Unbalanced mass identification device and method for harmonic oscillator with axisymmetric structure

Abstract

A device and a method for identifying the unbalanced mass of an axisymmetric structure harmonic oscillator are characterized in that a laser vibration meter is used for detecting the vibration of an outer rod of the axisymmetric structure harmonic oscillator so as to identify the unbalanced mass of the harmonic oscillator, the laser vibration meter is erected outside a vacuum chamber, and the vibration of the outer rod of the harmonic oscillator is detected through a glass window on the vacuum chamber. According to the non-contact measurement method, the vibration measurement sensor does not need to be placed in the vacuum chamber, so that the unbalanced mass of the harmonic oscillator can be directly removed in the vacuum chamber after the magnitude and the direction of the unbalanced mass are calculated, and the sensor does not need to be taken out from the vacuum chamber; and the situation that the leveling efficiency is reduced due to repeated vacuumizing is avoided. Meanwhile, the laser vibration meter only needs to be installed at one time, and measurement errors caused by repeated clamping when a contact type sensor is used are avoided.

Description

Technical Field

[0001] The invention relates to an unbalanced mass identification device and method for an axisymmetric structure resonator, and belongs to the field of precision instrument design. Background Art

[0002] The solid wave gyro is a new type of high-precision gyro instrument, which uses the Bryan effect caused by the Coriolis force in the rotating coordinate system to sense external rotation. Since there are no mechanical rotating parts inside, there are fewer potential failure factors, so it has the advantages of high reliability, high precision, and long life.

[0003] The core component of the solid wave gyroscope is the resonator of the axisymmetric structure, and its quality directly affects the final performance of the gyroscope. However, due to the limitation of processing accuracy, the actual resonator always has a certain error, which makes it not an ideal axisymmetric structure, which will have a great impact on the accuracy of the gyroscope. Therefore, it is very necessary to dynamically balance the resonator after processing, which is also the key to improving the accuracy of the gyroscope. The identification of unbalanced mass is the prerequisite for the dynamic balancing of the resonator.

[0004] In order to identify the unbalanced mass, it is necessary to electrically excite the resonator in a vacuum environment, and then calculate the size and orientation of the unbalanced mass by detecting the vibration of the outer rod of the resonator. Since the amplitude of the outer rod of the resonator is very small, a high-precision piezoelectric sensor is generally used to detect the vibration. However, as a contact measurement method, the piezoelectric sensor needs to be placed in a vacuum chamber together with the resonator. When removing the unbalanced mass, the sensor needs to be taken out of the vacuum chamber. Therefore, the sensor needs to be installed repeatedly during the leveling process, resulting in a decrease in the overall leveling efficiency. At the same time, due to the influence of repeated clamping of the sensor, the measurement repeatability of the piezoelectric sensor is poor, and the consistency of the measurement data is low. Summary of the invention

[0005] The technical problem solved by the present invention is: in view of various identification and measurement difficulties existing in the current prior art, a device and method for identifying the unbalanced mass of an axisymmetric structure resonator are proposed.

[0006] The present invention solves the above technical problems by the following technical solutions:

[0007] An unbalanced mass identification device for an axisymmetric resonator comprises a laser vibrometer, a resonator, an excitation electrode, an electrode base, a vacuum chamber, a glass window, and a signal analysis system, wherein:

[0008] An excitation electrode for oscillating the resonator is arranged on an electrode base, and the resonator is arranged outside the excitation electrode. The excitation electrode and the resonator are both installed inside a vacuum chamber. A laser vibrometer for collecting vibration signals emitted by the resonator is arranged directly above the vacuum chamber, and a glass window is provided on the top of the vacuum chamber to pass through and transmit vibration signals. The laser vibrometer and the signal analyzer are connected by a cable to realize vibration signal transmission.

[0009] The resonator is provided with an outer rod structure, the fixed position of the laser vibrometer is located directly above the glass window and the output optical path of the laser vibrometer is focused with the center position of the outer rod structure; the vacuum chamber is evacuated before the resonator identification test is performed.

[0010] The excitation electrode performs four-antinode excitation on the resonator before the resonator identification test. The resonator generates a vibration signal under the excitation of the excitation electrode and outputs the vibration signal to the laser vibrometer through the outer rod structure.

