Systematic calibration method based on acceleration and angular rate measurements for fiber-optic gyro SINS

Area of Science:

• Navigation Systems
• Inertial Sensing Technology
• Calibration Methodologies

Background:

• Strapdown inertial navigation systems (INS) rely on accurate inertial measurement unit (IMU) parameters.
• Fiber-optic gyroscopes (FOG) are crucial components in modern INS, requiring precise calibration.
• Existing calibration methods can be complex or limited in application scope.

Purpose of the Study:

• To introduce a simple, systematic calibration method for FOG IMUs.
• To enable FOG IMU parameter estimation both in manufacturing facilities and in field applications.
• To provide a unified mathematical framework and iterative calculation for calibration.

Main Methods:

• A two-stage procedure involving data accumulation in 19 specific FOG IMU positions.
• Utilizing acceleration and angular rate measurements for parameter estimation.
• Employing a unified mathematical framework and iterative calculation for processing raw data.

Main Results:

• Successful estimation of all FOG IMU parameters using the proposed method.
• Observability analysis confirms method's effectiveness across various initial orientations and complex terrains.
• Analysis of gravity disturbance influence on calibration accuracy was performed.

Conclusions:

• The developed systematic calibration method effectively meets FOG IMU calibration requirements.
• The method offers flexibility for both factory and field calibration scenarios.
• Observability analysis provides theoretical validation for diverse operational environments.