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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.
21

Design and implementation of three-phase inverters using a TMS320F2812 digital signal processor

Lee, Duehee 08 September 2010 (has links)
The goal of this thesis project was to design and build a three-phase inverter controlled by the TMS320F2812 DSP by Texas Instruments. The TMS320F2812 is controlled in order to make inverters generate output waveforms which mimic the main reference signal coming from a computer. The project included building three different inverters on two platforms including auxiliary circuits and designing five pulse width modulation (PWM) switching algorithms for the inverters. The motivation was that a newly designed inverter was required as an intermediary device between a computer and a laboratory-scaled model of a wind turbine. This type of wind turbine is used to educate students and engineers and to extract experimental wind power data. However, since commercial inverters don’t follow the main reference signal which is sent from the computer in order to operate the laboratory-scaled wind turbine, a controllable and variable inverter needed to be designed to receive that signal. The results are as follows. The voltage source inverter (VSI) and the current-controlled voltage source inverter (CC-VSI) were built on the VSI platform, and the current source inverter (CSI) was built on the CSI platform. Furthermore, the TMS320F2812’s analog digital converter (ADC) driver circuit and the output LC filter were also designed as auxiliary circuits. Five PWM switching programs were written; three switching algorithms for the VSI, and one algorithm each for the CC-VSI and the CSI. The output waveforms from the combination of hardware and software mentioned above were captured, and they follow the main reference signal very well. Although each of the inverters performed well, the VSI in combination with the Space Vector PWM switching algorithm produced the cleanest output voltage waveforms with the least amount of noise. The inverters built in this thesis project can be applied to the laboratory-scaled wind turbine, the maximum power tracking in solar panels, and equipment for analyzing digital signal processing. However, before using the inverters in those applications, much work remains to be done to solve the problems related to the signal distortion caused by the dead band time, harmonic signals caused by the fixed switching frequency, and the reliability issues caused by mounting on the bread board. In conclusion, although this thesis does not illustrate the entire process of or explain every requirement for building the three inverters, enough information about the topology of the inverters, the hardware design, and the PWM switching algorithms is provided in this thesis to enable one to remake all three of the three-phase inverters. / text
22

DSP Based Speech keyword Retrieval and Recognition System

Juang, Bo-Ya 27 July 2004 (has links)
This thesis established the DSP-based and PC-based system for speech keyword retrieval and recognition according to the same basic algorithm. This system does not need to train speech models, and the keywords and describing sentences do not put the limit of the number of words and could be any language. Before calculating the speech features, the speech signal need to be pre-processed. The pre-process includes DC bias removing, segment, Rabiner & Sambur end point detection, pre-emphasis, and windowing. About the speech features, the system used 12 degrees of Mel-Frequency cepstral coefficient and 12 degrees of delta coefficient to make a 24-degreed speech feature. The key point of the system is the process of pattern comparison. The system adopted dynamic time warping cooperating with one pass algorithm to improve the optimal process. In order to attain the DSP system, using an optimum likelihood ratio threshold to be the determine standard for not keyword rejection. All of the keywords use the same threshold in the method. It improves the original method which uses least differential to set up the threshold by reducing the requirement of ram. After testing in the experiments, the speech keyword retrieval and recognition system both have great recognition and efficiency.
23

DSP-Based Development of Tracking System for Multiple Persons

Yang, Chi-Yu 23 August 2006 (has links)
The purpose of this thesis is to develop a set of tracking systems for Multiple Persons on DSP-Based. There are three sub-systems in our tracking system, including ¡§Moving Object Detection¡¨, ¡§Contour Matching¡¨ and ¡§Ellipse Algorism¡¨. First of all, the system utilizes CCD camera to capture the image which we want to control, and then detects the moving object from the continuous image array. If the system detects an invador, it will make the position of this invador with the coordinate projection, and then lock the invador's head to track. Finally, the tracking system marks the coordinate separately and exports it in LCD. From the results of the experiment, this system does meet the expectation and obtain good performance and strong robustness.
24

ON-Line DSP-Based Uninterrupt Power Supply

Hu, Jenchieh 26 July 2001 (has links)
This thesis designs a DSP-based controller which is composed of two parts,voltage controller and current controller.A proportional controller,treated as the current controller,is designed in the inner loop to control the capacitor charging current fast and effectively,especially when the sudden load is occurred.An PI controller,treated as the voltage controller,is designed in the outer loop to improve the system response irrespectively of system¡¦s parameter variation and load disturbance.The experimental result shows the output voltage can follow a sin wave which can match command exactly under the control scheme.
25

Design and Implementation of Multi-function Monitoring Control System

Chung, Hung-Rung 30 July 2001 (has links)
This paper designs and implements a DSP based Multi-function Monitoring Control System, operate for induction motor, intelligent battery charger and residual capacity estimator and Uninterrupt Power System to develop effectively and complete well. This paper that Multi-function Monitoring Control System set up RS-232 standard, to use Asynchronous Receiver Transmitter Communication, to use DSP software refinement, to solve using ¡§8250¡¨ that Communication IC complete PC and DSP Communication generally. And DSP software monitor and control that induction motor, intelligent battery charger and residual capacity estimator and Uninterrupt Power System well. Monitoring control system utilize DSP operate very fast¡Aso DSP software function to supply hardware work¡Ato reduce prime cost.
26

