+publisher:"Texas A&M University" +contributor:("Kim, Won-jong")

Texas A&M University

1. Abdelzaher, Omar Mohamed. Downhole Wireline Mechatronics and Drillstring Vibration Dynamics.

Degree: MS, Mechanical Engineering, 2014, Texas A&M University

URL: http://hdl.handle.net/1969.1/157919

► The work is divided into two parts: The First part discusses and documents simulation investigations on the interactive effect of the different conveyance accessories tools… (more)

▼ The work is divided into two parts: The First part discusses and documents simulation investigations on the interactive effect of the different conveyance accessories tools and their designs on the wireline cable tension force, and how it can influence the wireline cable performance especially in open hole logging operations with highly deviated and rugose zones. A computer simulation model was built to predict the cable tension force applied on conveyed wireline string so as to assess and analyze the effect of the different conveyance accessories, such as centralizers, bottom-nose tools, and wireline coating, on wireline penetration rates. A numerical computing approach was then utilized to represent and analyze the simulation studies output results in a friendly graphical form. Improving the wireline logging performance, especially in highly deviated rugose openhole wells, could increase the percentage of successful logging operations, reducing time, cost and improving data quality with the increased wellbore coverage. The second part discusses the possible violent drillstring vibrations encountered during drilling and its effect on the overall rate of penetration and sustainability. This entails a complete identification and modeling of the drillstring dynamics and the sources of vibrations excitation that include stick-slip, bit-bounce, and whirling with its two forward and backward types to better control its functional operation and improve its performance. A Matlab numerical simulator model based on Finite-Element-Method of 3D- Timoshenko beam elements is developed for this purpose to predict and simulate the rotordynamic behavior of the bottom-hole-assembly (BHA) and the PDC-Drillbit cutting dynamics. The model also includes the coupling between the torsional and bending vibrations of drillstrings with the nonlinear effects of drillstring/wellbore friction contacts. The work extends previous models of drillstring vibrations in the literature to include the destructive drillstring vibration backward whirling type with Pure rolling behavior and answers some crucial questions: the operation conditions that possibly causes backward whirl vibrations, possible stabilizers’ configuration to reduce chance of backward whirl, best stabilizers locations in the BHA to minimize the sever vibration effects on the drillstring, and other arising questions. Advisors/Committee Members: Palazzolo , Alan (advisor), Ahmed, Shehab (advisor), jong%22%29&pagesize-30">Kim, Won-jong (committee member).

Subjects/Keywords: Downhole; Wireline; Mechatronics; Drillstring; Vibration; Dynamics; simulation; centralizers; bottom-nose; logging; wellbore; drilling; penetration; stick-slip; bit-bounce; whirling; Matlab; Finite-Element-Method; Timoshenko; rotordynamic; bottom-hole-assembly; Drillbit; nonlinear; Pur-rolling; backward-whirl; stabilizers; BHA

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APA (6^th Edition):

Abdelzaher, O. M. (2014). Downhole Wireline Mechatronics and Drillstring Vibration Dynamics. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/157919

Chicago Manual of Style (16^th Edition):

Abdelzaher, Omar Mohamed. “Downhole Wireline Mechatronics and Drillstring Vibration Dynamics.” 2014. Masters Thesis, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/157919.

MLA Handbook (7^th Edition):

Abdelzaher, Omar Mohamed. “Downhole Wireline Mechatronics and Drillstring Vibration Dynamics.” 2014. Web. 18 Jan 2021.

Vancouver:

Abdelzaher OM. Downhole Wireline Mechatronics and Drillstring Vibration Dynamics. [Internet] [Masters thesis]. Texas A&M University; 2014. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/157919.

Council of Science Editors:

Abdelzaher OM. Downhole Wireline Mechatronics and Drillstring Vibration Dynamics. [Masters Thesis]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/157919

Texas A&M University

2. Zhang, Xiaohua. Small Engine Flash Vapor JP-8 Fuel Injector Testing, Simulation and Development.

Degree: PhD, Mechanical Engineering, 2014, Texas A&M University

URL: http://hdl.handle.net/1969.1/174186

► Following U.S. Army’s single fuel initiative, Wankel rotary engines used in U.S. Army’s shadow unmanned aerial vehicles (UAVs) need to be retrofitted from running on… (more)

Subjects/Keywords: fuel injector; flash heating; JP-8; Wankel rotary engine; multi-physics modeling; spray measurement; ignition test

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APA (6^th Edition):

Zhang, X. (2014). Small Engine Flash Vapor JP-8 Fuel Injector Testing, Simulation and Development. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/174186

Chicago Manual of Style (16^th Edition):

Zhang, Xiaohua. “Small Engine Flash Vapor JP-8 Fuel Injector Testing, Simulation and Development.” 2014. Doctoral Dissertation, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/174186.

MLA Handbook (7^th Edition):

Zhang, Xiaohua. “Small Engine Flash Vapor JP-8 Fuel Injector Testing, Simulation and Development.” 2014. Web. 18 Jan 2021.

Vancouver:

Zhang X. Small Engine Flash Vapor JP-8 Fuel Injector Testing, Simulation and Development. [Internet] [Doctoral dissertation]. Texas A&M University; 2014. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/174186.

Council of Science Editors:

Zhang X. Small Engine Flash Vapor JP-8 Fuel Injector Testing, Simulation and Development. [Doctoral Dissertation]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/174186

Texas A&M University

3. Eib, Andrew. Design of a Backdrivable Upper-Limb Exoskeleton for Use in Rehabilitation Therapy of Stroke Patients.

Degree: MS, Mechanical Engineering, 2018, Texas A&M University

URL: http://hdl.handle.net/1969.1/173937

► The topic of this thesis is the development of a highly backdrivable exoskeleton for use in rehabilitation therapy of stroke patients. A synthetic rope drive… (more)

Subjects/Keywords: Capstan Drive; Backdrivable; exoskeleton; Upper-limb; stroke rehabilitation; stroke robotics

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APA (6^th Edition):

Eib, A. (2018). Design of a Backdrivable Upper-Limb Exoskeleton for Use in Rehabilitation Therapy of Stroke Patients. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/173937

Chicago Manual of Style (16^th Edition):

Eib, Andrew. “Design of a Backdrivable Upper-Limb Exoskeleton for Use in Rehabilitation Therapy of Stroke Patients.” 2018. Masters Thesis, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/173937.

MLA Handbook (7^th Edition):

Eib, Andrew. “Design of a Backdrivable Upper-Limb Exoskeleton for Use in Rehabilitation Therapy of Stroke Patients.” 2018. Web. 18 Jan 2021.

Vancouver:

Eib A. Design of a Backdrivable Upper-Limb Exoskeleton for Use in Rehabilitation Therapy of Stroke Patients. [Internet] [Masters thesis]. Texas A&M University; 2018. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/173937.

Council of Science Editors:

Eib A. Design of a Backdrivable Upper-Limb Exoskeleton for Use in Rehabilitation Therapy of Stroke Patients. [Masters Thesis]. Texas A&M University; 2018. Available from: http://hdl.handle.net/1969.1/173937

Texas A&M University

4. Stockton, Alexander. Design, Build, and Control of a Climbing Robot for Irregular Surface Geometry.

Degree: MS, Mechanical Engineering, 2015, Texas A&M University

URL: http://hdl.handle.net/1969.1/187472

► Climbing robots are ideal for situations were maintenance and inspection tasks can cause people to be in dangerous situations or require them to be present… (more)

▼ Climbing robots are ideal for situations were maintenance and inspection tasks can cause people to be in dangerous situations or require them to be present for extended periods of time. Applications include inspection, testing, civil construction, cleaning, transport and security. The focus of this thesis was on robots that used pneumatic means to attain adhesion and wheels for locomotion. Research objectives include designing or utilizing a pneumatic based adhesion method to allow the robot to stick to concrete, brick, glass, or other such surfaces; climb on a surface with the lowest possible coefficient of friction between it and the robot; have the ability to overcome a step-like obstacle while climbing; use a single body to passively transition through sharp surface changes while climbing; have the ability to traverse over a gap-type obstacle while climbing without loss of adhesion or mobility. To complete the objectives, a test rig was created that comprised of three surfaces that were hinged together and could be locked into place using aluminum struts at the hinge joint. Different material pallets were created and adhered to plywood that was then mounted to the test rig with screws. The robot was designed and built around laser cut and 3D printed parts. From the experiments it was found that the robot could adhere to a glass surface with a coefficient of friction of 0.43 between it and the glass. Furthermore it was able to overcome a 15mm tall speedbump while climbing without loss of adhesion as well as being able to passively transition between surfaces that had an acute angle of 80° between them and do wall to ceiling transitions. Finally the robot was able to pass over a 55mm gap that was 23mm deep while climbing on a concrete surface. It was concluded that by using thrust based adhesion the robot could handle a diverse array of surfaces and even gain greater ability to overcome obstacles while climbing. Future directions would improve on the robot by adding treads or multiple bodies to improve its base abilities. Advisors/Committee Members: Hsieh, Sheng-Jen (advisor), jong%22%29&pagesize-30">Kim, Won-jong (committee member), Cizmas, Paul (committee member).

Subjects/Keywords: Robot; Climbing; Thrust Based Adhesion; Irregular Surface Geometry; Arduino; Electric Ducted Fan; Android App.; Inverted Climbing

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APA (6^th Edition):

Stockton, A. (2015). Design, Build, and Control of a Climbing Robot for Irregular Surface Geometry. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/187472

Chicago Manual of Style (16^th Edition):

Stockton, Alexander. “Design, Build, and Control of a Climbing Robot for Irregular Surface Geometry.” 2015. Masters Thesis, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/187472.

MLA Handbook (7^th Edition):

Stockton, Alexander. “Design, Build, and Control of a Climbing Robot for Irregular Surface Geometry.” 2015. Web. 18 Jan 2021.

Vancouver:

Stockton A. Design, Build, and Control of a Climbing Robot for Irregular Surface Geometry. [Internet] [Masters thesis]. Texas A&M University; 2015. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/187472.

Council of Science Editors:

Stockton A. Design, Build, and Control of a Climbing Robot for Irregular Surface Geometry. [Masters Thesis]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/187472

Texas A&M University

5. Shin, Sungtae. Myoelectric Human Computer Interaction Using Reliable Temporal Sequence-based Myoelectric Classification for Dynamic Hand Gestures.

Degree: PhD, Mechanical Engineering, 2016, Texas A&M University

URL: http://hdl.handle.net/1969.1/174271

► To put a computerized device under human control, various interface techniques have been commonly studied in the realm of Human Computer Interaction (HCI) design. What… (more)

▼ To put a computerized device under human control, various interface techniques have been commonly studied in the realm of Human Computer Interaction (HCI) design. What this dissertation focuses on is a myoelectric interface, which controls a device via neuromuscular electrical signals. Myoelectric interface has advanced by recognizing repeated patterns of the signal (pattern recognition-based myoelectric classification). However, when the myoelectric classification is used to extract multiple discrete states within limited muscle sites, there are robustness issues due to external conditions: limb position changes, electrode shifts, and skin condition changes. Examined in this dissertation is the robustness issue, or drop in the performance of the myoelectric classification when the limb position varies from the position where the system was trained. Two research goals outlined in this dissertation are to increase reliability of myoelectric system and to build a myoelectric HCI to manipulate a 6-DOF robot arm with a 1-DOF gripper. To tackle the robustness issue, the proposed method uses dynamic motions which change their poses and configuration over time. The method assumes that using dynamic motions is more reliable, vis-a-vis the robustness issues, than using static motions. The robustness of the method is evaluated by choosing the training sets and validation sets at different limb positions. Next, an HCI system manipulating a 6-DOF robot arm with a 1-DOF gripper is introduced. The HCI system includes an inertia measurement unit to measure the limb orientation, as well as EMG sensors to acquire muscle force and to classify dynamic motions. Muscle force and the orientation of a forearm are used to generate velocity commands. Classified dynamic motions are used to change the manipulation modes. The performance of the myoelectric interface is measured in terms of real-time classification accuracy, path efficiency, and time-related measures. In conclusion, this dissertation proposes a reliable myoelectric classification and develops a myoelectric interface using the proposed classification method for an HCI application. The robustness of the proposed myoelectric classification is verified as compared to previous myoelectric classification approaches. The usability of the developed myoelectric interface is compared to a well-known interface. Advisors/Committee Members: Langari, Reza (advisor), Tafreshi, Reza (advisor), jong%22%29&pagesize-30">Kim, Won-jong (committee member), Choe, Yoonsuck (committee member).

