In this thesis, a number of novel techniques for error resilient coding and streaming for multiview video are presented. First of all, a novel coding technique for stereoscopic video is proposed where additional coding gain is achieved by downsampling one of the views spatially or temporally based on the well-known theory that the human visual system can perceive high frequencies in 3D from the higher quality view. Stereoscopic videos can be coded at a rate upto 1.2 times that of monoscopic videos with little visual quality degradation with the proposed coding technique. Next, a systematic method for design and optimization of multi-threaded multi-view video encoding/decoding algorithms using multi-core processors is proposed. The proposed multi-core decoding architectures are compliant with the current international standards, and enable multi-threaded processing with negligible loss of encoding efficiency and minimum processing overhead. End-to-end 3D Streaming system over Internet using current standards is implemented. A heuristic methodology for modeling the end-toend rate-distortion characteristic of this system is suggested and the parameters of the system is optimally selected using this model. End-to-end 3D Broadcasting system over DVB-H using current standards is also implemented. Extensive testing is employed to show the importance and characteristics of several error resilient tools. Finally we modeled end-to-end RD characteristics to optimize the encoding and protection parameters.

Orientador: Alberto Luiz Serpa / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-10T09:47:50Z (GMT). No. of bitstreams: 1 Wink_CarlosHenrique_D.pdf: 2304427 bytes, checksum: 74656d82cf5628ea8dd76c8ab1507dba (MD5) Previous issue date: 2007 / Resumo: O ruído gerado pelos sistemas de transmissão de potência por engrenagens pode ser incomodo e algumas vezes inaceitável para o usuário. Os pares de engrenagens geram um ruído incomodo ao ouvido humano devido as suas características de intensidade e freqüência. Este ruído é proveniente principalmente da irregularidade no movimento transmitido de uma engrenagem para a outra, que é conhecida como erro de transmissão (ET). A excitação proveniente do ET pode ser reduzida modificando-se a superfície dos dentes. Embora a modelagem matemática para o cálculo do ET tenha sido bastante estudada, não se conhece um método eficaz para definir os parâmetros ótimos das modificações. Os métodos existentes usam procedimentos exaustivos para a busca da solução, ou usam procedimentos de otimização que podem resultar em modificações de difícil obtenção. Neste trabalho desenvolveu-se um método para determinar as modificações da superfície dos dentes que minimizam a excitação do ET. No método proposto as modificações são obtidas resolvendo-se um problema particular de otimização de forma com contato, através de um procedimento iterativo com uma abordagem baseada em critérios de ótimo. Os valores calculados inicialmente para as modificações da superfície são aproximados aos obtidos por funções pré-definidas, resolvendo um problema de ajuste de curva, através de um método de programação seqüencial quadrática. Isto é feito para assegurar que a solução obtida seja simples do ponto de vista de fabricação de engrenagens. A verificação do método foi feita através de exemplos numéricos com pares de engrenagens helicoidais com características geométricas distintas. Nos exemplos numéricos estudados, o método se mostrou eficaz para determinar as modificações da superfície dos dentes que minimizam a excitação do ET / Abstract: Noise that comes from geared systems can be annoying, and in some cases unacceptable by users of those systems. Gear noise is dose to pure tone, presents high amplitude, and its frequency is near to most sensitive region of human ear. Transmission error (TE) excitation is recognized as one of the main sources of gear noise and vibration. It is well-known that TE excitation can be reduced by modifying tooth surfaces. Usually, tooth modifications are defined based on trial and error methods, or based on existent gear sets. Although there are some methods to calculate TE, a simple method to define the tooth modifications that mini mize the TE excitation is still unknown. Existent methods are based on exhaustive search of solution, or based on optimization procedures that. can end up in non practical solutions. In this work, an e:ffi.cient method to determine the tooth profile modification to minimize the TE excitation was developed. The proposed method defines the optimal modifications by solving a particular shape optimization problem with contact using an iterative procedure based on aptimal criteria approach. Initial modification results are converted to pre-defined functions by solving a curve fitting problem using a sequential quadratic programming. This assuresa worthy solution from the practical engineering viewpoint. Three different helical gear pairs were used to carry out numerical analysis in order to verify the proposed method. The results af the numerical analysis showed that the proposed method is efficient in solving this kind of problem. Significant reductionas on TE excitation were achieved for all three cases of study. The optimization procedure can be used as a useful design tool for gear design and development / Doutorado / Mecanica dos Sólidos e Projeto Mecanico / Doutor em Engenharia Mecânica

