Department of Electrical and Computer Engineering
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Item Data compression application to the MIL-STD 1553 avionics data bus.(2006-05-11T16:11:15Z) Weston, Bron O.; Duren, Russell Walker.; Thompson, Michael Wayne.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.With the current state of legacy military avionic systems reaching its ceiling in memory space, processing power, and data-bus through-put (bandwidth), a need has arisen to maximize its limited resources to avoid extensive costs of system overhaul. Specifically, F/A-18 C/D Aircraft is approaching message capacity on its MIL-STD-1553 buses. To slow this assent to capacity limits, one possible solution implements data compression techniques to increase bandwidth. In these efforts, this thesis examines different lossless compression schemes to find ideal options to consider for implementation on MIL-STD-1553 based F/A-18 C/D Aircraft. Several compression routines are identified that provide significant data compression while requiring very little computational effort. A surprising benefit is that the reduction in wasted time spent waiting on data communication more than offsets the time required to compress and decompress the data.Item Development and implementation of real-time distributed network with the CAN protocol.(2006-05-27T13:44:18Z) Ford, Walter Davis; Gravagne, Ian A.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.One of the most interesting applications of a new field of mathematics called dynamic equations on time scales is the modeling, analysis and design of distributed control networks. This thesis documents the development of a scalable, real-time test bed on which to test new time scale-based theories. The Controller Area Network (CAN) protocol is used as the communication backbone. A general description of CAN and reasons for its selection are included. A general purpose computational node is implemented on a desktop computer running the QNX real-time operating system. QNX development entailed writing a driver for an SJA1000-based CAN controller. Charmed Labs’ Xport and the Gameboy Advance (GBA) are used for the network of embedded nodes. Development for the GBA-Xport combination involved interfacing an OpenCores.org CAN core to the Xport’s bus on an FPGA in Verilog and writing a driver class. Appendices include the code and code documentation.Item Design of a microwave sensor for non-invasive determination of blood-glucose concentration.(2006-05-27T14:46:59Z) Green, Eric C.; Jean, B. Randall.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.Diabetes is a disease that afflicts millions worldwide. To control the effects of this disease, diabetics must check their blood glucose levels on a regular basis. Currently, all daily glucose monitoring techniques are invasive, requiring a sample of blood. Microwave sensors are non-destructive and non-contact measuring devices, making them ideal for the measurement of parameters in industrial processes. Current uses of microwave sensors range from measuring moisture content of corn chips to measuring concentration of a solute in water. If a microwave sensor were developed to determine blood glucose concentration, it could be the first daily-use glucose-measuring technique that is truly non-invasive. This thesis provides background on diabetes and microwave measurement. From this background, a sensor is developed and its advantages are illustrated. The thesis concludes by making suggestions for improving the sensor and recommendations on how to implement the sensor into a useful product.Item A new modality for microwave tomographic maging: transit time tomography.(2006-07-22T22:45:56Z) Trumbo, Matthew Lee.; Marks, Robert J., II (Robert Jackson), 1950-; Jean, B. Randall.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.A new method for tomographic imaging using time delay of microwaves as they pass through objects of varying dielectric is presented. To obtain this delay measurement, recording of transmitted waveforms is performed when broadband microwave signals are sent through objects. The experimental setup consists of a circular table with vertically polarized bi-conic horns as transmitting and receiving antennas, with a Vector Network Analyzer as the excitation and measurement device. By obtaining multiple point tomographic projections at multiple angles, a reconstruction of the classic X-ray Radon transform is possible. Results obtained show accuracy and resolution limits to be within acceptable ranges and offer many new, less expensive possibilities for tomographic imaging.Item A comparison of field programmable gate arrays and digital signal processors in acoustic array processing.(2006-07-29T16:28:42Z) Stevenson, Jeremy C.; Duren, Russell Walker.; Thompson, Michael Wayne.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.The Field Programmable Gate Array's (FPGA) constant growth in computing power has given embedded system developers a choice to replace their current processors with a FPGA. However, most systems continue to use the original processor due to familiarity and design speed. Design tools, such as Simulink for MATLAB, have created a potential for significantly reducing FPGA development time. This potential was explored by developing an acoustic array processing system on both a FPGA and a DSP (Digital Signal Processor). The system includes a filtering stage, a correlation stage, and a trigonometric math stage. All of these stages are computationally intensive which provide an accurate portrayal of the chips' capabilities. The paper documents the comparison of the FPGA and the DSP implementations in regards to the performance of each implementation, the design time of each implementation and the capability of the design tools used in each implementation.Item Determining the complex permittivity of materials with the Waveguide-Cutoff method.