A piezoelectric actuation-based micro-angle velocity generating device and method for fiber-optic gyroscope

Abstract

This invention discloses a device and method for generating minute angular velocities in a fiber optic gyroscope based on piezoelectric actuation. An H-shaped rigid base consists of two side flanges and a central web. A T-shaped swing lever consists of a horizontal beam and a vertical column. The vertical column is rotatably mounted in a through-hole in the middle of the web. One end of the horizontal beam is elastically connected to the inner wall of one side flange via a pre-tightening and reset mechanism. A drive rod is horizontally positioned, with one end mounted on the other side flange of the H-shaped rigid base. A groove is provided at the end face of the other end of the drive rod, and a protruding post is provided at the center of the bottom wall of the groove. A square piezoelectric actuation element with a hole is fitted onto the protruding post. A drive cap is inserted into the top of the protruding post through a central blind hole on the bottom surface. The top of the drive cap abuts against the end of the horizontal beam of the T-shaped swing lever away from the pre-tightening and reset mechanism. This invention completely avoids the vibration defects of traditional testing equipment, providing a reliable means for performance monitoring, parameter calibration, and ultimate performance verification of interferometric fiber optic gyroscopes.

Description

Technical Field

[0001] This invention relates to the fields of inertial sensing and fiber optic gyroscopes, and more particularly to a device and method for generating minute angular velocities in a fiber optic gyroscope based on piezoelectric actuation. Background Technology

[0002] As a core sensitive device in inertial navigation systems, the measurement accuracy of fiber optic gyroscopes directly determines and restricts the overall positioning accuracy, attitude calculation accuracy, and long-term navigation stability of the inertial navigation system. They are an indispensable key component in the field of inertial navigation for high-end equipment such as aerospace, ship navigation, precision guidance, and underground exploration. The accuracy and comprehensiveness of their performance calibration directly affect the working reliability and application adaptability of the entire inertial navigation system.

[0003] In existing technologies, conventional testing methods for fiber optic gyroscope performance are mainly divided into two categories: static testing and dynamic testing. Static testing involves fixing the fiber optic gyroscope on a high-precision vibration-isolated platform and collecting its output data over a long period in a static state without external angular velocity input. Then, through professional data processing and analysis methods, static performance indicators such as gyroscope noise characteristics, zero-bias stability, and zero-bias repeatability are detected and characterized. This method has undergone long-term technological development and optimization, and the existing testing procedures, data processing systems, and evaluation standards have become mature and complete, enabling accurate detection of the core static performance of fiber optic gyroscopes.

[0004] Dynamic testing primarily relies on multi-axis mechanical turntables. The fiber optic gyroscope is placed on the turntable, and its motor control system outputs controllable angular velocity signals (uniform or variable speed) to simulate angular velocity input under actual operating conditions, thus completing the gyroscope's dynamic performance test. However, traditional mechanical turntables have inherent technical limitations: firstly, the turntable depends on numerous mechanical transmission structures and motor drive components, resulting in complex structures and stringent assembly precision requirements, making it difficult to achieve stable output of high-precision, minute angular velocities, failing to meet the testing requirements of high-precision fiber optic gyroscopes for weak angular velocity signals; secondly, unavoidable mechanical vibrations occur during turntable operation, and this vibration noise directly interferes with the gyroscope's weak signal output, causing minute angular velocity signals to be easily drowned out by noise, resulting in an extremely low signal-to-noise ratio. For current dynamic testing of fiber optic gyroscopes, to ensure broad testing coverage and comprehensive test content, signals with adjustable amplitude and variable frequency are required, which is impossible to achieve with traditional gyroscope dynamic testing devices.

[0005] Currently, existing fiber optic gyroscope testing systems have significant technological gaps: static testing can only detect performance in a static state, failing to simulate the dynamic conditions during actual carrier motion and characterize the true response characteristics of fiber optic gyroscopes under dynamic environments with minute angular velocities. Test results deviate significantly from actual engineering applications, making it difficult to comprehensively reflect the gyroscope's performance across all operating conditions. Traditional dynamic testing platforms cannot stably generate high-precision minute angular velocity excitation signals, and mechanical vibrations introduce additional noise, severely impacting test accuracy. Some existing technologies attempt to simulate minute angular velocity inputs by adding external modulation signals, but this is an indirect simulation, not a physical angular velocity excitation, and cannot accurately reproduce the actual sensing mechanism and dynamic response process of the fiber optic gyroscope. The accuracy and reliability of the test results are insufficient, failing to provide reliable support for performance optimization and mass production calibration of high-precision fiber optic gyroscopes.

[0006] With the technological iteration of modern high-precision fiber optic gyroscopes, their sensitivity to weak signals has greatly improved, and their application scenarios increasingly rely on stable operation under dynamic conditions of small angular velocities. Existing testing methods are no longer suitable for their high-precision, low-noise, and micro-dynamic testing requirements, severely restricting the performance optimization and engineering application of high-precision fiber optic gyroscopes. Therefore, developing a dedicated testing device that is purely solid-state, free from mechanical vibration, and capable of achieving stable output of high-precision small angular velocities, filling the technological gap in the dynamic testing of small angular velocities of fiber optic gyroscopes, and solving the technical problems of insufficient accuracy, high noise interference, and inability to realistically simulate dynamic small angular velocities in traditional testing methods, has become an urgent technical problem to be solved in this field. Summary of the Invention

[0007] To address the shortcomings of the existing technology, this invention provides a piezoelectric-actuated fiber optic gyroscope micro-angular velocity generation device and method, aiming to overcome the problems of large vibration interference and insufficient micro-angular velocity output accuracy of traditional mechanical turntables, and to achieve stable generation of high-precision micro-angular velocities in a vibration-free environment.

[0008] The technical solution adopted in this invention is:

[0009] This invention includes a square perforated piezoelectric actuator, an H-shaped rigid base, a T-shaped swing lever, a tapered bearing, a drive rod, a drive cap, and a pre-tightening reset mechanism. The H-shaped rigid base is formed by two vertical flanges on both sides and a horizontal web in the middle, forming an H-shape. A through hole is provided in the middle of the web along the vertical direction. The T-shaped swing lever is formed by a vertical column and a horizontal beam. The vertical column is vertically fixed to the middle of the horizontal beam. The vertical column of the T-shaped swing lever is rotatably installed in the through hole in the middle of the web of the H-shaped rigid base through a tapered bearing. One end of the horizontal beam of the T-shaped swing lever is elastically hooked to the inner wall of one side flange of the H-shaped rigid base through the pre-tightening reset mechanism to provide a pull-back pre-tightening force for the T-shaped swing lever.