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Nowadays, increasing pressure from legislation and customer demands in the automotive industry are forcing manufacturers to produce greener vehicles with lower emissions and fuel consumption.As a result, electrified and hybrid vehicles are a growing popular alternative to traditional internal combustion engines (ICE). The noise from an electric vehicle comes mainly from contact between tyres and road, wind resistance and driveline. The noise emitted from the driveline is for the mostpart related to the gearbox. When developing a driveline, it is a factor of importance to estimate the noise radiating from the gearbox to achieve an acceptable design.Gears are used extensively in the driveline of electric vehicles. As the gears are in mesh, a main intrusive concern is known as gear whine noise. Gear whine noise is an undesired vibroacoustic phenomenon and is likely to originate through the gear contacts and be transferred through themechanical components to the housing where the vibrations are converted into airborne and structure-borne noise. The gear whine noise originates primarily from the excitation coming from transmission error (TE). Transmission error is defined as the difference between the ideal smoothtransfer of motion of a gear and what is in practice due to lack of smoothness.The main objective of this study is to simulate the vibrations generated by the gear whine noise in an electric powertrain line developed by AVL Vicura. The electric transmission used in this study provides only a fixed overall gear ratio, i.e. 9.59, under all operation conditions. It is assumed thatthe system is excited only by the transmission error and the mesh stiffness of the gear contacts. In order to perform NVH analysis under different operating conditions, a multibody dynamics model according to the AVL Excite program has been developed. The dynamic simulations are thencompared with previous experimental measurements provided by AVL Vicura.Two validation criteria have been used to analyse the dynamic behaviour of the AVL Excite model: signal processing using the FFT method and comparison with the experimental measurements.The results from the AVL Excite model show that the FFT criterion is quite successful and all excitation frequencies are properly observed in FFT plots. Nevertheless, when it comes to the second criterion, as long as not all dynamic parameters of the system such as damping or stiffnesscoefficients are provided with certainty in the model, it is too difficult to investigate the accuracy of the AVL Excite model. Another investigation is a numerical design study to analyses how the damping coefficients influence the response. After reducing the damping parameters, the results show that the housing and bearings have the highest influence on the response. If more acceptable results are desired,future studies must be concentrated on these to obtain more acceptable damping values. / För närvarande tvingar ökat tryck från lagstiftning och kundkrav inom bilindustrin tillverkarna attproducera grönare fordon med lägre utsläpp och bränsleförbrukning. Som ett resultat ärelektrifierade och hybridfordon ett växande populärt alternativ till traditionellaförbränningsmotorer (ICE). Bullret från ett elfordon kommer främst från kontakten mellan däckoch väg, vindmotstånd och drivlinan. Bullret från drivlinan är i huvudsak relaterat till växellådan.Vid utveckling av en drivlina är det av betydelse att uppskatta bullret från växellådan för att uppnåen acceptabel design.Utväxlingar används i stor utsträckning i elfordons drivlina. Eftersom kugghjulen är i kontaktuppstår ett huvudproblem som är känt som ett vinande ljud från kugghjulskontakten.Kugghjulsljud är ett oönskat vibro-akustiskt fenomen och uppstår sannolikt på grund avkugghjulkontakterna och överförs via de mekaniska komponenterna till växellådshuset därvibrationerna omvandlas till luftburet och strukturburet ljud. Kugghjulsljudet härstammarhuvudsakligen från exciteringen som kommer från transmissionsfel (TE) i kugghjulskontakten.