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Navigation, Guidance, Control and Dynamics Commons

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An Exploration Of Error-Correcting Codes For Use In Noise-Prone Satellite Environments, Min W. Kang 2018 Air Force Institute of Technology

An Exploration Of Error-Correcting Codes For Use In Noise-Prone Satellite Environments, Min W. Kang

Theses and Dissertations

Satellites are crucial for the modern world to function properly as they provide Global Navigation Satellite System (GNSS) and global communication. However, the data that is stored on these satellites can be corrupted by the radiation found in space, and its bits can be improperly flipped. In the past, Forward Error Correction (FEC) algorithms were selected based on their strength and implemented to correct these bit flips back to their original values. This thesis seeks to determine if the strength of the FEC algorithms Reed Solomon (RS) code and Reed Solomon Product Code (RSPC) directly translates to their effectiveness. These ...


Modeling A Space-Based Quantum Link, Alexander W. Duchane 2018 Air Force Institute of Technology

Modeling A Space-Based Quantum Link, Alexander W. Duchane

Theses and Dissertations

Quantum sources and single photon detectors have improved, allowing quantum algorithms for communication, encryption, computing, and sensing to transition from theory and small-scale laboratory experiments to field experiments. One such quantum algorithm, Quantum Key Distribution, uses optical pulses to generate shared random bit strings between two locations. These shared bit strings can be turned into encryption keys to be used as a one-time-pad or integrated with symmetric encryption techniques such as the Advanced Encryption Standard. This method of key generation and encryption is resistant to future advances in quantum computing which significantly degrade the effectiveness of current asymmetric key sharing ...


Integrity Monitoring For Automated Aerial Refueling: A Stereo Vision Approach, Thomas R. Stuart 2018 Air Force Institute of Technology

Integrity Monitoring For Automated Aerial Refueling: A Stereo Vision Approach, Thomas R. Stuart

Theses and Dissertations

Unmanned aerial vehicles (UAVs) increasingly require the capability to y autonomously in close formation including to facilitate automated aerial refueling (AAR). The availability of relative navigation measurements and navigation integrity are essential to autonomous relative navigation. Due to the potential non-availability of the global positioning system (GPS) during military operations, it is highly desirable that relative navigation can be accomplished without the use of GPS. This paper develops two algorithms designed to provide relative navigation measurements solely from a stereo image pair. These algorithms were developed and analyzed in the context of AAR using a stereo camera system modeling that ...


Stabilized Rpa Flight In Building Proximity Operations, Michael M. Kaniut 2018 Air Force Institute of Technology

Stabilized Rpa Flight In Building Proximity Operations, Michael M. Kaniut

Theses and Dissertations

The thesis seeks a solution to the requirement for a highly reliable and capable Unmanned Air Vehicle (UAV) to support a wide array of missions and applications that require close proximity flight to structures. The scope of the project includes the drafting of a concept of operations (CONOPs) describing how the mission requirements might be met using the sensor, operators, and air vehicle described here in. The demonstration of the wall-following section of that CONOPs is performed by cart testing a custom algorithm and evaluating its ability to react to its environment. Finally, a flight test was performed to characterize ...


Algorithms For Small Satellite Formation Flying, Robert B. LaRue 2018 Air Force Institute of Technology

Algorithms For Small Satellite Formation Flying, Robert B. Larue

Theses and Dissertations

This thesis presents algorithms for spacecraft formation flying using impulsive thrust and low-thrust methods. The general circular orbit formation initial conditions are derived in terms of equinoctial elements. Physical significance of the bounded relative motion parameters is presented for the case of general circular orbits. The developed algorithms are posed in terms of equinoctial elements for a singularity-free approach. The algorithms are assessed by numerical propagation of the inertial equations of motion with J2 and drag perturbations. Methods are presented for minimizing the ΔV required for formation initialization. An examination of the performance of open-loop and closed-loop control is provided ...


