A new in-motion initial alignment for land-vehicle SINS/OD integrated system

An in-motion initial alignment algorithm for Strapdown Inertial Navigation System (SINS) aided by the odometer (OD) is described. Because the vehicle velocity provided by the odometer is of high accuracy, the odometer dead-reckoning results are used as aiding information. In the fine alignment, a Kalman filter is designed, which uses the deviation of velocity and attitude between the SINS and the odometer dead-reckoning results as the measurements. After 30 seconds of stationary-based coarse alignment, the Vehicle leaves for destination at once. During the fine alignment period, the vehicle requires neither special maneuvering nor the helps of the waypoints on the road. It meets the requirements of modern weapons war for rapid response and mobile operations. Simulation results indicate that, the heading error of SINS is less than 4' after ten minutes fine alignment. The accuracy of the odometer aided vehicle SINS in-motion alignment is enhanced greatly by using the proposed approach.