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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.
161

Driving Simulator Development and Performance Study

Juto, Erik January 2010 (has links)
The driving simulator is a vital tool for much of the research performed at theSwedish National Road and Transport Institute (VTI). Currently VTI posses three driving simulators, two high fidelity simulators developed and constructed by VTI, and a medium fidelity simulator from the German company Dr.-Ing. Reiner Foerst GmbH. The two high fidelity simulators run the same simulation software, developed at VTI. The medium fidelity simulator runs a proprietary simulation software. At VTI there is a wish to integrate the medium fidelity Foerst Trainer simulator hardware into the VTI simulation software environment. This would increase research, development and maintanance flexibility and simulator availability since development and research could be performed on one additional simulator. Anintegration would lead to a homogenous software environment that also decreasesdevelopment, maintanance and training costs.To integrate the Foerst Trainer simulator and the VTI simulation software to communicate a program that translates and relays input and output between the two was developed. An assessment of the hardware-software integration was performed through an experiment where the high fidelity Simulator 3 and the medium fidelity Foerst Trainer simulator were compared. The experiment was designed to measure the participants driving performances and the perceived realism of the simulator. The results of the experiment shows that there is suprisingly small differences between the simulators, but more research is needed for more conclusive results.
162

Modelling of a Power System in a Combined Cycle Power Plant

Bengtsson, Sara January 2011 (has links)
Simulators for power plants can be used for many different purposes, like training for operators or for adjusting control systems, where the main objective is to perform a realistic behaviour for different operating conditions of the power plant. Due to an increased amount of variable energy sources in the power system, the role of the operators has become more important. It can therefore be very valuable for the operators to try different operating conditions like island operation. The aim of this thesis is to model the power system of a general combined-cycle power plant simulator. The model should contain certain components and have a realistic behaviour but on the same time be simple enough to perform simulations in real time. The main requirements are to simulate cold start, normal operation, trip of generator, a controlled change-over to island operation and then resynchronisation. The modelling and simulations are executed in the modelling software Dymola, version 6.1. The interface for the simulator is built in the program LabView, but that is beyond the scope of this thesis. The results show a reasonable performance of the power system with most of the objectives fulfilled. The simulator is able to perform a start-up, normal load changes, trip of a generator, change-over to island operation as well as resynchronisation of the power plant to the external power grid. However, the results from the changing-over to island operation, as well as large load losses during island operation, show an unreasonable behaviour of the system regarding the voltage magnitude at that point. This is probably due to limitations in calculation capacity of Dymola, and the problem has been left to further improvements due to lack of time. There has also been a problem during the development of a variable speed regulated induction motor and it has not been possible to make it work due to lack of enough knowledge about how Dymola is performing the calculations. Also this problem has been left to further improvements due to lack of time.
163

- De e bara å köra : Lärande i fysisk miljö och simulator / - It is just to drive : Learning in physical enviroment and simulator

Fyhr, Jeanette January 2011 (has links)
Denna studie handlar om lärande på ett yrkesgymnasium där de utbildar sig till lastbilschaufförer och där de varierande tränar i simulator och fysisk trafik. De tränandes erfarande i de olika lärsituationerna har undersökts ur ett sociokulturellt perspektiv genom kvalitativ metod. Resultatet visar att man kan se de olika lärmiljöerna som två olika träningssituationer där olika saker tränas. Simulatorn ger möjlighet att fördjupa sig i svårigheter där miljön hindrar från att gå in på detaljer och öva om och om igen i den fysiska trafiken. Man kan zooma in, skala av miljön eller se sina egna övningar på skärmar, som man inte kan i den fysiska träningssituationen. I simulatorn tränas främst precision, rutiner, noggrannhet, stresshantering, planering och koncentration. I simulatorn tvingas de tränande till att göra samma övning om och om igen tills det blir perfekt. När man tränar i den fysiska trafiken handlar det om helheten, uppmärksamhet, närvaro, riskbedömning och interaktion med andra trafikanter i miljön som man kör i. Det handlar också om manövrering, konsekvenser av handlande i situationer och hur man bör handla för att inte skapa risker. I körning i den fysiska miljön gäller det att snabba på och det finns ingen tid för detaljer. Många på skolan kommer från generationers åkare. De är på ett sätt födda in i rollen som lastbilschaufförer, kan språket, känner till miljön, har en självsäkerhet, hemtamhet och redan funnen identitet i sammanhanget. Detta påverkar deras resultat, deras attityd till uppgifter och hur de tar sig an det som ska göras. Även datorspelserfarenhet har betydelse för deltagarnas attityd till simulatorn. De som är vana att spela datorspel har lättare att förstå bilden i simulatorn, men uttrycker också att det tar tid att lära sig att förstå den. Speciellt avstånd och hastighet verkar vara extra problematiskt.
164

