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The CO2 emissions from road vehicles must be reduced in order to avoid a 1.5 ◦C global warming. To reduce tailpipe emissions, a strong trend is to electrify powertrains to shift away from the use of fossil fuel. Among alternatives, the fuel cellhybrid electric vehicle (FCHEV) is seen as a promising configuration. With the high energy density of hydrogen propulsion systems, it is regarded viable for heavy-dutylong cycle hauling. The aim of this thesis is thus to explore optimal control of energy and thermal management systems of FCHEVs. With the intention of increasing knowledge of how to control FCHEVs for a driving mission, this thesis models an FCHEV powertrain for optimal control purposes. The developed model is used in conjunction with dynamic programming to find the hydrogen optimal control strategies of the energy and thermal management systems. Finally, a sensitivity analysis is performed, investigating how the fuel cell characteristics influence the control strategies. The results propose a feasible complete powertrain model for optimal control purposes and provides insight on how to optimally control the powertrain for various scenarios, minimizing hydrogen consumption. It is concluded that for demanding missions, the fuel cell should consistently provide the main power output and together with the battery handle power transients. For less demanding missions, the fuel cell should be controlled with an on/off strategy, switching between being atidle and working in its most efficient region. It is also concluded that integrated energy and thermal strategies for the fuel cell during a driving mission can increase fuel efficiency, with the optimal thermal strategy being dependent on the fuel cell’s characteristics.

For internal combustion engines used in heavy-duty vehicles, increased engine efficiency and consequently reduced CO2 emissions can be obtained if the engine speed can be kept within an optimal speed range. This requires swift and frequent gear shifts where the dry friction clutch is utilized. Enhanced dry clutch simulation models and a better understanding of the involved phenomena can assist the development towards swifter gear shifts and help reduce CO2 emissions. The work presented in this thesis focuses on the modelling of dry clutch systems for heavy-duty applications and their effect on the torsional response of the driveline during transient events such as clutch engagement and disengagement. During these events it is primarily the first vibration mode of the driveline that is active and consequently it is possible to greatly reduce theof degrees of freedom (DOFs) of the powertrain model and still capture the relevant dynamics of the powertrain. The reduced set of differential equationsdescribe the torsional motion of the powertrain and the equations of motion are solved numerically in the time-domain. From a mathematical point ofview, the equations of motion turn "stiff" when the clutch is locked. This issue is resolved by utilizing numerical solution techniques suitable for stiff differential equations. In the simulations it was observed that no engine torque fluctuations were transferred through the slipping clutch. Consequently the response of the driveline is purely modal during sliding. If the gradient of the coefficient of friction is negative the modal response is possibly unstable with exponentially growing vibration amplitudes as an effect. Moreover, the way in which the clamp load evolves during clutch engagement is found to severely effect the excitation of transient vibrations during clutch synchronization. It can be shown that reducing the gradient of the evolving clamp load at the onset of sliding will reduce the amplitude of the friction induced vibrations. Reducing the torsional vibration amplitudes will help avoid the jerky motion of the vehicle during launch and increase comfort for driver and passengers. / Reduced transmission vibrations - reduced energy consumption and environmental impacts together with an increased competitiveness. Swedish Energy Agency (project No. 42100-1)

The market segment of hybrid-electric and full function electric vehicles is growing within the automotive transportation sector. While many papers exist concerning fuel economy or fuel consumption and the limitations of conventional powertrains, little published work is available for vehicles which use grid electricity as an energy source for propulsion. Generally, the emphasis is put solely on the average drive cycle efficiency for the vehicle with very little thought given to propelling and braking powertrain losses for individual components. The modeling section of this paper will take basic energy loss equations for vehicle speed and acceleration, along with component efficiency information to predict the grid energy consumption in AC Wh/km for a given drive cycle. This paper explains how to calculate the forces experienced by a vehicle while completing a drive cycle in three different ways: using vehicle characteristics, United States Environmental Protection Agency's (EPA) Dynamometer "target" coefficients, and an adaptation of the Sovran parameters. Once the vehicle forces are determined, power and energy demands at the wheels are determined. The vehicle power demands are split into propelling, braking, and idle to aide in the understanding of what it takes to move a vehicle and to identify possible areas for improvement. Then, using component efficiency data for various parameters of interest, the energy consumption of the vehicle as a pure EV is supplied in both DC (at the battery terminals) and AC (from the electric grid) Wh/km. The energy that flows into and out of each component while the vehicle is driving along with the losses at each step along the way of the energy path are detailed and explained. The final goal is to make the results of the model match the vehicle for any driving schedule. Validation work is performed in order to take the model estimates for efficiencies and correlate them against real world data. By using the Virginia Tech Range Extended Crossover (VTREX) and collecting data from testing, the parameters that the model is based on will be correlated with real world test data. The paper presents a propelling, braking, and net energy weighted drive cycle averaged efficiency that can be used to calculate the losses for a given cycle. In understanding the losses at each component, not just the individual efficiency, areas for future vehicle improvement can be identified to reduce petroleum energy use and greenhouse gases. The electric range of the vehicle factors heavily into the Utility Weighted fuel economy of a plug-in hybrid electric vehicle, which will also be addressed. / Master of Science

