Dissertations / Theses on the topic 'Simulation vehicle model'
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Shanmugam, Karthikeya. "Simulation model development of vehicle dynamics-brakes." Thesis, Uppsala universitet, Institutionen för informationsteknologi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-393300.
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Snare, Matthew C. "Vehicle Dynamics Model for Predicting Maximum and Typical Acceleration Rates for Passenger Vehicles." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/34779.
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Effectively modeling the acceleration behavior of vehicles is an important consideration in a variety of transportation engineering applications. The acceleration profiles of vehicles are important in the geometric design of roadways and are used to model vehicle behavior in simulation software packages. The acceleration profile of the vehicle is also a critical parameter in fuel consumption and emissions models. This paper develops and validates a vehicle dynamics model to predict the maximum acceleration rates of passenger vehicles. The model is shown to be superior to other similar models in that it accurately predicts speed and acceleration profiles in all domains and for a variety of vehicle types. The paper also modifies the model by introducing a reduction factor, which enables the model to predict the typical acceleration patterns for different driver types. The reduction factors for the driving population are shown to follow a normal distribution with a mean of 0.60 and a standard deviation of 0.08. The paper also provides new data sets containing maximum and typical acceleration profiles for thirteen different vehicles and twenty different drivers.Master of Science
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Kanarat, Amnart. "Modeling and Simulation of a Multi-Unit Tracked Vehicle." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/9755.
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A multi-unit tracked vehicle such as a continuous haulage system is widely used in underground mining applications due to its high mobility and payload capacity on rugged and soft terrain. To automate such a system, a high fidelity model of a tracked vehicle is essential in designing a controller for each tracked vehicle in the system, and a system model is required to simulate its response to input commands.
This thesis presents the 2-D mathematical models of a tracked vehicle and a multi-unit tracked vehicle. All existing track-terrain interaction models are investigated and modified. By employing the modified track-terrain interaction model and applying Newton's second law of motion, the equations of motion of both single and multi-unit tracked vehicles can be derived. Computer programs for simulating the motions of these tracked vehicles on level ground have been implemented on a digital computer based on the derived system of differential equations. The fourth-order Runge-Kutta and Keun's methods are adopted to numerically integrate these differential equations.
The simulation results clearly show that the programs can accurately predict the motion of a tracked vehicle maneuvered on horizontal plane, and closely predict the response of a multi-unit tracked vehicle operated on level ground its command inputs.Master of Science
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Carlsson, Magnus. "Methods for Early Model Validation : Applied on Simulation Models of Aircraft Vehicle Systems." Licentiate thesis, Linköpings universitet, Maskinkonstruktion, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-91277.
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Simulation models of physical systems, with or without control software, are widely used in the aeronautic industry in applications ranging from system development to verification and end-user training. With the main drivers of reducing the cost of physical testing and in general enhancing the ability to take early model-based design decisions, there is an ongoing trend of further increasing the portion of modeling and simulation. The work presented in this thesis is focused on development of methodology for model validation, which is a key enabler for successfully reducing the amount of physical testing without compromising safety. Reducing the amount of physical testing is especially interesting in the aeronautic industry, where each physical test commonly represents a significant cost. Besides the cost aspect, it may also be difficult or hazardous to carry out physical testing. Specific to the aeronautic industry are also the relatively long development cycles, implying long periods of uncertainty during product development. In both industry and academia a common viewpoint is that verification, validation, and uncertainty quantification of simulation models are critical activities for a successful deployment of model-based systems engineering. However, quantification of simulation results uncertainty commonly requires a large amount of certain information, and for industrial applications available methods often seem too detailed or tedious to even try. This in total constitutes more than sufficient reason to invest in research on methodology for model validation, with special focus on simplified methods for use in early development phases when system measurement data are scarce. Results from the work include a method supporting early model validation. When sufficient system level measurement data for validation purposes is unavailable, this method provides a means to use knowledge of component level uncertainty for assessment of model top level uncertainty. Also, the common situation of lacking data for characterization of parameter uncertainties is to some degree mitigated. A novel concept has been developed for integrating uncertainty information obtained from component level validation directly into components, enabling assessment of model level uncertainty. In this way, the level of abstraction is raised from uncertainty of component input parameters to uncertainty of component output characteristics. The method is integrated in a Modelica component library for modeling and simulation of aircraft vehicle systems, and is evaluated in both deterministic and probabilistic frameworks using an industrial application example. Results also include an industrial applicable process for model development, validation, and export, and the concept of virtual testing and virtual certification is discussed.Simmuleringsmodeller av fysikaliska system, med eller utan reglerande mjukvara, har sedan lång tid tillbaka ett brett användningsområde inom flygindustrin. Tillämpningar finns inom allt från systemutveckling till produktverifiering och träning. Med de huvudsakliga drivkrafterna att reducera mängden fysisk provning samt att öka förutsättningarna till att fatta välgrundade modellbaserade designbeslut pågår en trend att ytterligare öka andelen modellering och simulering. Arbetet som presenteras i denna avhandling är fokuserat på utveckling av metodik för validering av simuleringsmodeller, vilket anses vara ett kritiskt område för att framgångsrikt minska mängden fysisk provning utan att äventyra säkerheten. Utveckling av metoder för att på ett säkert sätt minska mängden fysisk provning är speciellt intressant inom flygindustrin där varje fysiskt prov vanligen utgör en betydande kostnad. Utöver de stora kostnaderna kan det även vara svårt eller riskfyllt att genomföra fysisk provning. Specifikt är även de långa utvecklingscyklerna som innebär att man har långa perioder av osäkerhet under produktutvecklingen. Inom såväl industri som akademi ses verifiering, validering och osäkerhetsanalys av simuleringsmodeller som kritiska aktiviteter för en framgångsrik tillämpning av modellbaserad systemutveckling. Kvantifiering av osäkerheterna i ett simuleringsresultat kräver dock vanligen en betydande mängd säker information, och för industriella tillämpningar framstår tillgängliga metoder ofta som alltför detaljerade eller arbetskrävande. Totalt sett ger detta särskild anledning till forskning inom metodik för modellvalidering, med speciellt fokus på förenklade metoder för användning i tidiga utvecklingsfaser då tillgången på mätdata är knapp. Resultatet från arbetet inkluderar en metod som stöttar tidig modellvalidering. Metoden är avsedd att tillämpas vid brist på mätdata från aktuellt system, och möjliggör utnyttjande av osäkerhetsinformation från komponentnivå för bedömning av osäkerhet på modellnivå. Avsaknad av data för karaktärisering av parameterosäkerheter är även ett vanligt förekommande problem som till viss mån mildras genom användning av metoden. Ett koncept har utvecklats för att integrera osäkerhetsinformation hämtad från komponentvalidering direkt i en modells komponenter, vilket möjliggör en förenklad osäkerhetsanalys på modellnivå. Abstraktionsnivån vid osäkerhetsanalysen höjs på så sätt från parameternivå till komponentnivå. Metoden är implementerad i ett Modelica-baserat komponentbibliotek för modellering och simulering av grundflygplansystem, och har utvärderats i en industriell tillämpning i kombination med både deterministiska och probabilistiska tekniker. Resultatet från arbetet inkluderar även en industriellt tillämplig process för utveckling, validering och export av simuleringsmodeller, och begreppen virtuell provning och virtuell certifiering diskuteras.
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Karanja, Bethuel, and Parsa Broukhiyan. "Commercial Vehicle Air Consumption: Simulation, Validation and Recommendation." Thesis, KTH, Maskinkonstruktion (Inst.), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-209657.
