For more than a century, public transportation has played a significant role in society. Transit agencies, like other service industries, are intent on improving their quality of service so as to increase transit ridership and attract passengers from other modes. In recent years transportation technologies have been improved which increase safety, mobility for people and goods, and reduce Green House Gas (GHG) emissions. An evaluation of the impacts of these operational and technological advancements is required for transit agencies to capture the potential benefits for their systems. The Region Municipality of Waterloo (RMOW), a mid-size region in Ontario has implemented an express transit service (iXpress) in Sept, 2005. The service has longer distances between stops and incorporates advanced technologies. The goal is to increase transit ridership and, as a result, to reduce GHG emissions. This research has been conducted to study the iXpress service and to develop several methods to determine the impacts of high speed transit service on passenger attraction, operational efficiency, and regional air quality. In this research, the change in total cost of travel between origin destination pairs is correlated to changes in observed ridership. Further, several surveys were conducted in the RMOW to evaluate the travel pattern changes of residents who switched from other modes to iXpress. Based on fuel consumption data, a model of GHG emissions as a function of route and vehicle characteristics has been developed to capture the operational impacts of a new iXpress service. The iXpress service of Grand River Transit (GRT) has been successful in attracting riders despite delays in technology implementation. The cost analysis presented in this research shows that the introduction of iXpress resulted in approximately 30% reduction in overall cost of travel by transit. As a result, ridership (boardings) has increased by 11% and 46% in the northern and southern sections of the iXpress service area respectively, while accounting for overall growth in the system. An analysis of travel patterns and mode shifts suggest that travelers switching from auto mode to iXpress have resulted in annualized reduction of approximately 530 tonnes of GHG. A fuel consumption analysis indicates that buses on the iXpress route have an average fuel consumption rate of 0.54 L/km while, buses serving local route consumes fuel of a rate of 0.62 L/km.

This thesis is an approach to improve a two-mode hybrid electric vehicle, which is currently under development by GM, with respect to fuel consumption. The study is not only restricted to the specific two-mode HEV but also presents results regarding parallel as well as serial HEV’s. GM whishes to verify if the online-based controller in the prototype vehicle utilizes the most of the HEV ability and if there is more potential to lower the fuel consumption. The purpose is that the results and conclusions from this work are to be implemented in the controller to further improve the vehicle’s performance. To analyze the behavior of the two-mode HEV and to see where improvements can be made, models of its driveline and components are developed with a focuson losses and efficiency. The models are implemented in MATLAB together with an optimization algorithm based on Dynamic Programming. The models are validated against data retrieved from the prototype vehicle and various cases with different inputs is set up and optimized over the NEDC cycle. Compensation for cold starts and NOx emissions are also implemented in the final model. Deliberate simplifications are made regarding the modeling of the power split’s functionality due to the limited amount of time available for this thesis. The optimizations show that there is potential to lower the fuel consumptionfor the two-mode HEV. The results are further analyzed and the behavior of the engine, motors/generators and battery are compared with recorded data from a prototype vehicle and summarized to a list of suggestions to improve fuel economy.

The situation when driving in dense traffic and at low speeds is called Stop and Go. A controller for automatic following of the car in front could under these conditions reduce the driver's workload and keep a safety distance to the preceding vehicle through different choices of gear and engine torque. The aim of this thesis is to develop such a controller, with an additional focus on lowering the fuel consumption. With help of GPS, 3D-maps and sensors information about the slope of the road and the preceding vehicle can be obtained. Using this information the controller is able to predict future possible control actions and an optimization algorithm can then find the best inputs with respect to some criteria. The control method used is Model Predictive Control (MPC) and as the name indicate a model of the control object is required for the prediction. To find the optimal sequence of inputs, the optimization method Dynamic Programming choose the one which lead to the lowest fuel consumption and satisfactory following. Simulations have been made using a reference trajectory which was measured in a real traffic jam. The simulations show that it is possible to follow the preceding vehicle in a good way and at the same time reduce the fuel consumption with approximately 3 %.

