|
|
Contactless measurement of operational deflection shape
Tomek, Tomáš ; Klusáček, Stanislav (referee) ; Beneš, Petr (advisor)
This bachelor's thesis provides an overview of 2D/3D laser scanners used in measuring operating deflection shapes. Describes the issue of measuring the operating deflection shapes and modal analysis. My work also contains a description of the measurement chain. From the contactless measurement of a vibrating surface using the application created in LabVIEW to its visualization in Pulse Reflex.
|
|
|
LED stroboscope speed meter
Krampoťák, Štefan ; Uher, Miroslav (referee) ; Beneš, Petr (advisor)
The bachelor´s thesis is dealing with design and realization of contactless rotation sensor based on stroboscope method. As the source of the light should be used power LED. The first part briefly deals with the scanning speed and a more detailed description of the stroboscope method, it´s advantages and disadvantages. The second part of this thesis is about designing and implementation of the measurement device, i.e. designing the block diagrams, electric circuit designing and the execution itself. It analyzes each part of the electric circuit and justifies their selection and design. In the last phase of this bachelor´s thesis is made the measurement of the device and were determinated it´s properties.
|
|
|
A Method to Supress Interferences in Wigner-Ville Distribution
Pikula, Stanislav ; Pazdera, Luboš (referee) ; Hájek, Karel (referee) ; Beneš, Petr (advisor)
The doctoral thesis focuses on signal representation in the time-frequency domain with constant resolution. In theoretical introduction the possibilities of displaying a signal in time and frequency are summarized. Attention is concentrated on comparison of short-time Fourier Transform (STFT) and Wigner-Ville Distribution (WVD). The latter achieves a significantly better resolution, especially for a linearly modulated signal. The disadvantage of WVD, which is the presence of interferences resulting from the calculation of the instantaneous autocorrelation function, is described in detail. These interferences are due to the presence of multiple components in the signal or its non-linear modulation. Subsequently, several methods are discussed, which can suppress these interferences, but at the cost of resolution loss. One of the interference suppression methods is smoothed pseudo Wigner-Ville distribution. It is further used in this thesis for the analysis of interference suppression when various filtrations in the time-frequency plane are applied. Several signals with multiple components or various non-linear modulations are used. Based on the analysis, a method using a set of variously smoothed pseudo Wigner-Ville distributions is designed to estimate the time-frequency representation with high resolution and minimal interferences. To compare the results to other methods, the quantitative metrics used in the literature are compared. To select the appropriate one a new metric is suggested. It is applicable to simulated signals and uses mean square error. Based on the comparison, the Stankovi\'{c} measure is selected as the most appropriate for comparing results. The selected metric is used to determine the appropriate minimal number of differently smoothed pseudo Wigner-Ville distributions. Using the selected metric, the proposed method is compared with other methods. These are STFT with optimized window length, S-method with optimized parameter and optimization method using radial Gaussian kernel (RGK). These methods are compared based on the set of signals previously used for interference suppression analysis. In addition, noises are added to the signals. Finally, the methods are also compared based on the real bat echo signal. In conclusion, the proposed method outperforms the compared methods in suppressing interference and resolution.
|
|
|
Flow measurement
Pátek, Tomáš ; Kunz, Jan (referee) ; Beneš, Petr (advisor)
This bachelor thesis deals with thermal flowmeter design. In the theoretical part are briefly described flow types, general formulas of fluid mechanics and different flow measurements methods. Second practical part this bachelor thesis deals with design of thermoanemometric gas flow sensor with FS7 sensor by IST AG. Design is based on many measurementrs to get basic features of sensor IST FS7 like heater warming depending on flow, heat transfer in zero flow and basic characteristic. Based on measurements, it is designed mathematical model of sensor by two methods. So it is designed universal performing electronics, which can be used with IST FS7 or IST DFOOL sensors. It is based on development kit Texas Instrumens MSP-EXP430FR2311. Firmware and MATLAB script which processing measured data is included.
