Engineering Commons^™

Multidisciplinary Design Optimization Of An Extreme Aspect Ratio Hale Uav, Bryan J. Morrisey

Master's Theses

ABSTRACT

Multidisciplinary Design Optimization of an Extreme Aspect Ratio HALE UAV

Bryan J. Morrisey

Development of High Altitude Long Endurance (HALE) aircraft systems is part of a vision for a low cost communications/surveillance capability. Applications of a multi payload aircraft operating for extended periods at stratospheric altitudes span military and civil genres and support battlefield operations, communications, atmospheric or agricultural monitoring, surveillance, and other disciplines that may currently require satellite-based infrastructure. Presently, several development efforts are underway in this field, including a project sponsored by DARPA that aims at producing an aircraft that can sustain flight for multiple years and …

Meshed Patch Antennas Integrated On Solar Cell - A Feasibility Study And Optimization, Timothy W. Turpin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis work presents the feasibility of integrating meshed patch antennas directly onto the solar cell assembly to save valuable surface real estate of a small satellite. The solar cell cover glass is used as the substrate for the patch antenna. The antenna topology is chosen to be a meshed patch so that it is transparent to light to ensure the proper operation of solar cells. We found that although there is a compromise between the antenna efficiency and see-through percentage, one is able to optimize the antenna by carefully designing the mesh. To verify the design and integration, a …

Efficiency Improvement Techniques For High Voltage Capacitor Charging Methods, Michael Islas

Electronic Theses and Dissertations

The goal of this thesis is to design and fabricate a DC-to-DC converter for use in high-voltage capacitor charging applications. The primary objectives include increasing the efficiency and reducing the cost of traditional methods used for this application. Traditional methods were not designed specifically for high-voltage capacitor charging and were thus very primitive and exhibited lower efficiency. Prior methods made use of a high voltage power supply and a current limiting resistor or control scheme. The power supply would often only operate efficiently at a single voltage value and would thus function poorly over a range used in charging a …

Fault Detection Filter Design For Linear Systems, Xiaobo Li

LSU Doctoral Dissertations

This dissertation considers residual generation for robust fault detection of linear systems with control inputs, unknown disturbances and possible faults. First, multi-objective fault detection problems such as $\mathscr{H_-}/ \mathscr{H_\infty}$, $\mathscr{H}_2/\mathscr{H_\infty}$ and $\mathscr{H_\infty}/\mathscr{H_\infty}$ have been formulated for linear continuous time-varying systems (LCTVS) in time domain for finite horizon and infinite horizon case, respectively. It is shown that under mild assumptions, the optimal solution is an observer determined by solving a standard differential Riccati equation (DRE). The solution is also extended to the case when the initial state for the system is unknown. Second, the parallel problems are also solved for linear …