A strong tracking Extended Kalman Observer for projectile attitude and position estimation

摘要

In this note we focus on convergence behavior of the Extended Kalman Filter used as a state estimator for projectile attitude and position estimation. We provide first the complete dynamical model, into a non linear state space form, to describe the projectile behavior. Due to strong non linearities and poor observability of the system, very few estimation techniques could be applied, among them the celebrate EKF. The later is, however, very sensitive to bad initializations and small perturbations. The main contribution of this work lies in the use of a modified EKF to assure a strong tracking using magnetometer sensor only. The modified EKF follows from the connection of some instrumental matrices, fixed by the user, and the convergence behavior. Simulation results show the good performances of the proposed approach.