How the silent electric cars of the future will 'talk' to pedestrians

10 December 2020 - 15:48 By Motoring Staff
Volvo Cars is researching a ground-breaking new technology that uses ultrasounds via parametric speakers to 'ping' pedestrians and cyclists.
Volvo Cars is researching a ground-breaking new technology that uses ultrasounds via parametric speakers to 'ping' pedestrians and cyclists.
Image: Supplied

For more than a century, internal combustion engines have provided the soundtrack to cities. Walking through a city centre, the noise is constantly there. It’s a part of life in the city — and in the suburbs too. Imagine being on a school run and arriving at the school — to the sounds of motoring silence.

Those sounds — while annoying to some — are vital for safety. It is for this reason that trucks sound audible warnings when reversing. There are other aspects of driving today that bolster safety too — thanks to a language of human-to-human communication. Take, for instance, the eye contact between road users that establishes the fact that “yes, I see you” or that friendly “go ahead” wave. As a pedestrian, you then know it is safe to cross a road — because the driver has seen you and will wait.

But what if a car no longer makes a noise and it has no driver? What then? Well, just like the noise of the reversing trucks, a new “language” will need to be created. And those cars will need to “talk” to us.

This won’t be easy. As Mikael Ljung Aust, senior technical leader for collision avoidance functions at the Volvo Cars Safety Centre, points out, there are some challenges. The first is replicating human-to-human communication, which — essentially — means creating a whole new body language sans a human driver. “Body language is global — irrespective of whether you’re in New York, Tokyo, Pretoria or Gothenburg. People speak the same body language and it’s fast. It’s something you learnt pretty much since the day you learnt to walk,” he points out.

Furthermore, the car’s “language” will need to be easy to understand. “We can’t ask people to bring a manual into traffic and look up the current year and model of the particular car you’re looking at to see what it actually is trying to communicate,” Aust notes.

But these challenges are not insurmountable. In fact, Volvo Cars is researching a ground-breaking new technology that uses ultrasounds via parametric speakers to “ping” pedestrians and cyclists. It is similar to a submarine’s sonar. This ping is essentially an ultrasonic sound beam which is targeted directly at a pedestrian or cyclist. When bouncing off the target’s body, the sound beam is modulated into a frequency range that only they can hear. They are effectively alerted to the car’s presence, and nobody else is disturbed.

This tech, which is still under development, could be useful today. It could warn someone who is listening to music or a podcast that a vehicle is approaching, for instance. But, in future, it won’t just be nice to have. With silent and driverless vehicles on the roads, “talking cars” will be essential for road safety.


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