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Full-Text Articles in Engineering
Improved Leaky-Mode Waveguide Spatial Light Modulators For Three Dimensional Displays, Scott Alexander Gneiting
Improved Leaky-Mode Waveguide Spatial Light Modulators For Three Dimensional Displays, Scott Alexander Gneiting
Theses and Dissertations
This thesis improves on the design of the leaky-mode spatial light modulator, LMW-SLM, presented by Dr. Smalley[1]. Improvements include: input coupling gratings, a pulsed laser input, output coupling gratings, and a 3D printed adjustable module for the stabilization of critical alignments. First, input coupling gratings reduce the cost of the LMW-SLM from $500 to around $2, a drop in cost of over two orders of magnitude. This enables multiple modulators to be used in a single display and allows for an inexpensive modular design to be created. Second, a pulsed laser input allows for image creation without the use of …
High-Speed Programmable Fpga Configuration Memory Access Using Jtag, Ammon Bradley Gruwell
High-Speed Programmable Fpga Configuration Memory Access Using Jtag, Ammon Bradley Gruwell
Theses and Dissertations
Over the past couple of decades Field Programmable Gate Arrays (FPGAs) have become increasingly useful in a variety of domains. This is due to their low cost and flexibility compared to custom ASICs. This increasing interest in FPGAs has driven the need for tools that both qualify and improve the reliability of FPGAs for applications where the reconfigurability of FPGAs makes them vulnerable to radiation upsets such as in aerospace environments. Such tools ideally work with a wide variety of devices, are highly programmable but simple to use, and perform tasks at relatively high speeds. Of the various FPGA configuration …
Configuration Scrubbing Architectures For High-Reliability Fpga Systems, Aaron Gerald Stoddard
Configuration Scrubbing Architectures For High-Reliability Fpga Systems, Aaron Gerald Stoddard
Theses and Dissertations
Field Programmable Gate Arrays (FPGAs) are being used more frequently in space applications because of their reconfigurability and intensive processing capabilities. FPGAs in environments like space are susceptible to ionizing radiation which can cause Single Event Upsets (SEUs) in the FPGA's configuration memory. These upsets may cause the programmed user design on the FPGA to deviate from its normal behavior. Space missions cannot afford to allow important data processing applications to become corrupted due to these radiation upsets.Configuration scrubbing is an upset mitigation technique that detects and corrects upsets in an FPGA's configuration memory. Configuration scrubbing periodically monitors an FPGA's …
Single Event Mitigation For Aurora Protocol Based Mgt Fpga Designs In Space Environments, Alexander Stanley Harding
Single Event Mitigation For Aurora Protocol Based Mgt Fpga Designs In Space Environments, Alexander Stanley Harding
Theses and Dissertations
This work has extended an existing Aurora protocol for high-speed serial I/O between FPGAs to provide greater fault recovery in the presence of high-energy radiation. To improve on the Aurora protocol, additional resets that affect larger portions of the system were used. Detection for additional error modes that occurred but were not detected by the Aurora protocol was designed. Radiation testing was performed on the Aurora protocol with the additional mitigation hardware. The test gathered large amounts of data on the various error modes of the Aurora protocol and how the additional mitigation circuitry affected the system. The test results …
Understanding Design Requirements For Building Reliable, Space-Based Fpga Mgt Systems Based On Radiation Test Results, Kevin M. Ellsworth
Understanding Design Requirements For Building Reliable, Space-Based Fpga Mgt Systems Based On Radiation Test Results, Kevin M. Ellsworth
Theses and Dissertations
Space-based computing applications often demand reliable, high-bandwidth communication systems. FPGAs with Mulit-Gigabit Transceivers (MGTs) provide an effective platform for such systems, but it is important that system designers understand the possible susceptibilities MGTs present to the system. Previous work has provided a foundation for understanding the susceptibility of raw FPGA MGTs but has fallen short of testing MGTs as part of a larger system. This work focuses on answering the questions MGT system designers need to know in order to build a reliable space-based MGT system. Two radiation tests were performed with a test architecture built on the Aurora protocol. …
An Onboard Vision System For Unmanned Aerial Vehicle Guidance, Barrett Bruce Edwards
An Onboard Vision System For Unmanned Aerial Vehicle Guidance, Barrett Bruce Edwards
Theses and Dissertations
The viability of small Unmanned Aerial Vehicles (UAVs) as a stable platform for specific application use has been significantly advanced in recent years. Initial focus of lightweight UAV development was to create a craft capable of stable and controllable flight. This is largely a solved problem. Currently, the field has progressed to the point that unmanned aircraft can be carried in a backpack, launched by hand, weigh only a few pounds and be capable of navigating through unrestricted airspace. The most basic use of a UAV is to visually observe the environment and use that information to influence decision making. …
Stabilization And Control Of A Quad-Rotor Micro-Uav Using Vision Sensors, Spencer G. Fowers
Stabilization And Control Of A Quad-Rotor Micro-Uav Using Vision Sensors, Spencer G. Fowers
Theses and Dissertations
Quad-rotor micro-UAVs have become an important tool in the field of indoor UAV research. Indoor flight poses problems not experienced in outdoor applications. The ability to be location- and movement-aware is paramount because of the close proximity of obstacles (walls, doorways, desks). The Helio-copter, an indoor quad-rotor platform that utilizes a compact FPGA board called Helios has been developed in the Robotic Vision Lab at Brigham Young University. Helios allows researchers to perform on-board vision processing and feature tracking without the aid of a ground station or wireless transmission. Using this on-board feature tracking system a drift stabilization control system …
Real-Time Implementation Of Vision Algorithm For Control, Stabilization, And Target Tracking For A Hovering Micro-Uav, Beau J. Tippetts
Real-Time Implementation Of Vision Algorithm For Control, Stabilization, And Target Tracking For A Hovering Micro-Uav, Beau J. Tippetts
Theses and Dissertations
A lightweight, powerful, yet efficient quad-rotor platform was designed and constructed to obtain experimental results of completely autonomous control of a hovering micro-UAV using a complete on-board vision system. The on-board vision and control system is composed of a Helios FPGA board, an Autonomous Vehicle Toolkit daughterboard, and a Kestrel Autopilot. The resulting platform is referred to as the Helio-copter. An efficient algorithm to detect, correlate, and track features in a scene and estimate attitude information was implemented with a combination of hardware and software on the FPGA, and real-time performance was obtained. The algorithms implemented include a Harris feature …
Three Enabling Technologies For Vision-Based, Forest-Fire Perimeter Surveillance Using Multiple Unmanned Aerial Systems, Ryan S. Holt
Three Enabling Technologies For Vision-Based, Forest-Fire Perimeter Surveillance Using Multiple Unmanned Aerial Systems, Ryan S. Holt
Theses and Dissertations
The ability to gather and process information regarding the condition of forest fires is essential to cost-effective, safe, and efficient fire fighting. Advances in sensory and autopilot technology have made miniature unmanned aerial systems (UASs) an important tool in the acquisition of information. This thesis addresses some of the challenges faced when employing UASs for forest-fire perimeter surveillance; namely, perimeter tracking, cooperative perimeter surveillance, and path planning. Solutions to the first two issues are presented and a method for understanding path planning within the context of a forest-fire environment is demonstrated. Both simulation and hardware results are provided for each …