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Integrated Measurement System for In-Field Compliance Testing
Chvalová, Aneta ; Morávek, Jan (referee) ; Dvořáček, Jiří (advisor)
As the number of renewable energy sources has increased, new installations have been subject to new requirements for their control, whether autonomous (responding to conditions at the point of connection) or dispatchable. An important step for the commissioning of photovoltaic (PV) plants is to perform compliance testing, which is sometimes only appropriate or necessary to perform in the field on a complete installed plant. The measurements are used to obtain a set of data which is then used to issue a certificate of correct operation (i.e. compliance with requirements). The main output is a measurement system assembled into a portable case that can be easily transported to the PV installation site and simply connect the measurement analyzer to both the AC at low voltage level (for recording voltage, current, power, frequency) and DC (for recording binary commands and signaling). Also included is elaborate documentation of the case itself.
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Vibration and Acoustic Emission Reduction of Powertrains using Virtual Engine
Svída, David ; Kovář, Rudolf (referee) ; Dundálek, Radim (referee) ; Kovář, Rudolf (referee) ; Dundálek, Radim (referee) ; Píštěk, Václav (advisor)
Doctoral thesis deals with combustion engine cranktrain vibrations and vibration analysis methods. The work applies new computational models aimed at powertrain vibration decrease. The computational models can be used in the first stages of powertrain development. Temperature dependences of the rubber shear modulus and loss factor characteristic are found by response analysis of the free damped vibrations in the first part of the thesis. Viscoelastic model parameters of two dampers with different rubber hardness are calculated using optimization methods. Temperature distribution inside the rubber part during the harmonic oscillation is calculated with the knowledge of previous values. Computational models together with a user interface are assembled in Matlab/Simulink software tool. Computational model results of the viscoelastic rubber damper are verified by measurements on a prototype diesel engine in the whole operating engine speed range. Torsional vibrations of the crankshaft with torsional damper are measured by POLYTEC laser rotational tools. The temperature distribution on the damper surface is obtained by Infratec VarioCAM thermographic system. Combustion pressures in the cylinder are measured by SMETEC Combi indication tools. Both the temperature distributions and combustion pressures are used for computational purposes. All the measurement procedures are described also in the thesis.
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CAN Protocol for Automation
Verčimák, Mário ; Jirgl, Miroslav (referee) ; Hynčica, Ondřej (advisor)
The thesis describes basic properties of CAN Protocol. Next point of this thesis is implementation of CAN protocol into Kinetis microcontrollers with use of Kinetis Design Studio. Thesis also describes real application for CAN communication testing. Measurement is realized in school and real industrial conditions. Next point is implementation of real time operating system MQX and creating a task for CAN communication.
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System for verification of the signal quality dependence of a laser vibrometer.
Skalský, Ondřej ; Čala, Martin (referee) ; Pikula, Stanislav (advisor)
This thesis deals with a general theoretical description of the laser Doppler vibrometer with respect to parasitic phenomena, the design and implementation of a measurement system verifying the effects of these phenomena and the measurements performed. For a better understanding, the theoretical part includes not only a discussion of the principles of the laser Doppler vibrometer and its parasitic effects, but also the principles that the laser Doppler vibrometer uses to operate and on which it is based are discussed in detail. Mention is also made of vibrometers of other principles. The practical part of the thesis deals mainly with the design and implementation of a measuring system that can measure the dependence of the quality of vibration measurement on the angle and distance of the surface. This includes, of course, the presentation of the measured data, which to some extent confirms the theoretical assumptions, but also reveals new findings.
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Workplace for automated conductivity measurement of liquids
Rajm, Martin ; Fialka, Jiří (referee) ; Havránek, Zdeněk (advisor)
Its aim the present Dissertation is to create a workplace for automated measurement of conductivity of liquids. Theoretical part describes principles and methods of measurement of conductivity of liquids and also measurement of temperatures of solutions. The reader is then made familiar with the program and development environment known as LabVIEW in which the measurement software has been created as well. This software serves also for the control of the LCR meter “HIOKI 3532-50” whose characteristic properties, control method and possibilities of measurement are briefly characterized in subsequent parts. The text includes also a mention about the GP-IB bus, thanks to which the LCR meter is able to communicate with PC. The actual liquid which is to be analyzed comes into contact, however, only with the four-electrode conductivity cell “WTW TetraCon 325” which is described in the Dissertation as well. The theoretical part is concluded with presentation of the multifunction card “NI USB-6008”, with the help of which the temperature of the solution analyzed is determined. In the practical part is description of the connection and explanation of the function of the measurement system as a whole. This is followed by a presentation of the actual measurement software intended for conductivity measurement. Both its structure, functions and some information about control are described there. This part of the Dissertation deals also with determination of the values of the elements of the conductivity probe replacement circuit and with the impact of measurement parameters on resulting measurement values.
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Printed circuit board tester
Stachera, Tomáš ; Havlíková, Marie (referee) ; Čejka, Miloslav (advisor)
The themes of this work is make a projection of printed circuit tester with focus on HW ans SW part of signal multiplexor . In the first part i will do general description of printed circuit board testing and on concrete example i will show connection of test system with connection of multiplexor. In the second part i will describe HW part of multiplexor board with real values of componets. In the third part i will describe SW for microcontroller and computer. In the end part i will review possibility of multiplexor and his parameters.
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Low-level measurement methods
Müller, Tomáš ; Steinbauer, Miloslav (referee) ; Fiala, Pavel (advisor)
This bachelor thesis discuss about low-level measurement methods. Also is outline the method, how to proceed in lay-out of measurement system and in selection of measurement device and its accessories. Thereinafter is stated the calculation of mistakes and in recent time also the calculation of often use mazes. Without them would be not the result total. Next part of this bachelor theses pointed to practical measurement in the area of low level current and voltage, where are shown and described wiring types used for these measurements. Next chapters discuss about measurement principles low level electric current and voltage. Than try to point to appearance, which indisposed participace on measurement accuracy and try to introduce with steps, which helps to reduce this effects. These voltages and currenties are in normal measurement insignificant, but in the low-levels influence they the result too much. Thereinafter is described the principle of measuring amplifier and closer mentioned parameters and usage of instrumentation amplifier with ultra low input bias current INA 116. Next to last point of this bachelor thesis is an example of usage this network in measurement with gerdien condenser. Therein is clarify its physical principle and proposal parameters. In the last part is described the air ions concentration measurement with gerdien condenser. Also are described the results of measurement and results of this.
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Crosswind Sensitivity of Road Vehicles
Vančura, Jan ; Dundálek, Radim (referee) ; Kaplan, Zdeněk (referee) ; Píštěk, Václav (advisor)
The aim of the thesis is to devise a methodology which is capable of reliable evaluation of road vehicle’s crosswind sensitivity. The work consists of writing the mathematical model of a vehicle which includes aerodynamic loads and conducting a validation by means of technical experiment as defined by ISO 12021. A sensitivity analysis describing the influence of individual inputs on evaluation criteria of vehicle’s crosswind sensitivity is performed using the model, thereby establishing the overall model error caused by possible inaccuracies of input parameters. At the end, the relationship between discrete pressures on the surface of the vehicle in several aerodynamic configurations and the properties representing the vehicle’s motion is presented.
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