A hemispherical resonator adjustment method and measurement device

Abstract

The present invention relates to the technical field of gyroscope manufacturing, and in particular to a hemispherical resonator adjustment method and a measuring device. The hemispherical resonator adjustment method comprises: step 1, measuring the hemispherical resonator to be adjusted, and obtaining the first low-frequency axis position and the first frequency splitting value of the hemispherical resonator to be adjusted; step 2, according to the first low-frequency axis position and the first frequency splitting value, removing the mass block of the first preset weight at the position where the surface elevation angle of the hemispherical resonator to be adjusted is 5° to 15°; step 3, measuring the hemispherical resonator after removing the mass block of the first preset weight, and obtaining the second low-frequency axis position and the second frequency splitting value; step 4, according to the second low-frequency axis position and the second frequency splitting value, removing the mass block of the second preset weight at the position where the surface elevation angle of the hemispherical resonator is 50° to 70°. The hemispherical resonator can achieve uniform mass distribution in the annular direction, and retain the surface morphology of the hemispherical resonator, thereby improving the adjustment effect of the hemispherical resonator.

Description

Technical Field

[0001] The invention relates to the technical field of gyroscope manufacturing, and in particular to a hemispherical resonator adjustment method and a measuring device. Background Art

[0002] The hemispherical resonant gyroscope is a new type of solid-state gyroscope with the characteristics of high precision, small mass and long life. It has broad application prospects in the fields of navigation, aviation, aerospace, etc. The hemispherical resonator is the core component of the hemispherical resonant gyroscope (HRG). The uneven distribution of the annular mass of the hemispherical resonant gyroscope is one of the main defects in the manufacturing process of the hemispherical resonator, which will cause a large frequency splitting value, thereby affecting the working accuracy and service life of the hemispherical resonant gyroscope. Therefore, it is necessary to make the annular mass distribution of the hemispherical resonator uniform by leveling to obtain a very small frequency splitting value, thereby ensuring the working accuracy and service life of the hemispherical resonant gyroscope.

[0003] The two main reasons for the uneven circumferential mass distribution of the hemispherical resonator are the uneven thickness of the spherical shell in the circumferential direction caused by the processing process (i.e., the thickness of the spherical shell at different positions at the same height is different) and the uneven distribution of the material density of the hemispherical resonator in the circumferential direction (i.e., the density at some positions is relatively high and the density at some positions is relatively low).

[0004] However, the existing methods for adjusting the hemispherical resonator usually use the means of removing or adding weight to achieve the adjustment. Although the adjusted hemispherical resonator can achieve uniform mass distribution in the annular direction, it sacrifices the appearance of the hemispherical resonator (such as pits or grooves formed after removing weight, and convex points formed by adding weight). The existence of these pits (or grooves) and convex points will affect the propagation of vibration waves. When the vibration waves propagate to these positions, they will be consumed by these pits (or grooves) and convex points, thereby increasing the energy loss of the hemispherical resonator during the vibration process, reducing the quality factor of the hemispherical resonator; on the other hand, it will also interfere with the propagation of vibration, thereby introducing new noise signals.

[0005] Therefore, it is urgently necessary to propose a new hemispherical resonator tuning method and measurement device, which can accurately measure the position that needs to be tuned, and can make the hemispherical resonator achieve a lower frequency breakup value with the same tuning process; it can also retain the surface morphology of the hemispherical resonator to the greatest extent while achieving uniform annular mass distribution of the hemispherical resonator, thereby improving the tuning effect of the hemispherical resonator. Summary of the invention

[0006] The purpose of the present invention is to provide a hemispherical resonator tuning method and measuring device, which can at least partially overcome the above-mentioned technical problems, can accurately measure the position that needs to be tuned, can make the hemispherical resonator reach a lower frequency breakup value with the same tuning process, and can also retain the surface morphology of the hemispherical resonator to the greatest extent while achieving uniform annular mass distribution of the hemispherical resonator, thereby improving the tuning effect of the hemispherical resonator.

[0007] On the one hand, the present invention provides a method for adjusting a hemispherical resonator, which can reduce the frequency cracking value caused by the fourth harmonic defect; the method for adjusting a hemispherical resonator comprises the following steps: step 1, measuring the hemispherical resonator to be adjusted to obtain a first low-frequency axis position and a first frequency cracking value of the hemispherical resonator to be adjusted; step 2, according to the first low-frequency axis position and the first frequency cracking value, removing a mass block of a first preset weight at a position where the surface elevation angle of the hemispherical resonator to be adjusted is 5° to 15°; step 3, measuring the hemispherical resonator after removing the mass block of the first preset weight, and obtaining a second low-frequency axis position and a second frequency cracking value of the hemispherical resonator after removing the mass block of the first preset weight; step 4, according to the second low-frequency axis position and the second frequency cracking value, removing a mass block of a second preset weight at a position where the surface elevation angle of the hemispherical resonator after removing the mass block of the first preset weight is 50° to 70°.

