A single-beam optical trap-based micro-gyroscope angular velocity closed-loop measurement device and method

Abstract

This invention relates to a closed-loop measurement device and method for the angular velocity of a micro-gyroscope based on a single-beam optical trap, belonging to the field of inertial navigation technology. It includes a vacuum cavity, a micro-gyroscope, an optical trap levitation module, a rotation detection module, and a feedback control module. The micro-gyroscope is placed inside the vacuum cavity, and the optical trap levitation module is positioned below the vacuum cavity. The optical trap levitation module can converge a first laser beam from bottom to top into the vacuum cavity to form a vertical optical trap, thus leviting the micro-gyroscope. The rotation detection module can horizontally converge a second laser beam onto the micro-gyroscope and split the second laser beam, after its polarization direction has been changed by the rotating micro-gyroscope, into two laser beams with different intensity ratios. The feedback control module can analyze the intensity ratio of the two laser beams and provide feedback control to the rotational angular velocity of the micro-gyroscope. This invention features high bandwidth, low noise, and high accuracy.

Description

Technical Field

[0001] This invention belongs to the field of inertial navigation technology, specifically relating to a micro gyroscope angular velocity closed-loop measurement device and method based on a single-beam optical trap. Background Technology

[0002] In the field of inertial navigation technology, a gyroscope is an inertial device used to measure the change in angle of a carrier relative to inertial space. Its development trend can be divided into mechanical gyroscopes, liquid-floated gyroscopes, optical gyroscopes, and quantum gyroscopes. Existing technologies have the following disadvantages: (1) The longitude of gyroscopes based on laser interferometry is limited by temperature stability, making it difficult to obtain angular velocity measurements of higher longitudes; (2) The rotor of gyroscopes based on electrostatic or magnetic field suspension needs to have electrical or magnetic sensitivity and is greatly affected by electric or magnetic field interference, limiting its application scenarios. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the purpose of this invention is to provide a micro gyroscope angular velocity closed-loop measurement device and method based on a single-beam optical trap, so as to solve or improve the defects existing in the prior art.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a closed-loop measurement device for the angular velocity of a micro-gyroscope based on a single-beam optical trap, comprising a vacuum cavity, a micro-gyroscope, an optical trap levitation module, a rotation detection module, and a feedback control module. The micro-gyroscope is placed inside the vacuum cavity, and the optical trap levitation module is positioned below the vacuum cavity. The optical trap levitation module can converge a first laser beam from bottom to top into the vacuum cavity to form a vertical optical trap, thereby leviting the micro-gyroscope. The rotation detection module can converge a second laser beam horizontally onto the micro-gyroscope and split the second laser beam, after its polarization direction has been changed by the rotating micro-gyroscope, into two laser beams with different intensity ratios. The feedback control module can analyze the intensity ratio of the two laser beams and provide feedback control for the rotational angular velocity of the micro-gyroscope.

[0005] The feedback control module includes driving electrodes, a balance detector, and a control device. Two sets of four orthogonal driving electrodes are symmetrically distributed about the center of the micro gyroscope in the vacuum cavity. The driving electrodes are connected to the feedback voltage output terminal of the control device. The control device can control the four orthogonal driving electrodes to apply an alternating electric field to the micro gyroscope to drive its rotation. The measurement signal output terminal of the balance detector is connected to the measurement signal input terminal of the control device. The balance detector can analyze the two laser beams output by the rotation detection module and output the rotation detection voltage signal of the micro gyroscope to the control device.

[0006] Preferably, the optical trap levitation module includes a capturing laser, which can output a first laser. The capturing laser is provided with a collimating lens group, a first reflecting mirror, and a first focusing objective lens in sequence along the transmission direction of the first laser. The output end of the first focusing objective lens is located directly below the vacuum cavity. The collimating lens group can adjust the first laser into parallel light. The first reflecting mirror can reflect the parallel light into the first focusing objective lens. The first focusing objective lens can focus the parallel light into the vacuum cavity to form a vertical optical trap. The vertical optical trap is used to overcome the gravity of the micro-gyroscope to achieve spatial levitation of the micro-gyroscope.

[0007] Preferably, the working wavelength range of the collimating lens group, the first reflecting mirror, and the first focusing objective lens covers the wavelength of the first laser.

