Noise and vibration transmitted through the tire and suspension system are strong indicators of overall vehicle ride quality. Often, during the tire design process, target specifications are used to achieve the desired ride performance. To validate the design, subjective evaluations are performed by expert drivers. These evaluations are usually done on a test track and are both quite expensive and time consuming due to the several experimental sets of tires that must be manufactured, installed, and then tested on the target vehicle. In order to evaluate the performance, expert drivers tune themselves to the frequency response of the tire/vehicle combination. Provided the right models exist, this evaluation can also be achieved in a laboratory. The research presented here is a method which utilizes the principles of frequency based substructuring (FBS) to separate or combine frequency response data for the tire and suspension. This method allows for the possibility of combining high fidelity tire models with analytical or experimental suspension data in order to obtain an overall response of the combined system without requiring an experimental setup or comprehensive simulations. Though high fidelity models are not combined with experimental data in the present work, these coupling/decoupling techniques are applied independently to several quarter car models of varying complexity and to experimental data. These models range from a simplified spring-mass model to a generalized 3D model including rotation. Further, decoupling techniques were applied to simulations of a rigid ring tire model, which allows for inclusion of nonlinearities present in the tire subsystem and provides meaningful information for a loaded tire. By reducing the need for time consuming simulations and experiments, this research has the potential to significantly reduce the time and cost associated with tire design for ride performance. In order to validate the process experimentally, a small-scale quarter car test rig was developed. This novel setup was specifically designed for the challenges associated with the testing necessary to apply FBS techniques to the tire and suspension systems. The small-scale quarter car system was then used to validate both the models and the testing processes unique to this application. By validating the coupling/decoupling process for the first time on the tire/vehicle system with experimental data, this research can potentially improve the current process of tire design for ride performance. / Ph. D. / Noise and vibration transmitted through the tire and suspension system of a vehicle strongly influence the comfort of passengers. Often, during the tire design process, target specifications are used to achieve the desired vibrational characteristics. Subjective evaluations are then performed by expert drivers in order to validate the tire design. These evaluations are usually done on a test track and are both quite expensive and time consuming due to the several experimental sets of tires that must be manufactured, installed, then tested on the target vehicle. The research presented here utilizes techniques from the field of Dynamic Substructuring which allow frequency data for the tire and suspension systems to be separated or combined. This method allows for the possibility of combining high fidelity tire models with analytical or experimental suspension data in order to obtain an overall response of the combined system without requiring an experimental setup or comprehensive simulations. Several analytical tire and suspension models were developed for this work and the process of separating/combining the frequency data was performed. Then, a small scale test system was developed and used to establish experimental procedures to collect the data necessary to carry out the Dynamic Substructuring techniques. Finally, the process was validated by repeating the process of separating/combing the frequency properties of the experimental data.