[0008] Furthermore, the measuring of the hemispherical resonator to be adjusted to obtain the first low-frequency axis position and the first frequency splitting value of the hemispherical resonator to be adjusted includes: step 1.1, exciting the hemispherical resonator to be adjusted once through an excitation electrode, so that the hemispherical resonator to be adjusted enters the second-order resonance mode, and then stopping the excitation to make the hemispherical resonator to be adjusted in a free vibration state; wherein, there are two excitation electrodes, and the two excitation electrodes are symmetrical about the axis of the hemispherical resonator to be adjusted; step 1.2, while stopping the excitation, detecting the vibration of the node of the hemispherical resonator to be adjusted through a detection electrode to obtain the first radial amplitude of the node; wherein, there are two detection electrodes, the two detection electrodes are symmetrical about the axis of the hemispherical resonator to be adjusted, and the two detection electrodes are symmetrical about the axis of the hemispherical resonator to be adjusted. The detection electrode and the two excitation electrodes are located on the same cross section of the shaft, and the angle between the line connecting the two detection electrodes and the line connecting the two excitation electrodes is 45°; step 1.3, rotate the hemispherical resonator to be adjusted 22.5° along the circumference of the shaft, and perform secondary excitation on the rotated hemispherical resonator to be adjusted through the excitation electrode to make it enter the second-order resonance mode, and then stop the excitation to make it in a free vibration state; step 1.4, while stopping the excitation, detect the vibration of the node of the rotated hemispherical resonator to be adjusted through the detection electrode to obtain the second radial amplitude of the node; step 1.5, obtain the first low-frequency axis position and the first frequency breakup value of the hemispherical resonator to be adjusted according to the first radial amplitude and the second radial amplitude.

[0009] Further, the first radial amplitude is expressed as:

[0010] ,

[0011] The second radial amplitude is expressed as:

[0012] ,

[0013] in, A 1 is the first radial amplitude, A is the initial equivalent amplitude of the hemispherical resonator to be adjusted, f 1 is the first frequency splitting value, t 1 is the time after the excitation stops. f is the angle between a rigid axis of the hemispherical resonator to be adjusted that is closest to the line connecting the two detection electrodes and the line connecting the two detection electrodes after rotation, A 2 is the second radial amplitude, t 2 is the time after the secondary excitation stops; t 1= t 2. According to t The first radial amplitude and the second radial amplitude corresponding to time 1 are obtained f1 and f .

[0014] Furthermore, the first low-frequency axis position is determined by: according to the connection line of the two detection electrodes and f , marking the position of a rigid axis closest to the connection line of the two detection electrodes as the calibration position, which includes: A 1< A 2, rotate the line connecting the two detection electrodes in the opposite direction of the rotation direction of the hemispherical resonator. f The position after is determined as the calibration position; A 1> A 2, rotate the line connecting the two detection electrodes along the rotation direction of the hemispherical resonator. f The position after the calibration is determined as the calibration position; a mass block with a third preset weight is removed from the calibration position, and then the third frequency breakup value of the hemispherical resonator after the mass block with the third preset weight is measured; when the third frequency breakup value is less than the first frequency breakup value, the calibration position is determined as the position of the first low-frequency axis; when the third frequency breakup value is greater than the first frequency breakup value, the position which is 45° different from the calibration position in the circumferential direction is determined as the position of the first low-frequency axis.

[0015] Furthermore, the method of removing a mass block of a first preset weight at a position where the elevation angle of the surface of the hemispherical resonator to be adjusted is 5° to 15° according to the first low-frequency axis position and the first frequency splitting value includes: step 2.1, removing a first preset volume of hemispherical resonator material at the first low-frequency axis position by ion beam etching technology; step 2.2, filling a first preset volume of first filling material in a pit formed after removing the first preset volume of hemispherical resonator material by chemical vapor deposition technology; wherein the first filling material is the same as the material used to manufacture the hemispherical resonator to be adjusted, and the density of the first filling material is less than the density of the first preset volume of hemispherical resonator material removed.

[0016] Further, the first preset volume is determined by: removing a second preset volume of hemispherical resonator material at the first low-frequency axis position by ion beam etching technology; filling a second preset volume of the first filling material in a pit formed after removing the second preset volume of the hemispherical resonator material by chemical vapor deposition technology; measuring the fourth frequency splitting value of the hemispherical resonator after the second preset volume of the first filling material is filled; according to the linear relationship between the weight of the fourth harmonic defect of the hemispherical resonator and the frequency splitting value, the relationship between the first preset volume and the first frequency splitting value is expressed as:

[0017] ,

[0018] And the relationship between the second preset volume and the change in the frequency cracking value is expressed as:

[0019] ,

[0020] in, l is the proportionality coefficient, r 1 is the density of the hemispherical resonator material after removing the second preset volume, r is the density of the first filling material, V 1 is the first preset volume, f 4 is the fourth frequency cracking value, V 2 is the second preset volume;

[0021] The first preset volume is obtained:

[0022] .

[0023] Furthermore, the ion beam incident direction of the ion beam etching technology coincides with the outer surface normal of the target position.

[0024] Furthermore, the cross section where the two detection electrodes and the two excitation electrodes are located is located between the center and the dome of the outer sphere of the hemispherical resonator to be adjusted, and the distance between the cross section and the center is less than 1 / 10 of the radius of the outer sphere.

[0025] On the other hand, the present invention provides a hemispherical resonator measuring device, which includes a clamping seat, two excitation electrodes and two detection electrodes; the clamping seat is rotatably mounted on a frame, and the clamping seat can clamp the shaft of the hemispherical resonator and make the axis of the shaft coincide with the rotation axis of the clamping seat; the two excitation electrodes and the two detection electrodes are fixedly arranged on the frame and located on the same cross section of the clamping seat, the two excitation electrodes are symmetrical about the rotation axis, the two detection electrodes are symmetrical about the rotation axis, and the angle between the line connecting the two detection electrodes and the line connecting the two excitation electrodes is 45°.

[0026] Furthermore, a first dial is fixedly provided on the frame, the first dial is perpendicular to the rotating shaft, and the center of the first dial coincides with the rotating shaft; a second dial is fixedly provided on the clamping seat, the second dial is perpendicular to the rotating shaft, and the center of the second dial coincides with the rotating shaft.

