Controls and Control Theory Commons^™

Static And Dynamic State Estimation Applications In Power Systems Protection And Control Engineering, Ibukunoluwa Olayemi Korede

Doctoral Dissertations

The developed methodologies are proposed to serve as support for control centers and fault analysis engineers. These approaches provide a dependable and effective means of pinpointing and resolving faults, which ultimately enhances power grid reliability. The algorithm uses the Least Absolute Value (LAV) method to estimate the augmented states of the PCB, enabling supervisory monitoring of the system. In addition, the application of statistical analysis based on projection statistics of the system Jacobian as a virtual sensor to detect faults on transmission lines. This approach is particularly valuable for detecting anomalies in transmission line data, such as bad data or …

Development Of A Soft Robotic Approach For An Intra-Abdominal Wireless Laparoscopic Camera, Hui Liu

Doctoral Dissertations

In Single-Incision Laparoscopic Surgery (SILS), the Magnetic Anchoring and Guidance System (MAGS) arises as a promising technique to provide larger workspaces and field of vision for the laparoscopes, relief space for other instruments, and require fewer incisions. Inspired by MAGS, many concept designs related to fully insertable magnetically driven laparoscopes are developed and tested on the transabdominal operation. However, ignoring the tissue interaction and insertion procedure, most of the designs adopt rigid structures, which not only damage the patients' tissue with excess stress concentration and sliding motion but also require complicated operation for the insertion. Meanwhile, lacking state tracking of …

Multiple Objective Co-Optimization Of Switched Reluctance Machine Design And Control, Timothy Burress

Doctoral Dissertations

This dissertation includes a review of various motor types, a motivation for selecting the switched reluctance motor (SRM) as a focus of this work, a review of SRM design and control optimization methods in literature, a proposed co-optimization approach, and empirical evaluations to validate the models and proposed co-optimization methods.

The switched reluctance motor (SRM) was chosen as a focus of research based on its low cost, easy manufacturability, moderate performance and efficiency, and its potential for improvement through advanced design and control optimization. After a review of SRM design and control optimization methods in the literature, it was found …

An Isostable Coordinate Based Amelioration Strategy To Mitigate The Effects Of Jet Lag, Talha Ahmed

Masters Theses

Commercial air travel has become extremely commonplace in the last 20 to 30 years especially as the world has moved towards new heights of globalization. Though air travel has greatly reduced transit times allowing people to cover thousand of miles within hours, it comes with its fair share of issues. jet-lag can be regarded to be at the top of those list of problems; jet-lag typically results from rapid travel through multiple time zones which causes a significant misalignment between the person's internal circadian clock and the external time. A person's circadian clock is governed by a population of coupled …

Decentralized Resource Allocation Through Constrained Centroidal Voronoi Tessellations, Bhagyashri Telsang

Doctoral Dissertations

The advancements in the fields of microelectronics facilitate incorporating team elements like coordination into engineering systems through advanced computing power. Such incorporation is useful since many engineering systems can be characterized as a collection of interacting subsystems each having access to local information, making local decisions, interacting with neighbors, and seeking to optimize local objectives that may well conflict with other subsystems, while also trying to optimize certain global objective. In this dissertation, we take advantage of such technological advancements to explore the problem of resource allocation through different aspects of the decentralized architecture like information structure in a team. …

Stability Analysis And Design Of Grid-Interactive Power Electronic Converters, Le Kong

Doctoral Dissertations

The increasing penetration of power electronic converters (PECs) can provide high flexibility, full controllability, sustainability, and improved efficiency for future electric power systems. However, it also introduces new challenges since the wide-frequency-band control dynamics of PECs can interact with the power system and result in different types of instability issues. To holistically address the instability issues, several research activities are conducted in this dissertation.

The modular multilevel converter (MMC), which is one of the most common PECs in high- or medium-voltage power systems, is investigated. An improved MMC dc impedance model is developed by considering both the submodule voltage and …

Efficient Control Approaches For Guaranteed Frequency Performance In Power Systems, Samaneh Morovati

Doctoral Dissertations

Due to high penetration of renewable energy, converter-interfaced sources are increasing in power systems and degrading the grid frequency response. Synthetic inertia emulation and guaranteed primary frequency response is a challenging task. Still, there is high potential for application of highly controllable converter-interfaced devices to help performance. Renewable energy sources and demand side smart devices also need to be equipped with innovative frequency control approaches that contribute to frequency regulation operations.

