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Title: Characterization of the acoustic signature of an Ocean Explorer class AUV.
Creator: Lambe, Frederic Lionel., Florida Atlantic University, Cuschieri, Joseph M., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The radiated noise from Autonomous Underwater Vehicles (AUV's) can interfere with on-board sensors and with certain type of missions. It is thus important to understand the parameters controlling the AUV self noise. In this thesis, measurement techniques and analyses are developed to investigate the mechanisms contributing to the acoustic noise of an Ocean Explorer class AUV. Measurements of the AUV acoustic signature are performed in a reverberant tank, after the tank is qualified to...
Show moreThe radiated noise from Autonomous Underwater Vehicles (AUV's) can interfere with on-board sensors and with certain type of missions. It is thus important to understand the parameters controlling the AUV self noise. In this thesis, measurement techniques and analyses are developed to investigate the mechanisms contributing to the acoustic noise of an Ocean Explorer class AUV. Measurements of the AUV acoustic signature are performed in a reverberant tank, after the tank is qualified to establish a reliable procedure to measure the AUV source levels. The measurement results are compared that obtained in an anechoic tank and in open-water. Acoustic measurements are correlated with vibration measurements performed on various components of the AUV, in order to identify the dominant components. From the results, some preliminary mitigation procedures to reduce the AUV acoustic signature are developed.
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Date Issued: 1999
PURL: http://purl.flvc.org/fcla/dt/15618
Subject Headings: Oceanographic submersibles, Underwater acoustics
Format: Document (PDF)

Title: Oceanic turbulence measurement using an AUV platform and development of graphical interfaces for data acquisition and analysis.
Creator: Leindecker, Eric-Olivier., Florida Atlantic University, Dhanak, Manhar R., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Application of a small autonomous underwater vehicle (AUV) is described as a platform for measurement of oceanic turbulence in coastal waters during cold atmospheric fronts. The turbulence package, mounted on the AUV, allows horizontal profiling and measurement of small-scale fluctuations of velocity and temperature and other characteristics of the flow in the ocean mixed layer. The turbulence measurements were made in conjunction with current profile measurements, conductivity, temperature,...
Show moreApplication of a small autonomous underwater vehicle (AUV) is described as a platform for measurement of oceanic turbulence in coastal waters during cold atmospheric fronts. The turbulence package, mounted on the AUV, allows horizontal profiling and measurement of small-scale fluctuations of velocity and temperature and other characteristics of the flow in the ocean mixed layer. The turbulence measurements were made in conjunction with current profile measurements, conductivity, temperature, and depth measurements, providing the background conditions. The navigation and tracking data from the ship and the underwater vehicle are also presented. The primary focus of this research was to collect and analyze data from the ocean in order to resolve the turbulent velocity fluctuations and the dissipation rates of turbulent kinetic energy. The aim of this thesis is to explain the approach for measurement and analysis of ocean data. It includes the manufacture of the measurement probes, the preparation of the electronic system, the coding of the acquisition software and use of several algorithms for detecting the presence of turbulence and mixing. Two observational oceanographic experiments are described as a basis for illustrating the techniques and methods in data acquisition and analysis of the oceanographic and turbulent quantities.
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Date Issued: 2001
PURL: http://purl.flvc.org/fcla/dt/12781
Subject Headings: Oceanographic submersibles, Turbulence, Oceanography
Format: Document (PDF)

Title: A convenient state machine formalism for high-level control of autonomous underwater vehicles.
Creator: Girard, Anouck Renee., Florida Atlantic University, Smith, Samuel M.
Abstract/Description: Recent successes in Autonomous Underwater Vehicle (AUV) technology have generated demand for broader, more general use of these vehicles, along with demand for longer, more complicated missions. However, AUVs are becoming more complex, and hence more difficult to program, test and maintain. A discrete event system would provide conditional execution for mission management, failure detection, and resource allocation techniques. The goal of this thesis is to provide a convenient formalism for...
Show moreRecent successes in Autonomous Underwater Vehicle (AUV) technology have generated demand for broader, more general use of these vehicles, along with demand for longer, more complicated missions. However, AUVs are becoming more complex, and hence more difficult to program, test and maintain. A discrete event system would provide conditional execution for mission management, failure detection, and resource allocation techniques. The goal of this thesis is to provide a convenient formalism for discrete event systems that reduces the apparent complexity of the system while maintaining its robust capabilities. The chosen formalism allows the convenient representation of hierarchies of concurrent hierarchical state machines. The formal semantics of the model are discussed, along with complete data structures and algorithms. As an example, a complete design of the navigator state machine is provided.
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Date Issued: 1998
PURL: http://purl.flvc.org/fcla/dt/15549
Subject Headings: Submersibles, Oceanographic submersibles
Format: Document (PDF)

