Dynamic angle measuring device

Abstract

The invention belongs to the technical field of dynamic angle measurement, and relates to a dynamic angle measurement device which comprises an integrated base, a rotary table, an annular laser gyroscope angle measurement unit, an adjustment fixture, a dynamic angle null unit and a control processing unit. The integrated base is arranged on the vibration isolation platform, a rotating part of the rotary table is connected with an annular laser gyroscope angle measurement unit arranged above the rotating part, the dynamic angle null unit comprises a sensitive module, and a target mirror of the sensitive module is arranged on the annular laser gyroscope angle measurement unit; the dynamic angle null unit further comprises a double-frequency laser-optical fiber coupling module and a measuring module, and a laser beam emitted by the double-frequency laser-optical fiber coupling module is emitted to the target mirror after passing through the measuring module; when the light emitted by the measuring module coincides with the direction of the reflected light passing through the target mirror, the dynamic angle null pointing unit emits null pointing pulses to the control processing unit, and the control processing unit starts to record the dynamic angle measured by the annular laser gyroscope angle measuring unit.

Description

Technical Field

[0001] The invention belongs to the technical field of dynamic angle measurement and relates to a dynamic angle measuring device. Background Art

[0002] Dynamic angle measurement is a major technological development direction for angle measurement to transcend static constraints and move towards universal measurement. Dynamic angle measurement involves the measurement of angular motion parameters and angular dynamic characteristics. This technology organically links the angle unit radian (rad) and the time unit second (s) to ensure that a series of key parameters such as angular velocity, angular acceleration rate, angular position measurement frequency response, harmonic distortion, etc. are accurately and reliably measured in typical applications such as aircraft control, multi-axis linkage of machine tools, and CT scanning. This technology plays an important basic guarantee role in the development of aerospace, high-end manufacturing, and precision medicine.

[0003] At present, the industry uses different methods for different dynamic angle measurements, such as circular grating angle measurement, autocollimation angle measurement, optical internal reflection small angle measurement, photoelectric shaft angle encoder angle measurement and laser interferometry. However, their common problems include:

[0004] 1. The circular grating angle measurement method and the photoelectric shaft angle encoder angle measurement method are prone to the problem of non-concentricity between the measuring axis and the rotating axis, resulting in a decrease in measurement accuracy. Although the laser interferometry method has very high measurement accuracy, it cannot achieve 360° full-circle measurement.

[0005] 2. Traditional dynamic zero pointing devices are easily affected by various factors such as ambient light interference, tilt motion error of the target mirror during rotation, and trigger threshold in the Schmidt trigger system, which can easily cause errors in the zero pulse emission time of the dynamic zero pointing device or even false triggering, thereby affecting the stability of the time reference during the dynamic angle measurement process, and further affecting the dynamic angle calibration accuracy with the target to be measured.

[0006] Finally, regarding the measurement of circular grating lines, there are also devices on the market that are specifically used for dynamic measurement of circular grating lines, such as high-speed spectral imaging systems, high-speed camera systems, dynamic grating scanning systems, etc. These devices use high-speed imaging technology and data processing algorithms to capture and analyze the motion trajectory, changes, and changes in related parameters of circular grating lines in real time. However, the biggest problem with the above devices is that they cannot dynamically measure the spacing of circular grating lines. They can only place the circular grating under the camera to take a photo, which is a static measurement rather than a dynamic measurement. The accuracy of the method of measuring grating lines with a high-speed camera is limited by the pixel resolution of the CCD in the camera, so it is impossible to dynamically measure the spacing of circular grating lines of the highest level of metrology. Summary of the invention

[0007] In view of this, the present invention provides a dynamic angle measuring device with a wide measuring range and high measuring accuracy. The measuring device also has the characteristic of dynamically collecting the spacing between the lines of the circular grating.

[0008] The dynamic angle measuring device comprises: an integrated base, a turntable, a ring laser gyro angle measuring unit, an adjustment fixture, a dynamic angle zeroing unit, and a control processing unit;

[0009] The integrated base is arranged on the vibration isolation platform,

[0010] The integrated base is provided with a turntable and a control processing unit;

[0011] The rotating part of the turntable is connected to the ring laser gyro angle measuring unit arranged above it.