First, the wind turbine generator is chosen to represent an example of a converter- interfaced source. An augmented system frequency response model is derived, including the system frequency response …

Modeling And Control Of A 7-Level Switched Capacitor Rectifier For Wireless Power Transfer Systems, Spencer Cochran

Doctoral Dissertations

Wireless power continues to increase in popularity for consumer device charging. Rectifier characteristics like efficiency, compactness, impedance tunability, and harmonic content make the multi-level switched capacitor rectifier (MSC) an exceptional candidate for modern WPT systems. The MSC shares the voltage conversion characteristics of a post-rectification buck-boost topology, reduces waveform distortion via its multi-level modulation scheme, demonstrates tank tunability via the phase control inherent to actively switched rectifiers, and accomplishes all this without a bulky filter inductor. In this work, the MSC WPT system operation is explained, and a loss model is constructed. A prototype system is used to validate the …

Impact And Application Of Real-Time Control On Stormwater Systems, Aaron A. Akin

Doctoral Dissertations

Stormwater control measures (SCMs) such as dry extended detention basins and wet ponds are common practices implemented by engineers and designers to mitigate the impact of stormwater runoff. These practices are designed based on historical rainfall data to attenuate runoff to pre-development conditions and, once they are installed, are unable to adapt to changing rainfall patterns or watershed restoration objectives. To solve these climate resiliency issues, several studies were conducted which investigated the impact of retrofitting such systems with a controllable outlet to increase or change detention times during rainfall events along with the novel instrumentation and methodologies necessary for …

Design And Simulation Of A Supervisory Control System For Hybrid Manufacturing, Michael Buckley

Masters Theses

The research teams of Dr. Bill Hamel, Dr. Bradley Jared and Dr. Tony Schmitz were tasked by the Office of Naval Research to create a hybrid manufacturing process for a reduced scale model of a naval ship propeller. The base structure of the propeller is created using Wire Arc Additive Manufacturing (WAAM), which is then scanned to compare created geometry to desired geometry. The propeller is then machined down to match the desired geometry. This process is iterated upon until the final product meets design tolerances. Due to the complex nature and numerous industrial machines used in the process, it …

Optimal And Model Free Control Of Tumor Immune Interaction Dynamic To Schedule Cancer Treatments, Mohamed Alsager

Masters Theses

Cancer is an intricate disease that can attack different parts of the human body. In the most common types of cancer, abnormal cells divide uncontrollably and impair body tissue. Cross disciplinary research has long aided expansion of our knowledge and ability to approach problems with a different perspective. Engineers and clinicians can collaborate to solve mysteries surrounding cancer cells function and responses. Engineers have contributed to cancer treatment, by studying new ways to diagnose and treat cancer. According to a study by John Hopkins university engineered Nano-particles can induce immune reaction and kill cancer cells. In addition, new ways of …

Torch Mounted Wire Nipper, Steven D. Patrick, Matt Montgomery, Ben Rouse, Garrett D. Foust

Chancellor’s Honors Program Projects

No abstract provided.

Modeling And Design Of A Low-Level Rf Control System For The Accumulator Ring At Spallation Neutron Source, Michael G. Trout

Masters Theses

Since its commissioning in 2006, Spallation Neutron Source (SNS) at Oak Ridge National Laboratory has greatly contributed to the field of neutron science, but some critical systems are reaching end-of-life. This obsolescence must be addressed for the accelerator to continue providing world-class research capabilities. One such system needing redesign is the low-level RF (LLRF) control system for the proton accumulator ring. While this system has performed acceptably for over a decade, it is sparsely documented and robust operational models are unavailable. To ensure the new design meets or exceeds current performance metrics, we analyzed the existing LLRF control system and …

Control Oriented Nonlinear Model Reduction For Distributed Parameter Systems, Samir Sahyoun

Doctoral Dissertations

The development of model reduction techniques for physical systems modeled by partial differential equations (PDEs) has been a very active research area. Large number of states is needed to accurately capture the dynamics of such systems which makes them unsuitable for control design. The order of the system must be reduced prior to control design. In this dissertation, new methods that generalize the popular proper orthogonal decomposition (POD) to nonlinear PDEs are investigated. In particular, cluster based POD algorithms are developed and applied to the one and two dimensional Burgers equations that govern a nonlinear convective ow. Each cluster contains …

A Practical Realization Of A Return Map Immune Lorenz Based Chaotic Stream Cipher In Circuitry, Daniel Robert Brown

Masters Theses

Some chaotic systems are advantageously capable of self-synchronizing with a like system through a single shared state. Using a plain text binary message, a single system parameter can be modulated to mask this message and transmit it securely through the single shared state. The most simple implementations of this encryption technique are, however, vulnerable to the return map attack. Using a time-scaling factor to further obfuscate the modulation process, a return map attack immunity is gained. We report on the progress towards a realization of this process in real-time analog circuitry using off-the-shelf components.

