Influence of Steering Wheel Gear Ratio on Drift Control

A drift-turn experiment to assess the influence of differences in steering wheel gear ratios was undertaken using a driving simulator. It is relatively easy to maintain control of a commercial vehicle if the tire is in contact with the road surface and the steering wheel gear ratio is 15.0:1 to 18.0:1. Conversely, in the event of a change in traction such as the rear wheel meeting a drift area, a steering wheel gear ratio of 7.5:1 to 9.0:1 is required to maintain control of the vehicle, even when the vehicle became unstable. Moreover, the stability of the vehicle deteriorates in drift running if the steering gear ratio is reduced too much. That is, the steering gear ratio in which the drift angle is maintained most easily is in the range 7.5∼9.0. And, a drift performance evaluation index D n=x was determined and was found to agree with the subjective ratings. Thus, evaluating drift control for drift cornering using the drift performance evaluation index was assumed to be effective.