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- Title
- DELAY MODELING AND LONG-RANGE PREDICTIVE CONTROL OF CZOCHRALSKI GROWTH PROCESS.
- Creator
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Shah, Dhaval, Klemenz, Christine, University of Central Florida
- Abstract / Description
-
This work presents the Czochralski growth dynamics as time-varying delay based model, applied to the growth of La3Ga5.5Ta0.5O14 (LGT) piezoelectric crystals. The growth of high-quality large-diameter oxides by Czochralski technique requires the theoretical understanding and optimization of all relevant process parameters, growth conditions, and melts chemistry. Presently, proportional-integral- derivative (PID) type controllers are widely accepted for constant-diameter crystal growth by...
Show moreThis work presents the Czochralski growth dynamics as time-varying delay based model, applied to the growth of La3Ga5.5Ta0.5O14 (LGT) piezoelectric crystals. The growth of high-quality large-diameter oxides by Czochralski technique requires the theoretical understanding and optimization of all relevant process parameters, growth conditions, and melts chemistry. Presently, proportional-integral- derivative (PID) type controllers are widely accepted for constant-diameter crystal growth by Czochralski. Such control systems, however, do not account for aspects such as the transportation delay of the heat from crucible wall to the crystal solidification front, heat radiated from the crucible wall above the melt surface, and varying melt level. During crystal growth, these time delays play a dominant role, and pose a significant challenge to the control design. In this study, a time varying linear delay model was applied to the identification of nonlinearities of the growth dynamics. Initial results reveled the benefits of this model with actual growth results. These results were used to develop a long-range model predictive control system design. Two different control techniques using long range prediction are studied for the comparative study. Development and testing of the new control system on real time growth system are discussed in detail. The results are promising and suggest future work in this direction. Other discussion about the problems during the crystal growth, optimization of crystal growth parameters are also studied along with the control system design.
Show less - Date Issued
- 2009
- Identifier
- CFE0002581, ucf:48250
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002581
- Title
- Distributed Extremum Seeking and Cooperative Control for Mobile Cooperative Communication Systems.
- Creator
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Alabri, Said, Qu, Zhihua, Wei, Lei, Vosoughi, Azadeh, Atia, George, University of Central Florida
- Abstract / Description
-
In this thesis, a distributed extremum seeking and cooperative control algorithm is designed for mobile agents to dispersethemselves optimally in maintaining communication quality and maximizing their coverage. The networked mobile agentslocally form a virtual multiple-input multiple-output (MIMO) communication system, and they cooperatively communicateamong them by using the decode and forward cooperative communication technique. The outage probability is usedas the measure of communication...
Show moreIn this thesis, a distributed extremum seeking and cooperative control algorithm is designed for mobile agents to dispersethemselves optimally in maintaining communication quality and maximizing their coverage. The networked mobile agentslocally form a virtual multiple-input multiple-output (MIMO) communication system, and they cooperatively communicateamong them by using the decode and forward cooperative communication technique. The outage probability is usedas the measure of communication quality, and it can be estimated real-time. A general performance index balancing outageprobability and spatial dispersion is chosen for the overall system. The extremum seeking control approachis used to estimate and optimize the value of the performance index, and the cooperative formation control is applied tomove the mobile agents to achieve the optimal solution by using only the locally-available information. Through theintegration of cooperative communication and cooperative control, network connectivity and coverage of the mobile agentsare much improved when compared to either non-cooperative communication approaches or other existing control results.Analytical analysis is carried out to demonstrate the performance and robustness of the proposal methodology, andsimulation is done to illustrate its effectiveness.
Show less - Date Issued
- 2013
- Identifier
- CFE0005082, ucf:50744
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005082
- Title
- Modeling and Contour Control of Multi-Axis Linear Driven Machine Tools.
- Creator
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Zhao, Ran, Lin, Kuo-Chi, Xu, Chengying, Bai, Yuanli, Das, Tuhin, An, Linan, University of Central Florida
- Abstract / Description
-
In modern manufacturing industries, many applications require precision motion control of multi-agent systems, like multi-joint robot arms and multi-axis machine tools. Cutter (end effector) should stay as close as possible to the reference trajectory to ensure the quality of the final products. In conventional computer numerical control (CNC), the control unit of each axis is independently designed to achieve the best individual tracking performance. However, this becomes less effective when...
