Engineering Commons^™

Transportable, Jung Sub Kim, Ellie Kitabjian, David Yang, Christopher Macias

Mechanical Engineering

This document is a Final Design Review (FDR) report for team TransporTable, a quartet of mechanical engineers at California Polytechnic State University, San Luis Obispo (Cal Poly). It chronicles our design and validation process through final design phase. Our project: to design and test concepts for a stackable table that streamlines group work. After conducting user/sponsor interviews and background research, we found that many products already exist, but none meet the specific blend of requirements set out by our sponsor. They include fast deploying/stowing times, durability, stiffness, and manufacturability. We ideated on the table’s functions, distilling many ideas into three …

Space Suit Attachment Quick Release System, Elyse C. Gillis-Smith, Andres I. Elzaurdia, Cole H. Stanton, Michael T. Roth

Mechanical Engineering

NASA plans to make it back to the Moon by 2024 with their Artemis Program, and stay there for a longer period of time to conduct research which will support the future of space exploration. While on the lunar surface, astronauts need to maximize their efficiency by carrying tools on their Exploration Extravehicular Mobility Unit (xEMU), and to accommodate this need, the Extravehicular Activity (EVA) Tools Team is pursuing a utility belt concept. The objective of this project is to develop a system capable of interfacing between the utility belt and any given tool, while also accommodating numerous restrictions and …

Uav For Medical Equipment Distribution, Richard Barakat, Logan Christensen, Brandon Halebsky, Justin Slavick

Mechanical Engineering

This Final Design Review report documents the senior project participating in the Vertical Flight Society’s 38th Annual Student Design Competition sponsored by The Boeing Company. The goal of this project and competition is to develop an unmanned vertical lift for medical equipment distribution capable of safely delivering a 50 kg payload over distances up to 200 km. This system must be autonomous and have a backup plan to land if any part of the system malfunctions. We discuss the research and justification that drove the selection of the aircraft configuration, a winged quadcopter with a rear propeller. Furthermore, we document …

Hands-On 3d Printed Dynamics Activities, Dakota Baker, Jacob Lindberg, Andrew Meyenberg, Junnior Rodriguez

Mechanical Engineering

The advancement of 3D printing has allowed everyday individuals to rapid prototype and manufacture in a more efficient, cost-effective, and timely manner. This has paved the way for a more adaptable educational model, by allowing instructors to easily access alternative instruments for teaching. By providing students with tangible tools, they will better be able to grasp complex principles. Dynamics professors need a way in which they can easily access these academic tools, transport them to and from class, and teach multiple dynamics principles through variations of a single 3D printed kit. Interviews with professors and students were conducted to gain …

Power Output Modeling And Optimization For A Single Axis Tracking Solar Farm On Skewed Topography Causing Extensive Shading, Logan J. Smith

Master's Theses

Many utility-scale solar farms use horizontal single axis tracking to follow the sun throughout the day and produce more energy. Solar farms on skewed topography produce complex shading patterns that require precise modeling techniques to determine the energy output. To accomplish this, MATLAB was used in conjunction with NREL weather predictions to predict shading shapes and energy outputs. The MATLAB models effectively predicted the sun’s position in the sky, panel tilt angle throughout the day, irradiance, cell temperature, and shading size. The Cal Poly Gold Tree Solar Farm was used to validate these models for various lengths of time. First, …

Failure Analysis Of The Ulnar Collateral Ligament For Youth Baseball Pitchers, Carlos Soto

Master's Theses

The objectives of this study were to (1) use kinetics from motion analysis and inverse dynamics to calculate the stress experienced by the ulnar collateral ligament (UCL) during a typical pitch cycle, (2) compare calculated maximum UCL pitching stresses to failure properties, and (3) investigate correlations between UCL stress with anthropometric and pitching biomechanical parameters. Prior motion analysis experiments of eighteen 10- to 11- year-old baseball pitchers throwing 10 fastballs were analyzed. Maximum internal elbow varus torques were calculated using inverse dynamics methods during a typical pitch cycle. Calculations used axial loading stress equations and maximum internal elbow varus torques …

