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Title: UTILIZATION OF TOTAL MASS AS A CONTROL IN DIFFUSION PROCESSES.
Creator: Salman, Mohamed, Cannon, John, University of Central Florida
Abstract / Description: As motivation for the mathematical problems considered in this work, consider a chamber in the form of a long linear transparent tube. We allow for the introduction or removal of material in a gaseous state at the ends of the tube. The material diffuses throughout the tube with or without reaction with other materials. By illuminating the tube on one side with a light source with a frequency range spanning the absorption range for the material and collecting the residual light that passes...
Show moreAs motivation for the mathematical problems considered in this work, consider a chamber in the form of a long linear transparent tube. We allow for the introduction or removal of material in a gaseous state at the ends of the tube. The material diffuses throughout the tube with or without reaction with other materials. By illuminating the tube on one side with a light source with a frequency range spanning the absorption range for the material and collecting the residual light that passes through the tube with photo-reception equipment, we can obtain a measurement of the total mass of material contained in the tube as a function of time. Using the total mass as switch points for changing the boundary conditions for introduction or removal of material. The objective is to keep the total mass of material in the tube oscillating between two set values such as $m0; \ u(x,0)=0,$ and $u(0,t)=u(1,t)=\psi(t),$ where $\psi(t)=u_0$ for $t_{2k} < t0; \ u(x,0)=0,$ and $u(0,t)=u(1,t)=\psi(t),$ where $\psi(t)=u_0$ for $t_{2k} < t0; \ u(x,0)=0,$ and $-u_x(0,t)=u_x(1,t)=\psi(t),$ where $\psi(t)=1$ for $t_{2k} < t0; \ u(x,0)=0,$ and $-u_x(0,t)=u_x(1,t)=\phi(t),$ where $a=a(x,t,u)$, and $\phi(t)=1$ for $t_{2k} < tShow less
Date Issued: 2005
Identifier: CFE0000551, ucf:46437
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000551

Title: DESIGN OF AN ADAPTIVE AUTOPILOT FOR AN EXPENDABLE LAUNCH VEHICLE.
Creator: Plaisted, Clinton, Leonessa, Alexander, University of Central Florida
Abstract / Description: This study investigates the use of a Model Reference Adaptive Control (MRAC) direct approach to solve the attitude control problem of an Expendable Launch Vehicle (ELV) during its boost phase of flight. The adaptive autopilot design is based on Lyapunov Stability Theory and provides a useful means for controlling the ELV in the presence of environmental and dynamical uncertainties. Several different basis functions are employed to approximate the nonlinear parametric uncertainties in the...
Show moreThis study investigates the use of a Model Reference Adaptive Control (MRAC) direct approach to solve the attitude control problem of an Expendable Launch Vehicle (ELV) during its boost phase of flight. The adaptive autopilot design is based on Lyapunov Stability Theory and provides a useful means for controlling the ELV in the presence of environmental and dynamical uncertainties. Several different basis functions are employed to approximate the nonlinear parametric uncertainties in the system dynamics. The control system is designed so that the desire dresponse to a reference model would be tracked by the closed-loop system. The reference model is obtained via the feedback linearization technique applied to the nonlinear ELV dynamics. The adaptive control method is then applied to a representative ELV longitudinal motion, specifically the 6th flight of Atlas-Centaur launch vehicle (AC-6) in 1965. The simulation results presented are compared to that of the actual AC-6 post-flight trajectory reconstruction. Recommendations are made for modification and future applications of the method for several other ELV dynamics issues, such as control saturation, engine inertia, flexible body dynamics, and sloshing of liquid fuels.
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Date Issued: 2008
Identifier: CFE0002006, ucf:47616
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002006

Title: DIGITAL CONTROLLER IMPLEMENTATION FOR DISTURBANCE REJECTION IN THE OPTICAL COUPLING OF A MOBILE EXPERIMENTAL LASER TRACKING SYSTEM.
Creator: Rhodes, Matthew, Richie, Samuel, University of Central Florida
Abstract / Description: Laser tracking systems are an important aspect of the NASA space program, in particular for conducting research in relation to satellites and space port launch vehicles. Often, launches are conducted at remote sites which require all of the test equipment, including the laser tracking systems, to be portable. Portable systems are more susceptible to environmental disturbances which affect the overall tracking resolution, and consequently, the resolution of any other experimental data being...
Show moreLaser tracking systems are an important aspect of the NASA space program, in particular for conducting research in relation to satellites and space port launch vehicles. Often, launches are conducted at remote sites which require all of the test equipment, including the laser tracking systems, to be portable. Portable systems are more susceptible to environmental disturbances which affect the overall tracking resolution, and consequently, the resolution of any other experimental data being collected at any given time. This research characterizes the optical coupling between two systems in a Mobile Experimental Laser Tracking system and evaluates several control solutions to minimize disturbances within this coupling. A simulation of the optical path was developed in an extensible manner such that different control systems could be easily implemented. For an initial test, several PID controllers were utilized in parallel in order to control mirrors in the optical coupling. Despite many limiting factors of the hardware, a simple proportional control performed to expectations. Although a system implementation was never field tested, the simulation results provide the necessary insight to develop the system further. Recommendations were made for future system modifications which would allow an even higher tracking resolution.
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Date Issued: 2006
Identifier: CFE0001168, ucf:46873
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001168

