Im Rahmen der geometrisch und physikalisch nichtlinearen Kontinuumsmechanik werden Beobachterkonzepte und Darstellungsformen tensorieller Größen diskutiert und zum Teil neu eingeführt, die insbesondere die Modellierung und FEM-Implementierung komplizierter Modelle für inelastisches Materialverhalten bei großen Deformationen wirkungsvoll unterstützen. / Observer concepts and several kinds of representations of tensorial quantities are discussed and partly introduced within the framework of geometrically und physically nonlinear continuum mechanics. They are intended to support the modelling of complicated inelastic materials undergoing large deformations.

Efficient energy use is primarily for any sensor networks to function for a longer time period. There have been many efficient schemes with various progress levels proposed by many researchers. Yet, there still more improvements are needed. This thesis is an attempt to make wireless sensor networks with further efficient on energy usage in the network with respect to rate of delivery of the messages. In sensor network architecture radio, sensing and actuators have influence over the power consumption in the entire network. While listening as well as transmitting, energy is consumed by the radio. However, if by reducing listening times or by reducing the number of messages transmitting would reduce the energy consumption. But, in real time scenario with critical information sensing network leads to information loss. To overcome this an adaptive routing technique should be considered. So, that it focuses on saving energy in a much more sophisticated way without reducing the performance of the sensing network transmitting and receiving functionalities. This thesis tackles on parts of the energy efficiency problem in a wireless sensor network and improving delivery rate of messages. To achieve this a routing technique is proposed. In this method, switching between two routing paths are considered and the switching decision taken by the server based on messages delivered comparative previous time intervals. The goal is to get maximum network life time without degrading the number of messages at the server. In this work some conventional routing methods are considered for implementing an approach. This approach is by implementing a shortest path, Gradient based energy routing algorithm and an observer component to control switching between paths. Further, controlled switching done by observer compared to normal initial switch rule. Evaluations are done in a simulation environment and results show improvement in network lifetime in a much more balanced way.

This master thesis addresses the control of electric propulsion motors in a marine context. The focus lies mainly on the implementation of field oriented control (FOC) in a field programmable gate array (FPGA). The hypothesis is that FPGAs provide performance advantages over microcontroller-based control solutions by enabling parallel processing. Zparq AB, a startup specializing in electric marine propulsion, serves as the industry partner for this project. They develop sustainable alternatives to traditional fossil fuel powered propulsion, and the aim is to develop every included part of their electric propulsion systems inhouse. That makes the development of an FPGA-based motor control solution relevant to their goal. The research question focuses on how multiple marine propulsion motors can be controlled from a single FPGA. To answer this, the study investigates relevant engineering aspects such as reference frame transformations, motor control strategies, pulse width modulation (PWM) methods and technological aspects of modern FPGA architectures. For developing the motor controller, a Digilent Arty Z7-20 FPGA board is used. In the design process, all included functions are written as code in a hardware description language (HDL). This approach aims at maintaining complete insight in all details of the solution. Two variants of conventional FOC are developed; one with position feedback from an encoder and one sensorless. The developed motor controller is tested by controlling a brushless direct current (BLDC) motor, and the results prove the functionality of the encoder-based variant. They also show a latency of less than 15 microseconds and indicate the feasibility of the chosen approach. The modularity of the FPGA is demonstrated by successfully controlling two motors, using two copies of the developed solution in a single FPGA. A discussion on combining FPGA-based controllers with wide bandgap (WBG) semiconductors is also included, where the main discussed advantage is high switching frequency. In conclusion, the results and insights from the project contribute to future development of FPGA-based motor control solutions, both within Zparq and the research field. The insights regarding the specific chosen approach for the FPGA development can also be useful for similar projects. / Detta masterarbete behandlar styrning av elektriska motorer i ett marint kontext. Fokus ligger huvudsakligen på implementeringen av fältorienterad styrning (FOC) i en ifält-programmerbar grindmatris (FPGA). Hypotesen är att FPGAer erbjuder prestandafördelar jämfört med mikrokontroller-baserade