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Influence of heavy vehicle load to the vehicle deceleration
Jirásková, Iveta ; Tylšar, Vladimír (referee) ; Bradáč, Albert (advisor)
The diploma thesis deals with the issue of braking trucks at different loads. The theoretical part defines the basic construction of trucks, truck brakes, the braking process and the factors that affect braking, braking deceleration, and legislative requirements for truck brakes. The practical part describes the course of experimental measurements, the use of the technique, the place of measurement, atmospheric conditions and used trucks. At the end of the work, based on experimental measurements, the obtained values of braking deceleration of trucks are evaluated.
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Systém ABS jako prvek aktivní bezpečnosti vozidla
Tvarůžek, Jiří
The thesis is focused on the issue of the ABS system, which is used for passenger vehicles. The first part of the work describes active safety elements that are used to eliminate and prevent traffic accidents. This group includes the ABS system, which is devoted to the second part of the literary research. It describes the operation of the system, the individual components of which the system is composed and its historical development. The second part of the work is focused on experimental measurements that assess the effect of ABS system activity on the braking distance of the vehicle at different road surface conditions. Results from laboratory measurements of ABS system activity are also processed in the work. The results show that, thanks to the active activities of the ABS system, it is possible to achieve a shorter braking distance even with different road surface conditions.
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Design of the Parking Brake Mechanism
Hagara, Adam ; Řehák, Kamil (referee) ; Prokop, Aleš (advisor)
The main goal of the presented diploma thesis is the design and solution of the design of the parking brake mechanism. The theoretical part is devoted to a more detailed description and analysis of the current parking brake mechanisms, specifically the ratchet parking brake mechanism located in the automatic vehicle transmission. The starting point for the practical design part of the thesis is the preparation of conceptual designs together with determination of the most suitable and optimal concept of the mechanism. The next step is the detailed development of the chosen concept, which is accompanied by a series of calculations of individual components while complying with the given requirements. Subsequently, the functionality of the mechanism itself is verified using dynamic analysis, while individual verification states are verified and evaluated. At the end, the FEM analysis of the relevant components of the parking brake mechanism is also performed in order to confirm functionality, while based on the results, the optimization of the geometry of the relevant components is subsequently performed. The thesis also includes a drawing documentation attached in the annex of the thesis.
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Braking of an induction machine
Mareček, Šimon ; Janda, Marcel (referee) ; Mach, Martin (advisor)
The work is focused on the braking of an induction engine and the risks associated with it. In the first part, there are readers acquainted with the technical parameters of the induction engine, which is used for simulations. The second part focuses on the simulation program Ansys Maxwell and the finite element method. In the third part, there are readers introduced to a general description of the induction machine. The fourth part consists of countercurrent braking. The penultimate part is devoted to dynamic braking. The last part contains a brief introduction to generator braking. The chapters focused on braking are supplemented by simulated waveforms.
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Braking of an induction machine
Mareček, Šimon ; Janda, Marcel (referee) ; Mach, Martin (advisor)
The work is focused on the braking of an induction engine and the risks associated with it. In the first part, there are readers acquainted with the technical parameters of the induction engine, which is used for simulations. The second part focuses on the simulation program Ansys Maxwell and the finite element method. In the third part, there are readers introduced to a general description of the induction machine. The fourth part consists of countercurrent braking. The penultimate part is devoted to dynamic braking. The last part contains a brief introduction to generator braking. The chapters focused on braking are supplemented by simulated waveforms.