Prototype Research and Development of DSP-Based Motion Control Card with USB2.0 Interface

Chao, Ping-Hsia 09 July 2002 (has links)
The thesis will be established as prototype of DSP-Based motion control card with USB2.0 interface. The whole system is composed of three subsystems: 1. Windows AP¡]Application Program¡^, 2.USB2.0 development tools, and 3.DSP development tools. Many motion control commands can be transmitted from friendly AP, through USB2.0 development board, to DSP development board, for example, position, velocity and acceleration. DSP will parse and execute these commands immediately; furthermore, the course and result of processing can be sent back to host by the same route. Then AP can display the data received from target with high readability. In a word, proved by experiment, the thesis achieved the expected goal: accomplish the prototype research and development of DSP-Based motion control card with USB2.0 interface.
27

Neonatal DSP-4 Treatment Impairs 5-HT<sub>1b</sub> Receptor Reactivity in Adult Rats. Behavioral and Biochemical Studies

Ferdyn-Drosik, Marzena, Nowak, Przemysław, Bojanek, Kamila, Bałasz, Michał, Kasperski, Jacek, Skaba, Dariusz, Muchacki, Rafał, Kostrzewa, Richard M. 01 January 2010 (has links)
To examine the effect of a central noradrenergic lesion on the reactivity of the 5-HT1B receptor we compared intact male rats with rats in which noradrenergic nerve terminals were largely destroyed with the neurotoxin DSP-4 (50 mg/kg × 2, on the 1st and 3rd days of postnatal life). When rats attained 10 weeks of age, control and DSP-4 rats were divided into two subgroups receiving either saline or the serotonin (5-HT) synthesis inhibitor (p-chlorophenylalanine; p-CPA; 100 mg/kg). Employing an elevated plus maze test, we demonstrated that CP 94,253 (5-propoxy-3-(1,2,3,6-tetrahydro-4-pyridinyl)-1H-pyrrolo[3,2-b]pyridine hydrochloride)(4.0 mg/kg; 5-HT1B agonist) induced an anxiogenic-like action in control rats; however, it failed to elicit this effect in the DSP-4 group. Surprisingly, in p-CPApretreated rats anxiogenic-like activity was observed both in control and DSP-4 treated rats. CP 94,253 significantly attenuated 5-HT synthesis in the medial prefrontal cortex (mPFC) of control rats, and SB 216641 (N-{3-[3-(dimethylamino) ethoxy]-4-methoxyphenyl}-2'-methyl-4'-(5-methyl-1,2,4-oxadiazol-3-yl)-[1,1'-biphenyl]-4-carboxamide hydrochloride) (4.0 mg/kg; 5-HT1B antagonist) was able to antagonize this effect. Conversely, CP 94,253 failed to significantly inhibit the 5-HT synthesis rate in DSP-4-treated rats. In the microdialysis study CP 94,253 induced long-lasting attenuation of 5-HT release in the mPFC of control rats but had no effect in DSP-4 rats. These data lead to the proposal that presynaptic 5-HT1B autoreceptors underwent desensitization in DSP-4 treated rats.
28

A New Standard for Temperature Measurement in an Aviation Environment

Grossman, Hy 10 1900 (has links)
ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, California / Accurate temperature measurement is an essential requirement in modern aircraft data acquisition systems. Both thermocouples and Platinum resistance temperature detectors (RTD) are used for this purpose with the latter being both more accurate and more repeatable. To ensure that only the sensor limits the accuracy of a temperature measurement, end-to-end system accuracy forward of the sensor, should be significantly greater than that of the sensor itself. This paper describes a new digital signal processing (DSP) based system for providing precision RTD based temperature measurements with laboratory accuracy in an aviation environment. Advantages of the new system include, true 3-wire RTD measurement, linear temperature output, on-board ultra-precision resistance standards and transparent dynamic calibration.
29

OVER QUANTIZING, THE NEXT STEP IN DIGITAL SIGNAL PROCESSING

Hicks, William T. 10 1900 (has links)
International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / Simplification of the analog front end of a signal conditioning circuit can be accomplished by over-quantizing the input signal and using DSP for gain and offset. In this case, a much higher precision A/D converter is used than required by the desired output accuracy. The excess bits are then used to allow the DSP math to give an effective gain to the signal. By a similar function, offset of over 100% can be mathematically removed as long as the input signal does not exceed the A/D input voltage range.
30

Antenna Array Beamforming Technology: Enabling Superior Aeronautical Communication Link Performance

Lu, Cheng Y., Zhang, Yimin, Wu, Jinsong, Cook, Paul, Li, Xin, Amin, Moeness 10 1900 (has links)
ITC/USA 2008 Conference Proceedings / The Forty-Fourth Annual International Telemetering Conference and Technical Exhibition / October 27-30, 2008 / Town and Country Resort & Convention Center, San Diego, California / In this paper, we propose the exploitation of array beamforming technology in high-speed aeronautical communication applications, e.g., the integrated Network Enhanced Telemetry (iNET) system. By flexible steering of beams and nulls, an array can enhance desired signals whereas the undesired signals such as interference and jammers are suppressed. The proposed adaptive beamforming technology is DSP-based and network-aware, and is designed for the use at aerial vehicle platforms to increase transmission power efficiency, improve receiving signal sensitivity, mitigate interference/multipath effects, and extend the communication range.

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