Dissertations / Theses on the topic 'Traction torque'

This thesis evaluates different controllers for traction control on an electric forklift truck and has been done in cooperation with Toyota Material Handling Manufacturing Sweden. The need for a traction control system has increased with the introduction of lithium-ion batteries replacing the older lead-acid batteries, reducing the battery weight and therefore the downward force on the driving wheel increasing the risk for slip. The forklift truck was modelled using Simulink and validated by experiment. Different possible control strategies were investigated and three were chosen for implementation in simulation. These were controllers based on Model Following Control, Maximum Transmissible Torque Estimation and Sliding Mode Control. Model Following Control makes use of a nominal model to compare actual wheel speed values with nominal wheel speed values to determine if slip is occurring, Maximum Transmissible Torque Estimation makes use of a closed-loop disturbance observer to compute the maximum transmissible torque possible without inducing slip and using it as a limitation on the input signal, and Sliding Mode Control uses different functions to \say{slide} along a sliding surface to stay around a specific slip value. All three controller types were developed both as speed controlled and torque controlled. All of the controllers could reduce slip heavily in simulation. The Maximum Transmissible Torque Estimation controller reduced slip the most and kept oscillations at a minimum, but was not as responsive as the others to driver commands. The conclusion was that the controller of choice would depend on the working environment of the forklift truck. In a low friction environment where slip is expected to occur often, the Maximum Transmissible Torque Estimation controller is advisable, while the other two would be a better choice for environment with low slip occurrence. The use of torque control, while often better with regards to decreasing slip, could not be advised due to a perceived increase in implementation cost.

The interest for Permanent Magnet (PM) synchronous machines has increased in the recent years. This is mainly due to important developments in the field of the electrical machine design, control systems and PM technology. These factors enable the possibility of designing electrical machines with a high torque density, power density, efficiency, low cost with wide degrees of freedom. Such requirements are highly sought in the automotive field, especially following the increasingly stringent energy efficiency and air pollution emissions policies. These conditions are pushing forward the transition from the conventional internal combustion engine mobility systems to the hybrid electric and full electric vehicles for the mass market production. Moreover, further requirements, especially in high demanding traction and auxiliary machines, such as Electric Power Steering (EPS) motors, are nowadays getting more and more important. Flux weakening performance, torque quality (cogging torque and torque ripple), demagnetization, acoustic performance and robustness of the designs has to be taken into account, together with stringent dimensional, electrical and thermal constraints typical for compact integrated automotive electrical drives. Due to recent sky-rocketing price, instability, critical availability of Rare Earth (RE) metals and the related environmental issue for their sourcing, Heavy (HR) RE free, RE-free and even PM free machines are hunted for in the automotive market. The novel PM motor topologies meet such a „market pull“. The main research subject of this PhD is the development of novel analysis and design procedures of PM synchronous machines for automotive applications. The latter range from low torque / power auxiliary systems, i.e. EPS machines, to high torque / high power applications, such as traction machines. It provides a comprehensive evaluation of various synchronous machine topologies. Particular attention is devoted to the study of HRE-free solutions and the development of Finite Element Analysis (FEA) and analytical procedures for the optimization of the motor designs. As mentioned above, these methodologies take into account several electromechanical constraints and various performance targets. As regards the traction machines, the investigation is focused to the permanent magnet assisted reluctance (PMASR) topology. The interest around the PMASR motors has grown in the last years especially as consequence of the price crisis of rare earth magnets. In fact these machines represent a potential low cost replacement of conventional PM machines due to several technical advantages, such as wide speed range, competitive torque density and efficiency, high overload capability and robust structure. On the other had, the most important drawback is represented by the high torque ripple. In the area of the electric power steering motors, several topologies, both with isotropic anisotropic rotor structures and equipped with fractional slot concentrated windings, are evaluated. Some novel motor designs, which employ the reluctance and flux concentration principle, are introduced, optimized by means of FEA procedures and experimentally validated in detail, including the acoustic and PM performance. Further considerations are derived on the robustness of the solutions against the manufacturing imperfections. Comparing to the isotropic topologies, these innovative motor configurations show higher torque density, extended speed range, optimal torque quality and acoustic performance, ensuring lower active cost and structural simplicity. Therefore, they represent attractive candidates for high performance automotive applications.<br>Negli ultimi anni l'interesse nel settore delle macchine sincrone a magneti permanenti ha riscontrato una notevole crescita. Questo e' stato determinato principalmente da importanti sviluppi nel campo della progettazione delle macchine elettriche, nei sistemi di controllo e nelle tecnologie dei magneti permanenti. Questi fattori hanno reso possibile la progettazione di macchine elettriche con elevata densita' di coppia, densita' di potenza, rendimento, basso costo unitamente ad ampi gradi di liberta' nella geometria e struttura della macchina. Tali requisiti sono fortemente ricercati nel campo automotive, soprattutto a seguito dell'introduzione di sempre piu' stringenti normative sull'efficienza energetica e sulle emissioni atmosferiche inquinanti. Questi aspetti hanno accelerato la transizione da sistemi di mobilita' tradizionali con motori a combustione interna a veicoli ibridi-elettrici e puramente elettrici, nella produzione industriale di massa. Inoltre, ulteriori requisiti, specialmente in macchine da trazione ed ausiliarie ad alte prestazioni, quali ad es. motori per servosterzo elettrico, stanno attualmente diventando sempre piu' importanti. Prestazioni in deflussaggio, qualita' della coppia (coppia di impuntamento ed oscillazione della coppia), smagnetizzazione, prestazioni acustiche e robustezza delle configurazioni devono essere tenute in conto, insieme a stringenti vincoli dimensionali, elettrici e termici tipici di azionamenti elettrici compatti ed integrati. A causa dell'incremento significativo ed instabilita' dei prezzi delle terre rare, della criticita' dei loro approvvigionamenti ed i relativi impatti ambientali, soluzioni prive di terre rare pesanti, senza terre rare od addirittura senza magneti permanenti, sono fortemente ricercate nel settore automotive. La principale tematica di ricerca di questo dottorato riguarda lo sviluppo di innovative procedure di analisi e sintesi di macchine sincrone a magneti permanenti per applicazioni automotive. Queste ultime spaziano da sistemi ausiliari a bassa coppia / bassa potenza, nella fattispecie motori per servosterzo elettrico, fino a applicazioni at alta coppia / alta potenza, quali ad es. motori da trazione. Questo lavoro fornisce una valutazione complessiva di differenti tipologie di macchine. Particolare attenzione e' dedicata allo studio di soluzioni con magneti permanenti privi di terre rare pesanti ed allo sviluppo di procedure di ottimizzazione ad elementi finiti ed analitiche della geometria del motore. Come menzionato precedentemente, tali metodologie tengono in considerazione numerosi vincoli elettromeccanici e differenti obiettivi. Per quanto riguarda le macchine da trazione, la ricerca si e' focalizzata sulla topologia di motori a riluttanza assistiti da magneti permanenti. L‘interesse attorno a tali macchine e' cresciuto negli ultimi anni soprattutto a seguito della crisi dei prezzi dei magneti permanenti a terre rare. Infatti, tali macchine rappresentano una soluzione alternativa a basso costo rispetto a motori a magneti permanenti tradizionali a causa di importanti vantaggi tecnici quali ad es. un ampio regime di velocita', competitivi valori di densita' di coppia ed efficienza, elevata capacita' di sovraccarico ed una robustezza della struttura. D'altra parte, uno dei principali svantaggi e' rappresentato dall'elevata oscillazione della coppia. Nel campo dei motori per servosterzo elettrico, differenti topologie, sia dotate di rotore isotropo che anisotropo ed equipaggiate con avvolgimenti concentrati, sono state valutate. Alcune nuove configurazioni, che sfruttano il principio della riluttanza e della concentrazione di flusso, sono introdotte, ottimizzate per mezzo di procedure ad elementi finiti ed infine validate per mezzo di misure sperimentali, includendo valutazioni delle prestazioni acustiche e quelle dei magneti permanenti. Ulteriori considerazioni sono tratte per quanto concerne la robustezza delle soluzioni nei confronti delle imperfezioni costruttive. Rispetto alle macchine isotrope, tali configurazioni sviluppano una densita' di coppia piu' alta, esibiscono un piu' ampio intervallo di velocita', maggiore rendimento raggiungendo un qualita' della coppia e prestazioni acustiche competitive ad un costo inferiore e con una buona semplicita' costruttiva. Esse si dimostrano, pertanto, dei candidati ottimali per applicazioni automotive ad alte prestazioni.

