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Articles 1 - 30 of 31
Full-Text Articles in Engineering
Comparison Of Methods For Estimating Instantaneous Turn Radius Of Ackermann Steering Vehicles, Kenneth Gennaro Stutts
Comparison Of Methods For Estimating Instantaneous Turn Radius Of Ackermann Steering Vehicles, Kenneth Gennaro Stutts
Doctoral Dissertations and Master's Theses
The instantaneous turn radius of an Ackermann steering vehicle is the distance to a point in space about which the vehicle will travel in an arc during a turn. There are at least six ways to estimate instantaneous turn radius and each method uses different inputs and has distinct advantages and disadvantages. In this thesis, six different methods will be used to estimate the instantaneous turn radius of a vehicle traveling on a closed circuit. This testing will clarify similarities and differences between the methods. This thesis clarifies which method will be the most appropriate for a given set of …
On-Board Artificial Intelligence For Failure Detection And Safe Trajectory Generation, Eduardo Morillo
On-Board Artificial Intelligence For Failure Detection And Safe Trajectory Generation, Eduardo Morillo
Doctoral Dissertations and Master's Theses
The use of autonomous flight vehicles has recently increased due to their versatility and capability of carrying out different type of missions in a wide range of flight conditions. Adequate commanded trajectory generation and modification, as well as high-performance trajectory tracking control laws have been an essential focus of researchers given that integration into the National Air Space (NAS) is becoming a primary need. However, the operational safety of these systems can be easily affected if abnormal flight conditions are present, thereby compromising the nominal bounds of design of the system's flight envelop and trajectory following. This thesis focuses on …
Machine Learning To Predict Warhead Fragmentation In-Flight Behavior From Static Data, Katharine Larsen
Machine Learning To Predict Warhead Fragmentation In-Flight Behavior From Static Data, Katharine Larsen
Doctoral Dissertations and Master's Theses
Accurate characterization of fragment fly-out properties from high-speed warhead detonations is essential for estimation of collateral damage and lethality for a given weapon. Real warhead dynamic detonation tests are rare, costly, and often unrealizable with current technology, leaving fragmentation experiments limited to static arena tests and numerical simulations. Stereoscopic imaging techniques can now provide static arena tests with time-dependent tracks of individual fragments, each with characteristics such as fragment IDs and their respective position vector. Simulation methods can account for the dynamic case but can exclude relevant dynamics experienced in real-life warhead detonations. This research leverages machine learning methodologies to …
Effect Of Passive Clean Air Injection Into The Wake Region Of A Moving Ground Vehicle, Angelos Kaminis
Effect Of Passive Clean Air Injection Into The Wake Region Of A Moving Ground Vehicle, Angelos Kaminis
Doctoral Dissertations and Master's Theses
The wake region on a moving ground vehicle is responsible for 70% of the aerodynamic drag when the speed of 90km/h is achieved. The topic of wake region manipulation has been revisited multiple times and with varying techniques. When manipulating the flow utilizing a fully passive method, pressure drag can be reduced, increasing the overall performance of the vehicle. To ensure high velocity fluid injection, a venturi shaped roof was implemented with an inlet size of 352mm x 12.7mm, and 2 outlets of size 88.011mm x 25.4mm resulting in an area of 4,470.959 for both inlet and outlet to maintain …
Active Control Of Coherent Structures In An Axisymmetric Jet, Michael Marques Goncalves
Active Control Of Coherent Structures In An Axisymmetric Jet, Michael Marques Goncalves
Doctoral Dissertations and Master's Theses
The primary objective of this work is to develop high-fidelity simulation model for jet noise control predictions and quantify the sound reduction when an external source frequency mode excitation is imposed on the jet flow. Whereas passive approaches using mixing devices, such as chevrons, have been shown to reduce low-frequency noise in jet engines, such approaches incur a performance penalty since they result in a reduced thrust. To avoid a performance penalty in reducing jet noise, the current work investigates a open-loop active noise control (ANC) system that utilizes a unsteady microjet actuator on the nozzle lip in the downstream …
