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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

REAL-TIME DIGITAL CONTROL FOR BIOMASS LIQUEFACTION SYSTEM (HIGH PRESSURE, TEMPERATURE, MICROPROCESSOR, AUTOCLAVE).

Jośī, Dilīpa. January 1985 (has links)
No description available.
52

Susceptibility of a digital turbine control system to IEEE 802.11 compliant emissions.

Carter, Clinton E. 12 1900 (has links)
Within the nuclear industry, there have been numerous instances of radio transmissions interfering with sensitive plant equipment. Instances documented vary from minor instrument fluctuations to major plant transients including reactor trips. With the nuclear power industry moving toward digital technologies for control and reactor protection systems, concern exists regarding their potential susceptibility to contemporary wireless telecommunications technologies. This study evaluates the susceptibility of Comanche Peak's planned turbine controls upgrade to IEEE 802.11 compliant wireless radio emissions. The study includes a review of previous research, industry emissions standards, and technical overview of the various IEEE 802.11 protocols and details the testing methodology utilized to evaluate the digital control system. The results of this study concluded that the subject digital control system was unaffected by IEEE 802.11 compliant emissions even when the transmitter was in direct contact with sensitive components.
53

A microprocessor controlled data analyzer for single-beam spectrophotometers

Pieszcynski, John Edward. January 1979 (has links)
Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1979. / Includes bibliographical references. / by John Edward Pieszcynski. / Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1979.
54

Applications of pulse width modulation to LEDs, fuel cells and battery technology

Unknown Date (has links)
It has become a case of great desire and, in some instances, a requirement to have systems in engineering be energy efficient, in addition to being effectively powerful. It is rare that there is a single technique that has the range to make this possible in a wide collection of areas in the field. The work done in this thesis exhibits how Pulse Width Modulation (PWM) bridges LEDs, plug in vehicles, fuel cells and batteries, all seemingly different sub categories of electrical engineering. It stems from an undergraduate directed independent study supervised by Dr. Zilouchian that encircled LEDs and electric vehicles and how they contribute to a smart electric grid. This thesis covers the design and development of a prototype board that test how PWM saves energy, prolongs lifespan and provides a host of customizable features in manufactured LED lights that are used in the marine industry. Additionally, the concept of charging batteries that provide power to electric vehicles was explored. It is stressed that consumers who are interested in electric vehicles are concerned about refueling and recharge times. It is natural that a competing product, such as the electric vehicle in a world dominated by internal combustion engines, will perform on par if not better than existing choices. Tests are conducted to investigate the methods of fast battery charging and the challenges this technique creates. Attention is also given to the development of a pulsed Proton Exchange Membrane (PEM) fuel cell, specifically to prove whether pulse modulation is more efficient in a hydrogen producing fuel cell as opposed to direct-driven voltage and current alternatives. / by Wayne W. Watt. / Thesis (M.S.C.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 200?. Mode of access: World Wide Web.
55

Computerised electro-mechanical control of the UWS astronomical telescope and the integration of a multi-tasking television system

Bird, Frank William, University of Western Sydney, College of Health and Science, School of Engineering January 2005 (has links)
Obtaining a very high level of precision and sophistication in automated computer control is now available inexpensively from a variety of hardware and software sources. Applying this automated technology to an astronomical telescope broadens the scope of applications of the instrument, particularly in areas such as photo electrics, CCD imaging and remote control. The ultimate design goal of the UWS telescope was that of full roboticism, giving access of the facility to off campus clients both in Australia and overseas. The first phase towards full robotic control is automation of the required optical and mechanical parameters, providing precision targeting and object tracking. This thesis describes the mechanical aspects of the UWS telescope and the procedures and equipment involved in its automation, including the drive system, electro mechanical design and associated computer hardware and software. Sample performance test data shows that using a high percentage of inexpensive proprietary robotics components, a very sophisticated and accurate measuring device can be produced. / Master of Science (Hons.)
56

Two-axis torque control of BLDC motors for electric vehicle applications.

Shields, Bradley. 29 October 2014 (has links)
This thesis begins with a literature review focusing on electric vehicle (EV) applications. Systems used for steering, braking and energy storage are investigated, with specific concentration on torque control in various DC and AC motors commonly used in EVs. A final solution for a low range personal transportation EV in the form of a wheelchair is proposed. The theme for this thesis is motion control, focusing on a two axis (or two wheel drive) brushless DC hub motor (BLDCHM) EV, with torque and direction control tracking a user reference. The operation principle for a BLDCHM is documented and the dynamic and electrical equations derived. Simulation results for motor response under different load and speed conditions are compared to practical measurements. Current and torque control loops are designed, implemented and tuned on a single-axis test-bed with an induction motor (IM) load coupled via a torque transducer. A Texas Instrument DSP development kit is used for the control algorithm bench testing. The final control algorithm is then duplicated and expanded in simulation to form a dynamic two axis system for an electric wheelchair. It incorporates both motor drive and regenerative capabilities. After demonstrating two axis controls for BLDCHMs, a control algorithm is designed simulated and compared to traditional systems. The final solution focuses specifically on an intuitive response to the driver input whilst maintaining direction tracking, even when there is a difference in smoothness of the individual terrains traversed by the left and right wheels. In addition the motor drives are equipped with controllers that ensure regenerative braking in order to recover as much energy as possible when the wheelchair is commanded to decelerate. / M. Sc. Eng. University of KwaZulu-Natal, Durban 2014.
57

