A robot that quickly homes in on odour sources could be used to sniff out the source of a fire, a chemical leak or even where a bomb has been planted.
There have been many attempts to give robots a sense of smell, from sensors that work like electronic noses to living biological tissue that responds to certain chemicals in the air. But what's been missing is a way for the robot itself to close in on a chemical plume as fast as possible.
Now engineer Tien-Fu Lu at the University of Adelaide in Australia has an answer: mimic the way insects do it. He has written a software routine that allows a robot to seek a hydrogen sulphide source – which stinks like rotten eggs – in a set of offices.
The algorithm can only store the current odour concentration and the previous two, as well as the robot's position when the measurements were taken. If the level goes down as the robot moves, it means it is no longer facing the source – so it returns to the previous position to try another direction (Robotics and Autonomous Systems, doi.org/m2g).
Lu is now honing the technique, adding ultrasound sensors so the robot can sense walls and travel to the source even faster, without wasting time zig-zagging along corridors.