Smoothing steering to prevent accidents

A discovery about how drivers steer cars could pave the way for systems which can anticipate steering movements that could lead to dangerous situations and correct for them before they occur, according to researchers at Chalmers University of Technology in Gothenburg. This could prevent skidding and mistakes made when drivers are tired, they claim.

It has been known for many years that drivers do not steer smoothly, even when guiding their car around a gentle curve. Rather, they tend to move the wheel in a jerky motion which, until now, has been unexplained and unpredictable.

Chalmers researcher Ola Benderius and Gustav Markkula made a link between steering and reaching for an object, which humans learn very early in their lives. When we reach, our hands move faster if the object we are reaching for is further away; the time taken to reach the object is the same regardless of how far away it is. ‘We immediately recognised this pattern from our measured steer signals,’ Benderius said in a statement. ‘It was a bit of a eureka moment. Was it possible that this basic human behaviour also controlled how we steer a car?’

Benderius and Markkula looked at over 100 hours of driving data  from cars and trucks, and found that over 95 per cent of the 1.3 million steering corrections in this data corresponded to reaching theory. ‘Rather than looking upon steering as continuously following the road, steering corrections seem to be applied in a very predetermined manner,’ said Benderius. ‘The control behaviour has also proven to be very natural; I saw this in an earlier study where I examined driving behaviour in 12 year olds and their parents.’

Using this theory, Benderius has developed a mathematical model to simulate steering behaviour, which he thinks can be used to predict how far and fast a driver will turn the wheel; this has been published by the university as Benderius’s doctoral thesis. In potentially dangerous situations, this model could be used to prevent drivers unknowingly steering into danger.

‘Imagine a fatigued driver on the verge of running off the road,’ Benderius said. ‘He or she suddenly wakes up and reflexively initiates a very large corrective manoeuvre, a potential misjudgement that can lead to something very dangerous. Since we are now able to predict how far the driver is going to turn the wheel, the vehicle’s support systems can identify potential misjudgements and intervene, which means a serious accident, such as the car travelling into approaching traffic, can be avoided.’