Digital Commons Network^™

Impact Force Helmet Device For Concussion Monitoring, Patrice Mulligan, Karina Mealey, Zack Borthwick, Benjamin Fick

General Engineering

To track head trauma in football, our device is placed inside a football helmet to measure both linear and gyroscopic (rotational) accelerations. These measurements are taken using an ADXL375 linear accelerometer and an LSM6DSOX accelerometer and gyroscope. The data from these sensors is processed and transmitted wirelessly by a SparkFun Thing Plus microcontroller to another SparkFun Thing Plus microcontroller connected to a laptop on the sidelines. Our program on the laptop stores the acceleration impact data into a .csv file for each player. If a likely concussive impact is detected, the program displays a popup warning. Testing results were promising …

Smart Cushion Device For Elderly Aging In Place, Anna Dion, Nate Colley, Leonardo Bravo

Biomedical Engineering

Our task at hand is to develop a consumer-focused solution for improving elder care to provide additional peace of mind for seniors and caregivers using technology to extend independent living. We intend to create a device that will improve the quality of life of elderly individuals living alone by encouraging periodical movement throughout the day, along with monitoring pressure distribution and alerting when pressure concentration is potentially harmful. It will also alert users to the presence of moisture which can arise from spills or incontinence. The key stakeholders of this project include elderly adults over the age of 65 who …

High-Power Microwave Antenna Design, Luke C. Chase

Electrical Engineering

High-power microwave antennas are essential for defense industry radar systems, cyber warfare, and power transmission. The US Department of Defense a SBIR proposal specifying the need for a high-power phased-array microwave antenna for the US Air Force.

Vivaldi antennas, invented in 1978 by Peter Gibson, have been widely adopted for radar applications due to their high bandwidth and gain performance. Considerable amounts of research exists on designing Vivaldis for different applications ranging from radar to communications. Using antenna theory and past research, a new Vivaldi antenna was designed to meet the requirements mandated by the DoD research contract.

This project …

Exploration Of Software Defined Radios To Increase Capabilities Of Affordable Mesh Networks, Liam K. Mccarthy

Electrical Engineering

Project OWL is developing a LoRa mesh network “DuckLinks” for emergency communications, and the current LoRa protocol the Clusterduck Protocol is based on is severely limited in data rate. OWL plans to use Raspberry Pi computers to develop the next phase of Duck radios, which greatly opens the computing potential and flexibility of the system the Ducks run on. Using LimeSDR and GNU Radio, an open source SDR programming environment, this project seeks to develop a simple SDR-based packet transmission system that allows for communication with Duck radios as well as the use of a different modulation scheme for higher …

Motor Controller Board For Cubesat Reaction Wheels, Tanner Ehlers

Electrical Engineering

Reaction wheels are crucial for CubeSats, providing precise attitude control and stability in the environment of space, enabling successful mission execution. The ‘Reaction Wheels’ project in the Cal Poly CubeSat Lab is in need of a new motor controller board due to the current board’s malfunction and inefficiencies in terms of size, complexity, power usage, and cost. Previously, other students have completed work on the mechanical design of the system, but little work has been done for the electrical components. The goal of this project is to design and test a new motor controller board that is compact, lightweight, power …

Prosthetic Forearm Controller, Claire Tylutki, Kevin Lopatka, Sofia Zaletel, Hardit Singh

Electrical Engineering

The EMG controlled prosthetic arm project represents a significant advancement in upper limb prosthetics, leveraging cutting-edge technology to address critical user needs. With over two million individuals in the United States living with limb loss, a substantial portion being upper limb amputees, the demand for accessible and functional prosthetic solutions is pressing. This project focuses largely on refining prosthetic limb control through the integration of electromyography (EMG) signal processing and control. Using surface electrodes, this project employs non-invasive means of data collection combined with modern digital signal processing methods to implement faster and more accurate control. The control system also …

Battery Energy Storage System, Alec C. Maclean, Kaylen H. Schwartz, Kyle A. Begley

