] The dual-grating zero-difference interferometric calibration system 1 includes a single-frequency laser source 101, a first self-traceable grating interference optical path 102 and a second self-traceable grating interference optical path 103 arranged on both sides of the micro-vibration displacement stage 2, and a photoelectric receiving device 104 for receiving signals from the two self-traceable grating interference optical paths. The light source is formed into the incident light source of the two self-traceable grating interference optical paths after passing through the transmission surface and the reflection surface of the polarization beam splitter, respectively. The photoelectric receiving device converts the received optical signal into a digital signal.

[0025] According to the appendix Figure 2 With appendix Figure 4The micro-vibration displacement stage 2 has a mechanical vibration module 206 located in the middle of the displacement base 205. Two grating adjustment devices are located above the mechanical vibration module 206. The two grating adjustment devices are respectively located on two identical rectangular blocks 207. The rectangular blocks 207 are connected and fixed to the mechanical vibration module 206 by two connecting short rods 208. The two connecting short rods 208 are clamped by their respective small claws 211, and the fixing screws are screwed into the through holes 210 of the mechanical vibration module 206 to achieve a fixed connection between the connecting short rods 208 and the mechanical vibration module 206. Grating adjustment frames 201 are respectively arranged above the two rectangular blocks 207 and are respectively connected and fixed by hexagonal bolts 212. The two grating adjustment frames 201 are arranged back to back, and grating fixing frames 202 are respectively installed on the side. The first self-traceable grating 203 and the second self-traceable grating 204 are respectively clamped by the two grating fixing frames 202.

[0026] The micro rotary encoder 301 in the micro rotary encoder and receiving system 3 is located between two self-traceable gratings and is spliced ​​with one of the two grating adjustment devices, and is connected to the single-chip microcomputer control module 302 circuit.

[0027] According to the appendix Figure 2 As a technical optimization of this utility model, the overall structure of the dual-grating interference micro rotary encoder calibration device adopts a modular design. Each module component is designed as an independent individual and placed on the optical air-bearing platform 4, so as to realize the quick disassembly and assembly of each module component.

[0028] Reference Appendix Figure 2 With appendix Figure 4As an optimized solution of this utility model, the single-frequency laser source 101 includes a single-frequency laser 5, an optical fiber patch cord 6, and an optical fiber connector 7. One end of the optical fiber patch cord 6 is connected to the corresponding interface of the single-frequency laser 5, and the other end is inserted into the matching optical fiber connector 7 and locked. The optical fiber connector 7 is used to provide the light source with a multi-degree-of-freedom propagation direction. The first self-traceable grating interference optical path 102 sequentially includes a first half-wave plate 18, a second reflector 9, and a second polarizing beam splitter 16. After the second polarizing beam splitter 16, it splits into two paths: one path consists of a first quarter-wave plate 20 and a fourth reflector 11, and the other path consists of a second quarter-wave plate 21 and a fifth reflector 12. The second self-traceable grating interference optical path 103 sequentially includes a second half-wave plate 19, a third reflector 10, and a third polarizing beam splitter 17. After the third polarizing beam splitter 17, it splits into two paths: one path consists of a third quarter-wave plate 22 and a sixth reflector 13, and the other path consists of a fourth quarter-wave plate 23 and a seventh reflector 14. The photoelectric receiving device 104 includes a first photodetector 24 and a second photodetector 25, as well as a data acquisition card and a signal processing system connected to the two photodetectors. The photodetectors are used to convert the received optical interference signal into an electrical signal in real time and transmit it to the signal processing system through the data acquisition card. The first photodetector 24 is located outside the first self-traceable grating interference optical path 102 and is coaxial with the second polarizing beam splitter 16. The second photodetector 25 is located outside the second self-traceable grating interference optical path 103 and is coaxial with the third polarizing beam splitter 17.

