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Real-time spectral analysis in LabVIEW software environment
Vašátko, Karel ; Průša, Zdeněk (referee) ; Rášo, Ondřej (advisor)
This bachelor thesis deals with issues of signal processing and display its spektrum in the environtment LabVIEW. Here is description signal processing theory, description of a block diagram of a spectral analysis and description of the methods for compute power spectral density. In the main part is a description of program developed for real-time spectral analysis. Part contains block diagrams and measurements.
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Pulse Detection from Video
Matuszek, Martin ; Hradiš, Michal (referee) ; Szentandrási, István (advisor)
The aim of the Master's thesis was to study contemporary methods for human pulse detection from standard video and suggest a method, which can be used to detect the pulse. Approaches of detecting miniature changes between frames of a video are presented. Position changes of the feature points or changes in colour of some part of an image are detected. It capitalize on the fact that those changes are caused by the pulse of blood. The method for color changes magnification is selected as a base for pulse detector. Face regions of interest are analyzed to detect frequency of changes of intensity between frames. 1D signal is gained and its analysis leads to heart rate. Approach to create heat map of frequency changes is also presented.
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Chord recognition
Soudek, Ondřej ; Glembek, Ondřej (referee) ; Černocký, Jan (advisor)
The goal of this bachelor thesis is to create an application, that will perform a real-time analysis of a signal from electric or acoustic guitar and will recognize a chord or tone, played by user. This document contains basics of music theory and the solution of the problem, as well as the results of testing.
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Chain Drive Computional Model as Virtual Engine Module
Vlastník, Jan ; Štětina, Josef (referee) ; Dundálek, Radim (referee) ; Píštěk, Václav (advisor)
his work deals with the methods of creating computational models for the analysis of the chain drive of camshafts in combustion engines. Methods are compared of the simulation of the drive mechanism; a new method is also presented for the simulation of the tensioning and guide bar by means of a modal reduction of an elastic body in the Multibody system. The work describes individual parts of the chain gear and the mathematical formulation of differential equations of motion. Algorithms are also indicated describing the mutual interaction of bodies in contact. Computations are here described for the determination of individual parameters necessary for setting up a chain drive model. The tensile characteristics of the chain is determined by the FEM programme. The chain model is analyzed in several alternatives of arrangement. FEM calculations are described here of the rigidity of contacts between the chain and the chain wheels and between the chain and the guide bars. The computational model has been created in the MSC ADAMS programme. The computation is carried out for a stabilized speed of the crankshaft of 3,000, 4,500 and 6,000 rpm and for a continuous start from the idle state up to the speed of 6,000 rpm with a constant load of the crankshafts by the torsion moment. Computation is also carried out for loading the crankshafts with a torsion moment deduced from the cam shape. The courses of the quantity obtained are processed by means of FFT; Campbell diagrams have been constructed for their evaluation. The results have been compared with the modal analyses of the individual parts of the chain gear for the determination of their mutual interaction.
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System for the support of comparison of algorithms for noise reduction in audiosignal
Bartoš, Jan ; Smékal, Zdeněk (referee) ; Míča, Ivan (advisor)
The main purpose is to create a system for working with audio-signal, which is user-friendly and ready for next expansion. The program is developed in the Qt library of the Linux Ubuntu 7.4 operating system with using of C/C++ language. Another purpose is to demonstrate the functionality of the program on simple channel speech. To this aim there are implemented algorithms of the spectral subtraction and of the spektrogram's tresholding with using of FFT algorithm. The parts of the work are the teoretical part of the GUI implementation and the implementation of denoising methods, a partial description of the program and his structure and instruction manual.
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OFDM modulator in FPGA chip
Kováč, Michal ; Fujcik, Lukáš (referee) ; Bohrn, Marek (advisor)
The master’s thesis deals with the design of modulator OFDM in the FPGA circuit. The thesis describes basic attributes of modulation OFDM, its pros and cons. With the help of created block level scheme, it describes all the components of the processing of the data signal on its way from the transmitter to the receiver. The Atlys Spartan-6 Development Board has been chosen for the implementation of the modulator. The other part of thesis is the design and realization of the analog-digital interface for the modulator OFDM. The interface consists of PCB, which is connected to the development board using expansion connector. The board is assembled with all the parts required for transmitting the signal as well as consecutive receiving, the description of used solutions is also a part of this master’s thesis. Proper function of both designed parts was verified using hardware co-simulation.
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Diagnosis of electromagnetic origin vibrations in asynchronous motor
Koníček, Pavel ; Dostál, Lukáš (referee) ; Janda, Marcel (advisor)
The aim of this master´s thesis is to introduce methods of diagnostics of vibrations in electrical machines. Describe the various vibration sources located inside and outside of the electric machine. Description of the sources of vibration is then preferably dedicated to vibration of electromagnetic origin. There is a description of the construction of an asynchronous motor and the magnetic circuit, the theory of vibrations and their origin. Described are also vibration sensor enables measurement and mathematical tools for their evaluation. In this work also practical vibration measurements on an asynchronous motor, data processing, their subsequent analysis and computer simulation of electromagnetic vibration origin. The conclusion of this work is devoted to the evaluation of the data obtained.
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FFT implementation in FPGA and ASIC
Dvořák, Vojtěch ; Bohrn, Marek (referee) ; Fujcik, Lukáš (advisor)
The aim of this thesis is to design the implementation of fast Fourier transform algorithm, which can be used in FPGA or ASIC circuits. Implementation will be done in Matlab and then this form of implementation will be used as a reference model for implementation of fast Fourier transform algorithm in VHDL. To verify the correctness ofdesign verification enviroment will be created and verification process wil be done. Program that will generate source code for various parameters of the module performing a fast Fourier transform will be created in the last part of this thesis.
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Device for diagnostic of induction machine
Buln, Tom ; Janda, Marcel (referee) ; Huzlk, Rostislav (advisor)
The aim of the thesis is to study the problems of induction motors, which belong among the most widespread and used machines. Due to their expansion, it is advisable to start the fault monitoring to prevent any more damage and losses. It can be used for condition monitoring different types of methods, which are variety technically and costly demanding to implement. It is used the method of measurement using stator currents in this thesis, because these currents are already monitored and it is easy to create devices for a more detailed analysis. The whole monitoring is carried out using products from National Instruments. The program of monitoring is created in graphical setting of LabVIEW. The analysis is conducted by calculating the Fast Fourier transform of the time signal. The result is the frequency spectrum, which contains frequency peaks and some of these peaks represent failure. The test data are collected with a DAQ device and then the same data are used for creating a methodology for evaluating online analysis and it is subsequently implemented into CompactRIO.
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