Acceleration sensing system and sensing detection method based on MEMS resonator phase noise

Abstract

The invention belongs to the technical field of sensors, and particularly relates to an acceleration sensing system based on MEMS resonator phase noise and a sensing detection method. The system comprises an MEMS resonator, a driving module and a phase noise signal processing module which are electrically connected to form a closed loop. The driving module provides voltage for the resonator and is connected with the driving end and the sensing end of the resonator to form a self-excited oscillation circuit, energy loss is compensated through real-time phase adjustment and signal amplification, and stable vibration of the resonator is maintained. When the external acceleration acts on the resonator, the phase noise spectral line characteristics of the resonator change and are acquired and analyzed by the phase noise signal processing module. By extracting the change of the peak value and the position of the phase noise spectral line, the high dynamic range monitoring of the acceleration and the frequency can be realized. The invention has the advantages of wide frequency response range, strong impact resistance and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of sensors, and particularly relates to an acceleration sensing system based on MEMS resonator phase noise and a sensing and detecting method. BACKGROUND

[0002] With the development of Micro-Electro-Mechanical Systems (MEMS) technology, MEMS acceleration sensors are widely used in consumer electronics, automotive industry, aerospace, etc. due to their small size, low cost, and integration.

[0003] According to the technical principle, MEMS accelerometers can be classified into capacitive, resonant, piezoelectric, optical, tunnel current, thermal, and piezoresistive accelerometers. In the inertial sensing market, capacitive micro-mechanical accelerometers have the advantages of good DC response and noise performance, low drift, and low temperature sensitivity compared with piezoresistive or piezoelectric accelerometers; the advantages of resonant accelerometers over other sensing principles mainly lie in their high scale factor, high resolution, and semi-digital output. The semi-digital output of the resonant accelerometer can effectively reduce the electrical drift or noise; although various progress has been made in the field of acceleration sensors, including resonator diversity, enhanced scale factor, expanded sensing direction, reduced temperature sensitivity, and integration of CMOS technology, there is a lack of measurement of frequency information and a small frequency range of measurable acceleration signals.

[0004] Mechanical vibration frequency is a very important concept in equipment vibration diagnosis. In various vibration diagnoses, the relationship between frequency and fault is often analyzed, and the characteristics of vibration in different frequency bands are analyzed. Low-frequency vibration may cause slow movement of objects or resonance of structures, and has a more significant impact on structures; high-frequency vibration may cause fatigue or damage to mechanical parts, and has a more significant impact on the service life of equipment. By analyzing the frequency information of the acceleration signal, the motion state of the object can be better understood, which helps in fault diagnosis, performance optimization, and safety evaluation. With more and more diverse application scenarios, the industry has put forward requirements for the acceleration frequency measurement capability of MEMS acceleration sensors. SUMMARY

[0005] One of the purposes of the present application is to provide an acceleration sensing system based on MEMS resonator phase noise and a sensing and detecting method to overcome the problems of the prior art. The system can measure fixed-frequency vibration acceleration signals and random vibration acceleration signals, has a large dynamic range, a large frequency response range, strong impact resistance, and a variety of resonator types.

[0006] To achieve the above purpose, the technical solution adopted by the present application is as follows: This invention provides an acceleration sensing system based on MEMS resonator phase noise, uniquely comprising: a measured vibration acceleration signal, a MEMS resonator, a driving module, and a phase noise signal processing module. The measured vibration acceleration signal is applied to the MEMS resonator, with the acceleration direction perpendicular to the MEMS resonator's surface. The MEMS resonator is a silicon-based Lamé-mode resonator, maintaining resonance during acceleration. The driving module integrates phase adjustment and amplification functions, forming a closed loop with the corresponding electrodes of the resonator to maintain stable self-oscillation. The phase noise signal processing module obtains the resonator signal frequency information from the driving module, converts it into a phase noise spectrum, and extracts the changes in the magnitude and position of the phase noise peaks, thereby enabling the detection of the acceleration magnitude and frequency.

