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Schultz, James Allen. "Autonomous Underwater Vehicle (AUV) Propulsion System Analysis and Optimization." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/33237.
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One of the largest design considerations for autonomous underwater vehicles (AUVâ s) that have specific mission scenarios is the propulsive efficiency. The propulsive efficiency affects the amount of power storage required to achieve a specific mission. As the efficiency increases the volume of energy being stored decreases. The decrease in volume allows for a smaller vehicle, which results in a vehicle that requires less thrust to attain a specific speed.
The process of selecting an efficient propulsive system becomes an iterative process between motor, propeller, and battery storage. Optimized propulsion systems for mission specific AUVâ s require costly motor and propeller fabrication which may not be available to the designer. Recent advancements in commercially available electric motors and propellers allows for cost effective propulsion systems. The design space selection of motors and propellers has recently increased due to component demand of remote control airplane and boats. The issue with such systems is how to predict small propeller and small motor performance interactions since remote control motor and propeller designers usually donâ t provide enough information about the performance of their product.
The mission statement is to design a propeller and motor combination that will allow an autonomous underwater vehicle to travel large distances while maintaining good efficiency. The vehicle will require 12 N of thrust with a forward velocity of 2 m/s. The propeller needs to be larger than 2.5â due to inflow velocity interaction and smaller than 4â due to loss of thrust when in surface transit due to suction.Master of Science
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Engelhardtsen, Øystein. "3D AUV Collision Avoidance." Thesis, Norwegian University of Science and Technology, Department of Engineering Cybernetics, 2007. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-9534.
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An underlying requirement for any Autonomous Underwater Vehicle (AUV) is to navigate through unknown or partly unknown environments while performing certain user specified tasks. The loss of an AUV due to collision is unjustifiable both in terms of cost and replacement time. To prevent such an unfortunate event, one requires a robust and effective Collision Avoidance System (CAS). This paper discusses the collision avoidance problem for the HUGIN AUVs. In the first part, a complete simulator for the HUGIN AUV is implemented in matlab and simulink. This includes a 6 degrees-of-freedom nonlinear AUV model, simulated environment including bottom profile and surface ice, navigation- and guidance functionality and sensor simulators. In the second part a number of well known strategies for the collision avoidance problem is presented with a short analysis of their properties. On the basis of the implemented simulator, a proposed CAS is developed and it’s performance is analyzed. This system is based on simple principles and known collision avoidance strategies, in order to provide effective and robust performance. The proposed system provides feasible solutions during all simulations and the collision avoidance maneuvers are performed in accordance with the specified user demands. The developed simulator and collision avoidance system is expected to provide a suitable framework for further development and possibly a physical implementation on the HUGIN AUVs.
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Åkerström, David. "Militärtekniskt perspektiv på AUV." Thesis, Försvarshögskolan, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:fhs:diva-4807.
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Sweden is dependent on secure sea transport. Shorter disruption of imports of fuel and crude oil can be managed with an emergency stock, but a prolonged halt in imports creates problems. For industry, the vulnerability is greater. Fragmented production chains in combination with expenditure reductions in inventory causes a dependency on proper transport of intermediate goods in the manufacturing industry. A lengthy disruption thus involves disruption of production for both domestic consumption and for export goods containing imported parts.In order to secure shipping routes with a limited number of vessels, Mine Counter Measures (MCM) capacity is required, and according to the Armed Forces, developed with new sensors and autonomous vehicles. Sweden has acquired small AUV systems for MCM, and has plans to acquire larger and more advanced. Before any acquisition is implemented, a number of considerations have to be made. How does advanced AUV inflict on existing methods and systems? Is the result is better, is it faster, do we need to make adjustments? The essay aims to examine the military technology influence an AUV have on today's MCM operations. The results of the study can serve as part of the decision support for the Armed Forces and FMV before a purchase of an advanced AUV.The results of the thesis show that Advanced AUV:s, with the qualities they have , can affect the way the Armed Forces are conducting MCM today.
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Brutzman, Donald P. "NPS AUV Integrated Simulation." Thesis, Monterey, Calif. : Naval Postgraduate School, 1992. http://handle.dtic.mil/100.2/ADA248120.
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Thesis (M.S. in Computer Science)--Naval Postgraduate School, March 1992.Thesis Advisor(s): Kanayama, Yutaka ; Zyda, Michael J. "March 1992." Appendix G videotape located at VHS 5000043. Includes bibliographical references (p. 240-247). Also available in print.
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Seely, William Forrester. "Development of a Power System and Analysis of Inertial System Calibration for a Small Autonomous Underwater Vehicle." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/33850.
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Compared to large vehicles acting individually, platoons of small, inexpensive autonomous underwater vehicles have the potential to perform some missions that are commonly conducted by larger vehicles faster, more efficiently, and at a reduced operational cost. This thesis describes the power system of a small, inexpensive autonomous underwater vehicle developed by the Autonomous Systems Controls Laboratory at Virginia Tech.
Reduction in vehicle size and cost reduces the accuracy of navigational sensors, leading to the need for autonomous calibration. Several models of navigational sensors are discussed, and the extended Kalman filter is used to form an observer for each, which are simulated and analyzed.
Master of Science
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LeBas, Phillip J. "Maximizing AUV slow speed performance." Springfield, Va. : Available from National Technical Information Service, 1997. http://handle.dtic.mil/100.2/ada339442.
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Thesis (M.S. in Ocean Engineering) Woods Hole Oceanographic Institution and the Massachusetts Institute of Technology, Sept. 1997.DTIC Descriptor(s): Underwater Vehicles, Autonomous Navigation, Optimization, Adaptive Control Systems, Pitch (Motion), Equations Of Motion, Hydrodynamic Characteristics, Performance (Engineering), Theses, Low Velocity, Control Theory, Energy Conservation, Submarine Models. Includes bibliographical references (leaves 101-104). Also available online.
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Brunner, Glenn M. "Experimental verification of AUV performance." Thesis, Monterey, California. Naval Postgraduate School, 1988. http://hdl.handle.net/10945/23226.
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Analog Systems, Control Systems, Underwater Vehicles, Adaptive Control Systems, Calibration, Control, Detectors, Diving, Equations, Identification, Input, Least Squares Method, Maneuvers, Models, Performance Tests, Radio Equipment, Recursive Functions, Response, Signals, Theses, Transfer Functions, Vehicles, Vertical Orientation, Water Tanks
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LeBas, Phillip J. (Phillip Jude) 1955. "Maximizing AUV slow speed performance." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/43544.
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Phaneuf, Matthew D. "Experiments with the REMUS AUV." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Jun%5FPhaneuf.pdf.
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Lee, Chin Siong. "NPS AUV workbench: collaborative environment for autonomous underwater vehicles (AUV) mission planning and 3D visualization." Thesis, Monterey, California. Naval Postgraduate School, 2004. http://hdl.handle.net/10945/1658.
