Engineering Commons^™

Development And Characterization Of An Iot Network For Agricultural Imaging Applications, Jacob D. Wahl

Master's Theses

Smart agriculture is an increasingly popular field in which the technology of wireless sensor networks (WSN) has played a large role. Significant research has been done at Cal Poly and elsewhere to develop a computer vision (CV) and machine learning (ML) pipeline to monitor crops and accurately predict crop yield numbers. By autonomously providing farmers with this data, both time and money are saved. During the past development of a prediction pipeline, the primary focuses were CV and ML processing while a lack of attention was given to the collection of quality image data. This lack of focus in previous …

Indoor Positioning Using Acoustic Pseudo-Noise Based Time Difference Of Arrival, Nicholas J. Luong

Master's Theses

The Global Positioning System (GPS) provides good precision on a global scale, but is not suitable for indoor applications. Indoor positioning systems (IPS) aim to provide high precision position information in an indoor environment. IPS has huge market opportunity with a growing number of commercial and consumer applications especially as Internet of Things (IoT) develops. This paper studies an IPS approach using audible sound and pseudo-noise (PN) based time difference of arrival (TDoA). The system’s infrastructure consists of synchronized speakers. The object to be located, or receiver, extracts TDoA information and uses multilateration to calculate its position. The proposed IPS …

Design Of Structural Stand For High-Precision Optics Microscopy, Sara T. Novell

Master's Theses

Lawrence Livermore National Lab (LLNL) is home to the National Ignition Facility (NIF), the world’s largest and most energetic laser. Each of the 192 beamlines contains dozens of large optics, which require offline damage inspection using large, raster-scanning microscopes. The primary microscope used to measure and characterize the optical damage sites has a precision level of 1 µm. Mounted in a class 100 clean room with a raised tile floor, the microscope is supported by a steel stand that structurally connects the microscope to the concrete ground. Due to ambient vibrations experienced in the system, the microscope is only able …

Modeling Artificial Groundwater Recharge In The Santa Rosa Creek Watershed, Alexander J. Murray

Master's Theses

The Santa Rosa Creek Watershed is an approximately 48 mi2 large watershed located on the central coast of California. This watershed drains to the Pacific Ocean through Santa Rosa Creek as it passes through agricultural land and the town of Cambria. Historically the groundwater within the Santa Rosa Creek Watershed has been used for irrigation, municipal and domestic uses, and the creek is critical habitat steelhead trout. During dry years, there is less water for all uses. When low groundwater levels occur, water can be drawn out of the creek and into the soil, drying out steelhead habitat. Seven agricultural …

Distance Estimation Using Ofdm Signals For Ultrasonic Positioning, Kyman Huang

Master's Theses

This paper describes a method of estimating distance via Time-of-Flight (TOF) measurement using ultrasonic Orthogonal Frequency Division Multiplexing (OFDM) signals. Using OFDM signals allows the signals and their sub-carriers to remain orthogonal to each other while continuously transmitting. This estimation method is based on the change of phase of a traveling wave as it propagates through a medium (air for ultrasonic signals). By using signals containing multiple tones, the phase change between each frequency component is slightly different. This phase difference is dependent on the distance traveled and can thus be used to estimate distance. This paper studies the impact …

Conceptual Design Of A South Pole Carrier Pigeon Uav, Kendrick M. Dlima

Master's Theses

Currently, the South Pole has a large data problem. It is estimated that 1.2 TB of data is being produced every day, but less than 500 GB of that data is being uploaded via aging satellites to researchers in other parts of the world. This requires those at the South Pole to analyze the data and carefully select the parts to send, possibly missing out on vital scientific information. The South Pole Carrier Pigeon will look to bridge this data gap.

The Carrier Pigeon will be a small unmanned aerial vehicle that will carry a 30 TB solid-state hard drive …

Design, Validation, And Verification Of The Cal Poly Educational Cubesat Kit Structure, Nicholas B. Snyder

Master's Theses

In this thesis, the development of a structure for use in an educational CubeSat kit is explored. The potential uses of this kit include augmenting existing curricula with aspects of hands on learning, developing new ways of training students on proper space systems engineering practices, and overall contributing to academic capacity building at Cal Poly and its collaborators. The design improves on existing CubeSat kit structures by increasing accessibility to internal components by implementing a modular backplane system, as well as adding the ability to be environmentally tested. Manufacturing of the structure is completed with both additive (Fused Deposition Modeling …

Thermal Modeling And Testing Of The Blue Thermal Vacuum Chamber, Madeline R. Jensma

Master's Theses

The Blue Thermal Vacuum Chamber (TVAC) located in the Space Environments Laboratory at California Polytechnic State University, San Luis Obispo (Cal Poly), may be used for thermal vacuum testing of test articles that fit with in the semi cylindrical test section that has a radius of approximately 18 cm and a length of 61 cm. The potential test articles include CubeSat systems and subsystem. The Blue TVAC can also be used for educational and research purposes. The goal of this thesis project is to develop a thermal model of the Blue TVAC to predict and analyze the thermal response of …