Electrical Engineering

The project is a continuation of part 1 of the “Reliability Measurement for Grid-Connected Solar System” project. The goal is to continue where the previous design failed. This project will configure an ITECH IT-6000C and Tabuchi Battery Energy Storage System (BESS) to the small-scale microgrid at the Cal Poly, San Luis Obispo EE Department. Initially, a system was designed to connect an ITECH IT-M3633 as a PV solar source emulator to the Tabuchi BESS within a grid-connected microgrid system in Room 20-102 at Cal Poly. A Photovoltaic Thevenin equivalent model was developed for the ITECH IT-M3633, but this setup failed …

Coordinated Controls Of Residential Ev Chargers Considering High Power Appliances, Steven B. Poore, Rosemary E. Alden, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

In addition to electric vehicle (EV) adoption, the electricity demand of the modern grid is also under change from the replacement of resistive electric water heaters (EWHs) with high-efficiency heat pump electric water heaters (HPWH). Typical load of a HPWH has two parts: a low power compressor and a backup high power resistive boosting element. Within this paper, residential load from a large field demonstration for over one thousand homes is simulated in virtual power plant (VPP) operation with realistic HPWH and EV synthetic modules based on big data from the latest CBECC-Res and National Household Travel Survey (NHTS). Simultaneous …

Echoes Of Nature: Using Biodata Sonification To Model Electrical Communication In Plants, Penelope Anna Alioshin

Electrical Engineering

The use of biodata sonification as a tool to visualize biological data is a response to recent developments in the intersection of art and technology. This project explores the intersection by converting the electrical impulses given off by plants into audio signals. By processing and amplifying the voltage difference between two electrodes on a plant, its communication is quantified. The goal is to use this communication model as a tool to increase ecological awareness as well as improve machine learning models. A deeper understanding of non-human communication systems, specifically those that employ superposition decision matrices, could help to drastically increase …

Advancing Embedded Iot Architectures For Space And Terrestrial Applications, Wuwei Douglas Liu, Nicolas Jesus Alvarez, Eric Huang

Electrical Engineering

Radio transceivers play a pivotal role in establishing communication networks, particularly in regions where existing infrastructures are unstable or compromised due to natural disasters or conflicts. By utilizing LoRa (Long Range) communication technology, OWL Integrations develops radio transceivers to establish mesh networks to communicate with one another during disasters. This project team continues development of a second generation OWL board, classified as Quacker Advanced Development (QuAD), with a focus on transitioning to a new microcontroller and integrating GNSS libraries and drivers. An ulterior objective involved R&D for a space application of the board.

X-Band Wireless Power Transfer System Using A Focused Array Lens, Jason Alexander Kunz, Tyler S. Bury, Oscar Damian Gonzalez, Jaime Garcia

Electrical Engineering

Wireless power beaming from space and energy harvesting were once stories of science fiction, until now. Wireless power transmission (WPT) is a field continually in development to provide energy in situations where energy transfer through wires is impractical or unfeasible. This engineering discipline abandons the use of wire technology for the energy transfer between the power source and a distant device. While various forms of WPT exist, our project focuses on transmission through means of radio frequency (RF), utilizing electromagnetic waves to power devices. Furthermore, WPT technology primarily assists in the elimination of a physical connection between devices, and it …

Design Of High Efficiency Doherty Power Amplifier, Kobi G. Kelly, Severin Pindell

Electrical Engineering

The project includes design and fabrication of a high efficiency power amplifier for a student design competition held at International Microwave Symposium (IMS) 2023. Efficient power amplifiers are critical for base station communication requiring efficient use of available power. The final design optimizes power added efficiency (PAE) and linearity. The amplifier will operate at 2.45 GHz. Competitive PAE above 50%, and C/I above 30 dB is achieved by leveraging a Doherty class amplifier using accurate discrete CGH4006P transistor models to simulate an efficient and linear design. Unique design features include optimal transistor bias point selection and power split ratios between …

A 4-Switch Buck-Boost Dc/Dc Converter For Electric Vehicle Applications, Andrew Hudak, Ashley Schiller

