A significant number of accidents could be avoided through timely threat recognition
and appropriate maneuvers for collision avoidance. This may be achieved
either by a suitable warning to the driver or by automatic support to longitudinal
or lateral control of the vehicle.
Adaptive cruise control (ACC) is a function for longitudinal control of vehicles,
which relieves the driver of a significant part of the task of driving, and in a comfortable
manner. ACC can be seen as a further development of cruise control,
which maintains constant speed. In regions where traffic situations commonly
permit steady speeds (such as in the USA) this function has been widely accepted:
cruise control is fitted to more than 90% of US vehicles. In regions characterized
by more unsteady traffic conditions with frequent speed changes, cruise
control is less often found. In Europe this function is fitted to less than 10% of
vehicles.
ACC is a logical derivative of cruise control; it automatically controls the speed
to adjust the distance of the car from the vehicle in front and speed relative to
preceding vehicles by employing suitable actuator systems [1