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Fadaptive Backstepping Control Of Active Magnetic Bearings, Silu You Jan 2010

Fadaptive Backstepping Control Of Active Magnetic Bearings, Silu You

ETD Archive

A new control methodology, adaptive backstepping control (ABC), is applied to a linearized model of an active magnetic bearing (AMB). Our control objective is to regulate the deviation of the magnetic bearing from its equilibrium position in the presence of an external disturbance. The control approach is based on adaptive backstepping control, which is a combination of a recursive Lyapunov controller and adaptive laws. In this thesis, two types of adaptive backstepping methods are used. The first method is based on full-state feedback, for which all three states in the linearized AMB model (velocity, position, and current) are used to …


Sensing And Control Of Mems Accelerometers Using Kalman Filter, Kai Zhang Jan 2010

Sensing And Control Of Mems Accelerometers Using Kalman Filter, Kai Zhang

ETD Archive

Surface micromachined low-capacitance MEMS capacitive accelerometers which integrated CMOS readout circuit generally have a noise above 0.02g. Force-to-rebalance feedback control that is commonly used in MEMS accelerometers can improve the performances of accelerometers such as increasing their stability, bandwidth and dynamic range. However, the controller also increases the noise floor. There are two major sources of the noise in MEMS accelerometer. They are electronic noise from the CMOS readout circuit and thermal-mechanical Brownian noise caused by damping. Kalman filter is an effective solution to the problem of reducing the effects of the noises through estimating and canceling the states contaminated …


Automatic Utility Meter Reading, Kaicheng Xie Jan 2010

Automatic Utility Meter Reading, Kaicheng Xie

ETD Archive

This thesis discusses research in the automation of reading a utility meter. The hardware required is a wireless camera pointed at the meter to be read. This meter can be a water, electricity or gas meter. After the wireless camera collects the image from the utility meter it transmits the image to a computer through a receiver. The computer analyzes the image with pattern recognition technology to obtain the numbers. We use image processing techniques in this thesis, including image preprocessing, image segmentation (Otsu threshold method), and number recognition. Finally we create a graphical user interface using Visual C#®


Evaluation And Comparison Of Mac Protocols In Wireless Sensor Networks, Sharmila Kollipara Jan 2010

Evaluation And Comparison Of Mac Protocols In Wireless Sensor Networks, Sharmila Kollipara

ETD Archive

Wireless sensor network applications call for different kinds of network protocols at different levels of the network stack based on application requirements. A number of medium access control (MAC) protocols have been proposed in the literature. Evaluation of most of these MAC protocols have typically been based on simulation, and while such simulation provides interesting insight into the behavior of these protocols, artifacts caused by behavior of hardware is ignored. Further more, MAC protocols are usually evaluated by comparing the new protocol with others based on one or two metrics, the ones that determined the design decisions for the protocol …


A Generalized Inverter Control Method For A Variable Speed Wind Power System Under Unbalanced Operating Conditions, Shuang Wu Jan 2010

A Generalized Inverter Control Method For A Variable Speed Wind Power System Under Unbalanced Operating Conditions, Shuang Wu

ETD Archive

This thesis presents a generalized control method for complete harmonic elimination and adjustable power factor of a grid side inverter under unbalanced operating conditions used in variable speed wind power systems. The theoretical analysis of the proposed control method is described and verified by simulation in Simulink®. Two types of traditional control methods are also explained and applied in the wind power system for comparison, which are the indirect current control in a-b-c reference frame and the active and reactive power control in d-q synchronous frame. This method is verified for the gird fault right-through operation as well


Dc-Dc Power Converter Design For Application In Welding Power Source For The Retail Market, Edward J. Oshaben Jan 2010

Dc-Dc Power Converter Design For Application In Welding Power Source For The Retail Market, Edward J. Oshaben

ETD Archive

The purpose of this study is to design and analyze a DC-DC power converter for application in a welding power source that is cost-competitive with the more traditional, lower-tech welding power source topologies. This thesis first presents a background study of recent design approaches to DC-DC power converters, as they relate to application in welding power converters. The background study also surveys recent design approaches to welding power source controls. Evaluation of available options in DC-DC converter topologies and switching schemes for application in a welding power source is presented. Design methodology of a low-cost DC-DC converter for application in …


