Acoustics, Dynamics, and Controls Commons^™

Polygait Conveyor Upgrade, William J. Schafer, Carolyn E. Palmer, Carly A. Tudor, Bryan C. Cordutsky

Mechanical Engineering

The PolyGAIT Conveyor Upgrade Mechanical Engineering Senior Project consisted of the complete design process to construct an operational “smart” control system for the conveyor belt loop on Cal Poly’s campus. As requested by project sponsor Dr. Tali Freed, an Industrial & Manufacturing Engineering professor at Cal Poly, the control system requirements included connecting existing conveyor components together, such as Radio Frequency Identification (RFID) reader tunnels, photo eye motion sensors, motor powered rollers, and diverting elastic bands. The main design problem is when packages with RFID tags are moving at industry high speed (10 ft/s) they are occasionally not scanned by …

Mtb Daq - Mountain Bike Data Acquisition System, Theodore J. Philliber, Ronan M. Shaffer, Dylan M. Ruiz, John M. Ringrose

Mechanical Engineering

Mountain bike suspensions systems are set up and tuned based only on qualitative, ‘feeling’-based metrics. The MTB DAQ, sponsored by Dr. Joseph Mello with the Cal Poly Mechanical Engineering Department, is a data acquisition system we developed to improve suspension tuning with a data-driven approach. The system mounts to a bicycle frame and has sensors that measure vibration and travel speed to characterize the bike’s motion. While similar systems exist, they cost in the thousands of dollars range and are very specific to individual bike geometry. Our system was designed to be more affordable to the average rider as well …

8 Dof Quadrupedal Hopping Robot, Clayton T. Elwell, John Bennett, Tyler Mccue, Daniel Munic

Mechanical Engineering

The goal of our senior project was to fabricate an eight degree of freedom (DOF) prototypical quadrupedal robot, develop a controller than commands the quadruped to repeatedly jump 10 cm in the air, and fabricate a modular test stand to safely deploy our controller on the quadruped. The creation of a functional quadruped will bring attention to Dr. Siyuan Xing and Charlie Refvem’s research group, Cal Poly Legged Robots, and will give future Cal Poly undergraduate and graduate students a learning tool to explore dynamic control of biomimetic robotic systems.

Over the course of our senior project, we successfully manufactured …

Mechanized Theatre Turntable, Chloe Huiyi Chou, Ethan Lee Stroh, Ruodolf Reller Quelnat Rumbaoa, Davide Lanfranconi

Mechanical Engineering

This project aimed to create a remote-control and drive system for a theatrical turntable that was constructed by the Theatre and Dance Department of California Polytechnic State University, San Luis Obispo. Over the course of three quarters, the team successfully designed and manufactured a working verification prototype. This verification prototype was then tested, and the project sponsor verified that it met all specifications. The current iteration of the verification prototype can support up to a load of 1400 lbf, rotate a 12 ft diameter turntable clockwise and counterclockwise with a speed range of 1 to 4 rpm, and is able …

Universal Tread For Power Wheelchairs, Daniel Ceja Gonzalez, Ryan Scarcella, Aaron Rocha, Brian Song

Mechanical Engineering

This project was centered around developing a fully independently driven powered wheelchair attachment that would allow users to traverse non-wheelchair accessible terrain. The initial goal was to create a full-scale model that would allow our user to use and test as a prototype to get over curbs and some light dirt off-roading. However, as the project progressed and limitations of time and money came up, this project was rescoped to a quarter-scale proof of concept model. The goal of this new project was to create a prototype that would carry a scaled-down load and traverse a scaled-down curb. This was …

Interactive Lego Girl Scout Arm, Chris Suzuki, Emi Okuyama, Bryson Shores, Karina Sandoval

Mechanical Engineering

This Senior Project Report document outlines the senior design project for Girl Scouts of California’s Central Coast (GSCCC) led by a team of four Mechanical Engineering students at California Polytechnic State University, San Luis Obispo. The project encompasses the researching, designing, prototyping, and testing of a LEGO robotic arm for the Girl Scouts to learn more about STEM (Science, Technology, Engineering, and Mathematics) and provide support to each Girl Scouts cookie sales in their stores. Their goal was to build a LEGO robotic arm that will interact with customers at the Girl Scout stores and promote the girl scouts' interest …

System Identification Of A Cantilever Beam With Interferometer Measurement Using Adaptive Filters, Jordan D. Kochavi

Master's Theses

Laser interferometry, commonly used in high-precision motion control systems, is rarely adopted in experimental vibration analysis because its installation and mounting is invasive to dynamical systems. However, metrology systems that already utilize laser interferometry, such as profilometry in semiconductor manufacturing, may benefit from interferometer feedback for signal processing. This study investigates the use of laser interferometry for system identification through a piezoelectrically actuated cantilevered beam.

