A driver assistance system is described which provides an automatic ro
ad-departure warning and intervention function. The system is intended
for drivers who are drifting off the roadway at a shallow angle of de
parture due to inattention, drowsiness, intoxication, or other causes.
An integrated set of model-based estimation algorithms serves to anti
cipate imminent road departures. Interventions are achieved using diff
erential braking - the application of unequal brake torques at the rig
ht and left wheels. The driver remains in the loop, always able to pro
vide the primary steering commands. A driver state assessment module i
s being developed to further adapt to individual drivers and to identi
fy changes in driver behavior. We describe the algorithms, present sim
ulation results, and include preliminary experimental data from a prot
otype vehicle.