Show moreIn modern manufacturing industries, many applications require precision motion control of multi-agent systems, like multi-joint robot arms and multi-axis machine tools. Cutter (end effector) should stay as close as possible to the reference trajectory to ensure the quality of the final products. In conventional computer numerical control (CNC), the control unit of each axis is independently designed to achieve the best individual tracking performance. However, this becomes less effective when dealing with multi-axis contour following tasks because of the lack of coordination among axes. This dissertation studies the control of multi-axis machine tools with focus on reducing the contour error. The proposed research explicitly addresses the minimization of contour error and treats the multi-axis machine tool as a multi-input-multi-output (MIMO) system instead of several decoupled single-input-single-output (SISO) systems. New control schemes are developed to achieve superior contour following performance even in the presence of disturbances. This study also extends the applications of the proposed control system from plane contours to regular contours in R3. The effectiveness of the developed control systems is experimentally verified on a micro milling machine.
Show less - Date Issued
- 2014
- Identifier
- CFE0005287, ucf:50552
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005287
- Title
- Lyapunov-Based Robust and Adaptive Control Design for nonlinear Uncertain Systems.
- Creator
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Zhang, Kun, Behal, Aman, Haralambous, Michael, Xu, Yunjun, Boloni, Ladislau, Marzocca, Piergiovanni, University of Central Florida
- Abstract / Description
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The control of systems with uncertain nonlinear dynamics is an important field of control scienceattracting decades of focus. In this dissertation, four different control strategies are presentedusing sliding mode control, adaptive control, dynamic compensation, and neural network for a nonlinear aeroelastic system with bounded uncertainties and external disturbance. In Chapter 2, partial state feedback adaptive control designs are proposed for two different aeroelastic systems operating in...
Show moreThe control of systems with uncertain nonlinear dynamics is an important field of control scienceattracting decades of focus. In this dissertation, four different control strategies are presentedusing sliding mode control, adaptive control, dynamic compensation, and neural network for a nonlinear aeroelastic system with bounded uncertainties and external disturbance. In Chapter 2, partial state feedback adaptive control designs are proposed for two different aeroelastic systems operating in unsteady flow. In Chapter 3, a continuous robust control design is proposed for a class of single input and single output system with uncertainties. An aeroelastic system with a trailingedge flap as its control input will be considered as the plant for demonstration of effectiveness of the controller. The controller is proved to be robust by both athematical proof and simulation results. In Chapter 3, a robust output feedback control strategy is discussed for the vibration suppression of an aeroelastic system operating in an unsteady incompressible flowfield. The aeroelastic system is actuated using a combination of leading-edge (LE) and trailing-edge (TE) flaps in the presence of different kinds of gust disturbances. In Chapter 5, a neural-network based model-free controller is designed for an aeroelastic system operating at supersonic speed. The controller is shown to be able to effectively asymptotically stabilize the system via both a Lyapunov-based stability proof and numerical simulation results.
Show less - Date Issued
- 2015
- Identifier
- CFE0005748, ucf:50110
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005748
- Title
- COVERAGE PATH PLANNING AND CONTROL FOR AUTONOMOUS MOBILE ROBOTS.
- Creator
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balakrishnan, mohanakrishnan, Guo, Yi, University of Central Florida
- Abstract / Description
-
Coverage control has many applications such as security patrolling, land mine detectors, and automatic vacuum cleaners. This Thesis presents an analytical approach for generation of control inputs for a non-holonomic mobile robot in coverage control. Neural Network approach is used for complete coverage of a given area in the presence of stationary and dynamic obstacles. A complete coverage algorithm is used to determine the sequence of points. Once the sequences of points are determined a...
Show moreCoverage control has many applications such as security patrolling, land mine detectors, and automatic vacuum cleaners. This Thesis presents an analytical approach for generation of control inputs for a non-holonomic mobile robot in coverage control. Neural Network approach is used for complete coverage of a given area in the presence of stationary and dynamic obstacles. A complete coverage algorithm is used to determine the sequence of points. Once the sequences of points are determined a smooth trajectory characterized by fifth order polynomial having second order continuity is generated. And the slope of the curve at each point is calculated from which the control inputs are generated analytically. Optimal trajectory is generated using a method given in research literature and a qualitative analysis of the smooth trajectory is done. Cooperative sweeping of multirobots is achieved by dividing the area to be covered into smaller areas depending on the number of robots. Once the area is divided into sub areas, each robot is assigned a sub area for cooperative sweeping.
Show less - Date Issued
- 2005
- Identifier
- CFE0000641, ucf:46497
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000641
- Title
- PREDICTIVE CONTROL FOR DYNAMIC SYSTEMS TO TRACK UNKNOWN INPUT IN THE PRESENCE OF TIME DELAY.
- Creator
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Li, Yulan, Qu, Zhihua, University of Central Florida
- Abstract / Description
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This study investigated a tracking system to trace unknown signal in the presence oftime delay. A predictive control method is proposed in order to compensate the time delay. Root locus method is applied when designing the controller, parameter setting is carried out through error and trail technique in w-plane. State space equation is derived for the system, with special state chose of tracking error. To analyze the asymptotic stability of the proposed predictive control system, the Lyapunov...