Subjects/Keywords: Human Computer Interaction (HCI); myoelectric classification; myoelectric interface

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APA (6^th Edition):

Shin, S. (2016). Myoelectric Human Computer Interaction Using Reliable Temporal Sequence-based Myoelectric Classification for Dynamic Hand Gestures. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/174271

Chicago Manual of Style (16^th Edition):

Shin, Sungtae. “Myoelectric Human Computer Interaction Using Reliable Temporal Sequence-based Myoelectric Classification for Dynamic Hand Gestures.” 2016. Doctoral Dissertation, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/174271.

MLA Handbook (7^th Edition):

Shin, Sungtae. “Myoelectric Human Computer Interaction Using Reliable Temporal Sequence-based Myoelectric Classification for Dynamic Hand Gestures.” 2016. Web. 18 Jan 2021.

Vancouver:

Shin S. Myoelectric Human Computer Interaction Using Reliable Temporal Sequence-based Myoelectric Classification for Dynamic Hand Gestures. [Internet] [Doctoral dissertation]. Texas A&M University; 2016. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/174271.

Council of Science Editors:

Shin S. Myoelectric Human Computer Interaction Using Reliable Temporal Sequence-based Myoelectric Classification for Dynamic Hand Gestures. [Doctoral Dissertation]. Texas A&M University; 2016. Available from: http://hdl.handle.net/1969.1/174271

Texas A&M University

6. Han, Xu. Analysis and Simulation of Mechanical Trains Driven by Variable Frequency Drive Systems.

Degree: MS, Mechanical Engineering, 2012, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8666

► Induction motors and Variable Frequency Drives (VFDs) are widely used in industry to drive machinery trains. However, some mechanical trains driven by VFD-motor systems have… (more)

▼ Induction motors and Variable Frequency Drives (VFDs) are widely used in industry to drive machinery trains. However, some mechanical trains driven by VFD-motor systems have encountered torsional vibration problems. This vibration can induce large stresses on shafts and couplings, and reduce the lifetime of these mechanical parts. Long before the designed lifetime, the mechanical train may encounter failure. This thesis focuses on VFDs with voltage source rectifiers for squirrel-cage induction motors of open-loop Volts/Hertz and closed-loop Field Oriented Control (FOC). First, the torsional vibration problems induced by VFDs are introduced. Then, the mathematical model for a squirrel-cage induction motor is given. Two common control methods used in VFD are discussed - open-loop Volts/Hertz and closed-loop FOC. SimPowerSystems and SimMechanics are used as the modeling software for electrical systems and mechanical systems respectively. Based on the models and software, two interface methods are provided for modeling the coupled system. A simple system is tested to verify the interface methods. The study of open-loop Volts/Hertz control method is performed. The closed-form of electromagnetic torque sideband frequency due to Pulse Width Modulation is given. A torsional resonance case is illustrated. The effects of non-ideal power switches are studied, which shows little in uence on the system response but which uses little energy consumption. A study of a non-ideal DC bus indicates that a DC bus voltage ripple can also induce a big torsional vibration. Next, the study of the closed-loop FOC control method is presented. Simulation for a complete VFD machinery train is performed. With the recti er and DC bus dynamic braking, the system shows a better performance than the ideal-DC bus case. Lastly, a parametric study of the FOC controller is performed. The effects of primary parameters are discussed. The results indicate that some control parameters (i.e. speed ramps, proportional gain in speed PI controller) are also responsible for the mechanical torsional vibration. Advisors/Committee Members: Palazzolo, Alan B. (advisor), jong%22%29&pagesize-30">Kim, Won-jong (committee member), Toliyat, Hamid A. (committee member).

Subjects/Keywords: Vibration; Variable Frequency Drive; VFD; Field Oriented Control; Mechanical System; Resonance; SimPowerSystems; SimMechanics

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APA (6^th Edition):

Han, X. (2012). Analysis and Simulation of Mechanical Trains Driven by Variable Frequency Drive Systems. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8666

Chicago Manual of Style (16^th Edition):

Han, Xu. “Analysis and Simulation of Mechanical Trains Driven by Variable Frequency Drive Systems.” 2012. Masters Thesis, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8666.

MLA Handbook (7^th Edition):

Han, Xu. “Analysis and Simulation of Mechanical Trains Driven by Variable Frequency Drive Systems.” 2012. Web. 18 Jan 2021.

Vancouver:

Han X. Analysis and Simulation of Mechanical Trains Driven by Variable Frequency Drive Systems. [Internet] [Masters thesis]. Texas A&M University; 2012. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8666.

Council of Science Editors:

Han X. Analysis and Simulation of Mechanical Trains Driven by Variable Frequency Drive Systems. [Masters Thesis]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8666

Texas A&M University

7. Lopez, Thomas Jai. Subsurface Flow Management and Real-Time Production Optimization using Model Predictive Control.

Degree: MS, Petroleum Engineering, 2012, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10561

► One of the key challenges in the Oil & Gas industry is to best manage reservoirs under different conditions, constrained by production rates based on… (more)

▼ One of the key challenges in the Oil & Gas industry is to best manage reservoirs under different conditions, constrained by production rates based on various economic scenarios, in order to meet energy demands and maximize profit. To address the energy demand challenges, a transformation in the paradigm of the utilization of "real-time" data has to be brought to bear, as one changes from a static decision making to a dynamical and data-driven management of production in conjunction with real-time risk assessment. The use of modern methods of computational modeling and simulation may be the only means to account for the two major tasks involved in this paradigm shift: (1) large-scale computations; and (2) efficient utilization of the deluge of data streams. Recently, history matching and optimization were brought together in the oil industry into an integrated and more structured approach called optimal closed-loop reservoir management. Closed-loop control algorithms have already been applied extensively in other engineering fields, including aerospace, mechanical, electrical and chemical engineering. However, their applications to porous media flow, such as - in the current practices and improvements in oil and gas recovery, in aquifer management, in bio-landfill optimization, and in CO2 sequestration have been minimal due to the large-scale nature of existing problems that generate complex models for controller design and real-time implementation. Their applicability to a realistic field is also an open topic because of the large-scale nature of existing problems that generate complex models for controller design and real-time implementation, hindering its applicability. Basically, three sources of high-dimensionality can be identified from the underlying reservoir models: size of parameter space, size of state space, and the number of scenarios or realizations necessary to account for uncertainty. In this paper we will address type problem of high dimensionality by focusing on the mitigation of the size of the state-space models by means of model-order reduction techniques in a systems framework. We will show how one can obtain accurate reduced order models which are amenable to fast implementations in the closed-loop framework .The research will focus on System Identification (System-ID) (Jansen, 2009) and Model Predictive Control (MPC) (Gildin, 2008) to serve this purpose. A mathematical treatment of System-ID and MPC as applied to reservoir simulation will be presented. Linear MPC would be studied on two specific reservoir models after generating low-order reservoir models using System-ID methods. All the comparisons are provided from a set of realistic simulations using the commercial reservoir simulator called Eclipse. With the improvements in oil recovery and reductions in water production effectively for both the cases that were considered, we could reinforce our stance in proposing the implementation of MPC and System-ID towards the ultimate goal of "real-time" production optimization. Advisors/Committee Members: Gildin, Eduardo (advisor), Gupta, Akhil D. (committee member), jong%22%29&pagesize-30">Kim, Won-jong (committee member).

Subjects/Keywords: Reservoir Simulation; Control; Smart Wells; Model Predictive Control; System Identification; Subspace Identification; MPC

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APA (6^th Edition):

Lopez, T. J. (2012). Subsurface Flow Management and Real-Time Production Optimization using Model Predictive Control. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10561

Chicago Manual of Style (16^th Edition):

Lopez, Thomas Jai. “Subsurface Flow Management and Real-Time Production Optimization using Model Predictive Control.” 2012. Masters Thesis, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10561.

MLA Handbook (7^th Edition):

Lopez, Thomas Jai. “Subsurface Flow Management and Real-Time Production Optimization using Model Predictive Control.” 2012. Web. 18 Jan 2021.

Vancouver:

Lopez TJ. Subsurface Flow Management and Real-Time Production Optimization using Model Predictive Control. [Internet] [Masters thesis]. Texas A&M University; 2012. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10561.

Council of Science Editors:

Lopez TJ. Subsurface Flow Management and Real-Time Production Optimization using Model Predictive Control. [Masters Thesis]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10561

Texas A&M University

8. Chen, Jinfa. An Intelligent Human-Tracking Robot Based-on Kinect Sensor.

Degree: MS, Mechanical Engineering, 2015, Texas A&M University

URL: http://hdl.handle.net/1969.1/156510

► This thesis provides an indoor human-tracking robot, which is also able to control other electrical devices for the user. The overall experimental setup consists of… (more)

Subjects/Keywords: kinect sensor; human-tracking; gesture control; feedback control; human-robot interaction

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APA (6^th Edition):

Chen, J. (2015). An Intelligent Human-Tracking Robot Based-on Kinect Sensor. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/156510

Chicago Manual of Style (16^th Edition):

Chen, Jinfa. “An Intelligent Human-Tracking Robot Based-on Kinect Sensor.” 2015. Masters Thesis, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/156510.

MLA Handbook (7^th Edition):

Chen, Jinfa. “An Intelligent Human-Tracking Robot Based-on Kinect Sensor.” 2015. Web. 18 Jan 2021.

Vancouver:

Chen J. An Intelligent Human-Tracking Robot Based-on Kinect Sensor. [Internet] [Masters thesis]. Texas A&M University; 2015. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/156510.

Council of Science Editors:

Chen J. An Intelligent Human-Tracking Robot Based-on Kinect Sensor. [Masters Thesis]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/156510

Texas A&M University

9. Nguyen, Vu Huy. Universal Framework for Linear Motors and Multi-Axis Stages with Magnetic Levitation.

Degree: PhD, Mechanical Engineering, 2015, Texas A&M University

URL: http://hdl.handle.net/1969.1/156534

► This dissertation presents the electromagnetic design and experimental validation of a new framework for linear permanent-magnet (PM) machines with targeted applications in precision motion control.… (more)

▼ This dissertation presents the electromagnetic design and experimental validation of a new framework for linear permanent-magnet (PM) machines with targeted applications in precision motion control. In this framework, a single forcer, which can generate two independent force components in two perpendicular directions, consists of a stationary Halbach magnet array and two Lorentz coils with a phase difference of 90° or 270°. Any number of coil pairs can be attached on the same moving frame to work with a common magnet array or matrix, forming a linear or planar PM motor. Key advantages of this framework are simple force calculation, a linear system model, and a reduced number of coils for force generation and allocation in multi-axis positioners. The proposed framework effectively allows for decoupled dynamics, simplifying the linear controller design and real-time implementation. To experimentally verify the theoretical framework proposed herein, a high-precision 6-axis magnetically levitated (maglev) stage is designed, constructed, and controlled. The development of this 6-axis positioning system is an integrated work, including magnetic-force calculation and analysis, mechanical design, fabrication, assembly, system modeling, system identification, and control system design. The mechanical components of the system include a stationary superimposed Halbach magnet matrix, which was previously built, and a moving platen with a plastic frame, four sets of 2-phase coils, and two precision mirrors. For position measurements, there are three laser interferometers for in-plane position measurements, three laser displacement sensors for out-of-plane position sensing, and two 2-channel Hall-effect sensors for the position feedback to initialize the position and expand the travel ranges of the platen in the XY plane. The positioning resolutions of 10 nm in the xy plane and in the vertical axis are demonstrated. In out-of-plane rotation about the two horizontal axes, experimental results show the unprecedented positioning resolution of 0.1 μrad. The maximum travel range in X and Y with nanoscale positioning resolution is 56 mm × 35 mm, limited by the lengths of the precision mirrors attached to the platen. With the trapezoidal-velocity input shaping, achieved performance specifications include the maximum acceleration and velocity of 0.6 m/s2 and 0.06 m/s, respectively, in translations in the horizontal plane. With the platen supported by the air bearings, the maximum acceleration and speed are 1.5 m/s2 and 0.15 m/s, respectively. A load test is performed with the platen carrying a load of 0.54 kg, which is 72% of its total mass, magnetically levitated in 6- axis closed-loop control. Experimental results show the reduced coupled dynamics between different axes in magnetic levitation. This framework of 2-phase Lorentz coils and linear Halbach arrays is highly applicable in precision-positioning linear motors and multi-axis stages, steppers, scanners, nano-scale manipulation and alignment systems, and vibration isolators. Advisors/Committee Members: jong%22%29&pagesize-30">Kim, Won-jong (advisor), Langari, Reza (committee member), Palazzolo, Alan (committee member), Toliyat, Hamid (committee member).