The department REI/EP at DaimlerChrysler Research and Technology and the Laboratory for Efficient Energy Systems at Trier University of Applied Science, are developing control functions and fuel optimal strategies for low speed conditions. The goal of this thesis project was to further develop the fuel optimal operating strategies, and implement them into a test vehicle equipped with a dSPACE environment. This was accomplished by making optimal reference signals using dynamic programming. Optimal, in this case, means signals that results in low fuel consumption, comfortable driving, and a proper distance to the preceding vehicle. These reference signals for the velocity and distance are used by an MPC controller (Model Predictive Control) to control the car. In every situation a suitable reference path is chosen, depending on the velocities of both vehicles, and the distance. The controller was able to follow another vehicle in a proper way. The distance was kept, the driving was pleasant, and it also seems like it is possible to save fuel. When accepting some deviations in distance to the preceding car, a fuel reduction of 8 % compared to the car in front can be achieved.

For more than a century, public transportation has played a significant role in society. Transit agencies, like other service industries, are intent on improving their quality of service so as to increase transit ridership and attract passengers from other modes. In recent years transportation technologies have been improved which increase safety, mobility for people and goods, and reduce Green House Gas (GHG) emissions. An evaluation of the impacts of these operational and technological advancements is required for transit agencies to capture the potential benefits for their systems. The Region Municipality of Waterloo (RMOW), a mid-size region in Ontario has implemented an express transit service (iXpress) in Sept, 2005. The service has longer distances between stops and incorporates advanced technologies. The goal is to increase transit ridership and, as a result, to reduce GHG emissions. This research has been conducted to study the iXpress service and to develop several methods to determine the impacts of high speed transit service on passenger attraction, operational efficiency, and regional air quality. In this research, the change in total cost of travel between origin destination pairs is correlated to changes in observed ridership. Further, several surveys were conducted in the RMOW to evaluate the travel pattern changes of residents who switched from other modes to iXpress. Based on fuel consumption data, a model of GHG emissions as a function of route and vehicle characteristics has been developed to capture the operational impacts of a new iXpress service. The iXpress service of Grand River Transit (GRT) has been successful in attracting riders despite delays in technology implementation. The cost analysis presented in this research shows that the introduction of iXpress resulted in approximately 30% reduction in overall cost of travel by transit. As a result, ridership (boardings) has increased by 11% and 46% in the northern and southern sections of the iXpress service area respectively, while accounting for overall growth in the system. An analysis of travel patterns and mode shifts suggest that travelers switching from auto mode to iXpress have resulted in annualized reduction of approximately 530 tonnes of GHG. A fuel consumption analysis indicates that buses on the iXpress route have an average fuel consumption rate of 0.54 L/km while, buses serving local route consumes fuel of a rate of 0.62 L/km.

In the development of modern rotorcraft vehicles, many unique challenges emerge due to the highly coupled nature of individual rotorcraft design disciplines therefore, the use of an integrated product and process development (IPPD) methodology is necessary to drive the design solution. Through the use of parallel design and analysis, this approach achieves the design synthesis of numerous product and process requirements that is essential in ultimately satisfying the customers demands. Over the past twenty years, Georgia Techs Center for Excellence in Rotorcraft Technology (CERT) has continuously focused on refining this IPPD approach within its rotorcraft design course by using the annual American Helicopter Society (AHS) Student Design Competition as the design requirement catalyst. Despite this extensive experience, however, the documentation of this preliminary rotorcraft design approach has become out of date or insufficient in addressing a modern IPPD methodology. In no design discipline is this need for updated documentation more prevalent than in propulsion system design, specifically in the area of gas turbine technology. From an academic perspective, the vast majority of current propulsion system design resources are focused on fixed-wing applications with very limited reference to the use of turboshaft engines. Additionally, most rotorcraft design resources are centered on aerodynamic considerations and largely overlook propulsion system integration. This research effort is aimed at bridging this information gap by developing a preliminary turboshaft engine design methodology that is applicable to a wide range of potential rotorcraft propulsion system design problems. The preliminary engine design process begins by defining the design space through analysis of the initial performance and mission requirements dictated in a given request for proposal (RFP). Engine cycle selection is then completed using tools such as GasTurb and the NASA Engine Performance Program (NEPP) to conduct thorough parametric and engine performance analysis. Basic engine component design considerations are highlighted to facilitate configuration trade studies and to generate more detailed engine performance and geometric data. Throughout this approach, a comprehensive engine design case study is incorporated based on a two-place, turbine training helicopter known as the Georgia Tech Generic Helicopter (GTGH). This example serves as a consistent propulsion system design reference highlighting the level of integration and detail required for each step of the preliminary turboshaft engine design methodology.

