The goal of this study is to determine if trust in autonomous vehicles is affected by whether the vehicle is being operated in a closed or open system. A PRQF survey method was used to complete this study. The survey contained items to assess pedestrian behavior, personal innovativeness, and receptivity to autonomous vehicles. Scenario questions were also utilized to determine differences in the trust of automated vehicles in open and closed settings. The results from this study indicated increased pedestrian receptivity scores for the closed system (M=14.11, SD=3.78), compared to the open system (M=13.70, SD=3.90). Average trust scores were also increased for the closed system (M=4.68, SD=1.82) compared to the open system (M=4.56, SD=1.85). These results were used to conclude that trust and receptivity of autonomous vehicles were increased for closed systems.

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This thesis presents experimental and finite element analysis results of eccentrically loaded carbon-fiber composite booms that can deploy solar sails. Using the collapsible tubular mast design along with the geometry from the upcoming Advance Composite Solar Sail System mission, short composite booms segments were manufactured for testing. New clamps were also designed to allow a column bending test to achieve eccentric loading. As buckling through eccentric loading has not previously seen much research, the geometry and composite layups were simplified to allow for ease of manufacturing and verification. The work presented here shows that a finite element simulation, using a new composite material model, can easily simulate the eccentric buckling of collapsible tubular mast booms. It was found that composite booms with this geometry realize two different buckling events. First, local buckles form near each set of clamps, and then a second buckling causes a loss of structural support.

A comparison of viscous hydrodynamic force models is presented, with application on an autonomous underwater vehicle (AUV). The models considered here are \emph{quasi-steady}, meaning that force is expressed as a function of instantaneous vehicle state. This is in contrast to physical reality, where the force applied to a rigid body moving through a viscous fluid is history-dependent. As a result, the comparison of models is restricted to how well they are able to recreate a force history, rather than how closely they represent the underlying physics. Of the models under consideration, no single model performs significantly better than the others, but several perform worse. Each viscous hydrodynamic force model presented here is expressed as a linear combination of basis functions, which are nonlinear functions of body-relative velocity. The greater dynamical model is presented in a rigid-body framework with six degrees of freedom, with terms which account for inviscid fluid flow, restoring forces due to gravity, and control forces due to actuator motion. The models are selected from several that have been proposed in the literature, which include empirically-derived and physics-based models. Some models assume that the relationship between force and velocity is fundamentally linear or quadratic in nature, or make assumptions about coupled motion. The models are compared by their relative complexities, and also by their ability to reproduce data sets generated from field experiments. The complete dynamical equations are presented for each model, including coefficients suitable for use with the Virginia Tech 690 AUV. / Master of Science

This thesis describes the development of a new zero-turn-radius (ZTR) differentially driven robotic vehicle hereinafter referred to as NEVEL. The primary objective of this work was to develop a device that could be used as a test-bed for continued autonomous vehicle research at Virginia Tech while meeting the entry requirements of the Annual International Unmanned Ground Robotics Competition. In developing NEVEL, consideration was given to the vehicle's mechanical and electrical design, sensing and computing systems, and navigation strategy. Each of these areas was addressed individually, but always within the context of optimal integration to produce the best overall vehicle system. A constraint that directed much of the design process was the desire to integrate industrially available and proven components rather than creating custom designed systems. This thesis also includes a review of the relevant literature as it pertains to both subsystem and overall vehicle design. NEVEL, the vehicle that was created from this research effort, is novel in several respects. It is one of the few true embodiments of a fully functioning, three-wheel, differential drive autonomous vehicle. Several previous studies have developed this concept for indoor applications, but none has resulted in a working test-bed that can be applied to an unstructured, outdoor environment. NEVEL also appears to be one of the few autonomous vehicle systems to fully incorporate a commercially available laser range finder. These features alone would make NEVEL a useful platform for continued research. In addition, however, by using common, off-the-shelf components and a personal computer platform for all computation and control, NEVEL has been created to facilitate testing of new navigation and control strategies. As testimony to the success of this design, NEVEL was recognized at the Sixth Annual International Unmanned Ground Robotics Competition as the best overall design. / Master of Science