[0012] The dynamic angle zeroing unit comprises a sensitive module, and the target mirror of the sensitive module is arranged on the ring laser gyro angle measurement unit;

[0013] The mounting fixture fixes the target to be measured above the target mirror and rotates with the ring laser gyro angle measurement unit;

[0014] The dynamic angle zeroing unit also includes a dual-frequency laser-fiber coupling module and a measurement module;

[0015] The laser beam emitted by the dual-frequency laser-fiber coupling module passes through the measurement module and then is emitted toward the target mirror;

[0016] When the direction of the light emitted by the measuring module coincides with the direction of the reflected light after passing through the target mirror, the dynamic angle zeroing unit sends a zeroing pulse to the control processing unit, and the control processing unit starts to record the dynamic angle measured by the ring laser gyro angle measuring unit.

[0017] Preferably, the dual-frequency laser-fiber coupling module comprises a dual-frequency laser, a coupling mirror and a polarization-maintaining fiber;

[0018] The laser beam emitted by the dual-frequency laser enters the polarization-maintaining optical fiber through the coupling mirror, and the polarization-maintaining optical fiber transmits the laser beam to the measurement module.

[0019] Preferably, the measurement module adopts a single-beam Michelson interference optical path structure, which includes a collimator, a non-polarizing beam splitter, a polarizing beam splitter prism, a reflector, a polarizer, a quarter wave plate, a half wave plate, a PIN photodetector and a four-quadrant detector;

[0020] The laser beam emitted from the dual-frequency laser-fiber coupling module passes through the collimator, and then passes through a non-polarizing beam splitter, a 1 / 2 wave plate, a polarizing beam splitter prism, and a 1 / 4 wave plate in sequence before being emitted to the target mirror of the sensitive module;

[0021] A polarizing plate and a PIN photodetector are provided on the non-polarizing beam splitter;

[0022] The reflected light incident on the non-polarizing beam splitter passes through the polarizer and is received by the PIN photodetector;

[0023] A quarter wave plate, a reflector and a four-quadrant detector are provided on the polarization beam splitter prism;

[0024] The laser beam passes through the polarization beam splitter prism and the quarter wave plate and then is directed toward the target mirror.

[0025] The reflected light reflected from the target mirror is directed toward the four-quadrant detector through the reflector on the polarization beam splitter prism;

[0026] The PIN photoelectric detector and the four-quadrant detector are used to realize photoelectric signal conversion;

[0027] The dynamic angle zeroing unit controls the output time of the zeroing pulse according to the phase change between the interference signals of each quadrant on the four-quadrant detector in the measurement module.

[0028] Preferably, it also includes a grating line dynamic aiming unit;

[0029] The grating line dynamic aiming unit is also arranged on the integrated base and is located on one side of the turntable. When the target to be measured is a circular grating, the grating line dynamic aiming unit can dynamically identify the spacing of the lines on the circular grating.

[0030] The control processing unit can receive the marking line pulse information sent from the grating marking line dynamic aiming unit.

[0031] Preferably, the laser gyro of the ring laser gyro angle measurement unit is square;

[0032] The laser gyroscope is an external cavity ring laser gyroscope, an internal cavity ring laser gyroscope or a fiber optic gyroscope.

[0033] Preferably, the bearings of the turntable are air-floating bearings.

[0034] A dynamic angle calibration method, using a dynamic angle measurement device according to any one of claims 1 to 6, comprising the following steps:

[0035] S1: Adjust the fixture to fix the target to be measured on the target mirror;

[0036] S2: The turntable drives the external cavity ring laser gyro and the target to be measured above to rotate at a set angular velocity under the control of the control processing unit, or performs variable angular velocity and variable angular acceleration motion according to the dynamic angle measurement requirements set for the target to be measured;

[0037] S3: The dynamic angle zeroing unit emits a laser beam to the target mirror, and the target mirror reflects the laser beam back to the dynamic angle zeroing unit;

[0038] S4: Control the output of the zero pulse according to the weighted phase average value between the photodiodes in adjacent quadrants in the measurement module. When the directions of the emitted light and the reflected light coincide, the dynamic angle zero unit sends a zero pulse signal to the control processing unit.

[0039] S5: The control processing unit starts to receive the gyro pulse signal sent by the laser gyro, and calculates the dynamic angle to obtain the actual dynamic angle parameter;

[0040] S5: Compare the dynamic angle output by the target to be measured itself with the dynamic angle calculated by the control processing unit.