Subjects/Keywords: Magnetic Levitation; Nanopositioning; Halbach Array; Positioning Stage; Mechatronics; Motion Control

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APA (6^th Edition):

Nguyen, V. H. (2015). Universal Framework for Linear Motors and Multi-Axis Stages with Magnetic Levitation. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/156534

Chicago Manual of Style (16^th Edition):

Nguyen, Vu Huy. “Universal Framework for Linear Motors and Multi-Axis Stages with Magnetic Levitation.” 2015. Doctoral Dissertation, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/156534.

MLA Handbook (7^th Edition):

Nguyen, Vu Huy. “Universal Framework for Linear Motors and Multi-Axis Stages with Magnetic Levitation.” 2015. Web. 18 Jan 2021.

Vancouver:

Nguyen VH. Universal Framework for Linear Motors and Multi-Axis Stages with Magnetic Levitation. [Internet] [Doctoral dissertation]. Texas A&M University; 2015. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/156534.

Council of Science Editors:

Nguyen VH. Universal Framework for Linear Motors and Multi-Axis Stages with Magnetic Levitation. [Doctoral Dissertation]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/156534

Texas A&M University

10. Tangirala, Ravindra Krishna. Fault Analysis of Electromechanical Systems using Information Entropy Concepts.

Degree: MS, Mechanical Engineering, 2011, Texas A&M University

URL: http://hdl.handle.net/1969.1/157903

► Fault analysis of mechanical and electromechanical systems has been a subject of considerable interest in the systems and control research community. Entropy, under its various… (more)

▼ Fault analysis of mechanical and electromechanical systems has been a subject of considerable interest in the systems and control research community. Entropy, under its various formulations is an important variable, which is unrivaled when it comes to measuring order (or organization) and/or disorder (or disorganization). Researchers have successfully used entropy based concepts to solve various challenging problems in engineering, mathematics, meteorology, biotechnology, medicine, statistics etc. This research tries to analyze faults in electromechanical systems using information entropy concepts. The objectives of this research are to develop a method to evaluate signal entropy of a dynamical system using only input/output measurements, and to use this entropy measure to analyze faults within a dynamical system. Given discrete-time signals corresponding to the three-phase voltages and currents of an electromechanical system being monitored, the problem is to analyze whether or not this system is healthy. The concepts of Shannon entropy and relative entropy come from the field of Information Theory. They measure the degree of uncertainty that exists in a system. The main idea behind this approach is that the system's dynamics may have regularities hidden in measurements that are not obvious to see. The Shannon entropy and relative entropy measures are calculated by using probability distribution functions (PDF) that are formed by sampling the time series currents and voltages of a system. The system's health is monitored by, first, sampling the currents and voltages at certain time intervals, then generating the corresponding PDFs and, finally, calculating the information entropy measures. If the system dynamics are unchanged, or in other words, the system continues to be healthy, then the relative entropy measures will be consistently low or constant. But, if the system dynamics change due to damage, then the corresponding relative entropy and Shannon entropy measures will be increasing compared to the entropy of the system with less damage. Advisors/Committee Members: Parlos, Alexander G (advisor), Jong%22%29&pagesize-30">Kim, Won-Jong (committee member), Datta, Aniruddha (committee member).

Subjects/Keywords: Relative Entropy; Shannon Entropy; Information Entropy; Fault Analysis

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APA (6^th Edition):

Tangirala, R. K. (2011). Fault Analysis of Electromechanical Systems using Information Entropy Concepts. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/157903

Chicago Manual of Style (16^th Edition):

Tangirala, Ravindra Krishna. “Fault Analysis of Electromechanical Systems using Information Entropy Concepts.” 2011. Masters Thesis, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/157903.

MLA Handbook (7^th Edition):

Tangirala, Ravindra Krishna. “Fault Analysis of Electromechanical Systems using Information Entropy Concepts.” 2011. Web. 18 Jan 2021.

Vancouver:

Tangirala RK. Fault Analysis of Electromechanical Systems using Information Entropy Concepts. [Internet] [Masters thesis]. Texas A&M University; 2011. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/157903.

Council of Science Editors:

Tangirala RK. Fault Analysis of Electromechanical Systems using Information Entropy Concepts. [Masters Thesis]. Texas A&M University; 2011. Available from: http://hdl.handle.net/1969.1/157903

Texas A&M University

11. Fu, Jianxi. A Non-intrusive Method for Mechanical Measurements in Constant Frequency Electric Motors.

Degree: PhD, Mechanical Engineering, 2018, Texas A&M University

URL: http://hdl.handle.net/1969.1/173683

► Electric motor-driven systems are basic components in most industrial processes. The four motor mechanical measurements of interest that dictate motor performance are shaft torque, shaft… (more)

▼ Electric motor-driven systems are basic components in most industrial processes. The four motor mechanical measurements of interest that dictate motor performance are shaft torque, shaft speed, mechanical power (motor load) and energy conversion efficiency. Torque and speed, along with the input electric power are needed to estimate load and efficiency. Mechanical performance monitoring is an ever-increasing trend, present in many industries. Such monitoring can identify equipment failures, predict system degradation, and monitor overload conditions. It also provides users with a deeper understanding of the operational demands of their machines, which is difficult to diagnose through standard vibration analysis. Nevertheless, it is extremely challenging to measure the in-situ motor shaft torque, and to a lesser extent shaft speed. A comprehensive literature survey indicates that many estimation methods exist for motor mechanical measurements. However, almost all of these methods require at least one of the following: (1) load tests involving measurements of shaft speed and torque at a stable temperature, (2) no-load tests, i.e. with motor mechanically decoupled from driven load, (3) deenergized stator resistance measurements, i.e. with motor electrically disconnected. These three conditions require a level of access to the motor under test not generally acceptable or possible in an industrial environment, i.e. these are the “intrusive” requirements of the mechanical measurement estimation methods. A non-intrusive approach to mechanical measurements is proposed, incorporating the equivalent circuit model of an operating induction motor. The estimation of the mechanical measurements is formulated as a non-linear, constrained optimization problem with the variables to be optimized being the parameters of the equivalent circuit model. The optimization problem iii is solved using the Covariance Matrix Adaptation Evolution Strategy (CMA-ES) method. The required inputs of the proposed method are the three-phase voltage and current phasors and the motor nameplate information. The resulting parameters of the equivalent circuit model and new voltage and current phasors are used to estimate the motor mechanical measurements. Five (5) manufacturer's catalog data sheets, two (2) small motors, 1 HP and 3 HP, and two (2) larger motors, 100 HP and 200 HP, are used to test the proposed approach against direct mechanical measurements of torque and speed. The experimental results demonstrate that the proposed method achieves speed estimates within ±5 RPM of the sensor readings, which is comparable to existing non-intrusive methods. For torque, load and efficiency, the proposed method achieves accuracy within ±2-3% for high (>25%) loads, and up to ±5% errors for low (<25%) loads. The presented shaft torque accuracy is an improvement over existing, nonintrusive techniques and in the case of load and efficiency estimation is an improvement over existing, non-intrusive and even some intrusive techniques. The novel contribution of this… Advisors/Committee Members: Parlos, Alexander (advisor), Jong%22%29&pagesize-30">Kim, Won-Jong (advisor), Rasmussen, Bryan (committee member), Silva-Martinez, Jose (committee member).

Subjects/Keywords: Mechanical measurements; Torque; Speed; Load; Efficiency; Non-intrusive approach; equivalent circuit; CMA-ES

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APA (6^th Edition):

Fu, J. (2018). A Non-intrusive Method for Mechanical Measurements in Constant Frequency Electric Motors. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/173683

Chicago Manual of Style (16^th Edition):

Fu, Jianxi. “A Non-intrusive Method for Mechanical Measurements in Constant Frequency Electric Motors.” 2018. Doctoral Dissertation, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/173683.

MLA Handbook (7^th Edition):

Fu, Jianxi. “A Non-intrusive Method for Mechanical Measurements in Constant Frequency Electric Motors.” 2018. Web. 18 Jan 2021.

Vancouver:

Fu J. A Non-intrusive Method for Mechanical Measurements in Constant Frequency Electric Motors. [Internet] [Doctoral dissertation]. Texas A&M University; 2018. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/173683.

Council of Science Editors:

Fu J. A Non-intrusive Method for Mechanical Measurements in Constant Frequency Electric Motors. [Doctoral Dissertation]. Texas A&M University; 2018. Available from: http://hdl.handle.net/1969.1/173683

Texas A&M University

12. Trevino, Alexis. Modular Micro-Wind Turbine for Providing Power to Train Sensing Systems.

Degree: MS, Mechanical Engineering, 2018, Texas A&M University

URL: http://hdl.handle.net/1969.1/173617

► The proposed work involves developing a wind turbine system that charges batteries to provide required power of sensing and communication systems, while railroad operates at… (more)

Subjects/Keywords: Modular Micro Wind Turbine; Micro-Wind Turbine; optimized wind turbine for powering train sensing systems; Wind Turbine Optimization

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APA (6^th Edition):

Trevino, A. (2018). Modular Micro-Wind Turbine for Providing Power to Train Sensing Systems. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/173617

Chicago Manual of Style (16^th Edition):

Trevino, Alexis. “Modular Micro-Wind Turbine for Providing Power to Train Sensing Systems.” 2018. Masters Thesis, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/173617.

MLA Handbook (7^th Edition):

Trevino, Alexis. “Modular Micro-Wind Turbine for Providing Power to Train Sensing Systems.” 2018. Web. 18 Jan 2021.

Vancouver:

Trevino A. Modular Micro-Wind Turbine for Providing Power to Train Sensing Systems. [Internet] [Masters thesis]. Texas A&M University; 2018. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/173617.

Council of Science Editors:

Trevino A. Modular Micro-Wind Turbine for Providing Power to Train Sensing Systems. [Masters Thesis]. Texas A&M University; 2018. Available from: http://hdl.handle.net/1969.1/173617

Texas A&M University

13. Tong, Xiaomeng. Nonlinear Prediction of Thermally Induced Rotor Instability (Morton Effect) and Experiment Verification.