A SystemC simulator for the dynamic segment of the FlexRay protocol

Podduturi, Venkata Rama Krishna Reddy January 2012 (has links)
FlexRay, developed by a consortium of over hundred automotive companies, is a real-time in-vehicle communication protocol for automotive networks. It is being used as a higher-performance, time-triggered, and deterministic serial bus in automobiles for many safety-critical and x-by-wire systems. In x-by-wire systems the hydraulic parts of systems such as steering and braking are replaced with electronics. As x-by-wire systems are safety-critical, they must be fault-tolerant, deterministic, and should have synchronized time base (global time). FlexRay fulfils all these requirements as it is a deterministic and fault-tolerant serial bus system with data rates of 10 Mbps for extremely safety- and time-critical applications. As, FlexRay has become the de-facto standard for high speed safety-critical communications in automotive domain, and timing analysis of FlexRay still continues to generate significant research interest. The FlexRay allows both time-triggered and event-triggered messages. The static (ST) segment allows time-triggered transmission, while dynamic (DYN) segment allows event-triggered transmission. As the DYN segment transmits messages based on their priorities; so the delay suffered by a message depends on the interferences by its higher priority messages. Computing interferences of the higher priority messages is a challenging problem for the DYN segment of FlexRay [32]. So, in order to compute interferences of the higher priority messages one way is to use simulation technique. The SystemC simulator proposed in this thesis is used to model and simulate the behaviour of the DYN segment of the FlexRay protocol. This modelling and simulation is done on system level using the system description language SystemC. The simulator estimates the delay suffered by a message instances because of the interferences of higher priority messages. This estimation of delay is done by taking no-jitter/jitter into consideration. Finally, in both the cases the delay suffered by each and every message instance is plotted.
165

A Behavioral Model of a DSP Processor with Scalable Structure / Beteendemodell for DSP-processor med skalbar struktur

Lindblad, Ulrik, Thalin, Patrik January 2002 (has links)
In mobile digital devices, low power consumption is an important matter to reduce the need for a heavy and big battery. One way of reducing the power consumption is to construct the hardware so that the performance is optimal for the application. The demand of performance is dependent of the tasks that the device will be performing. This is where scalable structure of the hardware is an idea to solve the problem. This master thesis serve as a starting point for developing a digital signal processor with scalable structure. The digital signal processor is a common and important part of digital processing. Scalable struture is in this case adding and removing parts of the memory and/or the instruction set, and to make the data wordlength variable. The development is simplified by modeling it on an existing processor. The result of this master thesis is an instruction simulator written in C language. The simulator will be a model for development of the hardware.
166

Kranspetsstyrning : en jämförande utvärdering av kranstyrning för skogsmaskiner utförd i simulator / Boomtip Control : a Comparative Evaluation of two Control Systems for Forestry Machines using a Simulator

Egermark, Therese January 2005 (has links)
Syftet med studien var att utvärdera om kranspetsstyrning i skogsmaskiner är ett enklare styrsystem att lära sig från grunden och om arbetsbelastningen värderades lägre, än den konventionella styrningen. Meningen var även att kartlägga skillnader i inlärningsprocessen samt i upplevd arbetsbelastning. Detta krävde konstruktion av mätmetoder för insamling av relevant information. Utvärderingen gjordes i enskogsmaskinsimulator vid manövrering av skotare samt genom enkätundersökningar. Studien genomfördes med hjälp av försöksdeltagare från naturbruksgymnasiet Jällaskolan i Uppsala. Övningar och tester utfördes i skogsmaskinsimulatorn. Prestationer dokumenterades med hjälp av färdighetstester och enkäter. Resultaten av studien visar tydligt att kranspetsgruppen presterar signifikant bättre i samtliga kategorier som mätts genom tester, med undantag av åtgången tid per test. Avseende tid är kranspetgruppen inte statistiskt säkert bättre, men gruppens förbättringstakt är avsevärt högre än den konventionella gruppen, vars resultat hålls på samma nivå över perioden. Därmed visar studien att kranspetsstyrning i de gjorda testerna är ett enklare system att lära sig från grunden. Kvalitativa undersökningar visade att kranspetsgruppen i genomsnitt värderade arbetsbelastningen av testkörningarna lägre än den konventionella gruppen.
167

Simulerade rattar : En studie om simulatorn som pedagogiskt verktyg i buss- och lastbilsförarutbildningar

