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Marine Energy Collegiate Competition - PolyWave Energy
Get PDFThis document is the final Electrical Engineering senior project report for Cal Poly’s 2025 Marine Energy Collegiate Competition (MECC) team. The goal of this project is to build and test a wave-energy converter designed to address the need for sustainable power generation for remote coastal community microgrids. These existing systems often rely on costly, fossil-fuel generators, creating both logistical and environmental challenges. Our device aims to provide a renewable, low-maintenance solution that can operate reliably in offshore environments and serve commercial or research applications. The goal of the electrical engineering team was to develop a system that can convert rotational energy to electrical energy and efficiently transmit the energy from an off-shore buoy to an on-shore battery pack. Additionally, a robust safety system was developed to allow the system to shut down manually and when excessive currents are detected. This project was completed alongside a team of mechanical engineers who designed a rotating inertial mass device to convert wave energy to rotational energy. Testing proved that the system was able to successfully generate and deliver 17W of power to a battery when powered by a handheld drill. The full system efficiency for the prototype was approximately 63%. This report will cover the details of the design, manufacturing, and testing of this system
2024 – 2025 Cal Poly Wind Power AC-DC Rectification Subsystem for Collegiate Wind Competition 2025
Get PDFThis project focuses on the design and development of a bidirectional AC-DC rectification subsystem for a wind energy conversion system (WECS), tailored for the 2025 Collegiate Wind Competition. The subsystem is defined by its core inputs and outputs where it receives AC power from the wind turbine generator and delivers stable DC power to auxiliary electronics and variable loads. Conversely, the system can also accept DC power, such as from wall power, and output AC power to drive the permanent magnet synchronous machine (PMSM) as a motor, overcoming cogging torque and initiating turbine blade rotation. This bidirectional functionality is enabled by a MOSFET-based active rectification system using a six-switch power factor correction (PFC) topology, also referred to as a three-phase voltage-source inverter (VSI). Control inputs, including rotor position feedback and command signals, ensure precise operation and efficiency. An ESP32 microcontroller unit (MCU) oversees real-time monitoring of voltages, currents, and power flow while interfacing with other electrical subsystems, such as the point of common coupling (PCC) and DC-DC converters. This report serves as both a foundational guide for future Cal Poly Wind Power teams and an evaluation of active rectification’s impact on power efficiency through different operating modes of the MOSFETs
Leader-Follower Platooning with Turtlebot3: A Low-Cost ROS Test-Bed Using Vision-LiDAR Fusion
Get PDFThis report presents the design, implementation, and indoor validation of a two-robot leader–follower platoon built on low-cost Turtlebot3 platforms. Each robot runs ROS Noetic on an on-board Raspberry Pi 4, fusing a fisheye camera for HSV-based lane detection with an LDS-02 LiDAR for clustering-based leader identification. A dual-loop architecture (PD steering for lateral control and PID for longitudinal gap regulation) maintains a 0.40m headway and keeps the follower centered within +/- 5 cm of the lane midline, without any inter-vehicle communication or external localization. Track experiments at speeds up to 0.18m/s achieved mean gap error of +/- 3 cm and lane-center error of +/- 4 cm. The fully open-source hardware–software stack offers a reproducible test-bed for cooperative driving research and underscores the feasibility of communication-free platooning for cost sensitive autonomous fleets
Development of a Novel Bio-Mimetic Ornithopter With Variable Flapping Angle
No full textFrom the beginnings of flight, flapping-winged flight has been a goal of many engineers to mimic and replicate. With gains in aerodynamic efficiency of flight and certain other favorable characteristics such as reduced noise, higher maneuverability, and surveillance opportunities in urban environments, flapping-wing aerial vehicle(FWAV) designs are consistently pursued in many corners of academia and industry. This thesis goes into the development of a flapping wing aerial vehicle with a Bio-mimetic novel drive mechanism that is cable-driven and can produce variable amplitude and frequency flapping stroke. Employing a Field-Oriented Control (FOC) Brushless Direct Current (BLDC) motor, paired with a bio-mimetic pull-pull cable mechanism replicating the avian flapping muscle structures, a novel flapping mechanism is created to achieve precise control over flapping angles and frequencies. This thesis highlights the development of the novel flapping mechanism and the development