Hemispherical harmonic oscillator global surface quality-rigidity combined trimming method and system

Abstract

The invention provides a hemispherical resonator full spherical surface quality-rigidity combined trimming method and system, and belongs to the field of solid-state vibrating gyroscopes. The invention aims to solve the problem of low trimming efficiency caused by mass and rigidity coupling in the trimming frequency splitting process because etching is not carried out on a full-hemispherical shell in the existing trimming process of the hemispherical harmonic oscillator. A laser Doppler vibration meter is used for obtaining the low-frequency axis, high-frequency axis orientation and frequency splitting decomposition value of a hemispherical resonator, a focused ion beam is controlled to conduct rigidity fine adjustment on the positions of the four high-frequency axes in a high-latitude area, and quality-rigidity coupling fine adjustment is conducted on the positions of the four low-frequency axes in a low-latitude area. Etching on the full-hemispherical shell is realized, the quality and rigidity of the hemispherical harmonic oscillator can be decoupled, and the trimming efficiency of the hemispherical harmonic oscillator is improved; the mass and the rigidity are decoupled through mass-rigidity combined trimming, and the uniformity of the mass and the rigidity of the hemispherical resonator gyroscope is improved; the method has certain universality and can be popularized and used for mass rigidity trimming of harmonic oscillators in different shapes.

Description

Technical Field

[0001] The invention relates to the technical field of solid-state vibrating gyroscopes, and in particular to a method and system for jointly adjusting the spherical surface mass and stiffness of a hemispherical resonator. Background Art

[0002] The hemispherical resonator gyroscope (HRG) is the most accurate solid-state vibratory gyroscope currently available. It is considered a disruptive technology in the field of high-precision navigation. The working principle of HRG is based on the inertia of elastic standing waves excited in a rotating axisymmetric shell. HRG has the advantages of high precision, long life, high reliability, strong resistance to shock and electromagnetic interference, and is the preferred gyroscope for cutting-edge equipment such as large ships and long-life satellites. The fused quartz hemispherical resonator is the core device of HRG. It is a hard and brittle hemispherical thin-walled structural component with the characteristics of difficult material processing, complex shape and structure, and small local feature scale. It is extremely difficult to achieve efficient processing with high performance, high precision and high surface quality. The processing process of hemispherical resonators includes: rough forming, ultra-precision grinding, ultra-precision polishing, pickling, ion beam / laser leveling, coating, and heat treatment. Due to the limitations of processing technology accuracy, the defects generated by the hemispherical resonator during ultra-precision grinding and magnetorheological polishing will lead to uneven circumferential mass stiffness damping of the hemispherical resonator, which will eventually lead to frequency cracking, reduced quality factor, and increased circumferential non-uniformity of the quality factor.

[0003] Trimming is to adjust the static and dynamic balance by removing part of the unbalanced material, reduce frequency cracking and improve the quality factor. The trimming process must be nearly defect-free, without causing damage to the surface and deep structure of the resonator, and its material removal efficiency is usually low. On the other hand, because of the influence of various factors such as shape and position errors and defects introduced by the forming process, there is a great deal of uncertainty in calculating the leveling mass distribution based on the vibration characteristic detection feedback, resulting in poor actual leveling effect, low efficiency and yield. The current mainstream trimming methods include laser ablation, chemical etching and focused ion beam etching, among which focused ion beam trimming adopts a stress-free processing method, which has the advantages of atomic-level removal accuracy, no subsurface damage, and continuous material removal. Therefore, it is of great significance to use a focused ion beam to achieve mass-stiffness decoupling trimming of a hemispherical resonator. Existing patents such as a method and measuring device for adjusting a hemispherical resonator (application number: CN117606510A) and a mass leveling system and mass leveling method for a hemispherical resonator (application number: CN 117190994A) use ion beams to remove unbalanced mass at the position of the hemispherical resonator's heavy axis (i.e., the main axis of low-frequency vibration) to achieve mass leveling of the hemispherical resonator, but the adjustment position is only on the outer surface near the lip edge of the hemispherical resonator, the adjustment efficiency is low, and the stiffness cannot be adjusted separately. Existing patents such as a three-dimensional mass leveling system and method for a hemispherical resonator (application number: CN118310496A) disclose a three-dimensional mass leveling system and method for a hemispherical resonator, which uses ion beams to adjust the first three harmonics of the unbalanced mass at different latitude positions of the hemispherical resonator, but does not adjust the fourth harmonic of the unbalanced mass.