Title: MODELING AND SIMULATION OF SOFT BODIES.
Creator: Mesit, Jaruwan, Guha, Ratan, University of Central Florida
Abstract / Description: As graphics and simulations become more realistic, techniques for approximating soft body objects, that is, non-solid objects such as liquids, gases, and cloth, are becoming increasingly common. The proposed generalized soft body method encompasses some specific cases of other existing models enabling simulation of a variety of soft body materials by parameter adjustment. This research presents a general method of soft body model and simulation in which parameters for body control, surface...
Show moreAs graphics and simulations become more realistic, techniques for approximating soft body objects, that is, non-solid objects such as liquids, gases, and cloth, are becoming increasingly common. The proposed generalized soft body method encompasses some specific cases of other existing models enabling simulation of a variety of soft body materials by parameter adjustment. This research presents a general method of soft body model and simulation in which parameters for body control, surface deformation, volume control, and gravitation, can be adjusted to simulate different types of soft bodies. In this method, the soft body mesh structure maintains configuration among surface points while fluid modeling deforms the details of the surface. To maintain volume, an internal pressure is approximated by simulated molecules within the soft body. Free fall motion of soft body is generated by gravitational field. Additionally, a constraint is specified based on the property of the soft body being modeled. There are several standard methods to control soft body volume. This work illustrates the simplicity of simulation by selecting a mass-spring system for the deformation of the connected points of a three-dimensional mesh, while an internal pressure force acts upon the surface triangles. To incorporate fluidity, smooth particles hydrodynamics (SPH) is applied where surface points are considered as free moving particles interacting with neighboring surface points within a SPH radius. Because SPH is computationally expensive, it requires an efficient method to determine neighboring surface points. Collision detection with soft bodies and other rigid body objects also requires such fast neighbor detection. To determine the neighboring surface point, Axis Aligned Bounding Box (AABB), Octree, and a partitioning and hashing schemes have been investigated and the result shows that the partitioning and hashing scheme provides the best frame rate. Thus a fast partitioning and hashing scheme is used in this research to reduce both computational time and the memory requirements. The proposed soft body model aims to be applied in several types of soft body application depending on the specific types of soft body deformation. The work presented in this dissertation details experiments with a variety of visually appealing fluid-like surfaces and organic materials animated at interactive speeds. The algorithm is also used to implement animated space-blob creatures in the Galactic Arms Race video game and a human lung simulation, demonstrating the effectiveness of the algorithm in both an actual video game engine and a medical application. The simulation results show that the general model of the soft body can be applied to several applications by adjusting the soft body parameters according to the appearance results.
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Date Issued: 2010
Identifier: CFE0003477, ucf:48930
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003477

Title: AIRPORT SECURITY: EXAMINING THE CURRENT STATE OF ACCEPTANCE OF BIOMETRICS AND THE PROPENSITY OF ADOPTING BIOMETRIC TECHNOLOGY FOR AIRPORT ACCESS CONTROL.
Creator: Sumner, Kristine, Liberman, Aaron, University of Central Florida
Abstract / Description: The terrorist attacks of September 11, 2001 propelled the issue of aviation security to the forefront of the U.S. domestic agenda. Although hundreds of individual airports exist in the U.S., the travel activities at each of these airports combine to holistically comprise an aviation system that represents a significant portion of the U.S. social and economic infrastructure. Disruption at one airport resulting from a criminal act, such as terrorism, could exert detrimental effects upon the...
Show moreThe terrorist attacks of September 11, 2001 propelled the issue of aviation security to the forefront of the U.S. domestic agenda. Although hundreds of individual airports exist in the U.S., the travel activities at each of these airports combine to holistically comprise an aviation system that represents a significant portion of the U.S. social and economic infrastructure. Disruption at one airport resulting from a criminal act, such as terrorism, could exert detrimental effects upon the aviation system and U.S national security (9/11 Commission, 2004). Each U.S. airport is individually responsible for various aspects of security including the control of physical access to sensitive and secure areas and facilities (9/11 Commission, 2004). Biometric technology has been examined as one method of enhancing airport access control to mitigate the possibility of criminal acts against airports. However, successful implementation of biometric technology depends largely on how individual security directors at each airport perceive, understand, and accept that technology. Backgrounds, attitudes, and personal characteristics influence individual decisions about technology implementation (Rogers, 1995; Tornatzky and Fleischer, 1990). This study examines the problem of airport access control, as well as, the current trends in biometric technology. Utilizing a survey of airport security directors and security managers, this study draws upon innovation diffusion theory and organizational theories to determine what personal, organizational, and technical variables contribute to the propensity of airport security directors and managers to adopt biometric technology for airport access control.
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Date Issued: 2007
Identifier: CFE0001693, ucf:47220
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001693