Numerical Methods For Predicting The Dynamic Crushing Response And Energy Absorption Of Composite Aluminum Honeycomb Sandwich Structures, Cody R. Volk

Master's Theses

Edgewise crushing responses of composite aluminum honeycomb sandwich structures were predicted using finite element analysis (FEA) software LS-DYNA by modeling the honeycomb as a material with anisotropic properties. The goal of the project was to develop a process for modeling the sandwich structure to rapidly iterate possible solutions for a safer workstation train table. Current workstation tables are too rigid and may cause injury or death in a head-on collision. Experimental compression tests were used to calibrate the aluminum honeycomb core with material type 26 (MAT 26, honeycomb). A published composite tensile test was used to validate the use of …

Design Of A Printed Circuit Board For A Sensorless Three-Phase Brushless Dc Motor Control System, Joshua Castle

Master's Theses

The use of brushless motors has increased in recent years due to superior performance characteristics compared with alternatives. The operation of a brushless motor is dependent upon a separate controller which is often in the form of a printed circuit board. As such, the size and performance capability of the controller can restrict the performance of the overall motor control system so advancements of these controllers further the potential use of BLDC motors. This project outlines the design of a PCB based, sensorless motor controller for operation of a three-phase BLDC motor powered by a 24 V, high current external …

The Design, Testing, And Analysis Of A Constant Jammer For The Bluetooth Low Energy (Ble) Wireless Communication Protocol, Aiku Shintani

Master's Theses

The decreasing cost of web-enabled smart devices utilizing embedded processors, sensors, and wireless communication hardware have created an optimal ecosystem for the Internet of Things (IoT). IEEE802.15.4, IEEE802.11ah, WirelessHART, ZigBee Smart Energy, Bluetooth (BT), and Bluetooth Low Energy (BLE) are amongst the most commonly used wireless standards for IoT systems. Each of these standards has tradeoffs concerning power consumption, range of communication, network formation, security, reliability, and ease of implementation. The most widely used standards for IoT are Bluetooth, BLE, and Zigbee. This paper discusses the vulnerabilities in the implementation of the PHY and link layers of BLE. The link …

Optimization And Longevity Of Functionalized Multi-Walled Carbon Nanotube-Enabled Membranes For Water Treatment, Madeleine Michael Isabella White

Master's Theses

Water scarcity is a growing concern at the global scale. Large scale water reuse is growing both in necessity and popularity. Before water reuse can be performed efficiently on a large scale or be used for potable supply, even indirectly, contaminants of emerging concern (CECs) will need to be treated at the full scale. Advanced oxidation processes (AOPs) are a form of advanced water treatment capable of treating a wide range of CECs. This study contributes to the growing field of AOPs and more specifically AOPs using ozone combined with functionalized multi-walled carbon nanotubes (MWCNTs). Ozonation of MWCNTs has been …

A Study Of The Standard Cirrus Wing Lift Distribution Versus Bell Shaped Lift Distribution, William H. Bergman

Master's Theses

This thesis discusses a comparison of the differences in aerodynamic performance of wings designed with elliptical and bell-shaped lift distributions. The method uses a Standard Cirrus sailplane wing with a lift distribution associated with the induced drag benefits of an elliptical distribution (span efficiency = 0.96) as the basis of comparison. The Standard Cirrus is a standard class sailplane with 15-meter wingspan that was designed by Schempp-Hirth in 1969. This sailplane wing was modeled and analyzed in XFLR5, then validated against existing wind tunnel airfoil data, and Standard Cirrus flight test data. The root bending moment of the baseline wing …

Design Of Prototype Prosthesis For A Canine With A Right Front Limb Deformity As An Alternate Approach To Stabilize Gait And Withstand Gait Forces, Tayler R. Kastlunger

Master's Theses

Congenital and developmental limb deformities in canines are rare and can occur as a genetic disorder or be caused by extrinsic factors. Without surgery to correct the deformity, conservative management can be implemented to manage exercise and restrict high-intensity activity of the canine. However, any alteration to the normal gait and locomotive biomechanics of a canine can have significant long-term effects on the musculoskeletal health and quality of life of the canine. To improve quality of life and provide an alternative and more cost-effective approach to surgery, a custom prosthetic was designed and developed for a canine born with a …

Investigation Of New Forward Osmosis Draw Agents And Prioritization Of Recent Developments Of Draw Agents Using Multi-Criteria Decision Analysis, Jodie Wei Yu