[0004] In summary, the hemispherical resonator tuning process rarely considers etching on the full hemispherical shell. This is because the hemispherical resonator will experience mass-stiffness coupling during the tuning frequency cracking process, resulting in low tuning efficiency. Summary of the invention

[0005] The technical problems to be solved by the present invention are:

[0006] In order to solve the problem that the existing hemispherical resonator tuning process is not etched on the full hemispherical shell, mass stiffness coupling occurs during the tuning frequency cracking process, resulting in low tuning efficiency.

[0007] The present invention adopts the following technical solutions to solve the above technical problems:

[0008] The present invention provides a method for joint adjustment of the mass and stiffness of the full surface of a hemispherical resonator, comprising the following steps:

[0009] S100, pre-treatment, cleaning the hemispherical resonator with a cleaning liquid to remove contaminants attached to the surface, and then installing it at the hemispherical resonator clamping end of the focused ion beam trimming system;

[0010] S200, knocking the clamping end base of the hemispherical resonator through the piezoelectric effect generated by the piezoelectric ceramic to excite the hemispherical resonator and make the hemispherical resonator vibrate at its natural frequency; adjusting the position of the laser Doppler vibrometer so that the incident laser direction passes perpendicularly through the axis of the central support rod of the hemispherical resonator and irradiates the lip position of the hemispherical resonator, collecting vibration information of the hemispherical resonator through the laser Doppler vibrometer, and obtaining the low-frequency axis orientation, high-frequency axis orientation and frequency splitting value of the hemispherical resonator;

[0011] S300, setting the focused ion beam energy to a constant value to obtain a stable removal function;

[0012] After the preparation work of S400 and steps S100-S300 is completed, the four high-frequency axis positions in the high-latitude region of the hemispherical resonator (5) are irradiated with a focused ion beam to perform stiffness adjustment. After each adjustment operation is completed, steps S100 and S200 are repeated to obtain the low-frequency axis orientation, high-frequency axis orientation and frequency splitting value of the hemispherical resonator (5), and determine whether the frequency splitting value is less than 0.001 Hz. If it is less than 0.001 Hz, the stiffness adjustment operation is completed. If it is greater than 0.001 Hz, S400 is repeated until the frequency splitting value is less than 0.001 Hz.

[0013] S500, after the stiffness adjustment in S400, determine whether the frequency splitting value is between 0.001 Hz and 0.0001 Hz. If so, use a focused ion beam to irradiate the four low-frequency axis positions in the low-latitude region of the hemispherical resonator (5) to perform mass stiffness coupling adjustment. After each adjustment operation is completed, repeat steps S100 and S200 to obtain the low-frequency axis orientation, high-frequency axis orientation and frequency splitting value of the hemispherical resonator (5), and determine whether the frequency splitting value is less than 0.0001 Hz. If it is less than 0.0001 Hz, complete the mass stiffness adjustment operation. If it is greater than 0.001 Hz, repeat S400 until the frequency splitting value is less than 0.001 Hz, then repeat S500 until the frequency splitting value is less than 0.0001 Hz.

[0014] Furthermore, in the adjustment of step S400, the frequency cracking is affected by the stiffness factor affecting the position of the removed material when removing the material in the high-latitude region; and in the adjustment of step S500, the frequency cracking is affected by the mass factor and stiffness factor affecting the position of the removed material when removing the material in the low-latitude region.

[0015] Furthermore, when performing the adjustment, the adjustment method includes:

[0016] In the second vibration mode, the azimuth of the ring's natural rigidity axis is:

[0017]

[0018] Among them, δ is the azimuth angle of the point mass m1; ε is the azimuth angle of the attachment stiffness k1; α is the amplitude ratio; T0 is the maximum kinetic energy; S0 is the maximum strain energy;

[0019] The natural frequency is:

[0020]

[0021] In the high latitude region, when the radial spring k1 is added to ζ1 = ε, the natural frequency is:

[0022]

[0023] For ζ2=ε+π / 4, the natural frequency is:

[0024]

[0025] Where, E is Young's modulus; A is the cross-sectional area of ​​the ring; R is the radius of the ring; H is the radial thickness of the ring, H< <R;

[0026] In the low latitude region, when the point mass m1 is added to ζ1=δ, the natural frequency is:

[0027]

[0028] For ζ2=δ+π / 4, the natural frequency is:

[0029]

[0030] Where M0 is the mass of the ring and w0 is the initial natural frequency of the ring.

