Contour tracking control for the REMUS autonomous underwater vehicle

Abstract

In the interest of enhancing the capabilities of autonomous underwater vehicles US Naval Operations, controlling vehicle position to follow depth contours presents exciting potential for navigation. Use of a contour tracking control algorithm in lieu of preprogrammed waypoint navigation offers distinct advantages within new challenges. The difficult nature of this problem lies in the non-trivial connection between the necessary corrective action and the feedback error used in traditional control methods. Stated simply, modern vehicle control algorithms separate horizontal and vertical plane navigation. The autonomous vehicle senses heading error and applies rudder to steer the vehicle to a desired heading. Simultaneously, the vehicle might sense altitude and apply stern plane angles to maintain a safe height above ground. This thesis research examines the new problem of sensing depth and altitude in the vertical plane while steering the vehicle horizontally to find a specified bathymetry contour. While more remains to understand, this research proves the existence of a solution and suggests similar approaches may facilitate tying vehicle navigation to other indirect sensors. This thesis presents two contour tracking control algorithms and examines the performance of each by simulating the response of the REMUS underwater vehicle to ideal and real-world bathymetry models.