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Approved for public release, distribution is unlimitedalities. The extensible Markup Language (XML) is used for data storage and message exchange, Extensible 3D (X3D) Graphics for visualization and XML Schema-based Binary Compression (XSBC) for data compression. The AUV Workbench provides an intuitive cross-platform-capable tool with extensibility to provide for future enhancements such as agent-based control, asynchronous reporting and communication, loss-free message compression and built-in support for mission data archiving. This thesis also investigates the Jabber instant messaging protocol, showing its suitability for text and file messaging in a tactical environment. Exemplars show that the XML backbone of this open-source technology can be leveraged to enable both human and agent messaging with improvements over current systems. Integrated Jabber instant messaging support makes the NPS AUV Workbench the first custom application supporting XML Tactical Chat (XTC). Results demonstrate that the AUV Workbench provides a capable testbed for diverse AUV technologies, assisting in the development of traditional single-vehicle operations and agent-based multiple-vehicle methodologies. The flexible design of the Workbench further encourages integration of new extensions to serve operational needs. Exemplars demonstrate how in-mission and post-mission event monitoring by human operators can be achieved via simple web page, standard clients or custom instant messaging client. Finally, the AUV Workbench's potential as a tool in the development of multiple-AUV tactics and doctrine is discussed.
Civilian, Singapore Defence Science and Technology Agency
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Lee, Chin Siong. "NPS AUV workbench : collabroative environment for autonomous underwayer vehicles (AUV) mission planning and 3D visualization /." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Mar%5FLee.pdf.
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Thesis (M.S. in Computer Science)--Naval Postgraduate School, March 2004.Thesis advisor(s): Donald P. Brutzman, Curtis L. Blais. Includes bibliographical references (p. 191-195). Also available online.
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Miller, Bryan D. "Design of an AUV recharging system." Thesis, Cambridge, Massachusetts, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/10945/37514.
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CIVINSThe Odyssey AUV Series uses a Lithium-ion Polymer battery which is able to supply the necessary power for a limited mission time. The current method of recharge includes surfacing the AUV, opening the vehicle, removing the battery from the vehicle and recharging the battery. A different approach is proposed which uses an inductive coupler and power electronics to conduct a battery charge without opening the vehicle or removing the battery.
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Miller, Bryan D. (Bryan David). "Design of an AUV recharging system." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/33561.
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Thesis (Nav. E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.Includes bibliographical references (p. 57-58).
The Odyssey AUV Series uses a Lithium-ion Polymer battery which is able to supply the necessary power for a limited mission time. The current method of recharge includes surfacing the AUV, opening the vehicle, removing the battery from the vehicle and recharging the battery. A different approach is proposed which uses an inductive coupler and power electronics to conduct a battery charge without opening the vehicle or removing the battery.
by Bryan D. Miller.
S.M.
Nav.E.
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Maurelli, Francesco. "Probablistic approaches for intelligent AUV localisation." Thesis, Heriot-Watt University, 2014. http://hdl.handle.net/10399/2818.
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This thesis studies the problem of intelligent localisation for an autonomous underwater vehicle (AUV). After an introduction about robot localisation and specific issues in the underwater domain, the thesis will focus on passive techniques for AUV localisation, highlighting experimental results and comparison among different techniques. Then, it will develop active techniques, which require intelligent decisions about the steps to undertake in order for the AUV to localise itself. The undertaken methodology consisted in three stages: theoretical analysis of the problem, tests with a simulation environment, integration in the robot architecture and field trials. The conclusions highlight applications and scenarios where the developed techniques have been successfully used or can be potentially used to enhance the results given by current techniques. The main contribution of this thesis is in the proposal of an active localisation module, which is able to determine the best set of action to be executed, in order to maximise the localisation results, in terms of time and efficiency.
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Gish, Lynn Andrew. "Design of an AUV recharging system." Thesis, Cambridge, Massaachusetts; Massachusetts Institute of Technology, 2004. http://hdl.handle.net/10945/1476.
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CIVINSApproved for public release; distribution is unlimited
The utility of present Autonomous Underwater Vehicles (AUVs) is limited by their on-board energy storage capability. Research indicates that rechargeable batteries will continue to be the AUV power source of choice for at least the near future. Thus, a need exists in both military and commercial markets for a universal, industry-standard underwater AUV recharge system. A novel solution using a linear coaxial wound transformer (LCWT) inductive coupling mounted on the AUV and a vertical docking cable is investigated. The docking cable may be deployed from either a fixed docking station or a mobile "tanker AUV". A numerical simulation of the simplified system hydrodynamics was created in MATLAB and used to evaluate the mechanical feasibility of the proposed system. The simulation tool calculated cable tension and AUV oscillation subsequent to the docking interaction. A prototype LCWT coupling was built and tested in saltwater to evaluate the power transfer efficiency of the system. The testing indicated that the surrounding medium has little effect on system performance. Finally, an economic analysis was conducted to determine the impact of the proposed system on the present military and commercial AUV markets. The recharge system creates substantial cost-savings, mainly by reducing support ship requirements. An effective AUV recharge system will be an important element of the Navy's net-centric warfare concept, as well as a valuable tool for commercial marine industries.
Lieutenant Commander, United States Navy
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Keegan, John J. "Trajectory planning for the Aries AUV." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02Jun%5FKeegan.pdf.
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Stoffle, Richard W., Diane E. Austin, Brian K. Fulfrost, III Arthur M. Phillips, and Tricia F. Drye. "Itus, Auv, Te'ek (Past, Present, Future)." Bureau of Applied Anthropology, University of Arizona, 1995. http://hdl.handle.net/10150/303173.
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This report concludes the first four years (1992 -1995) of Southern Paiute involvement in the Glen Canyon Environmental Studies (GCES), a program initiated by the Bureau of Reclamation (BOR) in 1982. Southern Paiutes have conducted ethnographic research and participated in the Congressionally mandated Environmental Impact Study (EIS) of Glen Canyon
Dam water release policies on natural and human-made resources found in the Colorado River Corridor. These ethnographic studies have taken place in what is called the Colorado River Corridor which extends 255 miles down stream from Glen Canyon Dam to the end of the free flowing river at Separation Canyon within the Grand Canyon National Park. They have concentrated on investigating the impacts of the Dam's water releases to Southern Paiute cultural resources. Since the Final EIS was published in March 1995, emphasis has been placed on what is called the Adaptive Management Program of the GCES and attention has shifted to monitoring the water release impacts.
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Singh, Hanumant. "An entropic framework for AUV sensor modelling." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/11449.
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Coe, Ryan Geoffrey. "Improved Underwater Vehicle Control and Maneuvering Analysis with Computational Fluid Dynamics Simulations." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/23777.
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The quasi-steady state-space models generally used to simulate the dynamics of underwater vehicles perform well in most steady flow scenarios, and are therefore acceptable for modeling today\'s fleet of endurance-focused autonomous underwater vehicles (AUVs). However, with their usage of numerous assumptions and simplifications, these models are not well suited to certain unsteady flow situations and for use in the development of AUVs capable of performing more extreme maneuvers. In the interest of better serving efforts to design a new generation of more maneuverable AUVs, a tool for simulating vehicle maneuvering within computational fluid dynamics (CFD) based environments has been developed. Unsteady Reynolds-averaged Navier-Stokes (URANS) simulations are used in conjunction with a 6-degree-of-freedom (6-DoF) rigid-body kinematic model to provide a numerical test basin for vehicle maneuvering simulations. The accuracy of this approach is characterized through comparison with experimental measurements and quasi-steady state-space models. Three state-space models are considered: one model obtained from semi-empirical database regression (this is the method most commonly used in application) and two models populated with coefficients determined from the results of prescribed motion CFD simulations. CFD analyses focused on supporting the design of a general purpose AUV are also presented.Ph. D.
