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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.
471

Robust Adaptive Control of a Laser Beam System for Static and Moving Targets

Samantaray, Swastik January 2016 (has links) (PDF)
The motivation of this thesis is to propose a robust control technique for a laser beam system with target estimation. The laser beam is meant to track and fall on a particular portion of the target until the operation is accomplished. There are many applications of such a system. For example, laser range finder uses laser beam to determine the distance of the target from the source. Recently, unmanned aerial drones have been developed that run on laser power. Drone batteries can be recharged with power sup-ply from laser source on the ground. Laser is also used in high energy laser weapon for defence applications. However, laser beams travelling long distances deviate from the desired location on the target due to continually changing atmospheric parameters (jitter effect) such as pressure, temperature, humidity and wind speed. This deviation error is controlled precisely using a lightweight fast steering mirror (FSM) for fine correction. Furthermore, for a moving target, minimizing the deviation of the beam is not sufficient. Hence, in coarse correction, the target has to be tracked by determining its position and assigning the corresponding azimuth and elevation angles to the laser sources. Once these firing angles are settled within an accuracy of +3 mrad, the effort for minimizing the beam deviation (fine correction) takes place to improve the accu-racy to +10 rad. The beam deviation due to jitter effect is measured by a narrow field of view (NFOV) camera at a high frame rate (1000 frames per second), which takes one frame to com-pute this error information. As a result, controller receives error information witha delay from NFOV. This data cannot be modelled for prediction and hence, a few promising data driven techniques have been implemented for one step ahead prediction of the beam deviation. The predictions are performed over a set of sliding window data online after rejecting the outliers through least square approximated straight line. In time domain, methods like auto-regressive least square, polynomial extrapolation (zeroth, first and second order), Chebyshev polynomial extrapolation, spline curve extrapolation are implemented. Further, a convex combination of zeroth order hold and spline extrapolation is implemented. In frequency domain, Fourier series-Fourier transform and L-point Discrete Fourier Transform stretching are implemented where the frequency component of the signal are analysed properly and propagated for one step ahead prediction. After one step ahead prediction, three nominal controllers (PID, DI and DLQR) are designed such that the output of FSM tracks the predicted beam deviation and the performances of these controllers are compared. Since the FSM is excited by high frequency signals, its performance degrades, which leads to parameter degradation in the mathematical model. Hence, three adaptive controllers have been implemented, namely, model reference adaptive control (MRAC), model reference adaptive sliding mode control (MRASMC) and model following neuro-adaptive control (MFNAC). The parameters of the FSM model are degraded up to 20% and the model is augmented with cross coupling terms because the same mirror is used for horizontal and vertical beam deviation. With this condition, the tracking performance and control rate energy consumption of the implemented adaptive controllers are analysed to choose the best among them. For a moving target, in coarse correction, two tracking radars are placed to measure the position of the target. However, this information is assumed to be noisy, for which an extended Kalman filter is implemented. Once the position of the target is known, the desired firing angles of the laser sources are determined. Given the laser source steering mathematical model, a controller is designed such that it tracks the desired firing angle. Once the residual error of the coarse correction settles inside 3 mrad, fine correction takes part to reduce the residual error to 10 rad. The residual error magnitude of the proposed mechanization was analysed for a moving target by perturbing the FSM model by 20% and zeroth order hold predictor with different combinations of angle tolerance and frame tolerance.
472

Les dérives nomopathes de la qualité et la figure émergente de l'Ingénieur-Stratège / The nomopathic drifts of quality and the emerging figure of the Engineer-strategist

