+publisher:"Clemson University" +contributor:("Vahidi , Ardalan")

Clemson University

1. Werner, Andrew. An Early Warning Monitoring System for CNC Spindle Bearing Failure.

Degree: MS, Mechanical Engineering, 2011, Clemson University

URL: https://tigerprints.clemson.edu/all_theses/1235

► Equipment employed in a manufacturing environment must be able to operate as long as possible having as little downtime as possible. Therefore, maintenance is… (more)

▼ Equipment employed in a manufacturing environment must be able to operate as long as possible having as little downtime as possible. Therefore, maintenance is crucial in order to allow for the equipment to perform its designated tasks without failure, especially on critical systems. In a CNC machine, if the spindle fails, the machine is useless. Having the ability to detect spindle degradation to the point where a replacement spindle installation can be planned, via condition monitoring, is invaluable to a manufacturer who utilizes these types of machines. An early warning monitoring system for CNC spindle bearing failure has been developed to be utilized directly on a CNC machine's controller employing an open architecture structure. The main system uses an ultrasonic sensor as its primary sensing component and provides a singular value as to the spindle condition. The system allows for both real time data recording as well as provides a trending history for the machine. Additionally, the system allows for the data to be seen remotely via the internet. Accessory devices can be added to perform an in-depth bearing failure analysis. The total system (including accessories) costs just under $2,400, allowing for a very effective system at a very low price. A few thousand dollars towards a predictive and preventive maintenance monitoring solution can prevent tens-of-thousands of dollars in lost production and unnecessary maintenance costs if the system is utilized as intended. System performance was tested to investigate sensor measurement applicability. Spindle speed was found to have an effect on the sensor's output, however excessive vibration did not. Therefore, the same spindle speed must be used each time a measurement is taken. Measurements while the machine is cutting can be performed, however, a test mode is recommended for the most accurate results. The amount of variation for an in-process reading was found to be lower for a harder material (ie: steel vs. aluminum), for the same spindle speed and depth of cut. The system was tested to see if it could detect the various stages of bearing failure. It was unable to detect a plastic/resin bearing cage degradation failure until it was too late as the failure was too quiet to detect. Advisors/Committee Members: Mocko, Gregory, Mears , Laine, Vahidi , Ardalan.

Subjects/Keywords: CNC Machine; Manufacturing; Predictive Maintenance; Spindle Bearing Failure; Ultrasonic Sensing; Mechanical Engineering

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APA (6^th Edition):

Werner, A. (2011). An Early Warning Monitoring System for CNC Spindle Bearing Failure. (Masters Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/1235

Chicago Manual of Style (16^th Edition):

Werner, Andrew. “An Early Warning Monitoring System for CNC Spindle Bearing Failure.” 2011. Masters Thesis, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_theses/1235.

MLA Handbook (7^th Edition):

Werner, Andrew. “An Early Warning Monitoring System for CNC Spindle Bearing Failure.” 2011. Web. 16 Jan 2021.

Vancouver:

Werner A. An Early Warning Monitoring System for CNC Spindle Bearing Failure. [Internet] [Masters thesis]. Clemson University; 2011. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_theses/1235.

Council of Science Editors:

Werner A. An Early Warning Monitoring System for CNC Spindle Bearing Failure. [Masters Thesis]. Clemson University; 2011. Available from: https://tigerprints.clemson.edu/all_theses/1235

Clemson University

2. Austin, Kelly. Power Generation and Control of Mechatronics Systems - Theory and Test.

Degree: MS, Mechanical Engineering, 2012, Clemson University

URL: https://tigerprints.clemson.edu/all_theses/1389

► An integrated, multi-disciplined approach to engineering design is a broad definition of mechatronics. Though some mechatronics proponents differ in their definitions of the topic,… (more)

▼ An integrated, multi-disciplined approach to engineering design is a broad definition of mechatronics. Though some mechatronics proponents differ in their definitions of the topic, an interdisciplinary approach to engineering is taken by many industries which should be reflected on campus in the approach to engineering education. In this thesis, two mechatronics systems are investigated. A laboratory experiment is developed for use in the mechanical engineering program at Clemson University, and a thermoelectric power generation from diesel engine exhaust heat is investigated as an automotive industry application. An electromagnet excited masspendulum system with attached spring and damper elements is introduced as an undergraduate/graduate engineering experiment. This laboratory offers mechanical, electrical, and control engineering challenges to the students. The non-linear coupled equations of motion are derived using both Newtonian and Lagrangian approaches. The dynamic system is pendulum actuated by a powerful electromagnet for which the magnetic force is modeled by a magnetostatic forcing function. By accounting for the characteristics of a fluctuating magnetic field, the forcing function is useful in simulating the system response for the experimentally determined system parameters. Representative numerical and experimental results are presented which validate the mathematical model. Overall, the percent difference between the numerical and experimental results range from 2% to 47% for positions of the electromagnet within ±7.5cm of the system's equilibrium position. Further, the bench top experiment offers hands-on opportunities for the students to explore science and classical engineering concepts. In the transportation industry, the need to improve powertrain efficiency and provide additional power to the many amenities in today's vehicles has encouraged research on engine waste heat recovery. Approximately one-third of the gasoline or diesel fuel energy passes through the exhaust system. With ongoing development in materials and module design, thermoelectric generation, used since the 1960s for its reliable power output in space applications, has potential for use in bulk applications of engine heat recovery. In this study, the capability of generating usable power from thermoelectric generation from the exhaust heat of a 3-cylinder, 4-cycle, 697 cubic-centimeter diesel engine was investigated. It was found that the maximum surface temperature of the exhaust thermoelectric generation system was approximately 204¡C. However, to ensure that the maximum temperature of the module's cold side was not exceeded, forced air was applied across the module's finned heat sinks. From laboratory testing, the maximum power outputs for a single module and four modules connected in series were 0.47W and 2.81W, with predicted maximum power outputs of 0.49W and 2.91W, respectively. Comparing the experimental values to numerically calculated values from the manufacturer's supplied data, it was observed that… Advisors/Committee Members: Wagner, John, Vahidi , Ardalan, Schweisinger , Todd.

Subjects/Keywords: laboratory experiment; Magnetic forcing function; mass-pendulum; thermoelectric generation; Waste heat recovery; Mechanical Engineering

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APA (6^th Edition):

Austin, K. (2012). Power Generation and Control of Mechatronics Systems - Theory and Test. (Masters Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/1389

Chicago Manual of Style (16^th Edition):

Austin, Kelly. “Power Generation and Control of Mechatronics Systems - Theory and Test.” 2012. Masters Thesis, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_theses/1389.

MLA Handbook (7^th Edition):

Austin, Kelly. “Power Generation and Control of Mechatronics Systems - Theory and Test.” 2012. Web. 16 Jan 2021.

Vancouver:

Austin K. Power Generation and Control of Mechatronics Systems - Theory and Test. [Internet] [Masters thesis]. Clemson University; 2012. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_theses/1389.

Council of Science Editors:

Austin K. Power Generation and Control of Mechatronics Systems - Theory and Test. [Masters Thesis]. Clemson University; 2012. Available from: https://tigerprints.clemson.edu/all_theses/1389

Clemson University

3. Liu, Xiyuan. An Electromagnetic Energy Harvester for Powering Consumer Electronics.

Degree: MS, Mechanical Engineering, 2012, Clemson University

URL: https://tigerprints.clemson.edu/all_theses/1415

► This thesis introduces an electromagnetic vibratory energy harvester to power consumer electronics by generating electricity from the strides taken during walking or jogging. The… (more)

Subjects/Keywords: Battery Charging; Electromagnetic; Energy Harvesting; Nonlinear Dynamics; Vibration and Control; Mechanical Engineering

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APA (6^th Edition):

Liu, X. (2012). An Electromagnetic Energy Harvester for Powering Consumer Electronics. (Masters Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/1415

Chicago Manual of Style (16^th Edition):

Liu, Xiyuan. “An Electromagnetic Energy Harvester for Powering Consumer Electronics.” 2012. Masters Thesis, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_theses/1415.

MLA Handbook (7^th Edition):

Liu, Xiyuan. “An Electromagnetic Energy Harvester for Powering Consumer Electronics.” 2012. Web. 16 Jan 2021.

Vancouver:

Liu X. An Electromagnetic Energy Harvester for Powering Consumer Electronics. [Internet] [Masters thesis]. Clemson University; 2012. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_theses/1415.

Council of Science Editors:

Liu X. An Electromagnetic Energy Harvester for Powering Consumer Electronics. [Masters Thesis]. Clemson University; 2012. Available from: https://tigerprints.clemson.edu/all_theses/1415

Clemson University

4. Zhang, Xian. PROGNOSTIC AND HEALTH-MANAGEMENT ORIENTED FUEL CELL MODELING AND ON-LINE SUPERVISORY SYSTEM DEVELOPMENT.

Degree: PhD, Automotive Engineering, 2012, Clemson University

URL: https://tigerprints.clemson.edu/all_dissertations/1006

► Of the fuel cells being studied, the proton exchange membrane fuel cell (PEMFC) is viewed as the most promising for transportation. Yet until today, the… (more)

▼ Of the fuel cells being studied, the proton exchange membrane fuel cell (PEMFC) is viewed as the most promising for transportation. Yet until today, the commercialization of the PEMFC has not been widespread in spite of its large expectation. Poor long term performances or durability, and high production and maintenance costs are the main reasons. For the final commercialization of fuel cells in the transportation field, durability issues must be addressed, while costs should be further brought down. At the same time, health-monitoring and prognosis techniques are of great significance in terms of scheduling condition-based maintenance (CBM) to minimize repair and maintenance costs, the associated operational disruptions, and also the risk of unscheduled downtime for the fuel cell systems. This dissertation presents a comprehensive on-line supervisory system to address the important issues related to the PEMFC durability, including: 1) diagnosis of critical operating conditions, 2) optimization of the operating conditions, and 3) health monitoring (or damage tracking) and remaining useful life (RUL) prediction. In order to design and implement this supervisory system, a comprehensive fuel cell model is developed that integrates a control/diagnostic oriented dynamic fuel cell model and a prognostic oriented fuel cell degradation model, due to a lack of such models in the existing literature. To address the first issue, a model-based on-line diagnostics system is developed for fuel cell flooding and drying diagnosis, thanks to the incorporation of the diagnostic feature in the dynamic fuel cell model. The channel flooding diagnostic problem is decoupled from the gas diffusion layer (GDL) flooding and membrane drying diagnostic problem. Simultaneous state and parameter estimation problems are formulated for both cases. Dual extended Kalman filter (EKF) and dual unscented Kalman filter (UKF) techniques are applied respectively to solve the problems. The second issue is addressed by a diagnostic based control design for the air supply of the fuel cell system. The design concept allows selection of the most suitable controller in a controller bank that delivers the best performance under specific operating conditions and that mitigates the faulty condition based on the feedback of the diagnosis results. The control problem is reformulated as an H-infinity robust control problem, the objective of which is to minimize the difference between the desired and actual excess O2 ratio, thus preventing and minimizing oxidant starvation at the cathode. Finally, an UKF-based health-monitoring and prognostic scheme is proposed and applied to the damage tracking and RUL prediction for the fuel cell. The developed aging model is employed as the kernel for this scheme, which utilizes the fuel cell output voltage as the only feature for the prognostic and health management task. Advisors/Committee Members: Pisu, Pierluigi, Omar , Mohammad, Prucka , Robert, Vahidi , Ardalan.

Subjects/Keywords: Operations Research; Systems Engineering and Industrial Engineering

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APA (6^th Edition):

Zhang, X. (2012). PROGNOSTIC AND HEALTH-MANAGEMENT ORIENTED FUEL CELL MODELING AND ON-LINE SUPERVISORY SYSTEM DEVELOPMENT. (Doctoral Dissertation). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_dissertations/1006

Chicago Manual of Style (16^th Edition):

Zhang, Xian. “PROGNOSTIC AND HEALTH-MANAGEMENT ORIENTED FUEL CELL MODELING AND ON-LINE SUPERVISORY SYSTEM DEVELOPMENT.” 2012. Doctoral Dissertation, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_dissertations/1006.

MLA Handbook (7^th Edition):

Zhang, Xian. “PROGNOSTIC AND HEALTH-MANAGEMENT ORIENTED FUEL CELL MODELING AND ON-LINE SUPERVISORY SYSTEM DEVELOPMENT.” 2012. Web. 16 Jan 2021.

Vancouver:

Zhang X. PROGNOSTIC AND HEALTH-MANAGEMENT ORIENTED FUEL CELL MODELING AND ON-LINE SUPERVISORY SYSTEM DEVELOPMENT. [Internet] [Doctoral dissertation]. Clemson University; 2012. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_dissertations/1006.

