Engineering Commons^™

Battery Hardware Simulator, Kian N. Orang, Marcelo Garcia

Electrical Engineering

This project aims to develop a battery hardware simulator, which will serve as a tool for studying microgrids. The primary objective is to create a simulation system that can emulate various battery technologies that are used in microgrids, including lithium-ion and lead acid. By utilizing this battery simulator, Cal Poly students can safely test battery management systems and battery-sensitive electronics without the inherent risks associated with real batteries. Our project implemented this design with a 4-quadrant programmable power supply (ITECH) connected to an AP Systems grid tied inverter. The power supply acts as the battery which can receive or supply …

Development Of Multiple Input Single Output Dc-Dc Converter, Ryan Bailey, Miguel Carmona, Jose Velez-Lopez

Electrical Engineering

This senior project report details the testing and validation of the designed DC-DC Multiple Input Single Output converter. The MISO uses four-switch buck-boost topology to output a single 48V from multiple nominal 24V inputs. The previous iteration of the MISO was plagued with an overheating mosfet that would drastically reduce the lifespan of the boards and reduce efficiency. This newest iteration includes more ground panes to combat the issues. In addition, the 200W MISO board was redesigned to utilize an edge connector for secure installment, removal, and replacement in the actual DC House system panel. The slots also have a …

Smart Table Top, Conner Sima, Nathan R. Jaggers, Jacob Barnes

Electrical Engineering

Dungeons and Dragons 5th Edition (D&D) is a tabletop role playing game (TTRPG) with complicated mechanics and a seemingly overwhelming amount of information. D&D players are often looking for ways to more effectively track information and products that enhance their game experience. One such product is a custom miniature; players use these to track their character’s location and for the enjoyment of creating a physical representation of their imagination. Virtual Tabletops (VTT’s) were developed to make the entire experience digital. The digital nature of VTT’s make all of the game’s rules and mechanics accessible at the click of the mouse; …

Wireless Energy Harvesting System, Matthew Palma, Audrey Toop, Andrew Fahey

Electrical Engineering

The modern world is built upon wireless transmission of data. The signals that carry this data travel through the air, an untapped source of power. Unreceived transmissions are dissipated into useless forms of energy when they should be reclaimed. Wireless electronics can theoretically be powered by harvesting energy from the electromagnetic signals in the wireless internet frequency band. The aim of this project is to develop a system to capture ambient energy, convert it into DC power, and store the power for later use. The product will consist of three subsystems: an antenna receiver, a rectifier and voltage-multiplier, and a …

Sky Survey Radio Telescope, Jack E. Mcguigan

Electrical Engineering

This document outlines the design of a radio telescope designed to perform hydrogen line sky surveys. The telescope produces radio images mapping the intensity and relative velocities of hydrogen concentrations to their sky coordinates. Over the course of a day, the telescope images the regions of space visible to it, allowing sky survey imagery to be updated daily. Sky survey images are comprised of an array of pixels corresponding to specific sky coordinates. Each 8-bit RGB pixel contains information on the concentrations of hydrogen in the brightness and relative velocity in the color. Radio images mapping the concentrations and velocities …

Spice Modeling Of Biosensing Field-Effect Transistor, Alex Castro

Electrical Engineering

This project created a user manual on how to generate an easily configurable and implementable Spice model for Field Effect Transistor (FET) devices created in the Cal Poly clean room. The document contained step by step procedures depicting the proper execution techniques and example results for different experiments required to gather the proper information for these models. This testing methodology was shown for finding the numerous different device parameters of a FET, including the I-V curves, threshold voltage, and subthreshold current values. The manual then described how to transfer this data into a new Spice model to allow for simulation …

Reaction Wheel Based Rocket Active Spin Stabilization, Tanuj Vemuri

Electrical Engineering

Cal Poly Space Systems is the high-powered and experimental rocketry club at Cal Poly SLO. They aim to design, test, and launch fully integrated launch vehicles. In order to create efficient and reliable vehicles, stabilization systems must be implemented. One parameter that can be actively stabilized is the vehicle’s roll. The roll of the vehicle can have noticeably effects on vehicle performance, as uncontrolled roll leads to decreased system stability in flight. Un-controlled roll can also have negative impacts on the quality of onboard video, which is used for post-flight analysis and marketing.