Duclos, Nicolas-Louis 27 January 2015 (has links)
A l’occasion de deux études de cas, une démarche de tableau de bord stratégique hospitalier et une réorganisation de direction des systèmes d’information dans une entreprise de services, nous avons, dans cette recherche, analysé les freins qui apparaissent dans les démarches de changement technologique et managérial.Nous avons montré dans le premier cas comment le modèle du Balanced Scorecard peut être adapté pour piloter un programme de projets et promouvoir un travail coopératif, sous condition d’une évolution du rôle des dirigeants. Le deuxième cas nous a permis de montrer comment les démarches qualité s’enferment dans une logique de qualité-conformité contre-productive qui n’est pas due au manque de formation ou d’implication. Dans les deux cas, nous avons constaté que l’insuffisance de capacité méthodologique des ingénieurs et des managers renforce leur résistance au changement et leurs difficultés en situation complexe. Nous avons montré que la résistance organisationnelle se manifeste en deux temps : des difficultés de premier niveau, dérives nomopathes, apparaissent sous la forme d’un appauvrissement méthodologique du modèle choisi, puis les actions correctives sont suivies de difficultés de deuxième niveau constituant un phénomène de déviance computo-cogitationnelle, sorte de résilience organisationnelle qui voit la transformation de l’état final attendu en un état final hybride. Ces acquis méthodologiques nous ont permis, après une analyse historique de l’évolution des concepts de la qualité puis sur l’évolution du rôle des managers, de dresser des constats à un niveau méso reliant le niveau macro-économique (domination financière dans les entreprises, révolution numérique, renouveau bureaucratique) au niveau micro des entreprises (injonctions paradoxales, juridicisation de la société et conformité généralisée). Nous avons enfin proposé plusieurs modélisations, notamment le concept cyclique d’information-valeur, la figure tripolaire d’un Ingénieur-Stratège et l’ébauche d’un futur modèle de management des intangibles. / The two case studies concern an approach of the strategic dashboard of a hospital and the reorganization of an IT department in a services company. We have, in this research, analyzed the brakes which appear in the technological and managerial change approaches. In the first study case, we have showed how the Balanced Scorecard model can be adapted to pilot a projects program and to promote a cooperative way of working, under the condition of an evolution of the managers role. In the second case we have shown how the quality approaches lock themselves in a counter-productive logical of quality-conformity which is not due to a lack of training or implication. In the both cases we have noticed that the insufficiency of methodological capacity of the managers strengthens their resistance to change and their difficulties in complex situation We have noticed that the organizational resistance express itself in two times : first level difficulties, nomopathic drifts, appear as a methodological impoverishment of the choosen model, then the corrective actions are followed by second level difficulties who form a phenomena of computo-cogitational deviancy, a kind of organizational resistance who transforms the awaited final state to a hybrid final state. These methodological grants, after a historical analysis of the evolution of quality concepts then of the evolution of the managerial roles, succeeded to meso level reports joining the macro-economic level (financial domination in companies, numeric revolution, bureaucratic revival) to the micro-economic level in companies (paradoxical orders, juridical transformation of society and generalized conformity). A last, several modellings are proposed, in particular the cyclic concept of information-value, and the three-pole figure of the engineer-strategist, towards the sketch of a future model of management of intangibles.
473

Multifunkční volant Formule Student / Multiple-funktion steering wheel Formule Student

Paulus, Luboš January 2011 (has links)
The Master‘s thesis deals with a creating of display writers on multiple-function steering wheel Formule Student. It is mainly about dates transfered through RS232 or CAN bus from control unit of the Formule to microcontroller. First of all it is necessary to find out, which informations and a which way of displaying them are more useful and readable for drivers. This leads to another point - right choice of display writers, which will be used on the steering wheel. Creation of the design and construction of display device follows.
474

Přední nezávislá náprava pro autobus / Independent front axletree of the bus

Moravec, Jan January 2008 (has links)
In those diploma work was solved problems of independent trapezoidal axletree for low-floor bus - NB12 CITY firm SOR Libchavy s.r.o . Work was divided into two main features: solving wheel-suspension kinematics and strenght calculation sorted parts of wheel suspension by the help of finite element method. There was effected fatigue calculation sorted parts of wheel suspension according to „Resetova metoda“ of predicting fatigue damage flowing from so – called cutaway methodics of fatigue tests at the close of this work.
475

Hållbar utveckling i teknikämnet : Analys av läroböcker i teknik förgrundskolans åk 7–9och teknik 1 för gymnasiet / Sustainable Development in theTechnology Subject : Analysis of Student Literature in Technology forlower and higher secondary school