Electrical Engineering

In this project, we develop a four switch buck-boost DC/DC converter that is to be integrated into a microgrid-inspired power distribution architecture for electric vehicles. The overall architecture includes DC/DC and DC/AC converters for bi-directional energy transfer between the DC and AC ports along with a communications port to control each energy interface. There is also the onboard battery and the internal combustion engine power exchange being done with DC/DC converters and AC/DC inverters to connect to the centralized DC bus. Hardware prototypes using an Arduino and Raspberry Pi for the 500 W DC/DC and DC/AC converters have been previously …

Software Defined Radio Applicability Investigation For Owl Integrations Inc., Daniel J. Gharib

Electrical Engineering

OWL Integrations Inc. is developing a LoRa mesh network using “Duck” radios to communicate using the LoRa modulation technique. This mesh network is intended for emergency communications in situations where Internet or cellular access is unavailable, such as disaster relief or warzones. The goal of this project is to investigate the feasibility of using the CaribouLite SDR as a potential base for a SDR-based “Duck”. This feasibility testing will be performed by integrating the CaribouLite with a Raspberry Pi single-board computer and investigating its compatibility and functionality for the purposes of a communication device

Formula Sae Vehicle Dynamics Controller, Luke Edward Bosworth

Electrical Engineering

Throughout the history of motorsports, engineers have continuously pushed the boundaries of speed and control in the pursuit of enhancing vehicle performance on the track. Today’s top performing motor-vehicles leverage electric motors to the deliver instantaneous torque to the vehicle’s tires. While these electric motors can deliver a lot of power very efficiently, the delivery must be well controlled to get the most performance out of the tires. The Formula SAE Vehicle Dynamics Controller (VDC) senior project integrates vehicle modeling, state estimation, and yaw moment controls into a small- scale Formula-one style electric vehicle, improving vehicle performance and laying the …

Multi-Hop And Automated Testing Of Wide-Area Network Radio Systems, Zachary C. Numa, Joseph S. Nuccio

Electrical Engineering

Requests for low-power and versatile wide-area Internet-of-Things (IoT) networks are becoming more prevalent with upcoming research in low-data rate ad-hoc mesh networks. Connections to terrestrial satellites have proven promising methods for increasing range capabilities for wide area networks (WAN). As research in communication with IoT networks and satellites progresses, reliable multi-hop mesh networks for Earth-based communication are still necessary to develop the base for satellite communication. These multi-hop communication mesh networks are being developed to allow communication where Line-of-Sight (LOS) from A to B is incapable due to environmental barriers. Hence, communication is possible without LOS by providing an intermediate …

2-Bit Schiffman Phase Shifter, Tavita Dayton, Enrique Ruiz

Electrical Engineering

Phase shifters are found in microwave/RF applications such as defense or wireless communications for their ability to control the relative phase of a system which allows for alignment of signals to obtain constructive interference. Typical phase shifters are chip level (digital and analog) which require a DC bias therefore restricting PCB use unless allowance for air gaps. The paper analyzes a passive and low-profile 2-bit phase shifter using the Schiffman architecture, which outputs a near-constant 90 degree shift over a wide band of frequencies. The design process initially confirmed a proper 90 degree phase shift over the desired WiFi band, …

Autonomous Apple Harvester Robot, Jack Ryan Cline, Tyus Green, Devon Woolston

Electrical Engineering

As agricultural demands rise and manual labor costs increase, there has become a dire need to automate apple harvesting. However, the precision and speed necessary for cost-efficient apple harvesting pose a significant challenge for robotic automation. To maintain cost-effective production, a harvester must be able to operate fast enough and long enough to compete with human labor. It must also be able to navigate and traverse apple orchards autonomously and pick apples without damaging the fruit or tree. This project presents an apple harvesting robot that uses a Mask R-CNN vision system with an RGB-D camera to detect the location …

2024 Marine Energy Collegiate Competition, Nora Riedinger, Miles Mikkelsen, Brendan Stratford, Derek Tom, Zach Kwast, Harmon Yanikian-Sutton, Kennedy Urcelay, Tori Thomas, Brady Caron

Mechanical Engineering

PolyWave Energy is the second team from California Polytechnic University at San Luis Obispo to compete in the Marine Energy Collegiate Competition. PolyWave Energy consists of Mechanical Engineering, Electrical Engineering, and Business Administration students who have worked together from September 2023 to May 2024 on designing, building, and testing a marine power device to serve a selected market.

