Angular-rate filtering of inertial navigation system based on missile rudder information

The low precision gyroscopes of the inertial navigation system in some missiles could cause obvious measurement error of the angular velocity. This paper presents a filtering method which is based on the dynamics equations between the control angle of rudders and the missile body attitude, and could previously indicate the change tendency of missile body angle. To reduce the computation complexity with the nonlinear filters such as EKF and UKF, an interlaced Kalman filter is applied to transform the nonlinear equations into the pseudo-linear state equation with coupling terms. The experiment results of a low-precision MEMS gyroscope prove the validity of the novel filter, in which the measured filtered errors of angular velocities have been reduced by 40%.