[0008] Preferably, the rotation detection module includes a probe laser, which outputs a second laser with a fixed polarization direction. The probe laser is sequentially equipped with a focusing lens, a second focusing objective lens, a polarization beam splitter, and a second reflecting mirror along the transmission direction of the second laser. The focusing lens and the second focusing objective lens are symmetrically arranged on both sides of the micro-gyroscope. The focusing lens can focus the second laser with a fixed polarization direction onto the micro-gyroscope. When the micro-gyroscope rotates, it can change the polarization direction of the second laser. The second focusing objective lens can diffuse the second laser with different polarization directions and input it to the polarization beam splitter. The polarization beam splitter can split the second laser with different polarization directions into reflected laser and transmitted laser with different intensity ratios and directly input the reflected laser to the balance detector. The second reflecting mirror can reflect the transmitted laser and input it to the balance detector.

[0009] Preferably, the operating wavelength range of the second focusing objective, polarizing beam splitter, and second reflecting mirror covers the wavelength of the second laser.

[0010] Preferably, the microgyroscope is a particle with a size of 0.1-100 micrometers.

[0011] Preferably, the micro-gyroscope is spherical, dumbbell-shaped, ellipsoidal, or cylindrical in shape.

[0012] Preferably, the control device is connected to a computer.

[0013] This invention also provides a closed-loop measurement method for the angular velocity of a micro-gyroscope based on a single-beam optical trap, using the aforementioned closed-loop measurement device for the angular velocity of a micro-gyroscope based on a single-beam optical trap, comprising the following steps:

[0014] S1. When there is no external angular velocity input, a fixed AC sinusoidal voltage is output to the four driving electrodes through the control device. The voltages on the four driving electrodes have a phase difference of π / 2. The resultant electric field formed by the four driving electrodes drives the micro-gyroscope to rotate uniformly in the vertical optical trap at the same rotational angular velocity w1. At this time, the balance detector outputs a stable rotational voltage signal V. r1 To the control device;

[0015] S2. When an external angular velocity input is present, the micro-gyroscope no longer rotates at a constant speed. At this time, the balance detector outputs a rotation detection voltage signal V. r2 The control device receives the rotation detection voltage signal V. r2 Obtain the rotational angular velocity w2 of the micro gyroscope at this time; subtract the rotational angular velocity w1 of the micro gyroscope when there is no external angular velocity input from the rotational angular velocity w2 of the micro gyroscope when there is an external angular velocity input to obtain the external angular velocity Δw;

[0016] S3. Based on the external angular velocity Δw, the control device outputs a drive feedback voltage signal V. f Four driving electrodes are used to change the intensity of the combined electric field, thereby adjusting the rotational angular velocity of the micro gyroscope, so that the micro gyroscope rotates at a rotational angular velocity w1 when there is no external angular velocity input, thus realizing closed-loop control of the rotational state of the micro gyroscope.

[0017] Preferably, the stable rotational voltage signal V r1 for:

[0018] V r1 =V bias ·sin(w1·t);

[0019] Among them, V bias ω is the voltage of the driving electrode, w1 is the rotational angular velocity of the micro gyroscope when there is no external angular velocity input, and t is the rotation time of the micro gyroscope.

[0020] The rotating detection voltage signal V r2 for:

[0021] V r2 =V bias ·sin(w2·t+φ i );

[0022] Where w2 is the rotational angular velocity of the micro-gyroscope when there is an external angular velocity input, and φ i This is a delayed signal of the external angular velocity that the micro-gyroscope is sensitive to;

[0023] The drive feedback voltage signal V f for:

[0024] V f =V bias·sin(Δw·t+φ i +φ rot );

[0025] Where Δw is the external angular velocity, Δw = w1 - w2, φ rot The phase differences between the voltages of the four driving electrodes are 90°, 180°, 270°, and 360°, respectively.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The micro gyroscope angular velocity closed-loop measurement device based on a single-beam optical trap of the present invention suspends the micro gyroscope in a vacuum cavity through an optical trap suspension module, so that there is no mechanical contact between it and external devices, thereby isolating the mechanical friction noise that is inevitably present in other gyroscopes and having extremely high angular velocity sensing sensitivity.