Title: Experimental analysis of the AUV acoustic signature.
Creator: Frandsen, Susan Eileen., Florida Atlantic University, Cuschieri, Joseph M.
Abstract/Description: This thesis presents an experimental analysis of the acoustic signature of an Ocean Explorer class AUV. The experimental analysis consists of three parts. The first part reports the measurements performed in an open water environment at NSWC in Lake Pend Oreille, Idaho. The second part reports on measurements performed at the FAU test tank on a mock model of the AUV and the third part reports the measurements also in the FAU test tank of the AUV under typical operating conditions. The model...
Show moreThis thesis presents an experimental analysis of the acoustic signature of an Ocean Explorer class AUV. The experimental analysis consists of three parts. The first part reports the measurements performed in an open water environment at NSWC in Lake Pend Oreille, Idaho. The second part reports on measurements performed at the FAU test tank on a mock model of the AUV and the third part reports the measurements also in the FAU test tank of the AUV under typical operating conditions. The model measurement results were also used to verify the prediction capabilities of a numerical FE model of the AUV using the reciprocity method. The measurements in the FAU tank considered different operating conditions and different mounting of the podule inside the AUV. The podule contains the main mechanical components of the AUV, which are the propulsion motor and the control surface motors. Also considered in these measurements is the influence of the propeller and the influence of covering the aft section of the AUV with a compliant layer. The results of this analysis show that the type of mounting of the podule is not very significant and that significant energy is transferred through the water trapped in between the podule and the hull. Furthermore, the propeller has a significant influence on the acoustic signature since it generates distinct tones. These tones were also observed in the results of the open water measurements.
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Date Issued: 2001
PURL: http://purl.flvc.org/fcla/dt/12768
Subject Headings: Underwater acoustics, Oceanographic submersibles
Format: Document (PDF)

Title: A purpose-built ROV for submersible rescue.
Creator: Clark, A. M., Neely, J. W., White, Dan G., Harbor Branch Oceanographic Institute
Date Issued: 1993
PURL: http://purl.flvc.org/fau/fd/FA00007451
Subject Headings: Submersibles, Oceanographic submersibles, Submarine rescue vehicles, Harbor Branch Oceanographic Institution
Format: Document (PDF)

Title: Ocean turbulence measurement using an autonomous underwater vehicle.
Creator: Holappa, Kenneth Walter., Florida Atlantic University, Dhanak, Manhar R., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The complex dynamics of the oceans are only beginning to be understood. There is a wide range of dynamic scales in the ocean from the Gulf Stream, with scales as large as the ocean itself, to the microstructure scales of turbulent dissipation. The program of work presented in this dissertation involves the implementation of a turbulence measurement package on board a recently developed small autonomous underwater vehicle (AUV), as well as the design of an optimized AUV platform and the...
Show moreThe complex dynamics of the oceans are only beginning to be understood. There is a wide range of dynamic scales in the ocean from the Gulf Stream, with scales as large as the ocean itself, to the microstructure scales of turbulent dissipation. The program of work presented in this dissertation involves the implementation of a turbulence measurement package on board a recently developed small autonomous underwater vehicle (AUV), as well as the design of an optimized AUV platform and the development of new oceanographic sensors for measurement of micro-structure velocity. Attention is focused on ensuring that the platform is sufficiently quiet since small-scale, low level measurements are easily contaminated by the measurement process, structural vibrations, rigid-body motions and electrical interference; particularly so with the requisite machinery of a self-propelled AUV. Successful measurement entails making suitable modification to the AUV and its mode of operation. In addition to optimization of the measurement platform, consideration is given here to the optimization of the sensors for flow measurement using an AUV. Included in the research are laboratory tests of the new probes and a successful mission in making high quality measurements of ocean turbulence. Modern adaptation of the well-known Pitot tube shows promise in being less sensitive to vehicle self motion as well as yielding a greater spectral range, thereby facilitating more accurate measurement. Comparisons with shear probes and hot film probes, conducted in an axisymmetric water jet and in a wind tunnel, suggest that the pressure probe, developed as part of the work presented here, resolves the dissipation scales more fully than the shear probe. Additionally, the pressure probe does not suffer from the spectral distortion of the signal observed in measurements using a shear probe. In addition to measurement of velocity microstructure, consideration is given to the implementation of modern signal processing hardware in designing a method for the direct measurement of density microstructure. This basic property of the ocean has never before been measured directly. Results, obtained off the Florida coast in 18 meter deep water with the Ocean Explorer AUV; Cook, reveal a complex mixing event. Simultaneous measurement of two components of the velocity microstructure and measurements with a CTD package are analyzed and the instantaneous rates of viscous dissipation of turbulent energy are calculated. The dissipation rate was not stationary and showed a gradient vertically with depth as well as horizontally. The AUV platform, modified for low vibration noise, allowed measurement of dissipation rates of O(10^-8 W/kg).
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Date Issued: 1997
PURL: http://purl.flvc.org/fcla/dt/12532
Subject Headings: Oceanographic submersibles, Turbulence--Measurement
Format: Document (PDF)