(2006-07-31) Anderson, Christopher.; Jean, B. Randall.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.A new method for the determination of complex permittivity values is explained. The Waveguide-Cutoff method consists of a rectangular chamber with loop antennas for excitation from a Vector Network Analyzer. It then utilizes a particle swarm optimization routine to determine Debye parameters for a given material within the sample. The system is compared to a common Open-Ended Coaxial Probe technique and found to have similar accuracy for determining the dielectric constant over the same frequency band. This syste, however, does not suffer from the same restrictions as the coaxial probe and has a much larger bandwidth than other transmission line methods of similar size.Item Principal component and neural network calibration of a microwave frequency composition measurement sensor.(2008-03-03T17:17:16Z) Maule, Charles Stephen.; Marks, Robert J., II (Robert Jackson), 1950-; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.Microwave sensors are becoming more prevalent throughout a variety of industries. While providing an effective form of measurement, microwave sensors are difficult to calibrate and provide results which can be difficult to interpret. An improved method for calibrating microwave sensors has been developed which transforms the waveform of a microwave spectrometer using principal component analysis and the results are used to train an artificial neural network to analyze a subject material. Broadband microwave spectrum calibration (BBMSC) is demonstrated using waveforms captured by a microwave spectrometer in a circular waveguide containing pulp stock slurry. This thesis provides a review of the general applications of microwave sensors, details state-of-the-art calibration methods, as well as providing an introduction to principal component analysis and neural networks. The thesis continues by presenting the BBMSC method in detail, as well as how this method is applied to a set of waveforms of pulp-stock data and concludes with a discussion of the potency of BBMSC and recommendations for the future.Item Experimental investigation of a time scales linear feedback control theorem.(2008-03-03T17:25:15Z) Allen, Benjamin T.; Gravagne, Ian A.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.Dynamic equations on time scales comprise an exciting new area of research in mathematics which promises applications in many areas, particularly control theory. This thesis describes the design and implementation of a simulator and real-time controller useful for experimentation with and demonstration of the applications of time scale control theory. Under the guidance of the Baylor time scales group, the system is used to test a time scales feedback control equation currently under research.Item Calibration methodology for a microwave non-invasive glucose sensor.(2008-06-09T15:41:02Z) McClung, Melanie J.; Jean, B. Randall.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.Non-invasive measuring techniques for determining biological parameters are more heavily researched with the growth of the biomedical industry. One of the top areas in non-invasive research deals with diabetes. This disease affects more than 20 million people in the United States, and there is an increasing desire to find a testing process that is non-invasive, easy to use, and safe for users. Microwave technology has improved greatly during recent years and is now seen more often in conjunction with biomedical research. Microwaves are capable of taking measurements of materials inside of a closed volume without the need to come into contact with the material. This makes them ideal for measuring biological parameters, specifically glucose concentrations in the blood. This thesis expands on the development of a microwave sensor to non-invasively measure blood glucose levels and will examine the possibility of developing a calibration for a device using the microwave sensor.Item An evaluation of CoWare Inc.'s Processor Designer tool suite for the design of embedded processors.(2008-12-01T16:28:01Z) Franz, Jonathan D.; Duren, Russell Walker.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.The goal of this thesis is to evaluate the Processor Designer family of tools from CoWare, Inc. Processor Designer uses the L.I.S.A. 2.0 (Language for Instruction Set Architecture) language. The evaluation is being performed to determine the suitability of the toolset for incorporation into a classroom environment and for the use in developing replacements for legacy processors. The main focus will be on the ease of use of the tools. This includes exploring how steep of a learning curve is involved with this new processor designer language and how well the tools have been documented. The limitations of the tools will also be explored, as far as what can and cannot be done in the language. The thesis is also intended to provide a tutorial introduction to the CoWare Inc. tool suite for future students.Item Evaluating Impulse C and multiple parallelism partitions for a low-cost reconfigurable computing system.(2009-04-01T12:08:36Z) Li Shen, Carmen C.; Duren, Russell Walker.