Mix of sensors seen in future driver assistance systems

German automotivesupplier Hella KgaA sees synergies in the design process if different sensor types are combined for future driver assistancesystems.

For instance, the company said, the combination of a front camera, a 24GHz distance warning radar system and IR-based distance warning system could be used to implement a pre-crash protection system. If such a system detects a high probability for an immanent front crash, it pre-triggers passive safety systems such as occupant restraint system, adjusts airbag ignition timing and closes the sun roof. If a crash is rendered unavoidable, it also triggers an emergency braking process, thus reducing the impact speed.

Hella announced it is presently developing a low-price 24GHz distance warning radar system whose signals could be used to implement a pre-crash protection system.

Other developments under way make use of cameras, whose signals are being processed and fed into systems that aim at improving the safety. For instance, a 'driver alertness assistance system' will use a camera located at the dashboardand watch the driver's eyelid activity. If the driver closes his eye for more than 1.5s, the system issues a warning sound. In addition, the camera signal could be used for face recognition in order to facilitate comfort functions. However, this function is in an early design stage and won't be available before several years, a spokesperson explained.

Another way to make use of image processing to improve safety and comfort is the so-called top view function. In order to implement it, four cameras are used: One at the front and the rear end and at two at the outside mirrors. Each camera sports an aperture angle of 180¡ã. A computer inside the carprocesses and combines the camera images and creates a top view of the car which is displayed on a dashboard monitor. The system is intended to support the driver when maneuvering through difficult environments.

In some disciplines, electronic assistance systems are already on the high-end market and now the design works concentrate on bringing the price level down so the devices can be integrated in medium and economy class cars, a Hella spokesperson explained.