Title: INTEGRATED SERVOMECHANISM AND PROCESS CONTROL FOR MACHINING PROCESSES.
Creator: Tang, Yan, Xu, Chengying, University of Central Florida
Abstract / Description: In this research, the integration of the servomechanism control and process control for machining processes has been studied. As enabling strategies for next generation quality control, process monitoring and open architecture machine tools will be implemented on production floor. This trend brings a new method to implement control algorithm in machining processes. Instead of using separate modules for servomechanism control and process control individually, the integrated controller is...
Show moreIn this research, the integration of the servomechanism control and process control for machining processes has been studied. As enabling strategies for next generation quality control, process monitoring and open architecture machine tools will be implemented on production floor. This trend brings a new method to implement control algorithm in machining processes. Instead of using separate modules for servomechanism control and process control individually, the integrated controller is proposed in this research to simultaneously achieve goals in servomechanism level and the process level. This research is motivated by the benefits brought by the integration of servomechanism control and process control. Firstly, the integration simplifies the control system design. Secondly, the integration promotes the adoption of process control on production floor. Thirdly, the integration facilitates portability between machine tools. Finally, the integration provides convenience for both the servomechanism and process simulation in virtual machine tool environment. The servomechanism control proposed in this research is based on error space approach. This approach is suitable for motion control for complex contour. When implement the integration of servomechanism control and process control, two kinds of processes may be encountered. One is the process whose model parameters can be aggregated with the servomechanism states and the tool path does not need real time offset. The other is the process which does not have direct relationship with the servomechanism states and tool path may need to be modified real time during machining. The integration strategies applied in error space are proposed for each case. Different integration strategies would propagate the process control goal into the motion control scheme such that the integrated control can simultaneously achieve goals of both the servomechanism and the process levels. Integrated force-contour-position control in turning is used as one example in which the process parameters can be aggregated with the servomechanism states. In this case, the process level aims to minimize cutting force variation while the servomechanism level is to achieve zero contour error. Both force variation and contour error can be represented by the servomechanism states. Then, the integrated control design is formulated as a linear quadratic regulator (LQR) problem in error space. Force variation and contour error are treated as part of performance index to be minimized in the LQR problem. On the other hand, the controller designed by LQR in error space can guarantee the asymptotic tracking stability of the servomechanism for complex contour. Therefore, the integrated controller can implement the process control and the servomechanism control simultaneously. Cutter deflection compensation for helical end milling processes is used as one example in which the process cannot be directly associated with the servomechanism states. Cutter deflection compensation requires real-time tool path offset to reduce the surface error due to cutter deflection. Therefore, real time interpolation is required to provide reference trajectory for the servomechanism controller. With the real time information about surface error, the servomechanism controller can not only implement motion control for contour requirement, but also compensation for the dimensional error caused by cutter deflection. In other words, the real time interpolator along with the servomechanism controller can achieve the goals of both the servomechanism and process level. In this study, the cutter deflection in helical end milling processes is analyzed first to illustrate the indirect relationship between cutter deflection and surface accuracy. Cutter deflection is examined for three kinds of surfaces including straight surface, circular surface, and curved surface. The simulation-based deflection analysis will be used to emulate measurement from sensors and update the real-time interpolator to offset tool path. The controller designed through pole placement in error space can guarantee the robust tracking performance of the updated reference trajectory combining both contour and tool path offset required for deflection compensation. A variety of cutting conditions are simulated to demonstrate the compensation results. In summary, the process control is integrated with the servomechanism control through either direct servomechanism controller design without tool path modification or servomechanism control with real time interpolation responding to process variation. Therefore, the process control can be implemented as a module within machine tools. Such integration will enhance the penetration of process control on production floor to increase machining productivity and product quality.
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Date Issued: 2009
Identifier: CFE0002758, ucf:48116
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002758

Title: Arms control and inadvertent general war.
Creator: Halperin, Morton H.
Date Issued: 1962
Identifier: 1927627, CFDT1927627, ucf:4880
Format: Document (PDF)
PURL: http://purl.flvc.org/FCLA/DT/1927627

Title: A COMPARISON AND EVALUATIONOFCOMMON PID TUNING METHODS.
Creator: Youney, Justin, Haralambous, Michael, University of Central Florida
Abstract / Description: The motivation behind this thesis is to consolidate and evaluate the most common Proportional Integral Derivative (PID) controller tuning techniques used in industry. These are the tuning techniques used when the plant transfer function is not known. Many of these systems are poorly tuned because such consolidated information is not easily found in one single source such as this thesis. Once one of the tuning methods are applied almost always there will be further fine tuning needed to bring...
Show moreThe motivation behind this thesis is to consolidate and evaluate the most common Proportional Integral Derivative (PID) controller tuning techniques used in industry. These are the tuning techniques used when the plant transfer function is not known. Many of these systems are poorly tuned because such consolidated information is not easily found in one single source such as this thesis. Once one of the tuning methods are applied almost always there will be further fine tuning needed to bring the system into the required design criteria. The purpose here is to find out which tuning technique will yield the lowest percent overshoot and the shortest settling time for all situations. This will give the engineer a good starting point; to minimally further adjust parameters to achieve the desired design criteria. There will also be discussion on the various algorithms used in industry. Four tuning methods will be evaluated based on their ability to control different style plants. The comparison criteria will be percent overshoot and settling time for an applied step input. The tuning methods chosen were the Ziegler-Nichols Open Loop method, the CHR method for 0% overshoot, the Ziegler-Nichols Closed Loop method, and the Rule of Thumb method. It is shown that for a second order plant with a lag and pure integration in its transfer function, the Open Loop method yielded the lowest results in terms of percent overshoot, yet the Closed Loop method had the shortest settling time. For systems of higher order than two it was shown that the CHR method gave the best performance however as the order increased the Closed Loop method gave a shorter settling time. For systems of higher order with varying lags in series the CHR method gave the best results. The Rule of thumb method usually gave similar results to that of the Closed Loop method; however for higher order systems the Rule of Thumb method gave less percent overshoot but with a longer settling time than the Closed Loop method. Since these tuning methods are used when the plant transfer function is not known, and none of the rules were found to give consistently the lowest percent overshoot, and settling time for all plants tested, there can not be a recommendation as to which method an engineer should choose to use. If the plant transfer function is known or can be reasonably modeled then the following recommendations can be followed. When tuning systems with pure integrations in their transfer function the Open Loop or Closed Loop method be used. When tuning systems of order higher than two the CHR or Closed Loop method should be used, however with high order systems with varying lags the CHR method should be used. It is the responsibility of the engineer to know how and when to implement each of the tuning rules properly.
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Date Issued: 2007
Identifier: CFE0001716, ucf:47301
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001716