Bellander, Erika, Manolopoulos, Dimitrios January 2019 (has links)
Uppsatsen handlar om att undersöka hur aktuella läroböcker i teknik på grundskolanshögstadium och teknik 1 på gymnasiet adresserar hållbar utveckling (HU). Läroböckerna harjämförts med aktuella läroplaner för både Lgr11 och Gy2011 samt några externa källor, FN:s17 Globala Mål och tidningen Ny Teknik. Som metod har valts en tematisk analys enligt Brown och Clark (2008), ur detkontextualistiska perspektivet. De olika temana har analyserats fram och räknats medavseende på förekomster i de olika källorna, vilket har resulterat i både en kvantitativ och kvalitativ analys. Analyserna har kopplats till litteratur angående forskning inom tre huvudområden;teknikämnet och HU, lärare – elev samt kunskaps- och läroboksperspektiv. Det kan konstateras att läroböckerna inte alls innehåller så stor procentandel (%) HU-textmassa, stycken, som kurs- och ämnesplanerna innehåller. Läroböckerna följer inte läroplanernas inriktningar särskilt väl, utan HU verkar ha adderats till det befintliga innehållet i tidigare utgåvor, i stället för att ha arbetats in från grunden i nya utgåvor. Detta gör att HU ibland betraktas som en valbar kompletteringsaktivitet i undervisningen. Läroplanerna följer i sin tur inte de 17 nya globala målen för HU. Detta eftersom de är på olikanivåer och synkronisering med de globala målen görs med en stor fördröjning. Först görs synkronisering till nationell nivå, därefter till institutionell nivå och sist till kurs- och ämnesnivå. Som det nu är verkar teknikämnet i läroplanerna lyfta fram viktigheten i att tänka på HU, hellre än att lyfta fram tekniker kring hållbar utveckling och hållbara produkter. Slutsatsen är att läroböcker och läroplaner behöver uppdateras och teknikämnena integreraHU på ett mer konkret och genuint sätt, inte som idag, på en allmänt fostrande nivå. Detta föratt betona betydelsen av HU i samhället och för att uppnå en aktuell och likvärdig undervisning samt kunskaps- och färdighetsinhämtning. / The thesis is about examining how certain current textbooks in technology at the lower secondary school and technology 1 in the upper secondary school address sustainable development (SD). The textbooks have been compared with current curricula for both Lgr11and Gy2011 as well as some external sources, the UN's 17 Global Goals and the magazine Nyteknik. As a method, a thematic analysis has been chosen according to Brown and Clark (2008), fromthe contextual perspective. The different themes have been analyzed and counted with regard to occurrences in the various sources, which has resulted in both a quantitative and qualitative analysis. The analyses have been linked to literature on research in three main areas; technical subject and HU, teacher - student and knowledge and textbook perspective. It can be stated that the textbooks do not contain as much percentage (%) of SD text mass, paragraphs, which the course and subject plans contain. The textbooks do not adhere specifically to the direction of the curricula, but SD seems to have been added to the existing content of previous editions, rather than having been worked in from scratch in new editions.This means that SD is sometimes regarded as an optional complementary activity in the teaching. The curricula do not follow the 17 new global goals for SD. This is because they are at different levels and synchronization with the global goals is done with a great delay. First, synchronization is made to the national level, then to the institutional level and last to the course and subject level (curricula). As it is now, the technical subject in the curricula seems to emphasize the importance of thinking about SD, rather than highlighting technologies relating to sustainable development and sustainable products. The conclusion is that textbooks and curricula need to be updated and the technology topics would integrate SD in a more concrete and genuine way, not as today, at a generally educational level. This is to emphasize the importance of SD in society and to achieve a current and equivalent teaching and acquiring knowledge and skill.
476

A Framework for Real-Time Autonomous Road Vehicle Emergency Obstacle Avoidance Maneuvers with Validation Protocol

Lowe, Evan 24 August 2022 (has links)
No description available.
477

Human Body Scattering Effects at Millimeter Waves Frequencies for Future 5G Systems and Beyond

