Mass leveling method and device for efficiently positioning inherent axis orientation of hemispherical harmonic oscillator

Abstract

In order to solve the problems that in an existing hemispherical harmonic oscillator quality leveling technology, the inherent rigid axis positioning efficiency is low, and manual intervention is relied on, the invention provides a method for rapidly positioning the azimuth of an inherent rigid axis of a hemispherical harmonic oscillator based on pulse broadband excitation and quasi standing wave response and a corresponding leveling device. Through an analytical expression of a main standing wave and an auxiliary wave in a second-order four-amplitude resonance working mode, a double-excitation vibration stopping system (comprising two knocking hammers and a vibration stopping hammer with the azimuth difference of 22.5 degrees odd times) is ingeniously designed, and the azimuth of an inherent rigid shaft is quickly positioned by combining orthogonal detection signals. According to the method, the limitation on the excitation direction and the detection direction is relaxed, and through the design of the vibration stopping hammer, the positioning efficiency of the inherent rigid shaft is improved, and the extraction precision of residual vibration on the characteristic parameters can be avoided. The formed hemispherical resonator leveling device provides reliable technical support for batch production of high-precision hemispherical resonator gyroscopes.

Description

Technical Field

[0001] The present invention belongs to the technical field of hemispherical resonator gyroscopes, and in particular relates to a mass leveling device and method for efficiently positioning the natural axis orientation of a hemispherical resonator based on pulse broadband excitation and quasi-standing wave response analysis. Background Art

[0002] Machining defects in the HRG directly contribute to its drift error. Therefore, the HRG must be mass-leveled before assembly. The mass-leveling position must be determined based on the HRG's inherent rigidity axis.

[0003] Traditional methods for locating an inherently rigid axis employ point-by-point excitation-response scanning, analyzing the characteristic parameters of the spectrum at different orientations to progressively approximate the inherently rigid axis of the resonator, as described in CN 210014788. However, given the 5kHz to 10kHz operating frequency characteristics of a hemispherical resonator gyroscope, this method suffers from low positioning efficiency and lengthy data acquisition and solution times. To address these issues, some research institutions have proposed using equal-amplitude step-by-step excitation to measure the time-domain vibration signal of the vibrator and locate the inherent rigid axis angle through fitting, as described in CN117824607. However, this method places extremely high demands on the amplitude consistency of the excitation signal and the accuracy of the electrodes. In practical applications, deviations in the excitation signal can easily lead to positioning failures. Furthermore, challenges remain, such as complex data analysis and insufficient repeatability. Summary of the Invention

