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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Analytical design of a parallel hybrid electric powertrain for sports utility vehicles and heavy trucks

Madireddy, Madhava Rao January 2003 (has links)
No description available.
52

Vehicle powertrain model to predict energy consumption for ecorouting purposes

Tamaro, Courtney Alex 27 June 2016 (has links)
The automotive industry is facing some of the most difficult design challenges in industry history. Developing innovative methods to reduce fossil fuel dependence is imperative for maintaining compliance with government regulations and consumer demand. In addition to powertrain design, route selection contributes to vehicle environmental impact. The objective of this thesis is to develop a methodology for evaluating the energy consumption of each route option for a specific vehicle. A 'backwards' energy tracking method determines tractive demand at the wheels from route requirements and vehicle characteristics. Next, this method tracks energy quantities at each powertrain component. Each component model is scalable such that different vehicle powertrains may be approximated. Using an 'ecorouting' process, the most ideal route is selected by weighting relative total energy consumption and travel time. Only limited powertrain characteristics are publicly available. As the future goal of this project is to apply the model to many vehicle powertrain types, the powertrain model must be reasonably accurate with minimal vehicle powertrain characteristics. Future work expands this model to constantly re-evaluate energy consumption with real-time traffic and terrain information. While ecorouting has been applied to conventional vehicles in many publications, electrified vehicles are less studied. Hybrid vehicles are particularly complicated to model due to additional components, systems, and operation modes. This methodology has been validated to represent conventional, battery electric, and parallel hybrid electric vehicles. A sensitivity study demonstrates that the model is capable of differentiating powertrains with different parameters and routes with different characteristics. / Master of Science
53

Modeling, Optimization and Control of Hybrid Powertrains

De Pascali, Luca 14 October 2019 (has links)
To cope with the increasing demand of a more sustainable mobility, the main Original Equipment Manufacturers are producing vehicles equipped with hybrid propulsion systems that increase the overall vehicle efficiency and mitigate the emission problem at a local level. The newly gained degrees of freedom of the hybrid powertrain need to be handled by advanced energy management techniques that allow to fully exploit the system capabilities. In this thesis we propose an optimal control approach to the solution of the energy management problem, putting emphasis on the importance of accurate models for the reliability of the optimization solution. In the first part of the thesis we address the energy management problem for a hybrid electric vehicle, including the mitigation of the battery aging mechanisms. We show that, with an optimal management strategy, we could extend the battery life up to 25% for some driving cycles while keeping the fuel savings performance substantially unaltered. In the second part of the thesis we focus on the hydrostatic hybrid transmission, a different hybridization solution that is able to fulfill the high power demand of heavy duty off-highway vehicles. Also in this case, we formulate the energy management problem as an optimal control problem, dealing with the complexity introduced by the discrete valve actuations in the framework of mixed-integer optimal control. We show that, using hydraulic accumulators to recover energy from the regenerative braking, we could reduce fuel consumption up to 13% for a typical driving cycle. In the third and last part of the thesis we show how the optimization approach can be used to systematically design and calibrate control algorithms, casting the calibration problem into a Linear Matrix Inequality. We first develop a non-overshooting closed-loop control for the actuation pressure of a wet clutch, proving the effectiveness of the control on an experimental setup. Finally, we focus on the design of a dead-zone based kinematic observer for the estimation of the lateral velocity of a road vehicle. The structure of the observer presents good noise rejection performance, allowing for the selection of a higher observer gain that improves the estimation accuracy.
54

Common Rail - En bränslebesparingsstudie : – En utvärdering av ett nyinstallerat bränsleinsprutningssystem på isbrytaren Ymer / Common Rail - A fuel saving study : - An evaluation of a newly installed fuel injection system on the icebreaker Ymer

