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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Control system integration in ADAMS : With emphasis on hauler Automatic Traction Control system

Furmanik, Olga, Famili, Alireza January 2015 (has links)
The thesis investigates control system integration in ADAMS and the thesis presents appropriate knowledge related to the topic as multi body system, acting forces between road and wheels, equation of motion regarding to the haulers, traction control system and differential locks. The emphasis of the thesis is to implement and test the automatic traction control (ATC) for the hauler into ADAMS and Simulink models. The ATC models are based on certain requirements provided by Volvo Construction Equipment. As expected, results indicate that the ATC model operates during simulation for various road conditions. Nevertheless, the ATC model includes a few defects which are observed in results. The significant achievement of the thesis is a great collaboration between ADAMS and Simulink model.
2

Implementation and evaluation of bounded invariant model checking for a subset of Stateflow / Implementering samt utvärdering av invariant-baserad begränsad modellprovning för en delmängd av Stateflow

Ung, Gustav January 2021 (has links)
Stateflowmodels are used for describing logic and implementing state machines in modern safety-critical software. However, the complete Stateflowmodelling language is hard to formally define, therefore a subset relevant for industrial models has been developed in previous works. Proving that the execution of Stateflow models satisfies certain safety properties is intractable in general. However, bounded model checking (BMC) can be used to either prove that safety properties are satisfied up to a bounded execution depth, commonly referred to as the reachability diameter, or find a concrete counterexample. One particular safety property of interest is an invariant property. This thesis project contributes with the following. A bounded model checking tool based on symbolic execution has been developed and is called Stateflow Model Verification Tool (SMVT). This tool has been tested on synthetic models and industrial models. The performance of Stateflow Model Verification Tool (SMVT) has been measured, but not compared against the Simulink DesignVerifier (SLDV) due to licensing issues. The study has shown that many industrial models share a similar model structure. Furthermore, it has been shown that SMVT can perform well for several models. / Stateflow-modeller används för att beskriva logik and implementation av tillståndsmaskiner i modern säkerhetskritisk mjukvara. Det kompletta Stateflowspråket är väldigt komplext, och därför har forskare tidigare definierat en begränsad version av språket relevant för industriella modeller. Bevisning att exekvering av Stateflow-modeller måste uppfylla säkerhetsegenskaper, är svårlösligt rent generellt. Begränsad modellprovning kan användas antingen för att bevisa att säkerhetsegenskaper uppfylls till ett begränsat exekveringsdjup, eller för att hitta ett motexempel. En väldigt viktig säkerhetsegenskap kallas för invariant. Detta examensarbete bidrar med följande. En begränsad modellprövare baserad på symbolisk exekvering har utvecklats och kallas för SMVT. Detta verktyg har blivit testat på syntetiska modeller samt industriella modeller. Prestandan har blivit mätt, men på grund av Simulink Design Verifier (SLDV) licens har ingen jämförelse kunnat göras. Studien har visat att många industriella modeller delar samma modellstruktur. Vidare har det utvecklade verktyget SMVT visats prestera väl för flertalet modeller.
3

Modellering av uppdragsberäkningar i JAS 39 Gripen

Lager, Mattias January 2009 (has links)
<p>I JAS 39 Gripen finns funktioner, kallade uppdragsberäkningar, som informerarpiloten om hur mycket bränsle och tid som förväntas gå åt för att slutföra detaktuella flyguppdraget. Uppdragsberäkningsdelen är stor och komplex och genomatt göra en modell av uppdragsberäkningarna kan man enklare simulera och verifieradem innan införandet av en ändring. I detta examensarbete har en modellav koden implementerats i MATLAB/Simulink.</p><p>Under arbetet har en bränsleberäkningskärna och en accelerationsberäkningsfunktionmodellerats. I samband med modelleringen har modelleringsmetoder utvecklatsför vanligt förekommande dataobjekt och funktionaliteter i koden, såsom variabler,loopar och if-satser. En stor del av arbetet har handlat om validering av modellen mot originalkoden. Valideringen är något som skulle behövas automatiserasför att effektivisera modelleringsarbetet.</p><p>Förbättringar av de befintliga uppdragsberäkningarna har föreslagits och undersökts.Till exempel har statiska och dynamiska modeller av ett modellfel skapatsmed hjälp av multipel linjär regression och systemidentifieringsteori. Då dessa modelleranvändes minskade skillnaden mellan modellernas skattade bränsleflöde ochdet verkliga bränsleflödet. En del av förbättringarna som presenteras är enkla attimplementera i befintlig kod medan andra kräver betydligt mer anpassning. Dagensuppdragsberäkningar har visat sig komplicerade att modellera i Simulink. Islutet av rapporten presenteras ett konceptförslag, baserat på ett reglerteknisktangreppsätt, på hur uppdragsberäkningarna skulle kunna omarbetas för att passaSimulink bättre.</p>
4