[0004] In response to the problems of low efficiency and reliance on manual intervention in the positioning of the inherent rigid axis in the above-mentioned existing hemispherical resonator mass leveling technology, the present invention proposes an efficient positioning method and supporting device based on pulse broadband excitation and quasi-standing wave response analysis. The broadband pulse signal characteristics of the striking hammer are utilized to synchronously excite the two splitting modes of the resonator, and the quasi-standing wave characteristics of the second-order four-amplitude mode of the hemispherical resonator are used to quickly locate the inherent axis orientation of the oscillator. The technical principle of the present invention is as follows: the pulse signal generated by the hammer is expressed as: F(t,θ)=Bδ(t) Where B is the excitation amplitude and θ is the excitation direction. By performing Fourier series expansion on the impulse function and considering only the resonance response of the second-order four-amplitude vibration model of the oscillator, the vibration of the oscillator's natural axis direction can be obtained as: in, is the azimuth angle between the excitation axis and the nearest natural low-frequency axis. ω1 and ω2 are the corresponding resonant angular frequencies, and A is the resonant amplitude. Under the "quasi-standing wave" assumption, according to X f1 and X f2 The expression of the main standing wave position X can be obtained θ0 and auxiliary wave position Xθ45 The expression is approximately X θ0 =A1cos(ωt) in If the position difference between the two taps is π / 8*(2N+1), the azimuth angle can be obtained by the following formula: The subscripts 1 and 2 represent the results of two knocks, respectively. The corresponding natural low-frequency axis orientation can be obtained by using the excitation axis orientation θ. From the results, it can be seen that this method removes the influence of the different amplitude responses of the two taps. The technical solutions of the present invention are as follows: An automated mass leveling method for efficiently and automatically locating the natural axis orientation of a hemispherical resonator is characterized by comprising the following steps: S1. initializing the device; S2. activating a knocking vibration suppression system a; S3. determining the amplitude ratio r1 of the main standing wave and the auxiliary wave of a quasi-standing wave; S4. activating a knocking vibration suppression system b; and S5. determining a new position r2 and determining the natural axis position by taking the average according to the following formula: S6. The rotary table rotates to the position of the inherent rigidity axis; S7. The mass is adjusted according to the position of the inherent rigidity axis. 3. Further, the step S1 specifically includes: S1.1 Install the component to be tested on the rotating table; S1.2 Align the rotary table at zero degree, the detection system at 1 degree, and the 0 degree hammer, and mark it as the system circumferential orientation 0 degree, with counterclockwise rotation as positive rotation. Furthermore, step S2 includes the following process: 1) Vibration-stopping oscillator, 2) Wait for a while 3) Determine whether the vibration is stopped successfully based on the amplitude of the vibrator. If successful, proceed to the next step. If unsuccessful, return to 1). 4) Tap the vibrator 5) Wait for a while 6) Determine whether the excitation is successful based on the amplitude of the vibrator. If successful, proceed to step S3. If unsuccessful, return to step 1). Furthermore, the step S3 specifically includes: S3.1 Data is collected for a period of time τ0. S3.2 obtains the amplitude ratio of the main standing wave and the auxiliary wave based on the collected data, which is recorded as r1. Furthermore, the step S3.1 is characterized in that: S3.1.1 The data acquisition time τ0 is related to the inherent rigidity axis frequency difference △ω, ensuring that △ω*τ0<<1. The data collected in S3.1.2 includes the amplitude data X of two detection positions with a 45-degree difference in azimuth. out1 、X out2 Furthermore, the step S3.2 is characterized in that: Assume that two detection signals X out1 and X out2 The directions are φ1 and φ2 respectively, and Then the amplitudes of the main standing wave and auxiliary wave of the quasi-standing wave are but r1=X θ45_1 / X θ0_1 Furthermore, in step S4, the knocking and vibration stopping process is consistent with S2. Furthermore, the step S5 includes: S5.1 Data is collected for a period of time τ1. S5.2 Determine the ratio of the amplitudes of the primary standing wave to the auxiliary standing wave based on the collected data, denoted as r2. Furthermore, the step S5.1 includes: S5.1.1 The data acquisition time τ1 is related to the inherent rigidity axis frequency difference △ω, ensuring that △ω*τ1<<1. The data collected in S5.1.2 includes the amplitude data X of two detection positions with a 45-degree difference in azimuth. out3 、X out4 Furthermore, the step S5.2 specifically includes: S5.2.1 Assume that two detection signals X out3 and X out4 The directions are φ3 and φ4 respectively, and The amplitudes of the main standing wave and the auxiliary wave are but r2=X θ45_2 / X θ0_2 .