[0031] Furthermore, in the low latitude angle range of the adjustment position of 0°-15°, the mass-stiffness coupling fine-tuning is performed; in the high latitude angle range of the adjustment position of 55°-70°, the stiffness fine-tuning is performed.

[0032] Furthermore, in step S100, the exhaust module of the focused ion beam trimming system is set to control the vacuum degree of the vacuum chamber (11) to be less than 1×10 -4 Pa.

[0033] The present invention discloses a hemispherical resonator full surface mass-rigidity joint adjustment system, which has a program module corresponding to the above steps and executes the steps in the hemispherical resonator full surface mass-rigidity joint adjustment method during operation.

[0034] The present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, wherein the computer program is configured to implement the steps of a method for jointly adjusting the mass-rigidity of a full surface of a hemispherical resonator when called by a processor.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The present invention discloses a method and system for joint adjustment of global mass-rigidity of a hemispherical resonator. The method uses a laser Doppler vibrometer to obtain the low-frequency axis and high-frequency axis orientations and frequency splitting values ​​of the hemispherical resonator, and controls a focused ion beam to perform mass-rigidity coupling fine adjustment on four low-frequency axis positions in low-latitude areas, and perform stiffness fine adjustment on four high-frequency axis positions in low-latitude areas.

[0037] The present invention achieves etching on a full hemispherical shell by adjusting four low-frequency axis positions at low latitudes and four high-frequency axis positions at high latitudes of a hemispherical resonator, thereby decoupling the mass and stiffness of the hemispherical resonator and improving the adjustment efficiency of the hemispherical resonator; through mass-stiffness joint adjustment, the mass and stiffness are decoupled, and the uniformity of the mass and stiffness of the hemispherical resonator gyroscope is improved; the method has certain universality and can be extended to the mass and stiffness adjustment of resonators of different shapes. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a flow chart of a method for joint adjustment of the mass and stiffness of the full surface of a hemispherical resonator in an embodiment of the present invention;

[0039] Figure 2 A schematic diagram of a trimming area in an embodiment of the present invention;

[0040] Figure 3 A schematic diagram of a hemispherical resonator test and ion beam adjustment in an embodiment of the present invention;

[0041] Figure 4 It is a line chart of the adjustment results of the low-frequency axis at low latitude and the high-frequency axis at high latitude in an embodiment of the present invention;

[0042] Figure 5 A diagram of a torus model with additional mass and stiffness in an embodiment of the present invention;

[0043] Figure 6 This is a comparison chart of the simulation rules of the effects of single mass factor adjustment, single stiffness factor adjustment and real adjustment on frequency splitting at different adjustment position latitude angles in an embodiment of the present invention.

[0044] Reference numerals:

[0045] 1. X-axis linear stage; 2. Hemispherical resonator turntable; 3. Three-dimensional adjustment stage; 4. Hemispherical resonator clamping end; 5. Hemispherical resonator; 6. Laser Doppler vibrometer; 7. Z-axis linear stage; 8. Ion beam angle adjustment turntable; 9. Ion beam source; 10. Piezoelectric ceramics; 11. Vacuum chamber. DETAILED DESCRIPTION

[0046] In the description of the present invention, it should be noted that the terminology nouns in the various embodiments, such as "up", "down", "front", "back", "left", "right", etc., which indicate directions, are only for simplifying the description of the positional relationship based on the drawings in the specification, and do not mean that the referred elements and devices must be operated according to the specific directions and defined operations and methods and structures in the specification. Such directional nouns do not constitute a limitation on the present invention.

[0047] In the description of the present invention, it should be noted that the terms "first", "second", and "third" mentioned in the embodiments of the present invention are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second", and "third" may explicitly or implicitly include one or more of the features.