Cal Poly Preschool Learning Lab Music Garden Design, Karl Heuchert

Construction Management

Colleges, universities and other educational institutions are always looking to improve their learning environments in order to provide students with the best resources, so that they can get the best education. This idea of improving learning environments not only applies to higher education but should be applied to primary education, especially for younger children. Young children should have a learning environment that they can actively engage with that can help them become more creative. This project aims to create a new environment for preschoolers that can allow them to interact with to test their cognitive skills and to give the …

San Luis Obispo Botanical Garden Amphitheater Bench Project – Concrete Formwork Construction, Kyler N. Cruz

Construction Management

This paper summarizes the efforts towards constructing formwork for 10 concrete benches. The formwork construction is a part of the San Luis Obispo Botanical Garden amphitheater seating senior project. The project included the design, construction, and installation of precast concrete benches to create seating for 40 people. The project was completed by Kyler Cruz, Brandon Keefer, Sydnee Greer, Makenna Gitchell, Devin Barthmaier, and Anthony Masarweh. The concrete formwork consisted of plywood, 2x4 lumber for bracing, rebar cages, and foam inserts. The key considerations for this scope of work included: reinforcing rebar, the number of forms built, formwork failure, and the …

Journeyman International: Haiti Hac Innovation Center In Croix Des Bouquets, Brent K. Underwood

Construction Management

The purpose of this project was to create and provide the necessary pre-construction documents for a multi-purpose building in Croix des Bouquets, Haiti. This project aims to give occupants a new space to work freely in as it will be equipped with the essential needs. The rooms to be included within this building are offices, meeting rooms, general spaces, a workshop and computer lab – all of which will give the occupants the ability to work in an innovative environment. The project is overseen by three organizations. These groups are Journeyman International (JI), the Haitian American Caucus (HAC), and Third …

Learn By Giving: Non-Profit Information For Future Senior Projects, Ryan H. Proctor

Construction Management

This report details the processes, deliverables, and partnerships between various non-profit construction organizations to provide students with accessible information about non-profit construction companies for future senior projects. The information and deliverables of this senior project also to be found in the portal for the construction management preliminary senior project class (CM 460). One of the main goals of this senior project is to encourage students to sharpen construction skills while helping communities in need. This project consists of interviewing local, national, and international non-profit companies to compile information so students understand the different opportunities they have. The first deliverable that …

The Impact Of Myoblast Transplantation On Collateral Capillary Arteriogenesis And Macrophage Phenotype, Christine Hue Do

Biomedical Engineering

Gangrene, pain, loss of limb function, amputation, and death are only few of the grievous consequences associated with peripheral arterial disease (PAD), a vascular disease caused by an obstruction that narrows the blood vessels. Since some patients have collateral vessels that can re-route blood to its downstream destination, much focus has been spotlighted upon discovering the mechanism of this process, termed arteriogenesis, as well as cell therapies to increase arterial diameter of collateral vessels. Since some patients do not have native pre-existing collateral vessels, another method to re-route blood is through arterialized collateral capillaries (ACC), which is the conversion of …

Calibrated Tensioner For Total Knee Arthroplasty Gap Balancer, Lauren Henigman, Jaypreet Dhanota, Corey Catuara

Biomedical Engineering

The purpose of this project was to design a device that interfaces with the previously created gap balancer to simultaneously measure the gap between the femur and tibia and measure the tension in the ligaments of the knee. First, we met with Dr. Delagrammaticas to outline the key customer requirements: we wanted the device to be precise, sterilizable, reliable, and compatible with the gap balancer. Based on the customer requirements, we outlined the specifications that would drive our design and testing, which included precision, ease of use, size, and material properties. The design process began by using a morphology to …

Stair Wagon To Heaven, Maria Cristina Solis Andrade, Nick Ryan Dion, Alexander Pham

