Turntable IMU Calibration Algorithm Based on the Fourier Transform Technique

Area of Science:

• * Mechanical Engineering
• * Signal Processing
• * Metrology

Background:

• * Accurate calibration of micromechanical inertial measurement units (IMUs) is crucial for navigation and motion tracking systems.
• * Existing calibration methods often require complex procedures, iterative algorithms, or specific laboratory equipment.
• * There is a need for a simplified, robust, and efficient IMU calibration technique.

Purpose of the Study:

• * To present a new, purely algebraic algorithm for calibrating micromechanical IMUs.
• * To demonstrate the effectiveness of the algorithm using data from a simple rotating turntable.
• * To reduce IMU calibration to an explicit, non-iterative process.

Main Methods:

• * Utilizing Fourier transform (specifically FFT) on experimental data from a rotating turntable.
• * Calculating spectral peak frequencies and amplitudes for calibration data.
• * Approximating accelerometer data as a 3D ellipsoid to determine IMU frame and calibrate accelerometers.
• * Employing linear least squares for gyro calibration based on calculated rotation frequency.

Main Results:

• * The algorithm successfully calibrated accelerometer triads and determined the IMU coordinate frame by fitting data to an ellipsoid.
• * Gyroscope calibration was achieved through a straightforward linear least squares method.
• * The method demonstrated robustness, requiring no iterations or initial parameter guesses, thus avoiding convergence issues.
• * Promising results were obtained from both simulated and experimental data.

Conclusions:

• * The proposed Fourier transform-based algebraic approach offers a simplified and efficient method for micromechanical IMU calibration.
• * The technique effectively calibrates both accelerometers and gyroscopes using readily available equipment.
• * The absence of iterative steps and initial parameter requirements makes the algorithm highly practical and reliable.