Роботу виконано на кафедрі автомобілів Тернопільського національного технічного університету імені Івана Пулюя Міністерства освіти і науки України. Захист відбудеться 23 грудня 2020 р. о 11:00 годині на засіданні екзаменаційної комісії № 10 у Тернопільському національному технічному університеті імені Івана Пулюя за адресою: 46001, м. Тернопіль, вул. Текстильна, 28, навчальний корпус № 9, ауд. 106.<br>В кваліфікаційній роботі розроблено технологію технічного обслуговування та ремонту трансмісії легкового автомобіля Skoda Octavia, а також досліджено тягово-швидкісних характеристик гідротрансформатора.<br>The qualification work developed the technology of maintenance and repair of the transmission of the car Skoda Octavia, as well as the traction and high-speed characteristics of the hydraulic transformer were investigated.<br>ВСТУП……………………………………………………………..…………… 1 ЗАГАЛЬНО-ТЕХНІЧНИЙ РОЗДІЛ ……………………………..……….. 1.1 Огляд та аналіз трансмісій сучасних автомобілів 1.2 Характеристика та конструктивні особливості автомобілів Skoda Octavia 1.3 Діагностика, неполадки та обслуговування трансмісії передньоприводного автомобіля 1.4 Постановка завдання 2 ТЕХНОЛОГІЧНИЙ РОЗДІЛ........................................................................ 2.1 Процес демонтажу трансмісії передньоприводного автомобіля 2.2 Розрахунок виробничої програми 2.3 Розрахунок кількості робітників та пропозиція обладнання 3 КОНСТРУКТОРСЬКИЙ РОЗДІЛ ……………………………………..…. 3.1 Попередній розрахунок зчеплення 3.2 Попередній розрахунок коробки передач. Визначення діапазону передаточних чисел 4 НАУКОВО-ДОСЛІДНИЙ РОЗДІЛ……………..………………… ……. 4.1 Дослідження тягово-швидкісних властивостей 4.2 Розрахунок та аналіз ефективної потужності двигуна 4.3 Розрахунок і уточнення передаточних чисел трансмісії 4.4 Основні критерії тягово-швидкісних властивостей 5 ОХОРОНА ПРАЦІ ТА БЕЗПЕКА В НАДЗВИЧАЙНИХ СИТУАЦІЯХ ……………………………………………………………….… 5.1 Розрахунок освітлення 5.2 Нормування захисту від випромінювань ЗАГАЛЬНІ ВИСНОВКИ …………………………………………………… БІБЛІОГРАФІЯ ……………….……..…………………………..………..… ДОДАТКИ

This thesis presents a new nonlinear automobile dynamical model and investigates the possibility of automobile dynamic control with wheel torque utilizing this model. The model has been developed from first principles by applying classical mechanics. Inputs to the model are the four independent wheel torques, while the steer angles at each wheel are specified as independent time-varying signals. In this way, consideration of a variety of steering system architectures, including rear-wheel steer, is possible, and steering introduces time-varying structure into the vehicle model. The frictional contact at the wheel-road interface is modeled by use of the LuGre dynamic friction model. Extensions to the existing two-dimensional LuGre friction model are derived and the steady-state of the friction model is compared to existing static friction models. Simulation results are presented to validate the model mathematics and to explore automobile behavior in a variety of scenarios. Vehicle control with wheel torque is explored using the theory of input-output linearization for multi-input multi-output systems. System relative degree is analyzed and use of steady-state LuGre friction in a control design model is shown to give rise to relative degree singularities when no wheel slip occurs. Dynamic LuGre friction does not cause such singularities, but instead has an ill-defined nature under the same no-slip condition. A method for treating this ill-defined condition is developed, leading to the potential for the system to have relative degree. Longitudinal velocity control and combined longitudinal and angular vehicle velocity control are demonstrated in simulation using input-output linearization, and are shown to produce improved vehicle response as compared to the open-loop behavior of the automobile. Robustness of the longitudinal velocity control to friction model parameter variation is explored and little impact to the controller's ability to track the desired trajectory is observed.