Council of Science Editors:

Zhang X. PROGNOSTIC AND HEALTH-MANAGEMENT ORIENTED FUEL CELL MODELING AND ON-LINE SUPERVISORY SYSTEM DEVELOPMENT. [Doctoral Dissertation]. Clemson University; 2012. Available from: https://tigerprints.clemson.edu/all_dissertations/1006

Clemson University

5. Jensen, Matthew. A METHODOLOGY FOR THE ANALYSIS OF IN-VEHICLE OPERATING DATA AND DESIGN OF INTELLIGENT VEHICLE SYSTEMS FOR IMPROVED AUTOMOTIVE SAFETY.

Degree: PhD, Mechanical Engineering, 2011, Clemson University

URL: https://tigerprints.clemson.edu/all_dissertations/702

► Every year global motorization increases as more motor vehicles are manufactured, and the total number of vehicle miles traveled rises. These increased travel opportunities result… (more)

▼ Every year global motorization increases as more motor vehicles are manufactured, and the total number of vehicle miles traveled rises. These increased travel opportunities result in higher numbers of injuries, fatalities, and monetary losses associated with traffic-related crashes. In the last decade, hundreds of thousands of people were killed by vehicle collisions in the United States. The World Health Organization has labeled traffic crashes as the ninth leading cause of global disease; by the year 2020, traffic crashes are expected to rise to number three. An opportunity exists to improve global human safety through research and innovation in driver training and evaluation and advanced vehicle safety systems. In this dissertation, four research studies were conducted: creation and evaluation of a safe driving program, driver classification using in-vehicle data collection and analysis, development of an obstacle avoidance warning system, and design of a run-off-the-road recovery controller. The most critical component of vehicle safety is the driver. For this reason, a safe driving program was developed to improve driver skills, knowledge, attitudes, and behaviors. The program consisted of driving and tent modules that were targeted to younger and less experienced drivers. Standardization of the modules allowed for student assessment using subjective and objective evaluation tools. A total of 86 students participated in a case study. Comparison of pre- and post-event tests indicated a 10% net increase of knowledge with a student and parent satisfaction level of 89.6%. One driving module focused on a tailgating scenario using a custom apparatus to simulate a tailgating situation. For this module, 75% of the evaluated students received a passing grade (85% or above), while the other 25% received valuable feedback on their specific driving eficiencies. The evaluation of normal driving tasks can be used as a tool to supply drivers with feedback regarding inadequate skills or poor behaviors, while providing off-line users with risk assessment. Three custom analysis techniques were developed to analyze real-world driver behavior and provide a normalized driving score, ultimately creating a driver classification system and risk assessment. A five-person case study was performed to demonstrate the capability of the developed methodologies; the results successfully differentiated each driver's overall performance. Driver safety may also be improved through the use of advanced on-board vehicle safety systems. A customizable hardware-in-the-loop steering simulator was used to create an obstacle avoidance system. Variable levels of vibration were provided to the driver through the steering wheel to communicate critical roadway information. Laboratory results demonstrated that haptic steering feedback improved driver performance as measured by a 62% reduction in obstacle hit rates. In addition, small reductions were found in peak steering wheel angle and peak vehicle yaw rate, as well as a… Advisors/Committee Members: Wagner, John, Vahidi , Ardalan, Switzer , Fred, Alexander , Kim.

Subjects/Keywords: automotive safety; driver classification; driving simulator; obstacle avoidance; run off the road; safe driving program; Mechanical Engineering

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

APA (6^th Edition):

Jensen, M. (2011). A METHODOLOGY FOR THE ANALYSIS OF IN-VEHICLE OPERATING DATA AND DESIGN OF INTELLIGENT VEHICLE SYSTEMS FOR IMPROVED AUTOMOTIVE SAFETY. (Doctoral Dissertation). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_dissertations/702

Chicago Manual of Style (16^th Edition):

Jensen, Matthew. “A METHODOLOGY FOR THE ANALYSIS OF IN-VEHICLE OPERATING DATA AND DESIGN OF INTELLIGENT VEHICLE SYSTEMS FOR IMPROVED AUTOMOTIVE SAFETY.” 2011. Doctoral Dissertation, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_dissertations/702.

MLA Handbook (7^th Edition):

Jensen, Matthew. “A METHODOLOGY FOR THE ANALYSIS OF IN-VEHICLE OPERATING DATA AND DESIGN OF INTELLIGENT VEHICLE SYSTEMS FOR IMPROVED AUTOMOTIVE SAFETY.” 2011. Web. 16 Jan 2021.

Vancouver:

Jensen M. A METHODOLOGY FOR THE ANALYSIS OF IN-VEHICLE OPERATING DATA AND DESIGN OF INTELLIGENT VEHICLE SYSTEMS FOR IMPROVED AUTOMOTIVE SAFETY. [Internet] [Doctoral dissertation]. Clemson University; 2011. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_dissertations/702.

Council of Science Editors:

Jensen M. A METHODOLOGY FOR THE ANALYSIS OF IN-VEHICLE OPERATING DATA AND DESIGN OF INTELLIGENT VEHICLE SYSTEMS FOR IMPROVED AUTOMOTIVE SAFETY. [Doctoral Dissertation]. Clemson University; 2011. Available from: https://tigerprints.clemson.edu/all_dissertations/702

Clemson University

6. Clippard, Robert. IN-WHEEL COUPLED SUSPENISON AND DRIVE SYSTEM FOR ATTITUDE CONTROL AND VEHICLE PROPULSION.

Degree: PhD, Automotive Engineering, 2011, Clemson University

URL: https://tigerprints.clemson.edu/all_dissertations/746

► The automotive marketplace is a volatile and dynamic system driven by consumer desires, marketing, fuel prices, technology, and legislation. Recently many of these factors have… (more)

▼ The automotive marketplace is a volatile and dynamic system driven by consumer desires, marketing, fuel prices, technology, and legislation. Recently many of these factors have culminated in a common effort to encourage hybrid and electric vehicle development. The technology for electric vehicles has finally found enough maturity to be implemented into consumer based vehicles from hybrid SUVs to high performance sports cars. This expansion in available propulsion systems and vehicle architectures has spurred research and development into new and novel approaches for propulsion as well as systems to provide increased ride comfort. This work presents a dual electric motor drive system that incorporates a mechanism that allows not only longitudinal actuation of the vehicle, but also low frequency vertical actuation of the vehicle. The system is able to achieve this by coupling two motors per wheel and combining them with a new kinematic mechanism that facilitates dual degree of freedom actuation with coupled motors. By utilizing two motors coupled together to actuate the two degrees of freedom, more efficient utilization of resources is possible. Rather than having a motor that provides longitudinal motion and another that provides vertical actuation, the system uses two motors coupled together to provide both. When one degree of freedom doesn't require actuation, the motors can be utilized to provide higher performance in the other degree of freedom. This system is designed, modeled, and actually converted into a prototype design throughout the entirety of this work. Initial conceptual modeling and performance metric definition occurs in a kinematic analysis of a basic mechanism. This is then developed into a more complex three dimensional model, and finally converted into physical hardware. In parallel to the hardware development, the controller that allows the system to operate is also explored. From actuating a single degree of freedom to a linearized coupling algorithm that allows both degrees of freedom to be controlled independently and simultaneously, the control system evolves into a functioning system. Advisors/Committee Members: Ziegert, John, Venhovens , Paul, Vahidi , Ardalan, Hubbing , Todd.

Subjects/Keywords: Operations Research; Systems Engineering and Industrial Engineering

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APA (6^th Edition):

Clippard, R. (2011). IN-WHEEL COUPLED SUSPENISON AND DRIVE SYSTEM FOR ATTITUDE CONTROL AND VEHICLE PROPULSION. (Doctoral Dissertation). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_dissertations/746

Chicago Manual of Style (16^th Edition):

Clippard, Robert. “IN-WHEEL COUPLED SUSPENISON AND DRIVE SYSTEM FOR ATTITUDE CONTROL AND VEHICLE PROPULSION.” 2011. Doctoral Dissertation, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_dissertations/746.

MLA Handbook (7^th Edition):

Clippard, Robert. “IN-WHEEL COUPLED SUSPENISON AND DRIVE SYSTEM FOR ATTITUDE CONTROL AND VEHICLE PROPULSION.” 2011. Web. 16 Jan 2021.

Vancouver:

Clippard R. IN-WHEEL COUPLED SUSPENISON AND DRIVE SYSTEM FOR ATTITUDE CONTROL AND VEHICLE PROPULSION. [Internet] [Doctoral dissertation]. Clemson University; 2011. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_dissertations/746.

Council of Science Editors:

Clippard R. IN-WHEEL COUPLED SUSPENISON AND DRIVE SYSTEM FOR ATTITUDE CONTROL AND VEHICLE PROPULSION. [Doctoral Dissertation]. Clemson University; 2011. Available from: https://tigerprints.clemson.edu/all_dissertations/746

Clemson University

7. Qaroush, Yousef. Implementation of Delayed-Feedback Controllers on Continuous Systems and Analysis of their Response under Primary Resonance Excitations.

Degree: PhD, Mechanical Engineering, 2011, Clemson University

URL: https://tigerprints.clemson.edu/all_dissertations/686

► During the last three decades, a considerable amount of research has been directed toward understanding the influence of time delays on the stability and stabilization… (more)

▼ During the last three decades, a considerable amount of research has been directed toward understanding the influence of time delays on the stability and stabilization of dynamical systems. From a control perspective, these delays can either have a compounding and destabilizing effect, or can actually improve controllers' performance. In the latter case, additional time delay is carefully and deliberately introduced into the feedback loop so as to augment inherent system delays and produce larger damping for smaller control efforts. While delayed-feedback algorithms have been successfully implemented on discrete dynamical systems with limited degrees of freedom, a critical issue appears in their implementation on systems consisting of a large number of degrees of freedom or on infinite-dimensional structures. The reason being that the presence of delay in the control loop renders the characteristic polynomial of the transcendental type which produces infinite number of eigenvalues for every discrete controller's gain and time delay. As a result, choosing a gain-delay combination that stabilizes the lower vibration modes can easily destabilize the higher modes. To address this problem, this dissertation introduces the concept of filter-augmented delayed-feedback control algorithms and applies it to mitigate vibrations of various structural systems both theoretically and experimentally. In specific, it explores the prospect of augmenting proper filters in the feedback loop to enhance the robustness of delayed-feedback controllers allowing them to simultaneously mitigate the response of different vibration modes using a single sensor and a single gain-delay actuator combination. The dissertation goes into delineating the influence of filter's dynamics (order and cut-off frequency) on the stability maps and damping contours clearly demonstrating the possibility of effectively reducing multi-modal oscillations of infinite-dimensional structures when proper filters are augmented in the feedback loop. Additionally, this research illustrates that filters may actually enhance the robustness of the controller to parameter's uncertainties at the expense of reducing the controller's effective damping. To assess the performance of the proposed control algorithm, the dissertation presents three experimental case studies; two of which are on structures whose dynamics can be discretized into a system of linearly-uncoupled ordinary differential equations (ODEs); and the third on a structure whose dynamics can only be reduced into a set of linearly-coupled ODEs. The first case study utilizes a filter-augmented delayed-position feedback algorithm for flexural vibration mitigation and external disturbances rejection on a macro-cantilever Euler-Bernoulli beam. The second deals with implementing a filter-augmented delayed-velocity feedback algorithm for vibration mitigation and external disturbances rejection on a micro-cantilever sensor. The third implements a filter-augmented… Advisors/Committee Members: Daqaq, Mohammed M., Li , Gang, Schiff , Scott, Vahidi , Ardalan.

Subjects/Keywords: Multi-Mode Feedback; Nonlinear Dynamics; Smart Structures; Time-Delay Systems; Vibration Control; Mechanical Engineering

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

APA (6^th Edition):

Qaroush, Y. (2011). Implementation of Delayed-Feedback Controllers on Continuous Systems and Analysis of their Response under Primary Resonance Excitations. (Doctoral Dissertation). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_dissertations/686

Chicago Manual of Style (16^th Edition):

Qaroush, Yousef. “Implementation of Delayed-Feedback Controllers on Continuous Systems and Analysis of their Response under Primary Resonance Excitations.” 2011. Doctoral Dissertation, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_dissertations/686.

MLA Handbook (7^th Edition):

Qaroush, Yousef. “Implementation of Delayed-Feedback Controllers on Continuous Systems and Analysis of their Response under Primary Resonance Excitations.” 2011. Web. 16 Jan 2021.

Vancouver:

Qaroush Y. Implementation of Delayed-Feedback Controllers on Continuous Systems and Analysis of their Response under Primary Resonance Excitations. [Internet] [Doctoral dissertation]. Clemson University; 2011. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_dissertations/686.

Council of Science Editors:

Qaroush Y. Implementation of Delayed-Feedback Controllers on Continuous Systems and Analysis of their Response under Primary Resonance Excitations. [Doctoral Dissertation]. Clemson University; 2011. Available from: https://tigerprints.clemson.edu/all_dissertations/686

Clemson University

8. Schkoda, Ryan. Clustering and Classification of Multivariate Stochastic Time Series in the Time and Frequency Domains.