[0010] The drive rod is horizontally set. One end of the drive rod is installed on the inner wall of the flange plate on the other side of the H-shaped rigid base. The other end face of the drive rod is provided with a groove. A protruding post is provided in the center of the bottom wall of the groove. A square piezoelectric actuator with a hole is fitted on the protruding post. The drive cap is inserted into the top of the protruding post through the blind hole in the center of the bottom surface of the drive cap. The top of the drive cap abuts against the end of the T-shaped swing lever horizontal beam away from the pre-tightening reset mechanism.

[0011] It also includes an electronically controlled excitation unit and a fiber optic gyroscope mounting plate. The electronically controlled excitation unit is electrically connected to a square perforated piezoelectric actuator and is used to apply a driving voltage signal to the square perforated piezoelectric actuator, so that the square perforated piezoelectric actuator extends and retracts along the axial direction, which drives the drive cap to transmit to the horizontal beam of the T-shaped swing lever, and pushes the T-shaped swing lever to rotate around the central axis of the conical bearing.

[0012] The fiber optic gyroscope mounting plate is fixedly installed on the top center of the horizontal beam of the T-shaped swing lever, and is used to install the fiber optic gyroscope to be tested.

[0013] The inner wall of the flange plate of the H-shaped rigid base opposite to the pre-tightening reset mechanism is provided with a horizontal slide rail groove. The height of the slide rail groove is the same as the height of the horizontal beam of the drive rod. One end of the drive rod is provided with a slide rail and forms a sliding fit with the slide rail groove.

[0014] Limiting blocks are provided on both sides of the slide rail of the drive rod along the direction of the vertical slide rail groove, and each limiting block is provided with a through hole. Each through hole has a limiting screw passing through and pressing against the bottom wall of the slide rail groove, so that the drive rod is fixed. The drive rod is used to move horizontally along the slide rail to a preset position and then be fixed. The amplitude of the angular velocity formed by the T-shaped swing lever can be controlled by adjusting the horizontal position of the drive rod.

[0015] The pre-tightening reset mechanism includes a first spring hook, a second spring hook, and a reset spring. The first spring hook is fixed to the end of the horizontal beam of the T-shaped swing lever, and the second spring hook is fixed to the inner wall of the flange plate near the first spring hook. The reset spring is hooked between the first spring hook and the second spring hook. The first spring hook, the second spring hook, and the horizontal beam of the T-shaped swing lever are located in the same horizontal plane, which is used to provide a horizontal reset pre-tightening force to one end of the horizontal beam of the T-shaped swing lever, so that the other end of the horizontal beam always maintains abutment contact with the drive cap.

[0016] The electronically controlled excitation unit includes a piezoelectric drive module and a signal generator. The output of the signal generator is electrically connected to the input of the piezoelectric drive module, and the output of the piezoelectric drive module is electrically connected to a square perforated piezoelectric actuator. The signal generator amplifies the voltage signal output by the signal generator and applies it to the square perforated piezoelectric actuator, causing the square perforated piezoelectric actuator to undergo expansion and contraction along the axial direction of the protrusion.

[0017] The square piezoelectric actuator with a hole is specifically a square lead zirconate titanate (PZT) piezoelectric ceramic device, and has a cylindrical through hole in the middle for the protrusion to pass through.

[0018] The groove depth is greater than the height of the square perforated piezoelectric actuator. The square perforated piezoelectric actuator and the drive cap are embedded in the groove to prevent the square perforated piezoelectric actuator and the drive cap from rotating.

[0019] The method for testing minute angular velocities of fiber optic gyroscopes based on piezoelectric actuation includes the following steps:

[0020] S1. Install the fiber optic gyroscope to be tested on the fiber optic gyroscope mounting plate, and move the drive rod to the preset position in the horizontal direction and fix it. Apply a constant preload to the T-shaped swing lever through the return spring so that the end face of the T-shaped swing lever is in contact with the drive top cap. At this time, the horizontal beam position of the T-shaped swing lever is taken as the initial working position.

[0021] S2. The signal generator outputs a voltage signal with a preset waveform, which is then amplified by the piezoelectric drive module and applied to the square piezoelectric actuator with holes, causing the square piezoelectric actuator with holes to undergo axial expansion and contraction along the drive rod.

[0022] S3. The expansion and contraction deformation generated by the square perforated piezoelectric actuator is transmitted to the end of the horizontal beam of the T-shaped swing lever through the drive cap, which pushes the T-shaped swing lever to rotate around the central axis of the conical bearing in the horizontal plane to generate angular velocity.

[0023] S4. The fiber optic gyroscope under test rotates synchronously with the T-shaped swing lever to obtain the angular velocity input and generate the measurement output signal of the fiber optic gyroscope under test.

[0024] S5. Based on the voltage signal amplified by the piezoelectric drive module and the initial working position of the horizontal beam of the T-shaped swing lever, the theoretical value of the angular velocity is obtained. The measured output signal of the fiber optic gyroscope under test is compared with the theoretical value of the angular velocity to obtain the measurement accuracy evaluation result of the fiber optic gyroscope under test.

[0025] Using the plane passing through the central axis of the vertical column and parallel to the flanges on both sides of the H-shaped rigid base as the reference plane, the theoretical value of the angular velocity is obtained according to the following formula:

[0026]

[0027] in, denoted by ω, h represents the theoretical value of angular velocity; ω represents the projection distance from the contact point between the drive cap and the T-shaped swing lever onto the reference plane; L represents the projection point of the contact point between the drive cap and the T-shaped swing lever onto the reference plane, and the distance from the projection point to the vertical column axis; k represents the voltage-displacement response slope of the square perforated piezoelectric actuator; and t represents time. This represents the voltage signal amplified by the piezoelectric drive module.

[0028] The range of generated angular velocities is controlled in the following way:

[0029] 1) By adjusting the horizontal position of the drive cap against the horizontal beam of the T-shaped swing lever, the angular velocity of the swing angle of the T-shaped swing lever is changed;

[0030] 2) By changing the amplitude of the output voltage signal of the signal generator, the amplitude of the extension and retraction displacement of the square perforated piezoelectric actuator along the axial direction of the drive rod is changed, thereby changing the angular velocity of the swing angle of the T-shaped swing lever.

[0031] The beneficial effects of this invention are:

[0032] (1) Multiple test modes are flexible and adjustable. The excitation mode and test conditions can be switched according to different test requirements. Only the driving electrical signal V(t) needs to be modified to adapt to diverse performance testing scenarios. For example, loading a single-frequency sine signal to test the single-frequency response of the gyroscope, loading a ramp signal to achieve stable small angular velocity loading, thereby realizing the test of the dead zone of the gyroscope, etc.