<p dir="ltr">This motorsport thesis explores the complete electrification of an IndyCar by simulations. Initial research was conducted on stock IndyCar specifications, and concurrently, a sequential approach was developed for MATLAB-based simulations to generate comprehensive results. The study aims to integrate extensive insights gained from courses such as Vehicle Dynamics, Aerodynamics, Data Acquisition, and Electric Powertrains, alongside practical experience from racing internships. The goal is to comprehend the impact of this conversion on engineering parameters. The analysis specifically emphasizes the engineering aspects, with a particular focus on the longitudinal dynamics of the vehicle through quarter-mile simulations.</p>

The power utilities in Sweden are planning to replace the major part of thenuclear power plants with renewable energy resource by the year 2030. Some ofthe renewable energy resources are intermittent, which may endanger the powersystem stability. A solution to this problem could be increased exibility in theend-users consumption, which is known as demand response. This is a usefultool that can be used to facilitate the large integration of renewable energyresource into the power grid. Therefore, several of the Swedish governmentauthorities have stated that the possibilities for demand response should befurther investigated.During this thesis, a case study is carried out at Volvo Group Truck OperationsPowertrain Productions in Koping, with the purpose of deriving theirtechnical possibilities for DR in the factory. Volvo in Koping mainly producesgearboxes to all trucks within the Volvo Group concern and belongs to the engineeringindustry sector. The engineering industry has previously not beeninvestigated for DR purposes in Sweden. The main goal of the thesis is to derivethe DR capacity of the factory and the associated time parameters. Onlydemand response by shifting the production in time is considered.One production group (Midiblock 2) in the factory is modelled using MixedInteger Linear Programming and the optimization problem is used to minimizethe electricity cost while fullling the production requirements. The optimizationproblem is done on daily basis and the result is binary operating pointsfor CNC-machines. The output from the Mixed Integer Linear Programmingproblem is sent to a discrete event model, which is used to validate the resultsand display the optimal energy consumption.The simulation results indicates that the modelled production group can performa load shift of 270 kWh/h during 4 hours by scheduling production. Duringthe reduction it should be possible to perform actions such as maintenance andchanging settings of machines. If the results are true for the entire factory, theresulting load reduction is 1.35 MWh/h during 4 hours. However, the nancialincentives to perform load reductions are low. Also, Volvo in Koping does nothave any routines to shut-o the CNC-machines and an extensive work is requiredto make a load reduction possible. Resulting in that DR at the factory isat the moment unrealistic. In addition to the possibilities for DR, the possibleeconomic savings by shutting o the CNC-machines when they are not producingunits are also approximated. Volvo in Koping can save a large amount ofenergy and yearly cut the cost by at least 5 000 000 SEK on these actions, whichis also the rst step towards enabling DR in the factory. / Elkraftsbolagen i Sverige planerar att ersätta kärnkraftverken med förnybaraenergikällor fram till och med år 2030. Några av de förnybara energikällornaär intermittenta i sin produktion och kan på grund av detta medföra en faraför stabilitet i kraftsystemet. En del av lösningen till detta problem kan varaefterfrågeflexibiltet, vilket innebär att el-användarna är mer flexibla i förbrukningenoch anpassar sig till viss del efter kraftsystemets tillstånd. Efterfrågeflexibiltetär ett användbart verktyg som kan underlätta integreringen av de förnybaraenergikällorna. På grund av detta har era svenska statliga företag sagtatt er undersökning bör genomföras inom området efterfrågeflexibiltet.Under detta arbeta har en fallstudie utförts hos Volvo Group Truck OperationPowertrain Production i Köping. Syftet av fallstudien har varit attundersöka möjligheterna för efterfrågeflexibilitet i fabriken. Volvo i Köping producerartill största dels växellådor till samtliga lastbilar inom Volvo Group koncernenoch de tillhör därför industrisektorn verkstadsindustrier.En produktionsgrupp i fabriken modelleras med hjälp av linjärprogrammeringoch modellen används för att för att minimera elkostnaderna genom att föryttalast i tid och samtidigt uppfylla produktionskraven. Optimeringsproblemetberäknas med elpriser för ett dygn och resultatet av problemet är binära tillståndför CNC-maskinerna i produktionsgruppen. De binära tillstånden skickas tillen diskret modell i Matlab som används för att verifiera produktionskraven ochvisa den resulterande energiförbrukningen för produktionsgruppen.Resultatet visar att det är teoretiskt möjligt att förytta 270 kWh/h underen period på 4 timmar genom att förskjuta produktion i tid. Under produktionsstoppenär det möjligt att genomföra underhåll och att förändring iinställningarna på CNC-maskinerna. Om resultaten skalas upp till hela fabrikenskulle den resulterande lastförflyttningen vara 1.35 MWh/h under 4 timmar.Dock så är de ekonomiska incitamenten låga och lastföryttningen är inteekonomiskt hållbar. Ett ytterligare problem är att Volvo i Köping förtillfälletinte har några rutiner för att stänga av maskinerna. Därför krävs det ett omfattandearbete innan det skulle vara möjligt att genomföra en lastförflyttning.Efterfrågeflexibiltet hos Volvo i Köping är därför orealistiskt. Utöver att undersöka möjligheterna för efterfrågeflexibiltet i fabriken, har en del av arbetetsom mål att undersöka de möjliga energi- och kostnadsbesparingar som skapasav att stänga av CNC-maskinerna när de inte producerar enheter. Arbetet harvisat att Volvo i Köping kan varje är spara 5 000 000 SEK på att stänga avmaskinerna, vilket också är ett första steg mot efterfrågeflexibilitet i fabriken.

