A Multisensor Fusion Method Based on Strict Velocity for Underwater Navigation System

Aiming at the inconsistency of the frame system defined by the velocity error in the underwater integrated navigation system and taking the strap-down inertial navigation system (SINS)/Doppler velocity logs (DVLs)/ultrashort baseline (USBL) integrated navigation system as the research object, a multisensor fusion method based on strict velocity is proposed. First, based on the azimuth angle, slope distance, and Doppler velocity information, a multisensor fusion model based on SINS/DVL/USBL is proposed. Second, in order to solve the problem of inaccurate calculation of the system matrix caused by the large quantization noise of the specific information, an error model based on strict velocity is proposed. According to the velocity error model, an improved Kalman filter fusion algorithm is proposed. Finally, simulations and Yangtze River tests verify that the method proposed by this question can effectively improve the accuracy of integrated navigation system, especially in the case that USBL signals cannot be received at a long distance, which has greater advantages.