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This report details the work done in a master thesis project. The project was conducted at the Brake Performance Department at Scania CV AB. The project involves the development of a numerical model (in Matlab) that calculates and predicts air consumption in a truck under different drive cycles. The report first details tests and experiments done so as to acquire the necessary information for the development of the model. The report then presents the model that was created and delves into tests that were conducted for its validation. A model is created that allows the user to select different component combinations on the trucks along with different loading scenarios and drive cycles. Finally the model is used to evaluate air consumption in trucks during particularly strenuous cycles. The model developed is found to be reliable and accurate to with 7% with regard to amount of air consumed. With its help, several recommendations on how air consumption in commercial vehicles can be improved are made. The best components’ combination is also found and presented.I denna rapport beskrivs ett examensarbete som genomfördes på bromsavdelningen på Scania CV AB. Projektet innefattar utveckling av en numerisk modell (i Matlab) som beräknar och förutspår luftförbrukningen i en lastbil under olika körcykler. I rapporten beskrivs det tester och experiment som gjordes för att ta fram nödvändiga uppgifter för utvecklingen av modellen. Sedan presenteras modellen som skapades och alla valideringstester som genomfördes. Modellen är gjord så att användaren kan kombinera olika komponentkombinationer för lastbilar med olika lastningskonfigurationer och körcykler. Slutligen används modellen för att utvärdera luftförbrukningen i lastbilar under särskilt ansträngande körcykler. Den utvecklade modellen visade sig vara pålitlig och korrekt med en felmarginal på 7% med avseende på mängden luft som konsumeras. Med dess hjälp kunde flera rekommendationer ges om hur luftförbrukningen i kommersiella fordon kan förbättras. De bästa komponentkombinationerna hittades också och presenteras i denna rapport
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Shakleton, Philip Andrew. "An optimised wheel-rail contact model for vehicle dynamics simulation." Thesis, Manchester Metropolitan University, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.515184.
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The wheel-rail interface is a complex component of the dynamic railway vehicle-track system. The wheel-rail interface governs the motion of a railway vehicle and is responsible for wheel and track damage such as wear and rolling contact fatigue. Wheelrail contact models are used extensively in railway engineering to calculate contact forces and stresses, in order to evaluate dynamic vehicle behaviour or assess track damage. Due to the complexity of the wheel-rail interaction, and computational limitations, all wheel-rail contact models make simplifying assumptions so that solutions may be obtained in an acceptable time. This thesis presents a survey of current wheel-rail contact models and theories, and associated literature, focussing on the various simplifications made by the different approaches. In order to allow an informative comparison of contact model performance a wheel-rail contact benchmark has been established, detailing carefully defined, challenging contact conditions. Interested parties were invited to submit solutions for the contact benchmark cases, and results from ten contributors were received and compared. From the analysis of current contact models and the contact benchmark results, a new wheel-rail contact model has been developed. The model is based on a novel relationship between the normal contact force and the intersecting volume found from virtually penetrating two, three dimensional contacting bodies. Results from the new contact model, named the 'Rectified Interpenetration method', were compared favourably to the recognised methods of Hertz and Kalker. To aid future validation of wheel-rail contact model and understanding of the wheel. rail interaction, a feasibility study of a new wheel-rail contact measurement technique has been undertaken. The technique is based on an established ultrasound method capable of measuring the normal contact pressure distribution for machined wheel and rail samples in laboratory conditions. The new technique aims to advance the state of the art to allow wheel-rail contact measurements under rolling conditions. The study concluded that there is scope for further development of the technique, and discusses the transitional difficulties in advancing the static method to rolling contacts.
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Gim, Gwanghun. "Vehicle dynamic simulation with a comprehensive model for pneumatic tires." Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184478.
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This study presents an analytical approach for the mechanics of the pneumatic tires and the vehicle dynamic simulation. Most of tire dynamic parameters in this study are derived by using the tire geometry rather than experimental data. For the tire dynamic properties, explicit formulations are derived analytically as functions of slip ratio, slip angle, camber angle, and other tire dynamic parameters. These formulations can be efficiently used for the general vehicle simulations of braking/traction and steering maneuvers with a varying camber angle at irregular terrains. For on-highway vehicle simulations, a conceptual sports car is modeled as a twenty-six degrees of freedom multi-body system, while the military 1/4 ton truck M151-A2 is modeled as a fourteen degrees of freedom multi-body system for off-highway vehicle simulations. To study vehicle ride comfort, stability, and maneuverability, numerous vehicle simulations are performed using the comprehensive tire model, steering, braking, traction, nonlinear suspension, and realistic irregular terrains. For these simulations, a general-purpose multi-body dynamic analysis code (named MBOSS) has been developed.
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Chen, Jen-Ming 1960. "Developing and validating a simulation model for emergency vehicle locations." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276894.
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This thesis deals with the problem of locating emergency ambulances in an urban area. We developed a simulation model to analyze possible improvements in ambulance service. A new point-to-point travel time model is introduced in our simulation. Validating the model proved to be a difficult task and is discussed in detail. Our model has been applied to the Tucson Emergency Medical Service system.
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Zheng, Pengjun. "A microscopic simulation model of merging operation at motorway on ramps." Thesis, University of Southampton, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289589.
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Lee, SeeWoo. "Development of new dynamic tire model for improved vehicle dynamics simulation." The Ohio State University, 1994. http://rave.ohiolink.edu/etdc/view?acc_num=osu1334584006.
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Rupp, Matthew Y. "Passive dynamic steering system model for use in vehicle dynamics simulation." Connect to resource, 1994. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1157568618.
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Olstam, Johan. "A model for simulation and generation of surrounding vehicles in driving simulators." Licentiate thesis, Linköpings universitet, Institutionen för teknik och naturvetenskap, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-4672.
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Driving simulators are used to conduct experiments on for example driver behavior, road design, and vehicle characteristics. The results of the experiments often depend on the traffic conditions. One example is the evaluation of cellular phones and how they affect driving behavior. It is clear that the ability to use phones when driving depends on traffic intensity and composition, and that realistic experiments in driving simulators therefore has to include surrounding traffic. This thesis describes a model that generates and simulates surrounding vehicles for a driving simulator. The proposed model generates a traffic stream, corresponding to a given target flow and simulates realistic interactions between vehicles. The model is built on established techniques for time-driven microscopic simulation of traffic and uses an approach of only simulating the closest neighborhood of the driving simulator vehicle. In our model this closest neighborhood is divided into one inner region and two outer regions. Vehicles in the inner region are simulated according to advanced behavioral models while vehicles in the outer regions are updated according to a less time-consuming model. The presented work includes a new framework for generating and simulating vehicles within a moving area. It also includes the development of enhanced models for car-following and overtaking and a simple mesoscopic traffic model. The developed model has been integrated and tested within the VTI Driving simulator III. A driving simulator experiment has been performed in order to check if the participants observe the behavior of the simulated vehicles as realistic or not. The results were promising but they also indicated that enhancements could be made. The model has also been validated on the number of vehicles that catches up with the driving simulator vehicle and vice versa. The agreement is good for active and passive catch-ups on rural roads and for passive catch-ups on freeways, but less good for active catch-ups on freeways.
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Girmay, Mesele Asmelash. "AUTOSARLang: Threat Modeling and Attack Simulation for Vehicle Cybersecurity." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-240410.