Show moreThis study investigated a tracking system to trace unknown signal in the presence oftime delay. A predictive control method is proposed in order to compensate the time delay. Root locus method is applied when designing the controller, parameter setting is carried out through error and trail technique in w-plane. State space equation is derived for the system, with special state chose of tracking error. To analyze the asymptotic stability of the proposed predictive control system, the Lyapunov function is constructed. It is shown that the designed system is asymptotically stable when input signal is rather low frequency signal. In order to illustrate the system performance, simulations are done based on the data profile technique. Signal profiles including acceleration pro le, velocity pro le, and trajectory profile are listed. Based on these profiles, simulations can be carried out and results can be taken as a good estimation for practical performance of the designed predictive control system. Signal noise is quite a common phenomenon in practical control systems. Under the situation that the input signal is with measurement noise, low pass filter is designed to filter out the noise and keep the low frequency input signal. Two typical kinds of noise are specified, i.e Gaussian noise and Pink noise. Simulations results are displayed to show that the proposed predictive control with low-pass filter design can achieve better performance in the case of both kinds of noise.
Show less - Date Issued
- 2005
- Identifier
- CFE0000819, ucf:46688
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000819
- Title
- A THIRD-ORDER DIFFERENTIAL STEERING ROBOT AND TRAJECTORY GENERATION IN THE PRESENCE OF MOVING OBSTACLES.
- Creator
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An, Vatana, Qu, Zhihua, University of Central Florida
- Abstract / Description
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In this thesis, four robots will be used to implement a collision-free trajectory planning/replanning algorithm. The existence of a chained form transformation so that the robot's model can be control in canonical form will be analyzed and proved. A trajectory generation for obstacles avoidance will be derived, simulated, and implemented. A specific PC based control algorithm will be developed. Chapter two describes two wheels differential drive robot modeling and existence of...
Show moreIn this thesis, four robots will be used to implement a collision-free trajectory planning/replanning algorithm. The existence of a chained form transformation so that the robot's model can be control in canonical form will be analyzed and proved. A trajectory generation for obstacles avoidance will be derived, simulated, and implemented. A specific PC based control algorithm will be developed. Chapter two describes two wheels differential drive robot modeling and existence of controllable canonical chained form. Chapter 3 describes criterion for avoiding dynamic objects, a feasible collision-free trajectory parameterization, and solution to steering velocity. Chapter 4 describes robot implementation, pc wireless interface, and strategy to send and receive information wirelessly. The main robot will be moving in a dynamically changing environment using canonical chained form. The other three robots will be used as moving obstacles that will move with known piecewise constant velocities, and therefore, with known trajectories. Their initial positions are assumed to be known as well. The main robot will receive the command from the computer such as how fast to move and to turn in order to avoid collision. The robot will autonomously travel to the desired destination collision-free.
Show less - Date Issued
- 2006
- Identifier
- CFE0001337, ucf:46968
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001337
- Title
- DESIGN IMPLEMENTATION OF A MICROCONTROLLER BASED EXTERNAL FACILITY ACCESS CONTROL SYSTEM.
- Creator
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Fulbright Jr., Thomas, Richie, Samuel, University of Central Florida
- Abstract / Description
-
In order to solve the College of Engineering and Computer Science facility access problem, an automated system that provides exterior doors with a time schedule and allows authorized users to gain access to the facility after hours was developed. A microcontroller based system has been designed to interface with a personal computer. The system designed within this thesis can be used as a starting point for multiple facility access control systems. This thesis will describe the design,...
Show moreIn order to solve the College of Engineering and Computer Science facility access problem, an automated system that provides exterior doors with a time schedule and allows authorized users to gain access to the facility after hours was developed. A microcontroller based system has been designed to interface with a personal computer. The system designed within this thesis can be used as a starting point for multiple facility access control systems. This thesis will describe the design, integration, test, and final delivery of a facility access system that incorporates the Texas Instruments MSP430 microcontroller, a magnetic card swipe reader, and software developed in Microsoft Visual Basic .Net to provide a reliable and robust system for the College of Engineering and Computers Sciences needs.
Show less - Date Issued
- 2005
- Identifier
- CFE0000484, ucf:52897
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000484
- Title
- Interactive Perception in Robotics.
