Motion estimation and mapping by autonomous underwater vehicles in sea environments

This paper describes a framework for motion estimation and mapping of unstructured underwater environment using multiple onboard sensors. The fundamental goal of this work is to estimate the current pose of the vehicle and build a map of its surroundings. This goal is framed with the context of improving autonomous underwater vehicle navigation for undersea explorations. The paper considers Inertial Navigation System (INS), Sector Scan Sonar and a monocular CCD camera for the purpose of mapping and motion estimation. It discusses a robust feature tracking technique from image sequences and thereby estimating the ego-motion. It also discusses about the trajectory recovery from the sonar and fusion of INS and sonar. Results are shown for the real world data set collected by an autonomous underwater vehicle (AUV) in an unstructured underwater environment.