Reaction wheels are a popular method for …

Directional Speaker, Gabriel Tramontina Ceribelli, Vincent Trevor Pierce

Electrical Engineering

Parametric Acoustic Arrays (PAA) are highly directional soundwaves whose attenuation and spread are much less affected by distance from the source as compared to traditional speakers. A well-known application for PAA is the directional speaker. Studies show that noise directly affects health and decreasing noise pollution can help improve the quality of life for millions of people. Directional speakers can revolutionize society by coupling space with sound. This project encodes audio into two RF-Pulse Width Modulated (PWM) waves to drive a transducer array. Each RF-PWM wave interferes with the other in air to generate a Single Sideband (SSB) frequency spectrum …

Bearing Health Detector, Natalie N. Tokhmakhian, Alexander J. Davis

Electrical Engineering

Bearings, a common component in rotating machinery, are essential components of modern rotating machines; thus, monitoring their health is crucial when reducing downtime and boosting production efficiency. The Bearing Health Detector (BHD), a hand-held device, captures and processes the sound of a machine under test in real time and estimates the level of wear and tear by comparing the sound to previous tests. The BHD encompasses audiences involved with roller bearings in rotating machinery and is designed to provide the diagnosis of wear through the universal detection of good, satisfactory, and very poor with the following color scheme: green, yellow, …

Multi-Effects Analog Guitar Pedal, Carson J. Bryan

Electrical Engineering

The Multi-FX Analog Guitar Pedal includes the analysis, design, performance, PCB layout, and packaging of an industry-standard effects pedal for an electric guitar. This project takes an analog input signal and utilizes analog circuitry to give the user the option to customize the way that their playing sounds. Effects include the options to add equalization filtering and distortion. The EQ filtering will allow the user to attenuate or gain certain frequencies divided into the 3 standard audio bands: bass (20-300 Hz), middle (300-4000 Hz), and treble (4-20 kHz). The soft-clipping distortion stage will allow the user to move around the …

Developments In Construction Workers’ Compensation Insurance With The Use Of Biometrics, Kobe Tooch

Construction Management

Construction insurance, especially that of workers’ compensation, is vital for the protection of general contractors, but it comes at a high cost and limits their control over contract terms. Biometric devices, such as heart rate monitors and motion capture, have the potential to revolutionize the industry by reducing construction insurance premiums. Heart rate monitors can provide real-time data on workers' physical activity and health, while motion capture analyzes movements to identify unsafe movement patterns performed by workers. By monitoring workers' biometrics, construction companies can ensure their safety, prevent hazards, and implement targeted training programs. This personalized data can lead to …

The Role Of High-Order Anharmonicity And Off-Diagonal Terms In Thermal Conductivity: A Case Study Of Multi-Phase Cspbbr3, Xiangdong Ding, Guimei Zhu, Yi Xia, Jie Ren, Jun Sun, Multiple Additional Authors

Mechanical and Materials Engineering Faculty Publications and Presentations

We investigate the influence of three- and four-phonon scattering, perturbative anharmonic phonon renormalization, and off-diagonal terms of coherent phonons on the thermal conductivity of CsPbBr3 phase change perovskite, by using advanced implementations and first-principles simulations. Our study spans a wide temperature range covering the entire structural spectrum. Notably, we demonstrate that the interactions between acoustic and optical phonons result in contrasting trends of phonon frequency shifts for the high-lying optical phonons in orthorhombic and cubic CsPbBr3 as temperature varies. Our findings highlight the significance of wavelike tunneling of coherent phonons in ultralow and glasslike thermal conductivity in halide perovskites.