styrlösningar, genom att möjliggöra parallella beräkningsprocesser. Zparq AB, ett startup som specialiserar sig på elektriska marina drivsystem, är industripartner för detta projekt. De utvecklar hållbara alternativ till traditionell fossildriven framdrift och målet är att på egen hand utveckla alla ingående delar i deras elektriska drivsystem. Det gör att utvecklingen av en FPGA-baserad lösning för motorstyrning är relevant inom ramen för deras mål. Forskningsfrågan fokuserar på hur ett flertal motorer för marin framdrift kan styras från en enda FPGA. För att svara på detta undersöks relevanta tekniska aspekter såsom koordinattransformationer, motorstyrningsstrategier, metoder för pulsbreddsmodulering (PWM) samt teknologiska aspekter av moderna FPGA-arkitekturer. För utvecklingen av motorstyrningen används ett Digilent Arty Z7-20 FPGA-kort. I designprocessen formuleras alla inkluderade funktioner som kod i ett hårdvarubeskrivande språk (HDL). Detta tillvägagångssätt syftar till att ha god insyn i hela lösningen, ner på detaljnivå. Två varianter av konventionell FOC utvecklas; en med positionsfeedback från vinkelgivare och en sensorlös. Den utvecklade motorstyrningen testas genom att driva en borstlös likströmsmotor (BLDC) och resultaten visar på den vinkelgivarbaserade variantens funktionalitet. De visar även att fördröjningen är under 15 mikrosekunder, samt på genomförbarheten av det valda tillvägagångssättet. Modulariteten i FPGAn demonstreras genom att framgångsrikt styra två motorer med hjälp av två kopior av den utvecklade lösningen i en och samma FPGA. En diskussion kring att kombinera FPGA-baserad styrning och halvledare med brett bandgap (WBG) är också inkluderad, där den huvudsakliga fördelen som diskuteras är hög switchfrekvens.svis bidrar resultaten och insikterna från projektet till framtida utveckling av FPGA-baserade lösningar för motorstyrning, både inom Zparq och övriga forskningsfältet. Insikterna från det specifika valda tillvägagångssättet för FPGA-utvecklingen kan även de vara användbara i liknande projekt.

Energy efficiency in electric machines is both environmentally and economically important. Water pumps with an integrated Variable Frequency Drive (VFD) and a Permanent Magnet Synchronous Machine (PMSM) have challenged the status quo of the Induction Machine (IM) for water pumps. The Synchronous Reluctance Machine (SynRM) is also a viable alternative that does not use permanent magnets. This degree project focuses on the control of SynRM, with particular attention on sensorless control methods. Simulation models for a SynRM and a Surface Permanent Magnet Synchronous Machine (SPMSM), together with their control systems, were developed in MATLAB Simulink. Two sensorless control methods were implemented and examined: the Luenberger state observer and the Model Reference Adaptive System (MRAS). The control system was adapted to use sensorless control methods. The investigated sensorless control methods allowed the application of the speed-torque test profile for two method and motor type combinations, without causing instability. The Luenberger observer was stable with the SPMSM and the MRAS with the SynRM. Parameter sensitivity with respect to the variation of inductance and stator resistance values used by the sensorless methods was also tested. The Luenberger observer kept the control system stable with up to a ±5 % variation of inductance. The MRAS kept the control system stable down to −12 %, but only up to +2 % for an overestimation of the inductance. The variation of stator resistance had a limited impact on the stability of both sensorless schemes. / Energieffektivisering av elektriska maskiner är betydelsefullt både ur ett miljömässigt och ekonomiskt perspektiv. Vattenpumpar med en synkron permanentmagnetsmaskin och en integrerad enhet för variabel hastighetsreglering (VFD) utmanar den mer konventionella lösningen baserad på en asynkronmaskin (IM). Den synkrona reluktansmaskinen (SynRM) är ett annat lämpligt alternativ som inte använder permanentmagneter. Det här examensarbetet behandlar huvudsakligen sensorlös reglering av SynRM. Simuleringsmodeller för reglering av en SynRM och en permanentmagnetiserad synkronmaskin med ytmonterade magneter (SPMSM) utvecklades i MATLAB Simulink. Två metoder för sensorlös reglering undersöktes, en på Luenbergers tillståndsobservatör och en baserad på adaptiv modellreferensreglering (MRAS). Systemet för reglering anpassades till metoderna för sensorlös reglering. De undersökta sensorlösa metoderna testades vid nominell hastighet med steg i vridmoment och hastighet. Luenberger observatören kunde köras med bibehållen stabilitet med en SPMSM och MRAS kördes med en SynRM, också den med bibehållen stabilitet. Även känsligheten för variationer i induktans och statorresistans för de sensorlösa reglermetoderna testades. Luenberger observatören kunde bibehålla stabiliteten med en variation i induktans på ±5 %. MRAS kunde bibehålla stabiliteten ner till en estimering av induktansen på −12 % av induktansen. På uppsidan nådde dock MRAS stabilitet endast upp till en överestimering av induktansen på 2 %. Felestimering av statorresistansen hade minimal påverkan på stabiliteten för båda sensorlösa reglermetoderna.

