This thesis project is conducted in collaboration with Swepart Transmission AB, aimed to dynamically simulate the compact gearbox design with planetary gears meant to be used in robots. The primary objective of this project is to analyze operational principles of planetary gears and their suitability for mitigating lost motion (backlash). Simulations have been carried out using MSC Adams software where the input speed is 1400 rpm on the pinion gear, which is equal to 1100 deg/s when applied to the sun gear. An adjustment gear is mounted atop sun gear, which is used to adjust the position of the planet gears and it is locked with different variations of 0, 5 and 10 degrees of angular displacement to adjust the planet gears. Additionally, one of the planet gears is selected and the position of teeth in that planet gear is deviated by 10, 20, 30 and 40 micrometers and these new gears are then placed in position of the existing planet gear one by one. These models are then simulated to study the variations and effects of angular velocity on the ring gears, angular velocity of the adjustment gear, displacement in radial direction of the planet gear after it is adjusted, force and torque generated on contact between the planet gear and the ring gear over a period of 5 seconds using 1000 time steps.

Die ersten Umlaufrädergetriebe wurden in Planetarien verwendet, um die Bewegung der Gestirne exakt aufzuzeigen. Bis in die zweite Hälfte des 19. Jahrhunderts wurden sie danach meist zur Lösung schwieriger Regelaufgaben verwendet. Erst durch größere Fortschritte in der Werkstoff- und Fertigungstechnik wurden Umlaufrädergetriebe als Drehmomentenwandler eingesetzt. Dadurch konnten die großen Vorteile der Umlaufrädergetriebe gegenüber Stirnradgetrieben in der Antriebstechnik genutzt werden. Umlaufrädergetriebe ermöglichen hohe Übersetzungen bei geringem Bauraum und Gewicht, da die Leistung über mehrere Zahnkontakte übertragen wird. Des Weiteren gibt es neben dem Zweiwellenbetrieb die Möglichkeit, im Dreiwellenbetrieb voneinander unabhängige Drehbewegungen zu überlagern. Dadurch sind beispielsweise Regelungsaufgaben bei Windenergieanlagen möglich. Dabei wird die Ungleichförmigkeit des Windes über einen zweiten drehzahlvariablen Antrieb ausgeglichen, damit am Abtrieb eine stets gleichmäßige Drehzahl am Generator anliegt. Weitere Vorteile sind die koaxiale Lage von Antrieb und Abtrieb und die symmetrische Bauform. MDESIGN LVR planet wurde entwickelt, um die Berechnung der Lastverteilung über der Zahnflanke und der Lastaufteilung auf die Planetenräder in Planetengetrieben zu übernehmen. Es ist möglich, diese Berechnung für geradverzahnte, einfachschräg- und doppeltschrägverzahnte Planetengetriebe im Zwei- und Dreiwellenbetrieb durchzuführen. Da doppelschrägverzahnte Planetengetriebe in Getrieben mit hohen Drehzahlen häufig in der Industrie verwendet werden, untersucht diese Forschungsarbeit die Theorie zur Umsetzung der Berechnung von Lastverteilungen unter dem Aspekt der Zeit – und Kosteneffizienz. Dabei sollen spezifische Probleme bei der Berechnung der Breitenlastverteilung über der Zahnflanke für doppelschrägverzahnte Planetengetriebe erfasst werden. Diese Probleme umfassen bei Doppelschrägverzahnung beispielsweise die hohen Torsionsverformungen, die Aufteilung der Last auf die Zahnhälften und die gegenseitige Beeinflussung der Verformung der Zahnhälften untereinander.