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The rapid growth and development of the Information and Communications Technology attract many industries including the automotive industry. Since the last four decades, the automotive engineering has been impacted by the Information Technology. Nowadays, modern vehicles are being designed with up to hundreds of electronic control units (ECUs) and be able to communicate with other vehicles, infrastructure, and other things via wireless networks and sensors. For such in-vehicle networks, serial bus systems like CAN bus, LIN bus, FlexRay, and MOST are standardized. Parallel to this, the automotive industry vendors designed and standardized automotive open systems architecture (AUTOSAR) software platform. AUTOSAR has two main standards - the classical platform and adaptive platform. The classical platform (CP) is designed for the current embedded ECUs, whereas the adaptive platform (AP) is being designed for the future intelligent ECUs. The intelligent AP ECU constitute many multi-processing processors and Ethernet to realize the future autonomous vehicles.On the other hand, automotive industries shall ensure “safety first” in their design and regard it as part of their market feature. Directly or indirectly, the safety of the modern connected vehicles is related to their cybersecurity. Today, cybersecurity professionals are conducting researches to bring remarkable solutions to the sophisticated cyberattacks. One approach of cybersecurity solution is to make a cyber threat modeling and attack simulations. Example, meta-attack-language (MAL) is a threat modeling and attack simulation language, which is designed to make domain-specific threat analysis.In this study, potential assets of an automotive vehicle with AP ECUs are identified. Then, threats of each identified asset are collected from different literature. With both inputs, a cyber threat model is written using MAL. Finally, validation of the model is made with a simulation language. Consequently, modern vehicle with AP ECUs is modeled and simulated.This study contributes four important things - list of potential assets that AP running vehicle constitutes, collected list of threats of the identified assets, validated cyber threat model, and simulation test cases for each potential attack paths in the model.Den snabba tillväxten och utvecklingen av informations- och kommunikationstekniken lockar många branscher, däribland bilindustrin. Sedan de senaste fyra decennierna har automotive engineering påverkats av informationstekniken. Numera är moderna fordon utformade med upp till hundratals elektroniska styrenheter (ECU) och kan kommunicera med andra fordon, infrastruktur och andra saker via trådlösa nätverk och sensorer. För sådana inbyggda nätverk är seriella bussystem som CAN-buss, LIN-buss, FlexRay och MOST standardiserade. Parallellt med detta har automotive-leverantörerna utformat och standardiserat automatsystem för öppna systemarkitekturer (AUTOSAR). AUTOSAR har två huvudstandarder - den klassiska plattformen och den adaptiva plattformen. Den klassiska plattformen (CP) är utformad för nuvarande inbyggda ECU, medan den adaptiva plattformen (AP) är utformad för framtida intelligenta ECU. Den intelligenta AP-enheten utgör många processorer och Ethernet för att förverkliga de framtida autonoma fordonen. Bilindustrin ska å andra sidan säkerställa "säkerhet först" i sin design och betrakta den som en del av deras marknadsfunktion. Direkt eller indirekt är säkerheten hos moderna anslutna fordon relaterad till sin cybersäkerhet. Idag genomför cybersecurity-proffs för att få anmärkningsvärda lösningar på de sofistikerade cyberattackarna. Ett tillvägagångssätt för cybersecurity-lösningen är att göra en modellering av cyberhot och attack simuleringar. Exempel, meta-attack-language (MAL) är ett hot modellerings-och attack simuleringsspråk, som är utformat för att göra domänspecifik hotanalys. I denna studie identifieras potentiella tillgångar i ett fordonsbil med AP-ECU. Därefter samlas hot av varje identifierad tillgång från olika litteratur. Med båda ingångarna skrivs en cyber-hotmodell med MAL. Slutligen görs validering av modellen med ett simuleringsspråk. Följaktligen modelleras och simuleras moderna fordon med AP-ECU. Denna studie bidrar till fyra viktiga saker - en lista över potentiella tillgångar som AP-körfordon utgör, samlad lista över hot av identifierade tillgångar, validerad cyberhot-modell och simuleringsprovfall för varje potentiell attackvägar i modellen.
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Matthews, Patricia Aileen 1963. "Validation of a vehicle mobility computer model for heavy earthmoving equipment." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/276946.
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The computer program WHEEL is a mathematical model which predicts off-road vehicle performance characteristics. The program was developed using empirical relationships resulting from mobility tests on conventional-sized trucks and tires. The model was subsequently validated by comparing the model's predicted values of vehicle performance parameters, such as net drawbar pull, slip, sinkage and torque, with field test results for conventional-sized vehicles. However, validity of the model for predicting the off-road mobility of vehicles with large diameter tires was not established. The purpose of this study was to provide this validation. Values of net drawbar pull and slip for a Case 2390 tractor with 70.2" diameter driven wheels predicted by computer program WHEEL compare favorably with traction data obtained from tractor performance tests conducted by the University of Arizona Department of Agricultural Engineering. Therefore, the model may be used confidently to analyze performance of vehicles with large diameter wheels.
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Bailey, William. "Using model-based methods to support vehicle analysis planning." Thesis, Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50377.
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Vehicle system analysis models are becoming crucial to automotive designers wishing to better understand vehicle-level attributes and how they vary under different operating conditions. Such models require substantial planning and collaboration between multidisciplinary engineering teams. To improve the process used to create a vehicle system analysis model, the broader question of how to plan and develop any model should be addressed. Model-Based Systems Engineering (MBSE) is one approach that can be used to make such complex engineering tasks more efficient.
MBSE can improve these tasks in several ways. It allows for more formal communication among stakeholders, avoids the ambiguity commonly found in document-based approaches to systems engineering, and allows stakeholders to all contribute to a single, integrated system model. Commonly, the Systems Modeling Language (SysML) is used to integrate existing analysis models with a system-level SysML model. This thesis, on the other hand, focuses on using MBSE to support the planning and development of the analysis models themselves.
This thesis proposes an MBSE approach to improve the development of system models for Integrated Vehicle Analysis (IVA). There are several contributions of this approach. A formal process is proposed that can be used to plan and develop system analysis models. A comprehensive SysML model is used to capture both a descriptive model of a Vehicle Reference Architecture (VRA), as well as the requirements, specifications, and documentation needed to plan and develop vehicle system analysis models. The development of both the process and SysML model was performed alongside Ford engineers to investigate how their current practices can be improved.
For the process and SysML model to be implemented effectively, a set of software tools is used to create a more intuitive user interface for the stakeholders involved. First, functionality is added to views and viewpoints in SysML so that they may be used to formally capture the concerns of different stakeholders as exportable XML files. Using these stakeholder-specific XML files, a custom template engine can be used to generate unique spreadsheets for each stakeholder. In this way, the concerns and responsibilities of each stakeholder can be defined within the context of a formally defined process. The capability of these two tools is illustrated through the use of examples which mimic current practices at Ford and can demonstrate the utility of such an approach.
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Akbarian, Mehdi. "Model based pavement-vehicle interaction simulation for life cycle assessment of pavements." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/73847.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 116-121).
Responsible for about a third of the annual energy consumption and greenhouse gas (GHG) emissions, the U.S. transportation Network needs to attain a higher level of sustainability. This is particularly true for the roadway Network and the design of pavements in it. Vehicle fuel consumption required to overcome resisting forces due to pavement-vehicle interaction (PVI) is an essential part of life-cycle assessment (LCA) of pavement systems. These PVIs are intimately related to pavement structure and material properties. While various experimental investigations have revealed potential fuel consumption differences between flexible and rigid pavements, there is high uncertainty and high variability in the evaluated impact of pavement deflection on vehicle fuel consumption. This report adopts the perspective that a mechanistic model can contribute to closing the uncertainty gap of PVI in pavement LCA. With this goal in mind, a first-order mechanistic pavement model is considered, and scaling relationships between input parameters and the impact of PVI on vehicle fuel consumption are developed. An original calibration-validation method is established through wave propagation using the complete set of Falling Weight Deflectometer (FWD) time history data from FHWA's Long Term Pavement Performance program (LTPP), representing the U.S. roadway Network. Distributions of model parameters are determined on pavement material properties (top layer and subgrade moduli), structural properties (thickness), and loading conditions obtained from model calibration and the LTPP datasets. These input distributions are used in Monte-Carlo simulations to determine the impact of flexible and rigid pavements on passenger car and truck fuel consumption within the roadway Network. It is shown that rigid pavements behave better than flexible ones in regard to PVI due to higher stiffness. A final comparison with independent field data provides a reality check of the order of magnitude estimates of fuel consumption due to PVI as determined by the model. The calculated change in fuel consumption is used in a comparative LCA of flexible and rigid pavements, and it is shown that the impact of PVI deflection becomes increasingly important for high volume flexible roadways and can surpass GHG emissions due to construction and maintenance of the roadway system in its lifetime.
by Mehdi Akbarian.
S.M.
