In der Version 2.0 des Simulationskopplungsstandards FMI (Functional Mockup Interface) wird die Möglichkeit zur Speicherung und Wiederherstellung einer Simulationseinheit/FMU (Functional Mockup Unit) definiert. Dieses ist eine elementare Voraussetzung für iterierende Co-Simulations-Masteralgorithmen, wie z.B. Gauss-Seidel oder Newton-Iteration. Für die gekoppelte Simulation von solchen Simulationseinheiten ist ein Co-Simulations-Master erforderlich. Das Simulationsmasterprogramm MASTERSIM ist ein solcher Co-Simulations-Master und enthält zahlreiche Algorithmen und eine effiziente Verwaltung von Simulationseinheiten unter Verwendung dieser neuen Schnittstellenfunktionen. Dieser Artikel dokumentiert grundlegende Co-Simulations-Algorithmen und beteiligte Parameter und illustriert deren Einfluss anhand eines Testbeispiels.:1. Grundlagen 2. Zeitintegration 3. Simulationsperformance 4. Testbeispiel 5. Kopplungsalgorithmen 6. Zusammenfassung

This dissertation presents simulation tools developed specifically for the design of solar array power systems. Contributions are made in several aspects of the system design phases, including solar source modeling, system simulation, and controller verification. A tool to automate the study of solar array configurations using general purpose circuit simulators has been developed based on the modeling of individual solar cells. Hierarchical structure of solar cell elements, including semiconductor properties, allows simulation of electrical properties as well as the evaluation of the impact of environmental conditions. A second developed tool provides a co-simulation platform with the capability to verify the performance of an actual digital controller implemented in programmable hardware such as a DSP processor, while the entire solar array including the DC-DC power converter is modeled in software algorithms running on a computer. This "virtual plant" allows developing and debugging code for the digital controller, and also to improve the control algorithm. One important task in solar arrays is to track the maximum power point on the array in order to maximize the power that can be delivered. Digital controllers implemented with programmable processors are particularly attractive for this task because sophisticated tracking algorithms can be implemented and revised when needed to optimize their performance. The proposed co-simulation tools are thus very valuable in developing and optimizing the control algorithm, before the system is built. Examples that demonstrate the effectiveness of the proposed methodologies are presented. The proposed simulation tools are also valuable in the design of multi-channel arrays. In the specific system that we have designed and tested, the control algorithm is implemented on a single digital signal processor. In each of the channels the maximum power point is tracked individually. In the prototype we built, off-the-shelf commercial DC-DC converters were utilized. At the end, the overall performance of the entire system was evaluated using solar array simulators capable of simulating various I-V characteristics, and also by using an electronic load. Experimental results are presented.

Cone crushers are used in both the construction and mining industries for the production of aggregates and extraction of ores. Aggregates are used when building for example houses, roads and railways, hence the cone crushers are a vital part of modern society. To ensure the performance of the cone crusher, it is important to properly adjust the feeding conditions. Using computational methods to virtually analyze the performance of the crushers is a more time and cost efficient solution compared to physical testing. This thesis was divided into two parts, where the main objective of the first part was to use the discrete element method (DEM) to analyze the segregation in cone crushers. Three different methods were developed, which later were utilized to compare the segregation for four different feeding conditions. Two of the analysis methods only considered the segregation in the feed hopper, whilst the third method aimed to give an understanding ofthe segregation inside the crushing chamber. The two first methods could successfully be used to compare how segregated the feed material was for the four feeding conditions, however, the third method proved to be both hard to validate and highly dependent on proper material flow inside the crushing chamber. The main objective during the second part of the thesis was to investigate the possibility of running the DEM simulations coupled to a multibody simulation (MBS) software. The simulation routine was then used to compare the foundation loads for the same four feeding conditions as in the first part. The subframe was later modeled as a flexible body to analyze and compare the stresses the subframe was subject to during operation for the same four feeding conditions. Setting up and running the coupled simulation was successful. Different simulation settings were tested, anda general guideline on how those settings should be defined was set up. The actual impact the coupling had on the foundation loads and stresses in the subframe was however almost non-existent. This could probably be directly related to the fact that the crushing forces in EDEM are known to be many times smaller than what they have been measured to in experiments. This also meant that changing the feeding conditions to alter the segregation did not have a noticeable effect on the results.

No description available.

No description available.

