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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.
1

Driver-truck models for software-in-the-loop simulations

Daniels, Oskar January 2014 (has links)
By using vehicle-to-vehicle communication, vehicles can cooperate in many waysby sending positions and other relevant data between each other. One popularexample is platooning where many, especially heavy vehicles, drive on a trailwith short distances resulting in a reduction of air resistance. To achieve a goodefficiency of the platooning it is required that vehicle fleets are coordinated, sothat the percentage of time for driving in platoon is maximized without affectingthe total driving time and distance too much. For large fleets, this is a complexoptimization problem which would be difficult to solve by only using the realworld as the test environment. To provide a more adaptable test environment for the communication and platooningcoordination, an augmented reality with virtual vehicles (“Ghost trucks")with relevant communication abilities are developed. In order to realise the virtualtesting environment for trucks, Scania initiated a project that could be dividedinto the workload of three master theses. This thesis involved the part ofdeveloping the virtual vehicles, which include the development of a truck modeland a driver model. The developed truck model consists of a single track vehicle model and severalpowertrain models of different complexity provided by Scania. Additionally, thedriver model consists of steering wheel and speed controls in order to keep thetruck on a safe distance from the lead truck and stay on a preferred lane. The keyfeature of the driver-truck model is its modular design, which provides great flexibilityin selecting the level of detail for each component. The driver-truck modelcan be duplicated and simulated together in real time and performs platooningwith each other in a road system based on the real world. As the driver-truckmodel is module based, it can easily be extended for future purposes with morecomplex functions. The driver-truck model is implemented in Simulink and the simulation performancefor different model complexity is evaluated. It is demonstrated that theflexibility of the developed model allows a balanced decision to be made betweenrealistic truck behavior and simulation speed. Furthermore, multi-truck simulationsare performed using the model, which demonstrate the effectiveness of themodel in the evaluation of truck platooning operations.
2

Variable Vehicle Dynamics Design : Objective Design Methods / Variabel Fordonsdynamik : Målrelaterade Designmetoder

Oscarsson, Magnus January 2003 (has links)
<p>The goal of this thesis has been to study the behaviour of the closed loop driver-vehicle-environment in simulation and to find parameters of the synthetic vehicle model, which minimise certain optimisation criteria. A method of optimising parameters using genetic algorithms has been implemented and has proven to work well. Two different driving strategies have been tried in the optimisation of an ISO lane-change maneouvre. The first approach has simulated a beginner driver and his or her behaviour. The second approach simulates an experienced driver and also the possibility of driver adaption to different vehicle types. The implemented driver model has shown to be sufficient to describe the driver's behaviour during lateral maneouvres. A parameter set which minimises the lateral acceleration response on steering wheel angle has proven to be the optimum. This includes a small steering wheel ratio, and a small but positive under steer gradient. The driver has demonstrated the ability to adapt to different vehicles, and therefore different parameter sets, describing the driver, should be used for different problems.</p>
3

Variable Vehicle Dynamics Design : Objective Design Methods / Variabel Fordonsdynamik : Målrelaterade Designmetoder

Oscarsson, Magnus January 2003 (has links)
The goal of this thesis has been to study the behaviour of the closed loop driver-vehicle-environment in simulation and to find parameters of the synthetic vehicle model, which minimise certain optimisation criteria. A method of optimising parameters using genetic algorithms has been implemented and has proven to work well. Two different driving strategies have been tried in the optimisation of an ISO lane-change maneouvre. The first approach has simulated a beginner driver and his or her behaviour. The second approach simulates an experienced driver and also the possibility of driver adaption to different vehicle types. The implemented driver model has shown to be sufficient to describe the driver's behaviour during lateral maneouvres. A parameter set which minimises the lateral acceleration response on steering wheel angle has proven to be the optimum. This includes a small steering wheel ratio, and a small but positive under steer gradient. The driver has demonstrated the ability to adapt to different vehicles, and therefore different parameter sets, describing the driver, should be used for different problems.

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