Engineering Commons^™

Spin Recovery Analysis On A Simulation Model Of The Nasa F-18 High Alpha Research Vehicle (Harv) Using Thrust Vectoring, Brock M. Dolly

Graduate Theses, Dissertations, and Problem Reports

In the early years of aviation, spins were poorly understood and frequently fatal. With just over a century of research and experiments dedicated to spins, today’s aviation world has a very firm grasp on spin aerodynamics. Most fighter aircraft have airframes and control surfaces specifically designed to ensure the ability of departure from the possible spin modes the aircraft can enter. An alternative and/or additional approach is given by thrust vectoring. Implementing thrust vectoring into spin recovery can potentially save an aircraft and/or the life of the pilot in situation where control-surface-only spin recovery is not able to recover the …

Design And Validation Of An Aerodynamic System For A Formula Sae® Vehicle Using Vehicle Dynamic Simulation And Experimentation, Evan S. Cole

Graduate Theses, Dissertations, and Problem Reports

This thesis presents the design, simulation, and experimental validation for the aerodynamic system for a Formula SAE® vehicle. The Society of Automotive Engineers ® (SAE) hosts a collegiate competition annually called Formula SAE® where students design, fabricate, and test a small “formula style” vehicle. The vehicle performs in relatively slow maneuvers, around different courses and tests to evaluate the vehicle’s overall performance. Over the years, collegiate teams have put significant research into the design and manufacturing of the aerodynamics of these vehicles. In order to justify this undertaking for future teams at West Virginia University’s Formula SAE® program, a comprehensive …

Missile Modeling And Simulation Of Nominal And Abnormal Scenarios Resulting From External Damage, James Manuel Floyd Iii

Graduate Theses, Dissertations, and Problem Reports

This thesis presents the development of a six-degree-of-freedom flight simulation environment for missiles and the application thereof to investigate the flight performance of missiles when exposed to external damage. The simulation environment was designed to provide a realistic representation of missile flight dynamics including aerodynamic effects, flight control systems, and self-guidance. The simulation environment was designed to be modular, expandable, and include realistic models of external damage to the missile body obtained by adversarial counteraction.

The primary objective of this research was to examine missile flight performance when subjected to unspecified external damage, including changes in trajectory, stability, and controllability, …

Optimal Deployment Of Air Vehicle As Communication Relay For Multiple Ground Vehicles, Juan David Pabon Arias

Graduate Theses, Dissertations, and Problem Reports

Heterogeneous teams of both air and ground mobile vehicles can combine the advantages of mobility, sensing capability, and operation time when performing complex tasks. However, when ground vehicles operate in cluttered environments with randomized obstacles, they may experience line of sight (LoS) obstructions and loss of communication due to those obstacles. To mitigate this issue, an airborne relay can be positioned in the vicinity of the ground vehicles to aid communication by establishing two-hop communication links between the vehicles.

This thesis develops an analytical framework to calculate the probability of spanning a two-hop communication between a pair of ground vehicles …

Probabilistic Short Term Solar Driver Forecasting With Neural Network Ensembles, Joshua Daniell

Graduate Theses, Dissertations, and Problem Reports

Commonly utilized space weather indices and proxies drive predictive models for thermosphere density, directly impacting objects in low-Earth orbit (LEO) by influencing atmospheric drag forces. A set of solar proxies and indices (drivers), F_10.7, S_10.7, M_10.7, and Y_10.7, are created from a mixture of ground based radio observations and satellite instrument data. These solar drivers represent heating in various levels of the thermosphere and are used as inputs by the JB2008 empirical thermosphere density model. The United States Air Force (USAF) operational High Accuracy Satellite Drag Model (HASDM) relies on JB2008, and …

Optimal Path Planning For Aerial Robots Using Genetic Algorithm, Anna Puigvert I Juan

Graduate Theses, Dissertations, and Problem Reports

This thesis presents a path optimization solution for a robot in two different constrained 3-dimensional (3D) environments. The robot is required to travel from its current position to a goal position following minimum cost paths (optimal paths). The first environment has 3D obstacles that interfere with the robot’s path. The path cost for this environment accounts for the minimum distance traveled by the robot from the start to the goal position while avoiding obstacles. The second environment is the atmosphere of Venus, specifically a flyable region of this atmosphere with characteristics similar to Earth’s. This environment has strong westward winds …

