‘How to stick like Stig’

It sure is handy if you have to make sharp turns while driving slowly, but for people who like to drive fast, power steering can have a serious downside. When tires start to lose their grip in sharp turns, the steering normally becomes lighter – road hogs are thus warned that they are pushing it to the limit – but when driving with power steering this effect is masked.

For his PhD research, Dr Diomidis Katzourakis, who is an amateur race driver himself, came up with a solution. He devised a steering support system that creates extra lightness on the power steering when tires are losing grip. Last week he defended his thesis (‘Driver steering support interfaces near the vehicle’s handling limits’) at the 3mE faculty.

“We reduced the steering torque and exaggerated the effect you would normally feel,” Katzourakis explains. “Such haptic cues promote the driver’s perception of the vehicle’s behavior.”

Katzourakis’ research was sponsored by SKF, a company that develops bearings, including special bearings that sense the tire road adhesion. Such bearings would combine well with the haptic steering support system, or at least that is the idea.

The researcher had 17 drivers experiment with his haptic system (installed in an Opel Astra). He conducted his tests with Prodrive Automotive, a UK company also known for its supportive work on Mini and Aston Martin racing cars.

The guinea pig drivers had to drive as fast as they could in a circle on a wet skid pad. “They reported that the task was easier to perform with the haptic support and that the support system made them feel more confident,” says Katzourakis.

Although the drivers reporting feeling less mental strain, and were more satisfied with the overall performance, what about the speed? Did they also improve their lap times?

No, they did not, Katzourakis admits, while grinning, although he can’t help showing a little frustration as well. His drivers weren’t exactly fast and furious. “Some of them were not so skilled,” the researcher says. “If I would test race drivers, I believe the system would help them to reduce lap times. But as it stands now, I can’t prove this.”