- Creator
-
Baghbahari Baghdadabad, Masoud, Behal, Aman, Haralambous, Michael, Lin, Mingjie, Sukthankar, Gita, Xu, Yunjun, University of Central Florida
- Abstract / Description
-
Interactive perception is a significant and unique characteristic of embodied agents. An agent can discover plenty of knowledge through active interaction with its surrounding environment. Recently, deep learning structures introduced new possibilities to interactive perception in robotics. The advantage of deep learning is in acquiring self-organizing features from gathered data; however,it is computationally impractical to implement in real-time interaction applications. Moreover, it can be...
Show moreInteractive perception is a significant and unique characteristic of embodied agents. An agent can discover plenty of knowledge through active interaction with its surrounding environment. Recently, deep learning structures introduced new possibilities to interactive perception in robotics. The advantage of deep learning is in acquiring self-organizing features from gathered data; however,it is computationally impractical to implement in real-time interaction applications. Moreover, it can be difficult to attach a physical interpretation. An alternative suggested framework in such cases is integrated perception-action.In this dissertation, we propose two integrated interactive perception-action algorithms for real-time automated grasping of novel objects using pure tactile sensing. While visual sensing andprocessing is necessary for gross reaching movements, it can slow down the grasping process if it is the only sensing modality utilized. To overcome this issue, humans primarily utilize tactile perceptiononce the hand is in contact with the object. Inspired by this, we first propose an algorithm to define similar ability for a robot by formulating the required grasping steps.Next, we develop the algorithm to achieve force closure constraint via suggesting a human-like behavior for the robot to interactively identify the object. During this process, the robot adjuststhe hand through an interactive exploration of the object's local surface normal vector. After the robot finds the surface normal vector, it then tries to find the object edges to have a graspable finalrendezvous with the object. Such achievement is very important in order to find the objects edges for rectangular objects before fully grasping the object. We implement the proposed approacheson an assistive robot to demonstrate the performance of interactive perception-action strategies to accomplish grasping task in an automatic manner.
Show less - Date Issued
- 2019
- Identifier
- CFE0007780, ucf:52361
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007780
- Title
- Energy-optimal Guidance of an AUV Under Flow Uncertainty and Fluid-Particle Interaction.
- Creator
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De Zoysa Abeysiriwardena, Demuni Singith, Das, Tuhin, Kumar, Ranganathan, Elgohary, Tarek, Behal, Aman, University of Central Florida
- Abstract / Description
-
The work presented gives an energy-optimal solution to the guidance problem of an AUV. The presented guidance methods are for lower level control of AUV paths, facilitating existing global planning methods to be carried out comparatively more efficiently. The underlying concept is to use the energy of fluid flow fields the AUVs are navigating to extend the duration of missions. This allows gathering of comparatively more data with higher spatio-temporal resolution. The problem is formulated...
Show moreThe work presented gives an energy-optimal solution to the guidance problem of an AUV. The presented guidance methods are for lower level control of AUV paths, facilitating existing global planning methods to be carried out comparatively more efficiently. The underlying concept is to use the energy of fluid flow fields the AUVs are navigating to extend the duration of missions. This allows gathering of comparatively more data with higher spatio-temporal resolution. The problem is formulated for a generalized two dimensional uniform flow field given a fixed final time andfree end states. This allows the AUVs to navigate to certain spatial positions while maintaining the required temporal resolution of each segment of its mission. The simplistic way the problem is posed allows an analytical closed form solution of the Euler-Lagrange equations. Two dimensional thrust vectors are obtained as optimal control inputs. The control inputs are then incorporated into afeedback structure, allowing the particle to navigate in the presence of disturbance in the flow field. Further, the work also explores the influence of fluid-particle interaction on the control cost and behavior of the particle. The concept of changing the cost weights of the optimal cost formulation in situ has been introduced. Potential applications of the present concept are explored through anobstacle avoidance scenario. The optimal guidance methods are then adapted to non-uniform flow fields with quadratic and discontinuous spatial variation being the primary focus.
Show less - Date Issued
- 2018
- Identifier
- CFE0007169, ucf:52282
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007169
- Title
- MONITORING LONG-TERM CONTROLLED GRAVE SCENARIOS USING GROUND PENETRATING RADAR.
- Creator
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Hawkins, William, Schultz, John, University of Central Florida
- Abstract / Description
-
Geophysical techniques, such as ground-penetrating radar (GPR), have been successfully used by law enforcement agencies to locate graves and forensic evidence. However, more controlled research is needed to better understand the potential and limitations of this technology in the forensic context. The goal of this study was to determine the potential of GPR using both a 250 MHz and 500 MHz antennae to monitor eight controlled graves with six different burial scenarios using pig carcasses as...