[0027] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0028] 1. A method for adjusting a hemispherical resonator provided by an embodiment of the present disclosure can significantly reduce the frequency splitting value of the hemispherical resonator by performing a primary adjustment at a small elevation angle by removing a mass block of a first preset weight, thereby achieving a "coarse adjustment" effect with a large resolution. Then, a secondary adjustment is performed at a large elevation angle by removing a mass block of a second preset weight, thereby further reducing the frequency splitting value of the hemispherical resonator, thereby achieving a "fine adjustment" effect with a small resolution. Therefore, the method for adjusting a hemispherical resonator provided by an embodiment of the present disclosure can reduce the lower limit of the frequency splitting value of the hemispherical resonator after adjustment under the leveling process under the same de-weighting and leveling process, thereby improving the working accuracy and service life of the hemispherical resonator gyroscope.

[0029] 2. A method for adjusting a hemispherical resonator provided in an embodiment of the present disclosure can accurately obtain the frequency splitting value and the low-frequency axis position of the hemispherical resonator to be adjusted, thereby facilitating the adjustment operation. The equipment used for measurement is simple, and the measurement operation is convenient and fast.

[0030] 3. A method for adjusting a hemispherical resonator is provided in an embodiment of the present disclosure. The method first uses ion beam etching technology to remove a first volume of hemispherical resonator material at a first low-frequency axis position, and then fills the pit formed after the removal with a first filling material of a corresponding volume and a lower density, thereby replacing the original large-density mass block with a small-density mass block of the same volume, removing the excess weight at this position without leaving a pit that affects the surface morphology of the hemispherical resonator. Therefore, the present embodiment achieves uniform annular mass distribution of the hemispherical resonator through de-weighting and leveling means, retains the surface morphology of the hemispherical resonator, and improves the tuning effect of the hemispherical resonator. Under the limitation of the minimum single removal volume that can be achieved by ion beam etching, the de-weighting and leveling means of "ion beam etching + chemical vapor deposition" adopted by the present invention can achieve a smaller frequency cracking value adjustment amount, thereby further reducing the lower limit of the frequency cracking value of the hemispherical resonator after adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0032] Figure 1 A method flow chart of a hemispherical resonator adjustment method according to an embodiment of the present invention;

[0033] Figure 2 is a schematic diagram of the three-dimensional structure of a hemispherical resonator according to an embodiment of the present invention;

[0034] Figure 3 FIG. 4 is a schematic diagram of the three-dimensional structure of a hemispherical resonator measuring device according to Embodiment 3 of the present invention.

[0035] Marks and corresponding parts names in the attached drawings:

[0036] 1-clamping seat; 11-second scale plate; 2-excitation electrode; 3-detection electrode; 4-frame; 41-first scale plate; 5-hemispherical resonator; 51-axis rod. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and drawings. The schematic implementation modes and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention. It should be noted that the present invention is already in the actual development and use stage.

[0038] The uneven circumferential mass distribution of the hemispherical resonator is one of the main defects in the manufacturing process of the hemispherical resonator, which will cause a large frequency splitting value, thereby affecting the working accuracy and service life of the hemispherical resonator gyroscope. Therefore, it is necessary to make the circumferential mass distribution of the hemispherical resonator uniform by leveling to obtain a very small frequency splitting value, thereby ensuring the working accuracy and service life of the hemispherical resonator. However, the existing hemispherical resonator adjustment method usually adopts the means of deweighting or weighting to achieve adjustment. Although the adjusted hemispherical resonator can achieve uniform circumferential mass distribution, it sacrifices the appearance of the hemispherical resonator (such as pits or grooves formed after deweighting, and convex points formed by weighting). The existence of these pits (or grooves) and convex points will affect the propagation of vibration waves on the one hand. When the vibration waves propagate to these positions, they will be consumed by these pits (or grooves) and convex points, thereby increasing the energy loss of the hemispherical resonator during the vibration process, which reduces the quality factor of the hemispherical resonator; on the other hand, it will also interfere with the propagation of vibration, thereby introducing new noise signals.

[0039] In order to achieve uniform mass distribution in the annular direction of the hemispherical resonator while retaining the surface morphology of the hemispherical resonator to the greatest extent, the present invention provides a hemispherical resonator adjustment method and a measuring device, which are used to at least partially overcome the above technical problems and achieve a better adjustment effect of the hemispherical resonator.

[0040] It should be understood that the frequency splitting of the hemispherical resonator is mainly caused by the fourth harmonic defect. Accordingly, in order to achieve a lower frequency splitting value through adjustment means, the present application is also aimed at the fourth harmonic defect of the hemispherical resonator to be adjusted. Based on the fact that the present invention can achieve uniformity in the annular mass distribution of the hemispherical resonator while retaining the surface morphology of the hemispherical resonator to the greatest extent, a hemispherical resonator adjustment method provided by the present invention is particularly suitable for a hemispherical resonator with a low surface roughness and nearly uniform wall thickness after grinding. The following is a detailed description of the ground quartz hemispherical resonator through various embodiments as an example.