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Carlsson, Erik. "Modeling Hydrostatic Transmission in Forest Vehicle." Thesis, Linköping University, Department of Electrical Engineering, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-6864.
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Hydrostatic transmission is used in many applications where high torque at low speed is demanded. For this project a forest vehicle is at focus. Komatsu Forest would like to have a model for the pressure in the hose between the hydraulic pump and the hydraulic motor. Pressure peaks can arise when the vehicle changes speed or hit a bump in the road, but if a good model is achieved some control action can be developed to reduce the pressure peaks.
For simulation purposes a model has been developed in Matlab-Simulink. The aim has been to get the simulated values to agree as well as possible with the measured values of the pressure and also for the rotations of the pump and the motor.
The greatest challenge has been due to the fact that the pressure is a sum of two flows, if one of these simulated flows is too big the pressure will tend to plus or minus infinity. Therefore it is necessary to develop models for the rotations of the pump and the motor that stabilize the simulated pressure.
Different kinds of models and methods have been tested to achieve the present model. Physical modeling together with a black box model are used. The black box model is used to estimate the torque from the diesel engine. The probable torque from the ground has been calculated. With this setup the simulated and measured values for the pressure agrees well, but the fit for the rotations are not as good.
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Doucette, Reed. "The Oxford Vehicle Model : a tool for modeling and simulating the powertrains of electric and hybrid electric vehicles." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:cfff8f27-f4a4-4c77-953e-09253aba3aa0.
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This dissertation addresses the challenges of scoping and sizing components and modeling the tank to wheel energy flows in new and rapidly evolving classes of automotive vehicles. It introduces a system of computer models, known as the Oxford Vehicle Model (OVEM), which provide for the novel simulation of the powertrains of electric (EV) and hybrid electric vehicles (HEV). OVEM has a three-level structure that makes a unique contribution to the field of vehicle analysis by enabling a user to proceed from performing scoping and sizing exercises through to accurately simulating the energy flows in powertrains of EVs and HEVs utilizing existing and emerging technologies based on real world data. Level 1 uses simplified models to support initial component scoping and sizing exercises in an analysis environment where uncertainty regarding component specifications is high. Level 2 builds on Level 1 by obtaining more refined component scoping and sizing estimates via the use of component models based on well-understood scientific principles that are product-independent – a crucial feature for obtaining unbiased scoping and sizing estimates. Level 3 employs a high degree of fidelity in that its models impose actual physical limits and are based on data from real technologies. This dissertation concludes with two chapters based on studies published as journal articles that used OVEM to address key issues facing the development of EVs and HEVs. The first study used OVEM to make the novel comparison between high-speed flywheels, batteries, and ultracapacitors on the bases of cost and fuel consumption while functioning as the energy storage systems in an HEV. The second study applied OVEM towards a novel examination of the CO2 emissions from plug-in HEVs (PHEVs) and compares their CO2 emissions to those from similar EVs and ICE-based vehicles.
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Robla, Sánchez Ignacio. "Wheel Wear Simulation of the Light Rail Vehicle A32." Thesis, KTH, Spårfordon, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-261228.
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During the last decade, a novel methodology for wheel wear simulation has been developed in Sweden. The practical objective of this simulation procedure is to provide an integratedengineering tool to support rail vehicle design with respect to wheel wear performance and detailed understanding of wheel-rail interaction. The tool is integrated in a vehicle dynamicssimulation environment.The wear calculation is based on a set of dynamic simulations, representing the vehicle, the network, and the operating conditions. The wheel profile evolution is simulated in an iterativeprocess by adding the contribution from each simulation case and updating the profile geometry.The method is being validated against measurements by selected pilot applications. To strengthen the confidence in simulation results the scope of application should be as wide aspossible in terms of vehicle classes. The purpose of this thesis work has been to try to extend the scope of validation of this method into the light rail area, simulating the light rail vehicleA32 operating in Stockholm commuter service on the line Tvärbanan.An exhaustive study of the wear theory and previous work on wear prediction has been necessary to understand the wear prediction method proposed by KTH. The dynamicbehaviour of rail vehicles has also been deeply studied in order to understand the factors affecting wear in the wheel-rail contact.The vehicle model has been validated against previous studies of this vehicle. Furthermore new elements have been included in the model in order to better simulate the real conditionsof the vehicle.Numerous tests have been carried out in order to calibrate the wear tool and find the settings which better match the real conditions of the vehicle.Wheel and rail wear as well as profile evolution measurements were available before this work and they are compared with those results obtained from the simulations carried out.The simulated wear at the tread and flange parts of the wheel match quite well the measurements. However, the results are not so good for the middle part, since themeasurements show quite evenly distributed wear along the profile while the results from simulations show higher difference between extremes and middle part. More tests would benecessary to obtain an optimal solution.
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Belousov, Dennis. "Development of a Vehicle Simulation Model Consisting of Low and High Frequency Dynamics." Thesis, Linköpings universitet, Fordonssystem, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-133236.
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As vehicle testing on existing vehicles is both time and resource consuming, the work of testing safety algorithms on vehicle is desired to be made more efficient. Therefore the goal of this thesis is to study and develop a vehicle simulation model that can simulate desired dynamics of existing and non-existing vehicles. The developed model consist of two areas of application: slow dynamics and vibrational dynamics. These areas are developed and validated using different methods, but as a part of the simulator, they are to be simulated together. For the slow, low frequency, vehicle motion, a three state transient motion model is derived and examined. The possibility of parametrisation is studied and performed using prediction error minimisation. For the vibration, high frequency model, a combination of a linear quarter car model with wheel motion is used to estimate road vibration characteristics. The modelled road is used to simulate the vehicle behaviour. The suggested methods regarding the vibration modelling and road estimation are performed using power spectral density as the road is not known determinately. Wheel speeds are used to study the power spectral densities as they are available at high sampling frequencies. The available tools and sensors used during this thesis are limited to existing vehicle sensors and GPS signals. The effect of this limitation is studied and the results are discussed.
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Blackshear, Henry L. "Developing a conceptual unmanned aerial vehicle communications mobile AD Hoc network simulation model." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02Jun%5FBlackshear.pdf.
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Krishnasamy, Jayaraman 1968. "A discretized contact patch to model tire-road interaction for vehicle dynamic simulation." Thesis, The University of Arizona, 1991. http://hdl.handle.net/10150/277952.
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This work deals with the problem of determining the tire-road interaction forces for vehicle dynamic simulations. The work is an attempt to develope a numerical scheme that is universally applicable to all possible running conditions. The tire-road contact patch is approximated as a two-dimensional array of nodal points. Properties such as distribution of normal pressure, deflection and stresses over the contact patch are expressed as sets of the respective nodal values rather than analytical functions. Such a representation enables the treatment of any arbitrary, two-dimensional variation of contact patch properties. The representation of non-rectangular contact patch shapes and trapezoidal pressure distributions is also discussed. For steady state running conditions the performance of the scheme is compared with that of an existing analytical model. The applicability of the scheme to transient running conditions is also shown.
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Lee, Sungjoon. "A Cell Transmission Based Assignment-Simulation Model for Integrated Freeway/Surface Street Systems /." Connect to this title online, 1996. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1103731343.
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Farmer, Jesse Lee. "Kinematic Analysis Of A Two Body Articulated Robotic Vehicle." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/32651.
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The kinematic analysis of an articulated twin body, four-wheel, robotic vehicle is
presented. Polaris, a research platform and contending robotic vehicle in the Intelligent
Ground Vehicle Competition (IGVC) at Virginia Tech, was redesigned in 2006 to improve
the mobility of the vehicle by incorporating an innovative four-bar linkage that connects
the two bodies. The new linkage design minimizes vehicle off-tracking by allowing the
rear wheels to closely track the path of the front wheels. This thesis will outline the theoretical
kinematic model of the four-bar linkage as applied to a twin-bodied, differentially
driven vehicle. The kinematic model is validated through computer simulation as well as
experimentation on a fully operational robotic vehicle. The kinematic model presented
here outlines the foundations for an autonomous, four-wheel drive, multi-body control
system and opens avenues for dynamically controlling the tracking of the vehicleâ s rear
body with an actuated linkage configuration.Master of Science
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Ivan. "Vehicle to vehicle communication systems performance evaluation : A simulation approcach combining physical layer implementation, propagation channel model and antenna properties." Rennes, INSA, 2012. http://www.theses.fr/2012ISAR0009.