This thesis is focused on a novel agricultural technique for orchard cultivations that allows to perform automatic and fossil fuel free cultivation operations. More specifically, the aim of this thesis work is to study and implement the electric traction system and control the vehicle that performs the automatic operations. Starting from the analysis of each single component of the traction system, the control of the mobile platform will be then performed. After a first control of the mobile platform in no load conditions, the implementation of the dynamic model will be performed in the Simulink environment. Different simulations representing typical operational missions will be performed to have a real idea concerning the behaviour of the traction system and the energy consumption of this solution. Finally, the obtained results will be analysed for the future implementation of the mobile platform on the field.

Lors de la présente étude, nous avons conçu et réalisé une structure de contrôle synchrone du couple et du flux d'une machine asynchrone dans le domaine des moyennes et hautes vitesses. En effet, sur cette plage de vitesse le contrôle vectoriel par flux orienté n'est pas actuellement utilisable. Cette structure est associée à différents modèles de MLI, également synchrones. Les limitations imposées par l'onduleur ne permettant plus un fonctionnement asynchrone, à fréquence fixe, pour l'ensemble de la commande. La conception de cette commande s'est appuyée sur une modélisation de la machine qui a aidé à comprendre le fonctionnement et qui a donné les moyens nécessaires pour le calcul des réglages. Cette commande, unique sur la plage de fonctionnement moyenne et haute vitesse, est synchrone, ce qui permet de rendre inobservables les oscillations du couple instantané. A haute et moyenne vitesse, le couple est contrôlé directement (contrôle direct du couple) à partir d'une estimation du couple des fondamentaux. De plus à moyenne vitesse, l'amplitude du flux rotorique est aussi contrôlée. Les changements de modes de commandes et de MLI ont conduit à étudier des phases de transitions avec comme critère principal l'avance régulière du vecteur flux statorique afin de réduire les transitoires de couple. Pour les contrôles du flux et du couple, différents types d'escamoteurs capables de fournir les valeurs des grandeurs à régler ont été conçus et comparés. Des tests en simulation ont été effectués sur le moteur du "TGVNG" et ont donné des résultats satisfaisants

Moderne Kraftfahrzeuge werden mit einer Vielzahl von Fahrerassistenzsystemen ausgestattet um die Sicherheit, die Traktion, die Energieeffzienz, die Agilität und den Komfort noch weiter zu verbessern. Diese Ziele können zu einem Großteil mit einer aktiven Drehmomentverteilung, auch Torque Vectoring genannt, erreicht werden. Dafür sind jedoch Getriebesysteme erforderlich, welche unabhängig vom Fahrzustand und vom Antriebsmoment eine nahezu beliebige Drehmomentverteilung ermöglichen. In der vorliegenden Arbeit werden zunächst Grundlagen zu Getriebesystemen, insbesondere zu Planetengetrieben, und zur Fahrzeugdynamik erläutert. Anschließend wird der Stand der Technik anhand einer Systematik zur Einteilung von aktiven Differenzialgetrieben dargelegt sowie einige Vor- und Nachteile aufgezeigt. Das folgende Kapitel stellt ein Verfahren zur Ermittlung der mechanischen Belastung des aktiven Differenzialgetriebes für beliebige Fahrzeuge und Strecken vor. Damit erfolgt eine Bewertung der bisher bekannten Systeme hinsichtlich Gesamtwirkungsgrad, konstruktiver Aufwand und regelungstechnische Eigenschaften. Im Anschluss wird ein Verfahren zur rechnergestützten Synthese neuer Getriebesysteme beschrieben. Abschließend werden die positiven Auswirkungen der aktiven Drehmomentverteilung auf die Fahrdynamik herausgestellt. Das Ergebnis der Arbeit zeigt drei neue Getriebestrukturen, welche anhand der deffinierten Vergleichskriterien besser sind als alle bekannten Systeme<br>Actual passenger cars are equipped with a lot of driver assistant systems to increase safety, traction, efficiency, agility and comfort. These aims can be achieved by a controlled transmission of the engine torque to each driven wheel (active torque distribution, Torque Vectoring). Therefore special gear systems are necessary. In this document firstly the basics on gear systems (planetary gears) and vehicle dynamics are explained. Furthermore the state of the art is shown based on a classification of active differentials and the advantages and disadvantages are envinced. The next chapter describes a method for determining the mechanic load of the active differential for any car and road track. This is used for an evaluation of every differential gear system in view of efficiency, mechanic effort and control properties. The result reveals significant differences between the gear structures. Subsequent a method for a computer synthesis of new gear systems is developped and applied to the demands of a front driven vehicle application. The last chapter points out the positive effects of an active torque distribution on the driving dynamics. As a result of this work three new gear structures are shown which are much better than all existing gear systems in terms of the evaluation properties

