Using magnets to help self-driving cars stick to the road
VOLVO seems to think so and has just completed a research project in its native Sweden that integrated them into the road surface to help cars identify where markings are and to stay in lane.
As such, magnets could be a potentially simple and very cost effective solution to an often complex problem: communicating to self- driving vehicles where the road is and where it is going.
Existing solutions, be they GPS positioning, cameras, batteries of radar or laser sensors, are all effective, but they are also more expensive and each has limitations. Poor weather or poor light can impinge on a camera’s performance, whereas a GPS system can lose the signal.
Volvo’s project, carried out in collaboration with the Swedish Transport Administration, took small magnets, measuring just 40x15mm, and embedded them in a pattern 200mm below the road surface on a 100-metre stretch of road. It also fitted a car with magnetic field sensors.
“The magnets create an invisible ‘railway’ that literally paves the way for a positioning inaccuracy of less than one decimetre. We have tested the technology at a variety of speeds and the results so far are promising,” says Jonas Ekmark, preventive safety leader at Volvo Car Group.
But as well as guiding selfdriving cars, the magnets could be used for other safety purposes. For example, during severe snowfall, they would help to indicate where road lane markings are to any type of car fitted with sensors.
They could also be used as an automatic switch for activating a car’s safety systems – for example, if it were to leave the road altogether in the course of an accident. And by using magnets as a guide, it is conceivable that road lanes could be made narrower.
“Our experience so far is that ferrite magnets are an efficient, reliable and relatively cheap solution, both when it comes to the infrastructure and on-board sensor technology. The next step is to conduct tests in real-life traffic,” explains Ekmark.— Relaxnews