Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 24 for “"Remote submersibles"”.
-
Search methods for an autonomous underwater vehicle using scalar measurements
The continuing development of the autonomous underwater vehicle as an oceanographic research tool has opened up the realm of scientific possibility in the field of deep ocean research. The ability of a vehicle to travel to the ocean floor untethered, collect data for an extended period of time and …
-
Underwater optical measurement of position and orientation using a prepared, passive target
… station keeping, and navigation for the JASON remotely operated vehicle, an optical tracking method is investigated. The method needs to be accurate enough for underwater control and fast enough to enable timely control. The method presented solves the camera location problem in a closed form …
-
Design of a controllable pitch underwater thruster system
Control systems for underwater vehicles have reached the level of sophistication where they are limited by the dynamic performance of the thrust actuators. Standard fixed-pitch propellers have been shown to have very poor dynamic characteristics, particularly at low thrust levels The dynamic …
-
Efficient control based on a verified model for an autonomous underwater vehicle : a case study of Autonomous Benthic Explorer
The Autonomous Benthic Explorer (ABE) is an unmanned underwater vehicle being developed for scientific study of the deep ocean sea:floor. ABE will be completely autonomous from the surface which means that the lifetime of the mission will depend largely on how the vehicle is controlled. An accurate …
-
Maximizing AUV slow speed performance
A review of the Odyssey IIB autonomous underwater vehicle shows that energy costs associated with vehicle controls can be reduced and operational flexibility improved with relatively simple, low cost improvements. Because the operating speed that minimizes forward drag is not necessarily the same …
-
Six degree of freedom vehicle controller design for the operation of an unmanned underwater vehicle in a shallow water environment
Closed loop control of an unmanned underwater vehicle (UUV) in the dynamically difficult environment of shallow water requires explicit consideration of the highly coupled nature of the governing non-linear equations of motion. This coupling between an UUV's six degrees of freedom (6 DOF) is …
-
Experiments and numerical simulations of the dynamics of an R.O.V. thruster during maneuvering
… uniform flows. Operational parameters of small remotely operated vehicles and autonomous underwater vehicles require a great deal of transient operation of the propellers. This and the small mass of the vehicles make the dynamics of the propellers a significant factor in vehicle control. …
-
Variable buoyancy system metric
Over the past 20 years, underwater vehicle technology has undergone drastic improvements, and vehicles are quickly gaining popularity as a tool for numerous oceanographic tasks. Systems used on the vehicle to alter buoyancy, or variable buoyancy (VB) systems, have seen only minor improvements …
-
Distributed autonomy and formation control of a drifting swarm of autonomous underwater vehicles
Recent advances in autonomous underwater vehicle (AUV) technology have led to their wide-spread acceptance and adoption for use in scientific, commercial, and defence applications in the underwater domain. At the same time, research progress in swarm robotics has seen swarm intelligence algorithms …
-
Autonomous & adaptive oceanographic feature tracking on board autonomous underwater vehicles
The capabilities of autonomous underwater vehicles (AUVs) and their ability to perform tasks both autonomously and adaptively are rapidly improving, and the desire to quickly and efficiently sample the ocean environment as Earth's climate changes and natural disasters occur has increased …
-
Terrain-relative navigation for autonomous underwater vehicles
Navigation is a key technology for autonomous underwater vehicles (AUVs), and currently, it limits potential and existing vehicle capabilities and applications. This thesis presents a terrain-relative navigation system for AUVs that does not require the deployment of acoustic beacons or other …
-
Computational strategies for understanding underwater optical image datasets
A fundamental problem in autonomous underwater robotics is the high latency between the capture of image data and the time at which operators are able to gain a visual understanding of the survey environment. Typical missions can generate imagery at rates hundreds of times greater than highly …
-
Advances in integrating autonomy with acoustic communications for intelligent networks of marine robots
Autonomous marine vehicles are increasingly used in clusters for an array of oceanographic tasks. The effectiveness of this collaboration is often limited by communications: throughput, latency, and ease of reconfiguration. This thesis argues that improved communication on intelligent marine …
-
Dynamics of a vertically tethered marine platform
Rapid and high resolution motion and tension measurements were made of a typical vertically tethered system, a caged deep-sea ROV, while it operated at sea. The system is essentially one-dimensional because only the vertical motions of the underwater platform and the ship were coherent, while …
-
Characterization of underwater target geometry from Autonomous Underwater Vehicle sampling of bistatic acoustic scattered fields
One of the long term goals of Autonomous Underwater Vehicle (AUV) minehunting is to have multiple inexpensive AUVs in a harbor autonomously classify hazards. Existing acoustic methods for target classification using AUV-based sensing, such as sidescan and synthetic aperture sonar, require an …
-
A parallel hypothesis method of autonomous underwater vehicle navigation
This research presents a parallel hypothesis method for autonomous underwater vehicle navigation that enables a vehicle to expand the operating envelope of existing long baseline acoustic navigation systems by incorporating information that is not normally used. The parallel hypothesis method …
-
Human factors engineering in sonar visual displays
Undersea technology is on the verge of equipping remotely operated vehicle (ROV) pilots with a three-dimensional (3-D), real-time display incorporating data from a wide variety of sensors including sonar (sound navigation and ranging), cameras, and lasers. Effective collection, computation, and …
-
Controller design for underwater vehicle systems with communication constraints
Real-time cooperation between autonomous vehicles can enable time-critical missions such as tracking and pursuit of a dynamic target or environmental feature, but relies on wireless communications. Underwater communication is almost exclusively accomplished through acoustics, which bring challenges …
-
Cooperative localization for autonomous underwater vehicles
Self-localization of an underwater vehicle is particularly challenging due to the absence of Global Positioning System (GPS) reception or features at known positions that could otherwise have been used for position computation. Thus Autonomous Underwater Vehicle (AUV) applications typically require …
-
Comparison of neural and control theoretic techniques for nonlinear dynamic systems
This thesis compares classical nonlinear control theoretic techniques with recently developed neural network control methods based on the simulation and experimental results on a simple electromechanical system. The system has a configuration-dependent inertia, which contributes a substantial …
Page 1 of 2