Degree: PhD, Mechanical Engineering, 2012, Clemson University

URL: https://tigerprints.clemson.edu/all_dissertations/907

► The dissertation primarily investigates the characterization and discrimination of stochastic time series with an application to pattern recognition and fault detection. These techniques supplement traditional… (more)

▼ The dissertation primarily investigates the characterization and discrimination of stochastic time series with an application to pattern recognition and fault detection. These techniques supplement traditional methodologies that make overly restrictive assumptions about the nature of a signal by accommodating stochastic behavior. The assumption that the signal under investigation is either deterministic or a deterministic signal polluted with white noise excludes an entire class of signals – stochastic time series. The research is concerned with this class of signals almost exclusively. The investigation considers signals in both the time and the frequency domains and makes use of both model-based and model-free techniques. A comparison of two multivariate statistical discrimination techniques, one based on a traditional covariance statistic and one based on a more recently proposed periodogram based statistic, is carried out through simulation study. This investigation validates the utility of the periodogram based statistic over the covariance based statistic. The periodogram based statistic proves more useful in identifying statistical dissimilarities in multidimensional time series than the more traditional statistic. Attention is then focused on using the periodogram based statistic as a distance measure for clustering and classifying time series, which is motivated by the periodogram method's increased discrimination capability. The test statistic is used in both clustering and classification algorithms, and the performance is evaluated though a simulation study. This measure proves capable of grouping like series together while simultaneously separating dissimilar series from one another. Finally, the techniques are adapted to the time-domain where they are used to cluster multidimensional, non-stationary, climatological data. The non-stationary model accounts for seasonal means, seasonal standard deviations, and stochastic components. The statistical approach results in the development of a level-α test for assessing signal equality. This improves upon typical dendrogram techniques by defining a level under which the distance should be considered zero. Climatological time series from the west coast, Gulf of Mexico, and east coast are analyzed using the aforementioned techniques. To complement the time series analysis work, some effort (Appendix A) is focused on improving the bachelor of science in the department of mechanical engineering via the undergraduate laboratories. This is accomplished by identifying desired outcomes and implementing specific improvements in the undergraduate laboratory courses over a period of four years. The effects of these improvements are quantified with survey results. Overall, the improvements are very well received and result in significant increases in student satisfaction. Advisors/Committee Members: Wagner, John, Lund , Robert, Vahidi , Ardalan, Dawson , Darren.

Subjects/Keywords: Fault Detection; Time Series Analysis; Mechanical Engineering

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APA (6^th Edition):

Schkoda, R. (2012). Clustering and Classification of Multivariate Stochastic Time Series in the Time and Frequency Domains. (Doctoral Dissertation). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_dissertations/907

Chicago Manual of Style (16^th Edition):

Schkoda, Ryan. “Clustering and Classification of Multivariate Stochastic Time Series in the Time and Frequency Domains.” 2012. Doctoral Dissertation, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_dissertations/907.

MLA Handbook (7^th Edition):

Schkoda, Ryan. “Clustering and Classification of Multivariate Stochastic Time Series in the Time and Frequency Domains.” 2012. Web. 16 Jan 2021.

Vancouver:

Schkoda R. Clustering and Classification of Multivariate Stochastic Time Series in the Time and Frequency Domains. [Internet] [Doctoral dissertation]. Clemson University; 2012. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_dissertations/907.

Council of Science Editors:

Schkoda R. Clustering and Classification of Multivariate Stochastic Time Series in the Time and Frequency Domains. [Doctoral Dissertation]. Clemson University; 2012. Available from: https://tigerprints.clemson.edu/all_dissertations/907

Clemson University

9. Montes-solano, Carlos. High Resolution Vision-Based Servomechanism Using a Dynamic Target with Application to CNC Machines.

Degree: PhD, Mechanical Engineering, 2011, Clemson University

URL: https://tigerprints.clemson.edu/all_dissertations/708

► This dissertation introduces a novel three dimensional vision-based servomechanism with application to real time position control for manufacturing equipment, such as Computer Numerical Control (CNC)… (more)

▼ This dissertation introduces a novel three dimensional vision-based servomechanism with application to real time position control for manufacturing equipment, such as Computer Numerical Control (CNC) machine tools. The proposed system directly observes the multi-dimensional position of a point on the moving tool relative to a fixed ground, thus bypassing the inaccurate kinematic model normally used to convert axis sensor-readings into an estimate of the tool position. A charge-coupled device (CCD camera) is used as the position transducer, which directly measures the current position error of the tool referenced to an absolute coordinate system. Due to the direct-sensing nature of the transducer no geometric error compensation is required. Two new signal processing algorithms, based on a recursive Newton-Raphson optimization routine, are developed to process the input data collected through digital imaging. The algorithms allow simultaneous high-precision position and orientation estimation from single readings. The desired displacement command of the tool in a planar environment is emulated, in one end of the kinematic chain, by an active element or active target pattern on a liquid-crystal display (LCD). On the other end of the kinematic chain the digital camera observes the active target and provides visual feedback information utilized for position control of the tool. Implementation is carried out on an XYθZ stage, which is position with high resolution. The introduction of the camera into the control loop yields a visual servo architecture; the dynamic problems and stability assessment of which are analyzed in depth for the case study of the single CAM- single image processing thread-configuration. Finally, two new command generation protocols are explained for full implementation of the proposed structure in real-time control applications. Command issuing resolutions do not depend upon the size of the smallest element of the grid/display being imaged, but can instead be determined in accordance with the sensor's resolution. Advisors/Committee Members: Ziegert, John C., Mears , Laine, Vahidi , Ardalan, Dawson , Darren.

Subjects/Keywords: Control System; Feedback; Precision Engineering; Vision; Mechanical Engineering

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APA (6^th Edition):

Montes-solano, C. (2011). High Resolution Vision-Based Servomechanism Using a Dynamic Target with Application to CNC Machines. (Doctoral Dissertation). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_dissertations/708

Chicago Manual of Style (16^th Edition):

Montes-solano, Carlos. “High Resolution Vision-Based Servomechanism Using a Dynamic Target with Application to CNC Machines.” 2011. Doctoral Dissertation, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_dissertations/708.

MLA Handbook (7^th Edition):

Montes-solano, Carlos. “High Resolution Vision-Based Servomechanism Using a Dynamic Target with Application to CNC Machines.” 2011. Web. 16 Jan 2021.

Vancouver:

Montes-solano C. High Resolution Vision-Based Servomechanism Using a Dynamic Target with Application to CNC Machines. [Internet] [Doctoral dissertation]. Clemson University; 2011. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_dissertations/708.

Council of Science Editors:

Montes-solano C. High Resolution Vision-Based Servomechanism Using a Dynamic Target with Application to CNC Machines. [Doctoral Dissertation]. Clemson University; 2011. Available from: https://tigerprints.clemson.edu/all_dissertations/708

Clemson University

10. Hashemi, Ali. MODEL-BASED SYSTEM FAULT DIAGNOSIS UTILIZING ADAPTIVE THRESHOLD WITH APPLICATION TO AUTOMOTIVE ELECTRICAL SYSTEMS.

Degree: MS, Mechanical Engineering, 2011, Clemson University

URL: https://tigerprints.clemson.edu/all_theses/1168

► Recent advancement in the field of automotive industry is largely due to the addition of electrical and electronic equipment; some of the safety features in… (more)

▼ Recent advancement in the field of automotive industry is largely due to the addition of electrical and electronic equipment; some of the safety features in the vehicle and advanced driver assistance systems are examples of such equipment. Furthermore, safe operation of the vehicle is highly dependent on the electrical power generation and storage system (EPGS). Therefore, to ensure optimal operation of this system, a reliable diagnosis of the system is essential. However, as the complexity of the electrical systems has increased, the identification of a malfunction has become an increasingly difficult task to handle. In the current work, a model-based diagnostic approach for the EPGS system is formulated using the residual generation and adaptive threshold method. The EPGS system comprises an alternator and a battery. Since the focus of the current work in on the vehicle alternator subsystem of the EPGS system, a mathematical model of the alternator subsystem based on the physics of the processes involved is derived. This model is characterized by time-varying nonlinear ordinary differential equations. To simplify the diagnosis scheme development, an equivalent linear time invariant model based on the behavior of the input/output of the alternator is presented. Afterwards, three typical faults for a vehicle alternator, namely belt slipping fault, open diode fault and voltage regulator fault, are modeled and injected into the model separately to observe the effectiveness of the adaptive threshold-based fault diagnosis scheme for fault detection and isolation (FDI). The proposed adaptive threshold scheme for the EPGS system has proven to be more sensitive and more robust than previously presented diagnostic schemes for the same system as available in the literature. In addition to the classical adaptive threshold method, a novel general methodology is presented for the derivation of adaptive thresholds in the case of linear time varying-parameter systems, and Gaussian distributed linear parameter systems. The high order of the threshold dynamics in general is the main drawback of this approach. To overcome this problem, order reduction methods can be used. In this thesis, we explore two approximations, namely the steady state threshold and a first order threshold approximation. The study shows that these approximations are effective in detection and isolation of faults, however, a false alarm rate is introduced. Moreover, the qualitative modeling of the equivalent system via stochastic automaton is also investigated, and a new approach for the evaluation of the transition probabilities based on the Divergence Theorem is proposed. Advisors/Committee Members: Pisu, Pierluigi, Vahidi , Ardalan, Miller , Richard.

Subjects/Keywords: Adaptive Threshold; EPGS Systems; Fault Diagnosis; Mechanical Engineering

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APA (6^th Edition):

Hashemi, A. (2011). MODEL-BASED SYSTEM FAULT DIAGNOSIS UTILIZING ADAPTIVE THRESHOLD WITH APPLICATION TO AUTOMOTIVE ELECTRICAL SYSTEMS. (Masters Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/1168

Chicago Manual of Style (16^th Edition):

Hashemi, Ali. “MODEL-BASED SYSTEM FAULT DIAGNOSIS UTILIZING ADAPTIVE THRESHOLD WITH APPLICATION TO AUTOMOTIVE ELECTRICAL SYSTEMS.” 2011. Masters Thesis, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_theses/1168.

MLA Handbook (7^th Edition):

Hashemi, Ali. “MODEL-BASED SYSTEM FAULT DIAGNOSIS UTILIZING ADAPTIVE THRESHOLD WITH APPLICATION TO AUTOMOTIVE ELECTRICAL SYSTEMS.” 2011. Web. 16 Jan 2021.

Vancouver:

Hashemi A. MODEL-BASED SYSTEM FAULT DIAGNOSIS UTILIZING ADAPTIVE THRESHOLD WITH APPLICATION TO AUTOMOTIVE ELECTRICAL SYSTEMS. [Internet] [Masters thesis]. Clemson University; 2011. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_theses/1168.

Council of Science Editors:

Hashemi A. MODEL-BASED SYSTEM FAULT DIAGNOSIS UTILIZING ADAPTIVE THRESHOLD WITH APPLICATION TO AUTOMOTIVE ELECTRICAL SYSTEMS. [Masters Thesis]. Clemson University; 2011. Available from: https://tigerprints.clemson.edu/all_theses/1168

Clemson University

11. Abdelhamid, Mahmoud. EXTRACTING DEPTH INFORMATION FROM STEREO VISION SYSTEM, USING A CORRELATION AND A FEATURE BASED METHODS.

Degree: MS, Mechanical Engineering, 2011, Clemson University

URL: https://tigerprints.clemson.edu/all_theses/1216

► This thesis presents a new method to extract depth information from stereo-vision acquisitions using a feature and a correlation based approaches. The main implementation of… (more)

Subjects/Keywords: 3D vision; Computer Vision; Pick and place; Robotics; Triangulation; Mechanical Engineering

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APA (6^th Edition):

Abdelhamid, M. (2011). EXTRACTING DEPTH INFORMATION FROM STEREO VISION SYSTEM, USING A CORRELATION AND A FEATURE BASED METHODS. (Masters Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/1216

Chicago Manual of Style (16^th Edition):

Abdelhamid, Mahmoud. “EXTRACTING DEPTH INFORMATION FROM STEREO VISION SYSTEM, USING A CORRELATION AND A FEATURE BASED METHODS.” 2011. Masters Thesis, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_theses/1216.

MLA Handbook (7^th Edition):

Abdelhamid, Mahmoud. “EXTRACTING DEPTH INFORMATION FROM STEREO VISION SYSTEM, USING A CORRELATION AND A FEATURE BASED METHODS.” 2011. Web. 16 Jan 2021.

Vancouver:

Abdelhamid M. EXTRACTING DEPTH INFORMATION FROM STEREO VISION SYSTEM, USING A CORRELATION AND A FEATURE BASED METHODS. [Internet] [Masters thesis]. Clemson University; 2011. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_theses/1216.

