Engineering Commons^™

Farmer Perceptions Of Land Cover Classification Of Uas Imagery Of Coffee Agroecosystems In Puerto Rico, Jose Cabrera, Blake Neal, Kevin Adkins, Ronny Schroeder, Gwendolyn Klenke, Shannon Brines, Nayethzi Hernandez, Kevin Li, Riley Glancy, Ivette Perfecto

Publications

Highly diverse agroecosystems are increasingly of interest as the realization of farms’ invaluable ecosystem services grows. Simultaneously there has been an increased use of uncrewed aerial systems (UAS) in remote sensing as drones offer a finer spatial resolution and faster revisit rate than traditional satellites. With the combined utility of UAS and the attention on agroecosystems, there exists an opportunity to assess UAS practicality in highly biodiverse settings. In this study, we utilized UAS to collect fine-resolution 10-band multispectral imagery of coffee agroecosystems in Puerto Rico. We created land cover maps through a pixel-based supervised classification of each farm and …

Immersive Framework For Designing Trajectories Using Augmented Reality, Joseph Anderson, Leo Materne, Karis Cooks, Michelle Aros, Jaia Huggins, Jesika Geliga-Torres, Kamden Kuykendall, David Canales, Barbara Chaparro

Publications

The intuitive interaction capabilities of augmented reality make it ideal for solving complex 3D problems that require complex spatial representations, which is key for astrodynamics and space mission planning. By implementing common and complex orbital mechanics algorithms in augmented reality, a hands-on method for designing orbit solutions and spacecraft missions is created. This effort explores the aforementioned implementation with the Microsoft Hololens 2 as well as its applications in industry and academia. Furthermore, a human-centered design process and study are utilized to ensure the tool is user-friendly while maintaining accuracy and applicability to higher-fidelity problems.

Six-Degree-Of-Freedom Optimal Feedback Control Of Pinpoint Landing Using Deep Neural Networks, Omkar S. Mulekar, Hancheol Cho, Riccardo Bevilacqua

Student Works

Machine learning regression techniques have shown success at feedback control to perform near-optimal pinpoint landings for low fidelity formulations (e.g. 3 degree-of-freedom). Trajectories from these low-fidelity landing formulations have been used in imitation learning techniques to train deep neural network policies to replicate these optimal landings in closed loop. This study details the development of a near-optimal, neural network feedback controller for a 6 degree-of-freedom pinpoint landing system. To model disturbances, the problem is cast as either a multi-phase optimal control problem or a triple single-phase optimal control problem to generate examples of optimal control through the presence of disturbances. …

Stability Of Deep Neural Networks For Feedback-Optimal Pinpoint Landings, Omkar S. Mulekar, Hancheol Cho, Riccardo Bevilacqua

Student Works

The ability to certify systems driven by neural networks is crucial for future rollouts of machine learning technologies in aerospace applications. In this study, the neural networks are used to represent a fuel-optimal feedback controller for two different 3-degree-of-freedom pinpoint landing problems. It is shown that the standard sum-ofsquares Lyapunov candidate is too restrictive to assess the stability of systems with fuel-optimal control profiles. Instead, a parametric Lyapunov candidate (i.e. a neural network) can be trained to sufficiently evaluate the closed-loop stability of fuel-optimal control profiles. Then, a stability-constrained imitation learning method is applied, which simultaneously trains a neural network …

Dual Quaternion Relative Dynamics For Gravity Recovery Missions, Ryan Kinzie, Riccardo Bevilacqua, Seo Dongeun

Student Works

A dual quaternion modeling approach is compared to traditional modeling methods for formation flying spacecraft utilized for gravity recovery missions. A modeling method that has traditionally been used for gravity recovery missions is presented which models the motion of two formation flying spacecraft and a test mass. This is followed by the dual quaternion-based formulation for the equations of motion of the twelve degree-of-freedom coupled relative dynamics of formation flying spacecraft and a test mass. Lastly, utilizing data products from the Gravity Recovery and Climate Experiment Follow-On mission, a comparison of these two modeling methods is presented which proves the …

