Angular Misalignment Calibration for Dual-Antenna GNSS/IMU Navigation Sensor

Area of Science:

• Navigation Systems Engineering
• Sensor Fusion Technology
• Mechatronics

Background:

• Angular misalignment between Global Navigation Satellite System (GNSS) antennas and inertial measurement units (IMUs) is a critical issue in integrated navigation.
• Physical alignment of low- to mid-grade MEMS sensors is often impractical due to their small size and lack of reference features.
• High-accuracy alignment (fraction-of-a-degree) is desirable for specific navigation applications.

Purpose of the Study:

• To develop a faster and more robust method for angular misalignment calibration in GNSS-IMU integrated systems.
• To address the limitations of traditional long-term averaging calibration techniques.
• To enable on-the-fly calibration and compensate for sensor bias instability and structural deformations.

Main Methods:

• Proposes a novel calibration approach utilizing sensor fusion during controlled rotations.
• Leverages the observability gained from specific rotational maneuvers.
• Integrates analytical compensation based on angle differences derived from fused sensor data.

Main Results:

• Achieves significantly faster convergence compared to traditional methods.
• Effectively accounts for run-to-run variations in inertial sensor bias.
• Enables continuous, on-the-fly fine-tuning of alignment during normal system operation.

Conclusions:

• The proposed sensor fusion method offers a superior solution for angular misalignment calibration in GNSS-IMU systems.
• This approach enhances navigation accuracy and system robustness by addressing sensor limitations and dynamic environmental factors.
• Facilitates practical implementation of high-precision integrated navigation solutions.