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L'objectif de cette thèse est de proposer l'approche la plus appropriée afin de minimiser le coût d'intégration de petite éolienne dans un micro-réseau DC urbain. Une petit éolienne basé sur un machine synchrone à aimant permanent (MSAP) est considéré à étudier. Un état de l'art concernant les énergies renouvelables, micro-réseau DC, et la production d'énergie éolienne, est fait. Comme le capteur mécanique de cette structure est relativement d'un coût élevé, les différents types de contrôle pour un système de conversion éolienne sont présentés afin de choisir une structure active de conversion d'énergie et un MSAP sans capteur. Par conséquent, un estimateur de vitesse/position est nécessaire pour contrôler le système. Ainsi, les méthodes différentes proposées dans la littérature sont considérées et classifiées à étudier dans les détails, puis les plus efficaces et largement utilisés sont à vérifier dans la simulation et expérimentalement pour le système étudié. Les méthodes choisies sont: estimation de la flux de rotor avec boucle à verrouillage de phase (PLL), observateur à mode glissement (SMO), observateur de Luenberger d'ordre réduit, et filtre de Kalman étendu (EKF). Face à d'autres méthodes, l'estimateur basé sur un modèle EKF permet une commande sans capteur dans une large plage de vitesse et estime la vitesse de rotation avec une réponse rapide. Le réglage des paramètres EKF est le problème principal à sa mise en œuvre. Par conséquent, pour résoudre ce problème, la thèse présente une méthode adaptative, à savoir réglage-adaptatif d’EKF. En conséquence, et grâce à cette approche, le coût total du système de conversion est réduite et la performance est garantie et optimisée. / The aim of this thesis is to propose the most appropriate approach in order to minimize the cost of integration of a wind generator into a DC urban microgrid. A small-scale wind generator based on a permanent magnet synchronous machine (PMSM) is considered to be studied. A state of the art concerning the renewable energies, DC microgrid, and wind power generation is done. As the mechanical sensor for this structure is relatively of high cost, various types of wind conversion system control are presented in order to choose an energy conversion active structure and a sensorless PMSM. Therefore, a speed/position estimator is required to control the system. Thus, different methods proposed in literatures are considered and classified to be studied in details, and then the most effective and widely used ones are to be verified in simulation and experimentally for the studied system. The methods which are chosen are: rotor flux estimation with phase locked loop (PLL), sliding mode observer (SMO), Luenberger observer of reduced order, and extended Kalman filter (EKF). Facing to other methods, the EKF model-based estimator allows sensorless drive control in a wide speed range and estimates the rotation speed with a rapid response. The EKF parameters tuning is the main problem to its implementation. Hence, to solve this problem, the thesis introduces an adaptive method, i.e. adaptive-tuning EKF. As a result and grace to this approach, the total cost of conversion system is reduced and the performance is guaranteed and optimized.