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.Impulse C is a C-to-HDL compiler from Impulse Accelerated Technology that facilitates the introduction of software programmers, mathematicians, and scientists, into the realm of FPGA-based algorithm development for high-speed numerical computation. This thesis evaluates the Impulse C programming language and explores differing levels of parallelism across multiple, homogeneous, FPGA development platforms using the Aurora serial communication scheme. Impulse C and Xilinx IP cores are employed in the numerical computation of a neural network consisting of 27 inputs and 1200 outputs. The artificial neural network is capable of emulating an underwater acoustic environment and has been used to determine characteristic parameters of reflections from the ocean floor. Timing, logic utilization and ease-of-use are metrics used to evaluate Impulse C in the automatic generation of VHDL code for the network test application. Implementations with parallelism at the system level and at the intermediate (loop) level are explored as part of this study.Item Implementation of lossless compression algorithms for the MIL-STD-1553.(2009-04-01T19:25:47Z) Lam, Bernard O.; Thompson, Michael Wayne.; Duren, Russell Walker.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.This thesis focuses on the bandwidth limitations faced by the legacy MIL-STD-1553 data bus. In order to improve bandwidth performance, lossless implementations of data compression routines have been proposed. Using data bus captures from the F/A-18 C/D simulator it has been possible to determine data characteristics, resulting in statistics showing the inherent redundancies within the data. This thesis proposes three compression algorithms which have been developed for use on the MIL-STD-1553 data bus. The three methods are Common Value Tracking, Modified Run-Length Encoding, and Differential Encoding. It will be shown that in some cases, compression ratios over 10 to 1 are possible, significantly improving the data transfer capabilities of the legacy communication system. The compression algorithms have been designed to provide bounded deterministic operation as required by real-time systems. In this thesis we will explore the strengths and weakness of each of these algorithms and also the decisions and challenges associated with integration with MIL-STD-1553 systems.Item Remotely sensed hyperspectral image unmixing.(2010-10-08T16:34:43Z) Yang, Zhuocheng.; Farison, James Blair.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.Estimating abundance fractions of materials in hyperspectral images is an important area of study in the field of remote sensing. The need for liner unmixing in remotely sensed imagery arises from the fact that the sampling distance is generally larger than the size of the targets of interest. We present two new unmixing methods, both of which are based on a linear mixture model. The first method requires two physical constraints imposed on abundance fractions: the abundance sum-to-one constraint and the abundance nonnegativity constraint. The second method relaxes the abundance sum-to-one constraint as this condition is rarely satisfied in reality and uses the relaxed sum-to-one constraint instead. Another contribution of this work is that the estimation is, unlike many other proposed methods, performed on noise reduced hyperspectral images instead of original images.Item Increased computation using parallel FPGA architectures.(2011-01-05T19:37:14Z) Dark, Stephen L.; Duren, Russell Walker.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.Two ways to improve algorithm performance in hardware are increasing the speed of each operation, or performing multiple operations simultaneously. However, the percent speed-up for the latter depends upon not only system constraints but also design decisions. When using multiple FPGAs as the implementation target, creating an optimal configuration requires the designer to be aware of many potential issues. A neural network inversion case study is presented in order to give future FPGA algorithm designers insight into the possible problems arising from parallel FPGA implementations. Initial work is performed implementing a large Neural Network and finding its inversion via Particle Swarm Optimization on a single FPGA. This algorithm is later broken up and performed in parallel with multiple FPGAs using several strategies on various hardware and software architectures. At the end, a discussion of the potential issues that arose during these implementations is presented along with some generalized guidelines.Item Non-deterministic modeling of the bulk thermal and electrical conductivity for dense thin film carbon nanotube networks.(2011-05-12T15:14:17Z) Ashtekar, Nikhil A.; Jack, David Abram, 1977-; Engineering.; Baylor University. Dept. of Mechanical Engineering.Thin films composed of single-walled carbon nanotubes, enjoy very high thermal and electrical conductivities, well beyond that of polymer matrix composites, and are very light in weight. Before these materials can experience industrial acceptance the underlying mechanisms dictating their performance must be understood. This research project intends to characterize using a physics based model the bulk thermal and electrical behavior of a neat carbon nanotube network conditions involving stochastic distributions of length, diameter, chirality, orientation obtained from the literature along with theoretical values of the inter-tube distance distribution obtained from in-house studies obtained through MD simulations. The work presents step by step development of the fully three dimensional model for linear, steady state loadings. Case studies using models are presented to better understand the dependence of the bulk thermal and electrical conductivity on the nanoscale parameters, such as bundle length, bundle diameter, orientation, volume fraction. The model is also used to investigate the sensitivity of the thermal and electrical conductivity on select stochastic parameters.Item Robust geolocation techniques for multiple receiver systems.(2011-05-12T15:25:52Z) Fisher, Gregory W.; Thompson, Michael Wayne.