[0041] A circular grating line spacing measurement method, the steps comprising:

[0042] S1: The fixture fixes the circular grating to be tested on the target mirror of the external cavity ring laser gyroscope;

[0043] S2: The turntable drives the external cavity ring laser gyro and the circular grating to be measured to rotate at a set fixed angular velocity under the control of the control processing unit, or performs variable angular velocity and variable angular acceleration motion according to the dynamic angle measurement requirements of the circular grating to be measured;

[0044] S3: When the dynamic angle zeroing unit emits laser to the target mirror, the target mirror reflects the laser back to the dynamic angle zeroing unit, and controls the output of the zeroing pulse according to the weighted phase average value between the photodiodes in adjacent quadrants in the measurement module. When the direction of the emitted light coincides with the direction of the reflected light, the dynamic angle zeroing unit sends a zeroing pulse signal to the control processing unit;

[0045] S4: The control processing unit starts to receive the line pulse information sent by the grating line dynamic aiming unit;

[0046] S5: The control processing unit collects the circular grating line pulse information and completes the circular grating line spacing measurement.

[0047] Beneficial effects:

[0048] (I) The turntable, laser gyro angle measurement unit, dynamic angle zeroing unit, adjustment fixture and control processing unit on the integrated base solve the problem of operators replacing and debugging different measuring devices to achieve different angle measurement ranges and angle measurement accuracies, and achieve a full-circle angle measurement range of 0°-360°, an angle measurement accuracy of 0.05″ (very high accuracy, can reach 1 / 20 second of the angle), and a measurement speed range of 1° / s-360° / s.

[0049] (ii) The dynamic angle zeroing unit in the present invention is based on the principle of differential wavefront interference. The unit uses a four-quadrant detector to realize the size of the phase difference between the measurement light and the reference light to determine the position and posture of the target mirror (reflector) during the rotation process, and determines whether to output a zeroing pulse according to the position and posture: a zeroing pulse will be output only when the phases of the four quadrants in the four-quadrant detector remain consistent. The dynamic angle zeroing unit does not rely on the intensity of the returning light or the threshold value of the Schmitt trigger, but generates a zeroing pulse by judging the phase difference between the four interference signals in the four-quadrant detector, thereby solving the problem of errors or even false triggering in the emission time of the zeroing pulse emitted by the existing dynamic angle zeroing device; the zeroing pulse can be output more accurately, ensuring the stability of the time reference of the entire dynamic angle measurement device during operation, and improving the calibration accuracy of the dynamic angle parameters.

[0050] (III) The measuring device is also provided with a grating line dynamic aiming unit, which, on the one hand, solves the technical problem that the existing dynamic angle measuring device cannot dynamically measure the line spacing of the circular grating; on the other hand, the dynamic angle measuring device of the present invention requires the circular grating to rotate on the laser gyroscope, so as to trace the angle between the lines in the circular grating to the laser wavelength in the ring laser gyroscope, and the tracing chain is clear. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A combined diagram of a dynamic angle measuring device of the present invention;

[0052] Figure 2 A structure and signal logic diagram of a dynamic angle measurement device of the present invention;

[0053] Among them, 1-vibration isolation platform, 2-integrated base, 3-turntable, 4-ring laser gyro angle measurement unit, 5-mounting fixture, 6-dynamic angle zeroing unit, 7-control processing unit, 8-grating line dynamic aiming unit, 61-dual-frequency laser-fiber coupling module, 62-measurement module, 63-sensitive module, 611-dual-frequency laser, 612-coupling mirror, 613-polarization-maintaining fiber, 621-collimator, 622-non-polarizing beam splitter, 623-polarizing beam splitter prism, 624-reflector, 625-polarizer, 626-1 / 4 wave plate, 627-1 / 2 wave plate, 628-PIN photodetector, 629-four-quadrant detector, 631-target mirror. DETAILED DESCRIPTION

[0054] The present invention will be further described below in conjunction with the accompanying drawings: It should be emphasized that the embodiments described in the present invention are illustrative rather than restrictive, and therefore the present invention is not limited to the embodiments described in the specific implementation manners, and any other implementation manners derived by those skilled in the art based on the technical solution of the present invention also fall within the scope of protection of the present invention.

