An Accurate Calibration Method Based on Velocity in a Rotational Inertial Navigation System

Area of Science:

• Navigation Systems
• Control Theory
• Sensor Fusion

Background:

• Inertial Navigation Systems (INS) accuracy is limited by sensor drifts and biases.
• Traditional rotational INS (RINS) modulates errors along a single axis, leaving some errors unaddressed.
• Azimuth angle error is particularly sensitive to vertical gyro drift, necessitating effective modulation.

Purpose of the Study:

• To propose a novel dual-axis rotation strategy for RINS.
• To effectively modulate drifts of all three gyros.
• To address and mitigate horizontal velocity errors introduced by rotation strategies.

Main Methods:

• Implementation of a new dual-axis rotation strategy in a RINS.
• Experimental validation on a real dual-axis RINS.
• Detailed analysis of horizontal velocity errors and development of a calibration method.

Main Results:

• Reduced maximum azimuth angle error from 0.04° to less than 0.01° over 1 hour.
• Identified and analyzed sources of horizontal velocity errors.
• Achieved improved velocity precision by eliminating fluctuations and stages after calibration and compensation.

Conclusions:

• The proposed dual-axis rotation strategy effectively reduces azimuth angle errors in RINS.
• A new calibration method successfully mitigates velocity errors, enhancing overall INS performance.
• This work advances RINS accuracy for high-precision navigation applications.