Council of Science Editors:

Abdelhamid M. EXTRACTING DEPTH INFORMATION FROM STEREO VISION SYSTEM, USING A CORRELATION AND A FEATURE BASED METHODS. [Masters Thesis]. Clemson University; 2011. Available from: https://tigerprints.clemson.edu/all_theses/1216

Clemson University

12. Oberklein, Daniel. Charging Kinetics of Micropores in Supercapacitors.

Degree: MS, Mechanical Engineering, 2012, Clemson University

URL: https://tigerprints.clemson.edu/all_theses/1347

► The charging kinetics of Electric Double Layer Capacitors (EDLC) were studied using a continuum model based on the Poisson-Nernst-Planck (PNP) Equations, with the additional modeling… (more)

Subjects/Keywords: electric double layer; supercapacitor; transport phenomena; Mechanical Engineering

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APA (6^th Edition):

Oberklein, D. (2012). Charging Kinetics of Micropores in Supercapacitors. (Masters Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/1347

Chicago Manual of Style (16^th Edition):

Oberklein, Daniel. “Charging Kinetics of Micropores in Supercapacitors.” 2012. Masters Thesis, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_theses/1347.

MLA Handbook (7^th Edition):

Oberklein, Daniel. “Charging Kinetics of Micropores in Supercapacitors.” 2012. Web. 16 Jan 2021.

Vancouver:

Oberklein D. Charging Kinetics of Micropores in Supercapacitors. [Internet] [Masters thesis]. Clemson University; 2012. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_theses/1347.

Council of Science Editors:

Oberklein D. Charging Kinetics of Micropores in Supercapacitors. [Masters Thesis]. Clemson University; 2012. Available from: https://tigerprints.clemson.edu/all_theses/1347

Clemson University

13. Bode, Roger. Parametric Amplification in the Context of Vibratory Energy Harvesting.

Degree: MS, Mechanical Engineering, 2011, Clemson University

URL: https://tigerprints.clemson.edu/all_theses/1134

► Using a vibratory energy harvester (VEH) to independently power a sensor has become an increasingly popular topic due to the small amount of power current… (more)

▼ Using a vibratory energy harvester (VEH) to independently power a sensor has become an increasingly popular topic due to the small amount of power current sensors require to operate. This can be achieved by scavenging energy from the ambient environment where the sensor is located. Numerous linear and nonlinear energy harvesters have been proposed in order to deal with various vibratory environments, along with improving the power production and/or bandwidth of the device. In this thesis, we propose a technique to harvest energy from excitation sources that possess two frequency components: a fundamental component with large energy content, and a super-harmonic component with smaller energy content at twice the fundamental component. Excitations of this nature are common in the environment due to inherent nonlinearities in the dynamics of the excitation source. Normally, two separate energy harvesters are needed to extract the energy at each frequency; however, this thesis discusses a single cantilevered piezoelectric VEH that exploits the parametric amplification phenomenon to scavenge energy from both frequencies by varying the tilt angle between the axis of the beam and the direction of the excitation. To investigate the efficacy of the proposed concept, the equations governing the electromechanical dynamics of the harvester are derived. The resulting partial differential equations and associated boundary conditions are then reduced to a single-mode Galerkin-based reduced-order model. Analytical expressions for the steady-state output power across a purely resistive load are obtained using the method of multiple scales. Theoretical and experimental results demonstrate that parametric amplification can be used to improve the output power for given excitation parameters, beam tilt angle, and mechanical damping ratio. It is observed that there exists an optimal beam tilt angle at which the flow of energy from the environment to the electric load is maximized. This angle increases as the amplitude of the super-harmonic component of excitation increases and the mechanical damping ratio decreases. Furthermore, the resistive load of the harvesting circuit, which significantly affects the output power, is shown to have little influence on the optimal tilt angle except for very low mechanical damping ratios. Therefore, for a given environment and system parameters, an optimal tilt angle and resistive load combinations should be maintained to maximize the power output of the harvester. Results indicate that the mechanical damping ratio plays a major role in characterizing the performance. Specifically, when the mechanical damping ratio is small, significant enhancement in the output power is attainable even when the magnitude of the super-harmonic is small as compared to the fundamental component. For instance, at a damping ratio of ζ=0.002, a 20% increase in power is observed at the optimal tilt angle when the super-harmonic component is half that of the… Advisors/Committee Members: Daqaq, Mohammed F, Li , Gang, Vahidi , Ardalan.

Subjects/Keywords: Mechanical Engineering

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APA (6^th Edition):

Bode, R. (2011). Parametric Amplification in the Context of Vibratory Energy Harvesting. (Masters Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/1134

Chicago Manual of Style (16^th Edition):

Bode, Roger. “Parametric Amplification in the Context of Vibratory Energy Harvesting.” 2011. Masters Thesis, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_theses/1134.

MLA Handbook (7^th Edition):

Bode, Roger. “Parametric Amplification in the Context of Vibratory Energy Harvesting.” 2011. Web. 16 Jan 2021.

Vancouver:

Bode R. Parametric Amplification in the Context of Vibratory Energy Harvesting. [Internet] [Masters thesis]. Clemson University; 2011. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_theses/1134.

Council of Science Editors:

Bode R. Parametric Amplification in the Context of Vibratory Energy Harvesting. [Masters Thesis]. Clemson University; 2011. Available from: https://tigerprints.clemson.edu/all_theses/1134

Clemson University

14. Desai, Akash. Laminar Flame Speed Estimation from Experimental Data Using a Quasi-Dimensional Turbulent Flame Entrainment Combustion Simulation For Spark Ignition Engines.

Degree: MS, Mechanical Engineering, 2011, Clemson University

URL: https://tigerprints.clemson.edu/all_theses/1281

► The goal of this research is to develop a thermodynamic simulation of spark-ignition engine combustion that uses a predictive burn-rate model. Previously done thermodynamic engine… (more)

▼ The goal of this research is to develop a thermodynamic simulation of spark-ignition engine combustion that uses a predictive burn-rate model. Previously done thermodynamic engine simulations in MATLAB are based on a specified burn rate model. Also, the effect of turbulence parameters on the rate of mass burn up is not considered. A predictive burn rate model is necessary to study the effect of different fuels on spark ignition engine combustion. The effect of laminar flame speed and turbulent intensity on combustion is difficult to assess experimental due to the difficulty in the measurement of these two variables. Thus, the aim of this simulation is to thermodynamically model the spark ignition engine cycle taking into account the turbulence parameters and their effect on the combustion process. The simulation can be used for predictive studies of combustion of different varieties of fuels by calibration of laminar flame speed, assuming the turbulent intensity to be a fuel-independent parameter. The key parameters of interest are the turbulence intensity and laminar flame speed. Both these parameters play a key role in controlling mass burn-up rate. The simulation intends to calculate mass fraction burned profile and turbulence intensity from a predictive combustion model based on the concept of turbulent flame entrainment and diffusive burn-up. An empirical relation for laminar flame speed is used for known fuel (gasoline) which can be later calibrated for variety of fuels. The simulation calculates the mass fraction burned profile based on calculated cylinder pressure, temperature and species concentration. The cylinder pressure and temperature predicted by the simulation match well with the experimental data for the engine used for calibration. The MFB10, MFB50 and MFB90 crank angle positions simulated by the predictive combustion model were compared with those calculated from a commercially available engine thermodynamics program (AVL Concerto) which is based on experimental data and were found within 5-10% of each other. The turbulence parameters, laminar flame speed and the length scales during combustion also showed results in accordance with those shown by previous experiments / simulation. The quasi-dimensional simulation is done in MATLAB for computational speed and acceptable accuracy. Using MATLAB also makes inserting additional sub-models easier to make the model more detailed and accurate. This simulation will serve as a student guide to engine modeling and also can be used as a base for more advanced simulations. Advisors/Committee Members: Prucka, Robert, Wagner , John, Vahidi , Ardalan.

Subjects/Keywords: Combustion; Mechanical Engineering

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APA (6^th Edition):

Desai, A. (2011). Laminar Flame Speed Estimation from Experimental Data Using a Quasi-Dimensional Turbulent Flame Entrainment Combustion Simulation For Spark Ignition Engines. (Masters Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/1281

Chicago Manual of Style (16^th Edition):

Desai, Akash. “Laminar Flame Speed Estimation from Experimental Data Using a Quasi-Dimensional Turbulent Flame Entrainment Combustion Simulation For Spark Ignition Engines.” 2011. Masters Thesis, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_theses/1281.

MLA Handbook (7^th Edition):

Desai, Akash. “Laminar Flame Speed Estimation from Experimental Data Using a Quasi-Dimensional Turbulent Flame Entrainment Combustion Simulation For Spark Ignition Engines.” 2011. Web. 16 Jan 2021.

Vancouver:

Desai A. Laminar Flame Speed Estimation from Experimental Data Using a Quasi-Dimensional Turbulent Flame Entrainment Combustion Simulation For Spark Ignition Engines. [Internet] [Masters thesis]. Clemson University; 2011. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_theses/1281.

Council of Science Editors:

Desai A. Laminar Flame Speed Estimation from Experimental Data Using a Quasi-Dimensional Turbulent Flame Entrainment Combustion Simulation For Spark Ignition Engines. [Masters Thesis]. Clemson University; 2011. Available from: https://tigerprints.clemson.edu/all_theses/1281

Clemson University

15. Borhan, Hoseinali. Optimization-Based Power Management of Hybrid Power Systems with Applications in Advanced Hybrid Electric Vehicles and Wind Farms with Battery Storage.

Degree: PhD, Mechanical Engineering, 2011, Clemson University

URL: https://tigerprints.clemson.edu/all_dissertations/822

► Modern hybrid electric vehicles and many stationary renewable power generation systems combine multiple power generating and energy storage devices to achieve an overall system-level efficiency… (more)

▼ Modern hybrid electric vehicles and many stationary renewable power generation systems combine multiple power generating and energy storage devices to achieve an overall system-level efficiency and flexibility which is higher than their individual components. The power or energy management control, ``brain' of these ``hybrid' systems, determines adaptively and based on the power demand the power split between multiple subsystems and plays a critical role in overall system-level efficiency. This dissertation proposes that a receding horizon optimal control (aka Model Predictive Control) approach can be a natural and systematic framework for formulating this type of power management controls. More importantly the dissertation develops new results based on the classical theory of optimal control that allow solving the resulting optimal control problem in real-time, in spite of the complexities that arise due to several system nonlinearities and constraints. The dissertation focus is on two classes of hybrid systems: hybrid electric vehicles in the first part and wind farms with battery storage in the second part. The first part of the dissertation proposes and fully develops a real-time optimization-based power management strategy for hybrid electric vehicles. Current industry practice uses rule-based control techniques with ``else-then-if' logic and look-up maps and tables in the power management of production hybrid vehicles. These algorithms are not guaranteed to result in the best possible fuel economy and there exists a gap between their performance and a minimum possible fuel economy benchmark. Furthermore, considerable time and effort are spent calibrating the control system in the vehicle development phase, and there is little flexibility in real-time handling of constraints and re-optimization of the system operation in the event of changing operating conditions and varying parameters. In addition, a proliferation of different powertrain configurations may result in the need for repeated control system redesign. To address these shortcomings, we formulate the power management problem as a nonlinear and constrained optimal control problem. Solution of this optimal control problem in real-time on chronometric- and memory- constrained automotive microcontrollers is quite challenging; this computational complexity is due to the highly nonlinear dynamics of the powertrain subsystems, mixed-integer switching modes of their operation, and time-varying and nonlinear hard constraints that system variables should satisfy. The main contribution of the first part of the dissertation is that it establishes methods for systematic and step-by step improvements in fuel economy while maintaining the algorithmic computational requirements in a real-time implementable framework. More specifically a linear time-varying model predictive control approach is employed first which uses sequential quadratic programming to find sub-optimal solutions to the power management problem. Next the objective function is further… Advisors/Committee Members: Vahidi, Ardalan, Rotea , Mario A., Wagner , John, Daqaq , Mohammed, Schmoll , Martin.

Subjects/Keywords: Battery storage; Hybrid electric vehicle (HEV); Model Predictive Control; Optimal energy management; Optimization-based power management; Wind farm with battery storage; Mechanical Engineering

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APA (6^th Edition):

Borhan, H. (2011). Optimization-Based Power Management of Hybrid Power Systems with Applications in Advanced Hybrid Electric Vehicles and Wind Farms with Battery Storage. (Doctoral Dissertation). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_dissertations/822

Chicago Manual of Style (16^th Edition):

Borhan, Hoseinali. “Optimization-Based Power Management of Hybrid Power Systems with Applications in Advanced Hybrid Electric Vehicles and Wind Farms with Battery Storage.” 2011. Doctoral Dissertation, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_dissertations/822.

MLA Handbook (7^th Edition):

Borhan, Hoseinali. “Optimization-Based Power Management of Hybrid Power Systems with Applications in Advanced Hybrid Electric Vehicles and Wind Farms with Battery Storage.” 2011. Web. 16 Jan 2021.

