Asleep at the wheel

Nodding off while driving a car can be extremely dangerous to your health and that of other road users. To counter the likelihood of that happening, engineers at Volvo have recently developed a new system that will alert a driver when his or her concentration level appears to be affected, for instance during long journeys.

The new driver alert control system will be available in the Volvo S80, V70 and XC70 models by the end of the year.

The system steps in at 65km/h and stays active as long as the speed of the vehicle exceeds 60km/h. In use, it monitors the car's movements and assesses whether the vehicle is being driven in a controlled or uncontrolled way.

'We do not monitor human behaviour - which varies from one person to another - but the effect that fatigue or decreased concentration has on driving behaviour. Our system is based on the car's progress on the road. It gives a reliable indication if something is likely to go wrong and alerts the driver before it is too late,' explained Daniel Levin, project manager for driver alert control at Volvo Cars.

'We have chosen this concept instead of monitoring the driver's eyes, because we don't think that technology is mature enough yet,' he added.

From a technical viewpoint, the driver alert control consists of a camera, a number of sensors and a control unit.

The camera, which is installed between the windscreen and the interior rear-view mirror, continuously measures the distance between the car and the road lane markings, while the sensors register the car's movements. The control unit stores the information and calculates whether the driver risks losing control of the vehicle.

If the risk is assessed as high, the driver is alerted via an audible signal. In addition, a text message appears in the car's information display, alerting him or her with a coffee cup symbol to take a break.

'It is, of course, always the driver's responsibility to take a break when necessary, but sometimes you might not realise that you're not alert enough to drive. In such situations, driver alert control can help the driver make the right decision, like taking a refreshing break or a nap, before the concentration level becomes too low,' Levin concluded.