Abstract
Keywords - handling characteristics, ease of control, driver parameters, identification, chassis control
Many investigations on vehicle handling evaluation by human drivers and it´s relation to the chassis design variables of vehicles and chassis control parameters, namely to vehicle response parameters, have been done, however, a generic way of understanding or explanation of them has not been established yet. Since it is recently regarded that active vehicle chassis controls are promising tools to improve vehicle handling and stability, it becomes more important than ever to have a general method of estimating or predicting the vehicle handling quality to be evaluated by human drivers subjectively, which is possible to be controlled by chassis design and controls.
Standing upon the above view, this study proposes a method to evaluate the vehicle handling quality based on driver steering characteristics identified with an existing simple driver model using measured time histories of driver steering behaviour and vehicle motions. It is supposed in this study that as a driver adapts his (or her) behaviour to the vehicle handling characteristics during maneuvering the vehicle, the driver´s handling parameters primarily reflect the vehicle handling quality evaluation. A driver´s handling parameters in the model are identified in this study by the experimental identification using measured time histories of vehicle path and steering angle during the lane change. So, that is to say that the basic idea in this study is to reason the vehicle handling quality by extrapolating from the driver´s handling parameters identified during the lane change.
In order to substantiate the effectiveness of the method proposed, the lane change tests are conducted with various vehicle speeds to find out reasonable driver handling parameters adapting to the vehicle speed. The lane change test for the identification of the driver parameters to discuss the handling quality of the variable handling vehicles with/without some chassis control is also conducted. It is possible to recognize that there is some difference in the time histories of the vehicle behaviours, however, it is difficult to find a reasonable difference by which it is possible to quantitatively explain the difference in the handling quality of the vehicles with/without control, even though there is a clear difference in the driver´s subjective handling quality evaluations on the vehicles. The parameter identification results obviously show that the driver parameters clearly reflect the vehicle handling characteristics and coincide with the driver´s handling quality evaluations.
It is concluded that the driver changes the handling parameters adapting to the vehicle response characteristics and that the driver handling parameters identified can give us a reasonable understanding the handling quality evaluation of the vehicle to be given by each driver respectively.