La plupart des simulations interactives ont besoin d'un modèle de détection de collisions. Cette détection nécessite d'une part d'effectuer des requêtes de proximité entre les entités concernées et d'autre part de calculer un comportement à appliquer. Afin d'effectuer ces requêtes, les entités présentes dans une scène sont soit hiérarchisées dans un arbre ou dans un graphe de proximité, soit plongées dans une grille d'enregistrement. Nous présentons un nouveau modèle de détection de collisions s'appuyant sur deux piliers : une représentation de l'environnement par des cartes combinatoires multirésolutions et un suivi en temps réel de particules plongées dans ces cartes. Ce modèle nous permet de représenter des environnements complexes tout en suivant en temps réel les entités évoluant dans cet environnement. Nous présentons des outils d'enregistrement et de maintien de l'enregistrement de particules, d'arêtes et de surfaces dans des cartes combinatoires volumiques multirésolutions. / Most interactive simulations need a collision detection system. First, this system requires the querying of the proximity between the objects and then the computing of the behaviour to be applied. In order to perform these queries, the objects present in a scene are either classified in a tree, in a proximity graph, or embedded inside a registration grid.Our work present a new collision detection model based on two main concepts: representing the environment with a combinatorial multiresolution map, and tracking in real-time particles embedded inside this map. This model allows us to simulate complex environments while following in real-time the entities that are evolving within it.We present our framework used to register and update the registration of particles, edges and surfaces in volumetric combinatorial multiresolution maps. Results have been validated first in 2D with a crowd simulation application and then in 3D, in the medical field, with a percutaneous surgery simulation.

L’objectif de cette thèse est de modéliser en temps réel la propagation d’un incendie dans des ensembles comportant un grand nombre de locaux. Un modèle semi-physique de réseau polydisperse amorphe prenant en compte les connexions à courte et longue distances entre sites, est proposé. Les phénomènes physiques liés au développement du feu dans un local et à sa transmission entre locaux par les parois sont simulés par des lois normales de probabilité. Les durées moyennes de transmission par les parois sont déterminées à l’aide d’un modèle à zones prenant en compte les spécificités du local en feu. Des expérimentations spécifiques dans un caisson en acier, représentatif d’un local de la Marine Nationale, ont permis de valider le modèle à zones. Un exemple détaillé du calcul par le modèle de réseau de la propagation d’un feu dans une maquette de navire à échelle un est ensuite décrit et analysé pour différents scénarios. Une analyse de sensibilité utilisant un plan factoriel complet à deux niveaux permet de hiérarchiser les paramètres du modèle et d’étudier la sensibilité de la solution aux variations de ces paramètres. Une étude statistique est conduite afin d’établir une cartographie du risque incendie à bord du navire. La transmission du feu par les gaines de ventilation est simulée par une loi normale de probabilité où la durée moyenne de transmission est déterminée à l’aide d’un code à champ unidimensionnel. Après avoir validé ce code sur des mesures obtenues par DGA dans une conduite cylindrique différentiellement chauffée, l’influence de ce mode de transmission sur la propagation du feu dans le navire est analysée. / This thesis work is devoted to the development of a semi-physical network model to predict real-time fire spread in polydisperse amorphous massively multi-compartmented spaces. This model takes into account short-range and long-range connections between adjacent and remote network sites. The physical phenomena of fire ignition and flashover, and of fire transmissions through the walls are simulated using time-dependent normal probability distributions. Mean durations of transmission though the walls are determined by a two-zone model which takes into account the fuel load, the room size and the thermal properties of walls. Specific experiments were conducted in a steel room, representative of a naval vessel compartment, in order to validate the zone model. Then a proof of concept is developed by applying the network model to different fire scenarios in a full-scale vessel mockup. A sensitivity analysis using a two-level full factorial design is performed to identify the most influential model parameters and to evaluate the sensitivity of the solution to variations of these parameters. A statistical study is conducted to produce fire risk maps. Finally, a special emphasis is put on the fire transmission by the ventilation ducts. This phenomenon is simulated using a time-dependent normal probability distribution where the mean duration is determined by means of a one-dimensional CFD model. This model is first validated using data obtained by DGA in a differentially heated duct and second, the influence of fire transmission through ventilation duct on its propagation throughout the vessel is investigated.