This research investigates a novel arrangement to pneumatic suspensions that are commonly used in heavy trucks, toward providing a dynamically balanced system that resists body roll and provides added roll stability to the vehicle. The new suspension, referred to as "balanced suspension," is implemented by retrofitting a conventional pneumatic suspension with two leveling valves and a symmetric plumbing arrangement to provide a balanced airflow and air pressure in the airsprings. This new design contributes to a balanced force distribution among the axles, which enables the suspension to maintain the body in a leveled position both statically and dynamically. This is in contrast to conventional heavy truck pneumatic suspensions that are mainly adjusted quasi-statically to level the body in response to load variations. The main objectives of the research are to discover and analyze the effects of various pneumatic components on the suspension dynamic response and numerically study the benefits of the pneumatically balanced suspension system. A pneumatic suspension model is established to capture the details of airsprings, leveling valves, check valves, pipes, and air tank based on the laws of fluid mechanics and thermodynamics. Experiments are designed and conducted to help determine and verify the modeling parameters and components. Co-simulation technique is applied to establish a multi-domain model that couples highly non-linear fluid dynamics of the pneumatic suspension with complex multi-body dynamics of an articulated vehicle. The model is used to extensively study effects of pneumatic balanced control of the suspensions on the tractor and trailer combination dynamics. The simulations indicate that the dual leveling valve arrangement of the balanced suspension provides better adjustments to the body roll by charging the airsprings on the jounce side, while purging air from the rebound side. Such an adjustment allows maintaining a larger difference in suspension force from side to side, which resists the vehicle sway and levels the truck body during cornering. Additionally, the balanced suspension better equalizes the front and rear drive axle air pressures, for a better dynamic load sharing and pitch control. It is evident from the simulation results that the balanced suspension increases roll stiffness without affecting vertical stiffness, and thereby it can serve as an anti-roll bar that results in a more stable body roll during steering maneuvers. Moreover, the Failure Mode and Effects Analysis (FMEA) study suggests that when one side of the balanced suspension fails, the other side acts to compensate for the failure. On the other hand, if the trailer is also equipped with dual leveling valves, such an arrangement will bring an additional stabilizing effect to the vehicle in case of the tractor suspension failure. The overall research results presented show that significant improvements on vehicle roll dynamics and suspension dynamic responsiveness can be achieved from the balanced suspension system. / PHD

Cooperative driving in a connected vehicle (CV) environment has received increasing attention over the years due to its ability to enhance driving safety and efficiency. Despite many efforts that have been made in this field, the role of human drivers and pedestrians is frequently omitted. It is important to consider them to develop cooperative driving algorithms that are intelligent and robust to incorporate any uncertainty brought by humans. In this dissertation, a framework of a multi-driver in-the-loop driving simulator and a pedestrian in-the-loop digital twin system is introduced. Three important topics in cooperative driving were investigated using the developed framework: the effects of human-machine interface (HMI) design for cooperative driving, vehicle-pedestrian interaction under occlusion scenarios, and multi-vehicle decision-making at weaving segments. In the first topic, three HMIs were designed for collaborative speed adaptation following the skills, rules, and knowledge (SRK) taxonomy. The HMI designs were tested using a multi-driver simulator, and the results showed that the graphic-based HMI improved cooperative driving performance and was preferred by the participants. In the second task, a Digital Twin framework for CV and pedestrian in-the-loop simulation was proposed based on Carla-Sumo Co-simulation and Cave automatic virtual environment (CAVE). The effects of Vehicle-Pedestrian (V2P) warning systems under occlusion scenarios were investigated for different connectivity and vehicle automation levels. In the third task, an edge-enhanced graph attention deep reinforcement learning algorithm was developed to aid autonomous vehicles in diverging at weaving segments. The results showed that the proposed algorithms outperformed existing models and performed well in real-world driving scenarios. The dissertation provides insights into developing safe and efficient cooperative driving algorithms and applying advanced simulation technologies to human-in-the-loop cooperative driving testing.

