Abstract
In the present study, following efforts have been made, relating to the unsteady straight running stability of a passenger car. To build a model, on-road vehicle experiment is performed and the straight running stability of a vehicle is verified. Also, to investigate a driving index, sensory test and evaluations of heart rate variability by a driver are performed. To investigate the relationships between vehicle dynamics and tire characteristics, a model for the straight running stability has been built. A 3-degree-of-freedom vehicle model together with a general drivers model are utilized for the analysis. Next, the proposed human-vehicle-model is investigated and the index to quantify straight running stability is determined. Also, by identifying the tire characteristics that improves straight running stability, the effectiveness of the proposed human-vehicle-model is demonstrated. Lastly, tire test is performed against the same operational conditions used for the on-road vehicle test, to verify the validity of the developed human-vehicle-model.