Romero Peña, Johan Samuel 13 January 2023 (has links)
[ES] Se espera que las futuras comunicaciones móviles experimenten una revolución técnica que vaya más allá de las velocidades de datos de Gbps y reduzca las latencias de las velocidades de datos a niveles muy cercanos al milisegundo. Se han investigado nuevas tecnologías habilitadoras para lograr estas exigentes especificaciones. Y la utilización de las bandas de ondas milimétricas, donde hay mucho espectro disponible, es una de ellas. Debido a las numerosas dificultades técnicas asociadas a la utilización de esta banda de frecuencias, se necesitan complicados modelos de canal para anticipar las características del canal de radio y evaluar con precisión el rendimiento de los sistemas celulares en milimétricas. En concreto, los modelos de propagación más precisos son los basados en técnicas de trazado de rayos deterministas. Pero estas técnicas tienen el estigma de ser computacionalmente exigentes, y esto dificulta su uso para caracterizar el canal de radio en escenarios interiores complejos y dinámicos. La complejidad de la caracterización de estos escenarios depende en gran medida de la interacción del cuerpo humano con el entorno radioeléctrico, que en las ondas milimétricas suele ser destructiva y muy impredecible. Por otro lado, en los últimos años, la industria de los videojuegos ha desarrollado potentes herramientas para entornos hiperrealistas, donde la mayor parte de los avances en esta emulación de la realidad tienen que ver con el manejo de la luz. Así, los motores gráficos de estas plataformas se han vuelto cada vez más eficientes para manejar grandes volúmenes de información, por lo que son ideales para emular el comportamiento de la propagación de las ondas de radio, así como para reconstruir un escenario interior complejo. Por ello, en esta Tesis se ha aprovechado la capacidad computacional de este tipo de herramientas para evaluar el canal radioeléctrico milimétricas de la forma más eficiente posible. Esta Tesis ofrece unas pautas para optimizar la propagación de la señal en milimétricas en un entorno interior dinámico y complejo, para lo cual se proponen tres objetivos principales. El primer objetivo es evaluar los efectos de dispersión del cuerpo humano cuando interactúa con el canal de propagación. Una vez evaluado, se propuso un modelo matemático y geométrico simplificado para calcular este efecto de forma fiable y rápida. Otro objetivo fue el diseño de un reflector pasivo modular en milimétricas, que optimiza la cobertura en entornos de interior, evitando la interferencia del ser humano en la propagación. Y, por último, se diseñó un sistema de apuntamiento del haz predictivo en tiempo real, para que opere con el sistema de radiación en milimétricas, cuyo objetivo es evitar las pérdidas de propagación causadas por el cuerpo humano en entornos interiores dinámicos y complejos. / [CA] S'espera que les futures comunicacions mòbils experimenten una revolució tècnica que vaja més enllà de les velocitats de dades de Gbps i reduïsca les latències de les velocitats de dades a nivells molt pròxims al milisegundo. S'han investigat noves tecnologies habilitadoras per a aconseguir estes exigents especificacions. I la utilització de les bandes d'ones millimètriques, on hi ha molt espectre disponible, és una d'elles. A causa de les nombroses dificultats tècniques associades a la utilització d'esta banda de freqüències, es necessiten complicats models de canal per a anticipar les característiques del canal de ràdio i avaluar amb precisió el rendiment dels sistemes cellulars en millimètriques. En concret, els models de propagació més precisos són els basats en tècniques de traçat de rajos deterministes. Però estes tècniques tenen l'estigma de ser computacionalment exigents, i açò dificulta el seu ús per a caracteritzar el canal de ràdio en escenaris interiors complexos i dinàmics. La complexitat de la caracterització d'estos escenaris depén en gran manera de la interacció del cos humà amb l'entorn radioelèctric, que en les ones millimètriques sol ser destructiva i molt impredicible. D'altra banda, en els últims anys, la indústria dels videojocs ha desenrotllat potents ferramentes per a entorns hiperrealistes, on la major part dels avanços en esta