Show moreGeophysical techniques, such as ground-penetrating radar (GPR), have been successfully used by law enforcement agencies to locate graves and forensic evidence. However, more controlled research is needed to better understand the potential and limitations of this technology in the forensic context. The goal of this study was to determine the potential of GPR using both a 250 MHz and 500 MHz antennae to monitor eight controlled graves with six different burial scenarios using pig carcasses as human proxy cadavers. In addition, a conductivity meter was employed to determine the applicability of using this technology to locate unmarked graves. For the conductivity meter, the data was processed using an EM38 program in conjunction with the SURFER program to display a conductivity contour map of the grid. For the GPR imagery, reflection profile data was processed using the program REFLEXW while horizontal slices were processed using the GPR-SLICE program. Results indicate that the conductivity meter is not a viable option in the detection of clandestine graves when other geophysical tools are available. For the GPR, results indicate that while graves can still be detected after a two-year period, there is a marked decrease in the response, or resolution, of the burial scenarios. Furthermore, burials with grave goods interred along with the carcasses were far more likely to be detected than burials that were interred with no accompanying grave goods. When comparing the performance of the two antennae, the 250 MHz antenna provided increased resolution for large cadavers buried in deep graves.
Show less - Date Issued
- 2011
- Identifier
- CFE0003601, ucf:48859
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003601
- Title
- Lyapunov-Based Control Design for Uncertain MIMO Systems.
- Creator
-
Wang, Zhao, Behal, Aman, Boloni, Ladislau, Haralambous, Michael, University of Central Florida
- Abstract / Description
-
In this dissertation. we document the progress in the control design for a class of MIMO nonlinear uncertain system from five papers. In the first part, we address the problem of adaptive control design for a class of multi-input multi-output (MIMO)nonlinear systems. A Lypaunov based singularity free control law, which compensates for parametric uncertainty in both the drift vector and the input gain matrix, is proposed under the mild assumption that the signs of the leading minors of...
Show moreIn this dissertation. we document the progress in the control design for a class of MIMO nonlinear uncertain system from five papers. In the first part, we address the problem of adaptive control design for a class of multi-input multi-output (MIMO)nonlinear systems. A Lypaunov based singularity free control law, which compensates for parametric uncertainty in both the drift vector and the input gain matrix, is proposed under the mild assumption that the signs of the leading minors of thecontrol input gain matrix are known. Lyapunov analysis shows global uniform ultimate boundedness (GUUB) result for the tracking error under full state feedback (FSFB). Under the restriction that only the output vector is available for measurement, an output feedback (OFB) controller is designed based on a standard high gain observer (HGO) (-) stability under OFB is fostered by the uniformity of the FSFB solution. Simulation results for both FSFB and OFB controllers demonstrate the ef?cacy of the MIMO control design in the classical 2-DOF robot manipulator model.In the second part, an adaptive feedback control is designed for a class of MIMO nonlinear systems containing parametric uncertainty in both the drift vector and the input gain matrix, which is assumed to be full-rank and non-symmetric in general. Based on an SDU decomposition of the gain matrix, a singularity-free adaptive tracking control law is proposed that is shown to be globally asymptotically stable (GAS) under full-state feedback. Output feedback results are facilitated via the use of a high-gain observer (HGO). Under output feedback control, ultimate boundedness of the error signals is obtained (&)#241; the size of the bound is related to the size of the uncertainty in the parameters. An explicit upper bound is also provided on the size of the HGO gain constant.In third part, a class of aeroelastic systems with an unmodeled nonlinearity and external disturbance is considered. By using leading- and trailing-edge control surface actuations, a full-state feedforward/feedback controller is designed to suppress the aeroelastic vibrations of a nonlinear wing section subject to external disturbance. The full-state feedback control yields a uniformly ultimately bounded result for two-axis vibration suppression. With the restriction that only pitching and plunging displacements are measurable while their rates are not, a high-gain observer is used to modify the full-state feedback control design to an output feedback design. Simulation results demonstrate the ef ? cacy of the multi-input multi-output control toward suppressing aeroelastic vibration and limit cycle oscillations occurring in pre and post? utter velocity regimes when the system is subjected to a variety of external disturbance signals. Comparisons are drawn with a previously designed adaptive multi-input multi-output controller.In the fourth part, a continuous robust feedback control is designed for a class of high-order multi-input multi-output (MIMO) nonlinear systems with two degrees of freedom containing unstructured nonlinear uncertainties in the drift vector and parametric uncertainties in the high frequency gain matrix, which is allowed to be non-symmetric in general. Given some mild assumptions on the system model, a singularity-free continuous robust tracking control law is designed that is shown to be semi-globally asymptotically stable under full-state feedback through a Lyapunov stability analysis. The performance of the proposed algorithm have been verified on a two-link robot manipulator model and 2-DOF aeroelastic model.
Show less - Date Issued
- 2012
- Identifier
- CFE0004345, ucf:49420
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004345
- Title
- Suppression of Turbofan and Turbojet Engine Generated Noise.
