Resonator gyroscope assembly gap trimming device and method

Abstract

The application discloses a kind of resonant gyro assembly gap trimming device and method.Device includes resonator, flat plate electrode, first to eighth electrode on flat plate electrode, turntable, ion source, diaphragm, detection and control circuit module, the center column of the resonator is fixedly connected with flat plate electrode, the spherical shell end surface of the resonator is equipped with preset gap between flat plate electrode, the lower end of flat plate electrode is fixedly connected with turntable, the ion source is equipped in the side of diaphragm, the through-hole for intercepting ion beam is equipped in the center of diaphragm, the first to eighth electrode are all arranged on flat plate electrode along anticlockwise direction equidistantly, and the detection and control circuit module is connected with the first to eighth electrode by cable.The application proposes and realizes the precision adjustment of the gap between resonator and flat plate electrode after assembly, realizes the high-precision trimming of the first four harmonics of gap, further reduces the non-uniformity of gap, and improves the precision of gyro.

Description

Technical Field

[0001] This invention relates to the field of vibrating gyroscope technology, and more specifically, to a device and method for adjusting the assembly gap of a resonant gyroscope. Background Technology

[0002] A resonant gyroscope is a solid-state wave gyroscope based on the Coriolis effect. It boasts advantages such as long lifespan, maintenance-free operation, small size, low cost, shock resistance, and radiation resistance, making it a promising candidate for various applications. A resonant gyroscope mainly consists of a resonator, electrode disks, a shell, a base, and circuitry. During manufacturing, the resonator and electrode disks are fixed together using methods such as gluing, brazing, and bonding. Electrode disks are primarily of two types: flat and spherical. Spherical electrode disks require a spherical fit, demanding high concentricity and precise sphericity in the electrode disk machining, making it difficult to ensure uniformity in the assembly gap. Flat electrode disks use a planar fit, significantly reducing assembly difficulty and machining requirements. Therefore, the flat assembly method is currently widely used in resonant gyroscope manufacturing. However, due to environmental factors, experimental conditions, and limitations in resonator machining precision, even with a flat assembly method, the non-uniformity of the gap between the resonator lip and the electrode disk can still reach the micrometer level.

[0003] The uniformity of the gap between the resonator and the electrode disk directly affects the gain of the gyroscope's electrostatic excitation detection, leading to errors in the detection and control of standing waves and severely impacting the gyroscope's accuracy. Although researchers in this field have proposed various precision assembly devices and methods for resonant gyroscopes, controlling the gap between the resonator lip and the electrode disk through multi-dimensional precision adjustment of the resonator's spatial position can reduce the gap non-uniformity to approximately 1 micrometer, thus improving the non-uniformity to some extent. However, even micrometer-level gap non-uniformity errors still significantly affect the gyroscope's electrostatic excitation and detection. Currently, various devices and methods exist for gap control during the resonator-electrode disk assembly process, but effective means are lacking for gap adjustment after assembly. Therefore, further reducing the gap non-uniformity between the resonator and the electrode disk is an urgent problem to be solved. Summary of the Invention

[0004] The purpose of this invention is to provide a device and method for adjusting the assembly gap of a resonant gyroscope, so as to overcome the defects of the prior art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A resonant gyroscope assembly gap adjustment device includes a resonator, a flat plate electrode, first to eighth electrodes located on the flat plate electrode, a turntable, an ion source, an aperture, and a detection and control circuit module. The central column of the resonator is fixedly connected to the flat plate electrode. A preset gap is provided between the spherical end face of the resonator and the flat plate electrode. The lower end of the flat plate electrode is fixedly connected to the turntable. The ion source is located on one side of the aperture. The aperture has a through hole at its center for intercepting the ion beam. The first to eighth electrodes are all equally spaced on the flat plate electrode in a counterclockwise direction. The detection and control circuit module is connected to the first to eighth electrodes via cables.