emulació de la realitat tenen a veure amb el maneig de la llum. Així, els motors gràfics d'estes plataformes s'han tornat cada vegada més eficients per a manejar grans volums d'informació, per la qual cosa són ideals per a emular el comportament de la propagació de les ones de ràdio, així com per a reconstruir un escenari interior complex. Per això, en esta Tesi s'ha aprofitat la capacitat computacional d'este tipus de ferramentes per a avaluar el canal radioelèctric millimètriques de la manera més eficient possible. Esta Tesi oferix unes pautes per a optimitzar la propagació del senyal en millimètriques en un entorn interior dinàmic i complex, per a la qual cosa es proposen tres objectius principals. El primer objectiu és avaluar els efectes de dispersió del cos humà quan interactua amb el canal de propagació. Una vegada avaluat, es va proposar un model matemàtic i geomètric simplificat per a calcular este efecte de forma fiable i ràpida. Un altre objectiu va ser el disseny d'un reflector passiu modular en millimètriques, que optimitza la cobertura en entorns d'interior, evitant la interferència del ser humà en la propagació, per a així evitar pèrdues de propagació addicionals. I, finalment, es va dissenyar un sistema d'apuntament del feix predictiu en temps real, perquè opere amb el sistema de radiació en millimètriques, l'objectiu del qual és evitar les pèrdues de propagació causades pel cos humà en entorns interiors dinàmics i complexos. / [EN] Future mobile communications are expected to experience a technical revolution that goes beyond Gbps data rates and reduces data rate latencies to levels very close to a millisecond. New enabling technologies have been researched to achieve these demanding specifications. The utilization of mmWave bands, where a lot of spectrum is available, is one of them. Due to the numerous technical difficulties associated with using this frequency band, complicated channel models are necessary to anticipate the radio channel characteristics and to accurately evaluate the performance of cellular systems in mmWave. In particular, the most accurate propagation models are those based on deterministic ray tracing techniques. But these techniques have the stigma of being computationally intensive, and this makes it difficult to use them to characterize the radio channel in complex and dynamic indoor scenarios. The complexity of characterizing these scenarios depends largely on the interaction of the human body with the radio environment, which at mmWaves is often destructive and highly unpredictable. On the other hand, in recent years, the video game industry has developed powerful tools for hyper-realistic environments, where most of the progress in this reality emulation has to do with the handling of light. Therefore, the graphic engines of these platforms have become more and more efficient to handle large volumes of information, becoming ideal to emulate the radio wave propagation behavior, as well as to reconstruct a complex interior scenario. Therefore, in this Thesis one has taken advantage of the computational capacity of this type of tools to evaluate the mmWave radio channel in the most efficient way possible. This Thesis offers some guidelines to optimize the signal propagation in mmWaves in a dynamic and complex indoor environment, for which three main objectives are proposed. The first objective has been to evaluate the scattering effects of the human body when it interacts with the propagation channel. Once evaluated, a simplified mathematical and geometrical model has been proposed to calculate this effect in a reliable and fast way. Another objective has been the design of a modular passive reflector in mmWaves, which optimizes the coverage in indoor environments, avoiding human interference in the propagation, in order to avoid its harmful scattering effects. And finally, a real-time predictive beam steering system has been designed for the mmWaves radiation system, in order to avoid propagation losses caused by the human body in dynamic and complex indoor environments. / Romero Peña, JS. (2022). Human Body Scattering Effects at Millimeter Waves Frequencies for Future 5G Systems and Beyond [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/191325
478