- Creator
-
Master, Harry D., Ventre, Gerald G., Engineering
- Abstract / Description
-
Florida Technological University College of Engineering Thesis; Every advance in the transformation of heat energy into mechanical energy has involved a noise problem, and in general it increases with the power production. The jet airplane is a good example: the large-scale turbulence of the exhaust gases in the jet forms an unusually intense source of sound the control of which is quite difficult. The additionally generated fan noises add characteristic fan tones which are particularly...
Show moreFlorida Technological University College of Engineering Thesis; Every advance in the transformation of heat energy into mechanical energy has involved a noise problem, and in general it increases with the power production. The jet airplane is a good example: the large-scale turbulence of the exhaust gases in the jet forms an unusually intense source of sound the control of which is quite difficult. The additionally generated fan noises add characteristic fan tones which are particularly noticeable on landing approaches. the human ear is the vulnerable receiver of these noises, and the problem becomes one of deciding how much jet engine noise reduction is required for the comfort or safety of the receiver, and then to devise ways to achieve it.
Show less - Date Issued
- 1972
- Identifier
- CFR0011987, ucf:53093
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0011987
- Title
- Flood Control Modeling.
- Creator
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Delle Donne, Peter E., Wanielista, Martin P., Engineering
- Abstract / Description
-
Florida Technological University College of Engineering Thesis; This is a research report that discusses some continuous and discrete modeling techniques. The report applies these techniques to the analysis of Canal 38 (Kissimmee River) part of Central and South Florida Flood Control District. The analysis is based on recorded data for defining the physical systems parameters. Established parameters are mathematically related to define a descriptive model for Canal 38. the modeling procedure...
Show moreFlorida Technological University College of Engineering Thesis; This is a research report that discusses some continuous and discrete modeling techniques. The report applies these techniques to the analysis of Canal 38 (Kissimmee River) part of Central and South Florida Flood Control District. The analysis is based on recorded data for defining the physical systems parameters. Established parameters are mathematically related to define a descriptive model for Canal 38. the modeling procedure of 'trial and error' is used to assemble themodel with measures of merit, the integral square error, and root mean squared error. General simulation considerations are discussed for application of the mathematical model.
Show less - Date Issued
- 1972
- Identifier
- CFR0012150, ucf:53126
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0012150
- Title
- Decentralized Power Management in Microgrids.
- Creator
-
Bhattacharjee, Amit, Das, Tuhin, Simaan, Marwan, Kassab, Alain, University of Central Florida
- Abstract / Description
-
A large number of power sources, operational in a microgrid, optimum power sharing andaccordingly controlling the power sources along with scheduling loads are the biggest challenges in modern power system. In the era of smart grid, the solution is certainly not simple paralleling. Hence it is required to develop a control scheme that delivers the overall power requirements while also adhering to the power limitations of each source. As the penetration of distributed generators increase and...
Show moreA large number of power sources, operational in a microgrid, optimum power sharing andaccordingly controlling the power sources along with scheduling loads are the biggest challenges in modern power system. In the era of smart grid, the solution is certainly not simple paralleling. Hence it is required to develop a control scheme that delivers the overall power requirements while also adhering to the power limitations of each source. As the penetration of distributed generators increase and are diversified, the choice of decentralized control becomes preferable. In this work, a decentralized control framework is conceived. The primary approach is taken where a small hybrid system is investigated and decentralized control schemes were developed and subsequently tested in a hardware in the loop in conjunction with the hybrid power system setup developed at the laboratory. The control design approach is based on the energy conservation principle. However, considering the vastness ofthe real power network and its complexity of operation along with the growing demand ofsmarter grid operations, called for a revamp in the control framework design. Hence, in thelater phase of this work, a novel framework is developed based on the coupled dynamicalsystem theory, where each control node corresponds to one distributed generator connectedto the microgrid. The coupling topology and coupling strengths of individual nodes aredesigned to be adjustable. The layer is modeled as a set of coupled differential equationsof pre-assigned order. The control scheme adjusts the coupling weights so that steady stateconstraints are met at the system level, while allowing flexibility to explore the solutionspace. Additionally, the approach guarantees stable equilibria during power redistribution.The theoretical development is verified using simulations in matlab simulink environment.
Show less - Date Issued
- 2014
- Identifier
- CFE0005465, ucf:50386
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005465
- Title
- Pressure Image Based Attitude Controller for Small Unmanned Aerial Vehicles.