[0007] Furthermore, the MEMS resonator employs a Lamé-mode resonator, comprising: a square resonant element, a resonant beam, anchor points, and electrodes; the square resonant element has a side length ranging from 160 to 300 μm; the four corners are connected to the anchor points via resonant beams, using a double resonant beam connection method, with a single resonant beam having a length ranging from 25 to 35 μm and a width ranging from 3 to 6 μm, and a spacing of 3 to 6 μm between the two resonant beams; the anchor point has a side length ranging from 40 to 60 μm, and the resonator thickness ranges from 20 to 30 μm.

[0008] Furthermore, the driving module is used to detect the motion of the resonator, adjust and amplify its phase, and feed back a precisely synchronized driving force to the resonator to compensate for the energy loss during its vibration process, thereby maintaining the stable self-excited oscillation of the resonator.

[0009] Furthermore, the phase noise signal processing module includes: a signal analyzer and a data acquisition card; the signal analyzer reads the resonant frequency signal of the resonator and plots the phase noise spectrum; the data acquisition card controls the signal analyzer to read the signal and converts the changes in the obtained phase noise spectrum into the magnitude and frequency changes of the vibration acceleration signal. The vibration acceleration signal to be measured is provided by a vibration table; the resonator is fabricated on a PCB board, and the resonator PCB board is fixed to the vibration table by an aluminum alloy clamp, thereby applying the acceleration signal to the resonator; the drive circuit is fabricated on another PCB board, and in application, the drive circuit board can be placed in a position with weak acceleration impact, thereby improving the impact resistance of the sensor; This invention also provides a detection method for an accelerometer based on the phase noise of a MEMS resonator, characterized by sensing acceleration by analyzing the phase noise spectrum of the resonator, specifically including the following steps: Step 1: Constructing the conversion model; Based on the MEMS resonator, construct a conversion model between the peak value of its phase noise sideband and the magnitude of the applied acceleration; Step 2: Generation of phase noise spectrum; Based on the frequency signal of the MEMS resonator, perform frequency domain analysis on its output signal and plot the phase noise spectrum; Step 3: Characterization of fixed-frequency vibration acceleration signal; Based on the position of the sideband peak on the phase noise spectrum, read its frequency and phase noise peak information, and calculate the applied acceleration amplitude using the conversion model to achieve sensing of the acceleration amplitude and frequency.

[0010] Step 4: Characterization of random vibration acceleration signal; Construct a transformation model to characterize random vibration acceleration signal.

[0011] Furthermore, the method for constructing the conversion model is as follows: the sensing principle is based on the change in the sideband peak of the phase noise spectrum of the resonator caused by acceleration. For a resonant frequency of... A MEMS resonator is subjected to a fixed amplitude and a fixed frequency. If the vibration acceleration signal is a vibration signal, then the phase of its output signal is modulated by the instantaneous frequency shift of the vibration signal, thereby generating sideband peaks in the output phase noise spectrum.

[0012] Sideband peaks appear , , , For positions with small modulation indices β In this case, most of the power is in the carrier wave, and a small amount is in the first sideband pair ( , In this context, the amplitude of the higher sidebands can be ignored. (See figure.) The carrier frequency, i.e., the resonant frequency of the MEMS resonator; the The vibration frequency of the applied vibration acceleration signal; the modulation index The The frequency shift caused by vibration; the first sideband pair is symmetrical about the carrier frequency, and only one of them is considered ( The peak value of the phase noise at the first sideband and the magnitude of the applied vibration acceleration signal approximately satisfy the following relationship:

[0013] The The peak value of the first sideband phase noise induced by the vibration acceleration signal; This refers to the acceleration sensitivity of the resonator. This value varies depending on the MEMS resonator. The value was experimentally measured for the resonator used in this invention. The magnitude of the vibration acceleration signal; Furthermore, the specific method for generating the phase noise spectrum is as follows: the vibration table is responsible for providing fixed-frequency vibration acceleration signals and random vibration acceleration signals of different frequencies and amplitudes as the acceleration signal source of the detection system. The core of the MEMS resonator-based phase noise acceleration sensor lies in a suspended square plate resonant element fixed to four anchor points by four resonant beams. Four electrodes are located around the resonant element; two opposing pairs of electrodes are used to input driving signals to the resonant element and measure its output signal, respectively. The driving circuit integrates phase adjustment and amplification functions, connecting to the corresponding electrodes of the resonator in a row-layer closed loop to maintain stable self-excited oscillation of the resonator. The signal analyzer is used to display the electrical signal output by the resonator through the driving circuit board, presented in the form of a phase noise spectrum. By analyzing the phase noise spectrum, the amplitude and frequency information of the applied acceleration can be obtained.

