Engineering Commons^™

Control Of Nonlinear Mechatronic Systems, Enver Tatlicioglu

All Dissertations

This dissertation is divided into four self-contained chapters. In Chapter 1, an adaptive nonlinear tracking controller for kinematically redundant robot manipulators is presented. Past research efforts have focused on the end-effector tracking control of redundant robots because of their increased dexterity over their non-redundant counterparts. This work utilizes an adaptive full-state feedback quaternion based controller developed in [1] and focuses on the design of a general sub-task controller. This sub-task controller does not affect the position and orientation tracking control objectives, but instead projects a preference on the configuration of the manipulator based on sub-task objectives such as the following: …

Nonlinear Control Strategies For Advanced Vehicle Thermal Management Systems, Mohammad Salah

All Dissertations

Advanced thermal management systems for internal combustion engines can improve coolant temperature regulation and servo-motor power consumption to positively impact the tailpipe emissions, fuel economy, and parasitic losses by better regulating the combustion process with multiple computer controlled components. The traditional thermostat valve, coolant pump, and clutch-driven radiator fan are upgraded with servo-motor actuators. When the system components function harmoniously, desired thermal conditions can be accomplished in a power efficient manner. Although the vehicle's mechanical loads can be driven by electric servo-motors, the power demands often require large actuator sizes and electrical currents. Integrating hydraulically-driven actuators in the cooling circuit …

Intrinsically Evolvable Artificial Neural Networks, Saumil Girish Merchant

Doctoral Dissertations

Dedicated hardware implementations of neural networks promise to provide faster, lower power operation when compared to software implementations executing on processors. Unfortunately, most custom hardware implementations do not support intrinsic training of these networks on-chip. The training is typically done using offline software simulations and the obtained network is synthesized and targeted to the hardware offline. The FPGA design presented here facilitates on-chip intrinsic training of artificial neural networks. Block-based neural networks (BbNN), the type of artificial neural networks implemented here, are grid-based networks neuron blocks. These networks are trained using genetic algorithms to simultaneously optimize the network structure and …

Analysis Of Simulated Electromyography (Emg) Signals Using Integrated Computer Muscle Model, Mohammad Abdul Ahad

Doctoral Dissertations

Introduction

Electromyography (EMG) is a technique used to study the activity of muscle through detection and analysis of the electrical signals generated during muscular contractions. Electromyographic activity is recorded from skeletal muscles to obtain information about their anatomy and physiology. Electromyography, in interplay with various anatomical techniques, provides the present knowledge of the structural organization and the nervous control of muscle. EMG is the prime source of information about the status of the neuromuscular system, and EMG has developed into a diagnostic tool that allows the clinician to follow changes in nerve and muscle caused by neuromuscular diseases.

EMG provides …

Analysis, Modeling And Testing Of A Multi-Receiver Wireless System For Telemetry Applications, Thomas Ebel

Masters Theses

This thesis investigates the potential value of multiple co-located receiver units for telemetry applications. In this thesis, a test board based on the NRF24L01 RF chip produced by Nordic Semiconductor was tested. Testing consisted of sending pseudo-random test data over a link between two test boards at progressive distances. Packet loss rate was identified as the dominant failure mode of the chip, and was used to determine performance increase. A parametric model of the chip performance was developed based on coherent and noncoherent FSK detectors and curve fit to the experimental data to model the performance of a single GFSK …

Predictive Models Of An Electro-Mechanical Driving System For Failure Testing Of Strain Gauges, Brent Ellis

Masters Theses

Strain gauges are bonded at high stress locations on the surface of critical structural components such as turbine blades to measure fatigue characteristics and detect early warning signs of high cycle fatigue. However, strain gauges do not always report expected measurements. The usual response by maintenance technicians to these failing signals is to investigate the component for weakness, check the placement of the gauges on the component, or examine the instrumentation for failure or damage. However, little research has been conducted to show when the failing signals are the fault of the strain gauge. Such failure modes of strain gauges …

Model Reduction Techniques For Fluid Dynamical Flow Based Pde Control Problems, Jason Harold Foster

