Acoustics, Dynamics, and Controls Commons^™

Marine Vehicle Dynamics Using Koopman Operator Theory With Hybrid Observables, Mikhalib A L Green

LSU Master's Theses

Accurate modeling of marine vehicle dynamics remains challenging due to strong nonlinear hydrodynamic effects, environmental disturbances, and sensitivity to configuration changes, particularly for small-scale platforms. Classical physics-based models require extensive parameter identification and often exhibit degraded performance outside narrow operating regimes, while purely data-driven approaches may lack structure or impose high computational cost. This thesis presents a data-driven Koopman operator framework with hybrid observables for modeling the dynamics of unmanned marine vehicles. The proposed approach combines structured monomial observables with a learned neural network embedding to construct a lifted state representation in which the nonlinear vehicle dynamics are approximated by …

Multi-Objective Design Optimization Of Hypoid Geared Rotor Systems, Xinqi Wei

Mechanical and Aerospace Engineering Dissertations - Archive

Hypoid gears represent one of the most generalized and complex forms of gearing, widely used for power transmission of skew shafts in vehicles, aviation, and marine transmission applications. Optimizing their performance remains challenging due to the complex tooth surface and contact behavior. Specifically, the design parameters of the tooth surface are multi-scale, interdependent, and subject to strong constraints, leading to strong nonlinearity and an ill-conditioned Jacobian matrix in the parameter identification model. Moreover, feasible and insensitive contact conditions are difficult to constrain due to the inherent complexity of local conjugate contact between the meshing surfaces. These challenges significantly increase optimization …

Dynamics And Steering Of A Vibration-Driven Bristle Bot In A Pipe System, Ian Stewart

All Theses

Soft vibrational robots are robots that incorporate compliant structures into their design and are driven by oscillating actuators. A recent, popular version of a soft vibrational robot is the bristle bot, which uses flexible bristles and a vibration motor to propel itself across surfaces and through pipes. This motion is primarily driven by stick-slip dynamics resulting from asymmetric frictional forces applied at the bristle tips. Depending on the frequency of vibration of the motor, the robot experiences various resonance regions allowing it to maneuver in different directions. Attaching bristles to all sides of the robot and placing it in a …

Locking Solar Tracking Bushing, Benjamin James Reed, Andrew Donald Maas, Angel Navarro-Iniguez, John Vincent Bruner

Mechanical Engineering

The contents of this final design review (FDR) outline the progress made by a team of four mechanical engineering students at California Polytechnic State University, San Luis Obispo to solve the problem of torsional galloping in solar tracker panels since the preliminary design review. The project proposed by the sponsor, Christian Friedrich, on behalf of ARaymond is a design for a friction based braking system integrated into a redesigned bushing.

The CDR contains details about the system design, the design justification, the manufacturing plan, and design verification plan. In the system design section, the four manufacturing subsystems (bushing mount, actuation, …

Understanding The Nonlinear Dynamics Governing Vertical-Lift Vehicles With Variable-Speed, Fixed Rotors, Stephanie Vavra, Micah Busboom, Aleea Stanford, Keegan Moore

UNL Student Research Days Posters, Undergraduate

Problem: Traffic significantly limits travel in urban areas. • The NASA Urban Air Mobility Project is developing an air taxi as an alternative mean of transportation (Fig. 1).

Challenge: Operating rotors at different frequencies may cause the cabin to vibrate at high amplitudes. Such effects are currently unknown.

Objective: Understand the effect of variable speed rotors on passenger comfort.

From the reduced-order modeling simulations, it can be assumed that counteracting the rotor speed in-balances can reduce the displacement and vibrations experienced at the center of the wing. In other words, should a rotor not maintain its optimal operation speed, reducing …

Nonlinear Model Development And Validation For Ball And Plate Control System, Zachary Richter

Master's Theses

Ball and plate balancing control systems are commonly studied due to the complex dynamics associated with the instability of the system in open-loop. For simplicity, mathematical models describing the ball and plate dynamics are often linearized and the effects of complex motion are assumed to be negligible. These assumptions are rarely backed with evidence or explanations validating the simplified form of the dynamical equations of motion. This thesis focuses on developing a nonlinear model that more accurately defines the dynamics of the system, in order to quantify the error of linear and nonlinear models when compared to a Simscape physical …

