"Ph. D. dissertation." / "December 1999." Includes bibliographical references (p. 299-318). Also available on the World Wide Web: http://engr.ucdavis.edu/%7Eits.

Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references (leaves 128-131). Available also in a digital version from Dissertation Abstracts.

Thesis (M. Phil.)--University of Hong Kong, 2002. / Includes bibliographical references (leaves.

Advanced fuel economies in both traditional internal combustion engine vehicles (ICEs) and electric vehicles (EVs) have a strong influence on transportation revenue by reducing fuel consumption per vehicle and ultimately drawing down the amount of fuel tax revenue received. It is expected that more ICE vehicle with advanced fuel economies and electric vehicles, especially gasoline hybrid electric vehicles, will enter the roadway in coming years, and fuel tax revenues and the Highway Trust Fund will increasingly become more affected. This study estimates the impact that increased sales of advanced ICEs and EVs will have on future fuel tax revenues by drawing on industry estimates of future EV and ICE market shares and anticipates future fleet mix and fuel economy for both vehicle technologies. An estimation process overview is provided and assumptions are described. Fuel tax revenue amounts that would be expected from future light vehicle fleets with increased shares of EVs are compared to equally sized fleets comprised of all ICEs, and future fleet mixes are estimated. Results show that as more electric vehicles enter the light vehicle fleet, greater revenue losses are expected, and total losses from years 2011 through 2050 depend on fleet composition and fuel economy of both vehicle types. Finally, it is found that the amount of fuel taxes paid by ICE drivers each year remain greater than fuel taxes paid by EV drivers even with advances in the average ICE vehicle fuel economy. / text

By utilizing the electric motor as the propulsion system, the electric vehicle (EV) establishes a new bridge between renewable energies and our daily life, which meanwhile has to face with a brand new technical issue, namely the energy management and conversion. Then, the performance of energy conversion systems has become a new evaluation criteria for EVs. Accordingly, this study works on the analysis and control of the EV energy conversion system, including the secure charging system via wireless power transmission (WPT), advanced driving control via electric propulsion system, and bidirectional power interface via electromagnetic interference (EMI) mitigation technique. First, this study proposes a novel energy encryption algorithm for WPT systems. In the presented scheme, the energy can be encrypted by chaotically regulating the frequency of the power source based on the unpredictable security key. The authorized receptor can effectively receive the energy by simultaneously adjusting the circuit to decoding the encrypted energy based on the acquired security key, while the unauthorized receptor cannot obtain the energy without knowledge of the security key. In this study, both simulation and experimental results are provided to verify the feasibility of the proposed secure WPT system. Subsequently, this study proposes a new dynamic model of EV powering steering systems, by synthetically taking into account characteristics of the electric propulsion motor, driver’s operation, and uncertain disturbances caused by irregularities of the road surface. By using various nonlinear analysis methods, the unstable chaotic behaviors can be revealed in the power steering system, especially when the vehicle turns a concern at a high speed. Additionally, a new control algorithm is designed and implemented to stabilize the EV power steering system, and corresponding validity is also mathematically proved in this study. Thirdly, an integrated driving control system is designed based on the aforementioned dynamic analysis, which is used to enhance the stability and maneuverability performances of four-in-wheel independently-driven (4WID) EVs. By adopting the supervisor-actuator structure, the proposed driving control scheme not only effectively improves the performance of tracking reference paths, but also optimally distribute the desired yaw moment to each in-wheel motor. In this study, the mathematical proof and the simulation are both conducted to demonstrate the feasibility of the proposed integrated driving control strategy. Lastly, this study also works on the EMI issue caused by switch-mode energy conversion devices for EVs. In this section, a new pulse-width-modulation (PWM) method is designed by utilizing the random-like sequence, aiming to suppress the conducted peaky EMI over the whole power spectrum, thereby ensuring the working performance for electronic instruments in EVs. For demonstrating the effectiveness of the proposed soft-chaoizing scheme, this study takes two exemplifications such as the electric propulsion drive system and the bidirectional power interface for vehicle-to-grid (V2G) systems. / published_or_final_version / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