[0041] Embodiment 1:

[0042] like Figure 1 As shown, an embodiment of the present invention provides a method for adjusting a hemispherical resonator, which can reduce the frequency splitting value caused by the fourth harmonic defect;

[0043] The hemispherical resonator adjustment method comprises the following steps:

[0044] Step 1, measuring the hemispherical resonator to be adjusted, and obtaining the first low-frequency axis position and the first frequency splitting value of the hemispherical resonator to be adjusted;

[0045] Step 2, according to the first low-frequency axis position and the first frequency splitting value, removing a mass block of a first preset weight at a position where the elevation angle of the surface of the hemispherical resonator to be adjusted is 5° to 15°;

[0046] Step 3, measuring the hemispherical resonator after removing the mass block of the first preset weight, and obtaining the second low-frequency axis position and the second frequency splitting value of the hemispherical resonator after removing the mass block of the first preset weight;

[0047] Step 4: According to the second low-frequency axis position and the second frequency splitting value, remove the mass block of the second preset weight at a position where the surface elevation angle of the hemispherical resonator after removing the mass block of the first preset weight is 50° to 70°.

[0048] It should be understood that if Figure 2 As shown, the elevation angle refers to a point on the outer spherical surface of the hemispherical resonator (corresponding to Figure 2 The angle between the line connecting the center of the outer sphere and the cross section of the hemispherical resonator, that is, the elevation angle satisfies cos i =d / R, where i is the elevation angle of a point on the outer sphere of the hemispherical resonator, d is the distance from the point to the axis of the hemispherical resonator, and R is the radius of the outer sphere of the hemispherical resonator. Obviously, at a specified elevation angle, there are countless corresponding points and these points constitute a "latitude circle" of the hemispherical resonator. Obviously, the position of the mass block with the first preset weight removed is determined by the position of the first low-frequency axis and the elevation angle, that is, the position is on the latitude circle corresponding to the set elevation angle and is located on the "meridian" corresponding to the first low-frequency axis. The position of the mass block with the second preset weight removed is the same and will not be repeated here.

[0049] In this embodiment, the position of the mass block of the first preset weight removed is in the "low latitude" area, that is, close to the lip edge of the hemispherical resonator, which can significantly change the frequency splitting value of the hemispherical resonator when the mass block of unit weight is removed. However, limited by the single minimum removal amount of the de-weighting and leveling process (such as mechanical processing, chemical etching, laser etching, ion beam etching, etc.), there must be an error between the weight of the "mass block" removed in actual operation and the first preset weight. When the minimum frequency splitting value that can be achieved by the currently adopted de-weighting and leveling process is reached, the frequency splitting value cannot be further reduced (removing the mass block of the single minimum removal amount will increase the frequency splitting value, that is, removing too much). The position of the mass block of the second preset weight removed is in the "mid-latitude" area closer to the axis of the hemispherical resonator. When the mass block of unit weight is removed, the change in the frequency splitting value of the hemispherical resonator is smaller. Accordingly, the mass block removal of the single minimum removal amount under any selected de-weighting and leveling process has a smaller impact on the frequency splitting value of the hemispherical resonator. Based on this, the embodiment of the present invention can significantly reduce the frequency splitting value of the hemispherical resonator by performing a primary adjustment by removing a mass block of a first preset weight at a small elevation angle, thereby achieving a "coarse adjustment" effect with a large resolution, and then perform a secondary adjustment by removing a mass block of a second preset weight at a large elevation angle, thereby further reducing the frequency splitting value of the hemispherical resonator, thereby achieving a "fine adjustment" effect with a small resolution; therefore, the hemispherical resonator adjustment method provided by the embodiment of the present invention can reduce the lower limit of the frequency splitting value of the hemispherical resonator after adjustment under the leveling process while adopting the same de-weighting and leveling process, thereby improving the working accuracy and service life of the hemispherical resonator gyroscope.

[0050] Preferably, the positions where the mass blocks of the first preset weight are removed include the point corresponding to the first low-frequency axis on the "latitude circle" determined by the preset elevation angle, and three points 90°, 180° and 270° away from the point in the circumferential direction. Accordingly, the weight of the mass blocks removed at each point is 1 / 4 of the first preset weight. Based on this, it is possible to avoid excessive removal at a single position.

[0051] Preferably, in this embodiment, measuring the hemispherical resonator to be adjusted to obtain the first low-frequency axis position and the first frequency splitting value of the hemispherical resonator to be adjusted comprises:

[0052] Step 1.1, exciting the hemispherical resonator to be adjusted once through an excitation electrode, so that the hemispherical resonator to be adjusted enters a second-order resonance mode, and then stopping the excitation, so that the hemispherical resonator to be adjusted is in a free vibration state; wherein, there are two excitation electrodes, and the two excitation electrodes are symmetrical about the axis of the hemispherical resonator to be adjusted;

[0053] Step 1.2,

[0054] While stopping the excitation, the vibration of the node of the hemispherical resonator to be adjusted is detected by the detection electrode to obtain the first radial amplitude of the node; wherein, there are two detection electrodes, the two detection electrodes are symmetrical about the shaft of the hemispherical resonator to be adjusted, the two detection electrodes and the two excitation electrodes are located on the same cross section of the shaft, and the angle between the connection line of the two detection electrodes and the connection line of the two excitation electrodes is 45°;

[0055] Step 1.3, rotating the hemispherical resonator to be adjusted by 22.5° along the circumference of the shaft, performing secondary excitation on the rotated hemispherical resonator to be adjusted through the excitation electrode to make it enter the second-order resonance mode, and then stopping the excitation to make it in a free vibration state;

[0056] Step 1.4, while stopping the excitation, detecting the vibration of the node of the hemispherical resonator to be adjusted after the rotation through the detection electrode to obtain the second radial amplitude of the node;

[0057] Step 1.5, obtaining a first low-frequency axis position and a first frequency breakup value of the hemispherical resonator to be adjusted according to the first radial amplitude and the second radial amplitude.