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Johnson, Jay H. "AUV steering parameter identification for improved control design." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2001. http://handle.dtic.mil/100.2/ADA397498.
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Thesis (M.S. in Mechanical Engineering) Naval Postgraduate School, June 2001.Thesis advisor(s): Healey, Anthony J. "June 2001." Includes bibliographical references (p. 55). Also Available in print.
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Good, Michael R. "Design and construction of a second generation AUV." Thesis, Monterey, California. Naval Postgraduate School, 1989. http://hdl.handle.net/10945/26966.
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Approved for public release; distribution is unlimited.The design and construction of an Autonomous Underwater Vehicle (AUV) for use as a research and development testbed at the Naval Postgraduate School (NPS) is presented. Design objectives, analysis and trade-offs are discussed with respect to a generic AUV and specifically detailed for the case of the NPS AUV II. System integration and flexibility is emphasized in the subject vehicle to support presently planned and future research employment. Hull, mobility, sensor, automatic control, and energy subsystemsl are described. Design and fabrication techniques for the NPS AUV II vehicle hull and equipments are documented
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Melvin, James E. "AUV fault detection using model based observer residuals." Thesis, Monterey, Calif. : Naval Postgraduate School, 1998. http://bosun.nps.edu/uhtbin/hyperion-image.exe/NPS-ME-98-004.pdf.
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Thesis (M.S. in Mechanical Engineering and Mechanical Engineer) Naval Postgraduate School, June 1998.Title from cover. Thesis advisor(s): Anthony J. Healey. "June 1998."--Cover. "NPS-ME-98-004"--Cover. Includes bibliographical references (p. 117-118). Also available online.
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Tan, Wee Kiat. "Horizontal steering control in docking the ARIES AUV." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Dec%5FTan%5FW.pdf.
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Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, December 2003.Thesis advisor(s): Fotis Papoulias, Anthony J. Healey. Includes bibliographical references (p. 83). Also available online.
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Bertsch, Louis James IV. "EXPLORING TRADE-OFFS IN AUV CONTROLLER DESIGN FOR SHARK TRACKING." DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/478.
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This thesis explores the use of an Autonomous Underwater Vehicle (AUV) to track and pursue a tagged shark through the water. A controller was designed to take bearing and range to the shark tag and then control the AUV to pursue it.
First, the ability of a particle filter to provide an accurate estimation of the location of the shark relative to the AUV is explored. Second, the ability of the AUV to follow the shark's path through the water is shown. This ability allows for localized environmental sampling of the shark's preferred path. Third, various path weightings are used to optimize the efficiency of pursuing the shark. This demonstrates that the proposed controller is efficient and effective. Fourth, the benefits of the addition of a second AUV are explored and quantified. The secondary AUV is shown to maintain formation without direct communication from the primary AUV. However, the communication of the AUVs increases the accuracy of all measurements and allows for future expansion in the complexity of the controller. Fifth, the effects of predicting the shark$'$s future movement is explored. Sixth, the effect of noise in the signal from the shark tag is tested and the level of noise at which the AUV can no longer pursue the shark is shown. This investigates the real world ability of the controller to accept noisy inputs and still generate the appropriate response. Finally, the positive results of the previous sections are combined and tested for various noise levels to show the improved controller response even under increased noise levels.
To validate the proposed estimator and controller, seven tests were conducted. All tests were conducted on existing shark path data recorded by a stationary acoustic receiver and a boat mounted acoustic receiver. Tests were conducted on data sets from two different species of sharks, (Shovelnose and White) with two very different swimming behaviors. This shows the solution's flexibility in the species of shark tracked.
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Jacobson, Jessica. "Using Single Propeller Performance Data to Predict Counter-Rotating Propeller Performance for a High Speed Autonomous Underwater Vehicle." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/32753.
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The use of counter-rotating propellers is often desirable for aerospace and ocean engineering applications. Counter-rotating propellers offer higher peak efficiencies, better off-design performance, and roll control capabilities. But counter-rotating propeller matching is a difficult and complex procedure. Although much research has been done on the design of optimal counter-rotating propeller sets, there has been less focus on predicting the performance of unmatched counter-rotating sets. In this study, it was desired to use off-the-shelf marine propellers to make a counter-rotating pair for a high speed autonomous underwater vehicle (AUV). Counter-rotating propellers were needed to provide roll control for the AUV. Pre-existing counter-rotating propeller design methods were not applicable because they all require inputs of complex propeller blade geometries. These geometries are rarely known for off-the-shelf propellers.
This study proposes a new method for predicting the counter-rotating performance of unmatched propeller sets. It is suggested here that propeller performance curves can be used to predict counter-rotating thrust and torque performance.
Propeller performance tests were run in the Virginia Tech Water Tunnel for a variety of small, off-the shelf propellers. The collected data was used to generate the propeller performance curves. The propellers were then paired up and tested as counter-rotating sets. A momentum theory based model was formulated that predicted counter-rotating performance using the propeller performance data. The counter-rotating data was used to determine the effectiveness of the method.
A solution was found that successfully predicted the counter-rotating performance of all of the tested propeller sets using six interaction coefficients. The optimal values of these coefficients were used to write two counter-rotating performance prediction programs. The first program takes the forward and aft RPMs and the flow speed as inputs, and predicts the generated thrust and torque. The second program takes the flow speed and the desired thrust as inputs and calculates the forward and aft RPM values that will generate the desired thrust while producing zero torque. The second program was used to determine the optimal counter-rotating set for the HSAUV.
Master of Science
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King, Sebastian John. "Applications of Autonomous Systems to Rapid Environmental Assessments." Thesis, The University of Sydney, 2022. https://hdl.handle.net/2123/29786.
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A Rapid Environmental Assessment (REA) is a methodology to quickly analyse a location’s environment and generate an operational view to inform subsequent decision making. Distinct from scientific surveys, REAs facilitate follow–on life–critical operations including amphibious landings and disaster responses, however, existing REA methods are resource intensive, predominantly manual, and risky. Potential solutions centred on autonomous systems are under research, but challenges have hindered their implementation, identified as Human–Robot Collaboration (HRC) issues concerning intuitive interfaces between humans and agents and a lack of trust in autonomously generated information. This thesis seeks to make progress towards these areas.