Solar Sailing Adaptive Control Using Integral Concurrent Learning For Solar Flux Estimation, Luis Enrique Mendoza Zambrano, Riccardo Bevilacqua

Student Works

In the interest of exploiting natural forces for propellant-less spacecraft missions, this investigation proposes an adaptive control strategy to account for unknown parameters in the dynamic modeling of a reflectivity-controlled solar sail spacecraft. A Lyapunov-based control law along with integral concurrent learning is suggested to accomplish and prove global exponential tracking of the estimated parameters and states of interest, without satisfying the common persistence of excitation condition, which in most nonlinear systems cannot be guaranteed a priori. This involves estimating the solar flux or irradiance from the Sun to account for uncertainty and variation over time in this value. To …

Spacecraft Systems & Navigation, Christopher Vanacore

Student Works

This textbook is steered towards higher educational course entailed in Commercial Space Operations. This textbook will be covering in detail Orbital Satellites, and Spacecraft. These topics are discussed according to their application, design, and environment. The power system, shielding and communication systems are reviewed along with their missions, space, environment and limitations. Any vehicle, whether manned or unmanned, intended for space travel is a spacecraft. A spacecraft's required systems and equipment depend on the information it will acquire and the tasks it will perform. Although their levels of sophistication vary widely, they re all subject to the harsh conditions of …

The Bobo Project: Hexa-Eagles, Anjana Mahesh Kumar, Huna Amad, Jean Samirah Venturina, Sakthivel Mithra, Suhasini, Sumaiyathul Faaliha

Student Works

The consumer business has undergone a substantial shift in how customers to shop since the introduction of online shopping. When the world was affected by Covid-19 in 2020, one of the most major repercussions was in the Food & Beverage (F&B) and grocery industries. As a result of the pandemic, many cities were put under lockdown, and everyone remained indoors. Consumer purchasing patterns changed dramatically, with malls closing or operating with limited access, and customers avoiding common spaces for fear of getting the virus. As the global epidemic progressed, several firms were forced to close their physical locations due to …

Robust Nonlinear Tracking Control For Unmanned Aircraft In The Presence Of Wake Vortex, Petr Kazarin, Vladimir Golubev, William Mackunis, Claudia Moreno

Publications

The flight trajectory of unmanned aerial vehicles (UAVs) can be significantly affected by external disturbances such as turbulence, upstream wake vortices, or wind gusts. These effects present challenges for UAV flight safety. Hence, addressing these challenges is of critical importance for the integration of unmanned aerial systems (UAS) into the National Airspace System (NAS), especially in terminal zones. This work presents a robust nonlinear control method that has been designed to achieve roll/yaw regulation in the presence of unmodeled external disturbances and system nonlinearities. The data from NASA-conducted airport experimental measurements as well as high-fidelity Large Eddy Simulations of the …

Air Navigation And Covid-19: Atm Efficiency In Pandemic Crisis, Fabio Lourenco Carneiro Barbosa

Graduate Student Works

The coronavirus crisis effects on aviation in 2020 are currently well-documented. Nonetheless, the widely registered low traffic due to the crisis does not necessarily lead to increased air navigation efficiency. Thus, the present work, developed to fulfill the program outcomes for the Master of Science in Aeronautics, Air Traffic Management (ATM) specialization, aimed to investigate what was the impact of the COVID-19 crisis on air navigation efficiency in Brazil. This research question was addressed through a quantitative, nonexperimental, observational approach with two parallel branches, designed to answer two sub-questions. For the first, regarding what was the impact of the crisis …

A Ranking Method To Prioritize Vfr Airports To Be Provided With Instrument Approach Procedures, Marcelo Soares Leao, Gustavo A.M. Ortegal Leal, Fabio Rodrigues Paukoski Fernandes

Graduate Student Works

The primary purpose of this work is to investigate the necessity of a more comprehensive and systematic method to prioritize airports to be provided with instrument approach and landing procedures in the Brazilian air transportation landscape. An overview of the main contributors to risks associated with the approach and landing phases is provided, covering the most important aspects of unstable approaches and CFIT events. Considering the emergence of Terrain Awareness and Alerting Systems (TAWS), the role of its contribution to safety is discussed, as well as the certification context related to the design, installation, and operation of those systems. A …