Degree: PhD, Mechanical Engineering, 2018, Texas A&M University

URL: http://hdl.handle.net/1969.1/174639

► The Morton effect (ME) is a thermally induced rotor instability problem that most commonly appears in rotating shafts with large overhung masses and supported by… (more)

▼ The Morton effect (ME) is a thermally induced rotor instability problem that most commonly appears in rotating shafts with large overhung masses and supported by fluid film bearings. The time-varying thermal bow, due to the asymmetric journal temperature distribution, may cause intolerable synchronous vibrations that exhibit a hysteresis behavior with respect to rotor speed. First discovered by Morton in the 1970s, and theoretically analyzed by Keogh and Morton in the 1990s, the ME is still not fully understood by industry and academia experts. Traditional rotordynamic analysis generally fails to predict the potential existence of ME induced instability in the design stage or troubleshooting process, and the induced excessive rotor vibrations cannot be effectively suppressed through conventional balancing, due to the continuous fluctuation of vibration amplitude and phase angle. The early ME prediction methodologies adopt three assumptions which simplify the ME analysis and meanwhile reduce its accuracy in predicting the ME response. (1) The ME is assumed to be static and speed-dependent and thus its stability can be analyzed with the classic control theories in the frequency (speed) domain. Nevertheless, the ME is proven to be highly transient and process-oriented, and not only the operating speed but also the transient speed acceleration can cause instability. (2) The thermal bow effect is only considered at the rotor overhung side and is simplified with thermal imbalance, which neglects the ME induced thermal bending moment. (3) Early ME prediction only focuses on the single rotor-bearing side and neglects the coupled effect on rotordynamics and bearing behavior from the other side. The assumptions above are abandoned in the current dissertation and replaced with the high-fidelity transient finite element analysis (FEA). The FEA is based on the recent thermo-elasto-hydro-dynamic bearing analysis and featured with (1) the nonlinear transient prediction of ME in the time domain through numerical integration, (2) analyzing both rotor-bearing sides to simultaneously account for the overall thermal bow effect, and thus the coupled rotordynamics effect from both rotor-bearing sides can be considered, and (3) the bowed rotor method, which also considers the thermal bow at the rotor midspan besides the rotor ends. The thermal bending moment is also included in the rotordynamics model, making this method more accurate than the traditional thermal imbalance method. Moreover, the ME testing rig is designed to measure the temperature distribution with 20 sensors across the journal circumference and record the peak-peak temperature difference (?T) with respect to various operating conditions. Supply oil temperatures of 28℃, 41℃ and bearing eccentricity of 0, 32%Cb are tested with rotating speed up to 5500 rpm. The journal ?T is found to increase almost linearly with speed up to 5500 rpm, slightly increase with eccentricity from 0 to 32%Cb, and decrease by nearly 20% by raising the supply temperature from 28℃ to 41℃ due to… Advisors/Committee Members: Palazzolo, Alan (advisor), Jong%22%29&pagesize-30">Kim, Won-Jong (committee member), Suh, Steve (committee member), Falzarano, Jeffrey (committee member).

Subjects/Keywords: Thermally Induced Instability; Morton Effect; Tilting Pad Bearing; Finite Element Method.

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Tong, X. (2018). Nonlinear Prediction of Thermally Induced Rotor Instability (Morton Effect) and Experiment Verification. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/174639

Chicago Manual of Style (16^th Edition):

Tong, Xiaomeng. “Nonlinear Prediction of Thermally Induced Rotor Instability (Morton Effect) and Experiment Verification.” 2018. Doctoral Dissertation, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/174639.

MLA Handbook (7^th Edition):

Tong, Xiaomeng. “Nonlinear Prediction of Thermally Induced Rotor Instability (Morton Effect) and Experiment Verification.” 2018. Web. 18 Jan 2021.

Vancouver:

Tong X. Nonlinear Prediction of Thermally Induced Rotor Instability (Morton Effect) and Experiment Verification. [Internet] [Doctoral dissertation]. Texas A&M University; 2018. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/174639.

Council of Science Editors:

Tong X. Nonlinear Prediction of Thermally Induced Rotor Instability (Morton Effect) and Experiment Verification. [Doctoral Dissertation]. Texas A&M University; 2018. Available from: http://hdl.handle.net/1969.1/174639

Texas A&M University

14. McCabe, James Terence. Street-Sign and Lane-Marker Recognition for the Control of an Autonomous Ground Vehicle.

Degree: MS, Mechanical Engineering, 2018, Texas A&M University

URL: http://hdl.handle.net/1969.1/174014

► Autonomous vehicles and driver-assistance features have become increasingly more common over the past 5 years. With such an increase in autonomous-vehicle technology, algorithms that identify… (more)

▼ Autonomous vehicles and driver-assistance features have become increasingly more common over the past 5 years. With such an increase in autonomous-vehicle technology, algorithms that identify and respond to the dynamic road environment are essential. Many current navigation programs require that the travel environment be mapped numerous times before an autonomous vehicle can travel with no assistance. However, the vehicle must be able to also navigate in cases where the current path is unfamiliar. This thesis explores the use of computer-vision techniques such as color masking, Hough transformations, and bird’s-eye perspective transformations for the purpose of implementing a pure pursuit navigation algorithm on a previously unknown course. The goal of this navigation program is to navigate the vehicle as closely as possible to the middle of the lane while smoothly following the path trajectory. An additional goal of this project is to implement a histogram of oriented gradients (HOG) detector for the identification of street signs and adjust the speed of the vehicle accordingly. This detector should have a near 100% success rate, and perform the detection more quickly than previously implemented object detectors. The pure path-planning algorithm proved successful in maintaining the vehicle in the lane and proved very adapt at following the slopes of turns. In the three turns on the track, the maximum deviations from the center line were 9.14 cm (3.6 in), 2.3 cm (0.87 in), and 8 cm (3.15 in), which is very good considering the sharpness of the turns. In the straightaways, the vehicle did not perform as well, deviating 11.2 cm (4.4 in) and 15 cm (5.9 in) on the first and second straightaways, respectively. This deviation is mostly due to the vehicle shallowing the steering angle too quickly on the turn exit, leading to the vehicle not being centered in the lane heading down the straightaway. However, the vehicle was able to perform all navigation with low latency, achieving 30 frames per second (fps) compared to the 5 fps of previous lane tracking attempts. Additionally, the vehicle achieved the main objective of remaining within the lane boundaries throughout the entirety of the Autonomous vehicles and driver-assistance features have become increasingly more common over the past 5 years. With such an increase in autonomous-vehicle technology, algorithms that identify and respond to the dynamic road environment are essential. Many current navigation programs require that the travel environment be mapped numerous times before an autonomous vehicle can travel with no assistance. However, the vehicle must be able to also navigate in cases where the current path is unfamiliar. This thesis explores the use of computer-vision techniques such as color masking, Hough transformations, and bird’s-eye perspective transformations for the purpose of implementing a pure pursuit navigation algorithm on a previously unknown course. The goal of this navigation program is to navigate the vehicle as closely as possible to the middle of… Advisors/Committee Members: jong%22%29&pagesize-30">Kim, Won-jong (advisor), Huff, Gregory (committee member), Hur, Pilwon (committee member).

Subjects/Keywords: Autonomous vehicle; path planning

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

McCabe, J. T. (2018). Street-Sign and Lane-Marker Recognition for the Control of an Autonomous Ground Vehicle. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/174014

Chicago Manual of Style (16^th Edition):

McCabe, James Terence. “Street-Sign and Lane-Marker Recognition for the Control of an Autonomous Ground Vehicle.” 2018. Masters Thesis, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/174014.

MLA Handbook (7^th Edition):

McCabe, James Terence. “Street-Sign and Lane-Marker Recognition for the Control of an Autonomous Ground Vehicle.” 2018. Web. 18 Jan 2021.

Vancouver:

McCabe JT. Street-Sign and Lane-Marker Recognition for the Control of an Autonomous Ground Vehicle. [Internet] [Masters thesis]. Texas A&M University; 2018. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/174014.

Council of Science Editors:

McCabe JT. Street-Sign and Lane-Marker Recognition for the Control of an Autonomous Ground Vehicle. [Masters Thesis]. Texas A&M University; 2018. Available from: http://hdl.handle.net/1969.1/174014

Texas A&M University

15. Chang, Yi-Chu. Design and Implementation of an Ionic-Polymer-Metal-Composite Biomimetic Robot.

Degree: PhD, Mechanical Engineering, 2013, Texas A&M University

URL: http://hdl.handle.net/1969.1/149538

► Ionic polymer metal composite (IPMC) is used in various bio-inspired systems, such as fish and tadpole-like robots swimming in water. The deflection of this smart… (more)

▼ Ionic polymer metal composite (IPMC) is used in various bio-inspired systems, such as fish and tadpole-like robots swimming in water. The deflection of this smart material results from several internal and external factors, such as water distribution and surface conductivity. IPMC strips with a variety of water concentration on the surfaces and surface conductivity show various deflection patterns. Even without any external excitation, the strips can bend due to non-uniform water distribution. On the other hand, in order to understand the effects of surface conductivity in an aquatic environment, an IPMC strip with two wires connected to two distinct spots was used to demonstrate the power loss due to the surface resistance. Three types of input signals, sawtooth, sinusoidal, and square waves, were used to compare the difference between the input and output signals measured at the two spots. Thick (1-mm) IPMC strips were fabricated and employed in this research to sustain and drive the robot with sufficient forces. Furthermore, in order to predict and control the deflection, researchers developed the appropriate mathematical models. The special working principle, related to internal mobile cations with water molecules, however, makes the system complicated to be modeled and simulated. An IPMC strip can be modeled as a cantilever beam with loading distribution on the surface. Nevertheless, the loading distribution is non-uniform due to the non-perfect surface metallic plating, and four different kinds of imaginary loading distribution are employed in this model. On the other hand, a reverse-predicted method is used to find out the transfer function of the IPMC system according to the measured deflection and the corresponding input voltage. Several system-identification structures, such as autoregressive moving average with exogenous (ARX/ARMAX), output-error (OE), Box-Jenkins (BJ), and prediction-error minimization (PEM) models, are used to model the system with their specific mathematic principles. Finally, a novel linear time-variant (LTV) concept and method is introduced and applied to simulate an IPMC system. This kind of model is different from the previous linear time-invariant (LTI) models because the IPMC internal environment may be unsteady, such as free cations with water molecules. This phenomenon causes the variation of each internal part. In addition, the relationship between the thickness of IPMC strips and the deflection can be obtained by this concept. Finally, based on the experimental results above, an aquatic walking robot (102 mm × 80 mm × 43 mm, 39 g) with six 2-degree-of-freedom (2-DOF) legs has been designed and implemented. It walked in water at the speed of 0.5 mm/s. The average power consumption is 8 W per leg. Each leg has a thigh and a shank to generate 2-DOF motions. Each set of three legs walked together as a tripod to maintain the stability in operation. Advisors/Committee Members: jong%22%29&pagesize-30">Kim, Won-jong (advisor), Palazzolo, Alan (committee member), Rasmussen, Bryan (committee member), Choe, Yoonsuck (committee member).

Subjects/Keywords: IPMC; EAP; robot; smart materials; LTV modeling

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Chang, Y. (2013). Design and Implementation of an Ionic-Polymer-Metal-Composite Biomimetic Robot. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/149538

Chicago Manual of Style (16^th Edition):

Chang, Yi-Chu. “Design and Implementation of an Ionic-Polymer-Metal-Composite Biomimetic Robot.” 2013. Doctoral Dissertation, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/149538.

MLA Handbook (7^th Edition):

Chang, Yi-Chu. “Design and Implementation of an Ionic-Polymer-Metal-Composite Biomimetic Robot.” 2013. Web. 18 Jan 2021.

Vancouver:

Chang Y. Design and Implementation of an Ionic-Polymer-Metal-Composite Biomimetic Robot. [Internet] [Doctoral dissertation]. Texas A&M University; 2013. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/149538.

