Vehicle Path Optimisation

Publication type: 
MSc thesis
Author: 
Danielsson, H.
Publication: 
ISRN LUTFD2/TFRT--5797--SE
Publisher: 
Department of Automatic Control, Lund University, Sweden, June 2007.
Year: 
2007
Abstract: 
<p>Optimal paths are useful when testing the performances of vehicles. In this thesis, optimal paths for vehicle models created in Modelica have been obtained. The optimal paths have been obtained by applying the theory of optimal control. The optimal control problem has been formulated with the Optimica language and has been solved with AMPL and IPOPT. Two approaches for finding optimal paths have been applied. In the first approach the vehicle models are dependent of time, and the time it takes for the vehicle to traverse a specified track is minimized. Finding optimal paths when using this approach has been difficult. In the second approach the vehicle models have been transformed to be dependent of distance instead of time before finding the optimal path. In this approach the cost function is formulated in a different way, and the cost function is minimized over travelled distance. Optimal paths for an one-track vehicle model with linear tyre characteristics driving on specified tracks have been found with both approaches. Some optimal paths have also been found for an one-track vehicle model with nonlinear tyre characteristics.</p>