[0028] The micro-gyroscope angular velocity closed-loop measurement device based on a single-beam optical trap of the present invention forms a closed-loop feedback system based on electric field polarization force by organically combining a rotation detection module and a feedback control module composed of a driving electrode, a balance detector and a control device. This maintains the stable rotation of the micro-gyroscope in the vertical optical trap, which can limit the nonlinear effects in the open-loop detection scheme, improve the anti-interference capability of the micro-gyroscope and effectively increase the range of the micro-gyroscope, and realize high operating bandwidth, low noise and high precision angular velocity measurement.

[0029] The micro-gyroscope angular velocity closed-loop measurement method based on a single-beam optical trap of the present invention introduces a closed-loop feedback method into the optical trap suspending gyroscope. By applying a controllable electric field signal to the suspending region of the micro-gyroscope, the stable rotation of the micro-gyroscope in the vertical optical trap is maintained, and the external angular velocity information is retrieved by feedback control voltage. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on the drawings described below without creative effort.

[0031] Figure 1 This is a schematic diagram of the micro-gyroscope angular velocity closed-loop measurement device based on a single-beam optical trap according to an embodiment of the present invention.

[0032] Figure 2 This is a schematic diagram of the micro-gyroscope rotation process in an embodiment of the present invention.

[0033] Figure 3 This is a block diagram of a typical closed-loop control process in an embodiment of the present invention.

[0034] The diagram shows: 1. Optical trap levitation module; 2. Rotation detection module; 3. Feedback control module; 4. Acquiring laser; 5. Collimating lens group; 6. First reflecting mirror; 7. First focusing objective lens; 8. Vacuum cavity; 9. Micro gyroscope; 10. Probe laser; 11. Focusing lens; 12. Driving electrode; 13. Second focusing objective lens; 14. Polarization beam splitter; 15. Second reflecting mirror; 16. Balance detector; 17. Control device; 18. Computer. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. To make the above features and advantages of this invention more apparent and understandable, specific embodiments are provided below with reference to the accompanying drawings for detailed description.

[0036] like Figure 1 As shown, an embodiment of the present invention provides a closed-loop measurement device for the angular velocity of a micro-gyroscope based on a single-beam optical trap, including a vacuum cavity 8, a micro-gyroscope 9, an optical trap levitation module 1, a rotation detection module 2, and a feedback control module 3. The micro-gyroscope 9 is placed inside the vacuum cavity 8, and the optical trap levitation module 1 is disposed below the vacuum cavity 8. The optical trap levitation module 1 can converge a first laser beam from bottom to top into the vacuum cavity 8 to form a vertical optical trap so that the micro-gyroscope 9 is levitated. The rotation detection module 2 can converge a second laser beam horizontally onto the micro-gyroscope 9 and split the second laser beam, after the polarization direction is changed by the rotating micro-gyroscope 9, into two laser beams with different light intensity ratios. The feedback control module 3 can analyze the light intensity ratio of the two laser beams and provide feedback control on the rotational angular velocity of the micro-gyroscope 9.

[0037] The feedback control module 3 includes a drive electrode 12, a balance detector 16, and a control device 17. Two sets of four orthogonal drive electrodes 12 are symmetrically distributed about the center of the micro gyroscope 9 in the vacuum cavity 8. The drive electrodes 12 are connected to the feedback voltage output terminal of the control device 17. The control device 17 can control the four orthogonal drive electrodes 12 to apply an alternating electric field force to the micro gyroscope 9 to drive its rotation. The measurement signal output terminal of the balance detector 16 is connected to the measurement signal input terminal of the control device 17. The balance detector 16 can analyze the two laser beams output by the rotation detection module 2 and output the rotation detection voltage signal of the micro gyroscope 9 to the control device 17.