The ride stability of an A-train 28-foot double tractor trailer when outfitted with different Roll Stability Control (RSC) systems with the same payload and suspension configurations is studied experimentally for various dynamic maneuvers. The primary goal of the study is to determine the effect of different commercially-available RSC systems on the extent of improvements they offer for increasing roll stability of commercial vehicles with double trailers, when subjected to limit-steering maneuvers that can rise during highway driving. A semitruck and two 28-foot trailers are modified for enduring the forces and moments that can result during testing. A load structure is used for placing the ballast loads within the trailers at a suitable height for duplicating the CG height of the trailers during their commercial use. Outriggers and jackknifing arresting mechanisms are used to prevent vehicle damage and ensure safety during the tests. The test vehicle is equipped with multiple sensors and cameras for the necessary measurements and observations. The analog and video data are time-synced for correlating the measurements with visual observation of the test vehicle dynamics in post-processing. An extensive number of tests are conducted at the Michelin Laurens Proving Grounds (MLPG) in Laurens, SC. The tests include evaluating each RSC system with different maneuvers and speeds until a rollover occurs or the vehicle is deemed to be unstable. The maneuvers that are used for the tests include: double lane change, sine-with-dwell, J-turn, and ramp steer maneuver. Both a steering robot and subjective driver are used for the tests. The test data are analyzed and the results are used to compare the three RSC systems with each other, and with trailers without RSC. The test results indicate that all three RSC systems are able to improve the speed at which rollover occurs, with a varying degree. For two of the systems, the rollover speed gained, when compared with trailers without RSC, is marginal. For one of the systems, there are more significant speed gains. Since most RSC systems are tuned for a conventional tractor-trailer, additional testing with some of the systems would be necessary to enable the manufacturers to better fine-tune the RSC control scheme to the dynamics of double trailers. / MS / The safety of driven semi-trailer trucks towing two trailers is analyzed in a study created to examine the behavior of the vehicle and its units during high speed, high maneuvering circumstances. The rolling over of a specific test truck is studied to study the ability of a common large vehicle to succeed in evasive or emergency maneuvers. Focus on the rolling over of a truck is placed in this project, as large freight vehicle rollovers are among the most popular and most dangerous type of accidents on highways today. A semi-trailer truck with two trailers, or double trailer vehicle, is instrumented with sensors and cameras to study several different characteristics associated with vehicle operation and conditions that incite rollover. The behavior of a double trailer vehicle is complicated due to the additional rotation joint between the adjacent trailers, where typical semi-trailer trucks (18-wheelers) only incorporate one: between the towing tractor and the towed trailer. Commercially available electronic appliances called Roll Stability Control (RSC) systems were designed to automatically control and apply the vehicle brakes under rollover conditions, and are installed and used individually to evaluate any improvements on the test vehicle’s ability to stay upright. Information regarding RSC system operation can be found. All vehicle testing is completed at a professional vehicle testing location in Laurens, SC and the same four test maneuvers are used to determine the effectiveness of each of the five RSC systems tested using data collected with the instrumented sensors. Different types of RSC systems exist due to different manners of operation, and are discussed in this document and analyzed. This project develops the conclusion that the five systems used during testing all improve vehicle stability, but provide differing results in doing so, largely due to their different operations. Therefore, commercially available RSC systems are proven to work differently and provide different results. Recommendations for further testing of RSC systems is provided. Although no recommendations are made regarding the tested RSC systems, the collected data show large, double trailer freight vehicles are more stable when using any of the tested commercially available RSC systems, especially during evasive maneuvering or emergency situations. These findings can bring immediate improvements to large freight vehicle operation and safety.

Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: The slip synchronous-permanent magnet generator (SS-PMG) is a direct-driven, direct-to-grid generator for wind turbine applications. This investigation focuses on achieving automated grid connection and low voltage ride-through for a small-scale SS-PMG. To reduce cost and complexity, components such as blade pitch controllers and frequency converters are avoided. Instead, electromagnetic braking is employed to control turbine speed prior to grid synchronisation and compensation resistances are used to facilitate grid fault ride-through. The conditions under which the SS-PMG can be successfully synchronised with the grid are determined, indicating a need for speed control. An evaluation of electromagnetic braking strategies reveals that satisfactory speed control performance can be achieved when employing back-to-back thyristors to switch in the braking load. Simulations show that controlled synchronisation can be executed successfully under turbulent wind conditions. All controllable parameters are held within safe limits, but the SS-PMG terminal voltage drop is higher than desired. Compensation is developed to allow the SS-PMG to ride through the voltage dip profile specified by the Irish distribution code. It is found that a combination of series and shunt resistances is necessary to shield the SS-PMG from the voltage dip, while balancing active power transfer. The flexibility offered by thyristor switching of the shunt braking load is instrumental in coping with turbulent wind conditions and unbalanced dips. The South African voltage dip profile is also managed with conditional success. Following on from the theoretical design, the grid connection controller is implemented for practical testing purposes. Protection functions are developed to ensure safe operation under various contingencies. Before testing, problems with the operation of the thyristors are overcome. Practical testing shows that grid synchronisation can be undertaken safely by obeying the theoretically determined conditions. The speed control mechanism is also shown to achieve acceptable dynamic performance. Finally, the SS-PMG is incorporated into a functioning wind turbine system and automated grid connection is demonstrated under turbulent wind conditions. Future investigations may be focused on optimal control strategies, alternative solid-state switching schemes, and reactive power control. Low voltage ride-through should also be optimised for the South African dip profile and validated experimentally. / AFRIKAANSE OPSOMMING: Die glip-sinchroon permanente magneet generator (GS-PMG) is ‘n direkte dryf, direkte netwerkgekoppelde generator vir windturbine toepassings. Hierdie ondersoek fokus op die bereiking van ’n ge-outomatiseerde netwerkkoppeling en lae spanning deurry vir ‘n kleinskaalse GS-PMG. Om kostes en kompleksiteit te verminder, word komponente soos lemsteekbeheerders en frekwensie-omsetters vermy. In plaas daarvan word elektromagnetiese remwerking gebruik om die turbine spoed, voorgaande net-werksinchronisasie, te beheer, en word kompensasieweerstande gebruik om netwerkfoutdeurry te handhaaf. Die omstandighede waaronder die GS-PMG suksesvol met die netwerk gesinchroniseer kan word, is vasgestel en dit het die behoefte aan spoedbeheer uitgewys. ‘n Evaluering van elektromagnetiese remstrategië wys uit dat ’n bevredigende spoedbeheervermoë verkry kan word as anti-parallelle tiristors gebruik word om die remlas te skakel. Simulasies wys dat beheerde netwerksinchronisasie suksesvol uitgevoer kan word, selfs onder turbulente windtoestande. Alle beheerbare parameters is binne veilige perke gehou, maar die GS-PMG se klemspanningsval is gevind as hoë as verwag. Kompensasie is ontwikkel om die GS-PMG toe te laat om deur die spanningsvalprofiel, soos gespesifieer deur die Ierse distribusiekode, te ry. Dit is gevind dat ‘n kombinasie van serie- en parallelle weerstande nodig is om die GS-PMG teen die spanningsval te beskerm, terwyl aktiewe drywingsoordrag gebalanseer word. Die buigbaarheid wat verkry word met die tiristorskakeling van die parallele weerstand is noodsaaklik in die hanteering van turbulente windtoestande en ongebalanseerde spanningsvalle. Die Suid-Afrikaanse spanningsvalprofiel is ook met voorwaardelike sukses hanteer. In opvolg van die teoretiese ontwerp is die netwerkkoppelingsbeheerder vir praktiese toetsdoeleindes in werking gestel. Beskermingsfunksies is ontwikkel om veilige werking onder verskeie gebeurlikhede te verseker. Die probleme met die werking van die tiristors is oorkom voor die aanvang van die toetse. Die praktiese toetse bewys dat netwerksinchronisasie veilig gedoen kan word deur die teoretiese bepaalde voorwaardes te volg. Dit is ook getoon dat met die spoedbeheermeganisme aanvaarbare dinamiese gedrag verkry kan word. Ten laaste is die GS-PMG in ‘n werkende windturbinestelsel geïnkorporeer en outomatiese netwerkkoppeling is onder turbulente windtoestande gedemonstreer. Toekomstige ondersoeke kan toegespits word op optimale beheerstrategië, alternatiewe vaste toestand skakelingskemas en reaktiewe drywingsbeheer. Lae spanning deurry moet nog vir die Suid- Afrikaanse spanningsprofiel ge-optimeer en eksperimenteel bevestig word.