[0014] Furthermore, the characterization method of the fixed-frequency vibration acceleration signal is as follows: the applied vibration acceleration signal causes a sideband peak of corresponding size at the corresponding frequency on the phase noise spectrum of the resonator. Thus, the relationship between the magnitude of the acceleration amplitude, frequency and the change of the phase noise spectrum can be obtained from the acceleration amplitude corresponding to the solution of the above equation.

[0015] Furthermore, the specific method for characterizing random vibration acceleration is as follows, using the transformation model:

[0016] The Let λ be the acceleration spectral density; λ is the compensation factor, which is measured through experimental data. Applying a random vibration acceleration signal to the resonator will induce sideband peaks at corresponding positions on its phase noise spectrum. By reading the magnitude and position of these peaks through a data acquisition card, and substituting these peaks into the conversion model described above, the magnitude of the vibration acceleration signal at the corresponding frequency can be obtained. The peak position is the frequency information of the acceleration signal, thus achieving the characterization of the random vibration acceleration signal.

[0017] The beneficial effects of this invention are as follows: First, this invention differs significantly from conventional MEMS accelerometers in its sensing principle. Based on the phase noise spectrum of a resonator, this invention uses the sideband peaks induced by the acceleration signal on the phase noise spectrum to reflect the frequency and amplitude information of the measured acceleration signal. Second, the horizontal segment of the resonator's phase noise spectrum can be used for sensing, resulting in a frequency response range of 100Hz to 25MHz, covering both low-to-mid-frequency and high-frequency ranges, and providing the frequency information of the measured acceleration signal. Third, the horizontal segment of the phase noise spectrum of the Lamé-mode resonator used is longer than that of other resonators, giving the accelerometer a wider frequency response range, and the Lamé-mode resonator achieves a Q value of 10.6 This effectively reduces losses; simultaneously, the double-beam design increases sensing sensitivity while also ensuring the sensor system's shock resistance. Fourth, the resonator and drive circuit board are fabricated separately on two different PCBs, allowing the drive circuit board to be placed in areas of weak or no acceleration, thus improving the sensor's shock resistance. Finally, the acceleration sensing system and detection method based on MEMS resonator phase noise provided by this invention have low equipment requirements, are simple to operate, and are conducive to widespread application. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings: Figure 1 This is a schematic diagram of the accelerometer sensor based on MEMS resonator phase noise of the present invention.

[0019] Figure 2 This is a test system diagram of an accelerometer based on MEMS resonator phase noise, according to an embodiment of the present invention.

[0020] Figure 3 These are the phase noise spectra of the accelerometer based on MEMS resonator phase noise of this invention under no acceleration and with accelerations of 10g, 20g, 30g, 40g, and 50g respectively.

[0021] Figure 4 It is the applied random vibration acceleration signal to be measured, and the test results of the applied random vibration acceleration signal by the accelerometer based on the phase noise of the MEMS resonator of this invention.

[0022] The numbers in the diagram are: 1- MEMS resonator, 2- dual-ended output DC power supply, 3- signal analyzer, 4- driver module, 5- DC power supply, 6- data acquisition card. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. The preferred embodiments of this invention will be described in detail below with reference to the accompanying drawings, so that the advantages and features of this invention can be more easily understood by those skilled in the art, thereby providing a clearer and more definite definition of the scope of protection of this invention.

[0024] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0025] The singular forms “a,” “the,” and “the” used in the embodiments of the invention and the appended claims are also intended to include the plural forms, and “multiple” generally includes at least two unless the context clearly indicates otherwise.

[0026] This invention belongs to the field of sensor technology, specifically relating to an accelerometer and sensing method based on MEMS resonator phase noise.

