CN-121995529-A - Grid value self-compensation method and device of MEMS (micro electro mechanical System) gravity meter, medium and gravity meter

Abstract

The invention discloses a grid value self-compensating method, a device, a medium and a gravity meter of an MEMS gravity meter, wherein the method comprises the steps of calibrating the MEMS gravity meter in a factory, determining an initial grid value SF 0 and a corresponding initial eigenfrequency f 0 of a spring oscillator, extracting the current eigenfrequency f (t) of the spring oscillator in real time when the MEMS gravity meter works, and obtaining the initial eigenfrequency f (t) of the spring oscillator according to a formula And calibrating the original data by using the real-time correction grid value SF (t) and outputting a compensated gravity measurement result. In addition, only the output signal of the MEMS chip is required to be subjected to data processing, an external sensor is not required, and the method is beneficial to reducing the introduction of new cost and size of an additional hardware band.

Inventors

• WU WENJIE
• GAO LE
• ZHANG ZHONG
• LI FANGZHENG
• CAI BINGYANG
• ZHANG ZHIQING

Assignees

• 华中科技大学

Dates

Publication Date

20260508

Application Date

20260311

Claims (9)

1. 1. A method for self-compensating a grid value of a MEMS gravity meter, comprising: Carrying out factory calibration on the MEMS gravimeter, and determining an initial lattice value SF 0 and a corresponding initial eigenfrequency f 0 of the spring vibrator; When the MEMS gravimeter works, the current eigenfrequency f (t) of the spring vibrator is extracted in real time; According to the formula Calculating a real-time correction grid value SF (t); and calibrating the original data by using the real-time correction grid value SF (t), and outputting a compensated gravity measurement result.
2. 2. The method of claim 1, wherein extracting in real time the current eigenfrequency f (t) of the spring oscillator comprises performing a fast fourier transform on raw data of the MEMS gravimeter, and calculating the current eigenfrequency f (t) in combination with a quality factor Q value and a resonant frequency of the spring-oscillator structure.
3. 3. A method according to claim 2, characterized in that the difference between the resonance frequency and the eigenfrequency is ignored when calculating the current eigenfrequency f (t), and the extracted resonance frequency is taken directly as the current eigenfrequency f (t).
4. 4. The method of claim 1, wherein the raw data comprises a gravity signal to be measured, an environmental disturbance impact, an amount of creep induced drift, and a lattice error introduced by a combination of spring vibrator creep and structural nonlinearity.
5. 5. The method of claim 1, wherein the MEMS gravimeter grid value is inversely proportional to the square of the spring vibrator eigenfrequency, satisfying a physical relationship: , Wherein, the The amount of change in the force of gravity, The displacement variation of the spring vibrator is obtained.
6. 6. A self-compensating device for a grid value of a MEMS gravity meter, comprising: The calibration module is used for carrying out factory calibration on the MEMS gravimeter and determining an initial lattice value SF 0 and a corresponding initial eigenfrequency f 0 of the spring vibrator; The frequency extraction module is used for extracting the current eigenfrequency f (t) of the spring vibrator in real time; The grid value correction module is used for correcting the grid value according to the formula Calculating a real-time correction grid value SF (t); And the data calibration module is used for calibrating the original data by utilizing the real-time correction grid value SF (t) and outputting a compensated gravity measurement result.
7. 7. The apparatus of claim 6, wherein the frequency extraction module comprises an FFT processing unit and a frequency calculation unit, the FFT processing unit performs a fast Fourier transform on raw data of the MEMS gravimeter, and the frequency calculation unit combines the Q value and the resonant frequency of the spring-vibrator to calculate the current eigenfrequency f (t).
8. 8. A computer readable storage medium having stored therein a plurality of program codes, wherein the program codes are adapted to be loaded and executed by a processor to perform the MEMS gravity-check value self-compensation method according to any one of claims 1 to 5.
9. 9. A MEMS gravity meter comprising a gravity sensing unit, a data processing unit, and the data processing unit is configured to perform the MEMS gravity meter grid self-compensation method of any of claims 1 to 5.