[0033] (2) Since the device excitation uses piezoelectric actuation elements, the device has a wide operating bandwidth coverage, which can meet the dynamic performance test requirements of the whole frequency band and is applicable to more comprehensive scenarios;

[0034] (3) The theoretically measurable minimum angular velocity is extremely low. The theoretical formula can realize the accurate capture and detection of weak angular velocity signals of fiber optic gyroscopes. The testing device is traceable and breaks through the lower limit of accuracy of traditional equipment.

[0035] (4) The dynamic test range is large. By further finely adjusting the amplitude of the driving electrical signal, it can take into account both weak signal detection and large-range angular velocity calibration, and the test compatibility is extremely strong.

[0036] (5) Adopting an all-solid-state integrated design, it completely abandons the traditional mechanical turntable structure, eliminating test interference caused by mechanical vibration from the root, making the test environment more stable and the data more accurate.

[0037] In summary, this device has a simple and compact overall structure, is easy to assemble, and has small mechanical errors. It combines high precision and high flexibility, and can stably realize wide bandwidth, large dynamic range, and low lower limit angular velocity simulation and testing. It completely avoids the vibration defects of traditional testing equipment and provides a new and reliable technical means for performance monitoring, parameter calibration and extreme performance verification of interferometric fiber optic gyroscopes. Attached Figure Description

[0038] Figure 1 This is a top-view schematic diagram of the micro angular velocity generation device for a piezoelectric-actuated fiber optic gyroscope in this embodiment.

[0039] Figure 2 This is a mathematical schematic diagram of the micro angular velocity generation device for a piezoelectric-driven fiber optic gyroscope in this embodiment.

[0040] Figure 3 This is an assembly diagram of the micro angular velocity generation device for the piezoelectric-actuated fiber optic gyroscope in this embodiment.

[0041] Figure 4 This is a cross-sectional view of the top of the drive rod of the piezoelectric-actuated fiber optic gyroscope micro angular velocity generation device in this embodiment.

[0042] Figure 5 This is a top view of the top of the drive rod of the piezoelectric-actuated fiber optic gyroscope micro angular velocity generation device in this embodiment.

[0043] Figure 6 This is a schematic diagram of the groove in the piezoelectric-actuated fiber optic gyroscope micro angular velocity generation device of this embodiment.

[0044] In the figure, 1. Square piezoelectric actuator with holes, 2. H-shaped rigid base, 3. T-shaped swing lever, 4. Conical bearing, 5. Drive rod, 6. Drive cap, 7. Protruding column, 8. Return spring, 9. Piezoelectric drive module, 10. Signal generator, 11. Fiber optic gyroscope mounting plate, 12. Slide rail groove. Detailed Implementation

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of this invention.

[0047] This embodiment includes a square perforated piezoelectric actuator 1, an H-shaped rigid base 2, a T-shaped swing lever 3, a tapered bearing 4, a drive rod 5, a drive cap 6, and a pre-tightening reset mechanism. The H-shaped rigid base 2 is formed by two vertical flanges on both sides and a horizontal web in the middle in an H-shape. A through hole is provided in the middle of the web along the vertical direction. The T-shaped swing lever is formed by a vertical column and a horizontal beam. The vertical column is vertically fixed to the middle of the horizontal beam, and the whole structure is T-shaped.

[0048] The vertical column of the T-type swing lever 3 is rotatably installed in the through hole in the middle of the web of the H-type rigid base 2 through the tapered bearing 4. One end of the horizontal beam of the T-type swing lever 3 is elastically connected to the inner wall of one side flange of the H-type rigid base 2 through the pre-tightening reset mechanism to provide the T-type swing lever 3 with the pull-back pre-tightening force.

[0049] The drive rod 5 is horizontally set, and one end of the drive rod 5 is vertically installed on the inner wall of the other flange plate of the H-shaped rigid base 2. That is, the length direction of the drive rod 5 is perpendicular to the flange plate of the H-shaped rigid base 2. A groove is provided at the end face of the other end of the drive rod 5. A protrusion 7 is provided at the center of the bottom wall of the groove along the length direction of the drive rod 5. A square piezoelectric actuator 1 with a hole is fitted on the protrusion 7. The drive cap 6 is inserted into the top of the protrusion 7 through the blind hole in the center of the bottom surface of the drive cap 6. The drive cap 6 is located on the side of the square piezoelectric actuator 1 away from the bottom wall of the groove. The top of the drive cap 6, i.e., the hemispherical top, abuts against the end of the horizontal beam of the T-shaped swing lever 3 away from the pre-tightening reset mechanism.

[0050] It also includes an electronically controlled excitation unit and a fiber optic gyroscope mounting plate 11. The electronically controlled excitation unit is electrically connected to the square perforated piezoelectric actuator 1 and is used to apply a driving voltage signal to the square perforated piezoelectric actuator 1, so that the square perforated piezoelectric actuator 1 extends and retracts along the axial direction, driving the drive cap 6 to transmit to the horizontal beam of the T-shaped swing lever 3, and pushing the T-shaped swing lever 3 to rotate around the central axis of the conical bearing 4.

[0051] The fiber optic gyroscope mounting plate 11 is fixedly installed on the top center of the horizontal beam of the T-shaped swing lever 3, and is used to install the fiber optic gyroscope to be tested.

[0052] The square perforated piezoelectric actuator 1 and the drive cap 6 are not fixedly connected, nor are the square perforated piezoelectric actuator 1 and the bottom wall of the groove. The square perforated piezoelectric actuator 1 and the drive cap 6 are pressed into the groove by the pre-tightening reset mechanism, so that no displacement occurs.

[0053] like Figure 1As shown, the core components of this device are the T-shaped swing lever 3 and the drive rod 5. Because the drive cap 6 contacts the side wall of the T-shaped swing lever 3 and a return spring 8 exists, there is a certain preload between the drive cap 6 and the square perforated piezoelectric actuator 1. Therefore, the three components are in close contact, and the minute movement of the square perforated piezoelectric actuator 1 can be transmitted to the T-shaped swing lever 3 without loss, enabling it to rotate slightly and thus generate angular velocity. Preferably, the square perforated piezoelectric actuator 1 can be a square lead zirconate titanate piezoelectric ceramic device (PZT) with a cylindrical through-hole in the center, to achieve a better driving effect.

[0054] The inner wall of the flange plate of the H-type rigid base 2 opposite to the pre-tightening reset mechanism is provided with a horizontal slide rail groove 12. The height of the slide rail groove 12 is the same as the height of the horizontal beam of the drive rod 5. One end of the drive rod 5 is provided with a slide rail and forms a sliding fit with the slide rail groove 12.

