A Method for Compensating the Uneven Damping Drift of a Full-Angle Hemispherical Resonant Gyro

Abstract

The present invention relates to a method for compensating the uneven damping drift of a full-angle hemispherical resonant gyroscope. The hemispherical resonant gyroscope implementing this method is designed with a pair of orthogonal detection electrodes, a pair of orthogonal excitation electrodes, a single detection electrode, and a single excitation electrode. The steps are as follows: 1. Apply excitation forces with a frequency of ω and an amplitude of f to the three excitation electrodes simultaneously; 2. Detect the vibration displacement amplitudes at three positions respectively by the three detection electrodes; 3. Obtain the circumferential damping of the hemispherical resonant gyroscope at the three positions according to the circumferential damping expression of the hemispherical resonant gyroscope and the positional relationship of the three detection electrodes; 4. Calculate the amplitude of the uneven damping drift and the angle by which the minimum damping axis rotates relative to the 0-degree vibration mode angle; 5. Compensate the above-mentioned uneven damping drift in the full-angle output of the gyroscope. The present invention realizes the compensation of the uneven damping drift of the full-angle hemispherical resonant gyroscope.

Description

Technical Field

[0001] The present invention belongs to a method for compensating the drift of a hemispherical resonator gyroscope, and particularly relates to a method for compensating the uneven damping drift of a full-angle hemispherical resonator gyroscope. Background Art

[0002] The hemispherical resonator gyroscope is a new type of high-precision gyroscope with great development prospects. Its advantages are: small volume, high precision, low power consumption, high reliability, short startup time, simple mechanical component structure, large working temperature range, strong anti-ionizing radiation ability, insensitive to linear overload, good stability when powered off, and can achieve automated production when manufacturing the hemispherical resonator gyroscope. In addition, the hemispherical resonator gyroscope also has a long lifespan. Relevant information shows that the hemispherical resonator gyroscope can work continuously for more than 15 years and maintain the required performance. Therefore, it is recognized as the gyroscope with the longest lifespan.

[0003] The production and manufacturing process of the resonator is restricted by the current process limitations, and tiny cracks will occur on the lip edge, the surface of the hemispherical shell, and the support rod of the resonator. When the resonator vibrates, the size and distribution of the cracks may also change, affecting the service life of the gyroscope. These cracks will also affect the stiffness of the resonator and residual internal stress; the uneven distribution of the cracks results in the uneven distribution of the residual internal stress, leading to inconsistent stiffness and inconsistent damping at different positions of the resonator.

[0004] The inconsistent damping at different positions of the hemispherical resonator gyroscope will cause two damping axes to be formed in the circumferential direction of the resonator, one is the maximum damping axis, and the other is the minimum damping axis, and cause additional drift. This drift is called uneven damping drift. The uneven damping drift is expressed by the following formula:

[0005]

[0006] Where ε(θ) represents the uneven damping drift varying with the vibration mode angle θ, represents the amplitude of the uneven damping drift, and θ τ represents the angle that the minimum damping axis rotates relative to the 0-degree vibration mode angle.

[0007] The circumferential damping of the hemispherical resonator gyroscope is expressed by the following formula:

[0008]

[0009] Where τ represents the damping time constant at this position, and τ0 represents the average damping time constant for one week of the resonator.

[0010] Aiming at the problem of uneven damping drift existing in the hemispherical resonator gyroscope, the present invention is intended to design a method for compensating the uneven damping drift of a full-angle hemispherical resonator gyroscope Summary of the Invention

[0011] The object of the present invention is to overcome the deficiencies of the prior art and provide a method for compensating the uneven damping drift of a full-angle hemispherical resonant gyroscope.

[0012] The above object of the present invention is achieved by the following technical solutions:

[0013] A method for compensating the uneven damping drift of a full-angle hemispherical resonant gyroscope, characterized in that: the hemispherical resonant gyroscope implementing this method is designed with a pair of orthogonal detection electrodes, a pair of orthogonal excitation electrodes, a single detection electrode, and a single excitation electrode; among them, excitation electrode 1 and excitation electrode 2 are a set of orthogonal excitation electrodes, and the spatial positions form an angle of 45°; the spatial positions of excitation electrode 2 and excitation electrode 3 form an angle of 22.5°; detection electrode 1 and detection electrode 2 are a set of orthogonal detection electrodes, and the spatial positions form an angle of 45°; the spatial positions of detection electrode 2 and detection electrode 3 form an angle of 22.5°; excitation electrode 1 and detection electrode 1 are on the same axis, and the method includes the following steps:

[0014] Step 1, apply excitation forces with a frequency of ω and an amplitude of f to excitation electrode 1, excitation electrode 2, and excitation electrode 3 simultaneously;

[0015] Step 2, respectively detect the vibration displacement amplitudes x1, x2, and x3 at three positions by detection electrode 1, detection electrode 2, and detection electrode 3;

