A robust tightly SINS/USBL based AUV localization method aided by dual transponder

Abstract

The main factors affecting the positioning accuracy of the Ultra-short base line (USBL) positioning system include sensor errors, marine environment-induced measurement errors, system acoustic array installation errors, and acoustic signal processing errors. These errors include common errors and random noise. The traditional SINS/USBL integrated navigation system models the measurement noise of USBL as random noise while neglecting the treatment of common errors. To solve the above problems, a new dual underwater transponder aided SINS/USBL integrated method is proposed. Firstly, different from the traditional tightly coupled model, a new model based on range difference is proposed to eliminate common errors in underwater acoustic communication, which replaces the traditional range measurement model. Due to slow sound speed and changes in the relative position between the transponder and the carrier, there is inconsistency in the measured arrival time of the dual responder. To solve the problem, a measurement timing inconsistency model is proposed. Secondly, an improved maximum correntropy robust filtering based on kernel density estimation (KDE) is proposed to estimate the characteristics of outliers and improve the adaptability of robust filter to time-varying systems. Finally, simulation and river experiments are conducted. Compared with the traditional tightly coupled method, the dual transponder aided coupled method proposed in this paper can effectively reduce the common errors in signal transmission for USBL and the proposed filter can effectively reduce the impact of complex environment on positioning accuracy.