To reduce resources when planning REAs, a novel optimisation framework is formulated to automatically ingest and analyse terrain data to determine optimal REA locations. To maintain trust, the framework is derived from established REA methods and provides human–interpretable results. Validation is performed over two Australian coastal regions, testing a wide variety of planning requirements, with the system proving robust and consistently producing the desired outcomes. To further improve HRC, a coalition formation and tasking method is developed to supplement autonomous planners. The method utilises Fuzzy Sets, allowing users to intuitively describe heterogeneous vehicles and tasks with high accuracy whilst also accounting for uncertain information. A MATLAB simulation was created for validation, with multiple vehicle types and tasks used to represent and test realistic scenarios encountered during REAs. Results are compared to a baseline vector–based system, with the fuzzy method developed here showing close alignment, while providing a more intuitive interface via fuzzy representations. Finally, to quantify risk and uncertainty in the previous results to build trust in the information, a risk framework is also developed. The framework is able to capture various obstacles and uncertainties generically through 2.5D maps, before producing an aggregate map and evaluating a single metric, Conditional Value at Risk (CVaR). A novel use of the CVaR metric provides a user–tunable parameter, enabling increased risk to be traded for decreased REA mission time. Validation is again performed in simulation, successfully capturing multiple risks and demonstrating a reduction in mission time of up to 40% under high risk tolerances.
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Yang, Rui. "Modélisation et commande robuste appliquée à un robot sous-marin." Thesis, Brest, 2016. http://www.theses.fr/2016BRES0011/document.
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L’utilisation des AUV pour une exploitation durable des ressources océaniques est pertinente. Un robot sous-marin peut être utilisé comme plateforme pour observer, recueillir des informations sur l’environnement marin. Afin d’améliorer la qualité des observations et d’augmenter la capacité de navigation, de nombreuses questions doivent être abordées et examinées simultanément. Nous abordons ici le problème du pilotage de ces robots autonomes.Atteindre la maniabilité nécessaire dépend de deux facteurs clés: un modèle hydrodynamique précis et un système de contrôle performant. Cependant, le coût de développement d’un modèle précis est généralement très élevé. De plus, lorsque la géométrie du robot est complexe, il devient très difficile d’identifier de manière pertinente les paramètres dynamiques et hydrodynamiques. En outre, du point de vue de la commande, les modèles obtenus sont non linéaire, en particuliers pour les amortissements.De nombreux phénomènes dynamiques ne sont pas modélisés: dynamiques internes au robot, environnementales, liées aux bruits des capteurs, aux retards intrinsèques. Dans les concours de robotique sous-marine, il est confirmé que le traditionnel régulateur Proportionnel-Intégral-Dérivé (PID) est peu efficace pour les robots légers. Dans ce cas, notre champ d’application est plus axé sur la combinaison des approches de modélisation numérique et la commande robuste.Dans ce travail, nous proposons un schéma de régulation basé sur la commande robuste et la modélisation. La régulation robuste a été mise en place et validée en mer sur un AUV de la marque CISCREA et la solution proposée utilise Computational Fluid Dynamic (CFD) pour caractériser les deux paramètres hydrodynamiques (matrice de masse ajoutée et matrice d’amortissement). Puis un modèle à quatre degrés de liberté est construit pour le CISCREA. Les résultats numériques et expérimentaux sont alors comparés.La commande robuste proposée est basée sur une compensation non linéaire et de la commande H∞. La validation de la robustesse a été testée par simulation en Matlab et finalement validée par des essais en mer à Brest. La simulation et l’expérience montrent que l’approche en plus d’être robuste est plus rapide que les régulateurs précédemment proposésAutonomous Underwater Vehicle (AUV) is a relevant technology for the sustainable use of ocean resources. AUV can be used as an important ocean observing platform to collect information on marine environmental characteristics for research and industry fields. In order to improve the observation quality and increase the navigation ability, many issues should be addressed and considered simultaneously. Achieve necessary maneuverability depends on two key factors: an accurate hydrodynamic model and an advanced control system. However, the cost to develop an accurate hydrodynamic model, which shrinks the uncertainty intervals, is usually high. Meanwhile, when the robot geometry is complex, it becomes very difficult to identify its dynamic and hydrodynamic parameters. In addition, according to the quadratic damping factor, underwater vehicle dynamic and hydrodynamic model is nonlinear from the control point of view. Moreover, unmodeled dynamics, parameter variations and environmental disturbances create significant uncertainties among the nominal model and the reality. Sensor noise, signal delay as well as unmeasured states also affect the stability and control performance of the motion control system. In many of our underwater competitions, it has been confirmed that the traditional Proportional-Integral-Derivative (PID) regulation is less efficient for low mass AUV. In this case, our scope is more focused on the combination of numerical modeling approaches and robust control schemes. In this work, we proposed a model based robust motion control scheme. Without loss of generality, a robust heading controller was implemented and validated in the sea on cubic-shaped CISCREA AUV. The proposed solution uses cost efficient Computational Fluid Dynamic (CFD) software to predict the two hydrodynamic key parameters: The added mass matrix and the damping matrix. Four Degree of Freedom (DOF) model is built for CISCREA from CFD calculation. Numerical and experimental results are compared. Besides, the proposed control solution inherited the numerically obtained model from previous CFD calculation. Numerically predicted the actuator force compensates the nonlinear damping behavior result in a linear model with uncertainties. Based on the bounded linear nominal model, we proposed H∞ approach to handle the uncertainties, we used kalman filter to estimate unmeasured states such as angular velocity and we developed smith compensator to compensate the sensor signal delay. The proposed robust heading control application uses only one compass as feedback sensor. This is important while AUV is working at certain depth where only magnetic sensors still work. Our robust control scheme was simulated in Matlab and validated in the sea near Brest. Simulation shows obvious advantage of the proposed robust control approach. Meanwhile, the proposed robust heading control is much faster than PID controller. The robust controller is insensitive to uncertainties and has no overshot. From both simulations and real sea experiments, we found our proposed robust control approach and the one compass heading control applications are efficient for low mass and complex-shaped AUV CISCREA
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Brown, James P. "Four quadrant dynamic model of the AUV II thruster." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1993. http://handle.dtic.mil/100.2/ADA274899.
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Thesis (M.S. in Mechanical Engineering) Naval Postgraduate School, September 1993.Thesis advisor(s): Anthony J. Healey. "September 1993." Includes bibliographical references. Also available online.
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Blank, Richard P. "A structured programming approach for complex AUV mission control." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1993. http://handle.dtic.mil/100.2/ADA274783.
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Ivarsson, Anna. "Conceptual design study of a modular fiber composite AUV." Thesis, KTH, Lättkonstruktioner, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-223388.