[0055] Embodiment 1:

[0056] like Figure 1-2 The dynamic angle measuring device is arranged on a vibration isolation platform 1, and includes an integrated base 2, a turntable 3, a ring laser gyro angle measuring unit 4, an adjustment fixture 5, and a dynamic angle zeroing unit 6. The integrated base 2 is arranged on the vibration isolation platform 1; the turntable 3 and the control processing unit 7 are arranged on the integrated base 2. The turntable 3 includes a base and a rotating component, the base is fixedly connected to the vibration isolation platform 1, and the rotating component is connected to the ring laser gyro angle measuring unit 4 above it. The ring laser gyro angle measuring unit 4 can rotate around the turntable 3 axis under the drive of the turntable 3, and the dynamic angle is solved by the laser gyro pulse signal output to the control processing unit 7 (belonging to the prior art); in addition to solving the dynamic angle of the target to be measured, the control processing unit 7 can also realize the control of the turntable 3 and the ring laser gyro angle measuring unit 4. The target to be measured is fixed on the ring laser gyro angle measuring unit 4 through the adjustment fixture 5, and rotates with the ring laser gyro angle measuring unit 4. The dynamic angle zeroing unit 6 is used to determine the measurement start position of the target to be measured, so as to improve the calibration accuracy of the dynamic angle measuring device.

[0057] The dynamic angle zeroing unit 6 includes a dual-frequency laser-fiber coupling module 61, a measurement module 62 and a sensitive module 63; wherein the dual-frequency laser-fiber coupling module 61 includes a dual-frequency laser 611, a coupling mirror 612 and a polarization-maintaining fiber 613; the laser beam emitted by the dual-frequency laser 611 enters the polarization-maintaining fiber 613 through the coupling mirror 612.

[0058] The sensitive module 63 is disposed on the ring laser gyro angle measurement unit 4 , and includes a target mirror 631 (eg, a multifaceted prism). The target mirror 631 is used to receive and reflect the laser beam emitted from the measurement module 62 .

[0059] The measurement module 62 compares and analyzes the laser beam emitted by the dual-frequency laser-fiber coupling module 61 and the laser beam received from the sensitive module 63 based on the differential wavefront interference principle (this principle has high-precision phase measurement capability, reducing the pulse output error caused by changes in the external environment and the pulse output error caused by the tilt motion error of the target mirror 631 during rotation), and determines the time to send a zero pulse to the control processing unit 7. The measuring module 62 adopts a single-beam Michelson interference optical path structure, which specifically includes a collimator 621, a non-polarizing beam splitter 622, a polarizing beam splitter prism 623, a reflector 624, a polarizer 625, a quarter wave plate 626, a half wave plate 627, a PIN photodetector 628, and a four-quadrant detector 629; the laser beam emitted from the dual-frequency laser-fiber coupling module 61 passes through the collimator 621, and then passes through the non-polarizing beam splitter 622, the half wave plate 627, the polarizing beam splitter prism 623, and the quarter wave plate 626 in sequence before being emitted to the target of the sensitive module 63. Mirror 631, a polarizing plate 625 and a PIN photodetector 628 are provided on the non-polarizing beam splitter 622, and a 1 / 4 wave plate 626, a reflecting mirror 624 and a four-quadrant detector 629 are provided on the polarizing beam splitter prism 623; the laser incident on the non-polarizing beam splitter 622 is divided into two beams, one beam is reflected light, which is received by the PIN photodetector 629 after passing through the polarizing plate 625, and the other beam is transmitted light, which enters the polarizing beam splitter prism 623 after passing through the 1 / 2 wave plate 627, and is irradiated onto the target mirror 631 after passing through the 1 / 4 wave plate 626 on the polarizing beam splitter prism 623.

[0060] The PIN photodetector 628 and the four-quadrant detector 629 are used to realize photoelectric signal conversion and send a zero pulse signal to the control processing unit 7.

[0061] The single beam Michelson interference optical path structure is a single beam of light emitted by a light source, which is split into two beams of light when passing through the non-polarization beam splitter 622. One beam of light is emitted to the target mirror 631 and then reflected back to form interference with the other beam of light. This structure changes the optical path difference as the position of the target to be measured changes through the target mirror 631, and determines the time to send the zero pulse to the control processing unit 7 according to the phase change between the interference signals of each quadrant on the four-quadrant detector 629.