Masters Theses

This thesis deals with the practical and theoretical implications of model reduction for aerodynamical flow based control problems. Various aspects of model reduction are discussed that apply to Partial Differential Equation (PDE) based models in general. Specifically, the Proper Orthogonal Decomposition (POD) of a high dimension system is discussed as well as frequency domain identification methods are discussed for initial model creation. Projections on the POD basis give a Galerkin model. Then, the methods of balanced truncation and Hankel optimal norm reduction are applied to the Galerkin model. A state space model is formed by a Galerkin projection of the …

Hardware Accelerated Scalable Parallel Random Number Generation, Junkyu Lee

Masters Theses

The Scalable Parallel Random Number Generators library (SPRNG) is widely used due to its speed, quality, and scalability. Monte Carlo (MC) simulations often employ SPRNG to generate large quantities of random numbers. Thanks to fast Field-Programmable Gate Array (FPGA) technology development, this thesis presents Hardware Accelerated SPRNG (HASPRNG) for the Virtex-II Pro XC2VP30 FPGAs. HASPRNG includes the full set of SPRNG generators and provides programming interfaces which hide detailed internal behavior from users. HASPRNG produces identical results with SPRNG, and it is verified with over 1 million consecutive random numbers for each type of generator. The programming interface allows a …

A Full Scale Camera Calibration Technique With Automatic Model Selection – Extension And Validation, Vitaliy Leonidovich Orekhov

Masters Theses

This thesis presents work on the testing and development of a complete camera calibration approach which can be applied to a wide range of cameras equipped with normal, wide-angle, fish-eye, or telephoto lenses. The full scale calibration approach estimates all of the intrinsic and extrinsic parameters. The calibration procedure is simple and does not require prior knowledge of any parameters. The method uses a simple planar calibration pattern. Closed-form estimates for the intrinsic and extrinsic parameters are computed followed by nonlinear optimization. Polynomial functions are used to describe the lens projection instead of the commonly used radial model. Statistical information …

The Reliability Of Signal Strength For Localization Of High-Density Zigbee Wireless Networks, Brandon Jeremy Rogers

Masters Theses

This thesis investigates the reliability of ZigBee signal strength within a high-density wireless network, specifically looking at the Link Quality Indicator (LQI) as provided by the physical layer and accessible at the networking and application layers within the stack protocol. It also investigates methods by which LQI can be used for discovery, identification, and localization of nodes within a ZigBee wireless network. The thesis concentrates on practical approaches specifically as it would pertain to commissioning a high-density network for an application such as lighting control in building automation. There are seven potential algorithms proposed using factors such as minimum distance …

Fabrication Of A Silicon Single Electron Transistor, Sharukh Roomy Chinoy

Electrical Engineering Theses

Single electronics has bright prospects because of its high scalability. The single electron transistor (SET) which utilizes these principles could replace the current workhorse of the industry, the MOSFET. The SET is plagued with limitations such as, a low operating temperature, background charge issues, a low voltage gain and high output impedance. The current generation SET devices have overcome most of the aforementioned issues but use highly complicated fabrication techniques. Electron beam lithography was used to pattern device structures on silicon-on-insulator (SOI) wafers with a hydrogen silsesquioxane (HSQ) system being the resist. The silicon was then etched using HSQ as …

Model Reference Adaptive Control Using Stacked Identifiers, Weider Chung

Electrical Engineering Dissertations

Model reference adaptive control is a major design method for controlling plants with uncertain parameters. The primary objective of this dissertation is to develop a new design approach for the model reference adaptive control of a single-input single-output linear time-invariant plant. The proposed method, called the "Model reference adaptive control using stacked identifiers," uses a stacked identifier structure that is new to the field of adaptive control. The goal is to make the output of the plant asymptotically track the output of the first identifier, and then driving the output of the first identifier to track that of the second …