[0048] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0049] Combination Figure 2 As shown, the edge of the hemispherical resonator is defined as the low-latitude region, and the area of ​​the hemispherical shell close to the support rod is defined as the high-latitude region. A focused ion beam is used to remove material from the low-frequency axis position and the high-frequency axis position in the low-latitude region and the high-latitude region, respectively. In order to ensure that the hemispherical resonator gyroscope has high performance, the hemispherical resonator should have very small frequency splitting, that is, the difference in the resonant frequencies of the two working modes is small. Fused quartz is a fragile material. Affected by various non-ideal factors such as current processing accuracy and residual stress, the processed quartz resonator will have isotropic stiffness anisotropy and uneven mass distribution, resulting in large frequency splitting, which will cause the hemispherical resonator to produce zero bias drift problems. Figure 2 In the case of a hemispherical resonator, when it vibrates, it will produce two inherent axes at 45° to each other, also known as the principle axis. When the hemispherical resonator vibrates along the two principle axes, the vibration frequencies are ω1 and ω2 respectively. The absolute value of the difference between the two is called frequency splitting. Figure 2 In the spectrum analyzer, the two main vibration axes are the low-frequency axis and the high-frequency axis.

[0050] Specific implementation plan 1: Combine Figures 1 to 5 As shown, the present invention provides a method for joint adjustment of the mass-stiffness of the full surface of a hemispherical resonator, comprising the following steps:

[0051] S100, pre-treatment, using cleaning fluid to clean the hemispherical resonator, after removing the contaminants attached to the surface, install it on the hemispherical resonator clamping end 4 of the focused ion beam trimming system, set the exhaust module to control the vacuum degree of the vacuum chamber to be less than 1×10 -4 Pa;

[0052] The cleaning liquid can be hydrochloric acid, anhydrous ethanol or other existing cleaning liquids;

[0053] S200, the base of the hemispherical resonator clamping end 4 is struck by the piezoelectric effect generated by the piezoelectric ceramic 10 to excite the hemispherical resonator 5; the position of the laser Doppler vibrometer 6 is adjusted so that the incident laser direction passes vertically through the axis of the central support rod of the hemispherical resonator 5 and irradiates the lip position of the hemispherical resonator 5, and the vibration information of the hemispherical resonator 5 is collected by the laser Doppler vibrometer 6 to obtain the low-frequency axis orientation, high-frequency axis orientation and frequency splitting value of the hemispherical resonator 5;

[0054] S300, controlling the displacement platform of the focused ion beam trimming system so that the incident direction of the focused ion beam is always perpendicular to the outer spherical surface of the hemispherical resonator 5, setting the focused ion beam energy to a constant value to obtain a stable removal function, and then irradiating the focused ion beam to four low-frequency axis positions in the low-latitude area and four high-frequency axis positions in the high-latitude area;

[0055] The hemispherical resonator clamping end 4 is placed on the three-dimensional adjustment platform 3, and the three-dimensional adjustment platform 3 has three degrees of freedom, two of which are used for linear motion, that is, for adjusting the adjusted latitude position of the hemispherical resonator 5, and the third degree of freedom is used for the rotational motion of the hemispherical resonator 5, that is, for adjusting the adjusted longitude angle of the hemispherical resonator 5; by adjusting the position and posture of the hemispherical resonator 5, the ion beam of the ion beam source 9 can be vertically incident on the specified position of the hemispherical resonator surface; wherein the three-dimensional adjustment platform 3 is arranged on the hemispherical resonator turntable 2, and the hemispherical resonator turntable 2 is arranged on the X-axis linear platform 1; the ion beam source 9 is arranged on the ion beam angle adjustment turntable 8, and the ion beam angle adjustment turntable 8 is arranged on the Z-axis linear platform 7, and the hemispherical resonator 5, the motion platform, and the ion beam source 9 are all located in the vacuum chamber 11;

[0056] S400, after the preparation work of steps S100-S300 is completed, the mass-stiffness decoupling and trimming of the hemispherical resonator 5 is performed, including:

[0057] The edge of the hemispherical resonator is defined as a low-latitude region, and the region of the hemispherical shell close to the support rod is defined as a high-latitude region; the focused ion beam emitted by the ion beam source 9 is irradiated to four low-frequency axis positions in the low-latitude region and four high-frequency axis positions in the high-latitude region; wherein, mass-rigidity coupling adjustment is performed on the four low-frequency axis positions in the low-latitude region, and stiffness fine-tuning is performed on the four high-frequency axis positions in the high-latitude region, specifically including:

[0058] First, a focused ion beam is used to irradiate the four high-frequency axis positions in the high-latitude region of the hemispherical resonator 5 to perform stiffness adjustment. After each adjustment operation is completed, steps S100 and S200 are repeated to obtain the low-frequency axis orientation, high-frequency axis orientation and frequency splitting value of the hemispherical resonator 5, and it is determined whether the frequency splitting value is less than 0.001 Hz. If it is less than 0.001 Hz, the stiffness adjustment operation is completed. If it is greater than 0.001 Hz, S400 is repeated.