Title: CONTROLS ALGORITHM FOR A SATELLITE USING EARTH''S MAGNETIC FIELD: ORBIT MANEUVERS & ATTITUDE POSITIONING.
Creator: Ganesh, Karthik, Johnson, Roger, University of Central Florida
Abstract / Description: This document describes the design, analysis of Orbit Maneuvers and Attitude Control for NanoSat class satellites, which uses an electro-magnetic force controller which was proposed by the Florida Space Institute (FSI). Orbit Maneuvering and the Attitude Control System (ACS) play a very important role for the success of this mission, as that can allow making the satellite go to the desired orbit as well do the sun pointing of the solar arrays with su¢ cient accuracy to achieve desired...
Show moreThis document describes the design, analysis of Orbit Maneuvers and Attitude Control for NanoSat class satellites, which uses an electro-magnetic force controller which was proposed by the Florida Space Institute (FSI). Orbit Maneuvering and the Attitude Control System (ACS) play a very important role for the success of this mission, as that can allow making the satellite go to the desired orbit as well do the sun pointing of the solar arrays with su¢ cient accuracy to achieve desired power levels. The primary mission would be to attain attitude stabilization using the torque from the coils. This is also used for pointing at the direction of the sun, for achieving desired power levels. The secondary mission would be to use the force of the magnetic field and utilize that for orbit maneuvering, and attain the desired trajectory. This thesis gives a presentation of this detailed analysis with a simulation using Matlab/Simulink. Mathematical model of the actuators and sensors used for this satellite are designed, so that the simulation gives us results very near to the actual ones.Health Monitoring is also one of the main issues addressed in this work. This simulation helps us in understanding the mission as well as the requirements very well, and helps us know all the shortcomings. The FUNSAT satellite is modeled as an example in Simulink together with a Kalman filter for attitude estimation based on all sensor measurements. The theory behind this, and extending the Kalman filter, is also presented.
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Date Issued: 2007
Identifier: CFE0001917, ucf:47476
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001917

Title: NONPARAMETRIC MULTIVARIATE STATISTICAL PROCESS CONTROL USING PRINCIPAL COMPONENT ANALYSIS AND SIMPLICIAL DEPTH.
Creator: Beltran, Luis, Malone, Linda, University of Central Florida
Abstract / Description: Although there has been progress in the area of Multivariate Statistical Process Control (MSPC), there are numerous limitations as well as unanswered questions with the current techniques. MSPC charts plotting Hotelling's T2 require the normality assumption for the joint distribution among the process variables, which is not feasible in many industrial settings, hence the motivation to investigate nonparametric techniques for multivariate data in quality control. In this research, the goal...
Show moreAlthough there has been progress in the area of Multivariate Statistical Process Control (MSPC), there are numerous limitations as well as unanswered questions with the current techniques. MSPC charts plotting Hotelling's T2 require the normality assumption for the joint distribution among the process variables, which is not feasible in many industrial settings, hence the motivation to investigate nonparametric techniques for multivariate data in quality control. In this research, the goal will be to create a systematic distribution-free approach by extending current developments and focusing on the dimensionality reduction using Principal Component Analysis. The proposed technique is different from current approaches given that it creates a nonparametric control chart using robust simplicial depth ranks of the first and last set of principal components to improve signal detection in multivariate quality control with no distributional assumptions. The proposed technique has the advantages of ease of use and robustness in MSPC for monitoring variability and correlation shifts. By making the approach simple to use in an industrial setting, the probability of adoption is enhanced. Improved MSPC can result in a cost savings and improved quality.
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Date Issued: 2006
Identifier: CFE0001065, ucf:46792
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001065

Title: MODELING SATELLITE FORMATIONS IN THE PRESENCE OF PERTURBATIONS.
Creator: Cannaday, Robert, Johnson, Roger, University of Central Florida
Abstract / Description: The potential benefits of autonomous satellite formation flying in such areas as high- resolution remote sensing, and sparse aperture radar, has stimulated interest in modeling the satellite environment for feasibility and simulation studies to help explore and define the technical challenges that must be solved in order to achieve successful autonomous satellite formations. The purpose of this paper is to develop and describe a numerical simulation of the orbital environment including...
Show moreThe potential benefits of autonomous satellite formation flying in such areas as high- resolution remote sensing, and sparse aperture radar, has stimulated interest in modeling the satellite environment for feasibility and simulation studies to help explore and define the technical challenges that must be solved in order to achieve successful autonomous satellite formations. The purpose of this paper is to develop and describe a numerical simulation of the orbital environment including central force field perturbations and atmospheric drag effects which will be a useful analytical tool for investigating issues relating to maintaining satellite formations in low-earth-orbit. Many of the studies done in this area confine their research to circular orbits, with and without perturbation effects. This study will investigate apply orbital dynamic equations to the problem of maintaining satellite formations in both circular and elliptical orbits, with and without the presence of J2 gravity perturbation effects and atmospheric drag. This effort is primarily focused on modeling the orbital mechanics of one and two satellites in the presence of J2 and drag perturbations This effort is being performed as part of a multi-disciplined University of Central Florida KnightSat project, sponsored by the Air Force, to develop a two-satellite formation in the nanosatellite class, for investigating issues related to using formation satellites for remote earth sensing, to develop three-dimensional mapping.
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Date Issued: 2005
Identifier: CFE0000898, ucf:46639
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000898