Implementation And Evaluation Of A Tdma Based Protocol For Wireless Sensor Networks, Robert M. Fiske Jan 2010

Implementation And Evaluation Of A Tdma Based Protocol For Wireless Sensor Networks, Robert M. Fiske

ETD Archive

When evaluating MAC layer network protocols for wireless sensor networks performing simulations of a protocol's operation can provide great insight into the performance of the protocol. In order to prove that a protocol will work in a real setting and not just at the theoretical level, however, there is no substitute for evaluation with a physical implementation. This thesis discusses a physical implementation and evaluation of the Many-to-One-Sensor-to-Sink (MOSS) MAC layer protocol for sink based wireless sensor networks using the MAC Layer Architecture for TinyOS. MOSS is a Time Division Multiple Access (TDMA) based protocol first proposed in an earlier …


Experimental Study Of Cooperative Communication Using Software Defined Radios, Murali Krishna Marunganti Jan 2010

Experimental Study Of Cooperative Communication Using Software Defined Radios, Murali Krishna Marunganti

ETD Archive

The aim of this thesis is to implement and test a real time wireless communication environment. Cooperative Communication is one of the methods by which a reliable communication can be obtained. This is performed using a Software Defined Radio. The received output is compared with the actual signal that is transmitted over the wireless channel. The wireless communications are often hindered by the noisy environments and make the system unreliable. The interference from neighboring nodes also poses a major disadvantage. There is a necessity to improve the performance of the system where the neighbor nodes can work in coordination with …


Computational Complexity Of Signal Processing Functions In Software Radio, Kushal Y. Shah Jan 2010

Computational Complexity Of Signal Processing Functions In Software Radio, Kushal Y. Shah

ETD Archive

The increased usage of mobile communication devices has imposed a challenge of achieving efficient communication with minimum power consumption. Moreover, with the advent of software defined radios (SDR), it is highly possible that signal processing functions would be implemented in software in future mobile devices. Hence, the power consumption of these future devices will be directly related to the power consumed by the processor that executes SDR software. This thesis aims at analyzing the computational complexity of different modulation schemes and signal processing communication functions of IEEE WiFi standard. This analysis provides good insight on how the computational load varies …


A Light Weight Fault Tolerance Framework For Web Services, Srikanth Dropati Jan 2010

A Light Weight Fault Tolerance Framework For Web Services, Srikanth Dropati

ETD Archive

The increased usage of web services by many of the corporate industries to exchange their critical information over World Wide Web has directly impacted the need for high availability of web services. So in this work of ours we designed and developed a light weight fault tolerance framework for web services, by strictly biding ourselves to the design specifications of web services. We developed our framework by extending the open source implementation of Web services reliable messaging specifications. Our framework provides fault tolerance capability using the replication strategy, and can easily be reverted back to basic point to point reliable …


Dynamics And Control Of An Electric Power Assist Steering System, Prasanth Babu Kandula Jan 2010

Dynamics And Control Of An Electric Power Assist Steering System, Prasanth Babu Kandula

ETD Archive

In this thesis an Active Disturbance Rejection Controller (ADRC) is applied to Electrical Power Assist Steering (EPAS) system which assists the driver in steering the steering wheel of an automobile. Our control objective is to reduce the steering torque exerted by a driver, so that good steering feel of the driver will be achieved in the presence of external disturbances and system uncertainties which are very common in the EPAS system. The robustness and stability of ADRC controlled EPAS system is investigated through frequency-domain analyses. The Bode diagrams and stability margins demonstrate that the control system is stable during the …


Reverse Engineering Aspects To Derive Application Class Models, Irenee Morcos George Magdalla Jan 2010

Reverse Engineering Aspects To Derive Application Class Models, Irenee Morcos George Magdalla

ETD Archive

Aspects provide a nice way to modify behavior and implement cross-cutting concerns in object-oriented systems. As such, aspects do not have an existence of their own the application classes that the aspects refer to must be present in order to instantiate the aspects. In this research, we present a reverse engineering approach to generate a minimal class model that has all the structural elements necessary in order to complete exercise a set of aspects