Title: Computation of hydrodynamic coefficients and determination of dynamic stability characteristics of an underwater vehicle including free surface effects.
Creator: Saout, Olivier., Florida Atlantic University, Ananthakrishnan, Palaniswamy, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The inviscid hydrodynamic coefficients of an underwater vehicle (Ocean EXplorer), including the nonlinear effects of the wave surface, are computed using a boundary-integral method. A mixed Eulerian-Lagrangian formulation (Longuet-Higgins and Cokelet, 1976) is used for the treatment of nonlinear free-surface conditions. The algorithm is validated using the work-energy theorem (Yeung, 1982) and experimental data. Results, in the form of free-surface elevations and hydrodynamic coefficients,...
Show moreThe inviscid hydrodynamic coefficients of an underwater vehicle (Ocean EXplorer), including the nonlinear effects of the wave surface, are computed using a boundary-integral method. A mixed Eulerian-Lagrangian formulation (Longuet-Higgins and Cokelet, 1976) is used for the treatment of nonlinear free-surface conditions. The algorithm is validated using the work-energy theorem (Yeung, 1982) and experimental data. Results, in the form of free-surface elevations and hydrodynamic coefficients, are obtained for a range of body geometries and maneuvers. The open-loop dynamics of underwater vehicles are then investigated by solving the 3DOF rigid-body equations of motion (OXY plane). The advantages and possible usage of the developed methodology for the design and control of underwater vehicles, as well as topics for further research, are addressed in the conclusion chapter of the thesis.
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Date Issued: 2003
PURL: http://purl.flvc.org/fcla/dt/12981
Subject Headings: Hydrodynamics, Oceanographic submersibles, Water waves
Format: Document (PDF)

