Grate value self-compensation method and device of MEMS (Micro Electro Mechanical System) gravimeter, medium and gravimeter
By extracting the spring oscillator frequency of the MEMS gravimeter in real time and performing self-calibration, the grid error problem of the MEMS gravimeter was solved, improving measurement accuracy and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HUAZHONG UNIV OF SCI & TECH
- Filing Date
- 2026-03-11
- Publication Date
- 2026-05-08
AI Technical Summary
Traditional gravimeters are large and expensive, while MEMS gravimeters suffer from grid errors during long-term use, which affects their application.
Self-calibration is achieved by extracting the current intrinsic frequency of the spring oscillator in real time from the MEMS gravimeter and calculating the real-time correction grid value using fast Fourier transform and physical relationships.
Significantly reduces the drift of MEMS gravimeters, improves the ability to measure long-period weak gravity signals, and reduces hardware costs.
Smart Images
Figure CN121995529A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of gravimeter technology, and particularly relates to a self-compensation method, device, medium and gravimeter for the grid value of a MEMS gravimeter. Background Technology
[0002] Gravimeters provide crucial data for Earth science research, earthquake prediction, volcanology, resource exploration, and gravity-assisted navigation by sensing the distribution of subsurface mass. However, traditional gravimeters suffer from drawbacks such as large size and high cost, limiting their applicability in emerging applications.
[0003] The emergence of microelectromechanical systems (MEMS) offers a promising technological solution to overcome these limitations, characterized by compact size, low cost, and suitability for mass production. To improve the sensitivity of MEMS gravimeters, achieving quasi-zero stiffness using a nonlinear anti-spring structure is currently the mainstream approach. However, with the drift in inspection quality, grid errors introduced by structural nonlinearity over large time scales become a key issue affecting the application of MEMS gravimeters. Summary of the Invention
[0004] To address the aforementioned technical problems, this invention provides a method, apparatus, medium, and gravimeter for self-compensation of the grid value of a MEMS gravimeter. By extracting the intrinsic frequency from the real-time output data of the MEMS gravimeter, the self-calibration of the grid value of the MEMS gravimeter is achieved.
[0005] To achieve the above objectives, in a first aspect, the present invention provides a self-compensation method for the grid value of a MEMS gravimeter, comprising: performing factory calibration on the MEMS gravimeter to determine the initial grid value SF0 and the corresponding initial intrinsic frequency f0 of the spring oscillator; during operation of the MEMS gravimeter, extracting the current intrinsic frequency f(t) of the spring oscillator in real time; and applying the formula... Calculate the real-time correction grid value SF(t); use the real-time correction grid value SF(t) to calibrate the original data, and output the compensated gravity measurement results.
[0006] In one technical solution of the above-mentioned self-compensation method for the grid value of the MEMS gravimeter, the real-time extraction of the current intrinsic frequency f(t) of the spring oscillator includes: performing a fast Fourier transform on the raw data of the MEMS gravimeter, and calculating the current intrinsic frequency f(t) by combining the quality factor Q and the resonant frequency of the spring-oscillator structure.
[0007] In one technical solution of the above-mentioned self-compensation method for the grid value of the MEMS gravimeter, when calculating the current intrinsic frequency f(t), the difference between the resonant frequency and the intrinsic frequency is ignored, and the extracted resonant frequency is directly used as the current intrinsic frequency f(t).
[0008] In one technical solution of the above-mentioned self-compensation method for the grid value of a MEMS gravimeter, the original data includes the gravity signal to be measured, the influence of environmental disturbance, the drift introduced by creep, and the grid value error introduced by the creep of the spring oscillator and the nonlinearity of the structure.
[0009] In one technical solution of the above-mentioned self-compensation method for the grid value of a MEMS gravimeter, the grid value of the MEMS gravimeter is inversely proportional to the square of the eigenfrequency of the spring oscillator, satisfying the physical relationship: ,in, This is the change in gravity. This represents the change in displacement of the spring oscillator.
[0010] Secondly, this invention discloses a self-compensating grid value device for a MEMS gravimeter, comprising: a calibration module for performing factory calibration on the MEMS gravimeter to determine the initial grid value SF0 and the corresponding initial intrinsic frequency f0 of the spring oscillator; a frequency extraction module for extracting the current intrinsic frequency f(t) of the spring oscillator in real time; and a grid value correction module for correcting the grid value according to the formula... Calculate the real-time correction grid value SF(t); the data calibration module is used to calibrate the original data using the real-time correction grid value SF(t) and output the compensated gravity measurement results.