[0058] Preferably, the cross section where the two detection electrodes and the two excitation electrodes are located is located between the center and the dome of the outer sphere of the hemispherical resonator to be adjusted, and the distance between the cross section and the center is less than 1 / 10 of the radius of the outer sphere. Based on this, the measured first radial amplitude and second radial amplitude can better represent the value of the first frequency splitting value and the rigid axis position of the hemispherical resonator.

[0059] Specifically, the first radial amplitude is expressed as:

[0060] ,

[0061] The second radial amplitude is expressed as:

[0062] ,

[0063] in, A 1 is the first radial amplitude, A is the initial equivalent amplitude of the hemispherical resonator to be adjusted, f 1 is the first frequency splitting value, t 1 is the time after one excitation stops, f is the angle between a rigid axis of the hemispherical resonator to be adjusted that is closest to the line connecting the two detection electrodes and the line connecting the two detection electrodes after rotation, A 2 is the second radial amplitude, t 2 is the time after the secondary excitation stops;

[0064] Pick t 1= t 2. According to t The first radial amplitude and the second radial amplitude corresponding to time 1 are obtained f 1 and f .

[0065] More specifically,

[0066] ,

[0067] .

[0068] Based on this, according to the initial equivalent amplitude of the hemispherical resonator to be adjusted A , the selected moment, and the first radial amplitude corresponding to that moment A 1st and 2nd radial amplitudes A 2. The first frequency decomposition value of the hemispherical resonator to be adjusted can be obtained f 1, and the angle between a rigid axis of the hemispherical resonator to be adjusted that is closest to the line connecting the two detection electrodes and the line connecting the two detection electrodes after rotation f Preferably, the first radial amplitude is selected A 1 or 2nd radial amplitude A 2The moment of maximum value.

[0069] Further, according to the connection of the two detection electrodes and f , as well as the first radial amplitude and the second radial amplitude, can determine the position of the first low-frequency axis, specifically including:

[0070] According to the connection of the two detection electrodes and f , marking the position of a rigid axis closest to the line connecting the two detection electrodes as the calibration position, which includes: selecting t 1= t 2 At any time, A 1< A 2, rotate the line connecting the two detection electrodes in the opposite direction of the rotation direction of the hemispherical resonator. f The position after is determined as the calibration position; A 1> A 2, rotate the line connecting the two detection electrodes along the rotation direction of the hemispherical resonator. f The position after the calibration is determined as the calibration position;

[0071] Removing a mass block of a third preset weight at the calibration position, and then measuring a third frequency splitting value of the hemispherical resonator after removing the mass block of the third preset weight;

[0072] When the third frequency breakup value is smaller than the first frequency breakup value, the calibrated position is determined as the position of the first low-frequency axis; when the third frequency breakup value is greater than the first frequency breakup value, the position 45° circumferentially different from the calibrated position is determined as the position of the first low-frequency axis.

[0073] It should be understood that de-weighting at the high-frequency axis of the hemispherical resonator will inevitably increase the frequency splitting value of the hemispherical resonator, but if de-weighting is performed at the low-frequency axis, if the weight removed exceeds the weight to be removed, it will be over-corrected, causing the position to change from "heavy" to "light", resulting in an increase in the frequency splitting value. Therefore, in the above operation, the third preset weight should be as small as possible to avoid misjudgment of the first low-frequency axis.

[0074] Based on this, the hemispherical resonator tuning method provided in this embodiment can accurately obtain the frequency splitting value and low-frequency axis position of the hemispherical resonator to be tuned. The low-frequency axis position is the operating position for removing the mass block. The frequency splitting value can characterize the weight of the mass block to be removed, thereby facilitating the tuning operation. The equipment used for measurement is simple, and the measurement operation is convenient and fast.

[0075] It should be understood that since the purpose of removing the mass block of the first preset weight is to significantly reduce the frequency splitting value of the hemispherical resonator, the first preset weight is "larger" and the corresponding mass block has a certain volume. The deviation between the center of mass of the mass block and the first low-frequency axis may cause the position of the rigid axis of the hemispherical resonator to change before and after adjustment, so a secondary measurement is required. Measuring the hemispherical resonator after removing the mass block of the first preset weight to obtain the second low-frequency axis position and the second frequency splitting value of the hemispherical resonator after removing the mass block of the first preset weight is also carried out in the above manner, which will not be repeated.

[0076] Embodiment 2:

[0077] This embodiment is based on Embodiment 1, except that, in this embodiment,

[0078] The removing of a mass block of a first preset weight at a position where the elevation angle of the surface of the hemispherical resonator to be adjusted is 5° to 15° according to the first low-frequency axis position and the first frequency splitting value comprises:

[0079] Step 2.1, removing a first preset volume of hemispherical resonator material at the first low-frequency axis position by ion beam etching technology;

[0080] Step 2.2, filling the first preset volume of the first filling material in the pit formed after removing the first preset volume of the hemispherical resonator material by chemical vapor deposition technology;

[0081] The first filling material is the same as the material used to manufacture the hemispherical resonator to be adjusted, and the density of the first filling material is less than the density of the hemispherical resonator material of the removed first preset volume.

