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Doctor's Theses (authored and supervised):

F. Magerl:
"Ein Fahrmodell für die Simulation des ISO-Doppelspurwechsels";
Supervisor, Reviewer: P. Lugner, B. Geringer; E325 Institut für Mechanik, 2003.



English abstract:
Computer simulations have becollie a staple in developing vehicles nowadays. It is thanks to simula- tion models that -despite the highly sophisticated technology used in vehicles -both development periods and development costs of new vehicles and innovations are still within reasonable parameters. Thus, this thesis should be regarded as a contribution to shifting development tasks from driving tests to simulations. The thesis presents a computer-aided procedure to calculate the minimum time required to colliplete the ISO double lane change maneuver. To make sure that the results are meaningful, the algorithm has been defined for detailed vehicle models which show strong non-linearities. While a simple controller keeps the longitudinal velocity roughly constant, optimization is used to determine the history of the steering wheel angle for each velocity. If these parameters lead to an error-free maneuver, the velocity is increased and the new history of the steering wheel angle is calculated for that velocity. This incremental increase in velocity is repeated until an error-free double lane change is no longer possible, which means that the velocity tested last is the optimal drive-through velocity.
This thesis presents a sequential and segmental control approach. In optimizing the steering wheel angle, the ISO double lane change is subdivided into two separate maneuver segments, which are investigated separately and successively. In addition, an area of overlap is defined in which a change in the history of the steering wheel angle is possible in the first as well as in the second maneuver segment.
Each optimization step consists of the three parts determination of the steering wheel angle setting, simulation, and evaluation of the vehicle movements, which are passed in this order. This sequence reflects the efforts of a human driver who, due to the short duration of the maneuver , acts much more than he reacts.
The steering wheel angle setting is determined in three steps. To guarantee efficient optimization, a steering wheel angle design which can be defined by a small number of design parameters is stipulated. This design curve shows kinks which are rounded off by parable segments, resulting in the rounded-off steering wheel angle design. In order to remove the physiologically atypical discontinuities in the acceleration of the steering wheel angle, a PT2 element is used to smooth the curve. Besides the drive-through velocity under review, the resulting steering wheel angle setting is the major input value for the vehicle model. By simulating the vehicle movements, the distances from the lane edges necessary to compute the cost function are determined. Based on this evaluation of the vehicle trajectory, the steering wheel angle design is varied according to the optimization algorithm used.
The developed procedure was used to examine the instationary road behavior of a vehicle in the upper-middle price range, with calculations being carried out both with a detailed model and with a non-linear two-wheel vehicle model. The thesis is concluded by a presentation and evaluation of the research findings.

Created from the Publication Database of the Vienna University of Technology.