[0055] Limiting blocks are provided on both sides of the slide rail of the drive rod 5 along the direction of the vertical slide rail groove 12, and each limiting block is provided with a through hole. Each through hole has a limiting screw passing through and pressing against the bottom wall of the slide rail groove 12, so that the drive rod 5 is fixed. The drive rod 5 is used to move horizontally along the slide rail to a preset position and then be fixed. The amplitude of the angular velocity formed by the T-shaped swing lever 3 can be controlled by adjusting the horizontal position of the drive rod 5.

[0056] The drive rod 5 is equipped with a limit screw, which is used to lock the drive rod 5 at any position in the slide rail groove 12 of the H-shaped rigid base 2, so as to adjust the contact point position between the drive rod 5 and the T-shaped swing lever 3.

[0057] The pre-tightening reset mechanism includes a first spring hook, a second spring hook, and a reset spring 8. The first spring hook is fixed to the end side of the horizontal beam of the T-shaped swing lever 3, and the second spring hook is fixed to the inner wall of the flange plate near the first spring hook. The reset spring 8 is hooked between the first spring hook and the second spring hook. The first spring hook, the second spring hook, and the horizontal beam of the T-shaped swing lever 3 are located in the same horizontal plane and are used to provide a horizontal reset pre-tightening force to one end of the horizontal beam of the T-shaped swing lever 3, so that the other end of the horizontal beam always maintains abutment contact with the drive cap 6.

[0058] The stiffness coefficient of the reset spring 8 is replaceable and adjustable, which is used to adjust the resonant frequency of the device and broaden the working bandwidth of the device.

[0059] There is no rigid fixing or bonding structure between the end face of the T-shaped swing lever 3 and the drive cap 6. The preload of the return spring 8 ensures that the two remain in close contact without gaps during dynamic reciprocating micro-displacement.

[0060] The electronically controlled excitation unit includes a piezoelectric drive module 9 and a signal generator 10. The output of the signal generator 10 is electrically connected to the input of the piezoelectric drive module 9, and the output of the piezoelectric drive module 9 is electrically connected to the square perforated piezoelectric actuator 1. The signal generator 10 amplifies the voltage signal output by the signal generator 10 and applies it to the square perforated piezoelectric actuator 1, causing the square perforated piezoelectric actuator 1 to undergo axial expansion and contraction along the protrusion 7 in the groove.

[0061] The square piezoelectric actuator 1 with a hole is specifically a square lead zirconate titanate (PZT) piezoelectric ceramic device, and has a cylindrical through hole in the middle for the protrusion 7 to pass through.

[0062] In summary, the H-shaped rigid base 2 is an integrally formed H-shaped structure. A through hole is located in the center of the middle web for mounting a tapered bearing. A slide rail groove 12 is machined on one inner wall to form a linear sliding fit with the trapezoidal slide rail structure of the drive rod 5. A spring hook is located on the other inner wall to provide a fulcrum for the spring. The T-shaped swing lever 3 is integrally formed from a central vertical column and the swing lever, forming a T-shaped structure. It is the core swing component of the device, hinged to the center of the crossbeam of the H-shaped rigid base 2 via a tapered bearing 4, and can rotate freely around the central axis of the tapered bearing 4. A fiber optic gyroscope fixing plate 11 is located at the center to fix the fiber optic gyroscope. A spring hook is located at the tail to connect the spring to the H-shaped rigid base 2, providing a stable pull-back preload. The drive rod 5 is generally long and narrow, with one side... The device has a trapezoidal slide rail structure that can form a linear sliding fit with the slide rail groove 12 of the H-type rigid base 2. The other end has a groove for accommodating the square piezoelectric actuator 1 with a hole. A cylindrical protrusion 7 extends from the center of the groove. The square piezoelectric actuator 1 with a hole is fitted onto the cylindrical protrusion 7. The driving top cap 6 has a square bottom and a hemispherical top with a blind hole in the center. It is inserted into the cylindrical protrusion 7. The cylindrical protrusion 7 enables the square piezoelectric actuator 1 with a hole to be coaxially positioned with the driving top cap 6. The hemispherical top of the driving top cap 6 forms a point contact with the end face of the T-shaped swing lever 3, ensuring that the micro-displacement output by the square piezoelectric actuator 1 with a hole is stably and without off-center load transmitted to the end face of the T-shaped swing lever 3 through the top cap, causing the T-shaped swing lever 3 to rotate slightly, thereby generating a small angular velocity signal.

[0063] The signal output terminal of the signal generator is electrically connected to the signal input terminal of the piezoelectric drive module, and the drive output terminal of the piezoelectric drive module is electrically connected to the electrode of the square perforated piezoelectric actuator.

[0064] The cylindrical protrusion 7 extending from the center of the groove has a dual positioning function: on the one hand, it is used for the coaxial mounting of the square piezoelectric actuator 1 with holes, so as to realize the stable installation and precise alignment of the piezoelectric actuator; on the other hand, it is used for inserting the matching drive cap 6 to realize the stable transmission of drive displacement.

[0065] The groove depth is greater than the height of the square perforated piezoelectric actuator 1. The square perforated piezoelectric actuator 1 and the drive cap 6 are embedded in the groove at the bottom to prevent the square perforated piezoelectric actuator 1 and the drive cap 6 from rotating.

[0066] In specific implementation, the crossbeam of the H-type rigid base 2 has mounting and positioning holes for installing the tapered bearing 4. After the tapered bearing 4 is installed into the H-type rigid base 2, the T-type swing lever 3 is inserted into the tapered bearing 4. The tapered bearing 4 has good axial and radial load-bearing capacity, and can stably support the T-type swing lever 3, allowing it to rotate on the H-type rigid base 2 with very little resistance. The drive rod 5 is fixed to the base via the slide rail on the right side of the H-type rigid base 2, can move along the slide rail groove 12, and can be locked onto the slide rail groove 12 by a limit screw. Its left head is designed with a groove, and a cylindrical protrusion 7 is provided in the middle of the groove. The side cross-sectional view of the drive rod 5 is shown below. Figure 4 As shown, the top view is as follows Figure 5 As shown, considering that the square perforated piezoelectric actuator 1 has lead wires, the groove design can not only accurately accommodate and hold the square perforated piezoelectric actuator 1, but also accommodate the lead wires of the square perforated piezoelectric actuator 1.