Le mémoire traite de la machine à réluctance variable en proposant d'une manière simultanée et du point de vue conception des solutions à ses deux inconvénients majeurs à savoir les ondulations de couple et les efforts radiaux. Les premières se propagent le long de la chaine de transmission diminuant ainsi le confort des usagers et les deuxièmes sont à l’origine d’une nuisance sonore. Dans une première partie et en s’intéressant à une structure axiale caractérisée par une faible force radiale, un bilan sur cette structure est donc établi. En effet, une configuration à deux stators et un rotor est la plus adéquate pour éventuellement remplacer la machine radiale de référence. Cette structure axiale est comparée à cette machine de référence après avoir établi des règles de passage d’une structure à une autre. Un premier passage est effectué en gardant le même encombrement et un deuxième passage en dimensionnant la machine axiale pour satisfaire le même cahier des charges que la machine radiale. Dans une deuxième partie, le travail s’oriente vers la modification de la structure radiale de la machine de référence et son optimisation. Plusieurs modifications sont proposées dont une structure avec une cale magnétique qui est la plus performante. Des optimisations géométriques à l’aide de l’algorithme génétique sur un point de fonctionnement sont ensuite effectuées pour remédier aux deux problèmes. A la fin, un récapitulatif de plusieurs structures optimisées est proposé pour servir de référence. Le choix de la machine la plus adéquate pourra donc être effectué en faisant un compromis entre la maximisation du couple, la réduction de ses ondulations et la réduction des efforts radiaux<br>This report deals with switched reluctance motor by offering design solutions to the drawbacks of torque ripples and radial forces in the same time. Torque ripples reduce the user comfort and radial forces are the origin of noise. In the first part, an axial structure characterized by low radial force is analysed. Indeed, an axial configuration with two stators and one rotor is the most appropriate to replace the reference radial machine. Ones the rules of passage from one structure to another are established, the axial structure is then compared to the reference one. A first passage is made by keeping the same volume and a second one by sizing the axial machine with the same specifications as the radial one. In the second part, the work concerns the modification of radial structure of the reference machine and its optimization. Several modifications are proposed including a structure with a magnetic wedge which is the most efficient. Geometric optimization using genetic algorithm are then performed on operating points to remedy the both problems. In the end, several optimized structures are proposed. The choice of the most suitable machine can be done by making a compromise between the torque maximization, reducing its ripples and reducing radial forces

Moderne Kraftfahrzeuge werden mit einer Vielzahl von Fahrerassistenzsystemen ausgestattet um die Sicherheit, die Traktion, die Energieeffzienz, die Agilität und den Komfort noch weiter zu verbessern. Diese Ziele können zu einem Großteil mit einer aktiven Drehmomentverteilung, auch Torque Vectoring genannt, erreicht werden. Dafür sind jedoch Getriebesysteme erforderlich, welche unabhängig vom Fahrzustand und vom Antriebsmoment eine nahezu beliebige Drehmomentverteilung ermöglichen. In der vorliegenden Arbeit werden zunächst Grundlagen zu Getriebesystemen, insbesondere zu Planetengetrieben, und zur Fahrzeugdynamik erläutert. Anschließend wird der Stand der Technik anhand einer Systematik zur Einteilung von aktiven Differenzialgetrieben dargelegt sowie einige Vor- und Nachteile aufgezeigt. Das folgende Kapitel stellt ein Verfahren zur Ermittlung der mechanischen Belastung des aktiven Differenzialgetriebes für beliebige Fahrzeuge und Strecken vor. Damit erfolgt eine Bewertung der bisher bekannten Systeme hinsichtlich Gesamtwirkungsgrad, konstruktiver Aufwand und regelungstechnische Eigenschaften. Im Anschluss wird ein Verfahren zur rechnergestützten Synthese neuer Getriebesysteme beschrieben. Abschließend werden die positiven Auswirkungen der aktiven Drehmomentverteilung auf die Fahrdynamik herausgestellt. Das Ergebnis der Arbeit zeigt drei neue Getriebestrukturen, welche anhand der deffinierten Vergleichskriterien besser sind als alle bekannten Systeme.:1 Einleitung 2 Grundlagen 2.1 Getriebesysteme 2.2 Fahrdynamik 3 Stand der Technik 3.1 Getriebesysteme 3.2 Fahrdynamikregelung 4 Analyse bekannter Getriebesysteme 4.1 Zeitlicher Verlauf fahrdynamischer Größen 4.2 Systematische Analyse von Planetengetrieben 4.3 Deffinition der Vergleichskriterien 4.4 Differenziallose Systeme 4.5 Differenzialsysteme 4.6 Elektromotorische Systeme 4.7 Sonderbauformen 4.8 Vergleich bekannter Systeme 5 Synthese neuer Getriebestrukturen 5.1 Anforderungen an aktive Differenzialgetriebe 5.2 Manuelle Struktursynthese 5.3 Rechnergestützte Struktursynthese 5.4 Ergebnisse der Struktursynthese 6 Auswirkung von aktiver Drehmomentverteilung auf die Fahrdynamik 6.1 Komplexe Fahrdynamiksimulation 6.2 Steigerung der Traktion 6.3 Steigerung der Agilität 6.4 Steigerung der Fahrstabilität 6.5 Steigerung des Fahrkomforts 6.6 Verringerung des Kraftstoffverbrauches Zusammenfassung und Ausblick Literaturverzeichnis<br>Actual passenger cars are equipped with a lot of driver assistant systems to increase safety, traction, efficiency, agility and comfort. These aims can be achieved by a controlled transmission of the engine torque to each driven wheel (active torque distribution, Torque Vectoring). Therefore special gear systems are necessary. In this document firstly the basics on gear systems (planetary gears) and vehicle dynamics are explained. Furthermore the state of the art is shown based on a classification of active differentials and the advantages and disadvantages are envinced. The next chapter describes a method for determining the mechanic load of the active differential for any car and road track. This is used for an evaluation of every differential gear system in view of efficiency, mechanic effort and control properties. The result reveals significant differences between the gear structures. Subsequent a method for a computer synthesis of new gear systems is developped and applied to the demands of a front driven vehicle application. The last chapter points out the positive effects of an active torque distribution on the driving dynamics. As a result of this work three new gear structures are shown which are much better than all existing gear systems in terms of the evaluation properties.:1 Einleitung 2 Grundlagen 2.1 Getriebesysteme 2.2 Fahrdynamik 3 Stand der Technik 3.1 Getriebesysteme 3.2 Fahrdynamikregelung 4 Analyse bekannter Getriebesysteme 4.1 Zeitlicher Verlauf fahrdynamischer Größen 4.2 Systematische Analyse von Planetengetrieben 4.3 Deffinition der Vergleichskriterien 4.4 Differenziallose Systeme 4.5 Differenzialsysteme 4.6 Elektromotorische Systeme 4.7 Sonderbauformen 4.8 Vergleich bekannter Systeme 5 Synthese neuer Getriebestrukturen 5.1 Anforderungen an aktive Differenzialgetriebe 5.2 Manuelle Struktursynthese 5.3 Rechnergestützte Struktursynthese 5.4 Ergebnisse der Struktursynthese 6 Auswirkung von aktiver Drehmomentverteilung auf die Fahrdynamik 6.1 Komplexe Fahrdynamiksimulation 6.2 Steigerung der Traktion 6.3 Steigerung der Agilität 6.4 Steigerung der Fahrstabilität 6.5 Steigerung des Fahrkomforts 6.6 Verringerung des Kraftstoffverbrauches Zusammenfassung und Ausblick Literaturverzeichnis

