DVL aided SINS coarse Alignment Solution with high Dynamics

To accelerate the strapdown inertial navigation system (SINS)/Doppler velocity logs (DVL) based underwater vehicle's coarse alignment process, an improved optimization based alignment (OBA) methodology is proposed, where the dynamic motions are taken into account. First, the DVL velocity measurements are analyzed to specify the extra velocity errors brought by the velocity difference between the transmitting and receiving epochs, where the influence of the dynamic motions is indicated. Then, a novel SINS/DVL coarse alignment method that accommodates dynamic motions is proposed, exploring the velocity relationship between the transmitting and receiving moments using SINS information. To evaluate the coarse alignment performance of the proposed method, simulations and field test are operated under different trajectories including various motions, such as turning and acceleration. Comparing to the traditional OBA method, the proposed coarse alignment solution shows its superiority in pitch, roll and yaw attitudes, where faster convergence rate and higher precision are obtained.