[0027] An acceleration sensing system based on MEMS resonator phase noise includes: a vibration acceleration signal to be measured, a MEMS resonator, a driving module, and a phase noise signal processing module. The vibration acceleration signal to be measured is applied to the MEMS resonator, with the acceleration direction perpendicular to the MEMS resonator plate surface. The MEMS resonator is a silicon-based Lamé-mode resonator, which maintains a resonant state when acceleration is applied. The driving module integrates phase adjustment and amplification functions, and is connected to the corresponding electrodes of the resonator to form a closed loop, maintaining stable self-excited oscillation of the resonator. The phase noise signal processing module obtains the resonator signal frequency information from the driving module, converts it into a phase noise spectrum, and extracts the changes in the magnitude and position of the phase noise peaks, thereby realizing the detection of acceleration magnitude and frequency.

[0028] The Lamé-mode MEMS resonator comprises: a square resonant element, resonant beams, anchor points, and electrodes. The square resonant element has a side length ranging from 160 to 300 μm. The square resonant element is suspended around its perimeter and connected to four anchor points by four resonant beams using a dual-resonant beam connection method. The length of a single resonant beam ranges from 25 to 35 μm, and its width ranges from 3 to 6 μm. The spacing between the two resonant beams is 3 to 6 μm. The anchor points have a side length ranging from 40 to 60 μm, and the resonator thickness ranges from 20 to 30 μm. Four electrodes surround the square resonant element; two opposing pairs of electrodes are used to input drive signals to the resonant element and to measure the output signal of the resonant element, respectively. The gap between the square resonant element and the electrodes is 0.5 to 1 μm. The driver module includes electronic components such as operational amplifiers, gain modules, linear regulators, and inverters; it is used to maintain the stable self-oscillation of the resonator and output the resonant frequency signal of the resonator. The driver module is fabricated on a PCB board.

[0029] The phase noise signal processing module includes: a signal analyzer and a data acquisition card; the signal analyzer reads the resonant frequency signal of the resonator and plots the phase noise spectrum; the data acquisition card controls the signal analyzer to read the signal and converts the changes in the obtained phase noise spectrum into the magnitude and frequency changes of the vibration acceleration signal according to the conversion model.

[0030] A detection method for an accelerometer based on the phase noise of a MEMS resonator, which realizes acceleration sensing by analyzing the phase noise spectrum of the resonator, specifically includes the following steps: Step 1: Constructing the conversion model; Based on the MEMS resonator, construct a conversion model between the peak value of its phase noise sideband and the magnitude of the applied acceleration; Step 2: Generation of phase noise spectrum; Based on the frequency signal of the MEMS resonator, perform frequency domain analysis on its output signal and plot the phase noise spectrum; Step 3: Characterization of fixed-frequency vibration acceleration signal; Based on the position of the sideband peak on the phase noise spectrum, read its frequency and phase noise peak information, and calculate the applied acceleration amplitude using the conversion model to achieve sensing of the acceleration amplitude and frequency. Step 4: Characterization of random vibration acceleration signal; Construct a transformation model to characterize random vibration acceleration signal.

[0031] The specific method for constructing the transformation model in step one is as follows: For the resonant frequency is f A MEMS resonator with a fixed amplitude and a fixed frequency is applied. f v If the vibration acceleration signal is such that the phase of its output signal is modulated by the instantaneous frequency shift of the vibration signal, then sideband peaks will be generated in the output phase noise spectrum; the sideband peaks appear in f 0+ f v , f 0- f v , f 0+ 2 f v , f 0-2 f v For positions with small modulation indices β In this case, most of the power is in the carrier wave, and a small amount is in the first sideband pair ( f 0+f v , f 0- f v In this context, the amplitude of the higher sidebands can be ignored; as shown... f 0 represents the carrier frequency, i.e., the resonant frequency of the MEMS resonator; the f v The vibration frequency of the applied vibration acceleration signal; the modulation index β = Δ f / f v The Δ f The frequency shift caused by vibration; the first sideband pair is symmetrical about the carrier frequency, and only one of them is considered ( f 0+ f v ); The peak value of the phase noise at the first sideband and the magnitude of the applied vibration acceleration signal approximately satisfy the following relationship:

[0032] The L v 1 ( β ) represents the peak value of the first sideband phase noise induced by the vibration acceleration signal, and Γ represents the acceleration sensitivity of the resonator, which is experimentally measured for the resonator used. A The amplitude of the vibration acceleration signal is Γ. Specifically, the acceleration sensitivity Γ of the resonator needs to be obtained. This value is obtained by experimentally measuring the peak value of the phase noise sideband when different accelerations are applied, and then fitting the measured value with the magnitude of the applied acceleration.

