Projected Velocity And Efficiency Trends For A Pulsed Fusion Magnetic Nozzle, 2011 University of Alabama in Huntsville
Projected Velocity And Efficiency Trends For A Pulsed Fusion Magnetic Nozzle, Lloyd M. Jackson
Von Braun Symposium Student Posters
No abstract provided.
Continuously Variable Rotorcraft Propulsion System: Modelling And Simulation, 2011 University of Tennessee, Knoxville
Continuously Variable Rotorcraft Propulsion System: Modelling And Simulation, Naveen Kumar Vallabhaneni
Masters Theses
This study explores the variable speed operation and shift response of a prototype of a two speed single path CVT rotorcraft driveline system. Here a Comprehensive Variable Speed Rotorcraft Propulsion system Modeling (CVSRPM) tool is developed and utilized to simulate the drive system dynamics in steady forward speed condition. This investigation attempts to build upon previous variable speed rotorcraft propulsion studies by:
1) Including fully nonlinear first principles based transient gas-turbine engine model
2) Including shaft flexibility
3) Incorporating a basic flight dynamics model to account for interactions with the flight control system.
Through exploring the interactions between the various …
Precision Position, Navigation, And Timing Without The Global Positioning System, 2011 Air Force Institute of Technology
Precision Position, Navigation, And Timing Without The Global Positioning System, Kenneth A. Fisher, John F. Raquet
Faculty Publications
The NAVSTAR Global Positioning System GPS has revolutionized modern warfare. Since 2005 almost all US precision-guided munitions have used GPS targeting data. Consequently, weapons delivery systems are able to strike enemy targets with precision, often resulting in little or no collateral damage. Furthermore, nearly all military assets, including aircraft, tanks, ships, missiles, mortar rounds, cargo boxes, and dismounted Soldiers rely on the accurate position determination that GPS provides. For military users of this system, two main limitations emerge. First, the system relies on line of sight that is, the satellites must be in view of the receiver s antenna so …
Optical Flow-Based Odometry For Underground Tunnel Exploration, 2011 Air Force Institute of Technology
Optical Flow-Based Odometry For Underground Tunnel Exploration, Terra Kier
Theses and Dissertations
As military operations in degraded or GPS-denied environments continue to increase in frequency and importance, there is an increased necessity to be able to determine precision location within these environments. Furthermore, authorities are finding a record number of tunnels along the U.S.-Mexico border; therefore, underground tunnel characterization is becoming a high priority for U.S. Homeland Security as well. This thesis investigates the performance of a new image registration technique based on a two camera optical- flow configuration using phase correlation techniques. These techniques differ from other image based navigation methods but present a viable alternative increasing autonomy and answering the …
An Analysis Of Stabilizing 3u Cubesats Using Gravity Gradient Techniques And A Low Power Reaction Wheel, 2011 California Polytechnic State University, San Luis Obispo
An Analysis Of Stabilizing 3u Cubesats Using Gravity Gradient Techniques And A Low Power Reaction Wheel, Erich Bender
Aerospace Engineering
The purpose of this paper is to determine the feasibility of gravity gradient stabilizing a 3U CubeSat and then using a miniature reaction wheel to further increase stability characteristics. This paper also serves as a guide to understanding and utilizing quaternions in attitude control analysis. The analytical results show that using 33 centimeter booms and 400 gram tip masses, a 3U CubeSat will experience a maximum of 6 degrees of angular displacement in yaw and pitch, and less than .5 degrees of angular displacement in the nadir axis. A .120 kilogram miniature reaction wheel developed by Sinclair Interplanetary was introduced …
Development And Design Of A Hovering Controller For Operation In A Dynamic Asteroid Environment, 2011 California Polytechnic State University, San Luis Obispo
Development And Design Of A Hovering Controller For Operation In A Dynamic Asteroid Environment, Nicholas Georgiades
Aerospace Engineering
The project seeks to develop a dynamic model similar to that present near a solar system small body, and to design a controller suggested in other resources that will allow a spacecraft operating in this environment to hover in a fixed location in the relative reference frame of the small body. The paper discusses the derivation of the equations of motion used in the non-linear dynamic model, the design of the controller that will allow the spacecraft to hover, and the development of the control loop that will simulate the spacecraft hovering in the dynamic environment of the asteroid 1999 …
Boom Stability Control Final Project Report, 2011 California Polytechnic State University - San Luis Obispo
Boom Stability Control Final Project Report, Michael Barnes, Justin Carnahan, Daniel Fluitt, Alicia Johnstone
Mechanical Engineering
The BOOMStiC Gravity Gradient Boom and Turnstile Antenna project was developed to provide a passive attitude control system and better communications for future CubeSat satellites developed by California Polytechnic State University. The system utilizes the energy from a coilable metal spring to deploy a tip mass to a length of one meter from the side of the satellite. Calculations show the resulting gravity gradient torque causes to the satellite to settle two degrees from normal to the earth’s surface.