Magnusson, Peter January 2009 (has links)
Syftet med studien är att undersöka lastbil- och bussimulatorers för- och nackdelar i användandet som pedagogiskt verktyg. I undersökningen har intervjuer med tre pedagoger och tre studenter genomförts för att utvärdera simulatorer som pedagogiskt verktyg. En strävan att informera och väcka ett intresse av tekniken som hjälpmedel i undervisningen har också legat till grund för arbetet. Enligt flera forskare finns ekonomiska och tidseffektiva vinster med att använda simulatorer i undervisningen. Fördelar med den virtuella miljön är att studenterna kan lära sig hur det är att köra ett stort fordon, möjlighet finns likaså att öva på oförutsedda kritiska händelser. Studenterna och pedagogerna som intervjuades ser fördelar med tidsvinsten samt att det är ett bra verktyg för nybörjaren. Nackdelar med fordonssimulatorn finns i återgivningen att efterlikna ett riktigt fordon samt den grafiska miljön. Studenter och pedagoger är väl överens om återgivning av miljön i simulatorn är mycket bra men den innehåller också brister. Informanterna har alla reflekterat över detta men ingen har antytt att det påverkat deras inlärning negativt. Fordonssimulatorer är relativt nytt i Sverige, idag finns det ett fåtal fordonssimulatorer i våra skolor. Tekniken har tidigare funnits men återgivningen av miljön och kostnaden har varit ett starkt argument för att inte investera i verktyget. Tekniken och kostnaden har förändrats och gör simulatorn till både ett ekonomiskt och pedagogiskt hjälpmedel
168

Wave-Pipelined Multiplexed (WPM) Routing for Gigascale Integration (GSI)

Joshi, Ajay Jayant 12 April 2006 (has links)
The main objective of this research is to develop a pervasive wire sharing technique that can be easily applied across the entire range of on-chip interconnects in a very large scale integration (VLSI) system. A wave-pipelined multiplexed (WPM) routing technique that can be applied both intra-macrocell and inter-macrocell interconnects is proposed in this thesis. It is shown that an extensive application of the WPM routing technique can provide significant advantages in terms of area, power and performance. In order to study the WPM routing technique, a hierarchical approach is adopted. A circuit-level, system-level and physical-level analysis is completed to explore the limits and opportunities to apply WPM routing to current VLSI and future gigascale integration (GSI) systems. Design, verification and optimization of the WPM circuit and measurement of its tolerance to external noise constitute the circuit-level analysis. The physical-level study involves designing wire sharing-aware placement algorithms to maximize the advantages of WPM routing. A system-level simulator that designs the entire multilevel interconnect network is developed to perform the system-level analysis. The effect of WPM routing on a full-custom interconnect network and a semi-custom interconnect network is studied.
169

Design and Implementation of Simulator Mechanisms of Architecture Description Language

Liu, Yi-ting 13 September 2012 (has links)
In the age of system-on-chip designs, design complexity of systems increases continuingly. This results in difficulty of design convergence. In design exploration of system architectures, we need to design, specify, and verify system designs effectively. By employing an architecture description language (ADL), we can effectively support specification and verification of system level designs. Existing ADLs have certain de-efficiencies in specification capabilities. We designed and improved specification capabilities in our architecture description language. Specification techniques in our ADL include behavioral description, structural description, regular structure description, built-in architecture feature description, and data integration description. In this thesis research, we focus on supporting verification capability of our ADL. We designed a simulator of the ADL. The simulation mechanisms include language input design, simulation data structure construction, behavioral simulation, structural simulation, regular architecture simulation, built-in architecture feature simulation, and data integration mechanism. With the ADL simulator, we can verify functionality and performance of architecture designs specified in the ADL. Simulation results can thus be used to guide design exploration and help design convergence.
170

Rigid Modeling of MRT Propulsion And Load Flow Analysis

Liao, Jung-Ting 12 June 2001 (has links)
The main goal of this thesis is to improve the efficiency of power consumption for single train and propose the effects of the voltage variation to AC/DC power flow. This thesis establishes a simplified mathematic model for motor drivers with the magnetic vector control laws. Furthermore, it designs the framework of the motor drives model with the power system blockset of the MATLAB/SIMULINK. The mass rapid transit(MRT) power system framework are also introduced in the thesis. Besides the power and propelment system model are developed. Due to the differences of the load pattern for the MRT system and the other customers, the analysis can be separated into static station load and dynamic load during the train operations. Static station load is constant and easy to measure. But dynamic load leads to some extent of variation depended on the MRT network characteristics and the headway of trains. The power consumption for dynamic load is about 60-70% of the whole MRT power consumption. The whole process of starting, acceleration, coasting and stopping are realistically concerned for the simulation of MRT operation. In this thesis, the DC system is composed of a 12 pulse rectifying transformer, a conductor rail, motor-driven induction drive control, VVVF inverter, and a 3-phase motor-driven induction electric power model. The performance for single train can be obtained very efficiently with the rate curves. To perform the MRT power system simulation, an AC/DC load flow analysis has been developed with Matlab. The power system model of an simulation for Taipei MRT system has been created, the AC/DC load flow analysis is executed to analyze the effects of traction substation, voltage fluctuation, and various load under the dynamic operation for multiple trains. The efficiency of proposed methodology to solve the optimal MRT operation is verified by comparing to the results of Train Performance Simulator (TPS), which has been used by Taipei MRT project. It is suggested that the proposed rigid modeling of propulsion driving system can enhance the accuracy of system simulation and provide the tool to achieve better planing of MRT operation.

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