[0011] In one technical solution of the above-mentioned self-compensation method for the grid value of a MEMS gravimeter, the frequency extraction module includes an FFT processing unit and a frequency calculation unit; the FFT processing unit performs a fast Fourier transform on the raw data of the MEMS gravimeter, and the frequency calculation unit calculates the current intrinsic frequency f(t) by combining the Q value of the spring-oscillator and the resonant frequency.
[0012] Thirdly, the present invention discloses a computer-readable storage medium storing a plurality of program codes, characterized in that the program codes are adapted to be loaded and run by a processor to perform the steps of the MEMS gravimeter grid value self-compensation method.
[0013] Fourthly, the present invention discloses a MEMS gravimeter, characterized in that it includes a gravity sensing unit and a data processing unit, wherein the data processing unit is configured to execute the grid value self-compensation method.
[0014] The above-described technical solutions of this invention have at least one or more of the following beneficial effects: improving the stability of MEMS gravimeter grid values, thereby significantly reducing MEMS gravity drift and improving the ability to measure long-period weak gravity signals. Zero hardware cost: only the MEMS chip output signal is needed for data processing; no external sensor is required, which helps reduce the cost and size introduced by additional hardware. Attached Figure Description
[0015] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a block diagram of the grid value self-compensation method according to an embodiment of the present invention; Figure 2 Solid tide observation and residuals before grid value self-compensation in this embodiment of the invention; Figure 3 This is an example of solid tide observation and residuals after grid value self-compensation in an embodiment of the present invention. Detailed Implementation
[0016] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.
[0017] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.
[0018] like Figure 1 As shown, the self-compensation method for the grid value of the MEMS gravimeter in this embodiment of the invention mainly includes the following steps S1-S4.
[0019] Step S1: Perform factory calibration on the MEMS gravimeter to determine the initial grid value SF0 and the corresponding initial intrinsic frequency f0 of the spring oscillator; Step S2: When the MEMS gravimeter is working, the current intrinsic frequency f(t) of the spring oscillator is extracted in real time. Step S3: According to the formula Calculate the real-time correction grid value SF(t); Step S4: Use the real-time correction grid value SF(t) to calibrate the original data and output the compensated gravity measurement result.
[0020] Figure 2 (a) is the output data of the MEMS gravimeter from day 155 to day 159 before the grid value was corrected. The theoretical solid tide model is used for comparison. It can be seen that the grid value of the MEMS gravimeter introduces a significant error, resulting in the observed solid tide amplitude being smaller than the theoretical solid tide. Figure 2 (b) is the residual after subtracting the gravimeter observation results from the theoretical solid tide, with a peak-to-peak value of approximately 60 μGal. Figure 3 (a) Comparison of MEMS gravimeter observation data after correction using the method of the present invention with theoretical solid tides. It can be seen that the error introduced by the MEMS gravimeter grid value is reduced. Figure 3 (b) is the residual after subtracting the gravimeter observation results from the theoretical solid tide. The peak value of the residual is about 30 μGal, which is about 50% lower than before the correction.
[0021] In one embodiment, real-time extraction of the current intrinsic frequency f(t) of the spring oscillator includes: performing a fast Fourier transform on the raw data from the MEMS gravimeter, and calculating the current intrinsic frequency f(t) by combining the quality factor Q and resonant frequency of the spring-oscillator structure.
[0022] In one embodiment, when calculating the current intrinsic frequency f(t), the difference between the resonant frequency and the intrinsic frequency is ignored, and the extracted resonant frequency is directly used as the current intrinsic frequency f(t).
[0023] In one embodiment, the raw data includes the gravity signal to be measured, the effects of environmental disturbances, the drift introduced by creep, and the grid error introduced by the creep of the spring oscillator and the nonlinearity of the structure.
[0024] In one embodiment, the grid value of the MEMS gravimeter is inversely proportional to the square of the eigenfrequency of the spring oscillator, satisfying the physical relationship: , in, This is the change in gravity. This represents the change in displacement of the spring oscillator.
[0025] Example 2 This invention also provides a self-compensating grid value device for a MEMS gravimeter. The self-compensating grid value device for a MEMS gravimeter in this embodiment mainly includes a calibration module, a frequency extraction module, a grid value correction module, and a data calibration module. In some embodiments, one or more of the calibration module, frequency extraction module, grid value correction module, and data calibration module can be combined into a single module. In some embodiments, the calibration module can be configured to execute the procedure of step S1. The frequency extraction module can be configured to execute the procedure of step S2. The grid value correction module can be configured to execute the procedure of step S3. The data calibration module executes the procedure of step S4. In one embodiment, a description of the specific functions can be found in steps S1-S4.