Integrated Immunity-Based Methodology For Uav Monitoring And Control, Ryan G. Mclaughlin

Graduate Theses, Dissertations, and Problem Reports

A general integrated and comprehensive health management framework based on the artificial immune system (AIS) paradigm is formulated and an automated system is developed and tested through simulation for the detection, identification, evaluation, and accommodation (DIEA) of abnormal conditions (ACs) on an unmanned aerial vehicle (UAV). The proposed methodology involves the establishment of a body of data to represent the function of the vehicle under nominal conditions, called the self, and differentiating this operation from that of the vehicle under an abnormal condition, referred to as the non-self. Data collected from simulations of the selected UAV autonomously flying a set …

Robust State Estimation Methods For Robotics Applications, Shounak Das

Graduate Theses, Dissertations, and Problem Reports

State estimation is an integral component of any autonomous robotic system. Finding the correct position, velocity, and orientation of an agent in its environment enables it to do other tasks like mapping and interacting with the environment, and collaborating with other agents. State estimation is achieved by using data obtained from multiple sensors and fusing them in a probabilistic framework. These include inertial data from Inertial Measurement Unit (IMU), images from camera, range data from lidars, and positioning data from Global Navigation Satellite Systems (GNSS) receivers. The main challenge faced in sensor-based state estimation is the presence of noisy, erroneous, …

Motion Planning In Artificial And Natural Vector Fields, Bernardo Martinez Rocamora Junior

Graduate Theses, Dissertations, and Problem Reports

This dissertation advances the field of autonomous vehicle motion planning in various challenging environments, ranging from flows and planetary atmospheres to cluttered real-world scenarios. By addressing the challenge of navigating environmental flows, this work introduces the Flow-Aware Fast Marching Tree algorithm (FlowFMT*). This algorithm optimizes motion planning for unmanned vehicles, such as UAVs and AUVs, navigating in tridimensional static flows. By considering reachability constraints caused by vehicle and flow dynamics, flow-aware neighborhood sets are found and used to reduce the number of calls to the cost function. The method computes feasible and optimal trajectories from start to goal in challenging …

Development And Verification Of Flight Data Informed Performance Estimation And Prediction Simulation Tool For Small Electrical Multi-Rotor Uav, Nicholas Scott Borelle

Graduate Theses, Dissertations, and Problem Reports

While small scale multi-rotor aircraft are becoming an increasingly large market with applications emerging every day, their ability to have both a high endurance/long range and a high speed/performance flight is severely limited. This leads to uncertainty in mission planning and aircraft design, specifically when deciding mission length and available on-board energy. Uncertainty like this leads to an increased chance of failure to complete the mission, and a failure to recover the aircraft. Considering that these aircraft are used by everyone from hobbyists to commercial companies to military personnel, the applications and missions being flown carry importance and a serious …

Probabilistic Space Weather Modeling And Forecasting For The Challenge Of Orbital Drag In Space Traffic Management, Richard J. Licata Iii

Graduate Theses, Dissertations, and Problem Reports

In the modern space age, private companies are crowding the already-congested low Earth orbit (LEO) regime with small satellite mega constellations. With over 25,000 objects larger than 10 cm already in LEO, this rapid expansion is forcing us towards the enterprise on Space Traffic Management (STM). STM is an operational effort that focuses on conjunction assessment and collision avoidance between objects. While the equations of motion for objects in orbit are well-known, there are many uncertain parameters that result in the uncertainty of an object's future position. The force that the atmosphere exerts on satellite - known as drag - …

Aerodynamic Performance Of A Biologically Inspired Hybrid Plasma-Mechanical Flow Control And Sensing Device, Joseph Dygert

Graduate Theses, Dissertations, and Problem Reports

The continued high global demand for passenger and freight air traffic along with increased use of unmanned aerial vehicles operating in broader Reynolds number regimes has resulted in researchers examining alternative technologies, which would result in safer, more reliable, and superior performing aircraft. Aerodynamic flow control may be one of the most promising approaches to solving this problem, having already proven its ability to enable higher flow efficiency while simultaneously improving overall control of flow behavior such as laminar-to-turbulent transition. Recent research in aerodynamic flow control has seen a pronounced growth in the areas of biomimicry and plasma flow control …