[0033] The specific method for generating the phase noise spectrum in step two is as follows: The resonant frequency signal of the resonator is read by a signal analyzer, and the phase noise spectrum is plotted. The data acquisition card controls the signal analyzer to read the signal. The functions of the data acquisition card include controlling the signal analyzer to start and stop reading the signal, changing the frequency range, number of sampling points, sampling interval, averaging times, etc.

[0034] The specific method for characterizing the fixed-frequency vibration acceleration signal in step three is as follows: Applying a vibration acceleration signal of a fixed frequency to a resonator will cause a sideband peak at the corresponding position on its phase noise spectrum. The magnitude and position of this peak are read by a data acquisition card, and the magnitude of the applied vibration acceleration signal can be obtained by substituting this peak value into the conversion model. The peak position is the frequency information of the acceleration signal, thus realizing the characterization of the fixed frequency vibration acceleration signal.

[0035] The specific method for characterizing the random vibration acceleration signal in step four is as follows: For random vibrational acceleration, when characterized by phase noise spectral lines in the frequency domain, the magnitude of the acceleration is represented by the following formula.

[0036] The Let λ be the acceleration spectral density and λ be the compensation factor. Applying a random vibration acceleration signal to the resonator will induce sideband peaks at corresponding positions on its phase noise spectrum. By reading the magnitude and position of these peaks through a data acquisition card, and substituting these peaks into the conversion model described above, the magnitude of the vibration acceleration signal at the corresponding frequency can be obtained. The peak position is the frequency information of the acceleration signal, thus achieving the characterization of the random vibration acceleration signal.

[0037] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. An acceleration sensing system based on MEMS resonator phase noise, characterized by, The application relates to a vibration acceleration sensor based on MEMS resonator. The vibration acceleration signal is applied to the MEMS resonator, and the acceleration direction is perpendicular to the plate surface of the MEMS resonator; the MEMS resonator is a silicon-based Lame mode resonator, and the resonator remains in a resonant state when the acceleration is applied; the driving module integrates phase adjustment and amplification functions, is connected with corresponding electrodes of the resonator to form a closed loop, and maintains stable self-excited oscillation of the resonator; The phase noise signal processing module obtains the resonator signal frequency information from the driving module, converts the information into a phase noise spectrum, and extracts the change of the phase noise peak value and position, so that the acceleration size and frequency are detected. The MEMS resonator comprises a square resonant element, a resonant beam, an anchor point and an electrode; the square resonant element has a side length ranging from 160 to 300 mu m; the four corners are connected with the anchor point through the resonant beam, and a double-resonant-beam connection mode is adopted; the single resonant beam has a length ranging from 25 to 35 mu m and a width ranging from 3 to 6 mu m, and the double resonant beams have a spacing of 3 to 6 mu m; the anchor point has a side length ranging from 40 to 60 mu m, and the resonator has a thickness ranging from 20 to 30 mu m.

2. The acceleration sensing system based on MEMS resonator phase noise according to claim 1, wherein, The driving module comprises operational amplifiers, gain modules, linear voltage stabilizers, inverters and other electronic elements; the driving module is used for maintaining stable self-excited oscillation of the resonator and outputting the resonant frequency signal of the resonator.

3. The acceleration sensing system based on MEMS resonator phase noise according to claim 1, wherein, The phase noise signal processing module comprises a signal analyzer and a data acquisition card; the signal analyzer reads the resonant frequency signal of the resonator and draws a phase noise spectrum line; the data acquisition card controls the signal analyzer to read the signal and converts the change of the obtained phase noise spectrum line into the size and frequency change of the vibration acceleration signal.

