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New launch: future technology

ELECTRONIC systems may be making cars ever more complex, but the technology has revolutionised many on-board systems including braking and handling. Without such advances, manufacturers would not be able to meet emissions legislation or optimise fuel economy, either.

There are still many things that electronics do not do, even though interactive systems are starting to appear, such as the Distronic intelligent cruise control Mercedes-Benz uses. Instead of simply maintaining a constant speed, regardless of what lies ahead, radar is used to sense the distance from the car in front, and an on-board computer can then speed up or slow down the car to maintain a constant distance.

Inevitably, a great deal more can be done and Daimler-Chrysler recently discussed how information can be gathered from around the car and used to improve safety.

Imagine how useful it could be for your car to identify a parking space and automatically manoeuvre into place or 'recognise' a pedestrian in the road ahead and automatically stop the car?

Although improvements in active and passive safety have made the car a far safer place for its occupants, accidents involving pedestrians and cyclists are still frequent. DaimlerChrysler is researching one system that may help to reduce accidents, particularly in urban areas where pedestrians can 'appear' from behind parked vehicles.

A pair of stereoscopic cameras mounted behind the windscreen, either side of the rear view mirror, monitor what is going on ahead of the car. Although humans can distinguish between a child running into the road and, say, a letterbox, it takes intensive programming for a computer to do the same thing. Using the way light is reflected from clothing can help the computer pick out humans.

As soon as the system monitors movement in the car's path, it applies full braking until the car stops. Although control over braking is taken from the driver, he or she remains in overall control. DaimlerChrysler laid on a demonstration in rain using an E-Class saloon equipped with a prototype system.

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A dummy on a skateboard was pushed into the car's path from behind a parked van. With full braking automatically applied, the car stopped before reaching the dummy, even on the wet surface. Such systems are still in the early stage and will be developed further under the EU SAVE-U project, which runs until 2005. The potential to reduce pedestrian casualties cannot be ignored.

Obviously, such a system has limitations. If the car is travelling at high speed, it cannot stop in a short distance. So the system is designed to take in what is happening over a distance of 25 metres ahead and eight metres across.

The camera images are scanned at between seven and 15 times a second for possible human movement. The system is capable of stopping the car before it reaches a pedestrian at speeds below 40km/h (25mph).

Other systems could be brought into play to reduce the risk of accidents and improve safety for car occupants. DaimlerChrysler, along with all other major European manufacturers believes that on-board short-range radar systems hold the key.

The favoured frequency is 24GHz because that means standard electronic components could be used, allowing large production volumes at favourable cost. If radar is adopted, one single sensor could be used to sweep 20m around a car.

Current parking assistance systems need around four sensors in the bumper, where they are vulnerable. One single radar sensor could trigger alarms for reverse and forward movements and many other safety related features besides.

Parking is an obvious application, but with potential to do far more than warn the driver that he or she is too close to other cars or objects.

A suitably equipped Mercedes-Benz S-Class automatic demonstrated the system's full capability. Once the driver activated the system, acceleration, braking and steering control were taken over by the on-board computer.

First, the car drove slowly past the available parking spaces until it found a suitable one. For demonstration purposes, the car was fitted with a full-size flat panel computer screen that could show the computer calculating the appropriate steering curves to manoeuvre the car. The system then slowly manoeuvred the car into the space, choosing forward or reverse gear as appropriate.

The demonstration was repeated showing that it could position the car in either a right angle or parallel roadside bay. The single radar sensor is constantly tracking the available space around the car and triggering the appropriate steering, braking and throttle responses accordingly.

While that makes for an interesting demonstration, it also hints at the potential possibilities. The radar sensor could equally pick up an impending impact from any angle and trigger the appropriate safety systems.

Current passive safety systems such as airbags can only respond after impact, but if the car can be prepared in advance, it could give better protection for its occupants.

Appropriate seat belts could be pre-tensioned, braking could be applied and other cars equipped with radar in the immediate area could be warned too, triggering their safety systems, if needed. With a system of roadside beacons, other radar-equipped cars further away could be alerted as well and re-routed if necessary.

To have maximum effect, the 24GHz standard would need to be adopted globally, so cars crossing national borders could still work effectively. But so far, only the US has adopted the rules for 24GHz radar.

Opposition has come from radio astronomy bodies and earth exploration satellite services, but the automotive industry believes that interference claims for the very low power radars needed have been wildly exaggerated.

The European Commission supports the proposals and if objections can be overcome, automotive radar applications could start next year.

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