A Study On The Design And Production Of A Desktop Vaccuum Cleaner, Aaryan Manoj Nair, Emanuel Pichardo, Isaiah Ortiz, Naeem Kotadia

Publications and Research

The goal of this project was to design a desk-top vacuum cleaner that is compact, portable, and effective in cleaning desktops and tabletops. Two concepts were proposed and compared using Quality Function Deployment (QFD) and various metrics, including in-use purposes and market, technical feasibility, ease of use, durability, and cost. The two concepts were a lifting design with hydraulics and a differently sized offset wheel design. After thorough analysis, it was determined that the lifting design with hydraulics was the better concept due to its adjustability and ability to reach different heights and angles on tabletops. The proposed product title …

Investigation Into Oxygen Diffusion As It Relates To Alpha Case Formation In Ti-6al-4v Based On Different Forging Thermal Cycles, Tyler J. Meador, Jon Leduc, Francesca Hope

Materials Engineering

An investigation into the growth kinetics of alpha case in Ti-6Al-4V in the presence of oxygen was conducted for different forging thermal cycles. This was done to determine whether the alpha case should be removed after each thermal cycle or as the final step after forging. The thermal cycles consisted of four hours at 1750 °F. Samples were subjected to this treatment one, two, three, and four times along with a continuous sixteen hour hold. Four cycle and Hold samples were subjected to an additional thermal cycle above the beta transus at 1925 °F. These then went through a final …

Surface Characterization Of Low-Density Polyethylene Mulch, Risha Shah

Materials Engineering

Plastic pollution in aquatic systems has traditionally been highlighted in past and current research due to the increase in plastic production every year. Unfortunately, quantitative and qualitative data regarding plastic pollution on land systems such as agricultural mulch is limited. Agricultural mulch breaks down into macroplastics and then degrades into microplastics. The microplastics investigated in this study are all secondary microplastics: microplastics that form due to weathering of larger fragments of plastic. Weathering can occur due to a variety of factors; however, UV radiation and mechanical weathering have been the factors of focus on most current research in microplastic formulation. …

Bruxism Biofeedback Device, Claire A. Dossey, Errin S. Abasolo, Isabelle A. Starr

General Engineering

This paper aims to summarize the design process for a biofeedback bruxism device, covering the necessary background research, engineering requirements, design process, prototyping, manufacturing, and testing for the device. The purpose of this project was to design an engineering solution for the treatment of bruxism. This entails both measuring and significantly reducing clenching and grinding during sleep, as many current solutions may reduce symptoms of the disorder, but do not treat bruxism itself. Engineering requirements included biocompatibility, size and weight, electrical safety, and easy of use and comfort. Many design options were proposed, and a Pugh Matrix was used to …

The Acme Building Fire Hazards Analysis, Russ Livesay

Fire Protection Engineering: Culminating Experience Project Reports

This Fire Hazards Analysis (FHA) was written using modern fire protection engineering principles to characterize the Applied Chemistry Management and Enrichment (ACME) Building at the Pacific Northwest National Research Area (PNNRA) using both a prescriptive-based and performance-based analysis to ensure the building and occupants can be safe in fire conditions. Recommendations are made as part of this analysis to improve the survivability of this structure if a fire were to occur.

This building was found to be compliant with the prescriptive code requirements from the 2018 International Building Code except for a few minor issues that are currently being repaired. …

Design Fire Robert E. Kennedy Library, California Polytechnic State, San Luis Obispo, Jennifer Ocampo

Fire Protection Engineering: Culminating Experience Project Reports

This report evaluates the fire protection system of the Kennedy Building using a prescriptive approach and a performance-based design. The prescriptive approach evaluates code compliance of the structural design, fire suppression system, alarm and detection and smoke control. The performance-based design evaluates egress and life safety protection and three design fires that could potentially compromise the goals and objectives of the design.