[0016] According to the dynamic displacement amplitudes at the three positions, the damping time constants τ at the three positions are obtained as follows:

[0017]

[0018]

[0019]

[0020] In the formula, m represents the mass of the resonator, ω0 represents the natural frequency of the resonator, and δω represents the difference between the excitation force frequency and the natural frequency of the resonator;

[0021] Step 3, set the vibration mode angle of 0 degrees to coincide with detection electrode 1. From the circumferential damping expression of the hemispherical resonant gyroscope and the

[0022] positional relationship of the three detection electrodes, it can be known that:

[0023]

[0024]

[0025]

[0026] In the formula, is the circumferential damping at detection electrode 1, To detect the circumferential damping at electrode 2 To detect the circumferential damping at electrode 3 It is the average value of the circumferential damping varying with the vibration mode for one cycle.

[0027] Step 4: Calculate the amplitude of the damping non-uniformity drift The angle θ that the minimum damping axis rotates relative to the 0-degree vibration mode angle τ :

[0028]

[0029]

[0030] Step 5: Compensate the damping non-uniformity drift in the full-angle output of the gyro

[0031] According to what is obtained in step (4) θ τ , model the damping non-uniformity drift of the gyro resonator for one week according to the damping non-uniformity drift expression; assume that before the full-angle output compensation of the gyro is and after compensation is Then:

[0032]

[0033] Furthermore: In step 1, the difference between the excitation force frequency and the natural frequency of the resonator is set as δω and set to 0.1 Hz - 0.3 Hz.

[0034] Advantages and positive effects of the present invention:

[0035] The method for compensating the damping non-uniformity drift of the full-angle hemispherical resonator gyro of the present invention detects the signal through the detection electrode at the coaxial line position by applying a sinusoidal perturbation signal to different excitation electrodes, and identifies the damping time constant at the excitation electrode through the ratio of signal attenuation, thereby obtaining the relevant parameters of the damping non-uniformity drift of the resonator for one week, and realizing the compensation of the damping non-uniformity drift of the full-angle hemispherical resonator gyro. Description of the Drawings

[0036] Figure 1 It is a schematic diagram of the electrode arrangement of the hemispherical resonator gyro of the present invention. Detailed Embodiment

[0037] The following further describes the structure of the present invention in conjunction with the drawings and through embodiments. It should be noted that this embodiment is narrative rather than restrictive.

[0038] A method for compensating the uneven damping drift of a full-angle hemispherical resonant gyroscope. The hemispherical resonant gyroscope implementing this method needs to be designed with a pair of orthogonal detection electrodes, a pair of orthogonal excitation electrodes, a separate detection electrode, and a separate excitation electrode, and their positions are as Figure 1 shown. Among them, excitation electrode 1 and excitation electrode 2 are a pair of orthogonal excitation electrodes, and their spatial positions form an angle of 45°; the spatial positions of excitation electrode 2 and excitation electrode 3 form an angle of 22.5°. Detection electrode 1 and detection electrode 2 are a pair of orthogonal detection electrodes, and their spatial positions form an angle of 45°; the spatial positions of detection electrode 2 and detection electrode 3 form an angle of 22.5°. Excitation electrode 1 and detection electrode 1 are on the same axis.

[0039] The resonator of the hemispherical resonant gyroscope is a band-pass filter, that is, it has the maximum vibration displacement response to the excitation force at the natural frequency of the resonator, while for the excitation forces of other frequencies, the corresponding vibration displacement responses are greatly attenuated.

[0040] The relationship between the amplitude of the excitation force and the amplitude of the vibration displacement response of the resonator is as follows:

[0041]

[0042] Where: x represents the amplitude of the vibration displacement response of the resonator, f represents the amplitude of the excitation force, τ is the damping time constant, m represents the mass of the resonator, ω0 represents the natural frequency of the resonator, and δω represents the difference between the excitation force frequency and the natural frequency of the resonator. The τ at this position is obtained through the circumferential damping expression of the above hemispherical resonant gyroscope. x can be obtained by detecting the vibration signal through the detection electrode; m can be obtained during the gyroscope assembly; ω0 is provided by the frequency tracking circuit; f is the amplitude of the actively applied excitation force. If the frequency of the excitation force is set to ω, then:

[0043] δω = ω - ω0

[0044] From the above expression of the relationship between the amplitude of the excitation force and the amplitude of the vibration displacement response of the resonator, τ is expressed as:

[0045]

[0046] The vibration of the resonator of the hemispherical resonant gyroscope is axially symmetric. The amplitudes of the vibration displacements at excitation electrode 1 and detection electrode 1 are the same; the amplitudes of the vibration displacements at excitation electrode 2 and detection electrode 2 are the same; the amplitudes of the vibration displacements at excitation electrode 3 and detection electrode 3 are the same.