Automated Scenario Generation Using Halton Sequences For The Verification Of Autonomous Vehicle Behavior In Simulation, Andrew Ferree
Automated Scenario Generation Using Halton Sequences For The Verification Of Autonomous Vehicle Behavior In Simulation, Andrew Ferree
Doctoral Dissertations and Master's Theses
As autonomous vehicles continue to develop, verifying their safety remains a large hurdle to mass adoption. One component of this is testing, however it has been shown that it is impractical to statistically prove an autonomous vehicle’s safety using real-world testing alone. Therefore, simulation tools and other virtual testing methods are being employed to assist with the verification process. Testing in simulation still faces some of the challenges of the real world, such as the difficulty in exhaustively testing the system in all scenarios it will encounter. Manual scenario creation is time consuming and does not guarantee scenario coverage. Pseudo-random …
Active Drag Reduction Of Ground Vehicles Using Air-Jet Wheel Deflectors, Kaloki Nabutola
Active Drag Reduction Of Ground Vehicles Using Air-Jet Wheel Deflectors, Kaloki Nabutola
Doctoral Dissertations and Master's Theses
Seven turbulence models were used to simulate the flow within the wheelhouse of a simplified vehicle body. The performance of each model was evaluated by comparing the aerodynamic coefficients obtained using computational fluid dynamics (CFD) to data collected from wind tunnel experiments. The performance of large eddy simulation (LES) and detached eddy simulation (DES) was largely dependent on the time step and grid size to accurately resolve turbulent eddies. The standard k-e, realizable k-e, k-w, DES, and LES all trended towards a drag coefficient which was 20% lower than the experimental value. In all numerical cases, the lift coefficient was …
Multirotor Uas Sense And Avoid With Sensor Fusion, Jonathan Mark Buchholz
Multirotor Uas Sense And Avoid With Sensor Fusion, Jonathan Mark Buchholz
Doctoral Dissertations and Master's Theses
In this thesis, the key concepts of independent autonomous Unmanned Aircraft Systems (UAS) are explored including obstacle detection, dynamic obstacle state estimation, and avoidance strategy. This area is explored in pursuit of determining the viability of UAS Sense and Avoid (SAA) in static and dynamic operational environments. This exploration is driven by dynamic simulation and post-processing of real-world data. A sensor suite comprised of a 3D Light Detection and Ranging (LIDAR) sensor, visual camera, and 9 Degree of Freedom (DOF) Inertial Measurement Unit (IMU) was found to be beneficial to autonomous UAS SAA in urban environments. Promising results are based …
A Data Mining Methodology For Vehicle Crashworthiness Design, Xianping Du
A Data Mining Methodology For Vehicle Crashworthiness Design, Xianping Du
Doctoral Dissertations and Master's Theses
This study develops a systematic design methodology based on data mining theory for decision-making in the development of crashworthy vehicles. The new data mining methodology allows the exploration of a large crash simulation dataset to discover the underlying relationships among vehicle crash responses and design variables at multiple levels and to derive design rules based on the whole-vehicle safety requirements to make decisions about component-level and subcomponent-level design. The method can resolve a major issue with existing design approaches related to vehicle crashworthiness: that is, limited abilities to explore information from large datasets, which may hamper decision-making in the design …
Finite Element Model Validation And Testing Of An Off-Road Vehicle Under Dynamic Loading Conditions, Mackenzie Susan Cunningham
Finite Element Model Validation And Testing Of An Off-Road Vehicle Under Dynamic Loading Conditions, Mackenzie Susan Cunningham
Doctoral Dissertations and Master's Theses
In the vehicle design life cycle, validation tests consume a significant portion of the available development time. With a short, one-year design cycle, the Embry-Riddle Baja Team leverages computer-aided engineering (CAE) tools to simulate critical test cases whose loading conditions can be accurately represented by a series of static loads and constraints. Using these conditions, a Finite Element Model (FEM) can be employed to accurately predict the effects of the loading conditions in the components. During the initial design of the front suspension, one major load case was determined to be the main failure load. However, after validation testing the …