The present work introduces a methodology to obtain a discrete time state space representation of an electrical network using the nodal [G] matrix of the Electromagnetic Transients Program (EMTP) solution. This is the first time the connection between the EMTP nodal analysis solution and a corresponding state-space formulation is presented. Compared to conventional state space solutions, the nodal EMTP solution is computationally much more efficient. Compared to the phasor solutions used in transient stability analysis, the proposed approach captures a much wider range of eigenvalues and system operating states. A fundamental advantage of extracting the system eigenvalues directly from the EMTP solution is the ability of the EMTP to follow the characteristics of nonlinearities. The system's trajectory can be accurately traced and the calculated eigenvalues and eigenvectors correctly represent the system's instantaneous dynamics. In addition, the algorithm can be used as a tool to identify network partitioning subsystems suitable for real-time hybrid power system simulator environments, including the implementation of multi-time scale solutions. The proposed technique can be implemented as an extension to any EMTP-based simulator. Within our UBC research group, it is aimed at extending the capabilities of our real-time PC-cluster Object Virtual Network Integrator (OVNI) simulator. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

This master’s thesis deals with creating a real-time simulation model of an aircraft piston engine with emphasis on heating and cooling of the engine cylinders. First part of this thesis focuses on characteristics of aircraft engines and differences with regular automotive engines. The next chapter describes the dependence of engine parameters on atmospheric conditions. The description of the real time model itself follows next. The results of the simulation model are presented and analysed at the end of this thesis.

Background Physics-based snow simulation in real time is an unexplored area, the reason being the difficulty introduced by the multitude of factors that affect the snow behaviour, such as cohesion, thermodynamics, and compression. Simulating snow in real time when considering these factors can become computationally demanding. However, the continued advancement of graphics processing units makes the exploration of real-time snow simulation attractive. Recently published research on real time physics-based snow simulation shows promising results in a parallel solution and will serve as motivation and base for this thesis. Objectives This thesis aims to improve the time-step of a previously proposed method using an iterative method and improve the snow behaviour with a particle-based boundary handling implementation. The aim consists of the following objectives. Integrate an iterative method, extend the snow behaviour with additional snow types, and implement a particle-based boundary handling method with two-way coupling. The proposed method should remain comparable to the original method in terms of snow behaviour. In order to gather results, the methods are measured in performance and used in a questionnaire to analyse the behaviour. Methods An iterative method along with a particle-based boundary handling method is implemented. The methods are both measured and compared using quantitative tests. Additionally, a questionnaire is deployed to gather qualitative results about the behaviour of the snow. Results The proposed method outperforms the original method in terms of time-step size. The proposed method is capable of increasing the time-step tenfold while decreasing the execution time by approximately eight times. Finally, the results from the questionnaire verify the perceived naturalism of the snow and its comparability to the original method. Conclusions The proposed method can perform with an increased time-step and a lower execution time compared to the original method, at the cost of time spent per frame. Lastly, the snow is perceived as natural with the boundary handling method at a significance level of 1 %. / Bakgrund Fysikbaserad snösimulering i realtid är ett outforskat område, anledning till detta är mängden faktorer som påverkar snö, exempelvis sammanhållning, termodynamik och kompression. Simulering av snö i realtid som tar hänsyn till dessa faktorer kan bli beräkningsmässigt krävande, däremot har den växande utvecklingen av grafikprocessorer gjort utforskning av realtidsmetoder ytterligare attraktivt. Nyligen publicerad forskning inom fysikbaserade snösimuleringar i realtid visar lovande resultat i en parallell lösning och kommer att användas som motivering samt bas i detta examensarbete. Syfte Detta examensarbete syftar till att förbättra tidsstegen i en tidigare implementerad metod med hjälp av att använda ett iterativt tillvägagångssätt samt förbättra snöbeteendet med en partikelbaserad gränshanteringsimplementation. Syftet är uppdelat i följande mål. Integrera en iterativ metod, utöka snöbeteendet med ytterligare snötyper, och implementera en partikelbaserad gränshanteringsmetod med tvåvägskoppling. Den föreslagna metoden ska förhålla sig jämförbar med originalmetoden med avseende på snöbeteendet. Slutligen för att samla in resultat mäts metoderna i prestanda och dessutom används ett frågeformulär för att analysera beteendet. Metod En iterativ metod tillsammans med en partikelbaserad gränshanteringsmetod är implementerad. Båda metoderna mäts och jämförs med hjälp av kvantitativa tester. Dessutom distribueras ett kvalitativt frågeformulär för att samla resultat om snöns beteende.  Resultat Den föreslagna metoden tillåter större tidsteg än originalmetoden. Den iterativa metoden är kapabel till att förstora tidsstegen tiofaldigt, samtidigt som den sänker exekveringstiden till en åttondel. Resultaten verifierar den uppfattade naturligheten av snön och jämförelsebarheten till originalmetoden. Slutsatser Den föreslagna metoden kan prestera med ett större tidssteg och en lägre exekveringstid jämfört med originalet i utbyte av högre tid spenderad per bildruta. Slutligen uppfattas snön som naturlig i sammankoppling med gränshanteringsmetoden vid en signifikansnivå på 1 %.

