Thesis (M.A.)--Ohio State University, 1987. / Includes vita. Includes bibliographical references (leaves 149-153). Available online via OhioLINK's ETD Center.

With connected and autonomous vehicles, no optimal standard or framework currently exists, outlining the right level of information sharing for cooperative autonomous driving. Cooperative Perception is proposed among vehicles, where every vehicle is transformed into a moving sensor platform that is capable of sharing information collected using its on-board sensors. This helps extend the line of sight and field of view of autonomous vehicles, which otherwise suffer from blind spots and occlusions. This increase in situational awareness promotes safe driving over a short range and improves traffic flow efficiency over a long range. This thesis proposes a methodology for cooperative perception for autonomous vehicles over a short range. The problem of cooperative perception is broken down into sub-tasks of cooperative relative localization and map merging. Cooperative relative localization is achieved using visual and inertial sensors, where a computer-vision based camera relative pose estimation technique, augmented with position information, is used to provide a pose-fix that is subsequently updated by dead reckoning using an inertial sensor. Prior to map merging, a technique for object localization using a monocular camera is proposed that is based on the Inverse Perspective Mapping technique. A mobile multi-robot testbed was developed to emulate autonomous vehicles and the proposed method was implemented on the testbed to detect pedestrians and also to respond to the perceived hazard. Potential traffic scenarios where cooperative perception could prove crucial were tested and the results are presented in this thesis. / MS

Sampling small scale ocean turbulence is one of the most important problems in oceanography. The turbulence can be near the noise level of current microscale profiling techniques and these techniques do not provide spatially and temporally dense measurements and can be labor intensive. A 5 beam acoustic Doppler current profiler (VADCP) can more accurately measure three components of fluid velocity in a column. By towing such a device in a sensor platform, called a towfish, one may measure turbulent mixing in a vertical swath of the ocean. If the towfish attitude is not precisely regulated, however, the turbulence measurements can be irreversibly corrupted. A two-part tow that includes a depressor weight between the towing vessel and the towfish can provide some degree of disturbance rejection. Passive devices alone, however, can not meet the performance requirements for measuring ocean turbulence. This thesis presents a design for a two-stage towing system which will be used to measure ocean turbulence. The focus is on the towfish, which includes independently actuated stern planes for pitch and roll disturbance rejection. The thesis also describes design and analysis of an active control system to precisely regulate the pitch and roll attitude of a streamlined towfish. A three dimensional numerical model is presented and a PID controller is developed to provide active attitude stabilization. The effect of random depressor motions on the towfish dynamics is assessed for both the uncontrolled and the feedback-controlled case. The numerical investigation also considers variations in parameters such as tether length and CG location. / Master of Science

Approved for public release; distribution is unlimited / The United States Navy is committed to implementing and using unmanned vehicles (UVs). Battlegroups have deployed and will continue to deploy with UVs because of their potential effectiveness. However, current UV doctrine does not set forth a standardized set of techniques and procedures for UV information exchange during maritime missions. The focus of this study is to analyze the structure of information flow for unmanned systems and suggest an exchange architecture to successfully inform and build decision maker understanding based on data from UVs in support of these missions. Through analysis of the knowledge-information-data (KID) model, and definition of highlevel functions and tasks created from fleet input, this thesis develops an IDEF0 and PERT representation. It outlines tasks and roles for successfully accomplishing information exchange from UV payload sensors to tactical decision makers. The study concludes with suggested measures of effectiveness and performance to determine the strength and validity of the architecture. / Ensign, United States Navy

"In this PhD dissertation, we propose distributed adaptation mechanisms for connected vehicles to deal with the connectivity challenges. To understand the system behavior of the solutions for connected vehicles, we first need to characterize the operational environment. Therefore, we devised a large scale fading model for various link types, including point-to-point vehicular communications and multi-hop connected vehicles. We explored two small scale fading models to define the characteristics of multi-hop connected vehicles. Taking our research into multi-hop connected vehicles one step further, we propose selective information relaying to avoid message congestion due to redundant messages received by the relay vehicle. Results show that the proposed mechanism reduces messaging load by up to 75% without sacrificing environmental awareness. Once we define the channel characteristics, we propose a distributed congestion control algorithm to solve the messaging overhead on the channels as the next research interest of this dissertation. We propose a combined transmit power and message rate adaptation for connected vehicles. The proposed algorithm increases the environmental awareness and achieves the application requirements by considering highly dynamic network characteristics. Both power and rate adaptation mechanisms are performed jointly to avoid one result affecting the other negatively. Results prove that the proposed algorithm can increase awareness by 20% while keeping the channel load and interference at almost the same level as well as improve the average message rate by 18%. As the last step of this dissertation, distributed cooperative dynamic spectrum access technique is proposed to solve the channel overhead and the limited resources issues. The adaptive energy detection threshold, which is used to decide whether the channel is busy, is optimized in this work by using a computationally efficient numerical approach. Each vehicle evaluates the available channels by voting on the information received from one-hop neighbors. An interdisciplinary approach referred to as entropy-based weighting is used for defining the neighbor credibility. Once the vehicle accesses the channel, we propose a decision mechanism for channel switching that is inspired by the optimal flower selection process employed by bumblebees foraging. Experimental results show that by using the proposed distributed cooperative spectrum sensing mechanism, spectrum detection error converges to zero."

Thesis (M.S.)--Auburn University, 2008. / Abstract. Vita. Includes bibliographical references (p. 65-68).

Thesis (M.S.) in Resource Economics and Policy--University of Maine, 2009. / Includes vita. Includes bibliographical references (leaves 105-115).

Thesis (M.S.)--California Polytechnic State University, 2009. / Mode of access: Internet. Title from PDF title page; viewed on Feb. 10, 2010. Major professor: Dr. Eric Mehiel. "Presented to the faculty of California Polytechnic State University, San Luis Obispo." "In partial fulfillment of the requirements for the degree of Master of Science in Aerospace Engineering." "October, 2009." Includes bibliographical references (p. 55-56).

Thesis (M.S.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains v, 131 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 128-131).

Thesis (M.S. in Applied Science (Operations Research))--Naval Postgraduate School, June 2004. / Thesis advisor(s): Susan M. Sanchez. Includes bibliographical references (p. 79-80). Also available online.