Title: SAW Correlator Temperature Compensation Using a Pulse Width Modulated Temperature Controller.
Creator: Betancourt, Daniel, Weeks, Arthur, Malocha, Donald, Richie, Samuel, Gong, Xun, University of Central Florida
Abstract / Description: A Surface Acoustic Wave (SAW) correlator built on a Lithium Niobate substrate is temperature compensated in order to maintain a constant center frequency. Frequency shifts as a result of temperature variations limit device performance. An Arduino(&)#174;-based PWM temperature controller is developed to read the device temperature from a resistance temperature detector located on the SAW wafer and to regulate its temperature to a specified setpoint by providing current to a heater which is co...
Show moreA Surface Acoustic Wave (SAW) correlator built on a Lithium Niobate substrate is temperature compensated in order to maintain a constant center frequency. Frequency shifts as a result of temperature variations limit device performance. An Arduino(&)#174;-based PWM temperature controller is developed to read the device temperature from a resistance temperature detector located on the SAW wafer and to regulate its temperature to a specified setpoint by providing current to a heater which is co-located with the temperature sensor on the SAW correlator substrate. The final temperature controller achieves frequency shifts of 0.013 MHz from room temperature with a worst-case PPM experienced over 30(&)deg;C of temperature variation of 0.48 PPM/(&)deg;C. Linear and non-linear plant models are developed successfully to predict the device's temperature based on any input setpoint. Although there are alternatives to limit temperature drift at different temperatures, this thesis presents a simple method that works on a standard Lithium Niobate substrate.
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Date Issued: 2019
Identifier: CFE0007787, ucf:52331
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007787

Title: NONLINEAR ESTIMATION AND CONTROL FOR ASSISTIVE ROBOTS.
Creator: Wang, Zhao, Behal, Aman, University of Central Florida
Abstract / Description: In this thesis, we document the progress in the estimation and control design of a smart assistive robot arm that can provide assistance during activities of daily living to the elderly and/or users with disabilities. Interaction with the environment is made challenging by the kinematic uncertainty in the robot, imperfect sensor calibration, limited view of angle as well as the fact that most activities of daily living are generally required to be performed in unstructured environments. For...
Show moreIn this thesis, we document the progress in the estimation and control design of a smart assistive robot arm that can provide assistance during activities of daily living to the elderly and/or users with disabilities. Interaction with the environment is made challenging by the kinematic uncertainty in the robot, imperfect sensor calibration, limited view of angle as well as the fact that most activities of daily living are generally required to be performed in unstructured environments. For monocular visual systems, range (or depth) information is always crucial for target modeling and system control design. In the first part of my thesis, a novel and effective method is developed to estimate the range information in perspective vision systems by observing the 2-D image information and known motion parameters. We have considered the presence of noise in the image space measurements and kinematic uncertainty in the motion parameters. Simulation and experiment results show the advantage of our algorithm in comparison with other approaches. In the second part of the thesis, Lyapunov-based design techniques are utilized to propose a 2.5D visual servoing controller which stabilizes the robot end-effector pose while satisfying practical constraints on the sensing and the actuation. First, a nominal feedback controller is introduced which is then modified through an optimization-based approach in order to satisfy the constraints related to limited camera field-of-view and size of actuation. In the absence of actuator constraints, the proposed control law yields semi-global asymptotic (exponential) stability. When actuator constraints are introduced, the result is local asymptotic stability with known bounds on the region of attraction. Simulation and experimental results demonstrate the effectiveness of the proposed control methodology.
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Date Issued: 2011
Identifier: CFE0003889, ucf:48755
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003889

Title: An Industrial Audiological Approach to Design and Construction of Enclosures for Control of Noise.
Creator: Smart, Dale G., Mullin, Thomas A., Social Sciences
Abstract / Description: Florida Technological University College of Social Sciences Thesis
Date Issued: 1975
Identifier: CFR0011993, ucf:53084
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFR0011993