[0029] As an optimized solution of this utility model, a first polarizing beam splitter 15 is used to form two incident beams of self-tracing grating interference light paths from the single-frequency laser source 101 after passing through a transmission surface and a reflection surface. The transmission surface is coaxially arranged with the incident surfaces of the first half-wave plate 18 and the second reflecting mirror 9, and the reflection surface is coaxially arranged with the incident surfaces of the second half-wave plate 19 and the third reflecting mirror 10. The transmission surface of the second polarizing beam splitter 16 is coaxially arranged with the incident surfaces of the first quarter-wave plate 20, the fourth reflecting mirror 11, and the receiving surface of the first photodetector 24, while the reflection surface is coaxially arranged with the incident surfaces of the second quarter-wave plate 21 and the fifth reflecting mirror 12. The transmission surface of the third polarizing beam splitter 17 is coaxially arranged with the incident surfaces of the third quarter-wave plate 22, the sixth reflecting mirror 13, and the receiving surface of the second photodetector 25, while the reflection surface is coaxially arranged with the incident surfaces of the fourth quarter-wave plate 23 and the seventh reflecting mirror 14.

[0030] As an optimized solution of this utility model, the optomechanical components of the dual-grating zero-difference interference calibration system 1 are all mounted on the optical air-bearing stage 4 using connecting rods 26, and are fixed by clamps 27 at the bottom of the connecting rods 26 and fastening bolts 28.

[0031] As an optimized solution of this utility model, the micro-vibration displacement stage 2 is connected to the displacement stage drive system via a communication cable. The host computer 29 inputs the target parameters and issues vibration commands. The vibration digital signal is converted into a voltage signal by a signal generator. The microcontroller control module controls the rotary encoder according to the target parameter information received from the host computer and drives the micro-vibration displacement stage 2 to vibrate continuously along the vector direction, causing the grating spliced ​​with the micro rotary encoder to rotate at a certain angle perpendicular to the movement direction of the micro-vibration displacement stage 2. The host computer is used to synchronously display and record the actual rotation cosine angle measurement value of the grating and compare it with the standard value of the rotary encoder's engraving angle to determine the completion of the calibration of the micro rotary encoder if it meets the standard value range.

[0032] Reference Appendix Figures 1-4 The specific propagation process of the optical path of the dual-grating zero-difference interferometry calibration system 1 in conjunction with the micro-vibration displacement stage 2 is as follows:

[0033] In this embodiment, to make the layout of the various structural modules on the optical air-bearing stage 4 more reasonable and compact, a first reflecting mirror 8 is provided at the incident end of the first polarizing beam splitter 15. The first reflecting mirror 8 is also mounted on the optical air-bearing stage 4 using a connecting rod 26 and a clamp 27. The single-frequency laser 5 emits laser light, which is linearly polarized at 405 nm. After being coupled to the fiber optic connector 7 via the fiber optic jumper 6, it is incident on the first reflecting mirror 8. After being reflected by the first reflecting mirror 8, it enters the first polarizing beam splitter 15, where it is decomposed into a first horizontally polarized light and a first vertically polarized light. The first horizontally polarized light enters the first self-traceable grating interference optical path 102, and is reflected by the first half-wave plate 18 and the second reflecting mirror 9 to the second polarizing beam splitter 16, where it is decomposed into two polarized lights again. The second vertically polarized light passes through the first half-wave plate 18 and the second reflecting mirror 9. The fourth wave plate 20 and the fourth mirror 11 convert the light into left-hand circularly polarized light. The second horizontally polarized light is converted into right-hand circularly polarized light through the second quarter wave plate 21 and the fifth mirror 12. The left-hand and right-hand circularly polarized light are incident on the surface of the first self-traceable grating 203 at Littrow angle and diffract. The two -1st order diffracted lights return along the original path and converge at the second polarizing beam splitter 16 to form the optical interference signal of the first self-traceable grating 203, which is received by the first photodetector 24. The first vertically polarized light enters the interference optical path 103 of the second self-traceable grating, is reflected by the second half-wave plate 19 and the third mirror 10 to the third polarizing beam splitter 17, and is decomposed into two polarized lights again. The third vertically polarized light is converted into left-hand circularly polarized light by the third quarter-wave plate 22 and the sixth mirror 13, and the third horizontally polarized light is converted into right-hand circularly polarized light by the fourth quarter-wave plate 23 and the seventh mirror 14. The left-hand circularly polarized light and the right-hand circularly polarized light are incident on the surface of the second self-traceable grating 204 at the Littrow angle and diffract. The two -1st order diffracted lights return along the original path and converge at the third polarizing beam splitter 17 to form the optical interference signal of the second self-traceable grating 204, which is received by the second photodetector 25.