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The conceptual design of a modular AUV hull in fiber composite material has been determined. The goal has been to minimize the hull weight. Matrix and fiber materials have been investigated to find a composite combination that reduces the hull weight whilst being resistant to changes in the mechanical properties caused by submersion in water and the operational temperatures. A composite of a PEEK thermoplastic matrix with high strength carbon fibers is picked as the most suitable material option and used for hull calculations. Different composite part manufacturing processes are investigated to find a suitable method for the geometry and material that can produce high quality hull modules. Part quality factors such as fiber waviness and out of roundness in shape affects the collapse pressure of the hull. Filament winding adapted for a thermoplastic composite with in situ consolidation is picked as the most suitable manufacturing option.The structural designs considered for the hull are a fiber composite single skin construction (ring-stiffeners possible) and a sandwich construction, these would be manufactured as shorter modules that can be joined together to form the hull. The minimum hull thickness required for a single skin hull operating at 300 meters depth, considering material compression failure and buckling failure of the structure, is calculated for the PEEK/carbon fiber composite material. Buckling is the dimensioning failure mode of a thin walled cylinder with the AUV hull dimensions at the intended operational depth. The lay-up of the composite affects the thickness required so the lay-up is optimized to minimize the hull weight. For the cylindrical modules under hydrostatic pressure a [90/0/90] lay-up minimizes the thickness required and is the recommended lay-up. For comparison of hull weight with the existing AUV the minimum thickness required for a single skin hull in aluminium 7075 considering material compression failure and buckling failure of the structure is also calculated.From the analytical buckling analysis of a simple cylinder hull without joints the minimum thickness is determined as 11.82 mm for the composite hull and 15.23 mm for the aluminium hull, both values with a safety factor of 1.3 for the collapse pressure equating to 3.9 MPa. The single skin composite hull weight becomes 153 kg and the aluminium hull weight becomes 343 kg for these thicknesses. If the added stiffness of the structure from the joints would be taken into consideration it is expected that the thickness could be decreased further, but the relative weight difference between the composite and aluminium hull is expected to remain similar. From the finite element linear buckling analysis of the composite hull with thickness 11.82 mm the buckling pressure is determined as 3.39 MPa and for the aluminium hull with thickness 15.23 mm it is determined as 4.42 MPa.For a sandwich hull the minimum core thickness (using a weak core approximation and quasi-isotropic faces) is calculated as 19.96 mm, with safety factor 1.3 for the collapse depth and factor 1.1 for material failure of the faces. The weight for this sandwich hull with a carbon foam core becomes 72 kg. Based on a heat generation of 3 kW maximum during AUV operation heat transfer calculations through the thickness of the single skin composite hull give the maximum hull thickness as 50 mm before the AUV will overheat. The maximum 3 thickness of a regular PVC foam core sandwich hull is 4 mm and for a carbon foam core it is 21 mm before the AUV will overheat, making a sandwich with a carbon foam core a possible structural design choice but with some complicating factors compared to the single skin composite hull.
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Woodford, Thomas James. "Propulsion optimization for ABE, an Autonomous Underwater Vehicle (AUV)." Thesis, Springfield, Virginia: Available from National Technical Information Service, 1991. http://hdl.handle.net/10945/28475.
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Caddell, Tymothy Wayne. "Three-dimensional path planning for the NPS II AUV." Thesis, Monterey, California. Naval Postgraduate School, 1992. http://hdl.handle.net/10945/28609.
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Ware, Laura M. (Laura Marie). "Design of control for efficiency of AUV power systems." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/74915.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 71).
The MIT Rapid Development Group designed and built an internal combustion hybrid recharging system for the REMUS 600 Autonomous Underwater Vehicle (AUV) in collaboration with the MIT Lincoln Laboratory. This power system will recharge the lithium ion battery pack of the REMUS 600 and allow the vehicle to travel for 40 consecutive 12-hour missions without returning to recharge. This study analyzes the optimization of time and fuel efficiency in systems of this type. First, the battery charging scheme for optimal time efficiency was investigated through theoretical simulation of the REMUS battery recharging, based on typical curves for lithium ion battery charging. Secondly, the optimal control system for optimizing fuel efficiency was found by examining behavior in several different engines and predicting behavior in MIT RDG hybrid system's engine. A system was developed to control the throttle of the engine while sensing the voltage coming out of a synchronous rectification bridge. This scheme keeps the throttle above 50% unless the power requirement of the charger drops suddenly. Finally, the control scheme was implemented in software, along with controls for engine starting and shutdown.
by Laura M. Ware.
S.B.
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Nickell, Christopher Lee. "Modular Modification of a Buoyant AUV for Low-Speed Operation." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/35029.
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Conventional streamlined autonomous underwater vehicles (AUVs) with a single thruster and stern planes are typically trimmed to be somewhat buoyant or heavy in water. To
maintain depth, they must generate a constant hydrodynamic force which requires that they swim at a constant pitch angle. Although tail fins are the typical mechanism for
generating this control moment, they become ineffective at low speeds. To enable an existing AUV to travel at lower speeds, one may easily incorporate a modular moving mass
actuator. In some cases, it may also be advantageous to include a fixed wing.
The equations of motion and equilibrium conditions to regulate depth are derived, and the effectiveness and low-speed efficiency of a fixed wing is evaluated. The effect of the
vertical offset of the moving mass is analyzed to establish the relation between the control angle and the moving mass linear position.
A description of the design of a one degree of freedom moving mass actuator module and preliminary experiments using the Virginia Tech Miniature AUV is provided. Data is
presented for a series of fixed MMA position experiments as well as a dynamic position test. The results illustrate the effectiveness of a moving mass actuator at generating
low-speed control moments. With the collected data, parameter identification is performed to get an estimate of the hydrodynamic parameters.Master of Science
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Sjölander, Erik, and Johan Nordfors. "Avvägningssystem för autonom undervattensfarkost." Thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-271537.
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This work is focusing on a buoyancy system in anautonomous underwater vehicle, and the purpose is topresent a theoretical proposal on how the system indetail and in general can be changed to improve theaccessibility to its internal components and to make itmore robust. The largest part in this work is to simplify thehydraulic system, not only to make it more accessiblebut also to mitigate the risk of leakage due todifficulty of handling pipes and couplings. To reacha solution, interviews as well as litterature studieshas been made to identify specific problems. Thecollected data has then been discussed in order tocombine each specific solution to a final construction.The construction is presented with motivation, calculationsand 3Dmodels. The logical thoughts behind the finalconstruction are also presented for easy understanding ofthe choices being made. The design proposal differs from the earlier, two of themajor changes are that the old single direction the pump isreplaced with a new dual directional pump, and the valvemanifold is replaced with a single valve. In addition, allcomponents are now mounted in a chassis that can be easilylifted out from the hull, making the mounting and servicework on the system easier
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Kim, Andrew Y. "A Comparative Study of Feature Detection Methods for AUV Localization." DigitalCommons@CalPoly, 2018. https://digitalcommons.calpoly.edu/theses/1852.
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Underwater localization is a difficult task when it comes to making the system autonomous due to the unpredictable environment. The fact that radio signals such as GPS cannot be transmitted through water makes autonomous movement and localization underwater even more challenging. One specific method that is widely used for autonomous underwater navigation applications is Simultaneous Localization and Mapping (SLAM), a technique in which a map is created and updated while localizing the vehicle within the map. In SLAM, feature detection is used in landmark extraction and data association by examining each pixel and differentiating landmarks pixels from those of the background. Previous research on the performance of different feature detection methods have been done in environments such as cisterns and caverns where the effects of the ocean are reduced. Our objective, however, is to achieves robust localization in the open ocean environment of the Cal Poly pier. This thesis performs a comparative study between different feature detection methods including Scale Invariant Feature Transform (SIFT), Speeded-Up Robust Features (SURF), and Oriented FAST and Rotated BRIEF (ORB) on different sensors. We evaluate the feature detection and matching performance of these algorithms in a simulated open-ocean environment.
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Marr, William J. "Using the ST1000/ST725 sonars on the NPS AUV II." Thesis, Monterey, California. Naval Postgraduate School, 1994. http://hdl.handle.net/10945/28634.