Council of Science Editors:

Chang Y. Design and Implementation of an Ionic-Polymer-Metal-Composite Biomimetic Robot. [Doctoral Dissertation]. Texas A&M University; 2013. Available from: http://hdl.handle.net/1969.1/149538

Texas A&M University

16. Algethami, Abdullah Ayedh B. Regenerative Suspension System Modeling and Control.

Degree: PhD, Mechanical Engineering, 2017, Texas A&M University

URL: http://hdl.handle.net/1969.1/173094

► Many energy indicators show an increase in the world’s energy deficit. Demand for portable energy sources is growing and has increased the market for energy… (more)

▼ Many energy indicators show an increase in the world’s energy deficit. Demand for portable energy sources is growing and has increased the market for energy harvesters and regenerative systems. This work investigated the implementation of a regenerative suspension in a two-degree-of freedom (2-DOF) quarter-car suspension system. First, an active controller was designed and implemented. It showed 69% improvement in rider comfort and consumed 8 – 9 W of power to run the linear motor used in the experiment. A regenerative suspension system was then designed to save the energy normally spent in active suspensions, approximately several kilowatts in an actual car. Regenerative suspension is preferable because it can regenerate energy. Experimental investigations were then conducted to find generator constants and damping coefficients. Additionally, generator damping effects and power regeneration in the quarter-car test bed were also investigated. The experiments showed that a linear regenerative damper can suppress up to 22% of vibrations and harvest 2% of the disturbance power. Since both harvesting and damping capabilities were noticeable in this test bed, it was used to implement regenerative suspension, and a regenerative controller was developed to provide riders with additional comfort. To implement this regenerative controller, an electronic interface was designed to facilitate controlling the regenerative force and storing energy after the rectification process. The electronic interface used was a symmetrical-bridgeless boost converter (SBBC) due to its few components and even fewer control efforts. The converter was then modeled in a manner that made the current and voltage in phase for the maximum power factor. The converter control allowed the motor’s external load to be presented as of variable resistance with the unity power factor. The generator was then considered a voltage source for energy regeneration purposes. The controller was designed to control regenerative force at a frequency of 20 kHz. This frequency was sufficient to enable another controller to manipulate the desired regenerative damping force, which was chosen to be 1 kHz. The input to this controller was the generator voltage used to determine the polarity of pulse-width modulation (PWM). Therefore, a combination of converter and controller was able to take the place of an active controller. A different controller was then designed to manipulate the desired damping force. This regenerative controller was designed in a manner similar to that of a semi-active controller. It improved vibration suppression and enhanced harvesting capabilities. The regenerative suspension showed better results than a passive suspension. The improvements are minimal at this time, but there is the potential for greater improvement with a more efficient controller. The harvested energy was so small in this experiment because the damper was inefficient. In practice, the damper’s efficiency should be improved. A regenerative damper will be more economical than a… Advisors/Committee Members: jong%22%29&pagesize-30">Kim, Won-jong (advisor), Ehsani, Mehrdad (committee member), Palazzolo, Alan (committee member), Suh, Steve (committee member).

Subjects/Keywords: regenerative suspension; regenerative controller; active suspension; regenerative interface

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Algethami, A. A. B. (2017). Regenerative Suspension System Modeling and Control. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/173094

Chicago Manual of Style (16^th Edition):

Algethami, Abdullah Ayedh B. “Regenerative Suspension System Modeling and Control.” 2017. Doctoral Dissertation, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/173094.

MLA Handbook (7^th Edition):

Algethami, Abdullah Ayedh B. “Regenerative Suspension System Modeling and Control.” 2017. Web. 18 Jan 2021.

Vancouver:

Algethami AAB. Regenerative Suspension System Modeling and Control. [Internet] [Doctoral dissertation]. Texas A&M University; 2017. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/173094.

Council of Science Editors:

Algethami AAB. Regenerative Suspension System Modeling and Control. [Doctoral Dissertation]. Texas A&M University; 2017. Available from: http://hdl.handle.net/1969.1/173094

Texas A&M University

17. Rana, Dibyendu. Analysis & Design of Active Inductor.

Degree: MS, Electrical Engineering, 2014, Texas A&M University

URL: http://hdl.handle.net/1969.1/152536

► Power conditioning topologies such as adjustable speed drives (ASDs) have a growing demand in industry for improving efficiency and reducing energy costs. Apart from efficiency… (more)

▼ Power conditioning topologies such as adjustable speed drives (ASDs) have a growing demand in industry for improving efficiency and reducing energy costs. Apart from efficiency improvement, the power density of these converters has increased considerably and a smaller form factor is preferred by modern industrial plants. Power converters produce unwanted harmonics which deteriorate the grid current quality. To mitigate the adverse effects of such harmonics, filtering techniques such as active/passive filters and harmonic traps are employed. Passive inductors play an important role in these filtering topologies. However, in higher power/utility scale power conversion systems, due to lower switching frequency, the size and weight of passive inductor is large and they occupy considerable space. In industries such as offshore oil drilling and maritime transportation, size and weight requirements are strict and such bulky solutions are not desirable. For such applications, an effective way to make passive components compact is to emulate using active devices. In this thesis, design of an Active Inductor for high power applications using an H-bridge topology is proposed. The performance of common filtering topologies such as LC and LCL with Active Inductor replacing a passive inductor is analyzed. The proposed topology emulates an inductance value which is linear for a wide range of operation, devoid of saturation issues and is compact in size and weight. Weight and volume analysis is done for an active topology and compared with equivalent passive inductors. It is shown that the emulated inductor is about 8 times lighter than a passive inductor of similar rating. Also, loss analysis proves that the topology has a high Q factor. A Zero Voltage Switching (ZVS) switching method is proposed to reduce switching losses further. In addition, the dynamic behavior of the Active Inductor improves system performance during faults and disturbances. The value of inductance can be tuned to suit the requirements of the overall power conditioning circuit. The Active Inductor is shown to limit the current and voltage overshoots occurring due to faults. Simulation and experimental results from a laboratory prototype confirm the validity and utility of the proposed topology. Advisors/Committee Members: Enjeti, Prasad (advisor), Balog, Robert (committee member), Bhattacharyya, Shankar (committee member), Jong%22%29&pagesize-30">Kim, Won-Jong (committee member).

Subjects/Keywords: power density; emulation

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APA (6^th Edition):

Rana, D. (2014). Analysis & Design of Active Inductor. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/152536

Chicago Manual of Style (16^th Edition):

Rana, Dibyendu. “Analysis & Design of Active Inductor.” 2014. Masters Thesis, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/152536.

MLA Handbook (7^th Edition):

Rana, Dibyendu. “Analysis & Design of Active Inductor.” 2014. Web. 18 Jan 2021.

Vancouver:

Rana D. Analysis & Design of Active Inductor. [Internet] [Masters thesis]. Texas A&M University; 2014. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/152536.

Council of Science Editors:

Rana D. Analysis & Design of Active Inductor. [Masters Thesis]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/152536

Texas A&M University

18. Albader, Mesaad. Advance Three Phase Power Factor Correction Schemes for Utility Interface of Power Electronic Systems.

Degree: MS, Electrical Engineering, 2014, Texas A&M University

URL: http://hdl.handle.net/1969.1/153331

► Modern power electronic systems operate with different voltage and/or frequency rating such as Adjustable speed drive, Micro Grid, Uninterruptable Power Supplies (UPS) and High Voltage… (more)

▼ Modern power electronic systems operate with different voltage and/or frequency rating such as Adjustable speed drive, Micro Grid, Uninterruptable Power Supplies (UPS) and High Voltage DC Transmission Systems. To match power electronic systems with the mains supply, DC link converters are used. The first stage of the DC link converter is the AC/DC conversion (rectifier). The rectifier type utility interface has substantial harmonics result in poor power quality due to low power factor and high harmonic distortion. Power Factor Correction (PFC) schemes are effective methods to mitigate harmonics and address this issue. In this thesis, analyses of three approaches for high power density rectifiers are developed. In the first study, modular three phase boost rectifiers operating in DCM are coupled in order to increase the power density. Major drawback of this rectifier is the high currents ripple in both the source and the DC link sides which require large EMI filter size -could be larger than the rectifier component size- and large DC filter capacitor size. This thesis proposes coupling modular three phase boost DCM rectifiers, the currents in both source and DC link sides are interleaved and consequently the currents ripple dramatically decreased results in small component size of the EMI filter and the DC filter capacitor leading to high power density rectification. Also, optimization of the number of the rectifier modules to achieve maximum power density is presented. Moreover, the switching function of each rectifier employs harmonic injection technique to reduce the low order harmonics. And, the DC output voltage is varied with the load power such that the operation is at the boundary between CCM and DCM to achieve maximum power density tracking. In the Second study, a resonant three phase single switch PFC is presented to overcome the high 5th and 7th order current harmonics drawback in the conventional single switch three phase PFC circuits. The input current has low THD for each individual low order harmonics with high current ripple at the switching frequency. Interleaving the input current by coupling modular rectifiers is also presented to reduce the input current ripple. System equations and modes of operation is analyzed and derived to design the circuit parameters, switching frequency and duty ratio for the desired output voltage and load power. In the Third study, an advancement of existing modular T-connected single phase PFCs by means of replacing the low frequency transformer with medium frequency electronic phase shifter to reduce the size and weight of the system. The approach has higher power density compared with the Y, delta and T-connected single phase PFC modules. The study examines the 3 to 2 phase conversion, system harmonics, switching technique for the AC chopper and the power flow of the system. Advisors/Committee Members: Enjeti, Prasad (advisor), Toliyat, Hamid (advisor), Bhattacharyya, Shankar (committee member), Jong%22%29&pagesize-30">Kim, Won-Jong (committee member).

Subjects/Keywords: Three Phase; PFC; Power Factor Correction; Rectifier; AC/DC Conversion; Utility Interface; Power Electronics; Harmonic Suppression

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APA (6^th Edition):

Albader, M. (2014). Advance Three Phase Power Factor Correction Schemes for Utility Interface of Power Electronic Systems. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/153331

Chicago Manual of Style (16^th Edition):

Albader, Mesaad. “Advance Three Phase Power Factor Correction Schemes for Utility Interface of Power Electronic Systems.” 2014. Masters Thesis, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/153331.

MLA Handbook (7^th Edition):

Albader, Mesaad. “Advance Three Phase Power Factor Correction Schemes for Utility Interface of Power Electronic Systems.” 2014. Web. 18 Jan 2021.

Vancouver:

Albader M. Advance Three Phase Power Factor Correction Schemes for Utility Interface of Power Electronic Systems. [Internet] [Masters thesis]. Texas A&M University; 2014. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/153331.

Council of Science Editors:

Albader M. Advance Three Phase Power Factor Correction Schemes for Utility Interface of Power Electronic Systems. [Masters Thesis]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/153331

Texas A&M University

19. Cheng, Yu-Che. A Hybrid Brain-computer Interface for Intelligent Prosthetics.

Degree: MS, Mechanical Engineering, 2014, Texas A&M University

URL: http://hdl.handle.net/1969.1/153806

► Over the past few decades, many researcher have shown that human can use brain signals to communicate with computers or machines by using brain-computer interfaces… (more)

▼ Over the past few decades, many researcher have shown that human can use brain signals to communicate with computers or machines by using brain-computer interfaces (BCIs). BCI systems can measure the brain activity and translate them into control signals to external devices. A hybrid BCI system is to integrate two or more different BCI systems. By combining two different BCIs, the disadvantages can be eliminated and the advantages can stay. One of the BCI developed in this thesis is electroencephalographic (EEG). EEG is one of imaging techniques for spontaneous recording of the electrical activity from the brain. The EEG has been widely used in research for cognitive and brain-state studies in psychology, neuroprosthetics, transportation safety and clinical diagnosis . In this thesis a commercial EEG product, NeuroSky MindWave, is used to measure the EEG signal from forehead. From the acquired EEG signal, humans attention and meditation level can be obtain. A EEG control algorithm is developed in LabVIEW based on the attention level, meditation level and eye blinks to control an intelligent prosthetic. The other BCI used is eye-gaze tracking technology. Eye-gaze tracking technology is used to obtain the human's gaze direction. A eye-gaze tracking system is developed in this research. The system consists of a wearable self-build eye-gaze tracker with a scene camera, and the eye-gaze tracking algorithm developed in LabVIEW which can locate the eye pupil center and estimate the gaze direction. Combing two BCIs above, a hybrid BCI system is complete. Suppose a person want to use a prosthetic arm to grab one specific item, the eye-gaze tracker provides the information of which item is the person want exactly, and EEG BCI controls the prosthetic arm to grasp the item. The hybrid BCI system is robust enough and have a reliable accuracy from the experimental result. Advisors/Committee Members: Langari, Reza (advisor), Jong%22%29&pagesize-30">Kim, Won-Jong (committee member), Song, Dezhen (committee member).