Överföringsfelet definieras som skillnaden mellan den ideala smidiga rörelseöverföringen hoskugghjulen och rörelsen som sker i verkligheten på grund av ojämnheter.Huvudsyftet med denna studie är att simulera vibrationerna som genereras avkugghjulskontakterna i en elektrisk drivlina utvecklad av AVL Vicura. Den elektriska drivlinan somanvänds i denna studie har endast ett fast utväxlingsförhållande, dvs 9,59, för alladriftsförhållanden. Det antas att systemet är exciterat endast av överföringsfelet och kugghjulensstyvhet i kuggkontakterna. För att kunna utföra NVH-analys under olika driftsförhållanden har enstelkroppsdynamikmodell utvecklats med hjälp av programmet AVL Excite. De dynamiskasimuleringarna jämförs sedan med tidigare experimentella mätningar som tillhandahålls av AVLVicura.Två valideringskriterier har använts för att analysera det dynamiska beteendet hos AVL Excitemodellen:signalbehandling med FFT-metoden och jämförelse med experimentella mätningar.Resultaten från AVL Excite-modellen visar att FFT-kriteriet är ganska framgångsrikt och allaexcitationsfrekvenser observeras korrekt i FFT-diagrammen. Men när det gäller det andra kriteriet,så länge som inte alla dynamiska parametrar i systemet, såsom dämpnings- ellerstyvhetskoefficienter, är tillförlitliga i modellen, är det för svårt att undersöka exaktheten hos AVLExcite-modellen.En annan undersökning som utförts är en numerisk designstudie för att analysera hurdämpningskoefficienterna påverkar responsen. Efter minskning av dämpningsparametrarna visarresultaten att växellådshus och lager har störst inflytande på resultatet. Om mer acceptabla resultatär önskvärda måste framtida studier koncentreras på dessa parametrar för att uppnå mer acceptabladämpningsvärden.

This diploma thesis is focused on compiling a computational model of the transmission of a Zetor Forterra HSX tractor in the Multibody software MSC ADAMS environment. It analyses the issue of creating gears in terms of vibration and noise. The thesis describes the creation of computational model which is used for simulation of the load conditions during tractor operation. The methodology is applied to a single-stage gearbox in which is verified. Then it is used on a model of a real tractor gearbox. The response of the input load conditions is projected during the forces in the engagement of the gears which are transmitted to the bearings.

This master’s thesis deals with the determination of the transmission error in spiral bevel gears and its minimization using tooth profile modification in order to reduce vibrations and noise of transmission systems. Gears are the primary source of vibrations transmitted through the shaft and bearings to the gearbox housing and adjacent surfaces that emit noise into the surrounding space. In order to increase the level of comfort and due to the legislative requirements, increasing emphasis is being placed on reducing the noise and vibrations of machine components, including transmission systems. This leads to the need to identify noise sources and evaluate them in terms of expected acoustic performance. The quality of the gear meshing can be judged by transmission error that is closely related to the noise and vibrations. To evaluate the quality of gears based on transmission error, experimental measurements are used that are costly and require quality equipment. Therefore, it is efficient to determine the expected transmission error already at the design stage using numerical methods. In this work a parametric model of bevel gear geometry and a numerical model for the simulation of gear meshing using FEM software Ansys Mechanical are created in order to determine the transmission error. Based on the transmission error, various load cases and gear modifications designed for transmission error reduction are compared.

Due to their large torque-speed ratio and transmission efficiency, planetary gears are widely used in the automotive industry. However, high amplitude vibrations remain their critical weakness, which limits their usage especially when new strict noise legislations come into action. A new approach to handle the instability problems of planetary gears encountered in real industrial context is presented in this work. First, the dynamic response of a planetary gear failing to pass the noise regulations is theoretically investigated through an analytical model. The equations of motion were solved using the Spectral Iterative Method. The observed experimental results correlated well with those from the developed model. In order to limit the resonance phenomena, impacts of different macro and micro-geometry modifications were analytically investigated: quadratic teeth profile, different planets positioning, different number of teeth and number of planets. Optimum modifications were retrieved and are expected to be tested experimentally on a test bench and on the truck. Finally, the analytical model’s limits and sensitivity to different parameters were investigated in order to certify its reliability, and suggestions for improvements were presented.