Cette thèse porte sur la caractérisation, la modélisation et l'analyse des phénomènes de «Pulling» et de «Pushing» dans les systèmes de boucles à verrouillage de phase (PLL), utilisant une approche globale où les effets de couplages électromagnétiques aux différents niveaux d'intégration (niveau puce, niveau assemblage, niveau report sur PCB) sont pris en compte de manière distribuée. L'approche de modélisation adopte une méthodologie hybride où l'analyse des couplages électromagnétiques combinée à des schémas équivalents large-bande (compatibles avec les modèles de composants actifs disponibles dans les librairies) est couplée à des représentations comportementales dynamiques. Les représentations comportementales développées permettent de capturer des effets de non-linéarités tant au niveau composant (caractéristique non-linéaire des Varicap en fonction des tensions de contrôle) qu'au niveau block de fonction (gain KVCO non uniforme de l'oscillateur contrôlé en tension (VCO) en fonction de la fréquence).Cette méthodologie hybride permet l'évaluation d'effets compétitifs résultant de phénomènes de «pulling» et de «Pushing» au niveau de la puce (influence de la PLL, effets de l'amplificateur de puissance, intégrité des alimentations ou distribution des références de masse, etc.) , et des distorsions induites par des éléments extérieurs à la puce (exemple de composants sur PCB : Filtre SAW, capacités de découplages, réseaux d'adaptation).L'approche proposée est utilisée pour l'étude et la conception de deux types de circuits développés par NXP-semi-conducteurs pour des applications liées à la sécurité automobile (PLL fonctionnant aux alentours de 1.736GHz) et à la réception satellitaire (PLL de faible consommation fonctionnant à 9.75/10.6 GHz pour les circuits LNB).Les résultats de modélisation obtenus sont validés par corrélations avec les données expérimentales et par comparaison avec les résultats obtenus de différents outils (ADS Harmonic- Balance/Transient de Agilent, Spectre de Cadence / This thesis work focuses on characterization, modeling and analysis of «Pulling» and «Pushing» phenomena in Phase Locked Loops (PLL) based on a global approach where distributed effects of electromagnetic couplings at different integration levels (chip-level, assembly-level, board or PCB-level) are taken into account. The modeling approach adopts a hybrid methodology where the analysis of electromagnetic couplings combined with broadband equivalent circuit synthesis (compatible with library models of active components) is coupled with dynamic behavioral representations. The derived behavioral representations properly capture the effects of nonlinearities both at component scale (non-linear characteristic of varicap as function of control voltages) and at function block level (non-uniform gain KVCO of VCO circuits depending on frequency).The hybrid methodology renders possible the assessment of competitive effects resulting from «Pulling» and «Pushing» phenomena at chip level (influence of the PLL, effects of the power amplifier, power integrity, or ground reference distribution, etc..), and the distortions induced by components external to the chip at package and board levels (such as components on PCB: SAW filters, decoupling capacitors, matching networks).The proposed approach is used for the study and design of two types of circuits developed by NXP- Semiconductors, for applications related to automotive security and immobilization (an RF low power transceiver Integrated Circuit (PLL running around 1.763GHz), and to satellite receiver (PLL operating at low power for LNB circuits working at 9.75/10.6 GHz).The obtained modeling results are validated by correlation with experimental data and by comparison with different time-domain and frequency-domain simulation tools results (ADS-Harmonic Balance, ADS-Shooting solutions, Cadence-Spectre)

