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Control of asynchronous motor by PowerFlex drive
Kovář, Pavel ; Bradáč, Zdeněk (referee) ; Štohl, Radek (advisor)
The Thesis deals with the basic principles of function of Asynchronous motor. It also describes Frequency invertor PowerFlex 700 and PLC ControlLogix from the company Allen Bradley, and marginally industrial network ETherNet/IP. The main part of this project is control of asynchronous motor in aid of frequency invertor. As an example of this control in this Thesis is used control of production line for drilling holes into the metal beams. Unfortunately, its activity is only simulating, because of this production line does not exist physically. The main problem of control of this production line is undoubtedly the control of asynchronous motor on correct location. The task of production line was designed with regard to using as a laboratory task for teaching. The last part of this Thesis deals with the animated visualization of this production line in the program FactoryTalk View Studio, which is possible to record to display terminal, which is designated for visualization in industry.
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Possibilities of Error Controls in Frequency hopping Stations
Pust, Radim ; Kovář, Pavel (referee) ; Wieser,, Vladimír (referee) ; Burda, Karel (advisor)
The doctoral thesis deals with design of coding for frequency hopping stations in band with intensive jamming. In digital modulations erroneous determination of the modulation state occurs due to jam at the receiver side. The result is erroneously transferred symbols of the message. Errors created during the transmission can be eliminated by using error control systems. It is also possible to prevent these errors by using algorithms (techniques) of frequency hopping which select the appropriate channel. Appropriate communication channel is a channel with a lower probability of erroneous symbol in the message. The main contribution of this thesis is to design a new frequency hopping technique with collision avoidance (FH/CA). The station with FH/CA technique measures signal levels in the considered several channels before every jump. Based on the measurements the most appropriate channel with the lowest value of measured signal level is selected. Therefore, it is more probable that a jump to an unoccupied channel with a transmission will occur. Using a mathematical model, the performance of the newly proposed FH/CA technique is compared with the currently used techniques FH and AFH. Comparison criteria are the probability of a collision between an FH/CA communication system and a static (device transmitting continuously at a fixed frequency) or dynamic jammer (i.e. other FH or AFH systems). By comparing the values of the probability of jammed transmission, indisputable theoretical advantages of the new FH/CA technique were found, compared to the currently used FH and AFH techniques. The FH/CA technique always has better or equal results compared with the FH technique in the case of interference by static and dynamic jammers. The FH/CA technique in a band with static and dynamic jammers usually has better results than the AFH technique. A significant contribution of the FH/CA technique can be seen in the case of dynamic jammers. On the other hand, in the case of static jammers the FH/CA technique is in certain situations worse than the AFH technique. The accuracy of the mathematical models were successfully verified on a simulation model that was created as a part of this thesis in the MATLAB environment. Based on the obtained data from the model there was designed coding for frequency hopping stations with the new technique of frequency hopping FH/CA which is designed for small-volume data transfer in a band with intensive jamming.
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Technology of Receiving of Very Weak Signals from Interplanetary Spacecrafts
Špaček, Jiří ; Bezoušek, Pavel (referee) ; Kovář, Pavel (referee) ; Kasal, Miroslav (advisor)
The work deals with the problematics of receiving very weak radio signals and it is focused especially on systems for low rate telemetry with carrier-subcarrier modulation. The part of this work is dedicated to calculation the link budget of typicall telemetry data transmission system between the Mars and the Earth in respect of the receiving equipment, which could be developed in the Experimental sattelites laboratory on the Institute of radio electronics BUT. The main part of this work is dedicated to developing and testing the low rate telemetry data transmission system model. The model is developed for the purpose of study the effects of AWGN and phase noise on the whole system and also on its component parts. The model has been developed and described in the way of easy parameters modification. The design for each parameter of the model is described carefully. With the developed model, the study of the effects of AWGN and phase noise on the whole system and also on its component parts has been performed.
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Cranktrain of three-cylinder in-line disel engine
Kovář, Pavel ; Ramík, Pavel (referee) ; Píštěk, Václav (advisor)
This master’s thesis describes design and comparison of three variants of the crankshaft in-line diesel engine for commercial vehicles. The work focuses on working with programs for 3D modelling and analysis proposed models, to be able to work under difficult conditions. Part of this work is a computational modal and strength analysis.
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Vertical rack
Kovář, Pavel ; Šindelář, Martin (referee) ; Brandejs, Jan (advisor)
Target of master thesis is constructional design of vertical rack with press of screenings for shaft type 501 up to 3200 mm deep. Part of this shaft system is atypical bottom with two inflows and one outflow of sewage water. According to these requirements there ware adapted dimensions and shapes of whole construction. Master thesis is divided into several parts, where is disposed construction design of rack with supplement, modification of shaft bottom and embedment of vertical rack.
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Algorithms for calculating the position, velocity and time from GNSS signals
Kučera, Tomáš ; Kovář, Pavel (referee) ; Tejmlová, Lenka (advisor)
This master thesis describes the principles of the Global Navigation Satellite System GNSS, specifically the GPS, GLONASS and Galileo systems. The thesis analyzes the structure of individual GNSS subsystems and introduces their properties. The algorithm for calculating the position is designed in the interactive programming environment MATLAB for the processing of GPS and GLONASS sampled signals. The position is calculated by a distance measurement method which searches for the intersection of spherical surfaces. The calculation is designed for four satellites and when more satellites are detected, the calculation is repeated for all possible combinations. From this position the combination with the lowest DOP (Dilution of Precision) factor is determined, and the calculation of the position is repeated for the best constellation of satellites. In this thesis the user graphical interface for entering the input of data, input parameters and the display of calculated values are created. Finally the calculation of the measured data is displayed on the selected location online map portal
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Model of CNC milling machine
Kovář, Pavel ; Bradáč, Zdeněk (referee) ; Štohl, Radek (advisor)
The master's thesis deals with the basic parts and principles of CNC machines with a focus on a CNC milling machine. There are also comparisons of several CNC machines sold. Furthermore, the project deals with the description of the manipulator, which is situated in laboratory E-132 in area Kolejní 4, Brno. The work also includes a description of the device, which is located in the manipulator model. We can find there a description of the program generating G-code from the image that you create in the editor. The next section describes possible modifications of the manipulator for its reconstruction on a CNC milling machine. The last chapter deals with the description of program developed for controlling the manipulator as a CNC milling machine.
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Design of satellite transmitter pylon.
Kovář, Pavel ; Sikora, Michal (referee) ; Vlach, Radek (advisor)
There is solved a task “Design of satellite transmitter pylon” in this bachelor‘s thesis. Type of the satellite transmitter pylon structure is designed for application level 24 meters – it is location of satellite transmitter. There is one limitation only, constant trianguloid cross-section of the pylon. This thesis presents engineering design and evalution of the pylon.
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Piston for 373kW 4-stroke SI-engine
Kovář, Pavel ; Svída, David (referee) ; Dundálek, Radim (advisor)
This bachelor work deals with the design of a piston for 373 kW 4-stroke SI-engine. The work is focused to main dimensions of the piston, to make it able to work in difficult conditions, which is exposed at cylinder. One of the most important part of design piston is strength calculation.
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