Research on INS/GNSS/Magnetometer Integrated Navigation Algorithm for Guided Ammunition

Abstract

To address the insufficient attitude calculation accuracy of guided projectiles under high-dynamic, strong-impact, and complex electromagnetic environments, this paper proposes a full-state asynchronous integrated navigation algorithm combining inertial/satellite/magnetometer. The core innovations are as follows: (1) By introducing satellite pulse signals and magnetic field vectors to construct attitude observation equations, direct constraints on attitude errors are achieved; (2) An asynchronous Kalman filtering strategy is adopted to solve multisource heterogeneous time synchronization problems, supporting independent observation updates from any sensor. Simulation experiments demonstrate that compared with pure inertial navigation (PIN), satellite-magnetometer integration (GNSS+Mag), and traditional Kalman filter-based integrated navigation (KF-INS), the attitude accuracy of the asynchronous Kalman filter-based integrated navigation (AKF-INS) is improved by more than 96.2%, 78.8%, and 38.6% respectively. Under conditions of magnetic interference and satellite signal loss, the position and velocity accuracy compared to the traditional method (KF-INS) are improved by more than 15.7% and 20.1% respectively. This algorithm provides an effective technical solution for high-precision attitude calculation of high-dynamic guided munitions.