[0038] The working principle of this embodiment is as follows: The optical trap levitation module 1 focuses the first laser beam from bottom to top into the vacuum cavity 8 to form a vertical optical trap, thereby leviting the micro-gyroscope 9; the feedback control module 3 applies an alternating electric field force to the micro-gyroscope 9 through two sets of driving electrodes 12 (each set of driving electrodes 12 includes a driving positive electrode and a driving negative electrode), thereby achieving stable rotation control of the micro-gyroscope 9. In addition to being affected by the electric field polarization force, the rotation state of the micro-gyroscope 9 is also sensitive to changes in external angular velocity. When there is an external angular velocity input, the rotation state of the micro-gyroscope 9 in the vertical optical trap will change accordingly, resulting in different orientation angles; the rotation detection module 2 uses the second laser beam... The light converges at the micro-gyroscope 9. In the suspended state, different orientation angles of the micro-gyroscope 9 will cause corresponding deflections in the polarization direction of the second laser. The rotation detection module 2 will split the second laser with a changed polarization direction into two laser beams with different intensity ratios. The feedback control module 3 analyzes the intensity ratio of the two laser beams output by the rotation detection module 2 through the balance detector 16 and outputs the rotation detection voltage signal of the micro-gyroscope 9 to the control device 17. After analyzing and calculating the rotation detection voltage signal of the micro-gyroscope 9, the control device 17 outputs four feedback drive voltages to the four drive electrodes 12. The feedback control keeps the micro-gyroscope 9 rotating stably and inverts the external angular velocity information.

[0039] In this embodiment, the optical trap levitation module 1 includes a capturing laser 4, which outputs a first laser beam. Along the transmission direction of the first laser beam, the capturing laser 4 is sequentially equipped with a collimating lens group 5, a first reflecting mirror 6, and a first focusing objective lens 7. The output end of the first focusing objective lens 7 is located directly below the vacuum cavity 8. The collimating lens group 5 adjusts the first laser beam into parallel light, and the first reflecting mirror 6 reflects the parallel light into the first focusing objective lens 7. The first focusing objective lens 7 converges the parallel light into the vacuum cavity 8 to form a vertical optical trap. This vertical optical trap overcomes the gravity of the micro-gyroscope 9 to achieve spatial levitation of the micro-gyroscope 9. The operating wavelength range of the collimating lens group 5, the first reflecting mirror 6, and the first focusing objective lens 7 covers the wavelength of the first laser beam.

[0040] In this embodiment, the optical trap levitation module 1 achieves levitation of the micro-gyroscope 9 in the vacuum cavity 8 by constructing a focused Gaussian beam. Its specific working principle is as follows: The capturing laser 4 outputs a first laser beam, which is adjusted into parallel light by the collimating lens group 5. The parallel light is reflected by the first reflecting mirror 6 and input to the first focusing objective lens 7. After passing through the first focusing objective lens 7, the parallel light converges within the vacuum cavity 8 to form a vertical optical trap. The vertical optical trap is used to overcome the gravity of the micro-gyroscope 9 to achieve spatial levitation. The first laser beam used for levitation of the micro-gyroscope 9 has a wavelength of 320~1550 nanometers, for example, 532nm.

[0041] In this embodiment, the rotation detection module 2 includes a detection laser 10, which outputs a second laser with a fixed polarization direction. The detection laser 10 is sequentially equipped with a focusing lens 11, a second focusing objective lens 13, a polarization beam splitter 14, and a second reflecting mirror 15 along the transmission direction of the second laser. The focusing lens 11 and the second focusing objective lens 13 are symmetrically arranged on both sides of the micro-gyroscope 9. The focusing lens 11 can focus the second laser with a fixed polarization direction onto the micro-gyroscope 9. When the micro-gyroscope 9 rotates, it can change the polarization direction of the second laser. The second focusing objective lens 13 can diffuse the second laser with different polarization directions and input it to the polarization beam splitter 14. The polarization beam splitter 14 can split the second laser with different polarization directions into reflected laser and transmitted laser with different intensity ratios and directly input the reflected laser to the balance detector 16. The second reflecting mirror 15 can reflect the transmitted laser and input it to the balance detector 16. The operating wavelength range of the second focusing objective lens 13, the polarization beam splitter 14, and the second reflecting mirror 15 covers the wavelength of the second laser.

[0042] The rotation detection module 2 in this embodiment is used to measure the rotation angle and orientation signal of the micro-gyroscope 9. Its specific working principle is as follows: The detection laser 10 outputs a second laser with a fixed polarization direction. This second laser, after passing through the focusing lens 11, converges onto the micro-gyroscope 9. Different orientation angles of the micro-gyroscope 9 in its suspended state will cause corresponding deflections in the polarization direction of the second laser. Therefore, the rotating micro-gyroscope 9 will change the polarization direction of the second laser. The second lasers with different polarization directions are diffused by the second focusing objective lens 13 and then input to the polarization beam splitter 14, where they are split into reflected and transmitted lasers with different intensity ratios. The reflected laser is directly input to the first optical input terminal of the balance detector 16, and the transmitted laser is reflected by the second reflecting mirror 15 and then input to the second optical input terminal of the balance detector 16. The second laser is used for rotation detection of the micro-gyroscope 9, and its wavelength is 320~1550 nanometers, for example, 1064nm. A wavelength difference of more than 1 nanometer between the wavelength of the second laser and the wavelength of the first laser is sufficient.

