Audi side assist – Audi side assist also makes use of intelligent radar technology. Designed specifically for lane changes, it warns the driver if a potentially hazardous situation is likely to arise. Two radar sensors in the rear bumper, operating at a frequency of 24 Gigahertz, scan the area next to and behind the car, up to a distance of 50 metres. A high-performance computer unit evaluates and interprets the signal data.
If another vehicle is moving at approximately the same speed in the critical zone, or is approaching rapidly from behind, a yellow LED display illuminates in the left or right outside mirror housing. Designed to be ‘subliminal’, the driver only sees this when looking directly into the mirror, and does not register it when looking forwards.
If the driver of the new Audi A4 operates the flashing turn indicator in preparation for changing lanes, despite the illuminated warning signal, the intensity of the LEDs is increased and they flash for about a second at a higher frequency. This signal is very difficult to overlook, since the human eye is extremely sensitive to changes in contrast in the peripheral viewing area. Audi has analysed the viewing behaviour and the effect of the display in full detail in an extensive series of tests with drivers of various statures and ages.
The display on the inner face of the mirror housing has been carefully aligned so that it can be seen by the driver but only with difficulty by other occupants of the car for psychological reasons. In accordance with vehicle licensing regulations, the display is invisible to drivers of following vehicles.
The brightness of the display varies according to ambient light conditions, and can also be adjusted via the MMI control terminal. The system operates at speeds of 37mph and above and is therefore inactive in built-up areas; it can be switched off at the touch of a button near the exterior mirror.Published 9 February 2008