[0005] The present invention also provides a low-cost, high-efficiency, and automated device for locating the orientation of an inherent rigid axis, the device comprising a vacuum chamber 1, a dual-excitation vibration-isolating system, a hemispherical resonator as a vibrating element to be measured, a detection system, a mass adjustment system, and a controller 7. The vacuum chamber 1 is used to generate the vacuum environment required for signal detection. A window is reserved on the vacuum chamber for observing the situation inside the chamber and integrating a mass adjustment system, such as a laser removal system or an ion beam removal system. The dual-excitation vibration-isolating system comprises two hammers that generate a signal that can cause the vibrator to vibrate; and a vibration-isolating hammer that is used to attenuate the movement of the vibrator. Each hammer and the vibration-isolating hammer form a set of excitation and vibration-isolating systems. The orientations of the two hammers are an odd multiple of half the orthogonal orientation (22.5 degrees) relative to the second-order four-antenna vibration of the vibrator. The detection system includes at least two azimuth signal detection systems with a phase difference of 45 degrees, which are used to detect signals at orthogonal positions of the vibrator 3 . The mass adjustment system is used to remove the non-uniform mass of the oscillator. The controller is used to control the excitation and vibration suppression system, and use the detection signal information to calculate the inherent rigid axis orientation and frequency difference information, and control the rotation of the vibrator to perform corresponding position quality adjustments. Compared with the prior art, the technical effect of the present invention is (1) Efficient positioning: A dual-excitation anti-vibration hammer system is used to quickly locate the inherent rigid axis of the vibrator. Existing inherent rigid axis positioning methods generally use azimuth scanning - gradual approach, which requires a lot of manual intervention and takes a long time to locate. (2) Low restrictions and strong compatibility: The present invention is based on the quasi-standing wave vibration characteristics of the second-order four-antinode of the oscillator. It does not impose strict restrictions on the direction of the excitation signal and the method of generating the excitation signal, or the direction of the detection signal and the detection method. Existing methods have strong restrictions on the excitation and detection directions. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 Schematic diagram of the mass imbalance identification and mass adjustment system of the hemispherical resonator of the present invention Figure 2 Schematic diagram of the internal cross-section of the device Figure 3 Flowchart for tap detection Figure 4 Electrode distribution diagram of the detection base, where (I) detection electrodes are evenly distributed at 45 degrees (II) detection electrodes are evenly distributed at 45 degrees Figure 5 Detection electrode signal diagram, where (a) the detection electrode output signal at 0 degrees after the first tap (b) the detection electrode output signal at 45 degrees after the first tap (c) the detection electrode output signal at 22.5 degrees after the second tap (d) the detection electrode output signal at 67.5 degrees after the second tap. DETAILED DESCRIPTION In order to make the technical means, creative features, purpose and efficacy of the present invention easy to understand, electrode detection and laser removal of mass leveling configuration are adopted, combined with the accompanying drawings Figure 1 Overall diagram of the equipment, Figure 2 Cross-sectional view of some internal components and Figure 3 The following is a flowchart of knock detection, further illustrating the method and apparatus of the present invention. It should be noted that the present invention is not limited to this detection and removal method, and can also adopt laser Doppler vibrometer detection and ion beam mass adjustment methods. The mass leveling device for quickly determining the natural axis orientation of a hemispherical resonator comprises a vacuum chamber 1, a dual excitation vibration stopping system 2, a hemispherical resonator 3, a detection system 4, a support frame 5, a mass adjustment system 6, and a controller 7. Figure 1 shown. The vacuum chamber 1 is used to generate the vacuum environment required for signal detection. The vacuum chamber is provided with a reserved window for observing the situation inside the chamber and integrating a mass adjustment system. However, it is not limited to a laser removal system and can also be integrated with an ion beam removal system. Dual-excitation vibration isolation system 2 includes two hammers 2-1 and 2-2 and one vibration isolation hammer 2-3. The hammers generate signals that cause oscillator 3 to vibrate; the vibration isolation hammer attenuates the vibration of oscillator 3. Hammer 2-1 and vibration isolation hammer 2-3 form excitation vibration isolation system a, while hammer 2-2 and vibration isolation hammer 2-3 form excitation vibration isolation system b. The circumferential orientations of hammers 2-1 and 2-2 differ by 22.5 degrees. The vibration isolation hammers can be placed in any non-interference orientation. The hemispherical resonator 3 , a vibration element to be measured, is fixed on a rotating table 9 by a clamping tool 8 . The detection system 4 includes a readout base 4-1 with a groove. A conductive film layer is deposited on the outside and