Optimal Trajectory Generation In A Dynamic Multi-Body Environment Using A Pseudospectral Method, Jacob A. Dahlke 2018 Air Force Institute of Technology

Optimal Trajectory Generation In A Dynamic Multi-Body Environment Using A Pseudospectral Method, Jacob A. Dahlke

Theses and Dissertations

High-altitude parking orbits could provide resiliency to the military space infrastructure by providing redundancy in key assets, allowing for rapid reconstitution of underperforming satellites. When analyzing trajectories in a high-altitude regime, two-body models of Keplerian motion become less accurate since the gravitational effects of other bodies are no longer negligible. To provide a higher fidelity model of the dynamics in a high-altitude regime, a multiple-body model can be used. In the Earth-Moon system, a spacecraft operating in the high-altitude regime can be modeled with three-body dynamics. With certain simplifying assumptions, the model is called the circular-restricted three-body problem (CR3BP). The ...


Estimation Of 3d Orientation From Inertial Sensors With Different/Nonuniform Sampling, Soulaimane Berkane 2018 sberkane@uwo.ca

Estimation Of 3d Orientation From Inertial Sensors With Different/Nonuniform Sampling, Soulaimane Berkane

Western Research Forum

No abstract provided.


Navigation Using Vector And Tensor Measurements Of The Earth's Magnetic Anomaly Field, Lauren A. Mount 2018 Air Force Institute of Technology

Navigation Using Vector And Tensor Measurements Of The Earth's Magnetic Anomaly Field, Lauren A. Mount

Theses and Dissertations

This research explores the viability of using a navigation system that relies on measurements of the magnetic anomaly field as an alternative to GPS navigation. Previous research has been conducted on developing a navigation system using the intensity of the Earth's magnetic anomaly field as an alternative signal. This research focuses on using vector and tensor measurements, as opposed to scalar measurements of the anomaly field, as a means of obtaining accurate position and orientation solutions. This paper presents two navigation systems. The first uses an Extended Kalman Filter (EKF) with vector measurements of the magnetic anomaly field to ...


Effects Of Position Uncertainty On Passive Multistatic Sar Resolution Measures, Duy K. Nguyen 2018 Air Force Institute of Technology

Effects Of Position Uncertainty On Passive Multistatic Sar Resolution Measures, Duy K. Nguyen

Theses and Dissertations

Given numerous exciting potentials including substantial cost savings, passive multistatic synthetic aperture radar (PMSAR) has been gaining more attention in the radar community. However, PMSAR research efforts such as emitters of opportunity selection thus far have not considered radar position uncertainty. Seeking to fill this knowledge gap, we run Monte Carlo trials to simulate transmitter position uncertainty and examine the effects on the multistatic resolution of radar sets of different geometries, center frequencies and bandwidths. By monitoring the 3dB contour of the multistatic point spread function, we find that the multistatic resolution worsens on average and the data spread grows ...


Some Insights Into The Migration Of Double Imaginary Roots Under Small Deviation Of Two Parameters, Dina Alina Irofti, Keqin Gu, Islam Boussaada, Silviu-Iulian Niculescu 2018 Laboratoire des Signaux et Systèmes (L2S) CNRS-CentraleSupélec-Université Paris-Sud, 3 rue Joliot-Curie, 91192 Gif-sur-Yvette cedex, France

Some Insights Into The Migration Of Double Imaginary Roots Under Small Deviation Of Two Parameters, Dina Alina Irofti, Keqin Gu, Islam Boussaada, Silviu-Iulian Niculescu

SIUE Faculty Research, Scholarship, and Creative Activity

This paper studies the migration of double imaginary roots of the systems’ characteristic equation when two parameters are subjected to small deviations. The proposed approach covers a wide range of models. Under the least degeneracy assumptions, we found that the local stability crossing curve has a cusp at the point that corresponds to the double root, and it divides the neighborhood of this point into an S-sector and a G-sector. When the parameters move into the G-sector, one of the roots moves to the right halfplane, and the other moves to the left half-plane. When the parameters move into the ...


Unmanned Aerial Systems: Research, Development, Education & Training At Embry-Riddle Aeronautical University, Michael P. Hickey 2018 Embry-Riddle Aeronautical University

Unmanned Aerial Systems: Research, Development, Education & Training At Embry-Riddle Aeronautical University, Michael P. Hickey

Publications

With technological breakthroughs in miniaturized aircraft-related components, including but not limited to communications, computer systems and sensors, state-of-the-art unmanned aerial systems (UAS) have become a reality. This fast-growing industry is anticipating and responding to a myriad of societal applications that will provide new and more cost-effective solutions that previous technologies could not, or will replace activities that involved humans in flight with associated risks.