Precise Landing Of Vtol Uavs Using A Tether, Jeremy W. Rathjen

Graduate Theses, Dissertations, and Problem Reports

Unmanned Aerial Vehicles (UAVs), also known as drones, are often considered the solution to complex robotics problems. The significant freedom to explore an environment is a major reason why UAVs are a popular choice for automated solutions. UAVs, however, have a very limited flight time due to the low capacity and weight ratio of current batteries. One way to extend the vehicles' flight time is to use a tether to provide power from external batteries, generators on the ground, or another vehicle. Attaching a tether to a vehicle may constrain its navigation but it may also create some opportunities for …

Aerodynamic Analysis Of Damage State Missiles Using Overset Meshing Techniques For Application To Computational Fluid Dynamics Simulation, Jonathan A. D'Alessio

Graduate Theses, Dissertations, and Problem Reports

Significant research over the years has aimed to redefine the flight capabilities of aircraft after sustaining structural damage to critical components. Flight survivability and controllability are key areas of concern when designing fault-tolerant flight control systems to handle a wide range of potential scenarios. However, there is a lack of research on the impact of physically damaged missile systems. Missile counter-defense and intercept capabilities have become more advanced as the United States has focused heavily on these areas over the years. Damaged missiles due to a kinetic intercept capability present an opportunity for analysis of the post-damage implications on flight …

Development Of Collision Resilient Drone For Flying In Cluttered Environment, Al Mahmud

Graduate Theses, Dissertations, and Problem Reports

The use of multi-rotor aerial vehicles, also known as drones, has increased significantly in the last decade due to their ease of use and applicability to an extended range of functions. Therefore, the importance of making these vehicles safe, for both themselves and the people around them, has also increased. A clear solution to this problem is the development of algorithms that generate collision-free paths using different sensors. However, even with such onboard computation, avoiding a collision is not always possible. Thus, the use of a protective structure (cage) around the aerial vehicle is a solution to keep it safe …

Planning Algorithms Under Uncertainty For A Team Of A Uav And A Ugv For Underground Exploration, Matteo De Petrillo

Graduate Theses, Dissertations, and Problem Reports

Robots’ autonomy has been studied for decades in different environments, but only recently, thanks to the advance in technology and interests, robots for underground exploration gained more attention. Due to the many challenges that any robot must face in such harsh environments, this remains an challenging and complex problem to solve.

As technology became cheaper and more accessible, the use of robots for underground ex- ploration increased. One of the main challenges is concerned with robot localization, which is not easily provided by any Global Navigation Services System (GNSS). Many developments have been achieved for indoor mobile ground robots, making …

Comparative Analysis Of Different Classes Of On-Line State Estimators For Aerodynamics Angles And True Airspeed Sensors For Applications To The Sensor Failure Problem, Alexandra Anne Augsberger

Graduate Theses, Dissertations, and Problem Reports

Throughout aviation history, there have been numerous incidents due to sensor failure that have caused a range of issues from loss of control of the aircraft to crashes resulting in loss of human life. Although there are many hardware-based solutions to this problem, the threat of control hardware failure still exists. This work investigates the efficacy of implementing neural networks (NN) and Kalman filters (KF) to solve the accommodation portion of the sensor failure detection, identification, and accommodation (SFDIA) problem through on-line real-time estimation of specific aircraft dynamic parameters. The implementation of on-line estimation architectures into the aircraft flight control …

Localization Algorithms For Gnss-Denied And Challenging Environments, Chizhao Yang

Graduate Theses, Dissertations, and Problem Reports

In this dissertation, the problem about localization in GNSS-denied and challenging environments is addressed. Specifically, the challenging environments discussed in this dissertation include two different types, environments including only low-resolution features and environments containing moving objects. To achieve accurate pose estimates, the errors are always bounded through matching observations from sensors with surrounding environments. These challenging environments, unfortunately, would bring troubles into matching related methods, such as "fingerprint" matching, and ICP. For instance, in environments with low-resolution features, the on-board sensor measurements could match to multiple positions on a map, which creates ambiguity; in environments with moving objects included, the …

Planetary Rover Inertial Navigation Applications: Pseudo Measurements And Wheel Terrain Interactions, Cagri Kilic