In response to the escalating concerns surrounding carbon emissions, climate change, and the depletion of fossil fuels, California Polytechnic State University’s Polywave Energy team has developed a sustainable and reliable energy source for Autonomous Underwater Vehicle (AUV) charging. Through extensive research of …

Enhancing Direction Finding Accuracy In Perturbed Digital Arrays Via Rf Ranging-Based Self Calibration, Ariel Freiman

Master's Theses

Direction finding with radio-frequency (RF) waves have numerous applications in radio navigation, wireless localization, emergency aid, and air traffic control, among others. Direction-finding using digital arrays outperforms traditional analog techniques but requires precise knowledge of the location of the array elements to obtain accurate results. Array perturbations can lead to algorithm failures and false detection, compromising direction-finding capabilities.

This research proposes implementing a Matched Filter - Least Square (MF-LS) algorithm for Two-Way Ranging (TWR) to enhance direction-finding accuracy in arrays with perturbed element locations. The MF-LS algorithm leverages the properties of matched filters to accurately determine element positions by measuring …

An Analysis Of Indoor Air Quality At Cal Poly For Sensor Design, Isabella M. Santi

Master's Theses

Prior research has shown that indoor air quality (IAQ) impacts cognitive performance. At Cal Poly, many older buildings are unable to maintain appropriate IAQ because of their outdated ventilation systems and the increasing number of students in the rooms. This work analyzes the IAQ of different buildings at Cal Poly, with a focus on Building 20. Carbon dioxide, temperature, and relative humidity inside classrooms are collected using an integrated circuit sensor and a microcontroller. A total of 38 hours of data was collected, with 22 of those hours in Building 20 specifically. We find that unlike temperature and relative humidity, …

A Hybrid Computer To Solve The Selective Harmonic Minimization Problem In Single-Phase Inverters, Dillon Nguyen

Master's Theses

Power electronics possess forms of non-ideality due to the nonlinearity present in physical switches. These switches are driven with pulse width modulation (PWM), which properly down-converts or up-converts based on converter topology. When these switches turn on or off, they introduce the main proponent of efficiency loss: harmonics. This becomes a nonlinear optimization problem with many converters. The solution proposed in this thesis is an analog/digital hybrid computer that utilizes the speed of analog computation and the accuracy of digital computing together. A Plexim RT Box provides the programmability needed for algorithms, while the analog circuit provides low-power, high-speed computation …

Optimal False Data Injection (Fdi) In Simulated Cooperative Adaptive Cruise Control (Cacc) Systems, Lovro Dukic

Master's Theses

In the rapidly advancing field of autonomous vehicles, ensuring the security and reliability of self-driving systems is crucial. Autonomous vehicle systems, such as cooperative adaptive cruise control (CACC), must undergo significant research and testing before their integration into commercial intelligent transportation systems. CACC considers multiple vehicles in close proximity as a single entity, or platoon, with each vehicle equipped with a controller that uses sensor-based measurements and vehicle-to-vehicle (V2V) communication to control inter-vehicle spacing. While this system offers numerous potential benefits for traffic safety and efficiency, it is also susceptible to False Data Injection (FDI) attacks, which can cause the …

Gps/Imu Board, Luke Chen, Steve Tran

Electrical Engineering

Providing information on a vehicle’s location during a competition can be used to provide greater insight to progress the car is making or what portion of the track caused failure. As a result, we will be designing a board that includes a Global Positioning System (GPS) and Inertial Measurement Unit (IMU) module to provide position coordinates, which is driven by an STM32 processor to feed into the DAQ through Controller Area Network (CAN) protocol.