[0082] Preferably, the hemispherical resonator is a quartz hemispherical resonator, and the ion beam incident direction of the ion beam etching technology coincides with the outer surface normal of the target position; the chemical vapor deposition technology is a plasma enhanced chemical vapor deposition technology; before chemical vapor deposition, the surface of the pit formed after removing the first preset volume of the hemispherical resonator material is also pre-treated, and the pre-treatment includes: placing the etched hemispherical resonator in an ultrasonic cleaning machine, cleaning it with deionized water, and drying the cleaned hemispherical resonator, thereby removing impurities on the surface of the pit formed by etching; exciting oxygen in a preset plasma treatment chamber to form oxygen plasma, placing the dried hemispherical resonator in a plasma treatment chamber, and exposing the pit to the oxygen plasma environment for a preset time. In this way, impurities on the surface of the pit of the etched hemispherical resonator can be removed, and hydroxyl groups can also be formed on the surface of the pit (during the oxygen plasma treatment process, some silicon-oxygen bonds on the quartz surface are broken under the action of oxygen atoms in the oxygen plasma, and the broken silicon-oxygen bonds react with hydrogen in the environment (mainly residual moisture in the environment) to generate hydroxyl groups). The generated hydroxyl groups can increase the polarity of the pit surface, which helps the subsequently deposited materials to adhere better and improves the bonding strength between the deposited quartz material and the original quartz material of the hemispherical resonator.

[0083] Based on this, the embodiment of the present invention first uses ion beam etching technology to remove the first volume of hemispherical resonator material at the first low-frequency axis position, and then fills the pit formed after the removal with a corresponding volume of first filling material with a lower density, thereby replacing the original large-density mass block with a small-density mass block of the same volume, removing the excess weight at this position without leaving a pit that affects the surface morphology of the hemispherical resonator; therefore, this embodiment achieves uniform annular mass distribution of the hemispherical resonator through de-weighting and leveling means, retains the surface morphology of the hemispherical resonator, and improves the adjustment effect of the hemispherical resonator.

[0084] It is worth noting that, under the de-emphasis and leveling method of "ion beam etching + chemical vapor deposition" adopted in this embodiment, the lower limit of the frequency splitting value of the trimmed hemispherical resonator under the same leveling process can be further reduced. Specifically, for the hemispherical resonator to be adjusted, the density fluctuation range of its various parts is much smaller than its average density; when only ion beam etching is used to remove the mass block per unit volume, the weight change caused is the product of the local density at that position and the unit volume; and when the de-weighting and leveling means of this embodiment is used to replace the mass block per unit volume, the weight change caused is the product of the difference between the local density at that position and the first filling density and the unit volume. Obviously, the weight change caused by replacing the mass block per unit volume using the de-weighting and leveling means of "ion beam etching + chemical vapor deposition" adopted in this embodiment is much smaller than the weight change caused by directly adopting ion beam etching to remove the mass block per unit volume. That is to say, under the limitation of the minimum single removal volume that can be achieved by ion beam etching, the de-weighting and leveling means of "ion beam etching + chemical vapor deposition" adopted in this embodiment can achieve a smaller frequency splitting value adjustment, thereby further reducing the lower limit of the frequency splitting value of the adjusted hemispherical resonator.

[0085] Specifically, the first preset volume is determined by:

[0086] Using ion beam etching technology, removing a second preset volume of hemispherical resonator material at the first low-frequency axis position; using chemical vapor deposition technology, filling a second preset volume of the first filling material in the pit formed after removing the second preset volume of the hemispherical resonator material; measuring the fourth frequency splitting value of the hemispherical resonator after the second preset volume of the first filling material is filled;

[0087] According to the linear relationship between the weight of the fourth harmonic defect of the hemispherical resonator and the frequency splitting value, the relationship between the first preset volume and the first frequency splitting value is expressed as:

[0088] ,

[0089] And the relationship between the second preset volume and the change in the frequency cracking value is expressed as:

[0090] ,

[0091] in, l is the proportionality coefficient, r 1 is the density of the hemispherical resonator material after removing the second preset volume, r is the density of the first filling material, V 1 is the first preset volume, f 4 is the fourth frequency cracking value, V 2 is the second preset volume;

[0092] The first preset volume is obtained:

[0093] .

[0094] As described above, if the weight removed exceeds the weight to be removed, over-correction will occur. Therefore, in the above operation, the second preset volume should be as small as possible, that is, the second preset volume is much smaller than the first preset volume, thereby ensuring that the calculated first preset volume is more accurate.

[0095] Based on this, the density of the second preset volume of hemispherical resonator material to be removed is equal to the density of the first preset volume of hemispherical resonator material to be removed, and then the first preset volume is inferred according to the second preset volume. The mass block of the first preset weight to be removed is converted into a volume removal amount, which is convenient for the ion beam etching technology to control the etching amount.

[0096] It is worth noting that the method for determining the first volume in this embodiment can be combined with the method for determining the position of the first low-frequency axis in Embodiment 1, that is:

[0097] At the calibration position, the third preset volume of the hemispherical resonator material is removed by ion beam etching technology, and then the fifth frequency splitting value of the hemispherical resonator after the third preset volume of the hemispherical resonator material is removed is measured, and the fifth frequency splitting value is compared with the first frequency splitting value. When the fifth frequency splitting value is less than the first frequency splitting value, the calibration position is determined as the position of the first low-frequency axis; when the fifth frequency splitting value is greater than the first frequency splitting value, the position 45° different from the calibration position in the circumferential direction is determined as the position of the first low-frequency axis; then, if the calibration position is the position of the first low-frequency axis, the filling material with a density less than the removed third preset volume of the hemispherical resonator material is filled in the pit (i.e., weight removal and leveling are performed); if the calibration position is not the first low-frequency axis position, the filling material with a density greater than the removed third preset volume of the hemispherical resonator material is filled in the pit (i.e., weight gain and leveling are performed). In this way, the operation steps can be saved and the one-time weight removal damage to the hemispherical resonator is reduced.