Dans un contexte mondial régi par de multiples facteurs économiques, énergétiques et environnementaux, la transition vers des modes de transport à zéro émission polluante semble inévitable. De ce fait, les constructeurs automobiles s’investissent de plus en plus dans le développement de groupes motopropulseurs électriques afin d’anticiper les besoins du marché. Parmi les différentes technologies de machines électriques considérées pour cette application, la Machine à Réluctance Variable à Double Saillance (MRVDS) présente des caractéristiques très attractives pour le milieu industriel.Les travaux présentés dans cette thèse visent à élaborer des solutions qui répondent aux points qui bloquent encore l’adoption de la MRVDS dans les véhicules électriques. Dans un premier temps, la commande en couple d’une MRVDS destinée à la traction électrique est analysée. En prenant en considération les exigences imposées par l’application envisagée, une stratégie de commande en couple est développée en intégrant deux méthodes complémentaires sur le plan de fonctionnement de la MRVDS choisie.Dans la deuxième partie, l’asservissement en courant est abordé. Les problématiques du contrôle propres à la MRVDS à forte dynamique de courant sont d’abord identifiées. Ensuite, deux régulateurs de courant, qui répondent à différents conditions d’implantation, sont présentés et validés par simulation.La dernière partie de cette thèse aborde le problème des à-coups d’accélération induits à basse vitesse et de leurs répercussions sur l'agrément de conduite. En effet, ce type de motorisation électrique introduit un nouvel aspect sur cette problématique. Une loi de commande anti-à-coups, composée de deux actions, est développée. Les simulations ont montré la conformité de la performance obtenue en utilisant la loi de commande proposée avec le cahier des charges industriel visé<br>In a global context governed by multiple economic, energetic and environmental factors, the transition towards transportation modes with zero polluting emissions seems inevitable. Hence, automotive manufacturers are investing increasingly in the development of electric powertrains in anticipation of the market needs. Among the different electric motors technologies considered for this application, the switched reluctance motor (SRM) presents attractive characteristics for the industry.The work presented in this thesis aims to elaborate solutions in response to the points still hindering the adoption of the SRM in electric vehicles. First, torque regulation of an SRM intended for an electric traction is analyzed. Taking into consideration the requirements of the application in hand, a regulation strategy is developed through the integration of two methods which complement each other over the studied SRM range of operation.In the second part, the subject of current regulation in the SRM is discussed. The issues related to current regulation in SRMs disposing of high current dynamics are firstly identified. Then, two current regulators, each adapted to different implementation conditions, are presented and validated through simulations.The last part of this thesis discusses the acceleration jerks induced at very low speeds and their repercussions on driving comfort . Indeed, electric traction introduces a new aspect on this rather classic issue. An anti-jerk control law, composed of two control actions, is developed. Simulations have shown the conformity of the performance obtained with the proposed control law with the target industrial specifications

The main goal of the work is development of the electric car with fuel cells. The whole complex drive will be optimized with respect of minimal consumption of the energy due to achievement of the maximal range of the car. The first part of the work deals with definition of the parameters of the whole drive in dependence of various operating state of the car. The second part describes some acceptable realizations of the traction drive. The most suitable solution was chosen for realization of the small electric car. The third part deals with principle of the minimization of the losses of the asynchronous machine in the wide range of torque and speed. The last part describes final conception and especially technical realization of the car and its parts.

Traction efficiency of tractors barely reaches 50 % in field operations. On the other hand, modern trends in agriculture show growth of the global tractor markets and at the same time increased demands for greenhouse gas emission reduction as well as energy efficiency due to increasing fuel costs. Engine power of farm tractors is growing at 1.8 kW per year reaching today about 500 kW for the highest traction class machines. The problem of effective use of energy has become crucial. Existing slip control approaches for tractors do not fulfil this requirement due to fixed reference set-point. The present work suggests an optimal control scheme based on set-point optimization and on assessment of soil conditions, namely, wheel-ground parameter identification using fuzzy-logic-assisted adaptive unscented Kalman filter.