[0007] Furthermore, the centers of the first to eighth electrodes are located in the same circle, the center of which coincides with the center of the plate electrode, and an isolation area of ​​a certain width is provided between adjacent electrodes.

[0008] Furthermore, the gap between the spherical shell end face of the resonator and the flat plate electrode is 10μm-100μm.

[0009] Furthermore, the diameter of the central through hole of the aperture is 1 / 2 to 2 / 3 of the gap between the end face of the spherical shell and the flat plate electrode.

[0010] Furthermore, the shape of the central through-hole of the aperture is circular or elliptical.

[0011] Furthermore, the excitation control and vibration detection of the resonator adopt a time-division multiplexing control method. The control method is as follows: within one clock cycle, the first half of the cycle is used to apply sinusoidal excitation signals to the first to eighth electrodes, and the second half of the cycle is used to detect the vibration signals on the first to eighth electrodes.

[0012] Furthermore, the resonant gyroscope assembly gap adjustment device is placed in a vacuum environment.

[0013] The present invention also provides a method for adjusting the assembly gap of the resonant gyroscope according to the aforementioned adjustment device, comprising the following steps:

[0014] S1. Apply a sinusoidal sweep frequency signal to the gyroscope to make it work in breathing mode, and adjust the excitation voltage to stabilize the amplitude of the gyroscope at the first set value.

[0015] S2. Measure the voltage output of the first to eighth electrodes, and calculate the gap d at the i-th electrode based on the voltage output of the i-th electrode. i ;

[0016] S3. Calculate the gap non-uniformity based on the calculated gaps between the first to eighth electrodes and the end face of the resonator spherical shell.

[0017] S4. If the gap non-uniformity is greater than the first target value, use Fourier series fitting to obtain the amplitude coefficients and orientation of the first four harmonic errors of the gap.

[0018] S5. Adjust the harmonic with the largest amplitude among the first four harmonics of the gap, including: when the amplitude of the i-th harmonic is the largest among the first four harmonics, the adjustment process is as follows: rotate the distribution orientation of the i-th harmonic to the direction of the ion source axis, so that the harmonic distribution orientation is coplanar with the ion source axis; select appropriate ion beam voltage, current parameters and etching time according to the magnitude of the i-th harmonic coefficient; start the ion source and etch between the resonator and the plate electrode according to the preset etching time;

[0019] S6. After completing the etching at the first etching position, rotate the resonator and the plate electrode by 360 / i degrees to complete the ion beam etching at the second to the i-th etching positions.

[0020] S7. Repeat steps S1-S6 until the gap non-uniformity is less than the first target value.

[0021] Furthermore, in step S2, the relationship between the voltage output of the i-th electrode of the resonant gyroscope and the gap conforms to the following formula:

[0022]

[0023] In the formula, v i Q is the detection voltage on the i-th electrode. s V is the quality factor of the harmonic oscillator breathing mode. dc V is the DC voltage in the excitation signal. ac Let ε be the AC voltage in the excitation signal, ε be the vacuum permittivity, A be the area of ​​the end face of the resonator's spherical shell facing the electrode, k be the equivalent stiffness of the resonator, and d be the AC voltage in the excitation signal. i The gap at the i-th electrode;

[0024] The gap d at the i-th electrode is obtained by solving the equation. i for:

[0025]

[0026] Furthermore, in step S3, the gap non-uniformity is calculated using the following formula:

[0027]

[0028] In the formula, d max d is the maximum value among the eight gaps between the first to eighth electrodes and the end face of the resonator spherical shell. min It is the minimum value among the eight gaps between the first to eighth electrodes and the end face of the resonator spherical shell.

[0029] Compared with the prior art, the advantages of the present invention are as follows: The present invention proposes and realizes the precise adjustment of the gap between the resonator and the plate electrode after assembly, realizes the high-precision adjustment of the first four harmonics of the gap, further reduces the gap non-uniformity, and improves the accuracy of the gyroscope. Attached Figure Description

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

[0031] Figure 1 This is a schematic diagram of the resonant gyroscope assembly gap adjustment device in this invention.