[0011] The position, structure and preset electric field strength of the excitation electrode are set according to the oscillation parameters of the resonator to be measured; the laser vibrometer interferes with the surface of the resonator by emitting interference laser to collect the vibration signal of the surface of the resonator.

[0012] The signal analysis system includes a signal processing module, a vibration analysis module, a mass calculation module, and an output display module, wherein:

[0013] The signal processing module performs filtering and amplification processing on the vibration signal transmitted by the laser vibrometer, and sends the filtered signal to the vibration analysis module;

[0014] The vibration analysis module performs frequency analysis and amplitude analysis on the filtered signal to obtain the vibration frequency and amplitude information of the resonator and send it to the mass calculation module;

[0015] The mass calculation module calculates the unbalanced mass of the resonator according to the vibration frequency and amplitude information of the resonator;

[0016] The output display module externally displays the vibration frequency and amplitude information and the unbalanced mass of the resonator.

[0017] The resonator is an axisymmetric structure. After the signal analysis system obtains the unbalanced mass, the vacuum chamber is controlled according to the unbalanced mass data to remove the unbalanced mass of the resonator.

[0018] The mass calculation module calculates the unbalanced mass of the oscillator by a method such as Newton iteration method that fits to the Fourier series. The calculation method is:

[0019]

[0020] In the formula, F x、F y 、F z are the components of the unbalanced force in the three directions of XYZ caused by the unbalanced mass when the resonator vibrates with four antinodes, A is the amplitude of the vibration of the four antinodes of the resonator, ω is the circular frequency of the vibration of the four antinodes of the resonator, is the standing wave azimuth of the four antinodes of the resonator, ∈1, ∈2, ∈3 are the values ​​of the 1st, 2nd, and 3rd harmonic components of the unbalanced mass of the resonator, is the azimuth angle of the 1st, 2nd and 3rd harmonic components of the unbalanced mass of the oscillator.

[0021] An identification method implemented by an unbalanced mass identification device comprises:

[0022] Design the excitation electrode position, structure, and preset electric field strength according to the resonator oscillation parameters;

[0023] Assemble the unbalanced mass identification device to ensure that the center of the laser vibrometer, the glass window, and the resonator are set on the same axis;

[0024] Control the excitation electrode to generate an electric field, and control the laser vibrometer to emit interference laser to the resonator;

[0025] The laser vibrometer is used to collect the vibration signal generated after the resonator is vibrated;

[0026] Forwarding vibration signals to a signal analysis system;

[0027] The vibration signal is solved by the signal analysis system to obtain the unbalanced mass of the resonator.

[0028] In the process of calculating the vibration signal, the signal analysis system implements the folded signal frequency analysis through Fourier transform, and performs amplitude analysis by calculating the peak value and effective value of the vibration signal.

[0029] The unbalanced mass of the resonator is eliminated by controlling the air pressure of the vacuum chamber through an external control system.

[0030] The advantages of the present invention compared with the prior art are:

[0031] (1) The present invention provides a device and method for identifying the unbalanced mass of an axisymmetric resonator. The resonator is installed on an electrode excitation base in a vacuum chamber, a laser vibrometer is fixed outside the vacuum chamber, and the laser is aimed at the center of the outer rod of the resonator and focused. After evacuation, the resonator is excited by four antinodes using the electrode excitation system, and the vibration signal of the outer rod of the resonator is collected using the laser vibrometer. Finally, based on the collected signal, the size and orientation of the unbalanced mass of the resonator are solved by the signal analysis system, thereby realizing non-contact identification of the unbalanced mass of the resonator;

[0032] (2) The signal analysis algorithm adopted in the present invention mainly adopts Newton's iteration method to calculate the size and orientation of the unbalanced mass of the resonator. Based on the four-antinode vibrations at different positions of the resonator and the corresponding amplitude of the laser vibration signal, the unbalanced mass information of the resonator is given by fitting the first to third order Fourier series. The accuracy of the calculation results can be guaranteed through high-precision calculation and data processing capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the unbalanced mass identification device provided by the present invention. DETAILED DESCRIPTION

[0034] A device and method for identifying the unbalanced mass of an axisymmetric resonator, which uses a laser vibrometer to detect the vibration of the outer rod of the axisymmetric resonator, and then identifies the unbalanced mass of the resonator. The laser vibrometer is set up outside the vacuum chamber, and the vibration of the outer rod of the resonator is detected through the glass window on the vacuum chamber. This non-contact measurement method does not require the vibration sensor to be placed inside the vacuum chamber, so that the unbalanced mass of the resonator can be directly removed in the vacuum chamber after the size and orientation of the unbalanced mass are calculated, and there is no need to remove the sensor from the vacuum chamber, thereby avoiding the reduction in leveling efficiency caused by repeated vacuuming. At the same time, the laser vibrometer only needs to be installed once, avoiding the measurement error caused by repeated clamping when using a contact sensor.