[0034] As an optimized solution of this utility model, the fast axis of the half-wave plate and the quarter-wave plate are both at an angle of 45° to the incident plane. The half-wave plate is used to make the polarization direction of the incident laser at 45° with the incident plane and to proportionally adjust the beam intensity of the first polarizing beam splitter 16. The quarter-wave plate is used to convert linearly polarized light into circularly polarized light.

[0035] As an optimized solution of this utility model, the grating adjustment frame 201 in the two grating adjustment device has a three-axis adjustment knob. By rotating the three-axis knob, the grating fixing frame 202 drives the first self-traceable grating 203 and the second self-traceable grating 204 to keep the grating lines parallel to the grating surface, and keep the vector motion direction of the two self-traceable gratings consistent with that of the micro-vibration displacement stage 2. Both self-traceable gratings are one-dimensional chromium self-traceable gratings with a grating spacing of 212.8 nm, which can be directly traced to the natural constant without measurement.

[0036] Reference Appendix Figures 1-3 The miniature rotary encoder and receiving system 3 consists of two parts: a miniature rotary encoder 301 and a microcontroller control system 302. The front rotating part of the miniature rotary encoder 301 is inserted into the corresponding interface of the grating fixing frame 202 of the first self-traceable grating 203, and the rear end is connected to the microcontroller control system 302 through a wire. The microcontroller control system 302 is connected to the host computer for communication through a USB serial port.

[0037] Although embodiments of the present invention have been shown and described, those skilled in the art will recognize that, based on the concept of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A calibration device for a miniature rotary encoder based on dual-grating interference, characterized in that: This includes a dual-grating zero-difference interferometry calibration system, a micro-vibration displacement stage, and a miniature rotary encoder and receiving system. The dual-grating zero-difference interferometry calibration system includes a single-frequency laser source, a first self-traceable grating interference optical path and a second self-traceable grating interference optical path positioned on either side of a micro-vibration displacement stage, and a photoelectric receiving device for receiving signals from the two self-traceable grating interference optical paths. The light source, after passing through the transmission and reflection surfaces of a polarizing beam splitter, forms the incident light source for the two self-traceable grating interference optical paths. The photoelectric receiving device converts the received optical signals into digital signals. The micro-vibration displacement stage has a mechanical vibration module located at the center of its displacement base. Above the mechanical vibration module are two grating adjustment devices. Each grating adjustment device includes a grating fixing frame mounted on a grating adjustment bracket. The grating fixing frame is used to clamp the grating, and the grating adjustment bracket is used to adjust the pose of the grating. The miniature rotary encoder in the receiving system is located between two gratings and is spliced ​​with one of the two grating adjustment devices. It is also connected to the microcontroller control module circuit. The microcontroller control module is connected to the host computer via a universal serial bus.

2. The micro rotary encoder calibration device based on dual-grating interference according to claim 1, characterized in that: The microcontroller control module is used to receive target parameter information input from the host computer and then control the rotary encoder, and drive the micro-vibration displacement stage to vibrate continuously along the vector direction. The micro-vibration displacement stage drives the grating to rotate perpendicular to the movement direction of the micro-vibration displacement stage by a set angle. The host computer is used to synchronously display and record the actual rotation cosine angle measurement value of the grating, and compare it with the standard value of the rotary encoder's engraving angle to determine whether the calibration of the micro rotary encoder is completed if it meets the standard value range.