[0043] In this embodiment, the micro-gyroscope 9 consists of particles ranging from 0.1 to 100 micrometers. Utilizing the radiation pressure of the vertical optical trap, the particles can overcome gravity and achieve stable suspension in air or a vacuum. They also rotate under the influence of the polarization force of the alternating rotating electric field. For particles rotating in space, they possess the fixed-axis and reverse-motion characteristics of a gyroscope rotor; therefore, they are also called optical trap-suspended micro-gyroscopes. The shape of the micro-gyroscope 9 can be spherical, dumbbell-shaped, ellipsoidal, or cylindrical, etc. In this embodiment, the micro-gyroscope 9 and the driving electrode 12 are placed inside a vacuum cavity to ensure that the micro-gyroscope is in a vacuum environment during angular velocity measurement, thereby reducing the influence of air damping and achieving higher sensing sensitivity.

[0044] In this embodiment, the control device 17 is connected to the computer 18. The control device 17 can output information such as the rotation of the micro gyroscope 9 and the externally input angular velocity to the computer 18 for easy viewing. The control device 17 is a microcontroller or a PLC, and the specific model is not limited, such as an STM32 microcontroller or a Siemens S7-1200 PLC.

[0045] like Figures 1 to 3 As shown, this embodiment also provides a closed-loop measurement method for the angular velocity of a micro-gyroscope based on a single-beam optical trap. Using the aforementioned closed-loop measurement device for the angular velocity of a micro-gyroscope based on a single-beam optical trap, the method includes the following steps:

[0046] S1. When there is no external angular velocity input, a fixed AC sinusoidal voltage is output to the four driving electrodes through the control device. The voltages on the four driving electrodes have a phase difference of π / 2. The resultant electric field formed by the four driving electrodes drives the micro-gyroscope to rotate uniformly in the vertical optical trap at the same rotational angular velocity w1. At this time, the balance detector outputs a stable rotational voltage signal V. r1 To the control device;

[0047] S2. When an external angular velocity input is present, the micro-gyroscope no longer rotates at a constant speed. At this time, the balance detector outputs a rotation detection voltage signal V. r2 The control device receives the rotation detection voltage signal V. r2 Obtain the rotational angular velocity w2 of the micro gyroscope at this time; subtract the rotational angular velocity w1 of the micro gyroscope when there is no external angular velocity input from the rotational angular velocity w2 of the micro gyroscope when there is an external angular velocity input to obtain the external angular velocity Δw;

[0048] S3. Based on the external angular velocity Δw, the control device outputs a drive feedback voltage signal V. f Four driving electrodes are used to change the intensity of the combined electric field, thereby adjusting the rotational angular velocity of the micro gyroscope, so that the micro gyroscope rotates at a rotational angular velocity w1 when there is no external angular velocity input, thus realizing closed-loop control of the rotational state of the micro gyroscope.

[0049] In this embodiment, the stable rotation voltage signal V r1 for:

[0050] V r1 =V bias ·sin(w1·t);

[0051] Among them, V bias ω is the voltage of the driving electrode, w1 is the rotational angular velocity of the micro gyroscope when there is no external angular velocity input, and t is the rotation time of the micro gyroscope.

[0052] The rotating detection voltage signal V r2 for:

[0053] V r2 =V bias ·sin(w2·t+φ i );

[0054] Where w2 is the rotational angular velocity of the micro-gyroscope when there is an external angular velocity input, and φ i This is a delayed signal of the external angular velocity that the micro-gyroscope is sensitive to;

[0055] The drive feedback voltage signal V f for:

[0056] V f =V bias ·sin(Δw·t+φ i +φ rot );

[0057] Where Δw is the external angular velocity, Δw = w1 - w2, φ rot The phase differences between the voltages of the four driving electrodes are 90°, 180°, 270°, and 360°, respectively.