Title: Microgrid Control and Protection: Stability and Security.
Creator: Keshavarztalebi, Morteza, Behal, Aman, Haralambous, Michael, Sun, Wei, Jain, Amit Kumar, Kutkut, Nasser, University of Central Florida
Abstract / Description: When the microgrid disconnects from the main grid in response to, say, upstream disturbance orvoltage fluctuation and goes to islanding mode, both voltage and frequency at all locations in themicrogrid have to be regulated to nominal values in a short amount of time before the operation ofprotective relays. Motivated by this, we studied the application of intelligent pinning of distributed cooperative secondary control of distributed generators in islanded microgrid operation in a power...
Show moreWhen the microgrid disconnects from the main grid in response to, say, upstream disturbance orvoltage fluctuation and goes to islanding mode, both voltage and frequency at all locations in themicrogrid have to be regulated to nominal values in a short amount of time before the operation ofprotective relays. Motivated by this, we studied the application of intelligent pinning of distributed cooperative secondary control of distributed generators in islanded microgrid operation in a power system. In the first part, the problem of single and multi-pinning of distributed cooperative secondary control of DGs in a microgrid is formulated. It is shown that the intelligent selection of a pinning set based on the number of its connections and distance of leader DG/DGs from the rest of the network, i.e., degree of connectivity, strengthens microgrid voltage and frequency regulation performance both in transient and steady state. The proposed control strategy and algorithm are validated by simulation in MATLAB/SIMULINK using different microgrid topologies. It is shown that it is much easier to stabilize the microgrid voltage and frequency in islanding mode operationby specifically placing the pinning node on the DGs with high degrees of connectivity than byrandomly placing pinning nodes into the network. In all of these research study cases, DGs areonly required to communicate with their neighboring units which facilitates the distributed controlstrategy.Historically, the models for primary control are developed for power grids with centralized powergeneration, in which the transmission lines are assumed to be primarily inductive. However, fordistributed power generation, this assumption does not hold since the network has significant resistive impedance as well. Hence, it is of utmost importance to generalize the droop equations, i.e., primary control, to arrive at a proper model for microgrid systems. Motivated by this, we proposed the secondary adaptive voltage and frequency control of distributed generators for low and medium voltage microgrid in autonomous mode to overcome the drawback of existing classical droop based control techniques. Our proposed secondary control strategy is adaptive with line parameters and can be applied to all types of microgrids to address the simultaneous impacts of active and reactive power on the microgrids voltage and frequency. Also, since the parameters in the network model are unknown or uncertain, the second part of our research studies adaptive distributed estimation/compensation. It is shown that this is an effective method to robustly regulate the microgrid variables to their desired values.The security of power systems against malicious cyberphysical data attacks is the third topic of this dissertation. The adversary always attempts to manipulate the information structure of the power system and inject malicious data to deviate state variables while evading the existing detection techniques based on residual test. The solutions proposed in the literature are capable of immunizing the power system against false data injection but they might be too costly and physically not practical in the expansive distribution network. To this end, we define an algebraic condition for trustworthy power system to evade malicious data injection. The proposed protection scheme secures the power system by deterministically reconfiguring the information structure and corresponding residual test. More importantly, it does not require any physical effort in either microgrid or network level. The identification scheme of finding meters being attacked is proposed as well. Eventually, a well-known IEEE 30-bus system is adopted to demonstrate the effectiveness of the proposed schemes.
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Date Issued: 2016
Identifier: CFE0006338, ucf:51569
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006338

Title: bio-inspired attitude control of micro air vehicles using rich information from airflow sensors.
Creator: Shen, He, Xu, Yunjun, Lin, Kuo-Chi, Kauffman, Jeffrey, An, Linan, University of Central Florida
Abstract / Description: Biological phenomena found in nature can be learned and customized to obtain innovative engineering solutions. In recent years, biologists found that birds and bats use their mechanoreceptors to sense the airflow information and use this information directly to achieve their agile flight performance. Inspired by this phenomenon, an attitude control system for micro air vehicles using rich amount of airflow sensor information is proposed, designed and tested. The dissertation discusses our...
Show moreBiological phenomena found in nature can be learned and customized to obtain innovative engineering solutions. In recent years, biologists found that birds and bats use their mechanoreceptors to sense the airflow information and use this information directly to achieve their agile flight performance. Inspired by this phenomenon, an attitude control system for micro air vehicles using rich amount of airflow sensor information is proposed, designed and tested. The dissertation discusses our research findings on this topic. First, we quantified the errors between the calculated and measured lift and moment profiles using a limited number of micro pressure sensors over a straight wing. Then, we designed a robust pitching controller using 20 micro pressure sensors and tested the closed-loop performance in a simulated environment. Additionally, a straight wing was designed for the pressure sensor based pitching control with twelve pressure sensors, which was then tested in our low-speed wind tunnel. The closed-loop pitching control system can track the commanded angle of attack with a rising time around two seconds and an overshoot around 10%. Third, we extended the idea to the three-axis attitude control scenarios, where both of the pressure and shear stress information are considered in the simulation. Finally, a fault tolerant controller with a guaranteed asymptotically stability is proposed to deal with sensor failures and calculation errors. The results show that the proposed fault tolerant controller is robust, adaptive, and can guarantee an asymptotically stable performance even in case that 50% of the airflow sensors fail in flight.
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Date Issued: 2014
Identifier: CFE0005711, ucf:50150
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005711

Title: OPTIMAL UPFC CONTROL AND OPERATIONS FOR POWER SYSTEMS.
Creator: Wu, Xiaohe, Qu, Zhihua, University of Central Florida
Abstract / Description: The content of this dissertation consists of three parts. In thefirst part, optimal control strategies are developed for UnifiedPower Flow Controller (UPFC) following the clearance of faultconditions. UPFC is one of the most versatile Flexible ACTransmission devices (FACTs) that have been implemented thus far.The optimal control scheme is composed of two parts. The first isan optimal stabilization control, which is an open-loop `Bang'type of control. The second is an suboptimal damping...
Show moreThe content of this dissertation consists of three parts. In thefirst part, optimal control strategies are developed for UnifiedPower Flow Controller (UPFC) following the clearance of faultconditions. UPFC is one of the most versatile Flexible ACTransmission devices (FACTs) that have been implemented thus far.The optimal control scheme is composed of two parts. The first isan optimal stabilization control, which is an open-loop `Bang'type of control. The second is an suboptimal damping control,which consists of segments of `Bang' type control with switchingfunctions the same as those of a corresponding approximate linearsystem. Simulation results show that the proposed control strategyis very effective in maintaining stability and damping outtransient oscillations following the clearance of the fault. Inthe second part, a new power market structure is proposed. The newstructure is based on a two-level optimization formulation of themarket. It is shown that the proposed market structure can easilyfind the optimal solutions for the market while takeing factorssuch as demand elasticity into account. In the last part, amathematical programming problem is formulated to obtain themaximum value of the loadibility factor, while the power system isconstrained by steady-state dynamic security constraints. Aniterative solution procedure is proposed for the problem, and thesolution gives a slightly conservative estimate of the loadibilitylimit for the generation and transmission system.
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Date Issued: 2004
Identifier: CFE0000052, ucf:46122
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000052

