Resonant gyroscope assembly clearance trimming device and method

Abstract

The invention discloses a resonant gyroscope assembly clearance trimming device and method. The device comprises a harmonic oscillator, a plate electrode, first to eighth electrodes located on the plate electrode, a rotary table, an ion source, a diaphragm and a detection and control circuit module, a central column of the harmonic oscillator is fixedly connected with the plate electrode, a preset gap is formed between the spherical shell end face of the harmonic oscillator and the plate electrode, and the lower end of the plate electrode is fixedly connected with the rotary table. The ion source is arranged on one side of the diaphragm, the center of the diaphragm is provided with a through hole for intercepting an ion beam, the first to eighth electrodes are arranged on the plate electrode at equal intervals along the anticlockwise direction, and the detection and control circuit module is connected with the first to eighth electrodes through cables. According to the invention, the precise adjustment of the gap between the harmonic oscillator and the plate electrode after assembly is provided and realized, the high-precision trimming of the first fourth harmonic of the gap is realized, the non-uniformity of the gap is further reduced, and the precision of the gyroscope is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of vibrating gyroscopes, and more specifically, to a device and method for adjusting the gap between assembling a resonant gyroscope. Background Art

[0002] The resonant gyroscope is a solid-state wave gyroscope based on the Coriolis effect. It has the advantages of long life, maintenance-free, small size, low cost, impact resistance, and radiation resistance, and has broad application prospects. The resonant gyroscope is mainly composed of a resonator, an electrode disk, a shell, a base, and a circuit. In the manufacturing process of the resonant gyroscope, it is necessary to use adhesive, brazing, bonding, etc. to fix the resonator and the electrode disk. There are two main types of electrode disks: flat plate and spherical. The spherical electrode disk assembly adopts spherical matching, which has high requirements for the concentricity of the assembly and the spherical degree of the electrode disk processing, and it is difficult to ensure the uniformity of the assembly gap. The flat plate electrode disk adopts a plane matching, and the difficulty of assembly and the requirements for electrode disk processing are greatly reduced. Therefore, the flat plate assembly scheme is currently widely used in the manufacture of resonant gyroscopes. However, due to environmental factors, experimental conditions, and the limitations of the processing accuracy of the resonator during assembly, the unevenness of the gap between the lip edge of the resonator and the electrode disk can still reach the micron level using the flat plate assembly scheme.

[0003] The uniformity of the assembly gap between the resonator and the electrode disk will directly affect the gain of the gyroscope's electrostatic excitation detection, resulting in errors in the detection and control of standing waves, which seriously affects the accuracy of the gyroscope. Although researchers in this field have proposed a variety of precision assembly devices and methods for resonant gyroscopes, by multi-dimensional precision adjustment of the spatial position of the resonator and controlling the gap between the lip edge of the resonator and the electrode disk, the gap unevenness can be controlled to about 1 micron, and the gap unevenness has been improved to a certain extent. However, the micron-level gap unevenness error will still have a significant impact on the electrostatic excitation and detection of the gyroscope. At present, there are a variety of devices and methods for gap control in the assembly link of the resonator and the electrode disk, but there is a lack of effective means for gap adjustment after assembly. Therefore, how to further reduce the gap unevenness between the resonator and the electrode disk is an urgent problem to be solved. Summary of the invention

[0004] The object of the present invention is to provide a resonant gyroscope assembly gap adjustment device and method to overcome the defects of the prior art.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A resonant gyroscope assembly gap adjustment device comprises 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, wherein the central column of the resonator is fixedly connected to the flat plate electrode, a preset gap is provided between the end surface of the spherical shell 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 provided on one side of the aperture, a through hole for intercepting an ion beam is provided at the center of the aperture, the first to eighth electrodes are arranged on the flat plate electrode at equal intervals in a counterclockwise direction, and the detection and control circuit module is connected to the first to eighth electrodes via a cable.

[0007] Furthermore, the centers of the first to eighth electrodes are located on the same circle, the center of the circle coincides with the center of the flat electrode, and an isolation region of a certain width is provided between adjacent electrodes.

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

[0009] Furthermore, the diameter of the central through hole of the aperture is 1 / 2-2 / 3 of the gap between the end surface of the spherical shell and the flat 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, which is: within a clock cycle, the first half of the cycle is used to apply a sinusoidal excitation signal to the first to eighth electrodes, and the second half of the cycle is used to detect the vibration signal 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 gap adjustment device for assembling a resonant gyroscope, comprising the following steps:

[0014] S1, applying a sine sweep signal to the gyroscope to make the gyroscope work in a breathing mode, and adjusting the excitation voltage to make the amplitude of the gyroscope stable at a first set value;

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

[0016] S3, calculating the gap non-uniformity according to the calculated gaps between the first to eighth electrodes and the end surface of the spherical shell of the resonator;