bottom of the base to form a detection electrode. The detection electrode includes at least two distributions a and b in orthogonal directions (45 degrees). It is used to simultaneously detect the orthogonal vibration signals of the vibrator 3, and convert the vibration signals into electrical signals, which are transmitted to the detection circuit board 4-4 through the lead pin 4-3 at the bottom for amplification and transmitted to the controller 7 for further analysis. The readout base 4-1 is fixed on the support ring 4-2, and the support ring 4-2 is fixed to the support frame 5 by screws. The lead pin 4-3 is fixed to the detection circuit board 4-4, and the detection circuit board 4-4 is fixed to the support frame 5 by screws. Figure 2 shown. The laser quality adjustment system 6 is used to remove the non-uniform quality of the vibrator. The laser and optical path system 6-1 are placed outside the vacuum chamber 1, and transmits the light beam 6-2 into the vacuum chamber through the lens to adjust the quality of the vibrator 3. The controller 7 primarily performs the following functions: 1) controls the excitation and vibration control of the dual-excitation vibration control system; 2) analyzes the amplitude of the signal from the orthogonal detection electrode 4-1 and determines the orientation of the inherent rigid axis; 3) controls the rotary stage 8 to rotate the vibrator 3 so that its inherent rigid axis is aligned with the laser spot processing position; and 4) controls the laser to generate a removal signal to adjust the vibrator's quality accordingly. According to this device, a method for quickly determining the orientation of the natural axis of a hemispherical resonator is described through two embodiments. Example 1 The hammer positions are 0 degrees and 22.5 degrees respectively, and the detection base has 16 detection electrodes evenly distributed along the lip of the vibrator at 22.5 degrees. Figure 4 As shown in (I), it mainly includes the following steps: S1. Initialize the device, install the vibrator 3 on the clamping rod 7, and install the clamping rod 7 to the center of the rotating table 8. Perform an end jump test on the vibrator to confirm that the coaxiality meets the requirements, such as 0.01mm. This parameter can be limited according to the required leveling accuracy. Determine the azimuth zero point of the coordinate system, which is the position of the detection electrode a in this example. Align the azimuth zero point of the rotating table 7 with the detection electrode a. Perform vacuum pumping for 10 -4 Pa around. S2. Start the 0 degree excitation vibration isolation system a. The working process of the knocking system is as follows Figure 3 shown. S3. Collect and read the time domain data of the detection electrode a (0 degrees) and the detection electrode c (45 degrees) on the base 4-1 for a period of time, here 0.9s, and record the signal amplitude as X out1 He He x out2 The amplitudes of the detection electrodes a and c are as follows: Figure 5 (a) and Figure 5 (b) and calculate r1 = X out2 / x out1 . S4. Start the 22.5 degree excitation vibration isolation system b. The working process of the knocking system is as follows Figure 3 shown. S5. Collect and read the time domain data of the detection electrode b (22.5 degrees) and the detection electrode d (67.5 degrees) on the base 4-1 for 0.9 seconds, and record the amplitude as X out3 He He x out4 The amplitudes of the detection electrodes b and d are as follows: Figure 5 (c) and Figure 5 (d) and calculate r2 = X out4 / x out3 . The inherent rigidity axis orientation, 18 degrees, is obtained by averaging the following equation: S6. The rotating table 7 automatically rotates to the 18-degree position. S7. Perform mass adjustment based on the inherent rigidity axis position. Example 2: The excitation positions are 0 degrees and 22.5 degrees respectively, and the detection electrodes can be evenly distributed at 45 degrees along the circumference of the vibrator lip edge. Figure 4 As shown in (II), it mainly includes the following steps: S1. Initialize the device, install the vibrator 3 on the clamping rod 7, and install the clamping rod 7 to the center of the rotating table 8. Perform an end jump test on the vibrator to confirm that the coaxiality meets the requirements, such as 0.01mm. This parameter can be limited according to the required leveling accuracy. Determine the azimuth zero point of the coordinate system, which is the position of the detection electrode a in this example. Align the azimuth zero point of the rotating table 7 with the detection electrode a. Perform vacuum pumping for 10 - About 4Pa. S2. Start the 0 degree excitation vibration isolation system a. S3. Collect and read the time domain data of the detection electrode a (0 degrees) and the detection electrode b (45 degrees) on the base 4-1 for a period of time, here 0.9s, and record the amplitude as X out1 He He x out2 , and calculate r1=X out2 / x out1 . S4. Start 22.5 degree excitation vibration prevention system b S5. Collect and read the time domain data of the detection electrode a (0 degrees) and the detection electrode b (45 degrees) on the base 4-1 for the same period of time, and record the amplitude as X out3 He He x out4 First, use the following formula to get the knock position X θ0 and the orthogonal knock position X θ45 Amplitude And calculate r2=X θ45 / X θ0 The inherent rigid axis orientation is obtained by averaging the following equation: S6. The rotating table 7 automatically rotates to the inherent rigid axis position. S7. Perform mass adjustment based on the inherent rigidity axis position.

