Research on a self-alignment algorithm for strap down inertial navigation system against abrupt line motion interference

Aiming at the problem that the self-alignment effect of strap down inertial navigation system is not ideal due to the disturbance of abrupt line motion under the shaking base, a self-alignment algorithm against the disturbance of abrupt line motion is proposed based on the combination of time-domain fitting and optimal estimation. The algorithm uses the time-domain characteristics of the gravity vector signal in the inertial frame to eliminate the abrupt line motion interference, then constructs the optimal state space model based on the gravity vector information, and uses the Kalman filtering algorithm to estimate the initial attitude of the strap down inertial navigation system. The simulation results show that the self-alignment can be realized within 5 minutes under the condition of abrupt line motion interference.