[0062] Working principle of dynamic angle zeroing unit:

[0063] The coupling mirror 612 couples the two lasers of different wavelengths emitted by the dual-frequency laser 611 to the polarization-maintaining optical fiber 613 and transmits them to the measuring module 62. The laser beams are collimated by the collimator 621 in the measuring module 62 and then enter the non-polarization beam splitter 622. In the non-polarization beam splitter 622, a part of the laser beam is reflected to the PIN photodetector 628, and the other part of the laser beam, i.e., the transmitted light, passes through the 1 / 2 wave plate 627 and enters the polarization beam splitter prism 623. A part of the transmitted light in the polarization beam splitter prism 623 passes through the 1 / 4 wave plate 626 and is reflected back to the polarization beam splitter prism 623 by the reflector 624. The other part of the transmitted light passes through the 1 / 4 wave plate 626 and irradiates the target mirror 631, and then is reflected by the target mirror 631 and passes through the 1 / 4 wave plate 626 again and returns to the polarization beam splitter prism 623. The two beams of transmitted light returning to the polarization beam splitter prism 623 are both irradiated to the four-quadrant detector 629 through the polarizer 625. The output zero pulse is controlled according to the weighted phase average value between the adjacent quadrant photodiodes in the four-quadrant detector 629. When the direction of the emitted light coincides with the direction of the reflected light, that is, when there is no angle between the light irradiated on the target mirror 631 and the light reflected by the target mirror 631, the PIN photodetector 628 and the four-quadrant detector 629 output the zero pulse through photoelectric signal conversion.

[0064] The dynamic angle zeroing unit 6 is located at one side of the ring laser gyro angle measuring unit 4, and is responsible for sending a zeroing pulse signal to the control processing unit 7. A target mirror 631 is provided on the laser gyro of the ring laser gyro angle measuring unit 4, and the target mirror 631 receives and reflects the laser beam emitted by the dynamic angle zeroing unit 6. After receiving the reflected laser beam, the dynamic angle zeroing unit 6 controls the output of the zeroing pulse according to the weighted phase average value between the adjacent quadrant photodiodes in the four-quadrant detector 629, and outputs the zeroing pulse when the direction of the emitted light coincides with the direction of the reflected light, that is, when there is no angle between the light irradiated on the target mirror 631 and the reflected light of the target mirror 631, and the dynamic angle zeroing unit 6 sends the zeroing pulse to the control processing unit 7. After receiving the zeroing pulse signal, the control processing unit 7 starts to receive the dynamic angle of the target to be measured output by the ring laser gyro angle measuring unit 4.

[0065] When the target to be measured can output a dynamic angle, the purpose of using the dynamic angle zeroing unit 6 is to compare the dynamic angles of the target to be measured and the ring laser gyro angle measuring unit 4 at the same time, and calibrate the dynamic angle output by the target to be measured.

[0066] When the target to be measured cannot output the dynamic angle itself, the dynamic angle zeroing unit 6 is also required to send a zeroing signal. The function of the zeroing signal is to determine the starting position of the measurement, that is, to set a measurement reference for the dynamic angle measured by the ring laser gyro angle measuring unit 4.

[0067] As an example, the laser gyroscope is an external cavity ring laser gyroscope.

[0068] As an example, the laser gyroscope is an intracavity ring laser gyroscope or a fiber optic gyroscope.

[0069] The mounting fixture 5 is also called a two-dimensional displacement stage, and has an in-plane displacement adjustment function. The mounting fixture 5 can achieve the coaxiality of the axis of the object to be measured and the axis of the turntable 3 .

[0070] As an example, the rotating part of the turntable 3 is an air-floating bearing, and the turntable 3 is an air-floating turntable. The air-floating turntable provides a hardware foundation for the dynamic angle measurement device and does not bring interference torque to the target to be measured.

[0071] Working principle:

[0072] The rotating components on the turntable 3 drive the annular laser gyro angle measurement unit 4 and the target to be measured above it to rotate; at the same time, the control processing unit 7 drives the dynamic angle zeroing unit 6 to emit laser to the target mirror 631, and receives the zeroing pulse signal from the dynamic angle zeroing unit 6 to complete the dynamic angle zeroing operation (the purpose of this is to ensure that the measuring device can accurately and stably identify the angle zero point position during operation).