4. The acceleration sensing system based on MEMS resonator phase noise according to claim 1, wherein, The acceleration is sensed by analyzing the phase noise spectrum of the resonator, and the method comprises the following steps:

5. A sensing method of an acceleration sensor based on the phase noise of a MEMS resonator, characterized in that, Step one: constructing a conversion model; a conversion model between the phase noise sideband peak of the MEMS resonator and the applied acceleration size is constructed based on the MEMS resonator; Step two: generating a phase noise spectrum; the output signal of the MEMS resonator is analyzed in the frequency domain based on the frequency signal of the MEMS resonator, and a phase noise spectrum diagram is drawn; Step three: representing a fixed-frequency vibration acceleration signal; the frequency and phase noise peak information of the sideband peak on the phase noise spectrum diagram are read, the applied acceleration amplitude is calculated by combining the conversion model, and the acceleration amplitude and frequency are sensed; Step four: representing a random vibration acceleration signal; a conversion model representing the random vibration acceleration signal is constructed. The specific method for constructing the conversion model in step one is shown as follows:

6. The sensing method of an acceleration sensor based on the phase noise of a MEMS resonator according to claim 5, characterized in that: The specific method for generating the phase noise spectrum in step two is shown as follows: A MEMS resonator with resonance frequency f 0 is excited by a vibration acceleration signal with fixed amplitude and frequency f v , the phase of its output signal is modulated by the instantaneous frequency shift of the vibration signal, resulting in sideband peaks in the output phase noise spectrum; the sideband peaks appear at f 0+ f v , f 0- f v , f 0+ 2 f v , f 0- 2 f v and so on; for small modulation index β , most of the power is in the carrier, a small amount in the first sideband pair ( f 0+ f v , f 0- f v ), and the amplitude of higher sidebands can be neglected; the f 0 is the carrier frequency, i.e. the resonance frequency of the MEMS resonator; the f v is the vibration frequency of the applied vibration acceleration signal; the modulation index β = Δ f / f v , the Δ f is the frequency shift caused by the vibration; the first sideband pair is symmetric about the carrier frequency, and only one of them ( f 0+ f v ) is concerned; the phase noise peak at the first sideband approximately satisfies the following relationship with the amplitude of the applied vibration acceleration signal The L v 1 β is the first sideband phase noise peak induced by the vibration acceleration signal, is the acceleration sensitivity of the resonator, which is measured experimentally for the resonator used, and A is the amplitude of the vibration acceleration signal.​ 7. The sensing method of an acceleration sensor based on the phase noise of a MEMS resonator according to claim 5, characterized in that: The resonant frequency signal of the resonator is read by the signal analyzer, and a phase noise spectrum line is drawn; the data acquisition card controls the signal analyzer to read the signal; the functions of the data acquisition card include controlling the signal analyzer to start and stop reading the signal, changing the frequency range, the sampling point number, the sampling interval, the average number and the like. The specific method for representing the fixed-frequency vibration acceleration signal in step three is shown as follows:

8. The sensing method of an acceleration sensor based on the phase noise of a MEMS resonator according to claim 5, characterized in that: ​ The fixed frequency vibration acceleration signal is applied to the resonator, which causes sideband peak at the corresponding position of the phase noise spectrum. The peak value and the peak position are read by the data acquisition card, and the peak value is substituted into the conversion model to obtain the size of the applied vibration acceleration signal. The peak position is the frequency information of the acceleration signal, thereby realizing the characterization of the fixed frequency vibration acceleration signal.

9. The sensing measurement method of an acceleration sensor based on the phase noise of a MEMS resonator according to claim 5, characterized in that: The specific method for characterizing the random vibration acceleration signal in step four is shown below: For random vibration acceleration, the acceleration size is characterized by the following formula when characterized by the phase noise spectrum in the frequency domain The For the acceleration spectrum density, λ is a compensation factor; applying a random vibration acceleration signal to the resonator will cause sideband peaks at the corresponding positions on its phase noise spectrum. By reading the peak values and peak positions through the data acquisition card, and substituting the peak values into the above conversion model, the size of the vibration acceleration signal at the corresponding frequency can be obtained. The peak position is the frequency information of the acceleration signal. Thus, the characterization of the random vibration acceleration signal is realized.

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