The Effect Of Task Load, Automation Reliability, And Environment Complexity On Uav Supervisory Control Performance, Sarah M. Sherwood
The Effect Of Task Load, Automation Reliability, And Environment Complexity On Uav Supervisory Control Performance, Sarah M. Sherwood
Doctoral Dissertations and Master's Theses
Over the last decade, military unmanned aerial vehicles (UAVs) have experienced exponential growth and now comprise over 40% of military aircraft. However, since most military UAVs require multiple operators (usually an air vehicle operator, payload operator, and mission commander), the proliferation of UAVs has created a manpower burden within the U.S. military. Fortunately, simultaneous advances in UAV automation have enabled a switch from direct control to supervisory control; future UAV operators will no longer directly control a single UAV subsystem but, rather, will control multiple advanced, highly autonomous UAVs. However, research is needed to better understand operator performance in a …
Design Of Flight Control Laws For A Novel Stratospheric Dual-Aircraft Platform, Cindy Nshuti
Design Of Flight Control Laws For A Novel Stratospheric Dual-Aircraft Platform, Cindy Nshuti
Doctoral Dissertations and Master's Theses
Dual-aircraft platform (DAP) is a novel concept that features two glider-like unmanned aerial systems (UAS) tethered via a thin adjustable cable allowing them to sail back-and-forth, without propulsion, using vertical wind shear. DAP offers the potential of a low-cost atmospheric satellite. This thesis presents the results of an initiative to demonstrate this novel flight concept through modeling, simulation, and flight testing at Embry-Riddle Aeronautical University (ERAU). A realistic simulation environment, described herein, was developed to support the development and testing of flight control systems. This environment includes nonlinear aerodynamic models for the aircraft, a multi-element cable dynamics model, propeller-motor thrust …
Supervisory Controls Strategy To Reduce Utility Factor Weighted Criteria Emissions For A Plug-In Hybrid Electric Vehicle, Thomas Francis Gorgia Iii
Supervisory Controls Strategy To Reduce Utility Factor Weighted Criteria Emissions For A Plug-In Hybrid Electric Vehicle, Thomas Francis Gorgia Iii
Doctoral Dissertations and Master's Theses
Criteria emission reduction techniques are being more sought out in the automotive industry due to current government regulation for light duty vehicles. Parallel-series plug in hybrid electric vehicles can have multiple strategies to balance emissions and fuel consumption. Common controls strategies in industry target fuel economy by using a large electric vehicle range, known as charge depletion, followed by maintaining a state of charge after a specific vehicle threshold, or charge sustaining. A charge preserve strategy works by running an engine at an optimal loading condition, the engine will burn the fuel more complete reducing criteria emissions. Charge preserve will …
Electrical Optimization Of A Plug-In Hybrid Electric Vehicle, Andre J. Napier
Electrical Optimization Of A Plug-In Hybrid Electric Vehicle, Andre J. Napier
Doctoral Dissertations and Master's Theses
Hybrid electric vehicles electrification and optimization is a prominent part of today’s automotive industry. GM and the Department of Energy challenge 16 universities across North America to redesign a Chevrolet Camaro into a hybrid electric vehicle. This thesis will address how Embry Riddle Aeronautical University’s EcoCAR team electrified and optimized the vehicle. The objective of the thesis is to optimize the electric portion of the vehicle, particularly the low voltage circuitry. Prior work is discussed in detail on the vehicle communication bus, building the power distribution unit and the approach the electrical team took when building the electric portion of …
Dynamic Understeer Control Using Active Rear Toe, Mark Oliver Dixon Kaufman
Dynamic Understeer Control Using Active Rear Toe, Mark Oliver Dixon Kaufman
Doctoral Dissertations and Master's Theses
This thesis was conducted to show the ability of Active Rear Toe to control the understeer characteristics of a vehicle. Active rear toe is the ability to control the angle of the rear wheels around the vertical axis, allowing the car’s turning radius to change. By changing this radius, the lateral acceleration can be controlled, therefore the understeer of the vehicle can be controlled. The controls scheme is a sliding mode control, specifically a hyperbolic tangent boundary layer and a type 1 zeno controller. The system shows effectiveness to control the understeer of the vehicle up until limit grip on …
Bio-Mimicry Of A Leopard Tortoise’ Shoulder Girdle In Space Frame Design Of An Ambulance Body, Sarah A. Matiko
Bio-Mimicry Of A Leopard Tortoise’ Shoulder Girdle In Space Frame Design Of An Ambulance Body, Sarah A. Matiko
Doctoral Dissertations and Master's Theses
It appears that there is a need for affordable, functional and safe emergency medical support service vehicles in rural Sub-Saharan Africa (SSA). It is inferred that the road conditions have an influence on the availability, durability and affordability of motorized and non-motorized vehicles in rural areas. Also, it is deduced that locally modified bicycle and motorcycle ambulances are not conducive to maternal patients during emergencies. This study investigates the feasibility of modelling an ergonomically and crashworthy patient compartment for road conditions in rural SSA. The patient compartment is modelled by establishing geometrical requirements via a design standard for emergency medical …
Development, Characterization, & Implementation Of Phase-Change Material Cold Plates For Hybrid-Electric Vehicle Battery Systems, Kevin Cwiok
Doctoral Dissertations and Master's Theses
Due to the regulations on internal combustion engine vehicles, there is a large demand of hybrid and electric vehicles with large battery packs as Energy Storage Systems (ESS) capable of long ranges and decreased emissions. These battery packs output large heat loads during charge-depletion mode and currently require active cooling to keep the batteries within operating conditions. The current systems relied onto achieve this are the air and liquid cooled thermal managements systems. A recent alternative approach to current cooling for ESS thermal management is the use of phase-change materials (PCMs). PCMs regulate the temperature of the ESS by leveraging …
Application Of Floating Pedal Regenerative Braking For A Rear-Wheel-Drive Parallel-Series Plug-In Hybrid Electric Vehicle With An Automatic Transmission, Dylan Lewis Lewton
Application Of Floating Pedal Regenerative Braking For A Rear-Wheel-Drive Parallel-Series Plug-In Hybrid Electric Vehicle With An Automatic Transmission, Dylan Lewis Lewton
Doctoral Dissertations and Master's Theses
As the world continues to move further away from our reliance on fossil fuels, hybrid vehicles are becoming ever more popular. Braking is a system on both hybrid and normal vehicles that involves a significant amount of power and energy. A hybrid can recapture some of that energy using regenerative braking. In this thesis, a method is devised to blend hydraulic and regenerative braking in the most effective manner. A MATLAB Simulink model was built to simulate a parallel-series plug-in hybrid electric vehicle. The model allows for the implementation of a regenerative brake controller that utilizes floating pedal regen, custom …
Traction And Launch Control For A Rear-Wheel-Drive Parallel-Series Plug-In Hybrid Electric Vehicle, Adam Michael Szechy
Traction And Launch Control For A Rear-Wheel-Drive Parallel-Series Plug-In Hybrid Electric Vehicle, Adam Michael Szechy
Doctoral Dissertations and Master's Theses
Hybrid vehicles are becoming the future of automobiles leading into the all-electric generation of vehicles. Electric vehicles come with a great increase in torque at lower RPM resulting in the issue of transferring this torque to the ground effectively. In this thesis, a method is presented for limiting wheel slip and targeting the ideal slip ratio for dry asphalt and low friction surfaces at every given time step. A launch control system is developed to further reduce wheel slip on initial acceleration from standstill furthering acceleration rates to sixty miles per hour. A MATLAB Simulink model was built of the …
Vision-Aided Navigation For Autonomous Vehicles Using Tracked Feature Points, Ahmed Saber Soliman Sayem
Vision-Aided Navigation For Autonomous Vehicles Using Tracked Feature Points, Ahmed Saber Soliman Sayem
Doctoral Dissertations and Master's Theses
This thesis discusses the evaluation, implementation, and testing of several navigation algorithms and feature extraction algorithms using an inertial measurement unit (IMU) and an image capture device (camera) mounted on a ground robot and a quadrotor UAV. The vision-aided navigation algorithms are implemented on data-collected from sensors on an unmanned ground vehicle and a quadrotor, and the results are validated by comparison with GPS data. The thesis investigates sensor fusion techniques for integrating measured IMU data with information extracted from image processing algorithms in order to provide accurate vehicle state estimation. This image-based information takes the forms of features, such …
Sensing, Actuation, And Embedded Control For A Custom Scr Nitrogen Oxides Emissions Reduction System, Anuj Kalidas Sharma
Sensing, Actuation, And Embedded Control For A Custom Scr Nitrogen Oxides Emissions Reduction System, Anuj Kalidas Sharma
Doctoral Dissertations and Master's Theses
Diesel engines are the main power source for medium and heavy duty on road vehicles. With the rising standards for mileage of vehicles set by the Corporate Average Fuel Economy and the Environmental Protection Agency, diesel engines should soon be considered in lieu of gas engines. Despite advantages of diesel engines, diesel emissions include harmful gasses like carbon monoxide, nitrogen oxides and particulate matter. Selective Catalytic Reduction (SCR) systems have long been used to reduce diesel emissions from medium to heavy-duty diesel engines. Primary focus of this research effort is the implementation and improvement of a SCR system on light …
An Approach To Automotive Electrification And Testing, Christopher Rowe
An Approach To Automotive Electrification And Testing, Christopher Rowe
Doctoral Dissertations and Master's Theses
In order to compete in the EcoCAR 2 competition, Embry-Riddle Aeronautical University has redesigned the Powertrain of a 2013 Chevrolet Malibu into a plug-in hybrid electric vehicle. This endeavor was made possible by the EcoCAR 2 competition sponsored by the Department of Energy, General Motors, and Argonne National Laboratory. The Powertrain was changed from a conventional internal combustion engine with a start/stop capability, to a fully electric Powertrain, with a diesel generator, and plug in charging capability. This paper will cover the electrical work performed on the vehicle during the summer prior to year three of the competition, EcoCAR 2 …
Development Of A System Architecture For Unmanned Systems Across Multiple Domains, Charles Randall Breingan Jr.
Development Of A System Architecture For Unmanned Systems Across Multiple Domains, Charles Randall Breingan Jr.
Doctoral Dissertations and Master's Theses
In the unmanned systems industry, there is no common standard for systems components, connections and relations. Such a standard is never likely to exist. Needless to say, a system needs to have the components that are required for the application, however, it is possible to abstract the common functionality out of an individual implementation. This thesis presents a universal unmanned systems architecture that collects all of the common features of an unmanned system and presents them as a set of packages and libraries that can be used in any domain of unmanned system operation. The research and design of the …
Run-Time Hev Engine-Generator Power-Speed Optimization For Fuel Consumption And Emissions Reduction, Chester Paul Rowe Ii
Run-Time Hev Engine-Generator Power-Speed Optimization For Fuel Consumption And Emissions Reduction, Chester Paul Rowe Ii
Doctoral Dissertations and Master's Theses
As fuel economy and emissions standards become more stringent, Plug-in Hybrid Electric Vehicles (PHEV) using series architectures are being increasingly explored. Due to the decoupling of the Internal Combustion Engine (ICE) from the road, the primary control challenge in this architecture is the optimization of an ICE control law. A run-time Genset speed controller is presented for use during the charge-sustaining mode in a Series PHEV to find the optimal operating parameters for a conventional diesel engine coupled to an electric generator in terms of minimized fuel consumption and emissions generation. On board vehicle sensors provide real time data to …
Execution Of A Hybrid Vehicle Controls Development Effort Utilizing Model-Based Design, Hardware-In-The-Loop Testing, Agile Scrum Methods And Requirements Engineering, Derek Simon Bonderczuk
Execution Of A Hybrid Vehicle Controls Development Effort Utilizing Model-Based Design, Hardware-In-The-Loop Testing, Agile Scrum Methods And Requirements Engineering, Derek Simon Bonderczuk
Doctoral Dissertations and Master's Theses
Modern hybrid vehicles require sophisticated supervisory control systems in order to realize competitive efficiency gains. Processes such as model-based design, HIL simulation and Agile Scrum methods can allow for quicker and less costly development of a complex product. The design of a supervisory control system for a prototype PHEV vehicle was executed with the intent of developing a mule vehicle into a 99% production ready vehicle. The control system design process was carried through from requirements definition to operating parameter optimization of utilizing model-based design, HIL simulation and the Scrum model. A prototype vehicle that has a fully functioning hybrid …
Decreasing The Power Consumption Of Hybrid Electric Vehicle Architectures, Domenic Leo Barsotti
Decreasing The Power Consumption Of Hybrid Electric Vehicle Architectures, Domenic Leo Barsotti
Doctoral Dissertations and Master's Theses
This paper presents the challenges seen by current automotive manufacturers in their investigation of more fuel efficient vehicles. The two main areas for improvement are aerodynamics and passive cooling of electrical systems. Aerodynamics of an Ahmed body is investigated with a drag reduction system proposed utilizing slot jets at the rear of the bluff body . Two separate systems show a decrease in drag of 16 and 25%. The paper also investigates the use of a phase change material for a hybrid electric vehicles energy storage system cooling. Phase change materials take advantage of the latent heat of fusion to …
Development Of A Hybrid Vehicle Powertrain Test Laboratory, Bennet Samuel Soundarraj
Development Of A Hybrid Vehicle Powertrain Test Laboratory, Bennet Samuel Soundarraj
Doctoral Dissertations and Master's Theses
During the last two years, Embry-Riddle Aeronautical University has installed and tested a fully functional eddy-current chassis dynamometer testing facility on campus. An automotive test facility requires a systems engineering approach to install, calibrate and commission a chassis dynamometer. This thesis shows that, the dynamometer test facility was successfully installed, commissioned and documented to safely support the power train development and testing. We can currently test the EcoCAR vehicle and a number of other front-wheel-drive vehicles at our university campus using the eddy current chassis dynamometer.
Development Of A Supervisory Control Unit For A Series Plug-In Hybrid Electric Vehicle, Brian Neal Harries
Development Of A Supervisory Control Unit For A Series Plug-In Hybrid Electric Vehicle, Brian Neal Harries
Doctoral Dissertations and Master's Theses
A Series PHEV was chosen, as ERAU's entry into EcoCAR2 through a multidisciplinary architecture selection process. The series architecture was chosen for its mechanical feasibility, consumer acceptability and its performance on energy consumption simulations. The Series PHEV architecture was modeled using Matlab, Simulink, and dSPACE ASM tools, to create a plant model for controller development. A supervisory controller was developed to safely control the interactions between powertrain components. The supervisory control unit was tested using SIL and HIL methodologies. The supervisory controller was developed with an emphasis on fault detection and mitigation for safety critical systems. A power management control …
The Engineering Process For The Design Of A Motorcycle Chassis And Suspension, Derek J. Noce
The Engineering Process For The Design Of A Motorcycle Chassis And Suspension, Derek J. Noce
Doctoral Dissertations and Master's Theses
The thesis objective is to define and establish an engineering process for the design of a modern motorcycle chassis and suspension. The engineering process focuses on the interdisciplinary fields of engineering dealing with design and structural optimization. Specialized software, such as Motorcycle Kinematics, MATLAB, CATIA, HEEDS Professional, and NASTRAN are utilized. Motorcycle Kinematics is used to set up the preliminary motorcycle geometry, and MATLAB is a used to analyze the kinematics and stability of the motorcycle based on this geometry. CATIA (Computer Aided Three-Dimensional Interactive Application) is used to graphically illustrate the geometry of the motorcycle in three dimensional space. …
Nonholonomic Feedback Control Among Moving Obstacles, Stephen Gregory Armstrong
Nonholonomic Feedback Control Among Moving Obstacles, Stephen Gregory Armstrong
Doctoral Dissertations and Master's Theses
A feedback controller is developed for navigating a nonholonomic vehicle in an area with multiple stationary and possibly moving obstacles. Among other applications the developed algorithms can be used for automatic parking of a passenger car in a parking lot with complex configuration or a ground robot in cluttered environment. Several approaches are explored which combine nonholonomic systems control based on sliding modes and potential field methods.