An optimal preview driver model applied to a non-linear vehicle and an impaired driver

This paper proposes an improved driver model based on the one introduced by MacAdam in 1981 where optimal preview control is applied. The details of the optimal preview driver model are derived. The modified model incorporating the steering angle into the performance index is used to compute the steering input. The parameters associated with reaction time and preview time characterize the adaptation of the driver to the changes of the vehicle, the road and the environment. The modified model exhibits better performance and its parameters are well related to the performance of the driver. The driver model is then coupled with a non-linear vehicle. Initial tests are performed to identify the driver's parameters. The coupling of the driver and the non-linear vehicle introduces enhanced path-following. An impaired driver model can be obtained by reducing the optimal parameters. When the safety criteria are chosen, the threshold for safe driving is identified.