Vancouver:

Borhan H. Optimization-Based Power Management of Hybrid Power Systems with Applications in Advanced Hybrid Electric Vehicles and Wind Farms with Battery Storage. [Internet] [Doctoral dissertation]. Clemson University; 2011. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_dissertations/822.

Council of Science Editors:

Borhan H. Optimization-Based Power Management of Hybrid Power Systems with Applications in Advanced Hybrid Electric Vehicles and Wind Farms with Battery Storage. [Doctoral Dissertation]. Clemson University; 2011. Available from: https://tigerprints.clemson.edu/all_dissertations/822

Clemson University

16. Wong, Chan yet. System integration for a novel positioning system using a model based control approach.

Degree: PhD, Automotive Engineering, 2011, Clemson University

URL: https://tigerprints.clemson.edu/all_dissertations/715

► This dissertation presents a model-based approach to perform system integration of a novel positioning sensing method, termed 'Direct Position Sensing.' Direct Position Sensing can actively… (more)

Subjects/Keywords: Intermittent feedback; Model based control; Motion control; Smith Predictor; System integration; Time delay; Engineering

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APA (6^th Edition):

Wong, C. y. (2011). System integration for a novel positioning system using a model based control approach. (Doctoral Dissertation). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_dissertations/715

Chicago Manual of Style (16^th Edition):

Wong, Chan yet. “System integration for a novel positioning system using a model based control approach.” 2011. Doctoral Dissertation, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_dissertations/715.

MLA Handbook (7^th Edition):

Wong, Chan yet. “System integration for a novel positioning system using a model based control approach.” 2011. Web. 16 Jan 2021.

Vancouver:

Wong Cy. System integration for a novel positioning system using a model based control approach. [Internet] [Doctoral dissertation]. Clemson University; 2011. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_dissertations/715.

Council of Science Editors:

Wong Cy. System integration for a novel positioning system using a model based control approach. [Doctoral Dissertation]. Clemson University; 2011. Available from: https://tigerprints.clemson.edu/all_dissertations/715

17. He, Qifan. Nonlinear Energy Harvesting Under White Noise.

Degree: ME, Mechanical Engineering, 2013, Clemson University

URL: https://tigerprints.clemson.edu/all_theses/1797

► While purposeful introduction of stiffness nonlinearities into the dynamics of energy harvesters is aimed at enhancing performance under non-stationary and random excitations, most of… (more)

▼ While purposeful introduction of stiffness nonlinearities into the dynamics of energy harvesters is aimed at enhancing performance under non-stationary and random excitations, most of the conclusions reported in the current literature are based on the steady-state response which assumes a harmonic fixed-frequency excitation. As a result, we still do not have a clear understanding of how the nature of the excitation influences the output power, or what role stiffness nonlinearities play in the transduction of energy harvesters under random excitations. To fill this gap in the current knowledge, this thesis investigates the response of nonlinear mono- and bi-stable energy harvesters to environmental excitations that can be approximated via a white noise process. For the mono-stable case, statistical linearization is utilized to analytically approximate the statistical averages of the response. The influence of the nonlinearity and the symmetry of the restoring force on the mean power is investigated under optimal electric loading conditions. It is shown that the nonlinearity has no influence on the output power unless the ratio between the time constant of the harvesting circuit and the period of the mechanical oscillator is small. In such case, a mono-stable harvester with a symmetric nonlinear restoring force can never produce higher mean power levels than an equivalent linear harvester regardless of the magnitude or nature of the nonlinearity. On the other hand, asymmetries in the restoring force are shown to provide performance improvements over an equivalent linear harvester. For energy harvesters with a bi-stable potential function, statistical linearization, direct numerical integration of the stochastic differential equations, and finite element solution of the Fokker-Plank-Kolmogorov equation governing the response probability density function are utilized to understand how the shape and symmetry of the potential energy function influence the mean output power of the harvester. It is observed that, both of the finite element solution and the direct numerical integration provide close predictions for the mean power regardless of the shape of the potential energy function. Statistical linearization, on the other hand, yields non-unique and erroneous predictions unless the potential energy function has shallow potential wells. It is shown that the mean power exhibits a maximum value at an optimal potential shape. This optimal shape is not directly related to the shape that maximizes the mean square displacement even when the time constant ratio, i.e., ratio between the time constants of the mechanical and electrical systems is small. Maximizing the mean square displacement yields a potential shape with a global maximum (unstable potential) for any value of the time constant ratio and any noise intensity, whereas maximizing the average power yields a bi-stable potential which possesses deeper potential wells for larger noise intensities and vise versa. Away from the optimal shape, the mean power drops… Advisors/Committee Members: Daqaq, Mohammed, Vahidi , Ardalan, Fadel , Georges M.

Subjects/Keywords: Energy Harvesting; Nonlinear Dynamics; Mechanical Engineering

14 more images…

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APA (6^th Edition):

He, Q. (2013). Nonlinear Energy Harvesting Under White Noise. (Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/1797

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

He, Qifan. “Nonlinear Energy Harvesting Under White Noise.” 2013. Thesis, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_theses/1797.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

He, Qifan. “Nonlinear Energy Harvesting Under White Noise.” 2013. Web. 16 Jan 2021.

Vancouver:

He Q. Nonlinear Energy Harvesting Under White Noise. [Internet] [Thesis]. Clemson University; 2013. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_theses/1797.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

He Q. Nonlinear Energy Harvesting Under White Noise. [Thesis]. Clemson University; 2013. Available from: https://tigerprints.clemson.edu/all_theses/1797

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

18. Masana, Ravindra. UNDERSTANDING THE ROLE OF NONLINEARITIES IN THE TRANSDUCTION OF VIBRATORY ENERGY HARVESTERS.

Degree: PhD, Mechanical Engineering, 2013, Clemson University

URL: https://tigerprints.clemson.edu/all_dissertations/1118

► The last two decades have witnessed several advances in micro-fabrication technologies and electronics, leading to the development of small, low-power devices for wireless sensing,… (more)

▼ The last two decades have witnessed several advances in micro-fabrication technologies and electronics, leading to the development of small, low-power devices for wireless sensing, data transmission, actuation, and medical implants. Unfortunately, the actual implementation of such devices in their respective environment has been hindered by the lack of scalable energy sources that are necessary to power and maintain them. Batteries, which remain the most commonly used power source, have not kept pace with the demands of these devices, especially in terms of energy density. In light of this challenge, the concept of vibratory energy harvesting has flourished in recent years as a possible alternative to power and maintain low-power electronics. While linear vibratory energy harvesters have received the majority of the literature's attention, a significant body of the current research activity is focused on the concept of purposeful inclusion of nonlinearities for broadband transduction. When compared to their linear resonant counterparts, nonlinear energy harvesters have a wider steady-state frequency bandwidth, leading to the common belief that they can be utilized to improve performance especially in random and non-stationary vibratory environments. This dissertation aims to critically investigate this belief by drawing a clearer picture of the role of nonlinearities in the transduction of energy harvesters and by defining the conditions under which nonlinearities can be used to enhance performance. To achieve this goal, the Thesis is divided into three parts. The first part investigates the performance of mono- and bi-stable energy harvesters under harmonic excitations and carries a detailed analysis of their relative performance. The second part investigates their response to broadband and narrowband random excitations and again analyzes their relative behavior. The third part exploits the super-harmonic resonance bands of bi-stable energy harvesters for the purpose of scavenging energy from low-frequency excitations. As a platform to achieve the Thesis objectives, a piezoelectric energy harvester consisting of an axially loaded clamped-clamped beam bi-morph is considered. The harvester can operate with mono- (pre-buckling) and bi-stable (post-buckling) characteristics with minimal alterations to the design. Theoretical and experimental studies performed on the proposed harvester are presented to delineate the influence of the nonlinearity on its performance, in particular, and nonlinear vibratory energy harvesters in general. It is demonstrated that the intentional inclusion of nonlinearities in energy harvesters makes these devices more tolerant to variations in the excitation and design parameters around their nominal values as compared to a linear device. However, the Thesis also pointed out many issues that can result from the complexity and non-uniqueness of solutions associated with nonlinear systems. It became apparent that the performance of a nonlinear energy… Advisors/Committee Members: Daqaq, Mohammed F, Biggers , Sherrill, Li , Gang, Vahidi , Ardalan.

Subjects/Keywords: Duffing oscillator; Energy harvesting; Nonlinear restoring force; Resonance; Vibrations; Mechanical Engineering

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APA (6^th Edition):

Masana, R. (2013). UNDERSTANDING THE ROLE OF NONLINEARITIES IN THE TRANSDUCTION OF VIBRATORY ENERGY HARVESTERS. (Doctoral Dissertation). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_dissertations/1118

Chicago Manual of Style (16^th Edition):

Masana, Ravindra. “UNDERSTANDING THE ROLE OF NONLINEARITIES IN THE TRANSDUCTION OF VIBRATORY ENERGY HARVESTERS.” 2013. Doctoral Dissertation, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_dissertations/1118.

MLA Handbook (7^th Edition):

Masana, Ravindra. “UNDERSTANDING THE ROLE OF NONLINEARITIES IN THE TRANSDUCTION OF VIBRATORY ENERGY HARVESTERS.” 2013. Web. 16 Jan 2021.

Vancouver:

Masana R. UNDERSTANDING THE ROLE OF NONLINEARITIES IN THE TRANSDUCTION OF VIBRATORY ENERGY HARVESTERS. [Internet] [Doctoral dissertation]. Clemson University; 2013. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_dissertations/1118.

Council of Science Editors:

Masana R. UNDERSTANDING THE ROLE OF NONLINEARITIES IN THE TRANSDUCTION OF VIBRATORY ENERGY HARVESTERS. [Doctoral Dissertation]. Clemson University; 2013. Available from: https://tigerprints.clemson.edu/all_dissertations/1118

19. Mehta, Parikshit. MODEL BASED CONTROL OF MACHINING PROCESSES: EXPLORATION OF BAYESIAN STATISTICAL METHODS FOR IDENTIFICATION AND CONTROL.

Degree: PhD, Mechanical Engineering, 2013, Clemson University

URL: https://tigerprints.clemson.edu/all_dissertations/1181

► Machining process modeling & simulation as well as in-process monitoring and control have been identified as key technological factors to power efficient manufacturing facilities… (more)

▼ Machining process modeling & simulation as well as in-process monitoring and control have been identified as key technological factors to power efficient manufacturing facilities of tomorrow. The effective utilization of process models and in-process control are aimed towards improving profitability of the manufacturing process. To that end, the objective of this research work is to improve machining performance by implementing in-process control using model based control strategies, while considering stochastic models of machining process. Towards satisfying that objective, three research questions are asked. 1) What are metrics of measuring machining performance and which machining process models are important to consider according to these metrics? 2) How does uncertainty in machining process affect the validity and accuracy of these models and how models can be altered to account for these uncertainties? 3) What is the appropriate control strategy to be implemented to use machining models with uncertainty to improve machining performance? Machining performance is derived from its relation to profitability. Single operation level and part machining level profitability relates to peak machining forces, dimensional accuracy and tool life. A holistic system perspective of machining process modeling is presented through which identification of machining performance metric becomes efficient. Since machining models are the relationships between machining performance metrics and the machining inputs and have dependence on the machining application chosen, an application dependence metric map is created. This answers the questions of 'What to control and what models to pick?' Uncertainty in machining process stems from variability from process and part inputs and complex mechanics of metal cutting process. Thus the uncertainty can be classified as parametric uncertainty (variation in parameter values of model) and systematic uncertainties (simplified description of actual cutting phenomenon). In this work, Bayesian statistical methods are deployed for parameter and state estimation for static and dynamic machining process models. Bayesian methods use probabilistic descriptions of models and leverage the prior knowledge of machining process. This way they combine the best of analytical (first principle based) and numerical (data generated) techniques. Current work explores the Bayesian inference techniques for linear, nonlinear and dynamic models for parameter and state estimation. Computational Bayesian inference is implemented by various methods (Gaussian Approximation, Laplace Approximation, variational approach, Monte Carlo methods, Grid based methods etc). In this work a novel Grid based Markov Chain Monte Carlo (MCMC) method has been proposed. This method alleviates the shortcomings of parent methods (Grid based estimation and MCMC method), and exhibits faster convergence to true parameter values. The proposed method is validated using both synthetic and experimental data. Bayesian… Advisors/Committee Members: Mears, Laine, Summers , Joshua, Vahidi , Ardalan, Kurfess , Thomas.

Subjects/Keywords: bayesian inference; Kalman Filter; machining control; MCMC; Model based control; Mechanical Engineering

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APA (6^th Edition):

Mehta, P. (2013). MODEL BASED CONTROL OF MACHINING PROCESSES: EXPLORATION OF BAYESIAN STATISTICAL METHODS FOR IDENTIFICATION AND CONTROL. (Doctoral Dissertation). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_dissertations/1181

Chicago Manual of Style (16^th Edition):

Mehta, Parikshit. “MODEL BASED CONTROL OF MACHINING PROCESSES: EXPLORATION OF BAYESIAN STATISTICAL METHODS FOR IDENTIFICATION AND CONTROL.” 2013. Doctoral Dissertation, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_dissertations/1181.