[0032] Figure 2 This is a magnified schematic diagram of the localized adjustment of the resonant gyroscope assembly gap in this invention.

[0033] Figure 3 This is a schematic diagram of the flat plate electrode in this invention.

[0034] Figure 4 This is a schematic diagram of the harmonic oscillator breathing mode in this invention.

[0035] Figure 5 This refers to the gap before adjustment and the distribution of the first four harmonics of the gap in the embodiment of the present invention.

[0036] Figure 6 This is the adjusted gap distribution in the embodiments of the present invention.

[0037] Figure 7 This is a flowchart of a preferred embodiment of the resonant gyroscope assembly gap adjustment method in this invention.

[0038] In the diagram: 101-Resonator; 102-Aperture; 103-Ion beam; 104-Ion source; 105-Plate electrode; 106-Turntable; 107-Detection and control circuit module; 200-Electrode; 201-First electrode; 202-Second electrode; 203-Third electrode; 204-Fourth electrode; 205-Fifth electrode; 206-Sixth electrode; 207-Seventh electrode; 208-Eighth electrode. Detailed Implementation

[0039] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0040] See Figures 1-7 As shown, this embodiment discloses a resonant gyroscope assembly gap adjustment device, including a resonator 101, a flat plate electrode 105, first to eighth electrodes 201-208 located on the flat plate electrode 105, a turntable 106, an ion source 104, an aperture 102, and a detection and control circuit module 107. The central column of the resonator 101 is fixedly connected to the flat plate electrode 105. A preset gap is provided between the spherical end face of the resonator 101 and the flat plate electrode 105. The lower end of the flat plate electrode 105 is fixedly connected to the turntable 106. The ion source 104 is located on one side of the aperture 102. The aperture 102 has a through hole in the center for intercepting the ion beam. The first to eighth electrodes are all equally spaced on the flat plate electrode 105 in a counterclockwise direction. The detection and control circuit module 107 is connected to the first to eighth electrodes 201-208 through cables.

[0041] The ion source 104 is located to the right of the resonator 101 and emits an ion beam with energies of several hundred to several thousand electron volts. The ion source 104 is installed at an angle; in this embodiment, the angle between the axis of the ion source 104 and the horizontal plane is 45 degrees.

[0042] The aperture 102 is disposed between the ion source 104 and the resonator 101, and the center of the aperture 102 coincides with the central axis of the ion source 104. The aperture 102 has a through hole in the center for intercepting ion beams of a specific beam diameter. In this embodiment, the diameter of the through hole in the center of the aperture 102 is 0.05 mm.

[0043] The planar electrode 105 has a metal film of a certain thickness and a central through-hole. The central through-hole is used for assembly with the central post of the resonator 101. The thickness of the metal film is typically 1-5 micrometers, and it is prepared by vacuum sputtering to ensure the uniformity of the film thickness. In this embodiment, the thickness of the metal film is 3 micrometers.

[0044] The first to eighth electrodes 201 are disposed on the surface of the planar electrode and formed by laser etching of a metal film. The first to eighth electrodes 201 have the same pattern shape. The center line of the first electrode 201 is coplanar with the axis of the ion source 104, and the first to eighth electrodes 201-208 are arranged sequentially in a counterclockwise direction. The first to eighth electrodes 201 are evenly distributed outside the resonator 101, and the angle between any two adjacent electrode center lines is 45°. The center lines of the first to eighth electrodes intersect at a point, and this point coincides with the center of the planar electrode. The eight electrodes are used for excitation and detection of the resonator's vibration.

[0045] The detection and control circuit module 107 adopts a time-division multiplexing control scheme, that is, in one clock cycle, the first half cycle is used to apply sinusoidal excitation signals to the first to eighth electrodes, and the second half cycle is used to detect the vibration signals on the first to eighth electrodes.

