By Jim Kerr

We are all aware of vehicle safety systems such as seat belts, head restraints or air bags. These are passive systems, waiting for something to happen to the vehicle before they help keep us safe.

Audi's blind-spot vehicle detector
Click image to enlarge

On the other hand, active safety systems intervene or warn us of impending or potential problems before something happens and allows us to react. Audi is introducing a new type of active safety system to the market in the Audi Q7 performance SUV. The Q7 is the first vehicle to showcase this technology and Audi calls it Side Assist.

Audi’s Accident Research Unit mission is to analyse collisions and look at those areas where people make the most mistakes. They then design high tech solutions to reduce those mistakes. Side Assist is one of the results of their work. This system warns the driver of other vehicles in adjacent lanes and in those blind spots you can’t see in the mirrors. Many collisions are a result of driver inattention to the task of driving and allowing the vehicle to wander out of its lane. This could be caused by a distraction from a cell phone, talking to the children in the back seat, or drowsiness from a lack of sleep or the effects of a good lunch on a warm day. Side assist alerts the driver of potential collisions so they can be avoided.

Audi isn’t the first company to offer a system that will detect vehicles in adjacent lanes. The 2007 Volvo XC90 can be equipped with BLIS (Blind Spot Information System). This system uses cameras integrated into the door mirrors to recognise vehicles in the blind spot. The system then illuminates a light in the relevant mirror to alert the driver.

Instead of camera recognition processing, Audi is using radar. Two sensors in the back bumper operating on 24 GHz frequency send information to a high-performance computer that identifies the objects from the signals it receives. The system is sensitive enough to detect motorcycles and other small vehicles when they approach within 50 metres of the rear of the vehicle and as it passes along side the vehicle. When the computer detects a vehicle in the next lane, it flashes light emitting diodes (LED’s) located in the outside mirror mounts so the driver knows there is another vehicle present.

Audi’s research tells them that several criteria must be met for a warning system to both be accepted and actually be useful. It must be unobtrusive yet attract attention to where the problem is. The warning system must clearly identify the problem, and important to many drivers, it must not make the driver look bad in the eyes of passengers, or the system won’t be accepted. Audi chose to use LED’s in both outside mirror mounts and positioned them so they are normally only visible from someone sitting in the driver’s seat.

As a vehicle approaches from behind, the yellow LED’s on the outside mirror mount of the Audi Q7 turn on. Brightness is adjusted according to ambient light conditions, so the LED’s are bright enough to see but remain unobtrusive. A quick glance to either side allows the driver to see the glowing LED’s and they know instantly there is a vehicle present. This could be called the system’s information mode. It provides information and allows the driver to learn the system behaviour during normal driving. I tried Side Assist on a busy highway and found that it was easy to use. The LED’s remained on until the vehicle in the next lane was almost all the way past the Q7.

When the driver signals for a lane change, the computer turns the LED’s on brighter and flashes them if another vehicle is present. The flashing LED’s tend to attract the driver’s eye, so a possible collision is avoided even when the other vehicle can’t be seen in the mirrors.

Side Assist only becomes active at speeds greater than 35 km/h and the driver can turn it off if they desire. My experience with the system clearly showed the benefits of Side Assist, especially in busy traffic, and I can’t imagine a situation where one would want to turn it off.
Right now it is only available on the Audi Q7, but this is a system that could easily be adapted to other vehicles.

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