LAVORO AUTONOMO E INTERESSI COLLETTIVI: RAPPRESENTANZA, ORGANIZZAZIONE E AZIONE SINDACALE DI TUTELA / Self-Employment and Collective Interests: Representation, Organization and Trade Union Action

FERRARIO, SUSANNA 18 February 2008 (has links)
La ricerca prende avvio dalla ricostruzione dei processi socio-economici che hanno portato alla crisi del modo di produzione taylorista-fordista. Muovendo da tali riflessioni, si constata come le imprese “post-fordiste” si avvalgano in misura crescente di lavoratori autonomi, un tempo coordinati e continuativi e, oggi, a progetto (artt. 61 e ss., d.lgs. 276/2003). Tali collaboratori sono, dunque, soggetti ad un potere (contrattuale) di coordinamento del committente che, alle volte, si somma ad una condizione di dipendenza economica dal committente medesimo. Si crea, quindi, una differenziazione interna all'area dell'autonomia coordinata che non pare adeguatamente valorizzata dal legislatore ordinario, ma che sembra interessare i sindacati. Il dato reale vede, infatti, agire rappresentanze varie, sicché occorre circoscrivere l'ambito di applicabilità degli artt. 39 e 40 Cost. L'assenza di un genuino interesse collettivo e di un'effettiva attività di autotutela inducono a ritenere che i collaboratori “forti” e il relativo associazionismo possano beneficiare delle sole tutele poste dagli artt. 2, 18 e 41 Cost. A conclusione si affrontano le problematiche che la ricostruzione così svolta solleva, ovverosia come garantire l'effettività delle tutele riconosciute al sindacalismo dei collaboratori “deboli” e come contemperare l'associazionismo dei collaboratori “forti” con il diritto antitrust comunitario. / The search starts with the reconstruction of socio-economic processes. Moving from these reflections, it's possible to see that today's companies take advantage of increasingly self-employed coordinated and continuous and, after d.lgs. 276/2003 “lavoratori a progetto”. These employees are, therefore, subject to a power (contractual) coordination of the customer that, at times, it adds up to a state of economic dependence by the same. It then creates an internal differentiation into autonomy area that does not seem properly valued by the ordinary legislator, but that seems to involve trade unions. Given that in reality there are different representations, we move to circumscribe the scope of applicability of the Arts. 39 and 40 Const. The absence of a genuine interest and genuine self activities suggest that employees "strong" and its associations can only benefit from the protections posed by Arts. 2, 18 and 41 Const. At the end tackling the problems so that the reconstruction turn raises, namely how to ensure the effectiveness of the safeguards recognized unionism collaborators "weak" and reconcile the associations of employees "strong" with the antitrust law.
479

Commander au long cours depuis la Guyenne : les capitaines de navire bordelais au XVIIIe siècle / Commanding from Guyenne : Ship captains in Bordeaux in the 18th century

Candelon-Boudet, Frédéric 05 September 2018 (has links)
L’activité du port de Bordeaux en plein essor au XVIIIe siècle est bien connue des historiens modernistes. Paradoxalement, les développements consacrés aux professionnels embarqués sur les gréements sont plus rares, alors qu’une telle étude a déjà été réalisée pour la capitale de la Guyenne à la fin du Moyen-âge. Parmi les « gens de mer » demeurés dans l’ombre, les capitaines de navire se démarquent à plus d’un titre. Par la charge symbolique mais aussi juridique que revêt la fonction, en premier lieu, dans le convoi des hommes et des marchandises au-delà des océans. Par le champ de compétences étendu que recouvre la profession, ensuite. Les commandants de bord doivent en effet non seulement être en capacité de piloter un bâtiment au long cours, mais en outre diriger un équipage bigarré, tout en versant dans le commerce au moment jugé le plus opportun. Les capitaines apparaissent ainsi comme des acteurs incontournables des échanges maritimes à l'époque moderne, cernés par un océan d’archives dont l’importance des fonds conservés à Bordeaux, en dépit des ravages du temps, rend parfaitement compte. Par les perspectives de mobilité sociale offertes par le métier, en dernier lieu. Affiliée aux négociants avec lesquels elle partage une même communauté de vues et de pratiques, contrôlant l’information, brouillant les pistes entre les acteurs de l’échange, la figure du « capitaine-géreur » placée à la tête des expéditions maritimes ou paradant parmi les cercles mondains révèle une confusion des genres pouvant induire des changements d’état. Il s’agit de déterminer si le négoce à temps plein constitue un horizon accessible puis pérenne, parmi d’autres opportunités de reconversion à portée du groupe. Alors que le commerce colonial et négrier assure la prospérité de la capitale de la Guyenne, c’est l’identité de la profession via sa capacité à se fondre parmi les élites urbaines qui questionne, de la Régence à la Révolution française. / Modern historians have good knowledge of the 18th century growth of Bordeaux harbour activity. But works about crew members are scarce while paradoxically such a study had already been led for the « Guyenne » capital as early as in the end of the Middle Ages. Ship commanders stand out from all other rather discreet socio-professional categories related to sailors for many reasons : first, because of the symbolical and legal dimension of their occupation which implies their responsibility whenever it comes to the transportation of men and goods ; secondly, because of their huge fields of expertise, like to be able to steer boats over long distance, to handle crews of dozens of members or to carry out commercial transactions ; last, but not least, because of the social mobility offered by their position. Highly documented in a rich archive collection kept and preserved in Bordeaux, captains have turned into key players of the maritime trade of the modern era. By frequently working and diverting themselves with traders and ship owners, they developed a trusting relationship with them. The question is to determine how this cooperation was shaped, and to know if trading or ship armament were possible career changes within the reach of captains, and if not, how they could integrate the urban elites at work under the « Ancien Régime ». When the colonial and slave trade ensured the Bordeaux harbour’s prosperity, it is the identity of the merchant navy ship commanders working from the capital of « Guyenne » that will be here studied, from the Regency to the French Revolution.
480

