In-motion coarse alignment method for SINS/DVL with the attitude dynamics

For underwater Strapdown Inertial Navigation System (SINS)/Doppler Velocity Log (DVL) integration system, there are intervals between DVL's transmitting and receiving epochs, which introduces velocity errors when the attitude dynamic occurs. To accelerate the coarse alignment process for SINS/DVL with attitude dynamics, an improved in-motion coarse alignment solution is proposed. First, the DVL aided in-motion coarse alignment method is explored. Then, a DVL velocity compensation algorithm for coarse alignment is proposed. Simulations and a field test are conducted to evaluate the effectiveness of the proposed algorithm under various trajectories. The results indicate that the proposed coarse alignment solution effectively applies the velocity compensation algorithm to the coarse alignment mission, which shows greater performance than the traditional optimization-based alignment (OBA) method in various trajectories.