Pedestrians should wear radar reflectors to avoid being run over by self-driving cars, says a team of researchers that has created a device to make people more visible to a vehicle鈥檚 artificial intelligence.
Self-driving cars rely on visual sensors, which can be blocked by fog, rain or snow, or radar sensors, which can struggle to pick out objects if they fail to reflect radio waves back to the car. Some cars also use a combination of both sensors.
Zhuqi Li at Princeton University and his colleagues say changing the radar reflectivity of objects could make self-driving cars safer. The team has developed a device that makes pedestrians, cyclists and road furniture more visible by focusing radar signals from a self-driving car before reflecting them back. They .
Advertisement
鈥淏oth the pedestrian and the cars are working together towards the same goal, which is to make everyone safer,鈥� says Li. 鈥淧reviously, people pushed very hard on the car side and tried to detect everything. It might be helpful to spend just a little more energy on the pedestrian side. I think we should try to explore every chance to make people safer.鈥�
The team鈥檚 device uses aerials to receive, focus and retransmit incoming radar signals back towards the car, without requiring a power source. In a laboratory test, the group was able to improve the maximum detection distance of a sensor from 10 metres to 36 metres.
This improvement could make a big difference to pedestrian safety 鈥� according to the , a car travelling at 64 kilometres per hour can stop within 36 metres, whereas one travelling at even half that speed still requires 12 metres stopping distance.
The prototype device consists of a single printed circuit board with several small antennas and costs $2000 to manufacture. The team believes this cost can be reduced with mass manufacturing and that it can be used as a safety device on the outside of vehicles, road furniture and on clothing for pedestrians and cyclists, in much the same way as reflective high-visibility tape.
But some question whether the onus on safety should be put on more vulnerable road users rather than on the manufacturers of self-driving cars. 鈥淣o matter how effective a device is at making people in the street more visible, it should be obvious that it鈥檚 the engineers鈥� job to make their vehicles safe and not the pedestrian鈥檚 job to help car-makers,鈥� says Ian Walker at the University of Bath, UK. 鈥淚t鈥榮 morally problematic to put a person in danger without their consent and then demand they take special steps to avoid the danger that鈥檚 been forced upon them.鈥�
