Engineering Commons^™

End-To-End Autonomous Quadcopter Using Reinforcement Learning, Mohamed Marwan Chawa

Theses and Dissertations

This thesis investigates the potential of Reinforcement Learning (RL) for achieving robust and adaptable quadcopter control, focusing on trajectory and attitude stabilization. We compare state-of-the-art RL algorithms, specifically Proximal Policy Optimization (PPO), against traditional Proportional-Integral-Derivative (PID) controllers across three tasks: hovering, slow trajectory following, and fast trajectory following. To enhance realism, we employ a modified PyFlyt simulation environment with a high-fidelity Crazyflie 2.x model, accounting for motor dynamics, noise, wind disturbances, and aerodynamic drag.

The challenge of operating a quadcopter can be divided into two distinct parts: planning a flight path and actually following that path. Our focus is on …

A Comparison Of Polymers By Layer Deposition And Open Molding Additive Processes Through Fused Granulate Fabrication, Alexander Ray Gibson

Theses and Dissertations

Additive manufacturing (AM) continues to offer new possibilities in both production and economics. Various industries have quickly adopted AM to rapidly produce parts that would be difficult or cost prohibitive otherwise. Despite ongoing innovations that expand the technology's capabilities, significant limitations persist. Most AM processes are restricted by materials available, an inability to produce large parts, or by not achieving material deposition speeds and volumes to allow for certain products feasible. In addition, tight tolerances for features and surfaces cannot be produced without substantial post processing. Some of the post-processing techniques can even affect the material properties of the finished …

Enhancing Concrete Sustainability With Self-Healing Technologies, Al Shimaa Abdullatif

Theses and Dissertations

Thanks to its strength, durability and affordability, Portland cement concrete is the most commonly used building material worldwide. However, concrete cracking is inevitable due to numerous factors including shrinkage, exposure to external chemicals, internals reactions, excessive loads, to name but a few. Self-healing is a promising technique that can enable concrete to autogenously heal cracks and alleviate much of the damage. Such healing can without a doubt extend the service life with less need for external repair works therefore it contributes to sustainability. Over the years, several means of self-healing agents have been explored including bio-based procedures and the incorporation …

Tensile Strain Validation Of Welded Wire Reinforcement, Alvaro Montes

Theses and Dissertations

There have been historical concerns regarding the ductility of welded wire reinforcement (WWR). Recent changes in ACI 318-19 now require all grades of A615 and Grade 100 A706 nonprestressed steel reinforcement to have a ratio of tensile strength to yield strength greater than 1.10 and 1.17 respectively. Although this code requirement does not currently apply to WWR, this preemptive study investigated the current state of the art of WWR manufactured in North America in preparation for such a possibility. This project included the tensile-testing of approximately 365 WWR material specimens of various cross-sectional sizes to determine the ratio of tensile-to-yield …

Post-Processing National Water Model Long-Range Forecasts With Random Forest Regression In The Cloud To Improve Forecast Accuracy For Decision-Makers And Water Managers, Jacob Matthew Anderson

Theses and Dissertations

Post-processing bias correction of streamflow forecasts can be useful in the hydrologic modeling workflow to fine-tune forecasts for operations, water management, and decision-making. Hydrologic model runoff simulations include errors, uncertainties, and biases, leading to less accuracy and precision for applications in real-world scenarios. We used random forest regression to correct biases and errors in streamflow predictions from the U.S. National Water Model (NWM) long-range streamflow forecasts, considering U.S. Geological Survey (USGS) gauge station measurements as a proxy for true streamflow. We used other features in model training, including watershed characteristics, time fraction of year, and lagged streamflow values, to help …

Local Food System Planning On Multiple Governance Scales: A Grounded Theory Analysis, Decker Ure

Theses and Dissertations

Local food systems (LFS) comprise the people, policies, infrastructure and practices of food production, distribution, and consumption in localized areas. LFS are becoming an increasingly important part of urban sustainable development and have recently gained significant traction in the urban planning and sustainable community spheres. Worldwide shocks to global food systems such as the COVID-19 pandemic and the Ukraine-Russia war have further elevated global interest in LFS, bringing local food to the forefront of many communities as they try to insulate themselves and their food supply from future risk. However, despite this growing interest in and policy momentum for local …

Kinetic Modeling Of Bacteria Removal From Suspensions By Magnetic Nanoparticle Capture And Magnetic Separation, Bowen J. Houser

Theses and Dissertations

This thesis investigates the kinetic modeling of bacteria removal from suspensions using magnetic nanoparticle (MNP) capture and magnetic separation. Functionalized magnetic nanoparticles, especially those coated with polydopamine (pDA), were employed to bind with various bacterial species in phosphate-buffered saline (PBS), apple juice, whole blood, and its components. By analyzing the capture efficiency and kinetics of capture across different bacterial species and mediums, we developed mathematical models describing the capture kinetics of bacteria by the pDA-MNPs. Experimental results demonstrated that pDA-coated MNPs achieved high capture efficiency with certain Gram-positive species like Staphylococcus aureus, and one Gram-negative species, Neisseria perflava; however, capture …

Phosphorus Adsorption Capacity Of Volcanic Scoria, Easton Jeffrey Perkins

Theses and Dissertations

Phosphorus (P) pollution in stormwater runoff poses a significant threat to water quality, contributing to eutrophication and ecosystem degradation. This research evaluates the potential of volcanic scoria (VSco), an abundant and cost-effective resource in Utah, USA, to influence P concentrations in urban stormwater systems. Batch adsorption experiments examined the behavior of VSco across three particle sizes—fine (<0.841 mm), medium (0.841–2 mm), and granular (2.38–9.5 mm)—under conditions mimicking stormwater scenarios. The results reveal that fine VSco exhibited higher adsorption efficiency than medium and granular sizes, achieving notable P removal at higher concentrations. However, at lower concentrations, fine VSco showed potential for P release due to desorption of pre-existing P. Medium and granular VSco showed minimal adsorption capacity and, in some cases, acted as P sources, highlighting a dual potential depending on stormwater conditions. Adsorption isotherms indicate that the adsorption behavior of fine VSco aligns with the Langmuir model, with a finite and relatively low adsorption capacity. Calculated distribution coefficient (Kd) values for fine VSco ranged from 0.04 to 0.005 L/g, indicating weak adsorption efficiency compared to materials like activated carbon (1–10 L/g) or soils with moderate adsorption capacity (0.1–0.5 L/g). Loss-on-ignition tests confirmed that VSco’s performance is driven by its physical and chemical properties, particularly its calcium content, rather than organic matter. The study emphasizes caution in applying fine VSco for stormwater remediation due to its potential to release P under typical runoff conditions. However, fine VSco may still be viable in specific scenarios where P levels are higher, such as in stormwater hotspots or localized areas with elevated concentrations, allowing for targeted remediation. The research underscores the need for further testing to refine VSco’s applications, particularly in low-impact development (LID) practices, such as infiltration basins and rain gardens, to effectively manage P levels while supporting ecological and aesthetic goals. These findings contribute to understanding the complex role of VSco in urban stormwater systems, offering insights for sustainable water quality management and nutrient cycling in urban landscapes.

Developing A New Liquefaction Ejecta Prediction Model Considering Soil Properties Of Non-Liquifiable Surface Layers Using New Large Database From The 2012 Emilia Romagna, Italy Earthquakes, Jonah Bradley Dundas

Theses and Dissertations

The presence of a non-liquefied crust overlying a liquefied layer has been found to have a significant effect on sand ejecta and surficial liquefaction damage, as observed by Ishihara (1985). Following the 2010-2011 Canterbury seismic sequence in New Zealand, almost no foundation deformation occurred in areas with liquefaction susceptible soils overlain by at least a 3 meter thick crust [1]. In contrast, the 2012 Emilia-Romagna earthquake in Italy provided surface evidence of liquefaction despite 6+ meter thick crusts. Several researchers have proposed liquefaction prediction models [e.g. LPI [2], Ishihara Curves [3], LSN [4], LPIISH [5] and the methods proposed by …