Background: Snow simulation can be used to increase the visual experience in applications such as games. Previously, snow has been simulated in real-time through two-dimensional grid based methods, which limits itself in the aspect of dynamic interactions. To widen the scope of what games current game engines can produce, an approach to simulating the behavior of snow with non-recoverable compression and phase transition is proposed. Objective: The objective of this thesis is to construct a particle simulation model to simulate the behaviors of snow in regards to compression and phase transition in real-time. The solution is limited to the behavior of deposited snow, and will therefore not consider the aspect of snowfall and realistic visualization. Method: The method consists of a particle simulation with incorporated functionality of compression and thermodynamics. Test cases based on compression, phase transition and performance have been conducted. Results and Conclusions: The results show that the model captures phase transition with the phases of snow, ice, and water. Compression by external forces and self-weight is also captured, but with missing behavior in terms of bond creation between grains. Performance measurements indicates that the simulation is applicable for real-time applications. It is concluded that the approach is a good stepping stone for future improvements of snow simulation. / Bakgrund: Snösimulering kan användas för att öka den visuella upplevelsen i applikationer såsom spel. Tidigare har simulering i realtid gjorts genom tvådimensionella rutnätsmetoder, vilka begränsar den dynamiska interaktionsaspekten. För att bredda omfattningen av vilka spel aktuella spelmotorer kan producera föreslås en metod för att simulera beteendet av snö med icke-återhämtande kompression och fasövergång. Syfte: Syftet med denna avhandling är att konstruera en partikel-simuleringsmodell för att simulera beteendet av snö i förhållande till kompression och fasövergång i realtid. Lösningen är begränsad till ackumulerad snö, och tar därmed inte upp snöfallaspeketen och realistisk visualisering. Metod: Metoden består av en partikel-simuleringsmetod med inbyggd funktionalitet av kompression och termodynamik. Testfall baserade på kompression, fasövergång och prestanda har utförts. Resultat och Slutsatser: Resultaten visar att fasövergång fångas av modellen med faser av snö, is och vatten. Kompression av självvikt samt externa krafter har också fångats, dock med saknat beteende av bandskapande mellan snökorn. Prestandamätningar indikerar att simuleringen är lämplig för realtidsapplikationer. Slutsatsen är att tillvägagångssättet är ett steg i rätt riktning inför framtida implementationer av snösimulering.