Finite-Time State Estimation For An Inverted Pendulum Under Input-Multiplicative Uncertainty, William Mackunis, Sergey V. Drakunov, Anu Kossery Jayaprakash, Krishna Bhavithavya Kidambi, Mahmut Reyhanoglu

Publications

A sliding mode observer is presented, which is rigorously proven to achieve finite-time state estimation of a dual-parallel underactuated (i.e., single-input multi-output) cart inverted pendulum system in the presence of parametric uncertainty. A salient feature of the proposed sliding mode observer design is that a rigorous analysis is provided, which proves finite-time estimation of the complete system state in the presence of input-multiplicative parametric uncertainty. The performance of the proposed observer design is demonstrated through numerical case studies using both sliding mode control (SMC)- and linear quadratic regulator (LQR)-based closed-loop control systems. The main contribution presented here is the rigorous …

Uas Flight Operations In Complex Terrain: Assessing The Agricultural Impact From Hurricane Maria In The Central Mountainous Region Of Puerto Rico, Kevin Adkins

Publications

Hurricane Maria struck Puerto Rico in September 2017 as a Category 4 storm causing major damage to infrastructure, agriculture and natural ecosystems, as well as the loss of many lives. Among the crops hardest hit was coffee, one of the most important crops in Puerto Rico. As a perennial system, coffee takes various production forms along a gradient from high shade/biodiversity coffee farms to low shade coffee monocultures and therefore offers an ideal means for the study of resistance and resilience of an agroecosystem to weather and climate disturbance. During the summer of 2018, 14 impacted farms across the production …

Traditional Vs Gesture Based Uav Control, Sam J. Holley, Brian Sanders, Dennis Vincenzi, Yuzhong Shen

Publications

Abstract. The purpose of this investigation was to assess user preferences for controlling an autonomous system. A comparison using a virtual environment (VE) was made between a joystick based, game controller and a gesture-based system using the leap motion controller. Command functions included basic flight maneuvers and switching between the operator and drone view. Comparisons were made between the control approaches using a representative quadcopter drone. The VE was designed to minimize the cognitive loading and focus on the flight control. It is a physics-based flight simulator built in Unity3D. Participants first spend time familiarizing themselves with the basic controls …

Hybrid Magneto-Active Propellant Management Device For Active Slosh Damping Within A Vehicle Fuel Tank, Balaji Sivasubramanian, Leander Paul, Sathya Gangadharan

Publications

This disclosure includes a hybrid magneto-active mem­brane, which can be used as part of a Magneto-active Propellant Management Device (MAPMD), to actively con­trol free surface effects of liquid materials, such as fuels, and to reduce fuel slosh. The disclosed MAPMD merges aspects of a diaphragm membrane with a magneto-active inlay to control the membrane during in-flight conditions.

Surgical And Medical Applications Of Drones: A Comprehensive Review, Brent Terwilliger, James C. Rosser Jr., Vudatha Vignesh, Brett C. Parker

Publications

Drones have the ability to gather real time data cost effectively, to deliver payloads and have initiated the rapid evolution of many industrial, commercial, and recreational applications. Unfortunately, there has been a slower expansion in the field of medicine. This article provides a comprehensive review of current and future drone applications in medicine, in hopes of empowering and inspiring more aggressive investigation.