of an ornithopter named K1 that utilizes the novel flapping mechanism. The K1 test platform is not only designed for flight tests but also acts as a test bed for wind tunnel tests, leveraging the unique capabilities of achieving flapping amplitudes and frequencies from take-off, cruise, loitering, and landing. The continued discussion highlights the necessary steps in the development of K1. Testing the craft in static wind on and off conditions proves that the novel drive mechanism enables the system to vary flapping amplitudes successfully. Flight testing also provides promising results, with a maximum capable amplitude of 6 Hz at 90 degrees peak-to-peak, providing similar performance compared to existing ornithopters with other drive mechanisms during cruise
Design Principles for Robotic-Controlled 3D Printing of Soft Tissue-Mimicking Materials
Get PDFGeometrically and physically accurate 3D models are emerging as essential tools for surgeons in pre-operative planning and training, but current methods of producing these models are not sufficient. Existing solutions have downsides such as high costs, long and tedious production times, high complexity resulting in a lack of scalability, or an inability to meet material requirements for accurately simulating human tissue.
The objective of this work is to develop principles for a low-cost, easy-to-use 3D printing system capable of prototyping with soft tissue-mimicking materials. To pursue this goal, a MyCobot280 robot arm was used as the mechanism to explore the relevant hardware, software, and material requirements for such a system. The first contribution of this work is the design of a robotic end effector that holds a syringe and depresses the plunger on command. Simultaneously, the robot is programmed to parse a given G-code file to move along specific coordinates, creating an extrusion process for any desired structure. The second contribution is to identify a material that meets both the extrudability criteria and the mechanical properties of human soft tissue. Finally, a relationship is to be developed between the two contributions, defining the extrusion parameters required for producing a successful 3D model.
For the first contribution, a mechanically actuated linkage design was implemented for successful depression of the syringe plunger, controlled via velocity control. A Python script was successfully developed to extract coordinates and extrusion data from a G-code file and then send the appropriate motion and end effector commands to the robot at the correct time.For the second contribution, a UV-curing resin and two two-part platinum-cure silicones—selected for their matching Shore Hardness and Young’s Modulus to fibrocartilage, as well as reasonable viscosity—were tested for functionality. Experiments were conducted to determine the optimal syringe size, line overlap, and extrusion speed. This analysis identified BASF’s UltraCur3D as the best selection and defined the parameters and methods necessary for customizing the Python script and slicing process accordingly. The results from robot motion and end effector control, identified material, and extrusion parameters outline a set of important principles for developing a low-cost, multi-material 3D printing process using materials that replicate soft tissue. These principles can be used to establish a design process that can be replicated and customized for use with a variety of machines or robots
Analyzing Steel Supply Chain Factors with Analytic Hierarchy Process
Get PDFThe global steel supply chain is a critical component of construction and manufacturing industries. It is a fundamental pillar supporting infrastructure development, economic growth, and technological innovation. However, disruptions in supply, price volatility, and logistical challenges necessitate an in-depth evaluation of key factors affecting the steel supply chain. These uncertainties can pose significant risks to project timelines, cost efficiency and sustainability. This study employes the Analytical Hierarchy Process (AHP), a multi-criteria decision-making approach to systematically rank and prioritize factors influencing the supply chain. A literature review identified critical variables, which are then structured into a hierarchical model after the opinion of industry experts. The findings of this study reveal that digital reporting and technical innovation are the most influential factors in enhancing steel supply chain performance, followed by the effectiveness of trade systems and the reliability of on-time delivery
Telling the Truth, Seeking Justice: Feminist Pedagogy and the Comfort Women Legacy
