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Acquisition of inputs by image processing for controlling an autonomous vehicle
Midrla, Daniel ; Píštěk, Václav (referee) ; Kučera, Pavel (advisor)
This master’s thesis deals with data acquisition by image processing in order to control an autonomous vehicle. Firstly, the thesis offers a summary of theoretical knowledge relevant to the given topic. Then follows a description of creating an algorithm, which acquires basic inputs for autonomous vehicle control with the use of a stereo camera and an object detection neural network. The inputs gained from this algorithm are the class of the detected object and its distance. Finally, an experimental evaluation of the correct functionality is performed with an emphasis on optimizing the accuracy and range of the distance computation. An assessment of the ability to deploy the created algorithm in real time on a compact computer with limited computing power is also performed.
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Autonomous control of the vehicle through image processing
Fronc, Leoš ; Píštěk, Václav (referee) ; Kučera, Pavel (advisor)
This diploma thesis deals with the topic of autonomous vehicles and especially lane detection. The paper describes and compares two main approaches to the lane detection - using traditional methods of computer vision and convolutional neural networks. The aim of the work was to create a system that would be able to recognize road lanes in a real time. The proposed system consisted of a Jetson Nano computer, a ZED stereo camera and a programmed algorithm. In total, two algorithms have been developed that use completely different approaches. Finally, the whole system was tested in terms of functionality and lane recognition.
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Synthetic fuels
Pitoňák, Adam ; Kučera, Pavel (referee) ; Píštěk, Václav (advisor)
The bachelor’s thesis on the topic “Synthetic fuels” aims to introduce the reader to the issue of synthetic fuels and the possibilities of their application for internal combustion engines as alternatives to the conventional fuels derived from fossil sources. The first part of the work is focused on the introduction and division of synthetic fuels according to primary raw material. Subsequently, the properties of the fuels are compared with commonly used fossil fuels. The thesis also deals with the comparison of the equivalents of the emissions of individual synthetic fuels per unit of thermal energy supplied to the engine. Thanks to the model presented in the thesis, it is possible to compare the amount of CO2 equivalent per driven kilometre. The conclusion of this work summarizes the result of the comparison of synthetic fuels with prospects of such fuel in the future.
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Hydrogen fuel cells
Kejval, Dan ; Kučera, Pavel (referee) ; Píštěk, Václav (advisor)
The replacement of the current fuels and engines presents one of the most important tasks not only for vehicle manufacturers but also in the energy industry. Whole world is trying to limit the production of greenhouse gasses which pollute the environment and switch to sources that will not produce any harmful emissions as fast as possible. One of these are hydrogen fuel cells, which are the focus of the thesis and explains how hydrogen is produced and stored. It shows the principle on which they work, what designs currently exist and also evaluates their efficiency. According to temperature and material of the electrolyte they can be divided into various types which offer a wide range of performances and their use. Thanks to that, this device began to spread both in the Czech Republic, where the effort is to firstly expand public transportation to include busses using the hydrogen fuel cells and at foreign vehicle manufacturers where carmakers such Toyota and Hyundai already mass-produce passenger cars, trucks or buses with this source of electricity.
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Crank mechanism with a high mechanical efficiency
Drápal, Lubomír ; Tůma, Jiří (referee) ; Páv,, Karel (referee) ; Píštěk, Václav (advisor)
This document describes the possibilities of increasing the mechanical efficiency of the crank train of an internal-combustion engine. For this purpose, a concept with a reduced number of main bearings is chosen and its contribution is verified experimentally. The proposed solution consists of an innovative crankshaft design of a four-cylinder spark-ignition engine with only three main journal bearings and laser-welded sheet metal crank webs. The new design is compared to the mass-produced one in terms of friction losses, vibrations and loading of engine parts by means of simulations of crank train dynamics using the Multi-Body System. The increase in vibration, accompanied by a reduction in friction losses, is compensated by a torsional vibration damper and its effect is experimentally verified. Experimental research of laser welds on the crankshaft in terms of fatigue life is also described. The overall potential is also summarised and further possible development of this innovative and patented design is outlined.
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Modification of a three-cylinder diesel engine to a single cylinder test engine
Rejnuš, Miroslav ; Kučera, Pavel (referee) ; Píštěk, Václav (advisor)
The master thesis deals with the design of a single-cylinder diesel piston internal combustion test engine by modifying the initial mass-produced three-cylinder engine. The first part of the thesis is devoted to the introduction to the problems of diesel and experimental single cylinder engines. Subsequent chapters focus on the adaptation of the baseline engine itself, including balancing of inertial forces. Furthermore, the crankshaft operability is checked, including the determination of safety against high-cycle fatigue. The last chapter deals with the design of the connection of the adapted unit to the dynamometer.
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Four-cylinder in-line gasoline aircraft engine
Kučera, Ondřej ; Kučera, Pavel (referee) ; Píštěk, Václav (advisor)
The thesis deals with the structural design of a steel connecting rod for the aircraft engine Walter Mikron III, which is currently still manufactured and developed by company PARMA-TECHNIK, s.r.o. The proposed connecting rod would replace the current duralumin connecting rod. The work also contains a strength analysis of the designed component, in which it was aimed to verify the stress on the connecting rod, based on which the fatigue safety factor was performed. This is crucial for dynamically stressed parts of internal combustion engines. Furthermore, was investigated the effect of the change of the connecting rod on the torsional vibration of the crank mechanism. For this purpose, was built a discrete torsion model. The output of the whole work is the drawing documentation of the new connecting rod, meeting the requirements for application in an aircraft engine.
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Gas exchange systems of two-stroke engines
Kovář, Michal ; Kučera, Pavel (referee) ; Píštěk, Václav (advisor)
This bachelor thesis is focused on the analysis of the development and critical evaluation of the gas exchange system of two-stroke engines. The aim of the work was to use research to concentrate various options for gas exchange system of two-stroke engines of various power categories, to describe individual solutions and point out the advantages and disadvantages of individual systems and then outline possible future developments in this area.
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Methanol as an alternative fuel
Balcárek, Ondřej ; Kučera, Pavel (referee) ; Píštěk, Václav (advisor)
This Bachelor thesis is a topic review of problematics of alternative fuel solutions, in particular of methanol and it's production. The aim was to describe properties and possibilities of use of methanol, not only as fuel, but also as a raw material in chemical industry. The information was obtained mainly from English-written sources. Finally, in conclusion part, use and potential of methanol in period of transition to renewable sources is being reviewed.
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Concept of an In-line Spark-ignition Engine
Kočvara, Antonín ; Píštěk, Václav (referee) ; Drápal, Lubomír (advisor)
This thesis deals with comparison of straight four-cylinder petrol engine with a displacement of 1,5 litres and its three-cylinder alternative, which is based on a four-cylinder. The thesis starts with a research, where are examples of some currently manufactured engines. The research is followed by design of both engines, where the design of the crank mechanisms is made more in detail. After that, both crank mechanisms are subjected to dynamic analysis using FEM and MBS methods. The thesis ends with comparison of both engines in terms of crankshaft load, mass and dimensions.
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