The Kennedy Building is on the Campus of Cal Poly, San Luis Obispo and serves as the primary library of the university. This building has five stories of mixed occupancies. It is partially sprinklered, has limited automatic detection …

Food Processing And Campus Market (Building 24), Ian De Vries

Fire Protection Engineering: Culminating Experience Project Reports

This report provides a prescriptive and performance-based analysis of the Food Processing Building located on Cal Poly’s campus in San Luis Obispo, California. Food science and nutrition classes take place at the facility where faculty and students manufacture food products such as chocolates, jams, and barbecue sauces. The finished products are offered for sale in the building’s mercantile area, known as the Campus Market, in addition to other retail locations around the city. The Food Processing Building is considered mixed use with portions of the building classified as moderate-hazard factory (F-1), moderate-hazard storage (S-1), business (B), mercantile (M), and assembly …

Office Building In Moffett Park District, Cody Williams

Fire Protection Engineering: Culminating Experience Project Reports

The objective of this review is to analyze and evaluate the fire safety of a 5-story office building located in the Moffett Park District in Sunnyvale, California. The building is constructed largely of mass timber and classified as a Type IIIA building used primarily as office space. The first section of the report focuses on the building’s defining characteristics and use cases. The second portion of the report presents a comprehensive review of egress design, fire alarm systems, fire suppression systems, structural design, implementation of mass timber elements, and flammability requirements. The results of the analysis show that the building …

Fire Protection Engineering For Building A, Ai Choong Loh

Fire Protection Engineering: Culminating Experience Project Reports

Building A is a 9-storey mixed used development in Singapore to be completed in 2028. Fire safety provisions of Building A shall be in accordance with Singapore Fire Code 2018.

The report has analyzed the fire safety provisions in the area of structural fire protection provision, means of escape provision, automatic water suppression system provision, automatic fire detection and alarm system provision, engineering smoke control system provision, flammability assessment as well as performance based assessment.

Generally, building A complied to the prescriptive requirements of automatic water suppression system provision, automatic fire detection and alarm system, structural fire provision and means …

Biomechanical Knee Joint For Exoskeleton, Gabriel Ireton Ahern, Calloway Miller, Christianna Altamura, Eric Mailes

Mechanical Engineering

Our senior design project consisted of designing and manufacturing a biomechanically accurate, actuated knee joint to be integrated into an exoskeleton being developed by the Lower Limb Exoskeleton Assist Project (LLEAP), a part of the EMPOWER student association at Cal Poly, San Luis Obispo. As the human knee flexes and extends throughout gait motion, the center of rotation changes. Currently marketed exoskeletons have one point of rotation, which over constrains the knee and causes misalignment between the user and the suit [1]. Our goal was to mimic natural knee joint motion by changing the center or rotation, thus reducing misalignment …

Turbine Integrated Pitching System, Elizabeth Costley, Josephine Maiorano, Jeff Larson, Cameron Jackson

Mechanical Engineering

The Cal Poly Wind Power Club (CPWP) tasked this senior project to design, manufacture, test, and deliver a mechanism to pitch the blades for their small-scale horizontal axis wind turbine. CPWP competes in the Collegiate Wind Competition (CWC) against schools across the country, and as such it was critical to comply with the provided competition rules in addition to the design requirement from CPWP. The purpose of the pitching mechanism is to improve the performance and efficiency of the wind turbine by allowing the blades to adjust angles with different wind speeds. Specifically, this project aimed to minimize hub size, …

Prove Primary Battery Structure, John D. Burkhart, Andy Mccormick, Ryan Yu, Soren Barclay

Mechanical Engineering

In conjunction with Prototype Vehicle (PROVE) Laboratory, our group designed, manufactured, and tested a prototype structure to house the battery boxes for PROVE’s endurance vehicle. Our structure was designed to support the batteries during normal use, and in the event of a front crash. Our design is comprised of a secondary composite box to house the battery boxes, a bottom plate to affix the secondary box to the chassis floor, a horizontal plate fastened to the chassis, and a brace structure welded to the chassis. From the outset, we chose to use a secondary box, the primary battery boxes must …