Title: Subsurface structure of an atmospherically forced water column in littoral waters.
Creator: Chernys, Michael., Florida Atlantic University, Dhanak, Manhar R., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The developing subsurface structure of a shallow sub-tropical water column during the passage of cold low-pressure atmospheric front is characterized through synoptic and in-situ observations during the passage of three separate fronts over South Florida. Subsurface distribution of current, salinity, temperature, density and dissipation rates were examined using an autonomous underwater vehicle (AUV), ship-based instruments, moored instruments and an Ocean Surface Current Radar (OSCR) as the...
Show moreThe developing subsurface structure of a shallow sub-tropical water column during the passage of cold low-pressure atmospheric front is characterized through synoptic and in-situ observations during the passage of three separate fronts over South Florida. Subsurface distribution of current, salinity, temperature, density and dissipation rates were examined using an autonomous underwater vehicle (AUV), ship-based instruments, moored instruments and an Ocean Surface Current Radar (OSCR) as the fronts passed through the region. Airfoil shear probes mounted in a package on the nose of the AUV were used to measure the level and distribution of small-scale turbulence in the water column and to estimate the in-situ dissipation rate of turbulent kinetic energy. Prevailing meteorological conditions were determined from two NOAA C-MAN stations and, for two of the experiments, from a local Air Sea Interaction Spar buoy (ASIS). The first atmospheric front examined was in December 1998. A significant 10°C drop in air temperature was recorded. The AUV carried out several pre-programmed surveys over a 6-day period. A turbulent kinetic energy dissipation rates of O(10-6W/kg) were observed in the water column during the passage of the front. Fetch-limited, offshore, wind-induced surface and subsurface currents were identified during the passage of the front on April 9, 2000. As the winds increased in magnitude and shifted direction, a change in surface current was apparent in the OSCR observations. A bottom-mounted ADCP and an AUV-mounted ADCP both recorded distinct corresponding contributions to the subsurface current due to the winds. Clockwise rotation of the current profile in the water column, consistent with wind-generated currents, was observed. A third low-pressure cold front passed through the region on April 18 an 19, 2000. AUV surveys were carried out as the front passed over the region for 19 hours within a 24-hour period. Dissipation rates reached O(10 -6W/kg) during the period of the survey and decreased to O(10 -8W/kg) subsequently. The distribution of dissipation rate appeared to agree with the characteristic log law for wind-induced turbulence at the start of the passage of the front, but was significantly higher subsequently and more dependent on the combination of convective fluxes and wind stress.
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Date Issued: 2002
PURL: http://purl.flvc.org/fau/fd/FADT12001
Subject Headings: Turbulence--Measurement, Oceanographic submersibles
Format: Document (PDF)

Title: Deepwater populations of the western atlantic pearlfish Carapus bermudensis (Ophidiiformes: Carapidae).
Creator: Tyler, James C., Robins, C. Richard, Smith, C. Lavett, Gilmore, R. G., Harbor Branch Oceanographic Institute
Date Issued: 1992
PURL: http://purl.flvc.org/FCLA/DT/3172853
Subject Headings: Ophidiiformes, Carapidae, Sea cucumbers, Larvae, Oceanographic submersibles
Format: Document (PDF)

Title: A new species of coronate scyphomedusa from the Bahamas, Atorella octogonos.
Creator: Mills, Claudia E., Larson, R. J., Youngbluth, Marsh J.
Date Issued: 1987
PURL: http://purl.flvc.org/FCLA/DT/3171641
Subject Headings: Gonads, Jellyfishes, Scyphozoa, Polyps, Oceanographic submersibles
Format: Document (PDF)

Title: COMMERCIAL SUBMERSIBLES: PERFORMANCE DESCRIPTION AND DESIGN SPECIFICATION.
Creator: MANSCHOT, DIRK, Florida Atlantic University
Abstract/Description: Following an introduction to the commercial type of submersible and a description of its relative importance, this thesis is primarily concerned with the performance description of such commercial submersibles. Since any description of a submersible will of necessity fail to give any idea of its actual working ability, a supplemental set of specifications is formulated. The three steps leading to an informative description are: 1) selecting and defining basic properties, 2) describing their...
Show moreFollowing an introduction to the commercial type of submersible and a description of its relative importance, this thesis is primarily concerned with the performance description of such commercial submersibles. Since any description of a submersible will of necessity fail to give any idea of its actual working ability, a supplemental set of specifications is formulated. The three steps leading to an informative description are: 1) selecting and defining basic properties, 2) describing their essential elements, 3) quantification by diagrams or numbers. Three steps have been completed for the description of Horizontal Maneuverability, Vertical Maneuverability and Field of Vision. Two steps have been completed for the specifications of Habitability, Controllability, Safety, Reliability/Maintenance and Instrumentability.
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Date Issued: 1975
PURL: http://purl.flvc.org/fcla/dt/13722
Subject Headings: Oceanographic research ships--Design and construction
Format: Document (PDF)

