Adaptive cruise control (ACC) employs sensing and control systems to monitor the vehicle’s position with respect to any vehicle ahead. When a vehicle equipped with ACC approaches a slower-moving vehicle, the ACC system reduces the vehicle speed in order to maintain a preset following distance (headway). However, when the traffic ahead clears, the ACC system automatically accelerates the vehicle back to the preset travel speed.
ACC systems use forward-looking radar or laser detection (lidar) systems to monitor the vehicle’s position with respect to any vehicle in front and change the speed in order to maintain a preset following distance (headway).
The system typically allows the driver to preset a “following time,” for example a two-second gap between vehicles. The ACC computer makes calculations of speed, distance and time based on the sensor inputs and makes appropriate adjustments to the vehicle’s speed to maintain the desired headway.