[0058] For a micro-gyroscope driven by an electric field in a vertical optical trap, the angular momentum transformation during its rotation in the vertical optical trap can be described by the following formula:

[0059] ;

[0060] in, The orbital angular momentum of the microgyroscope. It is the spin angular momentum of the micro-gyroscope. The electric dipole moment inside the micro gyroscope. The applied electric field force is β, where β is the damping coefficient of the micro-gyroscope in vacuum, and I is the moment of inertia of the micro-gyroscope.

[0061] like Figure 2 As shown, the four driving electrodes are connected to the feedback voltage output by the control device, which is used to form an alternating rotating electric field near the levitation space of the micro-gyroscope. This electric field polarization force controls the micro-gyroscope to rotate. When there is no external angular velocity input, the control device outputs a sinusoidal alternating voltage of the same amplitude to the four driving electrodes. The frequency of this alternating voltage is f, but there is a phase difference of π / 2 on each of the four driving electrodes. The resultant electric field generated by the four driving electrodes rotates in space, and the micro-gyroscope rotates at a frequency f in the vertical optical trap.

[0062] like Figure 3A typical feedback control scheme shown is the proportional-integral-derivative (PID) feedback algorithm. Its feedback control process is as follows: When there is an external angular velocity input, the external angular velocity input will cause the rotation state of the micro-gyroscope to change. The rotation frequency of the micro-gyroscope in the vertical optical trap will deviate from the frequency f. At this time, the rotation information of the micro-gyroscope can be detected, and after being analyzed and processed by the control device, the driving feedback voltage is output to the four orthogonal driving electrodes to change the direction and intensity of the electric field so that the micro-gyroscope continues to rotate stably at the frequency f in the vertical optical trap. This realizes closed-loop control of the rotation of the micro-gyroscope and obtains the external angular velocity information.

[0063] In the description of this invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0064] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "multiple" means two or more, unless otherwise explicitly specified.

[0065] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A micro-gyroscope angular velocity closed-loop measurement device based on a single-beam optical trap, characterized in that, The system includes a vacuum cavity, a micro-gyroscope, an optical trap levitation module, a rotation detection module, and a feedback control module. The micro-gyroscope is placed inside the vacuum cavity, and the optical trap levitation module is located below the vacuum cavity. The optical trap levitation module can focus a first laser beam from bottom to top into the vacuum cavity to form a vertical optical trap, thereby leviting the micro-gyroscope. The rotation detection module can focus a second laser beam horizontally onto the micro-gyroscope and split the second laser beam, after its polarization direction has been changed by the rotating micro-gyroscope, into two laser beams with different intensity ratios. The feedback control module can analyze the intensity ratio of the two laser beams and provide feedback to control the rotational angular velocity of the micro-gyroscope. The feedback control module includes driving electrodes, a balance detector, and a control device. Two sets of four orthogonal driving electrodes are symmetrically distributed about the center of the micro gyroscope in the vacuum cavity. The driving electrodes are connected to the feedback voltage output terminal of the control device. The control device can control the four orthogonal driving electrodes to apply an alternating electric field to the micro gyroscope to drive its rotation. The measurement signal output terminal of the balance detector is connected to the measurement signal input terminal of the control device. The balance detector can analyze the two laser beams output by the rotation detection module and output the rotation detection voltage signal of the micro gyroscope to the control device.

2. The micro-gyroscope angular velocity closed-loop measurement device based on a single-beam optical trap according to claim 1, characterized in that, The optical trap levitation module includes a capturing laser that outputs a first laser beam. The capturing laser is equipped with a collimating lens group, a first reflecting mirror, and a first focusing objective lens in sequence along the transmission direction of the first laser beam. The output end of the first focusing objective lens is located directly below the vacuum cavity. The collimating lens group can adjust the first laser beam into parallel light. The first reflecting mirror can reflect the parallel light into the first focusing objective lens. The first focusing objective lens can converge the parallel light into the vacuum cavity to form a vertical optical trap. The vertical optical trap is used to overcome the gravity of the micro-gyroscope to achieve spatial levitation of the micro-gyroscope.

3. The micro-gyroscope angular velocity closed-loop measurement device based on a single-beam optical trap according to claim 2, characterized in that, The collimating lens group, the first reflecting mirror, and the first focusing objective lens operate within a wavelength range that covers the wavelength of the first laser.