Assessing Coincidence Of Satellite Acquisitions And Flood Events To Predict Suitability For Flood Map Synthesis, Lyle Dale Prince

Theses and Dissertations

Flooding is a global problem that impacts people, communities, and governments every year. Better understanding of flooding in an area can enable improved emergency response before a flood hits. Flood maps are a crucial tool to translate what for most is an abstract flow, into a more understandable and actionable representation of who and what are at risk. Satellite based flood maps are a useful tool that has potentially global applications. We developed methods to determine which areas are suitable for generating satellite-based synthetic flood maps. For our processes we used Forecasting Inundation Extents using REOF analysis (FIER): a data-driven …

A Comparison Of Rfssw And Rsw For Automotive Manufacturing, Damon Michael Gale

Theses and Dissertations

Historically, automotive body panels have been made of steel and joined by a process called resistance spot welding (RSW). However, in efforts to reduce vehicle weight to improve the energy efficiency of the vehicle, automotive manufactures have begun substituting aluminum in place of steel. While aluminum can be joined with RSW, a myriad of challenges arise from doing so. These challenges result in less consistent weld quality and accelerated electrode wear. Refill friction stir spot welding (RFSSW) is an emerging joining technology that could replace RSW as it is believed to be capable of creating superior joints in thin sheet …

Design & Development Of Fr1 Band Antenna For V2x Communication, Sujanth Narayan Kg

Theses and Dissertations

The developing trends in the automotive industry are evolving towards connected and autonomous vehicles that provide various advantages namely enhanced safety & security, congestion less traffic, smart mobility, and environmental sustainability at a lower cost with greater cause to the society. Vehicle to Everything (shortly V2X) Communication plays a significant role in autonomous driving. Salient features of V2X provide improved better driving experience and traffic efficiency even during fast moving scenarios.

V2X technologies are being carried out in sub 6 GHz range mainly at the 5.9 GHz band called the Dedicated Short-Range Communication (DSRC) based on IEEE 802.11p providing support …

Site Amplification In The Salt Lake Valley, Utah, During The 2020 Magna Earthquake, Blair A. Hanson

Theses and Dissertations

Site amplification in the Salt Lake Valley, Utah, has been a focus for both geologists and engineers due to its complex geology and seismic vulnerability. This study utilizes data from the 2020 Magna Earthquake to analyze site amplification from previously unavailable strong ground motion data. Ground motion data from the University of Utah Regional Seismic Network and the National Strong Motion Project, combined with extensive soil profiles, was analyzed using the program DEEPSOIL. The study compares computed motions with measured motions, revealing differences in site amplification across the Salt Lake Valley. Notably, the highest amplification was observed at longer periods …

Discharge-To-Water Level Conversion Using Monthly Duration Curves (Dwl-Mdc): Enhancing The Utility Of The Geoglows Ecmwf Hydrological Model, Darlly Judith Rojas Lesmes

Theses and Dissertations

Flood early warning systems are crucial for disaster risk reduction strategies, enabling communities to take timely action against threats. However, the effectiveness of these systems depends on accurate and timely hydrological data, particularly river discharge and water level measurements. Unfortunately, many regions, face significant challenges in obtaining hydrological data, especially discharge data due to outdated rating curves, high equipment costs, and logistical constraints. Water level measurements, by contrast, offer reduced uncertainty and are often more accessible, providing an alternative for hydrological modeling in data-scarce regions. To address these limitations, we developed and validated the Discharge-to-Water Level Conversion Using Monthly Duration …

Development Of Sensing Capabilities For Agricultural Robotics, Carter Noh

Theses and Dissertations

Agricultural robotics is a rapidly growing industry with the possibility to revolutionize food production. Agricultural robots often require custom sensing solutions to perform specific tasks. Developing the appropriate sensing capabilities for an application is therefore an important step in the automation process. In this thesis I present two case studies in developing sensing capabilities for agricultural robotics applications. First, I introduce a sensor that can provide simultaneous measurements of force and position. The sensor was developed to enable high-throughput measurement of maize stalk stiffness on a robot platform. It uses multiple sets of strain gauges on a cantilever beam to …