Our society is heavily and intrinsically dependent on energy transformation and usage. In a world scenario where resources are being depleted while their demand is increasing, it is crucial to optimize every process. During the last decade the concept of energy efficiency has become a leitmotif in several fields and has directly influenced our everyday life: from light bulbs to airplane turbines, there has been a general shift from pure performance to better efficiency. In this vein, we focus on the mobility and tractive efficiency of off-road vehicles. These vehicles are adopted in military, agriculture, construction, exploration, recreation, and mining applications and are intended to operate on soft, deformable terrain. The performance of off-road vehicles is deeply influenced by the tire-soil interaction mechanism. Soft soil can drastically reduce the traction performance of tires up to the point of making motion impossible. In this study, a tire model able to predict the performance of rigid wheels and flexible tires is developed. The model follows a semi-empirical approach for steady-state conditions and predicts basic features, such as the drawbar pull, the driving torque and the lateral force, as well as complex behaviors, such as the slip-sinkage phenomenon and the multi-pass effect. The tractive efficiency of different tire-soil configurations is simulated and discussed. To investigate the handling and the traction efficiency, the tire model is implemented into a four-wheel vehicle model. Several tire geometries, vehicle configurations (FWD, RWD, AWD), soil types, and terrain profiles are considered to evaluate the performance under different simulation scenarios. The simulation environment represents an effective tool to realistically analyze the impact of tire parameters (size, inflation pressure) and torque distribution on the energy efficiency. It is verified that larger tires and decreased inflation pressure generally provide better traction and energy efficiency (under steady-state working conditions). The torque distribution strategy between the axles deeply affects the traction and the efficiency: the two variables canâ t clearly be maximized at the same time and a trade-off has to be found.<br>Ph. D.

Na hora de investir na compra de um novo trator o empresário do agronegócio se coloca diante da difícil missão de fazer uma escolha racional entre os diversos modelos comercias dos diferentes fabricantes e das suas reais necessidades. O objetivo principal deste trabalho foi desenvolver um ferramental que permita obter informações para a comparação teórica entre as demandas de torque e potência exigidas em trabalho de campo de um trator e os resultados de testes convencionais realizados em bancadas dinamométricas.Para tanto, foram realizados ensaios em tratores comerciais de variadas marcas e modelos sob condições de laboratório com um banco dinamométrico acoplado a tomada de força, seguindo a norma OECD “Code 2” - Standard Code for the Official Testing of Agricultural Tractors. Nestes testes determinou-se, entre outras características, o consumo específico de combustível nas diversas situações solicitadas pela norma. No campo foram executados sucessivos conjuntos de ensaios registrando níveis de torque e rotação do motor, necessários para caracterizar o perfil de desempenho na realização de diferentes atividades de um trator agrícola.O mesmo aparato adotado para as medições de laboratório foi utilizado nas medições em campo, com exceção da medida de consumo de combustível, da rotação do motor e do torque demandado, sendo que para este último fez-ae uso de um sistema digital de telemetria. Foram realizados estudos estatísticos para investigar as incertezas das medições associadas ao conjunto de sensores, transdutores e sistema de aquisição de dados usados nos testes.Os resultados alcançados nos diversos testes de laboratório formaram um banco de dados contendo as respectivas informações técnicas que seram disponibilizados em uma página da Internet. A análise estatística destes dados permitiu estabelecer limites para validar o sistema de medição desenvolvido e a comparação entre resultados de campo e de laboratório. Seguindo esta metodologia pode-se tomar uma decisão racional entre os diferentes modelos de trator agrícola.<br>While investing a new tractor that can live up to their demands, the agrobusiness entrepreneur encounters the difficult task of making a rational choice between different models from different manufacturers. The aim of this work is to develop a tool that provides information for the theoretical comparison between demands of torque and power in a tractor field work, as well as the results of conventional dynamometer tests. Tests were performed in laboratory, with commercial tractors of varied marks and models, with a dynamometric bench connected to power take-off according to “Code 2” - Standard Code for the Official Testing of Agricultural Tractors. These tests determine, among others characteristics, the specific fuel consumption in the different situations required by standard. In the field, a successive sets of tests are executed registering levels of torque and engine rotation, which are necessary to characterize a performance profile in the accomplishment of different activities performed by an agricultural tractor.The same apparatus of measurement adopted for laboratory tests was used for field tests, with the exception of fuel consumption measurement, engine rotation and demanded torque. The latter makes use of a digital telemetry system. Statistical studies were carried to investigate the uncertainties of the measurements associated with the set of sensors, transducers and data acquisition system used in the tests.The results achieved in the different laboratory tests form a database of technical information.The statistical analysis of the data allowed the establishment of limits to validate the developed measurement system; and the comparison between laboratory and field results. Following this methodology can assist in a rational decision making among the different models of agricultural tractor.

Afin de définir une conception optimale d'un système électromécanique, celui-ci doit intégrer des contraintes toujours plus drastiques et de nombreux phénomènes physiques issus de : l'électromagnétique, l'aérothermique, l'électronique, la mécanique et l'acoustique. L'originalité de cette thèse est de proposer une modélisation multi-physique pour la conception reposant sur des modèles à constantes localisées : solution intermédiaire entre la modélisation analytique et numérique. Ces différents modèles permettront l'étude et la conception sous contraintes d'une machine synchrone à aimants permanents dédiée pour la traction ferroviaire. Les résultats de simulations seront comparés à des résultats éléments finis mais aussi à des essais expérimentaux. Ce modèle multi-physique est entièrement paramétré afin d'être associé à des outils d'optimisation. On utilisera ici une optimisation par essaim de particules pour chercher des compromis entre différents objectifs sous forme de Front de Pareto. Dans ce papier, nous ciblerons les objectifs suivants : le couple d'origine électromagnétique et le bruit d'origine électromagnétique. Finalement une étude de sensibilité valide la robustesse de la conception retenue quand celle-ci est soumise aux contraintes de fabrication. L'objectif étant de poser les bases d'un outil d'aide à la décision pour le choix d'une machine électrique

碩士<br>國立臺北科技大學<br>車輛工程系所<br>96<br>The motor parameters of the electric scooter might change under different operating conditions. In this research, adaptive control is applied for the electric scooter to improve the performance of the traction torque control. First, a dynamic simulation model is established in Matlab/Simulink, which consists of driver model, motor dynamics, tire dynamics, and longitudinal dynamics. Recursive least square approach of system identification is used to identify the parameters of the electric motor with pulse width modulation dynamics. The identified parameters are then utilized to design an adaptive PI controller for traction torque control of the wheel motor. The dynamic simulation model is used to evaluate the performance of the proposed algorithm. Finally, an experimental platform is established in this research to verify the proposed algorithm. A driving circuit is designed for the wheel motor. Preliminary simulation and experimental results show that the traction torque error of the proposed algorithm is smaller than that of the conventional PI controller under various operating conditions.