[0067] Therefore, as Figure 6 As shown, in this embodiment, the groove is designed with one half being a small slot and the other half being a large slot, which makes it easier to lead out the wires of the square perforated piezoelectric actuator 1. The square perforated piezoelectric actuator 1 and the lower part of the drive cap 6 are embedded in the small slot, as shown. Figure 4 As shown, the cylindrical protrusion 7 passes through the central through hole of the square perforated piezoelectric actuator 1 and holds and fixes the square perforated piezoelectric actuator 1 in the groove, thereby preventing the square perforated piezoelectric actuator 1 from moving irregularly during operation, which would lead to poor device performance. After the square perforated piezoelectric actuator 1 is fixed, since the height of the cylindrical protrusion 7 is higher than that of the square perforated piezoelectric actuator 1, a part of it will pass through the square perforated piezoelectric actuator 1. This part of the height is used to fix the drive cap 6. The drive cap 6 has an upper hemispherical shape and a lower square structure with the same size as the groove 17 and the square perforated piezoelectric actuator 1. The upper hemispherical structure is used to contact the side wall of the T-shaped swing lever 3. A spring hook is provided on the other side of the T-shaped swing lever 3, and a spring hook is also provided on one side wall of the H-shaped rigid base 2. When the device is working, in order to make the T-shaped swing lever 3 fully contact the drive cap 6, a return spring 8 needs to be hung between the two spring hooks to achieve the loading of preload force, so that the T-shaped swing lever 3 can always be in close contact with the drive cap 6 throughout the entire working process of the device.

[0068] The overall three-dimensional structure diagram of the device is as follows Figure 3 As shown in the figure, the geometric positional relationship of the device of the present invention is revealed. The two side structures of the H-shaped rigid base 2 are higher than the middle crossbeam structure. The slide rail groove 12 and the spring hook are set on the side wall of the H-shaped rigid base 2 that is higher than the middle crossbeam. For ease of observation of the structure, the spring hook and the return spring 8 are not shown in this figure. In order to ensure that the preload can be correctly applied, the length of the drive rod 5 is designed to exceed half the length of the middle crossbeam of the H-shaped rigid base 2, so that the T-shaped swing lever 3 is off-center. At this time, the return spring 8 is stretched, thereby generating sufficient preload. At this time, the T-shaped swing lever 3 is in the center position. Figure 2 The working position is at point P.

[0069] The method for testing minute angular velocities of fiber optic gyroscopes based on piezoelectric actuation includes the following steps:

[0070] S1. Install the fiber optic gyroscope to be tested on the fiber optic gyroscope fixing plate 11, and then move the drive rod 5 to a preset position in the horizontal direction via the slide rail and fix it.

[0071] First, the assembly and pre-tightening of the device are completed: the fiber optic gyroscope to be tested is fixed on the fixed plate of the T-shaped swing lever 3, the position of the drive rod 5 in the slide rail groove 12 is adjusted and locked, and a constant pre-tightening force is applied to the T-shaped swing lever 3 by the return spring 8 so that the end face of the T-shaped swing lever 3 is tightly fitted with the hemispherical top of the drive top cap 6, thus determining the initial working position of the device.

[0072] S2. The signal generator 10 outputs a voltage signal with a preset waveform, which is then amplified by the piezoelectric drive module 9 and applied to the square piezoelectric actuator 1 with a hole, causing the square piezoelectric actuator 1 with a hole to undergo axial expansion and contraction along the drive rod 5.

[0073] That is, the square piezoelectric actuator 1 with holes generates a corresponding axial micro-displacement under the drive of the input voltage signal. The micro-displacement is transmitted to the end face of the T-shaped swing lever 3 along the axial direction without off-center load through the drive cap 6, which pushes the T-shaped swing lever 3 to generate a small reciprocating rotation around the central axis of the tapered bearing 4.

[0074] Preset waveforms include, but are not limited to, sine wave signals, square wave signals, triangle wave signals, or electrical signals with any custom waveform.

[0075] S3. The expansion and contraction deformation of the square perforated piezoelectric actuator 1 along the axial direction of the drive rod 5 is transmitted to the end of the horizontal beam of the T-shaped swing lever 3 through the drive cap 6, which pushes the T-shaped swing lever 3 to reciprocate around the central axis of the conical bearing 4 in the horizontal plane to generate angular velocity.

[0076] S4. The fiber optic gyroscope under test reciprocates synchronously with the T-shaped swing lever 3 to obtain the angular velocity input and generate the measurement output signal of the fiber optic gyroscope under test.

[0077] S5. Based on the voltage signal amplified by the piezoelectric drive module 9, the theoretical value of angular velocity is obtained. The measured output signal of the fiber optic gyroscope under test is compared with the theoretical value of angular velocity to obtain the measurement accuracy evaluation result of the fiber optic gyroscope under test.

[0078] The H-shaped rigid base 2 and the T-shaped swing lever 3 are connected by bearings, and one side of the T-shaped swing lever 3 is connected to the H-shaped rigid base 2 by a return spring 8, which provides preload to the T-shaped swing lever 3. Due to the preload provided by the spring, the other side of the T-shaped swing lever 3 is in close contact with the drive cap 6 and deviates from the reference plane. This position is called the working position, and the angle between the T-shaped swing lever 3 and the reference plane at this time is θ.

[0079] When a small angular velocity is generated, a voltage signal of any type is generated using a signal generator 10. This signal is then amplified by the piezoelectric drive module 9 and input to the square perforated piezoelectric actuator 1. Let this drive voltage signal be V(t), and f be the voltage-displacement transfer function of the square perforated piezoelectric actuator 1. Then f(V(t)) is the small displacement generated after passing through the square perforated piezoelectric actuator 1. Since the drive rod 5 is in contact with the T-shaped swing lever 3, the T-shaped swing lever 3 will rotate slightly due to the small displacement generated by the square perforated piezoelectric actuator 1 on the drive rod 5. This rotation will cause it to generate a small angular velocity.

[0080] In practice, the height of the drive rod 5 itself should also be considered in the calculation. Let h be the distance of the drive rod 5 beyond the reference plane of the T-shaped swing lever, and L be the distance from the projection point of the drive cap 6 on the reference plane of the T-shaped swing lever 3 to the tapered bearing. Then, the horizontal displacement of the drive cap at the contact point of the T-shaped swing lever 3 can actually be expressed as:

[0081]

[0082] Since angular velocity is the derivative of angle θ with time, according to geometric relations, we can obtain the following form:

[0083]

[0084]

[0085] Let Ω(t) be the angular velocity generated by the device. Taking the derivative with respect to θ, we can obtain the relationship between the change in the angular velocity generated by the device and the input voltage signal V(t). Considering the conversion between radians and degrees, we obtain the final angular velocity output in deg / s.