The industrial world is in constant demand for faster, cheaper and higher quality manufacturing. Robot utilisation and automation has evolved to become a necessary asset to master in order to stay competitive in the global market. With the growing dependency on robots, unexpected downtime and brakedowns can cause devastating loss of revenue. Consequently, this has lead to an increased importance for an accurate condition based way of performing robotic maintenance. As of writing, robots are predominantly maintained through time dependent maintenance. Part replacement is based on statistical models where maintenance is performed without taking the actual robot condition into consideration. As a result an overall level of uncertainty is ensued, where lacking the ability to properly diagnose the robot, also leads to superfluous repairs. Because of the costly impact this has on production, a condition based maintenance approach to robots would yield increased reliability at a lower cost of maintenance. This research focuses on trying to monitor vibrations in a robot, so as to infer about wear and to provide a first step in vibration based Robot Condition Monitoring. This research has been of multidisciplinary nature where robotics, tribology, mechanical component, signal analysis and diagnosis theory have overlapped in several areas throughout the project. The research has provided a vibration baseline and trends of the theoretical bearing defect frequencies for a hypocycloid gearbox installed on an ABB IRB6600 robot. The gearbox was not worn to a level that a severe gearbox degradation was irrefutably detectable and analysable. Accelerometers normally used on wind turbines were used for the project, and are believed to be sufficiently successful in capturing bearing related signals to accredit it for continued use at the preliminary stages of Robot Condition Monitoring development. A worn RV410F hypocycloid gearbox, was dismantled and analysed. Bearings found inside indicate high degrees of moisture corrosion and extensive surface wear. These findings had decisive roles in what future work recommendations where presented. Areas with great potential are condition monitoring through the use of Acoustic Emission and lubrication analysis. Further recommendations include investigating signal analysis techniques such as cepstrum pre-whitening and discrete wavelet transforms.

A simulation model for an automatic gearbox with primary retarder has been constructedand implemented, in this thesis. Together with other modelled vehicle components, thismodel could for example be used for fuel consumption estimation or optimizing vehicleparameters.The mechanical components and the control system inside the automatic gearbox weremodelled separately and then assembled into the nal gearbox model, using the objectorientedprogramming language Modelica. Modelica ensures that each individual componentcan be reused in other models.The gearbox model was validated through a number of test cycles designed to capturedierent vehicle behaviours. The test cycles were recreated in the simulation environmentand the simulation results could be compared to a real vehicle performing the same tests.Validation showed that the model succeeded in its goal, that the implemented model isreproducing similar behaviour as the real gearbox. With gear shifts taking place in aboutthe same situations and converter locking/unlocking occurring the same time in the simulationsas in the real vehicle testing. / I det här examensarbetet har en simuleringsmodell för en automatisk växellåda med primär retarder utvecklats och implementerats. Tillsammans med andra modeller från fordonoch drivlina skulle denna simuleringsmodell kunna användas för att uppskatta ett fordonsbränsleförbrukning eller till att optimera olika fordonsparametrar.De olika mekaniska komponenterna samt kontrollsystemet i växellådan modellerades separat.Dessa modeller kunde sedan sammanfogas för att bygga den slutliga växellådsmodellen.Alla modeller implementerades i det objektorienterade programmeringsspråket Modelica,som tillåter en stor återanvändningsbarhet till vardera enskild komponent.Den implementerade modellen verierades genom ett antal provcykler, utformade för attfånga olika beteenden hos växellådan. Dessa cykler har återskapats i simuleringsmiljön ochmed det kunde resultat från simuleringar jämföras mot data från ett verkligt fordon somutförde samma prov.Från verieringen har slutsatsen dragits att modellen uppfyllde målen med projektet. Målen var, att den slutliga simuleringsmodellen visar ett liknande beteende som en växellåda i ett verkligen fordon. Växlingar och låsning/upplåsning hos momentomvandlareninträande vid ungefär samma situationer i simuleringarna som i provningen med det verkligafordonet.