The model of the beam including piezo actuators and optical measurement components are established through the Euler-Bernoulli beam theory. From the method of separation of variables, the continuous system is transformed into a discrete system …

Model-Based Design Of An Optimal Lqg Regulator For A Piezoelectric Actuated Smart Structure Using A High-Precision Laser Interferometry Measurement System, Grant P. Gallagher

Master's Theses

Smart structure control systems commonly use piezoceramic sensors or accelerometers as vibration measurement devices. These measurement devices often produce noisy and/or low-precision signals, which makes it difficult to measure small-amplitude vibrations. Laser interferometry devices pose as an alternative high-precision position measurement method, capable of nanometer-scale resolution. The aim of this research is to utilize a model-based design approach to develop and implement a real-time Linear Quadratic Gaussian (LQG) regulator for a piezoelectric actuated smart structure using a high-precision laser interferometry measurement system to suppress the excitation of vibratory modes.

The analytical model of the smart structure is derived using the …

Modeling And Control Of A Planar Bounding Quadrupedal Robot, Patrick John Ward

Master's Theses

Legged robots have the potential to be a valuable technology that provides agile and adaptive locomotion over complex terrain. To realize legged locomotion's full abilities a control design must consider the nonlinear piecewise dynamics of the systems. This paper aims to develop a controller for the planar bounding of a quadrupedal robot.

The bounding of the quadruped robot is characterized by a simplified hybrid model that consists of two subsystems for stance and flight phases and the switching laws between the two states. An additional model, the Multibody model, with fewer simplifications, is used concurrently to best approximate real-world behavior. …

Investigation Of Topological Phonons In Acoustic Metamaterials, Wenting Cheng

Dissertations

Topological acoustics is a recent and intense area of research. It merges the knowledge of mathematical topology, condensed matter physics, and acoustics. At the same time, it has been pointed out that quasiperiodicity can greatly enhance the periodic table of topological systems. Because quasiperiodic patterns have an intrinsic global degree of freedom, which exists in the topological space called the hull of a pattern, where the shape traced in this topological space is called the phason. The hull augments the physical space, which opens a door to the physics of the integer quantum Hall effect (IQHE) in arbitrary dimensions. In …

Cloudbots: Autonomous Atmospheric Explorers, Akash Binoj

Honors Scholar Theses

The CloudBot is an autonomous weather balloon that operates on the principle of variable buoyancy to ascend and descend in the atmosphere. This project aims to develop a device that will collect atmospheric measurements and communicate them mid-flight. The apparatus consists of a helium-filled balloon, the robotic payload, and an air cell. The fixed-volume helium balloon at the top provides an upwards buoyancy force, while the air cell at the bottom can hold a variable amount of pressure to adjust the weight of the CloudBot. By doing so, it is able to travel in storm conditions and collect valuable atmospheric …

Experimental And Theoretical Investigation Of Vibro-Impact Triboelectric Energy Harvesters, Mostafa Hassan

Mechanical Engineering Theses

Improving the efficiency of energy harvesting, by investigating different techniques to increase the harvester bandwidth, as well as by exploring the influencing factors and adjusting them to optimal setups. Towards this, multiple Vibro-impact energy harvesters were proposed in this study. First, a Two-Degree of Freedom (2DOF) Vibro-impact Triboelectric Energy Harvester with a single and a double impact configuration is proposed. Multi-modality and piecewise linearity were combined to improve the harvesting bandwidth of triboelectric energy harvesters utilizing two resonant frequencies. The harvester structure consists of a primary cantilever beam attached to a secondary cantilever beam through a tip mass in the …

Design And Nonlinear Control Of A Haptic Glove For Virtual Palpation, Matthew Galla

Mechanical Engineering Research Theses and Dissertations

This dissertation presents the design, kinematic analysis, and nonlinear control of a Haptic Glove for medical elastographic imaging virtual palpation. Of the 13 degrees of freedom present in the index finger, middle finger, and thumb of the hand, the design fixes 4, constrains 2 and controls 6 with pneumatic air cylinder actuators, allowing uncontrolled, but measured motion in the remaining 1 degree of freedom. Nearly linear bijective transfer functions between the actuator positions and joint angles are found in closed form for all 6 actuated joints. A nonlinear, sliding-mode controller that allows each actuator to be controlled by a single …