Title: Design, implementation and testing of a bio-inspired propulsion system for autonomous underwater vehicles.
Creator: Le Goff, Ivan., Florida Atlantic University, Leonessa, Alexander, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Some Autonomous Underwater Vehicles have recently been designed to mimic the locomotion of underwater animals. A new way of propulsion which uses Oscillating Fin Thrusters (OFTs) has been implemented on the AUV Morpheus, with the Nektor module. In particular, first a low level adaptive controller has been developed with the purpose of studying the characteristics of the OFT. Then, a new vehicle using Morpheus' base has been built in order to implement this module and test it. This required...
Show moreSome Autonomous Underwater Vehicles have recently been designed to mimic the locomotion of underwater animals. A new way of propulsion which uses Oscillating Fin Thrusters (OFTs) has been implemented on the AUV Morpheus, with the Nektor module. In particular, first a low level adaptive controller has been developed with the purpose of studying the characteristics of the OFT. Then, a new vehicle using Morpheus' base has been built in order to implement this module and test it. This required for the Lonworks network to be interfaced with QNXnet to create a multi communication protocol vehicle. Concerning the high level control, some proportional controllers and a 6-degree of freedom adaptive controller have been implemented and tested on the new vehicle. The results from these tests have shown that the Nektor module is suitable for the Morpheus, providing high-maneuverability features unavailable when using more standard propulsion systems.
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Date Issued: 2003
PURL: http://purl.flvc.org/fcla/dt/13000
Subject Headings: Oceanographic submersibles--Computer simulation, Underwater propulsion
Format: Document (PDF)

Title: Development and simulation of vertical profiling capability for FAU autonomous underwater vehicles.
Creator: Lin, Huaying., Florida Atlantic University, Hsu, Sam, An, Edgar, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description: This thesis describes the development of a simulation environment for Autonomous Underwater Vehicles (AUVs) on UNIX platforms. AUV missions can therefore be carried out without going to the sea. The Yoyo controller, a component for AUVs is also described in this thesis. The main function of Yoyo is to control the vertical profile of an AUV while it is navigating underwater performing data collection missions. The development of the controller is done in the simulation environment. Several...
Show moreThis thesis describes the development of a simulation environment for Autonomous Underwater Vehicles (AUVs) on UNIX platforms. AUV missions can therefore be carried out without going to the sea. The Yoyo controller, a component for AUVs is also described in this thesis. The main function of Yoyo is to control the vertical profile of an AUV while it is navigating underwater performing data collection missions. The development of the controller is done in the simulation environment. Several test cases have been performed, and the test results have clearly demonstrated the successful development of the controller.
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Date Issued: 1998
PURL: http://purl.flvc.org/fcla/dt/15599
Subject Headings: Oceanographic submersibles--Computer simulation, Underwater navigation
Format: Document (PDF)

Title: Modeling the acoustic signature of an Ocean Explorer class autonomous underwater vehicle.
Creator: Debiesme, Francois-Xavier., Florida Atlantic University, Cuschieri, Joseph M.
Abstract/Description: Autonomous Underwater Vehicles (AUV) rely on acoustics for a number of mission functions such as communications (Acoustic Modem) and vision (Forward and Side Looking Sonars). The AUV acoustic signature (self-noise and vibration) can thus interfere with AUV operations. Additionally, underwater measurements such as turbulence measurements can be contaminated by interference between the AUV generated acoustics pressures and the low pressures of the turbulence. In this thesis a Finite Element and...
Show moreAutonomous Underwater Vehicles (AUV) rely on acoustics for a number of mission functions such as communications (Acoustic Modem) and vision (Forward and Side Looking Sonars). The AUV acoustic signature (self-noise and vibration) can thus interfere with AUV operations. Additionally, underwater measurements such as turbulence measurements can be contaminated by interference between the AUV generated acoustics pressures and the low pressures of the turbulence. In this thesis a Finite Element and Boundary Element approach is developed to characterize the self-noise (vibration and radiated sound pressure) of a simplified FAU Ocean Explorer AUV. Mechanical excitation from the "podule", which contains the motors for the propulsion and motion control, is assumed in the analysis. The low frequency (less than 1Khz) results are dominated by two types of modes. One type associated with the motion of the "podule" as a rigid body on the vibration isolation supports that connects it to the rest of the AUV structure. The second type is associated with local structural deformations of the "podule", support frame, and AUV hull. Modifying the stiffness of the supports reduces the frequency of the rigid body modes of the "podule", but does not influence the frequencies of the local structural deformations of the "podule" and the rest of the AUV. Decreasing the stiffness of the supports should result in a reduced AUV acoustic signature.
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Date Issued: 2000
PURL: http://purl.flvc.org/fcla/dt/15764
Subject Headings: Oceanographic submersibles, Underwater acoustics, Acoustic models
Format: Document (PDF)