Extracting Speech Content From High-Amplitude Background Machine Noise, Curtis L. Garner

Theses and Dissertations

The research presented in this dissertation aims to address the need for improved communication between heavy machinery operators and external personnel, aiming to improve safety and efficiency by overcoming the communication barriers posed by equipment noise and cab insulation. The primary purpose of this research was to develop a hands-free communication system that allows the operator to hear speech from outside the cab without requiring any personal communication devices like radios or headsets. Key objectives included effective speech extraction from ambient noise and accurate estimation of the location of the speaker. Operating without active user control, the system emphasizes clarity …

Applications Of Phosphorus Geochemistry To Utah Lake, Jacob Barry Taggart

Theses and Dissertations

This compilation of studies provides an examination of phosphorus dynamics in the suspended solids, water column, and lakebed sediments of Utah Lake, a large, shallow, and phosphorus-rich water body. The first study introduces a novel phosphorus microfractionation (P-MF) method designed for small samples of suspended solids and sediments. This method reveals that suspended solids in Utah Lake can have a significantly higher phosphorus content across most fractions compared to lakebed sediments, highlighting the importance of considering suspended solids in nutrient management strategies. The second study analyzes historical phosphorus mass and concentrations, demonstrating that water column phosphorus levels have remained stable …

Physics-Based And Data-Driven Constitutive Modeling Of Unsaturated Soils Under Multi-Physics Loading Conditions, Mohsen Ajdari

Theses and Dissertations

Understanding the behavior of unsaturated soils under multi-physics loading is crucial for addressing several challenges related to emerging geo-energy technologies, climate change, and geohazard mitigation. The main objective of this research is to enhance the state of the art for modeling unsaturated soils under multi-physics loading conditions through physics-based and data-driven approaches. Toward this objective, this dissertation is divided into two distinct yet interrelated parts. In the first part (Chapters 2, 3, and 4), thermodynamic principles are employed to develop new constitutive functions to describe soil suction and stress-dilatancy of unsaturated soils under temperature-dependent conditions. Building upon the insights gained …

Assessing Plate Load Testing And Modulus Of Subgrade Reaction Determination For Pavements, Jami Lynn Rushing

Theses and Dissertations

This thesis aims to: 1) determine the effect of plate size on the modulus of subgrade reaction (k), 2) investigate the differences between the ASTM D1196-21 and CRD-C 655-95 plate load test methods, and 3) develop new effective k curves. 150 plate load tests were executed on three subgrade materials under varying base course thicknesses. Plate load testing was designed to evaluate various plate sizes and testing standards (e.g., the military standard – CRD-C 655-96 and the ASTM standard – ASTM D1196-21). By performing plate load tests on varying base course thicknesses, newly developed effective k curves were developed from …

A Case Against Exclusive Reliance On Volumetric Mixture Characterization For Future Asphalt Pavements And The Advancement Of A Viable Alternative, Jonathan Randy Easterling

Theses and Dissertations

Volumetric properties have been the cornerstone of asphalt mixture design and control dating back to the early 20th century. However, social and economic drivers have caused the asphalt industry to make changes in materials and processes used to produce mixtures that have stretched the limits of volumetric centric methodologies. The primary objectives of this dissertation were to present an extensive case on how volumetrics is limited in their ability to characterize asphalt mixtures and to advance the body of knowledge of a viable alternative. State agency specifications were examined and found that Departments of Transportation (DOTs) were using asphalt volumetric …

Enhanced Intellectual Property Protection Mechanisms Towards Collaborative Data Sharing In Metal-Based Additive Manufacturing, Durant Hayes Fullington