[0046] Preferably, the ion source 104 can be a focusing ion source so that more ions can pass through the aperture and bombard the electrode, thereby improving the etching efficiency.

[0047] The centers of the first electrode 201 to the eighth electrode 208 are located on the same circle, the center of which coincides with the center of the plate electrode, and an isolation area of ​​a certain width is provided between adjacent electrodes. Preferably, 16 or 32 electrodes can be provided on the plate electrode 105 to further improve the identification accuracy of the gap distribution.

[0048] The gap between the spherical end face of the resonator 101 and the flat plate electrode 105 is 10μm-100μm.

[0049] The diameter of the central through hole of the aperture 102 is 1 / 2 to 2 / 3 of the gap between the end face of the spherical shell and the flat plate electrode 105.

[0050] The central through-hole of the aperture 102 is circular or elliptical in shape.

[0051] The resonant gyroscope assembly gap adjustment device is placed in a vacuum environment.

[0052] In this embodiment, the resonator is excited to operate at a state such as Figure 4 The breathing mode is shown. During the resonator's vibration in the breathing mode, the end face of the resonator's spherical shell will always move up and down along the axis of rotational symmetry of the resonator. By detecting the change in the resonator's amplitude, and based on the relationship between the amplitude change and the gap, the average gap of different electrode regions can be obtained, which can effectively avoid the interference of coupling capacitance in the traditional method of directly measuring static capacitance and then converting it into gap. For a resonant gyroscope operating in the n=2 mode, the first four harmonics of the gap are the main source of gyroscope error. Therefore, after obtaining the average gap of the first to eighth electrode regions, Fourier series is used to obtain the orientation and amplitude coefficients of the first four harmonic errors of the gap. On this basis, ion beam is used to etch the surfaces of the first to eighth electrodes, and the etching pattern is based on the orientation and amplitude of the first four harmonic errors. By changing the thickness of the electrode film after assembly, the gap can be precisely adjusted, thereby improving the uniformity of the gyroscope gap and reducing the error.

[0053] See Figure 7 As shown, the present invention also provides a method for adjusting the assembly gap of the resonant gyroscope according to the aforementioned adjustment device, comprising the following steps:

[0054] Step S1: Apply a sinusoidal sweep signal to the gyroscope to make it work in breathing mode, and adjust the excitation voltage to stabilize the amplitude of the gyroscope at a first set value. In this embodiment, the frequency of the breathing mode is 24629Hz, and the first set value is 0.5V.

[0055] Step S2: Measure the voltage output of the first to eighth electrodes, and calculate the gap d at the i-th electrode based on the voltage output of the i-th electrode. i The relationship between the voltage output of the i-th electrode of the resonant gyroscope and the gap conforms to the following formula:

[0056]

[0057] In the formula, v i Q is the detection voltage on the i-th electrode. s V is the quality factor of the harmonic oscillator breathing mode. dc V is the DC voltage in the excitation signal. ac Let ε be the AC voltage in the excitation signal, ε be the vacuum permittivity, A be the area of ​​the end face of the resonator's spherical shell facing the electrode, k be the equivalent stiffness of the resonator, and d be the AC voltage in the excitation signal. i The gap at the i-th electrode;

[0058] The gap d at the i-th electrode is obtained by solving the equation. i for:

[0059]

[0060] In this embodiment, the average gaps between the first to eighth electrodes are 101.415 μm, 101.703 μm, 101.944 μm, 99.583 μm, 100.186 μm, 100.093 μm, 102.186 μm, and 99.399 μm, respectively.

[0061] S3. Based on the calculated gaps between the first to eighth electrodes and the end face of the resonator spherical shell, calculate the gap non-uniformity using the following formula:

[0062]

[0063] In the formula, d max d is the maximum value among the eight gaps between the first to eighth electrodes and the end face of the resonator spherical shell. min It is the minimum value among the eight gaps between the first to eighth electrodes and the end face of the resonator spherical shell;

[0064] In this embodiment, after assembly using a precision assembly device, the gap non-uniformity of the gyroscope is 2.76%.