Title: Enhancement of the inertial navigation system for the Florida Atlantic University autonomous underwater vehicles.
Creator: Grenon, Gabriel Jean., Florida Atlantic University, An, Edgar
Abstract/Description: This thesis describes a new Inertial Navigation System (INS), designed for use on the latest generation of Autonomous Underwater Vehicle (AUV), the Morpheus AUVs, developed by the Department of Ocean Engineering. The INS makes use of a high precision Inertial Measurement Unit (IMU) along with a Doppler Velocity Log (DVL), a GPS/DGPS system and a flux gate magnetic compass to estimate the position of the vehicle during a mission. Extensive data processing methods are used in order to reduce...
Show moreThis thesis describes a new Inertial Navigation System (INS), designed for use on the latest generation of Autonomous Underwater Vehicle (AUV), the Morpheus AUVs, developed by the Department of Ocean Engineering. The INS makes use of a high precision Inertial Measurement Unit (IMU) along with a Doppler Velocity Log (DVL), a GPS/DGPS system and a flux gate magnetic compass to estimate the position of the vehicle during a mission. Extensive data processing methods are used in order to reduce the sources of error most critical to the navigation estimation. Accelerometers and gyroscopes are used to estimate the vehicle attitude in a complementary filter; a standard Kalman filter performs yaw rate bias estimation, whereas a second, extended Kalman filter, provides position estimation of the vehicle in real time, while also correcting for heading errors. Overall the INS is capable of providing the Morpheus with 1% navigation accuracy over an hour.
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Date Issued: 2000
PURL: http://purl.flvc.org/fcla/dt/12682
Subject Headings: Oceanographic submersibles--Computer simulation, Underwater navigation
Format: Document (PDF)

Title: Implementation of the Ocean Explorer AUV dock for use with the Morpheus AUV.
Creator: Lambiotte, Joseph Clayton, Jr., Florida Atlantic University, Smith, Samuel M., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: This report highlights important aspects of previous work with the Ocean Explorer (OEX) autonomous underwater vehicle (AUV) docking system as a background. This includes short baseline navigation, the Tracking Controller, Mechanical aspects of the dock, and results of testing of the docking system for the OEX Details of the Morpheus AUV are then given along with the major concerns faced in trying to adapt the OEX dock to the Morpheus. Using computer simulation, the reaction of the Morpheus...
Show moreThis report highlights important aspects of previous work with the Ocean Explorer (OEX) autonomous underwater vehicle (AUV) docking system as a background. This includes short baseline navigation, the Tracking Controller, Mechanical aspects of the dock, and results of testing of the docking system for the OEX Details of the Morpheus AUV are then given along with the major concerns faced in trying to adapt the OEX dock to the Morpheus. Using computer simulation, the reaction of the Morpheus when it impacts the dock is explored and the results of at sea testing (the collision of the vehicle and the dock) is discussed. A stinger strength analysis of the docking components is included and finally, suggestions for future work including modifications of the existing dock as well as another docking scheme are presented.
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Date Issued: 2001
PURL: http://purl.flvc.org/fcla/dt/12735
Subject Headings: Oceanographic submersibles--Computer simulation, Underwater navigation
Format: Document (PDF)

Title: Hydrodynamic analysis of an underwater body including free-surface effects.
Creator: Puaut, Christophe., Florida Atlantic University, Ananthakrishnan, Palaniswamy, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Boundary integral algorithms are developed to analyze three-dimensional inviscid fluid-body interactions, including the nonlinear free-surface effects. Hydrodynamic coefficients are computed for various body geometries, some corresponding to that of small underwater vehicles, in deep waters and near the free surface. The fully nonlinear unsteady wave-radiation problem corresponding to forced submerged-body oscillations and forward translation are solved using the mixed Eulerian-Lagrangian...
Show moreBoundary integral algorithms are developed to analyze three-dimensional inviscid fluid-body interactions, including the nonlinear free-surface effects. Hydrodynamic coefficients are computed for various body geometries, some corresponding to that of small underwater vehicles, in deep waters and near the free surface. The fully nonlinear unsteady wave-radiation problem corresponding to forced submerged-body oscillations and forward translation are solved using the mixed Eulerian-Lagrangian formulation (Longuet-Higgins and Cokelet, 1976). By implementing the leading-order free-surface conditions on the calm surface, linear time-domain solutions are also obtained. The nonlinear and linear results are compared to quantify the nonlinear free-surface effects. Linear frequency-domain analysis of the wave-body interactions is also carried out using a boundary-integral method based on the simple-source distribution (Yeung, 1974). The linear time-domain and the latter frequency-domain results are also compared for a validation of the algorithms.
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Date Issued: 2001
PURL: http://purl.flvc.org/fcla/dt/12845
Subject Headings: Boundary element methods, Oceanographic submersibles, Hydrodynamics
Format: Document (PDF)

