A Staggered Grid Based Water Current Aided SINS/DVL Integration Solution for Mid Water Navigation

Layer based water current aided strapdown inertial navigation system (SINS)/ Doppler velocity logs (DVL) integration system has provided continuously navigation solution for the underwater vehicles' diving and rising periods in deep water areas. However, as the water current varies both vertically and horizontally, difficulty arises when the vehicle travels with large horizontal range. Thus, in this work, a novel staggered grid based water current aided SINS/DVL mechanization is proposed, which can be commonly employed using direct DVL velocity outputs. First, the staggered grid partition scheme is presented, based on which the continuous navigation mechanism in mid water area with large horizontal motion can be built. Then, the corresponding SINS/DVL integration method is illustrated, along with the construction of the observation vectors under the staggered grid division. Finally, the water current estimation algorithm is explored. Simulations are conducted to evaluate the effectiveness of the proposed solution, where both navigation results and water current estimation accuracy are discussed. The results indicate that the proposed solution outperforms the layer based solution as it fits better to the water current variation characteristic. Besides, the recursive least squares (RLS) based water current estimation algorithm shows better performance than bin average estimation method.