MLA Handbook (7^th Edition):

Mehta, Parikshit. “MODEL BASED CONTROL OF MACHINING PROCESSES: EXPLORATION OF BAYESIAN STATISTICAL METHODS FOR IDENTIFICATION AND CONTROL.” 2013. Web. 16 Jan 2021.

Vancouver:

Mehta P. MODEL BASED CONTROL OF MACHINING PROCESSES: EXPLORATION OF BAYESIAN STATISTICAL METHODS FOR IDENTIFICATION AND CONTROL. [Internet] [Doctoral dissertation]. Clemson University; 2013. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_dissertations/1181.

Council of Science Editors:

Mehta P. MODEL BASED CONTROL OF MACHINING PROCESSES: EXPLORATION OF BAYESIAN STATISTICAL METHODS FOR IDENTIFICATION AND CONTROL. [Doctoral Dissertation]. Clemson University; 2013. Available from: https://tigerprints.clemson.edu/all_dissertations/1181

20. Panyam Mohan Ram, Meghashyam. Characterizing the Effective Bandwidth of Nonlinear Vibratory Energy Harvesters Possessing Multiple Stable Equilibria.

Degree: PhD, Mechanical Engineering, 2015, Clemson University

URL: https://tigerprints.clemson.edu/all_dissertations/1578

► In the last few years, advances in micro-fabrication technologies have lead to the development of low-power electronic devices spanning critical fields related to sensing, data… (more)

▼ In the last few years, advances in micro-fabrication technologies have lead to the development of low-power electronic devices spanning critical fields related to sensing, data transmission, and medical implants. Unfortunately, effective utilization of these devices is currently hindered by their reliance on batteries. In many of these applications, batteries may not be a viable choice as they have a fixed storage capacity and need to be constantly replaced or recharged. In light of such challenges, several novel concepts for micro-power generation have been recently introduced to harness, otherwise, wasted ambient energy from the environment and maintain these low-power devices. Vibratory energy harvesting is one such concept which has received significant attention in recent years. While linear vibratory energy harvesters have been well studied in the literature and their performance metrics have been established, recent research has focused on deliberate introduction of stiffness nonlinearities into the design of these devices. It has been shown that, nonlinear energy harvesters have a wider steady-state frequency bandwidth as compared to their linear counterparts, leading to the premise that they can used to improve performance, and decrease sensitivity to variations in the design and excitation parameters. This dissertation aims to investigate this premise by developing an analytical framework to study the influence of stiffness nonlinearities on the performance and effective bandwidth of nonlinear vibratory energy harvesters. To achieve this goal, the dissertation is divided into three parts. The first part investigates the performance of bi-stable energy harvesters possessing a symmetric quartic potential energy function under harmonic excitations and carries out a detailed analysis to define their effective frequency bandwidth. The second part investigates the relative performance of mono- and bi-stable energy harvesters under optimal electric loading conditions. The third part investigates the response and performance of tri-stable energy harvesters possessing a symmetric hexic potential function under harmonic excitations and provides a detailed analysis to approximate their effective frequency bandwidth. As a platform to achieve these objectives, a piezoelectric nonlinear energy harvester consisting of a uni-morph cantilever beam is considered. Stiffness nonlinearities are introduced into the harvesterâ€™s design by applying a static magnetic field near the tip of the beam. Experimental studies performed on the proposed harvester are presented to validate some of the theoretical findings. Since nonlinear energy harvesters exhibit complex and non-unique responses, it is demonstrated that a careful choice of the design parameters namely, the shape of the potential function and the electromechanical coupling is necessary to widen their effective frequency bandwidth. Specifically, it is shown that, decreasing the electromechanical coupling and/or designing the potential energy function to… Advisors/Committee Members: Daqaq, Mohammed F, Vahidi, Ardalan, Li, Gang, Tallapragada, Phanindra.

Subjects/Keywords: Mechanical Engineering

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APA (6^th Edition):

Panyam Mohan Ram, M. (2015). Characterizing the Effective Bandwidth of Nonlinear Vibratory Energy Harvesters Possessing Multiple Stable Equilibria. (Doctoral Dissertation). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_dissertations/1578

Chicago Manual of Style (16^th Edition):

Panyam Mohan Ram, Meghashyam. “Characterizing the Effective Bandwidth of Nonlinear Vibratory Energy Harvesters Possessing Multiple Stable Equilibria.” 2015. Doctoral Dissertation, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_dissertations/1578.

MLA Handbook (7^th Edition):

Panyam Mohan Ram, Meghashyam. “Characterizing the Effective Bandwidth of Nonlinear Vibratory Energy Harvesters Possessing Multiple Stable Equilibria.” 2015. Web. 16 Jan 2021.

Vancouver:

Panyam Mohan Ram M. Characterizing the Effective Bandwidth of Nonlinear Vibratory Energy Harvesters Possessing Multiple Stable Equilibria. [Internet] [Doctoral dissertation]. Clemson University; 2015. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_dissertations/1578.

Council of Science Editors:

Panyam Mohan Ram M. Characterizing the Effective Bandwidth of Nonlinear Vibratory Energy Harvesters Possessing Multiple Stable Equilibria. [Doctoral Dissertation]. Clemson University; 2015. Available from: https://tigerprints.clemson.edu/all_dissertations/1578

Clemson University

21. Keni, Saurabh. Stability Analysis and Decentralized Control of Coupled Oscillators with Feedback Delays.

Degree: MS, Mechanical Engineering, 2008, Clemson University

URL: https://tigerprints.clemson.edu/all_theses/416

► Most dynamic systems do not react instantaneously to actuation signals. The temporal evolution of some others is based on retarded communications or depends on information… (more)

▼ Most dynamic systems do not react instantaneously to actuation signals. The temporal evolution of some others is based on retarded communications or depends on information from the past. In such cases, the mathematical models used to describe these systems must include information about the past dynamics of the states. These models are often referred to as delay or retarded systems. Delays could channel energy in and out of a system at incorrect time intervals producing instabilities and rendering controllers' performance ineffective. The purpose of this research is two folds. The first investigates the effect of inherent system delays on the stability of coupled oscillators subjected to decentralized control and the second studies the prospectus of augmenting the delay into a larger delay period that could actually stabilize the coupled system and enhance its damping characteristics. Towards these ends, a system of two linearly-coupled oscillators with decentralized delayed-proportional feedback is considered. A comprehensive linear stability analysis is utilized to generate maps that divide the controllers' gain and delay domain into regions of stability for different coupling values. These maps are then used to draw definite conclusions about the effect of coupling on the stability of the closed-loop in the presence of delay. Once the stability maps are generated, the Lambert-W function approach is utilized to find the stability exponents of the coupled system which, in turn, is used to generate damping contours within the pockets of stability. These contours are used to choose gain-delay combinations that could augment the inherent feedback delays into a larger delay period which can enhance the damping characteristics and reduce the system settling time significantly. An experimental plant comprised of two mass-spring-damper trios coupled with a spring is installed to validate the theoretical results and the proposed control hypothesis. Different scenarios consisting of different gains and delays are considered and compared with theoretical findings demonstrating very good agreement. Furthermore, the proposed delayed-proportional feedback decentralized controller is tested and its ability to dampen external oscillations is verified through different experiments. Such a research endeavor could prove very beneficial to many vital areas in our life. A good example is that of the coupled system of the natural and artificial cardiac pacemakers where the natural pacemaker represents a rhythmic oscillating system and the coupled artificial pacemaker provides a stabilizing signal through a feedback mechanism that senses the loss in rhythm. In this system, even the minute amount of delay in the sensing-actuating could prove very detrimental. The result of this research contributes to the solution of this and similar problems. Advisors/Committee Members: Vahidi, Ardalan, Thompson , Lonny.

Subjects/Keywords: Engineering Mechanics

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APA (6^th Edition):

Keni, S. (2008). Stability Analysis and Decentralized Control of Coupled Oscillators with Feedback Delays. (Masters Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/416

Chicago Manual of Style (16^th Edition):

Keni, Saurabh. “Stability Analysis and Decentralized Control of Coupled Oscillators with Feedback Delays.” 2008. Masters Thesis, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_theses/416.

MLA Handbook (7^th Edition):

Keni, Saurabh. “Stability Analysis and Decentralized Control of Coupled Oscillators with Feedback Delays.” 2008. Web. 16 Jan 2021.

Vancouver:

Keni S. Stability Analysis and Decentralized Control of Coupled Oscillators with Feedback Delays. [Internet] [Masters thesis]. Clemson University; 2008. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_theses/416.

Council of Science Editors:

Keni S. Stability Analysis and Decentralized Control of Coupled Oscillators with Feedback Delays. [Masters Thesis]. Clemson University; 2008. Available from: https://tigerprints.clemson.edu/all_theses/416

Clemson University

22. Turlapati, Venkat vijay kishore. Modeling and Optimization of a Plug-in hybrid electric vehicle.

Degree: MS, Mechanical Engineering, 2010, Clemson University

URL: https://tigerprints.clemson.edu/all_theses/917

► Today, the world is faced with a situation where new technologies have to be developed to decrease the dependence on natural non-renewable resources. Each… (more)

▼ Today, the world is faced with a situation where new technologies have to be developed to decrease the dependence on natural non-renewable resources. Each day, as the demand for non-renewable resources increases, it puts great pressure on the scientific fraternity to develop new technologies that are aimed at reducing this dependence. Today's road traffic plays a major part in the energy consumption worldwide. Hence it is imperative that we develop environmentally friendly solutions to this problem that arises in the transportation sector. Hybrid vehicle is one of the alternatives that can be seen as a viable solution to this energy crisis. The recent strides in the field of controls and optimization has led to the evolution of new control and optimization tools to target several simultaneous objectives in a plug-in hybrid electric vehicle. The control strategies primarily target the minimization of fuel consumption, while meeting the power demand and also enhancing the drivability. The present work deals with the backward and forward modeling of a Power Split Plug-in Hybrid electric Vehicle. The Power-split plug-in hybrid electric vehicle is a combination of both series and parallel hybrid electric vehicles. A power split hybrid derives its name from the power split device namely the planetary gear set. The planetary gear set splits the engine power, allowing for both series and parallel modes. The model developed incorporates the fuel consumption minimization principle viz. Equivalent Consumption Minimization Principle(ECMS). ECMS principle deals with assigning future fuel costs and savings to the actual usage of electrical energy. Thus, the present usage of electrical energy would mean that this energy has to be balanced by replenishment in terms of future fuel costs and the present usage of fuel for replenishment would be associated with future savings as this energy is available at a lower cost. The ECMS principle used for optimization provided the necessary minimization by maintaining the State of Charge of Renewable Electrical Storage System(RESS) within the prescribed limits. When properly designed by appropriately tuning the Charging and Discharging coefficients in the minimization strategy, we can optimize the vehicle performance over a given cycle, with the generation of power being intact and perhaps more to conform to the best emission standards in any part of the world. Advisors/Committee Members: Pisu, Pierluigi, Vahidi , Ardalan.

Subjects/Keywords: Engineering Mechanics

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APA (6^th Edition):

Turlapati, V. v. k. (2010). Modeling and Optimization of a Plug-in hybrid electric vehicle. (Masters Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/917

Chicago Manual of Style (16^th Edition):

Turlapati, Venkat vijay kishore. “Modeling and Optimization of a Plug-in hybrid electric vehicle.” 2010. Masters Thesis, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_theses/917.

MLA Handbook (7^th Edition):

Turlapati, Venkat vijay kishore. “Modeling and Optimization of a Plug-in hybrid electric vehicle.” 2010. Web. 16 Jan 2021.

Vancouver:

Turlapati Vvk. Modeling and Optimization of a Plug-in hybrid electric vehicle. [Internet] [Masters thesis]. Clemson University; 2010. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_theses/917.