Andrén, Filip, Borgström, Olav January 2016 (has links)
Följande studie är gjord på uppdrag av Sjöfartsverket. I studien undersöktes hur en installation av ett Common Rail-system ombord på isbrytaren Ymer påverkat bränsleförbrukningen samt utsläppen av kväveoxider. Rådata som loggats ombord på Ymer har analyserat och bearbetat. Material och information från tillverkare, besättning samt teknisk chef på Sjöfartsverket, Albert Hagander har använts under studien. Tillsammans med uppmätta mätdata och tidigare gjord litteraturstudie stöds resultaten i studien. Det är ingen slump att system av Common Rail-typ redan är tillämpat inom de flesta branscher så som transport, personbilsindustri och jordbruk. Huvudsyftet med Common Rail är att minska bränsleåtgången samt minska utsläppen genom en renare och mer effektiv förbränning av bränslet.  Huvudsakligen undersöktes hur det nyinstallerade systemet påverkat bränsleförbrukningen och hur bränslebesparingen varierar med belastningen av maskinen. Vidare granskades hur utsläppen av kvävedioxider påverkats efter installationen. Problematiken med ökad NOx-produktion till följd av en högre förbränningstemperatur som Common Railsystemet medför diskuteras i rapporten. De resultat vi kommit fram till att en bränslebesparing kan göras ombord på Ymer genom att ersätta det gamla bränslesystemet med ett bränslesystem av Common Rail-typ. Vidare har installationen medfört andra förbättringar så som fartygsmaskinens reaktion på de många lastväxlingar som förekommer under isbrytning. / The following study has been carried out on behalf of Sjöfartsverket. The study examines how the installation of a common rail system on board the icebreaker Ymer affected fuel consumption and emissions of nitrogen oxides. The raw data logged on board Ymer was analyzed and processed. Materials and information from manufacturers, crew and the technical manager at the Swedish Maritime Administration, Albert Hagander have been used during the study. Together with measured data and previously made research study the findings of the study are supported. It is no coincidence that the system of the common rail type is already applied in most industries such as transport, car industry and agriculture. The main purpose of the Common Rail is to reduce fuel consumption and reduce emissions through cleaner and more efficient combustion of the fuel. We primarily examined how the newly installed system affected fuel consumption and the fuel savings will vary with the load of the machine. Furthermore, we examined how emissions of nitrogen oxides were affected after installation. The problem of increased NOx production due to a higher combustion temperature as the common rail system entails are discussed in the report. The result that was concluded was that fuel savings can be made on board Ymer by replacing the old fuel system with a common rail fuel type. Furthermore, the installation has brought other improvements such as ship machine's reaction to the many load changes that occur during icebreaking.
55

Optimal vehicle structural design for weight reduction using iterative finite element analysis

Tebby, Steven 01 June 2012 (has links)
The design and analysis of an automotive structure is an important stage of the vehicle design process. The structural characteristics have significant impact on the vehicle performance. During the design process it is necessary to have knowledge about the structural characteristics; however in the preliminary design stages detailed information about the structure is not available. During this period of the design process the structure is often simplified to a representative model that can be analyzed and used as the input for the detailed design process. A vehicle model is developed based on the space frame structures where the frame is the load carrying portion of the structure. Preliminary design analysis is conducted using a static load condition applied to the vehicle as pure bending and pure torsion. The deflections of the vehicle based on these loading conditions are determined using the finite element method which has been implemented in developed software. The structural response, measured as the bending and torsion stiffness, is used to evaluate the structural design. An optimization program is implemented to improve the structural design with the goal of reducing weight while increasing stiffness. Following optimization the model is completed by estimating suitable plate thicknesses using a method of substructure analysis. The output of this process will be an optimized structural model with low weight and high stiffness that is ready for detailed design. / UOIT
56

Hybrid powertrain performance analysis for naval and commercial ocean-going vessels

Gully, Benjamin Houston 11 October 2012 (has links)
The need for a reduced dependence on fossil fuels is motivated by a wide range of factors: from increasing fuel costs, to national security implications of supply, to rising concern for environmental impact. Although much focus is given to terrestrial systems, over 90% of the world's freight is transported by ship. Likewise, naval warfighting systems are critical in supporting U.S. national interests abroad. Yet the vast majority of these vessels rely on fossil fuels for operation. The results of this thesis illustrate a common theme that hybrid mechanical-electrical marine propulsion systems produce substantially better fuel efficiency than other technologies that are typically emphasized to reduce fuel consumption. Naval and commercial powertrains in the 60-70 MW range are shown to benefit substantially from the utilization of mechanical drive for high speed propulsion; complemented by an efficient electric drive system for low speed operations. This hybrid architecture proves to be able to best meet the wide range of performance requirements for each of these systems, while also being the most easily integrated technology option. Naval analyses evaluate powertrain options for the DDG-51 Flight III. Simulation results using actual operational profile data show a CODLAG system produces a net fuel savings of up to 12% more than a comparable all-electric system, corresponding to a savings of 37% relative the existing DDG-51 powertrain. These results prove that a mechanical linkage for the main propulsion engine greatly reduces fuel consumption and that for power generation systems requiring redundancy, diesel generators represent a vastly superior option to gas turbines. For the commercial application it is shown that an augmented PTO/PTI hybrid system can better reduce cruise fuel consumption than modern sail systems, while also producing significant benefit with regard to CO2 emissions. In addition, using such a shaft mounted hybrid system for low speed electric drive in ports reduces NOx emissions by 29-43%, while CO is reduced 57-66% and PM may be reduced up to 25%, depending on the specific operating mode. As an added benefit, fuel consumption rates under these conditions are reduced 20-29%. / text
57

Fartförlust på grunt vatten : En jämförelse av bränsleförbrukning och tidsåtgång för rutter med olika djup och distans