Description

Grid value self-compensation method and device of MEMS (micro electro mechanical System) gravity meter, medium and gravity meter Technical Field The invention belongs to the technical field of gravimeters, and particularly relates to a grid value self-compensating method and device of an MEMS gravimeter, a medium and the gravimeter. Background The gravity meter provides key data for geoscience research, earthquake prediction, volcanic research, resource exploration and gravity assisted navigation by sensing underground mass distribution. However, conventional gravimeters suffer from the disadvantages of being bulky, costly, etc., limiting their applicability in emerging applications. The advent of microelectromechanical systems has provided a promising technical solution to overcome these limitations, which is characterized by compact size, low cost, and suitability for mass production. In order to improve the sensitivity of the MEMS gravimeter, the adoption of a nonlinear rebound spring structure to realize quasi-zero rigidity is the mainstream scheme at present. However, as proof mass drifts, lattice errors introduced by structural nonlinearities at large time scales become a critical issue affecting MEMS gravimeter applications. Disclosure of Invention In order to solve the technical problems, the invention provides a self-compensating method, a self-compensating device, a self-compensating medium and a self-compensating gravity meter for the grid value of a MEMS gravity meter, wherein the self-calibration of the grid value of the MEMS gravity meter is realized by extracting the eigenfrequency from the real-time output data of the MEMS gravity meter. In order to achieve the above object, in a first aspect, the present invention provides a method for self-compensating a grating value of a MEMS gravity meter, comprising calibrating the MEMS gravity meter by factory, determining an initial grating value SF 0 and a corresponding initial eigenfrequency f 0 of a spring oscillator, extracting the current eigenfrequency f (t) of the spring oscillator in real time when the MEMS gravity meter works, and determining the initial eigenfrequency f (t) of the spring oscillator according to the formulaAnd calibrating the original data by using the real-time correction grid value SF (t) and outputting a compensated gravity measurement result. In one technical scheme of the grid value self-compensating method of the MEMS gravimeter, extracting the current eigenfrequency f (t) of the spring oscillator in real time comprises the steps of performing fast Fourier transform on original data of the MEMS gravimeter, and calculating the current eigenfrequency f (t) by combining the quality factor Q value and the resonance frequency of the spring-oscillator structure. In one technical scheme of the grid value self-compensating method of the MEMS gravimeter, when the current eigenfrequency f (t) is calculated, the difference between the resonance frequency and the eigenfrequency is ignored, and the extracted resonance frequency is directly used as the current eigenfrequency f (t). In one technical scheme of the grid value self-compensating method of the MEMS gravimeter, the original data comprise a gravity signal to be measured, an environmental disturbance influence, a drift amount introduced by creep and a grid value error commonly introduced by creep of a spring vibrator and nonlinearity of a structure. In one technical scheme of the grid value self-compensating method of the MEMS gravity meter, the grid value of the MEMS gravity meter is inversely proportional to the square of the eigenfrequency of the spring oscillator, and the physical relationship is satisfied: , wherein, The amount of change in the force of gravity,The displacement variation of the spring vibrator is obtained. The invention discloses a grid value self-compensating device of an MEMS gravity meter, which comprises a calibration module, a frequency extraction module, a grid value correction module and a grid value correction module, wherein the calibration module is used for carrying out factory calibration on the MEMS gravity meter, determining an initial grid value SF 0 and a corresponding initial eigenfrequency f 0 of a spring oscillator, the frequency extraction module is used for extracting the current eigenfrequency f (t) of the spring oscillator in real time, and the grid value correction module is used for carrying out factory calibration on the MEMS gravity meter according to a formulaAnd the data calibration module is used for calibrating the original data by utilizing the real-time correction grid value SF (t) and outputting a compensated gravity measurement result. In one technical scheme of the grid value self-compensating method of the MEMS gravity meter, the frequency extraction module comprises an FFT processing unit and a frequency calculation unit, wherein the FFT processing unit performs fast Fourier transform on original data of the MEMS gr