Rapid Composter, Shannon Shinozaki, Avin Atencio, Jonathan Fraser, Lukas Kolbl, Russell Occhipinti

Mechanical Engineering

This project was created with the intent of automatically composting equine bio waste to be reused as plant fertilizer. The system consists of four subsystems: power generation and storage, automatic controls, aeration, and structure. Each subsystem may be manufactured independently, then put together. This system will not have access to power outlets, so it was designed to be solar-powered.

Parametric Bicycle Yoke, Colin Reay, Walter Minehart, Robby Harrigan, Jordan Olson

Mechanical Engineering

This report outlines the entire design, fabrication, and validation process of a parametric yoke design that addresses the packaging problem of the bottom-bracket chainstay junction in modern bicycle frames. The goal was to create an elegant, space-efficient solution that is accessible to the Cal Poly Bike Builders Club. The report includes documentation of the three-part fixture system, manufacturing process, and testing results for the yoke.

Our yoke design outperforms traditional round-tube weldments in torsional and vertical stiffness. Additionally, all manufacturing fixtures and machining operations function as intended, resulting in a finished yoke that meets all required tolerances in under an …

Treadmill Platform For Quadrupedal Robots, Baxter J. Bartlett, Jack F. Butler, Phillip A. Shafik, Tarun S. Ganamur

Mechanical Engineering

Cal Poly Legged Robots, led by Professor Refvem and Professor Xing, has been leading Cal Poly’s attempts to simulate, produce, and test their legged robots. The initial testing of the locomotion of these robots can be dangerous to the robot since any bugs in the code could cause the robot to fall over and harm itself. Our responsibility as a team was to deliver a portable platform for testing the locomotion capabilities containing a fall prevention mechanism. In short, we have designed a platform for this purpose that consists of a treadmill surrounded by a wheeled chassis with a system …

Perforated Groove Cam Lock, Matthew J. Redmond, Samuel A. Potter, Dylan Weiglein, Andrew Reese

Mechanical Engineering

NASA Artemis III astronauts need a way to attach and detach various tools to an extension handle to be used during lunar EVA sample collection. Because lunar dust is so harsh and abundant, mechanisms must be designed to function regardless of the number of contact particulates. Past designs used on the Apollo missions proved to be problematic for their operators, opening the door for innovative improvement. A new mechanism has been proposed that directly addresses the performance issues of the original handle extension mentioned in NASA’s Apollo mission reports. The new mechanism boasts an open design that promotes dust tolerance …

3d Printed Aircraft, Matthew Nagy, Charles D'Amico, Alexis Salgado Medina

Mechanical Engineering

This project is to design, build, and test a 3D-printable aircraft. The goal is to create a final design that will be able to fly for the longest duration possible, around 20 seconds. To determine the correct preliminary design and manufacturing process for a 3D printed RC aircraft, an analysis of multiple design options and manufacturing materials was performed. This allowed for a variety of choices for aircraft type, airfoil design, structure, among other topics to be narrowed down to the most promising option. It has been found that the aircraft will follow a design similar to industry motor-gliders, with …

Backflow Relief Valve Test Stand, Olivia Mcnulty, Wiill Halvorsen, Ryan Dubois, David Leaman

Mechanical Engineering

This Final Design Review (FDR) document details the final design, manufacturing, testing, and results of the Zurn Wilkins Backflow Relief Valve Test Stand Project under the sponsorship of Brian Yale and Rueben Westmoreland. This project involves simulating real-world conditions of static pressure and water hammer cycling. The stand will give Zurn Wilkins’ engineers a method by which to test their relief valves prior to a rigorous, yearlong University of Southern California (USC) testing procedure. Our design involves using city water, a pump, a Zurn backflow preventer, and a control system to apply specific pressures to each end of the relief …