Imu Integration To The Cal Poly Spacecraft Attitude Dynamics Simulator Power System, 2011 California Polytechnic State University - San Luis Obispo
Imu Integration To The Cal Poly Spacecraft Attitude Dynamics Simulator Power System, Wayland Chan
Electrical Engineering
The Cal Poly Spacecraft Attitude Dynamics Simulator mimics the rotation dynamics of a spacecraft in orbit and acts as a test bed for spacecraft attitude control system development and demonstration. Prior to this project, the simulator measured its attitude dynamics from a total of seven sensors mounted on to the platform, including three micro-electromechanical system (MEMs) gyroscopes, and four motor encoders. This project entails the installation of an LN-200 high performance gyroscope, which will provide a greater measure of accuracy. The goal of this project is to design a power circuit that will integrate the LN-200 inertial measurement unit onto …
Airplane Landing Flare-The Last 5 Seconds, 2011 Minnesota State University, Mankato
Airplane Landing Flare-The Last 5 Seconds, Nihad E. Daidzic
Aviation Department Publications
No abstract provided.
Development And Analysis Of Onboard Translunar Injection Targeting Algorithms, 2011 University of Tennessee, Knoxville
Development And Analysis Of Onboard Translunar Injection Targeting Algorithms, Phillippe Lyles Winters Reed
Masters Theses
Several targeting algorithms are developed and analyzed for possible future use onboard a spacecraft. Each targeter is designed to determine the appropriate propulsive burn for translunar injection to obtain desired orbital parameters upon arrival at the moon. Primary design objectives are to minimize the computational requirements for each algorithm but also to ensure reasonable accuracy, so that the algorithm’s errors do not force the craft to conduct large mid-course corrections. Several levels of accuracy for dynamical models are explored, the convergence range and speed of each algorithm are compared, and the possible benefits of the Broyden and trust-region targeters are …
Some Considerations For Regional Airline Operations On Contaminated Runways., 2011 Minnesota State University, Mankato
Some Considerations For Regional Airline Operations On Contaminated Runways., Nihad E. Daidzic
Aviation Department Publications
No abstract provided.
Image Dependent Relative Formation Navigation For Autonomous Aerial Refueling, 2011 Air Force Institute of Technology
Image Dependent Relative Formation Navigation For Autonomous Aerial Refueling, James M. Howard
Theses and Dissertations
This research tests the feasibility, accuracy, and reliability of a predictive rendering and holistic comparison algorithm with use of an optical sensor to provide relative distance and position behind a lead or tanker aircraft. Using an accurate model of a tanker, an algorithm renders image(s) for comparison with actual collected images by a camera installed on the receiver aircraft. Based on this comparison, information used to create the rendered image(s) is used to provide the relative navigation solution required for autonomous air refueling. Given enough predicted images and processing time, this approach should reliably find an accurate solution. Building on …
Vision-Aided Autonomous Precision Weapon Terminal Guidance Using A Tightly-Coupled Ins And Predictive Rendering Techniques, 2011 Air Force Institute of Technology
Vision-Aided Autonomous Precision Weapon Terminal Guidance Using A Tightly-Coupled Ins And Predictive Rendering Techniques, Jonathan W. Beich
Theses and Dissertations
This thesis documents the development of the Vision-Aided Navigation using Statistical Predictive Rendering (VANSPR) algorithm which seeks to enhance the endgame navigation solution possible by inertial measurements alone. The eventual goal is a precision weapon that does not rely on GPS, functions autonomously, thrives in complex 3-D environments, and is impervious to jamming. The predictive rendering is performed by viewpoint manipulation of computer-generated of target objects. A navigation solution is determined by an Unscented Kalman Filter (UKF) which corrects positional errors by comparing camera images with a collection of statistically significant virtual images. Results indicate that the test algorithm is …
High Frequency Direction Finding Using Structurally Integrated Antennas On A Large Airborne Platform, 2011 Air Force Institute of Technology
High Frequency Direction Finding Using Structurally Integrated Antennas On A Large Airborne Platform, Clair F. Corbin
Theses and Dissertations
Estimating the angle of arrival (AOA) of a high frequency (HF) signal, 2-32 MHz, is challenging, especially if the antenna array is installed on a platform with dimensions on the order of one wavelength. Accurate AOA estimates are necessary for search and rescue operations and geolocating RF emitters of interest. This research examines the performance of a direction finding (DF) system using structurally integrated (SI) antennas installed on an airborne platform which allows the aircraft structure to become the receiving element. Two simulated DF systems are analyzed at 4 and 11 MHz. The relationship between the number of SI antennas …
Vision Aided Inertial Navigation System Augmented With A Coded Aperture, 2011 Air Force Institute of Technology
Vision Aided Inertial Navigation System Augmented With A Coded Aperture, Jamie R. Morrison