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System analysis of braking truck - trailer combination
Haring, Andrej ; Kubjatko,, Tibor (referee) ; Řehák,, Miloslav (referee) ; Semela, Marek (advisor)
The dissertation deals with the issue of braking of articulated vehicles, especially articulated vehicles consisting of a tractor and a semi-trailer. This configuration was chosen with regard to the number of accidents and their consequences, and often also does not suit the technical condition of the tractor and semi-trailer, which is closely related to the safety of operation of these combinations. In the case of road accidents, the consequences are often very serious, whether it is personal injury or material damage. Investigating these accidents is a relatively demanding process, requiring a high degree of expertise as well as the necessary technical equipment. In contrast to these requirements, the availability of sources from which the necessary information can be drawn is relatively low. The available resources are mostly in a foreign language and are usually solutions to partial problems, not systemically comprehensive literature. Therefore, it is possible to say a "constant demand" for the available professional literature dealing with issues related to the solution of traffic accidents not only of combinations of vehicles, but of commercial vehicles as a whole. From the point of view of the importance, or topicality of needs arising from expert practice, the dissertation is thematically focused on braking of combinations of vehicles. There are several key reasons to focus on articulated vehicles. First of all, this is due to the specific character of the vehicle itself, which consists of two communication-linked brake systems. Other reasons are that the information contained in the dissertation, whether it is descriptive information, assessment of the technical condition of the systems, or the measurement results themselves, can be partially or even fully used for stand-alone towing vehicles or trailers. However, not all problems related to this issue can be solved within the dissertation. Therefore, in the dissertation, significant influences are selected, the solution of which, given the frequency and severity, the author considers essential. From the title of the dissertation it follows that this is a system analysis of the braking of combinations of vehicles. The system concept of solving a problem situation and selected problems are a guarantee that really essential parameters are selected within the content possibilities and scope of the dissertation and the system approach to their solution allows a "general" application in solving similar problems. The aim of the dissertation is a system analysis of the influence of selected parameters on the overall braking effect and stability of commercial vehicle combinations, analysis of input parameters on the decision logic of electronic brake system control unit, where procedures but also conclusions can be applied in similar cases with similar input parameters and decision criteria. Another partial goal is to develop a framework methodology for determining the technical condition of individual components of brake systems of commercial vehicles, which will be possible to apply especially in trucks, where electronically controlled systems are installed. Here, too, a systemic concept is applied, which will enable a wider use of this methodology.
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Influence of heavy vehicle load to the vehicle deceleration
Jirásková, Iveta ; Tylšar, Vladimír (referee) ; Bradáč, Albert (advisor)
The diploma thesis deals with the issue of braking trucks at different loads. The theoretical part defines the basic construction of trucks, truck brakes, the braking process and the factors that affect braking, braking deceleration, and legislative requirements for truck brakes. The practical part describes the course of experimental measurements, the use of the technique, the place of measurement, atmospheric conditions and used trucks. At the end of the work, based on experimental measurements, the obtained values of braking deceleration of trucks are evaluated.
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Identification of Relevant Tire Traces in Traffic Accident Place Based on their physical characteristics
Bilík, Martin ; Kovanda, Jan (referee) ; Kledus, Robert (referee) ; Bradáč, Albert (advisor)
The thesis deals with the possibilities of identifying the relevant tire traces at the place of a traffic accident based on their physical characteristics. Braking traces on the road are one of the most important objective elements for accident analysis, their easy and accurate detection is very important for accurate accident assessment. With the increasing technical equipment of vehicles, especially with the introduction of newer generations of braking assistance systems, traces left by the tires become almost invisible to the human eye. It is therefore highly desirable that their detection should be not only as accurate as possible but also as easy and fast as possible, not only for forensic experts, but especially for members of the traffic police departments. In line with the development and introduction of new safety and assistance systems for vehicles should also be the development of means and methods of providing the basis for technical analysis of traffic accidents. Reality shows that the procedures, even if still functional, are practically identical for several decades, are dependent on the subjective capabilities of the documenting person. An essential element of the work, compared to the previously described measurement procedures, is the use of modern methods and devices at the highest known level of knowledge. The aim is to find and verify a simple, accurate, subjectively least influenced detecting method for tire traces on the road. A series of measurements confirmed the possibility of using the thermal camera at the technical level usually available at the place of the accident, under limited atmospheric and time conditions. In addition, laser-induced plasma spectroscopy and rLIBS were used. This method of detecting spotless tire treads can be marked as a minimally feasible documentary and at the same time as fast enough, based on the measurements made and the intended removal of defects of the instrument in the development phase of the prototype.
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The use of hydraulic disc brakes for road bikes
Dvořáková, Barbora ; Lošák, Petr (referee) ; Šebek, František (advisor)
This bachelor's thesis is focused on the usage of hydraulic disc brakes on road bikes. The thesis is divided into two parts. In the first part, there is a research focused on differences in construction and properties of hydraulic disc brakes in comparison with rim brakes. The main emphasis is placed on evaluating all advantages and disad-vantages of the hydraulic disc brakes in comparison with rim brakes. Evaluation is conducted both from the functional point of view and user point of view with taking different requirements of both recreational level cyclist and professional cyclist into account. The aim of the second part is the numerical simulation of loading of the frame and fork for both types of brakes. The goal of this part is an overall assessment of suitability of hydraulic disc brakes for the road bikes.
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