Enhanced Dual-Axis Rotation Modulation Scheme for Inertial Navigation Systems Using a 64-Position Approach.

Area of Science:

• Navigation Systems Engineering
• Inertial Navigation
• Sensor Error Analysis

Background:

• Strapdown inertial navigation systems (SINS) utilize rotational modulation of inertial measurement units (IMUs) to mitigate sensor errors.
• Existing dual-axis rotation schemes suffer from accumulated rotation angles and delayed error balancing, leading to residual attitude errors and reduced navigation accuracy.

Purpose of the Study:

• To develop an improved dual-axis rotational strategy for SINS that overcomes the limitations of existing methods.
• To maximize error cancellation across axes while constraining cumulative rotation for enhanced real-time navigation performance.

Main Methods:

• Proposed an odd-symmetric dual-axis rotation strategy optimizing rotation order and dwell positions.
• Designed a 64-position rotation scheme to analyze IMU error modulation/suppression characteristics (gyroscope drift, accelerometer bias, scale-factor errors, misalignment).
• Quantified the effects of these errors on attitude and velocity using simulations and experiments.

Main Results:

• Simulations demonstrated over 60% reduction in position and velocity errors compared to a 16-position scheme.
• The proposed scheme reduced longitude, east-velocity, and yaw errors by more than 30% compared to a 32-position scheme.
• Experimental validation confirmed consistent improvements in position, velocity, and attitude accuracy.

Conclusions:

• The proposed odd-symmetric dual-axis rotation strategy effectively enhances SINS accuracy by minimizing residual attitude and velocity errors.
• The 64-position scheme offers superior performance in error suppression and navigation precision for dual-axis SINS applications.