Not available / text

The total lifecycle of a vehicle contains many phases, from production to sales to first customer to second customer and so on until the end of life. Each one of these phases includes different activities in different business areas and under different conditions. This means that the customers´ needs will vary depending on which lifecycle phase the vehicle is in and the offered services have to be adapted to this. Therefore it is important for truck developing companies to know when a transition, from one lifecycle phase to another has occurred. This study is based on a case study provided by Scania, a company that develops trucks and busses. Delimitations were that the study would focus on connected long-haulage trucks that are in Europe under their first life cycle phase, that the developed services would be described on a conceptual level and not cover any economic aspects. With this in mind, the following research questions were created: RQ1) What defines a transition phase? RQ2) How can the long-haulage trucks’ usage pattern be used to identify a transition phase? RQ3) Which data is needed to identify a transition phase? RQ4) Based on the results of RQ2 and RQ3, how could the transition alert service be designed? RQ5) Which applications could the transitions alert service be used for? The study included a literature study covering product lifecycle theory, servicification, second-hand market, big data, telematics, intelligent vehicles and statistic hypothesis testing. Further, two truck drivers were observed in order to get better understanding of the transportation business and the truck driving activities. Two qualitative interview studies were made with hauliers, service salesmen, truck salesmen and distributors from Czech Republic, Denmark, Italy, Poland, Spain and Sweden. The results of the empirical studies were analysed and RQ1 could be answered. Transition phase is the period between two different vehicle owners and/or two different ways of utilizing the truck. The analysis also gave a good picture of how the trucks are used during their life and in the transition phases, which gave an idea about usage patterns that could answer RQ2. The answer was formulated as something named phase-DNA, composed by six parameters that should change during a transition phase: Geography, Route, Driver, Traffic Condition, Assignments and Services. Through a group brainstorming with experts in connected services, ideas of which data that could be used to describe each one of the parameters in the phase-DNA were found. These were sorted and evaluated until at least one data type for each parameter was set. The specific data types were chosen because they reflected their parameter well and because they were data that were accessible in order to conduct tests and validations. The final set of data types consisted of: Route Shape, Amount of Stops, Run Time, Idle Time, Distance Driven, Coasting, Driver ID, Average Speed, Fuel Consumption and Workshop History Data. This set of data types was used for the formulation of a hypothesis, that said that after a transition phase at least some of these data types should change. This was also the point where RQ3 was answered. II The hypothesis was analysed using an exploratory analysis by plotting all the data types over time and observing if a change could be seen close to the change of ownership. The result showed that Amount of Stops and Driver ID were the most indicative data types, these two were further analysed with a statistical hypothesis test and a visualisation method. The results were used to develop an algorithm that is able to give an indication if a transition phase has occurred. The algorithm searches for changes in the six data types: Driver ID, Amount of Stops, Run Time, Distance Driven, Idle Time and Route Shape. The results from the empirical studies were used to define requirements for the development of a service based on the information of phase transition called transition alert service (TAS), which is the answer to RQ4. Furthermore possible stakeholders that could be interested in the transition phase information were investigated together with an examination of their needs. TAS fulfils the five main needs identified from the stakeholders: ease start and cancellation of services, avoid unnecessary telecom expenses, avoid that information goes to the wrong customer, find new customers and customize services. In order to solve this, an algorithm detecting a transition phase was developed; it was done by searching for changes in the six data types: Driver ID, Amount of Stops, Run Time, Distance Driven, Idle Time and Route Shape. Moreover if the TAS information is combined with other information it could be used for creating new services. Through different idea generation workshops a large number of new ideas and concepts were generated, which became the answer to RQ5. In total eleven applications for the transition alert service were developed: nine connected to change in ownership and two connected to change in utilization. Additionally, one support service named "Vehicle History" that is based on collected historical TAS was created. Further, one total solution named "No Worries Second-Hand" was created that includes five of the developed services. This total solution offers the customer the perfectly suitable second-hand truck without having to spend time searching for it. It also consists of a contract saying that if the customer signs a R&M contract, the dealer will buy back the vehicle and offer a new used vehicle when the old one gets too old or used. TAS makes this total solution possible by giving the dealer access to information about the truck and through this predict phase transitions. In conclusion, the developed services and especially the combination of them into a total solution would, according to the authors, favour the transition from a product focused company to a total solution provider, and extend the knowledge about the second-hand market.

published_or_final_version / Electrical and Electronic Engineering / Master / Master of Philosophy

published_or_final_version / Electrical and Electronic Engineering / Master / Master of Philosophy

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