Theses and Dissertations

This dissertation aims to develop effective methodologies towards enhanced intellectual property protections for data sharing frameworks in metal-based additive manufacturing (AM). Currently, many small-to-medium sized manufacturers face data availability challenges due to the prohibitive high cost to collect, process, and analyze large amounts of process-related data for AM. Because these manufactures rely heavily on small-scale data, it can be difficult for them to effectively train complex machine learning (ML) algorithms, which are commonly used for AM process monitoring. One popular solution is to develop collaborative data sharing frameworks, where multiple independent AM users can share their data to increase the …

Investigation Of Coupled Fluid-Structure Interactions In Supersonic Flows, Seshendra Palakurthy

Theses and Dissertations

The skin panels used in high-speed flights are exposed to various types of loads, such as inertial, elastic, and aerodynamic loads. In addition, oblique shock impingement can cause flow separation and unsteady aerodynamic loading, which can reduce vehicle performance and result in acoustic noise and viscous heating. These loads, when combined, can result in a complex dynamic response, such as flutter. Flutter is characterized by sustained unsteadiness or structural vibrations. Although flutter might not be immediately harmful, it can lead to fatigue failure of the structural components. A vast amount of literature already exists on the panel flutter induced by …

Crystal Plasticity Modeling To Capture Microstructural Variations In Cold-Sprayed Materials, Aulora Gail Williams

Theses and Dissertations

The high-velocity impact of powder particles in cold-spray additively manufactured (CSAM) parts creates intersplat boundaries with regions of high dislocation densities and sub-grain structures. Upon microstructure and mechanical characterization, CSAM Aluminum 6061 showed non-uniformity, with spatial variation in the microstructure and mechanical properties affecting the overall response of the additively manufactured parts. Post-processing treatments are conducted in as-printed samples to improve particle bonding, relieve residual stresses, and improve mechanical properties. In this work, we attempt to implement the effects of grain size and distribution of smaller grains along the intersplat boundaries using the grain size distribution function and powder size …

Experimental And Numerical Investigation Of Phase Change Material Melting Cycle In Microgravity, Ethan Michael Schuetzle

Theses and Dissertations

Efficient thermal management of spacecraft systems is crucial to overcome the extreme thermal conditions in space. Phase change materials (PCMs) offer significant advantages in thermal energy storage (TES) systems due to their high latent heat of fusion, the amount of energy stored or released during phase transitions. However, PCMs face limitations due to low thermal conductivity, especially in microgravity where heat transfer is primarily through conduction. This research addresses this issue by incorporating a 3D-printed aluminum lattice structure to enhance heat transfer to PCMs. Experimental data from sub-orbital flight tests and ground-based experiments, coupled with numerical simulations, are used to …

The Plastics Crisis: Responsible Recycling In Civil Engineering And Infrastructure, Jason Howell Stewart

Theses and Dissertations

A global plastics crisis exists with around 400 million metric tons (MMT) of plastics production and 350 MMT of plastics waste generated annually around the globe. Plastics are durable and essentially non-biodegradable, so they accumulate in both terrestrial and marine environments as pollution and within landfills without breaking down over time. Plastics are ubiquitous in 21st-century society and culture, comprising essential elements in most industries including packaging, transportation, electrical/electronics, and building/construction. The role of civil engineering and infrastructure in addressing the plastics crisis was specifically explored. Responsible plastics recycling yields products with improved engineering properties, performance characteristics, marketability, and/or manufacturing …