Master's Theses

Forward osmosis (FO) is an emerging technology for water treatment due to their ability to draw freshwater using an osmotic pressure gradient across a semi-permeable membrane. However, the lack of draw agents that could both produce reasonable flux and be separated from the draw solution at a low cost stand in the way of widespread implementation. This study had two objectives: evaluate the performance of three materials — peptone, carboxymethyl cellulose (CMC), and magnetite nanoparticles (Fe₃O₄ NPs) — as potential draw agents, and to use multi-criteria decision matrices to systematically prioritize known draw agents from literature for …

Bootstrapping Massively Multiplayer Online Role Playing Games, Mitchell Miller

Master's Theses

Massively Multiplayer Online Role Playing Games (MMORPGs) are a prominent genre in today's video game industry with the most popular MMORPGs generating billions of dollars in revenue and attracting millions of players. As they have grown, they have become a major target for both technological research and sociological research. In such research, it is nearly impossible to reach the same player scale from any self-made technology or sociological experiments. This greatly limits the amount of control and topics that can be explored. In an effort to make up a lacking or non-existent player-base for custom-made MMORPG research scenarios A.I. agents, …

Overview And Uncertainty Analysis For An Irrigation Flow Measurement Facility, Kyle Feist, Zachary Markow, Stuart Styles

BioResource and Agricultural Engineering

Accurate flow measurement is critical for modern water resource management. At the irrigation district level, instantaneous flow rates must be well-measured at key bifurcation points to reliably meet downstream demand in open channel systems while also minimizing diversions. Furthermore, good flow measurement at each delivery point is a pre-requisite for successful volumetric water billing. Accuracy and repeatability are important characteristics of good flow measurement. Maximizing these traits requires periodic calibration to a common standard.

This paper presents an overview of calibration efforts and the engineering background behind an active flow measurement facility at the Irrigation Training and Research Center at …

Flow Rate Equation For Suppressed And Submerged Sluice Gates, Charles M. Burt, Albert J. Clemmens, Kyle Fesit

BioResource and Agricultural Engineering

In irrigation projects, the control and measurement of flow rates at key bifurcation points is essential. Sluice gates at the heads of irrigation canals are used by operators to control the flow into these canals. In US irrigation districts, canal operators often estimate flow rate at the heads of canals by “experience” unless they have a flume downstream. For example, they may open a gate a certain number of turns for a change in flow rate, regardless of upstream and downstream conditions. Theoretical estimates of discharge are often inaccurate in field situations. Problems include varying and uncertain discharge coefficients, entrance …

Potential Of Existing And Proposed Bicycle Facilities To Link Multiple Origin And Destination Needs For Non-Motorized Travel In San Luis Obispo, Sheridan Nansen

City and Regional Planning

The purpose of this study is to investigate the potential of linking multiple origins and destinations for efficient non-motorized travel in San Luis Obispo, California. The city currently has seventy-five miles of bicycle infrastructure with the intention to add thirty-five more miles to create a more functional bicycle network and foster an increase in bicycle trips taken.

Many cities in the United States are following their European counterparts in the push towards more sustainable forms of transportation by promoting bicycling, walking, and the use of public transit. Recently, we have seen an increase in both local and national legislative efforts …

Bike And Pedestrian Safety Planning: Excelsior/Outer Mission District, Alexandra Lee-Gardner

City and Regional Planning

San Francisco’s Outer Mission and Excelsior districts host a vibrant community of small business owners and residents from a variety of backgrounds and cultures. The neighborhood is known for its diversity and sense of community. However, lack of adequate infrastructure and high-speed roadways has created great safety concerns within the community. In the last five years, the Excelsior/Outer Mission area had 828 collisions, nine of which were fatal (Transbase, n.d.). San Francisco Municipal Transportation Agency (SFMTA) has identified nearly 14 miles of streets in the project area that are on the City’s high injury network, meaning collisions there are highly …

Cascaded Linear Regulator With Positive Voltage Tracking Switching Regulator, Brandon K. Nghe

Master's Theses

This thesis presents the design, simulation, and hardware implementation of a proposed method for improving efficiency of voltage regulator. Typically, voltage regulator used for noise-sensitive and low-power applications involves the use of a linear regulator due to its high power-supply rejection ratio properties. However, the efficiency of a linear regulator depends heavily on the difference between its input voltage and output voltage. A larger voltage difference across the linear regulator results in higher losses. Therefore, reducing the voltage difference is the key in increasing regulator’s efficiency. In this thesis, a pre switching regulator stage with positive voltage tracking cascaded to …

Portable Calorimeter For Fire Experiments, Kayla Collins, Kara Hewson, Christopher Chen, Joel Keddie

Mechanical Engineering

Executive Summary

An oxygen consumption calorimeter works by measuring the heat release rate of a burning substance. This value is calculated by measuring the oxygen and byproducts in smoke from afire.In order to get these values two types of sensors were used. A non-dispersive infrared sensor (NDIR) that measured CO and CO2 and a zirconium O2 sensor were used to find their respective gas concentrations.The design to calculate the heat release rate is focused on maximizing sensor accuracy and portability while simplifying the manufacturing by using off-the-shelf components. The goal included making the system simple to recreate and package in …

An Investigation Of Diode Failure, Nicholas James Adams

Physics

Solar electricity can be used to cheaply cook food and charge electronic devices. We investigate the viability of using diodes as heating elements for insulated solar electric cooking (ISEC). In addition, information on designing and constructing ISEC compatible phone chargers and rechargeable LED lighting systems is included.