[0073] The steps of using the device to calibrate a target to be measured that can output dynamic angles are as follows:

[0074] S1: The fixture 5 is adjusted to fix the target to be measured on the target mirror 631;

[0075] S2: The turntable 3 drives the external cavity ring laser gyro and the target to be measured above to rotate at a set fixed angular velocity under the control of the control processing unit 7, or performs variable angular velocity and variable angular acceleration motion according to the dynamic angle measurement set by the target to be measured;

[0076] S3: The dynamic angle zeroing unit 6 emits a laser to the target mirror 631, and the target mirror 631 reflects the laser back to the dynamic angle zeroing unit 6;

[0077] S4: The output zero pulse is controlled according to the weighted phase average value between the adjacent quadrant photodiodes in the four-quadrant detector 629. When the directions of the emitted light and the reflected light coincide, that is, when there is no angle between the light irradiated on the target mirror 631 and the light reflected by the target mirror 631, the dynamic angle zeroing unit 6 sends a zeroing pulse signal to the control processing unit 7;

[0078] S5: the control processing unit 7 starts to receive the gyro pulse signal sent by the laser gyro, and calculates the dynamic angle to obtain the actual dynamic angle parameter;

[0079] S5: Compare the dynamic angle output by the target to be measured itself with the dynamic angle calculated by the control processing unit 7 .

[0080] Embodiment 2:

[0081] On the basis of the above-mentioned embodiment 1, the measuring device further includes a grating line dynamic aiming unit 8; the grating line dynamic aiming unit 8 is also arranged on the integrated base 2 and is located on one side of the turntable 3; when the target to be measured is a circular grating, the line spacing on the circular grating can be dynamically identified by the grating line dynamic aiming unit 8. The control processing unit 7 on the integrated base 2 processes the line pulse information emitted by the grating line dynamic aiming unit 8.

[0082] Steps for dynamically collecting the spacing between circular grating lines:

[0083] S1: The mounting fixture 5 fixes the circular grating to be measured on the target mirror 631 of the external cavity ring laser gyroscope;

[0084] S2: The turntable 3 drives the external cavity ring laser gyro and the circular grating to be measured to rotate at a set fixed angular velocity under the control of the control processing unit 7, or performs variable angular velocity and variable angular acceleration motion according to the dynamic angle measurement requirements of the circular grating to be measured;

[0085] S3: When the dynamic angle zeroing unit 6 emits a laser to the target mirror 631, the target mirror 631 reflects the laser back to the dynamic angle zeroing unit 6, and controls the output of the zeroing pulse according to the weighted phase average value between the adjacent quadrant photodiodes in the four-quadrant detector 629. When the direction of the emitted light coincides with the direction of the reflected light, that is, there is no angle between the light irradiated on the target mirror 631 and the light reflected by the target mirror 631, the dynamic angle zeroing unit 6 sends a zeroing pulse signal to the control processing unit 7;

[0086] S4: The control processing unit 7 starts to receive the grating line dynamic aiming unit 8.

[0087] S5: The control processing unit 7 collects the circular grating line pulse information and completes the circular grating line spacing measurement.

[0088] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A dynamic angle measuring device, arranged on a vibration isolation platform, characterized in that: It includes an integrated base, a turntable, a ring laser gyro angle measurement unit, an adjustment fixture, a dynamic angle zeroing unit, and a control processing unit; The integrated base is arranged on the vibration isolation platform, The integrated base is provided with a turntable and a control processing unit; The rotating part of the turntable is connected to the ring laser gyro angle measuring unit arranged above it. The dynamic angle zeroing unit comprises a sensitive module, and the target mirror of the sensitive module is arranged on the ring laser gyro angle measurement unit; The mounting fixture fixes the target to be measured above the target mirror and rotates with the ring laser gyro angle measurement unit; The dynamic angle zeroing unit also includes a dual-frequency laser-fiber coupling module and a measurement module. The laser beam emitted by the dual-frequency laser-fiber coupling module passes through the measurement module and then is emitted toward the target mirror; When the direction of the light emitted by the measuring module coincides with the direction of the reflected light after passing through the target mirror, the dynamic angle zeroing unit sends a zeroing pulse to the control processing unit, and the control processing unit starts to record the dynamic angle measured by the ring laser gyro angle measuring unit.

2. A dynamic angle measuring device according to claim 1, characterized in that: The dual-frequency laser-fiber coupling module includes a dual-frequency laser, a coupling mirror and a polarization-maintaining fiber; The laser beam emitted by the dual-frequency laser enters the polarization-maintaining optical fiber through the coupling mirror, and the polarization-maintaining optical fiber transmits the laser beam to the measurement module.