[0035] The resonator is the object to be measured for measuring unbalanced mass. The resonator should have an axisymmetric structure to ensure the stability and accuracy of the vibration frequency.

[0036] The circuit controller is used to perform vacuum control on the resonator by exciting the electrodes, controlling the vibration of the resonator to generate four-antinode vibrations and controlling them at different positions. The circuit controller should be able to accurately control the vibration frequency and amplitude of the resonator.

[0037] The laser vibrometer is used to detect the vibration signal of the resonator. It shines the light onto the outer rod of the resonator through the glass window outside the vacuum chamber, receives the reflected light signal, and thus obtains the vibration information of the outer rod of the resonator.

[0038] The signal analysis system is used to process the signal received by the laser to extract the vibration characteristics of the resonator. The signal processor should be able to quickly and accurately analyze the signal and extract useful information as input data for the algorithm.

[0039] The identification device uses Newton's iteration method and other methods to solve the size and orientation of the unbalanced mass of the resonator based on the four-antinode vibrations at different positions of the resonator and the corresponding laser vibration signal amplitudes.

[0040] The external controller is operated by the user. It is used to control the operation and operation of the entire system. The controller should be able to achieve coordination and synchronization between various components to ensure that the system can operate stably and achieve the preset goals.

[0041] Among them, the connection and installation between the various components are as follows: the resonator is installed inside the vacuum chamber, and the electrodes, laser vibrometer, signal analysis system, and external controller are located outside the vacuum chamber. Specifically: the resonator is installed on a base with excitation and detection electrodes in the vacuum chamber. The electrodes on the base are led to the outside of the vacuum chamber through wires, and then the circuit controller controls the electrodes to make the resonator vibrate, causing it to produce four-antinode vibrations at different positions. The laser outside the vacuum chamber shines through the glass window onto the outer rod of the resonator, and the vibration of the outer rod of the resonator is detected by the light signal reflected back from the outer rod of the resonator. Finally, the signal processor uses the vibration signal of the outer rod of the resonator as input and uses Newton's iteration method and other methods to solve the size and orientation of the unbalanced mass of the resonator.

[0042] The implementation process of this system is mainly divided into the following steps:

[0043] Resonator Oscillation: Use electrodes to oscillate the resonator. Specifically, an electrode needs to be placed near the surface of the resonator to make it vibrate by applying an electric field. In order to ensure that the electrode can accurately control the vibration of the resonator, the position, shape and electric field strength of the electrode need to be precisely controlled.

[0044] Laser interference detection: This system uses laser interference detection technology to obtain the vibration signal of the resonator surface by irradiating the laser beam onto the resonator surface for interference. Laser interference detection has the advantages of high precision and high resolution, and can effectively detect the vibration of the resonator.

[0045] Signal processing: The collected vibration signal needs to be processed to improve the signal-to-noise ratio and resolution. The main signal processing methods include filtering, amplification, denoising, digitization, etc. Among them, filtering is the most basic signal processing method, which can filter out the noise in the signal through the filter, thereby improving the clarity and accuracy of the signal.

[0046] Vibration analysis: By performing frequency analysis and amplitude analysis on the signal, information such as the vibration frequency and amplitude of the resonator can be obtained. Frequency analysis can be achieved through methods such as Fourier transform, while amplitude analysis can be achieved by calculating parameters such as the peak value and effective value of the vibration signal.

[0047] Unbalanced mass calculation: Based on the vibration frequency and amplitude of the oscillator and other information, the unbalanced mass of the oscillator is obtained by fitting the first to third order Fourier series using Newton's iteration method.

[0048] Result output: Finally, the system outputs the calculated unbalanced mass results to a display or computer and other devices for display and recording.