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

[0018] S5. The harmonic with the largest amplitude of the first four harmonics of the gap is adjusted, including: when the i-th harmonic amplitude is the largest among the first four harmonic amplitudes, the adjustment process is: rotating the distribution direction of the i-th harmonic to the direction of the ion source axis, so that the harmonic distribution direction is coplanar with the ion source axis; selecting appropriate ion beam voltage, current parameters and etching time according to the size of the i-th harmonic coefficient; starting the ion source, and etching between the resonator and the plate electrode according to the preset etching time;

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

[0020] S7. Repeat steps S1-S6 until the gap non-uniformity is smaller 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 is the detection voltage on the i-th electrode, Q s is the quality factor of the resonator breathing mode, V dc is the DC voltage in the excitation signal, V ac is the AC voltage in the excitation signal, ε is the vacuum dielectric constant, A is the area facing the end surface of the spherical shell of the resonator and the electrode, k is the equivalent stiffness of the resonator, d i is 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] Where, d max is the maximum value among the eight gaps between the first to eighth electrodes and the end surface of the spherical shell of the resonator, d min It is the minimum value among the eight gaps between the first to eighth electrodes and the end surface of the spherical shell of the resonator.

[0029] Compared with the prior art, the advantages of the present invention are: the present invention proposes and realizes the precise adjustment of the gap between the resonator and the flat 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

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

[0032] Figure 2 It is a schematic diagram of a partial enlargement of the gap adjustment of the resonant gyroscope assembly in the present invention.

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

[0034] Figure 4 It is a schematic diagram of the breathing mode of the resonator in the present invention.

[0035] Figure 5 It is the gap before adjustment and the first four harmonic distributions of the gap in the embodiment of the present invention.

[0036] Figure 6 is the gap distribution after adjustment in the embodiment of the present invention.

[0037] Figure 7 It is a flow chart of a preferred embodiment of the method for adjusting the gap of the resonant gyroscope assembly in the present invention.

[0038] In the figure: 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 DESCRIPTION

[0039] The preferred embodiments of the present invention are described in detail below in conjunction with 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 making a clearer and more definite definition of the protection scope of the present invention.

[0040] See also Figure 1-Figure 7 As shown, this embodiment discloses a resonant gyroscope assembly gap adjustment device, including a resonator 101, a flat electrode 105, first to eighth electrodes 201-208 located on the flat 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 electrode 105, a preset gap is provided between the end surface of the spherical shell of the resonator 101 and the flat electrode 105, the lower end of the flat electrode 105 is fixedly connected to the turntable 106, the ion source 104 is provided on one side of the aperture 102, a through hole for intercepting an ion beam is provided in the center of the aperture 102, the first to eighth electrodes are arranged on the flat electrode 105 at equal intervals in a counterclockwise direction, and the detection and control circuit module 107 is connected to the first to eighth electrodes 201-208 through a cable.

[0041] The ion source 104 is disposed on the right side of the resonator 101 and emits an ion beam with energy 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. A through hole is provided in the center of the aperture 102 for intercepting an ion beam of a specific beam diameter. In this embodiment, the diameter of the central through hole of the aperture 102 is 0.05 mm.

[0043] The plate electrode 105 is provided with a metal film layer of a certain thickness, and a through hole is provided in the center. The central through hole is used to assemble with the central column of the resonator 101. The thickness of the metal film layer is usually 1-5 microns, and vacuum sputtering is used to ensure the uniformity of the film thickness. In this embodiment, the thickness of the metal film layer is 3 microns.

[0044] The first electrode 201 to the eighth electrode 208 are arranged on the surface of the flat electrode and are formed by laser etching of the metal film layer. The first electrode 201 to the eighth electrode 208 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 in a counterclockwise direction. The first electrode 201 to the eighth electrode 208 are evenly distributed outside the resonator 101, and the angle between the center lines of any two adjacent electrodes is 45°. The center lines of the first to eighth electrodes intersect at one point, and the point coincides with the center of the flat electrode. The eight electrodes are used for the excitation and detection of the vibration of the resonator.

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

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

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

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

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

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

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

[0052] In this embodiment, the resonator is excited to operate in the following manner: Figure 4 The breathing mode 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 resonator's rotational symmetry axis. By detecting the change in the resonator's amplitude, the average gap in different electrode areas can be obtained based on the relationship between the amplitude change and the gap, which can effectively avoid the interference of coupling capacitance in the traditional method of directly measuring static capacitance and then converting it into a gap. For a resonant gyroscope working 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 areas, the Fourier series is used to obtain the azimuth and amplitude coefficients of the first four harmonic errors of the gap. On this basis, the surface of the first to eighth electrodes is etched by an ion beam, and the etching rules are carried out according to the azimuth and amplitude of the first four harmonic errors. By changing the thickness of the electrode film layer after assembly, the gap can be precisely adjusted to achieve the purpose of improving the uniformity of the gyroscope gap and reducing the error.

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

[0054] Step S1, applying a sine sweep signal to the gyroscope to make the gyroscope work in a breathing mode, and adjusting 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 24629 Hz, and the first set value is 0.5V.

