This paper presents a new method for constructing 2D maps of enclosed un- derwater structures using an underwater robot equipped with only a 2D scanning sonar, compass and depth sensor. In particular, no motion model or odometry is used. To accomplish this, a two step offline SLAM method is applied to a set of stationary sonar scans. In the first step, the change in position of the robot between each consecutive pair of stationary sonar scans is estimated using a particle filter. This set of pair wise relative scan positions is used to create an estimate of each scan’s position within a global coordinate frame using a weighted least squares fit that optimizes consistency between the relative positions of the entire set of scans. In the second step of the method, scans and their estimated positions act as inputs to a mapping algorithm that constructs 2D octree-based evidence grid maps of the site. This work is motivated by a multi-year archaeological project that aims to construct maps of ancient water storage systems, i.e. cisterns, on the islands of Malta and Gozo. Cisterns, wells, and water galleries within fortresses, churches and homes operated as water storage systems as far back as 2000 B.C. Using a Remotely Operated Vehicle (ROV) these water storage systems located around the islands were explored while collecting video, still images, sonar, depth, and compass measurements. Data gathered from 5 different expeditions has produced maps of over 90 sites. Presented are results from applying the new mapping method to both a swimming pool of known size and to several of the previously unexplored water storage systems.

Hydrodynamic and thermal analyses performed during the conceptual design of an unmanned underwater vehicle are presented in this study. The hull shape is determined by considering alternative shapes and the dimensions are determined from the internal arrangement of components. Preliminary thermal analyses of the watertight section are performed with a commercial software called FLUENT to check the risk of over-heating due to the heat dissipation of devices. Performance of the proposed hull design is analyzed by FLUENT. Before simulations of the vehicle, validation studies are performed. Models 4159, 4158 and 4154 of Series 58 are chosen as the experimental reference. Their total resistance coefficients are compared with the results of the validations analyses. Mesh densities, turbulence models, near wall modeling approaches and inlet turbulence intensities are varied to understand their effects on the accuracy of predictions. A suitable turbulence modeling approach is chosen to analyze forward and vertical motions of the vehicle to check whether speed requirements are fulfilled. Hull configurations with and without appendages are used to observe their effects on total drag. It is observed that the proposed design satisfies speed requirements of the vehicle and no overheating is expected in the watertight section.

