Fast initial alignment algorithms for SINS based on rate biased RLG on a stationary base

摘要

In this paper, a new initial alignment algorithm is proposed, which is based on the error characteristic of rate biased RLG and accelerometer in the temperature rising process of SINS on a stationary base. At first, the second-order nonlinear error models of gyro scale factors and accelerometer biases are established to make online nonlinear estimation; then, the gyro drift rates are estimated by Kalman filter; finally, the initial angles are obtained. The results of initial alignment after 3 minutes show that, the alignment accuracy of two leveling angles is about 2", and the alignment accuracy of azimuth angle is better than 1', thus the rapidity and accuracy of initial alignment are increased.