The cruise control DISTRONICMercedes-Benz A-Class
Apart from keeping a set speed, DISTRONIC is also able to maintain a specific distance from the vehicle ahead, automatically decelerating and accelerating as necessary for this purpose. DISTRONIC adaptive cruise control is able to maintain a set time interval from the vehicle ahead or the selected speed. When a vehicle with DISTRONIC activated via the familiar cruise control lever approaches another vehicle, the system automatically decelerates or gently applies the brakes in order to maintain the set distance. When the distance from the vehicle ahead increases again or when the road ahead is clear, DISTRONIC operates like a conventional cruise control system, maintaining the previously set speed in the range from 30 to 180 km/h. The distance from the vehicle ahead can also be read from the multifunction display when DISTRONIC is not active. This additional functionality in comparison to standard cruise control makes DISTRONIC a comfort and convenience system which relieves the workload on the driver particularly on motorways and multi-lane roads, to the benefit of driver-fitness safety. A microcomputer in the DISTRONIC system employs the signals from the radar sensor in the radiator grille, which is able to monitor the situation on the road ahead of the vehicle up to a distance of 150 metres. When the vehicle ahead is travelling at a different speed to your own car, this induces a frequency shift in the radar signal, known as the Doppler effect. On the basis of this frequency shift, the system calculates the relative speed between the two vehicles and is also able to determine the distance between them by reference to the transit time of the reflected signals. When heavier braking is necessary, the system prompts the driver to step on the brake by means of a warning lamp in the instrument cluster and, if necessary, via an acoustic signal. When these signals are output, the driver is required to step on the brake pedal immediately. Note: The (DISTRONIC) radar sensor system requires approval for use in each individual country. Consequently, this technology is not available in all markets. The system is not to be used when passing through countries in which it has not received approval, e.g. on holiday.