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Automated tuning of drive controller
Adamec, Matúš ; Pohl, Lukáš (referee) ; Blaha, Petr (advisor)
This thesis deals with automated tuning of drive controller. To achieve this goal, system identification is needed. Therefore, the issue of identification is described at the beginning of this thesis. Spectral analysis was selected from many described methods. It was implemented in Matlab and also in C# language where was used averaging and Blackman-Tukey method. The C# application is linked to Beckhoff TwinCAT 3 and TwinCAT 2 runtime sytems that enable connections with real drive. Next, the problem of drive regulation is discussed and the results of using spectral analysis on real drives are shown. At the end of the thesis is described the algorithm of setting the speed controller with different types of frequency converters.
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Sensorless velocity control and positions of d.c. low-power brush motor
Svoboda, Jan ; Hanák, Pavel (referee) ; Prajzner, Václav (advisor)
This bachelor's thesis focuses on sensorless control of low load brushed DC motor that is used in the actuators made by the Honeywell company. The first part provides an introduction into motor control and common used methods of speed and position sensing of brushed DC motor. Sensorless method of sensing described in this work is the detection of commutation pulses from the signal of motor current. These pulses are caused by brushes leaping over the commutator bars. Correct evaluation of commutation pulses can provide the information about velocity and position of the motor. This relatively new method of detection of commutation pulses is investigated and arising problems are demonstrated on measured samples of signal. Suitable methods of signal processing are then proposed. Infallibility of these signal processing methods is then proved on the set of signals measured under circumstances of supply voltage and abrasion. Then it is decided which signal processing method that sensorless control system can use is the best.
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Dynamic analysis of structure with seismic loads
Šnajdárková, Jana ; Nevařil, Aleš (referee) ; Vlk, Zbyněk (advisor)
This thesis focuses on creation of two models of high-rise construction - beam and shell. A dynamic analysis is performed on these models. The selected program is RFEM software and the created high-rise construction is Hearst Tower skyscraper, which is interesting for its diagrid system around its perimeter. There is described process of creating both models and associated problems. Dynamic analysis is performed using standard EN 1998-1. There belongs calculations of sufficient number of modal shapes, spectral analysis and time analysis. Then the results are compared on selected point on the both models.
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Analysis of Spectra of Electric Guitars Made of Various Materials
Zezulová, Eliška ; Musil, Jaroslav (referee) ; Jirásek, Ondřej (advisor)
Bachelor‘s thesis focuses on the spectral analysis of two electric guitars. The Cort X-6 electric guitar is used for harder genres of music. The second Fokus-H Strat guitar is more of a rock-universal type of instrument. The work deals with the spectrums of tones using various guitar pickups and analyzes them with the use of psychoacoustic measurements in the perception of timbre. It examines variations in the sound spectrum when there’s a manipulation with tone and gain controls. The measured values of the tone control are divided into thirds of the potentiometer range. The volume has been halved. The following is a look at the change of sound spectrum when using a harder plectrum. The end of the work is devoted to the difference in colors of two tones that were recorded under the same conditions. Their difference lies in the way of holding the neck of an electric guitar.
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Collection system design for multichannel spectrometer
Sovadina, Petr ; Buday, Jakub (referee) ; Novotný, Jan (advisor)
In laser-induced breakdown spectroscopy, the intensity of radiation that enters the spectrometer is crucial. Ideally, the collection of radiation is from a single point of plasma. The greater the intensity of radiation is, the more perspicuous the graph of wavelengths is. Therefore, it is necessary to have the best optimized optical collection system. The existing collection system was not designed for connection to a multichannel spectrometer. The use of the optical multifibre resulted in a collection of radiation from different spots in plasma. Therefore, there was a request for a new optical system designed to collect radiation from a single point of plasma and would be suited for the best collection of radiation. The designed and manufactured collection system was tested. During the test was discovered that the collection system can be calibrated well and allows collection from one point of plasma. The test is considered successful.
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Analysis of spectral characteristics of signals
Sedláček, Matyáš ; Klejmová, Eva (referee) ; Poměnková, Jitka (advisor)
The subject of this bachelor’s thesis are the properties of power spectral density estimates, mainly how their properties depend on the analyzed signal’s parameters and the method being used. Important signal properties from the perspective of spectral analysis are defined, as well as measures for judging the estimate. Based on those, a choice of nonparametric and parametric spectral estimation methods is described. Analysis is performed on simulated signals and the results generalized into a set of recommendations for finding an estimate via an optimal method. These recommendations are then scrutinized and further discussed through estimation of real signal PSDs. Included is an application in MATLAB App Designer for generating spectral estimates and a collection of signals used.
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Measurement and analysis of electroencephalogram
Klus, Michal ; Chmelař, Milan (referee) ; Kubicová, Vladimíra (advisor)
The first theoretic part studies the origin and history of electroencephalography. It describes the basic part of the brain, neuron, from anatomical to functional sides. It discusses formation of electrical potential. It continues on overview and description of alternative diagnostic methods used for brain testing and testing of brain electrical activity. Describes the types of using electrodes and their location. Finish of theoretic part shows the descritpion of EEG record and characteristics of types of waves. The practical part shows the attempt to measurement. Procedure of correct measurement and capture the dates. Describes the transferring data into right format drawing EEG spectral analysis and brain mapping. All of this is included in the generated program analyza_EEG The end of practical part describes the outputs from progmam using own measurement data.
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Load effect on baroreflex sensitivity
Kamenec, Jan ; Čmiel, Vratislav (referee) ; Kolářová, Jana (advisor)
KAMENEC, J. Load effect on baroreflex sensitivity. Brno: Brno University of technology, Faculty of electrical engineering and communication, 2008. 52 p. Supervisor of bachelor’s thesis Ing. Jana Bardoňová, Ph.D. The aim of this baccalaureate thesis was study problems of the metering baroreflex and verify, whether the physical stress affects baroreflex sensitivity. The metering proceeded on the computer system Biopac, in which was projected the record of the metering. For the calculation was elected noninvasion spectral method. Measuring data by the computer system Biopac were processed by the help of the Matlab program that worked out found dependencies.
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The Innovation of organ pipes
Holba, Stanislav ; Musil, Jaroslav (referee) ; Jirásek, Ondřej (advisor)
The thesis deals with the sound colour of organ pipes in relation to the way of tone excitation, physical dimensions of organ pipes and the construction material used. The sound colour of individual organ pipes is described by means of spectral analysis and selected psychoacoustic variables. The obtained knowledge is further used for the production of organ pipes from atypical materials and modification of conventional organ pipes. Resonator simulations are performed for the materials used for the production in order to determine the theoretical value of the resonant frequencies. These values are compared with the results of spectral analysis of the sound of physical organ pipes.
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Analysis of the spectrum of cymbals and their time envelopes
Adamják, Adam ; Musil, Jaroslav (referee) ; Jirásek, Ondřej (advisor)
This Bachelor Thesis deals with the analysis of idiophones, the description of the measuring chain, and the analysis of the spectrum and time course of the measured samples. Based on spectral analysis, individual parameters and influences on the sound of cymbals were evaluated, such as the location of the blow or the type and hardness of the drum sticks. The theoretical basis also deals with the basic theory of the sound signal to the issue of noise and psychoacoustic perceptions. The conclusion deals with the basic mechanical properties and puts them into context with spectral analysis.
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