Title: Control design for highly maneuverable autonomous underwater vehicles.
Creator: Poirrier, Ronald., Florida Atlantic University, Leonessa, Alexander, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Accurate Autonomous Underwater Vehicles positioning requires an appropriate control design which takes into account the nonlinear coupling between the different degrees of freedom. Assuming a vehicle equipped with two side-thruster modules including two tunnel thrusters each, the control problem will be split into an outer control loop handling the motion of the vehicle, and an inner control loop designed to track the thrust commanded to each thruster. A multivariable Lyapunov function based...
Show moreAccurate Autonomous Underwater Vehicles positioning requires an appropriate control design which takes into account the nonlinear coupling between the different degrees of freedom. Assuming a vehicle equipped with two side-thruster modules including two tunnel thrusters each, the control problem will be split into an outer control loop handling the motion of the vehicle, and an inner control loop designed to track the thrust commanded to each thruster. A multivariable Lyapunov function based approach, characterized by robustness properties with respect to parametric uncertainties and linearly bounded control output, will be proposed for the outer-loop and simulation results will be discussed. Regarding the low-level control framework, the performance of nine different controllers including conventional PI, sliding mode fuzzy controllers, and adaptive schemes such as model reference and sliding mode adaptive controllers, will be compared through theoretical derivations and experimental results. Such a comparison will show the advantages of the adaptive schemes in terms of tuning, robustness, and tracking performances.
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Date Issued: 2001
PURL: http://purl.flvc.org/fau/fd/FADT12777
Subject Headings: Submersibles--Automatic control, Oceanographic submersibles
Format: Document (PDF)

Title: Simulation, control and optimization of underwater vehicle performance.
Creator: Zipf, David Glenn., Florida Atlantic University, Dunn, Stanley E., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: This project addresses the simulation, control and optimization of underwater vehicle performance. An analytical model of underwater vehicle motion has been developed. This model is based on a set of six degree of freedom nonlinear differential equations of motion. These equations incorporate inertial, hydrodynamic, hydrostatic, gravity and thruster forces to define the vehicle's motion. The forces are calculated and the equations of motion solved using a finite difference method of...
Show moreThis project addresses the simulation, control and optimization of underwater vehicle performance. An analytical model of underwater vehicle motion has been developed. This model is based on a set of six degree of freedom nonlinear differential equations of motion. These equations incorporate inertial, hydrodynamic, hydrostatic, gravity and thruster forces to define the vehicle's motion. The forces are calculated and the equations of motion solved using a finite difference method of integration. An automatic closed loop control strategy has been developed and integrated into the motion model. The controller determines control plane deflection and thruster output based on sensor provided input, maneuver request and control gain constants. The motion model simulates the effects of these controller requests on the vehicle motion. The controller effects are analyzed and an optimal set of control gains is determined. These optimal gains are determined based on a quantitative comparison of a pre-defined Performance Index (PI) function. The PI is a function of critical performance values, i.e., energy consumption, and user defined weighted constants. By employing an iteration technique the PI is minimized to provide an optimal set of control gains.
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Date Issued: 1989
PURL: http://purl.flvc.org/fcla/dt/14534
Subject Headings: Oceanographic submersibles--Automatic control, Oceanographic submersibles--Simulation methods, Vehicles, Remotely piloted
Format: Document (PDF)

Title: The R/V Seaward Johnson: a new state-of-the art submersible support ship.
Creator: Cook, Roger W., Jones, Robert S., Prentice, Jeffrey R.
PURL: http://purl.flvc.org/fcla/dt/3357465
Subject Headings: Oceanographic submersibles, Deep-sea research vessels, Manned exploration devices
Format: Document (PDF)

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