Development Of Instrumentation And Control Systems For An Integral Large Scale Pressurized Water Reactor, Matthew Rowland Morrow Lish

Doctoral Dissertations

Small and large scale integral light water reactors are being developed to supply electrical power and to meet the needs of process heat, primarily for water desalination. This dissertation research focuses on the instrumentation and control of a large integral inherently safe light water reactor (designated as I²S-LWR) which is being designed as part of a grant by the U.S. Department of Energy Integrated Research Project (IRP). This 969 MWe integral pressurized water reactor (PWR) incorporates as many passive safety features as possible while maintaining competitive costs with current light water reactors. In support of this work, the …

Design And Control Of Close Proximity Indirect Exposure For Nonthermal Atmospheric Pressure Plasma-Based Oxidation Of Carbon Fiber Precursor, Truman Andrew Bonds

Doctoral Dissertations

A new plasma-based method for the stabilization of polyacrylonitrile carbon fiber precursor utilizing reactive chemical species derived from a custom atmospheric pressure plasma generation system was developed and demonstrated. As opposed to the conventional stabilization method of convective heating in air, plasma-based stabilization efficiently introduces oxidative reactive species that both diffuse through and react faster with the precursor filaments, resulting in a faster and more efficient process. This method was successfully demonstrated with a variety of precursor chemistries, grades and sizes. The development effort was entirely experimental, with successive processing devices designed and constructed to examine various aspects of the …

Stochastic And Optimal Distributed Control For Energy Optimization And Spatially Invariant Systems, Jin Dong

Doctoral Dissertations

Improving energy efficiency and grid responsiveness of buildings requires sensing, computing and communication to enable stochastic decision-making and distributed operations. Optimal control synthesis plays a significant role in dealing with the complexity and uncertainty associated with the energy systems.

The dissertation studies general area of complex networked systems that consist of interconnected components and usually operate in uncertain environments. Specifically, the contents of this dissertation include tools using stochastic and optimal distributed control to overcome these challenges and improve the sustainability of electric energy systems.

The first tool is developed as a unifying stochastic control approach for improving energy efficiency …

Dynamic Extruder Control For Polymer Printing In Big Area Additive Manufacturing, Alex Christopher Roschli

Masters Theses

Big Area Additive Manufacturing (BAAM) is 3D Printing on a large scale and can be used to create structures on the scale of cars and houses. Scaling up 3D printing to BAAM size meant fundamentally altering the traditional fused deposition modeling process by switching from a filament to a pellet material feed. This meant switching from a stepper motor extruder to a servo driven screw extruder. While increasing the throughput of the system, this new extruder increases the overall complexity. Effective control of the system is paramount to the success of BAAM enabling it to effectively scale in speed in …

Characterization Of Optimal Cyber Attacks On Control Systems, Anis Drira

Doctoral Dissertations

Securing control systems which manage the nation's critical physical infrastructures and key resources is becoming one of the highest priorities and can no longer be ignored. Several researches and incidents have confirmed the real vulnerability of these systems. Due to the vital role of control systems, the study and the development of advanced strategies to overcome these cyber-security breaches are very important. Control systems are mainly composed of sensors and actuators, which cyber-security is vital for the security of the whole control system.

Characterizing and guarding against worst case attack scenarios is important to secure control systems. This dissertation proposes …

Neuron Clustering For Mitigating Catastrophic Forgetting In Supervised And Reinforcement Learning, Benjamin Frederick Goodrich

Doctoral Dissertations

Neural networks have had many great successes in recent years, particularly with the advent of deep learning and many novel training techniques. One issue that has affected neural networks and prevented them from performing well in more realistic online environments is that of catastrophic forgetting. Catastrophic forgetting affects supervised learning systems when input samples are temporally correlated or are non-stationary. However, most real-world problems are non-stationary in nature, resulting in prolonged periods of time separating inputs drawn from different regions of the input space.

Reinforcement learning represents a worst-case scenario when it comes to precipitating catastrophic forgetting in neural networks. …

Dynamic Simulation And Neuromuscular Control Of Movement: Applications For Predictive Simulations Of Balance Recovery, Misagh Mansouri Boroujeni

Doctoral Dissertations

Balance is among the most challenging tasks for patients with movement disorders. Study and treatment of these disorders could greatly benefit from combined software tools that offer better insights into neuromuscular biomechanics, and predictive capabilities for optimal surgical and rehabilitation treatment planning. A platform was created to combine musculoskeletal modeling, closed-loop forward dynamic simulation, optimization techniques, and neuromuscular control system design. Spinal (stretch-reflex) and supraspinal (operational space task-based) controllers were developed to test simulation-based hypotheses related to balance recovery and movement control. A corrective procedure (rectus femoris transfer surgery) was targeted for children experiencing stiff-knee gait and how this procedure …