Council of Science Editors:

Turlapati Vvk. Modeling and Optimization of a Plug-in hybrid electric vehicle. [Masters Thesis]. Clemson University; 2010. Available from: https://tigerprints.clemson.edu/all_theses/917

Clemson University

23. Ghotikar, Tejas. ESTIMATION OF VEHICLE MASS AND ROAD GRADE.

Degree: MS, Mechanical Engineering, 2008, Clemson University

URL: https://tigerprints.clemson.edu/all_theses/412

► This thesis describes development of a real-time-implementable algorithm for simultaneous estimation of a heavy vehicle's mass and time-varying road grade and its verification with experimental… (more)

▼ This thesis describes development of a real-time-implementable algorithm for simultaneous estimation of a heavy vehicle's mass and time-varying road grade and its verification with experimental data. Accurate estimate of a heavy vehicle's mass is critical in several vehicle control functions such as in transmission and stability control. The goal is to utilize the standard signals on a vehicle in a model-based estimation strategy, as opposed to a more costly sensor-based approach. The challenge is that unknown road grade complicates model-based estimation of vehicle mass and therefore the time-varying grade should be estimated simultaneously. In addition an estimate of road grade may be used as a feedforward input to transmission control and cruise control systems enhancing their responsiveness. The vehicle longitudinal dynamics model (F=ma) forms the core of this model-based approach. Mathematically this is a single equation with one unknown parameter (mass) and one time-varying input disturbance (grade). The goal is to estimate the constant parameter and time-varying grade by using engine torque and speed, vehicle speed and transmission state. The problem is fundamentally difficult because of i) variation of grade over time ii) lack of ``rich'' data during most of vehicle's cruise time, iii) uncertainty about available traction force during gear-shift periods and braking, and iv) low signal-to-noise ratio for vehicle acceleration signal. We have tested two independent estimation schemes using experimental data sets provided by Eaton Corporation. The first algorithm uses recursive least square with two forgetting factors for simultaneous estimation of mass and grade. The second algorithm is a two-stage scheme which cascades a Lyapunov-based nonlinear estimator next to a recursive least square scheme. These algorithms were conceived in our group in the past; however they needed modification and refinements for robust real-time implementation. After these refinements, the modified algorithms are capable of generating estimates for mass and time-varying road grade which are more accurate in realistic scenarios and for most part of the vehicle run. More specifically we are able to generate very accurate estimates of road grade, when the clutch is fully engaged and we have proposed fixes that improve the quality of estimates even during periods of gear change. Provided persistence of excitations we are able to generate accurate estimates of mass which in turn improves the quality of grade estimate. It is important to robustify initialization of algorithm 1 further which is now sensitive to an initial batch size; a task listed in the future work. Algorithm 2 does not rely on an initial batch and therefore is expected to be adopted as the preferred approach for implementation. Advisors/Committee Members: Vahidi, Ardalan, Thompson , Lonny, Ayalew , Beshah.

Subjects/Keywords: Engineering Mechanics

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APA (6^th Edition):

Ghotikar, T. (2008). ESTIMATION OF VEHICLE MASS AND ROAD GRADE. (Masters Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/412

Chicago Manual of Style (16^th Edition):

Ghotikar, Tejas. “ESTIMATION OF VEHICLE MASS AND ROAD GRADE.” 2008. Masters Thesis, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_theses/412.

MLA Handbook (7^th Edition):

Ghotikar, Tejas. “ESTIMATION OF VEHICLE MASS AND ROAD GRADE.” 2008. Web. 16 Jan 2021.

Vancouver:

Ghotikar T. ESTIMATION OF VEHICLE MASS AND ROAD GRADE. [Internet] [Masters thesis]. Clemson University; 2008. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_theses/412.

Council of Science Editors:

Ghotikar T. ESTIMATION OF VEHICLE MASS AND ROAD GRADE. [Masters Thesis]. Clemson University; 2008. Available from: https://tigerprints.clemson.edu/all_theses/412

Clemson University

24. Greenwell, Wesley. Real-Time Power Management of A Fuel Cell/Ultracapacitor Hybrid.

Degree: MS, Mechanical Engineering, 2008, Clemson University

URL: https://tigerprints.clemson.edu/all_theses/386

► This thesis presents the system architecture design, system integration methodology, and real-time control of a fuel cell/ultracapacitor hybrid power system. The main objective is for… (more)

▼ This thesis presents the system architecture design, system integration methodology, and real-time control of a fuel cell/ultracapacitor hybrid power system. The main objective is for the hybrid system to respond to real-world fluctuations in power without negatively impacting fuel cell life. A Proton Exchange Membrane (PEM) Fuel Cell is an electrochemical device which converts the chemical energy of pure hydrogen into electricity through a chemical reaction with oxygen. The high conversion efficiency, zero harmful emissions, high power-to-weight ratio, scalability, and low temperature operation make PEM fuel cells very attractive for stationary and portable power applications. However, fuel cells are limited in responding to fast transients in power demand, moreover power fluctuations have negative impact on fuel cell durability. This motivates the use of a supplementary energy storage device to assist the fuel cell by buffering sharp transients in power demand. The high power density, long cycle life, and efficiency of ultracapacitors make them an ideal solution for such auxiliary energy storage in a hybrid fuel cell system. The power management strategy that determines the power split between the fuel cell and ultracapacitor is key to the power following capability, long-term performance, and life-time of the fuel cell. In this thesis, a rule-based and a model predictive control strategy are designed, implemented and evaluated for power management of a fuel cell/ultracapacitor hybrid. The high-level control objectives are to respond to rapid variations in load while minimizing damaging fluctuations in fuel cell current and maintaining ultracapacitor charge (or voltage) within allowable bounds. An experimental test stand was created to evaluate the performance of the controllers. The test stand connects the fuel cell and ultracapacitor to an electronic load through two dc/dc converters, which provide two degrees of freedom, enabling independent low-level control of the DC BUS voltage and the current split between the fuel cell and ultracapacitor. Experiments show that both rule-based and model predictive power management strategies can be tuned to meet both high and low-level control objectives for a given power demand profile. However, the capability to explicitly enforce the constraints in model predictive scheme and its predictive nature in meeting power demands enables a more systematic design and results in general in smoother performance. Advisors/Committee Members: Vahidi, Ardalan, Wagner , John, Collins , Randy.

Subjects/Keywords: fuel cell; ultracapacitor; power managment; hybrid; Engineering Mechanics

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APA (6^th Edition):

Greenwell, W. (2008). Real-Time Power Management of A Fuel Cell/Ultracapacitor Hybrid. (Masters Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/386

Chicago Manual of Style (16^th Edition):

Greenwell, Wesley. “Real-Time Power Management of A Fuel Cell/Ultracapacitor Hybrid.” 2008. Masters Thesis, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_theses/386.

MLA Handbook (7^th Edition):

Greenwell, Wesley. “Real-Time Power Management of A Fuel Cell/Ultracapacitor Hybrid.” 2008. Web. 16 Jan 2021.

Vancouver:

Greenwell W. Real-Time Power Management of A Fuel Cell/Ultracapacitor Hybrid. [Internet] [Masters thesis]. Clemson University; 2008. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_theses/386.

Council of Science Editors:

Greenwell W. Real-Time Power Management of A Fuel Cell/Ultracapacitor Hybrid. [Masters Thesis]. Clemson University; 2008. Available from: https://tigerprints.clemson.edu/all_theses/386

Clemson University

25. Asadi, Behrang. PREDICTIVE ENERGY MANAGEMENT IN SMART VEHICLES: EXPLOITING TRAFFIC AND TRAFFIC SIGNAL PREVIEW FOR FUEL SAVING.

Degree: MS, Mechanical Engineering, 2009, Clemson University

URL: https://tigerprints.clemson.edu/all_theses/755

► This master thesis proposes methods for improving fuel economy and emissions of vehicles via use of future information of state of traffic lights, traffic flow,… (more)

Subjects/Keywords: Energy Management; Fuel Economy; Intelligent Transportation Systems; Predictive Cruise Control; Smart Vehicle; Traffic Management; Engineering Mechanics

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APA (6^th Edition):

Asadi, B. (2009). PREDICTIVE ENERGY MANAGEMENT IN SMART VEHICLES: EXPLOITING TRAFFIC AND TRAFFIC SIGNAL PREVIEW FOR FUEL SAVING. (Masters Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/755

Chicago Manual of Style (16^th Edition):

Asadi, Behrang. “PREDICTIVE ENERGY MANAGEMENT IN SMART VEHICLES: EXPLOITING TRAFFIC AND TRAFFIC SIGNAL PREVIEW FOR FUEL SAVING.” 2009. Masters Thesis, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_theses/755.

MLA Handbook (7^th Edition):

Asadi, Behrang. “PREDICTIVE ENERGY MANAGEMENT IN SMART VEHICLES: EXPLOITING TRAFFIC AND TRAFFIC SIGNAL PREVIEW FOR FUEL SAVING.” 2009. Web. 16 Jan 2021.

Vancouver:

Asadi B. PREDICTIVE ENERGY MANAGEMENT IN SMART VEHICLES: EXPLOITING TRAFFIC AND TRAFFIC SIGNAL PREVIEW FOR FUEL SAVING. [Internet] [Masters thesis]. Clemson University; 2009. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_theses/755.

Council of Science Editors:

Asadi B. PREDICTIVE ENERGY MANAGEMENT IN SMART VEHICLES: EXPLOITING TRAFFIC AND TRAFFIC SIGNAL PREVIEW FOR FUEL SAVING. [Masters Thesis]. Clemson University; 2009. Available from: https://tigerprints.clemson.edu/all_theses/755

Clemson University

26. Schepmann, Seneca. Ultracapacitor Heavy Hybrid Vehicle: Model Predictive Control Using Future Information to Improve Fuel Consumption.

Degree: MS, Mechanical Engineering, 2010, Clemson University

URL: https://tigerprints.clemson.edu/all_theses/886

► This research is concerned with the improvement in the fuel economy of heavy transport vehicles through the use of high power ultracapacitors in a mild… (more)

▼ This research is concerned with the improvement in the fuel economy of heavy transport vehicles through the use of high power ultracapacitors in a mild hybrid electric vehicle platform. Previous work has shown the potential for up to 15% improvement on a hybrid SUV platform, but preliminary simulations have shown the potential improvement for larger vehicles is much higher. Based on vehicle modeling information from the high fidelity, forward-looking modeling and simulation program Powertrain Systems Analysis Toolkit (PSAT), a mild parallel heavy ultracapacitor hybrid electric vehicle model is developed and validated to known vehicle performance measures. The vehicle is hybridized using a 75kW motor and small energy storage ultracapacitor pack of 56 Farads at 145 Volts. Among all hybridizing energy storage technologies, ultracapacitors pack extraordinary power capability, cycle lifetime, and ruggedness and as such are well suited to reducing the large power transients of a heavy vehicle. The control challenge is to effectively manage the very small energy buffer (a few hundred Watt-hours) the ultracapacitors provide to maximize the potential fuel economy. The optimal control technique of Dynamic Programming is first used on the vehicle model to obtain the 'best possible' fuel economy for the vehicle over the driving cycles. A variety of energy storage parameters are investigated to aid in determining the best ultracapacitor system characteristics and the resulting effects this has on the fuel economy. On a real vehicle, the Dynamic Programming method is not very useful since it is computationally demanding and requires predetermined vehicle torque demands to carry out the optimization. The Model Predictive Control (MPC) method is an optimization-based receding horizon control strategy which has shown potential as a powertrain control strategy in hybrid vehicles. An MPC strategy is developed for the hybrid vehicle based on an exponential decay torque prediction method which can achieve near-optimal fuel consumption even for very short prediction horizon lengths of a few seconds. A critical part of the MPC method which can greatly affect the overall control performance is that of the prediction model. The use of telematic based 'future information' to aid in the MPC prediction method is also investigated. Three types of future information currently obtainable from vehicle telematic technologies are speed limits, traffic conditions, and traffic signals, all of which have been incorporated to improve the vehicle fuel economy. Advisors/Committee Members: Vahidi, Ardalan, Wagner , John, Daqaq , Mohammed.

Subjects/Keywords: Heavy Vehicle; Hybrid Vehicle; Model Predictive Control; Optimal Control; Telematics; Ultracapacitors; Engineering Mechanics

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APA (6^th Edition):

Schepmann, S. (2010). Ultracapacitor Heavy Hybrid Vehicle: Model Predictive Control Using Future Information to Improve Fuel Consumption. (Masters Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/886

Chicago Manual of Style (16^th Edition):

Schepmann, Seneca. “Ultracapacitor Heavy Hybrid Vehicle: Model Predictive Control Using Future Information to Improve Fuel Consumption.” 2010. Masters Thesis, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_theses/886.

MLA Handbook (7^th Edition):

Schepmann, Seneca. “Ultracapacitor Heavy Hybrid Vehicle: Model Predictive Control Using Future Information to Improve Fuel Consumption.” 2010. Web. 16 Jan 2021.

Vancouver:

Schepmann S. Ultracapacitor Heavy Hybrid Vehicle: Model Predictive Control Using Future Information to Improve Fuel Consumption. [Internet] [Masters thesis]. Clemson University; 2010. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_theses/886.