Ce travail de thèse porte sur l'étude des systèmes complexes par une démarche de modélisation et simulation (M&S). La plupart des questionnements sur ces systèmes nécessitent de prendre en compte plusieurs points de vue simultanément. Il faut alors considérer des phénomènes évoluant à des échelles (temporelles et spatiales) et des niveaux de résolutions (de microscopique à macroscopique) différents. De plus, l'expertise nécessaire pour décrire le système vient en général de plusieurs domaines scientifiques. Les défis sont alors de concilier ces points de vues hétérogènes, et d'intégrer l'existant de chaque domaine (formalismes et logiciels de simulation) tout en restant dans le cadre rigoureux de la démarche de M&S. Pour répondre à ces défis, nous mobilisons à la fois des notions de modélisation multi-niveau (intégration de représentations micro/macro), de modélisation hybride (intégration de formalismes discrets/continus), de simulation parallèle, et d'ingénierie logicielle (interopérabilité logiciel, et ingénierie dirigée par les modèles). Nous nous inscrivons dans la continuité des travaux de M&S existants autour de l'approche AA4MM et du formalisme DEVS. Nous étudions en effet dans cette thèse en quoi ces approches sont complémentaires et permettent, une fois combinées dans une démarche d'Ingénierie Dirigée par les Modèles (IDM), de répondre aux défis de la M&S des systèmes complexes. Notre contribution est double. Nous proposons d'une part les spécifications opérationnelles de l'intergiciel de co-simulation MECSYCO permettant de simuler en parallèle un modèle de manière rigoureuse et complètement décentralisée. D'autre part, nous proposons une approche d'IDM permettant de décrire de manière non-ambiguë des modèles, puis de systématiser leur implémentation dans MECSYCO. Nous évaluons les propriétés de notre approche à travers plusieurs preuves de concept portant sur la M&S du trafic autoroutier et sur la résolution numérique d'un système d'équations différentielles / This thesis is focused on the study of complex systems through a modeling and simulation (M&S) process. Most questions about such systems requiere to take simultaneously account of several points of view. Phenomena evolving at different (temporal and spatial) scales and at different levels of resolution (from micro to macro) have to be considered. Moreover, several expert skills belonging to different scientific fields are needed. The challenges are then to reconcile these heterogeneous points of view, and to integrate each domain tools (formalisms and simulation software) within the rigorous framework of the M&S process. In order to solve these issues, we mobilise notions from multi-level modeling, hybrid modeling, parallel simulation and software engineering. Regarding these fields, we study the complementarity of the AA4MM approach and the DEVS formalism into the scope of the model-driven engineering (MDE) approach. Our contribution is twofold. We propose the operational specifications of the MECSYCO co-simulation middleware enabling the parallel simulation of complex systems models in a rigorous and decentralized way. We also define an MDE approach enabling the non-ambiguous description of complex systems models and their automatic implementation in MECSYCO. We show the properties of our approach with several proofs of concept

Modéliser et simuler (M&S) un système cyber-physique (SCP) peut nécessiter de représenter des éléments provenant de trois domaines d'expertise à la fois : systèmes physiques, systèmes d'informations et réseaux de communication (IP). Le simulateur universel disposant de toutes les compétences nécessaires n'existant pas, il est possible de regrouper des modèles issus des différentes communautés, à l'aide d'un multi-modèle. Les défis sont alors 1) intégrer toute l'hétérogénéité du multi-modèle (formalismes, représentations, implémentations), 2) intégrer des modèles IP de façon à ce qu'ils soient en capacité de représenter le transport de données applicatives produites par des modèles externes et 3) les intégrer de façon à ce qu'ils puissent se compléter, pour représenter ensemble les réseaux IP parfois hétérogènes d'un SCP. Pour parvenir à répondre à ces défis, nous nous inscrivons dans la continuité des travaux de M&S autour de MECSYCO, une plateforme de co-simulation basée sur la notion de wrapping DEVS. Nous proposons de définir un cadre général pour réussir à wrapper en DEVS des modèles IP, avec 1) une structuration des différents niveaux de problèmes pour l'intégration de modèles IP dans une co-simulation (délimitation des objectifs et contraintes du wrapping), et 2) une proposition de stratégie de wrapping DEVS de modèles IP et leurs simulateurs. Nous évaluerons notre approche à travers la démonstration de l'intégration de deux simulateurs IP populaires, et d'exemples concrets de M&S de SCP (avec notamment une interconnexion de modèles entre NS-3 et OMNeT++/INET, et une application industrielle utilisée par EDF R&D) / Modeling and simulation (M&S) of cyber-physical systems (CPS) can require representing components from three expertise fields: physics, information systems, and communication networks (IP). There is no universal simulator with all of the required skills, but we can gather and interconnect models provided by the communities, with a multi-model. The challenges are 1) integrating all heterogeneities in a multi-model (formalisms, representations, implementations), 2) integrating IP models in a way enabling them to represent the transport of application data produced by external models, and 3) integrating IP models in a way enabling them to complete each other, to be able to represent CPS heterogeneous IP networks. In order to meet these challenges, we relied our solution on the works around MECSYCO, a co-simulation platform based on the DEVS wrapping principle. We propose to define a comprehensive framework enabling to achieve DEVS wrapping of IP models, with 1) a structuration of different issue levels when integrating IP models in a co-simulation (goals and constraints of the wrapping) and 2) a proposition of a DEVS wrapping strategy for IP models and their simulators. We propose some evaluations of our approach, through the integration of two popular IP simulators, and concrete examples of CPS M&S (inter alia, with an example of a models interconnection between NS-3 and OMNeT++/INET, and an industrial application used by EDF R&D)