Graduate Theses, Dissertations, and Problem Reports

Accurate localization is a critical component of any robotic system. During planetary missions, these systems are often limited by energy sources and slow spacecraft computers. Using proprioceptive localization (e.g., using an inertial measurement unit and wheel encoders) without external aiding is insufficient for accurate localization. This is mainly due to the integrated and unbounded errors of the inertial navigation solutions and the drifted position information from wheel encoders caused by wheel slippage. For this reason, planetary rovers often utilize exteroceptive (e.g., vision-based) sensors. On the one hand, localization with proprioceptive sensors is straightforward, computationally efficient, and continuous. On the other …

Flow Field Measurement And Qualification Of The West Virginia University Environmental Wind Tunnel, Katherine Mary Reid

Graduate Theses, Dissertations, and Problem Reports

In 2013 West Virginia University acquired an Environmental Wind Tunnel from Cornell University. Due to the state of the tunnel, elements of the tunnel were redesigned and rebuilt at the West Virginia University Hangar in Morgantown, West Virginia. The motivation of this research was to evaluate and qualify the flow field within the test section of this redesigned and reconstructed wind tunnel. The tunnel has many uses for the university, including outside research opportunities as well as educational purposes for students in the Aerospace Engineering Department. The methods employed for this effort included developing a grid of pitot tubes to …

Updates And Improvements To The Satellite Drag Coefficient Response Surface Modeling Toolkit, Phillip Logan Sheridan

Graduate Theses, Dissertations, and Problem Reports

For satellites in Low Earth Orbit, the drag coefficient is a major area of uncertainty. Researchers at the Los Alamos National Laboratory have created a Response Surface Modeling (RSM) toolkit to provide the community with a resource for simulating and modeling satellite drag coefficients in Free Molecular Flow. The toolkit combines the high fidelity of numerical simulation techniques with the speed of regression modeling. Specifically, it uses a training sample of drag coefficients simulated with the Test Particle Monte Carlo method with the robust Gaussian Process Regression approach. The RSM toolkit is the prime process to become a toolkit of …

Uncertainty Estimation For Stereo Visual Odometry, Derek W. Ross

Graduate Theses, Dissertations, and Problem Reports

Over the past few decades, unmanned aerial vehicles (UAVs) have been increasingly popular for use in locations that are lacking, or have unreliable global navigation satellite system (GNSS) availability. One of the more popular localization techniques for quadrotors is the use of visual odometry (VO) through monocular, RGB-D, or stereo cameras. With primary applications in the context of Simultaneous Localization And Mapping (SLAM) and indoor navigation, VO is largely used in combination with other sensors through Bayesian filters, namely Extended Kalman Filter (EKF) or Particle Filter. This work investigates the accuracy of two standard covariance estimation techniques for a feature-based …

Active Localization For Robotic Systems: Algorithms And Cost Metrics, Jared Strader

Graduate Theses, Dissertations, and Problem Reports

In the real world, a robotic system must operate in the presence of motion and sensing uncertainty. This is caused by the fact that the motion of a robotic system is stochastic due to disturbances from the environment, and the states are only partially observable due noise in the sensor measurements. As a result, the true state of a robotic system is unknown, and estimation techniques must be used to infer the states from the belief, which is the probability distribution over all possible states. Accordingly, a robotic system must be capable of reasoning about the quality of the belief …

Increasing The Reliability Of Software Systems On Small Satellites Using Software-Based Simulation Of The Embedded System, Matthew D. Grubb

Graduate Theses, Dissertations, and Problem Reports

The utility of Small Satellites (SmallSats) for technology demonstrations and scientific research has been proven over the past few decades by governments, universities, and private companies. While the research and technology demonstration objectives that can be provided by these SmallSats are becoming similar to larger spacecraft, their reliability still falls behind. This is in part due to the reduced cost of SmallSat missions in comparison to large spacecraft, which requires cheaper components, rapid development schedules, and accepted risk. In these missions, the importance of the flight software is often overlooked, and the software is rushed through development and not fully …

Next-Generation Re-Entry Aerothermodynamic Modeling Of Space Debris Using Machine Learning, Nicholas Sia