Biomedical Engineering

Our design process began with developing a list of questions for our sponsor based on the problem statement we were provided. We took these questions to interview our sponsor. From this interview, we derived a series of customer requirements, which were then used to develop our more specific engineering specifications (Table 8.1). We used these engineering specifications to develop a design morphology. Each of our group mates used the concepts from our design morphology to develop their own full concept sketches. We used Pugh charts to compare the different aspects of each design. The designs were compared based off their …

Groundwater Model Studying Effects Of Existing Recharge Basin And Proposed Subsurface Barrier For A Ranch In Santa Rosa Creek Watershed, Stefan J. Young

Master's Theses

A groundwater model of a 126.2-acre ranch in Cambria, California was expanded upon to analyze the effects of artificial recharge and a subsurface barrier. The ranch lies within the 48mi² Santa Rosa Creek Watershed along the Central Coast of California. The mainly agricultural watershed outfalls to the Pacific Ocean to its west. Creek Lands Conservation, a non-profit that aims to conserve and restore habitat along the Central Coast, plans to identify projects to restore stream flow during dry seasons in the creek that runs through the Santa Rosa Creek Watershed and to increase artificial groundwater recharge. This study focuses …

First Order Self-Oscillating Class-D Circuit With Triangular Wave Injection, Matthew J. Carroll

Master's Theses

An investigation into performance improvements to the modulator stage of a class-D amplifier is conducted in this thesis. Two of the standard topologies, namely class-D open-loop pulse-width modulation (PWM), and the improved self-oscillating feedback system are benchmarked against a topology which includes both a hysteretic comparator in a feedback loop and triangle wave injection. Circuit performance is analyzed by comparing how the triangle injection circuit handles known issues with open-loop and self-oscillating circuits. Using this analysis, it is shown that the triangle injection topology offers an improved power supply rejection ratio relative to open-loop PWM and reduces distortion generated by …

Energy Efficient Computing Using Scalable General Purpose Analog Processors, Ethan Paul Palisoc De Guzman

Master's Theses

Due to fundamental physical limitations, conventional digital circuits have not been able to scale at the pace expected from Moore’s law. In addition, computationally intensive applications such as neural networks and computer vision demand large amounts of energy from digital circuits. As a result, energy efficient alternatives are needed in order to provide continued performance scaling. Analog circuits have many well known benefits: the ability to store more information onto a single wire and efficiently perform mathematical operations such as addition, subtraction, and differential equation solving. However, analog computing also comes with drawbacks such as its sensitivity to process variation …

Comparison Of Hilbert Transform And Derivative Methods For Converting Ecg Data Into Cardioid Plots To Detect Heart Abnormalities, Robert George Goldie

Master's Theses

Electrocardiogram (ECG) time-domain signals contain important information about the heart. Several techniques have been proposed for creating a two-dimensional visualization of an ECG, called a Cardioid, that can be used to detect heart abnormalities with computer algorithms. The derivative method is the prevailing technique, which is popular for its low complexity, but it can introduce distortion into the Cardioid plot without additional signal processing. The Hilbert transform is an alternative method which has unity gain and phase shifts the ECG signal by 90 degrees to create the Cardioid plot. However, the Hilbert transform is seldom used and has historically been …

Implementing A Data Acquisition System For The Training Of Cloud Coverage Neural Networks, Weston C. Montgomery

Master's Theses

Cal Poly is home to a solar farm designed to nominally generate 4.5 MW of electricity. The Gold Tree Solar Farm (GTSF) is currently the largest photovoltaic array in the California State University (CSU) system, and it was claimed to be able to produce approximately 11 GWh per year. These types of projections come from power generation models which have been developed to predict power production of these large solar fields. However, when it comes to near-term forecasting of power generation with variable sources such as wind and solar, there is definitely room for improvement.