"Braking and traction torques are not explicitly considered in most of the wagon dynamics simulation packages, as their primary focus is to provide a platform for long distance route simulations with near real-time scenarios which demands fast solution algorithms. These packages consider the braking scenarios through the definition of speed profile as a priori. It is commonly acknowledged that the speed profile is affected by tribological and geometric parameters at the wheel-rail interface as well as the characteristics of brake application. Hence it’s prudent to evaluate the speed profile based on input torque due to traction/ brake forces; this research has considered such an approach and developed the program that can simulate the longitudinal behaviour of railway wagon dynamics during braking and traction. Consequently, this program enables to simulate wheelset locking and wagon yaw, roll, pitch in a natural way."--Abstract.

"The limitations of current simulation packages in addressing the true longitudinal behaviour of railway bogie dynamics during braking/traction has prompted the development of a Rail Bogie Dynamics (RBD) program in this thesis. The RBD program offers novel features for the calculation of the speed profile as a function of the brake torque as well as explicitly determining wheelset angular velocity. With such capability, the speed profile is no longer treated as an input calculated as a priori as required by most of the current simulation systems. The RBD program has been developed using a formulation that includes the wheelset pitch degree of freedom explicitly with a coordinate reference system that is fixed in space and time. The formulation has made the simulation of the bogie dynamics during braking/traction possible in a natural way using the brake/traction torque as the input and the resulting speed profile as the output without any need for working out the speed profile as a priori. Consequently, severe dynamics during braking such as the wheelset skid and the onset of wheel climb derailment can be modelled and critical parameters investigated using the RBD program. The RBD program has been validated, where possible, through a series of simulations using a commercial software package (VAMPIRE). For cases which cannot be simulated by VAMPIRE such as the wheelset skid, a novel experimental program has been designed and commissioned in the Heavy Testing Laboratory of the Central Queensland University as reported in this thesis. One of the possible applications of the RBD program in examining the effect of asymmetric brake shoe force in bogies equipped with one-side push brake shoe arrangement is illustrated in this thesis. It is believed that the model and RBD program will have significant benefit in understanding the true longitudinal behaviour of wagons in suburban passenger trains that operate under braking/ traction torques for most of their travel. Similar studies will also be useful to freight train wagon dynamics during entry and exit of speed restriction zones and tight curves." -- abstract.

碩士<br>國立臺灣大學<br>機械工程研究所<br>81<br>Bearing traction torque is an important factor to a precision po sitioning system. The performance of precision controllers may be greatly improved if the bearing traction torque can be accurately estimated. In the conventional PID controllers, integrator are us ed to eliminate small steady state errors; however, they may creat e small stick-slip oscillations on the controller outputs if bear ing traction torque are presented. To improve the controller accuracy, one can either compute the be aring traction torque precisely or use a special control methodology. In this thesis, the boundary lubrication and partial thesis, the boundary lubrication and partial lubrication friction models are discussed to gain the knowledge on friction models. The full lubrication model was excluded because the angular velocity of the problem we are considering is too small to use th is model. The result shows that only boundary lubrication model is applied when stick-slip problems are considered. A new controller algorithm is also proposed in this thesis. It is named ``kick-and-go''controller. This controller tries to estimate the bearing traction torque at the current position, and send a up and down torque pulse to the output of the motor. This ``kicks'' the motor into a higher precision location. An adaptive scheme is also proposed once the traction torque estimation needs to be modified.

碩士<br>國立臺灣大學<br>機械工程學研究所<br>99<br>The purpose of this paper is to establish and to investigate a Vehicle Dynamic Control Strategy for an independent four-wheel driven electric vehicle. This strategy achieved those functions of Traction Control System (TCS), Anti-Slip Braking Control (ASBC), Active Yaw Control (AYC), and regenerative brake by integrating traction torque control, braking force control, and four-wheel torque distribution. In recent years, many research organizations and car manufacturer started electric vehicle (EV) development due to oil crisis and global warming problems. Compared to Internal Combustion Engine Vehicles (ICEV), EVs can not only reduce petroleum usage and greenhouse gas emission, but also have great potential in two aspects. First, electric power systems can recover vehicle kinetic energy during braking, which is beneficial to extend range and reduce wear of mechanical brake unit. Second, electric power systems have faster and more precise response than gasoline engine systems. Electric power systems are also capable to be arranged as independent four-wheel drive, which has high degrees of freedom for vehicle dynamic control. In this study we make use of those advantages mentioned above, and integrated TCS, ASBC, AYC, regenerative brake controller in Vehicle Control Unit (VCU) software, which formed a complete vehicle dynamic control system. Then, an independent four-wheel driven EV dynamic model is built up using MATLAB/Simulink and CarSim. This model is use to test and verify controller performance in simulation.

Independent-drive electric vehicles represent an advanced approach to vehicle dynamic control. The main feature of these systems is that they use traction motors that are independently connected to each wheel. This results in a shorter driveline, higher transmission efficiency, more compact packaging, and better utilisation of space. Combined with the torque information produced by electric traction motors, an independent-drive electric vehicle system is capable of performing traction control, antilock braking control and electronic power steering. Traction control is also an effective strategy to control longitudinal vehicle dynamics that functions by preventing the wheels from slipping while driving. It has potential for optimising vehicle dynamics during frequent acceleration and takeoff. Since the late 1990s, there have been several studies regarding traction control for fully electric motor drive vehicles. These studies have investigated traction control systems based on fuzzy methods, rule-based control, slidingmode control, Proportional–Integral–Derivative control and modification, optimal linearisation control and model-based control. A further distinction can be made between torque-based control, slip-based control and systems that combine both. Nevertheless, most of the existing studies of torque-based traction control have been investigated only in simulation. Further, since 2012, only four studies have focused on designing an electric motor controller with an embedded traction control algorithm. The aim of this project is to understand and develop a traction control system that can be used for the future University of Tasmania Formula SAE electric racing vehicle. Following the guidelines of the Formula SAE rules, the vehicle will be an 80 kW, 600 V peak, rear-wheel drive, open-wheel formula race vehicle.