With the maturation of the child custody investigative process, the role of investigators and the process of these investigations have come under increasing scrutiny. The investigators are expected to be objective, neutral, and professional while following procedures that conform to model standards. However, this assumption of a lack of bias has been largely overlooked in the literature regarding the investigative process. It is assumed that investigators should self-monitor to ensure that their stance is objective and neutral. Furthermore, this position of neutrality and objectivity is assumed to be intuitive and natural. By using a case study, this thesis investigates and describes the process of a child custody investigation predicated on a constructivist epistemology. It highlights the impossibility of any investigator to be objective and neutral in any investigation automatically, regardless of the procedures and methods employed. The thesis highlights the participant observer status of investigators. An aim of the thesis is thus to sensitise investigators to this inevitable vulnerability with the expectation that such an awareness may allow investigators to establish processes to render investigations consciously more balanced, considered, and transparent. A further aim is to describe a child custody evaluation from an eco-systemic perspective by contextualising the investigation in the larger ecosystem to which it belongs. This description includes the investigation as part of an evolving problem-determined system. An awareness of this wider and evolving context may enable investigators to approximate a position of objectivity and neutrality more effectively. It may also act as an inoculation against the ‘contamination’ of the investigator by the investigative system. With the maturation of the child custody investigative process, the role of investigators and the process of these investigations have come under increasing scrutiny. The investigators are expected to be objective, neutral, and professional while following procedures that conform to model standards. However, this assumption of a lack of bias has been largely overlooked in the literature regarding the investigative process. It is assumed that investigators should self-monitor to ensure that their stance is objective and neutral. Furthermore, this position of neutrality and objectivity is assumed to be intuitive and natural. By using a case study, this thesis investigates and describes the process of a child custody investigation predicated on a constructivist epistemology. It highlights the impossibility of any investigator to be objective and neutral in any investigation automatically, regardless of the procedures and methods employed. The thesis highlights the participant observer status of investigators. An aim of the thesis is thus to sensitise investigators to this inevitable vulnerability with the expectation that such an awareness may allow investigators to establish processes to render investigations consciously more balanced, considered, and transparent. A further aim is to describe a child custody evaluation from an eco-systemic perspective by contextualising the investigation in the larger ecosystem to which it belongs. This description includes the investigation as part of an evolving problem-determined system. An awareness of this wider and evolving context may enable investigators to approximate a position of objectivity and neutrality more effectively. It may also act as an inoculation against the ‘contamination’ of the investigator by the investigative system. xviii In South Africa, we have yet to formulate a document that establishes a model standard of practice or specific, dedicated training in this area. This thesis identifies what could be included in both areas (in addition to the expected protocols and procedures) by describing the investigator’s position as an expert learner, rather than just an ‘expert’. In line with current literature, it highlights the benefits of thinking consciously and in a considered manner. Furthermore, it indicates the benefits of a team approach to investigations, which could be considered an area for further investigation. In South Africa, we have yet to formulate a document that establishes a model standard of practice or specific, dedicated training in this area. This thesis identifies what could be included in both areas (in addition to the expected protocols and procedures) by describing the investigator’s position as an expert learner, rather than just an ‘expert’. In line with current literature, it highlights the benefits of thinking consciously and in a considered manner. Furthermore, it indicates the benefits of a team approach to investigations, which could be considered an area for further investigation. / Psychology / D. Litt. et Phil. ( Psychology)

