Proper PD steering assistance constant based on the driving situation

Abstract

Proportional derivative (PD) steering assistance can greatly improve the control stability of a vehicle. However, for all PD steering methods, the discomfort associated with the need to continuously turn the steering wheel during cornering is significant. Because the steering return phenomenon of the steering wheel stop like this is not preferable, PD steering assistance should be extremely weak (almost 0) during normal cornering. Alternatively, during drift cornering, during which the grip area of the tires is exceeded, PD steering assistance is helpful because the driver has good control over countersteering. Moreover, the use of PD steering assistance is preferable during lane changes because the response and settling of a vehicle is greatly improved when PD steering assistance is used. Based on these considerations, a previous report examined steering method controls in which the PD steering assistance constant was incorporated along with the drivers' perception changes in certain driving situations. This study aimed to determine a suitable PD steering assistance constant in relation to the driving situation. A proper PD steering assistance constant was found to exist for specific driving situations. Based on the results of gaze detection using an eye mark recorder, the study was able to reduce the right and left difference of the gaze at the driver by controlling PD steering assistance using a proper PD steering assistance constant for various driving situations.