Modellering av uppdragsberäkningar i JAS 39 Gripen

Lager, Mattias January 2009 (has links)
I JAS 39 Gripen finns funktioner, kallade uppdragsberäkningar, som informerarpiloten om hur mycket bränsle och tid som förväntas gå åt för att slutföra detaktuella flyguppdraget. Uppdragsberäkningsdelen är stor och komplex och genomatt göra en modell av uppdragsberäkningarna kan man enklare simulera och verifieradem innan införandet av en ändring. I detta examensarbete har en modellav koden implementerats i MATLAB/Simulink. Under arbetet har en bränsleberäkningskärna och en accelerationsberäkningsfunktionmodellerats. I samband med modelleringen har modelleringsmetoder utvecklatsför vanligt förekommande dataobjekt och funktionaliteter i koden, såsom variabler,loopar och if-satser. En stor del av arbetet har handlat om validering av modellen mot originalkoden. Valideringen är något som skulle behövas automatiserasför att effektivisera modelleringsarbetet. Förbättringar av de befintliga uppdragsberäkningarna har föreslagits och undersökts.Till exempel har statiska och dynamiska modeller av ett modellfel skapatsmed hjälp av multipel linjär regression och systemidentifieringsteori. Då dessa modelleranvändes minskade skillnaden mellan modellernas skattade bränsleflöde ochdet verkliga bränsleflödet. En del av förbättringarna som presenteras är enkla attimplementera i befintlig kod medan andra kräver betydligt mer anpassning. Dagensuppdragsberäkningar har visat sig komplicerade att modellera i Simulink. Islutet av rapporten presenteras ett konceptförslag, baserat på ett reglerteknisktangreppsätt, på hur uppdragsberäkningarna skulle kunna omarbetas för att passaSimulink bättre.
5

Modelling and programming embedded controllers with timed automata and synchronous languages

Bourke , Timothy Peter, Computer Science & Engineering, Faculty of Engineering, UNSW January 2009 (has links)
Embedded controllers coordinate the behaviours of specialised hardware components to satisfy broader application requirements. They are difficult to model and to program. One of the greatest challenges is to express intricate timing behaviours???which arise from the physical characteristics of components???while not precluding efficient implementations on resource-constrained platforms. Aspects of this challenge are addressed by this thesis through four distinct applications of timed automata and the synchronous languages Argos and Esterel. A novel framework for simulating controllers written in an imperative synchronous language is described. It includes a transformation of synchronous models into timed automata that accounts for timing properties which are important in constrained implementations but ignored by the usual assumption of synchrony. The transformation provides an interface between the discrete time of synchronous programs and a continuous model of time. This interface is extended to provide a way for simulating Argos programs within the widely-used Simulink software. Timed automata are well-suited for semantic descriptions, like the aforementioned transformation, and for modelling abstract algorithms and protocols. This thesis also includes a different type of case study. The timing diagram of a small-scale embedded component is modelled in more detail than usual with the aim of studying timing properties in this type of system. Multiple models are constructed, including one of an assembly language controller. Their interrelations are verified in Uppaal using a construction for timed trace inclusion testing. Existing constructions for testing timed trace inclusion do not directly address recent features of the Uppaal modelling language. Novel solutions for the problems presented by selection bindings, quantifiers, and channel arrays in Uppaal are presented in this thesis. The first known implementation of a tool for automatically generating a timed trace inclusion construction is described. The timed automata case study demonstrates one way of implementing application timing behaviours while respecting implementation constraints. A more challenging, but less detailed, example is proposed to evaluate the adequacy of Esterel for such tasks. Since none of the standard techniques are completely adequate, a novel alternative for expressing delays in physical time is proposed. Programs in standard Esterel are recovered through syntactic transformations that account for platform constraints.
6

Automatická uzávěrka diferenciálu / Automatic Locking Differential

Kimlová, Anna January 2015 (has links)
This thesis consists of two parts. The first one contains a research about different kinds of divorces in tractors. There is also a description of a modelling in MATLAB, Simulink and Stateflow programs. The second part focuses on designing an algorithm of an automatic locking differential and connection front-wheel drive and its testing on a model of tractor. Furthermore the thesis solves an implementation process of the algorithm into the control unit.
7

Stability of a Fuzzy Logic Based Piecewise Linear Hybrid System

Seyfried, Aaron W. 01 June 2013 (has links)
No description available.
8

Modeling and Control of a Vertical Hopping Robot

Kwan, Bradley Y. 01 June 2021 (has links) (PDF)
Single degree-of-freedom hopping robots are typically modeled as spring loaded inverted pendulums (SLIPs). This simplified model, however, does not consider the overall leg geometry, consequently making it difficult to investigate the optimized inertial distribution of the leg for agile locomotion. To address this issue, the first part of this thesis establishes an accurate mathematical model of a DC-motor-driven, two-link hopping robot where the motors are modeled as torque sources. The equations of motion for the two distinct phases of locomotion (stance and flight) are derived using the Lagrangian approach for holonomic systems. A Simulink/Stateflow model is developed to numerically simulate the robot’s locomotion. The model is then validated with the simulation data from Simscape Multibody, which allows for accurate modeling of the environment and inertial properties for complex geometries. With the accurate model of the hopping robot, two distinct control strategies are adopted. The first strategy focuses on implementing position control while the robot is in flight to prepare for touchdown. The second control method explores implementing impedance control during stance, allowing the response to mimic that of a mass-spring-damper model. It was found that concentrating the mass of the robot in the hip allows the robot to attain larger apex heights as opposed to evenly distributing the mass throughout the leg. With plans to implement the leg on a quadruped robot, the mathematical model is easily expandable to 2 or 3 degrees-of-freedom. This allows for further stability analysis and development of control strategies of the leg.
9