[0098] Embodiment 3:

[0099] like Figure 3 As shown, an embodiment of the present invention provides a hemispherical resonator measuring device, the measuring device comprising a clamping seat 1, two excitation electrodes 2 and two detection electrodes 3;

[0100] The clamping seat 1 is rotatably mounted on a frame 4, and the clamping seat 1 can clamp the shaft 51 of the hemispherical resonator 5, and make the axis of the shaft 51 coincide with the rotation axis of the clamping seat 1;

[0101] The two excitation electrodes 2 and the two detection electrodes 3 are fixedly arranged on the frame 4 and located on the same cross section of the clamping seat 1, the two excitation electrodes 2 are symmetrical about the rotation axis, the two detection electrodes 3 are symmetrical about the rotation axis, and the angle between the connecting line of the two detection electrodes 3 and the connecting line of the two excitation electrodes 2 is 45°.

[0102] Specifically, a first scale plate 41 is fixedly disposed on the frame 4, the first scale plate 41 is perpendicular to the rotation axis, and the center of the first scale plate 41 coincides with the rotation axis;

[0103] A second scale plate 11 is also fixedly disposed on the clamping seat 1 . The second scale plate 11 is perpendicular to the rotating shaft, and the center of the second scale plate 11 coincides with the rotating shaft.

[0104] Preferably, the rotating shaft of the clamping seat 1 is vertical, and the clamping seat 1 can be disassembled from and installed on the frame 4 while clamping the rotating shaft.

[0105] Based on this, the hemispherical resonator measuring device provided in this embodiment can facilitate the measurement and calibration of the frequency splitting value and the low-frequency axis position of the hemispherical resonator to be adjusted, and the calibration accuracy is high.

[0106] In a specific measurement work of the present embodiment, the two detection electrodes 3 are respectively installed at the 0° and 180° positions of the first scale plate 41, and the two excitation electrodes 2 are respectively installed at the 45° and 225° positions of the first scale plate 41; the hemispherical resonator 5 to be adjusted is clamped at an appropriate height position on the clamping seat 1, and the clamping seat 1 is rotated so that the 0° position of the second scale plate 11 is aligned with the 0° position of the first scale plate 41; then, the hemispherical resonator 5 to be adjusted is excited once to obtain the first radial amplitude of the node; thereafter, the hemispherical resonator 5 to be adjusted is excited twice to obtain the second radial amplitude of the node; and then it is calculated to obtain f , and then combined with the magnitude relationship between the first radial amplitude and the second radial amplitude, determine which side of the 0° position on the first scale plate 41 the position of a rigid axis in the hemispherical resonator 5 to be adjusted after rotation is closest to; so far, record the side of the 0° position on the first scale plate 41 facing the rigid axis. fThe first scale value of the angle, the first scale value corresponds to the position of the hemispherical resonator 5, which is the position of the rigid axis of the hemispherical resonator 5 to be adjusted, and the second scale value on the second scale plate 11 corresponding to the first scale value is recorded, and the second scale value is the position of the rigid axis. The hemispherical resonator 5 can be removed together with the clamping seat 1, and then ion beam etching, chemical vapor deposition and other operations are performed. After removal, the second scale value is used to present the calibration position of the rigid axis, which can effectively reduce the position marking error caused by conventional means (such as handwriting marking) on ​​the hemispherical resonator 5, thereby facilitating the precise positioning of the processing position in the ion beam etching operation.