|
|
| |
|
|
Measurement of MEMS gyroscope parameter changes
Raichl, Petr ; Beneš, Petr (referee) ; Kunz, Jan (advisor)
The thesis is aimed on determination of parameters of MEMS gyroscopes with Allan variance. In the introduction, there is principle of gyroscopes described. The first part describes deterministic and stochastic parameters. Methods for determining these parameters are also described. In the practical part, stochastic parameters of two gyroscopes are determined with Allan variance. In the next part, thesis describes determination of changes of stochastic parameters after vibrations and shocks.
|
|
|
MEMS Inertial Sensor
Mihaľko, Juraj ; Rášo, Peter (referee) ; Beneš, Petr (advisor)
The aim of this master’s thesis was to describe the basic measurement methods for measurement of inertial sensor, their physical principles and errors. The next step was to select a specific parameter, then test it on a number of sensors and evaluate the results. Measurement of inertial sensors is very important for the parametrization of their errors and their subsequent mathematical model by which it is possible to minimize their impact on inertial navigation. The practical part is dedicated to the measurement of stability of the offset. Data acquisition card NI-USB 6215, which can supply two accelerometers at the same time using analog outputs, was used for data acquisition and power supply. It was tested on seven inertial sensor from four manufacturers. Two connection methods with NI-USB 6215, by whose it was determined which one is better to suppress the crosstalk between channels, were used for measurement. The NI PXI 4462 was used to verify that the NI-USB 6215 card is sufficient. The parameters for description of the changes in inertial sensors were established, transition between the initial and final value of the output measurement, variance of the values on which the sensor fixates after 72 iterations, and the fixation time of the sensor.
|
|
|
Bypass of the village Ochoz u Brna
Beneš, Petr ; Klusáček, Ladislav (referee) ; Smělý, Martin (advisor)
The subject of the master´s thesis is designing a bypass of the village Ochoz u Brna. The bypass will by designed in four variations which will be compared to each other by several criterias. Then one variation will be chosen and designed in detail. The goal of the master´s thesis is reduction of the traffic intensity of the current road II/373 in Ochoz u Brna by redirecting transit traffic outside the village. This will lead to an increase of safety in the village.
|
|
|
Control Software for RLC meter HIOKI 3532
Slovák, Martin ; Beneš, Petr (referee) ; Keprt, Jiří (advisor)
Aim of work gets up on questions and methods about measuring by RLC meter and realize control software for RLC meter HIOKI 3532. Theoretic part of work put mind to problems about impedance measuring, especially about means of their measuring. Next part deal with RLC meter HIOKI 3532 in particular to his properties, possibility of configuration and his communication by means of GPIB. Therefore next section surveys on the measuring systems, in accordance with standard GPIB. The main section is survey to control software for RLC meter HIOKI 3532 which is realize in the graphic programming language LabVIEW. The software made as an instrument to control and configuration of RLC meter parameters, which is needed to frequency response characteristic measuring and archiving. Work notes basic adumbration about software realization. And instruction for taking frequency response characteristic of measured item. Last part of the work contains from validation measure which took by the software.
|
|
|
Measurement module with simultaneous-sampling A/D converter
Křížek, Miroslav ; Beneš, Petr (referee) ; Havránek, Zdeněk (advisor)
In this work is designed programme unit for acquisition analog acoustic signlas from sensors. There is used accurate A/D converter ADS1287 by the company Texas Iinstrument with resolution of 24 bits to digitizing these signals. There is used 32-bit microprocessor AT91SAM7S64 by the company Atmel to control this A/D converter and sending digitized data to PC. This microprocessor has implemented USB interface. By force of developmental programme units whit microprocessor and A/D converter is produced programme for microprocessor in developmental setting IAR Embedded Workbench IDE 5.0 and simple aplication for PC in setting Borland C++ Builder. Both of those programs are in language C++. Rate of sampling is 26 kHz. On the basis is realized programme unit USB-ADC whit microprocessor and A/D converter.
|
guest ::
RSS feed.