Embry-Riddle Aeronautical University has a long history of aviation-related research and education, and is heavily engaged in UAS activities. This document provides a summary of these activities, and is divided into two parts. The first part ...


Analysis And Verification Of Cost-Effective Design Modifications To Commercially Available Fixed-Wing Unmanned Aerial Vehicle To Improve Performance, Stability And Control Characteristics, And Structural Integrity, A Ram (Bella) Kim 2018 Iowa State University

Analysis And Verification Of Cost-Effective Design Modifications To Commercially Available Fixed-Wing Unmanned Aerial Vehicle To Improve Performance, Stability And Control Characteristics, And Structural Integrity, A Ram (Bella) Kim

A Ram (Bella) Kim

In this work, several cost-effective design modifications were made to a commercially available fixed-wing unmanned aerial vehicle in order to improve overall performance and reliability. These modifications included the addition of 3D-printed winglets to improve aerodynamic performance, applying fiberglass reinforcement to areas of structural concern, the addition of rudder control surfaces for improved control authority, increasing the length of the empennage booms for both stability and control improvements, and the addition of dorsal fins to improve vertical fin stall characteristics. Design methodology and manufacturing processes were outlined, a cost breakdown was presented, and results from dynamic analysis were validated through ...


Strong Stability Of A Class Of Difference Equations Of Continuous Time And Structured Singular Value Problem, Qian Ma, Keqin Gu, Narges Choubedar 2018 School of Automation, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China

Strong Stability Of A Class Of Difference Equations Of Continuous Time And Structured Singular Value Problem, Qian Ma, Keqin Gu, Narges Choubedar

SIUE Faculty Research, Scholarship, and Creative Activity

This article studies the strong stability of scalar difference equations of continuous time in which the delays are sums of a number of independent parameters τi, i = 1, 2, . . . , K. The characteristic quasipolynomial of such an equation is a multilinear function of e−τis. It is known that the characteristic quasipolynomial of any difference equation set in the form of one-delay-per-scalar-channel (ODPSC) model is also in such a multilinear form. However, it is shown in this article that some multilinear forms of quasipolynomials are not characteristic quasipolynomials of any ODPSC difference equation set. The equivalence between local strong stability, the ...


Strong Stability Of A Class Of Difference Equations Of Continuous Time And Structured Singular Value Problem, Qian Ma, Keqin Gu, Narges Choubedar 2018 Nanjing University of Science and Technology

Strong Stability Of A Class Of Difference Equations Of Continuous Time And Structured Singular Value Problem, Qian Ma, Keqin Gu, Narges Choubedar

SIUE Faculty Research, Scholarship, and Creative Activity

This article studies the strong stability of scalar difference equations of continuous time in which the delays are sums of a number of independent parameters tau_i, i = 1, 2, . . . ,K. The characteristic quasipolynomial of such an equation is a multilinear function of exp(-tau_i s). It is known that the characteristic quasipolynomial of any difference equation set in the form of one-delayper- scalar-channel (ODPSC) model is also in such a multilinear form. However, it is shown in this article that some multilinear forms of quasipolynomials are not characteristic quasipolynomials of any ODPSC difference equation set. The equivalence between local strong ...


Design Of Shape-Conforming Nosecone For Optimal Fluid Flow From Transonic To Supersonic Range, Anna Tombazzi 2018 The University of Akron

Design Of Shape-Conforming Nosecone For Optimal Fluid Flow From Transonic To Supersonic Range, Anna Tombazzi

Williams Honors College, Honors Research Projects

Modern flight vehicles, such as rockets, missiles, and airplanes, experience a force caused by forebody wave drag during the flight. This drag force is induced when the frontal point of each vehicle breaks the pressure wave during flight. Efforts to reduce this wave drag force to improve flight efficiency include modifying the nosecone profile of the flight vehicles to lower the drag force.

This project revolved around creating a design to make the transformation of nosecone shapes from a ¾ Parabolic profile to a ½ Power Series profile possible, mid-flight. Using a novel nosecone assembly, shape memory alloys (SMAs) and ...