[0049] The following is further described in conjunction with the accompanying drawings and preferred embodiments of the specification:

[0050] In the current embodiment, the unbalanced mass identification device of the axisymmetric structure resonator is as follows: Figure 1 As shown, it includes a laser vibrometer, a resonator, an excitation electrode, an electrode base, a vacuum chamber, a glass window, and a signal analysis system, wherein:

[0051] An excitation electrode for oscillating the resonator is arranged on an electrode base, and the resonator is arranged outside the excitation electrode. The excitation electrode and the resonator are both installed inside a vacuum chamber. A laser vibrometer for collecting vibration signals emitted by the resonator is arranged directly above the vacuum chamber, and a glass window is provided on the top of the vacuum chamber to pass through and transmit vibration signals. The laser vibrometer and the signal analyzer are connected by a cable to realize vibration signal transmission.

[0052] An outer rod structure is provided on the resonator, the fixed position of the laser vibrometer is located directly above the glass window and the output optical path of the laser vibrometer is focused with the center position of the outer rod structure; the vacuum chamber is evacuated before the resonator identification test is performed.

[0053] The excitation electrode excites the resonator with four antinodes before the resonator identification test. The resonator generates a vibration signal under the excitation of the excitation electrode and outputs the vibration signal to the laser vibrometer through the outer rod structure.

[0054] The position, structure and preset electric field strength of the excitation electrode are set according to the oscillation parameters of the resonator to be measured; the laser vibrometer interferes with the surface of the resonator by emitting interference laser to collect the vibration signal of the surface of the resonator.

[0055] The signal analysis system includes a signal processing module, a vibration analysis module, a mass calculation module, and an output display module, among which:

[0056] The signal processing module performs filtering and amplification processing on the vibration signal transmitted by the laser vibrometer, and sends the filtered signal to the vibration analysis module;

[0057] The vibration analysis module performs frequency analysis and amplitude analysis on the filtered signal to obtain the vibration frequency and amplitude information of the resonator and send it to the mass calculation module;

[0058] The mass calculation module calculates the unbalanced mass of the resonator according to the vibration frequency and amplitude information of the resonator;

[0059] The output display module externally displays the vibration frequency and amplitude information and the unbalanced mass of the resonator.

[0060] The resonator has an axisymmetric structure. After the signal analysis system obtains the unbalanced mass, it controls the vacuum chamber to remove the unbalanced mass of the resonator according to the unbalanced mass data.

[0061] The mass calculation module calculates the unbalanced mass of the oscillator by fitting to the Fourier series using methods such as the Newton iteration method. The calculation method is:

[0062]

[0063] In the formula, F x 、F y 、F z are the components of the unbalanced force in the XYZ directions caused by the unbalanced mass when the resonator vibrates with four antinodes, A is the amplitude of the vibration of the four antinodes of the resonator, ω is the circular frequency of the vibration of the four antinodes of the resonator, is the standing wave azimuth of the four antinodes of the resonator, ∈1, ∈2, ∈3 are the values ​​of the 1st, 2nd, and 3rd harmonic components of the unbalanced mass of the resonator, is the azimuth angle of the 1st, 2nd and 3rd harmonic components of the unbalanced mass of the oscillator.

[0064] The identification method implemented by the unbalanced mass identification device comprises the following steps:

[0065] Design the excitation electrode position, structure, and preset electric field strength according to the resonator oscillation parameters;

[0066] Assemble the unbalanced mass identification device to ensure that the center of the laser vibrometer, the glass window, and the resonator are set on the same axis;

[0067] Control the excitation electrode to generate an electric field, and control the laser vibrometer to emit interference laser to the resonator;

[0068] The laser vibrometer is used to collect the vibration signal generated after the resonator is vibrated;

[0069] Forwarding vibration signals to a signal analysis system;

[0070] The vibration signal is solved by the signal analysis system to obtain the unbalanced mass of the resonator.

[0071] When the signal analysis system calculates the vibration signal, the frequency analysis of the folded signal is realized through Fourier transform, and the amplitude analysis is performed by calculating the peak value and effective value of the vibration signal.

[0072] The unbalanced mass of the resonator is eliminated by controlling the gas pressure in the vacuum chamber through an external control system.

