Radar sensor detecting vehicles at a distance of up to 120 meters regardless of weather conditions.
Useful speed range from 30-180 km/h.
Driver assistance in keeping appropriate distances and speeds.
Greater comfort on the motorway and country roads.
ACC Active Cruise Control in the BMW 7 and 5 Series enhances the functions of conventional cruise control, helping the driver keep the appropriate distance and road speed at all times. This system not only maintains the desired speed pre-set by the driver, but also, whenever required, monitors and controls the distance to the vehicle ahead on the motorway or a country road.
As long as the lane ahead of the driver is free, ACC Active Cruise Control works largely in the same way as a conventional system. But as soon as the driver encounters another vehicle moving ahead at a lower speed detected by the radar distance sensor, ACC adjusts the distance form the vehicle ahead by modifying the driver's own speed accordingly.
When activated, ACC serves to give gas and apply the brakes slightly with the emphasis on superior motoring comfort. The driver can however intervene at any time or apply the brakes himself. And this is indeed necessary whenever the system reaches its limits, since it is BMW's philosophy to maintain the driver's responsibility in and for his car.
To activate ACC the driver first chooses his "personal" speed in comfortable 10 km/h increments by adjusting a control stalk on the steering column.
ACC is conceived for use between 30 and 180 km/h, the speed chosen by the driver being marked on the speedometer and consistently maintained as long as the vehicle ahead does not require a reduction in road speed.
A 77 GHz radar sensor, serving as the key component in the system, is able to detect vehicles ahead at a distance of up to 120 meters, largely independent of weather conditions. As soon as the driver's car approaches another vehicle from behind, Active Cruise Control adjusts the driver's speed smoothly and precisely to that of the car ahead, at the same time keeping a constant distance the driver is once again able to choose himself from four levels on the control lever.
Following the same mode as if the car were on a free stretch of road, ACC performs this function by masterminding the engine, the brakes and even the transmission. Operation of the brakes is limited to a comfortable 2 m/sec2 quite sufficient for fine adjustment of the car's speed and distance in maintaining the system function. And should the need arise to apply the brakes harder, the driver is informed accordingly by an optical and acoustic takeover message.
ACC relieves the driver of the permanent and monotonous chore of constantly adjusting the car's distance and speed - a particularly convenient feature above all in dense traffic on the motorway and expressways with road speeds constantly changing, where conventional cruise control is often useless. So now, with ACC, the driver is able to "flow along" smoothly and in relaxed style in such a situation wherever appropriate.
Photo Caption: Top: ConnectedDrive: Technology test bed BMW X5 with long range radar sensor