4. The micro-gyroscope angular velocity closed-loop measurement device based on a single-beam optical trap according to claim 1, characterized in that, The rotation detection module includes a probe laser that outputs a second laser with a fixed polarization direction. Along the transmission direction of the second laser, the probe laser is sequentially equipped with a focusing lens, a second focusing objective, a polarization beam splitter, and a second reflecting mirror. The focusing lens and the second focusing objective are symmetrically arranged on both sides of the micro-gyroscope. The focusing lens focuses the second laser with a fixed polarization direction onto the micro-gyroscope. As the micro-gyroscope rotates, it changes the polarization direction of the second laser. The second focusing objective diffuses the second laser with different polarization directions and inputs it to the polarization beam splitter. The polarization beam splitter splits the second laser with different polarization directions into reflected and transmitted lasers with different intensity ratios and directly inputs the reflected laser to the balance detector. The second reflecting mirror reflects the transmitted laser and inputs it to the balance detector.

5. The micro-gyroscope angular velocity closed-loop measurement device based on a single-beam optical trap according to claim 4, characterized in that, The operating wavelength range of the second focusing objective, polarizing beam splitter, and second reflecting mirror covers the wavelength of the second laser.

6. The micro-gyroscope angular velocity closed-loop measurement device based on a single-beam optical trap according to claim 1, characterized in that, The micro-gyroscopes are particles ranging from 0.1 to 100 micrometers in size.

7. The micro-gyroscope angular velocity closed-loop measurement device based on a single-beam optical trap according to claim 1, characterized in that, The micro-gyroscope can be spherical, dumbbell-shaped, ellipsoidal, or cylindrical.

8. The micro-gyroscope angular velocity closed-loop measurement device based on a single-beam optical trap according to claim 1, characterized in that, The control device is connected to a computer.

9. A closed-loop measurement method for the angular velocity of a micro-gyroscope based on a single-beam optical trap, using the closed-loop measurement device for the angular velocity of a micro-gyroscope based on a single-beam optical trap as described in claim 1, characterized in that, Includes the following steps: S1. When there is no external angular velocity input, a fixed AC sinusoidal voltage is output to the four driving electrodes through the control device. The voltages on the four driving electrodes have a phase difference of π / 2. The resultant electric field formed by the four driving electrodes drives the micro-gyroscope to rotate uniformly in the vertical optical trap at the same rotational angular velocity w1. At this time, the balance detector outputs a stable rotational voltage signal V. r1 To the control device; S2. When an external angular velocity input is present, the micro-gyroscope no longer rotates at a constant speed. At this time, the balance detector outputs a rotation detection voltage signal V. r2 The control device receives the rotation detection voltage signal V. r2 Obtain the rotational angular velocity w2 of the micro gyroscope at this time; subtract the rotational angular velocity w1 of the micro gyroscope when there is no external angular velocity input from the rotational angular velocity w2 of the micro gyroscope when there is an external angular velocity input to obtain the external angular velocity Δw; S3. Based on the external angular velocity Δw, the control device outputs a drive feedback voltage signal V. f Four driving electrodes are used to change the intensity of the combined electric field, thereby adjusting the rotational angular velocity of the micro gyroscope, so that the micro gyroscope rotates at a rotational angular velocity w1 when there is no external angular velocity input, thus realizing closed-loop control of the rotational state of the micro gyroscope.

10. The closed-loop measurement method for micro-gyroscope angular velocity based on a single-beam optical trap according to claim 9, characterized in that, The stable rotation voltage signal V r1 for: V r1 =V bias ·sin(w1·t); Among them, V bias ω is the voltage of the driving electrode, w1 is the rotational angular velocity of the micro gyroscope when there is no external angular velocity input, and t is the rotation time of the micro gyroscope. The rotating detection voltage signal V r2 for: V r2 =V bias ·sin(w2·t+φ i ); Where w2 is the rotational angular velocity of the micro-gyroscope when there is an external angular velocity input, and φ i This is a delayed signal of the external angular velocity that the micro-gyroscope is sensitive to; The drive feedback voltage signal V f for: V f =V bias ·sin(Δw·t+φ i +φ rot ); Where Δw is the external angular velocity, Δw = w1 - w2, φ rot The phase differences between the voltages of the four driving electrodes are 90°, 180°, 270°, and 360°, respectively.

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