[0059] S500. After the stiffness adjustment of S400 is completed, determine whether the frequency splitting value is within the range of 0.001Hz to 0.0001Hz. If so, use a focused ion beam to irradiate the four low-frequency axis positions in the low-latitude area of ​​the hemispherical resonator 5 to perform mass stiffness coupling adjustment. After each adjustment operation is completed, repeat steps S100 and S200 to obtain the low-frequency axis orientation, high-frequency axis orientation and frequency splitting value of the hemispherical resonator 5, and determine whether the frequency splitting value is less than 0.0001Hz. If it is less than 0.0001Hz, complete the mass stiffness adjustment operation. If it is greater than 0.001Hz, repeat S400 until the frequency splitting value is less than 0.001Hz, then repeat S500 until the frequency splitting value is less than 0.0001Hz.

[0060] The volume of material removed is controlled by the residence time, and the frequency cracking is measured after each removal to make the change in frequency cracking proportional to the adjustment time. Therefore, the efficiency of the ion beam's effect on frequency cracking can be obtained through multiple adjustments.

[0061] Specific implementation plan 2: Combined Figure 5 As shown, in the adjustment of step S400, the frequency cracking is affected by the stiffness factor affecting the position of the removed material when removing the material in the high latitude area; in the adjustment of step S500, the frequency cracking is affected by the mass factor and stiffness factor affecting the position of the removed material when removing the material in the low latitude area, specifically including:

[0062] The hemispherical shell of the hemispherical resonator is equivalent to the superposition of multiple rings in the meridian direction. The unbalanced local material is equivalent to the unbalanced point mass m1 and unbalanced stiffness k1 at the local position of the ring.

[0063] In the second vibration mode, the azimuth of the ring's natural rigidity axis is:

[0064]

[0065] Among them, δ is the azimuth angle of the point mass m1; ε is the azimuth angle of the attachment stiffness k1; α is the amplitude ratio; T0 is the maximum kinetic energy; S0 is the maximum strain energy;

[0066] The natural frequency is:

[0067]

[0068] In the high latitude region, the frequency splitting is caused by the stiffness factor of the unbalanced material; when the radial spring k1 is added to ζ1 = ε, the natural frequency is:

[0069]

[0070] For ζ2=ε+π / 4, the natural frequency is:

[0071]

[0072] Where, E is Young's modulus; A is the cross-sectional area of ​​the ring; R is the radius of the ring; H is the radial thickness of the ring, H< <R;

[0073] The reduction in local stiffness will lead to w k11 The decrease of stiffness has an effect on w k12 The influence of the axis is small; the position where the stiffness is reduced will become the position of the low-frequency axis; therefore, the high-frequency axis adjustment in the high-latitude area will reduce the frequency cracking;

[0074] In the low-latitude region, the frequency splitting is caused by the mass factor and stiffness factor of the unbalanced material; when the point mass m1 is added to ζ1=δ, the natural frequency is:

[0075]

[0076] For ζ2=δ+π / 4, the natural frequency is:

[0077]

[0078] Where M0 is the mass of the ring, w0 is the initial natural frequency of the ring;

[0079] The removal of point mass m1 will result in and and the position of the removed mass will become the position of the high-frequency axis, so the low-frequency axis adjustment in the low-latitude area will reduce the frequency cracking.

[0080] The other combinations and connection relationships of this embodiment are the same as those of the first embodiment.

[0081] Specific implementation scheme three: The present invention provides a hemispherical resonator full-spherical surface mass-stiffness joint adjustment system, which has a program module corresponding to the above steps, and executes the steps in the above-mentioned hemispherical resonator full-spherical surface mass-stiffness joint adjustment method during operation.

[0082] The other combinations and connection relationships of this embodiment are the same as those of the second embodiment.

[0083] Specific implementation scheme four: The present invention provides a computer-readable storage medium, which stores a computer program, and the computer program is configured to implement the steps of a method for jointly adjusting the mass-stiffness of a full surface of a hemispherical resonator when called by a processor.

