Thesis (M.S.)--California Polytechnic State University, 2009. / Title from PDF title page; viewed on August 3, 2009. Major professor: Daniel Biezad, Ph.D. "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." "May 2009." Includes bibliographical references (p. 90-91). Also available on microfiche.

Thesis (Ph.D)--Aerospace Engineering, Georgia Institute of Technology, 2010. / Committee Chair: Prasad, JVR; Committee Member: Costello, Mark; Committee Member: Johnson, Eric; Committee Member: Schrage, Daniel; Committee Member: Vela, Patricio. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Thesis (M.S.)--Rochester Institute of Technology, 2006. / Typescript. Includes bibliographical references (leaves 86-89).

The fact that pilots are not physically situated in the aircraft for UAS operations makes the current standards applicable to manned aircraft not suitable for UAS operations (FAA, 2013). FAA (2013:18) states that ―removing the pilot from the aircraft creates a series of performance considerations between manned and unmanned aircraft that need to be fully researched and understood to determine acceptability and potential impact on safe operations in the NAS. According to ERSG (2013), not all technologies necessary to ensure the safe integration of civil UASs into civilian airspace are available today. The extrapolation that can be made based on the above arguments is that advancement of UAS technologies will more likely have a significant bearing on the safe integration of UASs into civilian airspace. Therefore, as an identified research gap, the research/main objective of this research is to identify future technological factors affecting Unmanned Aircraft Systems in the Republic of South Africa leading towards the year 2025.

Tailsitter UAVs (Unmanned Aerial Vehicles) are a type of VTOL (Vertical Take off and Landing) aircraft that combines the agility of a quadrotor drone with the endurance and speed of a fixed-wing aircraft. For this reason, they have become popular in a wide range of applications from tactical surveillance to parcel delivery. This thesis details a clean sheet design process for a tailsitter UAV that includes the dynamic modeling, control design, simulation, vehicle design, vehicle prototype fabrication, and testing of a tailsitter UAV. The goal of this process was to design a robust controller that is able to handle uncertainties in the system's parameters and external disturbances and subsequently can control the vehicle through the transition between vertical and horizontal flight regimes. It is evident in the literature that most researchers choose to model and control tailsitter UAVs using separate methods for the vertical and horizontal flight regimes and combine them into one control architecture. The novelty of this thesis is the use of a single dynamical model for all flight regimes and the robust control technique used. The control algorithm used for this vehicle is a MRAC (Model Reference Adaptive Control) law, which relies on reference models and gains that adapt according to the vehicle's response in all flight regimes. To validate this controller, numerical simulations in Matlab and flight tests were conducted. The combination of these validation methods confirms our adaptive controller's ability to control the transition between the vertical and horizontal flight regimes when faced with both parametric uncertainties and external disturbances. / Master of Science / Unmanned aircrafts have been a topic of constant research and development recently due to their wide range of applications and their ability to fly without directly involving pilots. More specifically, VTOL UAVs have the advantage of being able to take off without a runway while retaining the efficiency of a classical aircraft. A tailsitter UAV behaves as a traditional quadrotor drone when in its vertical configuration and can rotate to a horizontal configuration, where it takes advantage of its wings to fly as a conventional aircraft. Modeling the dynamics of the tailsitter UAV and designing an autopilot controller is the main focus of this thesis. An adaptive controller was chosen for the tailsitter UAV due to its ability to modify the gains of the system based on the behavior of the vehicle to adapt to the unknown vehicle properties. This controller was validated using both computer simulations and actual flight tests. It was found that the adaptive controller was able to successfully control the transition between the vertical and horizontal flight regimes despite the uncertainties in the parameters of the vehicle.