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Approved for public release; distribution is unlimited.Autonomous Underwater Vehicles (AUVS) require further technological development in several key areas (including sensor systems) in order to assume a broader role in undersea military and commercial environments. This research was an experimental investigation of the TRITECH ST1000 and ST725 high resolution sonar systems used onboard the NPS AUV II. Test conducted with the ST1000 Profiler proved that the sonar could successfully be used in AUV positioning maneuvers but also revealed the requirement for some form of range dependent gain adjustment to ensure vehicle stability. The ST725 sonar was used in progressively complex static environments to clearly image objects. A scanline analysis of the ST725 data was shown to be useful in extracting stationary target information including range, bearing, and approximate size. AUV, Autonomous underwater vehicles, Sonars
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Riling, William D. "A microcomputer-based controller for an Autonomous Underwater Vehicle (AUV)." Thesis, Monterey, California. Naval Postgraduate School, 1990. http://hdl.handle.net/10945/30711.
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Approved for public release, distribution is unlimitedConsiderations of real-time control problems for an Autonomous Underwater Vehicle (AUV) are addressed in this research. Among these problems is the ability to control the submersible given its highly nonlinear operation environment. In order to account for these variations, robust control techniques must be used. In particular, Variable Structure Control (VSC) with Doyle-Stein Observer has proven to produce optimal results while maintaining a high degree of robustness. This led to the development of a real-time error detector using the robust observer to provide system redundancy through software. The culmination of this work is a real-time autopilot written in the "C" language which is ready for implementation and testing in the Naval Postgraduate School AUV prototype. We also address the aspect of real-time signal processing and conditioning in terms of Synchro-toResolver Conversion and anti-aliasing filters. The synchro problem involves converting a nonpotentiometric directional gyro output to a natural binary format which calls for an intricate design of power transformers, analog-to-digital converter, and passive element components. Lastly, the use of Generalized-Immittance Converter circuitry in the design of very low frequency anti-aliasing filter applications is developed and tested.
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Davis, Michael H. "Real time Adaptive Control of an Autonomous Underwater Vehicle (AUV)." Thesis, Monterey, California. Naval Postgraduate School, 1989. http://hdl.handle.net/10945/26198.
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Approved for public release; distribution is unlimited.In this research the problem of designing a controller for the dive maneuver of an Autonomous Underwater Vehicle (AUV) is addressed. The highly nonlinear nature of the vehicle dynamics and the requirement for the fast maneuvering call for robust control techniques. In particular Variable Structure Control (VSC) combined with Adaptive Control (AC) techniques seem to yield satisfactory performance in terms of robustness, capability to adjust to different operating conditions, and speed of response. Also linear robust techniques based on LQG and robust observers are presented to address the case when the whole state (in terms of pitch rate, pitch, and depth) is not available for measurement. Autonomous underwater vehicle; Variable structure control; AUV; Sliding mode control; Doyle-Stein observer; Adaptive control; Thesis; Sea floor mapping; Target identification; Remote reconnaissance; Underwater tracking
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Zanoni, Fábio Doro. "Modelagem e implementação do sistema de navegação para um AUV." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/3/3152/tde-23032012-114741/.
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Este trabalho apresenta o estudo e a implementação de um sistema de navegação em tempo-real utilizado para estimar a posição, a velocidade e a atitude de um veículo submarino autônomo. O algoritmo investigado é o do Filtro de Kalman Estendido. Este filtro é freqüentemente usado para realizar a fusão de dados obtidos de diferentes sensores, em uma estimativa estatisticamente ótima, quando se respeita algumas condições. Neste trabalho, fez se a fusão entre os seguintes sensores: unidade de navegação inercial do tipo strapdown, sensor acústico de posicionamento, profundímetro, sensor de velocidade de efeito Doppler e uma bússola. Para a aplicação embarcada do Filtro de Kalman, faz-se necessário o seu desenvolvimento em tempo real. Conseqüentemente, este trabalho apresenta o estudo das principais características de um sistema de tempo real. Para desenvolver o código em C utilizou-se de algumas funções do Matlab com a finalidade de se tentar minimizar os erros de implementação do filtro. Além disto, para facilitar a implementação e respeitar os critérios de sistemas de tempo real utilizou-se de um sistema operacional, C/OS-II que possibilita aplicar sistemas com multiprocessos e utilizar semáforos para o gerenciamento do EKF, além disto, foram utilizadas normas de programação, MISRAC, para padronizar o código e aumentar a sua confiabilidade. São apresentadas também a modelagem cinemática, a metodologia e as ferramentas computacionais utilizadas para o filtro. Com base nas simulações e nos ensaios de campo executados on-line, observou-se que os filtros projetados para se estimar a atitude e a posição do veículo obtiveram bons desempenhos, além disto, foi possível verificar a convergência dos EKFs. Para estas simulações e ensaios, foram também estudados casos de situações adversas como, por exemplo, uma falha no sensor de referência de posição, sendo que para esta situação, o EKF de posição e velocidade obteve resultados satisfatórios.This paper presents the study and implementation of a real-time navigation system used to estimate the position, velocity and attitude of an autonomous underwater vehicle. The Extended Kalman Filter, EKF, was adopted. This filter is often used to perform the data fusion from different sensors, in generating a statistically optimal estimate when some required conditions are fulfilled. The algorithm implements the fusion of the following sensors: an inertial navigation unit sensor (strapdown type), an acoustic positioning, a depth gauge, a Doppler velocity log sensor and a magnetic compass. This work presents the kinematic modelling, the methodology and computational tools used for developing the EKF algorithm. In order to integrate the EKF into an embedded system, it is necessary to develop it in real time. It was adopted the C / OS-II operational system, which allows to implement multithreaded systems and use traffic lights to manage the EKF. Furthermore, programming standards, such as MISRA C, was chosen to standardize the code and increase its reliability. The C code implementation took advantage of some Matlab functions to minimize implementation errors. Based on simulations and field tests carried out online, it was concluded that the filters designed to estimate the attitude and position of the vehicle provided good performances, in addition, it was possible to verify the EKFs convergence. The filters were tested in same adverse situations, e.g., a fault in the position reference sensor, providing satisfactory results as well.
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Steenson, Leo V. "Experimentally verified model predictive control of a hover-capable AUV." Thesis, University of Southampton, 2013. https://eprints.soton.ac.uk/355697/.