Graduate Theses, Dissertations, and Problem Reports

The number of resident space objects re-entering the atmosphere is expected to rise with increased space activity over recent years and future projections. Predicting the survival and impact location of the medium to large sized re-entering objects becomes important as they can cause on ground casualties and damage to property. Uncertainties associated with the re-entry process makes necessary a probabilistic approach, which can be computationally expensive when using high-fidelity numerical methods for estimating aerothermodynamic properties. To date, object-oriented analysis is the dominant tool used for atmospheric re-entry modeling and simulation, where aerothermodynamic coefficients are used to determine the risk a …

Improving The Biological Control Of Persicaria Perfoliata (Polygonaceae) Using Rhinoncomimus Latipes Korotyaev (Coleoptera: Curculionidae), Jaewon Kim

Graduate Theses, Dissertations, and Problem Reports

Persicaria perfoliata (L.) H. Gross (Polygonaceae; Mile-a-minute weed) is a rapid-growing invasive vine introduced from eastern Asia to northeastern United States in the 1930s. This vine has been invaded in disturbed areas and reforestation sites in 15 states in the U.S. and forms dense, monocultural patches that may inhibit natural forest regeneration. To control this weed, a host-specific biocontrol agent, Rhinoncomimus latipes Korotyaev (Coleoptera: Curculionidae) has been released in the P. perfoliata invaded states in the U.S. during the past 15 years. Currently, R. latipes is released by hand to the invaded area where the presence of the weed is …

Terrain Aware Traverse Planning For Mars Rovers, Gabrielle Hedrick

Graduate Theses, Dissertations, and Problem Reports

NASA is proposing a Mars Sample Return mission, to be completed within one Martian year, that will require enhanced autonomy to perform its duties faster, safer, and more efficiently. With its main purpose being to retrieve samples possibly tens of kilometers away, it will need to drive beyond line-of-sight to get to its target more quickly than any rovers before. This research proposes a new methodology to support a sample return mission and is divided into three compo-nents: map preparation (map of traversability, i.e., ability of a terrain to sustain the traversal of a vehicle), path planning (pre-planning and replanning), …

Aeroelasticity Of Composite Plate Wings Using Hsdt And Higher-Order Fem, Justin A. Haught

Graduate Theses, Dissertations, and Problem Reports

The aeroelasticity of composite wings is becoming an increasingly researched topic in aircraft design, as designers continue to replace aluminum alloy components with those made of composite materials because of their favorable strength-to-weight ratio, fatigue characteristics, and corrosion resistance. Additionally, the bending-torsion coupling exhibited by composite laminates readily allow for the aeroelastic optimization of an aerodynamic structure through the process of aeroelastic tailoring. Wings made of composites materials, however, are more vulnerable to shear deformation.

The objective of the present research is to study the divergence and flutter characteristics of composite plate wings using a higher-order shear deformation theory (HSDT) …

Synthesis Of Graphene Using Plasma Etching And Atmospheric Pressure Annealing: Process And Sensor Development, Andrew Robert Graves

Graduate Theses, Dissertations, and Problem Reports

Having been theorized in 1947, it was not until 2004 that graphene was first isolated. In the years since its isolation, graphene has been the subject of intense, world-wide study due to its incredibly diverse array of useful properties. Even though many billions of dollars have been spent on its development, graphene has yet to break out of the laboratory and penetrate mainstream industrial applications markets. This is because graphene faces a ‘grand challenge.’ Simply put, there is currently no method of manufacturing high-quality graphene on the industrial scale. This grand challenge looms particularly large for electronic applications where the …

Low-Cost Skewed Redundant Imu Configuration For State-Space Recovery In A Saturated Environment, Levi S. Hubbard

Graduate Theses, Dissertations, and Problem Reports

Low-cost sensors for state space determination can be used successfully for ground vehicles, robots, unmanned aerial vehicles, and Internet-of-Things applications. When a high fidelity Inertial Measurement Unit (IMU) cannot be obtained for state space determination, low-cost sensors can be used to satisfactory standards, despite their limitations in capabilities, by using various implementation techniques. The research group was experimentally investigating state space information of an unstable flying vehicle for motion simulation validation. The high fidelity motion capture system would intermittently lose track of the flight vehicle which lost critical flight data.

The goal was to determine the potential of low-cost off-the-shelf …