La géothermie est considérée comme une source d'énergie propre et inépuisable à échelle humaine. Actuellement, le rendement des centrales géothermiques est limité à l'exploitation de fluides de températures inférieures à 300°C. L'association de l'activité tectonique et volcanique aux dorsales océaniques fait de l'Islande un lieu où l'extraction de fluides supercritiques (T°>400°C) peut être envisagée. Cette exploitation pourrait multiplier par dix la puissance électrique délivrée par les puits géothermiques. Ces fluides peuvent-ils circuler dans la croûte océanique ? Ce travail propose de contraindre les observations géophysiques et de prédire le fonctionnement des réservoirs hydro-géothermaux de très haute température par l'étude des propriétés physiques des basaltes. La première approche est focalisée sur l'étude de roches ayant accueilli une circulation hydrothermale par le passé. L'étude de ces roches au site ODP 1256, montre que leur porosité est associée à la présence de minéraux d'altération hydrothermale du faciès amphibolite (T°>500°C ). La seconde approche a consisté à recréer en laboratoire les conditions des systèmes hydrothermaux à très haute température afin de prédire les propriétés mécaniques et électriques des basaltes dans ces conditions. Les résultats mécaniques indiquent que la transition fragile/ductile, souvent associée à une forte décroissance de perméabilité, intervient à une température d'environ 550°C. La mise en place d'une cellule de mesure de la conductivité électrique de haute températures a fournit les premiers résultats utiles à l'analyse des données géophysiques. Appliqués aux conditions de la croûte basaltique Islandaise, ces résultats indiquent que des fluides hydrothermaux pourraient circuler au moins transitoirement à l'état supercritique jusqu'à ~ 5 km de profondeur. / Geothermal energy is considered as a green and infinite energy source at human scale. Currently, the yield of geothermal power plants is limited to temperatures of the operating fluid which 300 °C. From tectonic and volcanic activity at mid-ocean ridges, Iceland is a locuswhere supercritical fluid extraction (T > 400° C) can considered for the near future. Exploiting such fluids could theoretically multiply by a factor of ten the electrical power delivered by geothermal wells. Can such fluids circulate at the base of brittle oceanic crust? This work investigates the petrophysical properties of basalts in order to constrain geophysical observations in Iceland and predict the behavior of very high temperature hydro-geothermal reservoirs. The first approach consisted in studying the physical properties of rocks that have hosted deep hydrothermal circulations at oceanic ridges. The study of these rocks at ODP Site 1256 shows that the porosity mea sured both in the field and in the lab is associated with amphibolite facies alteration minerals (T > 500° C). The second approach was to recreate in the laboratory the conditions of pressure, temperature and pore fluid pressure of high temperature to supercritical hydrothermal systems to predict the mechanical and electrical properties of basalts under these conditions. The mechanical results indicate that the brittle/ductile transition occurs at a temperature of about 550° C, where a strong permeability decrease is expected. The implementation and calibration of a new cell for measuring electrical conductivity at high temperature provide the first results for the interpretation of geophysical data. When applied to basaltic crustal conditions in Iceland, these results indicate that hydrothermal fluids could circulate, at least temporarily, in a supercritical state up to 5 km depth.

A designação de estruturas próprias de sistemas dinâmicos com retroação completa de estados ou saídas foi objeto de estudo de muitos pesquisadores durante a segunda metade do século XX. Os trabalhos mais relevantes sobre o tema foram revisados e serviram como base para a elaboração da metodologia apresentada neste trabalho. Que consiste na designação de estruturas próprias desejadas para um sistema linear em malha aberta com a modificação de parâmetros do sistema através da pseudo retroação de saídas devidamente definidas. O método foi aplicado na coxinização de um veículo de passeio. No qual os modos de vibrar de modelos lineares com 7 e 8 graus de liberdade do veículo foram adequados com o intuito de reduzir as acelerações verticais de chassi, características do fenômeno shake de motor e câmbio (faixa de frequência entre 7 e 25 Hz). Para tanto, reduziu-se a participação do grau de liberdade vertical de chassi nos modos com grande participação dos graus de liberdade de motor e massa não suspensa. Os resultados obtidos com a aplicação da metodologia na coxinização foram valores de rigidezes, amortecimentos e características de coxins hidráulicos que resultam na redução significativa da aceleração vertical de chassi, que implica em uma melhora perceptível para o consumidor na qualidade do conforto do veículo. / Eigenstructure assignment using full state or output feedback control had been object of study of many researchers during the second half of XX century. The most important works about eigenstructure assignment were reviewed, specially some applications within aerospace industry, that was the responsible for developing all the theory concerning pole and eigenvector placement. The review of the related theory was also based on the pioneering and most expressive works and were base for the methodology developed and described in this work. Which consists basically on the assignment of some desired eigensctructure of open loop linear systems modifying some parameters of the systems by means pseudo feedback of some outputs into inputs specifically defined. This methodology was applied to a 8 DOF vehicle model, a case of study, in order to adequate the system modes changing engine mounts parameters to improve the vehicle ride comfort, mainly eigenstructures about powertrain shake range frequencies.