Static Performance Results Of Propellers Used On Nano, Micro, And Mini Quadrotors, Robert W. Deters, D. Dantsker, S.C. Kleinke, Narcrisha Norman, Michael S. Selig

Publications

An increase in the number of small quadrotors has created the interest in having performance data on the propellers used by these aircraft. With an aircraft size less than 5 in and propellers diameters less than 3 in, these quadrotors are typically referred to mini, micro, or nano by hobbyists and manufacturers. The size of the propellers used on these aircraft operate at low Reynolds numbers that are typically less than 50,000 for diameters up to 3 in and less than 20,000 for diameters up to 2 in. Static performance testing of the propellers used on 11 small quadrotors was …

Single Axis Stability Autonomous Glider Control, Brian Study

Student Works

To investigate and increase knowledge on autonomous control systems, an autonomous glider was fitted with a control system with the purpose of creating a craft that would be capable of maintaining a wings level condition despite perturbations to the trim condition. The glider measures bank angle and roll rate information from an accelerometer and gyro, before it relays the data to an equipped microcontroller. Programmed on the microcontroller is a control law to take the input from the sensors and issue a command to a single servo that controls both ailerons, allowing for the vehicle to autonomously correct its bank …

Safety Analysis Of Automatic Dependent Surveillance – Broadcast (Ads-B) System, Rajee Olaganathan

Publications

ADS-B is one of the significant implementation systems of NextGen, to help pilots and air traffic controllers to create a safer, and more efficient National Airspace System (NAS). First, this research paper will briefly describe the ADS-B system, its design structure, ADS-B In and ADS-B Out systems, its efficiency both in pilot applications and in air traffic control applications, and then discuss about the system safety analysis. The preliminary hazard analysis and fault tree analysis will be done for the identified and selected hazards, and will be briefly discussed. The paper will conclude by providing recommendations to prevent/mitigate the hazards …

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 …

Synthetic Jet Actuator-Based Aircraft Tracking Using A Continuous Robust Nonlinear Control Strategy, N. Ramos-Pedroza, W. Mackunis, M. Reyhanoglu

Publications

A robust nonlinear control law that achieves trajectory tracking control for unmanned aerial vehicles (UAVs) equipped with synthetic jet actuators (SJAs) is presented in this paper. A key challenge in the control design is that the dynamic characteristics of SJAs are nonlinear and contain parametric uncertainty. The challenge resulting from the uncertain SJA actuator parameters is mitigated via innovative algebraic manipulation in the tracking error system derivation along with a robust nonlinear control law employing constant SJA parameter estimates. A key contribution of the paper is a rigorous analysis of the range of SJA actuator parameter uncertainty within which asymptotic …

Unmanned Aerial Vehicle (Uav): Flight Performance, Fevens Louis Jean

Student Works

It is important that when measuring the sideslip angle and angles of attack during flight test performance of a UAV (Unmanned Aerial Vehicle), to fully understand that the Angles of attack and sideslip are parameters that aid in determining the safety of the flight as they improve stability and control of the aircraft. The disadvantage of the measurement of these angles using this method is low accuracy of measurement due to friction to the potentiometers in connection with the vanes. To counter this, a new sensing method was developed to minimize friction and collect more accurate data. The method is …

Time Optimal State Feedback Control With Application To A Spacecraft With Cold Gas Propulsion, Samuel J. Kitchen-Mckinley, Sergey V. Drakunov

Publications

A cold gas propulsion system is well suited to provide the required thrust for a small surveyor spacecraft operated near an asteroid or planetary surface. The cold gas propellant can obtained in-situ from local surface or atmospheric constituents. For small spacecraft, the cold gas system may be limited to only on-off control of the main tank where the generated thrust is directly dependent on the tank pressure. As such the thrust will slowly decrease as the propellant is expended. A state feedback, time optimal, control law is developed for a vehicle with propellant is expended. A state feedback, time optimal, …

Static Testing Of Propulsion Elements For Small Multirotor Unmanned Aerial Vehicles, Robert W. Deters, S.C. Kleinke, Michael S. Selig

Publications

The growing use of small multirotor aircraft has increased the interest in having better performance results especially with the propulsion system. The size of the propellers used on these aircraft operate at low Reynolds numbers that are typically less than 200,000. Static performance testing of ten propeller pairs (tractor and pusher) were completed and is the beginning of a systematic test of propellers used on multirotor systems. The propellers chosen for this initial set of tests were selected from four popular quadrotors. Besides testing the propellers provided with the aircraft, propellers that are sold as replacements from third-party companies were …

Adopting Unmanned Flight Operations Into Controlled Airspace, Jennah C. Perry, Johnny Young, Jacqueline Luedtke, Benjamin Cook, Holly Hughes, Allison M. Little, Kyle Wilkerson

Publications

Unmanned aircraft activity is becoming more common within the National Airspace System (NAS) and is expected to dominate the NAS in the near future. Specific procedures for adopting unmanned aircraft into the National Airspace System (NAS).

