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Traction Drives with Asynchronous Motors
Běloušek, Josef ; Skala, Bohumil (referee) ; Richter, Aleš (referee) ; Patočka, Miroslav (advisor)
The first part of this work is devoted to the design of a traction asynchronous motor. The second part focuses on the developed method of the equivalent circuit parameters identification of the asynchronous motor in the form of -network. It is explained here that the equivalent circuit in the shape of a -network, alternatively of an inverse 'I-network, is exactly equivalent and fully-fledged to a T-network, although one of two stray inductances is formally missing. Furthermore, the relationships for the conversions of the T-network parameters to the -network parameters and back, and of the T-network to the inverse 'I-network and back are found. The third part deals with the calculation of the torque and the current characteristics of the asynchronous motor. A sensitive analysis of the torque characteristic is carried out on the individual parameters of the equivalent circuit of the asynchronous motor in the form of a -network and a method of the measurement by means of a flywheel is used for the torque characteristic measurement of the asynchronous motor. The fourth part focuses on the verification of the identified -network parameters in the Matlab-model of the traction drive.
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Analog Signal Processing with Integrated Current Feedback Amplifiers
Ben Ayad, Ibrahim R. H. ; Mikula, Vladimír (referee) ; Šimčák, Marek (referee) ; Musil, Vladislav (advisor)
Tato disertační práce pojednává o návrhu nových funkčních bloků použitelných v oblasti zpracování analogového signálu. Jde o obvody v proudové módu, které mohou ve vhodné konfiguraci pracovat v proudovém i v napěťovém módu. To umožnílo získat velmi nadějné výsledky v soustavách s nízkým napájecím napětím. Mnohostrannost těchto obvodů nalezne uplatnění v mnoha aplikacích. Zesilovač s proudovou zpětnou vazbou byl zavolen jako hlavní stavební blok pro detailní zkoumání funkce obvodů s RC operační sítí. Tato disertační práce pojednává o studiu, syntéze a návrhových aspektech realizace nových imitančních funkcí, jmenovitě induktivních a superkapacitních, proudových a napěťových konvejorech, kmitočtových filtrech s velkou jakostí, integrátorech a diferenciátorech, fázovacích členech s neminimální fází a napětím řízených oscilátorech. Disertační práce se detailně zabývá těmito novými bloky, které jsou popsány teoreticky a vyhodnoceny na základě simulací vlastností.
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Nonlinear analysis of load-bearing capacity of reinforced concrete bridge
Sadílková Šomodíková, Martina ; Novák,, Drahomír (referee) ; Lehký, David (advisor)
The subject of master’s thesis is determination of bridge load-bearing capacity and fully probabilistic approach to reliability assessment. It includes a nonlinear analysis of the specific bridge load-bearing capacity in compliance with co-existing Standards and its stochastic and sensitivity analysis. In connection with durability limit states of reinforced concrete structures, the influence of carbonation and the corrosion of reinforcement on the structure’s reliability is also mentioned.
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Tilt sensors
Hájek, Tomáš ; Caha, Luděk (referee) ; Beneš, Petr (advisor)
The topic of the Bachelor's thesis are MEMS sensors of inclination, which find their use inside integrated circuits, equipment of aerospace and automobile industry, but also in ordinary electrical appliance. The work serves the reader to build a grasp over production, usage, basic principles. Finally, it offers an overview of sensors to ease the orientation on the market. The design of the physical model, which can be used to prevent the sensor from apperance of mathematical errors, is tested in the practical part.
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Properties of ultrasound probes
Rusina, Michal ; Mézl, Martin (referee) ; Harabiš, Vratislav (advisor)
This master thesis deals with the measurement properties of ultrasound probes. Ultrasound probes and their parameters significantly affect the quality of the final image. Values of pa-rameters of the probes may change due to their use, because probes may be damaged and the final image may no longer be correct. For these reasons the measurements of parameters of probes are very important. In this master thesis there are described and implemented the possibility of measuring the spatial resolution, focal zone, the sensitivity of the probe and measuring the length of the dead zone. Two ultrasonic phantoms were used for measuring. In the practical part there was created the program called Mereni_parametru, which allows to determine the value of four parameters from captured images of the phantom. Further, there are listed and described measured values for five ultrasonic probes. Results for two of these probes are then compared with the parameters given by the manufacturers.
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Sensitivity analysis of frequency filters with current active elements
Kupčík, Petr ; Koton, Jaroslav (referee) ; Kubánek, David (advisor)
This bachelor´s thesis is about sensitivity analysis of frequency filters with current active elements. Includes theory of sensitivity analysis and sensitivity function. There are two second order multifunction frequency filters analysed. The first one is filter with Current Mirrors and Inverters (CMI). The second one is filter with Current Operational Amplifiers (COA). Conclusion is description how tolerances of passive and active elements affects frequency characteristics of filters and comparison of these filters in light of sensitivity. Next chapters are occupied by another two analyses: Parametric Sweep and Monte-Carlo. These analyses are applied on two fourth order frequency filters with Differential Input / Output Current Followers (DIOCF) and also on two previous second order filters (only low-pass filters). Parametric Sweep is applied on internal parameters of active filter elements (not in case COA). During Monte-Carlo analysis passive elements have tolerance 5% and active elements are considered ideal. Conclusion is description how tolerances of passive elements (Monte-Carlo) and parametres of active elements (Parametric Sweep) affects frequency characteristics of filters.
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Modeling of Inertial Sensors
Trličík, Jakub ; Klusáček, Stanislav (referee) ; Beneš, Petr (advisor)
This master thesis deals with measurement and modeling of MEMS inertial sensors. This paper describes basic principles of inertial sensors along with their most often errors. The next part shows results from inertial sensor market analysis, which enabling a selection of sensors to be measured. The following two chapters present methods for inertial sensor modeling and testing. The biggest part of text is dedicated to presentation of measurement results showing us static measurement of Allan variance, Earth rotation, temperature dependent bias and dynamic measurement of gyroscope sensitivity testing over temperature. In the last part of the thesis is presented a design of sensor error model by autocorrelation function and Allan variance and also an evaluation of achieved results.
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