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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Optimization of a Parallel Mechanism Design with Respect to a Stewart Platform Control Design / Optimization of a Parallel Mechanism Design with Respect to a Stewart Platform Control Design

Březina, Lukáš January 2010 (has links)
Předkládaná práce se zabývá návrhem modelu dynamiky paralelního manipulátoru optimálního pro účely návrhu řízení. Zvolený přístup je založen na modelování dynamiky systému v simulačním prostředí Matlab SimMechanics následovaném linearizací modelu. Výsledný stavový lineární model mimo jiné umožňuje snadné posouzení řiditelnosti a pozorovatelnosti modelu. Díky své relativní jednoduchosti je model také výpočetně nenáročný. Přístup je demonstrován na návrhu dvouvrstvého řízení SimMechanics modelu Stewartovy platformy, na kterém bylo následně navržené řízení úspěšně testováno. Podstatná část práce obsahuje přístup k modelování neurčitých parametrů dynamického modelu Stewartovy platformy a stejnosměrného motoru Maxon RE 35 a jeho výsledky. Předložený přístup je založen na modelování parametrické neurčitosti způsobem, kdy je neurčitost definována individuálně pro jednotlivé prvky stavových matic modelu. Samotná neurčitost je potom určena rozdílem mezi jednotlivými parametry příslušných matic nominálního modelu a modelu se stanovenou maximální neurčitostí parametrů. Výsledný neurčitostní model je vzhledem ke své stavové reprezentaci vhodný pro návrh regulátoru založeném na metodách návrhu robustního řízení, například minimalizaci normy H-nekonečno. Popsaná metoda byla použita pro kompenzaci posunu mezi pracovními body, okolo kterých je prováděna linearizace a pro kompenzaci nepřesnosti modelování vybraných parametrů modelů Stewartovy platformy a stejnosměrného motoru. Získané modely (v prostředí SimMechanics a neurčitostní model) byly experimentálně porovnány s chováním jednoho z lineárních pohonů Stewartovy platformy. Rozdíl v datech obdržených ze simulace v prostředí SimMechanics a naměřených na reálném stroji byl téměř kompletně pokryt neurčitostním modelem. Prezentovaná metoda neurčitostního modelování je velice univerzální a aplikovatelná na libovolný stavový model.
2

AeroWorks: Pohybová platforma pro simulátor / AeroWorks: Simulator Motion Platform

Morávek, Martin January 2012 (has links)
This diploma thesis is dealing with the concepts behind the Stewart platform based flight simulation phenomena along with the method of inverse kinematics computation. Further, a washout algorithm to provide appropriate vestibular sensing to the pilot and ensuring that platform will not reach its limits is presented. Digital filters designed to be used in the implementation of the washout algorithm and their characteristics are also covered. The last part describes the architecture of the whole system and the implementation of individual parts.
3

Hexagonální platforma se servořízením / Hexagonal Platform with Servo Control

Korgo, Tomáš January 2014 (has links)
Goal of the thesis is to show the possibilities of using ordinary hobbyist RC servos and means of their control by a computer. For demonstration of the capabilities of servos, we have created Stewart platform which is using hobbyist servos to position the platform. In the thesis there is explained principle of the inner working of a servo, their properties, abilities and also means of their control by a computer. In practical chapters of the thesis there is documented process of designing and implementing of functional Stewart platform along with specific properties of this platform which influence its design. This platform is also reviewed and based on the results we will show technical properties of the platform, advantages and disadvantages of using ordinary hobbyist servos to control the platform. Design of the platform and its documentation is created with respect to intent to make the ddesign, source codes, documentation available to public on wepages focused on aggregating of instructables and tutorials to make usage of outputs possible in practice.
4

OPTIMALIZACE NÁVRHU FUZZY ŘÍZENÍ VZHLEDEM K ROZSAHU POHYBŮ PARALELNÍHO MECHANISMU / OPTIMIZATION OF A FUZZY CONTROL DESIGN WITH RESPECT TO A PARALLEL MECHANISM WORKSPACE

Andrš, Ondřej January 2012 (has links)
The Ph.D. thesis is focused on using the fuzzy logic for control of a parallel manipulator based on a Stewart platform. The proposed mechanism makes possible to simulate the physiological movements of the human body and observe degradation processes of the cord implants. Parallel manipulators such as a Stewart platform represent a completely parallel kinematic mechanism that has major differences from typical serial link robots. However, they have some drawbacks of relatively small workspace and difficult forward kinematic problems. Generally, forward kinematic of a parallel manipulators is very complicated and difficult to solve. This thesis presents a simple and efficient approach to design simulation model of forward kinematic based on Takagi-Sugeno type fuzzy inference system. The control system of the parallel manipulator id based on state-space and fuzzy logic controllers. The proposed fuzzy controller uses a Sugeno type fuzzy inference system (FIS) which is derived from discrete position state-space controller with an input integrator. The controller design method is based on anfis (adaptive neuro-fuzzy inference system) training routine. It utilizes a combination of the least-squares method and the backpropagation gradient descent method for training FIS membership function parameters to emulate a given training data set. The proposed fuzzy logic controllers are used for the control of a linear actuator. The capabilities of the designed control system are shown on verification experiment.
5

MR vzpěra pro vibroizolační Stewardovu plošinu pro kosmonautiku / MR Strut of Steward Platform for Vibration and Shock Isolation

Macháček, Ondřej January 2014 (has links)
The thesis deals with design magnetorheological strut of vibration isolation adapter for cosmonautics. For its optimization is necessary to create several virtual models. The dynamic model of the mechanism - the Stewart platform, rheological model for determining the damping force of MR damper and model of the magnetic circuit to guarantee the required intensity in the gap. These models, along with controls models that are primarily concerned with strength calculations, will help with design. Designing using virtual models requires constant monitoring and verification. It is a rather broad topic including eliminate vibration also kinematics, dynamics, hydraulics, pneumatics and last but not least electronics and magnetism. It is necessary to communicate with experts in their field and use their knowledge and experience to create, but also to control of the individual models. The thesis was created in cooperation with Honeywell Aerospace Division (ESA).

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