Real time calculation method for roll angle of projectile based on twin axis geomagnetic sensor

DOI:	10.11809/bqzbgcxb2025.03.027
Keywords:	2D course correction; twin axis geomagnetic sensor; roll angle; rotating projectile
Abstract:	Two dimensional(2D) course correction requires information about the roll attitude of the projectile for rudder to ground angular control.In order to accurately measure the roll attitude of a rotating projectile and improve the accuracy of 2D course correction, a real time calculation method for roll angle of spinning projectile based on twin axis geomagnetic sensor was proposed for 2D correction component. The method utilized twin axis geomagnetic sensor to generate sinusoidal signals by sensing changes in the geomagnetic field, and then performed data preprocessing through the sliding mean filtering algorithm and ellipse fitting algorithm.Combined with the ballistic inclination and velocity declination provided by the satellite receiver to calculate the roll compensation angle, a compensation method was proposed to compensate for the roll angle error caused by the sensor installation error in order to accurately calculate the roll angle. The geomagnetic pulse was generated when the roll angle is 0°, and the method was verified using the phase difference between the geomagnetic pulse and the Hall pulse, using the Hall pulse as a baseline. Uncontrolled test and controlled test were conducted on the ground using 2D correction component. Uncontrolled test results show that the error between the average pulse phase difference and the real value is less than 0.5°, and the root mean square error (RMSE) is less than 1°. Controlled test results show that the error between the average pulse phase difference and the angle given by the control command is within ±3°, and the average error is -0.296 2°. Both uncontrolled test and controlled test results show that the method meets the requirements for control accuracy.
Issue:	Vol. 46 No. 3 (2025)
Published:	2025-03-31
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