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Development of electronic parking system
Šmíd, Josef ; Strecker, Zbyněk (referee) ; Paloušek, David (advisor)
This bachelor thesis deals with the development of the electronic parking system, which is intended to navigate the drivers to the nearest vacancies, using the Arduino platform. The introductory part deals with an overview of the current state of knowledge. The research section provides an overview of the Arduino base plates and other modules and sensors selected for conceptual design solutions. The construction part deals with the design of the casing according to the selected components and the subsequent realization of the whole device, including the program, for testing under real conditions. The test results are finally evaluated and summarized in the final discussion.
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Design of DH bike fork with magnetorheological damper
Salva, Matúš ; Robenek, Dětřich (referee) ; Strecker, Zbyněk (advisor)
When mountain biking over rough terrain, comfort and sufficient wheel pressure are often the limiting factors. That's why there is an effort to innovate suspension and develop dampers that provide better damping characteristics. The usage of semi-active suspension is one way to achieve the desired improvement over the currently used passive systems. In this work, the aim was to develop a magnetorheological damper that is suitable for implementation in commonly available mountain bike forks and whose damping characteristics allow the use of the Skyhook algorithm. A functional model of an MR damper with a stroke of 240 mm and an outer diameter of 29.5 mm, whose dynamic range is 9.5 at a piston velocity of 0.25 ms-1 and a time response of 17 ms, was developed. The magnetic circuit of the manufactured functional pattern is of 11SMn30. The damper served to verify the functionality of the concept and at the same time its damping characteristics were experimentally verified and compared with the predicted values. Due to the combination of numerical and analytical model, a very good agreement between prediction and experiment was achieved. Hence, an MR damper with a magnetic circuit made of Hiperco/Vacoflux 50 material was subsequently designed with a predicted dynamic range of 9.5 and a time response of less than 10 ms. The resulting total weight of the design is 0.68 kg. This design fully satisfies all requirements. When used in combination with semi-active control using the Skyhook algorithm, it is predicted to improve ride comfort by 28 %. The potential to use the proposed MR damper is with the increasingly widespread electric bicycles mainly due to the higher weight in conjunction. At the same time, however, the possibility of using it on a regular bicycle is not excluded. Semi-active suspension is a new and not yet widely used technology in cycling and has the potential to reach a new range of consumers. Considering all the advantages and disadvantages, it can be concluded that the proposed MR shock absorber allows to improve the rideability of mountain bikes both in terms of ride comfort, wheel traction or in the form of reduced energy expenditure during pedalling due to energy absorption by the suspension.
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Solution of Electronic Shifting for COMEX Gearbox
Crhová, Hana ; Strecker, Zbyněk (referee) ; Dvořáček, Jiří (advisor)
The subject of this barchelor's thesis is design of shifting of vehicle for handicapped people, with the emphasis on simply shifting of transmission gears. In the first part there is a comparison of Elbee with other vehicles of this category. Next part is about gearboxes divided by type of shifting. And there is comparison of these gearboxes. In the last part there is the choice of the best gearbox and construction of additional mechanism which provides correct functionality of transmission system.
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Design of fast magnetorheological damper piston group using selective laser melting technology
Vítek, Petr ; Růžička, Bronislav (referee) ; Strecker, Zbyněk (advisor)
The diploma thesis deals with the development of the magnetic circuit of Magnetoreological (MR) dampers with a short time response. To achieve a short response time, a shape approach was chosen whereby the geometry of the magnetic circuit was chosen to significantly eliminate the occurrence of eddy currents. The influence of structures on magnetic properties was first examined on a simpler toroidal core and then the optimization was subjected to the magnetic circuit of the MR damper itself. Geometry optimization was done using FEM simulations. The resulting geometry was made of pure iron using Selective Laser Melting technology (SLM). In addition, a MR damper was completed and its properties on air and with MR fluid were measured, which were then compared with previously developed rapid MR dampers. It has been found that the newly designed magnetic circuit achieves similar time responses as all other compared fast MR dampers and reaches a higher dynamic range than most of the compared variants. The proposed magnetic circuit also has a significantly reduced weight.