Title: ANATOMICAL AND FUNCTIONAL ASSESSMENT OF PNMT+ NEURONS IN THE MOUSE HYPOTHALAMUS AND CEREBELLUM: POTENTIAL ROLES IN ENERGY METABOLISM AND MOTOR CONTROL.
Creator: Lindo, Lake A, Ebert, Steven, University of Central Florida
Abstract / Description: Phenylethanolamine N-methyltransferase (Pnmt) is the enzyme in the catecholamine pathway responsible for converting norepinephrine to epinephrine. Pnmt is present in numerous areas; however, the scope of its expression in the mouse brain is not fully understood. A genetic mouse model was generated by the Ebert lab that exhibited the selective destruction of all Pnmt+ cells through the induction of apoptosis by Diphtheria Toxin A. Unexpected phenotypic defects arose that are characterized by...
Show morePhenylethanolamine N-methyltransferase (Pnmt) is the enzyme in the catecholamine pathway responsible for converting norepinephrine to epinephrine. Pnmt is present in numerous areas; however, the scope of its expression in the mouse brain is not fully understood. A genetic mouse model was generated by the Ebert lab that exhibited the selective destruction of all Pnmt+ cells through the induction of apoptosis by Diphtheria Toxin A. Unexpected phenotypic defects arose that are characterized by metabolic weight deficits and motor ataxia. The distribution of Pnmt+ neurons was examined throughout the hypothalamus and cerebellum to generate an anatomical map of current and historical Pnmt expression using various histochemical methods. Historical Pnmt expression appears more extensive than current expression levels at the adult stage, indicating that certain cells in the mouse brain may have experienced transient Pnmt expression. The presence of Pnmt in these regions suggests that the destruction of these neurons may play a role in the phenotypic defects observed in the ablation mouse model. Gaining a more comprehensive understanding of the potential role of Pnmt in these areas may elucidate new drug targets or novel methods to treat obesity and motor control disorders such as ataxia.
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Date Issued: 2018
Identifier: CFH2000547, ucf:45689
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000547

Title: ADAPTIVE EFFICIENCY OPTIMIZATION FOR DIGITALLY CONTROLLED DC-DC CONVERTERS.
Creator: AL-HOOR, WISAM, Batarseh, Issa, University of Central Florida
Abstract / Description: The design optimization of DC-DC converters requires the optimum selection of several parameters to achieve improved efficiency and performance. Some of these parameters are load dependent, line dependent, components dependent, and/or temperature dependent. Designing such parameters for a specific load, input and output, components, and temperature may improve single design point efficiency but will not result in maximum efficiency at different conditions, and will not guarantee improvement...
Show moreThe design optimization of DC-DC converters requires the optimum selection of several parameters to achieve improved efficiency and performance. Some of these parameters are load dependent, line dependent, components dependent, and/or temperature dependent. Designing such parameters for a specific load, input and output, components, and temperature may improve single design point efficiency but will not result in maximum efficiency at different conditions, and will not guarantee improvement at that design point because of the components, temperature, and operating point variations. The ability of digital controllers to perform sophisticated algorithms makes it easy to apply adaptive control, where system parameters can be adaptively adjusted in response to system behavior in order to achieve better performance and stability. The use of adaptive control for power electronics is first applied with the Adaptive Frequency Optimization (AFO) method, which presents an auto-tuning adaptive digital controller with maximum efficiency point tracking to optimize DC-DC converter switching frequency. The AFO controller adjusts the DC-DC converter switching frequency while tracking the converter minimum input power point, under variable operating conditions, to find the optimum switching frequency that will result in minimum total loss and thus the maximum efficiency. Implementing variable switching frequencies in digital controllers introduces two main issues, namely, limit cycle oscillation and system instability. Dynamic Limit Cycle Algorithms (DLCA) is a dynamic technique tailored to improve system stability and to reduce limit cycle oscillation under variable switching frequency operation. The convergence speed and stability of AFO algorithm is further improved by presenting the analysis and design of a digital controller with adaptive auto-tuning algorithm that has a variable step size to track and detect the optimum switching frequency for a DC-DC converter. The Variable-Step-Size (VSS) algorithm is theoretically analyzed and developed based on buck DC-DC converter loss model and directed towered improving the convergence speed and accuracy of AFO adaptive loop by adjusting the converter switching frequency with variable step size. Finally, the efficiency of DC-DC converters is a function of several variables. Optimizing single variable alone may not result in maximum or global efficiency point. The issue of adjusting more than one variable at the same time is addressed by the Multivariable Adaptive digital Controller (MVAC). The MVAC is an adaptive method that continuously adjusts the DC-DC converter switching frequency and dead-time at the same time, while tracking the converter minimum input power, to find the maximum global efficiency point under variable conditions. In this research work, all adaptive methods were discussed, theoretically analyzed and its digital control algorithm along with experimental implementations were presented.
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Date Issued: 2009
Identifier: CFE0002838, ucf:48072
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002838