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This work presents the development of control systems that enable a hover-capable AUV to operate throughout a wide speed range. The Delphin2 AUV was built as part of this project and is used to experimentally verify the prototype control systems. This vehicle is over-actuated with; four throughbody tunnel thrusters, four independently-actuated control surfaces and a rear propeller. The large actuator set allows the Delphin2 to operate at low speeds, using the through-body tunnel thrusters, and at high speeds, using the rear propeller and control surfaces. There lies a region between slow and high speed where neither the control surfaces nor tunnel thrusters are operating optimally. To maintain depth stability, both actuator sets are required to operate simultaneously. The model predictive control (MPC) algorithm is used to control the vehicle given its ability to handle multiple inputs and outputs along with system uncertainties. The basis of MPC is a mathematical model of the system to be controlled. Several experiments were conducted with the Delphin2 AUV to acquire the data necessary to develop this model. Bollard pull tests were used to measure thruster performance whilst wind-tunnel and open water experiments provided a measure of the control surfaces, hull and propeller performance. Depth control is the primary focus of this Thesis, however, pitch and surge control are also addressed. Three controllers are developed in this work, of increasing complexity; a depth and pitch controller for low speed operations, a depth and surge velocity controller for medium to high speed operation, and �nally, a depth and surge velocity controller for operation from low to high speed operations. All three controllers are multi-input multi-output (MIMO) and use the MPC algorithm. Input constraints are imposed on both the absolute limits and the rate of change limits. Simulations re performed to aid in the design of each controller before it is implemented on the Delphin2 AUV and experimentally verified. The depth and pitch controller, developed for low speed operation, uses the front and rear vertical thrusters as the system inputs. This case demonstrates the implementation of the MPC algorithm and studies the effects of the various tuning parameters. A model sensitivity study is performed, showing that the controller can handle modelling errors of up to �30%. The controller is experimentally tested and shows excellent performance with zero steady-state errors although there is an undesirably large overshoot of the depth demand. The simulation and experimental results match closely. The depth and surge controller uses the control surfaces and rear propeller as system inputs. Many of the forces and moments within this system are non-linear functions of the vehicles surge velocity. Therefore the standard MPC algorithm, that utilizes just one linearised model, would not be sufficient to capture the system dynamics of the vehicle throughout the full operational envelope. A time-variant MPC (TV-MPC) algorithm is developed and shown in simulation to have excellent performance. The controller did not perform as well when tested experimentally, however, depth regulation of �0:3 m was achieved. This degradation in performance is due to inaccuracies in the estimation of the vehicles surge velocity. The final controller is also a depth and surge velocity controller, however, it is tasked with maintaining stability through-out the full speed range of the vehicle. All of the system inputs used for depth control are utilised by this controller; the two vertical through-body tunnel thrusters, horizontal control surfaces and the rear propeller. The design of the controller makes use of the TV MPC algorithm. To improve system performance a modi�cation to the controllers cost function, used within the optimisation process, was made to penalise the use of the thrusters at high speeds. This enables the controller to use the thrusters at low speeds, when performing close range inspections, but then as surge velocity increases and the thrusters are no longer required, they are switched o�. Both simulation and experimental results show excellent performance, although when the thrusters switch o�, the depth control is similar to that of the previous controller due to poor surge velocity estimation.
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Vendel, Olofsson Billy. "Design and manufacture of structure and hull for large AUV." Thesis, KTH, Marina system, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-234909.
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The main goal with the master thesis was to design and manufacture a frame and hull to a large AUV which KTH will use in research. The general aim for the Maribot LoLo (Long Endurance, Long Range AUV) is to act as an experimental platform and tool for a wide range of research activities, where all four capabilities within the SMaRC area (Autonomy, Perception, Endurance and Communication) can be tested, improved and demonstrated.The frame was designed and shall be built in aluminum profiles from Bosch Rexroth with custom made brackets, manufactured in a corrosion resistant steal. When the frame was designed, the associated load case and beam elementary case was implemented. No mechanical calculations have been executed since the frame is planned to be tested against the above mentioned load case.The hull was manufactured in glass fiber with a laminate built from 0/90 and ±45 fabrics. The laminates total weight per square meter was 4800 g/m2. The hull was manufactured by performing vacuum infusion onto a female-mould. The method used and the result is presented in appendix 1. The total cost for manufacturing the frame and hull was about 129 000 SEK, where the largest expenses were due to the manufacturing cost of the male-mould, and the labor cost when manufacturing the hull. Manufacturing a new glass fiber hull would in the future cost approximately 16 000 SEK, given it’s manufactured by students at KTH and in the same female-mould. Manufacturing the hull in carbon fiber would cost approximately 60 000 SEK.The future work required before the AUV is seaworthy are; assemble the frame, cut the hull to its correct dimensions, design and manufacture the attachment solutions between the hull and frame, and to test the frame against the applied loads. Future optimization work would be applying laminate theory and extract the mechanical properties of the hull. Combine the laminate properties with beam theory in order to estimate the deflection of the laminate when evacuating the water. Mechanical calculations on the frame could as well lead to optimizing the weight of the frame, where hopefully smaller dimensions on the profiles could be used.Masterarbetet bestod av att designa och bygga en struktur och skrov till en stor AUV som KTH ämnar använda inom forskning. Målet med ubåten, även kallad Maribot LoLo (long endurance long range), är att agera som en experimentiell plattform inom en bred aktivitet av forskning, här alla fyra förmågor inom SMaRC (autonomi, uthållighet, kommunikation och iaktagelse) kan bli testade, förbättrade och demonstrerade.Strukturen designades och och ska byggas i aluminiumprofiler från Bosch Rexroth med specialtillverkade vinkeljärn som är tillverkade i ett korritionsbeständigt stål. När designen av strukturen var fastställd togs lastfallen och dess tillhörande elementarfall fram. Inga mekaniska beräkningar har genomförts då strukturen, när monterad, planeras bli testad med ovanstående nämda lastfall som pålagd last.Skrovet är byggt i glasfiber med ett laminatupplägg bestående av 0/90 och ±45 mattor. Den totala fiberhalten per kvadratmeter blev 4800 g/m2. Skrovet var tillverkat genom att vakuminjisera glasfiber i en hon-form, metod och resultat finns beskrivet i appendix 1. Den totala kostnaden för tillverkning av struktur och skrov uppskattades till 129 000 SEK, här de största utgifterna var tillverkning av ”han-form” och personal kostnad i samband med tillverkning av skrov. Tillverkning av ett nytt glasfiber skrov uppskattas kosta 16 000 kronor, om det i framtiden tillverkas av studenter på KTH. Motsvarande kostnad för att tillverka skrovet i kolfiber uppskattas till 60 000 kronor.Innan AUVn är sjöduglig krävs följande arbete; montera ihop ramen, kapa skrovet till rätt dimensioner, designa klart och tillverka sammanlänkningarna mellan skrov och ram, samt testa strukturen så den uppfyller de ställda kraven. Eventuella optimeringsarbeten som kan genomföras är; tillämpa laminat teori och beräkna skrovets mekaniska egenskaper. Tillsammans med dessa egenskaper och implementering av balk-teori, uppskappta skrovets utböjning när det evakuerar vattnet. Mekaniska beräkningar på struktur kan eventuellt leda till en optimering av ramens vikt, här kan troligen mindre dimensioner på profiler användass.
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Forney, Christina. "State Estimation for Tracking of Tagged Sharks with an AUV." DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/664.
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Presented is a method for estimating the planar position, velocity, and orientation states of a tagged shark. The method is designed for implementation on an Autonomous Underwater Vehicle (AUV) equipped with a stereo-hydrophone and receiver system that detects acoustic signals transmitted by a tag. The particular hydrophone system used here provides a measurement of relative bearing angle to the tag, but does not provide the sign (+ or -) of the bearing angle. A particle filter was used for fusing measurements over time to produce a state estimate of the tag location. The particle filter combined with an active control system allowed the system to overcome the ambiguity in the sign of the bearing angle. This state estimator was validated by tracking a stationary tag and moving tag with known positions. These experiments revealed state estimate errors were on par with those obtained by manually driven boat based tracking systems, the current method used for tracking fish and sharks over long distances. Final experiments involved the catching, releasing, and an autonomous AUV tracking of a 1 meter leopard shark (Triakis semifasciata) in SeaPlane Lagoon, Los Angeles, California.