3. A dynamic angle measuring device according to claim 1, characterized in that: The measuring module adopts a single-beam Michelson interference optical path structure, which includes a collimator, a non-polarizing beam splitter, a polarizing beam splitter prism, a reflector, a polarizer, a quarter wave plate, a half wave plate, a PIN photodetector and a four-quadrant detector; The laser beam emitted from the dual-frequency laser-fiber coupling module passes through the collimator, and then passes through a non-polarizing beam splitter, a 1 / 2 wave plate, a polarizing beam splitter prism, and a 1 / 4 wave plate in sequence before being emitted to the target mirror of the sensitive module; A polarizing plate and a PIN photodetector are provided on the non-polarizing beam splitter; The reflected light incident on the non-polarizing beam splitter passes through the polarizer and is received by the PIN photodetector; A quarter wave plate, a reflector and a four-quadrant detector are provided on the polarization beam splitter prism; The laser beam passes through the polarization beam splitter prism and the quarter wave plate and then is directed toward the target mirror. The reflected light reflected from the target mirror is directed toward the four-quadrant detector through the reflector on the polarization beam splitter prism; The PIN photoelectric detector and the four-quadrant detector are used to realize photoelectric signal conversion; The dynamic angle zeroing unit controls the output time of the zeroing pulse according to the phase change between the interference signals of each quadrant on the four-quadrant detector in the measurement module.

4. A dynamic angle measuring device according to claim 1, characterized in that: Also included is a grating-line dynamic aiming unit; The grating line dynamic aiming unit is also arranged on the integrated base and is located on one side of the turntable. When the target to be measured is a circular grating, the grating line dynamic aiming unit can dynamically identify the spacing of the lines on the circular grating. The control processing unit can receive the marking line pulse information sent from the grating marking line dynamic aiming unit.

5. A dynamic angle measuring device according to any one of claims 1 to 4, characterized in that: The laser gyro of the ring laser gyro angle measurement unit is square; The laser gyroscope is an external cavity ring laser gyroscope, an internal cavity ring laser gyroscope or a fiber optic gyroscope.

6. A dynamic angle measuring device according to any one of claims 1 to 4, characterized in that: The bearings of the turntable are air-floating bearings.

7. A dynamic angle calibration method, based on the ability of the target to be measured to output a dynamic angle, characterized in that: A dynamic angle measuring device according to any one of claims 1 to 6 is used, wherein the steps include: S1: Adjust the fixture to fix the target to be measured on the target mirror; S2: The turntable drives the external cavity ring laser gyro and the target to be measured above to rotate at a set angular velocity under the control of the control processing unit, or performs variable angular velocity and variable angular acceleration motion according to the dynamic angle measurement requirements set for the target to be measured; S3: The dynamic angle zeroing unit emits a laser beam to the target mirror, and the target mirror reflects the laser beam back to the dynamic angle zeroing unit; S4: Control the output of the zero pulse according to the weighted phase average value between the photodiodes in adjacent quadrants in the measurement module. When the directions of the emitted light and the reflected light coincide, the dynamic angle zero unit sends a zero pulse signal to the control processing unit. S5: The control processing unit starts to receive the gyro pulse signal sent by the laser gyro, and calculates the dynamic angle to obtain the actual dynamic angle parameter; S5: Compare the dynamic angle output by the target to be measured itself with the dynamic angle calculated by the control processing unit.

8. A method for measuring the spacing between circular grating lines, characterized in that: A dynamic angle measuring device according to any one of claims 4 to 6 is used, wherein the steps include: S1: The fixture fixes the circular grating to be tested on the target mirror of the external cavity ring laser gyroscope; S2: The turntable drives the external cavity ring laser gyro and the circular grating to be measured to rotate at a set fixed angular velocity under the control of the control processing unit, or performs variable angular velocity and variable angular acceleration motion according to the dynamic angle measurement requirements of the circular grating to be measured; S3: When the dynamic angle zeroing unit emits laser to the target mirror, the target mirror reflects the laser back to the dynamic angle zeroing unit, and controls the output of the zeroing pulse according to the weighted phase average value between the photodiodes in adjacent quadrants in the measurement module. When the direction of the emitted light coincides with the direction of the reflected light, the dynamic angle zeroing unit sends a zeroing pulse signal to the control processing unit; S4: The control processing unit starts to receive the line pulse information sent by the grating line dynamic aiming unit; S5: The control processing unit collects the circular grating line pulse information and completes the circular grating line spacing measurement.

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