Predicting Vegetation Override Force For Off-Road Autonomy, Marc Nicholas Moore

Theses and Dissertations

Vegetation override is an important aspect of off-road ground vehicle mobility. An autonomous ground vehicle’s (AGV) perception system must distinguish between vegetation that can be easily driven through from vegetation that cannot. Predicting the resistance of vegetation could allow path- planning systems to make this distinction. However, despite its importance, direct measurement of vegetation resistance is rare, as most studies use indirect proprioceptive data, such as inertial measurements, as proxies for override force. Notably, there is a lack of empirical data on the override resistance of small stems (< 2.5 cm) and clusters of vegetation on medium-sized (approx. 1000kg) vehicles. To address this gap, a comprehensive dataset of override measurements was collected for clumps of small vegetation relevant to intermediate-sized AGVs navigating off-road terrain. This dataset includes over 70 recordings using the Robot Operating System (ROS) during controlled driving experiments through small trees, grasses, and bushes. The collected data includes light detection and ranging (LiDAR) scans, imagery, force measurements from integrated load cells, and simultaneous localization and mapping (SLAM) information. A key contribution of this research is the development and calibration of a custom push bar system equipped with load cells to directly measure override forces. These measurements are compared to empirical models previously developed by the U.S. Army Corps of Engineers for larger single-stem vegetation. A preprocessing pipeline was developed to automatically extract and label LiDAR and camera data according to these force measurements. This self-labeled dataset was then used to train machine learning models that predict override resistance of vegetation from LiDAR and camera scans alone. This research characterizes the relationship between override forces and the observable features of vegetation as measured by LiDAR and camera sensors. Deep learning models were developed and trained to predict override forces based on different input modalities and features derived from point clouds and images. The performance of these models was compared across various input features to investigate how deep learning can create a generalizable and accurate force prediction system.

On Topological Measures And Network Vulnerability Patterns: A Review And Comparative Analysis, Saviz Saei

Theses and Dissertations

Despite much hope for climate change to slow down or even reverse, younger generations face a future overshadowed by extreme events. The indisputable reality is that unless the United Nations establishes comprehensive and sustained climate justice policies, children today will experience five times more extreme events than those that took place a century ago. On Monday, July 3rd of 2023, an unprecedented peak in global temperatures was documented, marking the highest global temperature ever recorded, as the U.S. National Centers for Environmental Prediction reported. These increasing temperatures indicate the ongoing and intensifying phenomenon of climate change, which amplifies the frequency …

Drainage Area Limitations Of Single Watershed, Peak Flow Estimates From Nrcs Methods, Timothy Alexander Maughan

Theses and Dissertations

Most roadway design sections of state Departments of Transportation predict peak flow for culvert design using Natural Resources Conservation Service (NRCS) TR-20 methodology. Even though the approach is more than 50 years old, there is no clear guideline for how large a single watershed drainage area may be while remaining appropriate for predicting peak discharge with this method. Our objective is to identify the drainage area where TR-20 peak flow predictions significantly deviate from flow frequency predictions. We aim to recommend to the Nebraska Department of Transportation (NDOT) a range of basin drainage areas appropriate for predicting peak flow using …

Traveling-Wave Vibration Control And Comparison Of Individuals With Insomnia And Good Sleepers Using Eeg Spectral Power And Sample Entropy, Joseph T. Lecheminant

Theses and Dissertations

This thesis explores the intersection of whole-body vibration (WBV) and neurophysiological analysis to improve sleep quality and understanding of insomnia. The work is divided into two primary areas: the development of a novel traveling-wave vibration system for sleep enhancement and the analysis of electroencephalography (EEG) metrics in individuals with insomnia versus good sleepers. A vibrating sleep system capable of generating programmable traveling-wave patterns is designed and prototyped. Through iterative development and user trials, the system enables highly controlled mechanical stimulation in the form of traveling-wave vibration. Key advancements include independent amplitude and speed modulation and customizable wave patterns. Simple wave …

Cellular Air Quality Sensors With Lora Backchannel A Robust Sensor Suited For Remote Deployment In Harsh Environments, Joseph R. Miera

Theses and Dissertations

Air quality significantly impacts health and overall quality of life, making its measurement essential. However, most affordable air quality devices are designed only for use within WiFi range and cannot handle extreme temperatures, limiting their usefulness for people in remote or extreme environments, such as regions with harsh winter climates. This limitation is concerning, as winter often brings worse air quality due to temperature inversions that trap pollutants and increase fuel burning for heating. Inversion is a problem as close to home as Utah Valley, and as far away as Ulaanbaatar, Mongolia. Most low-cost air quality sensors are not built …