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V2X est un système de communication entre les véhicules (ou V2V) et entre les véhicules et l'infrastructure routière (véhicule à l'infrastructure, ou V2I) fonctionnant à 5,9 GHz, avec pour principal objectif d'améliorer la sécurité routière et d'augmenter la fluidité du trafic. L'évaluation des performances du système V2X par simulation numérique, reposant sur des modèles précis et éprouvés, constitue une étape fondamentale dans une logique de conception-validation avant l'intégration sur véhicule réel. Le travail présenté dans ce document se concentre sur les techniques de simulation pour l'évaluation des performances du système de communication V2X dans différents environnements d'exploitation, avec différents types de récepteur, et avec différentes antennes au niveau du récepteur. Des résultats de mesure sur banc d’essai avec des prototypes de modems V2X et avec un émulateur de canal RF, valident certaines de nos techniques et résultats de simulationV2X is a communication system between vehicles (vehicle to vehicle, or V2V) and between vehicles and the infrastructure (vehicle to infrastructure, or V2I) operating at 5. 9 GHz, with main purpose to improve road safety and to increase traffic efficiency. The computer performance evaluation of the V2X system, while employing accurate simulation models, represents an important preliminary step before its integration into vehicles and thus a possible large-scale deployment. The work presented in this document focuses on simulation techniques for realistic performance evaluation of the V2X communication system in different operating environments, with different types of receiver implementations, and with different antennas at the receiver. On-bench measurement results with V2X prototypes and with a RF channel emulator validated some of our computer simulation techniques and results
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Amkoff, Leon. "Trailer Simulation Model for an Indirect Tire Pressure Monitoring System." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-185066.
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A car with underinflated tires can lead to both safety and environmental issues. To combat this, markets have begun requiring new cars to feature a Tire Pressure Monitoring System. Systems without pressure sensors are referred to as indirect Tire Pressure Monitoring Systems, often utilizing wheel speed sensors in combination with other available sensor information to detect tire pressure losses. NIRA Dynamics is a company founded in Linköping, Sweden, most known for its indirect Tire Pressure Monitoring System called TPI. TPI needs to be verified in a large number of scenarios, which may be both difficult and expensive to realize in real vehicle tests. The purpose of this master thesis was to investigate and model what physical phenomena are associated with having a trailer connected to a car, relevant for TPI. The goal was to construct a hybrid simulation framework, making it possible to modify car-only data to reflect the effects of having a trailer connected. A car-trailer model was developed, showing close resemblance in simulations to real collected car-trailer sensor data. The model was then used to design a hybrid simulation framework, where car-only sensor signals were modified to mimic having different types of trailers attached. The hybrid simulation results show close resemblance to real collected trailer sensor data. By not requiring real trailer data for every scenario to evaluate software performance on, the proposed framework opens up the possibility to simulate data from a much larger number of trailer combinations than would otherwise have been feasible to test in real vehicle tests.
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Cersovsky, Donald D. Kleinschmidt Edward. "Mathematical model and analysis of the Tactical Unmanned Ground Vehicle (TUGV) using computer simulation /." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1993. http://handle.dtic.mil/100.2/ADA272258.
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Cersovsky, Donald D., and Edward Kleinschmidt. "Mathematical model and analysis of the Tactical Unmanned Ground Vehicle (TUGV) using computer simulation." Thesis, Monterey, California. Naval Postgraduate School, 1993. http://hdl.handle.net/10945/26052.
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The purpose of this thesis is to mathematically model the Tactical Unmanned Ground Vehicle (TUGV) in the Janus(A) Combat Model. The TUGV has three sensors, an optical, thermal, and acoustic sensor. Algorithms currently exist in Janus(A) for both optical and thermal sensors. An acoustic detection algorithm exists although not available to all Janus(A) system users. This thesis examines the TUGV prototype, explains the Janus(A) TUGV model, discusses existing acoustic detection algorithms, and tests the TUGV model in a scenario driven experiment
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Kozhakenov, Temirzhan. "MODEL-BASED SIMULATION OF AUTOMOTIVE SOFTWARE SYSTEMS." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-48851.
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The car is the most common vehicle in the world. Millions of cars are produced annually. In order for each car to find its buyer, car companies are forced to constantly improve the design of the car. Modern models are emerging, new car systems are being developed and implemented. All this is accompanied by a huge flow of information, in which it is easy to get lost. This master’s work is devoted to the trace analysis and connection of two different files. The paper proposes a developed algorithm of trace analysis for some functions of the vehicle in the C++ programming language. The files that we use to trace analysis relate to the model and the final result of its simulation.EATOP is a tool with which a model based on the EAST-ADL language was developed. Adapt is an event simulator with which our model of automotive functionality was simulated. The purpose of the study is to identify possible ways to meet timing requirements. The work is carried out in collaboration with Volvo Group Truck Technology. This company provided the LogFile, which presents results of the simulation, and model. We get an analysis of performance, one of the ways to trace data and timing. The results of our implementation are presented and discussed.
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Pu, Davide. "Demand and Capacity Problems in the Next Generation Air Transportation System." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/51218.
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This thesis investigates two main aspects of air transportation system, demand and capacity. The first study aims to estimate the potential market for Zip Vehicles, an advanced commuter type of aircraft equipped with automation and electric propulsion technologies. A Multinomial Logit Model was developed to estimate the mode choice behavior of commuters between Zip vehicle, auto and transit in seven metropolitan areas in the United States. The results showed that the Out-of-Vehicle travel time plays an important role in the decision process of commuters. Zip Vehicle is predicted to achieve residual demand with the current technologies and could become more competitive if it was equipped with Vertical Take-Off Technology. The second study developed a hybrid airport runway capacity model that blends both deterministic and simulation techniques. The model includes a graphic user interface that allows high degree of freedom to modify input parameters, such as airport information, weather conditions, minimum separation distances and aircraft grouping system. The model is widely validated and it appears to be a consistent solution for estimating airport capacity at different levels and with various degree of extensibility.Master of Science
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Turley, Carole. "Calibration Procedure for a Microscopic Traffic Simulation Model." Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd1747.pdf.
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Prestero, Timothy (Timothy Jason) 1970. "Verification of a six-degree of freedom simulation model for the REMUS autonomous underwater vehicle." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/65068.
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Thesis (S.M.)--Joint Program in Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Ocean Engineering; and the Woods Hole Oceanographic Institution); and, (S.M.)--Joint Program in Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and the Woods Hole Oceanographic Institution), 2001.Includes bibliographical references (p. 125-127).
mproving the performance of modular, low-cost autonomous underwater vehicles (AUVs) in such applications as long-range oceanographic survey, autonomous docking, and shallow-water mine countermeasures requires improving the vehicles' maneuvering precision and battery life. These goals can be achieved through the improvement of the vehicle control system. A vehicle dynamics model based on a combination of theory and empirical data would provide an efficient platform for vehicle control system development, and an alternative to the typical trial-and-error method of vehicle control system field tuning. As there exists no standard procedure for vehicle modeling in industry, the simulation of each vehicle system represents a new challenge. Developed by von Alt and associates at the Woods Hole Oceanographic Institute, the REMUS AUV is a small, low-cost platform serving in a range of oceanographic applications. This thesis describes the development and verification of a six degree of freedom, non-linear simulation model for the REMUS vehicle, the first such model for this platform. In this model, the external forces and moments resulting from hydrostatics, hydrodynamic lift and drag, added mass, and the control inputs of the vehicle propeller and fins are all defined in terms of vehicle coefficients. This thesis describes the derivation of these coefficients in detail. The equations determining the coefficients, as well as those describing the vehicle rigid-body dynamics, are left in non-linear form to better simulate the inherently non-linear behavior of the vehicle. Simulation of the vehicle motion is achieved through numeric integration of the equations of motion. The simulator output is then checked against vehicle dynamics data collected in experiments performed at sea. The simulator is shown to accurately model the motion of the vehicle.
by Timothy Prestero.