Energy management and control for hybrid renewable energy sources in rural area / Gestion de l'énergie et de contrôle pour les hybrides sources d'énergie renouvelables en zone rurale

Ahmed, Rana 27 November 2015 (has links)
Cette thèse propose principalement, un algorithme État-Flow MPPT basé P&O, amélioré avec deux degrés de liberté, dans lequel le système événementiel (MPPT) de comportement est modélisé par le décrivant en terme de transition entre les états, sous certaines conditions. Secondairement, un algorithme étendu MPPT, base d'exploitation en parallèle de l'état-débit est en outre proposé d'être une solution difficile pour le contrôle indépendant du système hybride, où la caractéristique de contrôle continu peut se présenter au cours d'un certain état de travail tout en discrète, est indiquée le long des transitions d'état. Deux configurations possibles pour le système hybride sont proposées : deux convertisseurs DC/DC séparés, et un convertisseur de sortie unique à double entrée (DISO) de configurations. Enfin, il est proposé, un comportement du système DC modélisation utilisant État-Flow, menant à l'ensemble de la conception de la stratégie de commande qui concernent RES MPPT, RES et la coordination BESS, la stabilité du système d'alimentation et de régulation de la tension du bus DC. La simulation et les résultats expérimentaux valident l'efficacité et l'applicabilité de l'algorithme proposé. Les deux résultats montrent la supériorité du MPPT basé proposé État-Flow pour réduire les oscillations de puissance RESs à l'état d'équilibre dans diverses conditions d'exploitation, en plus de son démarrage plus rapide, et l’opération de transition sans divergence de la MPP, selon des conditions météorologiques variables. / This thesis primarily proposes, an improved P&O based State-Flow MPPT algorithm featuring two degree of freedom, in which the event driven system (MPPT) behaviour is modelled by describing it in terms of transitions among states under certain conditions. Secondarily, an extended parallel operating State-Flowbased MPPT algorithm is further proposed to be a challenging solution for the independent control of the hybrid system, where continuous control characteristic can present during a certain working state while discrete one is indicated along state transitions. Two possible configurations for the hybrid system are proposed; two separate DC/DC converters and dual input single output converter (DISO) configurations. Finally it is proposed, DC system behaviour modelling using State-Flow leading to the whole control strategy design which concern RESs MPPT, RESs and BESS coordination, power system stability and DC bus voltage regulation.Simulation and experimental results validate the effectiveness and applicability of the proposed algorithm, both results show the superiority of the proposed State-Flow based MPPT in reducing the RESs power oscillations at steady-state in various operating conditions in addition to its faster start-up and transition operation without divergence from the MPP during sudden varying weather conditions.
10

Modeling and Simulation of a Hybrid Powertrain

Hedon, Martin January 2018 (has links)
Hybrid powertrains represent the current trend on passenger cars. The purpose of thisreport is to create a basic model of a hybrid powertrain in Matlab/Simulinkenvironment and study their performance over certification driving cycle. Threecommonly used architectures are modeled and discussed in Simulink. Hence, the basiccomponents of a powertrain – battery, electric machine and combustion engine – arestudied and basic models are realized. A Thevenin equivalent circuit is used to simulatethe behavior of the battery, and the combustion engine is modeled after a Willansmodel. The electric machine model is based on a known efficiency map. Then, thearchitectures are created as well as their control strategies. The control strategies arecreated through state diagrams, and implemented into the Simulink model viaStateflow charts. A validation procedure is presented in order to study the consistencyof the models. / Hybrid drivlinor representerar en central personbilstrend. Syftet med rapporten är attpresentera en grundläggande modell för en hybrid drivlina i Matlab/Simulink. Trearkitekturer behandlas och har implementerats i Simulink. Sedan studeras degrundläggande komponenterna i ett drivaggregat (batteri, elmaskin ochförbränningsmotor). En Thevenin-ekvivalent krets används för att simulera batterietsbeteende. Förbränningsmotorn är modellerad efter en Willans-modell.Elmaskinmodellen är baserad på en känd verkningsgradsmapp. De tillhörandestyrstrategierna med hjälp av tillståndsdiagram. De implementeras i Simulinkmodellenmed hjälp av Stateflow-diagram. Ett valideringsförfarande presenteras ochvisar modellernas konsistens.

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