Bosch engineers have made an interplay of radar and video data, for optimum recognition of traffic situations.
Apart from the Bosch ESP brake control system, the Audi A8 features two long-range radar sensors, which are housed at the left and right of the front bumper. These new Bosch generation 3 sensors can detect objects within a beam width of approximately 40 degrees at a distance of up to 250 meters, and can determine their position and speed.
The video camera is positioned behind the front windshield, at the same height as the rear-view mirror. The advantage of video technology is the high level of information content, which makes persons, vehicles, or traffic signs easy to identify. Another benefit is the technology’s ability to set off one image against another, as well as the angle detection of objects. The radar signals, for their part, deliver precise data as to the position and speed of the persons, vehicles, or traffic signs featured in the video images.
In a first step, if the predictive emergency braking system detects a potential obstacle, such as a vehicle that is slowing down very fast or coming to a standstill, the brake is primed – the brake pads are brought close to the discs, so that they can provide immediate deceleration in the event of a subsequent braking operation.
If the driver does not react, and the vehicle comes closer, an acoustic warning is given, followed by automatic partial braking, initiated via a brief jerk on the brakes. If the driver still does not react, and if a collision can no longer be prevented, the system brakes automatically at maximum pressure roughly half a second before impact, in order to reduce speed of impact and mitigate the consequences of the accident.
The ACC function has also been extended. With the help of the video data for example, the system reacts more quickly when overtaking other vehicles and when other cars veer into the lane ahead. Moreover, in the new Audi, the signals from the Bosch video camera are used for the automatic headlight control and for the lane departure warning system.
Many other systems and components in the new A8 are also made by Bosch, including the instrument cluster with its large color display.