Nowadays, increasing pressure from legislation and customer demands in the automotive industryare forcing manufacturers to produce greener vehicles with lower emissions and fuel consumption.As a result, electrified and hybrid vehicles are a growing popular alternative to traditional internalcombustion engines (ICE). The noise from an electric vehicle comes mainly from contact betweentyres and road, wind resistance and driveline. The noise emitted from the driveline is for the mostpart related to the gearbox. When developing a driveline, it is a factor of importance to estimatethe noise radiating from the gearbox to achieve an acceptable design.Gears are used extensively in the driveline of electric vehicles. As the gears are in mesh, a mainintrusive concern is known as gear whine noise. Gear whine noise is an undesired vibroacousticphenomenon and is likely to originate through the gear contacts and be transferred through themechanical components to the housing where the vibrations are converted into airborne andstructure-borne noise. The gear whine noise originates primarily from the excitation coming fromtransmission error (TE). Transmission error is defined as the difference between the ideal smoothtransfer of motion of a gear and what is in practice due to lack of smoothness.The main objective of this study is to simulate the vibrations generated by the gear whine noise inan electric powertrain line developed by AVL Vicura. The electric transmission used in this studyprovides only a fixed overall gear ratio, i.e. 9.59, under all operation conditions. It is assumed thatthe system is excited only by the transmission error and the mesh stiffness of the gear contacts. Inorder to perform NVH analysis under different operating conditions, a multibody dynamics modelaccording to the AVL Excite program has been developed. The dynamic simulations are thencompared with previous experimental measurements provided by AVL Vicura.Two validation criteria have been used to analyse the dynamic behaviour of the AVL Excite model:signal processing using the FFT method and comparison with the experimental measurements.The results from the AVL Excite model show that the FFT criterion is quite successful and allexcitation frequencies are properly observed in FFT plots. Nevertheless, when it comes to thesecond criterion, as long as not all dynamic parameters of the system such as damping or stiffnesscoefficients are provided with certainty in the model, it is too difficult to investigate the accuracy ofthe AVL Excite model.Another investigation is a numerical design study to analyses how the damping coefficientsinfluence the response. After reducing the damping parameters, the results show that the housingand bearings have the highest influence on the response. If more acceptable results are desired,future studies must be concentrated on these to obtain more acceptable damping values. / För närvarande tvingar ökat tryck från lagstiftning och kundkrav inom bilindustrin tillverkarna attproducera grönare fordon med lägre utsläpp och bränsleförbrukning. Som ett resultat ärelektrifierade och hybridfordon ett växande populärt alternativ till traditionellaförbränningsmotorer (ICE). Bullret från ett elfordon kommer främst från kontakten mellan däckoch väg, vindmotstånd och drivlinan. Bullret från drivlinan är i huvudsak relaterat till växellådan.Vid utveckling av en drivlina är det av betydelse att uppskatta bullret från växellådan för att uppnåen acceptabel design.Utväxlingar används i stor utsträckning i elfordons drivlina. Eftersom kugghjulen är i kontaktuppstår ett huvudproblem som är känt som ett vinande ljud från kugghjulskontakten.Kugghjulsljud är ett oönskat vibro-akustiskt fenomen och uppstår sannolikt på grund avkugghjulkontakterna och överförs via de mekaniska komponenterna till växellådshuset därvibrationerna omvandlas till luftburet och strukturburet ljud. Kugghjulsljudet härstammarhuvudsakligen från exciteringen som kommer från transmissionsfel (TE) i kugghjulskontakten.Överföringsfelet definieras som skillnaden mellan den ideala smidiga rörelseöverföringen hoskugghjulen och rörelsen som sker i verkligheten på grund av ojämnheter.Huvudsyftet med denna studie är att simulera vibrationerna som genereras avkugghjulskontakterna i en elektrisk drivlina utvecklad av AVL Vicura. Den elektriska drivlinan somanvänds i denna studie har endast ett fast utväxlingsförhållande, dvs 9,59, för alladriftsförhållanden. Det antas att systemet är exciterat endast av överföringsfelet och kugghjulensstyvhet i kuggkontakterna. För att kunna utföra NVH-analys under olika driftsförhållanden har enstelkroppsdynamikmodell utvecklats med hjälp av programmet AVL Excite. De dynamiskasimuleringarna jämförs sedan med tidigare experimentella mätningar som tillhandahålls av AVLVicura.Två valideringskriterier har använts för att analysera det dynamiska beteendet hos AVL Excitemodellen:signalbehandling med FFT-metoden och jämförelse med experimentella mätningar.Resultaten från AVL Excite-modellen visar att FFT-kriteriet är ganska framgångsrikt och allaexcitationsfrekvenser observeras korrekt i FFT-diagrammen. Men när det gäller det andra kriteriet,så länge som inte alla dynamiska parametrar i systemet, såsom dämpnings- ellerstyvhetskoefficienter, är tillförlitliga i modellen, är det för svårt att undersöka exaktheten hos AVLExcite-modellen.En annan undersökning som utförts är en numerisk designstudie för att analysera hurdämpningskoefficienterna påverkar responsen. Efter minskning av dämpningsparametrarna visarresultaten att växellådshus och lager har störst inflytande på resultatet. Om mer acceptabla resultatär önskvärda måste framtida studier koncentreras på dessa parametrar för att uppnå mer acceptabladämpningsvärden.