Este trabalho apresenta o estudo da dinâmica vertical de um veículo off-road de competição e do comportamento elastocinemático de suas suspensões primárias de duplo estágio com o auxílio da ferramenta computacional de simulação de sistemas multicorpos MSC-ADAMS. O modelo multicorpos do veículo inclui os modelos da suspensão dianteira, suspensão traseira, sistema de direção, pneus e massa suspensa. As análises elastocinemáticas das suspensões definiram geometrias que permitem longos cursos de trabalho das suspensões sem variações indesejadas de parâmetros de projeto. Com a análise modal do modelo de veículo completo foram definidos os valores de rigidez das molas das suspensões de duplo estágio que resultaram em valores de freqüência natural no primeiro estágio semelhantes aos indicados para carros de passeio e no segundo estágio, próximos dos encontrados em veículos de competição. A análise de conforto do veículo durante simulação de passagem por trecho de pista demonstrou que os elementos de força definidos na análise modal resultam em níveis de conforto raramente encontrados em veículos de competição. / This dissertation presents the study of a off-road competition vehicle ride and the double rate suspensions elastokinematic behavior using the multibody software MSC-ADAMS. The vehicle multibody model includes the rear and front suspensions, the steering system, the tires and the sprung mass. The suspensions elastokinematic analysis defined geometric configurations that allowed long jounce and rebound travel of wheel, without undesirable project parameters variations. In the modal analysis of the vehicle multibody model, the springs rates that results in natural frequencies values similar to passenger cars for the first suspension stage and, for the second stage, similar to competition vehicles, were defined. The ride analysis during the simulation of the vehicle running on a rough track showed that the force elements defined on the modal analysis resulted in a good ride quality, rarely found in competition vehicles.

<p>U ovoj doktorskoj disertaciji razvijena je tehnika upravljanja za<br />pretvarač energetske elektronike pri nesimetričnim naponskim<br />prilikama u elektroenergetskom sistemu. Kao što je pokazano,<br />primenom tehnike poništavanja signala kašnjenjem moguće je<br />izdvajanje komponenti struje inverznog redosleda i njihovo<br />potpuno poništenje, što će omogućiti pouzdanu kontrolu<br />komponenti struje direktnog redosleda upotrebom klasičnih<br />tehnika upraljanja, uz adekvatno unapređenje tehnike za<br />sinhronizaciju sa vektorskim reprezentom napona. Predložena<br />je i upotreba algoritama za poboljšanje parametara kvaliteta<br />električne energije bez dodatnih pasivnih elemenata.</p> / <p>This PhD thesis presents an improved control technique for grid<br />connected converter under asymmetrical voltages at the point of<br />common coupling. As presented, using delay signal cancellation<br />technique it is possible to differentiate and completely mitigate the<br />negative sequence current, offering the possibility of reliable positive<br />sequence current control using classical control algorithms. The<br />improvements made in synchronization offered adequate<br />phase angle estimation under voltage asymmetry. Furthermore, a<br />technique for the improvement of power quality indices without<br />passive elements between the grid and</p>

Cette thèse s’intéresse à trouver des solutions informatiques à certains problèmes de l’optimisation combinatoire, à savoir les problèmes de tournées de véhicules. Elle aborde les problèmes de Transport A la Demande (TAD). L’objectif principal visé dans cette thèse fait appel à certaines approches exactes et certaines approches méta-heuristiques pour résoudre des problèmes d’optimisation multi-objective de Transport A la Demande avec plusieurs véhicules. En effet, nos principaux objectifs de recherche consistent à : -I) Résoudre un problème multi-objectif de Transport A La Demande multi-véhicules basé sur la qualité de service ; - II) Résoudre un autre problème de Transport A la Demande multi-objectifs multi-véhicules. Ce problème traite un cas spécifique et qui consiste à l’application de ce problème aux domaines de