This thesis investigates whether a game world based solely on fluid dynamics could be an interesting alternative to one based on rigid bodies by presenting a prototype to players where they can control the movement of a fluid. The players evaluate the prototype’s responsiveness, intuitiveness, visual appeal, immersion, and how well they think the fluid could represent ghosts, flocks, magic, and a platformer avatar by rating them vocally while playing. The fluid physics engine prototype is a simple grid-based one that utilizes the ideal gas law and pressure gradient force to calculate the flow between its cells. It is unstable and thus cannot handle too large time-steps. Therefore, simulating many cells (more than 10000 for two fluids) at the same is a slow process, and the prototype can only present a pixelated result. If a highresolution game is in general preferred by players, a computationally efficient solution could consist of utilizing shaders for cell blending. In the experiments, all categories except the platform avatar received positive evaluations despite the prototype’s early stage, which according to theories presented within Swink’s Game Feel (Swink, 2009) and the MDA framework (Hunicke et al., 2004) may indicate that a game based on a fluid physics engine like this one could be entertaining. The simulation could possibly be run as a separate system to add game mechanics to a game based on rigid bodies as well.

This thesis was written in collaboration with the department of electrical engineering at Uppsala University. It evaluates and tests the potentials and limitations of using the OPAL-RT simulator as a tool for designing and developing control strategies used in microgrids with a high penetration of distributed energy resources. As the world gradually transitions to a more decentralized power system with less conventional power production, new strategies to ensure reliable and robust power transmission and distribution must be developed.    The objectives of this thesis were to develop a model of a microgrid that can be used as a base for developing control strategies to limit slow voltage variations in microgrids with high penetration of distributed energy resources. When a template model and strategy for conducting this type of research had been developed the thesis started to focus on the Real-Time simulator. The power system part of the microgrid was converted into a Real-Time compatible model and was allocated to be run on one of the CPU cores of the simulator. In an iterative process, the power system was built and run on the simulator to get results concerning the size of the power system that can be simulated using the CPU cores where the limiting factor is the computational power of the cores. Since the power electronics found in the inverter part of the voltage source converter is operating at a very high switching frequency the inverter must be simulated on the simulator's FPGA. The last objective was to integrate the CPU model and the FPGA model into one model where two different time steps were used.  The results show that one CPU can simulate the 18-bus power system developed during this thesis. It is also assessed that the CPU is capable of simulating a considerably bigger system if no calculations or control strategies are present in the system. The FPGA is functioning and can simulate high-frequency switching power electronics in Real Time.    The conclusions are that Real Time simulators in general as well as the OPAL-RT simulator studied here at Uppsala University will be of great importance for the continuation of research connected to control strategies.

This work demonstrates the capability of a power electronic based power hardware-inthe- loop (PHIL) platform to emulate electric machines for the purpose of a motor drive testbench with a particular focus on induction machine emulation. PHIL presents advantages over full-hardware testing of motor drives as the PHIL platform can save space and cost that comes from the physical construction of multiple electric machine test configurations. This thesis presents real-time models that were developed for the purpose of PHIL emulation. Additionally, real-time modeling considerations are presented as well as the modeling considerations that stem from implementing the model in a PHIL testbench. Next, the design and implementation of the PHIL testbench is detailed. This thesis describes the design of the interface inductor between the motor drive and the emulation platform. Additionally, practical implementation challenges such as common mode and ground loop noise are discussed and solutions are presented. Finally, experimental validation of the modeling and emulation of the induction machine is presented and the performance of the machine emulation testbench is discussed. / Master of Science / According to the International Energy Agency (IEA), electric power usage is increasing across all sectors, and particularly in the transportation sector [1]. This increase is apparent in one's daily life through the increase of electric vehicles on the road. Power electronics convert electricity in one form to electricity in another form. This conversion of power is playing an increasingly important role in society because examples of this conversion include converting the dc voltage of a battery to ac voltage in an electric car or the conversion of the ac power grid to dc to power a laptop. Additionally, even within an electric car, power converters transform the battery's electric power from a higher dc voltage into lower voltage dc power to supply the entertainment system and into ac power to drive the car's motor. The electrification of the transportation sector is leading to an increase in the amount of electric energy that is being consumed and processed through power electronics. As was illustrated in the previous examples of electric cars, the application of power electronics is very wide and thus requires different testbenches for the many different applications. While some industries are used to power electronics and testing converters, transportation electrification is increasing the number of companies and industries that are using power electronics and electric machines. As industry is shifting towards these new technologies, it is a prime opportunity to change the way that high power testing is done for electric machines and power converters. Traditional testing methods are potentially dangerous and lack the flexibility that is required to test a wide variety of machines and drives. Power hardware-in-the-loop (PHIL) testing presents a safe and adaptable solution to high power testing of electric machines. Traditionally, electric machines were primarily used in heavy industry such as milling, processing, and pumping applications. These applications, and other applications such as an electric motor in a car or plane are called motor drive systems. Regardless of the particular application of the motor drive system, there are generally three parts: a dc source, an inverter, and the electric machine. In most applications, other than cars which have a dc battery, the dc source is a power electronic converter called a rectifier which converts ac electricity from the grid to dc for the motor drive. Next, the motor drive converts the dc electricity from the first stage to a controlled ac output to drive the electric machine. Finally, the electric machine itself is the final piece of the electrical system and converts the electrical energy to mechanical energy which can drive a fan, belt, or axle. The fact that this motor drive system can be generalized and applied to a wide range of applications makes its study particularly interesting. PHIL simplifies testing of these motor drive systems by allowing the inverter to connect directly to a machine emulator which is able to replicate a variety of loads. Furthermore, this work demonstrates the capability of PHIL to emulate both the induction machine load as well as the dc source by considering several rectifier topologies without any significant adjustments from the machine emulation platform. This thesis demonstrates the capabilities of the EGSTON Power Electronics GmbH COMPISO System Unit to emulate motor drive systems to allow for safer, more flexible motor drive system testing. The main goal of this thesis is to demonstrate an accurate PHIL emulation of a induction machine and to provide validation of the emulation results through comparison with an induction machine.