[0086]

[0087] The above formula is the theoretical formula for generating fiber optic gyroscope angular velocity signals using this device. Depending on the applied electrical signal, we can calculate the angular velocity response. Generally, during processing, since the voltage-displacement transfer function of the piezoelectric actuator is approximately linear, that is... Where k is the slope of the straight line, which varies depending on the type and material of the piezoelectric actuator. Since the maximum displacement of a piezoelectric actuator is generally on the order of micrometers, while the length of a T-shaped swing lever is generally on the order of meters, the displacement caused by the piezoelectric actuator in the denominator of the first term of the equation can be ignored. Therefore, the simplified formula for the device's output angular velocity can be written as:

[0088]

[0089] The first part of the formula consists of coefficients. In actual use of the device, the magnitude of the generated angular velocity is estimated based on the device's parameters. For example, if the parameters are L = 0.5 m and k = 4 × 10⁻⁶ m, then... -7 Substituting m / V into the formula, we get a coefficient term of only 8 × 10. - 7 The value of deg / s indicates that the theoretical angular velocity that the device can generate is extremely small, making it suitable as a precision dynamic testing platform.

[0090] This device only needs to generate a specific electrical signal waveform on the signal generator to produce the corresponding angular velocity signal. This gives the device the advantages of flexibility and controllability. Furthermore, since the magnitude of the coefficient is related to L, we can adjust the length L by moving the drive rod on the H-shaped rigid base, thereby coarsely adjusting the magnitude of the angular velocity generated by the device. Since the magnitude of the output angular velocity is also related to the form of the applied electrical signal, we can also finely adjust the amplitude of the output angular velocity by adjusting the amplitude of the applied electrical signal, thereby achieving a larger dynamic range of testing.

[0091] The surface passing through the central axis of the vertical column and parallel to the two side flanges of the H-shaped rigid base 2 is taken as the reference surface P0. The theoretical value of the angular velocity is obtained by processing according to the following formula:

[0092]

[0093] In the formula, L is the distance from the projection point of the contact point of the drive cap 6 on the T-shaped swing lever 3 onto the reference surface of the T-shaped swing lever 3 to the conical bearing 4, h is the vertical distance of the T-shaped swing lever 3 beyond the axis of symmetry of the H-shaped rigid base 2, f(V(t)) is the voltage-displacement transfer function of the square perforated piezoelectric actuator 1, and V(t) is the drive voltage signal after being amplified by the piezoelectric drive module 9 after being output by the signal generator 10.

[0094] Since the voltage-displacement transfer function of the square perforated piezoelectric actuator 1 can be approximated as a linear relationship, i.e., f(V(t)) = kV(t), where k is the voltage-displacement response slope of the piezoelectric actuator; and since the micro-displacement f(V(t)) of the piezoelectric actuator is much smaller than L, the formula for calculating the angular velocity is simplified to:

[0095]

[0096] in, denoted by angular velocity, h represents the projection distance from the contact point between the driving cap 6 and the T-shaped swing lever 3 at the initial working position of the horizontal beam to the reference plane; L represents the projection point from the contact point between the driving cap 6 and the T-shaped swing lever 3 at the initial working position to the reference plane, and the distance from the projection point to the vertical column axis; k represents the voltage-displacement response slope of the square perforated piezoelectric actuator 1; and t represents time. This indicates the voltage signal output from signal generator 10 and amplified by piezoelectric drive module 9.

[0097] In this embodiment, a sinusoidal signal is used as the driving signal. It should be understood that this is only an illustrative example, and the device can use electrical signals of any waveform to achieve driving. The working process of the device is explained as follows:

[0098] The fiber optic gyroscope to be tested is fixed on the fiber optic gyroscope mounting plate 11 of the T-shaped swing lever 3. The mathematical principle diagram of the device during operation is as follows. Figure 2 As shown, P0 is the reference plane, located on the axis of symmetry of the H-shaped rigid base 2, perpendicular to the drive rod 5. During operation, the T-shaped swing lever 3 is in the working position P, ensuring the presence of preload. A sinusoidal signal with adjustable amplitude and frequency is generated using a signal generator 10, and amplified by a wire connected to the piezoelectric drive module 9, thereby generating a high-voltage sinusoidal signal capable of driving the square perforated piezoelectric actuator 1. Let this signal be V(t), then the input voltage signal V(t) can be written as:

[0099]

[0100] Where V0 is the amplitude of the voltage signal, and ω is the signal frequency. Substituting these values ​​into the system response formula, the angular velocity of the T-shaped swing lever 3 can be obtained as:

[0101]

[0102] Where L is the distance between the projection point of the contact point of the drive cap 6 on the T-shaped swing lever 3 onto the reference plane and the tapered bearing 4. Figure 2The length of the drive rod 5 can be adjusted by changing its position on the slide rail groove 12, thereby adjusting the amplitude of the generated angular velocity. h is the length of the drive rod 5 extending beyond the reference plane of the T-shaped swing lever 3. f represents the voltage-displacement response of the piezoelectric actuator. Preferably, when using a lead zirconate titanate piezoelectric ceramic device (PZT) as the square perforated piezoelectric actuator 1, f can be approximated as a multiplier, meaning the piezoelectric response is approximately linear. Therefore, it can be considered that:

[0103]

[0104] Where k represents the slope of the voltage-displacement response of the square perforated piezoelectric actuator 1. Since the displacement of the square perforated piezoelectric actuator 1 is generally on the order of micrometers, this value is extremely small compared to L and can be ignored. At this time, the above formula can be rewritten as:

[0105]

[0106] Since the device's geometric parameters are fixed, this means that the coefficients in the formula will be constants. These constants can be coarsely adjusted not only by using the position of the drive rod 5 on the slide rail groove 12, but also finely adjusted by modifying the amplitude V0 of the applied drive voltage signal. Note that the amplitude of this signal is linearly related to the frequency of the applied sinusoidal signal; therefore, the amplitude of the angular velocity generated by the device can also be adjusted by changing the frequency of the sinusoidal signal.

[0107] Preferably, the contact point between the drive cap 6 and the T-shaped swing lever 3 is located at the top of the T-shaped swing lever 3, and the length of the drive rod 5 is designed so that the angle θ between the working position of the T-shaped swing lever 3 and the reference plane is 45°. At this point, the following geometric relationship exists:

[0108]

[0109] Under these conditions, when we select a signal frequency ω=0.01 Hz and k=1.2μm / 1000 V, the peak-to-peak value of the sinusoidal angular velocity signal generated is 0.00044° / h;

[0110] When the signal frequency is selected as ω=1000Hz and k=3μm / 200 V, the peak-to-peak value of the sinusoidal angular velocity signal generated is 870.11° / h.