Get PDFThis commentary explores the pedagogical significance of teaching the legacy of comfort women—women subjected to sexual slavery by the Japanese military during World War II—in U.S. gender studies classrooms. Drawing on feminist pedagogy, the essay examines how testimonies from survivors like Hak-sun Kim and Bok-dong Kim empower students to critically engage with the intersections of war, colonialism, gender-based violence, and transnational justice movements. Through assigned readings, survivor testimonies, and documentary media, students confront the ongoing impact of colonialism and are encouraged to reconceptualize peace as a radical, actionable process. The essay also highlights the role of the United States in shaping postwar narratives and political resolutions, challenging students to reflect on their own positionality within global power structures. Ultimately, the work advocates for a feminist classroom that bridges theory with community engagement, urging students to remember, speak out, and act in solidarity with survivors in the pursuit of justice and global peace
Skip the Grid 2025: Providing Power in the Navajo Nation
No full textSkip the Grid is an interdisciplinary initiative aimed at supporting the Navajo Nation by providing access to off-grid power to improve quality of life. This year, the Skip the Grid team centered its efforts around the Chinle Unified School District in Chinle, Arizona. This collaborative effort was composed of an interdisciplinary team of California Polytechnic State University (Cal Poly) students, along with industry partners including SOLV Energy, Heart of America, Goal Zero, and Nextracker. Many families in the Navajo Nation still live without access to reliable electricity. Between March 23rd and March 27th, 2025, the Skip the Grid team successfully installed solar panels, battery storage systems, lighting, and refrigeration units in forty homes throughout the Chinle community located in Northeastern Arizona. The project not only addressed pertinent infrastructure needs but also embodied Cal Poly’s motto of “learn by doing”, as students engaged directly in meaningful hands-on work that benefited the Navajo Nation. The Cal Poly team and its counterparts are proud to have made an immediate and lasting impact on the community for the fourth consecutive year, as well as to have been given a rare opportunity to apply our knowledge in real-world conditions and engage in community service
Shipping Container Library Project: Preconstruction Strategy and Planning
No full textThis report outlines the preconstruction planning phase for the development of a shipping container library to be deployed to a community in Sub-Saharan Africa. The library is designed as a modular and sustainable solution for delivering access to educational resources. Preconstruction efforts have focused on finalizing design documentation, procurement planning, trade coordination, permitting considerations, and site logistics. While no construction has begun, two 40-foot high-cube containers have been ordered—one for prototyping and one for shipment. One container is currently staged at Tilden-Coil Constructors’ yard in Riverside, California, and the project is approaching the procurement and mobilization phase. All tracking of procurement, labor, and risk management is being performed through a live Excel file, and funding has been secured exclusively through the Lights for Literacy charity with the support of Tilden-Coil Constructors
Assessing Fire Risks in San Luis Obispo: The Impact of Building Construction and Landscaping on Wildfire Vulnerability
No full textAs wildfires grow in frequency and intensity across California, understanding and mitigating residential fire risk has become a public safety priority. Communities in the wildland-urban interface (WUI), such as San Luis Obispo, are especially vulnerable due to their proximity to natural vegetation and the prevalence of older housing stock. While state and local agencies have introduced regulations and educational campaigns, there remains a need for accessible, scalable tools that help identify fire risks at the individual home level. This project assessed wildfire vulnerability across 140 homes in San Luis Obispo, California, using a custom visual grading rubric informed by academic research and an interview with Fire Chief Damon Pellegrini. The rubric evaluated ten factors, including roof and siding materials, window type, vent coverage, vegetation clearance, and home age. Each home was visually surveyed and given a score, then categorized as Low, Moderate, High, or Extreme Risk. Results showed significant variation between neighborhoods. Neighborhood 5, a newer and more affluent area, had the highest average score and the fewest high-risk homes, while Neighborhood 1, which featured older housing and more student rentals, had the lowest average and the most High and Extreme Risk homes. Citywide, over one-third of homes fell into the High or Extreme categories. Common issues included wood siding, single-pane windows, and vegetation in direct contact with the structure. The results highlight how structure-level risk is influenced by both physical conditions and socioeconomic factors. The rubric proved effective as a simple, repeatable tool for identifying vulnerabilities and can support targeted mitigation strategies for homeowners, fire departments, and local governments in wildfire-prone regions