La validation des systèmes Mécatroniques tels que la supervision d'une chaînede traction hybride utilise de plus en plus la simulation Hardware-in-the-Loop. Cela consiste à interconnecter des composants réels du système et des composantssimulés. On parle alors de simulation temps réel car les composants simulés doivent avoir le même comportement temporel que les réels. En d'autres termes, la simulation temps réel d'un modèle nécessite le maillage de l'évolution du temps simulé sur celle du temps réel. Sur les outils existants, l'intégration de modèles physiques représentatifs se heurte à des modèles de calculs et des contraintes temporelles pessimistes. Cette thèse propose des solutions, analytiques ou tirées d'expérimentations au sein d'IFP Energies nouvelles, pour l'implantation adéquate de la simulation temps réel de modèles physiques. Des métriques ont été introduites pourqualifier et quantifier la validité d'une simulation temps réel. Une définition des contraintes temporelles propres à la simulation temps réel a été proposée, accompagnée des règles régissant leur propagation aux calculs sous-jacents. Ces méthodes ont ensuite été déclinées en étude d'ordonnançabilité pour deux systèmes au comportement pseudo périodique : un simulateur de moteur à combustion et un contrôle moteur. Des expérimentations sur la simulation temps réel distribuée d'un moteur, intégrant des modèles phénoménologiques de combustion, ont permis de justifier et de validerles méthodes proposées. Les dégradations dues à la simulation distribuée ont été corrigées par un mécanisme d'extrapolation paramétrable dont le coût d'exécution a été étudié / Validation of Mechatronics systems such as hybrid automotive powertrains isincreasingly relying on Harware-in-the-Loop simulation. It consists in interconnecting real components to the real-time simulation of physical models, involving their timely behavior to match their real counterpart. In other words, the evolution of simulated and real time have to be meshed together. Involving representative physical models is currently hindered by both pessimistic models of computation and temporal constraints.This thesis proposes several analytical and experimental answers, carried out at IFP Energies nouvelles, toward the proper implantation of real-time simulation of physical models. Several metrics able to qualify and quantify the success of real-time simulation were proposed, as well as the definition of its dedicated timed constraints, along with the rules for their propagation toward the underlying computations involved.Then, we showed how to take advantage of the pseudo periodic behavior of two systems to reach better schedulability bounds for the real-time simulation of : a combustion engine and an engine control. The methods discussed were then accounted for and validated by several experiments, involving the distributed real-time simulation of an engine including phenomenological combustion models. Also, the perturbations induced by the distributed simulation were addressed by proposing a configurable extrapolation mechanism, taking into account its execution time