Acoustics, Dynamics, and Controls Commons^™

Discrete-Time Adaptive Control Algorithms For Rejection Of Sinusoidal Disturbances, Mohammadreza Kamaldar

Theses and Dissertations--Mechanical and Aerospace Engineering

We present new adaptive control algorithms that address the problem of rejecting sinusoids with known frequencies that act on an unknown asymptotically stable linear time-invariant system. To achieve asymptotic disturbance rejection, adaptive control algorithms of this dissertation rely on limited or no system model information. These algorithms are developed in discrete time, meaning that the control computations use sampled-data measurements. We demonstrate the effectiveness of algorithms via analysis, numerical simulations, and experimental testings. We also present extensions to these algorithms that address systems with decentralized control architecture and systems subject to disturbances with unknown frequencies.

Analysis Of The Shock Response Spectrum And Resonant Plate Testing Methods, William Larsen

Dissertations, Master's Theses and Master's Reports

Intricacies of the shock response spectrum were discovered and investigated by testing a circular plate structure with integral damping. Effects on the SRS from physical alterations to the nonlinear structure were monitored from low and high shock impulses. A method was developed and validated to estimate high amplitude shock inputs from low amplitude frequency response functions. Finite element models explored variable thickness plate designs.

Control Oriented Modeling Of An Automotive Drivetrain For Anti-Jerk Control, Gurijala Venkat Prithvi Reddy

Dissertations, Master's Theses and Master's Reports

Drivability is an important metric during the development of an automobile. Calibration engineers spend a significant amount of time trying to improve the drivability of vehicles for various driving conditions. With an increase in the available computational power in an automobile, novel model-based methods are being implemented for further improving the drivability, while reducing calibration time and effort. Phenomenon known as clunk and shuffle, which are caused due to backlash and compliance in the driveline, are a major cause of issues related to drivability and noise, vibration and harshness (NVH) during tip-in and tip-out scenarios.

This thesis focuses on developing …

Impedance Tube Alternative Via The Transfer Function Method, Nathan Palella, Griffin J. Binkley

Williams Honors College, Honors Research Projects

Typical industry-ready impedance tube systems for measuring sound absorption cost between $20,000 and $60,000. The scope of this project was to explore an industrial impedance tube and its functions as well as iteratively reduce the cost of each component of the system to its lowest possible conclusion without severely sacrificing quality of data acquisition. Replacement of the hardware and software with “off-the-shelf” alternatives and custom-made components can reduce the overall cost by as much as two orders of magnitude in order to be used in the education sector, mainly high schools. We find that the designed tube and driver replacements …

Elastodynamic Model For Wind Induced Ground Motion, Mohammad Mohammadi

Electronic Theses and Dissertations

No abstract provided.

Modeling And Analysis For Driveline Jerk Control, Prince Lakhani

Dissertations, Master's Theses and Master's Reports

In modern-day automotive industry, automotive manufacturers pay keen attention to driver’s safety and comfort by ensuring good vehicle drivability, feel of acceleration, limiting jerk and noise. The vehicle driveline plays a critical role to meet these criteria. By using high-fidelity simulation tool such as AMESim®, it is now possible to accurately model the vehicle driveline to be tested for different scenarios. With Simulink®, one can develop an efficient torque-based control system to limit the driveline oscillations and the generated noise. So, a joint simulation is used which provides a platform to evaluate the estimators and control system while considering the …

Commercialization Of The Carbon Nanotube Thermophone For Active Noise Control Applications, Steven A. Senczyszyn

Dissertations, Master's Theses and Master's Reports

The rate of commercialization for technology developed in junction with academic institutions has risen dramatically over the past 30 years. Since the introduction of the Bayh-Dole Act in 1980, the amount of intellectual property owned by academic institutions has increased exponentially, and with that, there has also been an increase in the number of university spinouts generated. However, the increase of spinouts does not match the rate of increase in intellectual property. The National Science Foundation has created the Innovation Corps (I-Corps) program to help bridge this gap and provide academic professionals and students the tools necessary to commercialize technology …

Optimization And Control Of An Array Of Wave Energy Converters, Jianyang Lyu

Dissertations, Master's Theses and Master's Reports

This study explored optimal configuration of both the array layout and the dimension of each WEC in the array. The array contains heaving buoys with full interaction and exact hydrodynamics. Optimization of dimension was done on each WEC in the array with a given optimal layout, and a higher q-factor was achieved. Both impedance matching optimal control and derivative control were employed, which provides both theoretical maximum energy and a more realistic case. Then the work was expanded to optimization of both the array layout and the dimension of each WEC in the array. An average of 39.21% higher q-factor …

Terahertz Imaging Of Thin Film Layers With Matched Field Processing, Scott Schecklman, Lisa M. Zurk

Electrical and Computer Engineering Faculty Publications and Presentations

Terahertz (THz) time of flight (TOF) tomography systems offer a new measurement modality for non-destructive evaluation (NDE) of the subsurface layers of protective coatings and/or laminated composite materials for industrial, security and biomedical applications. However, for thin film samples, the time-of-flight within a layer is less than the duration of the THz pulse and consequently there is insufficient range resolution for NDE of the sample under test. In this paper, matched field processing (MFP) techniques are applied to thickness estimation in THz TOF tomography applications, and these methods are demonstrated by using measured THz spectra to estimate the the thicknesses …