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.The purpose of this thesis is to investigate signal processing algorithms that allow multiple moving receivers to locate a stationary emitter. This problem has received considerable attention over the past 50 years, yet advances in computational power, sensor technologies and increasingly complex battle space scenarios continue to drive interest in this area. This work focuses on implementing well-known least squares and Kalman based algorithms within a realistic three dimensional simulation model. Techniques for evaluating the performance of various algorithms include generating ellipse-shaped confidence regions that bound the target under consideration, along with generating polygon shaped confidence regions based on intersecting regions from multiple receivers. The presence of outlier angle of arrival measurements is shown to significantly degrade the performance of geolocation algorithms. Methods for imparting robustness to outlier angle of arrival measurements are developed and shown to mitigate the corresponding loss in performance that would otherwise occur.Item An evaluation of error masking techniques for digital wireless audio systems.(2011-05-12T15:44:06Z) Michaud, Renée J.; Thompson, Michael Wayne.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.This thesis investigates the tradeoffs associated with typical communication system designs for packetized wireless transmission systems. Communication system design requires judicious selection of source data rate, data compression technique, error correction method, modulation scheme, and latency. In particular, we investigate a wireless system for live music, focusing on masking methods to mitigate the affect of dropped data packets. Three different masking methods were developed and tested in combination with three packet sizes, creating nine unique test environments. The efficacy of the masking methods was then evaluated. The packet error rate threshold is defined as the lowest packet error rate for which the subject can hear noise interference. A Matlab graphical user interface was used to automate a human subject protocol, which was designed to investigate the packet error rate threshold for each condition. A comparison of the results and statistical analysis of the effectiveness of the masking methods are presented.Item Optimizing multi-agent dynamics for underwater tactical applications.(2011-05-12T15:55:02Z) Yu, Albert Reynold, 1984-; Marks, Robert J., II (Robert Jackson), 1950-; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.Large groups of autonomous agents, or swarms, can exhibit complex emergent behaviors that are difficult to predict and characterize from their low-level interactions. These emergent behaviors can have hidden implications for the performance of the swarm should the operational theater be perturbed. Thus, designing the optimal rules of operation for coordinating these multi-agent systems in order to accomplish a given task often requires simulations or expensive implementations. This thesis project examines swarm dynamics and the use of inversion to optimize the rules of operation of a large group of autonomous agents in order to accomplish missions of tactical relevance: specifically missions concerning underwater frequency-based standing patrols and point-defense between two competing swarms. Modified genetic algorithms and particle swarm optimization are utilized in the inversion process, producing various competing tactical responses and patrol behaviors. Swarm inversion is shown to yield effective and often creative solutions for guiding swarms of autonomous agents.Item Design, analysis and simulation of a new current controller for wind power generation system using proportional plus resonance control.(2011-09-14) Liu, Bochuan, 1986-; Song, Byeong-Mun.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.This thesis presents design, analysis and simulation of a new current control scheme for wind power generation system (WPGS). Proportional plus resonance (PR) controller is proposed to improve the accuracy of the control loop. Adding a current sensor at the capacitor filter instead of the damping resistor, the proposed two-current loop controller overcomes the instability of the system caused by the LCL filter and minimizes the power loss on the damping resistor (usually 0.8% of rated power). When the impedance of the grid is changing, the proposed current controller still keeps system stable with phase margins more than 45 degree. Moreover, using the proposed current controller, voltage transient characteristics of WPGS are analyzed and a control scheme is introduced to meet the low-voltage ride-through standard. All analysis and evaluation have been conducted for a 250kW WPGS with 208V grid voltage.Item Design and modeling of a power conditioning system for the hybrid fuel-cell/turbine power plant.(2011-09-14) Guo, Zhitong, 1987-; Lee, Kwang Y.; Engineering.; Baylor University. Dept. of Electrical and Computer Engineering.This thesis presents the model of a power conditioning system (PCS) for the hybrid direct fuel-cell with turbine (DFC/T) power plant. It regulates voltage, current and power transmitted from the hybrid DFC/T power plant to utility grid. The proposed system consists of DC/DC converters, a grid-connected sinusoidal pulse width modulation (SPWM) DC/AC inverter, and an LCL filter. To regulate and stabilize the DC link voltage, DC/DC converter with PI controller is adopted. With three-phase SPWM inverter, both active and reactive power flow can be controlled. Both conventional proportional integral (PI) and the improved fuzzy PI control schemes are proposed. The LCL filter can greatly reduce the current total harmonic distortion (THD). Theoretical analysis and modeling methodologies are presented. Simulation results validate the proposed system and demonstrate that the proposed PCS can follow a dynamic load and reduce the current THD to 1.65%, which is much lower than IEEE standard of 5%.