PhD Thesis

DOCTORAL THESIS: Online Acoustic Localization Methods for Autonomous Underwater Vehicles

By Guillem Vallicrosa Massaguer Supervised by Dr. Pere Ridao Abstract Autonomous Underwater Vehicles (AUVs) true autonomy capabilities in complex poten-tially unknown environments, have not yet been fully achieved because of the lack of online algorithms that can solve fundamental problems such as localization, mapping and path-planning on-board the AUV and consequently react according to their outputs. These algorithms can empower them for new capabilities such as long-term deployments, au-tonomous exploration and autonomous intervention.   This thesis presents the development of two online localization algorithms for AUVs. The first algorithm is based on a Sum of Gaussian (SOG) filter for online range-only lo-calization of an acoustic beacon, e.g. localization of a Docking Station (DS) for battery recharging and data uploading. Two different versions of the algorithm are developed, one based on Dead Reckoning (DR) navigation and one based on a full Simultaneous Local-ization and Mapping (SLAM) solution. Moreover, an Active Localization...

DOCTORAL THESIS: Underwater Navigation and Mapping with an Omnidirectional Optical Sensor

Doctoral thesis “Underwater Navigation and Mapping with an Omnidirectional Optical Sensor” By Josep Bosch Alay Supervised by Dr. Nuno Gràcias / Dr. Pere Ridao   Abstract Omnidirectional vision has received increasing interest during the last decade from the computer vision community. A large number of camera models have reached the market to meet the increasing demand for panoramic imagery. However, the use of omnidirectional cameras underwater is still very limited. In this thesis we propose a number of methods to create a reference resource for designing, calibrating and using underwater omnidirectional multi-camera systems.     The first problem we address is the design and calibration of omnidirectional cameras for the underwater domain. Among the different imaging system approaches to capturing omnidirectional imagery we chose the use of multi-cameras, due to the higher resolution and quality of the final images obtained. In order to assist the design and insure a proper…

Online Path Planning for Autonomous Underwater Vehicles under Motion Constraints

Doctoral thesis “Online Path Planning for Autonomous Underwater Vehicles under Motion Constraints” By Juan David Hernández Vega Supervised by Dr. Marc Carreras   Abstract Thesis submitted to the University of Girona in fulfillment of the requirements for the degree of Doctor of PhilosophySince their beginning in the late 1950s, the capabilities and applications of autonomous underwater vehicles (AUVs) have continuously evolved. Their most common applications include imaging and inspecting different kinds of structures on the sea floor as well as collecting oceanographic informa-tion: biological, chemical, and even archaeological data.   Most of these applications require a priori information of the area or structure to be inspected, either to navigate at a safe and conservative altitude or to pre-calculate a survey path. However there are other applica-tions where it’s unlikely that such information is available (e.g., exploring confined natural environments like underwater caves). In these scenarios, AUVs must operate in unexplored…

ROBOT LEARNING APPLIED TO AUTONOMOUS UNDERWATER VEHICLES FOR INTERVENTION TASKS

Doctoral thesis “Robot Learning applied to Autonomous Underwater Vehicles for intervention tasks” By Arnau Carrera Viñas Supervised by Marc Carreras, Narcís Palomeras and Petar Kormushev   ABSTRACT The interest in performing underwater tasks using AUVs has been growing over the past few decades. The initial focus was on the exploration of underwater areas, performing survey trajectories harvesting data to build bathymetric maps or photo-mosaics. Later the focus of research switched to performing inspections of underwater structures or elements (e.g., pipelines) which required more complex behaviours and localization methods. Advances in these fields have awakened the interest of the community in using AUVs to perform intervention tasks, replacing ROVs and manned submersibles. This replacement offers the possibility of automatizing tasks, increasing the efficiency and repetitively, as well as reducing cost, time, and the equipment needed to perform an underwater intervention. I-AUVs open the door for more companies and scientists to increase the frequency of…