- Creator
-
Thompson, Kenneth, Xu, Yunjun, Gou, Jihua, Lin, Kuo-Chi, University of Central Florida
- Abstract / Description
-
As technology improves, small unmanned aerial vehicles (SUAV) have been identified for their utility in a variety of applications in which larger unmanned craft may be incapable of accomplishing mission objectives. These aircraft with their small size and long flight durations are ideal for hazardous inspection and long duration surveillance missions. One challenge preventing the widespread adoption of these systems is their instability to abrupt changes in the flow field around them due to...
Show moreAs technology improves, small unmanned aerial vehicles (SUAV) have been identified for their utility in a variety of applications in which larger unmanned craft may be incapable of accomplishing mission objectives. These aircraft with their small size and long flight durations are ideal for hazardous inspection and long duration surveillance missions. One challenge preventing the widespread adoption of these systems is their instability to abrupt changes in the flow field around them due to wind gusts or flow separation.Currently, traditional rigid body based sensors are implemented in their flight control systems, which are sufficient in higher inertia aircraft for accurate control.However, in low inertia SUAV applications during a flow event, often, the inertial sensors are incapable of detecting the event before catastrophic failure.A method of directly measuring the flow information around the SUAV in order to generate control commands will improve the stability of these systems by allowing these systems to directly react to flow events.In contrast, established inertial based control systems can only react to changes in vehicle dynamics caused by flow events.Such a method is developed utilizing a network of pressure and shear sensors embedded in the wing and used to create (")flow images(") which can be easily manipulated to generate control commands.A method of accurately calculating the aerodynamic moment acting on the aircraft based on the flow image is also developed for implementation of flow image-based control in real world systems.
Show less - Date Issued
- 2018
- Identifier
- CFE0007417, ucf:52722
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007417
- Title
- Bio-Inspired Cooperative Optimal Trajectory Planning for Autonomous Vehicles.
- Creator
-
Remeikas, Charles, Xu, Yunjun, Kassab, Alain, Lin, Kuo-Chi, University of Central Florida
- Abstract / Description
-
With the recent trend for systems to be more and more autonomous, there is a growing need for cooperative trajectory planning. Applications that can be considered as cooperative systems such as surveying, formation flight, and traffic control need a method that can rapidly produce trajectories while considering all of the constraints on the system. Currently most of the existing methods to handle cooperative control are based around either simple dynamics and/or on the assumption that all...
Show moreWith the recent trend for systems to be more and more autonomous, there is a growing need for cooperative trajectory planning. Applications that can be considered as cooperative systems such as surveying, formation flight, and traffic control need a method that can rapidly produce trajectories while considering all of the constraints on the system. Currently most of the existing methods to handle cooperative control are based around either simple dynamics and/or on the assumption that all vehicles have homogeneous properties. In reality, typical autonomous systems will have heterogeneous, nonlinear dynamics while also being subject to extreme constraints on certain state and control variables. In this thesis, a new approach to the cooperative control problem is presented based on the bio-inspired motion strategy known as local pursuit. In this framework, decision making about the group trajectory and formation are handled at a cooperative level while individual trajectory planning is considered in a local sense. An example is presented for a case of an autonomous farming system (e.g. scouting) utilizing nonlinear vehicles to cooperatively accomplish various farming task with minimal energy consumption or minimum time. The decision making and trajectory generation is handled very quickly while being able to consider changing environments laden with obstacles.
Show less - Date Issued
- 2013
- Identifier
- CFE0005053, ucf:49978
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005053
- Title
- FLOW CONTROL OF TANDEM CYLINDERS USING PLASMA ACTUATORS.
- Creator
-
Larsen, Jonah, Bhattacharya, Samik, University of Central Florida
- Abstract / Description
-
The flow over a set of tandem cylinders at a moderate Reynolds numbers (Re), and with different separation lengths has been studied. Two dimensional (2D) and three-dimensional (3D) plasma actuators were used to control the flow over the leading cylinder to change the vortex shedding, and subsequently the flow on the second cylinder. The 3D plasma actuator was segmented along the length of the cylinder with a spacing of ? = 4 while the 2D actuator simply ran straight down the span of the...
Show moreThe flow over a set of tandem cylinders at a moderate Reynolds numbers (Re), and with different separation lengths has been studied. Two dimensional (2D) and three-dimensional (3D) plasma actuators were used to control the flow over the leading cylinder to change the vortex shedding, and subsequently the flow on the second cylinder. The 3D plasma actuator was segmented along the length of the cylinder with a spacing of ? = 4 while the 2D actuator simply ran straight down the span of the cylinder. Particle image velocimetry (PIV) measurements were used to investigate the flow along the central plane in the wake of the cylinders. The image pairs were processed into velocity grids which were then averaged. Plots of the shear, vorticity, and turbulent kinetic energy were created. These plots are used to understand how the character of vortex shedding from the upstream cylinder changes the same from the downstream one.