Thesis (MEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Conventional electrical vehicles (EVs) favour mostly permanent magnet machines with single speed gearboxes. This is understandable, the PM machine has a high power density making the electrical machine smaller in size. The PM machine also has a favourable field weakening capability combining this with a single speed gearbox nearly perfectly matches the required traction curve. However the dependency of rare earth metals from China and the environmental issues raised by mining these metals raise concern. Therefore alternatives should be considered. Induction -, switch reluctance - and wound rotor machines are all gaining ground as favourable traction machines to power vehicles. The reluctance synchronous machine (RSM) is known for it’s robustness and high efficiency, however the machine has a limited field-weakening capability. To overcome this short coming a multi gearbox from an internal combustion engine (ICE) is suggested. By combining the RSM and multi speed gearbox it is possible to match the traction curve. There are numerous advantages offered by using this system, especially from an performance and efficiency point of view. However there are also numerous challenges faced by using the suggested powertrain, however the focus of this study is mainly on performance and efficiency of the motor and the powertrain. As a case study a Corsa 140i is used and the design specifications is taken from the ICE. The aim is to design a RSM that meets the specifications of the ICE. The RSM structure is mathematically modelled then optimized using commercial optimization and 2D finite element software. To evaluate the design of the RSM, the motor is then tested. The powertrain is then tested by connecting the motor onto the gearbox of the Corsa and the efficiency of the powertrain is evaluated. The test results it shown that the RSM can be used as a traction motor. There are two motors built one with NO20 and the other with M530-65A lamination steel. Both motors perform well throughout the speed and torque spectrum. The measured efficiency at the rated condition for the motor with the NO20 steel is above 91% and the motor with the M530-65A laminations above 89%. The power train is is tested in 4th and 5th gear. The efficiency of 4th and 5th gear is approximated and the efficiency is above 90% . This high efficiency makes the multi speed gearbox a competitor for the EV power train. / AFRIKAANSE OPSOMMING: Elektrisie voertuie (EVe) het meestal permanent magneet motors met ’n enkel spoed ratkas. Dit is verstaanbaar, die PMS masjien het ’n hoë krag digtigheid wat die masjien kleiner maak in grote. Die PMS masjien het ’n baie goeie vloed veld verswakkings gebied en as dit gekombineer word met ’n enkel spoed ratkas, volg dit die velangde traksie kurwe amper perfek. Die nadeel is dat die PMS motor skaars aard metale nodig het vir die magnete van China af. Die probleem is dat daar baie omgewings probleme gepaard gaan om die metale te myn en China beheer die mark. As gevolg hiervan moet ander tipe motors oorweeg word as traksie motors vir voertuie. Skakel reluktansie, induksie en ’n wikkel rotor motors is almal besig om vordering te maak as traksie motors vir EV’e. Die sinchroon reluktansie motor (RSM) is bekend as ’n robuuste en effektiewe motor. Die probleem met die RSM is dat dit nie ’n goeie vloed veld verswakkings gebied het nie. Om die probleem te oorkom, word ’n veranderlike spoed ratkas van ’n binnebrand engin voorgestel. Deur om die RSM en die veranderlike spoed ratkas as ’n dryfstelsel te gebruik kan die verlangde traksie kurwe ook verkry word. Daar is talle voordele om ’n veranderlike spoed ratkas te gebruik, veral van af ’n draaimoment verrigting en effektiwiteits oogpunt. Daar is ongelukkig ook baie uitdagings wat gepaard gaan as ’n veranderlike spoed ratkas gebruik wil word in die dryfstelsel. Alhoewel daar baie uitdagings is kyk die studie slegs na die draaimoment verrigting en die effektiwiteit van die dryfstelsel. ’n Corsa 140i word as ’n gevallestudie gebruik en die spesifikasies vir die elektrisie motor word vanaf die spesifikasies van die binnebrand engin geneem. Die doel is om ’n motor te ontwerp wat dieselfde spesifikasies het as die binnebrand engin. Die RSM strukstuur word wiskundig gemodelleer en dan geoptimeer deur gebruik te maak van kommersiele optimering en 2D eindige element sagteware. Om die ontwerp te verifieer word die motor getoets. Die dryfstelsel word dan getoets deur om die motor met die raktas te konnekteer. Die draaimoment verrigting en die effektiwiteit word dan ge-evalueer. Twee motors word gebou, een met NO20 laminasies en een met M530-65A laminasies. Beide motors het goeie verrigting deur die spoed en draaimoment gebied. Die gemeete effektiwiteit van die motor met die NO20 laminasies is bo 91% en die motor met die M530-65A laminasies het ’n gemeete effektiwiteit bo 89%. Die toets resultate wys dat die RSM as ’n traksie motor gebruik kan word. Die dryfstelsel word in 4de en 5de rat ge-evalueer. Die effektiwiteit van die ratkas in 4de en 5de word benader en ’n effektiwiteit bo 90% is verkry. Hierdie hoë effektiwiteit maak die veranderlike spoed ratkas ’n lewensvatbare mededinger in die EV dryfstelsel.