Revised version, September 2012 / Comments and Discussions : Shinichi NAGAO

<p>The possibilities to simulate fuel consumption and optimize a vehicle's powertrain to fit to the customer's needs are great strengths in the competitive bus industry where fuel consumption is one of the main sales arguments. In this master's thesis, bus specific powertrain component models, used to simulate and predict fuel consumption, are validated using measured data collected from buses.</p><p>Additionally, a sensitivity analysis is made where it is investigated how errors in the powertrain parameters affect fuel consumption. After model improvements it is concluded that the library components can be used to predict fuel consumption well.</p><p>During the work, possible model uncertainties which affect fuel consumption are identified. Hence, this study may serve as foundation for further investigation of these uncertainties.</p>

The objective of this thesis is to analyse driving behaviour and to characterize the effectsof an efficient way of driving, termed eco-driving, that enables the driver to reduce fuelconsumption and CO2emissions.The approach used to assess driving style is a collection of data from a CAN bus of acar equipped with OBD-II (on-board diagnostic) system. The driving experiment wasperformed for nine drivers who drove in a normal way or regular driving style and onedriver was an eco-driver who drove in an economical driving style. The driving routewas approximately 18.7 kms (which took between 25 to 30 minutes) in Halmstad city,Sweden.The drivers are compared using a statistical analysis of the driving parameters such as,speed, accelerator (gas pedal) and brake pressure, which are obtained from CAN busdata. A hierarchical clustering algorithm also used to classify the drivers based on theaverage result of the signals.In the results, a driving difference between the eco-driver and the normal drivers is visi-ble, most of the normal drivers have more or less similar behaviour. The average speed ofthe eco-driver lower than the normal drivers and the accelerator (gas pedal) result is alsoshown less usage by the eco-driver than the normal drivers. On the other hand, the eco-driver has braked more often than the normal drivers, but gently. Nevertheless, differenttraffic conditions during the experiment obstructs comparisons between the drivers.

Fuel consumption is one of the factors that are considered when deciding a vehicle’s optimal specification. In order to swiftly estimate the fuel consumed during real world driving scenarios, a simulation tool has been developed that is well suited for vehicle configuration exploration applications. The simulation method described in this paper differs from the static calculation method currently in use at Scania cv since the dynamic translation of the vehicle is considered, yet the simulation time is kept low. By adopting a more dynamic approach, the estimation accuracy is increased and simulation of fuel saving technology, e.g. intelli- gent driver support system, is enabled. In this paper, the modeling and implementation process is described. Different approaches is discussed and the choices made during the development is presented. In order to achieve a low simulation time and obtain a good compatability with Scania’s current software application, some of the influencial factors have been omitted from the model or described using simple relations. The validation of the fuel consumption estimation indicates an accuracy within three percent for motorway driving. Utilizing the newly devised simulation tool, a look-ahead cruise controller has been implemented and simulated. Instead of continuously finding the optimal control signals during the driving scenario like most look-aheadcontrollers, a dynamic programming algorithm is used to find a fuel efficient speed profile for the entire route. The speed profile is used as the reference speed for a conventional cruise controller and comparison with another simulation tool indicates that this is a fast and accurate way to emulate a real look-ahead controller.