Show less - Date Issued
- 2018
- Identifier
- CFH2000425, ucf:45872
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000425
- Title
- RELATIONSHIP BETWEEN SUPERVISOR LOCUS OF CONTROL AND EMPLOYEE SATISFACTION IN A RESIDENTIAL CARE FACILITY.
- Creator
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Nowotniak, Patricia, House, Jess, University of Central Florida
- Abstract / Description
-
The goal of this research was to identify factors that may contribute to employee satisfaction. Review of the literature revealed potential factors influencing employee satisfaction, such as locus of control, difficulty of the work itself, and working conditions. These literature findings guided this research, to establish if a relationship existed between employee satisfaction of caregivers employed in a developmental institution and locus of control. Supervisors and their employees were...
Show moreThe goal of this research was to identify factors that may contribute to employee satisfaction. Review of the literature revealed potential factors influencing employee satisfaction, such as locus of control, difficulty of the work itself, and working conditions. These literature findings guided this research, to establish if a relationship existed between employee satisfaction of caregivers employed in a developmental institution and locus of control. Supervisors and their employees were given a locus of control scale; employees were additionally given a job satisfaction survey. The relationship between the supervisors' locus of control and employee satisfaction was evaluated as well as the relationship between the employees' locus of control and their job satisfaction. The resignation rate and rate of transfers within the agency were established for each of the supervisors and were assessed in relationship to the locus of control of the supervisors. Factors such as the level of physical exertion required by employees in their job duties and the level of behavioral intervention in their homes were assessed as they related to their own job satisfaction, their transfers, and their rates of resignations. Findings from the correlation procedures revealed no relationship to a statistically significant degree between the locus of control of supervisors and their employees' job satisfaction. The locus of control of supervisors was also not found to be statistically significantly correlated with the numbers of employee transfers within the organization; however, a relationship between the locus of control of supervisors and employee resignations was established. The supervisors who had an internal locus of control had fewer resignations. A statistically significant negative relationship was also found between employees' job satisfaction and their own locus of control. The employees who had an internal locus of control reported higher job satisfaction. Although there was no relationship established between the employees' job satisfaction and type of exertion, there was a statistically significant negative relationship between behavioral exertion and requests for inter-agency transfers and resignations, and a positive correlation between physical exertion and number of resignations. Results of this study suggest that locus of control is an impacting variable for job satisfaction and turnover. Combining attribution training with effective management practices with all employees may increase employee satisfaction. Findings from this research suggest a need for a better refinement of the theoretical construct of job satisfaction and a need to evaluate the effectiveness of the instrumentation currently used to determine job satisfaction.
Show less - Date Issued
- 2005
- Identifier
- CFE0000558, ucf:46417
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000558
- Title
- DESIGN AND IMPLEMENTATION OF A DIGITAL CONTROLLER WITH DSP FOR HALF-BRIDGE DC-DC CONVERTERS.
- Creator
-
Wen, Yangyang, Batarseh, Issa, University of Central Florida
- Abstract / Description
-
DC-DC power converters play an important role in powering telecom and computing systems. With the speed improvement and cost reduction of digital control, digital controller is becoming a trend for DC-DC converters in addition to existed digital monitoring and management technology. In this thesis, digital control is investigated for DC-DC converters applications. To deeply understand the whole control systems, DC-DC converter models are investigated based on averaged state-space modeling....
Show moreDC-DC power converters play an important role in powering telecom and computing systems. With the speed improvement and cost reduction of digital control, digital controller is becoming a trend for DC-DC converters in addition to existed digital monitoring and management technology. In this thesis, digital control is investigated for DC-DC converters applications. To deeply understand the whole control systems, DC-DC converter models are investigated based on averaged state-space modeling. Considering half-bridge isolated DC-DC converter with a current doublers rectifier has advantages over other topologies especially in the application of low-voltage and high-current DC-DC converters, the thesis take it as an example for digital control modeling and implementation. In Chapter 2, unified steady-state DC models and small-signal models are developed for both symmetric and asymmetric controlled half-bridge DC-DC converters. Based on the models, digital controller design is implemented. In Chapter 3, digital modeling platforms are established based on Matlab, Digital PID design and corresponding simulation results are provided. Also some critical issues and practical requirements are discussed. In Chapter 4, a DSP-based digital controller is implemented with the TI's DSP chip TMS320F2812. Related implementation methods and technologies are discussed. Finally the experimental results of a DSP-based close-loop of HB converter are provided and analyzed in Chapter 5, and thesis conclusions are given in Chapter 6.
Show less - Date Issued
- 2004
- Identifier
- CFE0000246, ucf:46273
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000246