[0073] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

[0074] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. An unbalanced mass identification device for an axisymmetric resonator, characterized in that: It includes a laser vibrometer, a resonator, an excitation electrode, an electrode base, a vacuum chamber, a glass window, and a signal analysis system, wherein: An excitation electrode for oscillating the resonator is arranged on an electrode base, and the resonator is arranged outside the excitation electrode. The excitation electrode and the resonator are both installed inside a vacuum chamber. A laser vibrometer for collecting vibration signals emitted by the resonator is arranged directly above the vacuum chamber, and a glass window is provided on the top of the vacuum chamber to pass through and transmit vibration signals. The laser vibrometer and the signal analyzer are connected by a cable to realize vibration signal transmission.

2. The unbalanced mass identification device of an axisymmetric resonator according to claim 1, characterized in that: The resonator is provided with an outer rod structure, the fixed position of the laser vibrometer is located directly above the glass window and the output optical path of the laser vibrometer is focused with the center position of the outer rod structure; the vacuum chamber is evacuated before the resonator identification test is performed.

3. The unbalanced mass identification device of an axisymmetric resonator according to claim 1, characterized in that: The excitation electrode performs four-antinode excitation on the resonator before the resonator identification test. The resonator generates a vibration signal under the excitation of the excitation electrode and outputs the vibration signal to the laser vibrometer through the outer rod structure.

4. The unbalanced mass identification device of an axisymmetric resonator according to claim 3, characterized in that: The position, structure and preset electric field strength of the excitation electrode are set according to the oscillation parameters of the resonator to be measured; the laser vibrometer interferes with the surface of the resonator by emitting interference laser to collect the vibration signal of the surface of the resonator.

5. The unbalanced mass identification device of an axisymmetric resonator according to claim 1, characterized in that: The signal analysis system includes a signal processing module, a vibration analysis module, a mass calculation module, and an output display module, wherein: The signal processing module performs filtering and amplification processing on the vibration signal transmitted by the laser vibrometer, and sends the filtered signal to the vibration analysis module; The vibration analysis module performs frequency analysis and amplitude analysis on the filtered signal to obtain the vibration frequency and amplitude information of the resonator and send it to the mass calculation module; The mass calculation module calculates the unbalanced mass of the resonator according to the vibration frequency and amplitude information of the resonator; The output display module externally displays the vibration frequency and amplitude information and the unbalanced mass of the resonator.

6. The unbalanced mass identification device of an axisymmetric resonator according to claim 5, characterized in that: The resonator is an axisymmetric structure. After the signal analysis system obtains the unbalanced mass, the vacuum chamber is controlled according to the unbalanced mass data to remove the unbalanced mass of the resonator.

7. The unbalanced mass identification device of an axisymmetric resonator according to claim 5, characterized in that: The mass calculation module calculates the unbalanced mass of the oscillator by a method such as Newton iteration method that fits to the Fourier series. The calculation method is: In the formula, F x 、F y 、F z are the components of the unbalanced force in the three directions of XYZ caused by the unbalanced mass when the resonator vibrates with four antinodes, A is the amplitude of the vibration of the four antinodes of the resonator, ω is the circular frequency of the vibration of the four antinodes of the resonator, is the standing wave azimuth of the four antinodes of the resonator, ∈1, ∈2, ∈3 are the values ​​of the 1st, 2nd, and 3rd harmonic components of the unbalanced mass of the resonator, is the azimuth angle of the 1st, 2nd and 3rd harmonic components of the unbalanced mass of the oscillator.

8. An identification method implemented by the unbalanced mass identification device according to claim 6, characterized in that include: Design the excitation electrode position, structure, and preset electric field strength according to the resonator oscillation parameters; Assemble the unbalanced mass identification device to ensure that the center of the laser vibrometer, the glass window, and the resonator are set on the same axis; Control the excitation electrode to generate an electric field, and control the laser vibrometer to emit interference laser to the resonator; The laser vibrometer is used to collect the vibration signal generated after the resonator is vibrated; Forwarding vibration signals to a signal analysis system; The vibration signal is solved by the signal analysis system to obtain the unbalanced mass of the resonator.

9. The method for identifying unbalanced mass of an axisymmetric resonator according to claim 8, characterized in that: In the process of calculating the vibration signal, the signal analysis system implements the folded signal frequency analysis through Fourier transform, and performs amplitude analysis by calculating the peak value and effective value of the vibration signal.

10. The method for identifying unbalanced mass of an axisymmetric resonator according to claim 8, characterized in that: The unbalanced mass of the resonator is eliminated by controlling the air pressure of the vacuum chamber through an external control system.

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