Ring Laser Gyro G-Sensitive Misalignment Calibration in Linear Vibration Environments.

Area of Science:

• Navigation Systems
• Inertial Navigation
• Sensor Calibration

Background:

• Ring laser gyros (RLGs) are susceptible to g-sensitive misalignments, causing attitude errors in strapdown inertial navigation systems (SINS).
• These misalignments are often overlooked during SINS calibration, particularly in dynamic environments with coexisting forces and angular rates.
• Severe attitude errors occur in vibration or maneuver conditions, impacting navigation accuracy.

Purpose of the Study:

• To propose and validate a novel method for calibrating g-sensitive misalignments of an RLG triad.
• To establish a calibration scheme for RLG g-sensitive misalignments in linear vibration environments.
• To demonstrate the impact of compensating for these misalignments on SINS performance.

Main Methods:

• Developed a mathematical model to analyze the relationship between attitude errors, specific forces, and angular rates.
• Designed a calibration scheme utilizing approximately optimal observations.
• Conducted vibration experiments on a SINS attached to a linear vibration bench with rubber dampers to simulate flight conditions.

Main Results:

• Successfully calibrated g-sensitive misalignments of the RLG triad using the proposed vibration method.
• Vibration tests demonstrated a significant reduction in SINS velocity error after implementing g-sensitive misalignment compensation.
• The developed method effectively simulates harsh aircraft flight environments.

Conclusions:

• The proposed method provides an effective approach for calibrating RLG g-sensitive misalignments in linear vibration environments.
• Compensation for g-sensitive misalignments leads to improved SINS accuracy, particularly in velocity error reduction.
• This research addresses a critical gap in SINS calibration, enhancing navigation system reliability in dynamic conditions.