A Fast Calibration and Compensation Method for Magnetometers in Strap-Down Spinning Projectiles

Area of Science:

• Aerospace Engineering
• Geophysics
• Instrumentation and Measurement

Background:

• Magnetometers are crucial for projectile attitude measurement due to their size and cost.
• Launch disturbances and parameter drift degrade magnetometer accuracy over time.
• Accurate attitude estimation is vital for projectile trajectory correction.

Purpose of the Study:

• To develop a rapid magnetometer calibration method for spinning projectiles.
• To enhance the accuracy of attitude estimation in projectiles.
• To address the challenges posed by magnetic interference and parameter drift.

Main Methods:

• Optimal ellipsoid fitting based on a least squares criterion for rapid calibration.
• Pre-launch calibration and in-flight compensation of magnetometer data.
• Validation through numerical simulations and a semi-physical experimental system.

Main Results:

• The method effectively determines zero bias, scale factors, and alignment angle errors.
• Pitch angle error reduced from 3.52° to 0.58°.
• Roll angle error reduced from 2.59° to 0.65°.

Conclusions:

• The proposed calibration method significantly enhances magnetometer accuracy for spinning projectiles.
• Attitude estimation errors are substantially reduced, improving projectile guidance.
• This technique offers a practical solution for real-time attitude measurement challenges.