The GPS module will produce an initial positioning and will continue to do so unless it is unable to create a solution, possibly due to over-arching …

2-Channel Eeg Neurofeedback System, Tim Erwin, Donna Nikjou, Sebastian Turkewitz

Electrical Engineering

This work describes the design of an EEG-based neurofeedback system which provides users with real-time feedback on their level of focus or relaxation. By analyzing the spectral content of the brain activity measured via scalp electrodes, focus and relaxation levels can be quantified. Based on these measurements, live feedback in the form of moving bar graphs is provided to users, allowing them to gain awareness of their mental-state and more efficiently learn how to consciously relax or focus. This project covers the design of the system, including amplification and filtering stages, digitization, and signal processing. The system interfaces with a …

Design And Characterization Of A Broadband Rf Switch Utilizing Surface Mount Devices, Daniel Bracamontes

Master's Theses

High frequency solid-state switches are critical elements in communication systems, radio frequency (RF) systems and instrumentation. Key parameters to an RF switch include insertion loss while on and off-state isolation. Power handling and linearity are important to consider for a cost-effective construction. This becomes a design challenge into K-band frequencies as components required need to be small, dielectric losses and transmission lines need to be physically matched for proper isolative and through states. This thesis presents a novel single pole eight throw (SP8T) hybrid design composed of commercially available surface mount technology solutions to achieve high isolation and low insertion …

Underwater Acoustic Telemetry For Marine Permaculture, Jonathan Lin, Harrison Shaw, Ben Shiverdaker, Mark Ellersick

Electrical and Computer Engineering Senior Theses

As a result of global warming and rising ocean temperatures and sea levels, seaweed forests are degrading. Seaweed biomass loss presents significant risks to coastal communities that rely on seaweed forests for food, livestock feed, fertilizer, and more. Marine Permaculture is the Climate Foundation’s regenerative farming initiative to grow seaweed outside of its intended habitat. The “Deep Cycling” technique involves positioning a submersible bed near the water surface during the day and lowering it at night, allowing for seaweed to receive sunlight and cold water. Prior work on this project included establishing a temperature control loop, though did not include …

Remote Profiling Of Atmospheric Turbulence: Enhanced Resolution With Stacked Rayleigh Beacons In Tardis, Benjamin C. Wilson

Theses and Dissertations

A stacked beacon turbulence profiling methodology has been introduced and applied to have increased profiling on the Turbulence and Aerosol Research and Investigation System (TARDIS). The model was derived and demonstrated the applicability through discussion on data processing and inversion processes. The methodology was applied for two different nighttime experiments, one in Summer and one in Fall. C 2 n profiles were derived into the 1300 m altitude ranges for both nights and the summer experiment was compared to a co-located DELTA Sky measurements and LEEDR generated Climatological profiles. The comparison implied promise in the methodology with additional work needed …

Unconventional Computing With Photonic Oscillator Networks, Mostafa Honari Latifpour

Dissertations, Theses, and Capstone Projects

The ever-increasing demand for data processing and the challenges in scaling traditional computing architectures are driving intensive research into alternative computing paradigms. Optical computing has garnered renewed attention since the 2010s, driven by its potential to accelerate specialized computational tasks such as combinatorial optimization and neural networks.

Coherent light sources including lasers and parametric oscillators have been around for decades and become indispensable tools in modern technology, but these photonic oscillators are also nonlinear dynamical systems that can exhibit emergent, complex phenomena, especially when coupled in arrays. These nonlinear optical systems have recently been shown to be capable of doing …

Performance Analysis Of Underground-To-Aboveground Communication In Agricultural Iot Networks, Irfana Ilyas Manzil

Theses

This thesis investigates the potential of LoRa, a low-power, wide-area networking technology, for establishing reliable communication between underground sensors and aboveground infrastructure. We comprehensively analyze LoRa's performance in both single-hop and multi-hop configurations, considering the impact of diverse environmental factors such as soil composition, moisture content, underground transmission distance, and path loss on signal propagation. We delve into the crucial role of the spreading factor (SF) within the LoRa communication system, analyzing its influence on network performance. Furthermore, we develop a comprehensive mathematical model for bit error rate (BER) under various channel conditions, including additive white Gaussian noise (AWGN) and …