The two primary factors that …

Using Pitch Tipping For Baseball Pitch Prediction, Brian Ishii

Master's Theses

Data Analytics and technology have changed baseball as we know it. From the increase in defensive shifts to teams using cameras in the outfield to steal signs, teams will try anything to win. One way to gain an edge in baseball is to figure out what pitches a pitcher will pitch. Pitch prediction is a popular task to try to accomplish with all the data that baseball provides. Most methods involve using situational data like the ball and strike count. In this paper, we try a different method of predicting pitch type by only looking at the pitcher's pose in …

Understanding The Impact Of The Covid-19 Pandemic Within Educational Communities Using Longitudinal Analysis, Alexa Steidl

Master's Theses

At California State University, Los Angeles and California Polytechnic University, San Luis

Obispo, a longitudinal survey was created in response to the COVID-19 pandemic for students within their respective engineering departments. A combination of nonparametric and longitudinal analysis is performed to evaluate the impacts of the transition to a virtual educational environment and the stressors brought on by the global pandemic. Additional qualitative evaluation is performed to gain insight and make program recommendations to enhance the resilience of individuals in the academic systems. Results demonstrate a large shift in circumstances immediately at the start of the pandemic, with a variety …

The Car (Confront, Address, Replace) Strategy: An Antiracist Engineering Pedagogy, Amman Fasil Asfaw

Master's Theses

The CAR (confront, address, replace) Strategy is an antiracist pedagogy aiming to drive out exclusionary terminology in engineering education.

“Master-slave” terminology is still commonplace in engineering education and industry. However, questions have been raised about the negative impacts of such language. Usage of exclusionary terminology such as “master-slave” in academia can make students—especially those who identify as women and/or Black/African-American—feel uncomfortable, potentially evoking Stereotype Threat (Danowitz, 2020) and/or Curriculum Trauma (Buul, 2020). Indeed, prior research shows that students from a number of backgrounds find non-inclusive terminologies such as “master-slave” to be a major problem (Danowitz, 2020). Currently, women-identifying and gender …

Design And Modeling Of A Distributed Network For The Dc House Project, Lauren N. Rotsios

Master's Theses

This thesis covers the design and simulation of a model for a distributed network of DC Houses in MATLAB Simulink. The model will allow for sharing of power between houses within the network. The developed model consists of five separate DC House branches with local power generation. Each branch consists of a PV MPPT charge controller subsystem, a resistive load, and a bidirectional buck-boost converter subsystem. The high voltage side of every bidirectional buck-boost converter is connected together through the transmission line at a single high voltage DC bus. The performance of the individual components of the model is verified …

Modeling And Solving The Outsourcing Risk Management Problem In Multi-Echelon Supply Chains, Arian A. Nahangi

Master's Theses

Worldwide globalization has made supply chains more vulnerable to risk factors, increasing the associated costs of outsourcing goods. Outsourcing is highly beneficial for any company that values building upon its core competencies, but the emergence of the COVID-19 pandemic and other crises have exposed significant vulnerabilities within supply chains. These disruptions forced a shift in the production of goods from outsourcing to domestic methods.

This paper considers a multi-echelon supply chain model with global and domestic raw material suppliers, manufacturing plants, warehouses, and markets. All levels within the supply chain network are evaluated from a holistic perspective, calculating a total …

Transfer Learning Approach To Powder Bed Fusion Additive Manufacturing Defect Detection, Michael Wu

Master's Theses

Laser powder bed fusion (LPBF) remains a predominately open-loop additive manufacturing process with minimal in-situ quality and process control. Some machines feature optical monitoring systems but lack automated analytical capabilities for real-time defect detection. Recent advances in machine learning (ML) and convolutional neural networks (CNN) present compelling solutions to analyze images in real-time and to develop in-situ monitoring.