Challenges And Signal Processing Of High Strain Rate Mechanical Testing, Barae Lamdini

Theses and Dissertations

Dynamic testing provides valuable insight into the behavior of materials undergoing fast deformation. During Split-Hopkinson Pressure Bar testing, stress waves are measured using strain gauges as voltage variations that are usually very small. Therefore, an amplifier is required to amplify the data and analyze it. One of the few available amplifiers designed for this purpose is provided by Vishay Micro-Measurements which limits the user’s options when it comes to research or industry. Among the challenges of implementing the Hopkinson technology in the industry are the size and cost of the amplifier. In this work, we propose a novel design of …

Interaction Beyond Nearest Neighbor In Periodic Structures, Sudesh Pathak

Honors Theses

Periodic structures have been of particular interest to researchers and engineers due to their interesting vibrational characteristics leading to applications, namely acoustic filters, and waveguides. Many studies on the interaction of nearest neighbors have been performed. However, such studies are insufficient to understand the variation of band gaps and the maximum number of wave vectors for each frequency. The complex band structure obtained from the interaction beyond nearest neighbors can assist in the development of sophisticated acoustic technologies. This paper primarily emphasizes the study of such interactions with the development of mathematical models based on electrostatic forces, supported by the …

Cal Poly Fluid Power Vehicle Challenge 2022, Sangmin Sung, Eddy Rodriguez, Travis Welch, Jeremy Baechler, Kevin Pauls

Mechanical Engineering

In this report, the Featherweight Cycles design team puts forth the scope and overview of their design project, discusses background research and competitor analysis, and presents the project’s final design and manufacturing plans. The overall goal of this project is to fabricate and compete in the Fluid Power Vehicle Challenge, hosted by the National Fluid Power Association. To better define the design process, the team researched previous year’s designs from Cal Poly, as well as winning designs from the last two years to form a baseline of knowledge about competing schools’ designs. After researching multiple design paths, Featherweight Cycles chose …

Reducing Torsion In Asymmetric Structures During Earthquakes Through Active Control, Keona Lauren Banks

Honors Capstone Projects and Theses

No abstract provided.

Ambient Temperature Phase Change Launcher, Johnny Molloy

Senior Honors Projects

JOHNNY MOLLOY (Mechanical Engineering) Ambient Temperature Phase Change Launcher Sponsor: Bahram Nassersharif (Mechanical Engineering)

Deployment of payloads stored in watertight cylindrical bodies in underwater environmental conditions are of interest to the marine and naval community. The proposed work will investigate the possibility of using inert carbon dioxide gas compressed into its liquid state and stored under pressure to launch payloads by means of expansion from a cylindrical tube. To suit the needs of the Naval Undersea Warfare Center (NUWC), this launching system must fire from up to 14 ft underwater, have two degrees of freedom, and the payload must not …

Ballasting System For An Autonomous Underwater Vehicle, Noura Rayes, Bahram Nassersharif, Zach Champney, Kyle Alessandro, Jason Mirandou

Senior Honors Projects

NOURA RAYES (Mechanical Engineering); Ballasting System for an Autonomous Underwater Vehicle Sponsor: Bahram Nassersharif (Mechanical Engineering)

Over the last year, our Mechanical Engineering Capstone team, Nautilus, has been working to design a ballasting system for various Autonomous Underwater Vehicles (AUVs) sponsored by Raytheon Technologies. Common AUV systems are used for a wide range of applications from environmental monitoring, oceanic exploration, to data collection. AUVs also have many technical advantages that make underwater tasks more efficient, cost-effective, and generally safer. Raytheon Technology, specifically, is looking to improve their existing ballasting mechanism for their AUVs to use for military defense. For this …

A Central Compact Hybrid-Variable Method With Spectral-Like Resolution, Md Mahmudul Hasan

Open Access Theses & Dissertations

Numerical methods for hyperbolic conservation laws have been a driving force for theresearch in scientific computing and simulation science in the past decades, as many physical, biological, and engineering systems are governed by these equations, such as fluid mechanics, tumor growth, and virtual wind tunnel simulations. Despite the existence of many schemes in the literature, people have never stopped searching for more accurate and efficient methods for these problems. Indeed, the increasing complexity of systems in emerging applications demands better resolution of sub-grid scale phenomenon whereas classical methods usually fail to deliver high-fidelity simulation results of such systems within realistic …