Theses and Dissertations
Navigation through an indoor environment is a formidable challenge for an autonomous micro air vehicle. One solution is a vision aided inertial navigation system using depth-from-defocus to determine heading and depth to features in the scene. Depth-from-defocus uses a focal blur pattern to estimate depth. As depth increases, the observable change in the focal blur is generally reduced. Consequently, as the depth of a feature to be measured increases, the measurement performance decreases. The Fresnel zone plate, used as an aperture, introduces multiple focal planes. Interference between the multiple focal planes produce changes in the aperture that extend the depth …
Coupling Vanishing Point Tracking With Inertial Navigation To Estimate Attitude In A Structured Environment, 2011 Air Force Institute of Technology
Coupling Vanishing Point Tracking With Inertial Navigation To Estimate Attitude In A Structured Environment, Dayvid Prahl
Theses and Dissertations
This research aims to obtain accurate and stable estimates of a vehicle's attitude by coupling consumer-grade inertial and optical sensors. This goal is pursued by first modeling both inertial and optical sensors and then developing a technique for identifying vanishing points in perspective images of a structured environment. The inertial and optical processes are then coupled to enable each one to aid the other. The vanishing point measurements are combined with the inertial data in an extended Kalman filter to produce overall attitude estimates. This technique is experimentally demonstrated in an indoor corridor setting using a motion profile designed to …
Kernelized Locality-Sensitive Hashing For Fast Image Landmark Association, 2011 Air Force Institute of Technology
Kernelized Locality-Sensitive Hashing For Fast Image Landmark Association, Mark A. Weems
Theses and Dissertations
As the concept of war has evolved, navigation in urban environments where GPS may be degraded is increasingly becoming more important. Two existing solutions are vision-aided navigation and vision-based Simultaneous Localization and Mapping (SLAM). The problem, however, is that vision-based navigation techniques can require excessive amounts of memory and increased computational complexity resulting in a decrease in speed. This research focuses on techniques to improve such issues by speeding up and optimizing the data association process in vision-based SLAM. Specifically, this work studies the current methods that algorithms use to associate a current robot pose to that of one previously …
Multiple Integrated Navigation Sensors For Improving Occupancy Grid Fastslam, 2011 Air Force Institute of Technology
Multiple Integrated Navigation Sensors For Improving Occupancy Grid Fastslam, Christopher P. Weyers
Theses and Dissertations
An autonomous vehicle must accurately observe its location within the environment to interact with objects and accomplish its mission. When its environment is unknown, the vehicle must construct a map detailing its surroundings while using it to maintain an accurate location. Such a vehicle is faced with the circularly defined Simultaneous Localization and Mapping (SLAM) problem. However difficult, SLAM is a critical component of autonomous vehicle exploration with applications to search and rescue. To current knowledge, this research presents the first SLAM solution to integrate stereo cameras, inertial measurements, and vehicle odometry into a Multiple Integrated Navigation Sensor (MINS) path. …
Two Dimensional Positioning And Heading Solution For Flying Vehicles Using A Line-Scanning Laser Radar (Ladar), 2011 Air Force Institute of Technology
Two Dimensional Positioning And Heading Solution For Flying Vehicles Using A Line-Scanning Laser Radar (Ladar), Brady T. Christel
Theses and Dissertations
Emerging technology in small autonomous flying vehicles requires the systems to have a precise navigation solution in order to perform tasks. In many critical environments, such as indoors, GPS is unavailable necessitating the development of supplemental aiding sensors to determine precise position. This research investigates the use of a line scanning laser radar (LADAR) as a standalone two dimensional position and heading navigation solution and sets up the device for augmentation into existing navigation systems. A fast histogram correlation method is developed to operate in real-time on board the vehicle providing position and heading updates at a rate of 10 …
Polarimetric Enhancements To Electro-Optical Aided Navigation Techniques, 2011 Air Force Institute of Technology
Polarimetric Enhancements To Electro-Optical Aided Navigation Techniques, Jeremiah D. Johnson
Theses and Dissertations
Navigation in indoor and urban environments by small unmanned systems is a topic of interest for the Air Force. The Advanced Navigation Technology Center at the Air Force Institute of Technology is continually looking for novel approaches to navigation in GPS deprived environments. Inertial sensors have been coupled with image aided concepts, such as feature tracking, with good results. However, feature density in areas with large, flat, smooth surfaces tends to be low. Polarimetric sensors have been used for surface reconstruction, surface characterization and outdoor navigation. This thesis combines aspects of some of these algorithms along with a realistic, micro-facet …