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Optimization of Control Algorithm of MR Damper
Strecker, Zbyněk ; Kotaba, Ondřej (referee) ; Ondrůšek, Čestmír (referee) ; Šindelář, Martin (referee) ; Mazůrek, Ivan (advisor)
This work deals with the usage of magneto-rheological (MR) damper in the semi-active car suspension. Semi-active suspension can improve ride comfort or tyre grip to the level, which cannot be achieved with the common passive setting of the damper. MR damper has however features, like time response of the controller with MR damper and the control range of the MR damper, which limit area of application. It was found out that especially the time response of the damper significantly influences the efficiency of semi-active algorithms. Current MR dampers with controllers are not capable of efficient control of the semi-active suspension. For proper design of semi-active suspension with MR dampers, the time response must be decreased. Therefore, a new PWM current controller was designed and verified. Also changes in MR damper design which eliminate eddy-currents in the magnetic circuit were proposed. The results of this work should contribute to the better design of semi-active suspension systems with MR damper.
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Sedimentation of MR fluid at the start of new space lanucher
Berka, Pavel ; Strecker, Zbyněk (referee) ; Roupec, Jakub (advisor)
This bachelor thesis deals with sedimentation behavior of magnetorheological fluid exposed to acceleration 1-6 G. That simulates start of a space launcher. Main goal of this work is to bring new knowledge of MR fluids behavior. Experiment of accelera-ted sedimentation as well as the long term sedimentation is presented, including new method and measuring device developed to measure the sedimentation, in order to compare different commercial MR fluids. Results from this work will be used in development of the new semiactive dum-ping system for carrying load in ESA new space launcher.
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Design of linear clock controlled by Arduino Uno
Hladík, Ondřej ; Strecker, Zbyněk (referee) ; Svoboda, Petr (advisor)
The bachelor thesis deals with designing and realization of functional sample of linear clock with analog scale using 3D printing. Firstly, the structural arrangement of available devices and the selection of usable electronic components are solved based on the required parameters. After that, the work contains a design solution of printed parts, where the linear motion mechanism is designed as a rack and pinion and the feed of scales is solved using a sliding linear guide. The work includes a wiring diagram of used electronic parts. The Arduino Uno board takes care of the clock control, for which a program was created according to the required properties. In the end, the functionality on the created sample was verified. The work is accompanied by assembly drawings and drawings of the main parts and the complete program.
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Mechanical construction of electromagnetic valves in automotive
Sušovský, Martin ; Novák, Petr (referee) ; Strecker, Zbyněk (advisor)
The bachelor thesis brings complex view at electromagnetic valves used in automotive. Providing closer information about its function in important parts of car. This study is mostly focused on usage of the electromagnetic valves in an injection systems, like high pressure common-rail system used in diesel engine from BOSH. Furthermore, in main part of the study, technical solutions, that lead to reduced response time, which results to improved performance of the valves, are investigated.
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Design of rear bumper for passenger car
Tomeš, Jan ; Strecker, Zbyněk (referee) ; Klapka, Milan (advisor)
The Bachelor thesis deals with search about passenger car bumpers. It focuses especially on RCAR crash tests and currently used constructions of bumpers. There is suggested concept of rear bumper based on findings from the search. The concept was modeled on design study of Swell Company’s car.
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Design of MR clutch water cooling
Musil, Marek ; Strecker, Zbyněk (referee) ; Roupec, Jakub (advisor)
This paper describes the design and manufacture of water refrigeration for magneto clutch. MR clutch cooling problem was solved by designing of several variants of which was finally chosen the best. Model of water cooling was developed and subsequently made. The cooling is consolidated on a stator of MR clutch. Cooling completely surrounds the body of an MR clutch and thus achieves a high heat transfer between the cooling system and cooled. The proposal was developed with a view to good foldability, so its use is not complicated.
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