A Single-Stage Passive Vibration Isolation System For Scanning Tunneling Microscopy, Toan T. Le

Master's Theses

Scanning Tunneling Microscopy (STM) uses quantum tunneling effect to study the surfaces of materials on an atomic scale. Since the probe of the microscope is on the order of nanometers away from the surface, the device is prone to noises due to vibrations from the surroundings. To minimize the random noises and floor vibrations, passive vibration isolation is a commonly used technique due to its low cost and simpler design compared to active vibration isolation, especially when the entire vibration isolation system (VIS) stays inside an Ultra High Vacuum (UHV) environment. This research aims to analyze and build a single-stage …

Using Transfer Path Analysis And Frequency Based Substructuring To Develop A Robust Vibration Laboratory Dynamic Test Fixture Design Process, Cora Taylor

Dissertations, Master's Theses and Master's Reports

The objective of this research is to determine a robust method for designing shock and vibration laboratory test fixtures that accurately reproduce the field environment for the component of interest. The methods presented in this research examine the boundary conditions presented unto the component of interest through transfer path analysis with the intent of reproducing the next-structure attachment impedance with a laboratory test fixture of one and two attachments. The first method includes only using the next-structure relative motion and stiffness to design a test fixture, while the second method uses an optimization algorithm to develop a lumped parameter model …

Dyno-Mite Redesign, Brandon Joseph Miller, Daniel Robert Hoffman, Richard Demedici Young

Mechanical Engineering

The Cal Poly Mechanical Control Systems Laboratory currently employs an outdated device, known as the Motomatic, to teach students about various motor characteristics and control methods. These include open-loop vs. closed-loop control, speed vs. position control, and DC motor response curves. The current device does not function properly and produces unreliable data due to overwhelming non-linear effects such as stiction and shaft misalignment. Our team was tasked with designing a replacement device that retains many of the same educational goals as the original lab procedure, while also adding new educational goals pertaining to the device system dynamics. The new apparatus, …

Flag Raising Device, Josh Quintero

All Undergraduate Projects

The motivation for this project stems from a lifetime of boating with father Richard Jones. One problem that many people encounter, including Richard, was when towing someone behind a boat, is the difficulty with handling the warning flag. This flag is used to show other surrounding boats that someone has fallen into the water behind their boat. This warns other boats to stay far away from that area to keep safe from running over the swimmer. Although, when holding the flag in the boat, it can be hard to see at times. The boat driver, or other people standing in …

Visualizing Mechanics: Improving Student Learning Through Video Demonstrations, Blake A. Wetherton, Olumide A. Awofeso, Carolyn E. Creighton, Adam F. Potrzebowski, Charles M. Krousgrill, Jeffrey F. Rhoads

The Summer Undergraduate Research Fellowship (SURF) Symposium

The Purdue Mechanics Freeform Classroom (PMFC) is a project that seeks to reform engineering mechanics education by integrating content and technology; enhancing communication between students, their peers, and instructors; accommodating a broader range of learning styles; and facilitating greater depths of understanding. In an attempt to increase the PMFC’s efficacy, a series of demonstration videos has been produced. As demonstrated by the popularity and pervasiveness of websites such as YouTube, short videos have the potential to captivate audiences. As such, these videos have incredible promise in educational contexts. In the PMFC series of videos, entitled Visualizing Mechanics, each imitates the …

The Stability And Control Of The Single Track Vehicles, Shyngys Karimov, Martin Corless

The Summer Undergraduate Research Fellowship (SURF) Symposium

Bicycles, motorcycles and scooters are all examples of the single track vehicles. The dynamics of the single track vehicle involve many degrees of freedom and various modes which govern its performance, making a complicated and interesting research topic. Motorcycle in motion can roll, yaw, and steer about the steering axis. It has three main modes which determine the motion and stability of it, they are weave, capsize, and wobble. The motorcycle performance is limited by the behavior of its modes, and if even one of the modes becomes unstable, the vehicle will roll over, and crash. The goal of this …