Autonomous Uav Battery Swapping, Reed Jacobsen, Nikolai Ruhe, Nathan Dornback 2018 The University of Akron

Autonomous Uav Battery Swapping, Reed Jacobsen, Nikolai Ruhe, Nathan Dornback

Williams Honors College, Honors Research Projects

One of the main hindrances of unmanned aerial vehicle (UAV) technology are power constraints. One way to alleviate some power constraints would be for two UAVs to exchange batteries while both are in flight. Autonomous mid-air battery swapping will expand the scope of UAV technology by allowing for indefinite flight times and longer missions. A single board computer will control each UAV’s flight software to respond to inputs to align with each other mid-flight. When the two UAVs have joined, mechanical components will exchange a depleted battery on the worker UAV for a freshly charged battery that belongs to ...


Discrete-Time Adaptive Control Algorithms For Rejection Of Sinusoidal Disturbances, Mohammadreza Kamaldar 2018 University of Kentucky

Discrete-Time Adaptive Control Algorithms For Rejection Of Sinusoidal Disturbances, Mohammadreza Kamaldar

Theses and Dissertations--Mechanical Engineering

We present new adaptive control algorithms that address the problem of rejecting sinusoids with known frequencies that act on an unknown asymptotically stable linear time-invariant system. To achieve asymptotic disturbance rejection, adaptive control algorithms of this dissertation rely on limited or no system model information. These algorithms are developed in discrete time, meaning that the control computations use sampled-data measurements. We demonstrate the effectiveness of algorithms via analysis, numerical simulations, and experimental testings. We also present extensions to these algorithms that address systems with decentralized control architecture and systems subject to disturbances with unknown frequencies.


Instrumentation And Inertial Navigation Systems Design For Tensegrity Robot Implementations, Scott Edward Harper 2018 West Virginia University

Instrumentation And Inertial Navigation Systems Design For Tensegrity Robot Implementations, Scott Edward Harper

Graduate Theses, Dissertations, and Problem Reports

One of the major challenges faced when developing missions for the exploration of planetary bodies is the risk these terrains pose on the science platform when using a traditional lander or wheeled rover. One means of developing platforms to traverse these harsh terrains is to utilize mobility systems comprised of tensegrity structures. These structures have the capacity to distribute loads across a network of axially loaded members such that they can be constructed in a very lightweight manner and morph their geometries when required. In literature, there has been significant progress in simulated environments to utilize tensegrity structures as mobility ...


Space Operations In The Suborbital Space Flight Simulator And Mission Control Center: Lessons Learned With Xcor Lynx, Pedro Llanos, Christopher Nguyen, David Williams, Kim O. Chambers Ph.D., Erik Seedhouse, Robert Davidson 2018 Embry-Riddle Aeronautical University

Space Operations In The Suborbital Space Flight Simulator And Mission Control Center: Lessons Learned With Xcor Lynx, Pedro Llanos, Christopher Nguyen, David Williams, Kim O. Chambers Ph.D., Erik Seedhouse, Robert Davidson

Journal of Aviation/Aerospace Education & Research

This study was conducted to better understand the performance of the XCOR Lynx vehicle. Because the Lynx development was halted, the best knowledge of vehicle dynamics can only be found through simulator flights. X-Plane 10 was chosen for its robust applications and accurate portrayal of dynamics on a vehicle in flight. The Suborbital Space Flight Simulator (SSFS) and Mission Control Center (MCC) were brought to the Applied Aviation Sciences department in fall 2015 at Embry-Riddle Aeronautical University, Daytona Beach campus. This academic and research tool is a department asset capable of providing multiple fields of data about suborbital simulated flights ...


Design And Evaluation Of Novel Attitude Estimation System Using Mems Sensors For Indoor Uas, Joshua Bruce Milam 2018 WVU

Design And Evaluation Of Novel Attitude Estimation System Using Mems Sensors For Indoor Uas, Joshua Bruce Milam

Graduate Theses, Dissertations, and Problem Reports

Most small unmanned aerial systems in use today, employ extended Kalman filter sensor fusion algorithms in order to provide accurate estimations of attitude or orientation. These complex algorithms use measurements from GPS receivers and magnetometer sensors that can be rendered useless in GPS denied environments or areas of significant magnetic interference, such as inside buildings or other structures. The complexity of these algorithms makes them inaccessible for some researchers and hobbyists who wish to code their own attitude estimation algorithms. This complexity is also computationally expensive and requires processors that are powerful enough to operate the algorithms along with any ...


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