3. The micro rotary encoder calibration device based on dual-grating interference according to claim 1, characterized in that: The single-frequency laser source includes a driving power supply, a single-frequency laser, an optical fiber patch cord, and an optical fiber connector. One end of the optical fiber patch cord is connected to the corresponding interface of the single-frequency laser, and the other end is inserted into the matching optical fiber connector and locked. The single-frequency laser outputs 405 nm linearly polarized light, which is coupled to the optical fiber connector via the optical fiber patch cord. The optical fiber connector is used to provide the light source with a multi-degree-of-freedom propagation direction and is mounted on an optical air-bearing platform using a connecting rod.

4. The micro rotary encoder calibration device based on dual-grating interference according to claim 1, characterized in that: The first self-traceable grating interference optical path sequentially includes a first half-wave plate, a second reflector, and a second polarizing beam splitter. After the second polarizing beam splitter, it splits into two paths: one path consists of a first quarter-wave plate and a fourth reflector, and the other path consists of a second quarter-wave plate and a fifth reflector. The second self-traceable grating interference optical path sequentially includes a second half-wave plate, a third reflector, and a third polarizing beam splitter. After the third polarizing beam splitter, it splits into two paths: one path consists of a third quarter-wave plate and a sixth reflector, and the other path consists of a fourth quarter-wave plate and a seventh reflector. The photoelectric receiving device includes a first photodetector and a second photodetector. The first photodetector is located outside the first self-traceable grating interference optical path and is coaxial with the second polarizing beam splitter. The second photodetector is located outside the second self-traceable grating interference optical path and is coaxial with the third polarizing beam splitter. Each component in the optical path is mounted on an optical air-bearing platform using its corresponding connecting rod and clamp.

5. The micro rotary encoder calibration device based on dual-grating interference according to claim 4, characterized in that: Linearly polarized light output from a single-frequency laser is proportionally split into two beams by the transmission and reflection surfaces of a polarizing beam splitter. These beams then enter two self-traceable grating interference paths. The beam in the first self-traceable grating interference path passes sequentially through a half-wave plate, a mirror, and the polarizing beam splitter before being split into two beams again. These two beams then pass sequentially through a quarter-wave plate and a mirror before being incident on the corresponding grating surfaces and undergoing diffraction.

6. The micro rotary encoder calibration device based on dual-grating interference according to claim 4, characterized in that: The second self-traceable grating interference optical path structure and beam propagation path are the same as the first self-traceable grating interference optical path. The four beams that are finally incident on the corresponding grating surface all use the Littrow angle to be incident on the grating. The diffracted light returns along the original path and merges to cause interference, and the optical interference signal is collected by the photoelectric receiving device.

7. The micro rotary encoder calibration device based on dual-grating interference according to claim 1 or 4, characterized in that: The photoelectric receiving device includes two photodetectors, a data acquisition card and a signal processing system connected to the two photodetectors in a circuit. The photodetectors are used to convert the received optical interference signal into an electrical signal in real time and transmit it to the signal processing system through the data acquisition card.

8. The micro rotary encoder calibration device based on dual-grating interference according to claim 1, characterized in that: The two grating adjustment devices are used to adjust the clamped double gratings to keep them relatively parallel, while ensuring that the double gratings are parallel to the micro-vibration displacement stage along the vector motion direction.

9. The micro rotary encoder calibration device based on dual-grating interference according to claim 1, 2, or 8, characterized in that: The micro-vibration displacement stage is connected to the displacement stage drive system via a communication cable. The vibration digital signal of the target parameter information input from the host computer is converted into a voltage signal through a signal generator to drive the micro-vibration displacement stage to vibrate continuously along the vector direction.

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