Research on Nonlinear Compensation of the MEMS Gyroscope under Tiny Angular Velocity

Area of Science:

• Instrumentation and Measurement
• Signal Processing
• Mechanical Engineering

Background:

• Micro-Electro-Mechanical System (MEMS) gyroscopes exhibit significant output nonlinearity, particularly at low angular velocities, limiting their precision.
• Existing compensation methods, such as polynomial and standard Fourier series, struggle to fully address this nonlinearity in MEMS gyroscope data.

Purpose of the Study:

• To develop and validate an adaptive Fourier series compensation method (AFCM) for mitigating nonlinearity in MEMS gyroscope outputs under tiny angular velocities.
• To enhance the accuracy and reliability of MEMS gyroscopes for applications requiring precise low-speed angular measurements.

Main Methods:

• The proposed AFCM integrates Fourier series fitting with steepest descent optimization and residual correction tailored to MEMS gyroscope characteristics.
• Optimal weights for the Fourier series are determined using the steepest descent method.
• Fourier series are employed to correct fitting residuals, further refining compensation accuracy.

Main Results:

• Experimental validation using Earth's rotation angular velocity (-0.0036°/s to 0.0036°/s) demonstrated AFCM's effectiveness.
• AFCM reduced MEMS gyroscope output nonlinearity from 1150.87 ppm (original) to 68.89 ppm.
• Compared to polynomial and standard Fourier methods (641.13 ppm and 250.55 ppm, respectively), AFCM achieved superior nonlinearity reduction.

Conclusions:

• The adaptive Fourier series compensation method (AFCM) effectively reduces nonlinearity in MEMS gyroscope outputs at tiny angular velocities.
• AFCM offers a significant improvement in accuracy over existing compensation techniques, enhancing MEMS gyroscope performance.
• The proposed method is validated as a superior approach for precise angular velocity measurements using MEMS gyroscopes.