[0111] This demonstrates that the device not only generates extremely small angular velocity signals but also possesses a very large dynamic range of angular velocities. For different angular velocity ranges, the position of the contact point between the drive rod 5 and the T-shaped swing lever 3, as well as the angle θ between the working position and the reference plane, can be adjusted to further extend the range of angular velocities generated by the device. Regarding the device's resonance, the overall resonant frequency can be adjusted by regulating the stiffness coefficient of the return spring 8, thereby separating the device's resonant frequency from the applied signal and increasing the bandwidth of the measured angular velocity signal, showcasing the device's flexibility.

[0112] The specific embodiments illustrate that this device, compared to traditional fiber optic gyroscope turntables, features a large dynamic range and wide bandwidth. Furthermore, modifying the applied signal V(t) can generate different forms of angular velocity signals, not just sinusoidal signals, demonstrating that this device can test various types of gyroscope dynamic performance indicators. The all-solid-state design of the device fundamentally eliminates noise interference caused by motor vibration, significantly improving the measurement accuracy.

[0113] The range of generated angular velocities is controlled in the following manner:

[0114] 1) By adjusting the position of the drive cap 6 against the horizontal beam of the T-shaped swing lever 3, the angular velocity of the swing angle of the T-shaped swing lever 3 is changed;

[0115] 2) By changing the amplitude of the output voltage signal of the signal generator 10, the amplitude of the extension and retraction displacement of the square perforated piezoelectric actuator 1 along the axial direction of the drive rod 5 is changed, thereby changing the angular velocity of the swing angle of the T-shaped swing lever 3.

[0116] The amplitude of the output angular velocity of the device is achieved through two-stage adjustment. The first-stage adjustment is to adjust the position of the drive rod 5 in the slide rail groove 12 and change the size of the projection distance L to achieve coarse adjustment. The second-stage adjustment is to modify the amplitude of the drive voltage signal V(t) to achieve fine adjustment.

[0117] This device uses spring preload and piezoelectric actuators to achieve lever reciprocating motion, thereby generating minute angular velocity signals. It adopts an integrated rigid architecture design, eliminating additional mechanical vibration interference. It abandons the traditional mechanical turntable structure, is fully solid-state integrated, and has no low-frequency mechanical vibration interference. It has multiple core advantages, including flexible adjustment of multiple excitation modes, wide operating bandwidth coverage, extremely low theoretical minimum output angular velocity, and a very large dynamic range of angular velocity generation. With excellent structural rigidity and rapid response, it can realize high-precision, wide-range dynamic performance testing of fiber optic gyroscopes, adapt to the performance calibration requirements of multiple scenarios, and provide a new and reliable technical solution for high-precision dynamic performance calibration and extreme parameter testing of fiber optic gyroscopes.

[0118] This invention proposes a complete technical solution encompassing structure, electrical engineering, actuation, and algorithms, for directly generating minute angular velocity signals for fiber optic gyroscope testing at the physical level. Structurally, it employs a fully solid-state integrated rigid architecture, using a piezoelectric actuator as the driving source. The micro-displacement is transmitted to the swing lever mechanism via a transmission assembly, causing it to generate controllable minute reciprocating oscillations around the hinge point. A preload is applied by a preload member to ensure a tight, gapless fit throughout the transmission chain, fundamentally avoiding the mechanical vibration interference of traditional turntables. Electrically, a voltage signal with the desired waveform is generated by a signal generator 10, amplified by the piezoelectric drive module 9, and then applied to the piezoelectric actuator, realizing the conversion from electrical signal to mechanical displacement. In terms of actuation, the micro-displacement of the piezoelectric actuator is... The transmission component transmits load to the end face of the swing lever mechanism without bias, driving the fiber optic gyroscope fixed thereon to generate a real physical angular velocity input. The output amplitude is adjusted in two stages through mechanical position and drive signal parameters, and the waveform and frequency are flexibly controlled by the drive signal. In terms of algorithm, a mapping relationship between drive voltage and output angular velocity is established. Based on the geometric parameters of the swing lever and the voltage-displacement response characteristics of the piezoelectric actuator, the output angular velocity is calculated in real time. By changing the waveform, amplitude and frequency of the drive signal, a variety of dynamic excitation modes can be realized, ranging from extremely low angular velocity to large dynamic range and from sine to arbitrary waveform.

[0119] The above detailed embodiments illustrate the technical solution and beneficial effects of the present invention. It should be understood that the above description is only the most preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, additions, and equivalent substitutions made within the scope of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A micro angular velocity generation device for a fiber optic gyroscope based on piezoelectric actuation, characterized in that: The device includes a square perforated piezoelectric actuator (1), an H-shaped rigid base (2), a T-shaped swing lever (3), a tapered bearing (4), a drive rod (5), a drive cap (6), and a pre-tightening reset mechanism. The H-shaped rigid base (2) is formed by two vertical flanges and a horizontal web in the middle, forming an H-shape. A through hole is provided in the middle of the web in the vertical direction. The T-shaped swing lever is formed by a vertical column and a horizontal beam. The vertical column is vertically fixed to the middle of the horizontal beam. The vertical column of the T-shaped swing lever (3) is rotatably installed in the through hole in the middle of the web of the H-shaped rigid base (2) through the tapered bearing (4). One end of the horizontal beam of the T-shaped swing lever (3) is elastically connected to the inner wall of one side flange of the H-shaped rigid base (2) through the pre-tightening reset mechanism to provide a pull-back pre-tightening force for the T-shaped swing lever (3). The drive rod (5) is set horizontally. One end of the drive rod (5) is vertically installed on the inner wall of the flange plate on the other side of the H-type rigid base (2). The other end face of the drive rod (5) is provided with a groove. A protruding post (7) is provided in the center of the bottom wall of the groove. A square piezoelectric actuator (1) with a hole is fitted on the protruding post (7). The drive cap (6) is inserted into the top of the protruding post (7) through the center blind hole of the bottom surface of the drive cap (6). The top of the drive cap (6) abuts against the end of the horizontal beam of the T-type swing lever (3) away from the pre-tightening reset mechanism.

2. The piezoelectric actuation-based fiber optic gyroscope micro-angular velocity generation device according to claim 1, characterized in that: It also includes an electronically controlled excitation unit and a fiber optic gyroscope mounting plate (11). The electronically controlled excitation unit is electrically connected to the square perforated piezoelectric actuator (1) and is used to apply a driving voltage signal to the square perforated piezoelectric actuator (1), so that the square perforated piezoelectric actuator (1) extends and retracts along the axial direction, driving the drive cap (6) to transmit to the horizontal beam of the T-shaped swing lever (3), and pushing the T-shaped swing lever (3) to rotate around the central axis of the conical bearing (4); The fiber optic gyroscope mounting plate (11) is fixedly installed on the top center of the horizontal beam of the T-shaped swing lever (3) and is used to install the fiber optic gyroscope to be tested.