Evaluation And Applications Of Gas Sensors, Hung Viet Cao

Electrical Engineering Theses

Gas sensors are used widely for environmental and biomedical uses. This work focuses on verifying specifications of commercial-off-the-shelf (COTS) gas sensors and their particular applications. The first chapter in this thesis gives a literature review on gas sensors, especially metal-oxide based sensors and their advantages. The second chapter focuses on evaluation of COTS NO2 sensors. The purpose is to establish a characterization method to evaluate gas sensors. I have evaluated three COTS metal-oxide based NO2 sensors and a COTS electrochemical sensor for comparison. Four different tests have been implemented to investigate the sensitivity, humidity effects, temperature effects, and selectivity for …

Sequences Of Near-Optimal Feedforward Neural Networks, Pramod Lakshmi Narasimha

Electrical Engineering Dissertations

In order to facilitate complexity optimization in feedforward networks, several integrated growing and pruning algorithms are developed. First, a growing scheme is reviewed which iteratively adds new hidden units to full-trained networks. Then, a non-heuristic one-pass pruning technique is reviewed, which utilizes orthogonal least squares. Based upon pruning, a one-pass approach is developed for producing the validation error versus network size curve. Then, a combined approach is devised in which grown networks are pruned. As a result, the hidden units are ordered according to their usefulness, and less useful units are eliminated. In several examples, it is shown that networks …

Spatially Resolving Spectrometer For Characterisation Of Broad-Area Laser Diodes, Sheldon Fernandes

Electrical Engineering Theses

The mode pattern of the BALD (Broad-Area Laser Diode) is characterized and measured using a 1-GHz resolution double-pass spectrometer. The design of spectrometer allowed also a spatial discrimination with 1mkm resolution. The construction and design of the double-pass grating is analyzed and discussed. A matrix approach is developed for the double-pass measurement arrangement. The developed procedure of analysis of spatially resolved spectra provides unique information about broad-area laser diode active medium and cavity geometry and potentially will help to predict the reliability of the laser diode. The developed model is based on paraxial approximation. The laser diode modes are measured …

1/F Noise In Hafnium Based High-K Gate Dielectric Mosfets And A Review Of Modeling, Siva Prasad Devireddy

Electrical Engineering Dissertations

For next generation MOSFETs, the constant field scaling rule dictates a reduction in the gate oxide thickness among other parameters. Consequently, gate leakage current becomes a serious issue with very thin SiO2 that is conventionally used as gate dielectric since it is the native oxide for Si substrate. This has driven an industry wide search for suitable alternate 'high-k' gate dielectric that has a high value of relative permittivity compared to SiO2 thereby presenting a physically thicker barrier for tunneling carriers while providing a high gate capacitance. Consequently, it is essential to study the properties of these novel materials and …

Optimized Class-E Rf Power Amplifier Design In Bulk Cmos, Tao Wang

Electrical Engineering Theses

The telecommunication market calls for the integration of complicated wireless applications. To build RF power amplifiers in CMOS remains challenging due to the nonideal effects in CMOS. The aim of this thesis is to provide an optimized yet explicit design method for the Class-E amplifiers in CMOS. Taking the finite DC feed inductor into consideration, a simple but accurate numerical design method is proposed by applying polynomial interpolation. Combining with a practical design stategy for nonideal transistors of finite conductance and parasitic capacitances, a two-staged Class-E power amplifier is implemented in 0.18um CMOS. The simulation results show that this power …

Design And Simulation Of An Accurate Breast Biopsy System, Sumit Tandon

Electrical Engineering Theses

Core needle biopsy is a non-invasive technique for confirming breast and prostate cancer. Over the years, several non-real time image guided systems have been developed to guide the needle to the target lesion/tumor. Frequently used methods are those employing x-ray, ultrasound, MRI or x-ray fluoroscopy to guide the needle during biopsy. However, these methods suffer from the disadvantages that they are non-real time or the imaging technique is two dimensional or ionizing. Our broad objective is to develop a visually guided, haptic assisted breast biopsy system (henceforth called ViHAB) using real time 3D ultrasound imaging and haptic guidance. The system …

Cmos Vco & Lna Implemented By Air-Suspended On-Chip Rf Mems Inductors, Varun K. Shenoy