Submitted by ANDRÉ LUIS VINAGRE PEREIRA null (andreluisvp@gmail.com) on 2018-03-29T18:17:43Z No. of bitstreams: 1 Dissertação Mestrado Final.pdf: 7001331 bytes, checksum: 858704904256f11c8131d5f17bd44a78 (MD5) / Approved for entry into archive by Cristina Alexandra de Godoy null (cristina@adm.feis.unesp.br) on 2018-04-02T12:53:22Z (GMT) No. of bitstreams: 1 pereira_alv_me_ilha.pdf: 7001331 bytes, checksum: 858704904256f11c8131d5f17bd44a78 (MD5) / Made available in DSpace on 2018-04-02T12:53:22Z (GMT). No. of bitstreams: 1 pereira_alv_me_ilha.pdf: 7001331 bytes, checksum: 858704904256f11c8131d5f17bd44a78 (MD5) Previous issue date: 2018-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Na manutenção preditiva, as análises dos sinais de vibração e das partículas do óleo são frequentemente utilizadas para o diagnóstico de falhas em redutores, porque elas contêm informações das condições de seus elementos mecânicos. Os sinais de vibração de um redutor geralmente têm muito ruído e a relação sinal-ruído é tão baixa que a extração de informações dos componentes do sinal é muito difícil, especialmente em situações práticas. Uma das soluções para este problema é a aplicação de técnicas de processamento do sinal para facilitar a obtenção de informações. Neste trabalho, uma técnica de cancelamento de ruído, a média temporal síncrona (TSA), e outra técnica da transformada contínua de wavelet de Morlet foram desenvolvidas para extração de recursos e diagnóstico de diferentes tipos de danos locais da engrenagem. Estas técnicas são aplicadas em sinais medidos em uma bancada experimental, que consiste em um par engrenado acoplado a um motor e a um gerador. Outro método para monitorar o estado do sistema é pela análise de partículas presente no óleo provenientes do desgaste das engrenagens. Avaliando a quantidade, formato, tamanho e material das partículas é possível obter informações das condições do equipamento e do tipo de desgaste ocorrido. Neste trabalho, foram feitas a análise do óleo pelas técnicas da ferrografia e contagem de partículas. A parte experimental deste trabalho foi dividida em dois experimentos. No primeiro experimento as condições de um par engrenado durante toda a sua vida útil foi monitorada, enquanto que no segundo experimento, um entalhe foi feito na raiz do dente simulando uma trinca por fadiga. A análise das partículas de óleo mostrou quais tipos de desgastes estava ocorrendo e a técnica da transformada contínua de wavelet mostrou-se precisa na identificação de falhas em dentes de engrenagens, sendo possível indicar em qual dente a falha estava se desenvolvendo. / At the predictive maintenance, the vibration signals analysis and oil particles analysis are frequently used to diagnose failures in a gearbox, because they contain information about the condition of its mechanic’s elements. The vibration signals of a gearbox usually have a lot of noise and the ratio ‘signal-noise’ is very low, making the extraction of information from the signals component very hard, especially in a practical situation. One of the solutions to this problem is the application of technics of signal processing, to improve the collection of information. At this study, a technique of noise cancellation, Temporal Synchronous Average (TSA) and another technique called continuous transform with the Morlet wavelet were executed for the extraction of resources and diagnostics of different type of gears local damages. Those methods are applied to signals measured on an experimental test stand, consisting of a gearbox with an engine and a generator. Another method for monitoring system wear is by analyzing wear particles in the oil generated due to the wear on the gears. By evaluating the quantity, shape, size and material of the particles it is possible to obtain information about the conditions of the equipment and the type of wear that has occurred. During this work, it was done the analysis of the oil by the techniques of ferrography and particle counting. The experimental part of this study was divided into two experiments. On the first experiment was monitored the conditions of a couple meshed throughout its useful life and in the second was made a notch in the root of the tooth simulating a crack by fatigue. The analysis of the oil particles showed what types of wear was occurring and the technique of the continuous wavelet transform was accurate in the identification of defects in gear's teeth, and it was possible to indicate which tooth was failing.