3. The piezoelectric actuation-based fiber optic gyroscope micro-angular velocity generation device according to claim 1, characterized in that: The inner wall of the flange plate of the H-shaped rigid base (2) opposite to the pre-tightening reset mechanism is provided with a horizontal slide rail groove (12). The height of the slide rail groove (12) is the same as the height of the horizontal beam of the drive rod (5). One end of the drive rod (5) is provided with a slide rail and forms a sliding fit with the slide rail groove (12). Limiting blocks are provided on both sides of the slide rail of the drive rod (5) along the direction of the vertical slide rail groove (12), and each of the two limiting blocks is provided with a through hole. Each through hole has a limiting screw passing through and pressing against the bottom wall of the slide rail groove (12), so that the drive rod (5) is fixed. This is used to drive the drive rod (5) to move horizontally along the slide rail to a preset position and then fix it. The amplitude of the angular velocity formed by the T-shaped swing lever (3) can be controlled by adjusting the horizontal position of the drive rod (5).

4. The piezoelectric actuation-based fiber optic gyroscope micro-angular velocity generation device according to claim 1, characterized in that: The pre-tightening reset mechanism includes a first spring hook, a second spring hook, and a reset spring (8). The first spring hook is fixed to the end of the horizontal beam of the T-shaped swing lever (3), and the second spring hook is fixed to the inner side wall of the flange plate near the first spring hook. The reset spring (8) is hooked between the first spring hook and the second spring hook. The first spring hook, the second spring hook, and the horizontal beam of the T-shaped swing lever (3) are located in the same horizontal plane and are used to provide a horizontal reset pre-tightening force to one end of the horizontal beam of the T-shaped swing lever (3), so that the other end of the horizontal beam always maintains abutment contact with the drive cap (6).

5. The piezoelectric actuation-based fiber optic gyroscope micro-angular velocity generation device according to claim 2, characterized in that: The electronically controlled excitation unit includes a piezoelectric drive module (9) and a signal generator (10). The output of the signal generator (10) is electrically connected to the input of the piezoelectric drive module (9), and the output of the piezoelectric drive module (9) is electrically connected to the square perforated piezoelectric actuator (1). The voltage signal output by the signal generator (10) is amplified by the piezoelectric drive module (9) and loaded onto the square perforated piezoelectric actuator (1), so that the square perforated piezoelectric actuator (1) undergoes axial expansion and contraction along the protrusion (7).

6. The piezoelectric actuation-based fiber optic gyroscope micro-angular velocity generation device according to claim 1, characterized in that: The square perforated piezoelectric actuator (1) is specifically a square lead zirconate titanate (PZT) piezoelectric ceramic device, and a cylindrical through hole is provided in the middle for the protrusion (7) to pass through.

7. The piezoelectric actuation-based fiber optic gyroscope micro-angular velocity generation device according to claim 1, characterized in that: The groove depth is greater than the height of the square perforated piezoelectric actuator (1). The lower part of the square perforated piezoelectric actuator (1) and the drive cap (6) are embedded in the groove to prevent the square perforated piezoelectric actuator (1) and the drive cap (6) from rotating.

8. A method for testing the minute angular velocity of a piezoelectric-actuated fiber optic gyroscope applied to the device described in any one of claims 1-7, characterized in that, The method includes the following steps: S1. Install the fiber optic gyroscope to be tested on the fiber optic gyroscope fixing plate (11), and move the drive rod (5) to the preset position in the horizontal direction and fix it. Apply a constant preload to the T-shaped swing lever (3) through the reset spring (8) so that the end face of the T-shaped swing lever (3) is in contact with the drive top cap (6). At this time, the horizontal beam position of the T-shaped swing lever (3) is the initial working position. S2. The signal generator (10) outputs a voltage signal with a preset waveform, which is then amplified by the piezoelectric drive module (9) and applied to the square piezoelectric actuator (1) with holes, so that the square piezoelectric actuator (1) with holes will generate a stretching deformation along the drive rod (5) axial direction. S3. The expansion and contraction deformation generated by the square perforated piezoelectric actuator (1) is transmitted to the end of the horizontal beam of the T-shaped swing lever (3) through the drive cap (6), which pushes the T-shaped swing lever (3) to rotate around the central axis of the conical bearing (4) in the horizontal plane to generate angular velocity. S4. The fiber optic gyroscope under test rotates synchronously with the T-shaped swing lever (3) to obtain the angular velocity input and generate the measurement output signal of the fiber optic gyroscope under test. S5. Based on the voltage signal amplified by the piezoelectric drive module (9) and the initial working position of the horizontal beam of the T-shaped swing lever (3), the theoretical value of the angular velocity is obtained. The measurement output signal of the fiber optic gyroscope under test is compared with the theoretical value of the angular velocity to obtain the measurement accuracy evaluation result of the fiber optic gyroscope under test.

9. The method for testing minute angular velocities of a fiber optic gyroscope based on piezoelectric actuation according to claim 8, characterized in that: The surface passing through the central axis of the vertical column and parallel to the two flanges of the H-shaped rigid base (2) is taken as the reference surface. The theoretical value of the angular velocity is obtained by processing according to the following formula: in, denoted by angular velocity, h represents the projection distance from the contact point between the driving cap (6) and the T-shaped swing lever (3) to the reference plane, L represents the projection point of the contact point between the driving cap (6) and the T-shaped swing lever (3) to the reference plane, the distance from the projection point to the vertical column axis, k represents the voltage-displacement response slope of the square perforated piezoelectric actuator (1), and t represents time. This indicates the voltage signal amplified by the piezoelectric drive module (9).

10. The method for testing the minute angular velocity of a fiber optic gyroscope based on piezoelectric actuation according to claim 8, characterized in that: The range of generated angular velocities is controlled in the following way: 1) By adjusting the horizontal position of the drive cap (6) against the horizontal beam of the T-shaped swing lever (3), the angular velocity of the swing angle of the T-shaped swing lever (3) is changed; 2) By changing the amplitude of the output voltage signal of the signal generator (10), the amplitude of the extension and retraction displacement of the square perforated piezoelectric actuator (1) along the axial direction of the drive rod (5) is changed, thereby changing the angular velocity of the swing angle of the T-shaped swing lever (3).

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