En Power Transfer Unit (PTU) eller vinkelväxel i ett drivsystem för allhjulsdrift är enväxellåda med en hypoid-växel som drevsats. PTUn ar placerad mellan fordonets transmissionoch kardanaxel och används för att fördela momentet från drivsystemet mellanalla hjulen. De dynamiska egenskaperna hos vinkelväxeln är kopplade till de ljud ochvibrationer som uppfattas i bilen, speciellt tonalt ljud som växelvin. Källan till dennavibration kan relateras till transmissionsfelet i växeln. Transmissionsfelet beror pa faktorersom geometri, rotationshastighet och statiskt moment. Om faktorernas inverkankan identieras skapar det möjligheter att reducera felet genom designförändringar. 1D ellersystem-simulering ar en förenklad beskrivning av det dynamiska beteendet av systemet.Det är en flexibel metod som kan ge en uppskattning av systemets egenskaper iett tidigt skede och kan användas i såväl tids- som frekvensdomönen.Denna studie syftar till att bygga en 1-D system-modell av en PTU och studera dessdynamiska beteende. De typer av analyser och resultat som ar möjliga att få från en dynamisk1-D modell av en specic produkt har utvärderats. Befintliga komponenter frånmjukvarans bibliotek har används for att bygga en förenklad modell med lumpade massorav den fysiska systemet. Simuleringar har utförts både i tidsdomänen och frekvensdomänen.System-modellen är mycket användbar för modelling av hela system och av hur delarnaväxelverkar i ett tidigt skede av produktutvecklingen. Beräkningen av nivån på transmissionsfeletsgrundtonen stämmer väl med tillgängliga mätresultat. Rotationshastigheternasvariation då kopplingen kopplar i och ur vinkelväxeln illustrerar tydligt kopplingensinverkan på dynamiken i systemet. Det var dessutom möjligt att erhålla systemets torsionsegenfrekvenseroch modformer från den linjära frekvensanalysen. / A Power Transfer Unit (PTU) of an All-Wheel Drive system is a hypoid gearbox whichis a driveline component, used to distribute power from the powertrain to all the wheelsof a vehicle. The gearbox dynamics is closely related to the gearbox noise and vibration,especially tonal noise like gear whine. The source of this vibration is referred to as thetransmission error in the unit. Transmission error is attributed to various geometricaland operating conditions, which if mapped mathematically, allows the designer to reducethe error by varying the design parameters. The demand in the automotive industry toreduce time to market is high. A lot of time can be saved if system performance can beassessed at the concept stage, even before the detailed design. This is where system-levelsimulation plays a key role. 1-D or system simulation technique studies the dynamicbehaviour of the system in one dimension. This greatly simplies the model and allowsfor the exibility to get early estimates of the system behaviour with respect to time andfrequency. Here, such a system model is built for a hypoid gear based driveline system.This work aims to build a 1-D system model of the PTU and study the dynamic behaviourof the response. The evaluation helps in understanding the capabilities on 1-D systemmodel in simulating a specialised product dynamic characteristics. LMS AMESim wasthe commercial tool used in building the system model. Existing components from thesoftware library were used to build a sketch of a simplied, lumped mass model of thephysical system. The model was then simulated in both the time domain and frequencydomain through a temporal and linear analysis respectively.It is observed that the system model is very useful in early modelling of a system and itsinteractive eects. The fundamental harmonic of the transmission error is predicted wellin the system model. The clutch connect/disconnect behaviour can also be seen in therotary velocity response of the gear. The system eigenfrequencies and mode shapes wereobtained from the linear analysis.