Unmanned aerial vehicles (UAVs) will be a critical part of the U.S. Army's Future Force. The Future Force will be a highly mobile, network enabled family of systems with integrated sensors and precision munitions. The Future Force will rely heavily on UAVs to provide eyes on the battlefield. These eyes will trigger the deployment of precision munitions by other platforms, and possibly by UAVs themselves. To provide insight into how the numbers and capabilities of UAVs affect a Future Force Combined Arms Battalionâ s (CABâ s) ability to secure a Northeast Asia urban objective, a simulation was built and analyzed. 46,440 computational experiments were conducted to assess how varying the opposing force and the numbers, tactics, and capabilities of UAVs affects the CABâ s ability to secure the objective with minimal losses. The primary findings, over the factors and ranges examined, are: UAVs significantly enhance the CABâ s performance; UAV capabilities and their tactics outweigh the number of UAVs flying; battalion level UAVs, especially when armed, are critical in the opening phases of the battle, as they facilitate the rapid attrition of enemy High Pay-off Targets; and, at least one company level and a platoon level UAV enhances dismounts survivability later in the battle.

Warfighters are increasingly relying on Unmanned Aerial Vehicle (UAV) systems at all levels of combat operations. As these systems weave further into the fabric of our tactics and doctrine, their loss will seriously diminish combat effectiveness. This makes the survivability of these systems of utmost importance. Using Agent-based modeling and a Nearly Orthogonal Latin Hypercube design of experiment, numerous factors and levels are explored to gain insight into their impact on, and relative importance to, survivability. Factors investigated include UAV speed, stealth, altitude, and sensor range, as well as enemy force sensor ranges, probability of kill, array of forces, and numerical strength. These factors are varied broadly to ensure robust survivability results regardless of the type of threat. The analysis suggests that a speed of at least 135 knts should be required and that increases in survivability remain appreciable up to about 225 knts. The exception to speed's dominance is in the face of extremely high capability enemy assets. In this case, stealth becomes more important than speed alone. However, the interactions indicate that as both speed and stealth increase, speed yields a faster return on overall survivability and that speed mitigates increased enemy capabilities.

How does waging war effectively fade into the background for most Americans, even as it is one of the most defining aspects of the United States’ actions and priorities, both domestically and internationally? This dissertation takes up one dimension of this question by ethnographically engaging with a particular mode of contemporary US war making that involves the deployment of drones, large and high-altitude aerial vehicles, remotely controlled from within the United States. Based on fieldwork conducted over fourteen months between 2010 and 2015 within the US with communities involved in the deployment, planning, or assessment of Air Force drone operations, a primary contribution of the dissertation is to refocus critical discourses around drones through the lens of labor and the work entailed in war. By examining the divisions of labor implicated in ongoing drone warfare, a wider set of questions and implications takes shape about the nature of contemporary American war and where different kinds of responsibilities and modes of normalization lie. The dissertation begins by arguing that the distributions of action and control that characterize drone operations are neither obvious nor necessary, but rather have taken hold only in the context of specific historical conditions of possibility. These conditions are what enable drone operations to be seen as an effective and ideal form of US military engagement, and involve interwoven developments in post-World War II military command and control theory, digital data, global information networks, and a reliance on legal frameworks that render state violence justified. The dissertation also examines the discrepancies between the imagined capacities of “unmanned” and “autonomous” drones and the current practices that constitute and maintain these technologies, which must be continually managed and constructed as effective and legitimate actors through professionalized military discourses and practices. The second half of the dissertation, more ethnographic in focus, examines how drone operations are implicated in changing conceptions of military service and military-civilian distinctions. Through an examination of the tensions and controversies that have arisen around drone pilots, the dissertation presents how Air Force pilots and commanders involved in drone operations construct and position the value of drone operations as meaningful and honorable military service. The analysis demonstrates that while officers put forward the value of their work as professional and altruistic service, at the same time, an irreconcilable tension exists because the military labor of drone operations bears increasing similarity to other forms of contemporary civilian work, characterized by the language of compensation, flexibility, and in/security. The dissertation concludes by proposing the concept of the warzone as a way to encompass all the places in which war occurs, its consequences on the battlefield, but also its sites of execution and the range of people, places, and practices that are implicated in the ongoing conduct of war. The dissertation demonstrates that the increasing deployment of drone operations is a contributing factor to the seeming invisible state of war for the majority of Americans. However, this is not necessarily because war is being conducted at a distance, as most journalists and scholars propose. Rather it is because war is being conducted, sometimes literally, in Americans’ backyards, close-by in the United States, in ways that are obfuscated or rendered merely mundane.

No description available.

Thesis (Ph. D.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 125-134). Also available on the World Wide Web.