Traction efficiency of tractors barely reaches 50 % in field operations. On the other hand, modern trends in agriculture show growth of the global tractor markets and at the same time increased demands for greenhouse gas emission reduction as well as energy efficiency due to increasing fuel costs. Engine power of farm tractors is growing at 1.8 kW per year reaching today about 500 kW for the highest traction class machines. The problem of effective use of energy has become crucial. Existing slip control approaches for tractors do not fulfil this requirement due to fixed reference set-point. The present work suggests an optimal control scheme based on set-point optimization and on assessment of soil conditions, namely, wheel-ground parameter identification using fuzzy-logic-assisted adaptive unscented Kalman filter.:List of figures VIII List of tables IX Keywords XI List of abbreviations XII List of mathematical symbols XIII Indices XV 1 Introduction 1 1.1 Problem description and challenges 1 1.1.1 Development of agricultural industry 1 1.1.2 Power flows and energy efficiency of a farm tractor 2 1.2 Motivation 9 1.3 Purpose and approach 12 1.3.1 Purpose and goals 12 1.3.2 Brief description of methodology 14 1.3.2.1 Drive torque feedback 14 1.3.2.2 Measurement signals 15 1.3.2.3 Identification of traction parameters 15 1.3.2.4 Definition of optimal slip 15 1.4 Outline 16 2 State of the art in traction management and parameter estimation 17 2.1 Slip control for farm tractors 17 2.2 Acquisition of drive torque feedback 23 2.3 Tire-ground parameter estimation 25 2.3.1 Kalman filter 25 2.3.2 Extended Kalman filter 27 2.3.3 Unscented Kalman filter 27 2.3.4 Adaptation algorithms for Kalman filter 29 3 Modelling vehicle dynamics for traction control 31 3.1 Tire-soil interaction 31 3.1.1 Forces in wheel-ground contact 32 3.1.1.1 Vertical force 32 3.1.1.2 Tire-ground surface geometry 34 3.1.2 Longitudinal force 36 3.1.3 Zero-slip condition 37 3.1.3.1 Soil shear stress 38 3.1.3.2 Rolling resistance 39 3.2 Vehicle body and wheels 40 3.2.1 Short description of Multi-Body-Simulation 40 3.2.2 Vehicle body and wheel models 42 3.2.3 Wheel structure 43 3.3 Stochastic input signals 45 3.3.1 Influence of trend and low-frequency components 47 3.3.2 Modelling stochastic signals 49 3.4 Further components and general view of tractor model 53 3.4.1 Generator, intermediate circuit, electrical motors and braking resistor 53 3.4.2 Diesel engine 55 4 Identification of traction parameters 56 4.1 Description of identification approaches 56 4.2 Vehicle model 58 4.2.1 Vehicle longitudinal dynamics 58 4.2.2 Wheel rotational dynamics 59 4.2.3 Tire dynamic rolling radius and inner rolling resistance coefficient 60 4.2.4 Whole model 61 4.3 Static methods of parameter identification 63 4.4 Adaptation mechanism of the unscented Kalman filter 63 4.5 Fuzzy supervisor for the adaptive unscented Kalman filter 66 4.5.1 Structure of the fuzzy supervisor 67 4.5.2 Stability analysis of the adaptive unscented Kalman filter with the fuzzy supervisor 69 5 Optimal slip control 73 5.1 Approaches for slip control by means of traction control system 73 5.1.1 Feedback compensation law 73 5.1.2 Sliding mode control 74 5.1.3 Funnel control 77 5.1.4 Lyapunov-Candidate-Function-based control, other approaches and choice of algorithm 78 5.2 General description of optimal slip control algorithm 79 5.3 Estimation of traction force characteristic curves 82 5.4 Optimal slip set-point computation 85 6 Verification of identification and optimal slip control systems 91 6.1 Simulation results 91 6.1.1 Identification of traction parameters 91 6.1.1.1 Comparison of extended Kalman filter and unscented Kalman filter 92 6.1.1.2 Comparison of ordinary and adaptive unscented Kalman filters 96 6.1.1.3 Comparison of the adaptive unscented Kalman filter with the fuzzy supervisor and static methods 99 6.1.1.4 Description of soil conditions 100 6.1.1.5 Identification of traction parameters under changing soil conditions 101 6.1.2 Approximation of characteristic curves 102 6.1.3 Slip control with reference of 10% 103 6.1.4 Comparison of operating with fixed and optimal slip reference 104 6.2 Experimental verification 108 6.2.1 Setup and description of the experiments 108 6.2.2 Virtual slip control without load machine 109 6.2.3 Virtual slip control with load machine 113 7 Summary, conclusions and future challenges 122 7.1 Summary of results and discussion 122 7.2 Contributions of the dissertation 123 7.3 Future challenges 123 Bibliography 125 A Measurement systems 137 A.1 Measurement of vehicle velocity 137 A.2 Measurement of wheel speed 138 A.3 Measurement or estimation of wheel vertical load 139 A.4 Measurement of draft force 140 A.5 Further possible measurement systems 141 B Basic probability theoretical notions 142 B.1 Brief description of the theory of stochastic processes 142 B.2 Properties of stochastic signals 144 B.3 Bayesian filtering 145 C Modelling stochastic draft force and field microprofile 147 D Approximation of kappa-curves 152 E Simulation parameters 156