S.M.
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Pracný, Vladislav. "Neural network based shock absorber model with a thermodynamical coupling : experiment, modeling and vehicle simulation /." Aachen : Shaker, 2009. http://d-nb.info/994209967/04.
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Taheri, Shahyar. "A Hybrid Soft Soil Tire Model (HSSTM) For Vehicle Mobility And Deterministic Performance Analysis In Terramechanics Applications." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/76654.
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Accurate and efficient tire models for deformable terrain operations are essential for performing vehicle simulations. Assessment of the forces and moments that occur at the tire-terrain interface, and the effect of the tire motion on properties of the terrain are crucial in understanding the performance of a vehicle. In order to model the dynamic behavior of the tire on different terrains, a lumped mass discretized tire model using Kelvin-Voigt elements is developed. To optimize the computational time of the code, different techniques were used in memory allocation, parameter initialization, code sequence, and multi-processing. This has resulted in significant improvements in efficiency of the code that can now run close to real time and therefore it is suitable for use by commercially available vehicle simulation packages. Model parameters are obtained using a validated finite element tire model, modal analysis, and other experimental test procedures. Experimental tests were performed on the Terramechanics rig at Virginia Tech. The tests were performed on different terrains; tire forces and moments, soil sinkage, and tire deformation data were collected for various case studies based on a design of experiment matrix. This data, in addition to modal analysis data were used to validate the tire model. Furthermore, to study the validity of the tire model, simulations at conditions similar to the test conditions were performed on a quarter car model. The results have indicated the superiority of this model as compared to other lumped parameter models currently available.Ph. D.
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Wu, Jin. "CRASHWORTHINESS SIMULATION OF ROADSIDE SAFETY STRUCTURES WITH DEVELOPMENT OF MATERIAL MODEL AND 3-D FRACTURE PROCEDURE." University of Cincinnati / OhioLINK, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=ucin971273656.
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Asus, Zainab. "Effective simulation model and new control strategy to improve energy efficiency in hybrid electric land vehicle." Thesis, Dijon, 2014. http://www.theses.fr/2014DIJOS062/document.
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Les principaux objectifs de ce travail est de développer une méthode de modélisation efficace pour un déploiement facile et rapide d'une stratégie de contrôle, d'examiner et d'étudier cette stratégie pour une application spécifique, et d'analyser l'amélioration qui peut être apporté à un moteur pour une meilleure efficacité dans les systèmes électrique et hybride. Ce travail comprend une partie simulation du système étudié et sa validation avec les résultats expérimentaux. Les études de cas sont utilisées pour analyser l'optimisation qui peut être effectuée en comparaison au système d'origine (le véhicule étudié est la NOAO).Un outil d'optimisation est choisie pour optimiser la stratégie de contrôle actuellement déployée sur le véhicule. Cette outil nous a permis de développer une nouvelle stratégie de commande optimisée prêt à être déployé dans le véhicule. Un procédé de prédiction pour connaître la consommation d'énergie du système est mis au point en vue d'obtenir un contrôle optimal adapté à la demande du véhicule et à une utilisation spécifique.Comme perspectives, les principaux composants du système peuvent être étudiés et modélisé afin d'améliorer l’efficacité énergétique du véhicule. La Représentation Energétique Macroscopique (REM) est une bonne méthode pour représenter le modèle dynamique et peut être utilisé pour modéliser des machines électromécaniques. Cette méthode est également envisagé pour modéliser d’autre système que le système véhicule tel que les systèmes énergies renouvelables, les systèmes électromécanique ou robotiqueThe main objectives of this work is to develop an effective modeling method for an easydeployment of a control strategy, to review and study an optimal control strategy for a specific application, and to analyze improvement that can be effected to engine for better efficiency in hybrid vehicle architecture. The scopes of this work include the simulation part of the studied system and its validation with experimental results. Study cases are used to analyze optimization that can be effected to the original system. A well established optimization tool is chosen to optimize the actual control strategy and becomes a benchmark of a new optimal control strategy to be deployed in the system. A predictive method to know energy consumption of the system is developed in order to obtain an optimal control suitable with the vehicle application. Using the developed model, analysis is conducted to identify an optimal control strategy for a specific utilization. As perspectives, the main components of the system can be studied for improvements of its energy efficiency. The Energetic Macroscopic Representation (EMR) is a good method to represent dynamic model and it can be used to model any electromechanical machines and can be envisaged to model other system than a vehicle system, like a renewable energy system, a new electro-mechanical system or a robotic system
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Czechowicz, Maciej P. "Analysis of vehicle rollover using a high fidelity multi-body model and statistical methods." Thesis, Loughborough University, 2015. https://dspace.lboro.ac.uk/2134/18106.
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The work presented in this thesis is dedicated to the study of vehicle rollover and the tyre and suspension characteristics influencing it. Recent data shows that 35.4% of recorded fatal crashes in Sports Utility Vehicles (SUVs) included vehicle rollover. The effect of rollover on an SUV tends to be more severe than for other types of passenger vehicle. Additionally, the number of SUVs on the roads is rising. Therefore, a thorough understanding of factors affecting the rollover resistance of SUVs is needed. The majority of previous research work on rollover dynamics has been based on low fidelity models. However, vehicle rollover is a highly non-linear event due to the large angles in vehicle body motion, extreme suspension travel, tyre non-linearities and large forces acting on the wheel, resulting in suspension spring-aids, rebound stops and bushings operating in the non-linear region. This work investigates vehicle rollover using a complex and highly non-linear multi-body validated model with 165 degrees of freedom. The vehicle model is complemented by a Magic Formula tyre model. Design of experiment methodology is used to identify tyre properties affecting vehicle rollover. A novel, statistical approach is used to systematically identify the sensitivity of rollover propensity to suspension kinematic and compliance characteristics. In this process, several rollover metrics are examined together with stability considerations and an appropriate rollover metric is devised. Research so far reveals that the tyre properties having the greatest influence on vehicle rollover are friction coefficient, friction variation with load, camber stiffness, and tyre vertical stiffness. Key kinematic and compliance characteristics affecting rollover propensity are front and rear suspension rate, front roll stiffness, front camber gain, front and rear camber compliance and rear jacking force. The study of suspension and tyre parameters affecting rollover is supplemented by an investigation of a novel anti-rollover control scheme based on a reaction wheel actuator. The simulations performed so far show promising results. Even with a very simple and conservative control scheme the reaction wheel, with actuator torque limited to 100Nm, power limited to 5kW and total energy consumption of less than 3kJ, increases the critical manoeuvre velocity by over 9%. The main advantage of the proposed control scheme, as opposed to other known anti-rollover control schemes, is that it prevents rollover whilst allowing the driver to maintain the desired vehicle path.
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Sirin, Göknur. "Supporting multidisciplinary vehicle modeling : towards an ontology-based knowledge sharing in collaborative model based systems engineering environment." Thesis, Châtenay-Malabry, Ecole centrale de Paris, 2015. http://www.theses.fr/2015ECAP0024/document.