Orientador: Aparecido Carlos Gonçalves / Resumo: Na manutenção preditiva, as análises dos sinais de vibração e das partículas do óleo são frequentemente utilizadas para o diagnóstico de falhas em redutores, porque elas contêm informações das condições de seus elementos mecânicos. Os sinais de vibração de um redutor geralmente têm muito ruído e a relação sinal-ruído é tão baixa que a extração de informações dos componentes do sinal é muito difícil, especialmente em situações práticas. Uma das soluções para este problema é a aplicação de técnicas de processamento do sinal para facilitar a obtenção de informações. Neste trabalho, uma técnica de cancelamento de ruído, a média temporal síncrona (TSA), e outra técnica da transformada contínua de wavelet de Morlet foram desenvolvidas para extração de recursos e diagnóstico de diferentes tipos de danos locais da engrenagem. Estas técnicas são aplicadas em sinais medidos em uma bancada experimental, que consiste em um par engrenado acoplado a um motor e a um gerador. Outro método para monitorar o estado do sistema é pela análise de partículas presente no óleo provenientes do desgaste das engrenagens. Avaliando a quantidade, formato, tamanho e material das partículas é possível obter informações das condições do equipamento e do tipo de desgaste ocorrido. Neste trabalho, foram feitas a análise do óleo pelas técnicas da ferrografia e contagem de partículas. A parte experimental deste trabalho foi dividida em dois experimentos. No primeiro experimento as condições de um par engrenado d... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: At the predictive maintenance, the vibration signals analysis and oil particles analysis are frequently used to diagnose failures in a gearbox, because they contain information about the condition of its mechanic’s elements. The vibration signals of a gearbox usually have a lot of noise and the ratio ‘signal-noise’ is very low, making the extraction of information from the signals component very hard, especially in a practical situation. One of the solutions to this problem is the application of technics of signal processing, to improve the collection of information. At this study, a technique of noise cancellation, Temporal Synchronous Average (TSA) and another technique called continuous transform with the Morlet wavelet were executed for the extraction of resources and diagnostics of different type of gears local damages. Those methods are applied to signals measured on an experimental test stand, consisting of a gearbox with an engine and a generator. Another method for monitoring system wear is by analyzing wear particles in the oil generated due to the wear on the gears. By evaluating the quantity, shape, size and material of the particles it is possible to obtain information about the conditions of the equipment and the type of wear that has occurred. During this work, it was done the analysis of the oil by the techniques of ferrography and particle counting. The experimental part of this study was divided into two experiments. On the first experiment was monitored the... (Complete abstract click electronic access below) / Mestre

Dans le domaine automobile, les réductions de consommation de carburant et des émissions polluantes constituent des axes de recherches majeurs. Dans ce contexte, de nombreux efforts sont portés sur l’amélioration du rendement des boîtes de vitesses. Parmi l’ensemble des pertes générées dans une boîte de vitesses, les pertes par barbotage peuvent représenter une source de perte importante. Si différents modèles existent pour quantifier les pertes par barbotage, aucun d’entre eux ne prend en compte l’influence de la présence d’air dans le lubrifiant. Grâce à un banc d’essais spécifique, il est montré que l’aération de l’huile peut avoir un impact sur les pertes par barbotage. Un modèle original d’estimation des pertes dues à l’aération est alors développé. Ce dernier révèle que des propriétés du lubrifiant autres que la viscosité ou la masse volumique peuvent avoir une influence sur les pertes par barbotage. L’étude des pertes par barbotage conduit également à s’intéresser à ce mode de lubrification largement employé dans les boîtes de vitesses manuelles. Actuellement, la mise au point de cette méthode de lubrification souffre d’un manque d’informations portant principalement sur les débits mis en jeu lors du phénomène de projection d’huile par les pignons en rotation. L’analyse de ces débits d’huile est conduite au moyen d’un banc d’essais développé spécifiquement. Les nombreux résultats de mesures obtenus permettent de mieux appréhender ce phénomène de projection. Un modèle analytique est finalement proposé permettant d’estimer les débits d’huile projetée pouvant être utilisé lors de la mise au point de la lubrification d’une boîte de vitesses. / Reducing fuel consumption and automobile emissions are nowadays the main topics of research for the automotive industry. Therefore, the situation involves concentrating many efforts to improve gearbox efficiency. Churning losses may represent a significant source of loss among the losses generated in a gearbox. Several models have been developed to quantify churning losses but they do not consider the air present in the lubricant. The use of a specific test rig has revealed that oil aeration could have an impact on churning losses. A heuristic model estimating aeration induced losses has therefore been developed. The latter reveals that some unexpected lubricant's properties, apart from viscosity and density, may impact churning losses. Indeed, the study of churning losses also encourages learning more about this type of lubrication, widely used in manual gearboxes. There is currently a lack of information around the development of that method of lubrication. This lack of information bears mainly on the flows involved in the phenomenon of oil splashed up by the rotating gears. The analysis of the involved oil flows is carried out with a test rig designed for that purpose. Therefore, the numerous findings based on a series of measurements may help splash phenomenon to be better understood. Finally, an analytical model is proposed to help estimate the flow of oil splashed. Such model may be used for the development of gearbox lubrication.