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Roche, Emilie. "Commande à échantillonnage variable pour les systèmes LPV : application à un sous-marin autonome." Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00721970.
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L'utilisation de correcteur discret à période d'échantillonnage variable peut être intéressante dans plusieurs cas, par exemple lorsque la mesure, bien qu'envoyée de façon périodique, est reçue à intervalle variable. C'est le cas en milieu marin lorsque la mesure d'altitude est effectuée avec un capteur à ultrason (la durée du trajet du signal dans l'eau dépend de la distance par rapport au fond). Le délai variable entre deux réceptions de mesures, peut être vu comme une variation de période d'échantillonnage pour le contrôleur. La synthèse de lois de commande discrète à période d'échantillonnage variable a déjà été étudiée pour des systèmes stationnaires. On se propose ici d'étendre cette méthode pour des systèmes Linéaires à Paramètres Variants (LPV), qui permettent de conserver des paramètres importants d'un système non-linéaire en temps que paramètres d'un système linéaires. La synthèse de contrôleur repose sur le méthodologie H∞, appliquée aux systèmes LPV. En particulier, on s'intéressera à deux approches existantes dans la littérature : l'approche polytopique (où le paramètre variant évolue dans un volume convexe) et la Représentation Linéaire Fractionnelle (LFR). La méthode proposée est appliquée au contrôle d'un AUV (Autonomous Underwater Vehicle), qui est système difficile à contrôler du fait d'importantes non-linéarités. Des résultats de simulations permettront de montrer l'intérêt de la méthode pour le contrôle d'altitude d'un AUV, et notamment les améliorations apportées par l'ajout de paramètres issus du système non-linéaire au modèle utilisé pour la synthèse des régulateurs.
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Duelley, Richard Skyler. "Autonomous Underwater Vehicle Propulsion Design." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/34789.
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The goal of this design process was to achieve the most efficient propulsive system for the candidate autonomous underwater vehicle (AUV) as possible. A mathematical approach, using fundamental motor equations and derived quantities, was used to characterize and select an efficient brushless electric motor for the propulsion system. A program developed at MIT, Massachusetts Institute of Technology, called OpenProp versions 1 and 2.3 was utilized to design a custom propeller that maximizes the efficiency of the system.
A brushless electric motor was selected for the candidate AUV based on a survey of available off the shelf motors and a mathematical characterization process. In parallel with the motor characterization a propeller design was optimized using OpenProp v1 to perform a parametric analysis. OpenProp v2.3 was then used to design a unique propeller for the selected motor. The propeller design resulted in a final propeller with an efficiency of 79.93%. The motor characterization process resulted in two candidate motors being selected, the NeuMotor 1925-3Y and NeuMotor 1521-10.5Y, for in house testing and evaluation. A total propulsive system efficiency of between 44% and 46% was achieved depending on which motor is selected for the final design.Master of Science
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Pawar, Suraj Arun. "Hydrodynamic Design of Highly Loaded Torque-neutral Ducted Propulsor for Autonomous Underwater Vehicles." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/86888.
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The design method for marine propulsor (propeller/stator) is presented for an autonomous underwater vehicle (AUV) that operates at a very high loading condition. The design method is applied to Virginia Tech Dragon AUV. It is based on the parametric geometry definition for the propulsor, use of high-fidelity CFD RANSE solver with the transition model, construction of the surrogate model, and multi-objective genetic optimization algorithm. The CFD model is validated using the paint pattern visualization on the surface of the propeller for an open propeller at model scale. The CFD model is then applied to study hydrodynamics of ducted propellers such as forces and moments, tip leakage vortex, leading-edge flow separation, and counter-rotating vortices formed at the duct trailing edge. The effect of variation of thickness for stator blades and different approaches for modeling the postswirl stator is presented. The field trials for Dragon AUV shows that there is a good correlation between expected and achieved design speed under tow condition with the designed base propulsor. The marine propulsor design is further improved with an objective to maximize the propulsive efficiency and minimize the rolling of AUV. The stator is found to eliminate the swirl component of velocity present in the wake of the propeller to the maximum extent. The propulsor designed using this method (surrogate-based optimization) is demonstrated to have an improved torque balance characteristic with a slight improvement in efficiency than the base propulsor design.Master of Science
The propulsion system is the critical design element for an AUV, especially if it is towing a large payload. The propulsor for towing AUVs has to provide a very large thrust and hence the propulsor is highly loaded. The propeller has to rotate at very high speed to produce the required thrust and is likely to cavitate at this high speed. Also at this high loading condition, the maximum ideal efficiency of the propulsor is very less. Another challenge is the induced torque from the propeller on AUV that can cause the rolling of an AUV which is undesirable. This problem can be addressed by installing the stator behind the propeller that will produce torque in the opposite direction of the propeller torque. In this work, we present a design methodology for marine propulsor (propeller/stator) that can be used in AUV towing a large payload. The propulsor designed using this method has improved torque characteristics and has the efficiency close to 80 % of the ideal efficiency of ducted propeller at that loading condition.
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Briggs, Robert Clayton. "Mechanical Design of a Self-Mooring Autonomous Underwater Vehicle." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/36344.
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The Virginia Tech self-mooring autonomous underwater vehicle (AUV) is capable of mooring itself on the seafloor for extended periods of time. The AUV is intended to travel to a desired mooring location, moor itself on the seafloor, and then release the mooring and return to a desired egress location. The AUV is designed to be an inexpensive sensor platform. The AUV utilizes a false nose that doubles as an anchor. The anchor is neutrally buoyant when attached to the AUV nose. When the vehicle moors it releases the false nose, which floods the anchor making it heavy, sinking both the anchor and AUV to the seafloor. At the end of the mooring time the vehicle releases the anchor line and travels to the recovery location. A prototype vehicle was constructed from a small-scale platform known as the Virginia Tech 475 AUV and used to test the self-mooring concept. The final self-mooring AUV was then constructed to perform the entire long duration mission. The final vehicle was tested successfully for an abbreviated mission profile. This report covers the general design elements of the self-mooring AUV, the detailed design of both the prototype and final AUVs, and the results of successful field trials with both vehicles.Master of Science
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Zinni, Jerome. "Analysis of the DiveTracker acoustical navigation system for the NPS AUV." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1996. http://handle.dtic.mil/100.2/ADA308222.
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Beyazay, Bahadir. "Simulation and modeling of a soft grounding system for an AUV." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1999. http://handle.dtic.mil/100.2/ADA366791.
Full textAbstract:
Thesis (M.S. in Mechanical Engineering) Naval Postgraduate School, June 1999."June 1999". Thesis advisor(s): Anthony J. Healey. Includes bibliographical references (p. 79-80). Also avaliable online.
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Butt, Mark-Andrew. "Hydrodynamic improvements for the DOLPHIN, a surface-piercing semi-submersible AUV." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0005/MQ42358.pdf.
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