State estimation of an underwater robot using visual and inertial information

This paper presents an adaptation of a vision and inertial-based state estimation algorithm for use in an underwater robot. The proposed approach combines information from an Inertial Measurement Unit (IMU) in the form of linear accelerations and angular velocities, depth data from a pressure sensor, and feature tracking from a monocular downward facing camera to estimate the 6DOF pose of the vehicle. To validate the approach, we present extensive experimental results from field trials conducted in underwater environments with varying lighting and visibility conditions, and we demonstrate successful application of the technique underwater.