|
|
Rolling bearings for electromobility
Mbontar, Patrik ; Frýza, Josef (referee) ; Šperka, Petr (advisor)
The aim of this bachelor thesis is to describe the problems related to the use of rolling bearings in electric vehicles. Introduction includes history, distribution, and a brief description of the bearings. In the next section, there will be a description of the use, requirements and parameters for rolling bearings of combustion engine cars. In the main part of the thesis, the parameters and requirements of bearings used in electric vehicles and hybrid vehicles will be analyzed. I will continue with familiarization with dynamic actions affecting bearings and their critical requirements. In conclusion, the two types of cars and the possible development of this type of bearings will be compared.
|
|
|
Steam turbine
Skoupý, Pavel ; Ing.Duda (referee) ; Fiedler, Jan (advisor)
The master´s thesis concentrates on a project of steam turbine with controlled extraction points destined for a communal waste incineration plant. First, there the history of devices using steam as a moving medium is introduced and than follows the description of computing program, where the calculation was running. The master´s thesis subject consists in the thermodynamic project of turbine vaning, in basic project of gearbox including the check calculations and in technical economic comparison of single shaft and twin shaft constructional design. The design documentation is worked up according to the calculated outcomes and contains longitudinal section of turbine and dispositional turbine and gearbox settlement.
|
|
| |
|
|
Experimental study of artificial articular cartilage friction
Kulíšek, Vlastimil ; Ranuša, Matúš (referee) ; Rebenda, David (advisor)
Many conventional materials are used to replace damaged articular cartilage, which are beginning to be replaced by innovative biomimetic materials that mimic cartilage properties. One of these materials are poly(vinyl alcohol) (PVA) hydrogels crosslinked by freeze-thawing and cast-drying method. These hydrogels possess similar mechanical as articular cartilage. In order to clarify the effect of kinematic conditions on the friction of hydrogels, three levels of sliding speed and load and a uniform lubricant – PBS were chosen. The coefficient of friction of the FT hydrogel decreased with increasing load. The dependence of the sliding speed did not show a uniform trend and corresponded to the adsorption-repellent model for PVA gels. The coefficient of friction of the CD hydrogel increased with increasing sliding speed according to the repulsion-adsorption model for PVA gels. The increase in load at low sliding speeds of CD hydrogel caused a slight decrease in the coefficient of friction. At the highest speed, there was an optimal load at which a low coefficient of friction was achieved. The CD hydrogel showed a lower coefficient of friction than cartilage. The FT hydrogel achieved a lower coefficient of friction than cartilage only at 5 N and 10 mm s- 1. This work contributes to the understanding of the tribological properties of PVA hydrogels.
|
|
|
Analysis of the acoustic signal to detect the speed of vehicles
Koníčková, Tereza ; Beneš, Petr (referee) ; Klusáček, Stanislav (advisor)
The aim of this Bachelor thesis is to create software for sound signal analysis of a passing car with the aim to determine the driving speed. This work describes single methods of a car velocity measurement and it is submitting a new method of velocity measurement with using the Doppler principle at sound signal analysis. My work proved, that it is possible to use this method to determine the speed of vehicles.
|
|
|
Modification of Speech Rate
Kovářík, Aleš ; Schwarz, Petr (referee) ; Szőke, Igor (advisor)
This diploma thesis discusses modification of a speech rate. The PSOLA (Pitch Synchronous OverLap Add) method was used for the rate modification. This algorithm works in time domain. Another method -- phase vocoder, which works in frequency domain is also presented in an overview. This thesis extends the PSOLA method with a phoneme recognition, which allows for better understandability of the speech output by considering characteristics of the phonemes beeing pronounced. To examine this proposed method, an application connecting PSOLA and a phoneme recognizer was developed.
|
|
|
Perception of vehicle speed by pedestrian
Rak, Martin ; Semela, Marek (referee) ; Bilík, Martin (advisor)
This master’s thesis deals with the issue of the perception of speed of a vehicle from pedestrian’s point of view. The theoretical part consists of a research into sense perception of humans and construction of motor vehicles. The practical part designs and describes the experiment which was performed in order to provide data used for analyzing different factors and their effect on the accuracy of vehicle speed estimations.
|
|
|
Vibrodiagnostics of electrical machines
Boháček, Daniel ; Vítek, Ondřej (referee) ; Janda, Marcel (advisor)
This thesis deals with methods of vibration analysis in electric rotating machines. From the beginning, it is necessary to explain the basic concepts and introduce the issue of vibration. Next time, the work is focused on sources of vibration in electrical machines. Defects on electric rotating machines causing vibrations are described. Sensing is performed using sensors of deflection, speed and acceleration. The measured signal needs to be adjusted and filters, approximations and sampling will cover this in the next chapter. The main objective is the methods of analysis, which include the best known in the field of frequency analysis (FFT) and the envelope method in the time domain. This includes other methods such as Kurtosis factor, Crest factor, etc. There is also a basic block diagram for measuring vibrations. This block diagram is programmed and has a graphical user interface. The last part is an evaluation of the measured data of the engines.
|
|
|
Design, optimization and full load circuit simulation of the surface mounted permanent magnet machine
Bláha, Martin ; Ondrůšek, Čestmír (referee) ; Kurfűrst, Jiří (advisor)
This thesis deals with the possibility of using the finite elements method for the analysing of synchronous permanent magnets machines. The aim of this work is to discuss the possibility of the machine design more effectively with using the finite elements method and Maxwell software for the simulations. On the created parametric model, simulations were performed according to master thesis assignment. The aim of this work is to determine induced voltage, iron losses, machine inductances and make a permanent magnets demagnetization analysis. From simulations results the machine efficiency is calculated. The parametric model was used for the optimization of selected parameters. From results of optimization new dimensions of permanent magnets was obtained. Machine efficiency was increased by new permanent magnet material and optimized design.
|
|
|
Measuring the Manoeuvres of Public Transport Vehicles to Determine a Comfortable and Safe Ride
Hlavová, Vendula ; Petrás, Jan (referee) ; Tokař, Stanislav (advisor)
The comfort perceived by passengers during transport in public transport plays a vital role, and its improvement can lead to attracting more customers. For this reason, there is a constant effort to improve the comfort of the passenger. This thesis deals with the objective measurement of the maneuvers of MHD in Brno (tram, trolleybus, bus) with the XL Meter and together with the subjective evaluation of the standing and sitting figurant, determines the limit values of longitudinal and transverse acceleration for comfortable ride and dangerous ride, which can lead to accidents to passengers.
|
guest ::
