USBL integration and assessment in a multisensor navigation approach for AUVs

This paper presents the design and assessment of an USBL-aided navigation approach for Autonomous Underwater Vehicles (AUV). The system integrates an Ultra-Short Base Line (USBL) acoustic modem and positioning device in a two-parallel Extended Kalman Filter (EKF) navigation schema, which also includes the measurements provided by an Inertial Measurement Unit (IMU), a Doppler Velocity Log (DVL), a Visual Odometer (VO), a pressure sensor, and a Global Positioning System (GPS). In order to be integrated in the estimation filter, the precision of the USBL measurements is derived experimentally. Moreover, the accuracy of the system is evaluated using a ground truth (GT) trajectory produced by a visual Simultaneous Localization and Mapping (SLAM) approach. Experimental results are obtained from marine datasets gathered in the north coast of Mallorca with an AUV, model SPARUS II.