l’Hospitalisation A Domicile (HAD). Nous avons appliqué des algorithmes exacts de "Branch and Bound" et des méthodes méta-heuristiques telles que l’algorithme évolutionnaire "Algorithme Génétique" et l’algorithme de "Colonie de Fourmis" pour apporter des solutions efficaces à ces différents problèmes. Un ensemble de résultats numériques est présenté pour chacune de ces méthodes pour montrer leurs capacités de produire des solutions de haute qualité en temps de calcul raisonnables. / This thesis focuses on finding computer science solutions for some combinatorial optimization problems, namely Vehicle Routing Problems (VRP). The thesis addresses the Dial A Ride Problems (DARP). Its main objective is to use some exact and meta-heuristics approaches to solve multi-objective optimization of Dial A Ride Problem with multi-vehicles. Hence, our main research aims are : - I)Solve a multi-objective Dial A Ride Problem with multi-vehicles based on quality of service, this problem treats a general case ; - II) Solve another multi-objective Dial A Ride Problem with multi-vehicles, this problem deals with a specific case which is an application of the Dial A Ride Problem in Home Health Care (HHC). We have also applied exact algorithms "Branch and Bound" and meta-heuristic algorithms such as evolutionary algorithms "Genetic Algorithm" and "Ant Colony" algorithm to provide effective solutions to these different problems. A set of numerical results are presented for each of these methods. Our results show that they produce high quality solutions in a reasonable execution time for all the treated problems.

Le Problème de Transport à la Demande (PTD), consiste à prendre en charge le transport des personnes d'un lieu de départ vers un lieu d'arrivée. Il est caractérisé par un ensemble de demandes de transport et d'un nombre de véhicules disponible. L'ultime objectif dans ce travail de thèse est d'offrir une alternative optimisée au déplacement individuel et collectif. Le PTD est classé parmi les problèmes NP-difficile, la majorité des travaux de recherche ont été concentrés sur l'utilisation des méthodes approchées pour le résoudre.Ce problème est également multicritère, la solution proposée dans ce travail permet à la fois une réduction du temps de voyage et également de la distance parcourue. Dans cette thèse, nous proposons notre contribution à l'étude et à la résolution du problème de transport à la demande multicritère et dynamique en appliquant l'algorithme de recuit simulé multi-objectif. Une grande partie de notre travail concerne la conception, le développement et la validation des approches qui permettent de donner des solutions optimales ou quasi optimales, pour un PTD. Ces approches utilisent une méthode multicritère qui s’appuie sur l’algorithme de recuit simulé. La modélisation du PTD est représentée par une architecture multi-acteurs. Cette architecture met en évidence l’aspect distribué du système ainsi que les interactions et les relations qui peuvent avoir lieu entre les différents acteurs. Nous présentons dans ce travail un Système Multi-Agents pour la planification des itinéraires des véhicules affectés au transport des voyageurs. Les agents de ce système utilisent le module d’optimisation développé dans la première partie / The Dial a Ride Problem (DRP) is to take passengers from a place of departures to places of arrivals. Different versions of the dynamic Dial a Ride Problem are found in every day practice; transportation of people in low-density areas, transportation of the handicapped and elderly persons and parcel pick-up and delivery service in urban areas. In the DRP, customers send transportation requests to an operator. A request consists of a specified pickup location and destination location along with a desired departure or arrival time. The ultimate aim is to offer an alternative to displacement optimized individually and collectively. The DRP is classified as NP-hard problem that’s why most research has been concentrated on the use of approximate methods to solve it. Indeed the DRP is a multi-criteria problem, the proposed solution of which aims to reduce both route duration in response to a certain quality of service provided. In this thesis, we offer our contribution to the study and solving the DRP in the application using a multi agent system based on the Multi-Objective Simulated Annealing Algorithm