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.

This thesis highlights one of the most significant concerns that has preoccupied drivetrain engineers in recent times, namely drivetrain clonk. Clonk is an unacceptable audible sound, which is accompanied by a tactile drivetrain response. This may occur under several different driving conditions. Many drivetrain NVH concerns are related to impact loading of subsystems down-line of engine. These concerns are induced by power torque surge through engagement and disengagement processes, which may propagate through various transmission paths as structural waves. The coincidence of these waves with the acoustic modes of sub-system components leads to audible responses, referred to as clonk. The approach usually undertaken and reported in literature is either purely theoretical or constitutes experimental observation of vehicle conditions. A few research workers have reported rig-based investigations, but not under fully dynamic conditions with controlled and reproducible impulsive action. The research reported in this thesis combines experimental and numerical investigation of high frequency behaviour of light truck drivetrain systems, when subjected to sudden impulsive action, due to driver behaviour. The problem is treated as a multi-physics interactive phenomenon under transient conditions. The devised numerical method combines multi-body dynamics, structural modal analysis, impact dynamics in lash zones and acoustic analysis within an overall investigation framework. A representative drivetrain system rig is designed and implemented, and controlled tests simulating driver behaviour undertaken. The combined numerical predictions and experimental noise and vibration monitoring has highlighted the fundamental aspects of drivetrain behaviour. Good agreement is' also found between the detailed numerical approach and the experimental findings. Novel methods of measurement such as Laser Doppler Vibrometery have been employed. Simultaneous measurements of vibration and noise radiation confirm significant elasto-acoustic coupling at high impact energy levels. One of the major finds of the thesis is the complex nature of the clonk signal, being a combination of accelerative and ringing noise, with the latter also comprising of many other lower energy content as observed in the case of transmission rattle and bearing-induced responses. Therefore, the link between rattle and clonk, long suspected, but not hitherto shown has been confirmed in the thesis. Another major find of particular commercial interest is the insignificant contribution of torsional damping devices such as dual mass flywheels upon the accelerative component of the clonk response.

Global sustainability awareness and governmental regulations are pushing the automotive industry into finding alternatives to carbon dioxide emitting products. Solutions utilizing electricity in the vehicle powertrain is overtaking market share from internal combustion engines (ICE). This tendency has spread into the heavy-duty truck segment which poses questions regarding the future of the ICE. An alternative, electric motors, powered with batteries, fuel cells of even ICE’s, is thought to become a core part of future mobility. To mitigate discontinuities during a shift from ICE to electric motors, a study of possible factors affecting such transition has been performed. The result indicates 14 main factors which are thought to have a definite role in a major technology paradigm shift. These factors are: Supplier relations, Material management, Material availability, Available space, Scalability, Product flexibility, Risk management, External resource utilization, Internal relations, Demand estimation, Management endorsement, Appropriate methodology, Employee engagement, and Competence renewal. A structure using ISM methodology is established highlighting the factors’ influencing relation to each other. Anchored in the theory regarding paradigmatic shifts within industry, a tendency of technological, managerial, and institutional influence on organizational change can be discerned where the institutional level poses as the fundamental dimension of derived quality. The factors are identified from a Scania specific case but are broad enough to apply to similar situations facing challenges of a technological paradigm shift.