Cette thèse s'inscrit dans le cadre du projet Compacité qui vise à développer un compresseur électrique pour véhicules électriques à l’aide d’une démarche mécatronique. Dans cette thématique, le rôle du LGEP est de développer la partie électromécanique du compresseur. Cette thèse est constituée de deux parties, la première concerne la conception d’un moteur pour le compresseur et la deuxième a trait à la commande sans capteur mécanique de ce moteur. La première partie de la thèse est d'abord consacrée au dimensionnement d'une machine électrique pour un compresseur électrique. Le cahier des charges impose une machine compacte (97mm de diamètre et une profondeur inférieure à 50mm) et ayant une puissance massique élevée (6kW pour une masse de 1.8kg). Au préalable, un modèle analytique a été développé pour effectuer un dimensionnement rapide. Par la suite, la méthode des éléments finis a été appliquée à différents modèles physiques (magnétique, thermique, mécanique (résistance des matériaux et vibration)) pour une étude approfondie de la structure choisie. A l'issue de ces études, un prototype et un banc expérimental ont été réalisés. Dans un second temps, des algorithmes de commande avec ou sans capteur mécanique ont été étudiés pour le pilotage du moteur. La particularité de cette deuxième partie de thèse est la réalisation d'une commande peu gourmande en temps de calcul et implantable dans des microcontrôleurs de faibles performances. A l'issue de cette partie, une nouvelle loi de commande appelée commande passive échantillonnée ainsi qu'un observateur adaptatif étendu (observateur fondé sur l'estimation des fem) ont été développés et testés sur un banc expérimental. / This thesis is part of the project Compacite which aims to develop an electric compressor for electrical vehicles using a mechatronic approach. In this way, the LGEP contribution is to develop the electromechanical part of the compressor.The document is divided in two parts: the first one is related to the design of the motor and the second part is dedicated to the sensorless control.In the first part, the electromagnetic design is proposed to comply with the industrial constraints according to the compressor operation. The specifications require a compact motor (external diameter equal to 97 mm and an active depth less than 50 mm) and a good power/mass ratio (6 kW for a weight of 1.8 kg). At first the design is based on an analytical model in order to obtain a fast sizing. Thereafter the finite element method is used for multiphysical studies (magnetic, thermal and mechanical (in terms of strength of materials and vibration)). A prototype is built and characterized on a test bench. In the second part, some algorithmic control laws have been developed with sensor and sensorless control. In this part a particular control law (sampled data passivity based control) with a low algorithmic cost has been developed for driven the motor and has been validated on the test bench. At the end an observer based on the estimation of the electromotive force is used for sensorless control and validated on the test bench.

Les véhicules hybrides se démocratisent avec une utilisation croissante des éléments de stockage à base de lithium-ion. Dans ce contexte d'exploitation, le type d'usage est atypique et dépend fortement des stratégies de répartition des énergies au sein du véhicule. Parmi les hybridations, la catégorie "mild hybrid" conserve la motorisation thermique pour l'autonomie qu'elle apporte, et lui adjoint une machine électrique associée à un élément de stockage réversible, afin de permettre une récupération de l'énergie cinétique du véhicule. L'objet de ces travaux porte sur la mise en place d'algorithmes destinés à la détermination des états de charge (SoC), de santé (SoH) et de fonction (SoF) de chacune des cellules qui compose un pack batterie lithium-ion. Ces fonctionnalités sont implantées dans un système de gestion dénommé BMS pour Battery Management System. Dans un souci de réduction des coûts de production, nos travaux s'attachent à limiter la puissance de calcul et les moyens de mesure nécessaires à la détermination de ces états. À partir de mesures effectuées lors d'une utilisation de la batterie dans une application "mild hybrid", les méthodes développées permettent la détermination des états, ainsi que d'une partie des paramètres internes aux cellules. Cette utilisation est caractérisée par de forts courants et un maintien de l'état de charge autour de 50 %, ceci afin de maximiser la disponibilité de la batterie et d'en minimiser le vieillissement. L'utilisation d'observateurs et de méthodes en boucle ouverte, à partir d'une modélisation simplifiée de cellule, nous permet d'obtenir des résultats satisfaisants avec une puissance de calcul réduite / Hybrid vehicles are developing with increasing use of energy storage elements based on lithium-ion battery. In this context, the use of battery is atypical and highly dependent on energy allocation strategies within the vehicle. Among these vehicles, the mild hybrid category retains heat engine for the autonomy that offer and adds to it an electric machine associated with a reversible storage system, to allow the kinetic energy recovery of the vehicle. The object of this work involves the development of algorithms for determining the states of charge (SoC) and health (SoH) and function (SoF) of each cell that compose a lithium-ion battery pack. These features are implemented in a Battery Management System (BMS) for industrial production. In order to reduce production costs, our work attempts to limit the computing power and the measuring sensors necessary for these states determination. From battery measurements in a "mild hybrid" use, developed methods allow the states determination, as well as some of the internal parameters of cells. This application is characterized by high currents and maintaining a SoC of around 50%, in order to maximize the availability of the battery and to minimize aging. The use of observers and estimators, using a simplified model cell, allows us to achieve satisfactory results with a reduced computing power