Driver Drowsiness Detection is a term used to describe a feature or combination of features that observes
driver patterns and alerts you if the system detects signs of drowsiness or lack of attention.
Drowsiness detection systems are very useful on long trips requiring several hours of driving especially on
highways or long stretches or road. It may also be useful during late night driving even if the journey may not be
These systems use a variety of sensors, usually a combination of its own dedicated sensors and other sensors
that are used by other features such as the pedal position sensor for
These sensors measure one or both of two things;
By using the information from both of the measurements above an on board computer/
ECU can determine drowsiness or reduced attentiveness while driving and alert the driver.
- Driver patterns and habits, the system can monitor the operations of the driver during long trips to determine signs
of drowsiness and fatigue. For example if lane departure warning detects that
the vehicle is constantly drifting off lane.
- The position and expression of the driver's head and face, sensors usually located around the instrument panel
constantly monitor the driver's head and/or face. Facial recognition technology similar to what is found on digital
cameras may be used to identify facial features and position.
The alert given by various driver drowsiness detection systems is a visual warning in the instrument panel usually
telling the driver that he or she may be drowsy and should take a break.
The system can be used in other ways such as in the Lexus LS where the sensors monitor the driver's face and head while
the front of the car is being constantly scanned. If the LS is in close proximity of colliding into an object and the system
observes the driver is not looking forward then the driver is alerted and the brakes are
Several marques have driver drowsiness detection systems installed on some of their vehicles using different names
specific to each marque. Commom names are Volvo's "Driver Alert Control" and Mercedes Benz "Attention Assist".