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Les systèmes industriels (automobile, aérospatial, etc.) sont de plus en plus complexes à cause des contraintes économiques et écologiques. Cette complexité croissante impose des nouvelles contraintes au niveau du développement. La question de la maitrise de la capacité d’analyse de leurs architectures est alors posée. Pour résoudre cette question, les outils de modélisation et de simulation sont devenus une pratique courante dans les milieux industriels afin de comparer les multiples architectures candidates. Ces outils de simulations sont devenus incontournables pour conforter les décisions. Pourtant, la mise en œuvre des modèles physiques est de plus en plus complexe et nécessite une compréhension spécifique de chaque phénomène simulé ainsi qu’une description approfondie de l’architecture du système, de ses composants et des liaisons entre composants. L’objectif de cette thèse est double. Le premier concerne le développement d’une méthodologie et des outils nécessaires pour construire avec précision les modèles de simulation des architectures de systèmes qu’on désire étudier. Le deuxième s’intéresse à l’introduction d’une approche innovante pour la conception, la production et l’intégration des modèles de simulations en mode « plug and play » afin de garantir la conformité des résultats aux attentes, notamment aux niveaux de la qualité et de la maturité. Pour accomplir ces objectifs, des méthodologies et des processus d’ingénierie des systèmes basés sur les modèles (MBSE) ainsi que les systèmes d’information ont été utilisés. Ce travail de thèse propose pour la première fois un processus détaillé et un outil pour la conception des modèles de simulation. Un référentiel commun nommé « Modèle de carte d'identité (MIC) » a été développé pour standardiser et renforcer les interfaces entre les métiers et les fournisseurs sur les plans organisationnels et techniques. MIC garantit l’évolution et la gestion de la cohérence de l’ensemble des règles et les spécifications des connaissances des domaines métiers dont la sémantique est multiple. MIC renforce également la cohérence du modèle et réduit les anomalies qui peuvent interférer pendant la phase dite IVVQ pour Intégration, Vérification, Validation, Qualification. Finalement, afin de structurer les processus de conception des modèles de simulation, le travail s’est inspiré des cadres de l’Architecture d’Entreprise en reflétant les exigences d’intégration et de standardisation du modèle opératoire de l’entreprise. Pour valider les concepts introduits dans le cadre de cette thèse, des études de cas tirés des domaines automobile et aérospatiale ont été réalisées. L'objectif de cette validation est d'observer l'amélioration significative du processus actuel en termes d'efficacité, de réduction de l'ambiguïté et des malentendus dans la modélisation et la simulation du système à concevoirSimulation models are widely used by industries as an aid for decision making to explore and optimize a broad range of complex industrial systems’ architectures. The increased complexity of industrial systems (cars, airplanes, etc.), ecological and economic concerns implies a need for exploring and analysing innovative system architectures efficiently and effectively by using simulation models. However, simulations designers currently suffer from limitations which make simulation models difficult to design and develop in a collaborative, multidisciplinary design environment. The multidisciplinary nature of simulation models requires a specific understanding of each phenomenon to simulate and a thorough description of the system architecture, its components and connections between components. To accomplish these objectives, the Model-Based Systems Engineering (MBSE) and Information Systems’ (IS) methodologies were used to support the simulation designer’s analysing capabilities in terms of methods, processes and design tool solutions. The objective of this thesis is twofold. The first concerns the development of a methodology and tools to build accurate simulation models. The second focuses on the introduction of an innovative approach to design, product and integrate the simulation models in a “plug and play" manner by ensuring the expected model fidelity. However, today, one of the major challenges in full-vehicle simulation model creation is to get domain level simulation models from different domain experts while detecting any potential inconsistency problem before the IVVQ (Integration, Verification, Validation, and Qualification) phase. In the current simulation model development process, most of the defects such as interface mismatch and interoperability problems are discovered late, during the IVVQ phase. This may create multiple wastes, including rework and, may-be the most harmful, incorrect simulation models, which are subsequently used as basis for design decisions. In order to address this problem, this work aims to reduce late inconsistency detection by ensuring early stage collaborations between the different suppliers and OEM. Thus, this work integrates first a Detailed Model Design Phase to the current model development process and, second, the roles have been re-organized and delegated between design actors. Finally an alternative architecture design tool is supported by an ontology-based DSL (Domain Specific Language) called Model Identity Card (MIC). The design tools and mentioned activities perspectives (e.g. decisions, views and viewpoints) are structured by inspiration from Enterprise Architecture Frameworks. To demonstrate the applicability of our proposed solution, engine-after treatment, hybrid parallel propulsion and electric transmission models are tested across automotive and aeronautic industries
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Luco, Nicolas, and Keren Zhu. "Energy efficient cornering : Simulation and verification." Thesis, KTH, Fordonsdynamik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-234837.
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The purpose of this master thesis is to study the energy efficiency of a vehicle when it is cornering. To achieve this, a Simulink model was built from a simple basic bicycle model and theoretically validated. This model was then analysed and successively improved by adding velocity and yaw moment control. A study of the vehicle model behaviour by changing parameters such as cornering stiffness and centre of gravity position was the nconducted. The traction force needed for a constant radius was calculated and methods such as torque vectoring have been tested using the model to obtain the lowest traction force. The model was compared with different vehicle types and further validated by comparing the simulation results with experimental data acquired from a field test. The rolling resistance and aerodynamic resistance were taken into account when the model was validated with the experimental data and the result suggest that by distributing the required traction force (using torque vectoring between inner and outer driven wheels) the energy efficiency could be improved by 10%. This report ends with recommendations for future work.
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Cravotta, Stefan, and Emanuele Grimolizzi. "Simulation of vehicle impact into a steel building : A parametric study on the impacted column end-connections." Thesis, KTH, Bro- och stålbyggnad, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-172341.
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Understanding the true behaviour of impacted structures is the only way to assess their robustness under exceptional events such as vehicle collision. The primary objective of this master’s thesis was to perform a finite element parametric investigation on the influence that some parameters have in steel buildings subjected to vehicle impacts. The parameters chosen for the study, involved uncertainties in the material definition and in the load configuration of the bolts used in the impacted column end-connections. By using the Abaqus software, a finite element model of the structure has been created. The five storey steel building considered has been modelled in a simplified manner with the exception of the impacted area which, instead, has been defined in a more detailed fashion. During the simulations, different preload conditions have been used, comparing cases with and without the preload force. Regardless its variation, it has not been observed any increase in the structural resistance. On the other hand, the simulation provided interesting results for what concerns the material variations in the bolts. Although the changes have been small in magnitude, the effect on the structural response during the impact was remarkable. For all the cases considered, an increase of the material ductility, achieved by increasing the ultimate strain at failure, entailed higher resistance of the connections. Various failure modes have been observed when the material properties have been changed. Having clarified the influence of the assumptions made, the results provided helpful information in sight of future studies. Although the model still needs to be validated, the research clarified which of the parameters investigated are to be collected with more attention. Keywords: Vehicle collision, steel building, FE model, Abaqus/Explicit, parametric investigation, bolt preload, bolt material.
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Pracný, Vladislav [Verfasser]. "Neural network-based shock absorber model with a thermodynamical coupling : Experiment, modeling and vehicle simulation / Vladislav Pracny." Aachen : Shaker, 2009. http://d-nb.info/1161302549/34.
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Zheng, Yue. "Driver model for a software in the loop simulation tool." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-265668.