Annerstedt, Måns, Apoy, Axel January 2015 (has links)
Denna studie handlar om den fartförlust och därmed den ökade energiförbrukningen som drabbar fartyg på grunt vatten. Syftet var att ta reda på hur mycket kortare en grund passage behöver vara för att den ska vara ett bättre alternativ än en lång och djup rutt med hänsyn till bränsleförbrukning och tidsåtgång. Resultatet av detta blev att det inte går att dra några generella slutsatser som gäller för alla fartygstyper men att det går att se tydliga tendenser. Studien hade även som målsättning att skapa ett underlag som skulle kunna användas av nautiker vid planering av resor, detta presenterades i form av en sammanställning av de resultat som erhållits vid beräkning av fartförlust i öppet vatten. Någon sammanställning gjordes inte för begränsat vatten eftersom exempelfartygen där fick likadana resultat vilket skulle ha gjort en sådan överflödig. Syftet uppnåddes genom användande av kvantitativa studier i form av matematiska beräkningsmetoder för att beräkna fartförlust, bränsleförbrukning och tidsåtgång för ett antal exempelfartyg. / This study concerns the speed loss and thereby the increased energy consumption which affects ships in shallow water. The aim of the study was to gain knowledge of how much shorter a shallow passage is required to be in order to be the better alternative compared to a long and deep route with regard to fuel and time consumption. The result was that it is not possible to draw any definitive conclusions which are applicable to all ship types, however, there are clear patterns. Moreover, the goal of the study was to aid mariners facing a choice between a long and deep route and a short and shallow route, this was done by creating a compilation of the results for speed loss in open water. Due to the results for confined waters being the same for all the ships in the study, no compilation was done for confined waters as it was deemed excessive. The aim of the study was achieved by quantitative research in the form of mathematical models to calculate speed loss, fuel consumption and time consumption for a number of fictitious ships.
58

Regression Models to Predict Coastdown Road Load for Various Vehicle Types

Singh, Yuvraj January 2020 (has links)
No description available.
59

Разработка методики определения норм расхода топлива автомобилей в реальных условиях эксплуатации : магистерская диссертация / Development of methods for determining the rate of fuel consumption of cars in real conditions of exploitation

Рогачев, В. А., Rogachev, V. A. January 2019 (has links)
В данной работе проведено исследование по совершенствованию системы нормирования расхода топлива на основе конкретизации и установления закономерностей изменения его расхода под влиянием природно-климатических условий округов Свердловской области. / In this paper, a study was conducted to improve the system of fuel consumption rationing based on concretization and establishing patterns of changes in its consumption under the influence of the natural and climatic conditions of the districts of the Sverdlovsk region.
60

ASEMS: Autonomous Specific Energy Management Strategy

Amirfarhangi Bonab, Saeed January 2019 (has links)
This thesis addresses the problem of energy management of a hybrid electric power unit for an autonomous vehicle. We introduce, evaluate, and discuss the idea of autonomous-specific energy management strategy. This method is an optimization-based strategy which improves the powertrain fuel economy by exploiting motion planning data. First, to build a firm base for further evaluations, we will develop a high-fidelity system-level model for our case study using MATLAB/Simulink. This model mostly concerns about energy-related aspects of the powertrain and the vehicle. We will derive and implement the equations for each of the model subsystems. We derive model parameters using available data in the literature or online. Evaluation of the developed model shows acceptable conformity with the actual dynamometer data. We will use this model to replace the built-in rule-based logic with the proposed strategy and assess the performance.\par Second, since we are considering an optimization-based approach, we will develop a novel convex representation of the vehicle and powertrain model. This translates to reformulating the model equations using convex functions. Consequently, we will express the fuel-efficient energy management problem as the convex optimization problem. We will solve the optimization problem using dedicated numerical solvers. Extracting the control inputs using this approach and applying them on the high-fidelity model provides similar results to dynamic programming in terms of fuel consumption but in substantially less amount of time. This will act as a pivot for the subsequent real-time analysis.\par Third, we will perform a proof-of-concept for the autonomous-specific energy management strategy. We implement an optimization-based path and trajectory planning for a vehicle in the simplified driving scenario of a racing track. Accordingly, we use motion planning data to obtain the energy management strategy by solving an optimization problem. We will let the vehicle to travel around the circuit with the ability to perceive and plan up to an observable horizon using the receding horizon approach. Developed approach for energy management strategy shows a substantial reduction in the fuel consumption of the high-fidelity model, compared to the rule-based controller. / Thesis / Master of Science in Mechanical Engineering (MSME) / The automotive industry is on the verge of groundbreaking transformations as a result of electrification and autonomous driving. Electrified autonomous car of the future is sustainable, energy-efficient, more convenient, and safer. In addition to the advantages of electrification and autonomous driving individually, the intersection and interaction of these mainstreams provide new opportunities for further improvements on the vehicles. Autonomous cars generate an unprecedented amount of real-time data due to excessive use of perception sensors and processing units. This thesis considers the case of an autonomous hybrid electric vehicle and presents the novel idea of autonomous-specific energy management strategy. Specifically, this thesis is a proof-of-concept, a trial to exploit the motion planning data for a self-driving car to improve the fuel economy of the hybrid electric power unit by adopting a more efficient energy management strategy. With the ever-increasing number of autonomous hybrid electric vehicles, particularly in the self-driving fleets, the presented method shows an extremely promising potential to reduce the fuel consumption of these vehicles.

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