Development of a micro gas analyzer controller and an organic light emitting diode lifetime testing system /

Pirkle, Adam R., January 2008 (has links)
Thesis (M.S.)--University of Texas at Dallas, 2008. / Includes vita. Includes bibliographical references (leaves 85-91)
58

The development of an 8051 micro-controller evaluation and training board

De Beer, Daniel Nel January 1996 (has links)
Thesis MTech(Electrical Engineering)--Cape Technikon, Cape Town, 1996 / The development of the 8051 Evaluation and Training Board was in response to fulfill a need to have a training board available for students at the start of a micro-controller course. This board must be used to get hands-on experience in the internal architecture, programming and operation of the controller through the testing of sample programs and exercises. It can act as an example of a practical micro-controller application board, and also as part of, or as an aid in the design and application of own projects. The board had to be cheap enough so that each student can be issued with a personal board for the duration of the course. It had to be adequately selfsufficient to be portable and to operate independent of a host PC. In addition, it had to contain adequate "intelligence" to guide the student in the use of the board: have a quick re-programming turn-around cycle; and it must be possible to use the board for user program testing and debugging. After drawing up an initial set of objectives and investigating the economic viability of similar systems in industry, an outline of the required design was made. This included the selection of suitable communication between the onboard Operating System and a user; the easiest way to load user programs into the board memory; and methods to test and debug this program. All the normal support circuitry required by a micro-controller to accommodate a minimum system for operation was included into a single Field Programmable Gate Array. The execution of the project was therefore divided into three distinct sections, the hardware, the firmware (Programmable Array configuration) and the software. In the design, the harmony between these sections had to be consolidated to yield a successful final product. The simplicity and ergonomics of the operation and application from a user's point of view, had to be accentuated and kept in mind throughout. In a design of the complexity such as this, careful planning and the investigation of various methods of approach were essential. The use of many computer-aided design and other relevant computer packages was incorporated. Interaction between the user and the Operating System on the board was done through a standard 16-character by 1-line LCD Display Module and a 32-key keyboard. The main feature of the Operating System was to enable the inspection and editing of all the memory locations on the micro-processor.
59

Digital control of a class-D audio amplifier

Quibell, Jason January 2011 (has links)
Thesis (MTech (Electrical Engineering)--Cape Peninsula University of Technology, 2011 / Modern technologies have led to extensive digital music reproduction and distribution. It is fitting then that digital audio be amplified directly from its source rather than being converted to an analogue waveform before amplification. The benefits of using a digital controller for audio processing include being able to easily reconfigure the system and to add additional functions at a later stage. Digital audio is primarily stored as Pulse Code Modulation (PCM) while Pulse Width Modulation (PWM) is the most popular scheme used to drive a class-D amplifier. The class-D amplifier is selected in many applications due to its very high energy efficiency. Conventional PCM to PWM conversion is inherently nonlinear. Various interpolation schemes are presented in this research project which help to address the nonlinearity. Digitally generated PWM has a limited resolution which is constrained by the system clock. This thesis presents noise shaping techniques which increase the effective resolution of the PWM process without having to use an excessively high system clock. Noise shaping allows a low resolution modulator to be used to reproduce high resolution audio.
60

Otimização de parâmetros via metaheuristicas populacionais e validação de um controlador de estrutura variável

Bertachi, Arthur Hirata 25 February 2014 (has links)
CAPES / Este trabalho apresenta a aplicação dos métodos de otimização por enxame de partículas e por colônia de formigas na otimização dos parâmetros de um controlador não linear de estrutura variável baseado em um controlador de variância mínima generalizada. Este controlador é composto por duas parcelas distintas: uma parcela linear e outra não linear. A parcela não linear do controlador apresenta dois parâmetros que afeta diretamente o comportamento do controlador e tais parâmetros são obtidos de maneira empírica. As metaheurísticas foram aplicadas para se obter os valores otimizados destes parâmetros. Foi considerada uma função custo que leva em consideração o erro de rastreamento e a variação da ação de controle. Um exemplo numérico do projeto deste controlador também é apresentado. O controlador otimizado foi experimentado em três plantas reais: controle de velocidade de um servomecanismo, controle de nível e controle de vazão em uma planta didática industrial. Os resultados obtidos enfatizam a melhora do desempenho do controlador com os parâmetros otimizados. Também é apresentada a comparação do desempenho deste controlador com um controlador PI. / This work presents the application of particle swarm optimization and ant colony optimization in the parameters optimization of a non-linear controller with variable structure based on generalized minimum variance control. This controller is composed of two parts: linear and non-linear. The non-linear term of the controller consists of two parameters that directly affects the control action, and are obtained by trial and error. Metaheuristic methods were applied to find out the optimized values of these parameters. The cost function used in metaheuristic methods takes account the error and the control signal. A numerical example of the design of this controller is also presented. Three practical experiments were considered: a servomechanism velocity control and two control loops in a didactic industrial plant, level and flow control. Experimental results emphasize the improvement of the system performance when the optimization methods are applied. A comparision with PI controller is shown.

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