External Velocity Aided Coarse Attitude and Position Alignment for Dynamic SINS

This paper concerns about the dynamic alignment for the strapdown inertial navigation system (SINS), especially in the case of no GPS assistance. A novel coarse alignment algorithm using external reference velocity in b-frame is proposed. To get the observation vectors of the optimization-based attitude alignment method, the velocity algorithm of SINS is derived in the inertial coordinate frame, so the Coriolis Effect can be excluded. Meanwhile, the real-time position of the SINS is approximately located, and the deviation of the gravity vector caused by the vehicle’s displacement can be compensated, which further improves the alignment accuracy. Experimental results show that the proposed algorithm performs better than the existing algorithm and it can provide ideal initial conditions for the fine alignment.