Claims

1. A mass leveling method for efficiently locating the natural axis orientation of a hemispherical resonator, comprising the following steps: S1. Initialize the device, install the hemispherical resonator on the rotation stage and set the orientation reference; S2. Start the first excitation and vibration damping system a, apply pulse broadband excitation through the first hammer, and use the vibration damping hammer to attenuate the vibration S3. Collect the first set of orthogonal detection signals and calculate the amplitude ratio r1 of the main standing wave and the auxiliary wave; S4 starts the second excitation vibration control system b, applies a pulse broadband excitation through the second hammer, the azimuth difference between the second hammer and the first hammer is an odd multiple of 22.5 degrees; S5. Collect the second set of orthogonal detection signals and calculate the amplitude ratio r2 of the main standing wave and the auxiliary wave; S6. Calculate the natural low-frequency axis orientation The formula is as follows: S7. Control the rotating stage to rotate the hemispherical resonator to the inherent rigid axis orientation and perform mass adjustment.

2. The mass leveling method for efficiently locating the natural axis orientation of a hemispherical resonator according to claim 1 is characterized in that: The step S1 specifically includes: S1.1 Install the component to be tested on the rotating table; S1.2 Align the rotary table at zero degree, the detection system at 1 degree, and the hammer at 0 degree, and mark it as the system circumferential direction 0 degree, with counterclockwise rotation as positive rotation.

3. The mass leveling method for efficiently locating the natural axis orientation of a hemispherical resonator according to claim 1 is characterized in that: The step S2 includes the following process: S2.1 uses a vibration damping hammer to attenuate the residual vibration of the hemispherical resonator; S2.2 determines whether the vibration amplitude is lower than the threshold value, if not, repeat S2.1; S2.3 applying pulse broadband excitation through the first hammer; S2.4 determines whether the excitation is successful, if not, returns to S2.

1.

4. The mass leveling method for efficiently locating the natural axis orientation of a hemispherical resonator according to claim 1, characterized in that: The step S3 specifically includes: S3.1 collects two detection signals with an azimuth difference of 45 degrees at time τ0 S3.2 obtains the amplitude ratio of the main standing wave and the auxiliary wave based on the collected data, which is recorded as r1.

5. The mass leveling method for efficiently positioning the natural axis orientation of a hemispherical resonator according to claim 4 is characterized in that: The characteristics of step S3.1 are as follows: S3.1.1 The data acquisition time τ0 is related to the inherent rigidity axis frequency difference △ω, ensuring that △ω*τ0<<1. The data collected in S3.1.2 includes the amplitude data X of two detection positions with a 45-degree difference in azimuth. out1 、X out2 .

6. A mass leveling method for efficiently locating the natural axis orientation of a hemispherical resonator according to claim 4, characterized in that: The characteristics of step S3.2 are as follows: S3.2.1 Assume that two detection signals X out1 and X out2 The directions are and and Then the amplitudes of the main standing wave and auxiliary wave of the quasi-standing wave are but r1=X θ45_1 / X θ0_1 。 7. The mass leveling method for efficiently locating the natural axis orientation of a hemispherical resonator according to claim 1, characterized in that: The step S5 is characterized in that: S5.1 Data is collected for a period of time τ1. S5.2 Determine the ratio of the amplitudes of the primary standing wave to the auxiliary standing wave based on the collected data, denoted as r2.

8. The mass leveling method for efficiently locating the natural axis orientation of a hemispherical resonator according to claim 7, characterized in that: The characteristics of step S5.1 are as follows: S5.1.1 The data acquisition time τ1 is related to the inherent rigidity axis frequency difference △ω, ensuring that △ω*τ1<<1. The data collected in S5.1.2 includes the amplitude data X of two detection positions with a 45-degree difference in azimuth. out3 、X out4 .

9. The mass leveling method for efficiently locating the natural axis orientation of a hemispherical resonator according to claim 7, characterized in that: The characteristics of step S5.2 are as follows: S5.2.1 Assume that two detection signals X out3 and X out4 The directions are and and The amplitudes of the main standing wave and the auxiliary wave are but r2=X θ45_2 / X θ0_2 。 10. A device for implementing the method according to any one of claims 1 to 9, characterized in that: include: The vacuum chamber is used to provide the vacuum environment required for detection, and a window is reserved on the vacuum chamber for observation; A rotating stage for fixing and rotating the hemispherical resonator; Dual excitation vibration isolation system, including: The first hammer and the second hammer are used to generate a pulse excitation signal that can make the vibrator vibrate, and the circumferential orientations of the first hammer and the second hammer differ by an odd multiple of 22.5 degrees; Vibration-damping hammer, used to dampen the movement of the vibrator; A detection system consisting of at least two azimuth signal detection electrodes with a 45-degree difference; Mass trimming system for mass removal in inherently rigid axis orientations; The controller is used to control the excitation and vibration-stopping system, and use the detection signal information to calculate the inherent rigid axis orientation and frequency difference information, and control the rotation of the vibrator to perform corresponding position quality adjustment.

11. The device according to claim 10, characterized in that The excitation directions of the first striking hammer and the second striking hammer are tangent to the lip edge of the hemispherical resonator; the vibration-stopping direction of the vibration-stopping hammer is orthogonal to the excitation direction.

12. The device according to claim 10, characterized in that The controller includes: Excitation control module, used to control the timing of the striking hammer and the vibration-damping hammer; Signal processing module for solving the inherent rigid axis orientation; Motion control module, used to control the positioning of the rotary table; The adjustment control module is used to control the quality adjustment process.

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