A six-legged robot can find its way home without the help of GPS, thanks to tactics borrowed from desert ants.
The robot, called AntBot, uses light from the sky to judge the direction it is going. To assess the distance travelled, it uses a combination of counting its steps and observing the apparent motion of objects it passes. All three of these techniques are used by desert ants.
To test the 50-centimetre-wide robot, Stéphane Viollet at the Aix-Marseille University in France and his colleagues set it an outdoor homing task: first go to several checkpoints, and then return home.
AntBot consistently completed the task and was only a few centimetres off its home target on average.
Many insects naturally perform similar tasks when foraging. They take meandering paths when visiting their favourite spots before returning directly home in a straight line. AntBot did the same.
However, one drawback was that AntBot’s positioning system overheated after long periods of use, limiting the distance it could travel to 14 metres.
The researchers are now developing a new version of the robot that can travel further. They believe the technology could provide an important back-up navigation system when GPS fails, as often happens when moving between tall buildings.
“We are working with a French car manufacturer to try to implement our ‘celestial compass’ on board a [driverless] vehicle,” says Viollet. The next challenge will be to improve the sensor to ensure that the navigation system is accurate at night, in rainfall or under the cover of trees.