Dissertação(mestrado) - Universidade Federal do Rio Grande, Programa de Pós-Graduação em Engenharia Oceânica, Escola de Engenharia, 2007. / Submitted by Lilian M. Silva (lilianmadeirasilva@hotmail.com) on 2013-04-23T20:52:40Z No. of bitstreams: 1 Projeto e construção de um veículo subaquático não tripulado de baixo custo.pdf: 1267914 bytes, checksum: de003a4ec22d232cb5b78deb87dd39c5 (MD5) / Approved for entry into archive by Bruna Vieira(bruninha_vieira@ibest.com.br) on 2013-06-08T23:09:06Z (GMT) No. of bitstreams: 1 Projeto e construção de um veículo subaquático não tripulado de baixo custo.pdf: 1267914 bytes, checksum: de003a4ec22d232cb5b78deb87dd39c5 (MD5) / Made available in DSpace on 2013-06-08T23:09:06Z (GMT). No. of bitstreams: 1 Projeto e construção de um veículo subaquático não tripulado de baixo custo.pdf: 1267914 bytes, checksum: de003a4ec22d232cb5b78deb87dd39c5 (MD5) Previous issue date: 2007 / A escassez de alguns recursos naturais como petróleo e gás na superfície terrestre, têm feito com que a raça humana volte sua atenção para as profundezas dos oceanos nestas últimas décadas. Os ROVs (Remotely Operated Vehicle) possuem função importante para o estudo, preservação e execução de tarefas em ambiente subaquático com segurança. Infelizmente no Brasil, as iniciativas de produzir um ROV com tecnologia nacional e de baixo custo, quando comparado a equivalentes importados, são ainda raras e se restringem a algumas poucas instituições acadêmicas, não tendo sido localizado nenhum fabricante comercial deste tipo de veículo no país. Visando preencher esta lacuna, o presente trabalho deu continuidade ao projeto e construção de um ROV de baixo custo iniciado por Moraes em 2005, do qual efetivamente foi aproveitado o projeto estrutural mecânico, que através de pequenas modificações, ganhou uma câmera de vídeo, propulsores mais potentes, e sistema de iluminação. A eletrônica embarcada foi totalmente modificada visando atender às novas exigências de potência do sistema, e de funções antes inexistentes tais como: zoom, foco,nível de iluminação e controle de trajetória efetivado através de um único joystick. O novo modelo de acelerômetro empregado permitiu a medição de aceleração em três eixos ortogonais. Na fase final do trabalho foi incorporado ao ROV um altímetro, o que propiciou alguns resultados experimentais envolvendo controle de profundidade em malha fechada. No último capítulo desta dissertação foram incluídas algumas conclusões e considerações que deverão colaborar para futuras melhorias deste projeto. / The scarcity of some natural resources as oil and gas in the terrestrial surface has called human race attention toward the deepness of the oceans in these last decades. ROVs(Remotely Operated Vehicles) have important function for the study, preservation and execution of tasks in subaqueous environment with security. In Brazil, the initiatives to produce a ROV with national technology and low cost, when compared with imported devices, are still rare and restrict to some academic institutions, not having been found commercial manufacturer of this type of vehicle in the country. Aiming to fill this gap, the present work gave continuity to the project and construction of the ROV of low cost initiated by Moraes in 2005, from which effectively the mechanical structural project was used and, through small modifications, it was incorporaded a video camera, more powerful propellants, and lighting system. The embarked electronics was totally modified aiming to supply the new requirements of power system, and functions before inexistent such as zoom, focus, level of illumination and control of trajectory accomplished through only one joystick. The new model of accelerometer employed allows the measurement of acceleration in three orthogonal axes. In the final phase of the work an altimeter was incorporated to the ROV, which propitiated some experimental results in depth closed loop control. In the last chapter of this dissertation were enclosed some conclusions and considerations that will collaborate for future improvements in this project.

Ships and vessel conditions demand regular assessment to maintain their safety. In the traditional environment, their assessment was conducted using surveys and complex and time-consuming operations. But now, with the emergence of Industry 4.0 where intelligence and smart devices serve the imagery, drone-based, and many other alternative methods for inspection, the subject is obtaining considerable interest. The concept is highly effective with low cost and less disruption delivering a safer inspection approach. This study has examined Industry 4.0 technology as a quality inspection technique of a ship/vessel, examined drone-based ship inspection techniques for quality inspection of the ship/vessel without human involvement, to analyse robotic underwater surveillance methods for quality inspection of the ship/vessel, and to identify vision-based corrosion detection techniques for quality inspection of the ship/vessel. In the finding, it was revealed ship inspection through Industry 4.0 technology and other techniques can help the marine industries rely more on automated systems to gather the information that is required to be capable of authenticating process and product conformance also they can reduce human error, risks and uncover useful insights from the gathered vessel/ship data.

Approved for public release, distribution is unlimited / Autonomous Underwater Vehicles (AUVs) are now being introduced into the fleet to improve Mine Warfare capabilities. Several AUVs are under government-contracted development. Mission planning and data reporting vary between vehicles and systems. This variance does not pose an immediate problem, as only one AUV is currently in production. However, as more AUVs are put into production, commands will begin to get multiple AUVs. Without a single mission command language, multiple systems will require familiarity with multiple languages. Extensible Markup Language (XML) and related technologies may be used to facilitate interoperability between dissimilar AUVs and extract and integrate mission data into Navy C4I systems. XML makes archive maintenance easier, XML documents can be accessed via an http server, and, in root form, XML is transferable on the fly by stylesheet. This thesis presents an XML-based mission command for the command and control of AUVs. In addition, this thesis discusses XML technology and how XML is a viable means of achieving interoperability. Furthermore, this thesis provides an example mission file using existing software, and demonstrates the future of XML in AUV technology. Finally, this work ends with a compelling argument for the use of an XML-based mission command language to command all AUVs. / Ensign, United States Navy / Captain, United States Air Force

