There has been recent interest by the military to have platforms capable of operating close to a point of interest without being detected while providing critical surveillance. By providing information that is not readily available, these platforms could provide a useful tool for small unit commanders in potentially life-threatening situations. Highly maneuverable, slow-flying micro air vehicles could fly under canopies, through alleys, or indoors to provide such intelligence. This study consists of a survey of current micro-sized technologies and commercially available components. The findings are presented and used in the design process of a larger payload-carrying variant of the NPS flapping wing micro air vehicle. The intent is to develop a readily deployable, backpackable, slow-flying micro air vehicle that can be used by smaller-size ground units in theatre for urban reconnaissance.

Approved for public release; distribution is unlimited / Next-generation U.S. Navy destroyers, known as DD(X), will use electric drive motors to meet their propulsion needs instead of the traditional mechanical drives. The use of electric drive motors in naval vessels has spurred the development of high power converters. This thesis examines the feasibility of using an advanced control algorithm known as Sine-triangle Pulse Width Modulation (SPWM) in combination with a Cascaded Multi-Level Converter (CMLC) in order to meet the U.S. Navy's strict requirements. The SPWM control algorithm was designed in Simulink and experimentally tested on a CMLC previously constructed at the Naval Postgraduate School. The controller and converter successfully powered a quarter horsepower three-phase induction motor. / Ensign, United States Navy

No description available.

Poon, Ho Shing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 66-69). / Abstracts in English and Chinese. / ACKNOWLEDGEMENTS --- p.III / TABLE OF CONTENTS --- p.IV / TABLE OF FIGURES --- p.VI / LIST OF TABLES --- p.IX / Chapter CHAPTER 1: --- INTRODUCTION --- p.1 / Chapter 1.1 --- Intrinsic Problem of Conventional Aerodynamic Flying Devices --- p.1 / Chapter 1.2 --- Novel Ionic Propulsion Technology - Ionic Flyer --- p.2 / Chapter 1.3 --- Historical Development and Related Work of Ionic Flyer --- p.2 / Chapter 1.4 --- Existing Results in Our Group --- p.3 / Chapter 1.5 --- Objective and Current Achievements --- p.4 / Chapter 1.6 --- Organization of the remaining thesis --- p.5 / Chapter CHAPTER 2: --- FUNDAMENTAL KNOWLEDGE OF IONIC FLYERS --- p.6 / Chapter 2.1 --- Basic structure of Ionic Flyers --- p.6 / Chapter 2.2 --- Working Principle of Ionic Flyers --- p.7 / Chapter 2.3 --- Parametric models of the Ionic Flyers --- p.8 / Chapter 2.3.1 --- Electrical Current-Voltage Model --- p.8 / Chapter 2.3.2 --- Mechanical Lift-Force Model --- p.9 / Chapter CHAPTER 3: --- STRUCTURAL ANALYSIS OF IONIC FLYERS --- p.11 / Chapter 3.l --- Analysis on the Electrode Length --- p.11 / Chapter 3.2 --- Analysis on the Emitter radius --- p.12 / Chapter 3.3 --- Analysis on the Gap Distance between Emitter and Collector --- p.13 / Chapter 3.4 --- Analyses on the Emitter-Collector Electrodes Configuration --- p.15 / Chapter 3.4.1 --- Single-Emitter-Single-Collector Wire-Plate Configuration --- p.15 / Chapter 3.4.2 --- Multiple-Emitter-Single-Collector Wire-Plate Configuration --- p.16 / Chapter 3.4.3 --- Single-Emitter-Multiple-Collector Wire-Plate Configuration --- p.17 / Chapter 3.4.4 --- Single-Emitter-Surface-Collector Wire-Plate Configuration --- p.19 / Chapter 3.5 --- Summary - Optimization Design Methodology --- p.21 / Chapter CHAPTER 4: --- HIGH VOLTAGE POWER GENERATION SYSTEM --- p.22 / Chapter 4.1 --- Existing Marketable High Voltage Power Supplies --- p.22 / Chapter 4.2 --- design of the High Voltage Power Supply --- p.24 / Chapter 4.2.1 --- Battery --- p.25 / Chapter 4.2.2 --- Step-up Transformer --- p.25 / Chapter 4.2.3 --- Voltage Multiplier --- p.26 / Chapter 4.2.4 --- Driving Circuit --- p.27 / Chapter 4.3 --- Testing prototypes --- p.28 / Chapter 4.3.1 --- First Prototype --- p.28 / Chapter 4.3.2 --- Second Prototype --- p.29 / Chapter 4.3.3 --- Third Prototype --- p.30 / Chapter 4.3.4 --- Fourth Prototype --- p.31 / Chapter 4.3.5 --- Comparison of the Four Prototypes --- p.32 / Chapter 4.4 --- Performance of the High Voltage Power Supply --- p.34 / Chapter 4.4.1 --- Vary with Frequency --- p.34 / Chapter 4.4.2 --- Vary with Duty Cycle --- p.34 / Chapter 4.4.3 --- Efficiency --- p.35 / Chapter 4.5 --- Resonance Frequency Tracking Algorithm --- p.36 / Chapter 4.5.1 --- Fixed Frequency --- p.37 / Chapter 4.5.2 --- Scan Through a Frequency Range --- p.37 / Chapter 4.5.3 --- Continuous Comparison of Feedback Voltages --- p.38 / Chapter 4.5.4 --- Comparison of the Three Approaches --- p.40 / Chapter 4.6 --- Possibility Analysis on Self-Sufficient On-board Power Supply --- p.41 / Chapter 4.6.1 --- Analysis Based on the Parametric models --- p.41 / Chapter 4.6.2 --- Proposed Solution - Ionic Propulsion Blimp --- p.43 / Chapter CHAPTER 5: --- DEVELOPMENT OF IONIC PROPULSION BLIMP --- p.44 / Chapter 5.l --- Design and Structure of Ionic Propulsion Blimp --- p.44 / Chapter 5.1.1 --- Required Volume of the Blimp --- p.45 / Chapter 5.1.2 --- Initial Experimental results of Ionic Propulsion Blimp --- p.46 / Chapter 5.2 --- Advanced Navigation System for Ionic Propulsion Blimp --- p.47 / Chapter 5.2.1 --- Direction Control System --- p.47 / Chapter 5.2.2 --- Vision-Based Sensing and Control System --- p.48 / Chapter 5.3 --- Experimental results of the Advanced Navigation System --- p.55 / Chapter 5.3.1 --- Manual Control for Directional Movement --- p.55 / Chapter 5.3.2 --- Object Tracking using L-K Feature Tracking method --- p.56 / Chapter 5.3.3 --- Object Tracking using CamShift method --- p.57 / Chapter 5.3.4 --- Short summary for Vision-Based Control --- p.57 / Chapter CHAPTER 6: --- FURTHER DEVELOPMENT --- p.58 / Chapter 6.1 --- Improvement on Fabrication of Ionic Flyer --- p.58 / Chapter 6.2 --- Feasibility study on decreasing the operation voltage by minimizing the Gap Distance --- p.59 / Chapter 6.3 --- Improvement of the Design of Ionic Propulsion Blimp --- p.60 / Chapter 6.3.1 --- Design of Configuration of the Navigation System --- p.60 / Chapter 6.3.2 --- Design of the Ionic Flyer --- p.60 / Chapter 6.4 --- Commercialization Issue --- p.61 / Chapter 6.4.1 --- Safety Concerns --- p.61 / Chapter 6.4.2 --- Potential Application of Ionic Propulsion Technology --- p.63 / Chapter CHAPTER 7: --- CONCLUSION --- p.64 / BIBLIOGRAPHY --- p.66 / PUBLICATIONS --- p.69

