Thesis (M.S.)--Air Force Institute of Technology, 2007. / "AFIT/GCS/ENG/07-02." Title from PDF title screen. Includes bibliographical references (p. 104-115). Also available online via the Defense Technical Information Center website (http://www.dtic.mil/).

Thesis (M.S.)--University of Tennessee, Knoxville, 2003. / Title from title page screen (viewed Oct. 14, 2003). Thesis advisor: Ralph Kimberlin. Document formatted into pages (x, 64 p. : ill. (some col.), col. maps). Vita. Includes bibliographical references (p. 58-63).

Simple, cheap and reliable echo-based ultrasonic ranging systems such as the Polaroid ranging unit are easily applied to indoor applications. However, to measure the range between an unmanned helicopter and a moving ship deck at sea using ultrasound requires a more robust ranging system, because rushing air and breaking water are known ultrasound noise sources. The work of designing, constructing and testing such a system is described in this dissertation. The compact, UAV ready ultrasound transmitter module provides high power, broadband arbitrary signal generation. The separate field-ready receiver is based on a modern embedded Digital Signal Processor (DSP), providing high speed matched-filter correlation processing. Large time-bandwidth signalling is employed to maximise the signal to noise ratio of the ranging system. Synthesised experiments demonstrate the ability of the correlation processing to reliably recover timing from signals buried in noise. Real world experiments demonstrate decimetre accuracy with two centimetre resolution, ten metre range and 32Hz refresh rate. A maximum boresight range of up to 38m is supported.

Thesis (M.S.)--California Polytechnic State University, 2009. / Title from PDF title page; viewed on June 11, 2009. "May 2009." "In partial fulfillment of the requirements for the degree [of] Master of Science in Aerospace Engineering." "Presented to the faculty of California Polytechnic State University, San Luis Obispo." Major professor: Daniel Biezad, Ph.D. Includes bibliographical references (p. 78-79). Also available on microfiche.

Thesis (Ph. D.)--Aerospace Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Johnson, Eric; Committee Co-Chair: Calise, Anthony; Committee Member: Prasad, J.V.R.; Committee Member: Tannenbaum, Allen; Committee Member: Tsiotras, Panagiotis.

The objective of this thesis is to design a relative navigation and guidance system for unmanned aerial vehicles (UAVs) for vision-based control applications. The vision-based navigation, guidance and control has been one of the most focused on research topics for the automation of UAVs. This is because in nature, birds and insects use vision as the exclusive sensor for object detection and navigation. In particular, this thesis studies the monocular vision-based navigation and guidance. Since 2-D vision-based measurements are nonlinear with respect to the 3-D relative states, an extended Kalman filter (EKF) is applied in the navigation system design. The EKF-based navigation system is integrated with a real-time image processing algorithm and is tested in simulations and flight tests. The first closed-loop vision-based formation flight has been achieved. In addition, vision-based 3-D terrain recovery was performed in simulations. A vision-based obstacle avoidance problem is specially addressed in this thesis. A navigation and guidance system is designed for a UAV to achieve a mission of waypoint tracking while avoiding unforeseen stationary obstacles by using vision information. A 3-D collision criterion is established by using a collision-cone approach. A minimum-effort guidance (MEG) law is applied for a guidance design, and it is shown that the control effort can be reduced by using the MEG-based guidance instead of a conventional guidance law. The system is evaluated in a 6 DoF flight simulation and also in a flight test. For monocular vision-based control problems, vision-based estimation performance highly depends on the relative motion of the vehicle with respect to the target. Therefore, this thesis aims to derive an optimal guidance law to achieve a given mission under the condition of using the EKF-based relative navigation. Stochastic optimization is formulated to minimize the expected cost including the guidance error and the control effort. A suboptimal guidance law is derived based on an idea of the one-step-ahead (OSA) optimization. Simulation results show that the suggested guidance law significantly improves the guidance performance. Furthermore, the OSA optimization is generalized as the n-step-ahead optimization for an arbitrary number of n, and their optimality and computational cost are investigated.