[0026] The aforementioned MEMS gravimeter's grid self-compensation device is used for performing... Figure 1The embodiments of the self-compensation method for the grid value of the MEMS gravimeter shown are similar in technical principle, technical problem solved and technical effect. Those skilled in the art can clearly understand that, for the sake of convenience and brevity, the specific working process and related descriptions of the self-compensation device for the grid value of the MEMS gravimeter can be found in the embodiments of the self-compensation method for the MEMS gravimeter, and will not be repeated here.
[0027] Example 3 The present invention also provides a computer-readable storage medium. In one embodiment of the computer-readable storage medium according to the present invention, the computer-readable storage medium can be configured to store a program for performing the grid value self-compensation method of a MEMS gravimeter according to the above-described method embodiments. This program can be loaded and run by a processor to implement the above-described grid value self-compensation method of the MEMS gravimeter. For ease of explanation, only the parts related to the embodiments of the present invention are shown; for specific technical details not disclosed, please refer to the method section of the embodiments of the present invention. The computer-readable storage medium can be a storage device comprising various electronic devices. Optionally, in the embodiments of the present invention, the computer-readable storage medium is a non-transitory computer-readable storage medium.
[0028] Example 4 The present invention also provides a MEMS gravimeter. In one embodiment of the MEMS gravimeter according to the present invention, the MEMS gravimeter includes a processor and a storage device. The storage device can be configured to store a program for executing the grid value self-compensation method of the MEMS gravimeter described in the above method embodiment. The processor can be configured to execute the program in the storage device, which includes, but is not limited to, a program for executing the grid value self-compensation method of the MEMS gravimeter described in the above method embodiment. For ease of explanation, only the parts related to the embodiments of the present invention are shown; for specific technical details not disclosed, please refer to the method section of the embodiments of the present invention. The control device can be a control device device comprising various electronic devices.
[0029] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.
Claims
1. A self-compensation method for grid values in a MEMS gravimeter, characterized in that, include: Perform factory calibration on the MEMS gravimeter to determine the initial grid value SF0 and the corresponding initial eigenfrequency f0 of the spring oscillator; When the MEMS gravimeter is working, the current intrinsic frequency f(t) of the spring oscillator is extracted in real time; According to the formula Calculate the real-time correction grid value SF(t); The original data is calibrated using the real-time correction grid value SF(t), and the compensated gravity measurement result is output.
2. The method according to claim 1, characterized in that, Real-time extraction of the current intrinsic frequency f(t) of the spring oscillator includes: performing a fast Fourier transform on the raw data of the MEMS gravimeter, and calculating the current intrinsic frequency f(t) by combining the quality factor Q and resonant frequency of the spring-oscillator structure.
3. The method according to claim 2, characterized in that, When calculating the current intrinsic frequency f(t), the difference between the resonant frequency and the intrinsic frequency is ignored, and the extracted resonant frequency is directly used as the current intrinsic frequency f(t).
4. The method according to claim 1, characterized in that, The raw data includes the gravity signal to be measured, the effects of environmental disturbances, the drift introduced by creep, and the grid error introduced by the creep of the spring oscillator and the nonlinearity of the structure.
5. The method according to claim 1, characterized in that, The scale value of the MEMS gravimeter is inversely proportional to the square of the eigenfrequency of the spring oscillator, satisfying the physical relationship: ， in, This is the change in gravity. This represents the change in displacement of the spring oscillator.
6. A self-compensating grid value device for a MEMS gravimeter, characterized in that, include: The calibration module is used to perform factory calibration on the MEMS gravimeter to determine the initial grid value SF0 and the corresponding initial eigenfrequency f0 of the spring oscillator. The frequency extraction module is used to extract the current intrinsic frequency f(t) of the spring oscillator in real time. The grid value correction module is used to adjust the grid value according to the formula. Calculate the real-time correction grid value SF(t); The data calibration module is used to calibrate the original data using the real-time correction grid value SF(t) and output the compensated gravity measurement results.
7. The apparatus according to claim 6, characterized in that, The frequency extraction module includes an FFT processing unit and a frequency calculation unit; the FFT processing unit performs a fast Fourier transform on the raw data of the MEMS gravimeter, and the frequency calculation unit calculates the current intrinsic frequency f(t) by combining the Q value of the spring-oscillator and the resonant frequency.
8. A computer-readable storage medium storing a plurality of program codes, characterized in that, The program code is adapted to be loaded and run by a processor to perform the MEMS gravimeter grid value self-compensation method as described in any one of claims 1 to 5.
9. A MEMS gravimeter, characterized in that, It includes a gravity sensing unit and a data processing unit, wherein the data processing unit is configured to perform the MEMS gravimeter grid value self-compensation method as described in any one of claims 1 to 5.