A warning and intervention system to prevent road-departure accidents

A driver assistance system is described which provides an automatic road-departure warning and intervention function. The system is intended for drivers who are drifting off the roadway at a shallow angle of departure due to inattention, drowsiness, intoxication, or other causes. An integrated set of model-based estimation algorithms serves to anticipate imminent road departures. Interventions are achieved using differential braking - the application of unequal brake torques at the right and left wheels. The driver remains in the loop, always able to provide the primary steering commands. A driver state assessment module is being developed to further adapt to individual drivers and to identify changes in driver behavior. We describe the algorithms, present simulation results, and include preliminary experimental data from a prototype vehicle.