[0065] Step S4: If the gap non-uniformity is greater than the first target value, use Fourier series fitting to obtain the amplitude coefficients and orientations of the first four harmonic errors of the gap.

[0066] In this embodiment, the first target value is 1%, the amplitude coefficient and azimuth of the first harmonic error of the gap are 118nm and 2.62rad, the amplitude coefficient and azimuth of the second harmonic error of the gap are 14nm and 1.12rad, the amplitude coefficient and azimuth of the third harmonic error of the gap are 11nm and 4.29rad, and the amplitude coefficient and azimuth of the fourth harmonic error of the gap are 478nm and 1.96rad, respectively.

[0067] Step S5: Adjust the harmonic with the largest amplitude among the first four harmonics of the gap, including: when the amplitude of the i-th harmonic is the largest among the first four harmonics, the adjustment process is as follows: rotate the distribution orientation of the i-th harmonic to the ion source axis direction so that the harmonic distribution orientation is coplanar with the ion source axis; select appropriate ion beam voltage, current parameters and etching time according to the magnitude of the i-th harmonic coefficient; start the ion source and etch between the resonator and the plate electrode according to the preset etching time.

[0068] In this embodiment, the fourth harmonic has the largest amplitude among the first four harmonics of the gap. Therefore, the fourth harmonic is tuned. In this embodiment, the resonator and the plate electrode are rotated by 112.3 degrees so that the fourth harmonic is coplanar with the axis of the ion source. The ion source voltage is set to 1000V, the current to 50mA, and the etching time to 60s.

[0069] Step S6: After completing the etching of the first etching position, rotate the resonator and the plate electrode 360 / i degrees to complete the ion beam etching of the second to the i-th etching positions; In this embodiment, rotate the resonator and the plate electrode 90 degrees, and after each position is etched, rotate 90 degrees to the next position for etching, and complete the etching of all 4 positions.

[0070] Step S7: Repeat steps S1-S6 until the gap non-uniformity is less than the first target value.

[0071] In this embodiment, after gap adjustment, the gap non-uniformity is 0.51%, and the adjusted gap distribution is as follows: Figure 6 As shown.

[0072] This invention proposes and implements precise adjustment of the gap between the resonator and the plate electrode after assembly, achieving high-precision adjustment of the first four harmonics of the gap, further reducing gap non-uniformity and improving the accuracy of the gyroscope.

[0073] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, the patent owner may make various modifications or alterations within the scope of the appended claims, as long as they do not exceed the protection scope described in the claims of the present invention, they shall be within the protection scope of the present invention.

Claims

1. A device for adjusting the assembly gap of a resonant gyroscope, characterized in that: The system includes a resonator, a flat plate electrode, first to eighth electrodes located on the flat plate electrode, a turntable, an ion source, an aperture, and a detection and control circuit module. The central column of the resonator is fixedly connected to the flat plate electrode. A preset gap is provided between the spherical end face of the resonator and the flat plate electrode. The lower end of the flat plate electrode is fixedly connected to the turntable. The ion source is located on one side of the aperture. The aperture has a through hole at its center for intercepting the ion beam. The first to eighth electrodes are all equally spaced on the flat plate electrode in a counterclockwise direction. The detection and control circuit module is connected to the first to eighth electrodes via cables. The system adjusts the largest harmonic amplitude of the first four harmonics of the gap, including: when the amplitude of the i-th harmonic is the largest among the first four harmonic amplitudes, the adjustment process is as follows: rotate the distribution orientation of the i-th harmonic to the ion source axis direction, so that the harmonic distribution orientation is coplanar with the ion source axis; select appropriate ion beam voltage, current parameters, and etching time according to the magnitude of the i-th harmonic coefficient; start the ion source and etch between the resonator and the flat plate electrode according to the preset etching time.