Cascaded Linear Regulator With Negative Voltage Tracking Switching Regulator, Ernest Lei

Master's Theses

DC-DC converters can be separated into two main groups: switching converters and linear regulators. Linear regulators such as Low Dropout Regulators (LDOs) are straightforward to implement and have a very stable output with low voltage ripple. However, the efficiency of an LDO can fluctuate greatly, as the power dissipation is a function of the device’s input and output. On the other hand, a switching regulator uses a switch to regulate energy levels. These types of regulators are more versatile when a larger change of voltage is needed, as efficiency is relatively stable across larger steps of voltages. However, switching regulators …

Opendrop Elisa: Surface Development For Digital Microfluidic Elisa Testing, Michaela Q. Mead, Madeline G. Jackson, Jacob G. Taylor

Biomedical Engineering

This project aimed to develop a process to create a hydrophobic coating with capture antibodies attached. This process was developed in an attempt to create a digital microfluidic platform upon which an enzyme-linked immunosorbent assay (ELISA) could be run, indicated for clinicians and educators in low-resource settings. Four requirements dictated the course of the design process: 1) the contact angle with water of the hydrophobic layer must be greater than 90º, 2) the colorimetric response of a positive ELISA result on our platform must be at least 85% of that run on polystyrene with the same result, 3) the platform …

Discontinuous Grain Boundaries Of Forged René 41, Aaron Rabin, Bryce Bitter

Materials Engineering

Certain nickel-based alloys, particularly René 41, characteristically have many low-angle grain boundaries (grain arrangements of less than 15 degrees), present in the microstructure of an in-use component. Frequently, these low-angle grain boundaries are not optically visible after the etching process, leading to the phenomena of discontinuous grain boundaries. There exists a risk for René 41 grain boundary characterization; since one cannot assume that a grain boundary continues beyond a discontinuity, the grain size requirements become difficult to meet. Despite favorable characteristics of René 41, such as the corrosion and oxidation resistance coupled with excellent strength at high temperatures, the risks …

Service Dog Ramp, Matthew Lundgren, Ariel Tolentino, Dallas Rocha, Adam Mayeda

Mechanical Engineering

This project involves designing a device to help a service dog easily get into and out of a truck. It details the design and manufacturing process. The project was interrupted due to the COVID-19 pandemic, so detailed instructions are provided for whoever takes on the project in the future.

Multiple Input Single Output Converter With Maximum Power Point Tracking For Renewable Energy Applications, Kenneth K. Nguyen, Taufik Taufik

Master's Theses

In this thesis, a maximum power point tracking (MPPT) for multiple input single output (MISO) converter is presented such that power generated from multiple individual energy sources can be combined to deliver the maximum amount of power to a common resistive load. Typically, MISO converters will employ techniques that yield equal current sharing from each energy source. However, this may not be desirable since each source may be rated at different power ratings and/or may experience different operating conditions, preventing the system MISO converter to acquire the most available total power from the sources. Utilizing MPPT control would therefore be …

Multiple Input Single Output Converter With Uneven Load Sharing Control For Improved System Efficiency, Kristen Y. Chan

Master's Theses

This paper presents the development and study of multiple-input single-output converter (MISO) for the DC House project that utilizes a controller to maximize the overall converter’s efficiency. The premise of this thesis is to create uneven load current sharing between the converters at different loading conditions in order to maximize the efficiency of the overall MISO converter. The goal is to find a proper ratio of current from each converter to the total load current of the MISO system to achieve the greatest efficiency. The Arduino microcontroller is implemented to achieve this goal. The design and operation of the MISO …

A Novel Arc Welding Power Supply With Improved Power Factor Correction, Benjamin H. Tan

Master's Theses

This paper presents the design and development of a novel Arc Welding Power Supply utilizing a modified two-switch forward converter topology. The proposed design improves the power quality by improving power factor to near unity and reducing total harmonic distortion. State space analysis of the proposed circuit showed that the circuit followed a boost-buck input output relationship. Simulation of the circuit was first implemented in LTspice to verify the functionality of the new topology. Hardware implementation of the proposed design was built on a scaled-down prototype for a proof-of-concept of the new topology. The prototype specifications were created for a …