Electrical Engineering Theses

In this thesis, a CMOS 2.4 GHz Low noise amplifier (LNA) and Voltage-controlled oscillator (VCO) was designed and simulated. These circuits were designed to operate in the 2.4GHz Industrial Scientific Medicine (ISM) band and to achieve Bluetooth and Wifi standard specifications. High-Q RF MEMS air-suspended circular spiral inductors are used in both circuits. High-Q inductors give the circuit better performance parameters including higher gain, lower noise figure and narrower bandwidth. The integration of these RF MEMS inductors onto RF circuit chips was carried out using the UV-LIGA technique and an additive pattern transfer technique such as electroplating. The LNA maintains …

A Potential Field Approach To Multiple Robot Formation Control, Rohit Santosh Talati

Electrical Engineering Theses

A special case of cooperative control for mobile robots is considered - formation control. A potential field based algorithm is developed in which geometric, communication and information centric influences are considered and allowed to deform the formation. Control is accomplished in a leader-follower(s) method. One leader robot defines the overall trajectory and follower nodes individually and autonomously maintain the formation while simultaneously moving toward a goal position. The particular nodes considered are the ARRIbots developed at the Distributed and Intelligence and Autonomy Lab (DIAL) in the Automation and Robotic and Research Institute (ARRI), which are non-holonomic differential-drive wheeled robots. In …

Discrete Event Controller: Application Using Dynamic Resource Allocation, Abhishek Trivedi

Electrical Engineering Theses

This work consists of developing a Discrete Event Controller with Dynamic Resource Allocation, simulating it and than applying it on a test-bed using robots and static sensor nodes. These are the contributions made: 1. Interfacing the Garcia robot with Mica2/Cricket Sensor. 2. Implementing Obstacle Avoidance and Path planning on Garcia Robot for navigational purposes. 3. Localizing the Garcia Robot with the help of Cricket sensor and controlling it from the Base Station to perform assigned tasks. 4. Simulating a Discrete Event Controller which dynamically coordinates multiple missions and simultaneously performing dynamic resource assignment and solving any shared resource conflicts. 5. …

Optimization Of Coupling From A Sub-Wavelength Metal Nanoaperture To A Gaussian Mode, Muthiah Annamalai

Electrical Engineering Theses

We model the surface resonance effects in a 1D-array of corrugations on a metal-dielectric film with a sub-wavelength nanoaperture, following the earlier work by Moreno et-al [Moreno:2003]. We are interested in computing the coupling of the highly-directional light field emerging from the metal nanoaperture to the lowest-order Gaussian mode. We follow the approach by Vasilyev [Vasilyev:2005], to compute the coupling to a fundamental Gaussian mode. We have developed an optimization routine to compute the field emission patterns from a metal nanoaperture, resonant wavelength and transmission coupling to fundamental Gaussian mode for various geometrical parameters of the metal nanoastructure. We optimize …

Polymer-Based Rf Mems Devices, Jianqun Wang

Electrical Engineering Dissertations

The radio frequency micro-electro-mechanical system (RF MEMS) technology is rapidly transitioning from the research stage to commercial applications. Reducing material and fabrication costs, realizing IC compatibility, and improving the RF performance have been main focal points of many recent works. In this dissertation, we target at developing a RF MEMS methodology which realizes CMOS compatibility, cost effectiveness and high performance at the same time. The current RF MEMS devices are mostly constructed on quartz and III-V compound materials to achieve low RF losses. These approaches proved to have excellent RF performance. However these materials are expensive and unable to be …

Fabrication Of Nano-Injection Needles For Neural Pathway Study In Mice, Sangeetha Swaminathan

Masters Theses

The potential of micro-needles to provide an interconnection between the microscopic and the macroscopic worlds makes it one of the most revolutionary fields in health care, allowing for precise transdermal drug delivery of highly targeted small doses of the active compound. Current micro electro mechanical systems (MEMS) technologies, originally designed for the micro-electronics industry, have been utilized in the fabrication of different micro-needle designs and their integration with various micro-fabricated micro-fluidics devices. The target of this thesis is to achieve a micro-needle injection system to deliver several strains of pico-liter volumes of a fluid combination of transgenic virus and luminescent …

