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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.
21

Výpočtový model tlumiče odpružení / Computational Model of Shock Absorber

Svršek, David January 2019 (has links)
The diploma thesis titled, Computational model of shock absorber, is concerned with ways to simulate individual actuators of dampening with the goal of obtaining F-v characteristics dependent on the setup of the shock absorber. The work is divided into two halves, the first one being a review of literature and the second half being practical. The review part is focused on ways of shock absorber constructions and the physical principles involved with the present forces. The practical part of the work contains a computational model of a monotube shock absorber in the Matlab programming software.
22

Efekt tlumiče na limity vozidla / Effect of Shock Absorber on Vehicle Limits

Jurka, Adam January 2020 (has links)
The aim of this master’s thesis is to evaluate the effect of shock absorber on vehicle limits. At the beginning of the thesis, shock absorber properties were described. Then computational model was created and manoeuvres for shock absorber behaviour were defined. Created mathematical model is based on quarter model of a car and excitation in form of road with a random profile is an essential part of the model. This model was used for evaluation of heave. After heave analysis, shock absorber behaviour during drive was investigated. Drive conditions were defined as set of handling manoeuvres. For the drive investigation, complete multibody virtual model of racing car was used. Based on drive investigation analysis, optimal damping characteristics for each manoeuvre were found. Furthermore, each optimal characteristic was compared for different manoeuvres. Obtained results were compared. As a conclusion, compromise damping characteristic was suggested with the aim to fit the combination of all defined drive conditions. Final part of the thesis was aimed at validation of the computational model. Data measured during real drive were used as an input for this validation.
23

Magnetoreologický tlumič kmitání / Megnetorheological shockabsorber

Lazar, Jaroslav January 2011 (has links)
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.
24

Mechatronická soustava pro prezentaci kmitání a tlumení / Mechatronic system for presentation of damped oscillation

Sirota, Tomáš January 2015 (has links)
This work is aimed to creating a system for presentation of oscilations. The main part consist of electromagnetic damper, which properties are suitable for use in this system. In the first part are some conditions for design of damper body . In he second part are selected next parameters for electromagnetic damper and of the whole system by MATLAB / Simulink with iterative method. In last part is whole system analyzed and the results indicate next changes in the structure of the system.
25

Lagring och visualisering av information om stötdämpare

Settlin, Johan, Ekelund, Joar January 2019 (has links)
Att genom simuleringar få en förståelse för hur en stötdämpares inställningar påverkar dess egenskaper kan leda till förbättrad väghållning, ökad trafiksäkerhet samt snabbare varvtider på racerbanan. Genom att visualisera de simulerade data för att ge användare en uppfattning om hur inställningarna på stötdämparen kommer att bete sig i praktiken.Det här arbetet hade som mål att utforma en databas som efterliknar en stötdämpares egenskaper samt att visualisera dessa egenskaper på en webbsida. Kravinsamling gjordes genom intervjuer med experter och information införskaffades via litteraturstudier. Utifrån insamlade krav och fallstudier utvecklades en relationsdatabas som innehåller information om en dämpares komponenter och uppbyggnad samt ett visualiseringsverktyg där egenskaperna hos dämparen visualiserades på en webbsida. Databasen och visualiseringsverktyget sammanfogades sedan till en prototyp för att möjliggöra simulering av en dämpares egenskaper på webben.Resultatet av fallstudierna visade att databashanteringssystemet MySQL och grafbiblioteket Chart.js var bäst lämpade för prototypen utifrån de insamlade kraven. Funktionaliteten av protypen validerades av projektets uppdragsgivare och felmarginalen för simuleringarna var under 1%. Detta implicerar att databasmodellen som tagits fram håller god kvalitet och att resultatet visualiseras på ett korrekt och förståeligt sätt. / By perform simulations to achieve an understanding of how a shock absorbers setting affect its characteristics could result in improved road holding, increased roadworthiness and faster lap times at the racetrack. By visualizing the simulated data, users can get an understanding in how the settings on the shock absorber will behave.This work had as a goal to design a database that mimic a shock absorbers characteristic and to visualize these characteristics on a website. Requirements was gathered through interviews with experts and information was procured through literature studies. From the gathered requirements and case studies a relational database, that contain information about a shock absorbers components and construction, was developed. A visualization tool to visualize the characteristics of a shock absorber was also developed. The database and the visualization tool where then joined to create a prototype for simulating a shock absorbers characteristic on the web.The result from the case studies indicated that the database management system MySQL and the graph library Chart.js was best suited for the prototype, based on the collected requirements. The functionality of the prototype was validated by the client and the margin of error for the simulation was below 1%. This implies that the database model that has been produced is of good quality and that the visualization of the result is presented in a correct and apprehensible manner.
26