Approximately 30,000 selective laser melting (SLM) build images from 31 previous builds are gathered and labeled as either “okay” or “defect”. Then, 14 open-sourced CNN were trained using transfer learning to classify the SLM build images. These models were evaluated by F1 …

Evaluation Of Blood Vessel Mimic Scaffold Biocompatibility, Nicole M. Abraham

Master's Theses

The Tissue Engineering Research Lab at California Polytechnic State University, San Luis Obispo focuses on creating tissue-engineered blood vessel mimics (BVMs) for use in preclinical testing of vascular devices. These BVMs are composed of electrospun scaffolds made of an assortment of polymers that are seeded with different cell types. This integration of polymers with cells leads to the need for biocompatibility testing of the polymer scaffolds. Many of the lab’s newest scaffolds have not been fully characterized for biologic interactions. Therefore, the first aim of this thesis developed methods for in vitro cytotoxicity testing of polymers used in the fabrication …

A Github-Based Voice Assistant For Software Developers And Teams, Siriwan Sereesathien

Master's Theses

Software developers and teams typically rely on source code and tasks management tools for their projects. They tend to depend on different platforms such as GitHub, Azure DevOps, Bitbucket, and GitLab for task-tracking, feature-tracking, and bug-tracking to develop and maintain their software repositories. Individually, developers may lose concentration when having to navigate through numerous screens consisting of various platforms to perform daily tasks. Additionally, while in meetings (non-virtual), teams are often separate from their machines and often would have to rely on pure recollection of the tasks and issues related to their work. This can delay the decision-making process and …

Modeling The Groundwater Basin In The Northern Cities Management Area, Allyson Swain

Master's Theses

A model was developed to simulate the groundwater of 8,300 acres of the Northern Cities Management Area (NCMA), which encompasses the northern portion of the Arroyo Grande Watershed and a small subset of the Santa Maria Valley Groundwater Basin. This watershed and groundwater basin is located on the coast and contains Oceano and the Cities of Arroyo Grande, Grover Beach, Pismo Beach. Groundwater in the NCMA is used heavily for agricultural irrigation in the southern portion and municipal applications in the northern portion. Up to 18 of these municipal wells and over 50 irrigation wells are drawing groundwater at any …

Passive Disposal Of Launch Vehicle Stages In Geostationary Transfer Orbits Leveraging Small Satellite Technologies, Marc Alexander Galles

Master's Theses

Once a satellite has completed its operational period, it must be removed responsibly in order to reduce the risk of impacting other missions. Geostationary Transfer Orbits (GTOs) offer unique challenges when considering disposal of spacecraft, as high eccentricity and orbital energy give rise to unique challenges for spacecraft designers. By leveraging small satellite research and integration techniques, a deployable drag sail module was analyzed that can shorten the expected orbit time of launch vehicle stages in GTO. A tool was developed to efficiently model spacecraft trajectories over long periods of time, which allowed for analysis of an object’s expected lifetime …

Scalable Cognitive Radio Network Testbed In Real Time, Kevin Z. Yu

Master's Theses

Modern society places an increasingly high demand on data transmission. Much of that data transmission takes place through communication over the frequency spectrum. The channels on the spectrum are limited resources. Researchers realize that at certain times of day some channels are overloaded, while others are not being fully utilized. A spectrum management system may be beneficial to remedy this efficiency issue. One of the proposed systems, Cognitive Radio Network (CRN), has progressed over the years thanks to studies on a wide range of subjects, including geolocation, data throughput rate, and channel handoff selection algorithm, which provide fundamental support for …

The Application Of Post-Hoc Correction Methods For Soft Tissue Artifact And Marker Misplacement In Youth Gait Knee Kinematics, Kaila L. Lawson

Master's Theses

Biomechanics research investigating the knee kinematics of youth participants is very limited. The most accurate method of measuring knee kinematics utilizes invasive procedures such as bone pins. However, various experimental techniques have improved the accuracy of gait kinematic analyses using minimally invasive methods. In this study, gait trials were conducted with two participants between the ages of 11 and 13 to obtain the knee flexion-extension (FE), adduction-abduction (AA) and internal-external (IE) rotation angles of the right knee. The objectives of this study were to (1) conduct pilot experiments with youth participants to test whether any adjustments were necessary in the …