Analysis of Gyro Bias Depending on the Position of Inertial Measurement Unit in Rotational Inertial Navigation...

Area of Science:

• Navigation Systems Engineering
• Inertial Navigation Technology
• Sensor Calibration Techniques

Background:

• Ring-laser-gyro-based rotational inertial navigation systems (RINS) are crucial for navigation but susceptible to inertial sensor errors.
• Conventional RINS designs assume sensor errors are position-independent, neglecting factors like temperature and gravity variations.
• These position-dependent errors, particularly gyro bias, degrade long-term navigation performance.

Purpose of the Study:

• To propose and validate a novel calibration method for gyro bias in RINS.
• To address the degradation of navigation performance caused by position-dependent gyro bias in RLG-based RINS.
• To enhance the accuracy and reliability of RINS through improved calibration.

Main Methods:

• Review of RINS using a dual-axis 16-position rotation scheme and ring-laser-gyros (RLG).
• Derivation of attitude error using navigation equations, analyzing the impact of gyro bias changes.
• Implementation of system-level indirect calibrations for Z-axis up and down positions to quantify bias variations.

Main Results:

• Analysis confirmed that changes in IMU attitude significantly affect gyro bias and RINS navigation performance.
• The proposed calibration method effectively calculates gyro bias changes related to IMU attitude.
• Long-term navigation tests demonstrated superior performance of the proposed method over conventional approaches.

Conclusions:

• The developed calibration method successfully compensates for position-dependent gyro bias in RLG-based RINS.
• This approach significantly improves the long-term navigation accuracy of RINS.
• The findings offer a practical solution for enhancing the reliability of inertial navigation systems.