Les couples d'engrenages présents dans les boîtes de vitesses automobiles sont une source de bruit importante à prendre en compte et à maîtriser. L'acyclisme du moteur observable en entrée de boîte a notamment pour conséquence de provoquer des impacts entre les dents des engrenages non chargés, à l'origine du bruit de grenaille. Ce travail de thèse s'intéresse aux cas de grenaille dits périodiques, dont l'apparition et la sévérité dépendent, entre autres, des conditions de fonctionnement régime/charge. Pour détecter la présence et quantifier la sévérité de ce bruit, il est nécessaire de construire des indicateurs pertinents et dédiés, où il est particulièrement intéressant de conserver la dualité des informations temporelles (relatives aux voies de transfert des phénomènes vibratoires) et angulaires (relatives aux cycles de la machine) mesurées sur des boîtes en montée de régime. Une extension de l'approche cyclostationnaire classique est ainsi exploitée et la cohérence spectrale ordre/fréquence est utilisée afin de définir un indicateur de sévérité du bruit de grenaille. Deux campagnes d'essais ont été réalisées afin de valider la pertinence de cet indicateur, utilisant un banc d'essais qui permet d'imposer des montées en régime et de générer un acyclisme. Dans la première campagne d'essais, un pignon fou est instrumenté à l'aide d’un codeur optique afin de mesurer la vitesse relative pignon fou/pignon menant qui est utilisée comme référence pour détecter l'apparition des impacts. La comparaison avec l'indicateur proposé, calculé à partir du signal vibratoire d'un accéléromètre positionné sur le carter de boîte, démontre sa capacité à détecter effectivement des chocs. Des sessions d'écoute ont été organisées afin de comparer le ressenti d'auditeurs qualifiés pour faire des évaluations subjectives à l'évolution des valeurs données par l’indicateur, à partir d'une seconde campagne d'essais. Cet indicateur apparaît représentatif du ressenti des auditeurs. Une fois la grenaille détectée et quantifiée globalement en intensité, il est intéressant d'extraire sa composante du signal global mesuré. Pour cela, une extension du filtre de Wiener cyclique pour des signaux cyclostationnaires angle/temps est proposée. Le signal extrait étant supposé être généré uniquement par les impacts produisant le bruit de grenaille, les impulsions extraites sont exploitées afin d'estimer la fonction de transfert entre les points d'excitation et le capteur localisé sur le carter de boîte. Cette fonction de transfert est comparée à celle obtenue par une seconde méthode, également développée dans le cadre de cette thèse, qui consiste en une extraction de la partie déterministe de l'excitation à l'aide d'un filtre en peigne dans le domaine des ordres, puis en une identification aveugle de la réponse impulsionnelle dans le domaine cepstral. / The improvement of the engine noise emissions causes the emergence of new sources which were previously masked, like gearbox noises. Because of the engine acyclism some impacts can appear between the teeth of unloaded gears. Those impacts generate the so called rattle noise which is a current problem for car manufacturers. This work is focused on periodic cases of rattle noise. Their appearance and their level depend on operating conditions. In order to propose a specific detection indicator it is particularly useful to exploit the angle/time duality from measures in non-stationary conditions: the angle domain is linked to the periodicity of the impacts while the time domain is linked to their nature. An extension of the cyclostationary approach is thus exploited and the order/frequency spectral coherence is used to define a severity indicator of rattle noise. The validation of this indicator is obtained from measurements. For a first level of validation, a loose gear has been instrumented with an optical encoder in order to measure the relative velocity between this loose gear and the driving gear. The comparison with the proposed indicator shows its ability to effectively detect the impacts. For a second level of validation some listening sessions have been organized. The evolution of values of our indicator appears in accordance with the feeling of the listeners. After the detection of rattle noise it is interesting to extract its contribution from the measured signal. An extension of the cyclic Wiener filter is thus proposed for angle/time cyclostationary sources. The extracted signal being supposed only produced by impacts, the extracted impulses are then exploited in order to estimate a transfer function. This transfer function is compared with the other one obtained by a second method, also developed in this work. This method exploits the non-stationary regime and proposes a blind identification with cepstrum.

This thesis deals with the vibration and noise of the gearbox for an electric vehicle. The gearbox itself acts as an emitter of unwanted noise caused by vibration excitation of the internal components of the gearbox. It is therefore necessary to deal with a complex unit such as the gearbox at system level as soon as it is being designed. This can be achieved using analytical tools and software. In this thesis, in order to evaluate the validity of the designed gearbox, a procedure is developed using both technical experiment and numerical simulations. The effect of the bolt preload is not overlooked for the following computational modelling dealing with the radiated noise of the gearbox. The results obtained from the performed technical experiments were then evaluated and compared with the results of the computational models. In this way, it is possible to compare the different approaches, their limitations and weaknesses. Furthermore, the thesis deals with design modifications that are analyzed using computational modeling. The thesis is concluded with a brief description of the application of each approach and an evaluation of the gearbox design modifications.