L’industrie offshore, pétrolière et gazière est le principal utilisateur des robots sous-marins, plus particulièrement de véhicules télé-opérés (ou ROV, Remotely Operated Vehicle). L'inspection, la construction et la maintenance de diverses installations sous-marines font parties des applications habituelles des ROVs dans l’industrie offshore. La capacité à maintenir un positionnement stable du véhicule ainsi qu’à soulever et déplacer des charges lourdes est essentielle pour certaines de ces applications. Les capacités de levage des ROVs sont cependant limitées par la puissance de leur propulsion. Dans ce contexte, cette thèse présente un nouveau concept d’actionnement hybride constitué de câbles et de propulseurs. Le concept vise à exploiter les fortes capacités de levage des câbles, actionnés par exemple depuis des navires de surfaces, afin de compléter l’actionnement d’un robot sous-marin. Plusieurs problèmes sont soulevés par la nature hybride (câbles et propulseurs) de ce système d'actionnement. En particulier, nous étudions l’effet de l'actionnement supplémentaire des câbles par rapport à un actionnement exploitant uniquement des propulseurs et nous tâchons de minimiser les efforts exercés par ces derniers. Ces deux objectifs sont les principales contributions de cette thèse. Dans un premier temps, nous modélisons la cinématique et la dynamique d'un robot sous-marin actionné à la fois par des propulseurs et des câbles et équipé d'un bras manipulateur. Un tel système possède une redondance cinématique et d'actionnement.. L'étude théorique sur l'influence de l'actionnement supplémentaire par câbles est appuyée par une étude en simulation, comparant les capacités de force d'un système hybride (câbles et propulseurs) à celles d'un système actionné uniquement par des propulseurs. L'évaluation des capacités est basée sur la détermination de l'ensemble des forces disponibles, en considérant les limites des forces d'actionnement. Une nouvelle méthode de calcul est proposée, pour déterminer l'ensemble des forces disponibles. Cette méthode est basée sur le calcul de la projection orthogonale de polytopes et son coût calculatoire est analysé et comparé à celui d'une méthode de l’état de l’art. Nous proposons également une nouvelle méthode pour le calcul de la distribution des forces d'actionnement, permettant d'affecter une priorité supérieure au sous-système d'actionnement par câbles afin de minimiser les efforts exercés par les propulseurs. Plusieurs cas d'études sont proposés pour appuyer les méthodes proposées. / The offshore industry for oil and gas applications is the main user of underwater robots, particularly, remotely operated vehicles (ROVs). Inspection, construction and maintenance of different subsea structures are among the applications of ROVs in this industry. The capability to keep a steady positioning as well as to lift and deploy heavy payloads are both essential for most of these applications. However, these capabilities are often limited by the available on-board vehicle propulsion power. In this context, this thesis introduces the novel concept of Hybrid Cable-Thruster (HCT)-actuated Underwater Vehicle-Manipulator Systems (UVMS) which aims to leverage the heavy payload lifting capabilities of cables as a supplementary actuation for ROVs. These cables are attached to the vehicle in a setting similar to Cable-Driven Parallel Robots (CDPR). Several issues are raised by the hybrid vehicle actuation system of thrusters and cables. The thesis aims at studying the impact of the supplementary cable actuation on the capabilities of the system. The thesis also investigate how to minimize the forces exerted by thrusters. These two objectives are the main contributions of the thesis. Kinematic, actuation and dynamic modeling of HCT-actuated UVMSs are first presented. The system is characterized not only by kinematic redundancy with respect to its end-effector, but also by actuation redundancy of the vehicle. Evaluation of forces capabilities with these redundancies is not straightforward and a method is presented to deal with such an issue. The impact of the supplementary cable actuation is validated through a comparative study to evaluate the force capabilities of an HCT-actuated UVMS with respect to its conventional UVMS counterpart. Evaluation of these capabilities is based on the determination of the available forces, taking into account the limits on actuation forces. A new method is proposed to determine the available force set. This method is based on the orthogonal projection of polytopes. Moreover, its computational cost is analyzed and compared with a standard method. Finally, a novel force resolution methodology is introduced. It assigns a higher priority to the cable actuation subsystem, so that the forces exerted by thrusters are minimized. Case studies are presented to illustrate the methodologies presented in this thesis.