Dans de nombreuses mégalopoles, la progression de la part modale du vélo, par ailleurs soutenue grâce à des politiques publiques, crée un intérêt grandissant pour la sécurité des cyclistes qui représente un véritable enjeu de santé publique. La plupart des études sur le sujet utilisent des données officielles issues des forces de police. Cependant ces données sous enregistrent les cyclistes et tout particulièrement les victimes d'accidents seuls. En France, une étude menée sur le Registre médical du Rhône, quasi exhaustif en termes de chutes et de collisions à vélo, a permis d'estimer qu'un cycliste a 8 fois plus de chances d'être victime d'un accident, par heure passée sur la route, qu'un automobiliste. Cette même étude identifie un sur-risque d'accident chez les femmes. Partant de ces constats, ce travail de thèse propose une image complète de l'accidentalité à vélo qui prend en compte les facteurs d'accidents identifiés dans la littérature et propose de comprendre comment le comportement du cycliste interagit avec eux. L'objectif de nos travaux est de décrire les configurations d'accident corporel pour proposer des actions en sécurité primaire ou secondaire. Pour ce faire, nous avons mené une enquête auprès de 3337 cyclistes accidentés en 2009-2011 et identifiés dans le Registre des victimes d'accidents de la circulation du Rhône. Sur la base d'un taux important de répondants, les analyses descriptives améliorent la connaissance en accidentalité cycliste, certains facteurs d'accidents étant scrutés pour la première fois par notre enquête. A la suite des différentes analyses, le rôle du sexe du cycliste dans l'accident est apparu incertain, justifiant une étude approfondie des accidents à vélo à travers le prisme du genre. Dans un ultime volet, nous proposons un ensemble de mesures et d'idées visant l'amélioration de la sécurité des déplacements cyclistes ainsi que des perspectives de recherche en accidentalité à vélo qui combleraient les lacunes du travail proposé / In many major cities, the growing modal share of cycling, mainly supported by public policies, raises the issue of cycling safety. Most of the existing work on this topic is based on police data. However, these data underreport cyclists, especially the victims of single accidents. In France, a recent study based on the Rhône road trauma registry, a medical database covering almost all cyclist falls or collisions, considers that a cyclist is 8 times more likely to be injured than a driver by hour spend on a road. The same review also reveals an increased risk of crash for women. Based on these observations, this thesis comes up with a full picture of cycling accidents, taking into account accident factors identified in the literature. The proposed work offers a better understanding on how the cyclist’s behavior interacts with them. It aims to describe accident configurations to propose preventive primary and secondary safety actions. To do so, we surveyed 3337 cyclists injured in 2009-2011 and identified in the Rhône Road Trauma Registry. Based on a significant response rate, descriptive analyses improve existing knowledge in cycling safety, some accident factors being examined for the first time in our survey. Following these analyses, gender roles were unclear, justifying an intensive investigation on cycling accidents through the prism of gender. In order to achieve this goal, we select the 44 accidents on utilitarian trips and built a logistical regression model to explain the likelihood that the victim is a woman. All factors being equal, when a injured cyclist had a load on his bike, did not know the route, fell ascending or descending a curbside, it is more likely that the victim is a woman. Conversely, the probability for the victim to be a men increases if the cyclist’s speed is one of the accident factors. These results are confirmed and illustrated analyzing textual data on accidents stories. The last part is dedicated to a proposal of a set of actions and ideas aiming at improving cycling safety. Some research perspectives are proposed to address the weaknesses of the thesis work