Design of Driveline for Mobile Robot Platform / Design av drivmodul för mobilrobotplattform

Savant, Chirag January 2018 (has links)
Avhandlingen presenterar resultatet av ett examensarbete i maskindesign på KTH. Uppgiften utfördes för ABB AB, Corporate Research.ABB vill undersöka en ny drivlinjekonstruktion för lågkostnadsautomatisering. ABB Robotiks har begränsat utbud av produkter rörande mobila plattformar. Det finns en stor marknadspotential för samarbetsrobotar på mobila plattformar bland kunder med både låg och hög grad av automation.I denna rapport diskuteras en möjlig designlösning av drivlinan för en mobil robotplattform. Generellt är utformningen av en robust drivlina för mobilplattform en komplex uppgift eftersom inte alla arbetsförhållanden är lika i en industriell installation. Till exempel kan vissa industriområden för logistik och andra för tung teknik etc. Idag finns det mycket fa designer av mobila industriplattformar konstruerade för ojämn yta, ytor med sprickor, stötar och liknande ojämna egenskaper. Befintliga industriella lösningar är utformade för jämna ytor inom gränserna for golvdesignen och överensstämmer också med lasterna på plattformens drivlina. En robust lösning föreslås i denna rapport. Detta baseras på en litteraturöversikt med konstruktionsarbete inkluderande lättillgängliga billiga komponenter samt modellutvärdering för att klara specifikationen av grova golv ojämnheter. Studien för att implementera en stötdämpare baserad drivlinjemodul har också inkluderats för att undersöka möjligheten att ha ett sådant drivsystem. Andra funktioner inkluderar också en inbyggd styrenhet som gör den mer kompakt genom att minska ledningar runt plattformen. Prestanda utfördes i en simuleringsmiljö för att se stötdämparens beteende. Den slutliga konstruktionen versionen byggdes som prototyp för vidare utvärdering i test. / This thesis presents the result of a master thesis in Machine Design at KTH. The task was performed for ABB AB, Corporate Research.ABB wants to investigate in a new driveline designs for low cost automation. ABB robotics doesn’t have any products concerning mobility application. There is a huge market potential for collaborative robots on mobile platforms with customers with both low and high budget of automation.This report discusses one possible design solutions of the driveline for a mobile robot platform. Generally, designing a robust driveline for mobile platform is a complex task since not all working conditions are alike in an industrial setup. For instance, some industrial area might for logistics, some might be for heavy engineering, etc. Moreover, there aren’t industrial platforms designed for uneven surface, surfaces having cracks, bumps and similar uneven features. The ones which can cope unevenness are for extreme off-road military conditions. Existing industrial solutions are designed for even surfaces within limits and the floor design is also in accordance to the platform driveline. A robust solution is proposed here after conducting a literature review with solid evidence and evaluation for the same to sustain rough floor designs with readily available inexpensive components. Study for implementing a shock absorber-based driveline module has also been included within to look at a possibility to have such a drive system. Other features also include an on-board controller which reduces the hassle of wiring around the complete platform. The performance was conducted on a simulation environment to see the behaviour of the shock absorber. The final design was prototyped for further evaluation.
27

Adoção de inovações na indústria automotiva: modelo conceitual e aplicação para sistemas semiativos de amortecimento / Innovation adoption in the automotive industry: conceptual model and application for semiactive damping systems