[0107] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for adjusting a hemispherical resonator, characterized in that: Can reduce the frequency splitting value caused by the fourth harmonic defect; The hemispherical resonator adjustment method comprises the following steps: Step 1, measuring the hemispherical resonator to be adjusted, and obtaining the first low-frequency axis position and the first frequency splitting value of the hemispherical resonator to be adjusted; Step 2, according to the first low-frequency axis position and the first frequency splitting value, removing a mass block of a first preset weight at a position where the elevation angle of the surface of the hemispherical resonator to be adjusted is 5° to 15°; Step 3, measuring the hemispherical resonator after removing the mass block of the first preset weight, and obtaining the second low-frequency axis position and the second frequency splitting value of the hemispherical resonator after removing the mass block of the first preset weight; Step 4, according to the second low-frequency axis position and the second frequency splitting value, removing a mass block of a second preset weight at a position where the surface elevation angle of the hemispherical resonator after removing the mass block of the first preset weight is 50° to 70°; The elevation angle refers to the angle between a line connecting a point on the outer spherical surface of the hemispherical resonator and the center of the outer spherical surface and a cross section of the hemispherical resonator; The step of measuring the hemispherical resonator to be adjusted to obtain the first low-frequency axis position and the first frequency splitting value of the hemispherical resonator to be adjusted comprises: Step 1.1, exciting the hemispherical resonator to be adjusted once through an excitation electrode, so that the hemispherical resonator to be adjusted enters a second-order resonance mode, and then stopping the excitation, so that the hemispherical resonator to be adjusted is in a free vibration state; wherein, there are two excitation electrodes, and the two excitation electrodes are symmetrical about the axis of the hemispherical resonator to be adjusted; Step 1.2, while stopping the excitation, detecting the vibration of the node of the hemispherical resonator to be adjusted through the detection electrode to obtain the first radial amplitude of the node; wherein, there are two detection electrodes, the two detection electrodes are symmetrical about the shaft of the hemispherical resonator to be adjusted, the two detection electrodes and the two excitation electrodes are located on the same cross section of the shaft, and the angle between the connection line of the two detection electrodes and the connection line of the two excitation electrodes is 45°; Step 1.3, rotating the hemispherical resonator to be adjusted by 22.5° along the circumference of the shaft, performing secondary excitation on the rotated hemispherical resonator to be adjusted through the excitation electrode to make it enter the second-order resonance mode, and then stopping the excitation to make it in a free vibration state; Step 1.4, while stopping the excitation, detecting the vibration of the node of the hemispherical resonator to be adjusted after the rotation through the detection electrode to obtain the second radial amplitude of the node; Step 1.5, obtaining a first low-frequency axis position and a first frequency breakup value of the hemispherical resonator to be adjusted according to the first radial amplitude and the second radial amplitude; The first radial amplitude is expressed as: ， The second radial amplitude is expressed as: ， in, A 1 is the first radial amplitude, A is the initial equivalent amplitude of the hemispherical resonator to be adjusted, f 1 is the first frequency splitting value, t 1 is the time after one excitation stops, φ is the angle between a rigid axis of the hemispherical resonator to be adjusted that is closest to the line connecting the two detection electrodes and the line connecting the two detection electrodes after rotation, A 2 is the second radial amplitude, t 2 is the time after the secondary excitation stops; Pick t 1= t 2. According to t The first radial amplitude and the second radial amplitude corresponding to time 1 are obtained f 1 and φ ; The first low-frequency axis position is determined by: According to the connection of the two detection electrodes and φ , marking the position of a rigid axis closest to the connection line of the two detection electrodes as the calibration position, which includes: A 1< A 2, rotate the line connecting the two detection electrodes in the opposite direction of the rotation direction of the hemispherical resonator. φ The position after is determined as the calibration position; A 1> A 2, rotate the line connecting the two detection electrodes along the rotation direction of the hemispherical resonator. φ The position after the calibration is determined as the calibration position; Removing a mass block of a third preset weight at the calibration position, and then measuring a third frequency splitting value of the hemispherical resonator after removing the mass block of the third preset weight; When the third frequency breakup value is less than the first frequency breakup value, the calibration position is determined as the position of the first low-frequency axis; when the third frequency breakup value is greater than the first frequency breakup value, the position that differs from the calibration position by 45° in the circumferential direction is determined as the position of the first low-frequency axis; The removing of a mass block of a first preset weight at a position where the elevation angle of the surface of the hemispherical resonator to be adjusted is 5° to 15° according to the first low-frequency axis position and the first frequency splitting value comprises: Step 2.1, removing a first preset volume of hemispherical resonator material at the first low-frequency axis position by ion beam etching technology; Step 2.2, filling the first preset volume of the first filling material in the pit formed after removing the first preset volume of the hemispherical resonator material by chemical vapor deposition technology; Wherein, the first filling material is the same as the material used to manufacture the hemispherical resonator to be adjusted, and the density of the first filling material is less than the density of the hemispherical resonator material of the first preset volume removed; The first preset volume is determined by: Using ion beam etching technology, removing a second preset volume of hemispherical resonator material at the first low-frequency axis position; using chemical vapor deposition technology, filling a second preset volume of the first filling material in the pit formed after removing the second preset volume of the hemispherical resonator material; measuring the fourth frequency splitting value of the hemispherical resonator after the second preset volume of the first filling material is filled; According to the linear relationship between the weight of the fourth harmonic defect of the hemispherical resonator and the frequency splitting value, the relationship between the first preset volume and the first frequency splitting value is expressed as: ， And the relationship between the second preset volume and the change in the frequency cracking value is expressed as: ， in, λ is the proportionality coefficient, ρ 1 is the density of the hemispherical resonator material after removing the second preset volume, ρ is the density of the first filling material, V 1 is the first preset volume, f 4 is the fourth frequency cracking value, V 2 is the second preset volume; The first preset volume is obtained: 。 2. A method for adjusting a hemispherical resonator according to claim 1, characterized in that: The ion beam incident direction of the ion beam etching technology coincides with the outer surface normal of the target position.

3. A method for adjusting a hemispherical resonator according to claim 1, characterized in that: The cross section where the two detection electrodes and the two excitation electrodes are located is located between the center and the dome of the outer sphere of the hemispherical resonator to be adjusted, and the distance between the cross section and the center is less than 1 / 10 of the radius of the outer sphere.

4. A hemispherical resonator measuring device, used to implement the hemispherical resonator adjustment method according to any one of claims 1 to 3, characterized in that: The measuring device comprises a clamping seat (1), two excitation electrodes (2) and two detection electrodes (3); The clamping seat (1) is rotatably mounted on a frame (4), and the clamping seat (1) is capable of clamping a shaft (51) of a hemispherical resonator (5), and making the axis of the shaft (51) coincide with the rotation axis of the clamping seat (1); The two excitation electrodes (2) and the two detection electrodes (3) are fixedly arranged on the frame (4) and located on the same cross section of the clamping seat (1); the two excitation electrodes (2) are symmetrical about the rotation axis; the two detection electrodes (3) are symmetrical about the rotation axis; and the angle between the connecting line of the two detection electrodes (3) and the connecting line of the two excitation electrodes (2) is 45°.

5. A hemispherical resonator measuring device according to claim 4, characterized in that: A first scale disk (41) is also fixedly arranged on the frame (4), the first scale disk (41) is perpendicular to the rotating shaft, and the center of the first scale disk (41) coincides with the rotating shaft; A second scale disk (11) is also fixedly arranged on the clamping seat (1), the second scale disk (11) is perpendicular to the rotating shaft, and the center of the second scale disk (11) coincides with the rotating shaft.

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