The Ultrasound sensor gives the vehicle its 'sense of touch', allowing it to register its surroundings.

The second generation of sensors soon followed, and was installed by Mercedes-Benz in its S-class. In 1995, Bosch sold 100,000 ultrasound sensors to the automotive industry. Five years later, this total had risen to 2.5 million sensors a year. Currently, 14 automakers worldwide install Bosch parking assistant technology in some 200 vehicle models.

The technology has matured considerably, and is now in its fourth generation. “We have been able to reduce the volume of today’s sensor to one-fifth of the ultrasound sensor of 1993. The smaller installation volume and a variable connector design make it much easier for automakers to install these sensors in bumpers,” says Dr Rainer Kallenbach, executive vice-president (sales) in the Automotive Electronics division. Bosch covers worldwide demand for ultrasound sensors and the electronic control units that go with them at three manufacturing sites in Europe, Asia, and America.

From Parking Aid to the Parking Assistant

The ultrasound sensor was originally developed for the classic parking aid, which kept drivers informed during parking manoeuvres about the distance between the bumper and the nearest obstacle. More recently, ultrasound sensors have formed the basis for a modular system which allows Bosch to provide all the ultrasound-based functions associated with the vehicle. The latest example is the Parking Assistant, which is available as an optional feature in the most recent Mercedes-Benz A- and B-class. This assistant uses ultrasound sensors to identify suitable parking spaces and, with the support of electric power-assisted steering, to automatically park the vehicle in just a few seconds, even in the tightest of spaces. All the steering movements are performed by the assistant, while the driver controls the parking maneuver by accelerating and braking.

On the basis of the same ultrasound sensors, Bosch also offers a variant of the Parking Assistant for vehicles with conventional hydraulic power steering. Here, the driver still has to steer, but is guided into a perfect parking position by clear instructions from the assistant as to steering-wheel position and ideal points at which to stop or to reverse the steering.

This variant recently debuted in the Opel Insignia and the Mercedes-Benz E-class. By 2011, 17 vehicle models will be equipped with the Bosch Parking Assistant. The component supplier expects that many further models will soon follow suit. There is a good chance they will do so, for by then the second generation of this electronic Parking Assistant will be ready for series production. It will not only be able to parallel-park, but also provide automatic support for parking at a right angle and driving out of a parking space.