On INS in-motion alignment for land vehicles

The Kalman filter(KF)-based method and Inertial reference frame(IRF)-based method for land inertial navigation system in-motion alignment are comprehensively compared and analyzed in this paper. According to the characters of odometer, we choose the displacement increments as the measurements and establish the corresponding model, so as to improve the accuracy of KF-based method. While analyzing the IRF-based method, the factors, which are harmful to the alignment accuracy are presented and the solutions are proposed. Ground based navigation experiments have been carried out to evaluate the performance of these two methods. The results show that both methods can achieve the alignment precision within 0.1°(1σ) in azimuth under well environment. While under complex environment, it should be noted that the IRF-based method cannot guarantee the alignment accuracy.