Subjects/Keywords: Eye tracking; EEG; Brain-computer interface

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APA (6^th Edition):

Cheng, Y. (2014). A Hybrid Brain-computer Interface for Intelligent Prosthetics. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/153806

Chicago Manual of Style (16^th Edition):

Cheng, Yu-Che. “A Hybrid Brain-computer Interface for Intelligent Prosthetics.” 2014. Masters Thesis, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/153806.

MLA Handbook (7^th Edition):

Cheng, Yu-Che. “A Hybrid Brain-computer Interface for Intelligent Prosthetics.” 2014. Web. 18 Jan 2021.

Vancouver:

Cheng Y. A Hybrid Brain-computer Interface for Intelligent Prosthetics. [Internet] [Masters thesis]. Texas A&M University; 2014. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/153806.

Council of Science Editors:

Cheng Y. A Hybrid Brain-computer Interface for Intelligent Prosthetics. [Masters Thesis]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/153806

Texas A&M University

20. Guerrero, Roberto. Low-cost Rigid-frame Exoskeleton Glove with Finger-joint Flexion Tracking Mapped onto a Robotic Hand.

Degree: MS, Mechanical Engineering, 2015, Texas A&M University

URL: http://hdl.handle.net/1969.1/155298

► This thesis provides a representation of a low-cost rigid-frame exoskeleton glove that is used to track finger-joint flexion mapped onto a robotic hand to mimic… (more)

▼ This thesis provides a representation of a low-cost rigid-frame exoskeleton glove that is used to track finger-joint flexion mapped onto a robotic hand to mimic user movements. The overall setup consists of an exoskeleton glove (exo-glove), sensors, a microcontroller, and a telerobotic hand. The design of the exo-glove is crafted to fit onto a left hand. SolidWorks was used for the prototype designs which were then sent to the Stratasys 400 rapid prototyping machine to be 3D printed in ABS-M30 plastic. The exo-glove houses five rotary position sensors and three flexible sensors to track angle changes of the finger joints from two fingers and a thumb. Five low-pass filters are implemented as signal filtering for the rotary position sensors. An Arduino Mega microcontroller is connected to the sensors of the exo-glove and processes the input values. Using an open-loop controller to control the robotic hand, the values processed by the microcontroller from the exo-glove are sent to the servo motors on the robotic hand to operate the corresponding fingers of the user. Throughout the initial calibration and testing phase, each sensor was tested individually to ensure the sensor functionally performs well. Signal analysis was conducted on the sensors at steady state and while in operation to show fluctuations in sensor readings and response to finger flexion. Experimental results show that averaging sensor data in the processing code yields smoother values and better precision. Due to the use of low-pass filtering with the rotary position sensors, the data sets collected were grouped together tightly compared to the flex sensors without filtering. However, the actual angles measured were not accurately portrayed in sensor readings. The true flexion angles were compared in the data samplings to find a variety of ranges spanning around the angles desired to track. Many of the actual flexion angles were offset from the sensor readings by a variation of degrees, but the data shows the sensor readings were able to follow the general magnitude of the true flexion angles. The precision seen in the data was also apparent in the robotic hand mirroring the posture. Changes in sensor readings caused jerking movements to occur in the robotic fingers but were able to maintain an overall flexion mirroring of the RF exo-glove. There is quarter-second delay between the exo-glove sensor reading and the robotic hand mirroring capability when not implementing averaging. When averaging the sensor values, there was a delay of more than half a second between the exo-glove posture and robotic hand mirroring. Advisors/Committee Members: jong%22%29&pagesize-30">Kim, Won-jong (advisor), Ehsani, Mehrdad (committee member), McAdams, Daniel (committee member).

Subjects/Keywords: exo-glove; exoskeleton glove; flex sensors; rotary position sensors; rigid frame glove; finger flexion tracking; hand tracking; hand rehabilitation; finger rehabilitation

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APA (6^th Edition):

Guerrero, R. (2015). Low-cost Rigid-frame Exoskeleton Glove with Finger-joint Flexion Tracking Mapped onto a Robotic Hand. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/155298

Chicago Manual of Style (16^th Edition):

Guerrero, Roberto. “Low-cost Rigid-frame Exoskeleton Glove with Finger-joint Flexion Tracking Mapped onto a Robotic Hand.” 2015. Masters Thesis, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/155298.

MLA Handbook (7^th Edition):

Guerrero, Roberto. “Low-cost Rigid-frame Exoskeleton Glove with Finger-joint Flexion Tracking Mapped onto a Robotic Hand.” 2015. Web. 18 Jan 2021.

Vancouver:

Guerrero R. Low-cost Rigid-frame Exoskeleton Glove with Finger-joint Flexion Tracking Mapped onto a Robotic Hand. [Internet] [Masters thesis]. Texas A&M University; 2015. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/155298.

Council of Science Editors:

Guerrero R. Low-cost Rigid-frame Exoskeleton Glove with Finger-joint Flexion Tracking Mapped onto a Robotic Hand. [Masters Thesis]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/155298

Texas A&M University

21. Chiu, Cheng-Wei 1979-. Interfacial Interactions between Implant Electrode and Biological Environment.

Degree: Doctor of Engineering, Mechanical Engineering, 2012, Texas A&M University

URL: http://hdl.handle.net/1969.1/148123

► Electrodes implanted into neural systems are known to degrade due to encapsulation by surrounding tissues. The mechanisms of electrode-tissue interactions and prediction of the behavior… (more)

▼ Electrodes implanted into neural systems are known to degrade due to encapsulation by surrounding tissues. The mechanisms of electrode-tissue interactions and prediction of the behavior of electrode are yet to be achieved. This research will aim at establishing the fundamental knowledge of interfacial interactions between the host biological environment and an implanted electrode. We will identify the dynamic mechanisms of such interfacial interactions. Quantitative analysis of the electrical properties of interface will be conducted using Electrochemical Impedance Spectroscopy (EIS). Results will be used to develop a general model to interpret electrical circuitry of the interface. This is expected to expand our understanding in the effects of interfacial interactions to the charge transport. The interfacial interactions of an implanted electrode with neural system will be studied in two types of electrodes: silver and graphene coated. The interfacial impedance of both samples will be studied using EIS. The development of the cellular interaction will be investigated using histological procedure. X-ray photoemission spectroscopy (XPS) will be employed to study the chemical effects on the silver electrodes. Atomic force microscopy and Raman spectroscopy will be used for material characterization of graphene-coated electrodes. In the study of silver electrode, two mechanisms affecting the interfacial impedance are proposed. First is the formation of silver oxide. The other is the immuno-response of tissue encapsulation. Histological results suggest that higher cell density cause higher impedance magnitude at the interface. It is also found that the cellular encapsulation dominates the increase in impedance for longer implanted time. In the study of graphene-coated electrode, it is found that the graphene can strongly prevent the metal substrate from being oxidized. It not only provides good electrical conductivity for signal transport, but also reduces the speed of the accumulation of tissue around the electrode. Such characteristics of graphene have great potential in the application of neural implant. Finally, the dynamic mechanisms of biological interaction are proposed. A model is also developed to represent the general circuitry of the interface between an implanted electrode and the neural system. The model has three major components, which are interfacial double layer, cellular encapsulation, and the substrate. The model presented in this study can compensate for selection and prediction of materials and their behaviors. Advisors/Committee Members: Liang, Hong (advisor), Harlow, Mark (committee member), Ames, Aaron (committee member), jong%22%29&pagesize-30">Kim, Won-jong (committee member).

Subjects/Keywords: Interfacial interaction; Neural Implant

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APA (6^th Edition):

Chiu, C. 1. (2012). Interfacial Interactions between Implant Electrode and Biological Environment. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/148123

Chicago Manual of Style (16^th Edition):

Chiu, Cheng-Wei 1979-. “Interfacial Interactions between Implant Electrode and Biological Environment.” 2012. Doctoral Dissertation, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/148123.

MLA Handbook (7^th Edition):

Chiu, Cheng-Wei 1979-. “Interfacial Interactions between Implant Electrode and Biological Environment.” 2012. Web. 18 Jan 2021.

Vancouver:

Chiu C1. Interfacial Interactions between Implant Electrode and Biological Environment. [Internet] [Doctoral dissertation]. Texas A&M University; 2012. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/148123.

Council of Science Editors:

Chiu C1. Interfacial Interactions between Implant Electrode and Biological Environment. [Doctoral Dissertation]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/148123

Texas A&M University

22. Lai, Lin. A Development of Design and Control Methodology for Next Generation Parallel Hybrid Electric Vehicle.

Degree: PhD, Electrical Engineering, 2013, Texas A&M University

URL: http://hdl.handle.net/1969.1/149289

► Commercially available Hybrid Electric Vehicles (HEVs) have been around for more than ten years. However, their market share remains small. Focusing only on the improvement… (more)

▼ Commercially available Hybrid Electric Vehicles (HEVs) have been around for more than ten years. However, their market share remains small. Focusing only on the improvement of fuel economy, the design tends to reduce the size of the internal combustion engine in the HEV, and uses the electrical drive to compensate for the power gap between the load demand and the engine capacity. Unfortunately, the low power density and the high cost of the combined electric motor drive and battery packs dictate that the HEV has either worse performance or much higher price than the conventional vehicle. In this research, a new design philosophy for parallel HEV is proposed, which uses a full size engine to guarantee the vehicle performance at least as good as the conventional vehicle, and hybridizes with an electrical drive in parallel to improve the fuel economy and performance beyond the conventional cars. By analyzing the HEV fuel economy versus the increasing of the electrical drive power on typical driving conditions, the optimal hybridization electric power capacity is determined. Thus, the full size engine HEV shows significant improvement in fuel economy and performance, with relatively short cost recovery period. A new control strategy, which optimizes the fuel economy of parallel configured charge sustained hybrid electric vehicles, is proposed in the second part of this dissertation. This new approach is a constrained engine on-off strategy, which has been developed from the two extreme control strategies of maximum SOC and engine on-off, by taking their advantages and overcoming their disadvantages. A system optimization program using dynamic programming algorithm has been developed to calibrate the control parameters used in the developed control strategy, so that the control performance can be as close to the optimal solution as possible. In order to determine the sensitivity of the new control strategy to different driving conditions, a passenger car is simulated on different driving cycles. The performances of the vehicle with the new control strategy are compared with the optimal solution obtained on each driving condition with the dynamic programming optimization. The simulation result shows that the new control strategy always keeps its performance close to the optimal one, as the driving condition changes. Advisors/Committee Members: Ehsani, Mehrdad (advisor), Singh, Chanan (committee member), Bhattacharyya, Shankar (committee member), jong%22%29&pagesize-30">Kim, Won-jong (committee member).

Subjects/Keywords: Control strategy; Dynamic programming; Hybrid electric vehicle

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Lai, L. (2013). A Development of Design and Control Methodology for Next Generation Parallel Hybrid Electric Vehicle. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/149289

Chicago Manual of Style (16^th Edition):

Lai, Lin. “A Development of Design and Control Methodology for Next Generation Parallel Hybrid Electric Vehicle.” 2013. Doctoral Dissertation, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/149289.

MLA Handbook (7^th Edition):

Lai, Lin. “A Development of Design and Control Methodology for Next Generation Parallel Hybrid Electric Vehicle.” 2013. Web. 18 Jan 2021.

Vancouver:

Lai L. A Development of Design and Control Methodology for Next Generation Parallel Hybrid Electric Vehicle. [Internet] [Doctoral dissertation]. Texas A&M University; 2013. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/149289.

