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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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Hydrodynamic dampers on the principle of magnetic fluid
Přikryl, Matěj ; Himr, Daniel (referee) ; Pochylý, František (advisor)
This bachelor's thesis deals with damping vibrations emerging due to the movement of a vehicle. The first section provides an overview of contemporary types of dampers with thorough explanation of the principle of hydrodynamic damper. This section also contains simulation of vibrating vehicle equipped with passive damper. Literature research of magnetic fluids and description of magnetoviscous phenomenon is presented in the second part, which freely continues to the topic of magnetorheological (MR) dampers. The final chapter firstly describes current hydrodynamic dampers based on squeeze film (SF) mode of magnetorheological fluid and at the conclusion the author's concept of SF MR damper is submitted.
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Hydraulic shock absorbers of train bogie
Odehnal, Lukáš ; Jeniš, Filip (referee) ; Kubík, Michal (advisor)
This bachelor thesis mainly deals with design solutions of adaptive dampers used on railway vehicle bogies. The first part gives a general overview of the topic. The main part discusses current designs of adaptive dampers that have already been tested. Final part of the thesis compares the designs including their determining parameters in order to obtain a large enough sample to contribute to the development of a new, electronically controlled damper at the VUT in Brno.
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Design of semiactive suspension for mountain terrain bike
Mráz, Kryštof ; Kubík, Michal (referee) ; Strecker, Zbyněk (advisor)
This Bachelor Thesis is focused to design semiactive suspension of mountain bike using MR damper. In research part of thesis is summarised knowledge about passive and semiactive suspension of mountain bikes and about MR dampers. Behaviour of suspended front fork was simulated using virtual dynamic model which was created in graphic environment MATLAB Simulink. Semiactive algorithms Skyhook and modified Groundhook and for comparison also passive settings are simulated. According to results of these simulations is designed semiactive suspension with MR damper which has effect to stabilising contact force of front wheel and therefore increases safety of rider.
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The construction of MR damper for MTB fork suspension
Salva, Matúš ; Macháček, Ondřej (referee) ; Strecker, Zbyněk (advisor)
In MTB is front suspension very important part of bike. It ensures comfort of ride and security. This Bachelor thesis deals with the theoretical design of semi-active suspension for MTB fork. For this purpose of simulation models of suspension used adaptive damper and MR damper with Skyhook algorithm were made. Range of forces for MR damper for use in MTB was made on basis of simulation. Simulation results of semi-active suspension were compared to simulation results of adaptive suspension which contained F-v characteristics of damper used in downhill bike. MR damper with Skyhook had better results in field of riding comfort and it retained adhesion of adaptive damper. Final range of forces for MR damper in possible to use for more tests or for design of MR damper for fork of mountain bike.
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Testing of automotive sport suspension
Čípek, Pavel ; Růžička, Bronislav (referee) ; Strecker, Zbyněk (advisor)
The diploma thesis deals with testing of sports car suspension. The aim is the testing of fast magnetorheological damper in semiactive suspension that corresponds to quarter car model. The fast magnetorheological damper has a response time 2 ms. If the response time is short enough (order of units miliseconds) it is possible (based on earlier simulations) to achieve improvement of driving safety (better stability of force of tyre on roadway) and comfort (reduction of vibrations). The thesis proves this statement with series of experiments.
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Numerical hydraulic model of active zone in magnetorheological damper
Regner, Dominik ; Roupec, Jakub (referee) ; Kubík, Michal (advisor)
This bachelor thesis deals with the comparison of analytic hydraulic model and numerical models of MR damper‘s active zone. Next is the study of the influence of annular gap geometry and rheological properties of MR fluid to damper‘s performance. In the first part, there is the summary of knowledge about MR dampers and used numerical approaches. Next part describes the creation of models and in the final part there is the comparison of these models and validation is completed with data from the real damper. Also, there is an evaluation of results about changes of geometry and rheology.
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Megnetorheological shockabsorber
Lazar, Jaroslav ; Růžička, Bronislav (referee) ; Mazůrek, Ivan (advisor)
This master's thesis deals with an engineering design of an external reservoir for hydraulic shock absorbers with combined filling of oil and magnetorheological fluid. The first part describes existing designes of magnetorheological shock absorbers and characteristics of magnetorheological fluid. Next part describes a design of an experimental external reservoir and a test of its functionality on a prototype. This is followed by an optimalized engineering design of the experimental external reservoir.
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Hydrodynamic dampers on the principle of magnetic fluid
Přikryl, Matěj ; Fialová, Simona (referee) ; Pochylý, František (advisor)
This diploma thesis covers the topic of magnetic fluids and their utilisation in hydrodynamic dampers. The first part of the work consists of research on the current state of technology in hydraulic dampers with the focus on dampers using magnetorhelogical fluid. This chapter is followed by research on magnetic fluids with regard to their physical properties and mathematical description, which is used for CFD simulation of flow. The second part deals with the computational simulation of the flow of MR liquid in real MR damper in order to determine the damping characteristic and it's comparison with the experimental data.
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The design survey of magnetorheological dampers
Tran, Adam ; Macháček, Ondřej (referee) ; Kubík, Michal (advisor)
Bachleor´s thesis deals with the damping systems such as magnetorheological dampers or magnetorheological valves. At beginning MR effect is described in MR devices. Next part deals with the designs, materials, characteristics of FEM models e.g. magnetic inductions, tested characteristics (F-v, time response), and used MR fluids in MR devices. In second part there are compared each MR device (MR damper or MR valve) in listed characteristics from previous part and describes issues, which are not in publications.
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