Thesis (Ph.D.)--Université Laval, 2001. / "A doctoral thesis submitted to Laval University." "November 2001." Includes bibliographical references. Also available via the World Wide Web.

Thesis (M.S.)--Missouri University of Science and Technology, 2008. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed April 25, 2008) Includes bibliographical references (p. 57).

Thesis (Ph.D.)--University of Rhode Island, 2006. / Includes bibliographical references (leaves 130-134).

Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 141-147). Also available on the World Wide Web.

Thesis (M.Eng.)--Memorial University of Newfoundland, 2004. / Bibliography: leaves 177-180.

Hall Effect Thrusters (HETs) are a form of electric propulsion device which uses external electrical energy to produce thrust. When compared to various other electric propulsion devices, HETs are excellent candidates for future orbit transfer and interplanetary missions due to their relatively simple configuration, moderate thrust capability, higher thrust to power ratio, and lower thruster mass to power ratio. Due to the short history of HETs, the current design process of a new HET is a largely empirical and experimental science, and this has resulted in previous designs being developed in a narrow design space based on experimental data without systematic investigations of parameter correlations. In addition, current preliminary low-thrust trajectory optimizations, due to inherent difficulties in solution procedure, often assume constant or linear performances with available power in their applications of electric thrusters. The main obstacles come from the complex physics involved in HET technology and relatively small amounts of experimental data. Although physical theories and numerical simulations can provide a valuable tool for design space exploration at the inception of a new HET design and preliminary low-thrust trajectory optimization, the complex physics makes theoretical and numerical solutions difficult to obtain. Numerical implementations have been quite extensively conducted in the last two decades. An investigation of current methodologies reveals that to date, none provide a proper methodology for a new HET design at the conceptual design stage and the coupled low-thrust trajectory optimization. Thus, in the first half of this work, an efficient, robust, and self-consistent numerical method for the analysis of HETs is developed with a new approach. The key idea is to divide the analysis region into two regions in terms of electron dynamics based on physical intuition. Intensive validations are conducted for existing HETs from 1 kW to 50 kW classes. The second half of this work aims to construct a simultaneous design optimization environment though collaboration with experts in low-thrust trajectory optimization where a new HET and associated optimal low-thrust trajectory can be designed simultaneously. A demonstration for an orbit raising mission shows that the constructed simultaneous design optimization environment can be used effectively and synergistically for space missions involving HETs. It is expected that the present work will aid and ease the current expensive experimental HET design process and reduce preliminary space mission design cycles involving HETs.