The magnets are positioned in the roadway and programed with compass bearings, able to communicate with similar magnets attached to the autonomous vehicle to determine the car’s position.
Volvo says reliable and accurate positioning is crucial in the development of autonomous cars, and the road magnet project is backed by the Swedish Transport Administration (Trafikverket).
Magnets were the chosen method of navigation due to the limitations of current technologies, such as vehicle-mounted cameras and GPS satellite navigation.
Current navigational technologies can be confused by tall buildings, poor weather and tunnels, whereas magnets carry no such limitations.
“The magnets create an invisible ‘railway’ that literally paves the way for a positioning inaccuracy of less than one decimetre,” Volvo’s Jonas Ekmark said.
“We have tested the technology at a variety of speeds and the results so far are promising. It is fully possible to implement autonomous vehicles without changes to the present infrastructure. However, this technology adds interesting possibilities, such as complementing road markings with magnets.”
Volvo claims the benefits of road magnets don’t end with autonomous cars, saying current semi-autonomous technology such as lane-assist and radar-guided cruise control could also be improved by magnets.
Magnets could also make the job of clearing snow-covered roads easier, and eventually road lanes could be narrower, as magnets would reduce the margin of error so cars could travel closer together.