A variation of the Military Grid Reference System was developed and digitally overlaid onto the radar display. To incorporate this grid system, a customized flight plan database was created for the storage of operator submitted flight plans. Instead of verbal communication, a computer chat system is used for communication because of the low altitude operations in the field.

The Federal Aviation Administration (FAA) has …

Integrating Unmanned Aircraft Operations Into The National Airspace System, Benjamin Cook, Holly Hughes, Allison Little, Kyle Wilkerson, Jennah C. Perry, Johnny Young, Jacqueline Luedtke

Publications

Commercial unmanned aircraft systems (UAS) are expected to dominate the National Airspace System (NAS) in the years to come. One particular barrier preventing integration of UAS into the NAS is the lack of standardized procedures for separating aircraft and communicating with ATC. In preparation for adopting unmanned flight operations into a complex control system, it is important to identify solutions to effectively control UAS in the NAS.

The Joint UAS and ATC Team (JUAT) group has designed several simulated ATC scenarios in order to determine effective solutions for integration. Through the use of digitized radar display overlays that replicate the …

Cognitive Loading, Affect Regulation And Aerodynamic Considerations In Uninhabited Aerial Vehicle Systems Refueling Operations, Sam Holley, Ian R. Mcandrew

Publications

Factors influencing aerodynamics involved in aerial refueling illustrate the potential for specialist operators to manage these operations for remotely piloted vehicles. The authors review aerodynamic characteristics of uninhabited aerial systems during refueling, drogue and boom design and associated flight dynamics, cognitive factors associated with control transfer and refueling, and affective components and their influence on decision making and operator performance. Attention is directed to cognitive loading and encoding challenges, with considerations for hippocampal mapping and hemispheric asymmetry. Implications for system state awareness are examined. Advantages for specially trained refueling pilot operators are discussed and recommendations given for areas of concentration.

System And Method For Location Of Aircraft, Albert D. Helfrick

Publications

A system and method are provided that includes an aircraft secondary radar transponder activity detector that monitors an aircraft's transponder transmissions and activates an emer­gency locator transmitter to begin transmitting should the aircraft transponder transmissions cease to help locate an aircraft that may have become undetectable by conventional aircraft surveillance and tracking systems.

A Sliding Mode Lco Regulation Strategy For Dual-Parallel Underactuated Uav Systems Using Synthetic Jet Actuators, N. Ramos-Pedroza, W. Mackunis, M. Reyhanoglu

Publications

"A sliding mode control- (SMC-) based limit cycle oscillation (LCO) regulation method is presented, which achieves asymptotic LCO suppression for UAVs using synthetic jet actuators (SJAs). With a focus on applications involving small UAVs with limited onboard computational resources, the controller is designed with a simplistic structure, requiring no adaptive laws, function approximators, or complex calculations in the control loop. The control law is rigorously proven to achieve asymptotic regulation of both pitching and plunging displacements for a class of systems in a dual-parallel underactuated form, where a single scalar control signal simultaneously affects two states. Since dual-parallel underactuated systems …

Slipstream Measurements Of Small-Scale Propellers At Low Reynolds Numbers, Robert W. Deters, Gavin K. Ananda, Michael S. Selig

Publications

The continuing growth in the use of small UAVs has required the need to more fully understand the propellers that power them. Part of this understanding is the behavior of the propeller slipstream. Using a 7-hole probe, the slipstreams of several small-scale propellers (diameters of 4.2, 5, and 9 in) were measured in both static (V∞ = 0) and advancing-flow (V∞ > 0) conditions at several locations downstream. For static conditions, as the slipstream expanded downstream, the maximum values of the axial and swirl velocities decreased. The general shape of the static slipstream was also found to be nearly the same …