Luiz Antonio Bloem da Silveira Junior 12 December 2018 (has links)
A centenária indústria automotiva está passando por profundas transformações nos seus modelos de negócio, processos de desenvolvimento em produto e de produção. Inovações tais como veículos autônomos, transporte compartilhado, células de combustível, entre outras, apresentam-se aos estrategistas das montadoras como alternativas para gerar um diferencial competitivo e garantir a sobrevivência das empresas. Assim sendo, o entendimento dos mecanismos e fatores que influenciam na decisão de adoção de inovações em produto pelas montadoras é um tema relevante para a academia. Artigos sobre adoção de inovação em produto pelas organizações da indústria automotiva não são comuns na literatura, e quando realizados concentram-se no estudo de tecnologias de propulsão alternativa. Este estudo propõe, a partir de uma ampla revisão sistemática da literatura disponível sobre adoção de inovações pelas organizações, um modelo teórico contendo dimensões e fatores de influência na adoção de inovações em produto pelas montadoras de veículos, aplicando o modelo a um componente específico do automóvel, os chamados sistemas semiativos de amortecimento ou \'amortecedores inteligentes\'. Um diferencial do modelo conceitual desenvolvido foi a introdução da dimensão \'gestão da inovação\', analisando diversos fatores relacionados à estratégia tecnológica da montadora. A aplicação deste modelo foi realizada utilizando a metodologia de pesquisa qualitativa básica, por meio de entrevistas com funcionários de montadoras e fabricantes de sistemas de suspensão e amortecedores estabelecidos no mercado automotivo brasileiro. Uma pesquisa adicional foi realizada com o objetivo de identificar de que maneira a importância relativa entre os fatores que influem na adoção de inovações em produto pelas montadoras de veículos muda entre um país desenvolvido (EUA) e outro em desenvolvimento (Brasil). Dessa forma, o modelo conceitual desenvolvido foi aplicado por meio de entrevistas realizadas com funcionários de empresas do segmento automotivo estabelecidas no mercado dos EUA. As análises dos resultados permitiram identificar os fatores de maior influência na adoção da inovação em estudo pelas montadoras, bem como os fatores de menor influência. Análises comparativas foram realizadas entre estes fatores, para discutir as razões das semelhanças e diferenças entre eles. Esta tese produziu três artigos correlacionados entre si, o primeiro denominado Adoção de inovações em produto pelas organizações: Uma revisão sistemática de literatura. O segundo artigo foi intitulado como Adoção de inovações em produto na indústria automotiva: Modelo conceitual e aplicação para sistemas semiativos de amortecimento. O artigo Adoção de inovações em produto na indústria automotiva: Um estudo comparativo entre Brasil e EUA é o terceiro e último da tese. Estudos comparando a influência de fatores de adoção de inovação em produto pelas organizações foram realizados em outras áreas da tecnologia, porém artigos com comparações internacionais entre estes fatores não são comuns na literatura. Nenhum estudo sobre adoção de sistemas semiativos de amortecimento ou \'amortecedores inteligentes\' foi identificado na revisão de literatura realizada, o que evidencia o ineditismo deste trabalho de pesquisa. / The centenary automotive industry has gone through significant transformations in its business models, product development and production processes. Innovations like autonomous vehicles, transportation sharing, fuel cells, among others, show themselves as alternatives to create a competitive differential and assure companies survival. Therefore, the understanding of mechanisms and factors that influence automaker\'s decision to adopt product innovations is a relevant issue for the academy. Papers about product innovation adoption by organizations in the automotive industry are not common in the literature. When made, they focus mostly on the study of alternative propulsion technologies. This research proposes a theoretical model comprising dimensions and factors influencing product innovation adoption by automakers based on a broad literature systematic analysis about organizational innovation adoption. This model was applied to a specific automotive component, the so-called semi active damping systems or \"smart shock absorbers.\" The conceptual model presents the unpublished dimension \"innovation management\", which analyses several factors related to the automakers technological strategy. This research used basic qualitative analysis methodology and performed interviews with employees from automakers and suspension system manufacturers settled in the Brazilian automotive market. An extra research aimed to identify the way the relative importance between the factors that influence in the product innovation adoption by the automakers changes from a developed country (USA) and another country in development (Brazil). Interviews with employees from automotive companies settled in the USA market applied the conceptual model. The result of the analysis allowed the identification of the most influencing factors in the adoption of the product innovation by automakers, as well the less influencing factors. Comparative analyses between these factors were made in order to discuss the reasons of similarities and differences between them. This dissertation produced three correlated papers se, the first one is \"Product innovation adoption by organizations: A systematic literature review.\" The second one is \"Product innovation adoption in the automotive industry: Conceptual model and application for semi active damping systems.\" The third and last one of this dissertation is \"Product innovation adoption in the automotive industry: A comparative study between Brazil and USA.\" There are papers comparing the factors influencing product innovation adoption by organizations in other technology fields, but international comparisons between these factors are not common in literature. This research found no paper about semi active damping systems (\"smart shock absorbers\") in the literature review, which evidences the brand new characteristic of this dissertation.
28