[0055] Step S2: Measure the voltage outputs of the first to eighth electrodes, and calculate the gap d at the i-th electrode according to 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 is the detection voltage on the i-th electrode, Q s is the quality factor of the resonator breathing mode, V dc is the DC voltage in the excitation signal, V ac is the AC voltage in the excitation signal, ε is the vacuum dielectric constant, A is the area facing the end surface of the spherical shell of the resonator and the electrode, k is the equivalent stiffness of the resonator, d i is 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, 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. Calculate the gap non-uniformity based on the calculated gaps between the first to eighth electrodes and the end surface of the spherical shell of the resonator. The gap non-uniformity is calculated using the following formula:

[0062]

[0063] Where, d max is the maximum value among the eight gaps between the first to eighth electrodes and the end surface of the spherical shell of the resonator, d min is the minimum value among the eight gaps between the first to eighth electrodes and the end surface of the spherical shell of the resonator;

[0064] In this embodiment, after being assembled by 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, Fourier series fitting is used to obtain the first four harmonic error amplitude coefficients and orientations of the gap.

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

[0067] Step S5, adjusting the harmonic with the largest 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 harmonics, the adjustment process is: rotating 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; selecting appropriate ion beam voltage, current parameters and etching time according to the size of the i-th harmonic coefficient; starting the ion source, and etching between the resonator and the flat 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 adjusted. In this embodiment, the resonator and the plate electrode are rotated 112.3 degrees so that the fourth harmonic is coplanar with the ion source axis, and the ion source voltage is set to 1000V, the current is 50mA, and the etching time is 60s.

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

[0070] Step S7, repeat steps S1-S6 until the gap non-uniformity is smaller than the first target value.

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

[0072] The present invention proposes and realizes the precise adjustment of the gap between the resonator and the flat 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.

[0073] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, the patent owner may make various variations or modifications 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 should be within the protection scope of the present invention.

Claims

1. A resonant gyroscope assembly gap adjustment device, characterized in that: It includes a resonator, a flat electrode, first to eighth electrodes located on the flat 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 electrode, a preset gap is provided between the end surface of the spherical shell of the resonator and the flat electrode, the lower end of the flat electrode is fixedly connected to the turntable, the ion source is provided on one side of the aperture, a through hole for intercepting ion beams is provided in the center of the aperture, the first to eighth electrodes are arranged on the flat electrode at equal intervals in a counterclockwise direction, and the detection and control circuit module is connected to the first to eighth electrodes through a cable.

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 the circle coincides with the center of the flat 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 end surface of the spherical shell of the resonator and the flat electrode is 10 μm-100 μm.

4. The resonant gyroscope assembly gap adjustment device according to claim 1, characterized in that: The diameter of the aperture center through hole is 1 / 2-2 / 3 of the gap between the end surface of the spherical shell and the flat 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, which is: in one clock cycle, the first half of the cycle is used to apply a sinusoidal excitation signal to the first to eighth electrodes, and the second half of the cycle is used to detect the vibration signal 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 gap adjustment device for a resonant gyroscope assembly according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, applying a sine sweep signal to the gyroscope to make the gyroscope work in a breathing mode, and adjusting the excitation voltage to make the amplitude of the gyroscope stable at a first set value; S2. Measure the voltage outputs of the first to eighth electrodes, and calculate the gap d at the i-th electrode according to the voltage output of the i-th electrode. i ; S3, calculating the gap non-uniformity according to the calculated gaps between the first to eighth electrodes and the end surface of the spherical shell of the resonator; S4. If the gap non-uniformity is greater than the first target value, Fourier series fitting is used to obtain the first four harmonic error amplitude coefficients and orientations of the gap; S5. The harmonic with the largest amplitude of the first four harmonics of the gap is adjusted, including: when the amplitude of the i-th harmonic is the largest among the first four harmonics, the adjustment process is: rotating the distribution direction of the i-th harmonic to the direction of the ion source axis, so that the harmonic distribution direction is coplanar with the ion source axis; selecting appropriate ion beam voltage, current parameters and etching time according to the size of the i-th harmonic coefficient; starting the ion source, and etching between the resonator and the plate electrode according to the preset etching time; S6. After completing the etching of the first etching position, the resonator and the plate electrode are rotated 360 / i degrees to complete the ion beam etching of the second to i-th etching positions; S7. Repeat steps S1-S6 until the gap non-uniformity is smaller 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 is the detection voltage on the i-th electrode, Q s is the quality factor of the resonator breathing mode, V dc is the DC voltage in the excitation signal, V ac is the AC voltage in the excitation signal, ε is the vacuum dielectric constant, A is the area facing the end surface of the spherical shell of the resonator and the electrode, k is the equivalent stiffness of the resonator, d i is the gap at the i-th electrode; The gap d at the i-th electrode is obtained by solving the equation 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: Where, d max is the maximum value among the eight gaps between the first to eighth electrodes and the end surface of the spherical shell of the resonator, d min It is the minimum value among the eight gaps between the first to eighth electrodes and the end surface of the spherical shell of the resonator.

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