Risk assessment for integral safety in operational motion planning of automated driving

Hruschka, Clemens Markus 14 January 2022 (has links)
New automated vehicles have the chance of high improvements to road safety. Nevertheless, from today's perspective, accidents will always be a part of future mobility. Following the “Vision Zero”, this thesis proposes the quantification of the driving situation's criticality as the basis to intervene by newly integrated safety systems. In the example application of trajectory planning, a continuous, real-time, risk-based criticality measure is used to consider uncertainties by collision probabilities as well as technical accident severities. As result, a smooth transition between preventative driving, collision avoidance, and collision mitigation including impact point localization is enabled and shown in fleet data analyses, simulations, and real test drives. The feasibility in automated driving is shown with currently available test equipment on the testing ground. Systematic analyses show an improvement of 20-30 % technical accident severity with respect to the underlying scenarios. That means up to one-third less injury probability for the vehicle occupants. In conclusion, predicting the risk preventively has a high chance to increase the road safety and thus to take the “Vision Zero” one step further.:Abstract Acknowledgements Contents Nomenclature 1.1 Background 1.2 Problem statement and research question 1.3 Contribution 2 Fundamentals and relatedWork 2.1 Integral safety 2.1.1 Integral applications 2.1.2 Accident Severity 2.1.2.1 Severity measures 2.1.2.2 Severity data bases 2.1.2.3 Severity estimation 2.1.3 Risk assessment in the driving process 2.1.3.1 Uncertainty consideration 2.1.3.2 Risk as a measure 2.1.3.3 Criticality measures in automated driving functions 2.2 Operational motion planning 2.2.1 Performance of a driving function 2.2.1.1 Terms related to scenarios 2.2.1.2 Evaluation and approval of an automated driving function 2.2.2 Driving function architecture 2.2.2.1 Architecture 2.2.2.2 Planner 2.2.2.3 Reference planner 2.2.3 Ethical issues 3 Risk assessment 3.1 Environment model 3.2 Risk as expected value 3.3 Collision probability and most probable collision configuration 4 Accident severity prediction 4.1 Mathematical preliminaries 4.1.1 Methodical approach 4.1.2 Output definition for pedestrian collisions 4.1.3 Output definition for vehicle collisions 4.2 Prediction models 4.2.1 Eccentric impact model 4.2.2 Centric impact model 4.2.3 Multi-body system 4.2.4 Feedforward neural network 4.2.5 Random forest regression 4.3 Parameterisation 4.3.1 Reference database 4.3.2 Training strategy 4.3.3 Model evaluation 5 Risk based motion planning 5.1 Ego vehicle dynamic 5.2 Reward function 5.3 Tuning of the driving function 5.3.1 Tuning strategy 5.3.2 Tuning scenarios 5.3.3 Tuning results 6 Evaluation of the risk based driving function 6.1 Evaluation strategy 6.2 Evaluation scenarios 6.3 Test setup and simulation environment 6.4 Subsequent risk assessment of fleet data 6.4.1 GIDAS accident database 6.4.2 Fleet data Hamburg 6.5 Uncertainty-adaptive driving 6.6 Mitigation application 6.6.1 Real test drives on proving ground 6.6.2 Driving performance in simulation 7 Conclusion and Prospects References List of Tables List of Figures A Extension to the tuning process

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