Adoção de inovações na indústria automotiva: modelo conceitual e aplicação para sistemas semiativos de amortecimento / Innovation adoption in the automotive industry: conceptual model and application for semiactive damping systems

Silveira Junior, Luiz Antonio Bloem da 12 December 2018 (has links)
A centenária indústria automotiva está passando por profundas transformações nos seus modelos de negócio, processos de desenvolvimento em produto e de produção. Inovações tais como veículos autônomos, transporte compartilhado, células de combustível, entre outras, apresentam-se aos estrategistas das montadoras como alternativas para gerar um diferencial competitivo e garantir a sobrevivência das empresas. Assim sendo, o entendimento dos mecanismos e fatores que influenciam na decisão de adoção de inovações em produto pelas montadoras é um tema relevante para a academia. Artigos sobre adoção de inovação em produto pelas organizações da indústria automotiva não são comuns na literatura, e quando realizados concentram-se no estudo de tecnologias de propulsão alternativa. Este estudo propõe, a partir de uma ampla revisão sistemática da literatura disponível sobre adoção de inovações pelas organizações, um modelo teórico contendo dimensões e fatores de influência na adoção de inovações em produto pelas montadoras de veículos, aplicando o modelo a um componente específico do automóvel, os chamados sistemas semiativos de amortecimento ou \'amortecedores inteligentes\'. Um diferencial do modelo conceitual desenvolvido foi a introdução da dimensão \'gestão da inovação\', analisando diversos fatores relacionados à estratégia tecnológica da montadora. A aplicação deste modelo foi realizada utilizando a metodologia de pesquisa qualitativa básica, por meio de entrevistas com funcionários de montadoras e fabricantes de sistemas de suspensão e amortecedores estabelecidos no mercado automotivo brasileiro. Uma pesquisa adicional foi realizada com o objetivo de identificar de que maneira a importância relativa entre os fatores que influem na adoção de inovações em produto pelas montadoras de veículos muda entre um país desenvolvido (EUA) e outro em desenvolvimento (Brasil). Dessa forma, o modelo conceitual desenvolvido foi aplicado por meio de entrevistas realizadas com funcionários de empresas do segmento automotivo estabelecidas no mercado dos EUA. As análises dos resultados permitiram identificar os fatores de maior influência na adoção da inovação em estudo pelas montadoras, bem como os fatores de menor influência. Análises comparativas foram realizadas entre estes fatores, para discutir as razões das semelhanças e diferenças entre eles. Esta tese produziu três artigos correlacionados entre si, o primeiro denominado Adoção de inovações em produto pelas organizações: Uma revisão sistemática de literatura. O segundo artigo foi intitulado como Adoção de inovações em produto na indústria automotiva: Modelo conceitual e aplicação para sistemas semiativos de amortecimento. O artigo Adoção de inovações em produto na indústria automotiva: Um estudo comparativo entre Brasil e EUA é o terceiro e último da tese. Estudos comparando a influência de fatores de adoção de inovação em produto pelas organizações foram realizados em outras áreas da tecnologia, porém artigos com comparações internacionais entre estes fatores não são comuns na literatura. Nenhum estudo sobre adoção de sistemas semiativos de amortecimento ou \'amortecedores inteligentes\' foi identificado na revisão de literatura realizada, o que evidencia o ineditismo deste trabalho de pesquisa. / The centenary automotive industry has gone through significant transformations in its business models, product development and production processes. Innovations like autonomous vehicles, transportation sharing, fuel cells, among others, show themselves as alternatives to create a competitive differential and assure companies survival. Therefore, the understanding of mechanisms and factors that influence automaker\'s decision to adopt product innovations is a relevant issue for the academy. Papers about product innovation adoption by organizations in the automotive industry are not common in the literature. When made, they focus mostly on the study of alternative propulsion technologies. This research proposes a theoretical model comprising dimensions and factors influencing product innovation adoption by automakers based on a broad literature systematic analysis about organizational innovation adoption. This model was applied to a specific automotive component, the so-called semi active damping systems or \"smart shock absorbers.\" The conceptual model presents the unpublished dimension \"innovation management\", which analyses several factors related to the automakers technological strategy. This research used basic qualitative analysis methodology and performed interviews with employees from automakers and suspension system manufacturers settled in the Brazilian automotive market. An extra research aimed to identify the way the relative importance between the factors that influence in the product innovation adoption by the automakers changes from a developed country (USA) and another country in development (Brazil). Interviews with employees from automotive companies settled in the USA market applied the conceptual model. The result of the analysis allowed the identification of the most influencing factors in the adoption of the product innovation by automakers, as well the less influencing factors. Comparative analyses between these factors were made in order to discuss the reasons of similarities and differences between them. This dissertation produced three correlated papers se, the first one is \"Product innovation adoption by organizations: A systematic literature review.\" The second one is \"Product innovation adoption in the automotive industry: Conceptual model and application for semi active damping systems.\" The third and last one of this dissertation is \"Product innovation adoption in the automotive industry: A comparative study between Brazil and USA.\" There are papers comparing the factors influencing product innovation adoption by organizations in other technology fields, but international comparisons between these factors are not common in literature. This research found no paper about semi active damping systems (\"smart shock absorbers\") in the literature review, which evidences the brand new characteristic of this dissertation.
29