Development And Evaluation Of A Cost Effective Plant Growth Media Moisture Sensor And Development Of An Aqueous Data Transmission System For Irrigation Purposes, Steven Michael Pickett

Masters Theses

The ability to accurately monitor and transit the moisture content of soilless growing media in the rooting zone is critical for plant-based research, production of high value crops, and other agricultural production. The focus of this study is the development and evaluation of a cost effective moisture sensor designed to measure the plant-available moisture content of growing media and the development of a aqueous data transmission method for relaying this information back to a central location. While there are currently many commercially available soil moisture sensors on the market, the aim of this research is not to develop a more …

Increasing Efficiency Of Thermal Desalination, Jarrod A. Edwards, Mackinzie Washington, Chan Jung, Ben Garrison

Chancellor’s Honors Program Projects

No abstract provided.

Modeling, Analysis, And Control Of A Mobile Robot For In Vivo Fluoroscopy Of Human Joints During Natural Movements, Matthew A. Young

Doctoral Dissertations

In this dissertation, the modeling, analysis and control of a multi-degree of freedom (mdof) robotic fluoroscope was investigated. A prototype robotic fluoroscope exists, and consists of a 3 dof mobile platform with two 2 dof Cartesian manipulators mounted symmetrically on opposite sides of the platform. One Cartesian manipulator positions the x-ray generator and the other Cartesian manipulator positions the x-ray imaging device. The robotic fluoroscope is used to x-ray skeletal joints of interest of human subjects performing natural movement activities. In order to collect the data, the Cartesian manipulators must keep the x-ray generation and imaging devices accurately aligned while …

Optimal Control Of Energy Efficient Buildings, Cale David Nelson

Masters Theses

The building sector consumes a large part of the energy used in the United States and is responsible for nearly 40% of greenhouse gas emissions. Therefore, it is economically and environmentally important to reduce the building energy consumption to realize massive energy savings. Commercial buildings are complex, multi-physics, and highly stochastic dynamic systems. Recent work has focused on integrating modern modeling, simulation, and control techniques to solving this challenging problem. The overall focus of this thesis is directed toward designing an energy efficient building by controlling room temperature. One approach is based on a distributed parameter model represented by a …

Control Studies Of Dfig Based Wind Power Systems, Zhiqiang Jin

Doctoral Dissertations

Wind energy as an outstanding and competitive form of renewable energy, has been growing fast worldwide in recent years because of its importance to reduce the pollutant emission generated by conventional thermal power plants and the rising prices and the unstable supplies of fossil-fuel. However, in the development of wind energy, there are still many ongoing challenges.

An important challenge is the need of voltage control to maintain the terminal voltage of a wind plant to make it a PV bus like conventional generators with excitation control. In the literature with PI controllers used, the parameters of PI controllers need …

Control Law Calculation And Verification Methods For The Variable Stability Navion In-Flight Simulation Aircraft, Joe Ming Yin Siu

Masters Theses

The University of Tennessee Space Institute’s (UTSI) variable stability research aircraft, Ryan Navion N66UT, was extensively modified by the Princeton University in the 1960’s. When UTSI acquired the aircraft from Princeton, volumes of calibration data, charts, and schematics manuals were transferred to UTSI.

Based on the study and research of available Princeton documents, methods of calculating flight control laws were “reverse-engineered”. The Variable Stability Navion employs an implicit model following structure to achieve in-flight simulation of other aircraft’s flying quality. Mathematical formulas were derived to calculate stability derivative potentiometer settings, for the analog response feedback flight controls system. MATLAB scripts …

Control Design And Filtering For Wireless Networked Systems, Xiao Ma

Doctoral Dissertations

This dissertation is concerned with estimation and control over wireless networked systems. Several problems are addressed, including estimator design over packet loss links, control and estimation over cognitive radio systems, modeling and prediction of wireless sensor networks (WSNs), and localization with the Theater Positioning System (TPS). The first problem addressed is the state estimation of a discrete-time system through a packet loss link modeled by a Bernoulli random variable. The optimal filter is derived by employing exact hybrid filtering. The performance of the optimal filter is illustrated by numerical simulations. Next, we consider the problem of estimation and control over …

Exploration Of Neural Structures For Dynamic System Control, Scott Frederick Hansen

Masters Theses

Biological neural systems are powerful mechanisms for controlling biological sys- tems. While the complexity of biological neural networks makes exact simulation intractable, several key aspects lend themselves to implementation on computational systems.

This thesis constructs a discrete event neural network simulation that implements aspects of biological neural networks. A combined genetic programming/simulated annealing approach is utilized to design network structures that function as regulators for continuous time dynamic systems in the presence of process noise when simulated using a discrete event neural simulation.

Methods of constructing such networks are analyzed including examination of the final network structure and the algorithm …