Council of Science Editors:

Schepmann S. Ultracapacitor Heavy Hybrid Vehicle: Model Predictive Control Using Future Information to Improve Fuel Consumption. [Masters Thesis]. Clemson University; 2010. Available from: https://tigerprints.clemson.edu/all_theses/886

Clemson University

27. Bibo, Amin. Electromechanical Modeling and Analysis of a Self-excited Micro-power Generator.

Degree: MS, Mechanical Engineering, 2010, Clemson University

URL: https://tigerprints.clemson.edu/all_theses/885

► Micro-power generators (MPGs) are compact, scalable, and low-maintenance energy harvesting devices that capture and transform wasted ambient energy into electricity. Such devices, which are currently… (more)

▼ Micro-power generators (MPGs) are compact, scalable, and low-maintenance energy harvesting devices that capture and transform wasted ambient energy into electricity. Such devices, which are currently being researched as a possible replacement for batteries, can act as a power source to maintain and allow autonomous operations of remote low-power consumption sensors. This thesis introduces a novel MPG which transforms wind energy into electricity via wind-induced self-excited oscillations of piezoelectric cantilever beams. The operation concept of the device is simple: similar to music-playing harmonica that create tones via oscillations of reeds when subjected to air blow, the proposed device uses flow-induced self-excited oscillations of a piezoelectric beam embedded within a cavity to generate electric power. When the volumetric flow rate of air past the beam exceeds a certain threshold, the energy pumped into the structure via nonlinear pressure forces offsets the intrinsic damping in the system setting the beam into self-sustained limit-cycle oscillations as a result of a Hopf bifurcation. The vibratory energy is then converted into electricity through principles of piezoelectricity. The objectives of this thesis are two folds: The first investigates the development of an analytical aero-electromechanical model to describe the response behavior of the device, and the second deals with understanding the influence of the design parameters on its cut-on wind speed and the generated power. To achieve the first objective, we obtain a mathematical model describing the dynamic evolution of the four essential system's parameters. These are the spatial and temporal dynamics of the beam deflection, the temporal dynamics of the voltage developed across the electric load, the temporal evolution of the exciting pressure on the surface of the beam, and the flow rate through the aperture between the beam and the support. The modeling is carried out at three successive levels. First, we employ Hamilton's principle in combination with the nonlinear Euler-Bernoulli's beam theory and the linear constitutive equations of piezoelectricity to obtain the nonlinear partial differential equation relating the flexural dynamics of the beam to the output voltage and the exciting pressure. Second, we use basic electric circuits theories to obtain the nonlinear ordinary differential equation relating the output voltage of the harvester to the strain rate in the piezoelectric layer. Third, assuming that the flow rate through the aperture is irrotational, two dimensional, and steady; we utilize the steady Bernoulli's equation in conjunction with the continuity equation to relate the exciting pressure on the surface of the beam to the in- and outflow rates of air. Subsequently, we use a Galerkin expansion to… Advisors/Committee Members: Daqaq, Mohammed F, Li , Gang, Vahidi , Ardalan.

Subjects/Keywords: Energy Harvesting; Hopf Bifurcation; Self-Excitation; Wind; Engineering Mechanics

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APA (6^th Edition):

Bibo, A. (2010). Electromechanical Modeling and Analysis of a Self-excited Micro-power Generator. (Masters Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/885

Chicago Manual of Style (16^th Edition):

Bibo, Amin. “Electromechanical Modeling and Analysis of a Self-excited Micro-power Generator.” 2010. Masters Thesis, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_theses/885.

MLA Handbook (7^th Edition):

Bibo, Amin. “Electromechanical Modeling and Analysis of a Self-excited Micro-power Generator.” 2010. Web. 16 Jan 2021.

Vancouver:

Bibo A. Electromechanical Modeling and Analysis of a Self-excited Micro-power Generator. [Internet] [Masters thesis]. Clemson University; 2010. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_theses/885.

Council of Science Editors:

Bibo A. Electromechanical Modeling and Analysis of a Self-excited Micro-power Generator. [Masters Thesis]. Clemson University; 2010. Available from: https://tigerprints.clemson.edu/all_theses/885

Clemson University

28. Molla, Sisay. SYSTEM MODELING AND POWER MANAGEMENT STRATEGY FOR A SERIES HYDRAULIC HYBRID VEHICLE.

Degree: MS, Mechanical Engineering, 2010, Clemson University

URL: https://tigerprints.clemson.edu/all_theses/844

► A hydraulic hybrid vehicle draws propulsion power from an internal combustion engine as its prime mover and a gas-charged hydro-pneumatic accumulator as its energy buffer.… (more)

▼ A hydraulic hybrid vehicle draws propulsion power from an internal combustion engine as its prime mover and a gas-charged hydro-pneumatic accumulator as its energy buffer. The accumulator serves the purposes of storing regenerated braking energy and supplementing engine power as determined by an on-board power management strategy. In the configuration known as a series hydraulic hybrid powertrain, the engine is mechanically decoupled from the vehicle's wheels thereby offering excellent opportunities for maximizing energy efficiency and reducing pollutant emissions. This thesis dealt with the development of a causally interconnected, non-linear, dynamic model of a series hydraulic hybrid powertrain featuring independently controllable wheel-end drives. Using the model so developed, the work investigated the potentials of three proposed power management strategies on the fuel/energy use of a test vehicle. The strategies studied included: a real-time implementable rule-based strategy, an on-line solvable instantaneous consumption minimization strategy, and a non-causal trip/globally optimal power management strategy based on dynamic programming. The results indicated that, when properly designed, all three power management strategies can help realize the fuel economy benefits of the proposed hydraulic hybrid drive system. Over a standard city drive cycle, the rule-based power management strategy was shown to provide a fuel economy improvement of more than 30% with four-motor drive over the conventional drive system. The trip/globally optimal strategy obtained via dynamic programming gave an average of over 50% higher fuel economy improvement with four-motor drive. The instantaneous consumption minimization strategy, which is adopted to overcome the non-causality of dynamic programming and the lack of rigorous optimality of the rule-based strategy, gave fuel economy improvements that generally fell between the other two strategies. Results are also included from the analysis of the effects of accumulator size and two-motor vs. four motor drive options along with the choice of the power management strategy. Advisors/Committee Members: Ayalew, Beshah, Vahidi , Ardalan, Law , Harry.

Subjects/Keywords: Dynamic programming and ECMS strategy for hybrid vehicles; Hydraulic hybrid vehicles; Independent wheel drive system; Modeling of a hydraulic hybrid vehicle; Optimization based power management strategy; Series hybrid Vehicles; Engineering Mechanics

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

APA (6^th Edition):

Molla, S. (2010). SYSTEM MODELING AND POWER MANAGEMENT STRATEGY FOR A SERIES HYDRAULIC HYBRID VEHICLE. (Masters Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/844

Chicago Manual of Style (16^th Edition):

Molla, Sisay. “SYSTEM MODELING AND POWER MANAGEMENT STRATEGY FOR A SERIES HYDRAULIC HYBRID VEHICLE.” 2010. Masters Thesis, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_theses/844.

MLA Handbook (7^th Edition):

Molla, Sisay. “SYSTEM MODELING AND POWER MANAGEMENT STRATEGY FOR A SERIES HYDRAULIC HYBRID VEHICLE.” 2010. Web. 16 Jan 2021.

Vancouver:

Molla S. SYSTEM MODELING AND POWER MANAGEMENT STRATEGY FOR A SERIES HYDRAULIC HYBRID VEHICLE. [Internet] [Masters thesis]. Clemson University; 2010. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_theses/844.

Council of Science Editors:

Molla S. SYSTEM MODELING AND POWER MANAGEMENT STRATEGY FOR A SERIES HYDRAULIC HYBRID VEHICLE. [Masters Thesis]. Clemson University; 2010. Available from: https://tigerprints.clemson.edu/all_theses/844

Clemson University

29. Cagle, Clint. Charging Kinetics of Electric Double Layer Capacitors.

Degree: MS, Mechanical Engineering, 2009, Clemson University

URL: https://tigerprints.clemson.edu/all_theses/716

► A recent increase in the popularity of EDLCs and AC-EOF has necessitated a deeper understanding of the structure and charging kinetics of electrical double layers… (more)

Subjects/Keywords: AC Electroosmotic flow; charging; electrical double layer; electrical double layer capacitor; Electrochemical engineering; supercapacitors; Engineering Mechanics

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

APA (6^th Edition):

Cagle, C. (2009). Charging Kinetics of Electric Double Layer Capacitors. (Masters Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/716

Chicago Manual of Style (16^th Edition):

Cagle, Clint. “Charging Kinetics of Electric Double Layer Capacitors.” 2009. Masters Thesis, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_theses/716.

MLA Handbook (7^th Edition):

Cagle, Clint. “Charging Kinetics of Electric Double Layer Capacitors.” 2009. Web. 16 Jan 2021.

Vancouver:

Cagle C. Charging Kinetics of Electric Double Layer Capacitors. [Internet] [Masters thesis]. Clemson University; 2009. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_theses/716.

Council of Science Editors:

Cagle C. Charging Kinetics of Electric Double Layer Capacitors. [Masters Thesis]. Clemson University; 2009. Available from: https://tigerprints.clemson.edu/all_theses/716

Clemson University

30. Rotenberg, Dean. Ultracapacitor Assisted Powertrains: Modeling, Control, Sizing, and The Impact on Fuel Economy.

Degree: MS, Mechanical Engineering, 2008, Clemson University

URL: https://tigerprints.clemson.edu/all_theses/472

► This thesis investigates possible fuel economy gains attainable by a combination of high-power density ultracapacitors (also called supercapacitors) and an induction motor integrated into… (more)

▼ This thesis investigates possible fuel economy gains attainable by a combination of high-power density ultracapacitors (also called supercapacitors) and an induction motor integrated into a conventional vehicle powertrain for power assistance. Periods of quick acceleration require a much higher power output from an automobile than what is encountered under more typical driving conditions. A simple kinetic energy calculation can show that accelerating a 2000 kg vehicle (roughly the size of a Ford Explorer SUV) from 0 to 60 mph in 10 seconds requires almost 70 kW of power, in addition to the power needed to overcome road and air drag forces. Situations such as these consume a disproportionately high amount of fuel, and have a negative impact on the fuel economy of the vehicle. In conventional powertrains, the engine is typically sized much larger than is needed for steady-state operation, in order to meet these spikes in power demand. A larger engine is more expensive to manufacture and to operate. Such rapid transients in power may be better handled by the use of high power density ultracapacitors which represent the latest trend in electrostatic energy storage systems. While the total energy an ultracapacitor can store is typically ten times less than a battery of the same size, the ultracapacitor is capable of releasing or storing energy roughly ten times faster. The potential of this relatively new technology to assist the combustion engine during brief demand spikes, and to capture kinetic energy through regenerative braking, is the subject of this study. A mild parallel hybrid powertrain is considered in which an ultracapacitor-supplied motor assists the engine during periods of high power demand, and the ultracapacitor may be recharged by the engine during periods of low demand, and through regenerative braking. A detailed simulation model of the powertrain is created to evaluate the fuel economy of the vehicle. The fuel economy gains are strongly dependent on how well the power split decision is made, that is the decision of how to distribute the power demand between the engine and the electric motor at each instant in time. To this end two forms of implementable control are designed to determine the power split between the engine and motor. A rule-based controller, which can be quickly tuned and implemented, is applied for more exploratory simulations. Simplicity and expedience in both tuning and implementation make this method useful for testing the impact of different component combinations on fuel economy. After a suitable combination of engine, motor, and ultracapacitor sizes has been determined, an optimization-based power management strategy is created which shows a better overall performance. Various component sizing and control strategies tested consistently indicate a potential for 10 to 15 percent improvement in fuel economy in city driving with the proposed mild hybrid powertrain. This order of improvement to fuel economy was confirmed by deterministic dynamic programming (DDP) which… Advisors/Committee Members: Vahidi, Ardalan, Jalili , Nader, Wagner , John.

Subjects/Keywords: Engineering Mechanics

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

APA (6^th Edition):

Rotenberg, D. (2008). Ultracapacitor Assisted Powertrains: Modeling, Control, Sizing, and The Impact on Fuel Economy. (Masters Thesis). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_theses/472

Chicago Manual of Style (16^th Edition):

Rotenberg, Dean. “Ultracapacitor Assisted Powertrains: Modeling, Control, Sizing, and The Impact on Fuel Economy.” 2008. Masters Thesis, Clemson University. Accessed January 16, 2021. https://tigerprints.clemson.edu/all_theses/472.

MLA Handbook (7^th Edition):

Rotenberg, Dean. “Ultracapacitor Assisted Powertrains: Modeling, Control, Sizing, and The Impact on Fuel Economy.” 2008. Web. 16 Jan 2021.

Vancouver:

Rotenberg D. Ultracapacitor Assisted Powertrains: Modeling, Control, Sizing, and The Impact on Fuel Economy. [Internet] [Masters thesis]. Clemson University; 2008. [cited 2021 Jan 16]. Available from: https://tigerprints.clemson.edu/all_theses/472.

Council of Science Editors:

Rotenberg D. Ultracapacitor Assisted Powertrains: Modeling, Control, Sizing, and The Impact on Fuel Economy. [Masters Thesis]. Clemson University; 2008. Available from: https://tigerprints.clemson.edu/all_theses/472

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