Abstract
When braking in a turn (BIT), gentle braking of about 0.2∼0.4 G with high lateral acceleration causes the vehicle to enter a spin, which requires a high level of skill to control. Ordinary drivers executing gentle braking when BIT may lose control of the vehicle. Professional drivers driving on a circuit, however, intentionally execute gentle braking when BIT, taking advantage of this spin behavior to generate rotary motion more effectively around the center of gravity of the vehicle for better lap times. In this study, the driving behavior of a professional driver was compared with that of ordinary drivers when BIT at the entry of a constant-radius corner of a circuit. When BIT, the professional driver executed gentle braking of 0.2∼0.4 G for longer than the ordinary drivers. The professional driver took advantage of the spin of the vehicle by executing gentle braking in combination with high-skill steering maneuvers. As a result, the mean values of mean lateral acceleration and mean yaw rate were higher, and the mean variation in velocity tended to be smaller for the professional driver compared to that of the ordinary drivers. The ordinary drivers often executed heavy braking of 0.6 G or higher to avoid entering an uncontrollable spin.