Council of Science Editors:

Lai L. A Development of Design and Control Methodology for Next Generation Parallel Hybrid Electric Vehicle. [Doctoral Dissertation]. Texas A&M University; 2013. Available from: http://hdl.handle.net/1969.1/149289

Texas A&M University

23. Saeed, Ahmed. Vibration Suppression and Flywheel Energy Storage in a Drillstring Bottom-Hole-Assembly.

Degree: PhD, Mechanical Engineering, 2012, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-11035

► In this study, a novel concept for a downhole flywheel energy storage module to be embedded in a bottom-hole-assembly (BHA) is presented and modeled, as… (more)

▼ In this study, a novel concept for a downhole flywheel energy storage module to be embedded in a bottom-hole-assembly (BHA) is presented and modeled, as an alternative power source to existing lithium-ion battery packs currently deployed in measurement-while-drilling (MWD) or logging-while-drilling (LWD) operations. Lithium-ion batteries disadvantages include deteriorated performance in high temperature, limited lifetime that necessitates frequent replacement which elevates operational costs, and environmental disposal. Extreme and harsh downhole conditions necessitate that the flywheel module withstands temperatures and pressures exceeding 300 ?F and 20 kpsi, respectively, as well as violent vibrations encountered during drilling. Moreover, the flywheel module should adhere to the geometric constraints of the wellbore and its corresponding BHA. Hence, a flywheel sizing procedure was developed that takes into consideration the required energy to be stored, the surrounding environmental conditions, and the geometric constraints. A five-axis magnetic levitation control system was implemented and tuned to maintain continuous suspension of the flywheel under the harsh lateral, axial and torsional drilling vibrations of the BHA. Thus, an integrated finite element model was developed that included the rotordynamic behavior of the flywheel and the BHA, the component dynamics of the magnetic levitation control system, and the cutting dynamics of the drillbit for both PDC and tricone types. The model also included a newly developed coupling between lateral, axial and torsional vibrations. It was demonstrated through simulations conducted by numerical integration that the flywheel maintains levitation due to all different types of external vibration as well as its own lateral vibration due to mass unbalance. Moreover, a passive proof-mass-damper (PPMD) was developed that suppresses axial bit-bounce vibrations as well as torsional vibrations, and was extended to also mitigate lateral vibrations. Optimized values of the mass, stiffness and damping values of the PPMD were obtained by the hybrid analytical-numerical Chebyshev spectral method that was superior in computational efficiency to iterative numerical integration. This also enabled the fine-plotting of an operating stability chart indicating stability regions where bit-bounce and stick-slip are avoided. The proof-mass-damping concept was extended to the flywheel to be an active proof-mass-damper (APMD) where simulations indicated functionality for a light-weight BHA. Advisors/Committee Members: Palazzolo, Alan B. (advisor), Ahmed, Shehab (advisor), jong%22%29&pagesize-30">Kim, Won-jong (committee member), McAdams, Daniel (committee member).

Subjects/Keywords: Downhole Flywheel; Bottom-Hole-Assembly (BHA); Drillstring Vibrations; Drillbit Cutting Dynamics; Active Magnetic Bearing (AMB)

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APA (6^th Edition):

Saeed, A. (2012). Vibration Suppression and Flywheel Energy Storage in a Drillstring Bottom-Hole-Assembly. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-11035

Chicago Manual of Style (16^th Edition):

Saeed, Ahmed. “Vibration Suppression and Flywheel Energy Storage in a Drillstring Bottom-Hole-Assembly.” 2012. Doctoral Dissertation, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-11035.

MLA Handbook (7^th Edition):

Saeed, Ahmed. “Vibration Suppression and Flywheel Energy Storage in a Drillstring Bottom-Hole-Assembly.” 2012. Web. 18 Jan 2021.

Vancouver:

Saeed A. Vibration Suppression and Flywheel Energy Storage in a Drillstring Bottom-Hole-Assembly. [Internet] [Doctoral dissertation]. Texas A&M University; 2012. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-11035.

Council of Science Editors:

Saeed A. Vibration Suppression and Flywheel Energy Storage in a Drillstring Bottom-Hole-Assembly. [Doctoral Dissertation]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-11035

Texas A&M University

24. Pattanshetti, Shivanand. Multi Degree of Freedom Hinge Joints Embedded on Tubes for Miniature Steerable Medical Devices.

Degree: MS, Mechanical Engineering, 2017, Texas A&M University

URL: http://hdl.handle.net/1969.1/165974

► With the proliferation of successful minimally invasive surgical techniques, comes the challenge of shrinking the size of surgical instruments further to facilitate use in applications… (more)

Subjects/Keywords: Robotics; Medical

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APA (6^th Edition):

Pattanshetti, S. (2017). Multi Degree of Freedom Hinge Joints Embedded on Tubes for Miniature Steerable Medical Devices. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/165974

Chicago Manual of Style (16^th Edition):

Pattanshetti, Shivanand. “Multi Degree of Freedom Hinge Joints Embedded on Tubes for Miniature Steerable Medical Devices.” 2017. Masters Thesis, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/165974.

MLA Handbook (7^th Edition):

Pattanshetti, Shivanand. “Multi Degree of Freedom Hinge Joints Embedded on Tubes for Miniature Steerable Medical Devices.” 2017. Web. 18 Jan 2021.

Vancouver:

Pattanshetti S. Multi Degree of Freedom Hinge Joints Embedded on Tubes for Miniature Steerable Medical Devices. [Internet] [Masters thesis]. Texas A&M University; 2017. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/165974.

Council of Science Editors:

Pattanshetti S. Multi Degree of Freedom Hinge Joints Embedded on Tubes for Miniature Steerable Medical Devices. [Masters Thesis]. Texas A&M University; 2017. Available from: http://hdl.handle.net/1969.1/165974

Texas A&M University

25. Wang, Yunyi. Mechanical Design, Control and Evaluation of A Portable Rehabilitation Device for Upper Arm.

Degree: MS, Mechanical Engineering, 2015, Texas A&M University

URL: http://hdl.handle.net/1969.1/187000

► There is a need for functional and effective rehabilitation devices for humans with upper arm injuries. Existing devices are either too heavy, not portable, or… (more)

Subjects/Keywords: Rehabilitation Robot; Upper Arm; Parallel structure; Portable

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APA (6^th Edition):

Wang, Y. (2015). Mechanical Design, Control and Evaluation of A Portable Rehabilitation Device for Upper Arm. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/187000

Chicago Manual of Style (16^th Edition):

Wang, Yunyi. “Mechanical Design, Control and Evaluation of A Portable Rehabilitation Device for Upper Arm.” 2015. Masters Thesis, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/187000.

MLA Handbook (7^th Edition):

Wang, Yunyi. “Mechanical Design, Control and Evaluation of A Portable Rehabilitation Device for Upper Arm.” 2015. Web. 18 Jan 2021.

Vancouver:

Wang Y. Mechanical Design, Control and Evaluation of A Portable Rehabilitation Device for Upper Arm. [Internet] [Masters thesis]. Texas A&M University; 2015. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/187000.

Council of Science Editors:

Wang Y. Mechanical Design, Control and Evaluation of A Portable Rehabilitation Device for Upper Arm. [Masters Thesis]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/187000

Texas A&M University

26. Anil Kumar, Namita. Design of a Portable and Compact Gyroscopic Device for Hand Rehabilitation.

Degree: MS, Mechanical Engineering, 2017, Texas A&M University

URL: http://hdl.handle.net/1969.1/187198

► User centered design is an apt process for developing assistive devices, as user needs are given the utmost importance in this approach. On studying current,… (more)

▼ User centered design is an apt process for developing assistive devices, as user needs are given the utmost importance in this approach. On studying current, state of the art hand rehabilitation devices, it was inferred that there exists a need for a compact and portable hand rehabilitation device – one suitable for patients with adversely limited active range of motion of the hand. This thesis proposes a novel hand-held, portable device that is composed of a fully actuated rotor-gimbal assembly (US Patent Application: 62/413,130). The simultaneous motion of the rotor and gimbal results in a controlled gyroscopic torque that acts on the user’s hand. Based on the hand’s strength and mobility, the user may either synchronize the hand movement with that compelled by the device or restrict it. While the former results in the relaxation of muscles, the latter can potentially increase muscle co-ordination and muscle strength. The target specifications of the device were determined through interviews with personnel specialized in the field of hand rehabilitation. A working principle of the device was then established via a proof-of-concept model and mathematical simulations, which were further used to firm up the design parameters. The dynamic analysis of the device was then conducted to attest the structural integrity. Also, the range of forces imposed by the device on the hand were evaluated to be within safe measures through simulation and consecutive comparison with existing literature. Future work includes fabricating the final device and evaluating its performance via experiments with human subjects. hand were evaluated to be within safe measures through simulation and consecutive comparison with existing literature. Future work includes fabricating the final device and evaluating its performance via experiments with human subjects. Advisors/Committee Members: Hur, Pilwon (advisor), Jong%22%29&pagesize-30">Kim, Won-Jong (committee member), Moreno, Michael (committee member).

Subjects/Keywords: Gyroscope; Hand; Rehabilitation; Design; Stress analysis; Contact forces

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APA (6^th Edition):

Anil Kumar, N. (2017). Design of a Portable and Compact Gyroscopic Device for Hand Rehabilitation. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/187198

Chicago Manual of Style (16^th Edition):

Anil Kumar, Namita. “Design of a Portable and Compact Gyroscopic Device for Hand Rehabilitation.” 2017. Masters Thesis, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/187198.

MLA Handbook (7^th Edition):

Anil Kumar, Namita. “Design of a Portable and Compact Gyroscopic Device for Hand Rehabilitation.” 2017. Web. 18 Jan 2021.

Vancouver:

Anil Kumar N. Design of a Portable and Compact Gyroscopic Device for Hand Rehabilitation. [Internet] [Masters thesis]. Texas A&M University; 2017. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/187198.

Council of Science Editors:

Anil Kumar N. Design of a Portable and Compact Gyroscopic Device for Hand Rehabilitation. [Masters Thesis]. Texas A&M University; 2017. Available from: http://hdl.handle.net/1969.1/187198

Texas A&M University

27. Dong, Jiawei. Output Feedback Control and Optimal Bandwidth Allocation of Networked Control Systems.

Degree: PhD, Mechanical Engineering, 2013, Texas A&M University

URL: http://hdl.handle.net/1969.1/149367

► A networked control system (NCS) is a control system where sensors, actuators, and controllers are interconnected over a communication network. This dissertation presents a framework… (more)

▼ A networked control system (NCS) is a control system where sensors, actuators, and controllers are interconnected over a communication network. This dissertation presents a framework for modeling, stability analysis, optimal control, and bandwidth allocation of the NCS. A ball magnetic-levitation (maglev) system, four DC motor speed-control systems, and a wireless autonomous robotic wheelchair are employed as test beds to illustrate and verify the theoretical results of this dissertation. This dissertation first proposes an output feedback method to stabilize and control the NCSs. The random time delays in the controller-to-actuator and sensor-to-controller links are modeled with two time-homogeneous Markov chains while the packet losses are treated with Dirac delta functions. An asymptotic mean-square stability criterion is established to compensate for the network-induced random time delays and packet losses in the NCS. Then, an algorithm to implement the asymptotic mean-square stability criterion is presented. Experimental results illustrate effectiveness of the proposed output feedback method compared to conventional controllers. The proposed output feedback controller could reduce the errors of the NCS by 13% and 30–40% for the cases without and with data packet losses, respectively. The optimal bandwidth allocation and scheduling of the NCS with nonlinear-programming techniques is also presented in the dissertation. The bandwidth utilization (BU) of each client is defined in terms of its sampling frequency. Two nonlinear approximations, exponential and quadratic approximations, are formulated to describe the system performance governed by discrete-time integral absolute error (DIAE) versus sampling frequency. The optimal sampling frequencies are obtained by solving the approximations with Karush-Kuhn-Tucker (KKT) conditions. Simulation and experimental results are given to verify the effectiveness of the proposed approximations and the bandwidth allocation and scheduling algorithms. In simulations and experiments, the two approximations could maximize the total BU of the NCS up to about 98% of the total available network bandwidth. Advisors/Committee Members: jong%22%29&pagesize-30">Kim, Won-jong (advisor), Langari, Reza (committee member), Rasmussen, Bryan (committee member), Zhang, Xi (committee member).