[0084] The other combinations and connection relationships of this embodiment are the same as those of the second embodiment.

[0085] Simulation experiment

[0086] The focused ion beam removed material at four low-frequency axis positions in the low-latitude region and four high-frequency axis positions in the high-latitude region, and the dwell time at each trimming point was set to 180 seconds.

[0087] The relationship between the number of ion beam fine-tuning times and frequency splitting during the experiment is as follows: Figure 4 As shown in the figure, when trimming is performed at the four low-frequency axis positions in the low-latitude region and the four high-frequency axis positions in the high-latitude region of the hemispherical resonator, the frequency splitting decreases linearly with the increase of the number of focused ion beam trimming. And under the condition of the same number of trimming times, Figure 4 (b) The change in frequency splitting caused by adjusting the high-frequency axis position in the high-latitude region is Figure 4 (a) In the low-latitude region, the frequency splitting value is twice the adjustment of the low-frequency axis position. When the frequency splitting value is greater than 0.0001Hz, the frequency splitting value is large and the frequency splitting needs to be reduced as soon as possible. Therefore, when the high-frequency axis position is adjusted in the high-latitude region, the frequency splitting value can be greatly reduced. When the frequency splitting is less than 0.0001Hz, the frequency splitting is already very small. Due to the ion beam positioning error and the instability of the removal function, fast adjustment sometimes causes excessive adjustment, resulting in increased frequency splitting. Therefore, in order to accurately reduce the frequency splitting, a slow adjustment position is required to adjust the low-frequency axis position in the low-latitude region.

[0088] exist Figure 6 It can be observed that:

[0089] (1) By Figure 6 From the single quality factor adjustment curve (blue curve) in the figure, it can be seen that considering only the quality factor, the frequency cracking decreases with the increase of the latitude angle of the adjustment and removal material; the quality factor of the adjustment and removal material has a significant effect on the frequency cracking at the latitude angle of 0°-15°; in other latitudes, the quality factor of the adjustment and removal material has no obvious effect on the frequency cracking;

[0090] (2) By Figure 6From the single stiffness factor adjustment curve (green curve), it can be seen that, considering only the stiffness factor, the stiffness factor of the material removed has a significant effect on the frequency cracking in the low latitude angle range of 0°-15° and the high latitude angle range of 55°-70°; the stiffness factor of the material removed has a greater effect on the frequency cracking in the high latitude range than in the low latitude range; in other latitude regions, the stiffness factor of the material removed has no obvious effect on the frequency cracking;

[0091] (3) By Figure 6 From the real tuning curve (red curve), it can be seen that in the low latitude angle range of 0°-15° and the high latitude angle range of 55°-70°, the trimming and removing of materials has a significant effect on the frequency splitting; in other latitudes, the trimming and removing of materials has no obvious effect on the frequency splitting; in high latitudes, the frequency splitting caused by the trimming and removing of materials is basically the same as the frequency decomposition caused by the stiffness factor of the trimming and removing of materials; therefore, in low latitudes, the frequency splitting is mainly determined by the mass factor and stiffness factor of the trimming and removing of materials; in high latitudes, the frequency splitting is mainly determined by the stiffness factor of the trimming and removing of materials, which further explains the trimming methods of S400 and S500. The efficiency of trimming at high latitudes is about twice that of low latitudes. Therefore, when the frequency splitting is large in the early stage of trimming, the method of trimming at high latitudes is adopted, and in the fine trimming process of less than 0.001Hz, the method of trimming at low latitudes is adopted to reduce the influence of ion beam source fluctuations on the precise trimming of frequency splitting.