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For this project, a Software-In-the-Loop (SIL) simulation tool is used at Scania (“VTAB” – Virtual Truck and Bus), which simulates the submodels of the mechanical vehicle components together with the real control units. The simulation tool contains the following submodels: Engine model, Drivetrain model, Drive cycle model, Restbus model, and Driver model. The simulated human driver submodel in the restbus model outputs two pedal control signals to the control unit, namely the gas and brake pedals. With these two pedal signals, the control unit decides the modes of mechanical vehicle components. This driver model needs to be reworked to obtain a better velocity following performance. Two controllers, fuzzy PI anti-windup and backward calculation, are implemented in the driver model and compared by the velocity tracking accuracy and the pedal switching frequency. In the comparison and analysis section, two different cycles and two weights of payload are simulated. The simulation results demonstrate that both controllers can improve the driver model’s velocity tracing accuracy. Further, the fuzzy PI anti-windup controller is better when considering pedal signals fluctuation frequency and implementation complexity.För detta projekt används ett simuleringsverktyg Software-In-the-Loop (SIL) på Scania (“VTAB” - Virtual Truck and Bus), vilket simulerar submodellerna för de mekaniska fordonskomponenterna tillsammans med de verkliga styrenheterna. Simuleringsverktyget innehåller följande submodeller: Motormodell, Drivmotormodell, Drivcykelmodell, Restbusmodell och Drivermodell. Den simulerade submodellen för mänsklig förare i restbussmodellen kommer att sända två pedalsstyrsignaler till styrenheten, nämligen gas och broms. Med dessa två pedalsignaler kan styrenheten avgöra lägen av mekaniska fordonskomponenter. Denna drivrutinmodell måste omarbetas för att få en bättre hastighetsspårnings presentationsförmåga. Två styrenheter, fuzzy PI anti-windup och bakåtberäkning, implementeras i förarmodell och jämförs respektive med hastighetsspårningsnoggrannhet och pedalväxelfrekvens. I jämförelseoch analysavsnittet simuleras två olika cyklar och två nyttolast. Simuleringsresultaten visar att båda kontrollerna kan förbättra förarmodellens hastighetsspårningskapacitet. Vidare är fuzzy PI-anti-windup-kontroller bättre när man tar hänsyn till pedalsignalernas fluktueringsfrekvens och implementeringskomplexitet
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King, Jonathan Charles. "Model-Based Design of a Plug-In Hybrid Electric Vehicle Control Strategy." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/34962.
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For years the trend in the automotive industry has been toward more complex electronic control systems. The number of electronic control units (ECUs) in vehicles is ever increasing as is the complexity of communication networks among the ECUs. Increasing fuel economy standards and the increasing cost of fuel is driving hybridization and electrification of the automobile. Achieving superior fuel economy with a hybrid powertrain requires an effective and optimized control system. On the other hand, mathematical modeling and simulation tools have become extremely advanced and have turned simulation into a powerful design tool. The combination of increasing control system complexity and simulation technology has led to an industry wide trend toward model based control design. Rather than using models to analyze and validate real world testing data, simulation is now the primary tool used in the design process long before real world testing is possible. Modeling is used in every step from architecture selection to control system validation before on-road testing begins.
The Hybrid Electric Vehicle Team (HEVT) of Virginia Tech is participating in the 2011-2014 EcoCAR 2 competition in which the team is tasked with re-engineering the powertrain of a GM donated vehicle. The primary goals of the competition are to reduce well to wheels (WTW) petroleum energy use (PEU) and reduce WTW greenhouse gas (GHG) and criteria emissions while maintaining performance, safety, and consumer acceptability. This paper will present systematic methodology for using model based design techniques for architecture selection, control system design, control strategy optimization, and controller validation to meet the goals of the competition. Simple energy management and efficiency analysis will form the primary basis of architecture selection. Using a novel method, a series-parallel powertrain architecture is selected. The control system architecture and requirements is defined using a systematic approach based around the interactions between control units. Vehicle communication networks are designed to facilitate efficient data flow. Software-in-the-loop (SIL) simulation with Mathworks Simulink is used to refine a control strategy to maximize fuel economy. Finally hardware-in-the-loop (HIL) testing on a dSPACE HIL simulator is demonstrated for performance improvements, as well as for safety critical controller validation. The end product of this design study is a control system that has reached a high level of parameter optimization and validation ready for on-road testing in a vehicle.Master of Science
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Cooley, Robert Bradley. "Engine Selection, Modeling, and Control Development for an Extended Range Electric Vehicle." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1281546071.
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Tu, Ran. "Network-wide Assessment of Eco-Cooperative Adaptive Cruise Control Systems on Freeway and Arterial Facilities." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/71385.
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The environmental impact of a transportation system is critical in the assessment of the transportation system performance. Eco-Cooperative Adaptive Cruise Control (Eco-CACC) systems attempt to minimize vehicle fuel consumption and emission levels by controlling vehicle speed and acceleration levels. The majority of previous research efforts developed and applied Eco-CACC systems on either freeway or signalized intersections independently on simple and small transportation networks without consideration of the interaction among these controls.
This thesis extends the state-of-the-art in Eco-CACC evaluation by conducting a comprehensive evaluation on a complex network considering Eco-CACC control on both freeways and arterials individually and simultaneously. The goal of this study is to compare Eco-CACCs on arterial facilities (Eco-CACC-A), freeway facilities (Eco-CACC-F) and both facilities (Eco-CACC-F+A). The effects of Eco-CACC are evaluated considering various Measures of Effectiveness (MOEs), including: average vehicle delay, fuel consumption, and emission levels using simulated results from INTEGRATION, a microscopic traffic assignment and simulation software, considering different freeway speed limits, traffic demand levels and system market penetration rates. In total, 19 traffic scenarios for each of the four different cases (Eco-CACC-A, Eco-CACC-F and Eco-CACC-F+A plus a base no control case) were tested. In total 760 simulation runs were conducted (4 cases * 19 scenarios * 10 repetitions). T-tests and pairwise mean comparison (Tukey HSD) were conducted to identify any statistical differences between control cases and the base case from the simulation results. This thesis shows that arterial and freeway Eco-CACCs can work well together and their effects will be largely influenced by network characteristics.Master of Science
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Duprey, Benjamin Lawrence Blake. "A New Fuzzy Based Stability Index Using Predictive Vehicle Modeling and GPS Data." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/32762.
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The use of global positioning systems, or GPS, as a means of logistical organization for fleet vehicles has become more widespread in recent years. The system has the ability to track vehicle location, report on diagnostic trouble codes, and keep tabs on maintenance schedules. This helps to improve the safety and productivity of the vehicles and their operators. Additionally, the increasing use of yaw and roll stability control in commercial trucks has contributed to an increased level of safety for truck drivers. However, these systems require the vehicle to begin a yaw or roll event before they assist in maintaining control. This thesis presents a new method for utilizing the GPS signal in conjunction with a new fuzzy logic-based stability index, the Total Safety Margin (TSM), to create a superior active safety system.
This thesis consists of four main components:
- An overview of GPS technology is presented with coverage of several automotive-based applications. The proposed implementation of GPS in the new Hardware-in-the-Loop (HIL) driving simulator under development at the Virginia Tech Center for Vehicle Systems and Safety (CVeSS) is presented.
- The three degree-of-freedom (3DOF), linear, single track equation set used in the Matlab simulations is derived from first principles.
- Matlab and TruckSim 7® simulations are performed for five vehicle masses and three forward velocities in a ramp-steer maneuver. Using fuzzy logic to develop the control rules for the Total Safety Margin (TSM), TSM matrices are built for both the Matlab and TruckSim 7® results based on these testing conditions. By comparing these TSM matrices it is shown that the two simulation methods yield similar results.
- A discussion of the development and implementation of the aforementioned HIL driving simulator is presented, specifically the steering subsystem. Using Matlab/Simulink, dSPACE ControlDesk, and CarSim RT® software it is shown that the steering module is capable of steering the CarSim RT® simulation vehicle accurately within the physical range of the steering sensor used.
Master of Science
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Kammann, Richard W. "Computer model and simulation of a theater ballistic missile (TBM) counterforce plan involving a lethal unmanned air vehicle (UAV)." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1995. http://handle.dtic.mil/100.2/ADA305347.
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Enblom, Roger. "On Simulation of Uniform Wear and Profile Evolution in the Wheel - Rail Contact." Doctoral thesis, Stockholm : Dept. of aeronautics and vehicle engineering, Royal Institute of Technology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4184.
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Lu, Ming. "System Dynamics Model for Testing and Evaluating Automatic Headway Control Models for Trucks Operating on Rural Highways." Diss., This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-01292008-113749/.
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Chakravarthy, Krishnan Veeraraghavan. "DEVELOPMENT OF A STEER AXLE TIRE BLOWOUT MODEL FOR TRACTOR SEMITRAILERS IN TRUCKSIM." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1367533852.
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