Subjects/Keywords: Networked control systems; Output feedback control; Optimal bandwidth allocation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Dong, J. (2013). Output Feedback Control and Optimal Bandwidth Allocation of Networked Control Systems. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/149367

Chicago Manual of Style (16^th Edition):

Dong, Jiawei. “Output Feedback Control and Optimal Bandwidth Allocation of Networked Control Systems.” 2013. Doctoral Dissertation, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/149367.

MLA Handbook (7^th Edition):

Dong, Jiawei. “Output Feedback Control and Optimal Bandwidth Allocation of Networked Control Systems.” 2013. Web. 18 Jan 2021.

Vancouver:

Dong J. Output Feedback Control and Optimal Bandwidth Allocation of Networked Control Systems. [Internet] [Doctoral dissertation]. Texas A&M University; 2013. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/149367.

Council of Science Editors:

Dong J. Output Feedback Control and Optimal Bandwidth Allocation of Networked Control Systems. [Doctoral Dissertation]. Texas A&M University; 2013. Available from: http://hdl.handle.net/1969.1/149367

Texas A&M University

28. Chour, Kenny. Development of an Electrotactile Haptic Device with Application to Balance Rehabilitation.

Degree: MS, Mechanical Engineering, 2018, Texas A&M University

URL: http://hdl.handle.net/1969.1/188903

► Balance impairments affect many individuals especially those in the older age bracket, and can lead to severe complications from falls. Research has shown that the… (more)

▼ Balance impairments affect many individuals especially those in the older age bracket, and can lead to severe complications from falls. Research has shown that the cause of these impairments can be attributed to degraded sensory inputs. With ample sensory supplementation (or sensory augmentation), these deficiencies may be overcome. The purpose of this research is to verify a design of a low-cost custom electrotactile stimulation device that can aid in balance rehabilitation purposes. To this end, a major focus will be on wearability. Presently, there is a large research gap in the field of electrotactile stimulation for achieving wearable designs. Additionally, few devices incorporate a sensing mechanism for detecting balance impairment such as with an inertial measurement unit. Many researchers still rely on expensive commercial devices that are very large and bulky. Additionally, the design and implementation of electrotactile stimulation devices require working knowledge of circuits, thus there is mainly a general lack of instructions for the design of such devices. The thesis hopes to address these gaps by studying a design that may be simple to replicate from scratch. The design includes the use of several half H-bridge circuits to produce localized dipole stimulation through a 4 by 4 electrode array. Feasibility of the design will be verified via oscilloscope measurements and a small pilot study that is aimed at obtaining user feedback. The wearable components of the device include a custom-fabricated electrode array to be worn on the wrist or arm, and also an IMU (inertial measurement unit) belt along the waist to measure the user’s sway angle along the sagittal plane. Preliminary results show that a user can detect sensations from dry-skin stimulation while wearing the electrode array. The detected sensations also include directional information. Additionally, verification with the subject showed that the device is able to provide biofeedback through an electrode array as a result of the IMU orientation information. Further design refinements such as better point discrimination, pattern generation, and consistent pulsing are required before proceeding to the human testing and validation stage. Advisors/Committee Members: Hur, Pilwon (advisor), Jong%22%29&pagesize-30">Kim, Won-Jong (committee member), Moreno, Michael (committee member), Park, Hangue (committee member).

Subjects/Keywords: electrotactile stimulation; balance rehabilitation; Inertial measurement unit; PCB fabrication; design verification; sensory augmentation, wearables, haptics, tactile

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Chour, K. (2018). Development of an Electrotactile Haptic Device with Application to Balance Rehabilitation. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/188903

Chicago Manual of Style (16^th Edition):

Chour, Kenny. “Development of an Electrotactile Haptic Device with Application to Balance Rehabilitation.” 2018. Masters Thesis, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/188903.

MLA Handbook (7^th Edition):

Chour, Kenny. “Development of an Electrotactile Haptic Device with Application to Balance Rehabilitation.” 2018. Web. 18 Jan 2021.

Vancouver:

Chour K. Development of an Electrotactile Haptic Device with Application to Balance Rehabilitation. [Internet] [Masters thesis]. Texas A&M University; 2018. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/188903.

Council of Science Editors:

Chour K. Development of an Electrotactile Haptic Device with Application to Balance Rehabilitation. [Masters Thesis]. Texas A&M University; 2018. Available from: http://hdl.handle.net/1969.1/188903

Texas A&M University

29. Han, Je Heon. Investigation on Wave Propagation Characteristics in Plates and Pipes for Identification of Structural Defect Locations.

Degree: PhD, Mechanical Engineering, 2013, Texas A&M University

URL: http://hdl.handle.net/1969.1/151345

► For successful identification of structural defects in plates and pipes, it is essential to understand structural wave propagation characteristics such as dispersion relations. Analytical approaches… (more)

▼ For successful identification of structural defects in plates and pipes, it is essential to understand structural wave propagation characteristics such as dispersion relations. Analytical approaches to identify the dispersion relations of homogeneous, simple plates and circular pipes have been investigated by many researchers. However, for plates or pipes with irregular cross-sectional configurations or multi-layered composite structures, it is almost impossible to obtain the analytical dispersion relations and associated mode shapes. In addition, full numerical modeling approaches such as finite element (FE) methods are not economically feasible for high (e.g., ultrasonic) frequency analyses where an extremely large number of discretized meshes are required, resulting in significantly expensive computation. In order to address these limitations, Hybrid Analytical/Finite Element Methods (HAFEMs) are developed to model composite plates and pipes in a computationally-efficient manner. When a pipe system is used to transport a fluid, the dispersion curves obtained from a “hollow” pipe model can mislead non-destructive evaluation (NDE) results of the pipe system. In this study, the HAFEM procedure with solid elements is extended by developing fluid elements and solid-fluid boundary conditions, resulting in the dispersion curves of fluid-filled pipes. In addition, a HAFEM-based acoustic transfer function approach is suggested to consider a long pipe system assembled with multiple pipe sections with different cross-sections. For the validation of the proposed methods, experimental and full FE modeling results are compared to the results obtained from the HAFEM models. In order to detect structural defect locations in shell structures from defect-induced, subtle wave reflection signals and eliminate direct-excitation-induced and boundary-reflected, relatively-strong wave signals, a time-frequency MUSIC algorithm is applied to ultrasonic wave data measured by using an array of piezoelectric transducers. A normalized, structurally-damped, cylindrical 2-D steering vector is proposed to increase the spatial resolution of time-frequency MUSIC power results. A cross-shaped array is selected over a circular or linear array to further improve the spatial resolution and to avoid the mirrored virtual image effects of a linear array. Here, it is experimentally demonstrated that the proposed time-frequency MUSIC beamforming procedure can be used to identify structural defect locations on an aluminum plate by distinguishing the defect-induced waves from both the excitation-generated and boundary-reflected waves. Advisors/Committee Members: Kim, Yong-Joe (advisor), Palazzolo, Alan (committee member), Chang, Kuang-An (committee member), Jong%22%29&pagesize-30">Kim, Won-Jong (committee member).

Subjects/Keywords: Non-destructive evaluation (NDE); Acoustic Transfer Function Approach; Dispersion Curves; Hybrid Analytical Finite Element Method (HAFEM); Multiple Signal Classification (MUSIC)

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Han, J. H. (2013). Investigation on Wave Propagation Characteristics in Plates and Pipes for Identification of Structural Defect Locations. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/151345

Chicago Manual of Style (16^th Edition):

Han, Je Heon. “Investigation on Wave Propagation Characteristics in Plates and Pipes for Identification of Structural Defect Locations.” 2013. Doctoral Dissertation, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/151345.

MLA Handbook (7^th Edition):

Han, Je Heon. “Investigation on Wave Propagation Characteristics in Plates and Pipes for Identification of Structural Defect Locations.” 2013. Web. 18 Jan 2021.

Vancouver:

Han JH. Investigation on Wave Propagation Characteristics in Plates and Pipes for Identification of Structural Defect Locations. [Internet] [Doctoral dissertation]. Texas A&M University; 2013. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/151345.

Council of Science Editors:

Han JH. Investigation on Wave Propagation Characteristics in Plates and Pipes for Identification of Structural Defect Locations. [Doctoral Dissertation]. Texas A&M University; 2013. Available from: http://hdl.handle.net/1969.1/151345

Texas A&M University

30. Jalal, Rawand Ehsan. Limited-Communication Distributed Model Predictive Control for HVAC Systems.

Degree: PhD, Mechanical Engineering, 2016, Texas A&M University

URL: http://hdl.handle.net/1969.1/159057

► This dissertation proposes a Limited-Communication Distributed Model Predictive Control algorithm for networks with constrained discrete-time linear processes as local subsystems. The introduced algorithm has an… (more)

▼ This dissertation proposes a Limited-Communication Distributed Model Predictive Control algorithm for networks with constrained discrete-time linear processes as local subsystems. The introduced algorithm has an iterative and cooperative framework with neighbor-to-neighbor communication structure. Convergence to a centralized solution is guaranteed by requiring coupled subsystems with local information to cooperate only. During an iteration, a local controller exchanges its predicted effects with local neighbors (which are treated as measured input disturbances in local dynamics) and receives the neighbor sensitivities for these effects at next iteration. Then the controller minimizes a local cost function that counts for the future effects to neighbors weighted by the received sensitivity information. Distributed observers are employed to estimate local states through local input-output signals. Closed-loop stability is proved for sufficiently long horizons. To reduce the computational loads associated with large horizons, local decisions are parametrized by Laguerre functions. A local agent can also reduce the communication burden by parametrizing the communicated data with Laguerre sequences. So far, convergence and closed-loop stability of the algorithm are proven under the assumptions of accessing all subsystem dynamics and cost functions information by a centralized monitor and sufficient number of iterations per sampling. However, these are not mild assumptions for many applications. To design a local convergence condition or a global condition that requires less information, tools from dissipativity theory are used. Although they are conservative conditions, the algorithm convergence can now be ensured either by requiring a distributed subsystem to show dissipativity in the local information dynamic inputs-outputs with gain less than unity or solving a global dissipative inequality with subsystem dissipativity gains and network topology only. Free variables are added to the local problems with the object of having freedom to design such convergence conditions. However, these new variables will result into a suboptimal algorithm that affects the proposed closed-loop stability. To ensure local MPC stability, therefore, a distributed synthesis, which considers the system interactions, of stabilizing terminal costs is introduced. Finally, to illustrate the aspects of the algorithm, coupled tank process and building HVAC system are used as application examples. Advisors/Committee Members: Rasmussen, Bryan P (advisor), Bhattacharya, Raktim (committee member), Jong%22%29&pagesize-30">Kim, Won-Jong (committee member), Kim, Yong-Joe (committee member).

Subjects/Keywords: Distributed MPC; HVAC systems

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Jalal, R. E. (2016). Limited-Communication Distributed Model Predictive Control for HVAC Systems. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/159057

Chicago Manual of Style (16^th Edition):

Jalal, Rawand Ehsan. “Limited-Communication Distributed Model Predictive Control for HVAC Systems.” 2016. Doctoral Dissertation, Texas A&M University. Accessed January 18, 2021. http://hdl.handle.net/1969.1/159057.

MLA Handbook (7^th Edition):

Jalal, Rawand Ehsan. “Limited-Communication Distributed Model Predictive Control for HVAC Systems.” 2016. Web. 18 Jan 2021.

Vancouver:

Jalal RE. Limited-Communication Distributed Model Predictive Control for HVAC Systems. [Internet] [Doctoral dissertation]. Texas A&M University; 2016. [cited 2021 Jan 18]. Available from: http://hdl.handle.net/1969.1/159057.

Council of Science Editors:

Jalal RE. Limited-Communication Distributed Model Predictive Control for HVAC Systems. [Doctoral Dissertation]. Texas A&M University; 2016. Available from: http://hdl.handle.net/1969.1/159057

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