Title: REACTIVE CONTROL OF AUTONOMOUS DYNAMICAL SYSTEMS.
Creator: Chunyu, Jiangmin, Qu, Zhihua, University of Central Florida
Abstract / Description: This thesis mainly consists of five independent papers concerning the reactive control design of autonomous mobile robots in the context of target tracking and cooperative formation keeping with obstacle avoidance in the static/dynamic environment. Technical contents of this thesis are divided into three parts. The first part consists of the first two papers, which consider the target-tracking and obstacle avoidance in the static environment. Especially, in the static environment, a...
Show moreThis thesis mainly consists of five independent papers concerning the reactive control design of autonomous mobile robots in the context of target tracking and cooperative formation keeping with obstacle avoidance in the static/dynamic environment. Technical contents of this thesis are divided into three parts. The first part consists of the first two papers, which consider the target-tracking and obstacle avoidance in the static environment. Especially, in the static environment, a fundamental issue of reactive control design is the local minima problem (LMP) inherent in the potential field methods (PFMs). Through introducing a state-dependent planned goal, the first paper proposes a switching control strategy to tackle this problem. The control law for the planned goal is presented. When trapped into local minima, the robot can escape from local minima by following the planned goal. The proposed control law also takes into account the presence of possible saturation constraints. In addition, a time-varying continuous control law is proposed in the second paper to tackle this problem. Challenges of finding continuous control solutions of LMP are discussed and explicit design strategies are then proposed. The second part of this thesis deals with target-tracking and obstacle avoidance in the dynamic environment. In the third paper, a reactive control design is presented for Omni-directional mobile robots with limited sensor range to track targets while avoiding static and moving obstacles in a dynamically evolving environment. Towards this end, a multi-objective control problem is formulated and control is synthesized by generating a potential field force for each objective and combining them through analysis and design. Different from standard potential field methods, the composite potential field described in this paper is time-varying and planned to account for moving obstacles and vehicle motion. In order to accommodate a larger class of mobile robots, the fourth paper proposes a reactive control design for unicycle-type mobile robots. With the relative motion among the mobile robot, targets, and obstacles being formulated in polar coordinates, kinematic control laws achieving target-tracking and obstacle avoidance are synthesized using Lyapunov based technique, and more importantly, the proposed control laws also take into account possible kinematic control saturation constraints. The third part of this thesis investigates the cooperative formation control with collision avoidance. In the fifth paper, firstly, the target tracking and collision avoidance problem for a single agent is studied. Instead of directly extending the single agent controls to the multi-agents case, the single agent controls are incorporated with an existing cooperative control design. The proposed decentralized control is reactive, considers the formation feedback and changes in the communication networks. The proposed control is based on a potential field method; its inherent oscillation problem is also studied to improve group transient performance.
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Date Issued: 2010
Identifier: CFE0003421, ucf:48384
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003421

Control (7)	+ -
control (7)	+ -
Digital Control (6)	+ -
simulation (5)	+ -
Adaptive Control (4)	+ -

Robotics (4)	+ -
cooperative control (4)	+ -
digital control (4)	+ -
locus of control (4)	+ -
Control Systems (3)	+ -
Motor Control (3)	+ -
Noise control (3)	+ -
corrosion control (3)	+ -
corrosion inhibitor (3)	+ -
gender (3)	+ -
gun control (3)	+ -
intimate partner violence (3)	+ -
modeling (3)	+ -
nonholonomic (3)	+ -
optimal control (3)	+ -
robust control (3)	+ -
social control (3)	+ -
soft switching (3)	+ -
workload (3)	+ -
Adolescents (2)	+ -
Bandwidth (2)	+ -
Cerebellum (2)	+ -
Compatibilism (2)	+ -
Cooperative Control (2)	+ -
Corrosion (2)	+ -

ETD Collection (183)	+ -
Honors Collection (18)	+ -
PRISM: Political & Rights Issues & Social Movements (2)	+ -

University of Central Florida (195)	+ -
Batarseh, Issa (18)	+ -
Qu, Zhihua (16)	+ -
Xu, Yunjun (15)	+ -
Haralambous, Michael (13)	+ -

Behal, Aman (12)	+ -
Lin, Kuo-Chi (12)	+ -
Das, Tuhin (11)	+ -
Simaan, Marwan (8)	+ -
Kassab, Alain (7)	+ -
Corzine, Harold (5)	+ -
Kutkut, Nasser (5)	+ -
Sundaram, Kalpathy (5)	+ -
Arnold, Vicky (4)	+ -
Duranceau, Steven (4)	+ -
Engineering (4)	+ -
Hancock, Peter (4)	+ -
Huff-Corzine, Lin (4)	+ -
Jasinski, Jana (4)	+ -
Kauffman, Jeffrey (4)	+ -
Reckdenwald, Amy (4)	+ -
Sims, Valerie (4)	+ -
Vosoughi, Azadeh (4)	+ -
Wu, Xinzhang (4)	+ -
Xu, Chengying (4)	+ -
Yuan, Jiann-Shiun (4)	+ -
Abdel-Aty, Mohamed (3)	+ -
Atia, George (3)	+ -
Boloni, Ladislau (3)	+ -
Chow, Louis (3)	+ -

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