2. The resonant gyroscope assembly gap adjustment device according to claim 1, characterized in that: The centers of the first to eighth electrodes are located in the same circle, the center of which coincides with the center of the plate electrode, and an isolation area of ​​a certain width is provided between adjacent electrodes.

3. The resonant gyroscope assembly gap adjustment device according to claim 1, characterized in that: The gap between the spherical end face of the resonator and the flat plate electrode is 10μm-100μm.

4. The resonant gyroscope assembly gap adjustment device according to claim 1, characterized in that: The diameter of the central through hole of the aperture is 1 / 2 to 2 / 3 of the gap between the end face of the spherical shell and the flat plate electrode.

5. The resonant gyroscope assembly gap adjustment device according to claim 1, characterized in that: The shape of the central through-hole of the aperture is circular or elliptical.

6. The resonant gyroscope assembly gap adjustment device according to claim 1, characterized in that: The excitation control and vibration detection of the resonator adopt a time-division multiplexing control method. The control method is as follows: within one clock cycle, the first half of the cycle is used to apply sinusoidal excitation signals to the first to eighth electrodes, and the second half of the cycle is used to detect the vibration signals on the first to eighth electrodes.

7. The resonant gyroscope assembly gap adjustment device according to claim 1, characterized in that: The resonant gyroscope assembly gap adjustment device is placed in a vacuum environment.

8. A method for adjusting the assembly gap adjustment device of a resonant gyroscope according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Apply a sinusoidal sweep frequency signal to the gyroscope to make it work in breathing mode, and adjust the excitation voltage to stabilize the amplitude of the gyroscope at the first set value. S2. Measure the voltage output of the first to eighth electrodes, according to the... i The voltage output of the first electrode is calculated to obtain the first... i The gap d at each electrode i ; S3. Calculate the gap non-uniformity based on the calculated gaps between the first to eighth electrodes and the end face of the resonator spherical shell. S4. If the gap non-uniformity is greater than the first target value, use Fourier series fitting to obtain the amplitude coefficients and orientation of the first four harmonic errors of the gap. S5. Adjust the harmonic with the largest amplitude among the first four harmonics of the gap, including: when the amplitude of the i-th harmonic is the largest among the first four harmonics, the adjustment process is as follows: rotate the distribution orientation of the i-th harmonic to the ion source axis direction so that the harmonic distribution orientation is coplanar with the ion source axis; select appropriate ion beam voltage, current parameters and etching time according to the magnitude of the i-th harmonic coefficient; start the ion source and etch between the resonator and the plate electrode according to the preset etching time; S6. After completing the etching at the first etching position, rotate the resonator and the plate electrode by 360 / i degrees to complete the ion beam etching at the second to the i-th etching positions. S7. Repeat steps S1-S6 until the gap non-uniformity is less than the first target value.

9. The method according to claim 8, characterized in that: In step S2, the relationship between the voltage output of the i-th electrode of the resonant gyroscope and the gap conforms to the following formula: In the formula, v i For the first i The detection voltage on each electrode Q s For the quality factor of the harmonic oscillator breathing mode, V dc This refers to the DC voltage in the excitation signal. V ac The AC voltage in the excitation signal. ε The vacuum permittivity, A Let be the area of ​​the end face of the resonator's spherical shell facing the electrodes. k d is the equivalent stiffness of the harmonic oscillator. i For the first i The gap at each electrode; The first equation is obtained by solving the equation. i The gap d at each electrode i for: 。 10. The method according to claim 8, characterized in that: In step S3, the gap non-uniformity is calculated using the following formula: In the formula, d max This is the maximum value among the eight gaps between the first to eighth electrodes and the end face of the resonator's spherical shell. d min It is the minimum value among the eight gaps between the first to eighth electrodes and the end face of the resonator spherical shell.

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