[0047] The specific compensation steps are as follows:

[0048] Step 1: Apply an excitation force with a frequency of ω and an amplitude of f to the excitation electrode 1, excitation electrode 2, and excitation electrode 3 simultaneously. It is necessary to make the signal detectable after attenuation and also avoid the influence of the disturbance signal on the normal operation of the gyroscope. σω is set to 0.1 Hz to 0.3 Hz.

[0049] Step 2: Detect the vibration displacement amplitudes x1, x2, and x3 at three positions respectively by the detection electrode 1, detection electrode 2, and detection electrode 3.

[0050] According to the dynamic displacement amplitudes at the three positions, the damping time constants τ at the three positions are obtained from the above τ expression as follows:

[0051]

[0052]

[0053]

[0054] Step 3: Set the vibration mode angle of 0 degrees to coincide with the detection electrode 1. The vibration mode angle is defined as the angle between the standing wave antinode and the detection electrode 1. From the circumferential damping expression of the hemispherical resonator gyroscope and the positional relationship of the three detection electrodes, it can be known that:

[0055]

[0056]

[0057]

[0058] In the formula, in the formula, is the circumferential damping at the detection electrode 1, is the circumferential damping at the detection electrode 2, is the circumferential damping at the detection electrode 3, is the average value of the circumferential damping varying with the vibration mode for one period.

[0059] Step 4: Calculate the amplitude of the damping non-uniform drift The angle θ by which the minimum damping axis rotates relative to the vibration mode angle of 0 degrees τ :

[0060]

[0061]

[0062] Step 5: Compensate for the damping non-uniform drift in the full-angle output of the gyroscope

[0063] According to the θ τ, model the damping non-uniform drift of the gyro resonator in one cycle according to the damping non-uniform drift expression; set the gyro full-angle output before compensation as after compensation as Then:

[0064]

[0065] This method designs a damping non-uniform compensation method for a full-angle hemispherical resonator gyro, which can solve the problem that the damping non-uniform drift affects the gyro zero-bias stability with time and temperature changes. It is convenient to implement in engineering and has strong engineering application value.

[0066] Although the embodiments and drawings of the present invention are disclosed for illustrative purposes, those skilled in the art can understand that various substitutions, changes, and modifications are possible without departing from the spirit of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the content disclosed in the embodiments and drawings.

Claims

1. A method for compensating the uneven damping drift of a full-angle hemispherical resonant gyro, characterized in that: The hemispherical resonator gyroscope designed to implement this method has a pair of orthogonal detection electrodes, a pair of orthogonal excitation electrodes, a single detection electrode, and a single excitation electrode; among them, excitation electrode 1 and excitation electrode 2 are a pair of orthogonal excitation electrodes with a spatial position of 45°; the spatial position between excitation electrode 2 and excitation electrode 3 is 22.5°; detection electrode 1 and detection electrode 2 are a pair of orthogonal detection electrodes with a spatial position of 45°; the spatial position between detection electrode 2 and detection electrode 3 is 22.5°; excitation electrode 1 and detection electrode 1 are on the same axis, and the following steps are included: Step 1: Apply excitation forces with a frequency of ω and an amplitude of f to excitation electrode 1, excitation electrode 2, and excitation electrode 3 simultaneously; Step 2: Detect the vibration displacement amplitudes x1, x2, and x3 at three positions respectively by detection electrode 1, detection electrode 2, and detection electrode 3; According to the dynamic displacement amplitudes at the three positions, the damping time constants τ at the three positions are obtained as follows: In the formula, m represents the mass of the resonator, ω0 represents the natural frequency of the resonator, and δω represents the difference between the excitation force frequency and the natural frequency of the resonator; Step 3: Set the vibration mode angle of 0° to coincide with detection electrode 1. It can be known from the circumferential damping expression of the hemispherical resonator gyroscope and the positional relationship of the three detection electrodes that: Wherein, is the circumferential damping at the detection electrode 1, is the circumferential damping at the detection electrode 2, is the circumferential damping at the detection electrode 3, is the average value of the circumferential damping varying with the vibration mode for one cycle; Step 4: Calculate the amplitude of damping non-uniform drift The angle θ by which the minimum damping axis rotates relative to the mode shape angle of 0 degrees τ : Step 5: Compensate for the damping non-uniform drift in the full-angle output of the gyro Obtained according to Step 4 θ τ , model the damping non-uniform drift of the gyro resonator in one cycle according to the damping non-uniform drift expression; set the gyro full-angle output before compensation as After compensation is Then:

2. The method for compensating the uneven damping drift of a full-angle hemispherical resonant gyro according to claim 1, characterized in that: In Step 1, the difference between the excitation force frequency and the natural frequency of the resonator is set to δω, and δω is set to 0.1 Hz - 0.3 Hz.

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