[0092] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A method for joint adjustment of the mass and stiffness of the spherical surface of a hemispherical resonator, characterized in that: The following steps are involved: S100, pre-treatment, using a cleaning liquid to clean the hemispherical resonator (5), after removing the contaminants attached to the surface, installing it on the hemispherical resonator clamping end (4) of the focused ion beam trimming system; S200, the piezoelectric effect generated by the piezoelectric ceramic (10) is used to strike the base of the hemispherical resonator clamping end (4), thereby exciting the hemispherical resonator (5) and causing the hemispherical resonator to vibrate at a natural frequency; the position of the laser Doppler vibrometer (6) is adjusted so that the direction of the incident laser passes perpendicularly through the axis of the central support rod of the hemispherical resonator (5) and irradiates the lip position of the hemispherical resonator (5), and the vibration information of the hemispherical resonator (5) is collected by the laser Doppler vibrometer (6), so as to obtain the low-frequency axis orientation, high-frequency axis orientation and frequency splitting value of the hemispherical resonator (5); S300, setting the focused ion beam energy to a constant value to obtain a stable removal function; After the preparation work of S400 and steps S100-S300 is completed, the four high-frequency axis positions in the high-latitude region of the hemispherical resonator (5) are irradiated with a focused ion beam to perform stiffness adjustment. After each adjustment operation is completed, steps S100 and S200 are repeated to obtain the low-frequency axis orientation, high-frequency axis orientation and frequency splitting value of the hemispherical resonator (5), and determine whether the frequency splitting value is less than 0.001 Hz. If it is less than 0.001 Hz, the stiffness adjustment operation is completed. If it is greater than 0.001 Hz, S400 is repeated until the frequency splitting value is less than 0.001 Hz. S500, after the stiffness adjustment in S400, determine whether the frequency splitting value is between 0.001 Hz and 0.0001 Hz. If so, use a focused ion beam to irradiate the four low-frequency axis positions in the low-latitude region of the hemispherical resonator (5) to perform mass stiffness coupling adjustment. After each adjustment operation is completed, repeat steps S100 and S200 to obtain the low-frequency axis orientation, high-frequency axis orientation and frequency splitting value of the hemispherical resonator (5), and determine whether the frequency splitting value is less than 0.0001 Hz. If it is less than 0.0001 Hz, complete the mass stiffness adjustment operation. If it is greater than 0.001 Hz, repeat S400 until the frequency splitting value is less than 0.001 Hz, then repeat S500 until the frequency splitting value is less than 0.0001 Hz.

2. The method for joint adjustment of the mass and stiffness of the spherical surface of a hemispherical resonator according to claim 1 is characterized in that: In the adjustment of step S400, the frequency cracking is affected by the stiffness factor affecting the position of the removed material when removing the material in the high-latitude region; in the adjustment of step S500, the frequency cracking is affected by the mass factor and stiffness factor affecting the position of the removed material when removing the material in the low-latitude region.

3. The method for joint adjustment of the mass-stiffness of the spherical surface of a hemispherical resonator according to claim 2 is characterized in that: When making adjustments, the adjustment methods include: In the second vibration mode, the azimuth of the ring's natural rigidity axis is: Among them, δ is the azimuth angle of the point mass m1; ε is the azimuth angle of the attachment stiffness k1; α is the amplitude ratio; T0 is the maximum kinetic energy; S0 is the maximum strain energy; The natural frequency is: In the high latitude region, when the radial spring k1 is added to ζ1 = ε, the natural frequency is: For ζ2=ε+π / 4, the natural frequency is: Where, E is Young's modulus; A is the cross-sectional area of ​​the ring; R is the radius of the ring; H is the radial thickness of the ring, H< <R; In the low latitude region, when the point mass m1 is added to ζ1=δ, the natural frequency is: For ζ2=δ+π / 4, the natural frequency is: Where M0 is the mass of the ring and w0 is the initial natural frequency of the ring.

4. The method for joint adjustment of the mass and stiffness of the spherical surface of a hemispherical resonator according to claim 5, characterized in that: In the low latitude angle range of the adjustment position of 0°-15°, the mass-stiffness coupling is fine-tuned; in the high latitude angle range of the adjustment position of 55°-70°, the stiffness is fine-tuned.

5. The method for joint adjustment of the mass and stiffness of the spherical surface of a hemispherical resonator according to claim 4, characterized in that: In step S100, the exhaust module of the focused ion beam trimming system is set to control the vacuum degree of the vacuum chamber (11) to be less than 1×10 -4 Pa.

6. A hemispherical resonator full surface mass-stiffness joint adjustment system, characterized by: The system has a program module corresponding to the steps of any one of claims 1 to 5, and executes the steps in the above-mentioned method for joint adjustment of the mass-stiffness of the full surface of the hemispherical resonator when running.

7. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and the computer program is configured to implement the steps of the method for joint adjustment of the spherical mass-stiffness of a hemispherical resonator according to any one of claims 1 to 5 when called by a processor.

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