A tolerance allocation framework using fuzzy comprehensive evaluation and decision support processes

Kumar, Abhishek 05 August 2010 (has links)
Tolerances play an important role in product fabrication. Tolerances impact the needs of the designer and the manufacturer. Engineering designers are concerned with the impact of tolerances on the variation of the output, while manufacturers are more concerned with the cost of fitting the parts. Traditional tolerance control methods do not take into account both these needs. In this thesis, the author proposes a framework that overcomes the drawbacks of the traditional tolerance control methods, and reduces subjectivity via fuzzy set theory and decision support systems (DSS). Those factors that affect the manufacturing cost (geometry, material etc) of a part are fuzzy (i.e. subjective) in nature with no numerical measure. Fuzzy comprehensive evaluation (FCE) is utilized in this thesis as a method of quantifying the fuzzy (i.e. subjective) factors. In the FCE process, the weighted importance of each factor affects the manufacturing cost of the part. There is no systematic method of calculating the importance weights. This brings about a need for decision support in the evaluation of the weighted importance of each factor. The combination of FCE and DSS, in the form of Conjoint Analysis (CA), is used to reduce subjectivity in calculation of machining cost. Taguchi's quality loss function is considered in this framework to reduce the variation in the output. The application of the framework is demonstrated with three practical engineering applications. Tolerances are allocated for three assemblies; a friction clutch, an accumulator O-ring seal and a Power Generating Shock Absorber (PGSA) using the proposed framework. The output performances of the PGSA and the clutch are affected by the allocated tolerances. On using the proposed framework, there is seen to be a reduction in variation of output performance for the clutch and the PGSA. The use of CA is also validated by checking efficiency of final tolerance calculation with and without use of CA.
30

Návrh konstrukce rychlého elektromagnetického ventilu semiaktivního tlumiče / The design of fast electromagnetic valve for semiactive damper

Žižlavský, Vít January 2021 (has links)
This diploma thesis’s focuses on the mechanical design of fast solenoid throttle valve for DCC semiactive damper. Current DCC dampers work with a time response of over 10 ms, which is not suitable for fast semiactive control of vehicle chassis. The time response needs to be shortened, to improve quality of regulation. The required time response is archived by new fast electromagnetic actuator for original CES valve. The actuator has been accelerated by reducing induction of eddy currents and by reducing weight of moving parts. New valve helped to reduce the time response of damper by 28 % to 8,1 ms. The results proved, that the time response is affected more by speed of the servo effect, which is closing main orifice, than by electromagnetic actuator. There is no more potential in accelerating CES valve by actuator.

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