Decentralized Control Of Multiple Uavs For Perimeter And Target Surveillance, Derek B. Kingston

Theses and Dissertations

With the recent development of reliable autonomous technologies for small unmanned air vehicles (UAVs), the algorithms utilizing teams of these vehicles are becoming an increasingly important research area. Unfortunately, there is no unified framework into which all (or even most) cooperative control problems fall. Five factors that affect the development of cooperative control algorithms are objective coupling, communication, completeness, robustness, and efficiency. We classify cooperative control algorithms by these factors and then present three algorithms with application to target and perimeter surveillance and a method for decentralized algorithm design. The primary contributions of this research are the development and analysis …

Transitions Between Hover And Level Flight For A Tailsitter Uav, Stephen R. Osborne

Theses and Dissertations

Vertical Take-Off and Land (VTOL) Unmanned Air Vehicles (UAVs) possess several desirable characteristics, such as being able to hover and take-off or land in confined areas. One type of VTOL airframe, the tailsitter, has all of these advantages, as well as being able to fly in the more energy-efficient level flight mode. The tailsitter can track trajectories that successfully transition between hover and level flight modes. Three methods for performing transitions are described: a simple controller, a feedback linearization controller, and an adaptive controller. An autopilot navigational state machine with appropriate transitioning between level and hover waypoints is also presented. …

Particle Filter Based Mosaicking For Forest Fire Tracking, Justin Mathew Bradley

Theses and Dissertations

Using autonomous miniature air vehicles (MAVs) is a cost-effective, simple method for collecting data about the size, shape, and location characteristics of a forest fire. However, noise in measurements used to compute pose (location and attitude) of the on-board camera leads to significant errors in the processing of collected video data. Typical methods using MAVs to track fires attempt to find single geolocation estimates and filter that estimate with subsequent observations. While this is an effective method of resolving the noise to achieve a better geolocation estimate, it reduces a fire to a single point or small set of points. …

A Wind And Rain Backscatter Model Derived From Amsr And Seawinds Data, Seth Niels Nielsen

Theses and Dissertations

The SeaWinds scatterometers aboard the QuikSCAT and ADEOS II satellites were originally designed to measure wind vectors over the ocean by exploiting the relationship between wind-induced surface roughening and the normalized radar backscatter cross-section. Recently, an algorithm for simultaneously retrieving wind and rain (SWR) from scatterometer measurements was developed that enables SeaWinds to correct rain-corrupted wind measurements and retrieve rain rate data. This algorithm is based on co-locating Tropical Rainfall Measuring Mission Precipitation Radar (TRMM PR) and SeaWinds on QuikSCAT data. In this thesis, a new wind and rain radar backscatter model is developed for the SWR algorithm using a …

Hardware Support For A Configurable Architecture For Real-Time Embedded Systems On A Programmable Chip, Spencer W. Isaacson

Theses and Dissertations

Current FPGA technology has advanced to the point that useful embedded SoPCs can now be designed. The Real Time Processor (RTP) project at Brigham Young University leverages the advances in FPGA technology with a system architecture that is customizable to specific applications. A simple real-time processor has been designed to provide support for a hardware-assisted real-time operating system providing fast context switches. As part of the hardware RTOS, the following have been implemented in hardware: scheduler, register banks, mutex, semaphore, queue, interrupts, event, and others. A novel circuit called the Task-Resource Matrix has been created to allow fast inter/intra processor …

Compilation And Generation Of Multi-Processor On A Chip Real-Time Embedded Systems, Randall S. Klingler

Theses and Dissertations

Current FPGA technology has advanced to the point that useful embedded System-on-Programmable-Chips (SoPC)s can now be designed. The Real Time Processor (RTP) project leverages the advances in FPGA technology with a system architecture that is customizable to specific real-time applications. The design and implementation of the framework for architecting such a system from ANSI-C code is presented. The Small Device C Compiler (SDCC) was retargeted to the RTP architecture and extended to produce a generator directive file. The RTPGen hardware generator was created to consume the directive file and produce a highly customized top-level structural VHDL file that can be …